description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
The present invention relates to a machine which forms fiber material into a length of sliver, such as a carding machine or a roller card, and which includes measured value sensors for generating input values and an electronic conrol unit for forming setting values which can be fed to setting members.
In a known carding machine, regulation and control of the type and quantity of fiber material processed is effected by a plurality of separate devices. For example, delivery speed and draft are each controlled by a separate electronic motor control for the drives of the feed roller and of the doffer. The regulation of the thickness of the sliver leaving the carding machine is effected, for example, independently thereof by way of a pneumatic signal fed to an lectric three-point regulator which produces an electrical output signal to cause the fiber material fed into the carding machine to be regulated. All of this makes the system rather expensive. Moreover, various components, such as the electronic motor control and the three-point regulator, are subject to malfunction.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a machine of the above-mentioned type which avoids the above-mentioned drawbacks, which permits, in particular, central regulation and control of the type and quantity of fiber material processed and which, as a system, is less expensive and less subject to malfunction than prior art machines.
The above and other objects are achieved, according to the present invention, by the provision of apparatus for forming fiber material into a length of sliver, which apparatus includes: a machine for receiving such fiber material and forming it into the length of sliver; sensors for monitoring the operation of the machine and providing signals representative of that operation; an analog/digital converter connected to the sensors for receiving the signals provided by the sensors and converting those signals into digital representations of the operation of the machine; a digital electronic control unit connected to receive the digital representations formed by the analog/digital converter and including a microprocessor having memories, a device for generating digital representations of desired values of selected operating parameters of the machine, and a device performing operational, regulating, control and display functions, the control unit being arranged to provide digital signals for regulating the operation of the machine; a digital/analog converter connected to the control unit for deriving analog signals corresponding to the digital signals provided by the control unit; and a controllable regulator controlled by the analog signals derived by the digital/analog converter for regulating the operation of the machine.
A significant feature of the invention resides in the provision of the circuit, for example for regulating the speed of, for example, the feed roller and of the doffer by the cooperative action of the measuring value sensors, the microcomputer in conjunction with output converters, for example thyristors, and the regulator members.
A costly and malfunction prone electronic motor control is no longer necessary. Simultaneously, the necessary related functions, i.e. the matching of speed between feed roller, doffer and carding machine cylinder, are realized. Processing of the measured and setting signals for thickness regulation of the sliver is likewise effected by the microcomputer. The continuous monitoring of all significant measured values permits the early detection and localization of errors. In an advantageous manner, the microcomputer can simultaneously realize a direct speed regulation of the drive for the feed roller, the doffer, the tuft feed connected upstream, or the like. The use of an electronic three-point control is no longer required.
Due to the ability of the microprocessor to store data, it is possible to store optimum values as determined once for a given lot, e.g. values for draft, delivery rate and the like, and to reuse such values for processing a similar lot if required, without the need for resetting so that no additional setting work is required when lots are changed. The regulating behavior for the drive motors is fixed by the program and can be varied at will, e.g. PI behavior, start-up integrator and the like.
Other advantageous features are described below.
By using a guide computer, various tasks can be performed:
(a) error detection and localization (clear test) for carding master and the like;
(b) compilation of operating data (dead times, production, breaks in the sliver, flaws);
(c) information regarding maintenance, cleaning and repair work (operating hour counter);
(d) for a group of cards as determined by the guide computer, all cards can be programmed or adjusted for a certain lot;
(e) each individual carding machine can be corrected or influenced by the guide computer (production rate and the like).
Because of the "intelligence" of the system, it is possible to act at once if there are any malfunctions and to prevent the occurrence of possibly disadvantageous effects, as shown by the following examples:
Breaks in a conductor, operator errors or the like may provide an indication that 50,000 meters of sliver have been filled into a can but the system memory indicates that only 9000 m/can is accurate. Before the incorrect can fill of 50,000 m/can is put into operation, the guide computer or some other report inquires from the operator whether this value is correct. Only the correctness is expressly confirmed, e.g. by a change in coilers, will the instruction be implemented. Information that a certain production rate belongs to a certain speed of the feed roller is also stored. If it is noted that the drive motor for the feed roller suddenly has a speed which exceeds the given limit, the machine is shut down at once and the error is reported, localized and possibly the situation is corrected automatically. Even if the speed of the cylinder drops, e.g. when it labors, this can also be detected, reported and evaluated at once.
Of importance for the invention are the central control or regulation and control of all measuring, instruction and setting signals during processing of fiber material by the microcomputer, or microprocessor system. The microcomputer is thus used for regulating functions, e.g. regulation of the speed of the feed roller, of the doffer and the like. Additionally, the microcomputer is used for control functions, e.g. on/off switching of the carding machine or roller card, control of the velocity stages of the rollers, e.g. of the licker-in, the cylinder, the doffer for start-up movement, fast movement and slow movement and the like.
The present invention will now be explained in greater detail with reference to embodiments that are illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block circuit diagram of a fully automatic control for a carding machine or a roller card according to the invention.
FIG. 2 is a block circuit diagram of a system for the regulation of the feed roller and of the doffer of the carding machine and a simplified representation of the machine itself.
FIG. 3 is a block circuit diagram of a control system according to the invention performing further regulating and control functions.
FIG. 4 is a detail view of a sliver thickness measuring device with transducer for converting pneumatic signals into electrical signals.
FIG. 5 is a programming flow diagram illustrating the operation performed in a control system according to the invention.
FIG. 6 is a programming flow diagram illustrating a modified version of the operation depicted in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The control system shown in FIG. 1 has a microprocessor 1 as the central processing unit, CPU, connected on the one hand, with a data memory 2 and a program memory 3 and, on the other hand, with an interface 4. These control members 1 through 4 in their entirety constitute a microcomputer 7.
The memory 2 receives the data for the respective production program as fed in by the operator via keyboard 5. Permanently programmed data for the sequence control for each production program are stored in the memory 3. These are data, inter alia, which permit or suppress certain machine functions upon the occurrence of certain determined operating states. These data determine, for example, the permissible speed range of the doffer.
The microprocessor 1, on the one hand, produces all control signals required to operate the microcomputer and, on the other hand, performs, under control of the program stored in the PMEM memory 3, all data transfers between the memories and the external circuits and devices which are coupled in via the interface 4. Moreover, the microprocessor 1 makes all necessary calculations and decisions as will be explained below.
The interface 4 is basically a buffer memory including input and output registers which make it possible to read into the microcomputer, upon instruction therefrom, external information as input signals, i.e. keyboard signals and signals which represent the machine state, and to read out the information stored therein, i.e. instructions, to transmit them as output signals to the external control logics, display devices and the like.
The external devices include a display 6 with which the significant program data and, for example, information regarding the respective production rate and further machine states are displayed. Various sensors 8 generate reporting signals regarding the machine state. Such signals provide information, for example, as to whether the cylinder of the carding machine is running or not.
Finally, there is provided a production, or control, logic system 9 with connected regulating motors 10 for the transport of material. During automatic operation, the logic system 9 receives its instruction signals from the microcomputer 7 and controls operation, for example, of the feed roller and of the doffer in dependence on the production program.
As already mentioned above, the production programs are fed into the memory 2 via an input device, e.g. the keyboard 5. The depression of a program key on keyboard 5 generates a code which is read into the microprocessor 1 via the interface 4. The microprocessor determines whether the respective code represents an instruction, i.e. for example, storing, erasing or using a signal, or information for the production program. In the former case, the respective instruction is followed. If the microprocessor 1 determines that an instruction signal means "store", it causes the last fed-in data to be transferred into memory 2. In the latter case, numbers or functions are intermediately stored in the data memory 2 for later use.
FIG. 2 is a schematic representation of a carding machine which can be controlled according to the invention. This machine includes a feed roller 11, a licker-in 12, a carding cylinder 13, a doffer 14, a stripper roller 15, two pinch rollers 16 and 17, a trumpet 18 and two calender rollers 19 and 20 which deliver a sliver. The feed roller 11 has an associated sensor in the form of an electronic tachogenerator 21 which is connected to an analog/digital converter 22. The analog/digital converter 22 is connected to the microcomputer 7, via its microprocessor interface 4. The analog/digital converter 22 is in turn controlled by the microcomputer 7. The microcomputer 7 is also associated with a desired value generator signal 23.
The microcomputer 7 is connected to a first digital/analog power converter 24 which is controlled by the microprocessor 1 and is in communication with a regulating motor 25 for driving the feed roller 11. The doffer 14 similarly has an associated electronic tachogenerator 26 constituting a measured value sensor, which is connected to the analog/digital converter 22. The microcomputer 7 is additionally connected to a second digital/analog power converter 27 which is in communication with the regulating motor 28 for the doffer 14.
As will be apparent, elements 21, 22 and 26 of FIG. 2 form components of unit 8 of FIG. 1, while elements 24, 25, 27 and 28 of FIG. 2 form part of unit 10 of FIG. 1.
During operation, the speeds of the feed roller 11 and of the doffer 14 are converted to speed-proportional analog electrical signals by the tachogenerators 21 and 26, respectively, which form input signals for the microcomputer 7. From the input signals and the stored program data, electrical output signals are developed via the microprocessor 1. These digital signals are converted back to analog electrical signals by the subsequent digital/analog power converters 24 and 27, respectively, and then are fed to the regulating motors 25 and 28, respectively by which the rotation of the feed roller 11 and the doffer 14, respectively, are controlled.
FIG. 3 shows a control arrangement similar to that of FIG. 2 but constructed to perform additional regulating and control functions. The carding cylinder has an associated measured value sensor in the form of an electrical techogenerator 30 which is connected to the analog/digital converter 22. Also connected to the analog/digital converter is a testing device 31. Finally, an analog signal is fed to the analog/digital converter from a sliver thickness measuring device 32 which will be described in greater detail with reference to FIG. 4.
The following devices are further connected electrically to the microcomputer:
operating elements, such as on/off switches for the carding machine and the like; a device 34 for the input of preliminary or primary signals, e.g. identifying the degree of can fill; monitoring members 35 which report malfunctions in the system, or in the operating sequence, respectively; a higher order guide computer 36 for a plurality of carding machines or roller cards; a programming module 37 with which variable data can be programmed once or when they change; a display device 38 to display production and counter states; and a control device 39, with which, for example, signal lights 40, relays 41 and valves 42 can be controlled directly.
The digital/analog power converters 24 and 27 are in communication with the regulating motors 25 and 28 via devices 43 and 44, respectively.
Device 43, 44 is, for example, a measuring device for motor current and/or motor voltage. To measure the motor current, for example, device 43, 44 includes a shunt and an operational amplifier. The input signal is the motor current and/or the motor voltage. The output signal is an equivalent measurement signal (resulting from the measurement), the measurement of the motor current also producing a voltage as the output signal.
As shown in FIG. 4, a sliver F passes through trumpet 18, thus producing a pneumatic signal x which is converted into an electrical signal y in a suitable transducer 45. In the analog/digital converter 22, the signal y is converted into a digital electric signal z, which is fed into the microcomputer 7 (see FIGS. 1 through 3). From this signal, an output signal is developed which serves to control, for example, the rotation of the feed roller 11 to vary the rate at which fibers are fed to the carding machine and thus to regulate the uniformity of the sliver leaving the carding machine.
According to the invention it is possible, by using an electronic microcomputer control and regulating device, to eliminate the need for a considerable amount of apparatus previously required. In particular, the need for a separate control circuit with separate regulating device for each parameter to be regulated can be avoided. It should be noted, for example, that the power converters 27 are not regulating devices but, for example, are only power transistors which are actuated by corresponding pulses from the control device. The regulation of machine dependent and fiber technological data is no longer effected separately but together in the apparatus according to the invention. The particular advantage is that this links together the machine related and the fiber technological characteristics and enables them to act on one another.
For example, the actual values from the sliver thickness measuring device can be processed in the control device and can be used as machine dependent control values for the speed of the feed roller and/or of the doffer of the carding machine. Moreover, for example, the optimum fiber technological data, such as draft, production rate and the like can be measured for a certain lot of fibers and this information can be stored in the control device so that upon later processing of a similar lot the same machine-related control values can be set for the rollers of the carding machine.
Finally, the necessary fiber technological data can be matched to the possible machine output and thus the relationship of carding technology to card structure can be optimized. A further advantage is that for other functions, e.g. the drive and/or the carding technology, a certain regulating behavior can be realized via desired, predeterminable characteristics. As a result, the information required for carding work, such as roller and doffer speeds, sliver thickness, speed ratios and the like, are centrally compiled, evaluated and processed in an optimum manner.
FIG. 5 is a programming flow diagram illustrating the sequence of operations carried out by the microprocessor 1 according to a basic embodiment of the invention. As is the general practice in this art, the operating sequence is performed cyclically at a rate selected to assure that adjustments will be made sufficiently rapidly. Since variations in a carding process occur very slowly compared to conventionally microprocessor cycle times, this requirement does not present any difficulty in the present case, particularly given the relatively small number of steps involved in a complete operating cycle.
In the operating sequence depicted in FIG. 5, the first calculation block indicates that the desired and actual values for the speeds of the doffer 14 and the feed roller 11 are determined based on values provided by the data memory 2 and the tachogenerators 21 and 26. The desired and actual values for the doffer speed are compared and the comparison result is supplied to the second control block. If equality does not exist, a new doffer speed control value is determined, as indicated by the second calculation block, to supply a control value which will bring the doffer speed to the desired value. The control value is supplied to power converter 27.
If the actual and desired doffer speed values are found to be equal, or after determination of a new doffer speed control value, the result achieved by comparison of the actual and desired speed values for the feed roller are supplied to the second decision block. If this comparison result indicates that the values are not equal, a new feed roller speed control value is determined in the following calculation block, and the new control value is supplied to power converter 24.
If the actual and desired speed values for the feed roller were found to be equal, or after determination of a new feed roller speed control value, the desired and actual sliver thickness values are stored. The desired value can be supplied from the data memory 2, while the actual sliver thickness value will be derived from regulator 45 via converter 22. These values are then compared and the comparison result is supplied to a further decision block.
If this decision block indicates that the values are not equal, the last calculation block indicates that a new desired value for the doffer and/or feed roller speed is calculated. These calculations will, of course, be based on relationships between sliver thickness and doffer and feed roller speeds which are already well known in the art. The new desired value, or values, are then supplied to the first calculation block. If the last decision block indicates equality between the actual and desired sliver thickness values, the operating sequence returns to the input of the first decision block.
Into the data memory 2 (see FIG. 1), of microcomputer 7 (see FIGS. 1 and 3), signals are fed which represent the actual value recorded by the electrical tachogenerator 30 (see FIG. 1) serving as the measuring value sensor for the rpm of the drum 13 (see FIG. 2).
Into the data memory 2 (see FIG. 1), signals are fed which represent the actual value of the motor current determined by the measuring device 43 (see FIG. 3) for the drive of the feed roller 11 (see FIG. 2).
Into the data memory 2 (see FIG. 1), signals are fed which represent the actual value of the motor current determined by the measuring device 44 (see FIG. 3) for the drive of the doffer 14 (see FIG. 2).
Into the data memory 2 (see FIG. 1), signals are fed which represent the motor voltage determined by the measuring device 43 (see FIG. 3) for the drive of the feed roller 11 (see FIG. 2).
Into the data memory 2 (see FIG. 1), signals are fed which represent the actual value of the motor voltage determined by measuring device 44 (see FIG. 3) for the drive of the doffer 14 (see FIG. 2).
Into the data memory 2 (see FIG. 1), signals are fed from a known testing device 31 (see FIG. 3). Such a testing device is known, for example, from the brochure "Pocket VDU-Fully Alphanumeric Hand-Held Terminal" by Neumunster Messtechnik.
Into the data memory 2 (see FIG. 1) signals are fed from machines connected ahead of the carding machine (see FIG. 2) or the roller card, for example a tuft supplier 46 (see FIG. 3) as disclosed in U.S. Pat. No. 3,169,664 or U.S. Pat. No. 4,219,828 or a known fine opener.
Into the data memory 2 (see FIG. 1), signals are fed from a machine connected downstream of the carding machine (see FIG. 2), for example from a drawing mechanism 47 as disclosed in U.S. Pat. No. 4,199,844 (see FIG. 3).
Into the data memory 2 (see FIG. 1), signals are fed from monitoring elements 35 (see FIG. 3), for example from a known motor protection switch.
Into or out of the data memory 2 (see FIG. 1), signals are fed from and/or to a higher order known guide computer 36 (see FIG. 3), a higher order control or the like for a plurality of cards or roller cards.
Into or out of the data memory 2 (see FIG. 1) signals are fed from and/or to a known programming module 37 (see FIG. 3). Such a programming module is known, for example, from the brochure "Pocket VDU-Fully Alphanumeric Hand-Held Terminal" by Neumunster Messtechnik.
Into or out of the data memory 2 (see FIG. 1), signals are fed from and/or for the machine operation 33 (see FIG. 3), for example known devices to switch on and off the carding machine or roller card.
The invention includes control as well as regulating functions, i.e. control as well as regulating processes can be realized.
FIG. 6 shows a similar flow diagram as FIG. 5. Here, the desired and given value for the doffer speed and the desired and given value for the feed roller speed are initially calculated. The results of this calculation are processed further in the same manner as shown in FIG. 5. In contradistinction to FIG. 5, after the last calculation box, the operating sequence returns to the input of the first decision box. While in FIG. 5 actual values are determined in the first calculation box, at the input of FIG. 6 control values are calculated instead.
It will be understood the above description of the present invention is susceptible to various modifications, changes and adaptations and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | Apparatus for forming fiber material into a length of sliver. The apparatus includes: a machine for receiving such fiber material and forming it into the length of sliver; sensors for monitoring the operation of the machine and providing signals representative of that operation; an analog/digital converter connected to the sensors for receiving the signals provided by the sensors and converting those signals into digital representations of the operation of the machine; a digital electronic control unit connected to receive the digital representations formed by the analog/digital converter and including a microprocessor having memories, a device for generating digital representations of desired values of selected operating parameters of the machine, and a device performing operational, regulating, control and display functions, the control unit being arranged to provide digital signals for regulating the operation of the machine; a digital/analog converter connected to the control unit for deriving analog signals corresponding to the digital signals provided by the control unit; and a controllable regulator controlled by the analog signals derived by the digital/analog converter for regulating the operation of the machine. | 3 |
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to a method for removing flashes formed in a molded resin product such as a plastic encapsulated semiconductor package.
II. Description of the Prior Art
In a plastic encapsulated semiconductor package 1 shown in FIG. 1, a semiconductor element (not shown) such as an IC or an LSI is placed on a lead frame 2. After wiring is formed, the structure is placed in a mold, and an epoxy resin is injected into the mold for encapsulation. However, during molding, the epoxy resin leaks through the gap between the lead frame 2 and the mold to form flashes 3 on the lead frame 2 and in the gaps between the leads of the lead frame 2. When a columnar electric element such as a diode is to be plastic-encapsulated, the epoxy resin leaks out through the gap between a pair of upper and lower molds, thereby forming flashes around the columnar molded product. Plastic encapsulation of such a columnar electric element therefore requires a post-molding step to remove such flashes. In view of this problem, a hard abrasive such as alumina, silicon carbide or glass bead, or a soft abrasive such as a walnut shell powder is blasted onto the flashes 3 to remove them.
However, a problem is encountered when a hard abrasive is used. That is, an abrasive with a hardness H R C of 70 or more while the epoxy resin useful for a semiconductor device has a hardness H R M of about 100. Thus, the abrasive is far harder than the epoxy resin, and has a specific gravity four times that of the epoxy resin. For this reason, when the flashes 3 are removed, the surface of the package 1 is damaged, to have a poor outer appearance. In addition to this, moisture may be introduced through the damaged portions of the package 1, adversely affecting reliability of the semiconductor element. On the other hand, a problem is also encountered when a soft abrasive such as a walnut shell powder is used. Since such a soft abrasive has an removal ability which is weaker than that of a hard abrasive, a soft abrasive must be blasted at a higher pressure than a hard abrasive. This leads to deformation of the lead frame 2 and a higher running cost of the equipment for manufacturing the molded products, since a larger amount of compressed air is used. Furthermore, when a soft abrasive is used, static electricity is generated between the abrasive and the molded product 1 upon contact therebetween. The static electricity firmly attaches the fine powder of the abrasive, flashes and the like to the surface of the package 1. As a result, an outer appearance of the package 1 is degraded in a subsequent soldering or plating step. This also leads to a problem of corrosion of the lead frame 2.
SUMMARY OF THE INVENTION
To prevent these problems the present invention has as its object a method for removing flashes from a workpiece or molded resin product with greater efficiency which will not damage the molded resin product, which significantly reduces attachment of the small pieces of the abrasive to the molded product, and which allows an easy post-treatment after flash removal.
In order to achieve the above object, there is provided according to the present invention a method for removing flashes from a molded resin product by wet-blasting, wherein a slurry comprising a synthetic resin abrasive, water and a surfactant is blasted onto the molded resin product.
According to the present invention, a synthetic resin having a relatively high hardness and a small ductility is preferred. Examples of such a synthetic resin may include thermosetting resins such as an epoxy resin, a urea resin, an unsaturated polyester resin, an alkyd resin, or a melamine resin; or relatively hard thermoplastic resins such as polystyrene, polycarbonate or an acrylic resin. In particular, since a thermosetting resin can provide particles which have a polygonal shape and sharp edges, it is preferred for flash removal.
When flashes are to be removed from a plastic encapsulated semiconductor package, an unsaturated polyester resin or an alkyd resin having a hardness equal or close to that of the resin for encapsulation (e.g., hardness H R M of 80 to 120) is optimal when the product is encapsulated with an epoxy resin having a hardness H R M of about 100. The size of the synthetic resin particles can be freely selected in accordance with the application of the abrasive. However, when an abrasive is to be used for removing flashes from a molded product, the abrasive should, preferably, consist of particles having an average size (defined as 1/2 the sum of the maximum diameter and the minimum diameter) of 0.05 to 2.0 mm (i.e., more than 50% of all the particles preferably have sizes distributed in the range of 0.05 to 2.0 mm).
The shape of the particles of the resin may be arbitrarily selected and may be spherical, needle-like, flat, polygonal and so on. Also, a mixture of particles having different shapes may be used. An abrasive consisting of particles having different shapes generally has a better performance than an abrasive consisting of particles of a single shape.
The particles of the resin abrasive preferably have a large number of cutting edges to grind a workpiece or remove flashes therefrom upon being blasted against the workpiece by a compressor.
Thus, the average size and shape of particles of an abrasive can be determined depending upon various features of a workpiece to be worked upon, the precision required for this specific workpiece, and so on.
The synthetic resin abrasive particles as described above are obtained by the following procedures. A synthetic resin mass is formed into a thin sheet or the like. The sheet is crushed by a crusher or a hammer to obtain resin granules. The resin granules are milled by a roll mill, a ball mill, a jet mill, a cutter or an impact grinder. The particles obtained are passed through a mesh to have the required predetermined size distribution.
The slurry consisting of a synthetic resin abrasive, water and a surfactant to be used with the present invention can be produced by adding a suitable amount, for example, 0.0001 to 1% by weight of the surfactant with respect to the total amount of the slurry, and either mixing it with the abrasive or coating it thereon so that the surfactant gradually smears out into the slurry during abrasion. When cracks are formed in resin flashes by collision of synthetic resin particles, the surfactant allows easy entrance of water into gaps between the flashes and the lead frame. The surfactant also serves to prevent electric charging of the workpiece to be treated upon collision with the synthetic resin particles. The surfactant to be used herein may be of cationic, anionic, non-ionic, or ampholytic type. For example, derivatives of imidazoline and carboxylic acid may be employed. However, when removing flashes from a plastic encapsulated semiconductor package, it is preferable to use a non-ionic surfactant which does not contain metal ions, halogens, ammonia, phosphorus, sulfur or the like, which may adversely affect the semiconductor element. Examples of such a non-ionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl phenol ether, sorbitan alkyl ester, polyoxyethylene glycol ether, and polyoxyethylene sorbitan alkyl ester. The amount of such a surfactant to be contained in the synthetic resin abrasive of the present invention is not determined by the type of surfactant used or application of the abrasive. However, a surfactant can be added, in general, in the amount of 0.0001 to 1% by weight. When a surfactant is mixed in the particles of a synthetic resin abrasive, it is mixed to such a degree that the surfactant slightly spreads out from the surface of the particles.
According to the present invention, a slurry consisting of water, a synthetic resin abrasive and a surfactant, and having a low surface tension is used for removing resin flashes from resin molded products. Accordingly, the synthetic resin abrasive is homogeneously dispersed in the slurry and is uniformly blasted onto the workpiece. Water can easily enter gaps between the resin flashes and the workpiece through cracks which are formed upon collision of the abrasive against the workpiece. With the aid of vibration caused upon collision of the abrasive particles against the resin flashes, removal of the flashes is facilitated, resulting in high performance. Since use of a surfactant can prevent electric charging of the workpiece being treated, generation of static electricity upon spraying of the slurry onto the workpiece is prevented. Neither the abrasive particles nor pieces of the flashes become attached to the workpiece, thereby facilitating a subsequent cleaning step. Thus, if a workpiece is a molded product such as a plastic encapsulated semiconductor package, neither defects in outer appearance caused in a subsequent soldering or plating step nor corrosion will occur. Since the surfactant does not contain a component which may adversely affect the operation of a semiconductor device, such as chlorine or sulfur, reliability of the semiconductor device is not impaired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing a plastic encapsulated semiconductor package showing the appearance of resin flashes;
FIG. 2 is a representation of a wet-type blasting apparatus for practicing the method of the present invention; and
FIG. 3 is a partial sectional view for explaining flash removal using a synthetic resin abrasive according to the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described through examples.
EXAMPLE 1
A catalyst 55% "MEKPO" (methyl ethyl ketone peroxide) was added in the amount of 2% to an unsaturated polyester ester "R235A-1" (tradename of Mitsui Toatsu Chemicals, Inc.) The resultant mixture was injected into a mold having dimensions of 300×300×20 (mm). After the resultant unsaturated polyester resin block were granulated by a crusher, a hammer or the like, the granules were then milled by a ball mill, a roll mill, a jet mill or an impact grinder to provide unsaturated polyester resin particles having an average size of about 0.7 mm and a number of blade-like edges.
An abrasive consisting of these unsaturated polyester resin particles was suspended in water in the amount of 5 to 30% by weight (about 20% by weight for optimal effects). Polyoxyethylene nonyl ether (a non-ionic surfactant) was then added in the amount of 0.0001 to 1% by weight to the suspension to provide a slurry.
A slurry 7 prepared in this manner was deposited in a hopper 8 of a wet-type blasting apparatus shown in FIG. 2. Subsequently, the slurry 7 was drawn by suction by a first pump 9 and was drawn toward the bottom of the hopper 8. Then, the slurry 7 was uniformly agitated until a synthetic resin abrasive 5 was uniformly dispersed. The slurry 7 was then drawn by suction by a second pump 10 from the bottom of the hopper 8 and was supplied to a gun 11. The gun 11 served to accelerate the slurry 7 and blasted a three-phase high-speed jet flow 13 of water, abrasive and air onto a plastic encapsulated semiconductor package (not shown) placed a treatment chamber 14.
When the synthetic resin abrasive 5 collides against a resin flash 17 formed on a lead frame 16 of a semiconductor device 15, the resin flash 17 consisting of a brittle cured thermosetting resin forms cracks 18. Water rendered by the surfactant to have a low surface tension for a higher osmotic pressure easily enters into the gap between the resin flash 17 and the cracks 18. Thus, the resin flash 17 is floated away from the lead frame 16 to facilitate separation. Together with the vibration caused upon collision of the synthetic resin abrasive 5 against the resin flash 17, a gap is formed between the lead frame 16 and the resin flash 17. As particles of the synthetic resin abrasive 5 repeatedly collide against the cracks 18, the resin flash 17 is completely removed.
Flash removal was performed for 100 samples each using Example 1 in which a surfactant was contained in the slurry 7 and using a Control to which no surfactant was added. The flash removal was performed under identical conditions including spray pressure, slurry flow rate, and spray time, in each case. The flash removal performance was evaluated on the basis of the number of samples of the original 100 from which all flashes were completely removed. In the case of the Control, resin flashes remained in 20 to 30 samples, while the flashes were completely removed from all of the 100 samples using Example 1. Furthermore, Example 1 resulted in a spray time 20% faster than that of the Control. Accordingly, using Example 1, the flashes can be completely removed even if the spray pressure is not particularly high. Thus, deformation of the lead frame due to the jet flow can be prevented.
In Example 1, generation of static electricity was prevented, and neither the removed flashes nor the abrasive particles became attached to the semiconductor device 15 or to a jig for conveying it. In synergism with the self-cleaning effect of the surfactant, a subsequent cleaning step was thereby facilitated.
EXAMPLE 2
Polyoxyethylene nonyl ether (a non-ionic surfactant) was added to an unsaturated polyester resin solution, and the mixture was agitated to provide a homogeneous mixture. A catalyst 55% "MEKPO" as used in Example 1 was added in the amount of 2% to the mixture and the resultant mixture was injected into a mold having the dimensions of 300×300×20 (mm) for curing.
A cured resin block was granulated by a crusher, a hammer or the like. The granules were then milled by a ball mill, a roll mill or an impact grinder. The obtained particles were classified to provide synthetic resin particles having a hardness H R M of 100 and an average size of 0.7 mm. The synthetic resin particles contained 0.01 to 0.1% by weight of the surfactant and had a polygonal shape.
The particles were suspended in water (three parts water to one part particles based on weight). A resultant slurry was used for flash removal from plastic encapsulated semiconductor packages in a similar manner to that used in Example 1. Similar results to those in Example 1 were obtained.
EXAMPLE 3
After submerging a synthetic resin abrasive obtained in Example 1 in a 1% by weight of aqueous solution of sorbitan alkyl ester several times, or after spraying the abrasive with the aqueous solution of sorbitan alkyl ester, it was dried and was then coated with a surfactant. The abrasive was then suspended in water (five parts water to one part abrasive based on weight) to provide a slurry. The slurry was used for flash removal from plastic encapsulated semiconductor packages using the same blasting apparatus as that used in Example 1. Similar effects to those obtained in Example 1 were obtained.
Although polygonal particles consisting of a cured thermosetting resin are used for a synthetic resin abrasive of the present invention, the present invention is not limited to this application. It was confirmed that similar results to those obtained in Examples 1 to 3 can be obtained if a synthetic resin abrasive consisting of a thermoplastic resin such as a polyamide resin, a polycarbonate resin or a polystyrene resin is used. | A method for removing resin flashes formed during molding of a workpiece by wet blasting, wherein the wet blasting is carried out by blasting onto the workpiece a slurry comprising a synthetic resin abrasive, water and a surfactant. | 1 |
BACKGROUND
The present invention relates to coating systems for applying coatings to workpieces, and more particularly to coating systems that include a manipulator having planetary gearing.
In order to apply coatings to workpieces with desirable coating distribution, manipulators can be used to move the workpiece within a stream, plume or cloud of coating material. Such manipulators allow more even coating thickness distribution on various surfaces of workpieces, especially workpieces with relatively complex geometries and hard-to-reach (e.g., non-line-of-sight) areas. Gear-driven manipulators exist, including those with gear-driven arms that rotate and move upward and downward at up to +/−45° in a “butterfly” movement to provide one complete axis of rotation and one partial axis of rotation.
Gas turbine engines include numerous components with a variety of coatings. For example, gas turbine engines often include vane segments, such as “doublets” with a pair of airfoils extending between inner and outer platforms. Such doublets can include thermal barrier coatings (TBCs) made of ceramics or other materials, as well as environmental or other coatings. The configuration of typical vane doublets with highly contoured end walls can make coating uniform coating distribution difficult, including in the throat area between the airfoils.
Therefore, it is desired to provide an alternative coating system having an alternative workpiece manipulator.
SUMMARY
A coating system according to the present invention includes a coating source and a planetary manipulator assembly that includes a first driveshaft capable of receiving rotational input, a sun gear rotationally fixed to the first driveshaft, a planetary gear engaged with the sun gear, a second driveshaft rotationally fixed to the planetary gear such that torque is transmitted from the sun gear to the planetary gear, a support shaft operatively engaged with the second driveshaft, a carrier body supporting the planetary gear relative to the sun gear, a third driveshaft capable of receiving rotational input, and a drive gear rotationally fixed to the third driveshaft. The support shaft is arranged substantially perpendicular to the second driveshaft. The carrier body is rotatable by the drive gear about a common axis with the sun gear, and rotation of the carrier body rotates the planetary gear and the second driveshaft about the sun gear.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of an embodiment of a coating application system according to the present invention.
FIG. 2 is a perspective view of a portion of the coating application system of FIG. 1 .
While the above-identified drawing figures set forth an embodiment of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale.
DETAILED DESCRIPTION
It is desired to provide a workpiece manipulator for a coating application system that allows for workpiece movement that approaches random movement. More random workpiece movement facilitates more even coating application and resultant thickness distribution. According to the present invention, a workpiece manipulator assembly is provided that utilizes planetary movement to provide pseudo- or near-random part movement to provide desirable coating distribution. The system of the present invention can be utilized to provide electron beam physical vapor deposition (EB-PVD) application of thermal barrier coatings (TBCs) to gas turbine engine components, as well as to provide a variety of other types of coating materials with a variety of different coating application methods to desired workpieces.
It has been discovered that movement of coating delivery mechanisms (e.g., coating sprayers for use with large workpieces) can produce undesirable flow effects in material supply conduits. Therefore, improved part manipulation according to the present invention without reliance on coating delivery mechanism manipulation allows for consistent coating application without dependence upon particular coating delivery mechanisms. Various features and benefits of the present invention will be appreciated by those of ordinary skill in the art in view of the figures and the description that follows.
FIG. 1 is a schematic illustration of an embodiment of a coating application system 10 , and FIG. 2 is a perspective view of a portion of the coating application system 10 . In the illustrated embodiment, the system 10 includes a manipulator assembly 11 that includes a driveshaft 12 , a sun gear 14 , a planetary gear 16 , a driveshaft 18 , bevel gears 20 and 22 , a support shaft (or spindle) 24 , a fixture 26 , a driveshaft 28 , a drive gear 30 , a carrier gear 32 , a carrier body 34 , and a housing 36 . The manipulator assembly 11 can be used to hold and manipulate a workpiece 38 (e.g., a gas turbine engine vane doublet) for application of a coating delivered by a coating source 40 . Portions or all of the manipulator assembly 11 , workpiece 38 and the coating source 40 can be positioned within an enclosure 42 .
In one embodiment, a geartrain defined by the manipulator assembly 11 can be configured as follows. The driveshaft 12 is rotationally fixed to the sun gear 14 for common rotation about an axis A. The sun gear 14 is engaged with the planetary gear 16 , such that rotation of the sun gear 14 rotates the planetary gear 16 . In one embodiment a gear ratio of approximately 2.5:1 can be used between the planetary gear 16 and the sun gear 14 , though any desired gear ratio can be used in alternative embodiments. The driveshaft 18 is rotationally fixed to the planetary gear 16 and rotates with the planetary gear 16 . The driveshaft 18 is arranged parallel to the driveshaft 12 . The bevel gear 20 is fixed to the driveshaft 18 , and the bevel gear 22 is fixed to the support shaft 24 . The bevel gears 20 and 22 engage each other to transmit torque between the driveshaft 18 and the support shaft 24 . The fixture 26 is supported at a distal end of the support shaft 24 , opposite the bevel gear 22 . The shaft 28 is arranged parallel and adjacent to the shaft 12 . The drive gear 30 is rotationally fixed to the shaft 28 for common rotation. The carrier gear 32 can be rotatably supported on the shaft 12 about the axis A, with the carrier gear 32 configured to allow rotation independent of the shaft 12 . Drive gear 30 and the carrier gear 32 engage each other to transmit torque. The carrier gear 32 is rotationally fixed to the carrier body 34 . The driveshaft 12 can pass through the carrier body 34 , but the carrier body 34 is rotationally independent from the driveshaft 12 . The planetary gear 16 is supported and carried by the carrier body 34 , though the planetary gear 16 can rotate relative to the carrier body 34 . Rotation of the carrier body 34 about the axis A causes the planetary gear 16 to travel about a circumference of the sun gear 14 (about the axis A). The housing 36 can enclose components of the manipulator assembly 11 to shield them from coating materials and help prevent coating material accumulation on sensitive gears, etc. of the assembly 11 .
The fixture 26 can engage and retain at least one workpiece 38 , and can have any suitable configuration to secure one or more desired workpieces. In FIG. 2 , the workpiece 38 is shown exploded relative to the support shaft 24 , and the fixture 26 is omitted for simplicity. As shown in the embodiment of FIG. 2 , the workpiece 38 is a gas turbine engine vane segment “doublet” having a pair of airfoils 38 - 1 and 38 - 2 extending between an inner platform 38 - 3 and an outer platform 38 - 4 . The fixture 26 supports the vane segment workpiece 38 with the support shaft 24 positioned at a midpoint located in between the airfoils 38 - 1 and 38 - 2 and in between the inner and outer platforms 38 - 3 and 38 - 4 . In general, the workpiece 38 can be positioned relative to the support shaft 24 to provide optimal line-of-sight positioning relative to one or more axes of movement and a coating source 40 .
The coating source 40 can be an EB-PVD assembly with a material pool 40 - 1 that can produce a coating vapor plume 40 - 2 directed toward the workpiece 38 . Any conventional EB-PVD assembly can be used. In the illustrated embodiment, the coating plume 40 - 2 can extend toward the workpiece 38 in a direction generally perpendicular to the axis A and aligned with a plane in which the support arm 24 moves, in order to deliver vaporized coating material to the workpiece 38 . Those of ordinary skill in the art should recognize that the EB-PVD system described herein is but one example of a configuration of the coating source 40 , and in alternative embodiment other types of coating delivery techniques and systems can be utilized.
The enclosure 42 can be provided to surround at least portions of the manipulator assembly 11 , the workpiece 38 and the coating source 40 . It should be recognized that portions of those components, particularly portions of the manipulator assembly 11 and the coating source 40 can extend outside the enclosure 42 .
During operation, torque can be selectively provided to the driveshafts 12 and 28 to provide rotational input to the manipulation assembly 11 . One or more conventional motors or other mechanisms (not shown) can be used to provide torque input to the driveshafts 12 and 28 , which can be rotated independently at the same speed or different speeds. The driveshaft 12 rotates the sun gear 14 about the axis A. The sun gear 14 transmits torque to the planetary gear 16 , which causes the associated driveshaft 18 to rotate. The bevel gears 20 and 22 transmit torque from the shaft 18 to the support shaft 24 , which rotates about an axis B perpendicular to the axis A. In addition, the driveshaft 28 rotates the drive gear 30 , which engages the carrier gear 32 thereby rotating the carrier body 34 . The planetary gear 16 and the driveshaft 18 , as well as the support shaft 24 and the workpiece 38 carried at the end of the support shaft 24 , are moved around the circumference of the sun gear 14 by rotation of the carrier body 34 about the axis A. Coating material can be delivered from the coating source 40 while the workpiece 38 is manipulated by the manipulation assembly 11 . Manipulation of the assembly 11 tends to cause end-to-end rotational movement of the inner and outer platforms 38 - 3 and 38 - 4 of the workpiece 38 about the axis B, with additional rotation (including orbital movement) in relation to the axis A. The movement of the workpiece 38 allows the coating plume 40 - 2 to tend to focus on the airfoils 38 - 1 and 38 - 2 and adjacent surfaces of the platforms 38 - 3 and 38 - 4 while reducing the amount of coating directed to non-flowpath-boundary surfaces of the platforms 38 - 3 and 38 - 4 . It should be noted that the particular orientation of the workpiece 38 relative to the coating plume 40 - 2 shown in FIG. 2 would only occur momentarily during operation. In general, the movement of the workpiece 38 while the manipulator assembly 11 operates approaches or approximates random movement. It should also be noted that manipulation movement can be adjusted to include dwell times, during which movement of the workpiece 38 is slowed or stopped to increase expose to the coating plume 40 - 2 at a particular orientation.
It should be appreciated that exact workpiece orientation on a given support shaft, as well as manipulation angles and dwell times can be adjusted as desired for particular applications to optimize coating thicknesses and coating microstructure (e.g., vertical columns) in difficult to coat areas. Workpiece orientation is driven in large part by workpiece configuration, and the manipulation angles and dwell positions can be prioritized by the amount of coating need in each area on a particular part (e.g., where more thermal protection is needed, more TBC is applied). For instance, in some embodiments, more coating may be applied to an inner platform than an outer platform of a gas turbine engine vane segment because the inner platform runs hotter than the outer platform during engine operation.
Any relative terms or terms of degree used herein, such as “substantially”, “approximately”, “essentially”, “generally” and the like, should be interpreted in accordance with and subject to any applicable definitions or limits expressly stated herein. In all instances, any relative terms or terms of degree used herein should be interpreted to broadly encompass any relevant disclosed embodiments as well as such ranges or variations as would be understood by a person of ordinary skill in the art in view of the entirety of the present disclosure, such as to encompass ordinary manufacturing tolerance variations and the like.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. For example, a workpiece manipulator according to the present invention can be used in conjunction with coating supply manipulation, and can be utilized with a variety of different types of coatings and coating delivery mechanisms. Moreover, in further embodiments, one or more additional support arms, with additional associated planetary gears, shaft and bevel gears can be engaged with the sun gear to support and manipulate additional workpieces simultaneously. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. | A coating system includes a coating source and a planetary manipulator assembly that includes a first driveshaft capable of receiving rotational input, a sun gear rotationally fixed to the first driveshaft, a planetary gear engaged with the sun gear, a second driveshaft rotationally fixed to the planetary gear such that torque is transmitted from the sun gear to the planetary gear, a support shaft operatively engaged with the second driveshaft, a carrier body supporting the planetary gear relative to the sun gear, a third driveshaft capable of receiving rotational input, and a drive gear rotationally fixed to the third driveshaft. The support shaft is arranged substantially perpendicular to the second driveshaft. The carrier body is rotatable by the drive gear about a common axis with the sun gear, and rotation of the carrier body rotates the planetary gear and the second driveshaft about the sun gear. | 5 |
BACKGROUND OF INVENTION
[0001] The invention relates to novel compositions and a process for making fragrance friendly aluminum zirconium salts that are commonly considered active antiperspirant materials and are covered by FDA OTC Final Monograph as Category I.
[0002] The antiperspirant and deodorant market offers a wide diversity of products to meet consumer needs. The physical forms of antiperspirants vary greatly. They include aerosols, pump sprays, squeeze sprays, creams, roll-ons, suspension roll-ons, deodorant sticks, clear gels, soft solids, etc. Different physical forms of final formulations require that antiperspirant actives meet certain specific chemical or physical properties or both to achieve the desired results. Prominently in the hierarchy of consumer wants is long lasting control of fragrance and wetness. Consumers also want their antiperspirant to have excellent sensory properties on application and certain aesthetics.
[0003] The reasons for such a variety of individual preference products is that the manufacturers increasingly turn to market segmentation to increase their total share of dollar sales and today's customers have sophisticated expectations. For example, clarity remains a market force in the personal care industry as consumers associate clarity with lack of unsightly white residue on skin and clothing. Given these circumstances, it is evident that growth of individual brands must come primarily through product improvement. This can be achieved either by improving product aesthetics or antiperspirancy, or both. Prospects for such improvements have provided an impetus for the development of newer actives and their modifications to meet specific formulation requirements.
[0004] The antiperspirant product group is probably the most demanding in terms of creative (aesthetic) and technical implications when it comes to creating fragrances that are compatible. (Hoffinan, H. M. and Ansari, R., Fragrancing of Antiperspirant Products, Reheis Report 11, 1983).
[0005] Fragrance is an important part of antiperspirant and deodorant appeal. According to a research (1) ( Cult of Personality, Soap, Perfumery & Cosmetics, July 2001, pp. 18-21). Half of all consumers cite fragrance as an important reason for choosing when purchasing antiperspirant devices. Young consumers in particular are influenced by fragrance.
[0006] Fragrance plays a key role in personal care products such as deodorants and antiperspirants. It attracts customer interest, inspires the first purchase, retains brand loyalty, communicates sensory perception that the product is doing its job and gives the overall feeling of confidence and personal freshness.
[0007] Fragrance is highly important in the development of any new product, while a fragrance may not contribute to the properties of an antiperspirant product, it can by its very nature, influence the consumer's expectations of the product's performance. A successful fragrance must coordinate with the product's attributes. Its initial impact, continuing impression, performance and stability are crucial in ensuring a harmonious commercially attractive product. Thus, good understanding of chemical and physical characteristics of both the fragrance and product and possible interactions are essential to a successful antiperspirant such as a a clear antiperspirant stick that is introduced in the market place. In one situation, for example, dibenzylidene sorbitol as a gelling agent in an antiperspirant found it degraded in the presence of acidic antiperspirant and generated a not too pleasing cherry-almond aroma particularly noticeable on storage due to the release of benzaldehyde. Since then, several attempts have been made to address the issue of the instability of this gelling agent and how it can be stabilized while also retaining the efficacy of incorporated fragrances.
[0008] As noted in Nicoll (Nicoll, S., Fragrance Stability in Three Cosmetic Applications, C&T, Vol. 114, No. 7, July 1999, pp. 59-63), when the fragrance is added to the base of a product any of the following reactions may occur:
[0009] the product discolors,
[0010] off-odors develop in the product,
[0011] fragrance is short lived or disappears with time,
[0012] fragrance looses its ability to mix with the base either initially or progressively.
[0013] Many reactions can occur when metal ions are present in the product. These metals can develop highly colored oxides when combined with fragrance ingredients leading to product discoloration. Color is one of those issues that can be quite frustrating. Often the color change may not be significant but visual change draws a strong customer response, e.g., if the product does not look good, it cannot be good. Color change can be caused by a number of factors for example citrus and fruit fragrances cause color with antiperspirant active due to oxidation or hydrolysis of esters. Oxidation can be further catalyzed by iron or other materials.
[0014] Although antiperspirants and deodorants are two different product groups, they are often grouped together. In fact, the two are quite different in their mode of action and their formulation, requiring different technical considerations. These differences have far reaching implications when it comes to fragrancing these products.
[0015] The function of deodorants is essentially to mask underarm odor with fragrance and inhibit the proliferation of bacteria responsible for the sweaty smells. In many cases, a product sold as a deodorant may solely be based on an alcoholic solution of the fragrance and a bactericide. The medium to fragrance is usually mild and the perfumer is able to concentrate largely on the aesthetics in the selection of raw materials for the creation of fragrances. On the other hand, the fragrancing of antiperspirants is very different and hedonically pleasing fragrances for antiperspirants are challenging.
[0016] Antiperspirants inhibit eccrine perspiration and thereby reduce wetness; the aluminum salts and aluminum zirconium complexes, the active ingredients of antiperspirants, are also known to have antibacterial activity and must, therefore, inhibit the proliferation of bacteria responsible for the degradation of apocrine sweat, giving rise to malodorous fatty acids and other volatile nitrogeneous compounds. Whatever malodor problem that might remain is supposed to be taken care of by the fragrance. The antiperspirant then becomes a deodorant too and the fragrancing becomes a crucial factor in determining the consumer acceptability of the product.
[0017] The majority of antiperspirants use aluminum chlorohydrate or Al/Zr products having Al/Zr ratio from 2:1 to 10:1 and metals to chloride ratio of 0.9:1 to 2.1:1 in micronized dry powder form or solutions depending upon the final product form. All these preparations work under acidic conditions (e.g., a 20% w/w solution of aluminum chlorohydrate has an approximate pH of 4.0), rendering many fragrances unstable in the base. As the metals/anion ratio decreases, the product becomes more efficacious, more acidic and less compatible with fragrances. To compensate for acidity, usually higher amount of glycine is employed which makes the product more expensive. Acidity could also have an effect on its compatibility with fragrance as a source of primary amine, like glycine is likely to react with aldehydes present in fragrance and form imines which impart color to the product. This instability causes changes in odor and induces discoloration of the final formulation over a period of time.
[0018] Since a fragrance is a complex mixture of blend of aromatic materials of natural and synthetic origin, it is very difficult to ensure that all the ingredients present will be stable and free from degradative changes induced by the pH of the medium and other changes catalyzed by the metals present. In general, it is recommended that natural oils be avoided, since they invariably contain a great number of chemicals of differing functionalities, making it almost impossible to predict the behavior of the individual components once incorporated into the base. According to Hoffman and Ansari, exception to this is probably the woody complexes based on Patchouly, Cedarwood and Sandalwood. Another point of importance is that aluminum and zirconium salts almost always contain iron as an impurity which complexes with fragrance materials bearing phenolic functionality and causes serious discoloration problems. Stating it differently, the antiperspirant base imposes considerable limitations on the use of fragrance raw materials. It is noted that aldehydic fragrances have dominated this segment of the market; probably the reason is that many aldehydes are fairly stable in the base media. Most of other known types found on the market are only marginally stable.
[0019] Although the fragrance industry has provided the formulators of antiperspirants with fragrances that are stable and have consumer acceptance, consumers desire for new fragrances are ever increasing.
[0020] Most widely used aluminum zirconium antiperspirants usually contain primary amino acids like glycine as buffers to avoid gelling of aluminum zirconium aqueous system. The source of primary amines present in antiperspirant active can react with aldehydes present in fragrance to form a Schiff base that is usually highly colored. This change in color can be problematic especially because it is usually catalyzed by light or heat exposure.
[0021] In summary, it can be stated that antiperspirant bases are acidic, cationic and contain metal ions which can catalyze the degradation of many fragrance ingredients causing odor changes and discoloration. In perfuming, the pH of the antiperspirant product plays an important role. Antiperspirants are typically in the pH range of 3.5 to 4.5 and perfumes are more unstable at lower pH. Many perfume materials react with the aluminum and aluminum zirconium actives used in antiperspirant. This can lead to a change in the odor of the perfume or to a discoloration of the product. Imines are formed when aldehyde reacts with a primary amine to release a water molecule. The glycine, a common component present in aluminum zirconium complexes, is a primary source of amine and can react with fragrances to give a color.
[0022] Iron is usually present in USP grade antiperspirant active as an impurity at a fairly high level up to 50 ppm in solution to 125 ppm in powders. Pink coloration of an antiperspirant product is usually traced directly to metal interactions, primarily iron. Other metals such as Mn, Cu, Co, Cr or Ni can cause color generation if they are present in significant amounts.
[0023] It has been well established that axillary malodour is caused by biotransformation of non odorous precursors present in apocrine sweat and sebum by the axillary microflora. To counter this, deodorants normally contain bactericides. However, after the initial kill of bacteria, the surviving cells grow, producing a concomitant rise in axillary odor. Long lasting deodorant effect is achievable only if bacterial growth is inhibited for an extended period such as by a controlled release of a bactericide. Another approach is to inhibit bacterial growth by nutrient deprivation, primarily that of iron Fe(III) as has been proposed by L. Andrew and Stephen Makin ( Iron Sequestration on Skin: a new route to improved deodorancy, 22 nd IFSCC Congress, Edinburgh 2002). The content of that publication and of the patent disclosure in WO 03/007903A, titled “Deodorant Compositions Comprising A Transition Metal Chelator and A Silicon Fluid”, are incorporated herein by reference in their entirety. Based on reported research the indication is that the deprivation of iron Fe(III) has the most profound effect on bacterial growth.
[0024] However, it should be recognized that while reduction in iron contribution by antiperspirant is beneficial, it does not deprive microflora of all the iron as there are two other source of iron from the skin, namely losses of iron in sweat and losses of iron in desquamated epithelial cells. The latter are probably fairly constant in the single individual and independent of the amount of sweat lost whereas sweat iron loss vary considerably. Various studies have been reported in the literature concerning the loss of iron and other trace metals through the skin. Concentration of iron values reported in the sweat vary considerably depending upon how the sweat was collected, analytical techniques used and whether the sweat was collected under thermal stress or at room temperature, etc. The following references provide useful insight into trace metal losses through skin. Of particular interest is the iron in cell-free sweat in the underarm area. Brune, M.; Magnusson, B.; Persson, H. and Hallberg, L. reported their findings on the loss of iron in whole body cell-free sweat in eleven healthy men in an article titled Iron Losses in Sweat (Journal of American Clinical Nutrition, Vol. 43, March 1986, pp. 438-443). In this study a new experimental design was used with a very careful cleaning procedure of the skin and repeated consecutive sampling periods of sweat in a sauna. The purpose was to achieve a steady state of sweat iron losses with minimal influence from iron originating from desquamated cells and iron contaminating the skin. Iron loss was directly related to the volume of sweat lost and amounted to 22.5±2.29 μg of iron/liter of sweat. The findings indicated that iron is a physiological constituent of sweat and the iron content of cell rich, compared to cell free, sweat was about five (5) times higher.
[0025] Green, et al., ( Body Iron Excretion in Man, A Collaborative Study, American Journal of Medicine, Vol. 45, 1968, pp. 336-53) reported sweat iron losses in laundry workers with heavy sweat losses. The calculations of sweat iron losses were based on the rate of decline in specific activity of 55 Fe over several years. The average extra iron loss due to the perspiration (from the whole body) calculated from that study was about 0.1 mg/day.
[0026] On its web page titled Inspired to Perspire, Gillette Uncovers Sweat Gillette has reported several of the findings about sweat from its experts as follows: (1) the average amount of perspiration from underarms in one hour at room temperature equals 200 mg; (2) the average amount of perspiration from underarms in one hour at room temperature during emotional stress equals 700 mg; (3) underarms are the top sweat producing areas of the body; (4) men have a much higher sweat rate than women; (5) the usage rate of antiperspirant and deodorant varies with the age group; (6) men use an antiperspirant or deodorant an average of 7.9 times a week and women 8.3 times a week; (7) young men and women use antiperspirants and deodorants more frequently than any other group; (for example, women age 13-17 use 10.3 times/week and men age 15-17 use 9.8 times/week); and (8) more than 90% of men and women use a deodorant or an antiperspirant. Thus, it is safe to assume that on an average antiperspirant is used at least once/day.
[0027] Using the information of iron concentration in cell free sweat as determined by Brune et al., and the average amount of perspiration from underarms reported by Gillette, iron contribution by cell free sweat in underarm areas is computed to be 0.108 μg /day.
[0028] Maximum iron content of a typical USP grade antiperspirant powder can be 125 ppm and average usage rate of an antiperspirant product per application per underarm is about 0.4±0.05 gm. According to the final OTC monograph issued by FDA in June 2003, maximum anhydrous solids content of aluminum zirconium active in an antiperspirant formulation can be 20%. Thus, the maximum iron contribution by Al/Zr antiperspirant salt to underarm can be about 28.8 μg/day. Assuming an iron content of 70 ppm in Al/Zr active iron contribution could be about 16 μg/day.
[0029] While the exact amount of iron contribution by sweat and desquamation in the underarms area is not known the aforementioned computed numbers give some perspective as to the amount of iron involved and whether reduction in iron content of the active would help improve deodorancy of antiperspirant product or not. It is not known whether the iron from the active is readily available to the microflora as it is from the iron carrier protein transferring, present in ocarina sweat. Since the iron contribution by antiperspirant appears to be significant, reduction in its value is hypothesized to improve deodorancy of the final product assuming that iron from the active is available as a nutrient to the axillary microflora.
[0030] Thus, the objective is to make aluminum zirconium actives with low trace metal impurities, low iron, glycine free and at least equal in efficacy to the products currently used.
[0031] Accordingly, to improve fragrance compatibility it is preferred to have an aluminum zirconium active without primary amine, with low or no iron content and very low Mn, Co, Cr,Cu and Ni levels.
[0032] Because the antiperspirant market is flooded with a variety of products and this imposes many different requirements on antiperspirant actives and finished formulations and because almost all forms of antiperspirant formulations are scented compatibility of different actives in different product forms with fragrances is extremely important and the nemesis of all product marketers is color change.
[0033] With reference to the prior art patents, aluminum zirconium antiperspirant salts have been known since about 1954; numerous patents have been issued for the processes and compositions of making these salts. Patent documents which are cited in connection with the disclosed invention are U.S. Pat. No. 2,814,585 (Daley), U.S. Pat. No. 2,854,382 (Grad), GB 1,353,916 (Bolich), GB 2,075,289 (Mackles), U.S. Pat. No. 3,979,510 (Rubino), U.S. Pat. No. 4,017,599 (Rubino), U.S. Pat. No. 4,331,609 (Orr), U.S. Pat. No. 4,775,528 (Callaghan), U.S. Pat. No. 4,871,525 (Giovenniello), U.S. Pat. No. 4,900,534 (Inward), U.S. Pat. No. 5,225,187 (Carmody), U.S. Pat. No. 5,296,623 (Katsoulis), U.S. Pat. No. 5,33,751 (Curtin), U.S. Pat. No. 5,718,876 (Parekh), U.S. Pat. No. 6,066,314 (Tang), U.S. Pat. No. 6,375,937 (Chopra), U.S. Pat. No. 6,436,381 (Carrillo), etc.
[0034] Some of these aluminum zirconium antiperspirant salts are described as having enhanced efficacy, which means that they provide greater sweat reduction than conventional antiperspirant salts. The enhanced efficacy salts are typically differentiated from conventional antiperspirant salts by reference to the various aluminum peaks that can be identified when the salt is analyzed by size exclusion chromatography, typically HPLC. For more discussion on peak assignments of HPLC chromatography reference is made to copending application Ser. No. 10/807,996 filed Mar. 24, 2004.
[0035] A common aspect of all the patents cited is that they use mostly neutral amino acid or salts of amino acid to avoid gelling and to reduce acidity when basic aluminum halides and zirconium salts, like zirconium oxychloride (ZrOCl 2 ) or zirconium hydroxychloride (ZrO(OH)Cl) solutions, are combined to create more efficacious aluminum zirconium antiperspirants. In some of the recent patents, for example, U.S. Pat. No. 6,066,314 discloses post addition of glycine to aluminum zirconium salts containing glycine in an amount of 1:1.2-1.5 of zirconium to amino acid on a weight weight basis. Marginal, if any, associated increase in efficacy is expected. However, the product is more expensive. Also, U.S. Pat. No. 6,375,937 comprises aluminum zirconium salts which have a metal to chloride molar ratio in the range of 0.9-1.2:1 and glycine:zirconium molar ratio greater than 1.3:1 and more particularly greater than 1.4:1. Such excessive amounts of glycine increases cost of the product significantly and probably make the product less compatible with fragrances. In U.S. Pat. No. 2,814,585 Daley discloses (column 3, lines 50 to 70) that high concentration of the amino acids in aluminum zirconium antiperspirant compositions have a deleterious effect upon the efficacy of the composition. Moreover, antiperspirant preparations containing such large amount of amino acids are not economically attractive from a marketing standpoint.
[0036] Accordingly an object of the invention is to develop a process for making aluminum zirconium antiperspirant salt over the entire range covered by the OTC Monograph without the requirement of inclusion of any amino acid or salts of amino acids or other buffers.
[0037] U.S. Pat. Nos. 4,775,528; 5,114,705; 5,225,187; 5,486,347; 5,589,196; 5,955,064; 5,939,057; 6,066,314; 6,074,632; 6,451,296 B1; and EP 0633203 A1, and WO 01/56539 disclose aluminum zirconium antiperspirant compositions containing either both glycine and polyhydric alcohol or only polyhyric alcohol. With respect to formulations containing solely polyhydric alcohol the prior art indicates that stable and efficacious antiperspirant is obtained by eliminating glycine and replacing it with polyhydric alcohol. While the replacement of glycine by polyhydric alcohol in aluminum zirconium yields efficacious antiperspirant, it also tends to introduce an undesirable tackiness to the antiperspirant active and formulations of this kind have limited product application.
[0038] Thus, it is highly desirable to have a stable and effective aluminum zirconium active which is free of glycine as well as polyhydric alcohol.
[0039] In U.S. Pat. No. 2,906,668, Beekman disclosed a process for preparing aluminum/zirconium complex with aluminum to zirconium atomic ratio in the range of 2 to 10; but in both the examples cited, a gel was formed which was changed to opalescent or cloudy liquid by heating. Gelling is due to polymerization of zirconium species and this renders the product to be less efficacious. Daley, in U.S. Pat. No. 2,814,585 discloses that prevention of gelling of antiperspirant preparation is extremely important since gels have been found to have limited antiperspirant properties so as to be considered useless from a practical standpoint.
[0040] In U.S. Pat. No. 3,405,153 Jones disclosed a process for preparing aluminum-zirconium complex by adding zirconium oxychoride to hot aluminum chlorohydroxide and the gel that was formed was said to be essentially dissolved with prolonged heat and agitation and reflux which yielded cloudy solution. Thus it suffers from the same limitations as those for U.S. Pat. No. 2,906,668 noted above.
[0041] In U.S. patent application Ser. No. 10/625,038 is disclosed a process to make aluminum zirconium salts without amino acid and polyhydric alcohol, but the process is not capable of producing all the aluminum zirconium salts approved by FDA under the OTC Final Monograph issued on June 2003. This is demonstrated on the FIGURE of the accompanying drawing. Only products covered by the shaded area in FIG. 1 can be made using the system described in that patent application. Specific products that can be prepared using the process of the above mentioned patent application include aluminum zirconium tetrachlorohydrate with Al/Zr atomic ratio from about 2 to 6 and metal/chloride atomic ratio from about 0.9 to 1.25; aluminum/zirconium octachlorohydrate having Al/Zr atomic ratio from about 6 to about 10 and metal to chloride atomic ratio about 0.9 to about 1.5 and aluminum zirconium pentachlorohydrate having Al/Zr atomic ratio from about 6 to 10 and metal to chloride atomic ratio of about 1.51 to about 1.65. According to the novel process of the present invention, it has been discovered that all of the aluminum zirconium products under FDA OTC Final Monograph issued on June 2003, i.e., those encompassed by the figure of the drawing can be made. It is important to note that the two most widely used aluminum zirconium antiperspirant are aluminum zirconium trichlorohydrex (with Al/Zr ratio of 3 to 6 and M/Cl ratio of 1.51 to 2) and aluminum zirconium tetrachlorohydrex (with Al/Zr ratio in the range of 3-5 and metals to chloride ratio of 1.35 to 1.5) and with respect thereto, process of U.S. patent application Ser. No. 10/625,038 has very limited application. Also, that application does not address the issue of color formation (fragrance compatibility) achieved by the novel product of the present invention in which iron and trace metal (Co, Cr, Ni, Mn and Cu) levels are closely controlled to minimize color formation with the fragrances. Fragrances are more stable and compatible with higher metals to chloride ratio aluminum zirconium products, but such products are incapable of being made with the process of U.S. patent application Ser. No. 10/625,038 as shown by FIG. 1 . In summary, the novel process of the present invention is unique in that it facilities formulation of the entire range of very low iron aluminum zirconium antiperspirant salts that fall within the scope of the OTC Final Monograph without incorporating amino acid or polyhydric alcohol; which are cost effective; which minimize the probability of the final product's color change; which are more compatible with fragrance; and which improve deodorancy by reducing iron contribution to underarm area.
[0042] U.S. patent application Publication No. 2003/0138389 A1 discloses a deodorant antiperspirant comprising an aluminum chlorohydrate with an iron content of less than 20 ppm on a dry basis having improved efficacy and deodorancy for low iron product (10 ppm) compared to high iron product (80 ppm). The disclosure of that patent application is incorporated herein in its entirety by the reference. No disclosure is contained in that application which deals with color formation or fragrance compatibility for low iron glycine free aluminum zirconium product or regarding the preparation of more cost effective amino acid free aluminum zirconium products.
[0043] U.S. Pat. No. 6,451,296 B1 discloses that low molecular weight aluminum species as measured by HPLC Band IV (or peak 5) lead to more efficacious products. However, it is important to note that U.S. Pat. No. 6,451,296 B1 teaches use of high concentration of polyhydric alcohol during the reaction phase to avoid polymerization of zirconium species and does not teach how to make low iron low trace metal, glycine free and cost effective aluminum zirconium salts which are more compatible with fragrances. Also the product of this patent tend to be tacky and have limited application. In Carrillo, et al., U.S. Pat. No. 6,436,381 improved efficacy is correlated with low metal to chloride (0.9:1 to 1:1) aluminum zirconium products with peak 5 (or Band IV). The disclosure of U.S. Pat. No. 6,436,381 does not embrace glycine free aluminum zirconium salts over the metal/chloride ratio range greater than 1.1. The requisite process parameters and composition of the present invention are outside those employed in the patent.
[0044] None of the foregoing referenced prior art discloses or teaches the process of the present invention: of making low iron (less than 30 ppm, preferably less than 20 ppm, more preferably less than 10 ppm and most preferably less than 5 ppm) aluminum zirconium antiperspirant salts without amino acid or amino acid salt or polyhydric alcohol; having very low trace metal (Co, Cr, Ni, Mn, and Cu) impurity level (less than 2 ppm and more preferably less than 1 ppm) and which are fragrance friendly, very cost effective and very efficacious. Because zirconium and amino acids or salts of amino acids are the most expensive ingredients in any aluminum zirconium antiperspirant actives, the elimination of glycine and/or its salts and increasing the Al/Zr ratio from 3.5-4 to 7-8 without sacrificing efficacy makes the novel product of this invention most cost effective and attractive from marketing standpoint. Where efficacy comparable to that of enhanced efficacy salt is desired, it can be achieved by lowering the concentration of basic aluminum chloride to about 15-20 wt % and lowering Al/Zr ratio from 7-8 to 3-4 range. Addition of highly acidic ZrOCl 2 or ZrO(OH)Cl result in depolymerization of aluminum species resulting in higher concentration of aluminum species in peaks II, IIII and IV.
SUMMARY OF THE INVENTION
[0045] The present invention is directed at aluminum zirconium actives, with their unique ability to stop wetness more effectively than conventional aluminum actives. Antiperspirants of this kind have come to dominate the antiperspirant market. For this reason, it is important that antiperspirant actives which improve specific aesthetic properties of the final product also have efficacy at least equal to the products being used currently and the process of making the actives be economical.
[0046] Accordingly it is an object of the present invention to provide Al/Zr antiperspirant salts over the entire range of the Final OTC Monograph that are free of amino acids or salts of amino acids and are free of polyhydric alcohols thereby improving fragrance compatibility and providing formulators wider choices in coming up with newer and better fragrances.
[0047] It is another object of the present invention to produce aluminum zirconium antiperspirant products with very low iron content that have improved compatibility with fragrance; minimize probability of the product's color change; possibly reduce fabric staining; and minimize iron contribution to underarm area where growth of microflora, that is responsible for axillary malodour by the biotransformation of non-odorous precursors present in apocrine sweat and seabum takes place.
[0048] It is a further object of the present invention to provide novel aluminum zirconium antiperspirant products with efficacy at least equal to that of currently prevailing conventional aluminum zirconium products but at a lower cost.
[0049] It is still a further object of the present invention to produce antiperspirant products that have chromium, nickel and cobalt present in levels of each less than 2 ppm, and preferably less than 1 ppm, and iron content of less than about 30 ppm preferably less than 20 ppm and more preferably less than 10 ppm and most preferably less than 5 ppm.
BRIEF DESCRIPTION OF THE DRAWING
[0050] The FIGURE of the drawing illustrates diagrammatically the area inclusive of the aluminum zirconium products encompassed within the FDA OTC Final Monograph.
DETAILED DESCRIPTION OF INVENTION
[0051] High pressure liquid chromatography (HPLC) is used to characterize macromolecular distribution of aluminum zirconium species. For details of the specific methodology used reference is made to copending patent application Ser. No. 10/807,996 filed Mar. 24, 2004.
[0052] The term “metals/chloride” ratio is used interchangeably herein with “metals/halide” ratio or “metals/anion” ratio and metals refer to (Al+Zr) or (Al+Zr+Hf) and ratio always refers to atomic ratio.
[0053] It is important to note that the weight percentage of antiperspirant salt is indicated herein as percent of anhydrous solids (% A.S.), which excludes any bound water. This is calculated in accordance with the following equation (USP 27):
% A.S. in Al/Zr Salt=Al({26.98 y+ 92.37+17.01 [3 y+ 4−( y+ 1)/z]+35.43 ( y+ 1)/z}/26.98 y ),
in which Al is percentage of aluminum, y is the aluminum/zirconium atomic ratio, z is the aluminum plus zirconium/chloride atomic ratio, 26.98 is the atomic weight of aluminum, 92.97 is the atomic weight of zirconium corrected for 2% hafnium content, 17.01 is the molecular weight of the hydroxide ion (OH) and 35.453 is the atomic weight of chlorine Cl.
[0054] The percent A.S. in basic aluminum chloride salt=Al{[26.98x+17.01(3x−1)+35.453]/26.98x} where x is the aluminum/chloride atomic ratio.
[0055] Aluminum zirconium halides prepared in accordance with the novel method of the invention are characterized as having metals to chloride ratio between 0.9:1 to 2:1, preferably between 1.2:1 to 1.7:1 and aluminum to zirconium ratio of 2:1 to 10:1, preferably in the range of 5.5:1 to 8.5:1 and most preferably 7.5 to 8.5 to reduce cost while maintaining efficacy which is statistically not significantly different from that of aluminum zirconium tetrachlorohydrex having Al/Zr atomic ratio of about 3.5 and metal to chloride ratio of about 1.35.
[0056] The method of the present invention comprises reacting two components namely low iron basic aluminum halide solution having low trace metal (Co, Cr, Ni, Cu and Mn) impurities and represented by the empirical formula
Al 2 (OH) 6-x1 Y x1 .nH 2 O
wherein Y is Cl, Br, or I, n is about 0.8 to 4 and 0<x 1 <6 and a zirconium compound selected from the group having the following general empirical formula;
ZrO(OH) 2-nz B z
and having an iron content of less than 10 ppm more preferably less than 5 ppm and wherein z may vary from 0.9 to 2 and n is the valence of B and 2-nz is greater than or equal to 0 and B is selected from the group consisting of halides.
[0057] As an alternative to or in conjunction with the above described zirconium salts, a zirconium basic carbonate represented by empirical formula
[ZrO(OH)(CO 3 ) 0.5 .nH 2 O] or [Zr 2 (OH) 4 (CO 3 ) 2 .nH 2 O]
may also be employed. However, such carbonates should not be interpreted as precise with respect to chemical structure but should be regarded only as a guide to molar ratio and wherein n represents the amount of water required to bring the equivalent ZrO 2 content to any specified concentration for this product; for example, for ZrO 2 content of about 40%, n will be about 8.7.
[0058] The basic aluminum halides may be made by a number of processes. A first preferred process is the method disclosed in U.S. Pat. No. 5,908,616 (Parekh), i.e., reacting (a) aluminum powder, (b) an aluminum halide solution and (c) water at a temperature greater than about 85° C. Another method involves mixing and reacting standard aluminum chlorohydrate with AlCl3 or HCl at a temperature from about room temperature (RT) to about reflux for a period that may range from about 0.5 hr. to about 2 hrs. The resultant solution is processed thru a ligand column to achieve iron concentration of less than 30 ppm preferably less than 20 ppm more preferably less than 10 ppm and most preferably less than 5 ppm.
[0059] In general, any standard basic aluminum halide conventionally used in the art may be used in the present method. Such solutions generally have anhydrous solids concentration of about 15% to 40%. However, it will be evident to one skilled in the art that selection of the appropriate concentration will depend upon the specific product physical and chemical properties desired. Standard basic aluminum chloride may be processed using available technologies to reduce iron content below 30 ppm preferably to below 20 ppm, more preferably to less than 10 ppm and most optimally to less than 5 ppm.
[0060] The zirconium complexes could be either low iron zirconium oxychloride solution in water or the zirconium halide complexes which can be prepared by mixing basic zirconium carbonate with hydrochloric acid or zirconium oxychloride at an elevated temperature of about 60° C.-70° C. Once a clear solution is formed, it is cooled and filtered. With aluminum halide solution of very low basicity it may be possible to use aqueous zirconium basic carbonate slurry having empirical formulas [ZrO(OH)(CO 3 ) 0.5 .nH2O] or [Zr 2 (OH) 4 (CO 3 ) 2 .nH 2 O] such compounds should not be interpreted as precise with respect to chemical structure but should be regarded as a guide to molar ratio at a controlled rate such that the solution at reflux condition does not become cloudy or opaque.
[0061] The two components are reacted at a reflux temperature of about 105° C.±5° C. under closely monitored addition rate of zirconium compound, i.e., the zirconium salts, to avoid formation of cloudiness or gelation during the reaction phase. Where cloudiness develops, addition of zirconium compound is stopped until the reacting solution clears up at which time a controlled addition of the zirconium compound is resumed. Following a completion of the addition of the zirconium compound, the solution is refluxed for additional 30 to 90 minutes. If the product is to be used for clear gel or low residue antiperspirant optionally, a suitable organic solvent can be added to replace desirable amount of water by evaporation or distillation. The final solution is cooled and filtered. The final solution can be dried using any of the industrial drying methods such as spray drying. The resultant dry powder can be micronized, sieved, air-classified to achieve the desired particle size and/or shape distribution. The type of atomizer used is a function of the desired particle shape, size and density. Thus, any one of the following atomizing devices can be used for spray drying: CSC disc, two fluid nozzle, single fluid nozzle, porous metal disc or drilled hole disc.
[0062] Concentration of basic aluminum chloride and zirconium salt solution may be varied to achieve the desired anhydrous solids concentration of aluminum zirconium salt in the final solution. Lower concentrations (about 10% to about 20%) lead to higher concentration of depolymerized aluminum species similar to those of enhanced efficacy actives but they may not be stable in aqueous solutions. Such dilute solutions may be stabilized by drying within a time frame of about 10 to 24 hrs.
[0063] Iron content and other trace metal impurity level can be reduced by several available technologies. One such technology is based on a principle called molecular recognition or “host guest” chemistry. This approach resides in the use of a family of compounds (host) designed to recognize the guests and to bind them. In contrast to classical separation techniques such as precipitation, ion exchange and solvent extraction, molecular recognition technology (MRT) developed by IBC (IBC Advanced Technologies Inc., American Fork, Utah) exhibit several orders of magnitude increase in affinity and selectivity for specific elements even when these species have similar charge, shape or other attributes. Molecular Recognition Technology is a highly selective, non-ion exchange process using organic ligands that are chemically bonded to solid supports such as silica gel. The system consists of the ligand material packed into fixed bed columns that can be built in the modular form. The processing of basic aluminum chloride solution thru the ligand column results in lowering of iron concentration to less than 10 ppm. The ligand column is regenerated by elutting with dilute HCl. Concentration of iron in the treated solution can vary from less than 1 ppm to less than 20 ppm depending upon the basicity of the solution being treated and age of the column. Further reduction can be achieved by using multiple columns in series. Iron content of ⅚ basic aluminum chloride solution (commonly known as aluminum chlorohydrate or ACH) was reduced from about 97 ppm iron to 1 ppm in one run the reduction was less than 15 ppm in a run made with the same column one week later.
[0064] Tables I and II show the results of two experimental runs made about one week apart using ⅚ th basic aluminum chloride solution. Results show significant reduction (about 85% to 99%) in iron content of the solution. As noted in these tables there were no significant changes in HPLC or chemical analysis except for the iron content.
TABLE I Chemical Analysis of 50% ACH Solution Prior to and After Ligand Treatment Untreated Treated Untreated Treated % Al 11.79 1.97:1 11.80 11.80 % Cl 7.86 .69 7.86 7.86 pH (as is) 3.94 3.94 3.94 3.94 Fe ppm 97 1 98 15 Al:Cl Ratio 1.97:1 1.97:1 1.97:1 1.97:1
[0065]
TABLE II
% HPLC* Peak Areas
Untreated
Treated
Untreated
Treated
Peak I
50.05
52.36
53.65
57.53
Peak II
30.42
27.69
25.99
24.45
Peak III
13.20
14.30
12.41
11.95
Peak IV
6.33
5.65
6.30
6.07
*HPLC Clumn used was Maxil RP2
[0066] Several samples of aluminum zirconium tetrachlorohydrex and trichlorohydrex were prepared using a spray dried basic aluminum chloride solution and zirconium hydroxy chloride solution available from Reheis Inc. of Berkeley Heights, N.J. The resultant powders were specifically analyzed for Pb, Ni, Co, Cr and Hg and their respective concentrations in ppm were ≦1.0, ≦1, ≦0.2≦2 and none detected (ND).
[0067] The majority of iron and other trace metal impurities in antiperspirants are primarily contributed by the aluminum metal and aluminum chloride or HCl used in the manufacture of basic aluminum chloride solutions which are the basic building blocks of all antiperspirant actives. The lower desirable values of trace metal impurities were achieved by controlling quality of raw materials and/or treatment with ligand columns.
[0068] Samples of basic aluminum chloride (BAC) powders (Microdry ACH and RE-301 SUF) and aluminum zirconium powders (Rezal® 36GP and Reach® AZP908) were prepared using untreated and ligand treated BAC solution and micronized. ΔYB values were measured (using Macbeth color spectrophotometer) for treated and untreated samples. Results showed significant improvement in yellow coloration of the powder as shown below.
Untreated Treated ΔYB ΔYB Reach-301 Superultrafine 2.3 0.14 Microdry ACH 0.44 0.10 Rezal 36GP Superultrafine 2.5 0.10 Reach AZP-908 Superultrafine 1.6 0
[0069] Reach-301, Microdry ACH, Rezal 36GP and Reach AZP-908 are Reheis' brand names for Reheis Inc. of Berkeley Heights, New Jersey for aluminum sesquichlorohydrate, ⅚ th basic aluminum chlorohydrate, aluminum zirconium tetrachlorohydrex and activated aluminum zirconium tetrachlrohydrex.
[0070] The following examples illustrate a novel process used to prepare low iron, glycine free aluminum zirconium actives details of which except as recited in the appended claims, are not to be construed as limitations.
EXAMPLE 1
[0071] 7917 gms of basic aluminum chloride solution (% Al 9.03, % Cl 6.59) having Al/Cl atomic ratio of 1.80:1 and anhydrous solids content of 29.54% was heated to reflux temperature and 3084 gms of zirconium oxychloride (ZOC) solution (% Zr 9.45, % Cl 7.35) was added slowly to maintain clarity of the reacting solution over a 3 hour period and the solution was refluxed for one hour after the addition of ZOC was completed. The solution was filtered and analyzed. About 5100 gms of solution was spray dried at an outlet temperature of 240° F. Chemical analysis of solution and powder were as follows:
Solution % Al 6.32, % Zr 2.58, % Cl 7.11, Al/Zr atomic ratio 8.44, iron 18 ppm, M/Cl atomic ratio 1.31, pH of 15% w/w solution 3.60, % A.S. 26.44 Powder % Al 19.0, % Zr 7.85, % Cl 19.99, Al/Zr atomic ratio 8.34, iron 49 ppm, M/Cl atomic ratio 1.40. % A.S. 78.93. The micronized powder had a particle size of 97.56% less than 10 μ
EXAMPLE 2
[0072] The same procedure was followed as in Example 1 except that metals to chloride ratio was targeted to be 1.62 to make aluminum zirconium penta salt. 8670 gms of basic aluminum chloride solution having Al/Cl atomic ratio of 1.95:1 (% Al 9.66, % Cl 6.49, anhydrous solid content of 31.31%) was brought to reflux and 1670 gms of zirconium hydroxy chloride (ZHC) solution (% Zr 18.24, % Cl 12.95, Cl/Zr atomic ratio 1.86) was added over 3.25 hours and the final solution was refluxed for an additional hour. The final solution was spray dried and micronized. Chemical analysis of the solution and the powder were as follows:
Solution % Al 7.99, % Zr 2.82, % Cl 7.14, Al/Zr atomic ratio 9.75, M/Cl atomic ratio 1.62, % A.S. content 31.7%, iron 23 ppm Powder % Al 20.7, % Zr 7.32, % Cl 18.0, Al/Zr atomic ratio 9.74, M/Cl atomic ratio 1.66, anhydrous solids content 81.9%, iron 40 ppm
[0073] Aluminum zirconium octa salt of example 1 was tested for antiperspirant efficacy against most widely used aluminum zirconium tetrachlorohydrex in a suspension roll-on formulation using the standard hot room procedure. In the standard hot room procedure, human volunteers are subjected to thermal stress and gravimetric determination of the perspiration produced under the thermal stress with and without antiperspirant product applications are made. The data is subjected to analysis of covariance method described by Murphy and Levine (T. D. Murphy, et al., Analysis of Antiperspirant Efficacy Test Results, Journal of the Society of Cosmetic Chemists, Vol. 42, May 1991, pp. 167-197) and compared for percent sweat reduction capacity. Antiperspirancy tests were conducted by an outside independent lab employing “Controlled Hot Room Gravimetric Test” in conformance with FDA guidelines.
[0074] The anhydrous suspension roll-ons were prepared using an aluminum zirconium salt concentration of about 20% on an anhydrous basis (about 25% on weight basis) and approximate concentration of other ingredients were Dow Coming 245 , 70.5%, Bentone 38 , 2.70%, SDA Alcohol 40 (95% alcohol+5% water) 1.8%.
[0075] Aluminum zirconium tetrachlorohydrex powder used for comparison had the following chemical analysis. % Al 14.8, % Zr 14.5, % Cl 18.36, % Glycine 11.7, Al/Zr atomic ratio 3.52 and M/Cl atomic ratio of 1.36, % A.S. 77.46.
[0076] Efficacy study was based on 37 female subjects and there was no statistically significant difference (p=0.127) in the reduction in perspiration between aluminum zirconium octachloro-hydrate having Al/Zr ratio of 8.44 and no glycine and aluminum zirconium tetrachlorohydrex having Al/Zr ratio of 3.52 with glycine. Without being bound by any theory it is hypothesized that glycine-free octa salt having Al/Zr ratio in the range of about 6.5 to 7.5 and metals/chloride ratio of about 1.20-1.25 will give about the same sweat reduction numerically as the tetrasalt (which is widely used currently), with Al/Zr ratio of about 3.5 and metals/chloride ratio of about 1.35-1.40. No adverse experiences were observed by the subjects. Sweat reduction values for the octa and tetra salts were 48% and 52% respectively. Results of this study established that amino acid free cost effective aluminum zirconium salts could be prepared without sacrificing efficacy.
[0077] It is known that fragrances in antiperspirants can discolor over time due to the acidic nature and high transition metals concentration especially Fe, Cr, Co, Mn, Cu, and Ni. It is also known that glycine can initiate Schiff base reaction with aldehydes present in fragrances. Hence, to compare novel product of this invention with the conventional aluminum zirconium tetrachlorohydrex for their ability to form color with fragrances, laboratory work was done with 14 different fragrances from nine different suppliers (Quest, Flavor & Fragrance Specialties, Shaw & Mudge Company, Firminich, Noville, Bell, Drom, Harmann & Reimer and Takasago) using samples from Examples 1, 2 and Al/Zr Tetrachlorohydrex used for efficacy testing. Fragrance dispersions were prepared as follows: 0.75% perfume, 1.0% Arlasolve 200, 20% antiperspirant active (on an anhydrous basis), q.s. DI water. Samples were stored at 45° C. for four weeks and were analyzed for color visually as well as using Macbeth Color Spectrophotometer. Aluminum zirconium tetrachlorohydrex was compared against aluminum zirconium penta and octa salts of Examples 1 and 2. Color was measured as ΔYB (yellow blue) and ΔRG (red green) for all the fourteen fragrances and three actives. Results of these measurements are shown in Table III.
[0078] While the average ΔYB and ΔRG value for all the fragrances tested are almost similar for octa and penta salts they are significantly lower than those of aluminum zirconium tetrachlorohydrex. In other words, low iron, glycine free and higher Al/Zr ratio actives of this invention are not only comparable in efficacy to the conventional product but are more fragrance friendly and less likely to form colors as intense as the conventional aluminum zirconium glycine complexes with lower Al/Zr atomic ratio. The reduction in ΔYB is about 45% and in ΔRG is about 39%.
[0079] Summarizing, based on work with 14 different fragrances (as indicated in Table III) from nine different suppliers, it can be stated that amino acid free low iron penta and octa salts having low trace metal impurities result in less discoloration then tetrasalt after four weeks of shelf aging at 45° C. The color assessments were made visually as well as instrumentally.
TABLE III Fragrance Compatibility Study ΔYB @ 45° C. ΔRG @ 45° C. Fragrance Tetra Penta Octa Tetra Penta Octa Q-26238 11.51 6.31 8.49 8.67 4.69 7.45 Q-26240 10.51 5.64 5.04 8.68 4.92 4.07 Q-26241 11.29 6.60 7.13 7.98 3.71 3.76 Q-26242 14.50 10.32 9.77 9.21 6.42 6.54 Q-26239 12.12 8.07 9.40 8.24 4.93 6.65 AC 10278/498988 7.12 4.40 3.77 4.67 2.30 1.86 FFS 52847 8.63 6.70 6.76 6.48 6.18 6.37 SM 25105D 11.76 8.65 8.57 9.49 9.07 8.65 Takasago RM 9.49 9.94 10.02 9.14 10.38 10.51 1595 Quest Q-14072 16.59 12.08 9.61 14.66 11.30 10.05 Firm. 430-507 20.27 13.52 14.63 18.73 12.66 12.82 Noville AN 16.28 13.19 12.23 16.50 12.92 11.91 119738 Bell J-8381 7.45 5.36 5.56 4.69 3.19 2.88 Drom99-920 9.69 4.16 4.45 5.55 2.53 2.28 Average 11.94 8.21 8.2 9.48 6.8 6.84 Std. Dev. ±3.76 ±3.16 ±3.0 ±4.77 ±3.75 ±3.59
[0080] Since octa-salt is more acidic than tetra- or penta-salt and as both the salts of this invention do not contain glycine, their cumulative irritation potential were compared using fourteen days of epidermal contact to the antiperspirant products being used widely at the current time. A total of twenty eight (28) subjects, male and female, were selected for this study and the study was conducted by an independent lab. The methodology used was as follows.
[0081] The upper back between the scapulae served as the treatment area. Approximately 0.2 ml of each test material (an amount sufficient to cover the contact surface), was applied to the ¾″×¾″ absorbent pad portion of an adhesive dressing. These were then applied to the appropriate treatment sites to form occluded patches.
[0082] Each test material was applied to the appropriate treatment site Monday through Friday to maintain fourteen consecutive days of direct skin contact. Patches applied on Friday remained in place until the following Monday. Evaluations of the test sites were conducted prior to each patch application.
[0083] If a test has been observed to exhibit an evaluation score of a “3”, the application of test material to this site would have been discontinued and the observed score of “3” would be recorded for the remaining study days.
[0084] The following scoring procedure was used
0—No visible skin reaction +—Barely perceptible or spotty erythema 1—Mild erythema covering most of the test site 2—Moderate erythema, possible presence of mild edema 3—Marked erythema, possible edema 4—Severe erythema, possible edema, vesiculation, bullae and/or ulceration
[0091] The compounds selected for the study were aluminum zirconium octa chlorohydrate and penta chlorohydrate salt solutions, 50% aluminum chlorohydrate solution, activated aluminum zirconium tetrachlorohydrex solution as control. Chemical analysis of the samples are shown in Table IV.
TABLE IV Activated Al/Zr Al/Zr Octa Al/Zr Penta Tetrachloro- 50% ACH Product Chlorohydrate Chlorohydrate hydrate Solution % Al 6.43 8.02 7.34 11.86 % Zr 2.7 3.11 6.12 0 % Cl 7.33 7.60 9.01 8.07 % Gly 0 0 5.04 0 Al/Zr 8.21 8.89 4.13 — M/Cl 1.29 1.54 1.33 1.93 % A.S. 27.1 32.53 36.51 38.49 pH 15% w/w 3.76 4.08 3.93 4.41 pH as is 3.15 3.18 3.16 3.75
[0092] All the aluminum zirconium salt solution for irritancy test were prepared based on 20% anhydrous solids concentration except for 50% ACH solution which was based on 23% anhydrous solids.
[0093] Results of the 14-day cumulative irritation patch study are summarized in Table V below.
TABLE V pH CIT Active* (15% w/w) Score Rezal 885 Solution (Al/Zr octa salt soln.) 3.76 0.5 Rezal 95 Solution (Al/Zr penta salt soln.) 4.08 0.0 Reach AZP-908 Concentrate (Al/Zr tetra salt soln.) 3.93 0.0 Chlorhydrol 50% Solution (ACH soln.) 4.41 0.0
[0094] The cumulative irritation test is most sensitive to small differences between test materials. Results show that octa- and penta-salt without glycine do not show higher irritancy potential than the compounds most widely used, like aluminum zirconium tetrachlorohydrex and aluminum chlorohydrate (ACH).
[0095] As noted heretofore, different forms of finished formulations require antiperspirant actives with different chemical and physical properties. For clear gel emulsion it is desirable to have an active with a specific refractive index (RI), less water to achieve specific aesthetic and certain solubility requirements. It is also desirable that the organic solvent used does not impart “tackiness” to the final formulation. The following examples demonstrate preparation of amino acid free Al/Zr actives for less or non-tacky clear gel or clear stick. The spray dried product can be used for low or no residue opaque antiperspirant stick.
EXAMPLE 3
[0096] 2500 gms of aqueous solution of basic aluminum chloride (BAC) having chemical analysis of 11.8% Al, 9.11% Cl, Al:Cl atomic ratio of 1.7 and anhydrous solids content of 38.86 was heated in a three neck round bottom flask using a heating mantal equipped with a rheostat for temperature control. The flask was equipped with a reflux condenser, a separator addition funnel to add zirconium salt solution at a controlled rate and was fitted with an overhead stirring device. The BAC solution was heated to a reflux temperature. 1300 gms of zirconium hydroxy chloride (ZHC) solution (prepared by reacting zirconyl oxychloride (ZOC) with zirconium basic carbonate at 60° C.) having chemical composition of 22.7% Zr, 11.58% Cl, Cl/Zr atomic ratio of 1.33 was added dropwise using the addition funnel over four hours. ZHC solution addition rate was controlled to assure that the solution remained clear during the entire addition. At the completion of ZHC addition, 1100 gms of dipropylene glycol (DPG supplied by Dow Chemical) was added and 600 gms of water was distilled off over 1.5 hrs. The solution was cooled to room temperature and filtered off giving a crystal clear solution. The chemical analysis and some of the physical properties of the final solution were as follows:
[0097] % Al 6.95, % Zr 6.91, % Cl 8.92, pH 15% w/w solution 3.76, % DPG 25.94, % A.S. 36.7, Al/Zr atomic ratio 3.47, M/Cl atomic ratio 1.32, viscosity 248 cps, RI at 21° C 1.4513.
[0098] This anhydrous solution is suitable for use in a clear gel emulsion and low or no residue or clear stick formulation.
EXAMPLES 4, 5, AND 6
[0099] The same equipment set up and procedure of Example 3 were followed for Examples 4, 5, and 6 except for the use of different organic solvents and chemical analysis of ingredients as listed in Table VI.
TABLE VI Example 4 Example 5 Example 6 Chemical analysis of BAC Al 11.8%, Same as Same as solution used Cl 9.11% Example 4 Example 4 Al:Cl ratio 1.7:1 % AS 38.86 Chemical analysis of ZHC Zr 23.34% Same as Same as solution used Cl 12.13% Example 4 Example 4 Cl/Zr 1.37:1 % A.S. 46.73 Organic Solvent used Polyethylene Polyethylene Glycerin glycol 200 glycol-400 (USP grade (PEG 200) (PEG 400) supplied by supplied supplied Callahan by Dow by Dow Chemical Chemical Chemical Co.)
[0100] Results of chemical analysis, HPLC and physical properties for Examples 4, 5 and 6 are shown in Table VII.
TABLE VII Example 4 Example 5 Example 6 Polyol PEG - 200 PEG - 400 Glycerin % Al 6.8 7.06 6.8 % Zr 6.89 6.92 6.23 % Cl 8.69 8.9 8.21 % Polyol 25 22.47 11.2 Fe(ppm) 20 20 17 pH 15% (w/w) 3.7 3.74 3.69 Viscosity CPS* 450 1000 40 RI° 21° C.* 1.4543 1.4527 — Al/Zr Atomic Ratio 3.4 3.51 3.76 M/Cl Atomic Ratio 1.33 1.34 1.38 % A.S. 36.1 37 34.7 HPLC (Initial) 32.13/25.47/ 32.45/22.49/ 36.47/21.73/ (Band I/II/III/IV) 12.06/30.34 13.69/31.37 10.15/30.23 HPLC (After 55 days 32.76/22.13/ 37.19/22.24/ 36.99/22.05/ of aging at RT) 8.89/36.22 8.47/32.10 10.29/30.67 *Viscosity was measured using Brookfield viscometer spindle # 2 at 30 or 60 rpm and reading was taken after 5 minutes. RI was measured using Leica refractometer model #10500.
[0101] Conventional enhanced antiperspirant salt would ordinarily lose peak ratio rapidly in aqueous solution. Thus, stability of enhanced efficacy active is usually measured by the degree of degradation of Band III/II peak area (or peak 4/peak 3 peak area) ratio. By stabilized or stable it is meant that Band III/II peak area ratio while it may degrade somewhat it will not degrade quickly to as low a point as an unenhanced salt. A review of the prior art shows that the known enhanced efficacy salts have HPLC Band III/II area ratio of about 0.5 or higher, in contrast, conventional nonenhanced antiperspirant salt have area of about 0.2 or less. (Ref. U.S. Pat. No. 6,436,381 B1, Col. 1, 40-50)
[0102] To check stability of the aluminum zirconium salt solution prepared by the novel process of this invention HPLC of samples prepared under Examples 4, 5 and 6 were monitored initially and after about 55 days and ratio of Band III/II were compared. Results are shown in Table VIII. The products exhibited good stability over almost two months.
TABLE VIII % HPLC Peak Areas Exam- Exam- Exam- Peak Exam- ple 4 Exam- ple 5 Exam- ple 6 Area ple 4 After ple 5 After ple 6 After Ratio Initial Aging + Initial aging + Initial Aging + Band 0.47 0.40 0.61 0.38 0.5 0.5 III/II + Aged for about 2 months at room temperature.
[0103] Although the present invention has been described in terms of specific embodiments, the invention is not meant to be so limited. Various changes can be made to the composition and proportions used while still obtaining the benefits of the invention. Thus the invention is only to be limited by the scope of the appended claims. | A cost effective process is provided for making stable, efficacious, amino acid and polyhydric alcohol free concentrated aqueous aluminum zirconium salt solutions. Absence of amino acid, low iron content and low trace metal impurity levels improve compatibility with fragrances and minimizes the probability of the product color change and possibly fabric staining significantly. The novel aluminum zirconium actives also minimize iron contribution to underarm area that supports growth of microflora which is responsible for axillary malodour by the biotransformation of nonodorous precursors present in perspiration. The astringent complexes of the present invention may be obtained in solution or dry powder form. As a result, the complexes are satisfactory for use in any of wide variety of conventional antiperspirant forms. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 62/172,835 filed Jun. 9, 2015, and U.S. Provisional Application 62/277,550 filed Jan. 12, 2016, which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus for securing mining chain links.
BACKGROUND OF THE INVENTION
[0003] Cutting chains are frequently found in mining operations, including in continuous longwall miners. These chains have tool bits mounted to them that act as picks to repeatedly break apart the surface being mined as the chain is driven around a sprocket.
[0004] Although these mining chains are well known in the prior art, previously known mining chains are prone to failure due to breakage rather than normal wear.
[0005] One frequent area for failure of the mining chain occurs in the connection between links. The links of a mining chain are connected together by drive pins. FIG. 1 , FIG. 2 , and FIG. 3 depict commonly found mining chains of the prior art. Newer designs of mining chain links, such as that shown in FIG. 4 of applicant's own design, also employ drive pins. Previously known retention systems for the drive pin use dowel pins that can shear or break from lateral force or contact with the mining material. When this occurs, the chain breaks and the miner fails.
[0006] The breakage of the chains results in significant downtime and loss of productivity as the continuous longwall miner can no longer function until the chains are repaired or replaced. We disclose herein a drive pin retention mechanism that does not suffer from the problems of the prior art.
SUMMARY OF THE INVENTION
[0007] We disclose herein a new drive pin retention system for use in mining chains and other chains comprising: a drive pin having a pin, with retainer cap and various locking mechanisms for securing the retainer cap to the drive pin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings:
[0009] FIG. 1 depicts a portion of a mining chain of the prior art.
[0010] FIG. 2 depicts a cutting link of the mining chain of the prior art.
[0011] FIG. 3 depicts a cutting link of the mining chain of the prior art.
[0012] FIG. 4 depicts a cutting link of a mining chain of applicant's own design.
[0013] FIG. 5 depicts a perspective view of the presently disclosed drive pin with retention mechanism attached using a rubber sandwich pin.
[0014] FIG. 6A and 6B depict a diagram of a drive pin and retainer used with a perpendicular rubber sandwich pin. Individually, FIG. 6A depicts a drive pin, and FIG. 6B depicts a retainer.
[0015] FIG. 7A-7E depicts a rubber sandwich pin to be used with the drive pin of FIG. 6 . Individually, FIG. 7A depicts a perspective view of the rubber sandwich pin. FIG. 7B depicts a side elevational view of FIG. 7A . FIG. 7C depicts a cross section along plane A-A of FIG. 7A . FIG. 7D depicts a side elevational view of the rubber sandwich pin. FIG. 7E depicts a cross section along plane B-B of FIG. 7D .
[0016] FIG. 8 depicts a drive pin and retainer secured with a rubber sandwich pin oriented in line with the drive pin.
[0017] FIG. 9A-9E depicts a D-shaped drive pin and retainer secured with a steel spring pin. Individually, FIG. 9A depicts a D-shaped drive pin and retainer secured with a steel spring pin. FIG. 9B depicts a D-shaped drive pin. FIG. 9C depicts a retainer. FIG. 9D depicts a perspective view of a steel spring pin. FIG. 9E depicts a side elevational view of the steel spring pin.
[0018] FIG. 10 depicts a threaded drive pin with retainer secured with a rubber sandwich pin oriented in line with the drive pin.
[0019] FIG. 11 depicts a perspective view of a pivot pin.
[0020] FIG. 12 depicts a perspective view of the presently disclosed chain pin.
[0021] FIG. 13 depicts a perspective view of another embodiment of the presently disclosed mining pin.
[0022] FIG. 14 depicts a perspective view of the presently disclosed mining pin retainer.
[0023] FIG. 15A-D depicts a perspective view of the one embodiment disclosed mining pin with retainer. Individually, FIG. 15A depicts a drive pin retention system. FIG. 15B depicts a retainer ring. FIG. 15C depicts a plastic seal. FIG. 15D depicts a dowel pin.
[0024] FIG. 16A-B depicts a perspective view of the one embodiment disclosed mining pin with retaining cap and bolt. Individually, FIG. 16A depicts a drive pin retention system. FIG. 16B depicts a retaining cap.
[0025] FIG. 17A-B depicts a cross-sectional view of one embodiment of the disclosed mining pin and retaining cap and bolt. Individually, FIG. 17A depicts a drive pin retention system. FIG. 17B depicts a bolt secured by a nylon insert lock nut, also known as a nyloc nut.
[0026] FIG. 18 depicts a cross-sectional view of one embodiment of the disclosed mining pin and retaining cap with fully threaded bolt.
DETAILED DESCRIPTION
[0027] The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.
[0028] A common point of failure in mining chains of the prior art is in the retention mechanism that holds the drive pins 840 (also known as pivot pins) in place. The drive pin 840 is a generally cylindrically-shaped pin that passes through the transverse bores 410 of the mining chain links. It has a pin head 842 on one end and a fastener end 844 at the opposite end.
[0029] Often, in the prior art, the drive pin 840 was held in place by a retainer 850 that surrounds the fastener end 844 of the drive pin 840 . A dowel pin was driven through a hole in the retainer 850 , and through the drive pin hole 848 in the side of the drive pin 840 . The dowel pin protruded through the retainer 850 , and could easily shear or break from the lateral force or contact with the mining material. When this occurs, the mining chain would break, and the miner fails. Some prior art roller links had protective rings surrounding the retainer that were intended to contain the dowel pin in its location. However, this protective ring could break off, and because there is no positive retention holding the dowel pin in, it could slide out.
[0030] In the presently disclosed invention, the drive pin has a retainer 850 held on by dowel pins that are substantially flush with the retainer. In one embodiment, such as depicted in FIGS. 5, 6, 7 and 9 , a rubber sandwich pin 860 is used. The rubber sandwich pin 860 , as shown in FIG. 7A-E , is constructed of two pieces of elongated metal 864 with a rubber center 862 between them. The rubber center 862 is typically injected into the mold between the elongated metal pieces 864 , causing it to adhere to the two elongated metal pieces 864 . As can be seen from FIG. 7A and FIG. 7B , the elongated metal pieces 864 are angled inwards toward the ends, with a middle section that is narrower. As the rubber sandwich pin 860 is driven into the drive pin hole 848 , it is compressed, and re-expands as it exits the other side of the drive pin 840 . This positive retention prevents the rubber sandwich pin 860 from sliding out of the drive pin hole 848 .
[0031] In another embodiment, as shown in FIG. 9A-9E , a steel spring pin 870 is used. The steel spring 870 depicted in FIGS. 9D and 9E has three prongs and a handle 872 . As the steel spring 870 is pushed into the drive pin hole 848 of the drive pin shown in FIG. 9B , the outer prongs 874 extend outward as they pass into the interior of the drive pin hole 848 . Because of the spring force of the outer prongs 874 against the retainer 850 shown in FIG. 9C , the steel spring does not easily come out from the drive pin hole 848 . Once again, this positive retention keeps the steel spring pin from sliding out of the drive pin hole.
[0032] Because this rubber sandwich pin 860 or steel spring pin 870 does not substantially protrude past the retainer 850 , there is a significantly reduced chance that either pin will become damaged resulting in the retainer 850 separating from the drive pin 840 .
[0033] Other potential retainers and dowel pins are shown in FIGS. 11 to 18 . In another embodiment, a Hendrix pin or threaded steel pin with a castle nut is used. The castle nut can be held in place using a cotter pin. This is an excellent solution for repairs.
[0034] The presently disclosed drive pin retention system can be used with any shaped retainer 850 that fits over the fastener end 844 of the drive pin 840 . In one embodiment as shown in FIGS. 13 and 14 , a D-shaped retainer is used in applications where the drive pin 840 has at least one flat surface cut into the curved sidewall of the drive pin. In another embodiment, such as that shown in FIG. 10 , the drive pin 840 can be threaded such that the retainer 850 screws into place. Once the holes in the retainer 850 and the drive pin hole 848 are aligned, a rubber sandwich pin or steel spring pin can be placed into the hole.
[0035] FIG. 15A shows another embodiment of a drive pin retention system. In this embodiment, the retainer 850 is placed over the fastener end 844 of the drive pin 840 (as numbered similarly to FIG. 10 ). However, in this embodiment, the retainer 850 has two holes that pass all the way through the sidewalls of the retainer along the diameter of the retainer. The drive pin 840 similarly has a drive pin hole 848 that passes through the drive pin 840 . FIG. 15D depicts a dowel pin 880 having two notched sections in the surface of the dowel pin such that the diameter at the notched sections is smaller than the diameter of the rest of the dowel pin 880 . The dowel pin 880 is intended to pass through the retainer 850 and the drive pin 840 . FIG. 15B depicts a retainer ring 882 having an interior diameter slightly larger than the diameter of the notched section, but smaller than the diameter at the unnotched section. The retainer ring 882 is able to open up slightly under pressure to accommodate the wider sections of the dowel pin 880 . This is accomplished by having the retainer ring 882 be C-shaped so that it can be forced to open wider. Alternatively, the retainer ring 882 can be made of a flexible material that allows it to open wider. FIG. 15C depicts a plastic seal 884 that is used to hold the retainer ring 882 in place in the holes of the drive pin 840 . The plastic seal 884 also helps prevent the steel pieces from weakening as they rub against each other. A plastic seal 884 and retainer ring 882 are used on each side of the drive pin 840 to keep the dowel pin 880 in place.
[0036] As will be appreciated from FIG. 15A-D , the notched dowel pin 880 is held in place by two retainer rings 882 located in the holes of the drive pin 840 . Each of the two retainer rings 882 acts individually as a lock to keep the dowel pin 880 in place. The double locking mechanism ensures that the dowel pin 880 stays in place, even if one retainer ring 882 fails.
[0037] To operate this drive pin retention system, the retainer 850 is placed over the end of the drive pin 840 such that the holes of the retainer 850 line up with the holes of the drive pin 840 . The dowel pin 880 is then hammered through the first hole of the retainer 850 and to the first hole of drive pin 840 which has a retainer ring 882 against its opening, held in place by the plastic seal 884 . The hammering of the dowel pin 880 causes the retainer ring 882 to open up as the dowel pin 880 is squeezed through. As the hammering continues, the dowel pin 880 will then pass through the second retainer ring 882 causing it to open up. As the leading notch of the dowel pin 880 passes through the second retainer ring 882 , the retainer 850 closes around the leading dowel pin notch. The first retainer ring 882 will then also close around the trailing notch. Thus, each retaining ring 882 will be wrapped tightly in a closed position around the notches of the dowel pin 880 .
[0038] FIG. 16A shows another embodiment of a drive pin retention system. In this embodiment, the retainer 850 is placed over the fastener end 844 of the drive pin 840 (as numbered similarly to FIGS. 10 and 15A ). However, in this embodiment, the retainer 850 has two holes that pass all the way through the sidewalls of the retainer 850 along the diameter of the retainer 850 as shown in FIG. 16B . FIG. 17A depicts a bolt 886 which is passed into the interior of the drive pin hole 848 and secured by a nyloc nut 888 as shown in FIG. 17B . The nylon component of the nyloc nut 888 has a smaller inside diameter than the actual nut, thereby acting to lock the nut in place by squeezing the nylon firmly around the bolt when tightened. Unlike a standard locking washer, the nyloc nut 888 prevents the nut from loosening under vibration as the nylon is tightly wedged into the bolt thread and provides resistance to turning once tightened.
[0039] In other potential embodiments of a drive pin retention system, a socket head style bolt can be used. Alternatively a fully threaded bolt as shown in FIG. 18 is passed into the interior of the drive pin hole 848 and secured by a nyloc nut 888 to strengthen the retention system and ensure the drive pin 840 does not loosen due to vibration.
[0040] It should be appreciated that the cutting link 400 and the pin retention mechanism does not require a whole new mining chain, but instead can be employed by replacing specific links or the retainer cap. Furthermore, although the invention has been described for use with mining, it can be used in other applications, such as trencher chains. The pin retention system can also be used in any chain application.
[0041] The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
[0042] The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques other than those specifically described herein can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. Whenever a range is disclosed, all subranges and individual values are intended to be encompassed. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example and not of limitation.
[0043] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
[0044] All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference). | An improved drive pin retention system for mining chains is disclosed, including several embodiments. The drive pin retention system further decreases the chance that the chain can break due to sheared dowel pins. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to the production of power, and more particularly to an apparatus and method for generating power by utilizing the force of a flowing liquid.
The need to generate power in times of crisis and the need to generate power from a relatively inexpensive resource have long been felt. Inventors have tried for some time to create an apparatus and method that will generate power for little cost. The ability to generate power from an inexpensive resource when access to traditional power, namely power supplied by a power company, is not available due to power shortages or natural disasters is needed.
Also, in times when emergency power is not required, the ability to generate such power assists in preserving the environment by lessening the burden on power companies to provide power, and the ability to generate power would save consumers money on monthly electric bills. The need to generate power from an inexpensive resource will become of even more importance as other more expensive resources of the world dwindle and disappear over the course of time.
There have been attempts in the prior art to harness the kinetic energy of a flowing liquid in order to generate power. However, these attempts are either impractical, difficult to scale, difficult to distribute, awkward to use, or simply will not work. Therefore, an apparatus and method are needed that generates power from a flowing liquid.
SUMMARY OF THE INVENTION
This invention provides an apparatus and a method for generating power from a flowing liquid. The invention provides an apparatus comprising a control unit selectively operable between a first control unit configuration and a second control unit configuration for receiving the flowing liquid and selectively directing the flowing liquid to a first power unit aperture when the control unit is in the first control unit configuration, and selectively directing the flowing liquid to a second power unit aperture when the control unit is in the second control unit configuration; a power unit for generating power, including: (1) a power chamber having the first power unit aperture for receiving the flowing liquid from the control unit, and a second power unit aperture for receiving the flowing liquid from the control unit, (2) a power operator operable between a first power operator position and a second power operator position and disposed within the power chamber, operatively configured so the power operator becomes disposed in the first power operator position when the control unit is disposed in the first control unit configuration, and so that the power operator becomes disposed in the second power operator position when the control unit is disposed in the second control unit configuration, and (3) a power transmission linkage operatively communicating with said power operator for transmitting power as said power operator reciprocates between said first power operator position and said second power operator position; and a reversing unit to adjust the control unit configuration to become disposed in the first control unit configuration when the power operator becomes disposed in the second power operator position, and to adjust the control unit configuration to become disposed in the second control unit configuration when the power operator becomes disposed in the first power operator position.
The invention provides a method comprising passing the flowing liquid to a control unit selectively operable between a first control unit configuration and a second control unit configuration; directing, selectively, the flowing liquid to a first power unit aperture when said control unit is in said first control unit configuration, and selectively directing said flowing liquid to a second power unit aperture when said control unit is in said second control unit configuration; forcing a power operator operable between a first power operator position and a second power operator position and disposed within the power unit, to the first power operator position when receiving flowing liquid from the first power unit aperture and to the second power operator position when receiving flowing liquid from the second power unit aperture; transmitting power through a power transmission linkage operatively communicated with the power operator as said power operator reciprocates between the first power operator position and the second power operator position; and directing the flowing liquid to a reversing unit to adjust the control unit configuration to become disposed in the first control unit configuration when the power operator becomes disposed in the second power operator position, and to adjust the control unit configuration to become disposed in the second control unit configuration when the power operator becomes disposed in the first power operator position.
BRIEF DESCRIPTION OF THE DRAWINGS
A particularly preferred embodiment of the invention will be described in detail below in connection with the drawings in which:
FIG. 1 is a plan view of an apparatus of this invention;
FIG. 2 is a plan view of a power transmission linkage of this invention;
FIG. 3 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 4 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 5 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 6 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 7 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 8 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 9 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 10 is a plan view of an apparatus of this invention, illustrating the manner in which power is generated from a flowing liquid.
FIG. 11 is a flow chart illustrating a preferred method of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Particularly preferred embodiments of the present invention are illustrated in the drawings, which illustrate a preferable apparatus and method for generating power from a flowing liquid. FIG. 1 illustrates a preferred embodiment of the apparatus of the present invention. The apparatus allows a flowing liquid, represented in direction of movement by black arrows 10 , to enter the apparatus through aperture 20 , and the apparatus conveniently releases the flowing liquid through aperture 30 . The apparatus preferably comprises a control unit generally indicated by reference numeral 40 . The control unit is conveniently selectively operable between a first control unit configuration and a second control unit configuration for receiving the flowing liquid and selectively directing the flowing liquid to a first power unit aperture 50 when the control unit is in the first control unit configuration, and selectively directing the flowing liquid to a second power unit aperture 60 when the control unit is in the second control unit configuration.
A control unit operator 70 is preferably disposed in the control unit and suitably has ports 80 and 90 disposed in and through the control unit operator. The control unit operator 70 is preferably selectively operable between a first control unit operator position 100 and a second control unit operator position 110 . Suitably, when the control unit operator is disposed in the first control unit operator position 100 , the control unit is in the first control unit configuration. Conversely, when the control unit operator is disposed in the second control unit operator position 110 , the control unit is in the second control unit configuration. Preferably, when the control unit operator is disposed in the first control unit operator position 100 , the flowing liquid is directed to the first power unit aperture 50 . Conversely, when the control unit operator is disposed in the second control unit operator position 110 , the flowing liquid is directed to the second power unit aperture 60 . Conveniently, the control unit operator can be such devices as a slide valve or a piston.
Preferably, the control unit 40 has a first control unit channel 120 and a second control unit channel 130 . Suitably, when the control unit is in the first control unit configuration, the flowing liquid is directed to the power unit through the first control unit channel 120 to the first power unit aperture 50 , and when the control unit is in the second control unit configuration, the flowing liquid is directed to the power unit through the first control unit channel 120 to the second power aperture 60 . Conveniently, when the control unit is in the first control unit configuration, the flowing liquid exits the power unit through the second power unit aperture 60 to the second control unit channel 130 , and when the control unit is in the first control unit configuration, the flowing liquid exits the power unit through the first power aperture 50 to the second control unit channel 130 .
The apparatus also preferably comprises a power unit, generally indicated by reference number 140 . The power unit suitably includes a power chamber 150 having the first power unit aperture 50 for receiving said flowing liquid from said control unit 40 , and the second power unit aperture 60 for receiving a flowing liquid from said control unit 40 .
Conveniently, a power operator 160 is operable between a first power operator position 170 and a second power operator position 180 and is disposed within the power chamber 150 . The power operator 160 is suitably operatively configured so the power operator 160 becomes disposed in the first power operator position 170 when the control unit 40 is disposed in the first control unit configuration. Conversely, the power operator 160 becomes disposed in the second power operator position 180 when the control unit 40 is disposed in the second control unit configuration. The power unit may suitably be a piston.
Preferably, a power transmission linkage, generally indicated by reference numeral 190 and herein illustrated by a rectangle representing any device used as a transmission known in the art, is operatively communicated with the power operator 160 for transmitting power as the power operator 160 reciprocates between the first power operator position 170 and the second power operator position 180 . As illustrated in FIG. 2, the power transmission linkage 190 may suitably comprise a rack and spur gear 200 , a sprocket 210 , a chain 220 , an output power shaft 230 , a timing gear 240 , and a timing belt 250 . Conveniently, a power generator 260 , herein illustrated by a rectangle representing any device used to generate power known in the art, is operatively associated with the power transmission linkage 190 . In a preferred embodiment, the power transmission linkage 190 is operatively communicated with the power operator 160 by a shaft 270 .
A compressed air generator, generally indicated by reference numeral 280 , may also suitably be operatively associated with the power transmission linkage 190 . As the power operator 160 reciprocates between the first power operator position 170 and the second power operator position 180 , a piston 290 operable between a first piston position 300 and a second piston position 310 and contained in the compressed air generator 280 compresses air.
The apparatus also preferably comprises a reversing unit 320 to adjust the control unit configuration to become disposed in the first control unit configuration when the power operator 160 becomes disposed in the second power operator position 180 , and to adjust the control unit configuration to become disposed in the second control unit configuration when the power operator becomes disposed in the first power operator position 170 . Preferably, the reversing unit 320 adjusts the control unit configuration by selectively directing the flowing liquid to the control unit 40 through a first reversing unit channel 380 to a first control unit aperture 400 when the power operator 160 is in the first power operator position 170 and through the first reversing unit channel 380 to the second control unit aperture 410 when the power operator 160 is in the second power operator position 180 .
Conversely, the flowing liquid exits the control unit 40 through the second control unit aperture 410 to the second reversing unit channel 390 when the power operator 160 is in the first power operator position 170 , and the flowing liquid exits the control unit 40 through the first control unit aperture 400 to the second reversing unit channel 390 when the power operator 160 is in the second power operator position 180 . Conveniently, the reversing unit 320 may be operatively communicated with the power transmission linkage 190 by a yoke 420 having a first strike 430 and a second strike 440 .
A reversing unit operator 330 is preferably disposed in the reversing unit 320 and suitably has ports 360 and 370 disposed in and through the reversing unit operator 330 . The reversing unit operator 330 is preferably selectively operable between a first reversing unit operator position 340 and a second reversing unit operator position 350 . Preferably, the reversing unit operator 330 adjusts the control unit configuration to become disposed in the first control unit configuration when said power operator 160 becomes disposed in the second power operator position 180 . Conversely, the reversing unit operator 330 adjusts the control unit configuration to become disposed in the second control unit configuration when the power operator 160 becomes disposed in the first power operator position 170 . Conveniently, the reversing unit operator 330 may, among other things, be a slide valve or a piston.
FIGS. 3 through 11 illustrate the manner in which a preferred apparatus and method of this invention generates power from a flowing liquid. The manner in which this preferred apparatus operates may be explained by beginning at any of FIG. 3 through FIG. 10 . For the sake of simplicity, the process is described beginning with FIG. 3, where the control unit operator 70 is disposed in the second control unit operator position 110 . The flowing liquid enters the apparatus through aperture 20 and passes through the control unit 40 and the first control unit channel 120 into second power unit aperture 60 , forcing the power operator 160 to the second power operator position 180 . Upon reaching the second power operator position 180 , the flowing liquid is directed through the reversing unit 320 , the first reversing unit channel 380 , and the reversing unit operator 330 to the second control unit aperture 410 .
Looking at FIG. 4, as the flowing liquid enters the control unit 40 through the second control unit aperture 410 , the control unit operator 70 begins to move towards the first control unit operator position 100 , which forces the flowing liquid through the first control unit aperture 400 to the second reversing unit channel 390 . The flowing liquid then exits the apparatus through port 30 .
In FIG. 5, the control unit is disposed in the first control unit configuration and the control unit operator 70 has reached the first control unit operator position 100 , forcing the flowing liquid entering the apparatus through port 20 to travel through the control unit 40 and the first control unit channel 120 to the first power unit aperture 50 . This forces the power operator 160 to begin moving towards the first power operator position 170 . As the power operator 160 moves towards the first power operator position 170 , the flowing liquid exits the power chamber 150 through the second power unit aperture 60 to the second control unit channel 130 . The flowing liquid then exits the apparatus through aperture 30 .
FIG. 6 illustrates the movement of the power operator 160 as the power operator is forced towards the first power operator position 170 . As the power operator 160 travels to the first power operator position 170 , the power operator forces the power transmission linkage 190 to move. This movement causes the power transmission linkage to transmit power to the power generator 260 .
FIG. 7 illustrates the movement of the reversing unit operator 330 towards the first reversing unit operator position 340 . The power transmission linkage 190 contacts the first strike 430 of the yoke 420 . As the power operator 160 moves towards the first power operator position 170 , the yoke 420 forces the reversing unit operator 330 towards the first reversing unit operator position 340 . The movement of the power transmission linkage 190 continues to cause the power generator 260 to generate power.
In FIG. 8, the power operator 160 completely moves to the first power operator position 170 , thereby causing the reversing unit operator 330 to move completely to the first reversing unit operator position 340 . As a result, the flowing liquid entering the apparatus travels through the first reversing unit channel 380 to the first control unit aperture 400 . The flowing liquid forces the control unit operator 70 towards the second control unit operator position 110 . As a result of the movement of the control unit operator 70 , the flowing liquid exits the control unit 40 through the second control unit aperture 410 to the second reversing unit channel 390 .
In FIG. 9, the control unit is disposed in the second control unit configuration and the control unit operator 70 is disposed in the second control unit operator position 110 . This allows the flowing liquid to travel through the first control unit channel 120 to the second power unit aperture 60 . Simultaneously, the power operator 160 moves towards the second power operator position 180 , and flowing liquid is forced to exit the power chamber 150 through the first power unit aperture 50 to the second control unit channel 130 . As the power operator 160 moves, the power transmission linkage 190 causes the power generator 260 to generate power.
In FIG. 10, the power transmission linkage 190 contacts the second strike 440 of the yoke 420 as the power operator 160 proceeds towards the second power operator position 180 . The movement of the power operator forces the reversing unit operator 330 towards the second reversing unit operator position 350 . At this point, the apparatus has completed one full cycle, and the cycle begins again at FIG. 3 .
FIG. 11 illustrates a preferred method of this invention. An act is preferably passing 500 the flowing liquid to a control unit selectively operable between a first control unit configuration and a second control unit configuration for receiving said flowing liquid. Suitably, an act is directing 510 , selectively, the flowing liquid to a first power unit aperture when the control unit is in the first control unit configuration, and selectively directing the flowing liquid to a second power unit aperture when the control unit is in the second control unit configuration.
Conveniently, an act is forcing 520 a power operator operable between a first power operator position and a second power operator position and disposed within the power unit, to the first power operator position when receiving flowing liquid from the first power unit aperture and to the second power operator position when receiving flowing liquid from the second power unit aperture.
Preferably, an act is transmitting 530 power through a power transmission linkage operatively communicated with the power operator as the power operator reciprocates between the first power operator position and the second power operator position.
Conveniently, an act is directing 540 the flowing liquid to a reversing unit to adjust the control unit configuration to become disposed in the first control unit configuration when the power operator becomes disposed in the second power operator position, and to adjust the control unit configuration to become disposed in the second control unit configuration when the power operator becomes disposed in the first power operator position. | This invention provides an apparatus and a method for generating power from a flowing liquid. The apparatus has three main components. The first component is a control unit for selectively directing the flowing liquid to the second component, the power unit, which is responsible for generating power. The third component, a reversing unit, is used to adjust the control unit between two control unit configurations. The method involves the manner in which the liquid is passed and directed through the apparatus in order to generate power. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application No. 61/174,568 filed on May 1, 2009, the teachings of which are incorporated herein by reference in their entirety.
The subject matter of this application is related to the subject matter of U.S. patent application Ser. No. 12/500,060, the teachings of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the writing of information to, and the reading of information from optical discs.
2. Description of the Related Art
Pre-recorded, read-only optical discs, such as the compact disc (CD) and digital versatile disc (DVD), are a popular medium for the storage and distribution of digital information, e.g., digitally encoded movies. The typical movie DVD offers the user multiple playback options, e.g., different dialogue languages (French, Spanish, etc.), different audio options (5.1 surround sound, stereo, etc.), different screen formats (widescreen, fullscreen), commentary on or off, subtitles on or off, etc. The typical process for changing a playback option is for the user to navigate through one or more on-screen menus using the player's controls or a remote control, a potentially tedious process. Typically, this process is performed when a disc is played on a particular player for the first time. Furthermore, for those players that cannot remember settings for a particular disc, the user might have to repeat the playback-option setting process every time the disc is inserted in the player.
SUMMARY OF THE INVENTION
In one embodiment, the invention is a player-implemented method for controlling operation of an optical-disc player having an optical-disc reader. The method derives out-of-band information from surface marks of an optical disc and uses the derived out-of-band information to control the operation of the optical-disc reader.
In another embodiment, the invention is an optical-disc player comprising (i) an optical-disc reader adapted to derive out-of-band information from surface marks of an optical disc and (ii) a controller adapted to control operation of the optical-disc reader based on the derived out-of-band information.
In yet another embodiment, the invention is a user-implemented method of using an optical-disc player to playback an optical disc. The user applies, to the optical disc, surface marks corresponding to one or more selected playback options. The user then operates the optical-disc player to enable the optical-disc player to (i) derive, from the surface marks, out-of-band information corresponding to the one or more selected playback options and (ii) control the rendering of embedded data of the optical disc based on the out-of-band information to implement the one or more selected playback options.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, features, and advantages of the invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which like reference numerals identify similar or identical elements.
FIG. 1 is a cross-section of a typical read-only optical disc 100 .
FIG. 2 is a block diagram of disc player 200 according to one embodiment of the present invention.
FIG. 3 is a functional flowchart of a disc player 200 of FIG. 2 according to various embodiments of the present invention.
FIG. 4 is a flowchart describing one possible use of a disc player 200 of FIG. 2 according to one embodiment of the present invention.
FIG. 5 is an example of the surface marks a user might make on optical disc 100 of FIG. 1 according to certain embodiments of the present invention.
FIG. 6 is a depiction of lens assembly 600 reading surface mark 500 on disc 100 .
DETAILED DESCRIPTION
FIG. 1 is a cross-section of a typical read-only optical disc 100 . Optical disc 100 is a flat, circular disc comprising several layers. Bottom-most layer 102 is clear polycarbonate plastic. The bottom surface 104 of layer 102 (i.e., the bottom surface of disc 100 ) is smooth. Data is typically stored as a single, continuous, spiral track of pits 106 and lands 108 etched on the top surface of layer 102 . Data stored in this manner is referred to as the embedded data. The dimensions of the pits and lands depend on the specific optical-disc format. On a CD, pits are 100 nanometers deep, 500 nanometers wide, and a minimum of 850 nanometers long. On a DVD, pits are 120 nanometers deep, 320 nanometers wide, and a minimum of 400 nanometers long.
Layer 110 is a reflective material, typically aluminum. Layer 112 is an acrylic layer that protects reflective layer 110 . Optional layer 114 is a label or printing.
A disc player is a system for reading and outputting the information stored on an optical disc. A disc player can be a self-contained device, e.g., a standalone DVD player, or it can be a subsystem of a larger system, e.g., the CD reader and associated software within a personal or laptop computer. A disc player can include the components necessary to render in-band data, e.g., a DVD player with a built-in monitor, or it cannot, e.g., a standalone DVD player.
FIG. 2 is a block diagram of disc player 200 according to one embodiment of the present invention. Disc player 200 comprises disc reader 202 and controller 204 . Disc reader 202 comprises disc drive 206 and signal processor 208 . Signal processor 208 contains an optical character recognition (OCR) module 222 .
The data flows of disc player 200 are typically either in-band data or out-of-band data. In-band data refers to data that is outputted by the disc player, e.g., a movie displayed on a screen or music played over speakers. In FIG. 2 , disc drive 206 reads the embedded data on an optical disc and outputs in-band data 210 to processor 208 . Processor 208 performs one or more processing operations (e.g., error-detection/correction, decoding, digital-to-analog conversion) on in-band data 210 and outputs processed in-band data 212 .
Out-of-band data refers to data that controls the operation of the disc player. Out-of-band data, e.g., data 214 , 216 , or 218 , might be generated by any of controller 204 , disc drive 206 , or processor 208 , respectively. Alternatively or in addition, out-of-band data, e.g., data 220 , might be received from a source outside disc player 200 .
Controller 204 controls the operations of both disc drive 206 and processor 208 . For example, controller 204 might be an executable program that receives out-of-band data 220 from an infrared remote-control device and displays various playback options on a screen. A user uses the remote control to select playback options. The controller converts the selected playback options into out-of-band data 214 to disc drive 206 and out-of-band data 216 to processor 208 .
Disc drive 206 is an electromechanical assembly comprising three major components (not shown): the drive motor, the tracking mechanism, and the lens assembly. The drive motor rotates the disc. The tracking mechanism moves the lens assembly along the spiral track of embedded data, and adjusts the distance between the disc surface and the lens assembly, e.g., to focus the lens assembly. The lens assembly comprises (i) one or more light sources (e.g., lasers), (ii) one or more lenses, and (iii) one or more optical sensors (e.g., photodiodes).
Disc drive 206 is adapted to read the embedded data of an optical disc and executes a read process to read the embedded data. The drive motor spins the optical disc, and keeps the disc spinning for the duration of the read process. The tracking mechanism moves the lens assembly to the correct location adjacent to the optical disc for reading the data. The tracking mechanism focuses the lens assembly on the pits and lands embedded within the disc. The laser(s) in the lens assembly shoot light upwards at reflective layer 110 through clear polycarbonate 102 . The reflective layer reflects the light back to the lens assembly. Pits 106 and lands 108 alter the reflected light. The photodiodes within the lens assembly detect the alterations in the reflected light and output a corresponding electrical signal.
The area of an optical disc which the lens assembly can read is known as the readable area of the optical disc. The readable area is not necessarily the same as the area that contains embedded data, i.e., there might be areas on an optical disc to which embedded data cannot be or typically is not written, but which can nevertheless be read by the lens assembly.
Although a typical lens assembly is specifically adapted to read the nanometer-scale pits and lands of the embedded data of an optical disc, the lens assembly is not physically limited to read only the embedded data. The lens assembly also might be able to read surface marks made on the top or bottom surface of an optical disc that are within the readable area of the disc. For example, a word written in black ink on the bottom surface of an optical disc and within the readable area will most likely result in variations in the reflected light detected by the photodiodes of the typical lens assembly.
Embodiments of the present invention are methods and apparatuses, e.g., optical-disc players, for deriving out-of-band data from surface marks of an optical disc, and using the derived out-of-band data to control the operation of the disc player.
The surface marks may be any mark which can be detected, either by the typical lens assembly of a disc drive or by an additional/other detector system. The surface marks may be made in any manner, e.g., written by hand, printed, applied in the form of a sticker, etched, etc. The surface marks might be applied to either or both surfaces of the optical disc.
In certain embodiments of the present invention, surface marks are read using the same lens assembly that is used to read embedded data. In other embodiments of the present invention, other components, e.g., lasers, lenses, photodiodes, are added to the lens assembly for the specific purpose of reading surface marks. In yet other embodiments of the present invention, a mechanism for detecting surface-marks is added to the disc player separate from the lens assembly.
In those embodiments of the present invention where the lens assembly is used to read both embedded data and surface marks, the focus settings used by the lens assembly to read surface marks are the same as the focus settings used to read embedded data. In other embodiments of the present invention, the two focus settings are different. Specifically, when reading surface marks, the lens assembly is defocused, lowering the resolution of the lens assembly, but also reducing the time required to scan the entire disc. Since surface marks are typically significantly larger than the pits and lands typically read by the lens assembly, the loss of resolution does not affect the accuracy of the scanning of the surface marks.
FIG. 3 is a functional flowchart of a disc player 200 of FIG. 2 according to various embodiments of the present invention. Processing begins at step 302 and proceeds to step 304 where out-of-band information is derived from the surface marks of an optical disc. Next, at step 306 , the derived out-of-band information is used to control the operation of a disc player. Processing then terminates at step 308 .
Disc drive 206 is adapted to read surface marks, either with the same mechanism used to read embedded data or with a separate mechanism. Second, out-of-band signals 218 and/or 214 outputted by disc drive 206 might be derived from surface marks.
FIG. 4 is a flowchart describing one possible use of a disc player 200 of FIG. 2 according to one embodiment of the present invention. Processing begins at step 402 and proceeds to step 404 where surface marks are made on an optical disc. Next, at step 406 , the optical disc is inserted in disc player 200 . Next, at step 408 , the disc player reads the surface marks and sends the resulting image data (e.g., a bitmap) as out-of-band data 218 to processor 208 of FIG. 2 , which processor comprises an optical character recognition (OCR) module 222 . Next, at step 410 , OCR module 222 converts the received bitmap to text and sends that text as out-of-band information 216 to controller 204 . Next, at step 412 , the controller parses the received text file, sets various controller parameters, e.g., playback options, and transmits those parameters to disc drive 206 (as out-of-band data 214 ) and/or processor 208 (as out-of-band data 216 ). Processing then terminates at step 414 .
FIG. 5 is an example of the surface marks a user might make on optical disc 100 of FIG. 1 according to certain embodiments of the present invention. The user makes three surface marks 500 , “French,” “Dolby 5.1,” and “No cursor” on the bottom surface 104 of optical disc 100 . The viewer inserts the disc into a standalone DVD player (the disc-player system) and presses PLAY.
FIG. 6 is a depiction of the reading of surface mark 500 on disc 100 . The reading can be performed by a conventional lens assembly 600 . When reading the embedded data of an optical disc, lens assembly 600 emits focused light 606 at pits 106 and lands 108 . When reading surface marks, lens assembly 600 emits defocused light 602 at bottom surface 104 of disc 100 , which surface contains surface mark 500 . Alternatively, the disc reader might contain a separate imaging device 608 adapted to read only surface marks. Imaging device 608 , too, emits defocused light 602 at bottom surface 104 of disc 100 , which surface contains surface mark 500 .
Lens assembly 600 or imaging device 608 detect variations in reflected light 604 and send the resulting bitmap as out-of-band data 218 to processor 208 , which processor comprises an OCR module 222 . The OCR module converts the bitmap into a text file and sends the text file as out-of-band data 216 to controller 204 , e.g., Microsoft's HDi runtime program. The HDi runtime program parses the text file and (i) sets the dialogue language to French, (ii) sets audio to Dolby 5.1, and (iii) turns off the cursor.
In another example, the optical disc is an installation CD for a software program. A user writes a special unlock code on the surface of the installation CD and inserts the CD into disc drive 206 , e.g., a CD player on the user's personal computer (PC). The CD player reads the surface marks, and OCR module 222 in processor 208 OCRs the bitmap and sends the unlock code to controller 204 . Here, the controller is an executable installation program running on the PC. The installation program verifies the unlock code. If the verification succeeds, then installation proceeds. Otherwise, installation is halted.
The present invention can be embodied in the form of methods and apparatuses for practicing those methods. The present invention can also be embodied in the form of program code embodied in tangible media, such as magnetic recording media, optical recording media, solid state memory, floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. The present invention can also be embodied in the form of program code, for example, whether stored in a storage medium or loaded into and/or executed by a machine, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a unique device that operates analogously to specific logic circuits.
Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value of the value or range.
It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims.
The use of figure numbers and/or figure reference labels in the claims is intended to identify one or more possible embodiments of the claimed subject matter in order to facilitate the interpretation of the claims. Such use is not to be construed as necessarily limiting the scope of those claims to the embodiments shown in the corresponding figures.
It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention.
Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.” | An optical-disc player having a reader and a controller. The reader derives out-of-band information from surface marks of an optical disc, where the controller controls operations of the reader based on the derived information. The controlled operations may involve the reading and rendering of embedded data of the optical disc. For example, a person writes the words “Spanish” and “widescreen” on the surface of a DVD with a marker and inserts the DVD in a DVD player. The DVD player scans the surface of the DVD and sends the resulting image data to an optical character recognition (OCR) module. The OCR module outputs a text file containing the words “Spanish” and “widescreen” to a controller (e.g., Microsoft HDi runtime). In response, the controller sets the playback language to Spanish and the screen format to widescreen. | 6 |
FIELD OF THE INVENTION
This invention pertains to a seal for a fluid-discharge port on a fluid reservoir. The seal is configured to prevent loss of fluid from the fluid reservoir through the port, for example, during shipping or storage. In particular, this invention pertains to aspects of a surface of the seal that faces the port opening and opposes a direction in which the port is configured to discharge fluid. Such aspects improve, among other things, the retention of fluid on the surface of the seal during removal of the seal, thereby reducing spillage or splattering of fluid during removal of the seal.
BACKGROUND OF THE INVENTION
Fluid reservoirs, such as ink cartridges for ink jet printers, commonly have one or more fluid-discharge ports with an opening through which fluid is delivered during use. In order to prevent loss of fluid, for example by spillage or evaporation during shipping or storage, it is common to provide a seal for the port or each of the ports. When the seal is removed so that the fluid reservoir can be used, it is important not to spill or splatter droplets of the fluid.
Fluid-ejection printing devices, such as ink jet printers, commonly have at least one fluid reservoir (or ink cartridge) and a printhead chassis that supports the ink cartridge. The ink cartridge may contain one or more fluid chambers that provide fluid to a printhead. If the ink cartridge has more than one ink chamber, each such chamber often retains fluid of a different color or function for multi-color printing. On the other hand, if the ink cartridge has only a single ink chamber, typically such chamber is used to retain a single fluid, such as black ink for black-and-white printing.
The printhead die containing the nozzles is typically connected directly or indirectly to the chassis. In order to form an image, the printhead die, along with the chassis and the ink cartridge, generally are moved in a lateral direction across a width of a substrate, such as paper, as fluid is ejected from the printhead. After the printhead forms a row-portion of the image along the width of the substrate, the substrate is advanced in a direction perpendicular to the lateral direction along a length of the substrate, so that the printhead can form a subsequent row-portion of the image. This process of advancing the substrate for each row-portion is repeated until a next substrate is needed or the image is completed.
When an ink chamber in the ink cartridge runs out of ink, a user is charged with the responsibility of removing the empty ink cartridge from the chassis and replacing it with a full ink cartridge. The task of replacing an ink cartridge must be simple and clean. Ink should not be allowed to stain the user's hands or clothes, and it also must not be allowed to drip into areas of the printer where it might cause damage.
When a new ink cartridge is shipped, a shipping seal is provided to seal the fluid discharge port(s). The shipping seal helps to prevent ink evaporation during long-term storage, as well as ink spillage due to air pressure changes that occur, for example, during air travel. However, subsequent to shipping, conventional seals have been found to allow fluid to splatter during a user's removal of the seal, thereby possibly causing staining or damage. Accordingly, a need in the art exists for a solution that mitigates the risk of fluid splatter during removal of a shipping seal from an ink cartridge.
SUMMARY
The above-described problem is addressed and a technical solution is achieved in the art by a seal for a fluid-discharge port on a fluid reservoir, according to various embodiments of the present invention. The seal has a surface containing channels that oppose a direction in which the port is configured to discharge fluid. Such channels facilitate the retention of fluid by the seal during removal of the seal, thereby reducing the likelihood of fluid spillage.
At least one of the channels may have a smallest dimension, such as a width of approximately 0.05 mm to 0.25 mm. At least one of the channels may have a rounded or substantially rounded bottom. And, at least one of the channels may have a pointed or substantially pointed bottom.
According to various embodiments of the present invention, at least some of the channels may intersect at right angles, at substantially right angles, or obliquely. According to various embodiments of the present invention, the channels may be formed between protrusions. The protrusions may comprise a sloped side wall. In addition, the protrusions may include sloped side walls that form a point, substantially a point, an edge, or substantially an edge. In this case, the smallest dimension of the point or edge may be approximately 0.05 mm or 0.25 mm. According to an embodiment of the present invention, the protrusions may comprise rounded or substantially rounded tops.
According to various embodiments of the present invention, the protrusions may have approximately a first height and the seal may further include a containment wall around or substantially around a periphery of the seal, such that the containment wall has a height approximately greater than or equal to the first height. A width of a top surface of the containment wall may be approximately between 1 mm and 2 mm. The containment wall may have an outside edge that is stepped, and the outside edge may include a plurality of steps.
According to various embodiments of the present invention, the seal may include a storage area configured to retain excess fluid from the reservoir. In this case, the surface of the seal may include openings communicatively connected to the storage area. The storage area may be located beneath the surface.
According to various embodiments of the present invention, the seal may be formed of a compressible material, such as EPDM rubber or a thermoplastic elastomer, known in the art. The seal may be a hydrophilic material.
According to various embodiments of the present invention, a printer ink cartridge is provided, the printer ink cartridge including a fluid reservoir, a fluid-discharge port, a porous media, and a seal according to one of the various embodiments of the present invention highlighted above. The porous media is positioned in the port. According to these embodiments, the surface of the seal includes (a) protrusions between which are the channels, and (b) a containment wall around or substantially around a periphery of the seal. Also according to these embodiments, a space may exist between the protrusions and the porous media, and a space may exist between the containment wall and the porous media.
In addition to the embodiments described above, further embodiments will become apparent by reference to the drawings and by study of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more readily understood from the detailed description of exemplary embodiments presented below considered in conjunction with the attached drawings, of which:
FIG. 1 illustrates a printhead chassis for retaining one or more print cartridges;
FIG. 2 shows an isometric view of a multi-chamber ink cartridge;
FIG. 3 shows an exploded view of a multi-chamber ink cartridge;
FIG. 4 shows a bottom view of a multi-chamber ink cartridge;
FIG. 5 shows a side view of a fluid reservoir with a sealing member held in place against the port opening by a seal retainer;
FIG. 6 shows an isometric view of a sealing member, according to an embodiment of the present invention;
FIG. 7 shows close-up isometric view of a portion of a sealing member, according to an embodiment of the present invention;
FIG. 8 shows a top view of a portion of a sealing member, according to an embodiment of the present invention;
FIG. 9 shows a close-up isometric view of an array of protrusions and channels on the surface of a sealing member, according to an embodiment of the present invention;
FIG. 10 shows a close-up isometric view of protrusions having a top edge which may be sharp or flat or rounded, according to embodiments of the present invention;
FIG. 11 shows a close-up isometric view of an array of protrusions and channels with rounded bottoms on the surface of a sealing member, according to an embodiment of the present invention; and
FIG. 12 shows a close-up isometric view of an array of protrusions and channels with openings in the surface of a sealing member, according to an embodiment of the present invention.
It is to be understood that the attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.
DETAILED DESCRIPTION
Embodiments of the present invention provide one or more channels in the surface of a sealing member which faces the opening of a port of a fluid reservoir. Although particular examples of a fluid reservoir often are provided in the context of an ink jet ink cartridge, it is to be understood that the invention is applicable more generally to sealing members for ports of fluid reservoirs.
FIG. 1 illustrates a printhead chassis 10 having a region 12 for a multi-chamber ink cartridge, and also a region 14 for a single-chamber ink cartridge. Regions 12 and 14 are separated by one or more partitions 16 which also serve as guides for inserting the ink cartridges into the printhead chassis. In region 12 , several fluid reception ports 18 are shown which make connection with the corresponding fluid discharge ports of a multi-chamber ink cartridge, when the ink cartridge is inserted. Region 14 also has a single fluid reception port (hidden by partition 16 ) corresponding to the fluid discharge port of a single-chamber ink cartridge. Not shown in the view of FIG. 1 is the printhead die and its nozzles. Typically, the printhead die would be located underneath the printhead chassis, in a region below the fluid reception ports 18 .
FIG. 2 shows an isometric view of a multi-chamber ink cartridge 20 which may be inserted into region 12 of printhead chassis 10 . The particular ink cartridge 20 shown in FIG. 2 has five chambers within reservoir body 22 , each chamber of which leads to a fluid discharge port 24 . The five chambers serve as reservoirs intended to hold five fluid sources. The five sources may be, for example, cyan ink, magenta ink, yellow ink, photo black ink, and a protective fluid. Alternatively, they may be cyan ink, light cyan ink, magenta ink, light magenta ink, and yellow ink; or they may be a different combination of fluids. Ink cartridge 20 is shown as having a lid 30 in the example shown in FIG. 2 . Lid 30 may be affixed to reservoir body 22 . Together, lid 30 and reservoir body 22 make up the ink cartridge body. Typically the lid 30 and the reservoir body 22 are each formed by injection molding.
FIG. 3 shows an exploded view of multi-chamber ink cartridge 20 as well as seal assembly 50 . For the particular example shown in FIG. 3 , pressure regulation for the ink cartridge is provided by capillary media 42 and wick 44 , as is described in greater detail in the co-filed application titled “Ink Jet Ink Cartridge with Vented Wick”, by Pearson, et al., application Ser. No. 11/679,925, filed Feb. 28, 2007. Both the capillary media and the wick are typically formed of porous media, such as foam, or felt, or fiber bundles. However, the wick and capillary media are not essential features for this invention. Lid 30 is affixed to reservoir body 22 by ultrasonic welding or other means of adhering the lid to the reservoir body 22 . One or more labels 36 may optionally be applied to the top surface of the lid 30 . Ink or fluids of various types are typically held in the various chambers of the ink cartridge.
FIG. 4 shows a bottom view of multi-chamber ink cartridge 20 with the bottom surface 45 of each wick 44 visible within each port 24 . Note that the bottom surface 45 of wick 44 is recessed somewhat relative to the outer rim (or bottom surface) 26 of port 24 .
Before the ink cartridge 20 is ready to be shipped to the customer, the ports must be sealed in order to prevent leakage or excessive evaporation of volatile ink components. Many different styles of seals are possible to be used. For example, a film may be affixed to the outer rim of each port. For this type of seal, the customer may pull a tab at an end of the film and thereby pull the seal away from each port. A second alternative is a twist-off seal, although this type of seal is more compatible with a cartridge having only a single port. With a row of ports 24 as in multi-chamber ink cartridge 20 , the amount of torque to twist off seals from five adjacent chambers would be excessively difficult for the user to apply. A third alternative is a seal of the type provided by seal assembly 50 shown in FIG. 3 . Seal assembly 50 includes a compliant seal member 52 which is held in place at the ports 24 by seal retainer 54 . Compliant seal member 52 is typically is formed using an elastomeric material such as EPDM rubber. Seal retainer 54 is typically formed by injection molding. The sealing member may protrude somewhat into the port, but typically there is still an air space between the bottom surface 45 of wick 44 and the sealing member. A fourth alternative is to use the compliant seal member without a seal retainer. In such an alternative, the elastic properties of the seal member material would be used to hold it in place—for example, by having a portion of the seal member material surround the outer rim of the port(s) to hold the seal member in place.
FIG. 5 shows a cutaway side view of ink cartridge 20 with seal assembly 50 installed in order to prepare it for shipping and other fluid-retention purposes. Sealing member 52 is shown pressed against port 24 and held in place by seal retainer 54 . In order to remove seal retainer 54 , the user presses on seal retainer lever 56 in a downward direction denoted by arrow 60 . As a result, the sealing member 52 is pulled away from outer rim 26 of fluid discharge port 24 in a direction denoted by arrow 62 .
As the sealing member 52 is pulled away from the port, some amount of ink may be located on the surface of the sealing member which had faced the port opening and which opposed a direction in which the port 24 is configured to discharge ink. If the seal is pulled away suddenly, droplets of ink may splatter out and stain the hands of the user or get onto the printer or other objects. This is true whether the seal is a compliant seal such as sealing member 52 , or whether the seal is an adhesively affixed film. This problem, which is addressed by the present invention, is exacerbated for configurations of fluid reservoirs and seals such that transient pressure changes occur when the seal is removed, due to air volume changes between the port and the surface of the seal. Somewhat less susceptible to such pressure changes are the types of seals which may be removed in a twisting motion, since the volume change is very small as the seal is broken. However, as mentioned above, twist-off type seals are not very compatible with multi-chamber ink cartridges having a row of adjacent ports 24 .
FIG. 6 shows an isometric view of a sealing member 52 according to an embodiment of this invention. In the example shown in FIG. 6 , sealing member 52 is configured with five port seals 70 (corresponding to five ports of a five-chamber fluid reservoir). The port seals 70 are joined by and extend from a sealing member base top surface 72 . The port seals may include a containment wall 74 having a flat top surface and/or a stepped edge 76 . Within the region surrounded by containment wall 74 may be a plurality of protrusions 82 which are separated from one another by channels 84 (see also the top view shown in FIG. 8 ).
In a preferred embodiment, the sealing member 52 is formed of a compressible material, such as EPDM rubber or a thermoplastic elastomer. The port seals 70 are configured such that each containment wall 74 fits within the outer rim 26 of the corresponding fluid discharge port 24 . When the sealing member 52 is pressed against the fluid discharge ports 24 (for example by seal retainer 54 ), it is the stepped edge 76 that provides the seal against the inner surface 27 of the outer rim 26 . Although not required, providing a plurality of steps in stepped edge 76 can improve seal reliability. A function of containment wall 74 , protrusions 82 and channels 84 is to retain residues of ink or other fluid which may be on the surface of the port seal 70 when the sealing member 52 is removed from the fluid discharge ports 24 . The channels 84 between the protrusions 82 provide capillary forces, which tend to hold the fluid residue, as well as some amount of storage volume, so that the fluid has less tendency to splatter off the surface of the port seal 70 when the sealing member 52 is removed from the fluid discharge ports 24 . In some applications, for example, when the inks or fluids are water-based, the surface of the sealing member 52 may be made of a hydrophilic material to provide additional holding forces for the fluid residue.
FIG. 7 shows a close-up isometric view of a portion of sealing member 52 in order to provide a better view of the containment wall 74 , the protrusions 82 , and the stepped edge 76 . In the embodiment shown in FIG. 7 , the protrusions 82 are shown as pyramid-shaped, with sloping walls. The height of the protrusions 82 relative to the top surface 72 of the sealing member 52 is h 1 . The height of containment wall 74 relative to the top surface 72 of the sealing member 52 is h 2 . In some embodiments, it is advantageous for fluid retention if the height of containment wall 74 is greater than or equal to the height of protrusions 82 . In other words, h 2 ≧h 1 . Further, in some embodiments, it is advantageous for the interference of the stepped edge 76 against the inner surface 27 of outer rim 26 to be such that neither the protrusions 82 nor the containment wall 74 touch any solid feature with fluid discharge port 24 , such as a wick 44 or capillary media 42 .
FIG. 8 shows a top view of a port seal 70 to show the two-dimensional array of protrusions 82 and channels 84 . In the embodiment shown in FIG. 8 , the protrusions 82 in the two-dimensional array are separated from neighboring protrusions 82 by a series of horizontal channels 83 and vertical channels 85 . In this example, the channels are shown as intersecting at right angles, but they can alternatively intersect obliquely. In fact, channels may be configured in a spiral pattern, for example, and not intersect at all. The primary requirement is that the channels 84 and protrusions 82 have geometries conducive to providing capillary forces to promote the retention of fluid on the surface when the sealing member 52 is removed from the fluid discharge ports 24 .
Further geometrical details of shapes and dimensions will be discussed with reference to FIG. 7-11 . The distance between adjacent channels (pitch p shown in FIG. 8 ) is typically on the order of 1 mm, but may range, for example, between 0.3 mm and 2 mm. The height h 1 of protrusions 82 is typically on the order of 0.5 mm. The width of the top surface of containment wall 74 ranges between approximately 1 mm and 2 mm.
FIG. 9 shows a close-up isometric view of several protrusions 82 and channels 84 . In the embodiment of FIG. 9 each protrusion 82 consists of four sloping sidewalls 81 which meet at a point 86 . In other words, the protrusions are pyramid shaped. The horizontal channels 83 and the vertical channels 85 are shown in the example of FIG. 9 to have sharp corners and well defined widths. It is not required that the width of the horizontal channels 83 and the width of the vertical channels 85 be equal to each other.
FIG. 10 shows a close-up isometric view of other alternative shapes for protrusions 82 . For example, rather than meeting at point 86 , the sloping sidewalls 81 may meet at an edge or line 87 . In other words, the protrusion 82 can be tent-shaped. Alternately the protrusion 82 may be truncated at the top to provide a flat or rounded surface 88 . A smallest dimension of the top of the protrusion 82 is shown as 89 . Whether the top of the protrusion is a point, an edge, or a flat or rounded surface, a typical smallest dimension of the top of the protrusion 82 ranges from 0.05 mm to 0.25 mm.
FIG. 11 shows a close-up isometric view of an alternate shape for channels 84 . In FIG. 11 , rather than the channels 84 having a flat bottom, they have a rounded bottom 90 . Other non-flat channel options include V-shaped channels. In any case, the smallest dimension, such as a width, of the channels typically ranges from approximately 0.05 mm to 0.25 mm.
FIG. 12 shows a close-up isometric view (with a sliced open front edge) of a sealing member 52 having increased storage capacity for fluid residue. FIG. 12 shows a portion of sealing member 52 in the region of the protrusions 82 and channels 84 for an alternative embodiment of the invention. In this embodiment, openings 92 are provided in the surface 91 of the channels 84 . Openings 92 lead to a storage region 93 within sealing member 52 in which additional fluid may be stored.
Although the examples above discuss embodiments in a multi-chamber fluid reservoir 20 , it is to be understood that the same advantages apply to a single chamber fluid reservoir.
The various embodiments of this invention are particularly advantageous for, among other things, fluid reservoirs and sealing members such that the sealing member is removed in a fashion that momentarily increases the air volume between the sealing member and the interior of the fluid discharge port, such that a transient reduction of air pressure occurs within the fluid discharge port. Such configurations are particularly susceptible to fluid residue being transferred to the surface of the sealing member, resulting in ink splatters if the surface cannot hold the residue. For example, embodiments of the present invention are particularly advantageous for, among other things, seals which are not removed by twisting them off.
It is to be understood that the exemplary embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by one skilled in the art without departing from the scope of the invention. It is therefore intended that all such variations be included within the scope of the following claims and their equivalents.
PARTS LIST
10
Printhead chassis
12
Region for multi-chamber cartridge
14
Region for single chamber cartridge
16
Partition
18
Fluid reception port
20
Multi-chamber ink cartridge
22
Reservoir body
24
Fluid discharge port
26
Outer rim of fluid discharge port
27
Inner surface of outer rim
30
Lid
36
Label
42
Capillary media
44
Wick
45
Bottom surface of wick
46
Wick opening
50
Seal assembly
52
Seal member
54
Seal retainer
56
Seal retainer lever
60
Direction arrow
62
Direction arrow
70
Port seal
72
Sealing member base
74
Containment wall
76
Stepped edge
81
Sloping sidewalls of protrusions
82
Protrusions
83
Horizontal channels
84
Channels
85
Vertical channels
86
Point of protrusions
87
Edge intersection of protrusions
88
Truncated top of protrusion
89
Smallest dimension of protrusion
90
Rounded bottom of channel
91
Surface of channel
92
Opening
93
Storage region | A seal for an ink-discharge port on a printer ink cartridge, according to various embodiments of the present invention, is disclosed. The seal has a surface containing channels that oppose a direction in which the port is configured to discharge ink from the ink cartridge. Such channels facilitate the retention of ink by the seal during removal of the seal, thereby reducing the likelihood of ink spillage during such removal. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to peptides which inhibit the binding of von Willebrand factor (vWF) to Factor VIII (FVIII).
vWF and FVIII both have important but different functions in the maintenance of hemostasis. vWF participates in platelet-vessel wall interactions at the site of vascular injury whereas FVIII accelerates the activation of Factor X by Factor IXa in the presence of platelets and calcium ions. vWF and FVIII circulate in plasma as a noncovalently linked complex thought to be held together by both electrostatic and hydrophobic forces. vWF is thought to stabilize FVIII in vitro and prolong its half-life in the circulation. Consequently, in the absence of endogeneous vWF the circulating half-life of FVIII is markedly reduced. Since FVIII participates in the intrinsic pathway of blood coagulation, agents capable of interfering with the interaction of FVIII and vWF would alter the FVIII level in plasma and in this manner serve as anti-thrombotic agents. The peptides of the present invention have the ability to act as anti-thrombotic agents by their prevention of the binding of vWF to FVIII. They also have the ability to stabilize FVIII in an in vitro environment in which FVIII is being produced.
SUMMARY OF THE INVENTION
The present invention comprises a 29 kDa polypeptide fragment selected from the following sequence: ##STR1## which inhibits binding of von Willebrand Factor to Factor VIII, whose amino acid sequence is that of a fragment of von Willebrand Factor and reacts with a monoclonal anti-vWF antibody C3 deposited with the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md., 20852 with the designation (ATCC No. HB 9425) capable of specifically binding to the region of von Willebrand Factor containing the Factor VIII binding domain.
Particularly preferred is a polypeptide which inhibits binding of von Willebrand Factor to Factor VIII wherein the polypeptide has the amino-terminal sequence beginning with amino-terminal amino acid residue 3 Ser and ending approximately with carboxy-terminal amino acid residue 244 Leu.
Additionally preferred is a polypeptide which inhibits binding of von Willebrand Factor to Factor VIII wherein the polypeptide has the amino-terminal sequence beginning with amino-terminal amino acid residue 24 Glu and ending approximately with carboxy-terminal amino acid residue 265 Ser.
Additionally preferred is a polypeptide which inhibits binding of von Willebrand Factor to Factor VIII wherein the polypeptide has the amino-terminal sequence beginning with amino-terminal acid residue 44 Gly and ending approximately with carboxy-terminal amino acid residue 285 Asn.
The invention further comprises a peptide comprising a sequential subset of at least three amino acid residues of a polypeptide fragment which inhibits binding of von Willebrand Factor to Factor VIII and reacts with a monoclonal anti-vWF antibody C3 capable of specifically binding to the region of von Willebrand Factor containing the Factor VIII binding domain and which has the following sequence: ##STR2##
The invention further comprises a new mouse-mouse hybridoma cell line which provides as a component of the supernatant of its growth a monoclonal anti-vWF antibody C3 capable of specifically binding to the region of von Willebrand Factor containing the Factor VIII binding domain.
The invention further comprises a monoclonal anti-vWF antibody capable of specifically binding to the region of von Willebrand Factor containing the Factor VIII binding domain.
The invention further comprises an improved method of preparing Factor VIII by the addition of a polypeptide fragment and any sequential subset of at least three amino acids of the polypeptide fragment which inhibit binding of von Willebrand Factor to Factor VIII.
The invention further comprises an improved method of preparing Factor VIII using particles bound to a polypeptide fragment and any sequential subset of at least three amino acids of the polypeptide fragment which inhibit binding of von Willebrand Factor to Factor VIII.
The invention further comprises a method of preparing by recombinant DNA or synthetic peptide techniques a polypeptide fragment and any sequential subset of at least three amino acids of the polypeptide fragment which inhibit binding of von Willebrand Factor to Factor VIII.
The invention further comprises an improved method for expressing recombinant DNA produced Factor VIII using a polypeptide fragment and any sequential subset of at least three amino acids of the polypeptide fragment which inhibit binding of von Willebrand Factor to Factor VIII.
DETAILED DESCRIPTION OF THE INVENTION
As indicated the present invention encompasses polypeptide fragments and synthetic peptides which inhibit binding of vWF to FVIII, whose amino acid sequences are that of fragments of vWF and react with a monoclonal anti-vWF antibody C3 capable of specifically binding to the region of vWF containing the FVIII binding domain.
The monoclonal anti-vWF antibody C3 was found to have the ability to block the binding of purified human FVIII to purified human vWF in a crossed immunoelectrophoresis system. The epitope of C3 must reside close to that of the FVIII binding domain of vWF. The C3 antibody was therefore used as a marker of the FVIII binding domain.
Whole unreduced 125 I-labeled vWF was treated with subtilisin at a 1/25 (w/w) ratio for 24 hours at room temperature. This reaction mixture was then placed in microtiter wells which had previously been coated with monoclonal anti-vWF antibody C3. The wells were thoroughly washed and then treated with SDS buffer heated to approximately 90° C. and the solution run on a 5-15% gradient SDS-PAGE gel. An autoradiograph of the SDS-PAGE gel demonstrated predominately a single band with a molecular weight of approximately 29 kDa. A similar digest of unlabeled vWF was made and this reaction mixture was placed on chromatography column made up of monoclonal anti-vWF antibody C3 coupled to Sepharose 4B. The C3 reactive fragments were then eluted with 3M NaSCN, dialyzed, and concentrated. A band reactive with C3 by immunoblotting techniques was identified. Amino acid sequencing of this band revealed that approximately 60% of the amino-termini began with amino acid residue number 44 of the mature vWF subunit, approximately 20% began with residue number 24 and approximately 10% began with residue number 3.
The above described experiment localized the C3 epitope and indirectly the FVIII binding domain to the amino-terminal region of vWF. Since the molecular weight of the peptide so identified was approximately 29 kDa and its predominant amino-terminus was amino acid residue 44 of the mature subunit, then the carboxy-terminus should be approximately at amino acid residue 285 based on an average molecular weight per amino acid residue of approximately 120. Based on the published amino acid sequence of vWF in Titani et al., Biochemistry 25, 3174-3184 (1986) it is possible to synthesize peptides from the region beginning with residue 3 and ending with amino acid residue 285 which comprises the region of vWF containing the FVIII binding domain.
In Titani et al. the sequence analysis identified both Ala, and Thr at a molar ratio of about 4:1 at residue 26. In contrast, the nucleotide sequence of the lambda HvWF1 clone predicted Thr at residue 26 according to Sadler et al., Proc. Natl. Acad. Sci. USA 82, 6394-6398 (1985). This discrepancy can be due to polymorphism in the protein or to an error in cDNA replication during the preparation of the DNA library. In view of this uncertainty at residue 26, the amino acid at residue 26, is identified by X which represents an undetermined amino acid. These peptides can interfere with FVIII-vWF interaction and thus serve as antithrombotic agents. Additional monoclonal antibodies to this region can be produced which will also interfere with FVIII-vWF interaction and thus can also serve as anti-thrombotic agents.
Experimental procedures used in localizing the C3 epitope and indirectly the FVIII binding to the 29 kDa polypeptide fragment are explained in more detail below when these same procedures are used in localizing the C3 epitope and indirectly the FVIII binding to the 170 kDa polypeptide fragment.
The purification of FVIII from commercial factor VIII concentrate (Armour Pharmaceutical, Kankakee, Ill.), by immunoadsorbent chromatography with monoclonal anti-vWF antibody is described in Fulcher et al., Proc. Natl. Acad. Sci. USA 79, 1648-1652 (1982). FVIII preparations obtained by this method and used in the following experiments had specific activities of 2900-3800 units/mg. Purified vWF was obtained from commercial factor VIII concentrate (Armour Pharmaceutical, Kankakee, Ill.), by immunoadsorbent chromatography with a monoclonal anti-vWF antibody bound to Sepharose as described in Fulcher et al. The bound vWF was eluted by 3M NaSCN as described in Fujimara et al., J. Biol. Chem. 261, 381-385 (1986) and concentrated and desalted with a tangential flow Minitan ultrafiltration system (Millipore, Bedford, Mass.), with a 100,000 molecular weight cut off membrane. The protein was further dialyzed extensively against 0.05M Tris, 0.15M NaCl, pH 7.35 (TBS).
Mouse monoclonal anti-FVIII and anti-vWF antibodies were produced, purified, and characterized and described in Fulcher et al., and Fujimara et al. Radioiodination of monoclonal anti-FVIII and anti-vWF antibodies were done according to the method of Fraker and Speck, Biochem. Biophys. Res. Commun. 80, 849-857 (1978), to a specific activity of 3-10×10 9 cpm/mg.
SP fragment-III was obtained by limited proteolysis of vWF with Staphylococcus aureus V8 protease (Sigma, St. Louis, Mo.), and purified by the method of Girma et al., Biochemistry 25, 3156-3163 (1986), with modifications as described by Titani et al., Biochemistry 25, 3171-3184. All fragments were dialyzed against TBS pH 7.35 before testing.
The reduction and alkylation of vWF was performed as has been previously described in Fujimara et al.
Two dimensional crossed immunoelectrophoresis of vWF was performed as described in Zimmerman et al., Immunoassays: Clinical Laboratory Techniques for the 1980's, pp. 339-349, Alan R. Liss, Inc., New York (1980), with the following modifications. Agarose was poured in a 1.5 cm strip at the bottom of a 10.2 cm×8.3 cm piece of Gelbond (FMC Corporation, Rockland, Me.). Purified vWF or fragments of vWF, FVIII, and 125 I-labeled monoclonal anti-FVIII antibody were mixed in the sample well and electrophoresed. A second gel containing 125-250 μl of rabbit serum containing polyclonal anti-vWF antibodies was then poured and the second dimension was electrophoresed at right angles to the first dimension. Autoradiographs were made of the gels and compared to Coomassie brilliant blue staining of the gels.
Competitive inhibition assay of FVIII binding to solid phase vWF: 50 μg of whole unreduced vWF in 1 ml of 0.01M PO 4 , 0.15M NaCl, 0.02% NaN 3 , pH 7.3 (PBS), was incubated with three 1/4 inch in diameter polystyrene beads (Pierce Chemical Company, Rockford, Ill.) per 16 mm in diameter tissue culture well for 2 hours at room temperature. The solution was removed and the wells and the beads were then blocked with 1 ml of PBS containing 0.05% Tween-20 and 3% human serum albumin for 1 hour at room temperature. The wells and the beads were stored in the blocking solution at 4° C. for 16 hours to 10 days before use. The wells and beads were then washed ×3 with PBS 0.05% Tween-20 and incubated for 11/2 hours at room temperature with 1.3 μg of purified FVIII and 0-100 μg of the competitive ligand in 1 ml of 0.05M imidazole, 0.15M NaCl, 0.02% NaN 3 , pH 7.0, 3 mM CaCl. The beads then were washed ×5 with PBS 0.05% Tween-20 and incubated for 11/2 hour at room temperature with 1.5×10 6 cpm of 125 I-monoclonal anti-FVIII antibody C2 (specific activity 3.8×10 9 cpm/mg), in 1 ml of PBS 0.05% Tween-20 containing 0.5% bovine gamma globulin. After incubation, the wells and beads were washed with PBS 0.05% Tween-20×2. The beads were then transferred to clean wells and washed an additional four times and separately counted. Total cpm in the absence of competing ligands ranged from 1340-2520 cpm in different experiments Background counts were those obtained when 125 I-monoclonal anti-FVIII antibody C2 was incubated with the vWF coated beads in the absence of FVIII. These ranged from 60-200 cpm
Protein concentrations were determined by the method of Bradford, Anal. Biochem 72:248-254 (1976), using bovine serum albumin as a standard.
Crossed immunoelectrophoresis demonstrated complex formation between purified vWF and purified FVIII. This was shown by co-precipitation of 125 I-labeled monoclonal anti-FVIII antibody with unlabeled vWF only when purified FVIII was included in the sample well. In order to localize the FVIII binding domain, similar experiments were performed with vWF fragments obtained by Staphylococcus aureus V8 protease digestion. Limited digestion of vWF with Staphylococcus aureus V8 protease has been reported to produce primarily a single cleavage in vWF yielding two major fragments. SP fragment II is a 110-kDa homodimer containing the carboxy-terminal portion of the vWF molecule (residues 1366-2050) and SP fragment III is a 170-kDa homodimer containing the amino-terminal portion of the vWF molecule. This 170-kDa polypeptide fragment has an amino-terminal sequence beginning with amino-terminal amino acid residue 1 Ser and a carboxy-terminal amino acid residue extending no further than amino acid residue 1365-Glu according to the amino acid sequence published in Titani et al., Biochemistry, 25, 3171-3184 (1986). These two fragments represent 100% of the molecular mass of the vWF subunit. Complex formation was demonstrated between FVIII and the amino-terminal SP fragment III but not with the carboxy-terminal SP fragment II. This indicates that the amino-terminal SP fragment III in its homodimer form maintains the capability of interaction with FVIII in a qualitatively similar way as that of whole vWF. The carboxy-terminal SP fragment II in its homodimer form does not demonstrate this FVIII binding capability.
The monoclonal anti-vWF antibody C3 largely inhibited complex formation between FVIII and vWF when it was included in the sample well, whereas 80 other monoclonal anti-vWF antibodies (tested in pools of 5 each) were without effect. C3 also inhibited complex formation between FVIII and SP fragment III in this system. Direct reactivity of C3 with SP fragment III was shown by adding 125 I-labeled C3 to a sample well containing purified SP fragment III. Autoradiographs of the crossed immunoelectrophoresis gel showed co-precipitation of the radiolabeled antibody with SP fragment III. In a similar experiment, no co-precipitation with SP fragment II occurred.
In order to better characterize FVIII binding to vWF, a competitive inhibition assay was developed. In this assay purified vWF or SP fragment III was adsorbed to the surface of polystyrene beads. The beads were then incubated with purified FVIII. Purified FVIII bound to both unreduced vWF and unreduced SP fragment III which had been immobilized on the surface of the polystyrene beads. This was demonstrated by the binding of 125 I-labeled monoclonal anti-FVIII antibody to polystyrene beads sequentially incubated with vWF and FVIII.
Both the binding of FVIII to vWF and the binding of 125 I-labeled monoclonal anti-FVIII antibody to FVIII were specific in this system as demonstrated by the following experiments. First, the binding of FVIII was shown to be dependent on the presence of vWF adsorbed to the surface of the polystyrene beads. When the polystyrene beads were coated with human serum albumin and then incubated with FVIII, followed by 125 I-labeled monoclonal anti-FVIII antibody, the counts per minute measured were only 2% of that seen with FVIII binding to vWF coated polystyrene beads. Secondly, when vWF coated polystyrene beads were not incubated with FVIII, the bead associated counts per minute were only 1% of that seen when the FVIII incubation was included.
The reversibility of the binding of FVIII to the immobilized vWF could also be demonstrated. Dissociation of FVIII from the vWF-FVIII complex has been shown to occur in the presence of 0.25M CaCl 2 according to Cooper et al., J. Clin. Invest. 54, 1093-1094 (1974), 10-20 mM EDTA according to Tran et al., Thromb. Haemostas. 50, 547-551 (1983) or 1-1.5M NaCl according to Weiss et al., Thromb. Diath. Haemorrh. 27, 212-219 (1972). In the polystyrene bead system, five washings of the polystyrene beads with an imidazole buffered saline containing 0.25M CaCl 2 at 37° C. produced 70±4% dissociation of FVIII from vWF. Similarly, five washings with an imidazole buffered saline containing 20 mM EDTA produced 66±5% dissociation and with an imidazole buffer containing 1.5M NaCl produced 86±1% dissociation of FVIII from vWF. Five washings with the same imidazole buffered saline containing 3 mM CaCl 2 produced no FVIII dissociation from vWF adsorbed to the polystyrene beads.
The specificity of the binding of fluid phase FVIII to vWF immobilized to the surface of the polystyrene beads was also shown by the ability of whole, unreduced vWF in fluid phase to completely inhibit this binding. Reduced and alkylated vWF had no inhibitory effect on FVIII binding. Reduced and alkylated vWF, and reduced and alkylated SP fragment III, were also unable to bind FVIII in the crossed immunoelectrophoresis system. These findings are consistent with the observation that under mild reducing conditions FVIII can be dissociated from vWF, see Blomback et al., Thromb. Res. 12, 1177-1194 (1978).
SP fragment III demonstrated dose dependent inhibition of FVIII binding with 90% inhibition at a concentration of 50 μg/ml. SP fragment I, a product of Staphylococcus aureus V8 protease digestion of SP fragment III which contains the middle portion of the vWF molecule (residues 911-1365 as described in Titani et al., Biochemistry 25, 3171-3184 (1986)) produced only 15% inhibition at concentrations up to 100 μg/ml. These data localized a major FVIII binding domain to the amino-terminal portion of vWF. SP fragment II inhibited FVIII binding by 29% at a concentration of 50 μg/ml. Doubling the concentration produced no significant increase in inhibition.
The complete 2050 amino acid sequence of vWF has been determined by protein sequence analysis, see Titani et al., Biochemistry 25, 3171-3184 (1986). With such information a nucleotide sequence can be inserted into the appropriate vector for expression of the 29 kDa and 170 kDa polypeptide fragments and sequential subsets of polypeptide fragments which inhibit binding of vWF to FVIII. For a description of recombinant DNA techniques for cloning vWF fragments, see Ginsburg et al., Science 228:1401-1406 (1985) and Sadler et al., Proc. Nat. Acad. Sci. USA 82, 6394-6398 (1985).
Peptides at least three amino acid residues in length beginning from the amino-terminal region of the 29 kDa polypeptide fragment are synthesized as described by Houghton et al., Proc. Natl. Acad. Sci. USA 82:5135 (1985).
In the well known procedure for solid-phase synthesis of a peptide, the desired peptide is assembled starting from an insoluble support such as benzhydryl amine or chloromethylated resin (derived from cross-linked polystyrene, and available from chemical supply houses). The amino acid at the carboxy-terminal end of the desired polypeptide, carrying protecting groups on the alpha-amino nitrogen and on any other reactive sites, is attached to the resin from solution using known peptide coupling techniques. The protecting group on the alpha-amino group is removed (leaving other protecting groups, if any, intact), and the next amino acid of the desired sequence (carrying suitable protecting groups) is attached, and so on. When the desired polypeptide has been completely built up, it is cleaved from the resin support, all protecting groups are removed, and the polypeptide is recovered. Examples of suitable protecting groups are: alpha-tert-butyloxycarbonyl for the alpha-amino-group; benzyl, 4-methoxybenzyl, or 4-methylbenzyl for the thiol group of cysteine, the beta-carboxylic acid group of aspartic acid, the gamma-carboxylic acid group of glutamic acid and the hydroxyl groups of serine, threonine, and tyrosine; benzyloxycarbonyl or a 2-chloro- or 3, 4-dimethoxy-derivative thereof for the ring nitrogens of histidine and tryptophan and the epsilon-amino group of lysine; p-nitrophenyl for the amide nitrogens of asparagine and glutamine; and nitro or tosyl for the guanidine group of arginine.
For purposes of this disclosure, accepted short-hand designations of the amino acids have been used. A complete listing is provided herein below:
One and Three-letter Amino Acid Abbreviations
______________________________________A Ala AlanineC Cys CysteineD Asp Aspartic AcidE Glu Glutamic AcidF Phe PhenylalanineG Gly GlycineH His HistidineI Ile IsoleucineK Lys LysineL Leu LeucineM Met MethionineN Asn AsparagineP Pro ProlineQ Glu GlutamineR Arg ArginineS Ser SerineT Thr ThreonineV Val ValineW Trp TryptophanY Tyr TyrosineB Asx Asp or Asn, not distinguishedZ Glx Glu or Gln, not distinguishedX X Undetermined or atypical amino acid______________________________________
One or more of the peptides of the present invention can be formulated into pharmaceutical preparations for therapeutic, diagnostic, or other uses. To prepare them for intraveneous administration, the compositions are dissolved in water containing physiologically compatible substances such as sodium chloride (e.g. 0.35-2.0M), glycine, and the like and having a buffered pH compatible with physiological conditions. The amount to administer for the prevention of thrombosis will depend on the severity with which the patient is subject to thrombosis, but can be determined readily for any particular patient.
The following example is given as illustrative of the present invention. The present invention is not restricted only to this example.
EXAMPLE 1
Preparation of monoclonal antibody, C3, from hybridoma cell line
In the procedure for production of the hybridoma cell line producing monoclonal anti-vWF antibody C3 mice of strain BALB/c (Research Institute of Scripps Clinic) were immunized intraperitoneally with purified FVIII immunogen containing small amounts of vWF which co-purified with it as a contaminant. The FVIII was prepared as described in Fulcher et al., Proc. Natl. Acad. Sci. USA 79, 1648-1652 (1982). The mice were immunized intraperitoneally with 1 μg of immunogen in complete Freund's adjuvant. Seven days later the mice were immunized intraperitoneally with 10 μg of immunogen in incomplete Freund's adjuvant. Seven days after this second injection they were immunized intraperitoneally with 50 μg of immunogen in incomplete Freund's adjuvant. Eight days after this third injection they were immunized intraperitoneally with 100 μg of soluble immunogen. Spleens were removed three days later, and spleen cells were fused with P3×63-AG8.653 (mouse myeloma cell line).
P3X653-AG8.653 was maintained (before fusion) at log phase growth in a medium of 90% Dulbecco's modified Eagle's medium (high glucose) and 10% Fetal bovine serum (FBS). The following recommended supplements were added to 475 ml of the above medium: glutamine (100x) 5 ml, sodium pyruvate (100x) 5 ml, nonessential amino acids (100x) 5 ml, Pen-strep-fungizone (100x) 5 ml and 8-azaguanine 6.6×10 -3 M (50x) 10 ml. Spleen and myeloma cells were washed thoroughly without FBS in Dulbecco's modified Eagle's medium before fusion. Cells were fused with 1 ml 40% PEG 1500 for 1 minute. Then cells were diluted 1:2 with growth medium for 1 minute. Cells were diluted further 1:5 with growth medium for 2 minutes. Next cells were spun 900 RPM for 10 minutes. The supernatant was removed, the cells were selected by suspension in HAT medium and placed in 96 well plates. The Hat medium contained 90% Dulbecco's modified Eagle's medium (high glucose), 10% FBS and the following recommended supplements added to 405 ml of the above two components: glutamine (100x) 5 ml, NCTC 109 50 ml, sodium pyruvate (100x) 5 ml, nonessential amino acids (100x) 5 ml, Pen-strep-fungizone (100x) 5 ml, (hypoxanthine 10 -2 M+thymidine 1.6×10 -3 M) (100x) 5 ml, bovine insulin (20 I.U./ml)(100x) 5 ml, oxaloacetate (10 -1 M) (100x) 5 ml and aminopterin (2×10 -5 M)(50x) 10 ml. For 4 weeks following selection the cells were maintained in growth medium--HT (selection medium minus aminopterin). Subcloning was accomplished by limiting dilution. Wells with growth are tested by ELISA assay. Test plates were coated with 100 ng/well immunogen or human fibrinogen, or human fibronectin, or human vWF, each protein being a potential contaminant of the immunogen. 50 μg of culture supernatant were tested. Those wells containing cells whose supernatants were positive with a vWF were grown at 37° C. in 10% CO 2 .
For ascites production the mice were primed with 0.5 ml pristine at least 4 days before cell injection. The cells were injected intraperitoneally (5×10 6 /mouse) in 0.5 ml media with on FBS. The ascites were harvested when the mice bloated. The monoclonal anti-vWF antibody C3 contained in the mouse ascites is of the IgG-1 type.
The following Protein A sepharose purification of monoclonal anti-vWF antibody C3 from mouse ascites is a modified procedure of that disclosed in Ey et al, Immunochemistry, 15, 429-436 (1978). The amounts used were for a column 1 cm×15 cm which bound about 25-30 mg IgG-1, but which allowed separation of about 50 mg IgG-1 from non IgG proteins. The column can also bind 50 mg of IgG2a. IgG2b also binds to the column, but IgM, IgA and IgE do not bind. 4-6 ml of ascites was centrifuged at 30,000 rpm for 45 minutes. The lipids were removed on top. The addition of 20% sucrose weight/column to the ascites aided in the removal of lipids. Ascites was diluted to 25-30 ml with 140 mM NaPO 4 buffer, pH8, containing 0.02% NaN 3 . The ascites was diluted to prevent the interference of chloride ion with the binding of IgG. Approximately 2 g of Protein A sepharose (Sigma) was swollen in 10 mM phosphate buffered saline with 0.02% NaN 3 and packed into a 1 cm diameter column. The column was equilibrated in 140 mM NaPO 4 buffer with 0.02% NaN 3 . The column was loaded with diluted ascites at 0.06-0.03 ml/min or less. The column was allowed to sit at 4° C. overnight after loading to increase binding of IgG. The column was washed with buffers at 0.6-0.8 ml/min in the following order:
1) 140 mM NaPO 4 , pH 8.0; 2) 0.1M Na citrate-citric acid, pH 6.0 (IgG-1 eluted); 3) 0.1M Na citrate-citric acid, pH 5.0--IgG2a eluted and a small percentage of remaining IgG-1; 4) 0.1M Na citrate-citric acid (small percentage of remaining IgG2a eluted); and 5) 0.1M Na citrate-citric acid, pH 3.0 (IgG2b eluted). As soon as the column was washed with pH 3.0 buffer, it was washed with 140 mM NaPO 4 buffer, pH 8.0+0.02% NaN 3 until pH of effluent is 8.0. The column was stored at 4° C. During the washing of the column approximately 5 ml fractions were collected. To any fraction of pH 5.0, 1 ml of 1M tris HCl was added. | Peptides which inhibit the binding of von Willebrand Factor to Factor VIII. Monoclonal antibodies capable of specifically binding to the region of von Willebrand Factor containing the Factor VIII binding domain. Improved methods of preparing Factor VIII. | 2 |
FIELD OF THE INVENTION
The present invention relates to papermaking headboxes in general and in particular to headboxes employing constant volumetric flow tubes between the headbox manifold and the slice.
BACKGROUND OF THE INVENTION
In the formation of paper, wood fibers are dispersed in water to form a papermaking stock. The stock is usually at least 99 percent water and contains one-half to one percent paper fibers. The paper stock is injected through a tapered flow control channel known as a slice onto a fourdrinier moving wire screen to form the paper web. In some circumstances the stock is injected between two moving wire screens on a so-called twin wire machine. Water is drawn from the stock through the forming screens or wires leaving a web of paper fibers which is pressed and dried to form a web of paper.
Modern papermaking machines are between one and four hundred inches wide and operate at speeds up to and in excess of 4,000 feet per minute. Thus, the headbox and the slice which supply the paper stock which is formed into the paper web must supply not only a large quantity of stock to meet the high forming speeds of modern papermaking processes, but also supply the stock extremely uniformly if the sheet of paper formed is to be of uniform thickness across the width of the web.
To achieve the high flow rates and uniformity of stock injected through the slice, the stock is pumped at extremely high pressures by means of pumping equipment. An attenuator is disposed upstream relative to the headbox for damping pressure pulses caused by the stock pumping equipment. The arrangement is such that the rate of stock entering the headbox is relatively constant.
To achieve a uniform flow of stock onto the forming wire or wires, the headbox employs an inlet header or manifold which is of a tapered configuration. Between the inlet header and the slice are a plurality of distributor tubes which are arrayed in a tube bank. The tube bank is typically in the neighborhood of six tubes high by several hundred tubes long. The stock flows from the tapered tube inlets through each tube disposed within the tube bank. It is essential that the rate of flow of stock through each distributor tube be uniform in order that the stock exiting the lips of the slice be uniform from one edge of the forming wire to the other.
In order to achieve such constant flow rate, the inlet header or manifold is tapered in the cross-machine direction. In other words, the width of the manifold in the machine direction decreases further away from the stock inlet. The cross-sectional area of the inlet header at its narrowest is equal to the cross-sectional area of the inlet header at the stock inlet less three times the total area of the tubes opening off the header. As the flow of stock moves down the tapered header, a portion of the main flow is diverted through the tubes. Therefore, the cross-sectional area of the header is reduced as it moves in the cross-machine direction so that its area remains substantially equivalent to three times the cross-sectional area of the tubes not yet reached by the header. Thus, the cross-sectional area of the header is decreased in order to compensate for the loss of fluid volume as paper stock flows from one side of the header to the other. This change in cross-sectional area maintains the same pressure in the header in the cross-machine direction which in turn maintains the same flow through the tubes in the cross-machine direction.
Consequently, the rate of flow of stock through all of the tubes in the cross-machine direction is maintained substantially constant. However, in practice the consistency has not been sufficiently uniform to prevent some variation in paper weight or thickness in the cross-machine direction. Thus, in some paper forming headboxes actuators on the lip of the slice have been used to deform the slice lip to change the width of the slice opening in an effort to maintain a uniform paper weight across the paper web. In one recently developed system, described in U.S. Pat. No. 5,196,091 to Richard E. Hergert and incorporated herein by reference, the injection of diluting water into the headbox header or manifold adjacent to the tube inlets has been used to control the dilution of the stock in the cross-machine direction. This dilution control in turn acts to control the paper web weight or thickness. This technique in fact has resulted in the production of paper webs of more uniform characteristics.
The stock from which paper is formed contains not only paper fibers but various additives designed to improve or facilitate the production of the paper web. These additives include fillers such as clay which increase the opaqueness of the paper. Other additives include long chain polymers which aid in the retention of the filler within the paper web. Other materials combined with the stock include softening agents used with certain grades of tissue paper. Additionally, additives may be supplied which facilitate the bonding of fibers to one another, for example the starch. In the existing process for forming paper, these additives are added well before the headbox inlet header and are uniformly mixed with the stock.
Thus, while the addition of chemicals or fillers is often necessary for the formation of a particular paper web, current methods of dispersing the chemicals in the paper forming stock may be less effective than desirable because many of the additives are high molecular polymers which break down under the application of fluid shear. Thus these long chain polymers lose their effectiveness when subjected to the increasing shear which is often present in the stock as it proceeds to the head box distribution header. Other additives such as fillers would ideally not be uniformly distributed through the thickness or the z-direction of the paper web but rather be concentrated at the surfaces. This is not possible with current methods employing a single headbox and single slice.
Multi-ply webs are known to be formed employing headboxes wherein the header is divided into sections allowing stocks of different types to be simultaneously injected through a single slice to form a multi-ply web. However, these systems are designed to give webs with distinct fiber contents rather than a uniform fiber content with varying amounts of chemical additives or fillers. Further, such devices may have difficulties employing the stock dilution method discussed above in two or more headers simultaneously.
What is needed is an apparatus for varying the chemical and filler additives concentrations in the z-direction of a paper web.
SUMMARY OF THE INVENTION
The present invention is a headbox apparatus and method for injecting stock onto a forming wire for forming a web. The apparatus includes a housing which is connected to a pressurized source of stock. The housing defines a stock manifold or headbox which is tapered in the machine direction. A bank of tubes composed of a multiplicity of tubes allows stock to flow from the stock manifold to a slice for injecting stock onto a forming wire. Each tube in the tube bank extends in a plane which is substantially parallel to the direction of motion of the paper web being formed. Because each tube has a substantially constant flow of stock which progresses from the headbox manifold to the slice, the flow of stock from the slice onto the forming wire is substantially uniform in the cross-machine direction.
The tubes forming the tube bank are connected to the interior of the headbox manifold along a stock supply wall or surface. A plurality of supply conduits are connected to the plenum supply wall in a manner similar to the tubes for conducting stock to the slice. The supply conduits open between tube drain openings. The supply tubes supply chemicals and fillers to the manifold where they are immediately drawn, together with the stock, into adjacent tube ends which feed the stock and added chemicals to the slice for forming a paper web. The supply conduits are typically arrayed to supply a uniform stream of chemicals in the cross-machine direction. The tubes are also arranged to supply filler material or chemicals to the tube bank to preferentially supply chemicals to a particular location along the cross-machine axis, or to preferentially supply additives to a certain level within the forming web in the z-direction.
A typical tube bank consists of six tubes positioned one over the other with stock outlets that are deformed to form substantially rectangular openings with the tubes extending in the cross-machine direction numbering up to a few hundred. Thus, in the array formed of six tubes by a few hundred tubes, stock additives or chemicals will be added by supply conduits which extend along the entire cross-machine direction of the tube bank while being positioned adjacent to one of the six layers of tubes. If the stock additive is desired to affect the surface of the paper web being formed, the supply conduits will be adjacent to rows of tubes which will form the upper or lower layers of the paper whereas if the stock additives are to affect the interior properties of the paper web, they will be positioned near the middle of the six tubes forming the z-direction of the paper web.
It is a feature of the present invention to provide a headbox for forming a paper web which can provide controlled injection of stock modifying components in the z-direction.
It is another feature of the present invention to provide a headbox which controls base weight profile while at the same time supplying additives which are locally concentrated in a z-direction of the paper web and uniform in the cross-machine direction.
It is also a feature of the present invention to provide an apparatus and method for injecting stock additives to paper stock which does not subject the additives to excessive hydrodynamic shear before the stock is formed into a paper web.
It is an additional feature of the present invention to provide a headbox which facilitates the forming of a paper web with fiber bonding additives concentrated in the center of the through thickness of the web.
It is a further feature of the present invention to provide a headbox and method of forming which facilitates a paper web formed with fillers wherein the fillers are concentrated near the surfaces of the paper web.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the headbox apparatus of this invention.
FIG. 2 is an enlarged isometric view, partly cut away, of the headbox apparatus of FIG. 1.
FIG. 3 is a cross-sectional view of the apparatus of FIG. 1 taken along section line 3--3.
FIG. 4 is an enlarged isometric view of one of the tubes of the apparatus of FIG. 1.
FIG. 5 is a diagrammatic representation of the tapered tubes taken along section line 5--5 of FIG. 6.
FIG. 6 is a cross-sectional view of the apparatus of FIG. 1 taken along section line 6--6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to FIGS. 1-6, wherein like numbers refer to similar parts, a headbox apparatus 10 is shown in FIG. 1. As shown in FIG. 2, the headbox 10 has a housing 14 which is connected to a pressurized source 15 of stock. The housing 14 defines a tapered inlet of the stock supply manifold 16 through which stock is introduced to a tube bank 18. The tube bank 18 comprises an array of tubes 24 which are stacked alongside and one above the other. A means for introducing the emollients at selected levels within the formed paper web is provided by an arrangement of supply conduits described more fully below.
Each tube 24 extends from the supply manifold 16 to the slice chamber 30. The tube bank thus has an upstream end 20 at the manifold 16, and a downstream end 22 at the slice chamber 30. The upstream end 20 of the tube bank 18 joins the interior of the headbox manifold 16 at a stock supply wall or surface 21, shown in FIG. 2. Thus, the individual tubes 24 penetrate the stock supply wall 21 and, thus, communicate with the interior 23 of the headbox manifold 16 and are, thus, supplied with stock.
The tube bank 18 has an array of tubes 24. The array has a plurality of super-positioned rows 50 of tubes 24, generally five to seven rows, or the exemplary six rows shown in FIGS. 1, 2, and 3. Each row 50 has up to several hundred tubes 24 and extends substantially the entire length of the housing 14. The length of the housing 14 is approximately equal to the width of the paper web formed by the stock flowing through the headbox 10.
The downstream end 22 of the tube bank 18 is connected to the inlet or upstream end 32 of the slice chamber 30. The stock supplied to the slice chamber 30 passes through the slice chamber 30 and is ejected from the downstream end or lip 34 of the slice chamber 30 onto a forming wire 12, shown in FIG. 1. The rows 50 of the tube bank 18 define the width of the paper web formed on the wire 12 and each of the rows defines a portion of the through thickness or z-direction of the web. As shown in FIG. 2, trailing elements 64, long, thin hinged members disposed between rows 50 of the tube bank 18, keep the flow from the individual rows 50 separated from one another. The trailing elements 64 terminate adjacent to the lip 34 of the slice 30. The flow from each row 50 of tubes thus deposits fibers which form super-positioned, partially intermingled, strata in the z-direction of a paper web formed on the wire 12.
As shown in FIG. 3, individual rows 50 of tubes 24 provide a nearly continuous sheet of stock to the slice 30. The rows 50 of tubes 24 are super-positioned with the uppermost row 51 corresponding to the uppermost layer of fibers in the paper web formed. The lowermost row 53 corresponds to the paper fibers at the bottom of the sheet in the z-direction which are formed against the moving wire 12.
As shown in FIG. 5, six rows of individual tubes 24 are vertically arrayed and extend from the supply wall 21. The tubes 24, thus, are positioned to receive stock from the stock manifold 16. Each tube 24 in a vertical array is from a different super-positioned row 50 of the tube bank 18. A plurality of supply conduits 36 discharge emollients into the manifold 16. A single supply conduit 36 injects emollients such as starch into the manifold 16 through the stock supply wall 21.
Although conduits may be positioned at different levels within the manifold, an exemplary supply conduit 36 is shown in FIG. 5 injecting stock between two rows 50 of tubes 24. As shown in FIG. 3, a plurality of supply conduits 36 connect a source of emollients 38 to a multiplicity of emollient injection points or openings 39 between individual tubes 24 in a row of tubes 50.
The illustrated emollient injection points 39 are positioned to add emollients to the center of the paper web. Emollients which may be added to the center of the paper web would include starch. When base weight paper or liner board is formed between a twin wire former, the center of the sheet can be subject to delamination. The center of the sheet can be strengthened by the selective addition of a binding agent such as starch to the central portion of the fiber web. If the injection points 39 are positioned adjacent to the uppermost row 51, or lowermost row 53, materials such as clay fillers could be selectively added near the surfaces of the paper where they improve the surface qualities.
The openings in the wire screen 12 used in a fourdrinier forming section are such that the majority of paper fibers can pass freely through them and thus the fourdrinier wire or the twin wires of a twin wire former rely on a mat of fibers of slightly larger size which builds up first on the wires to retain subsequent fibers from the stock. Certain long chain molecular additives can improve the initial retention of fibers on the wire thus facilitating a wire with a greater open area for more ready drainage of the paper web without excessive loss of fibers through the forming wires. These chemicals, while presently added generally to the stock, if selectively injected into the portion of the stock which first comes in contact with the forming wires, should perform their function of retaining initial fibers on the wire while at the same time reducing the quantity of chemical needed, as only that portion of the stock immediately adjacent to a forming wire need contain the polymer. This reduces costs by reducing chemical feeds as well as reducing the total concentration of chemicals in the waste water. Additionally, because long chain molecules can be broken down by fluid shear, subjecting the fluid to a relatively limited amount of shear between the headbox manifold 16 and the slice lip 34 means that less chemicals are needed to be effective.
The headbox 10 is designed to produce a uniform orientation and consistency of fibers laid down in the cross-machine direction on the wire 12. This uniformity starts with an attenuator (not shown) disposed upstream relative to the headbox for damping pressure pulses caused by the stock pumping equipment. The stock then flows into the manifold 16. The manifold is tapered in a cross-machine direction, either linearly or parabolically so that the pressure within the manifold remains constant in the cross-machine direction.
The job of each tube 24, an example of which is best shown in FIG. 4, is to change the direction of the stock flow from the cross-machine direction to the machine direction. Each tube has an upstream section 54 which is generally cylindrical and which receives stock from the manifold 16. The upstream section 54 is joined at an expansion joint 61 to a flattened downstream section 60 which discharges stock onto the wire 12. The length of the upstream section 54 of the tube 24 is selected so the flow becomes completely symmetrical and aligned in the machine direction. The flow then undergoes a sudden expansion at the juncture 61 with the downstream section 60. The sudden expansion creates shear for improved fiber dispersion, and also creates head loss for cross-machine uniformity. Because flow through a pipe 24 is dependent on the entire pressure drop, a large pressure drop caused at the expansion joint 61 reduces the effect of upstream pressure variations so increasing uniformity of the flow through all of the tubes 24 in the tube bank 18.
The transition between the circular first section 54 and the circular second section 60 produces uniform and stable profiles within a short distance downstream of the expansion joint 61. The flow then smoothly transitions to a generally rectangular shaped outlet 62. The perimeter of the tube is kept constant, allowing the cross-sectional area to be decreased. The result is a tube section in which the flow accelerates, enhancing both flow stability and uniformity.
The critical parameter is the length of the downstream section 60 after the expansion joint 61. Proper length prevents a water rich, low consistency layer from building up near the tube walls.
Consistency measurements obtained by direct sampling of flow as it exits tubes of different lengths, shows that the longer the tube, the greater the consistency profile non-uniformity. The pressure drop in the tubes 24 combined with the uniform pressure profile within the manifold 16 means that the injection points 39 of the supply conduit 36 have minimal or no effect on the volumetric flows through the individual tubes 24. Further, because the injection points will preferably be evenly spaced in the cross-machine direction, any dilution effects caused by the emollient will be uniform in the cross-machine direction. Flow stability is enhanced in the slice chamber 30 by utilizing trailing elements 64 which have thicker base dimensions which limit the expansion of the flow as it enters the nozzle formed by the slice 30. For grades that are sensitive to paper orientation, it is desirable to align the flow path so that it is in line from the manifold 16 through the tube bank 18 and the slice 30.
As shown in FIG. 3, valves 88 may control the addition of emollients in the cross-machine direction from the emollient source 38. However, the valves will in general be adjusted to achieve a uniform injection of emollients in the cross-machine direction. Although the valves could be adjusted for downstream measurements of the effect produced by the emollients, they will in general remain relatively constantly actuated over time, and in many instances, valves 88 will not be required.
Although supply conduits have been shown within a single row or adjacent to two rows of tubes, two or more sets of supply conduits could be installed in a single headbox so that emollients of different types could be injected into different layers or regions in the through direction or z-direction of the paper web.
The injection of emollients could also be combined with a separate system for injecting white water to control the sheet consistency in the cross-machine direction. Such white water injection systems are described in U.S. Pat. No. 5,196,091 to Hergert, which is incorporated herein by reference. As shown in FIG. 2, a control means 40 may be installed between a source of emollient 38 and the supply conduits 36. One typical control means may be a metering pump which can supply a precisely controlled quantity at a controlled flow rate of emollient to the supply conduits 38 which inject through the injection points 39 into the manifold 16.
It should be understood that the high turbulent expansion joints 61 may facilitate the uniform mixing of the emollients with the stock flowing through the tubes 24. By utilizing the correct injection tube pattern and regulating the additive flow rates to the various injection tubes separately, the additive addition can be precisely controlled to preferentially concentrate the additives in any z-direction location in the sheet, bottom, center or top, or it can vary in the cross-machine direction to optimize the additive usage across the machine width.
Since the additives are injected directly into the headbox, the amount of fluid shear applied to the additives is minimized. This ensures minimum breakdown of high molecular weight polymers, and the maximum effectiveness of the chemicals used. Also, using several small injection tubes ensures better distribution of the emollients, and the localized mixing is improved as the region over which the additives diffuse is greatly reduced.
It should further be understood that the flow of the injection tubes can be supplied by a commonly controlled source to provide equal emollient addition at multiple injection locations. Alternatively, the additional flow rate to the various injection tubes can be regulated separately, providing the added flexibility to vary the additive addition rate in the cross-machine and z- or thickness direction for most effective emollient use. Further, it should be understood that this new method of injecting emollients which is controlled in both the z-direction and the cross-machine direction may advantageously be employed in the development of new chemical and chemical systems which cannot be utilized today because of the requirement of mixing the emollient or additive throughout the stock supply. Further, it should be understood that a parabolically tapered manifold, in one example where the manifold is nine meters long, would vary from the linear profile by approximately thirty millimeters at the point of maximum difference between the linear and the parabolic curve of the manifold.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. | A papermaking machine has a stock manifold or headbox which is tapered in the machine direction. Paper stock flows through a bank of tubes from the stock manifold to a slice for injecting stock onto a forming wire. Each tube in the tube bank extends in a plane which is substantially parallel to the direction of motion of the paper web being formed. The tubes are connected to the interior of the headbox manifold along a stock supply wall. A plurality of supply conduits are connected to the supply wall and discharge emollients such as chemicals and fillers into the manifold where they are immediately drawn, together with the stock, into adjacent tube ends which feed the stock and added chemicals to the slice for forming a paper web. | 3 |
This is a division of application Ser. No. 08/261,554, filed Jun. 17, 1994, now pending.
FIELD OF THE INVENTION
The invention relates to dispersant additives comprising polymeric amides prepared from functionalized hydrocarbon polymers reacted (e.g. derivatized) with "heavy polyamines". "Heavy polyamine" as referred to herein is a mixture of higher oligomers of ethylene amines containing essentially no tetraethylene pentamine, small amounts of pentaethylenehexamine but primarily oligomers with more than 6 nitrogens and more branching. Use of heavy polyamine allows for incorporation of greater amounts of nitrogen into the dispersant molecule than prior art amines. The polymeric amide dispersants disclosed herein are useful as additives in fuel and lubrication oils.
The term "hydrocarbon" is used herein to refer to both nonpolymeric compounds comprising hydrogen and carbon as well as materials comprising large molecules built up by the repetition of small, simple chemical units. When only several such units are linked, the resulting composition is sometimes referred to as an oligomer, whereas the linking of many units is typically referred to as a polymer; there is no "bright line" distinguishing oligomers and low molecular weight polymers. In a hydrocarbon polymer those units are predominantly formed of hydrogen and carbon. Nonpolymeric compounds typically have uniform properties such as molecular weight (M n ), although this term can be applied to both polymeric and nonpolymeric compositions. The term hydrocarbon is not intended to exclude mixtures of such compounds which individually are characterized by uniform properties.
Such hydrocarbon compounds have been reacted to form carboxyl group-containing compounds and their derivatives. Carboxyl groups have the general formula --CO--OR, where R can be H, a hydrocarbyl group, or a substituted hydrocarbyl group.
BACKGROUND OF THE INVENTION
U.S. Ser. No. 992,403 discloses amidation (derivatization) of polymers functionalized by the Koch reaction with amine and is incorporated by reference herein.
U.S. Ser. No. 261,507 Amidation of Ester Functionalized Polymers; U.S. Ser. No. 261,557, Prestripped Polymer Used to Improve Koch Reaction Dispersant Additives; U.S. Ser. No. 261,559, Batch Koch Carbonylation Process; U.S. Ser. No. 261,534, Derivatives of Polyamines With One Primary Amine and Secondary or Tertiary Amines: U.S. Ser. No. 261,560, Continuous Process for Production of Functionalized Olefins; and U.S. Ser. No. 261,558, Functionalized Additives Useful In Two-Cycle Engines, all filed Jun. 17, 1994, all contain related subject matter as indicated by their titles and are hereby incorporated by reference in their entirety for all purposes.
Polyalkenyl succinimides are a widely used class of dispersants for lubricant and fuels applications. They are prepared by the reaction of, for example, polyisobutylene with maleic anhydride to form polyisobutenyl-succinic anhydride, and then a subsequent condensation reaction with ethylene amines.
EP-A 0 475 609 Al discloses the use of "heavy polyamine" which is disclosed to be a mixture of poiyethyleneamines sold by Union Carbide Co. under the designation Polyamine HPA-X.
U.S. Pat. No. 5,230,714 discloses the use of "polyamine bottoms" derived from an alkylene polyamine mixture. "Polyamine bottoms" are characterized as having less than two, usually less than 1% by weight of material boiling below about 200° C. In the case of ethylene polyamine bottoms, the bottoms were disclosed to contain less than abut 2% by weight total diethylene triamine (DETA) or triethylene tetraamine (TETA). A typical sample of such ethylene polyamine from Dow Chemical Company, designated as "E-100" was disclosed to have a percent nitrogen by weight of 33.15 and gas chromatography analysis showed it to contain about 0.93% "Light Ends" (DETA), 0.72% TETA, 21.74% tetraethylene pentamine and 76.61% pentaethylene hexamine and higher (by weight).
U.S. Pat. No. 4,938,881 similarly discloses the use of "polyamine bottoms".
U.S. Pat. No. 5,164,101 discloses the polybutenylsuccinimide of polyamines, wherein the polyamine has a specific formula.
U.S. Pat. No. 5,114,435 discloses a polyalkylenesuccinimide prepared from a polyalkylenesuccinnic acid or anhydride reacted with a polyalkylene polyamine of a specific formula. Hexaethylene heptamine is disclosed to be a suitable amine.
U.S. Pat. No. 4,927,551 discloses a polybutenyl succinnic anhydride reacted with Dow E-100 heavy polyamine (average Mw=303 available from Dow Chemical Company).
U.S. Pat. No. 5,241,003 discloses succinimides derived from amines of a specific formula. Various suitable low cost polyethylene polyamine mixtures are disclosed to be available under various trade designations such as "Polyamine H", "Polyamine 400", "Dow Polyamine E-100" and "Dow S-1107".
SUMMARY OF THE INVENTION
The present invention relates to dispersant additives comprising polymeric amides prepared from functionalized hydrocarbon polymers reacted (e.g. derivatized) with "heavy polyamines". "Heavy polyamine" as referred to herein is a mixture of higher oligomers of ethylene amines containing essentially of no tetra ethylene pentamine, small amounts of pentaetylenehexamine but primarily oligomers with more than 6 nitrogens and more branching. The polymeric amides dispersants disclosed herein are useful as additives in fuel and lubricating oils.
A functionalized hydrocarbon of less than 500 M n wherein functionalization comprises at least one group of the formula --CO--Y--R 3 wherein Y is O or S; R 3 is aryl, substituted aryl or substituted hydrocarbyl; and --Y--R 3 has a pKa of 12 or less and wherein at least 50 mole % of the functional groups are attached to a tertiary carbon atom; and a process for producing such functionalized hydrocarbon,
Also disclosed are derivatized hydrocarbon dispersants which are the product of reacting (1) a functionalized hydrocarbon of less than 500 M n wherein functionalization comprises at least one group of the formula --CO--Y--R 3 wherein Y is O or S; R 3 is H, hydrocarbyl, aryl, substituted aryl or substituted hydrocarbyl and wherein at least 50 mol % of the functional groups are attached to a tertiary carbon atom: and (2) a nucleophilic reactant; wherein at least 80% of the functional groups originally present in the functionalized hydrocarbon are derivatized.
The present invention is directed to a dispersant composition for lubricating or fuel oil applications comprising polymers functionalized using the Koch reaction and derivatized using a "heavy polyamine".
The heavy polyamine as the term is used herein contains more than six nitrogens per molecule, but preferably polyamine oligomers containing more than seven nitrogens per molecule. Commercial dispersants are based on the reaction of carboxylic acid moieties with a polyamine such as tetraethylenepentamine (TEPA) with five nitrogens per molecule. Commercial TEPA is a distillation cut and contains oligomers with three and four nitrogens as well. Other commercial polyamines known generically as PAM, contain a mixture of ethylene amines where TEPA and pentaethylene hexamine (PEHA) are the major part of the polyamine, usually about 80%. Typical PAM is commercially available from the Dow Chemical Company under the trade name E-100 or from the Union Carbide Company as HPA-X This mixture typically consists of less than 1.0 wt. % low molecular weight amine, 10-15 wt. % TEPA's, 40-50% PEHA's and the balance hexaethylene heptamine (HEHA) and higher oligomers. Typically PAM has 8.7-8.9 milliequivalents of primary amine per gram and a total nitrogen content of about 33-34 wt. %.
It has been discovered that heavier cuts of PAM oligomers with practically no TEPA and only very small amounts of PEHA but containing primarily oligomers with more than 6 nitrogens and more extensive branching produce dispersants with improved dispersancy when compared to products derived from regular commercial PAM under similar conditions with the same polymer backbones. An example of one of these heavy polyamine compositions is commercially available from the Dow Chemical Company under the trade name of Polyamine HA-2.
HA-2 is prepared by distilling out all the lower boiling ethylene amine oligomers (light ends) including TEPA. The TEPA content is less than 1%. Only a small amount of PEHA, usually 5-15%, remains in the mixture. The rest being higher nitrogen content oligomers with greater degree of branching.
Typical analysis of HA-2 gives primary nitrogen values of 7.8 milliequivalents (meq) of primary amine per gram of polyamine. This calculates to be about an equivalent weight (EW) of 128 grams per equivalent (g/eq). The total nitrogen content is about 32.0-33.0 wt. %. Commercial PAM analyzes for 8.7-8.9 meq of primary amine per gram of PAM and a nitrogen percentage of about 33 to about 34 wt. %.
The present invention uses "heavy" ethylene polyamine which contains primarily oligomers higher than pentaethylene hexamine, to produce dispersants that are superior to dispersants made from conventional PAM which contain lower molecular weight amine oligomers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a derivatization, using a heavy polyamine of functionalized hydrocarbon polymer wherein the polymer backbone has M n ≧500, functionalisation is by groups of the formula:
--CO--Y--R.sup.3
wherein Y is O or S, and either R 3 is H, hydrocarbyl and at least 50 mole % of the functional groups are attached to a tertiary carbon atom of the polymer backbone or R 3 is aryl, substituted aryl or substituted hydorcarbyl.
Thus the functionalized polymer may be depicted by the formula:
POLY--(CR.sup.1 R.sup.2 --Co--Y--R.sup.3).sub.n (I)
wherein POLY is a hydrocarbon polymer backbone having a number average molecular weight of at least 500, n is a number greater than 0, R 1 , R 2 and R 3 may be the same or different and are each H, hydrocarbyl with the proviso that either R 1 and R 2 are selected such that at least 50 mole % of the --CR 1 R 2 groups wherein both R 1 and R 2 are not H, or R 3 is aryl substituted aryl or substituted hydrocarbyl.
As used herein the term "hydrocarbyl" denotes a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character within the context of this invention and includes polymeric hydrocarbyl radicals. Such radicals include the following:
(1) Hydrocarbon groups; that is, aliphatic, (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic, aliphatic- and alicyclic-substituted aromatic, aromatic-substituted aliphatic and alicyclic radicals, and the like, as well as cyclic radicals wherein the ring is completed through another portion of the molecule (that is, the two indicated substituents may together form a cyclic radical). Such radicals are known to those skilled in the art; examples include methyl, ethyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl, eicosyl, cyclohexyl, phenyl and naphthyl (all isomers being included).
(2) Substituted hydrocarbon groups; that is, radicals containing non-hydrocarbon substituents which, in the context of this invention, do not alter predominantly hydrocarbon character of the radical. Those skilled in the art will be aware of suitable substitutents (e.g., halo, hydroxy, alkoxy, carbalkoxy, nitro, alkylsulfoxy).
(3) Hetero groups; that is, radicals which, while predominantly hydrocarbon in character within the context of this invention, contain atoms other than carbon present in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms will be apparent to those skilled in the art and include, for example, nitrogen particularly non-basic nitrogen which would deactivate the Koch catalyst, oxygen and sulfur.
In general, no more than about three substituents or hetero atoms, and preferably no more than one, will be present for each 10 carbon atoms in the hydrocarbon-based radical.
Polymeric hydrocarbyl radicals are those derived from hydrocarbon polymers, which may be substituted and/or contain hetero atoms provided that they remain predominantly hydrocarbon in character.
The functionalized polymer may be derived from a hydrocarbon polymer comprising non-aromatic carbon-carbon double bond, also referred to as an olefinically unsaturated bond, or an ethylenic double bond. The polymer is functionalized at that double via a Koch reaction to form the carboxylic acid, carboxylic ester or thio acid or thio ester.
In the Koch process as practiced herein, a hydrocarbon or low molecular weight hydrocarbon polymer having at least one ethylenic double bond is contacted with an acid catalyst and carbon monoxide in the presence of a nucleophilic trapping agent such as water or alcohol. The catalyst is preferably a classical Bronsted acid or Lewis acid catalyst. These catalysts are distinguished from the transition metal catalysts of the type described in the prior art. The Koch reaction, as applied in the process of the present invention, can result in good yields of functionalized polymer, even 90 mole % or greater.
Koch reactions have not heretofore been applied to polymers having number average molecular weights greater than 500. The hydrocarbon polymer preferably has Mn greater than 1,000. In the Koch process a polymer having at least one ethylenic double bond is contacted with an acid catalyst and carbon monoxide in the presence of a nucleophilic trapping agent such as water or alcohol. The catalyst is preferably a classical Broensted acid or Lewis acid catalyst. These catalysts are distinguishable from the transition metal catalysts of the type described in the prior art. The Koch reaction, as applied to the present invention, may result in good yields of functionalized polymer, even 90 mole % or greater.
POLY, in general formula I, represents a hydrocarbon polymer backbone having Mn of at least 500. Mn may be determined by available techniques such as gel permeation chromatography (GPC).
POLY is derived from unsaturated polymer.
The hydrocarbons and polymers which are useful in the present invention contain at least one carbon-carbon double bond (olefinic or ethylenic unsaturation). Thus, the maximum number of functional groups per molecule (e.g., per polymer chain) is limited by the number of double bonds per molecule. Such hydrocarbons have been found to be receptive to Koch mechanisms to form carboxylic acids or derivatives thereof, using the catalysts and nucleophilic trapping agents of the present invention.
Polymers
The polymers which are useful in the present invention are polymers containing at least one carbon-carbon double bond (olefinic or ethylenic) unsaturation. Thus, the maximum number of functional groups per polymer chain is limited by the number of double bonds per chain. Such polymers have been found to be receptive to Koch mechanisms to form carboxylic acids or derivatives thereof, using the catalysts and nucleophilic trapping agents of the present invention.
Useful polymers in the present invention include polyalkenes including homopolymer, copolymer (used interchangeably with interpolymer) and mixtures. Homopolymers and interpolymers include those derived from polymerizable olefin monomers of 2 to about 16 carbon atoms; usually 2 to about 6 carbon atoms.
Particular reference is made to the alpha olefin polymers made using organo metallic coordination compounds. A particularly preferred class of polymers are ethylene alpha olefin copolymers such as those disclosed in U.S. Pat. No. 5,017,299. The polymer unsaturation can be terminal, internal or both. Preferred polymers have terminal unsaturation, preferably a high degree of terminal unsaturation. Terminal unsaturation is the unsaturation provided by the last monomer unit located in the polymer. The unsaturation can be located anywhere in this terminal monomer unit. Terminal olefinic groups include vinylidene unsaturation, R a R b C═CH 2 ; trisubstituted olefin unsaturation, R a R b C═CR c H; vinyl unsaturation, R a HC═CH 2 ; 1,2-disubstituted terminal unsaturation, R a HC═CHR b ; and tetra-substituted terminal unsaturation, R a R b C═CR c R. At least one of R a and R b is a polymeric group of the present invention, and the remaining R b , R c and R d are hydrocarbon groups as defined with respect to R, R 1 , R 2 , and R 3 above.
Low molecular weight polymers, also referred to herein as dispersant range molecular weight polymers, are polymers having Mn less than 20,000, preferably 500 to 20,000 (e.g. 1,000 to 20,000), more preferably 1,500 to 10,000 (e.g. 2,000 to 8,000) and most preferably from 1,500 to 5,000. The number average molecular weights are measured by vapor phase osmometry. Low molecular weight polymers are useful in forming dispersants for lubricant additives.
Medium molecular weight polymers Mn's ranging from 20,000 to 200,000, preferably 25,000 to 100,000; and more preferably, from 25,000 to 80,000 are useful for viscosity index improvers for lubricating oil compositions, adhesive coatings, tackifiers and sealants. The medium Mn can be determined by membrane osmometry.
The higher molecular weight materials have Mn of greater than about 200,000 and can range to 15,000,000 with specific embodiments of 300,000 to 10,000,000 and more specifically 500,000 to 2,000,000. These polymers are useful in polymeric compositions and blends including elastomeric compositions. Higher molecular weight materials having Mn's of from 20,000 to 15,000,000 can be measured by gel permeation chromatography with universal calibration, or by light scattering. The values of the ratio Mw/Mn, referred to as molecular weight distribution, (MWD) are not critical. However, a typical minimum Mw/Mn value of about 1.1-2.0 is preferred with typical ranges of about 1.1 up to about 4.
The olefin monomers are preferably polymerizable terminal olefins; that is, olefins characterized by the presence in their structure of the group --R--C═CH 2 , where R is H or a hydrocarbon group. However, polymerizable internal olefin monomers (sometimes referred to in the patent literature as medial olefins) characterized by the presence within their structure of the group: ##STR1## can also be used to form the polyalkenes. When internal olefin monomers are employed, they normally will be employed with terminal olefins to produce polyalkenes which are interpolymers. For this invention, a particular polymerized olefin monomer which can be classified as both a terminal olefin and an internal olefin, will be deemed a terminal olefin. Thus, pentadiene-1,3 (i.e., piperylene) is deemed to be a terminal olefin.
While the polyalkenes generally are hydrocarbon polyalkenes, they can contain substituted hydrocarbon groups such as lower alkoxy, lower alkyl mercapto, hydroxy, mercapto, and carbonyl, provided the non-hydrocarbon moieties do not substantially interfere with the functionalization or derivatization reactions of this invention. When present, such substituted hydrocarbon groups normally will not contribute more than about 10% by weight of the total weight of the polyalkenes. Since the polyalkene can contain such non-hydrocarbon substituent, it is apparent that the olefin monomers from which the polyalkenes are made can also contain such substituents. As used herein, the term "lower" when used with a chemical group such as in "lower alkyl" or "lower alkoxy" is intended to describe groups having up to seven carbon atoms.
The polyalkenes may include aromatic groups and cycloaliphatic groups such as would be obtained from polymerizable cyclic olefins or cycloaliphatic substituted-polymerizable acrylic olefins. There is a general preference for polyalkenes free from aromatic and cycloaliphatic groups (other than the diene styrene interpolymer exception already noted). There is a further preference for polyalkenes derived from homopolymers and interpolymers of terminal hydrocarbon olefins of 2 to 16 carbon atoms. This further preference is qualified by the proviso that, while interpolymers of terminal olefins are usually preferred, interpolymers optionally containing up to about 40% of polymer units derived from internal olefins of up to about 16 carbon atoms are also within a preferred group. A more preferred class of polyalkenes are those selected from the group consisting of homopolymers and interpolymers of terminal olefins of 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms. However, another preferred class of polyalkenes are the latter, more preferred polyalkenes optionally containing up to about 25% of polymer units derived from internal olefins of up to about 6 carbon atoms.
Specific examples of terminal and internal olefin monomers which can be used to prepare the polyalkenes according to conventional, well-known polymerization techniques include ethylene; propylene; butene-1; butene-2; isobutene; pentene-1; etc.; propylene-tetramer; diisobutylene; isobutylene trimer; butadiene-1,2; butadiene-1,3; pentadiene-1,2; pentadiene-1,3; etc.
Useful polymers include alpha-olefin homopolymers and interpolymers, and ethylene alpha-olefin copolymers and terpolymers. Specific examples of polyalkenes include polypropylenes, polybutenes, ethylene-propylene copolymers, ethylene-butene copolymers, propylene-butene copolymers, styrene-isobutene copolymers, isobutene-butadiene-1,3 copolymers, etc., and terpolymers of isobutene, styrene and piperylene and copolymer of 80% of ethylene and 20% of propylene. A useful source of polyalkenes are the poly(isobutene)s obtained by polymerization of C 4 refinery stream having a butene content of about 35 to about 75% by wt., and an isobutene content of about 30 to about 60% by wt., in the presence of a Lewis acid catalyst such as aluminum trichloride or boron trifluoride.
Also useful are the high molecular weight poly-n-butenes of U.S. Ser. No. 992,871 filed Dec. 17, 1992.
A preferred source of monomer for making poly-n-butenes is petroleum feedstreams such as Raffinate II. These feedstocks are disclosed in the art such as in U.S. Pat. NO. 4,952,739.
Ethylene Alpha-Olefin Copolymer
Preferred polymers are polymers of ethylene and at least one alpha-olefin having the formula H 2 C═CHR 4 wherein R 4 is straight chain or branched chain alkyl radical comprising 1 to 18 carbon atoms and wherein the polymer contains a high degree of terminal ethenylidene unsaturation. Preferably R 4 in the above formula is alkyl of from 1 to 8 carbon atoms and more preferably is alkyl of from 1 to 2 carbon atoms. Therefore, useful comonomers with ethylene in this invention include propylene, 1-butene, hexene-1, octene-1, etc., and mixtures thereof (e.g. mixtures of propylene and 1-butene, and the like). Preferred polymers are copolymers of ethylene and propylene and ethylene and butene-1.
The molar ethylene content of the polymers employed is preferably in the range of between about 20 and about 80%, and more preferably between about 30 and about 70%. When butene-1 is employed as comonomer with ethylene, the ethylene content of such copolymer is most preferably between about 20 and about 45 wt %, although higher or lower ethylene contents may be present. The most preferred ethylene-butene-1 copolymers are disclosed in U.S. Ser. No. 992,192, filed Dec. 17, 1992. The preferred method for making low molecular weight ethylene/α-olefin copolymer is described in U.S. Ser. No. 992,690, filed Dec. 17, 1992.
Preferred ranges of number average molecular weights of polymer for use as precursors for dispersants are from 500 to 10,000, preferably from 1,000 to 8,000, most preferably from 2,500 to 6,000. A convenient method for such determination is by size exclusion chromatography (also known as gel permeation chromatography (GPC)) which additionally provides molecular weight distribution information. Such polymers generally possess an intrinsic viscosity (as measured in tetralin at 135° C.) of between 0.025 and 0.6 dl/g, preferably between 0.05 and 0.5 dl/g, most preferably between 0.075 and 0.4 dl/g. These polymers preferably exhibit a degree of crystallinity such that, when grafted, they are essentially amorphous.
The preferred ethylene alpha-olefin polymers are further characterized in that up to about 95% and more of the polymer chains possess terminal vinylidene-type unsaturation. Thus, one end of such polymers will be of the formula POLY-C(R 11 )═CH 2 wherein R 11 is C 1 to C 18 alkyl, preferably C 1 to C 8 alkyl, and more preferably methyl or ethyl and wherein POLY represents the polymer chain. A minor amount of the polymer chains can contain terminal ethenyl unsaturation, i.e. POLY-CH═CH 2 , and a portion of the polymers can contain internal monounsaturation, e.g. POLY-CH═CH(R 1 1), wherein R 11 is as defined above.
The preferred ethylene alpha-olefin polymer comprises polymer chains, at least about 30% of which possess terminal vinylidene unsaturation. Preferably at least about 50%, more preferably at least about 60%, and most preferably at least about 75% (e.g. 75 to 98%), of such polymer chains exhibit terminal vinylidene unsaturation. The percentage of polymer chains exhibiting terminal vinylidene unsaturation may be determined by FTIR spectroscopic analysis, titration, HNMR, or C 13 NMR.
The polymers can be prepared by polymerizing monomer mixtures comprising ethylene with other monomers such as alpha-olefins, preferably from 3 to 4 carbon atoms in the presence of a metallocene catalyst system comprising at least one metallocene (e.g., a cyclopentadienyl-transition metal compound) and an activator, e.g. alumoxane compound. The comonomer content can be controlled through selection of the metallocene catalyst component and by controlling partial pressure of the monomers.
The polymer for use in the present invention can include block and tapered copolymers derived from monomers comprising at least one conjugated diene with at least monovinyl aromatic monomer, preferably styrene. Such polymers should not be completely hydrogenated so that the polymeric composition contains olefinic double bonds, preferably at least one bond per molecule. The present invention can also include star polymers as disclosed in patents such as U.S. Pat. Nos. 5,070,131; 4,108,945; 3,711,406; and 5,049,294.
The letter n is greater than 0 and represents the functionality (F) or average number of functional groups per polymer chain. Thus, functionality can be expressed as the average number of moles of functional groups per "mole of polymer". It is to be understood that the term "mole of polymer" includes both functionalized and unfunctionalized polymer, so that F which corresponds to n of Formula (I). The functionalised polymer will include molecules having no functional groups. Specific preferred embodiments of n include 1≧n>0; 2≧n>1; and n>2. n can be determined by C 13 NMR. The optimum number of functional groups needed for desired performance will typically increase with number average molecular weight of the polymer. The maximum value of n will be determined by the number of double bonds per polymer chain in the unfunctionalized polymer.
In specific and preferred embodiments the "leaving group" (--YR 3 ) has a pKa of less than or equal to 12, preferably less than 10, and more preferably less than 8. The pKa is determined from the corresponding acidic species HY--R 3 in water at room temperature.
Where the leaving group is a simple acid or alkyl ester, the functionalized polymer is very stable especially as the % neo substitution increases.
The present invention is especially useful to make "neo" functionalized polymer which are generally more stable and labile than iso structures. In preferred embodiments the polymer can be at least 60, more preferably at least 80 mole percent neofunctionalised. The polymer can be greater than 90, or 99 and even about 100 mole percent neo.
In one preferred composition the polymer defined by formula (I), Y is O (oxygen), R 1 and R 2 can be the same or different and are selected from H, a hydrocarbyl group, and a polymeric group.
In another preferred embodiment Y is O or S, R 1 and R 2 can be the same or different and are selected from H, a hydrocarbyl group a substituted hydrocarbyl group and a polymeric group, and R 3 is selected from a substituted hydrocarbyl group, an aromatic group and a substituted aromatic group. This embodiment is generally more reactive towards derivatization with the heavy amines of the present invention especially where the R 3 substituent contains electron withdrawing species. It has been found that in this embodiment, a preferred leaving group, HYR 3 , has a pKa of less than 12, preferably less than 10 and more preferably 8 or less. pKa values can range typically from 5 to 12, preferably from 6 to 10, and most preferably from 6 to 8. The pKa of the leaving group determines how readily the system will react with derivatizing compounds to produce derivatized product.
In a particularly preferred composition, R 3 is represented by the formula: ##STR2## wherein X, which may be the same or different, is an electron withdrawing substituent, T, which may be the same or different, represents a non-electron withdrawing substituent (e.g. electron donating), and m and p are from 0 to 5 with the sum of m and p being from 0 to 5. More preferably, m is from 1 to 5 and preferably 1 to 3. In a particularly preferred embodiment X is selected from a halogen, preferably F or Cl, CF 3 , cyano groups and nitro groups and p=0. A preferred R 3 is derived from 2,4-dichlorophenol.
The composition of the present invention includes the derivatized polymer which is the reaction product of the Koch functionalized polymer and the derivatizing compound (e.g., heavy amine). Derivatized polymer will typically contain at least amide. The suitability for a particular end use may be improved by appropriate selection of the polymer Mn and functionality used in the derivatised polymer as discussed hereinafter.
The Koch reaction permits controlled functionalization of unsaturated polymers. When a carbon of the carbon-carbon double bond is substituted with hydrogen, it will result in an "iso" functional group, i.e. one of R 1 or R 2 of Formula I is H; or when a carbon of the double bond is fully substituted with hydrocarbyl groups it will result in an "neo" functional group, i.e. both R 1 or R 2 of Formula I are non-hydrogen groups.
Polymers produced by processes which result in a terminally unsaturated polymer chain can be functionalized to a relatively high yield in accordance with the Koch reaction. It has been found that the neo acid functionalized polymer can be derivatized to a relatively high yield.
The Koch process also makes use of relatively inexpensive materials i.e., carbon monoxide at relatively low temperatures and pressures. Also the leaving group --YR 3 can be removed and recycled upon derivatizing the Koch functionalized polymer with the heavy amine.
The functionalized or derivatized polymers of the present invention are useful as lubricant additives such as dispersants, viscosity improvers and multifunctional viscosity improvers.
The present invention includes oleaginous compositions comprising the above functionalized, and/or derivatized polymer. Such compositions include lubricating oil compositions and concentrates.
The invention also provides a process which comprises the step of catalytically reacting in admixture:
(a) at least one hydrocarbon or hydrocarbon polymer having a number average molecular weigh to less than 500 or at least one hydrocarbon polymer having a number average molecular weight of at least about 500, and an average at least one ethylenic double bond per polymer chain;
(b) carbon monoxide,
(c) at least one acid catalyst, and
(d) a nucleophilic trapping agent selected from the group consisting of water, hydroxy-containing compounds and thiol-containing compounds, the reaction being conducted a) in the absence of reliance on transition metal as a catalyst; or b) with at least one acid catalyst having a Hammett acidity of less than -7; or c) wherein functional groups are formed at least 40 mole % of the ethylenic double bonds; or d) wherein the nucleophilic trapping agent has a pKa of less than 12.
The process of the present invention relates to a polymer having at least one ethylenic double bond reacted via a Koch mechanism to form carbonyl or thio carbonyl group-containing compounds, which may subsequently be derivatised. The polymers react with carbon monoxide in the presence of an acid catalyst or a catalyst preferably complexed with the nucleophilic trapping agent. A preferred catalyst is BF 3 and preferred catalyst complexes include BF 3 .H 2 O and BF 3 complexed with 2,4-dichlorophenol. The starting polymer reacts with carbon monoxide at points of unsaturation to form either iso- or neo-acyl groups with the nucleophilic trapping agent, e.g. with water, alcohol (preferably a substituted phenol) or thiol to form respectively a carboxylic acid, carboxylic ester group, or thio ester.
In a preferred process, at least one polymer having at least one carbon-carbon double bond is contacted with an acid catalyst or catalyst complex having a Hammett Scale acidity value of less than -7, preferably from -8.0 to -11.5 and most preferably from -10 to -11.5. Without wishing to be bound by any particular theory, it is believed that a carbenium ion may form at the site of one of carbon-carbon double bonds. The carbenium ion may then react with carbon monoxide to form an acylium cation. The acylium cation may react with at least one nucleophilic trapping agent as defined herein.
At least 40 mole %, preferably at least 50 mole %, more preferably at least 80 mole %, and most preferably 90 mole % of the polymer double bonds will react to form acyl groups wherein the non-carboxyl portion of the acyl group is determined by the identity of the nucleophilic trapping agent, i.e. water forms acid, alcohol forms acid ester and thiol forms thio ester. The polymer functionalized by the recited process of the present invention can be isolated using fluoride salts. The fluoride salt can be selected from the group consisting of ammonium fluoride, and sodium fluoride.
Preferred nucleophilic trapping agents are selected from the group consisting of water, monohydric alcohols, polyhydric alcohols hydroxyl-containing aromatic compounds and hetero substituted phenolic compounds. The catalyst and nucleophilic trapping agent can be added separately or combined to form a catalytic complex.
Following is an example of a terminally unsaturated polymer reacted via the Koch mechanism to form an acid or an ester. The polymer is contacted with carbon monoxide or a suitable carbon monoxide source such as formic acid in the presence of an acidic catalyst. The catalyst contributes a proton to the carbon-carbon double bond to form a carbenium ion. This is followed by addition of CO to form an acylium ion which reacts with the nucleophilic trapping agent. POLY, Y, R 1 , R 2 and R 3 are defined as above. ##STR3##
The Koch reaction is particularly useful to functionalize poly(alpha olefins) and ethylene alpha olefin copolymers formed using metallocene-type catalysts. These polymers contain terminal vinylidene groups. There is a tendency for such terminal groups to predominate and result in neo-type (tertiary) carbenium ions. In order for the carbenium ion to form, the acid catalyst is preferably relatively strong. However, the strength of the acid catalyst is preferably balanced against detrimental side reactions which can occur when the acid is too strong.
The Koch catalyst can be employed by preforming a catalyst complex with the proposed nucleophilic trapping agent or by adding the catalyst and trapping agent separately to the reaction mixture. This later embodiment has been found to be a particular advantage since it eliminates the step of making the catalyst complex.
The following are examples of suitable acidic catalyst and catalyst complex materials with their respective Hammett Scale Value acidity: 60% H 2 SO 4 , -4.32; BF 3 .3H 2 O, -4.5; BF 3 .2H 2 O, -7.0; WO 3 /Al 2 O 3 , less than -8.2; SiO 2 /Al 2 O 3 , less than -8.2; HF, -10.2; BF 3 .H 2 O, -11.4; -11.94; ZrO 2 less than -12.7; SiO 2 /Al 2 O 3 , -12.7 to -13.6; AlCl 3 , -13.16 to -13.75; AlCl 3 /CuSO 4 , -13.75 to -14.52.
It has been found that BF 3 .2H 2 O is ineffective at functionalizing polymer through a Koch mechanism ion with polymers. In contrast, BF 3 .H 2 O resulted in high yields of carboxylic acid for the same reaction. The use of H 2 SO 4 as a catalyst involves control of the acid concentration to achieve the desired Hammett Scale Value range. Preferred catalysts are H 2 SO 4 and BF 3 catalyst systems.
Suitable BF 3 catalyst complexes for use in the present invention can be represented by the formula:
BF.sub.3.xHOR
wherein R can represent hydrogen, hydrocarbyl (as defined below in connection with R') --CO--R', --SO 2 --R', --PO--(OH) 2 , and mixtures thereof wherein R' is hydrocarbyl, typically alkyl, e.g., C 1 to C 20 alkyl, and, e.g., C 6 to C 14 aryl, aralkyl, and alkaryl, and x is less than 2.
Following reaction with CO, the reaction mixture is further reacted with water or another nucleophilic trapping agent such as an alcohol or phenolic, or thiol compound. The use of water releases the catalyst to form an acid. The use of hydroxy trapping agents releases the catalyst to form an ester, the use of a thiol releases the catalyst to form a thio ester.
Koch product, also referred to herein as functionalized polymer, typically will be derivatized as described hereinafter. Derivatization reactions involving ester functionalized polymer will typically have to displace the alcohol derived moiety therefrom. Consequently, the alcohol derived portion of the Koch functionalized polymer is sometimes referred to herein as a leaving group. The ease with which a leaving group is displaced during derivatization will depend on its acidity, i.e. the higher the acidity the more easily it will be displaced. The acidity in turn of the alcohol is expressed in terms of its pKa.
Preferred nucleophilic trapping agents include water and hydroxy group containing compounds. Useful hydroxy trapping agents include aliphatic compounds such as monohydric and polyhydric alcohols or aromatic compounds such as phenols and naphthols. The aromatic hydroxy compounds from which the esters of this invention may be derived are illustrated by the following specific example: phenol, -naphthol, cresol, resorcinol, catechol, 2-chlorophenol. Particularly preferred is 2,4-dichlorophenol.
The alcohols preferably can contain up to about 40 aliphatic carbon atoms. They may be monohydric alcohols such as methanols, ethanol, benzyl alcohol, 2-methylcyclohexanol, beta-chloroethanol, monomethyl ether of ethylene glycol, etc. The polyhydric alcohols preferably contain from 2 to about 5 hydroxy radicals; e.g., ethylene glycol, diethylene glycol. Other useful polyhydric alcohols include glycerol, monomethyl ether of glycerol, and pentaerythritol. Useful unsaturated alcohols include allyl alcohol, and propargyl alcohol.
Particularly preferred alcohols include those having the formula R* 2 CHOH where an R* is independently hydrogen, an alkyl, aryl, hydroxyalkyl, or cycloalkyl. Specific alcohols include alkanols such as methanol, ethanol, etc. Also preferred useful alcohols include aromatic alcohols, phenolic compounds and polyhydric alcohols as well as monohydric alcohols such as 1,4-butanediol.
It has been found that neo-acid ester functionalized polymer is extremely stable due, it is believed, to stearic hindrance. Consequently, the yield of derivatized polymer obtainable therefrom will vary depending on the ease with which a derivatizing compound can displace the leaving group of the functionalized polymer.
The most preferred alcohol trapping agents may be obtained by substituting a phenol with at least one electron withdrawing substituent such that the substituted phenol possesses a pKa within the above described preferred pKa ranges. In addition, phenol may also be substituted with at least one non-electron withdrawing substituent (e.g., electron donating), preferably at positions meta to the electron withdrawing substituent to block undesired alkylation of the phenol by the polymer during the Koch reaction. This further improves yield to desired ester functionalized polymer.
Accordingly, and in view of the above, the most preferred trapping agents are phenolic and substituted phenolic compounds represented by the formula: ##STR4## wherein X, which may be the same or different, is an electron withdrawing substituent, and T which may be the same or different is a non-electron withdrawing group; m and p are from 0 to 5 with the sum of m and p being from 0 to 5, and m is preferably from 1 to 5, and more preferably, m is 1 or 2. X is preferably a group selected from halogen, cyano, and nitro, preferably located at the 2- and/or 4-position, and T is a group selected from hydrocarbyl, and hydroxy groups and p is 1 or 2 with T preferably being located at the 4 and/or 6 position. More preferably X is selected from Cl, F, Br, cyano or nitro groups and m is preferably from 1 to 5, more preferably from 1 to 3, yet more preferably 1 to 2, and most preferably 2 located at the 2 and 4 locations relative to --OH.
The relative amounts of reactants and catalyst, and the conditions controlled in a manner sufficient to functionalize typically at least about 40, preferably at least about 80, more preferably at least about 90 and most preferably at least about 95 mole % of the carbon-carbon double bonds initially present in the unfunctionalized polymer.
The amount of H 2 O, alcohol, or thiol used is preferably at least the stoichiometric amount required to react with the acylium cations. It is preferred to use an excess of alcohol over the stoichiometric amount. The alcohol performs the dual role of reactant and diluent for the reaction. However, the amount of the alcohol or water used should be sufficient to provide the desired yield yet at the same time not dilute the acid catalyst so as to adversely affect the Hammett Scale Value acidity.
The polymer added to the reactant system can be in a liquid phase. Optionally, the polymer can be dissolved in an inert solvent. The yield can be determined upon completion of the reaction by separating polymer molecules which contain acyl groups which are polar and hence can easily be separated from unreacted non-polar compounds. Separation can be performed using absorption techniques which are known in the art. The amount of initial carbon-carbon double bonds and carbon-carbon double bonds remaining after the reaction can be determined by C 13 NMR techniques.
In accordance with the process, the polymer is heated to a desired temperature range which is typically between -20° C. to 200° C., preferably from 0° C. to 80° C. and more preferably from 40° C. to 65° C. Temperature can be controlled by heating and cooling means applied to the reactor. Since the reaction is exothermic usually cooling means are required. Mixing is conducted throughout the reaction to assure a uniform reaction medium.
The catalyst (and nucleophilic trapping agent) can be prereacted to form a catalyst complex or are charged separately in one step to the reactor to form the catalyst complex in situ at a desired temperature and pressure, preferably under nitrogen. In a preferred system the nucleophilic trapping agent is a substituted phenol used in combination with BF 3 . The reactor contents are continuously mixed and then rapidly brought to a desired operating pressure using a high pressure carbon monoxide source. Useful pressures can be up to 138000 kPa (20,000 psig), and typically will be at least 2070 kPa (300 psig), preferably at least 5520 kPa (800 psig), and most preferably at least 6900 kPa (1,000 psig), and typically will range from 3450 to 34500 kPa (500 to 5,000 psig) preferably from 4485 to 20700 kPa (650 to 3,000 psig) and most preferably from 4485 to 13800 kPa (650 to 2000 psig). The carbon monoxide pressure may be reduced by adding a catalyst such as a copper compound. The catalyst to polymer volume ratio can range from 0.25 to 4, preferably 0.5 to 2 and most preferably 0.75 to 1.3.
Preferably, the polymer or hydrocarbon or low molecular weight polymer catalyst, nucleophilic trapping agent and CO are fed to the reactor in a single step. The reactor contents are then held for a desired amount of time under the pressure of the carbon monoxide. The reaction time can range up to 5 hours and typically 0.5 to 4 and more typically from 1 to 2 hours. The reactor contents can then be discharged and the product which is a Koch functionalized polymer comprising either a carboxylic acid or carboxylic ester or thiol ester functional groups separated. Upon discharge, any unreacted CO can be vented off. Nitrogen can be used to flush the reactor and the vessel to receive the polymer.
Depending on the particular reactants employed, the functionalized polymer containing reaction mixture may be a single phase, a combination of a partitionable polymer and acid phase or an emulsion with either the polymer phase or acid phase being the continuous phase.
Upon completion of the reaction, the polymer is recovered by suitable means.
When the mixture is an emulsion, a suitable means can be used to separate the polymer. A preferred means is the use of fluoride salts, such as sodium or ammonium fluoride in combination with an alcohol such as butanol or methanol to neutralize the catalyst and phase separate the reaction complex. The fluoride ion helps trap the BF 3 complexed to the functionalized polymer and helps break emulsions generated when the crude product is washed with water. Alcohols such as methanol and butanol and commercial demulsifiers also help to break emulsions especially in combination with fluoride ions. Preferably, nucleophilic trapping agent is combined with the fluoride salt and alcohols when used to separate polymers. The presence of the nucleophilic trapping agent as a solvent minimizes tranesterification of the functionalized polymer.
Where the nucleophilic trapping agent has a pKa of less than 12 the functionalized polymer can be separated from the nucleophilic trapping agent and catalyst by depressurization and distillation. It has been found that where the nucleophilic trapping agent has lower pKa's, the catalyst, i.e. BF 3 releases more easily from the reaction mixture.
As indicated above, polymer which has undergone the Koch reaction is also referred to herein as functionalized polymer. Thus, a functionalized polymer comprises molecules which have been chemically modified by at least one functional group so that the functionalised polymer is (a) capable of undergoing further chemical reaction (e.g. derivatization) or (b) has desirable properties, not otherwise possessed by the polymer alone, absent such chemical modification.
It will be observed from the discussion of formula I that the functional group is characterized as being represented by the parenthetical expression ##STR5## which expression contains the acyl group ##STR6## It will be understood that ##STR7## moiety is not added to the polymer in the sense of being derived from a separate reactant it is still referred to as being part of the functional group for ease of discussion and description. Strictly speaking, it is the acyl group which constitutes the functional group, since it is this group which is added during chemical modification. Moreover, R 1 and R 2 represent groups originally present on, or constituting part of, the 2 carbons bridging the double bond before functionalization. However, R 1 and R 2 were included within the parenthetical so that neo acyl groups could be differentiated from iso acyl groups in the formula depending on the identity of R 1 and R 2 .
Typically, where the end use of the polymer is for making dispersant, e.g. as derivatized polymer, the polymer will possess dispersant range molecular weights (Mn) as defined hereinafter and the functionality will typically be significantly lower than for polymer intended for making derivatized multifunctional V.I. improvers, where the polymer will possess viscosity modifier range molecular weights (Mn) as defined hereinafter.
Accordingly, while any effective functionality can be imparted to functionalized polymer intended for subsequent derivatization, it is contemplated that such functionalities, expressed as F, for dispersant end uses, are typically not greater than about 3, preferably not greater than about 2, and typically can range from about 0.5 to about 3, preferably from 0.8 to about 2.0 (e.g. 0.8 to 1).
Similarly, effective functionalities F for viscosity modifier end uses of derivatized polymer are contemplated to be typically greater than about 3, preferably greater than about 5, and typically will range from 5 to about 10. End uses involving very high molecular weight polymers contemplate functionalities which can range typically greater than about 20, preferably greater than about 30, and most preferably greater than about 40, and typically can range from 20 to 60, preferably from 25 to 55 and most preferably from 30 to 50.
The functionalized hydrocarbon or polymer can be used as a dispersant if the functional group contains the requisite polar group. The functional group can also enable the hydrocarbon to participate in a variety of chemical reactions. Derivatives of functionalized hydrocarbons can be formed through reaction of the functional group. These derivatized hydrocarbons may have the requisite properties for a variety of uses including use as dispersants. A derivatized hydrocarbon is one which has been chemically modified to perform one or more functions in a significantly improved way relative to the unfunctionalized hydrocarbon and/or the functionalized hydrocarbon. Representative of such functions is dispersancy in lubricating oil compositions.
The derivatized compound typically contains at least one reactive derivatizing group selected to react with the functional groups of the functionalized hydrocarbon by various reactions. Representative of such reactions are nucleophilic substitution, transesterification, salt formation, and the like. The derivatizing compound preferably also contains at least one additional group suitable for imparting the desired properties to the derivatized hydrocarbon, e.g., polar groups, at least one of the following groups: amide, imide, oxazoline, ester, and metal salt.
Derivatization by Heavy Amines
Novel dispersants of the present invention are based on the α-olefin and ethylene/α-olefin polymers as disclosed in U.S. Ser. No. 972,192 and incorporated herein by reference. These polymers can be functionalized via "ene" reaction, phenol alkylation or carbonylation via the Koch reaction. The Koch reaction is disclosed in U.S. Ser. No. 992,403 and is incorporated herein by reference. It has been found that the amine segment of the dispersant is very critical both to product performance of neo-amide dispersants and to the amination process of hindered phenyl esters.
Typical disclosures of polyamine reactants for the preparation of lubricant dispersants teach a range of nitrogens per molecule of from 1-12, a variety of spacing groups between the nitrogens, and a range of substitution patterns on the amine groups. We have discovered that dispersants derived from the preferred compositions described below exhibit surprisingly enhanced dispersancy and/or viscometric properties relative to the prior art.
Specifically, one embodiment of this invention comprises oil-soluble derivatized compositions of C 2 -C 18 α-olefin polymers or copolymers, functionalized with neo-acid/ester groups, further reacted with polyamines which contain >28% N, more preferably >30% N, e.g. >32% N, and an equivalent weight of primary amine groups of between 120-160 g/eq, more preferably 120-150 g/eq, e.g. 125-140 g/eq. Best results are obtained when the polyamines contain more than 6 nitrogen atoms per molecule on the average (more preferably >7. e.g. >8 nitrogen atoms per molecule), and more than two primary nitrogens per molecule on the average (preferably >2.2, e.g. >2.4). The ideal spacings between the nitrogens are C 2 -C 3 with C 3 preferred at the terminal ends of the polyamine.
Polyamines with these characteristics are commercially available and can be produced by distilling out the tetraethylenepentamine and most of the pentaethylenehexamine from standard polyethyleneamine mixtures. Alternatively, they could be synthesized by cyanoethylation of the primary amine groups of polyethylene or polypropylene pentamines or hexamines followed by hydrogenation.
Preferred polymer compositions are those derived from olefins of structure RHC═CH 2 where R is H or a hydrocarbon substituent containing from C 1 to C 16 with at least 30% of the olefin moieties comprising vinylidene groups.
As the molecular weight of a dispersant backbone is increased, the polar segment of the molecule becomes the limiting factor in dispersancy performance with polyamine systems of the prior art such as triethylenetetramine and tetraethylenepentamine. Increasing the stoichiometric ratio of amine to polymer raises the nitrogen content, but results in significant levels of free unreacted polyamine which is detrimental to diesel engine and elastomer seal performance. The novel preferred compositions allow the benefit of the higher hydrodynamic volumes of high molecular weight dispersant backbones to be realized without the debit of limited degree of polymerization of the backbone increases above 25 (especially above 40, e.g. above 50).
Conversion of olefin polymers to neo-acids and esters is described in U.S. Ser. No. 992,403. Derivatizations to neoamides could be carried out under standard conditions at temperatures of 150°-220° C. as described in U.S. Ser. No. 992,403. An alternative method is to carry out the reaction to 95+% yield, and then add a volatile amine such as dimethylaminopropylamine in excess to complete the reaction. The excess amine is then removed by distillation. This process has the advantage of reducing the overall cycle time because second order reactions slow down considerably at the tail end of the reaction unless one of the reactants is present in excess. The small amount of ester (5%) not converted to a high nitrogen dispersant can often be neglected.
A preferred process is the one described in commonly assigned copending application U.S. Ser. No. 261,507, filed this date herewith (Attorney Docket No. PT-1143) where low pressure is used to drive the reaction to completion by removing the leaving group being displaced during amination. The low volatility of the preferred polyamine compositions are particularly suited for this latter process. More volatile polyamines distill to some extent at the low pressures and high temperatures used in the reaction, and are not as suitable.
For example, a commercial polyamine with equivalent weight (EW) of primary amine of 115 and 33.5% N with an average of about 6 nitrogen atoms per molecule exhibits 2.5% wt. loss at 100° C. in a thermal gravimetric analysis experiment (heating rate of 5° C./min.). One of the preferred compositions of this invention (EW-130, 32.8% N, with >7 nitrogens per molecule) yields less than 1% wt. loss even at 200° C.
Generally, the amine employed in the reaction mixture is chosen to provide at least an equal number of equivalents of primary amine per equivalent of ester groups in the functionalized hydrocarbon polymer. More particularly, the total amount of amine charged to the mixture typically contains about 1 to 10, preferably about 1 to 6, more preferably about 1.1 to 2, and most preferably about 1.1 to 1.5 (e.g., 1.2 to 1.4) equivalents of primary amine per equivalent of ester groups. The excess of primary amine groups is intended to assure substantially complete conversion of the ester groups to amides.
In the process of the invention, the reaction between the functionalized hydrocarbon polymer containing ester groups (i.e., substituted alkyl ester functional groups and/or aryl ester functional groups) and the heavy polymer amine is carried out for a time and under conditions sufficient to form amide groups on the functionalized polymer with the concomitant release of hydroxy compound.
Dispersants
Dispersants maintain oil insolubles, resulting from oil use, in suspension in the fluid thus preventing sludge flocculation and precipitation. Suitable dispersants include, for example, dispersants of the ash-producing (also known as detergents) and ashless type, the latter type being preferred. The derivatized polymer compositions of the present invention, can be used as ashless dispersants and multifunctional viscosity index improvers in lubricant and fuel compositions.
Post Treatment
The derivatised polymers may be post-treated. U.S. Ser. No. 992,403 discloses processes for post treatment and is incorporated herein by reference.
Lubricating Compositions
The additives of the invention may be used by incorporation into an oleaginous material such as fuels and lubricating oils. U.S. Ser. No. 992,403 discloses the use of the additive derived from the present invention in fuels and lubricating oils and is incorporated herein by reference.
The present invention will be further understood by the following examples which include preferred embodiments. In the following examples M n and the ethylene content of the polymers were determined by carbon-13 NMR.
EXAMPLES
The following examples are representative of polymers functionalized via the Koch reaction and derivatized using heavy polyamine (HA-2).
Example 1
An ethylene/butene copolymer (46% ethylene, Mn=3300) prepared via Ziegler-Natta polymerization with zirconium metallocene catalyst and methyl alumoxane cocatalyst according to known procedures was carbonylated with carbon monoxide in the present of BF 3 and 2,4-dichlorophenol in a continuous stirred tank reactor at 50° C. The resulting ester was aminated with a prior art polyamine of 34.3% N and an equivalent weight of primary amine of 111 using a stoichiometry of 1.2 equivalents of primary amine per equivalent of ester by heating for 14-20 hours at 150°-230° C. under reflux and then removing the phenol given off by distillation. The product was diluted with base oil and borated using 7.9 parts of a 30% boric acid slurry in base oil, 118.6 parts of aminated polymer and 98 parts of base oil at 1 50° C for 1-2 hours.
After filtration, the product contained 0.52% N and 0.18% B.
Example 2
Another dispersant was prepared from the same functionalized polymer described in Example 1 by reacting with a polyamine of the present invention having 32.4% N and an equivalent weight of primary amine of 129 using a stoichiometry of 1.2 equivalents of primary amine per equivalent of ester. The amine was added to the ester at 220° C. over a period of three hours and the reaction mixture was soaked for three hours at 220° C. Excess dimethylaminopropylamine (1.5 equivalent per equivalent of original ester) was then added and the reaction mixture was soaked for a further three hours and then stripped to remove the excess amine. The product was diluted with base oil, and borated as above with 11.2 parts of a 30% boric acid slurry per 140 parts of aminated polymer and 110.4 parts of base oil to give a product containing 0.57% N and 0.26% B after filtration.
Example 3
Another dispersant was prepared from an ethylene/butene copolymer (35% ethylene, Mn=4000) which was carbonylated to a dichlorophenyl ester in a batch reactor. Amination was performed with a polyamine of the present invention of 32.8% N and equivalent weight of primary amine of 131 using a stoichiometry of 1.4 equivalents of primary amine per equivalent of ester 300° C. for 8 hours at a pressure of 24 mm removing the phenol as it formed. Last traces of phenol were distilled by stripping for an additional hour with nitrogen at 200° C. at atmospheric pressure. The product was diluted and borated using 1.33 parts of a 30% boric acid slurry in base oil, 16.4 parts of aminated polymer and 13.5 parts of base oil as above yielding a product containing 0.72% N and 0.21% B.
Example 4
A dispersant was prepared from an ethylene/butylene copolymer (51% E, Mn=5500) which was carbonylated to a dichlorophenyl ester as in Example 7. Amination was performed with the same polyamine and stoichiometry as Example 7 at 200° C. for 12 hours at a pressure of 2-4 mm. After stripping residual phenol for an additional hour with nitrogen, the product was diluted with 1.1 parts of base oil per part of aminated polymer and filtered to give a product with 0.48% N.
Examples 5-6
Two 5W30 oils were formulated incorporating the dispersants of Example 1 and Example 2 along with the detergents, antioxidants, anti-wear agents, etc. typically used in a passenger car motor oil. The same additive components and treat rates of active ingredient were used in each case except that in Oil A the dispersant of Example 1 was used and in Oil B the dispersant of Example 2 was used. The dispersant in Oil B was also blended at a reduced concentration relative to that of Oil A (95%). The kinematic viscosities at 100° C. and the ccs viscosities at -25° C. were then adjusted to equivalent values by adjusting the amount of ethylene propylene viscosity modifier and base stock. Despite the fact that Oil B contained less active dispersant than Oil A, it required less viscosity modifier (92%) to reach the same kinematic viscosity target.
Examples 7-8
The two oils of Examples 5-6 were compared in the standard ASTM sequence V-E engine test which is an industry measure of dispersant performance. Oil B, despite having less dispersant, equaled or exceeded the performance of Oil A in every category related to dispersant performance:
______________________________________OIL AV SLUDGE PSV AV VARNISH______________________________________A 9.0 6.7 5.8B 9.0 7.2 6.1______________________________________
Average sludge, piston skirt varnish (PSV) and average varnish are merit ratings with the larger numbers being better.
Table 1 shows results of experimental dispersants derived from heavy amine in a typical SAE 10W30 lubricant oil formulation using Exxon basestocks. When compared to a reference oil the formulations tested showed a marked improvement in both sludge and varnish performance as measured in the ASTM Sequence V-E engine test. Average Sludge, Varnish and Piston Skirt Varnish are merit ratings with the larger numbers being better. In addition, the results demonstrated this improved performance at equal or reduced treat rates from the reference. Using the experimental dispersant the viscosity modifier treat rate as required to meet SAE 10W30 visiometric targets was also reduced.
TABLE 1______________________________________SAE 10W30 LUBRICATING OIL USING EXXON BASESTOCKS Example A Example B Example C Experimental Experimental ExperimentalDispersant Comparative with Heavy with Heavy with HeavyType Reference Polyamine Polyamine Polyamine______________________________________Dispersant 5.77 5.77 4.62 5.17Treat Rate @50% Al MassV-E EngineTest ResultsAvg. Sludge 9.07 9.43 9.47 9.41Avg. Varnish 5.12 6.74 6.75 6.72Piston Skirt 6.68 6.95 6.68 7.06VarnishViscosity 6.0 2.0 1.5 2.0ModifierRequiredMass %Kinematic 10.45 10.39 10.60 10.81Viscosity @100° C.Cold Cranking 3249 3276 3262 3376Simulator(CCS) @-20° C.______________________________________ | A Koch functionalized product, which is the reaction product of at least one hydrocarbon with carbon monoxide and a nucleophilic trapping agent is derivatized with a heavy polyamine. A heavy polyamine is a mixture of polyamines comprising small amounts of lower polyamine oligomers such as tetraethylene pentamine and pentahexamine but primarily oligomers with more than 6 nitrogens and more extensive branching. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to underbed thread trimmer mechanisms for sewing machines.
2. Description of the Prior Art
Underbed thread trimmers for simultaneously trimming both the needle and the bobbin threads are well known in the prior art. Prior art thread trimmers have incorporated combinations of cams and solenoids for drawing a thread against a cutting surface. Many of the known thread trimming mechanisms are bulky and require numerous moving parts to effectuate their purpose. See for example U.S. Pat. No. 3,359,933 of Dec. 26, 1967 to Bono, and U.S. Pat. No. 3,776,161 of Dec. 4, 1973 to Papajewski et al. The area surrounding a loop taker is generally confined and occupied by the drive means required for the loop taker and associated instrumentalities. Thread trimmer mechanisms, which must be located in close proximity to the loop taker, must therefore be compact in size. An additional desirable feature is that they not be prone to jamming. A further constraint is placed on the size and complexity of the thread trimmer mechanism if it is designed to be contained within the feeding post of a post type sewing machine wherein the feeding post is especially prone to crowding of components. See, for example, U.S. Pat. No. 3,371,633 to Hedegaard which shows a thread cutting device adapted for use within the feeding post of a post type sewing machine. An additional limitation stems from the desire to utilize a thread trimmer which will cooperate with the loop taker shaft to provide the driving power for conducting the thread cutting operation, but which will also provide a long excursion of the thread severing means to insure that sufficient thread is withdrawn prior to the thread cutting operation to allow a proper and safe lock stitch to be formed during the next sewing cycle.
SUMMARY OF THE INVENTION
One object of this invention is to provide an underbed thread trimmer which will fit within the feeding post of a post type sewing machine.
Another object of this invention is to provide an underbed thread trimmer which is driven by the rotation of the loop taker shaft of a post type sewing machine.
It is also an object of this invention to provide an underbed thread trimmer whose operating cycle is easily adjusted to the operating cycle of the loop taker.
An additional object of this invention is to provide as a component of the underbed thread trimmer a thread catcher element which engages the needle and bobbin threads when the loop formed by the needle thread is at its widest diameter.
An additional object of this invention is to provide an underbed thread trimmer which severs the needle thread without unfavorably influencing the bobbin thread when it is pulled, thereby insuring the proper starting conditions for a new sewing cycle.
The disclosed objects and other advantages of this invention are obtained by an underbed thread trimming mechanism which is adapted to be contained within the feeding post of a post type sewing machine and which is driven by the rotation of the loop taker drive shaft. A solenoid is incorporated into the drive means to initiate operation of the thread trimming mechanism at the command of the machine operator. The loop taker shaft drives a thread handling disc-like member through a combination of cams and levers. Means are incorporated into the drive mechanism to insure that the thread trimmer is returned to its initial operating position upon completion of the thread trimming cycle. The thread handling member is disposed in close arcuately pivotal relation to the loop taker and contains a thread catcher which operatively engages the needle and bobbin threads at the commencement of the thread trimming cycle. A thread cutting knife is fixed to the feeding post and is situated in covering relation to the thread handling member. The thread cutting knife contains a notched finger which cooperates with the thread catcher to position the needle and bobbin threads so that they may be drawn across the knife surface. The thread handling member is linked to the rotary loop taker shaft by a drive means which permits the member to pivot through a sufficient arc to insure that an adequate length of needle and bobbin thread are withdrawn prior to being severed by the thread cutting knife. A combination of cams and followers are driven by the loop taker shaft to permit the invention to be compactly contained within the interior of the feeding post of a post type sewing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects of this invention will be evident from an understanding of the preferred embodiment which is hereinafter set forth in such detail as to enable those skilled in the art to readily understand the function, operation, construction, and advantages of it when read in conjunction with the accompanying drawings in which:
FIG. 1 is a cross-section view of the feeding post of a post type sewing machine having the underbed thread trimmer mechanism of this invention applied thereto;
FIG. 2 is a side view of a portion of the post type sewing machine shown in FIG. 1 taken through section line 2--2 shown in FIG. 1;
FIG. 3 is an isometric view of the underbed thread trimmer mechanism;
FIG. 4 is an isometric view of the cams and follower pins which cooperate to effectuate the operation of the underbed thread trimmer;
FIG. 5 is a top view of the loop taker of a post type sewing machine with the thread handling member and thread cutting knife of this invention applied thereto, and showing the position of the needle and bobbin threads just prior to being engaged by the thread catcher of the thread handling member; and
FIG. 6 is a top view of the loop taker mechanism after the needle and bobbin threads have been severed, showing the position of the thread catcher disposed on the thread handling member and the severed threads, and also showing the cooperation between the thread cutting finger mounted on the thread handling member and the knife surface on the thread cutting knife.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawings shows a feeding post 10 of a post type sewing machine to which the underbed thread trimmer mechanism of this invention may be applied. Journalled in the post 10 is a loop taker shaft 14 which has a loop taker 12 attached at one end thereof and which is driven by the loop taker shaft 14 in timed relation to the reciprocation of the needle bar 16.
A bracket 18 is attached to the feeding post 10 with conventional fastener means such as screws 20. The bracket 18 has an upper bracket extension 22 which forms an extension of the bracket 18 through the shoulder 24. As best illustrated in FIG. 3, a slot 26 is contained in the shoulder 24 to receive a driving member 28. The upper bracket extension 22 contains a journal 30, having a bore 32 for rotatably mounting a disc-like thread handling member 34 with conventional fastener means such as a screw 36. The member 34 is substantially circular about a major portion thereof and has a thread catcher 38 disposed on its circumference and projecting outwardly from the face adjacent the upper bracket extension 22. A thread cutting finger 40 is also disposed on the circumference of the member 34 and is situated behind the thread catcher 38, and on the opposite face of the member 34.
A thread cutting knife 42 is shown mounted on the feeding post 10 with a plate 44 and conventional fastener means such as screws 46 in covering relation to the member 34. The thread cutting knife 42 contains a knife surface 48 for severing needle and bobbin threads drawn against it. The thread cutting knife 42 also has a notched finger 50 disposed in spaced relation to the disc-like member 34 for trapping needle and bobbin threads and restraining them until they are engaged by the thread catcher 38 of the disc-like thread handling member. FIG. 6 best shows the cooperation of the thread cutting finger 40 and the notched finger 50 in catching the needle and bobbin threads and restraining them until they are drawn across and severed by the knife surface 48.
The driving member 28 is pivotally attached to the thread handling disc 34 by a shaft 52, whereby reciprocal motion of the driving member 28 will be converted into arcuate reciprocation of the member 34 about the thread handling disc journal 30. The driving member 28 translates in the slot 26 of the shoulder 24 which joins the bracket 18 and the upper bracket extension 22.
The operation of the underbed thread trimmer is initiated by electrially energizing a solenoid 54 which causes a solenoid plunger 56 to retract downward into the body of the solenoid 54. The downward movement causes a tripping pawl 58 to arcuately rotate about a mounting shaft 60. The arcuate rotation of the tripping pawl 58 results in the application of force by an extension tab 62 of the tripping pawl against the backward pressure normally exerted by a return spring 64. The resultant forward biasing of the return spring 64 urges an axially movable follower pin 66 to axially translate through a bore 68 in a swivel lever 70 until its head 72 contacts the track contained on the face of a lower cam 74.
FIG. 4 best illustrates the relation of a fixed follower pin 76 and the axially movable follower pin 66 and an upper cam 78 and the lower cam 74. The engagement of the head 72 of the axially movable follower pin 66 against the track contained in the face of the lower cam 74 causes the swivel lever 70 to pivot about a bearing pin 80 in response to the counterclockwise rotation of the lower cam 74 by the loop taker shaft 14. The pivoting of the swivel lever 70 is transmitted to the thread handling member 34 by the driving member 28 which is pivotally connected to the swivel lever 70 by a driving member pin 82 and pivotally to the thread handling disc 34 by the shaft 52.
The swivel lever 70 continues to pivot about the bearing pin 80 until the fixed follower pin 76 is pivoted into contact with the track contained in the face of the upper cam 78. Shortly before the time that the fixed follower pin 76 first contacts the track of the upper cam 78, the head 72 of the axially movable follower pin 66 will be so situated to be at a void in the face of the lower cam 74. The axially movable follower pin 66 will then be retracted from contact with the lower cam 74 by the tension of the return spring 64 which will urge its head 72 to axially translate backward until it contacts the swivel lever 70. The lower cam 74 will thereafter, and until the next initiation of the thread cutting cycle, be free to rotate in spaced relation to the head 72 of the axially movable follower pin 66.
The continued rotation of the upper cam 78 which is drivingly in contact with the fixed follower pin 76 will cause the swivel lever 70 to reverse its pivotal direction about the bearing pin 80. The reversal of direction of pivoting of the swivel lever 70 provides a reversal in the direction of translation of the driving member 28 which consequently results in a reversal in the direction of arcuate rotation of the member 34. The member 34 thereafter continues its backward rotation until the fixed follower pin 76 is driven out of contact with the upper cam 78 by the movement of the upper cam 78 at which time the fixed follower pin 76 will be located in the free space between the two cams. The underbed thread trimmer will thereby be made ready for the initiation of the next thread trimming cycle and will be uninfluenced by normal rotation of the loop taker shaft.
The preferred embodiment of a driving mechanism which may be used to drive the underbed thread trimmer of this invention has thus been briefly described. A more complete description may be had by reference to the copending application of R. Papajewski which is owned by the common assignee of the present invention.
FIGS. 5 and 6 show the cooperation between the thread handling disc-like member 34, the thread cutting knife 42, and the loop taker 12 to effectuate the purposes of this invention. FIG. 5 is a representation of the positions of the cooperating elements just after the underbed thread trimmer has commenced operation, showing a needle thread 84 and a bobbin thread 86 as they emerge from a work piece 88 and cooperate with the loop taker 12. Rotation of the loop taker 12 proceeds in a clockwise direction. The needle thread 84 is shown in FIG. 5 just before it is cast off by the loop taker 12, which occurs when the loop formed in the needle thread 84 by the loop taker 12 passing therethrough is at its largest diameter. The thread catcher 38, which projects outwardly from the face of the thread handling member 34, engages the needle and bobbin threads by being driven counterclockwise (which is illustrated in FIGS. 5 and 6 as toward the left) by the driving member 28 and by further rotation of the thread handling member 34 sweeps them to the notch formed between the intersection of the thread cutting finger 40 and the thread handling member 34 where they are fixedly restrained. The thread handling member 34 rotates in a direction which causes the thread cutting finger 40 and the restrained threads to move toward the knife surface 48 disposed on the thread cutting knife 42.
FIG. 6 shows the thread handling member 34 rotatably displaced from the position shown in FIG. 5. The bobbin thread 86 is shown fixedly held by the notched finger 50 and the thread cutting finger 40. The needle thread 84 and the bobbin thread 86 are restrained in the notch formed between the thread cutting finger 40 and the thread handling member 34 while they are drawn beneath the knife surface 48 by the rotation of the thread handling member 34. The knife surface 48 is spaced in covering relation to the circumference of the thread handling member 34 and is so disposed to be capable of severing a thread that passes between the knife surface 48 and the circumference of the thread handling member 34. The knife surface 48 severs the needle thread 84 and the bobbin thread 86 as they are drawn under the knife surface by the rotary motion of the thread handling member 34.
After the thread handling member 34 has been sufficiently moved to cause the needle and bobbin threads trapped between the thread handling member 34 and thread cutting finger 40 to be severed by the knife surface 48, the fixed follower pin 76 engages the track on the face of the upper cam 78. Shortly before the upper cam 78 rotates sufficiently to contact the fixed follower pin 76, the axially movable follower pin 66 moves to a void on the face of the lower cam 74. The spring force of the return spring 64 retracts the axially movable follower pin 66 from further contact with the cam 74 and allows it to assume a position in spaced relation to the cam. The continued rotation of the loop taker shaft 14 causes the fixed follower pin 76 to engage the track located on the upper cam 78. As the upper cam 78 rotates, the swivel lever 70 is forced to pivot about the bearing pin 80 as the fixed follower pin 76 is pushed toward the free space between the upper cam 78 and the lower cam 74. The pivoting of the swivel lever 70 causes the driving member 28 to retract from its maximum extended position and consequently causes the thread handling member 34 to reverse its rotation about the journal 30. The thread handling member 34 ceases to rotate when the fixed follower pin 76 enters the free space between the cams 78 and 74, thereby disengaging the thread trimmer driving mechanism from the loop taker shaft. The underbed thread trimmer is thereafter available to commence another thread trimming cycle.
It should be apparent that numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. | An underbed thread trimmer mechanism for severing the needle and bobbin threads upon completion of a sewing operation. Operation of the thread trimmer may be selectively initiated by operator command. A plurality of cams and members cooperate to transfer power from a loop taker shaft to a thread handling disc-like member situated in close proximity to the sewing machine loop taker. A thread cutting knife is disposed in covering relation to the thread handling member and cooperates with the thread handling member to trap the needle and bobbin threads and direct them to a knife surface of the thread cutting knife where they are severed. The mechanism that drives the thread trimmer resets itself at the completion of the thread cutting cycle. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/112,928, filed Mar. 29, 2002, pending, which is a divisional of application Ser. No. 09/829,161, filed Apr. 9, 2001, pending, which is a divisional of application Ser. No. 09/388,031, filed Sep. 1, 1999, pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to the field of semiconductor device design and fabrication. Specifically, the invention relates to methods for manufacturing metallization structures in integrated circuit devices and the resulting structures.
[0004] 2. State of the Art
[0005] Integrated circuits (ICs) contain numerous individual devices, such as transistors and capacitors, that are interconnected by an intricate network of horizontal and vertical conductive lines commonly termed “interconnects.” Exemplary interconnect structures are disclosed in U.S. Pat. Nos. 5,545,590, 5,529,954, 5,300,813, 4,988,423, and 5,356,659, each of which patents is hereby incorporated herein by reference.
[0006] Aluminum interconnect structures are decreasing in size and pitch (spacing), as the industry trend continues toward, and includes, submicron features and pitches. The resultant reduction in structure sizes leads to numerous reliability concerns, including electromigration and stress voiding of the interconnect structures.
[0007] Stress notches (also known as stress voids) on the surface of conductive interconnect structures are of concern because the voids or notches degrade reliability and device performance. Stress notches, when formed in a conductive line, may render the line substantially discontinuous and unable to effectively transmit a signal. Stress notches at a grain boundary are extremely detrimental, as they may propagate along the boundary and sever the conductive line completely.
[0008] Stress notches are also undesirable because they can alter the resistivity of a conductive line and change the speed at which signals are transmitted. Resistivity changes from stress notching are especially important as line dimensions shrink, because notching in a submicron conductive line alters resistivity more than notching in a larger line with its consequently greater cross-sectional area. Thus, the ever more stringent pitch sizing and higher aspect ratios (height to width of the structure or feature) sought by practitioners in the art have imitated considerable stress voiding concerns.
[0009] It is believed that stress notching results from both structural and thermal stresses between conductive lines and adjacent insulating and passivation layers. Kordic et al., Size and Volume Distributions of Thermally Induced Stress Voids in AlCu Metallization, Appl. Phys. Lett., Vol. 68, No. 8, 19 Feb. 1996, pp. 1060-1062, incorporated herein by reference, describes how stress voids begin at the edge of a conductive line where the density of the grain boundaries is largest. As illustrated in FIG. 12 herein, stress notches form at the exterior surfaces and surface intersections of the conductive lines in order to relieve areas of high stress concentration. The notches may then propagate into, and across, the interior of the conductive line until the line becomes disrupted, cracked, and/or discontinuous.
[0010] Aluminum (Al) and Al alloy (such as Al/Cu) lines are especially susceptible to stress notching because of both the thermal expansion mismatch between Al and adjacent layers and the relatively low melting point of Al. As the temperature changes, stresses are induced in Al or Al alloy lines because aluminum's coefficient of thermal expansion (CTE) differs from the CTE of the materials comprising the adjacent layers. To relieve these stresses, Al atoms migrate and form stress notches. Further, because Al has a low melting point, Al atoms migrate easily at low temperatures and aggravate a tendency toward stress notch formation.
[0011] Several methods have been proposed to reduce stress notching. One proposed method uses a material less susceptible to stress notching, such as copper (Cu) or tungsten (W), in the conductive line. Using Cu in conductive lines, however, has in the past resulted in several problems. First, copper is difficult to etch. Second, adhesion between copper and adjacent insulating layers is poor and thus poses reliability concerns. Third, adding Cu to Al lines may reduce stress notching, but beyond a certain Cu concentration, device performance may begin to degrade. Fourth, as conductive line geometries shrink, adding Cu to Al lines seems less effective in reducing stress notching. Finally, even using Cu interconnects in the manner employed in the prior art can still lead to notching effects, especially at 0.1 μm geometries and below since, at such dimensions, line widths have become so small that any imperfection can cause openings. Using W in Al conducting lines is also undesirable—W has a high resistivity and, therefore, reduces signal speed.
[0012] Another proposed method to reduce stress notching modifies how the layers adjacent conductive lines (e.g., insulating and passivation layers) are formed. This method has focused, without notable success, on the rate, temperature, and/or pressure at which the adjacent layers are deposited, as well as the chemical composition of such layers.
[0013] Yet another proposed method to reduce stress notching comprises forming a cap on the conductive lines. Such caps can be formed from TiN, W, or Ti—W compounds. These materials have higher melting points than Al and, therefore, have a higher resistance to stress notching. A disadvantage in using such caps, however, is that additional process steps, such as masking steps, are required.
[0014] U.S. Pat. No. 5,317,185, incorporated herein by reference, describes still another proposed method for reducing stress notching. This patent discloses an IC device having a plurality of conductive lines where the outermost conductive line is a stress-reducing line. This stress-reducing line is a nonactive structure which reduces stress concentrations in the inner conductive lines.
BRIEF SUMMARY OF THE INVENTION
[0015] The present invention relates to a metallization structure for semiconductor device interconnects comprising a substrate having a substantially planar upper surface, a metal layer disposed on a portion of the substrate upper surface, a conducting layer overlying the metal layer, and metal spacers flanking the sidewalls of the conducting layer and the underlying metal layer. The metal layer and metal spacers do not encapsulate the conducting layer. The substrate upper surface is preferably a dielectric layer. The conducting layer preferably comprises aluminum or an aluminum-copper alloy, but may also comprise copper. When the conducting layer comprises Al, the metal layer and metal spacer preferably comprise titanium, such as Ti or TiN. An optional dielectric layer, preferably silicon oxide, may be disposed on the conducting layer. When the optional dielectric layer is present, the metal spacer extends along the sidewall of the dielectric layer.
[0016] The present invention also relates to a metallization structure comprising a substrate having a metal layer disposed thereon, a dielectric layer having an aperture therethrough disposed on the substrate so the bottom of the aperture exposes the upper surface of the metal layer, at least one metal spacer on the sidewall of the aperture, and a conducting layer filling the remaining portion of the aperture. The metal layer and metal spacer preferably comprise titanium, such as Ti or TiN. At least one upper metal layer may be disposed on the conducting layer.
[0017] The present invention further relates to a method for making a metallization structure by forming a substantially planar first dielectric layer on a substrate, forming a metal layer over the first dielectric layer, forming a conducting layer over the metal layer, forming a second dielectric layer over the conducting layer, removing a portion of the second dielectric layer, conducting layer, and metal layer to form a multi-layer structure, and forming metal spacers on the sidewalls of the multi-layer structure. The process optionally removes both the second dielectric layer portion of the multi-layer structure and the laterally adjacent portions of the metal spacers.
[0018] The present invention additionally relates to a method for making a metallization structure by forming a substrate comprising a metal layer disposed thereon, forming a dielectric layer comprising an aperture on the substrate so the bottom of the aperture exposes the upper surface of the metal layer, forming a metal spacer on the sidewall (in the case of a via) or sidewalls (in the case of a trench) of the aperture, and forming a conducting layer in the remaining portion of the aperture. At least one upper metal layer may optionally be formed on the conducting layer.
[0019] The present invention also relates to a method for making a metallization structure by forming a substrate comprising a metal layer on the surface thereof, forming on the substrate a dielectric layer comprising an aperture so the bottom of the aperture exposes the surface of the metal layer, forming a conducting layer in the aperture, forming an upper metal layer overlying the dielectric layer and the aperture, removing the portions of the upper metal layer overlying the dielectric layer, removing the dielectric layer, removing the portions of the metal layer not underlying the aperture to form a multi-layer metal structure, and forming a metal spacer on the sidewall or sidewalls of the multi-layer metal structure.
[0020] The present invention provides several advantages when compared to the prior art. One advantage is that thermally induced stress voids are reduced because the metal layer and metal spacer comprise materials exhibiting good thermal-voiding avoidance characteristics. Another advantage is that the size of conductive lines can be shrunk further in comparison to dimensions achievable by conventional processes, since only one additional deposition and etch step, without an additional masking step, is needed to form the metallization structure. Shrinking of conductive lines is necessary as device geometries decrease to less than 0.1 μm. At these small geometries, even small notches can significantly decrease conductivity.
[0021] The invention also specifically includes semiconductor devices including the inventive metallization structures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] The present invention, in part, is illustrated by the accompanying drawings in which:
[0023] FIGS. 1, 2 , 3 a , and 3 b illustrate cross-sectional views of one process of forming a metallization structure, and the structure formed thereby, according to the invention;
[0024] FIGS. 4, 5 , 6 , 7 a , and 7 b illustrate cross-sectional views of another process of forming a metallization structure, and the structure formed thereby, according to the invention;
[0025] FIGS. 8 and 9 illustrate cross-sectional views of yet another process of forming a metallization structure, and the structure formed thereby, according to the invention;
[0026] FIGS. 10 and 11 illustrate cross-sectional views of still another process of forming a metallization structure, and the structure formed thereby, according to the invention; and
[0027] FIG. 12 illustrates a partial cross-sectional, perspective view of a conventional, prior art metallization structure exhibiting stress voids or notches.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Generally, the present invention relates to a metallization structure for interconnects and semiconductor devices including same. Specifically, the present invention reduces stress voiding, especially thermally induced stress voiding, in conducting lines. The metallization structures described below exemplify the present invention without reference to a specific device because the inventive process and structure can be modified by one of ordinary skill in the art for any desired device.
[0029] The following description provides specific details, such as material thicknesses and types, in order to provide a thorough description of the present invention. The skilled artisan, however, would understand that the present invention may be practiced without employing these specific details. Indeed, the present invention can be practiced in conjunction with conventional fabrication techniques employed in the industry.
[0030] The process steps described below do not form a complete process flow for manufacturing IC devices. Further, the metallization structures described below do not form a complete IC device. Only the process steps and structures necessary to understand the present invention are described below.
[0031] One embodiment of a process and resulting metallization structure of the present invention is illustrated in FIGS. 1, 2 , 3 a , and 3 b . This embodiment may be characterized as a predominantly “subtractive” process, in comparison to the second embodiment discussed hereinafter, in that portions of superimposed material layers are removed to define the interconnect structure features, such as lines. As shown in FIG. 1 , a portion of semiconductor device 2 includes substrate 4 with overlying first dielectric layer 6 . Substrate 4 may be any surface suitable for integrated circuit device formation, such as a silicon or other semiconductor wafer or other substrate, and may be doped and/or include an epitaxial layer. Substrate 4 may also be an intermediate layer in a semiconductor device, such as a metal contact layer or an interlevel dielectric layer. Preferably, substrate 4 is a silicon wafer or bulk silicon region, such as a silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) structure.
[0032] First dielectric layer 6 may comprise any dielectric material used in IC device fabrication. Examples of such dielectric materials include silicon oxide, silicon nitride, silicon oxynitride, silicon oxide containing dopants such as boron (B) or phosphorus (P), organic dielectrics, or a layered dielectric film of these materials. Preferably, first dielectric layer 6 is silicon oxide or borophosphosilicate glass (BPSG). First dielectric layer 6 may be formed by any process yielding the desired physical and chemical characteristics, such as thermal oxidation, thermal nitridation, or vapor deposition.
[0033] Overlying first dielectric layer 6 is metal layer 8 . One or more individual metal layers may be used as metal layer 8 . For example, if two superimposed metal layers are employed (represented by the dashed line in metal layer 8 ), an adhesion-promoting metal layer can be a first, lower portion of metal layer 8 on first dielectric layer 6 and a stress-reducing layer can be a second, upper portion of metal layer 8 . Other metal layers might be included for other functions, such as a layer for reducing electromigration. Preferably, a single metal layer is used as metal layer 8 , especially when the single layer can reduce electromigration, function as an adhesion-promoting layer, and function as a stress-reducing layer. If two metal layers are employed, the first, upper metal layer may, for example, comprise tantalum, titanium, tungsten, TaN, or TiN and the second, lower metal layer overlying first dielectric layer 6 may, for example, comprise TiN, TiW, WN, or TaN.
[0034] Metal layer 8 includes not only metals, but their alloys and compounds (e.g., nitrides and silicides). For example, a metal layer containing titanium might also contain nitrogen or silicon, such as titanium nitride or titanium silicide. Any metal, metal alloy, or metal compound can be employed in metal layer 8 , provided it exhibits the characteristics described above, either alone or when combined with other metal layers. Examples of metals that can be employed in metal layer 8 include cobalt (Co), Ti, W, Ta, molybdenum (Mo), and alloys and compounds thereof, such as TiW or TiN. Preferably, metal layer 8 comprises titanium. Titanium is a good adhesion layer and serves as a stress-reducing layer since Ti exhibits good thermal voiding resistance characteristics.
[0035] Metal layer 8 is deposited or otherwise formed by any process used in IC device fabrication. For example, metal layer 8 may be deposited by chemical vapor deposition (CVD) or physical vapor deposition (PVD) techniques, depending on the characteristics required of the layer. As used herein, the term “CVD techniques” encompasses, without limitation, plasma-enhanced CVD, or PECVD. Preferably, when metal layer 8 is Ti, this layer is formed by sputtering (a form of PVD) a film of Ti. If metal layer 8 is a metal nitride, it may be formed, for example, by depositing the metal in a nitrogen-containing atmosphere or by depositing the metal and annealing in a nitrogen-containing atmosphere. If metal layer 8 is a metal silicide, it may be formed, for example, by first depositing either the metal layer or a silicon layer, then depositing the other, and heating to react the two layers and form the silicide. If metal layer 8 is a metal alloy, it may be formed by any process suitable for depositing the metal alloy. For example, either sputtering or CVD techniques can be employed.
[0036] Conducting layer 10 is then formed over metal layer 8 . Conducting layer 10 may comprise any conducting material used in IC device fabrication. Preferably, conducting layer 10 comprises a conducting metal, such as Al, optionally containing other elements such as Si, W, Ti, and/or Cu. More preferably, conducting layer 10 is an aluminum-copper alloy. Conducting layer 10 may also be formed of Cu. Conducting layer 10 may be formed by any method used in IC device fabrication such as CVD or PVD techniques. Preferably, conducting layer 10 is deposited by a PVD method such as sputtering, as known in the art. Second dielectric layer 12 is next deposited or otherwise formed on top of conducting layer 10 . Second dielectric layer 12 comprises any dielectric material used in IC device fabrication, including those listed above. Preferably, second dielectric layer 12 comprises a material that serves as an etch stop, as explained below. More preferably, second dielectric layer 12 comprises fluorine-doped silicon oxide or other low dielectric constant material. Second dielectric layer 12 may be formed by any suitable process giving the desired physical and chemical characteristics, such as CVD, PECVD (plasma enhanced chemical vapor deposition), spin-on methods, or otherwise, depending upon the dielectric material selected. For use of the preferred fluorine-doped silicon oxide, the preferred deposition method is PECVD.
[0037] As shown in FIG. 2 , portions of second dielectric layer 12 , conducting layer 10 , and metal layer 8 have been removed, forming multi-layer structure 13 . The portions of layers 8 , 10 and 12 are removed by any IC device fabrication process, such as a photolithographic patterning and dry etching process. The resulting multi-layer structure forms the basis for an interconnect structure according to the present invention. Of course, the patterning and etch process would normally be performed to define a large number of interconnect structures, such as conductive lines 100 (see FIGS. 3 a and 3 b ) extending across substrate 4 .
[0038] As also shown in FIG. 2 , second metal layer 14 (also termed a metal spacer layer) is then deposited on first dielectric layer 6 and over multi-layer structure 13 . In similar fashion to the structure of metal layer 8 , one or more individual metal layers, illustrated by the dashed line within second metal layer 14 , may be used as second metal layer 14 . Preferably, a single metal layer is used as second metal layer 14 for the same reasons as those set forth for metal layer 8 .
[0039] Like metal layer 8 , second metal layer 14 includes not only metals but their alloys and compounds (e.g., nitrides and silicides). Preferably, when conducting layer 10 comprises aluminum, second metal layer 14 comprises Ti. If conducting layer 10 comprises Cu, second metal layer 14 preferably comprises TiW. More preferably, second metal layer 14 comprises the same metal as metal layer 8 . Second metal layer 14 may be deposited or otherwise formed by a process similar to the process used to form metal layer 8 . Preferably, second metal layer 14 is formed by a conformal deposition process, such as CVD.
[0040] Next, as illustrated in FIG. 3 a , second metal layer 14 is spacer etched to remove portions of the second metal layer 14 on first dielectric layer 6 and on second dielectric layer 12 , thereby leaving metal spacers 16 on the multi-layer structure 13 . A spacer etch is a directional sputtering etch which removes second metal layer 14 so that metal spacers 16 remain on the sidewalls of multi-layer structure 13 . The spacer etch uses the first and second dielectric layers as an etch stop.
[0041] If desired, second dielectric layer 12 can then be removed. Second dielectric layer 12 can be removed by any process which removes the second dielectric layer without removing first dielectric layer 6 . If the first and second dielectric layers comprise different materials (e.g., when second dielectric layer 12 is silicon oxide and the first dielectric layer 6 is BPSG), any process which selectively etches the second dielectric layer 12 can be employed. The etch process would also remove the portions of metal spacers 16 laterally adjacent dielectric layer 12 , thus resulting in the metallization structure illustrated in FIG. 3 b . When the first and second dielectric layers 6 , 12 are similar or have similar etch rates (e.g., when both are silicon oxide or fluorine-doped), a facet etch process can be used. As shown in broken lines in FIG. 3 b , when the first and second dielectric layers 6 and 12 exhibit similar etch rates, the thickness of layer 6 will be reduced by substantially the thickness of removed layer 12 .
[0042] The metallization structures illustrated in FIGS. 3 a and 3 b reduce thermally induced stress voids in conductive lines 100 . Metal layer 8 and metal spacers 16 serve as a protective coating at the respective lower and lateral surfaces of conductive lines 100 and at intersections thereof, thereby reducing the incidence of stress voids by preventing them from starting at these surfaces and intersections thereof on conductive line 100 . Metal layer 8 and metal spacers 16 also increase reliability of conductive line 100 without reducing its resistance.
[0043] The metallization structures of FIGS. 3 a and 3 b can then be processed as desired to complete the IC device. For example, an interlevel dielectric layer could be deposited thereover, contact or via holes could be cut in the interlevel dielectric, a patterned metal layer could be formed to achieve a desired electrical interconnection pattern, and a protective dielectric overcoat deposited and patterned to expose desired bond pads.
[0044] Another embodiment of a process and resulting metallization structures of the present invention is represented in FIGS. 4 through 11 . This embodiment may be characterized as more of an “additive” method or process than that described with respect to FIGS. 1 through 3 b , in that metallization structures for interconnects are formed by deposition in apertures, such as vias or trenches. As such, it should be noted that cusping of material deposited to line the sidewall or sidewalls of an aperture may be of concern if the method of deposition is not sufficiently anisotropic or, in some instances, the aperture exhibits a very high aspect ratio. In FIG. 4 , metal layer 52 has been deposited or otherwise formed over substrate 50 . Any of the substrates employable as substrate 4 above can be used as substrate 50 . Preferably, substrate 50 is a silicon wafer or bulk silicon region, such as an SOI or SOS structure. Such substrate 50 can have active and passive devices and other electrical circuitry fabricated on it, these circuit structures being interconnected by the metallization structures of the present invention. Therefore, a direct electrical path may exist between the devices and circuitry of the substrate 50 (or 4 ), the devices and circuitry being omitted herein for simplicity.
[0045] Metal layer 52 may comprise a discrete conductive member, such as a wire, a stud, or a contact. Preferably, metal layer 52 is substantially similar to metal layer 8 described above and may be of any of the same metals, alloys or compounds. If desired, a dielectric layer 51 can be formed on substrate 50 and beneath metal layer 52 . Dielectric layer 51 is substantially similar to first dielectric layer 6 described above.
[0046] As illustrated in FIG. 4 , dielectric layer 54 is then deposited or otherwise formed on metal layer 52 . Dielectric layer 54 may be any dielectric or insulating material used in IC device fabrication, such as those listed above for second dielectric layer 12 . Preferably, dielectric layer 54 is silicon oxide or spin-on glass (SOG). Dielectric layer 54 may be formed by any IC device fabrication process giving the desired physical and chemical characteristics.
[0047] An aperture 56 such as a via or trench is then formed in dielectric layer 54 by removing a portion of dielectric layer 54 to expose underlying metal layer 52 . Aperture 56 may be formed by any IC device manufacturing method, such as a photolithographic patterning and etching process.
[0048] As shown in FIG. 5 , metal collar 60 is formed on the sidewalls of aperture 56 , using a spacer etch as known in the art. It will be understood that the term “collar” encompasses a co-parallel spacer structure 60 if aperture 56 is a trench extending over substrate 50 . Similar to second metal layer 14 , collar 60 may contain one or more metal layers with a single metal layer preferably used. Also in similar fashion to second metal layer 14 , collar 60 may include not only metals, but their alloys and compounds. Like second metal layer 14 , any metal can be employed in collar 60 , provided it exhibits the desired characteristics, either alone or when combined with other metal layers, and the metals applicable to metal layer 14 are equally applicable to collar 60 . Preferably, collar 60 comprises the same metal as metal layer 52 . More preferably, when metal layer 52 comprises Al, collar 60 comprises Ti.
[0049] Collar 60 is formed by an IC device fabrication process which does not degrade metal layer 52 , yet forms a collar or spacer-like structure 60 on the sidewall or sidewalls of aperture 56 . For example, layer 61 (shown in FIG. 4 ) of a material from which collar 60 is formed can be conformally deposited on dielectric layer 54 and the walls of aperture 56 . Conformal coverage yields a substantially vertical sidewall in the dielectric aperture. While not preferred, a partially conformal layer of the material can be deposited instead. A highly conformal process is preferably employed to form layer 61 . Portions of layer 61 on the bottom of aperture 56 and top of dielectric layer 54 are then removed, preferably by using an appropriate directional etch, such as reactive ion etching (RIE).
[0050] Conducting layer 62 is next deposited or otherwise formed to fill aperture 56 and extend over dielectric layer 54 , as shown in broken lines in FIG. 5 . Conducting layer 62 may be deposited by any IC device fabrication method yielding the desired characteristics. For example, conducting layer 62 may be deposited by a conformal or non-conformal deposition process. An abrasive planarization process, such as chemical-mechanical planarization (CMP), is then used to remove portions above the horizontal plane of the upper surface of dielectric layer 54 and leave conductive plug (in a via 56 ) or line (in a trench 56 ) 64 as illustrated in FIG. 6 .
[0051] Similar to conducting layer 10 , conducting layer 62 comprises any conducting material used in IC devices. Preferably, conducting layer 62 comprises aluminum, optionally containing other metals such as Si, W, Ti, and/or Cu. More preferably, conducting layer 62 is an aluminum-copper alloy. Conducting layer 62 may also comprise copper metal.
[0052] Dielectric layer 54 can then be optionally removed, thus forming the interconnect structure represented in FIG. 7 a . Dielectric layer 54 can be removed by any process which does not degrade any of metal layer 52 , conducting layer 62 , or collar 60 . For example, when dielectric layer 54 is silicon oxide, it may be removed by an HF wet etch solution or an oxide dry etch process. If desired, portions of metal layer 52 can then be removed, preferably by a directional etching process, to obtain the interconnect structure shown in FIG. 7 b.
[0053] In an alternative method, upper metal layer 66 can be formed over conductive plug or line 64 as depicted in FIG. 8 . Like metal layer 52 , upper metal layer 66 may contain one or more individual metal layers. Preferably, a single metal layer is used as upper metal layer 66 . Similar to metal layer 52 , upper metal layer 66 may contain not only metals but their alloys and compounds. Preferably, upper metal layer 66 comprises the same material as collar 60 . More preferably, when conductive plug 64 comprises Al, upper metal layer 66 comprises Ti.
[0054] Upper metal layer 66 can be formed over conductive plug 64 in the following manner. Conducting layer 62 is deposited in aperture 56 and over dielectric layer 54 as described above with respect to FIG. 5 . Prior to completely filling aperture 56 , however, the deposition of conducting layer 62 is halted as shown at 62 a in FIG. 5 , leaving an upper portion of aperture 56 empty (i.e., a recess is left at the top of aperture 56 ). Upper metal layer 66 is then deposited over conducting layer 62 , including the still-empty upper portion of aperture 56 . Portions of conducting layer 62 and upper metal layer 66 above the horizontal plane of dielectric layer 54 are then removed by a planarization process, such as CMP, to form a completely enveloped, or clad, interconnect structure. If desired, portions of dielectric layer 54 and metal layer 52 flanking the interconnect structure can be removed as described above to form the structure of FIG. 9 .
[0055] In another process variant, after forming metal layer 52 on substrate 50 and forming dielectric layer 54 with aperture 56 therethrough, but prior to forming collar 60 , conductive plug or line 64 could be formed in aperture 56 as described above. Upper metal layer 66 could then be deposited, as described above, over conductive plug or line 64 and dielectric layer 54 to obtain the structure illustrated in FIG. 10 . Portions of upper metal layer 66 not overlying conductive plug or line 64 could then be removed by a photolithographic pattern and etch process, followed by removing dielectric layer 54 by the method described above, to obtain the structure illustrated in FIG. 11 . As explained above, the structure of FIG. 11 could then have a conformed metal layer deposited and etched (similar to the deposition and etch of second metal layer 14 above) to form a structure similar to that depicted in FIG. 3 a.
[0056] While the preferred embodiments of the present invention have been described above, the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations thereof are possible without departing from the spirit or scope thereof. | The present invention provides a metallization structure for semiconductor device interconnects such as a conductive line, including a substrate with a substantially planar upper surface, foundation metal layer disposed on a portion of the substrate upper surface, primary conducting metal layer overlying the foundation metal layer, and metal spacer on the sidewalls of the primary conducting metal layer and the foundation metal layer. The present invention also provides a metallization structure including a substrate with a foundation metal layer disposed thereon, a dielectric layer with an aperture therethrough being disposed on the substrate, where the bottom of the aperture exposes the foundation metal layer of the substrate, and a metal spacer on the sidewall of the aperture and a line or plug of a primary conducting metal fill the remaining portion of the aperture. The present invention also includes methods for making the metallization structures. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to high intensity arc discharge lamps and more particularly to high intensity ceramic metal halide lamps.
Due to the ever-increasing need for energy conserving lighting systems that arc used for interior and exterior lighting, lamps with increasing lamp efficacy are being developed for general lighting applications. Thus, for instance, electrodeless fluorescent lamps have been recently introduced in markets for indoor, outdoor, industrial, and commercial applications. An advantage of such electrodeless lamps is the removal of internal electrodes and heating filaments that are a life-limiting factor of conventional fluorescent lamps. However, electrodeless lamp systems are much more expensive because of the need for a radio frequency power system which leads to a larger and more complex lamp fixture design to accommodate the radio frequency coil with the lamp and electromagnetic interference with other electronic instruments along with difficult starting conditions thereby requiring additional circuitry arrangements.
Another kind of high efficacy lamp is the arc discharge metal halide lamp that is being more and more widely used for interior and exterior lighting. Such lamps arc well known and include a light-transmissive arc discharge chamber sealed about an enclosed a pair of spaced apart electrodes. This chamber typically further contains a chamber materials composition of suitable active materials such as an inert starting gas and one or more ionizable metals or metal halides in specified molar ratios, or both. They can be relatively low power lamps operated in standard alternating current light sockets at the usual 120 Volts rms potential with a ballast circuit, either magnetic or electronic, to provide a starting voltage and current limiting during subsequent operation.
Such lamps may more particularly have a ceramic material arc discharge chamber that usually contains a chamber materials composition having quantities of sodium iodide (NaI), thallium iodide (TlI) and rare earth halides such as dysprosium iodide (DyI 3 ), holmium iodide (HoI 3 ), and thulium iodide (TmI 3 ) along with mercury (Hg) to provide an adequate voltage drop or power loading between the electrodes. Lamps containing those materials have good performance with respect to Correlated Color Temperature (CCT), which lamps typically exhibit relatively lower correlated color temperatures of 2700K to 3700K, and to Color Rendering Index (CRI), and which also have a relatively high efficacy, up to 95 lumens-per-Watt (LPW) when operated at rated power of 150 W. Of course, to further save electric energy in lighting by using more efficient lamps, high intensity arc discharge metal halide lamps with even higher lamp efficacies are needed.
Also, further savings of electrical energy can be had by dimming such lamps during use when full light output is not needed through reducing the electrical current therethrough, and so high intensity arc discharge metal halide lamps with good performance under such dimming conditions are desirable for many lighting applications. However, under these dimming conditions when lamp power is reduced to about 50% of rated value, the performance of currently available lamps of this kind deteriorate significantly. Typically, the correlated color temperature increases significantly, while the color-rendering index (CRI) decreases. Furthermore the efficacy of the lamp usually decreases significantly.
In addition, the lamp hue will deteriorate under such dimming conditions from white to greenish depending on the chemistry. That is, such ceramic material chamber arc discharge metal halide lamps radiate light in which the color rendering index decreases significantly through having a strong green hue due to relatively strong thallium radiation at its characteristic spectral green lines of wavelength 535.0 nm. The discharge tube wall temperatures as well as its cold-spot temperature are much lower at dimming compared to the corresponding temperatures at rated power. At the lower cold-spot temperature occurring under dimming conditions, the ratio of partial pressure of thallium iodide, or TlI, in the discharge tube is much higher compared to the partial pressures of other metal halides leading to this relatively higher TlI partial pressure causing relatively stronger green Tl radiation at the wavelength 535.0 nm. Since the Tl radiation at 535.0 nm is very close to the peak of the human eye sensitivity curve, however, higher lumen efficacy is achieved at rated lamp power with TlI as one of the discharge tube filling components so that it is used in almost all typical commercially available ceramic metal halide lamps.
One possible way of removing the greenish hue under dimming conditions is to remove TlI from the arc discharge chamber altogether and substitute therefor another active material such as PrI 3 . Another way is to have the arc discharge tube contain halides of Mg, Tl and one or several of the elements from the group formed by scandium (Sc), ytterbium (Y) and lanthanum (Ln). Magnesium iodide, or MgI 2 , is included as an addition to improve lumen maintenance through influencing the balance of one or several chemical reaction between Sc, Y and Ln and spinel (MgAl 2 O 4 ) to such an extent that this balance is achieved shortly after the beginning of the lamp operating life after which further removals of Sc, Y and Ln do not take place. Since the Mg addition through MgI 2 is for reducing chemical reaction between the chamber materials composition components and the chamber wall, the quantity of MgI 2 used in chamber materials composition components in this arrangement is based on the surface area of the inner wall of the discharge vessel.
The arc discharge tube in this last described arrangement is operated within an evacuated outer envelope to reduce convection heat loss from the cold spot of the discharge chamber, and with a metal beat shield used on the discharge chamber to reduce radiation heat loss from the cold-spot during dimming because of the thermal emissivity of the metal shield being much lower than that of the arc discharge chamber ceramic surface, and because of the emissivity of the metal going down as the temperature drops thereby keeping the chamber cold spot temperature and the vapor pressure of the salts in the chamber substantially constant. However, such a lamp still has the disadvantage of radiating with a relatively strong green hue when dimmed to lower than the rated power due to the relatively higher vapor pressure of TlI under dimming conditions, and the further disadvantage that the widely used high voltage starting pulses on low wattage metal halide lamps, when used in conjunction with a vacuum envelope, may make the lamp susceptible to arcing if the discharge tube leaks or slow outer jacket leaks exist. Thus, there is a desire for arc discharge metal halide lamps having higher efficacies and better color performance under dimming conditions.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with electromagnetic radiation or visible light permeable walls of a selected shape bounding a discharge region through which walls a pair of electrodes are supported in the discharge region spaced apart from one another. Ionizable materials are provided in the discharge region of the discharge chamber comprising mercury, a noble gas, and at least two metal halides including a magnesium halide and a sodium halide, a rare earth element, and thallium iodide in a molar quantity which is between 0.7 and 5% of that total molar quantity of all halides present in the discharge chamber.
The discharge chamber can have walls formed of polycrystalline alumina among other materials, and is enclosed in a visible light permeable bulbous envelope positioned in a base with electrical interconnections extending from the discharge chamber to the base and contains a nitrogen gas atmosphere. A shroud of a visible light permeable material can be provided about the discharge chamber. The ionizable materials can further include halides of a series of rare earth elements comprising dysprosium, holmium, thulium, cerium, praseodymium, scandium, neodymium, europium, lutetium and lanthanum so that the total molar quantity of such halides along with the metal halides present in said discharge chamber is between 95 and 99.3% of that total molar quantity of all halides present in said discharge chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partially in cross section, of an arc discharge metal halide lamp of the present invention having a ceramic arc discharge chamber of a selected configuration therein,
FIG. 2 shows the arc discharge chamber of FIG. 1 in cross section in an expanded view,
FIG. 3 shows a graph of the changes in the Correlated Color Temperature (CCT) with changes in lamp power dissipation for a 100-hour photometry measurement of the lamp of FIG. 1 and a typical prior art lamp,
FIG. 4 shows a graph of the changes in the Color Rendering Index (CRI) with changes in lamp power dissipation for a 100-hour photometry measurement of the lamp of FIG. 1 and a typical prior art lamp,
FIG. 5 shows a graph of the changes in the lamp efficacy in lumens per watt (LPW) with changes in lamp power dissipation for a 100-hour photometry measurement of the lamp of FIG. 1 and a typical prior art lamp, and
FIG. 6 shows a graph of the changes in the deviation of lamp radiation from the radiation of a blackbody radiator with changes in lamp power dissipation for a 100-hour photometry measurement of the lamp of FIG. 1 and a typical prior art lamp.
DETAILED DESCRIPTION
Referring to FIG. 1, an arc discharge metal halide lamp, 10 , is shown in a partial cross section view having a bulbous, transparent borosilicate glass envelope, 11 , partially cut away in this view, fitted into a conventional Edison-type metal base, 12 . Lead-in, or electrical access, electrode wires, 14 and 15 , of nickel or soft steel, each extend from a corresponding one of the two electrically isolated electrode metal portions in base 12 parallely through and past a borosilicate glass flare, 16 , positioned at the location of base 12 and extending into the interior of envelope 11 along the axis of the major length extent of that envelope. Electrical access wires 14 and 15 extend initially on either side of, and in a direction parallel to, the envelope length axis past flare 16 to have portions thereof located further into the interior of envelope 11 with access wire 15 extending after some bending into a borosilicate glass dimple, 16 ′, at the opposite end of envelope 11 . Electrical access wire 14 is provided with a second section in the interior of envelope 11 extending at an angle to the first section that parallels the envelope length axis by having this second section welded at such an angle to the first section so that it ends after more or less crossing the envelope length axis.
Some remaining portion of access wire 15 in the interior of envelope 11 is bent at acute angle away from the initial direction thereof parallel to the envelope length axis. Access wire 15 with this first bend therein past flare 16 directing it away from the envelope length axis, is bent again to have the next portion thereof extend substantially parallel that axis, and further along bent again at a right angle to have the succeeding portion thereof extend substantially perpendicular to, and more or less cross that axis near the other end of envelope 11 opposite that end thereof fitted into base 12 . The portion of wire 15 extending parallel to the envelope length axis has welded thereto a pair of spaced apart support straps, 17 A and 17 B, of the same material as wire 15 which in turn support a shroud, 18 , formed as an optically transparent, truncated cylindrical shell of quartz to limit gaseous flows in the interior thereof so as to maintain relatively constant temperatures therein. The succeeding portion of wire 15 perpendicular to the envelope length axis supports a conventional getter, 19 , to capture gaseous impurities. Two additional right angle bends are provided further along in wire 15 to thereby place a short remaining end portion of that wire below and parallel to the portion thereof originally described as crossing the envelope length axis which short end portion is finally anchored at this far end of envelope 11 from base 12 in glass dimple 16 ′.
A ceramic arc discharge chamber, 20 , configured about a contained region as a shell structure having polycrystalline alumina walls that are translucent to visible light, is shown in one of various possible geometric configurations in FIG. 1 positioned within shroud 18 . Alternatively, the walls of arc discharge chamber 20 could be formed of aluminum nitrite, yttria (Y 2 O 3 ), sapphire (Al 2 O 3 ), or some combinations thereof. Both shroud 18 and discharge chamber 20 are provided within envelope 11 in a nitrogen gas atmosphere at a relatively high pressure greater than 300 mmHg, typically between about 360 and 600 mmHg, which makes the lamp much less susceptible to catastrophic failure compared to a vacuum in envelope 11 that risks the occurrence of arcing should a slow leak develop in arc chamber 20 or envelope 11 . Thus this shroud can not only stabilize the temperature about chamber 20 , as indicated above, but can also provide containment of resulting debris, etc. from any explosive structural failure of that chamber to thereby protect envelope 11 from any resulting impulsive stresses that may otherwise lead to the breaking apart thereof.
The region enclosed in arc discharge chamber 20 contains various ionizable materials, including metal halides and mercury which emit light during lamp operation and a starting gas such as the noble gases argon (Ar) or xenon (Xe). In this structure for arc discharge chamber 20 as better seen in the cross section view thereof in FIG. 2, a pair of polycrystalline alumina, relatively small inner and outer diameter truncated cylindrical shell portions, or capillary tubes, 21 a and 21 b, are each concentrically joined to a corresponding one of a pair of polycrystalline alumina end closing disks, 22 a and 22 b, about a centered hole therethrough so that an open passageway extends through each capillary tube and through the hole in the disk to which it is joined. These end closing disks are each joined to a corresponding end of a polycrystalline alumina tube, 25 , formed as a relatively large diameter truncated cylindrical shell, to be about the enclosed region to provide the primary arc discharge chamber. These various portions of arc discharge tube 20 are formed by compacting alumina powder into the desired shape followed by sintering the resulting compact to thereby provide the preformed portions, and the various preformed portions are joined together by sintering to result in a preformed single body of the desired dimensions having walls impervious to the flow of gases.
Chamber electrode interconnection wires, 26 a and 26 b, of niobium each extend out of a corresponding one of tubes 21 a and 21 b to reach and be attached by welding to, respectively, access wire 14 at its end portion crossing the envelope length axis and to access wire 15 at its portion first described as crossing the envelope length axis. This arrangement results in chamber 20 being positioned and supported between these portions of access wires 14 and 15 so that its long dimension axis approximately coincides with the envelope length axis, and further allows electrical power to be provided through access wires 14 and 15 to chamber 20 .
FIG. 2 shows the discharge region contained within the bounding walls of arc discharge chamber 20 that are provided by structure 25 , disks 22 a and 22 b, and tubes 21 a and 21 b of FIG. 1 . Chamber electrode interconnection wire 26 a, being of niobium, has a thermal expansion characteristic that relatively closely matches that of tube 21 a and that of a glass frit, 27 a, affixing wire 26 a to the inner surface of tube 21 a (and hermetically sealing that interconnection wire opening with wire 26 a passing therethrough) but cannot withstand the resulting chemical attack resulting from the forming of a plasma in the main volume of chamber 20 during operation. Thus, a molybdenum lead-through wire, 29 a, which can withstand operation in the plasma, is connected to one end of interconnection wire 26 a by welding, and other end of lead-through-wire 29 a is connected to one end of a tungsten main electrode shaft, 31 a, by welding.
In addition, a tungsten electrode coil, 32 a, is integrated and mounted to the tip portion of the other end of the first main electrode shaft 31 a by welding, so that an electrode, 33 a, is configured by main electrode shaft 31 a and electrode coil 32 a. Electrode 33 a is formed of tungsten for good thermionic emission of electrons while withstanding relatively well the chemical attack of the metal halide plasma. Lead-through wire 29 a, spaced from tube 21 a by a molybdenum coil, 34 a, serves to dispose electrode 33 a at a predetermined position in the region contained in the main volume of arc discharge chamber 20 . A typical diameter of interconnection wire 26 a is 0.9 mm, and a typical diameter of electrode shaft 31 a is 0.5 mm.
Similarly, in FIG. 2, chamber electrode interconnection wire 26 b is affixed by a glass frit, 27 b, to the inner surface of tube 21 b (and hermetically sealing that interconnection wire opening with wire 26 b passing therethrough). A molybdenum lead-through wire, 29 b, is connected to one end of interconnection wire 26 b by welding, and other end of lead-through-wire 29 b is connected to one end of a tungsten main electrode shaft, 31 b, by welding. A tungsten electrode coil, 32 b, is integrated and mounted to the tip portion of the other end of the first main electrode shaft 31 b by welding, so that an electrode, 33 b, is configured by main electrode shaft 31 b and electrode coil 32 b. Lead-through wire 29 b, spaced from tube 21 b by a molybdenum coil, 34 b, serves to dispose electrode 33 b at a predetermined position in the region contained in the main volume of arc discharge chamber 20 . A typical diameter of interconnection wire 26 b is also 0.9 mm, and a typical diameter of electrode shaft 31 is again 0.5 mm.
The lamp of FIGS. 1 and 2 achieves superior lamp performance under dimming conditions with ceramic discharge vessel 20 , positioned in nitrogen filled envelope 11 , having therein a provision of magnesium iodide, or Mgl 2 , to replace the major part of the TlI chamber materials composition component used in the chamber materials compositions of typical ceramic chamber metal halide lamps. Mgl 2 is used to replace the major part of TlI as one of the chamber materials composition components because Mg exhibits green radiation for higher efficacy and has a similar vapor pressure variation with temperature as that of the rare earth iodides also present in the discharge chamber materials composition. A small amount of TlI as a chamber materials composition component is added to the chamber composition for metal halide lamps with relatively lower correlated color temperatures (2700K to 3700K) to assure that the light emitted under dimming conditions is still close to that emitted by a black body. Since ceramic metal halide lamps with relatively lower correlated color temperatures have relatively higher NaI content, lamps without TlI will emit light with lower correlated color temperature under dimming conditions compared to that at rated wattage. They will also have a pinkish hue due to the relatively higher NaI content in the lamp chamber materials composition for the lower color temperatures. A small amount of TlI in the chamber materials composition will help to raise the—y coordinate of the chromaticity under dimming conditions so the light emitted will be close to that emitted by a black body even under such conditions. Since only a small amount of TlI is added in the lamp chamber materials composition, there is no green hue in the light emitted from such lamps being operated at rated lamp power.
On the other hand, due to metal halide vapor pressure variation with temperature variation that is similar to that of rare-earth halides, the partial pressure of the MgI 2 component replacing most of the TlI component will drop under dimming conditions proportionally to that of the other rare-earth halides used as components in the lamp chamber materials composition. This performance leads to a white light output from the lamp even under dimming conditions rather than the greenish hue of the lamps with a relatively large TlI dose in typical commercially available ceramic chamber metal halide lamps.
In addition, the relatively higher vapor pressure of MgI 2 at rated lamp power results in relatively strong green radiation at the wavelength of 518.4 nm in these conditions. Since the Mg radiation at the wavelength of 518.4 nm is very close to the peak of the human eye sensitivity curve, higher lumen efficacy is achieved at rated lamp power with MgI 2 as one of the lamp chamber materials composition components. The quantity of the MgI 2 used as a component in the chamber materials composition is chosen for light emission reasons and for better lamp performance under dimming conditions so that the optimum quantity is based on the lamp performance under rated lamp power and reduced lamp power conditions and not the surface area of the discharge vessel.
In one realization of the lamp of FIGS. 1 and 2 having a rated power of 150W, the chamber materials composition in arc discharge chamber 20 includes 12 mg Hg and 10.6 mg total of the metal halides HoI 3 , TmI 3 , MgI 2 , NaI and TlI in respective molar ratios of 1:3.2:8.7:24.1:0.5. In addition, the composition comprises Ar with a filling pressure of 160 mbar as an ignition gas. Generally, in any realization of the lamp of FIGS. 1 and 2, TlI should be present in arc discharge chamber 20 in a molar quantity which is between 0.7 and 5% of the total molar quantity of the total halides present in the chamber. Halides of one or more of the rare earth elements of the series dysprosium (Dy), holmium (Ho), thulium (Tm), Cerium (Ce), praseodymium (Pr), scandium (Sc), neodymium (Nd), europium (Eu), lutetium (Lu) and lanthanum (La) can be alternatively or jointly used such that the total molar quantity of halides of Na and Mg, and of the rare earth elements, present in arc discharge chamber 20 is between 95 and 99.3%. In one example, a halide of dysprosium can be used in discharge chamber 20 having a molar quantity that is between 0 to 20% of that total molar quantity of all halides present therein.
In the following Table 1 for a pair of lamps of one correlated color temperature and Table 2 for a pair of lamps of another correlated color temperature, characteristics are presented in tabular form of FIGS. 1 and 2 ceramic arc discharge chamber metal halide lamps, as just described, with a small amount of TlI in the chamber materials compositions, and of corresponding typical commercially available lamps with typically used doses of TlI in the chamber materials compositions thereof. The data are listed for these lamps operated both at the rated lamp power of 150W and at 50% of rated lamp power in a dimmed condition:
TABLE 1
Na, rare earth halides +
Mg, Na, and rare earth
typical amount of T1I
3500 K
halides + 1.3 mole % T1I
(9.1 mole %)
Lamps
150 W
75 W
150 W
75 W
LPW
91
72
85
68
CCT
3513
3574
3552
4484
CRI
90
71
92
70
Duv
−0.8
−1.7
3.3
17.2
Lamp characteristics of a 3500K correlated color temperature lamp with a very low TlI dose and a 3500K correlated color temperature lamp with a typical TlI dose.
TABLE 2
Na, rare earth halides +
Mg, Na, and rare earth
typical amount of T1I
3000 K
halides + 0.5 mole % T1I
(9.8 mole %)
Lamps
150 W
75 W
150 W
75 W
LPW
86.4
69.0
87.4
68.8
CCT
3039
3013
3072
4075
CRI
87
63
83
62
Duv
−5.1
−6.6
−2.8
25.3
Lamp characteristics of a 3000K correlated color temperature lamp with a very low TlI dose and a 3000K correlated color temperature lamp with a typical TlI dose. Duv is a parameter to represent a comparison of light emitted from a lamp to the light emitted from a black body radiator. The greater the value of the Duv parameter the larger the deviation of the light emitted by a lamp from the light correspondingly emitted by a black body with respect to whiteness of that light. Note in Table 1 that a small amount of TlI in combination with MgI 2 results in a lamp that is vastly superior in dimming performance to a lamp with a large amount of TlI and without MgI 2 For example, the Duv and CCT change in going from 150W to 75W with a low TlI dose in the lamp chamber is only 0.9 units and 61K, respectively, while, in a typical commercially available lamp of the kind offered under the brand name PANASONIC, the changes in Duv and CCT are 13.9 units and 932K, respectively. The changes of Duv and CCT in the lamp of FIGS. 1 and 2 are not distinguishable to the naked eye, while the changes of Duv and CCT in typical commercially available lamps are very distinguishable and very annoying to the naked eye. The same conclusions can be drawn from the data in Table 2.
FIGS. 3 to 6 show comparisons of results of lamps corresponding to FIGS. 1 and 2 with a typical commercially available ceramic chamber metal halide lamp. The lamps were operated with a reference ballast and measured in a two meter integrating sphere under accepted conditions promulgated by the Illuminating Engineering Society of North America. The data was acquired with a charge coupled device-based computerized data acquisition system. All data presented in FIGS. 3 to 6 were obtained with the operating position of the lamp being vertical base up. The experiments, for which the data is presented in FIGS. 3 to 6 were conducted using 150W ceramic metal halide arc discharge chamber.
During operation of the lamps according to the present invention, and when comparing them to typical commercially available lamps, the latter lamps turned greenish on dimming and deviated substantially from the black body emission performance upon dimming to about 50% of rated power. In contrast, when the lamps of FIGS. 1 and 2 realized with the chamber materials composition described above were dimmed to about 50%, they still emitted substantially as a black body, had no greenish hue, and generally looked white. Such color was satisfactory to the eye and it was substantially impossible to discern any color or hue change under dimmed conditions.
FIG. 3 shows in graphical form the changes of correlated color temperature (CCT) when these lamps are dimmed from operation at rated power. The CCT of the FIGS. 1 and 2 lamp realized as above did not have any significant change when the lamp was dimmed to 50% of its rated power. The typical commercial lamp, however, had a CCT change that was significant when that lamp was dimmed to 50% of its rated power.
FIG. 4 shows in graphical form the changes of in the color rendering index (CRI) when these lamps are dimmed from operation at rated power. The CRI of the FIGS. 1 and 2 lamp realized as above changed less than the CRI of the typical commercial lamp when these lamps were dimmed to 50% of rated power.
FIG. 5 shows in graphical form the changes in lamp efficacy in lumens per watt (LPW) when these lamps are dimmed from operation at rated power. The LPW of the FIGS. 1 and 2 lamp realized as above and of the typical commercial lamp change in a very similar fashion when dimmed to 50% of rated power.
FIG. 6 shows in graphical form the changes of lamp Duv when these lamps are dimmed from operation at rated power. The Duv of the FIGS. 1 and 2 lamp realized as above did not have significant change when that lamp was dimmed to 50% of its rated power. The typical commercial lamp, however, had a Duv change that was significant when that lamp was dimmed to 50% of its rated power.
Therefore, FIGS. 1 and 2 lamps realized as above, containing MgI 2 and very low molar ratio of TlI, are shown to perform comparably to typical commercial lamps at rated lamp power. The indict of such performance relied upon includes efficacy, CCT, CRI and Duv. However, when typical commercial lamps are dimmed to 50% of their rated power their resulting performance measured by the same indict deteriorates substantially. Most significant in this deterioration, from the end user's point of view, are the changes in CCT and hue with the latter being indicated by the changes in the Duv. These unwanted changes during dimmings are eliminated by the substitution for major portion of TlI chamber materials composition component in typical commercially available ceramic chamber metal halide lamps by MgI 2 to thereby leave only a very small relative amount of TlI in the lamp arc discharge chambers of the FIGS. 1 and 2 lamps so that they substantially retain the same CCT and hue throughout the dimming range, that is, remaining white throughout the dimming range.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | An arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable ceramic walls about a discharge region. A pair of electrodes are supported in the discharge region spaced apart from one another. Ionizable materials are provided in the discharge region comprising mercury, a noble gas, and at least two metal halides including a magnesium halide and a sodium halide, a rare earth clement, and thallium iodide in a molar quantity which is between 0.7 and 5% of that total molar quantity of all halides present in the discharge chamber. | 7 |
This is a Divisional application of application Ser. No. 09/788,874, filed on Feb. 20, 2001, now U.S. Pat. No. 6,532,910.
TECHNICAL FIELD
This invention relates to engine cooling systems and more particularly to a novel and improved cooling system in a turbo charged internal combustion engine.
BACKGROUND ART
The development of internal combustion engines for reduced exhaust emissions has resulted in significant increases in the amount of heat dissipation into engine cooling systems. Traditionally, increases in the required amount of heat dissipation has been accomplished by improving the radiator cooling capacity through increasing the core size of the radiator. In addition, increased coolant and cooling air flow has been used to deal with the increase in required heat dissipation.
Packaging space for larger radiator cores and high energy consumption due to increased coolant and cooling air flow limit the amount of heat dissipation capacity increase that can be accomplished with these traditional approaches.
It is possible to improve cooling capacity by elevating the maximum permissible coolant temperature above traditional levels. The adoption of pressurized cooling systems which permitted operation with coolants at 100° C./212° F. was a step in this direction. The addition of expansion tanks assisted in maintaining such temperature levels. However, it has become desirable to elevate coolant temperatures to even higher levels.
Utilization of elevated coolant temperatures requires proper pressurization under all operating, stand-still and ambient conditions in order to control cooling characteristics, secure coolant flow, prevent cavitation and cavitation erosion and to prevent unwanted boiling and overflow.
Temperature and pressure increase becomes more critical as the heat dissipation from the engine approaches the cooling capacity of the cooling system. A now traditional approach for pressurizing cooling systems is to rely on closed expansion or pressure tanks which depend on temperature increases of coolant and air to create and maintain desired pressures. Such a system communicates with ambient air by opening two way pressure valves to thereby communicating the system with ambient air to entrain new air into the pressure tank when entrapped air and the coolant cool to create a vacuum in the system. Such systems are passive and vulnerable to leaks. Moreover, if such a system is depressurized for any reason, such as maintenance or top-off, pressure is reduced to ambient and operating time and cycles are needed to increase the pressure in the system.
SUMMARY OF THE INVENTION
According to the present invention, an internal combustion engine cooling system is pressurized by introducing air under pressure from an external pressurized source. More specifically, in the preferred and disclosed embodiment, air under pressure from an engine intake manifold is communicated into the cooling system thereby to pressurize the system and elevate the maximum available coolant temperature. In its simplest form, a conduit connects an engine intake manifold with a cooling system expansion tank via a flow control check valve. The flow control valve is in the form of a spring loaded non-return valve connected in the conduit for enabling unidirectional flow from the intake manifold to the expansion tank.
In an alternate embodiment, a flow control valve in the form of a spring loaded non-return valve is also used. A second spring loaded non-return valve allows decompression of the expansion tank to a threshold pressure level corresponding to the spring pressure of the second valve plus the pressure in the engine air inlet system. In order to dampen decay of pressure in the coolant system, a restrictor is interposed in series with the second non-return valve.
A further alternative includes an electric or pneumatic switch between the restrictor and the second non-return valve. A control algorithm for this switch is based on coolant pressure, temperature, engine load parameters and duty cycles for optimizing the expansion tank pressure.
In a still further alternative, a two directional two way control valve is used together with pressure sensors respectively located on opposite sides of the control valve. A control algorithm for pressure control is based on selected parameters such as coolant pressure, engine load, charge air pressure, coolant temperature, ambient temperature and pressure, cooling system capacity, cooling fan speed and duty cycles.
The alternate embodiments using electronic control units enable diagnosis of the systems actual functioning condition. The system compares actual pressure levels, time temperatures and valve positions with expected critical pressures under given conditions in the setting and design parameters for the system and components used in it. Diagnostic information is available for drivers and service information. It also can be used for actively changing the functioning of the system to enable continued use of the engine vehicle in a so-called limp home mode in case of system malfunction.
Accordingly, the objects of this invention are to provide a novel and improved engine coolant system and a method of engine cooling.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic view of an over the highway heavy duty truck or tractor equipped with a turbo charged engine and cooling system made in accordance with the present invention;
FIG. 2 is a schematic view of one embodiment of the novel portions of the cooling system of the present invention;
FIG. 3 is a schematic showing of an alternate flow control valve arrangement for the system of FIG. 2 ;
FIG. 4 is a further alternate arrangement of the flow control valving for the system of FIG. 2 ; and
FIG. 5 is a schematic view of yet another alternate flow control valving arrangement for the system of FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and FIG. 1 in particular, an over the highway truck or tractor is shown generally at 10 . The truck is equipped with a turbo charged engine 12 . As shown somewhat schematically in FIG. 2 the engine 12 is equipped with a cylinder head 14 having an air intake manifold 15 . The engine 12 is equipped with a turbo charger pressurizing the intake manifold 15 as shown schematically at 16 in FIG. 2 .
The engine 12 is equipped with a cooling system which includes an expansion tank 18 , FIG. 2 . The expansion tank 18 is a now standard tank including an outlet 20 connected to an inlet of a water or coolant pump. The tank 18 includes a fill opening equipped with a pressure cap 22 . In the disclosed embodiment, the cap 22 includes a tank pressure relief and coolant overflow valve 24 and a vacuum relief valve 25 as is now conventional in coolant systems.
A conduit 26 connects the intake manifold 15 to the expansion tank 18 . The conduit 26 communicates with the expansion tank 18 through an inlet 28 . A floating check valve 30 functions to control unidirectional fluid flow through the inlet 28 when a level of coolant 32 in the tank 18 rises to a higher level than that depicted in FIG. 2 . Thus, the check valve 28 functions to prevent coolant 32 from entering the conduit 26 .
A flow control valve 34 is interposed in the conduit 26 . In its simplest form, the flow control valve is a simple spring loaded non-return valve which allows pressurized flow from the manifold 15 to the tank 18 , but prevents reverse flow of pressurized fluid from the tank 18 to the manifold 15 .
With the embodiment of FIG. 2 , the tank pressure relief valve 24 will control the pressure in the cooling system. So long as the pressure level at which the tank pressure relief valve operates is higher than the pressure in the system, the operating pressure in the system will always be above the opening pressure of the flow control valve and below the tank pressure relief valve's opening pressure due to the one way functioning of the flow control valve 34 .
In the embodiment of FIG. 3 , a second valve in the form of another spring loaded non-return valve 35 is provided. The valve 35 allows decompression of the expansion tank pressure down to a threshold pressure level corresponding to the spring pressure of the valve 35 plus the pressure of the engine air inlet system. In order to dampen the pressure decay in the cooling system, a restrictor 36 is in series with the second flow control valve 35 . In FIG. 3 , the restrictor is shown on the coolant side of the valve but it could be on the engine side.
With the embodiment of FIG. 4 , a directional control flow valve 38 is added to the system in series with the restrictor 36 and the second or decompression control valve 35 . The directional control valve 38 functions to prevent automatic pressure decay in the expansion tank by maintaining a higher pressure when the engine load and the pressure in the engine intake system is reduced.
An electronic control unit 40 controls the positioning of the directional control valve. The control algorithm for this function is based on coolant pressure, temperature, engine load parameters, and duty cycles relevant for optimizing the expansion tank pressure. Alternatively, a pneumatic switch may be substituted for the electrically control directional control valve that has been described.
FIG. 5 discloses an alternative which offers full flexibility in building up and maintaining pressure in the expansion tank 18 and therefore in the coolant system. The alternate of FIG. 5 includes control of pressure variations and amplitudes. The system of FIG. 5 utilizes a two directional, two way control valve 42 . Pressure sensors 44 , 45 are respectively positioned between the one way valve 42 and the expansion tank 18 and between the one way valve and the engine intake manifold 15 . A restrictor 46 is interposed in series with the direction control valve 42 and the pressure sensor 45 .
The direction control valve 42 is controlled by an electronic control unit 48 . A control algorithm for the control unit 48 is based on selected parameters such as coolant pressure, engine load, charge pressure, coolant temperature, ambient temperature, ambient pressure, cooling system capacity, cooling fan speed, and duty cycles. The pressure in the expansion tank is optimized by actively pressurizing to satisfy coolant system function. While the pressure is optimized, it is only to necessary pressure levels and with pressure variations and amplitudes which match the properties of materials used in the coolant system.
A passive pressure build-up in the expansion tank will take place naturally and in parallel with the active pressure control systems that have been described. How the passive pressure build-up will interact depends on which of the embodiments is employed.
The embodiments of FIGS. 4 and 5 make it possible to diagnose a system's actual functioning condition and to identify problems. Such a system compares actual pressure levels, time, temperatures and valve positions with expected critical pressures under given conditions and the setting of design parameters for the system as well as components used in it.
Diagnostic information derived when either the embodiment of FIGS. 4 or 5 is in use, can be used for driver and service information. It can also be used for actively changing the functioning of the system to enable continued use of the vehicle in a so-called limp home mode in case of an identified system malfunction. Examples of changing functions are modifying valve functions, shutting off the active system pressurizing by the turbo charger, reduction of available engine power and heat dissipation, and altered cooling fan, speed and fan-clutch engagement.
Operation
In operation from cold engine start up, operation of the turbo charger will transmit air under pressure through the conduit 26 to the expansion tank 18 . Assuming the pressure relief setting of the cap pressure relief valve 24 is high enough, air under pressure will flow through the flow control valve 34 until pressure in the expansion tank 18 is approaching the relief valve opening pressure (but not higher). Should the pressure of air from the turbo charger 16 drop, the one way flow control valve 34 will prevent a pressure drop in the expansion tank 18 .
With the embodiment of FIG. 3 , the second non-return flow valve 35 functions to reduce the pressure in the coolant system when outlet pressure from the turbo charger is reduced, but not lower than the pre-set opening pressure of the second flow control valve 35 .
With the embodiment of FIG. 4 , the directional control valve 38 functions to prevent automatic pressure decay in the expansion tank to maintain higher pressure when the engine load and the pressure of the engine intake system is reduced. The electronic control unit 40 of the FIG. 4 embodiment, will function based on the parameters that have been selected to control pressure decay in the coolant system.
With the embodiment of FIG. 4 , pressure in the coolant system in relation to pressure in the engine air inlet 15 is totally controlled by the one way directional control valve 42 which in turn is controlled by the electronic control unit 46 . This functioning is in accordance with the parameters that have been described.
The embodiment of FIG. 5 is effective to control coolant system pressure appropriate for operating parameters and as such to maximize performance benefits of a pressurized cooling system.
Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction, operation and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. | An improved cooling system for a turbo charged internal combustion engine is disclosed. A conduit connects a pressurizing engine air intake to the cooling system to raise the pressure in the cooling system thereby enabling an increase of the maximum temperature which coolant in the cooling system can reach. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a continuous melt-plating apparatus and, more particularly, to a continuous melt-plating apparatus suitable for adjusting the flatness of a gas wiping portion of a steel strip subjected to a continuous melt-plating method in which gas wiping is effected.
2. Description of the Prior Art
Conventional continuous melt-plating methods include: a type of method in which the steel strip is not subjected to acid cleaning or flux treatment, but is surface cleaned by performing oxidation and reduction before plating; and another type in which acid cleaning and flux treatment are performed before plating. An example of a method of the former type is disclosed in Japanese Patent Unexamined Publication No. 61-147900.
In a continuous melt-plating apparatus for carrying out such a continuous melt-plating method, an arrangement for maintaining the flatness of the steel strip in the gas wiping portion is disclosed in, for instance, Japanese Patent Publication No. 45-41085. In this arrangement, two guide rollers are provided between the gas wiping nozzle and a sink roller disposed below the nozzle, with one of the guide rollers being positioned lower than the other. The lower guide roller is adjusted in such a manner as to be offset from the mating guide roller, so that widthwise curving resulting from the rising of the steel strip can be corrected in order to maintain the flatness of the steel strip right at the portion opposing the gas wiping nozzle.
Gas wiping has been developed for use in plating a steel strip with a melt such as zinc, aluminum and nickel, and since it has various advantageous features, gas wiping is at present adopted in almost all the plating methods in this field. When gas wiping is to be effected with a view of blowing off and wiping off an excess of the plated melt layer, it is important to give consideration to the fact that the amount by which the melt can be blown and wiped off is greatly varied depending on the gap between the nozzle and the steel strip (i.e., the gap between the gas injection port and the steel strip). Certain experiments have shown that the resultant thickness Δt of a plating is expressed by the following formula:
Δt∝C·√δwhere Δt: thickness of plating
δ: gap between the tip of the nozzle and the steel strip
C: constant
Therefore, if the gas wiping portion of a steel strip has any irregularities occurring in the widthwise direction thereof, the irregularities cause corresponding variations in the gap between the steel strip and the nozzle and, hence, variations in the thickness of the plated layer. When the thickness of a plating is to be set, because the thickness of the thinnest portion has to be used as the reference from the viewpoint of assuring the performance of the plating, the thickness is inevitably set to a rather large value capable of compensating for those possible variations in the thickness of the plating. Thus, the thickness of a plated layer includes a margin corresponding to variations therein, which is termed a dead thickness. The thickness of the plating is also affected by the waving and curving of a portion of the steel strip which moves above the nozzle. In particular, when the steel strip has a relatively small thickness, curving occurs severely. Since a portion of the steel strip which has left the plating path cannot be held by, e.g., rollers until it is cool, the portion gradually curves in the widthwise direction after leaving the roller in the plating bath because of widthwise difference in thermal expansion resulting from changes in temperature generated during the plating. In order to compensate for the widthwise difference in expansion and also to center the steel strip, a crown is often provided for the sink roller within the plating bath. However, such a crown itself often causes the curving and waving of the steel strip. A high degree of curving amounts to about ±20 mm. Since the gap between the nozzle and the steel strip generally averages about 30 to 50 mm, there is a risk of large variations being caused in the thickness of the plated layer.
Curving leads to the following problem as well. When the plated melt layer and the nozzle opening are brought into mutual contact by attracting action between the tip of the nozzle and the curved steel strip, part of melt in the plated layer adheres to the nozzle opening, resulting in clogging or other disadvantages.
In order to overcome these problems, Japanese Patent Publication No. 45-41085 proposes a solution in which curving is corrected by means of the offset between or the overlap of the two guide rollers provided between the sink roller and the gas wiping nozzle. According to this proposal, however, since the curving of the steel strip is corrected solely by the overlap of straight rollers, the amount and the configurations provided by this correction are inevitably limited. Thus, the proposal has not been able to correct very large curving or complicated waving. Also, the degree of precision with which the gas wiping portion is kept flat has not been sufficient. Hitherto, because the plating speed (i.e., the speed at which the steel strip is passed) has been relatively low (i.e., approximately 50 to 100 m/min at most), the proportion in which the gap between the nozzle tip and the steel strip is varied has not been very large even if the gap is relatively large and the precision of the flatness is poor. It has therefore been possible to achieve thickness of platings which is uniform to a substantially satisfactory degree. In the case of the above-described prior art, although the correcting ability of the guide rollers is limited and, in addition, the difference in height between the guide rollers and the gas wiping nozzle is restricted to 300 mm or below, no problem has been encountered in practice.
Although gas wiping was at first used in the molten-zinc plating lines, as the application of gas wiping broadens during the passage of a long period into almost all the platings of Zn, Al, Ni, etc., an increasingly higher level of performance has been required. Currently, it is clearly seen that there are strong demands for, e.g., the achievement of plating thickness which is uniform to a higher degree with a view to saving resources and reducing the unit, and for the enhancement of the plating speed and, hence, the production efficiency. In order to enhance the plating speed (i.e., the steel strip passing speed) with the same thickness of the plating, it is necessary either to bring the tip of the gas wiping nozzle closer to the steel strip or to increase the gas discharge pressure. Since an increase in the gas pressure leads to an increase in the unit, and also leads to an increase in the noise generated in the vicinity of the plating bath and, hence, to deterioration in the working environment, the present situation is such that, on the contrary, the gas pressure is gradually lowered. For these reasons, in order to achieve thin platings at high speed, the gap between the tip of the nozzle and the steel strip must be much smaller than that conventionally provided. When the steel strip passing speed is increased, this causes an increase in the amount by which plating melt material (e.g., melt zinc) in the plating bath is attached to and thus raised by the steel strip. Therefore, it is necessary to increase the height of the gas wiping nozzle from the plating bath, and allow the excess of the plated layer to quickly drop off by its own weight, for the purpose of making it easy for blowing and wiping by gas wiping to achieve a thin thickness and for preventing the plating melt from scattering toward the nozzle and, hence, from causing clogging.
In the case where a sink roller is combined with a bearing portion disposed below the surface of the melt in the bath, plain bearings are in general used to form the bearing structure, as disclosed in Japanese Patent Unexamined Publication No. 54-18430. However, since the bearing surfaces are subjected to severe corrosion by the molten zinc, wear occurs in a short period. This has led to a loose fitting, with which the sink roller greatly vibrates in the transverse direction, resulting in great variations in the gap between the tip of the gas wiping nozzle and the steel strip and, hence, variations in the thickness of the plating. In order to avoid this risk, an arrangement is adopted in which the bearing portion is disposed above the upper surface of the bath melt.
In this way, in compliance with the demand for a drastic reduction in the gap between the tip of the nozzle and the steel strip, a higher degree of precision is achieved for the flatness of the gas wiping portion of the steel strip in the widthwise direction thereof.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-stated points. An object of the present invention is to provide a continuous melt-plating apparatus which is capable of maintaining a constant gap between the gas wiping nozzle and the steel strip in the widthwise direction of the strip, thereby achieving constant force with which the excess of plating melt is blown off and wiped off by the operation of the nozzle, and which is thus capable of providing platings of very uniform thickness.
In order to achieve the above-stated object, according to the present invention, a guide roller provided above the sink roller is capable of curving into a configuration arbitrarily varied in the widthwise direction of the steel strip, in such a manner that the waving and curving of the steel strip, which is very variable depending on the thickness, the width and the material of the steel strip, aging changes of the sink roller, the plating speed, and the thickness of the plating, can be coped with precisely in accordance therewith. Specifically, in order to maintain the flatness of the steel strip right at the position of the gas wiping nozzle, the pushing of the roller is provided with an arbitrary variation such as a crown-type variation in which the widthwise center of the steel strip is pushed slightly beyond the pass line of the steel strip flowing from the sink roller while the widthwise ends of the strip are kept free, or a taper-type variation in which the pushing linearly is varied widthwise from one widthwise end. According to the present invention, in order to further enhance the degree of reliability of the precision, a detector for detecting the degree of flatness of the steel strip in the widthwise direction thereof is provided downstream of the gas wiping nozzle, and feedback control is performed for adjusting the amount of variation of the guide roller's pushing, so that the flatness can be precisely maintained right at the portion corresponding to the gas wiping nozzle. Further, the steel strip cannot be held by means of rollers after it has left the plating bath until the plated melt layers cool down to solidify, during which time it travels several tens of meters. This might lead to the risk of the gap between the tip of the nozzle and the steel strip being varied by vibration of the strip which is enlarged from the vibration at the vibration source such as the sink roller. In order to avoid this risk, the bearings for the sink roller and the guide roller are disposed outside the melt in the bath, thus providing bearings with a high degree of precision. This contributes to a further increase in the precision with which the flatness of the strip is maintained.
Thus, according to the present invention, the guide roller is capable of applying a pushing, with the pushing amount being varied in the widthwise direction of the steel strip; or widthwise bending, and even waving and inclination, are caused in the guide roller per se. Feedback control is performed for adjusting the amount of variation of the guide roller's pushing. By virtue of this arrangement, it is possible to eliminate bowing, waving or the like of the steel strip in the widthwise direction thereof. Accordingly, the gap between the gas wiping nozzle and the steel strip can be maintained substantially constant in the widthwise direction, so as to achieve the above-stated object.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view schematically showing the overall structure of one embodiment of the continuous melt-plating apparatus of the present invention;
FIG. 2 is a view showing a part of the apparatus shown in FIG. 1 which includes a guide roller used in the apparatus;
FIG. 3 is a view schematically showing essential parts of the apparatus shown in FIG. 1;
FIG. 4 is a schematic illustration of the behavior of the guide roller in the embodiment;
FIGS. 5(a) to (d) are views showing various configurations of a steel strip;
FIG. 6 is a view schematically showing another embodiment of the apparatus of the present invention;
FIG. 7 is a sectional view showing a modification of the guide roller; and
FIG. 8 is a view schematically showing the overall structure including a control system of the embodiment shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described hereunder in detail with respect to embodiments thereof shown in the drawings.
FIG. 1 shows the overall structure of one embodiment of the continuous melt-plating apparatus of the present invention. The apparatus is of the type in which the surfaces of a steel strip 1 are cleaned by oxidation and reduction before plating. A steel strip 1 is continuously fed from a coil 50 through a cutting shear 51 and a welder 52 to an oxidation furnace, 53 and a reduction furnace comprising 20 a reduction zone 54 and a cooling zone 55, in these furnaces the steel strip 1 is subjected to pretreatment for plating. The steel strip 1 is fed to a plating bath 2 and is then passed therethrough. Provided in combination with the plating bath 2 are a sink roller 4, a guide roller 6, and gas wiping nozzles 8 and 8' for attaining a necessary plating thickness of molten zinc 3 attached to the steel strip 1. These members will be described later in detail. The plated steel strip 1 is fed through a deflecting roller 5 to pass through a cooling zone 56, then passes through a chromate treatment layer 57, etc., is subjected to final treatment, and is finally wound on a winding reel 58.
Referring to FIG. 2, the steel strip 1, which has a thickness of 0.2 to 3.2 mm and may be used mainly as steel plates for motor vehicles, has been heated in the upstream furnaces 53 and 54, and is kept in a condition enabling suitable formation of alloy layers without causing rapid solidification of the plated melt layers. While the steel strip 1 is kept in a reduction atmosphere, it is passed through molten zinc 3 in the plating bath 2. (The molten zinc 3 is provided for a continuous moltenzinc plating, a typical example to which the present invention may be applied; the following description will be given concerning this example). The sink roller 4 holds in position a plating bath portion of the steel strip 1 and also a portion between the sink roller 4 and the deflecting roller 5. The guide roller 6 is provided immediately downstream of the sink roller 4. A portion of the steel strip 1 which has left the plating bath 2 carries excess molten zinc 7 attached thereto. This excess molten zinc 7 is blown off and wiped off by high-temperature and high-pressure gas injected from the gas wiping nozzles 8 and 8', thereby attaining the necessary thickness of the plated layer. The distance from the gas wiping nozzles 8 and 8' to the deflecting roller 5 is about 40 m. While the steel strip 1 portion ascends through this distance, the solidification and cooling of the plated layers proceed, so that when the portion has reached the deflecting roller 5, it is cool at a suitable temperature. Thereafter, the portion passes through a cooling device, not shown, in the cooling zone 56 and is thus cooled down to normal temperature. Finally, the steel strip portion is fed to a winder where it is formed into a coil.
FIG. 2 is a plan view of the guide roller 6 shown in FIG. 3, taken from above and showing the condition in which the steel strip 1 is in contact with the guide roller 6. Two ends 9 and 9' of a shaft through the guide roller 6 are supported by spherical bearings 10 and 10' provided in a frame 11, and also by bearings 12 and 12'. The bearings 12 and 12', and the frame 11 operate in the directions indicated by the arrows shown in FIG. 2 by the action of hydraulic cylinders 13 and 13', and 14 and 14', respectively. Hydraulic pressure is delivered from a supply tank 15 by a pump 16, and is supplied through electromagnetic changeover valves 17 and 17', and 18 and 18' in accordance with the direction of operation of the corresponding hydraulic cylinders.
FIG. 4 shows the behavior of the guide roller 6 which is obtainable by the action of the hydraulic cylinders 13, 13', 14 and 14'. When the hydraulic cylinders 13 and 13' are operationally advanced, with the centers d and d' of the spherical bearings 10 and 10' being fixed by holding the hydraulic cylinders 14 and 14' at their operational intermediate positions, the guide roller 6 and the shaft 9 - 9' become curved in a concaved manner along the line c" - c - c' (shown in FIG. 4), about the centers d and d'. Conversely, when the hydraulic cylinders 13 and 13' are operationally retracted while the hydraulic cylinders 14 and 14' remain the same, the guide roller and the shaft become curved in a convex manner along the line a" - a - a', about the centers d and d'. When the hydraulic cylinders 13 and 13' are brought to their central positions while the hydraulic cylinders 14 and 14' remain the same, the guide roller becomes flat together with the shaft along the line b" - b - b'. When the hydraulic cylinder 13' is operationally advanced and the hydraulic cylinder 13 is operationally retracted, with the hydraulic cylinders 14 and 14' remaining the same, curves occur at c" - d' and d - a', with the intermediate portion d' - d of the guide roller 6 being curved along a complicated curve. If, for instance, the hydraulic cylinder 14' is operationally advanced and the hydraulic cylinder 14 is operationally retracted, the frame 11 becomes inclined toward the right-lower side, as viewed in FIGS. 2 and 4. In this case, therefore, the axes of the various curves shown in FIG. 4 each becomes inclined toward the right-lower side. Needless to say, the reverse operation is also possible.
In this way, the shaft 9 - 9' of the guide roller 6 can be curved to provide the roller surface with a convex, concave, waving, or inclined configuration, so as to cope with the curved condition of the steel strip 1. However, an alternative arrangement may be adopted in which the roller surface of the guide roller 6 per se is formed with a convex, concave, waving, or inclined configuration in accordance with the curved condition of the strip 1.
As described above, the guide roller 6 is capable of imparting to the steel strip 1 a curve in the direction of the arrow A shown in FIG. 3, the curve being arbitrarily varied in the widthwise direction of the strip 1. Specifically, if a pushing amount Δh beyond the pass line of the steel strip 1 is provided between the sink roller 4 and the guide roller 6, and if a curve arbitrarily varied in the widthwise direction is imparted to the steel strip 1 by the guide roller 6, it is possible to make the steel strip 1 flat in the widthwise direction thereof at the position of the gas wiping nozzles 8 and 8'.
While the steel strip 1 travels from the sink roller 4 to the deflecting roller 5, it actually assumes various widthwise configurations, such as those shown in FIGS. 5. It is desired that the configuration at the height of the gas wiping nozzle should be flat, as shown in FIG. 5(a), in other words, it should be such that the distance between the tip of the nozzle and the steel strip 1 is constant in the widthwise direction of the strip, so that the thickness of the plating will be uniform in the widthwise direction. From the viewpoint of maintaining the surface configuration, the distance from the sink roller 4 to the deflecting roller 5 is too long for the travel of the steel strip 1 which must be kept contact-free until the plated layers solidify. Accordingly, at the position of the gas wiping nozzles 8 and 8' located midway between the rollers 4 and 5, since the steel strip 1 has a high degree of freedom, it assumes configurations such as those shown in FIGS. 5 or more complicated configurations, depending on such factors as the hysteresis resulting from the rolling in a previous process, the tensile force, the crown configuration of the sink roller 4. In practice, correction is performed in such a manner that waving, curving, or inclination which is approximately reverse to the sectional configuration of the sink roller 4 is imparted by the guide roller 6.
If the plating speed (the steel strip line speed) is increased in view of enhancing the productivity, splashes of excess molten zinc 7 being raised from the plating bath 2 tend to adhere to the tip of the nozzles. This tendency is strong particularly when the plating speed is beyond a speed of about 130 m/min. Also, the amount of adhering zinc 7 increases. By these reasons, the height h of the nozzles must be greater than the conventionally used value of about 300 mm, and should be 500 to 800 mm. With this arrangement, however, since the correction curve or the like imparted by the guide roller 6 must be greater, the problem cannot be coped with by adopting the conventional adjustment of the pushing amount Δh alone. Thus, the degree of flatness of the steel strip 1 at the nozzle portion can be maintained only if the arrangement of the present invention is adopted.
FIG. 6 shows another embodiment. Two sink rollers 4 are provided and the shafts of the sink rollers are supported by bearings on the outside of the plating bath melt 3, and a guide roller 6 is also supported on the outside of the plating bath melt 3. In this embodiment, since the portion of contact between the sink roller 4 and the guide roller 6 is located outside of the bath melt 3, molten zinc forming the plating bath melt 3 is supplied by a pump to a position above the contact portion, thereby facilitating the attachment of molten zinc to the surfaces of the steel strip 1.
FIG. 7 shows a modification of the guide roller 6 shown in FIG. 1. The inside of the guide roller 6 is divided into small chambers denoted at 19, 19', 20, 20' and 21. Each of these small chambers is capable of expanding by hydraulic pressure delivered from a pump 24 through holes such as those denoted at 22 and 22', and through rotary couplings 23 and 23'. The pressure within the chambers are varied by means of pressure reducing values 25, 25', 26, 26' and 27, thereby adjusting the amount of expansion. For instance, when the pressure within the central chamber 21 is made relatively low while those of the chambers 20 and 20' are made slightly higher and those of the chambers 19 and 19' are made much higher, a curve 27, such as that denoted by the two-dot-chain lines in FIG. 7, can be achieved. If the pressure of the pressure reducing valves 25, 25', 26, 26' and 27 is varied, it is possible to achieve, not only the curves shown in FIG. 4, but also any arbitrary curves and inclinations varied in a more complicated manner. Although the number of the small chambers shown in FIG. 7 is five, if this number is increased, the degree of precision is further enhanced as compared to the embodiment shown in FIG. 1. In addition, waves can be set in a more linear manner and, hence, more easily.
Referring to FIG. 8, a steel strip 30 is fed from a furnace having a reduction atmosphere, and is held by sink rollers 28 and 29 while it is passed through, e.g., a molten zinc 32 within the plating bath 31 for a certain period. Similarly to the embodiment shown in FIG. 1, a guide roller 33 imparts to the steel strip 30, a waving or bowing correction in the widthwise direction. Gas wiping nozzles 34 and 34' blow off and wipe off excess molten zinc 35 attached to and raised by the steel strip 30, so as to achieve an appropriate thickness. The strip 30 further moves upward while it cools, to reach a deflecting roller 36. The bearing portions of the sink rollers 28 and 29 and the guide roller 33 are positioned higher than the upper surface of the plating bath melt 32. In contrast to the arrangement of the sink roller 4 shown in FIG. 3, if the arrangement shown in FIG. 8 is adopted, in which the bearing portions are positioned above the upper surface of the plating bath melt, it is possible to use bearings such as ball-and-roller bearings. Because such bearings involve smaller gaps than plain bearings and only a very low degree of wear, it is possible to ensure that there is substantially no loose fitting.
A plurality of range finders 37 are provided close to the steel strip 30 and arranged in the widthwise direction. These range finders 37 momentarily measure changes in the gap between the steel strip 30 and the range finders 37 resulting from the bowing and waving of the steel strip 30 in the widthwise direction. A widthwise bowing computing element 38 performs calculations on the result of this measurement. A tachometer (not shown) is mounted on the shaft of the sink roller 28, for measuring the number of revolutions of the sink roller 28. The measured value is sent to a correction bending amount computing element 39. In the element 39, the value is referred to together with the calculated current amount of the widthwise bowing and the machine eigenvalues, and the amount of waving, widthwise bending, and inclination which should be imparted by the guide roller 33 to the steel strip 30 is calculated, so that the steel strip 30 will be flat in the widthwise direction right at the position of the nozzles 34 and 34'. On the basis of a command indicating the result of this calculation, another computing element 40 calculates a necessary cylinder moving amount, and on the basis of this amount, electromagnetic valves 41 and 42 are operated for a predetermined period so as to operate hydraulic cylinders 44 and 45 in a necessary direction by a necessary amount of operation. Although two hydraulic cylinders are shown in FIG. 8, four hydraulic cylinders may be alternatively provided, as shown in FIG. 2. A further alternative arrangement may be adopted in which a roller has a plurality of small chambers, and electromagnetic hydraulic pressure reducing valves, such as the electromagnetic hydraulic pressure changeover valves shown in FIG. 7, are provided for varying the pressure within the small chambers, so as to effect necessary control.
With the above-described arrangement, since the bearing portions of the sink rollers 28 and 29 are free from loose fitting, it is possible to hold the steel strip 30 in its constant position. This advantage, together with the advantage in which the widthwise bowing and waving of the steel strip is eliminated, enables maintenance of a substantially constant the widthwise gap between the gas wiping nozzle 34 and 34' and the steel strip 30. Accordingly, the force from the nozzles with which the excess molten zinc 35 is blown off and wiped off can be kept constant, and, in this way, plating layers having very uniform thickness can be attained.
Although the above description concerned an example in which the surfaces of the steel strip 1 are cleaned by oxidation and reduction before plating, the continuous melt-plating apparatus of the present invention may also be applied in a similar manner to the case where acid cleaning and flux treatment are performed before plating.
As has been described, with the continuous melt-plating apparatus of the present invention, since the widthwise gap between the gas wiping nozzle and the steel strip can be maintained constant, it is possible to obtain plating layers having very uniform thickness. | A continuous melt-plating apparatus has a guide roller provided above the sink roller. The guide roller is capable of curving into a configuration arbitrarily varied in the widthwise direction of the strip, in such a manner that the waving and curving of the steel strip, which is very variable depending on the thickness, the width and the material of the steel strip, changes of the sink roller, the plating speed, and the thickness of the plating, can be coped with precisely in accordance therewith. A detector for detecting the degree of flatness of the steel strip in the widthwise direction is provided downstream of the gas wiping nozzle, and the curving of the guide roller is controlled through a feedback control for adjusting the amount of variation of the guide roller's pushing, so that the flatness can be precisely maintained right at the portion corresponding to the gas wiping nozzles. By virtue of this arrangement, it is possible to achieve flatness of the steel strip with a high degree of precision in the portion corresponding to the gas wiping nozzle. Therefore, the gap between the gas wiping nozzle and the steel strip can be maintained constant widthwise, thereby making constant the force from the nozzle with which excess of the plating melt is blown off and wiped off, which in turn makes it possible to obtain platings of very uniform thickness. | 2 |
This is a division of application Ser. No. 969,571 filed Dec. 14, 1978, now U.S. Pat. No. 4,222,126.
FIELD OF THE INVENTION
The invention relates to prosthetic devices, and, in particular, a valve useful in replacing natural heart valves.
BACKGROUND OF THE INVENTION
Currently there are various types of artificial heart valves which have been proposed for clinical use. They include: (1) those made of a rigid metal frame with a central occluder which functions as a check valve with each beat of the heart, (2) tissue valves made from an animal's (pig) heart valve that is stretched and sewn over a rigid metal framework to provide central flow of blood, and (3) tri-leaflet valves of limited longevity and reliability. Such valves have never been clinically acceptable.
Central occluder valves consist, typically, of "ball-in-cage" or low-profile "disc-in-cage" designs utilizing plastic, silicone rubber, carbon or metal occluders. The rubber occluders suffer from two major shortcomings: (a) they are subject to "lipid" adsorption from the blood stream with concomitant changes in dimensions and physical integrity; splitting, tearing, and clotting result (see:
Bonnabeau, R. C. Jr., and Lillehei, C. W.: "Mechanical ball failure in Starr-Edwards Prosthetic Valves", J. Thorac. Cardiovas. Surg. 56: 258, 1968;
Hylen, J. C.: "Durability of Prosthetic Heart Valves", Am. Heart J. 81: 299, 1971;
Hylen, J. C., Hodam, R. P. and Kloster, F. E.: "Changes in the Durability of Silicone Rubber in Ball-Valve Prostheses", Annals Thorac. Surg. 13: 324, 1972;
Aston, S. J. and Mulder, D. G.: "Cardiac Valve Replacement, A Seven-Year Follow-up", J. Thorac. Cardiovas. Surg. 61: 547, 1971;
Starr, A., Pierie, W. R., Raible, D. A., Edwards, M. L., Siposs, G. C., and Hancock, W. D.: "Cardiac Valve Replacement, Experience With the Durability of Silicone Rubber", Suppl. I to Circulation, 33, 34, April 1966) and
(b) they possess a low order of wear resistance (see Boretos, J. W., Detmer, D. E. and Donachy, J. H. "Segmented Polyurethane: A polyether Polymer, II, Two Years Experience", J. Biomed. Mater. Res. 5: 373, 1971).
Clinical evidence with the "low profile" design exemplifies this characteristic, (Detmer, D. E.; McIntosh, C. L.; Boretos, J. W.; Braunwald, N. S.: "Polypropylene Poppets for Low-Profile Prosthetic Heart Valve", Annals Thorac. Surg. 13: 122, 1972).
The metal and carbon occluders are: (a) abrasive to cloth covered struts causing fragmentation of the cloth with ensuing emboli, (Detmer, D. E. and Braunwald, N. S.: "The Metal Poppet and the Rigid Prosthetic Valve", J. Thorac. Cardiovas. Surg. 61: 175 1971;
Ablaza, S. G. G., Blanco, G., Javan, M. B., Maranhao, V. and Goldberg, H. "Cloth Cover Wear of the Struts of the Starr-Edwards Aortic Valve Prosthesis", J. Thorac, Cardiovas. Surg. 61: 316, l971;
Thomas, C. S., Killen, D. A., Alford, W. C., Burrus, G. R. and Stoney, W. S.: "Cloth Disruption in the Starr-Edwards Composite Mitral Valve Prosthesis", Annals Thorac. Surg. 15: 434, 1973).
Cloth covering has been shown to minimize thrombus formation on metal frames and is generally considered necessary for these designs, (Detmer, D. E. and Braunwald, N. S. "The Metal Poppet and the Rigid Prosthetic Valve", J. Thorac. Cardiovas. Surg. 61: 175, 1971;
Ablaza, S. G. G., Blanco, G., Javan, B. B., Maranhao, V. and Goldberg, H. "Cloth Cover Wear of the Struts of the Starr-Edwards Aortic Valve Prosthesis", J. Thorac. Cardiovas. Surg. 61: 316, 1971 ).
However, paravalvular leaks caused by cloth wear on the valve seats are responsible for high blood hemolysis, (Thomas, C. S., Killen, D. A., Alford, W. C., Burrus, G. R. and Stoney, W.: "Cloth Disruption in the Starr-Edwards Composite Mitral Valve Prosthesis", Annals Thorac. Surg. 15: 434, l973).
The metal and carbon occulders are also: (b) abrasive to bare metal valve surfaces, especially for metal to metal contact, and (c) hard and they accordingly generate a "clicking" sound with each cycle. This noise and its associated anticipation is highly distressing to patients. In addition, in metal and carbon occluders (d) the central flow of blood is blocked by the presence of the occluder, reducing the potential volume output, increasing resistance to flow, and causing turbulance of flow which is believed to add to the incidence of thrombo embolism.
Tissue valves are generally made by sewing excised pig valves over a rigid framework. These have the following disadvantages: (a) Tissue valves individually variable due to the fact that they are extracted from a living animal and subject to extremes of physical and physiological differences which have occured during growth of the animal (b) There is no absolute way of testing individual valves for strength and durability prior to use. (c) Fixation techniques must be used to preserve tissue valves after extraction and during fabrication and storage and bacterial invasion has been difficult to control. Absolute sterility is difficult to assure, and patients occasionally become physically distressed due to bacterial endocarditis following surgical placement of a tissue valve. (d) Long-term implants have shown evidence of calcium deposits generated on the surface of the leaflets in some cases rendering them stiff and non-functional. (e) Tissue valves are not suitable for use in artificial heart assist devices where assembly, storage, and sterilization of the device must be done well in advance of surgery and under conventional sterilization techniques which would greatly impair or destroy living tissues.
Over the past 20 years a number of trileaflet valves has been constructed. Various materials and combinations of materials such as epoxies, silicones, Teflon, Dacron, and polyester polyurethanes have been used. For example, the patent to Sako et al, U.S. Pat. No. 3,940,802 discloses a non-toxic compound for use in heart valves, comprising 100 parts by weight PVC and 50-100 parts by weight of polyurethane. Generally these valves have been clinically unsuccessful for the following reasons: Sinicone-Dacron polyester valves of a trileaflet configuration require the cusps to be made thick, relative to normal tissue valves, to give them strength and shape. Unreinforced silicone rubber is too weak to be used alone. Unfortunately, the Dacron reinforcement prevents efficient opening and closing of the valve and significantly reduces the flexural fatigue resistance of the silicone. Fracture of the fibers results in premature failure. Poor performance in the form of regurgitation of blood is a common problem with such stiff valves.
Uncoated fabric valves of Dacron or Teflon have proven unsatisfactory because of the loss of function due to heavy fiberous tissue ingrowth which impairs opening and closing. Teflon has been shown to rapidly fragment due to fatigue failure.
Polyurethane tri-leaflet valves attempted in the past suffer from the following defects: (a) Leaflets detach from their mounting frames when assembled from individual leaflets. (b) Leaflets flex-fatigue at the mounting frame when the frame is rigid, concentrating the flexural strain pattern at a point along the rigid-flexible junction. (c) The thin leaflet construction, when unreinforced, has a propensity to tear along its commissure line; reinforced materials are too stiff to function (d) Previous polyurethane leaflet valves were constructed of a hydrolytically unstable polyester polyurethane which rapidly degrades in the blood stream causing premature failure. (e) Thrombi generated on the surface were common occurrences with earlier designs using polyester polyurethanes. (f) Use of dissimilar materials can induce adverse reactions in designs where polyurethane leaflets are attached to an epoxy frame. In such cases, residual amines from the epoxy can migrate into the polyurethane causing degradation of physical properties and adverse surface characteristics may develop which can stimulate an inflamatory, toxic, or otherwise incompatible condition.
The patents to Hancock, U.S. Pat. No. 3,755,823; Parsonnet, U.S. Pat. No. 3,744,062, and Kischer, U.S. Pat. No. 3,548,417 are examples of prior art heart valves which suffer from one or more of the defects noted above.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to overcome the deficiencies of the prior art, such as mentioned above.
It is another object to provide for improved heart function for hearts having diseased or otherwise defective valves.
It is a further object of the present invention to provide an artificial heart valve made of polyurethane, having three projecting struts integral with an elastomeric membrane whose contours make up the three leaflets of the valve.
It is a further object of the present invention to provide an artificial heart valve made of polyurethane, preferably polyether polyurethane, which has outstanding physical strength and durability, physiological acceptability and can be easily manufactured.
If the heart should fail during surgery and not respond to emergency measures such as electrical stimulation, drugs, or intravascular balloon techniques, the surgeon may elect to sustain life with an artificial assist pump to maintain function until normal cardiac output is restored. Although assist pumps are still in the developmental stage, some designs have been successful for periods of several weeks in experimental animals and to a limited extent clinically. These devices incorporate conventional artificial heart valves for controlling diastolic/systolic sequelae. The present tri-leaflet valve can be used in these devices and is capable of providing unobstructed flow, minimal turbulence, efficient cyclic performance, and endurance.
The device which achieves these objectives uses a "unitized" trileaflet design, comprising a semi-rigid polyurethane framework whose three projecting struts are an integral part of and support, a one-piece, highly flexible, elastomeric membrane whose contours make up the three leaflets of the valve. The leading edges of the leaflets, which go together to form the commissure line, are reinforced with a narrow band of the same elastomer which makes up the membrane leaflets and is an integral part of the membrane. Further reinforcement by means of radiating lines projecting from the frame into the leaflet area combine with a smooth and filleted transition line between the two to enhance strength and durability without appreciably adding bulk or stiffness. These lines simulate collagen formation as it appears in natural leaflets. A compliant base which is a permanent part of the valve body provides for attachment of the valve to the tissues of the heart.
The invention offers mechanical reliability in the form of outstanding physical strength and durability, improved functional performance, physiological acceptability, and practical manufacturing capabilities. The combination of these attributes offers a degree of sophistication and utility not previously available in artificial heart valves.
The unitized tri-leaflet construction offers mechanical reliability in the following manner:
(a) leaflets are not readily torn or fatigued due to flexing during use;
(b) the valve does not require the use of cloth, flocking or other textile forms for strength;
(c) the possibility of abrasion due to bearing or rubbing surfaces is avoided;
(d) leaflets are of a thin membrane structure and biaxially oriented for unusually high strength and durability while, at the same time, maintaining a gossimer-like characteristic for ease of operation at normal blood pressures;
(e) the entire structure is made from one material, such as polyether polyurethane, thereby precluding the possibility of interactions between dissimilar materials;
(f) all three leaflets are basically one piece and cannot separate from each other or the frame to which they are attached;
(g) the edges or lips of the leaflets are heavier than the main body of the leaflets and form a tight and durable seal at the commissure line of the valve with each closing cycle whereby flexing of the valve struts accomodates the complete and natural closing configuration and minimizes stress along the leaflet edges;
(h) the junction between the leaflets and the frame is a smooth transition to obviate stress concentration and distribute it throughout;
(i) radiating lines from the above junction add additional reinforcement for flexural strength and stress distribution without increasing bulk or stiffness;
(j) valves of this design are not subject to being mis-shapened due to misalignment when sutured in place of the natural valve;
(k) the base of the valve cannot be detached and is a permanent part of the valve;
(l) the base can be of a rigid polurethane flange shape or a flexible porous or foam polyurethane construction or a combination of both, and can be covered with cloth or incorporate cloth padding to lend strength and ease of insertion for permanent fixation to the living tissues, heart wall or vessel.
The unitized tri-leaflet construction offers improved functional performance by:
(a) allowing for uninterrupted central laminar flow of blood similar to that of the natural valve;
(b) providing the leaflets with a gossimer nature that offers very little resistance;
(c) providing rapid opening and closing;
(d) providing complete, unobstructed opening and complete non-regurgitant closing;
(e) simulating the natural valve in size and shape without blocking adjacent blood vessel orifices when implanted;
(f) providing struts that are rigid enough not to allow the leaflets to invert upon themselves even though a very low profile is used.
The unitized tri-leaflet construction offers physiological acceptability by:
(a) providing surfaces which are compatible with the blood and of a polyether urethane type;
(b) providing surfaces which are free from tissue-in-growth of fibrous encapsulation;
(c) providing a valve which is hydrolytically and enzymatically stable and does not degrade in the blood stream over extended periods of time;
(d) providing surfaces which are smooth and clean and do not encourage calcium deposits on their surfaces;
(e) obviating the formation of emboli to the brain or lungs by excluding release of fragments of textile materials from flexing areas of the valve;
(f) using biocompatible polyurethanes of a polyether type which are free from absorption of body fluids which could alter them physically or chemically;
(g) providing all surfaces that can be readily treated with anti-coagulants or other blood compatible materials.
The unitized tri-leaflet design offers practical manufacturing capabilities by being:
(a) readily sterilized by conventional methods;
(b) manufactured in large numbers. Its structure can be varied in size according to patient needs and does not rely upon living donors;
(c) constructed entirely from man-made materials and as such is suiable for use in artificial heart assist devices which must undergo conditions of complex assembly, sterilization and storage;
(d) industrially producible to a high degree of duplication and reliability.
Polyether polyurethanes, from which the valve can be made, have shown themselves to have outstanding biocompatibility, strength, flex-life, and versatility.
For a better understanding of the invention, a possible embodiment thereof will now be described with reference to the attached drawing, it being understood that this embodiment is exemplary and not limitative.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the heart valve of the present invention, in the diastolic mode;
FIG. 2 is a perspective view of the embodiment of FIG. 1 in the open position during systole;
FIG. 3 is a top view of the heart valve of the embodiment of FIG. 1.
FIG.4 is a horizontal sectional view taken along line 4--4 of FIG. 1; and
FIGS. 5 and 6 are vertical sectional views along lines 5--5 and 6--6, respectively, of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A tri-leaflet heart valve 10 as shown in FIG. 1 comprises a rigid polyurethane frame 12 covered with a one-piece membrane 14 that forms the three polyurethane leaflets 14a, 14b, and 14c and bonded in place to the frame 12 to form a single integral unit. The material of construction can be any polyether polyurethane such as Biomer ® (Ethicon, Inc.) or Pellethane ® (Upjohn Co.) or a combination of these and others that have biocompatibility and strength.
The frame 12 is of a construction which serves to anchor the leaflets and maintain proper alignment after implantation. The frame 12 consists of two distinct but inseparable areas, namely a base ring 12' which establishes the orifice size, and the three struts 12a, 12b and 12c which support the leaflets and distribute the strain of cyclic flexing. The height of the struts 12a, 12b and 12c are important, as when the struts are too short (less than 1/4 inch), the strain force in the leaflets 14a, 14b, and 14c caused by the blood pressure against them becomes seriously high. Sustained operation under these conditions would result in rapid fatigue failure of the leaflets. To avoid this problem, the height of the leaflets 14a, 14b and 14c can exceed the height of the struts. When the struts 12a, 12b and 12c are too long (more 3/4 inch), the bending force against the struts, caused by the pressure of the blood against the leaflets, concentrates the strain at a point within the struts leading to fatigue. Thus, the most suitable and preferred length of the struts 12a, 12b and 12c is 1/2 to 3/4 inch and most particularly 1/2 inch. With this construction, the stress within the struts and the leaflets is reduced to an optimum level.
The construction of the leaflets 14a, 14b and 14c are such that they function similarly to that of the natural heart valve even though they are partially supported by the frame 12. In the open position, i.e. when the blood is flowing freely throughout the central opening formed by the leaflets as shown in FIG. 2, the orifice consists of a complete and uninterrupted circle equal to or larger than the inside diameter of the base ring 12', thereby providing unrestrained and laminar fluid flow. This flow pattern does much to obviate artificially induced thrombii that could be produced due to random flow patterns, turbulence of back-flow. In the closed position, i.e. when the blood is checked from flowing through the heart valve, as shown in FIG. 1, the leaflets abut each other at the commissure line 16 insuring complete closure and competency. Strain levels along the commissure line 16 are reduced to a minimum by the distribution of strain to the frame struts 12a, 12b and 12c and through the body of the device.
Further, the membrane 14 is provided with a thickened lip 18 which forms the free ends of the leaflets 14a, 14b, and 14c which thickened lip 18 effects strong sealing along the commissure line 16. This lip 18 approaches the size and shape of the natural commissure line of human heart valve. Tear strength of the lip 18 is equivalent of that of a film 10 times the thickeness of any one leaflet. The combination of this heavy lip and leaflet provides for unusually reliable longevity since the ease of flexing depends upon the gossimer nature of the leaflet and the resistance to fatigue and tear upon the strength of the leading edge, i.e. the lip 18.
Provision is made to distribute any flexural stress at the base of the leaflets 14a, 14b and 14c where they join and frame by means of a smooth transitional area 20 of tapering thickness. Also, in conjunction with this transitional area20 are radiating lines 22 consisting of heavier areas that give additional strength to the leaflets without adding to their overall bulk. These radiating reinforcement lines 22 serve also as built-in struts to aid in preventing prolapse of the leaflets and add dimensional stability over the extended periods of flexing.
The base 12' of the valve 10 serves as a suture ring which can be constructed from the same material as the rest of the frame or from a semi-rigid polyurethane foam as previously described. Cloth can be added for additional cushioning if desired. While the base 12' is preferably formed unitary with the struts 12a, 12b and 12c to form a one-piece frame 12 as shown, it will be understood that it can be formed as a separate flange piece and permanently bonded in place to the rest of the frame 12. The frame 12 which consists of the base ring section 12' and three struts 12a, 12b and 12c can be readily injection molded from Pellethane polyurethane (a polyether urethane) or the equivalent, under heat and pressure to form a uniform one-piece unit free from seams, joints, welds or other strain areas. A valuable adjunct to the injection molding of the frame is the incorporation of a vacuum chamber over the feeding hopper and hot-melt area of the machine. Much of the quality of the frame 12 is due to the total exclusion of small amounts of air which are usually trapped within injection molded parts. This arrangement excludes such inclusions and significantly increases the strength and fatigue resistance of the frame.
Subsequent annealing of the frame 12 is an important aspect of the fabrication scheme. Through this procedure, residual strains induced by the molding process are relieved, solvent resistance is significantly improved and heat distortion temperature is increased. A suitable set of conditions for this annealing is 200°-300° F. for 1 to more than 24 hours. In particular, 220°-260' F. for 12-20 hours or 240' F. for 16 hours, depending upon size of the frame, is suitable.
The three leaflets 14a, 14b and 14c which utlimately are attached to the frame 12, to make a one-piece unit 10, are formed in a series of steps. These steps consists of (1) forming a thin membrane by solvent casting techniques, (2) reinforcing the commissure area and radiating base lines by build-up discretely heavier areas, (3) drying the membrane and removing it from its former, (4) placing the so-formed membrane over a mandrel of metal (or any other rigid, heat resistant material) whose shape resembles that of the final leaflet design and (5) vacuum forming with heat and negative pressure to permanently establish the leaflet shape. These steps will be discussed seriatim.
(1) Forming a thin membrane by solvent casting
A dipping mandrel, such as a round ended glass tube, is carefully lowered into a solvent solution of the polyurethane and carefully withdrawn to preclude inclusion of entrapped air. Several dips may be required to achieve the appropriate thickness of polymer onto the glass. Prior to dipping, vacuum is used to remove all traces of air from the solution. Several solvents are suitable to achieve the optimum dipping viscosity such as dimethyl acetamide, tetrahydrafuran, dimethyl formamide, cyclohexanone, etc. A thin syrup-like consistency is best to provide enough body yet prevent the aforementioned inclusion of air. Once the appropriate thickness is achieved, the membrane is dried slowly in an air circulating oven to remove all traces of solvent. The membrane can then be readily stripped from the glass and is ready for the next step of the sequence.
(2) Reinforcing the commissure area by building up a heavy edge of the membrane
Before removing the membrane from the mandrel, as previously described, the lip or leading edge of the so-formed leaflet is built-up with a heavier band of polyurethane. This band is intended to add strength and tear resistance to the membrane in the area of the commissure line. This can conveniently be done by providing the glass mandrel with a groove into which the polyurethane will accumulate excessively. The shape of the groove can vary from three symmetrically arranged loops to a simple circumferential one. Excess material from this lip can be precisely removed by cutting with a razor knife while the entire assembly is afixed in a machine lathe. The radiating lines 22 extending from the base of the leaflets are formed in the same manner.
(3) Drying the membrane and removing it from its former
It is essential that all solvent be removed from the membrane. This may be accomplished by drying overnight in a filtered air circulating oven at 50° C. Upon drying, the film can be readily peeled off the glass.
(4) Placing pre-formed membrane over a mandrel of metal whose shape resembles that of the final leaflet design and vacuum forming.
The pre-formed membrane is placed over a metal mandrel having the shape of the final construction. Vacuum and heat are applied, typically 15 psi for 5 minutes to one hour at 240-320° F. The hot assembly is allowed to cool to room temperature before the vacuum is cut off and the formed membrane removed.
The polyurethane frame 12 and the formed three leaflet membrane 14 are then joined as an integral unit in the following manner: The frame is oriented over a mandrel containing the shape of the tri-leaflet design (similar to that previously described). The pre-formed leaflet membrane is placed over the frame which has been treated with a coating of solvent (e.g. one of those solvents previously mentioned). This provides a bonding site in the area where the membrane overlaps the frame. An outer chamber of silicone rubber is used to cover the above assembly and provides a means of applying positive pressure to the bond line. This pressure is applied until the bond becomes permanent (typically about 5 minutes to one hour). The frame and its now intact membrane is removed from the assembly. The suture ring 12' if not formed unitary with the remainder of the frame, is applied to the frame's base. The final unit is dried in a filter air circulating oven at 50° C. overnight or until all solvent is removed.
The valve 10 is typically 0.55" high with a 0.86" inner diameter and 1.35" outer diameter (of the base ring 12' ). The membrane 14 is suitably 4 to 10 mils thick with the commissure lip 18 being 8-30 mils thick and 20-80 mils wide.
Example
A tri-leaflet valve, constructed entirely of polyether urethane to optimize compatibility and strength, consists of a semi-rigid polyurethane framework 12 of 75 shore "D" durometer whose three projecting struts are continuous with and support of one-piece, highly flexible 0.15 mm membrane 14 of 80 shore "A" durometer which makes up the three leaflets of the valve. The leading edge of the leaflets forms the commissure and is reinforced with a narrow integral band of the same elastomer. Further reinforcement lines radiate from the frame/leaflet junction 20 to enhance durability without contributing appreciable bulk or stiffness. The highly gossimer leaflets require minimal operating force yet possess strength necessary at points of stress. Uniform stress distribution is effected by the flexibility of the valve frame which moves with the leaflets. The base 12' acts as a torsion bar to impart rigidity to the struts to prevent inversion.
Such valve 10 is formed using a two stage injection molding process from two polyurethanes of different hardnesses. Bond strengths at the interface approach that of the parent materials. Complex contours are achieved by machining and photoetching the stainless steel molds.
The valve obviates problems associated with previous tri-leaflet valves such as disruption of the union between frame and leaflets, premature leaflet failure and hydrolytic stability.
In vitro tests run on a modified pulse duplicator (Cornhill, J. F.: "An aortic-left ventricular pulse duplicator used in testing prosthetic aortic heart valves," J. Thorac. & Cardio. Surg. 73: 550-558, 1977) show performance to be near physiological over a wide range of heart rates, systolic/diastolic ratios, left ventricular and aortic pressures, flow rates, and fuid viscosity. Flow visualization using cinemaphotography shows complete closure and well oriented alignment along the commissure line with minimal regurgitation or stasis. Accelerated tests at twice the normal rate over a period of 14 days resulted in little or no change in dimensions and wear.
It will be obvious 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 in the drawing and described in the specification. | An artificial heart valve comprising a semi-rigid framework having three projecting symmetrical struts and open axially therethrough, as well as a polyurethane elastomeric membrane attached to the struts and constituting three leaflets, is formed by molding the framework, including the base and strut, using polyurethane resin; forming the elastomeric membrane, of polyurethane resin which is thin relative to the framework, and forming a thickened commissure along the leading edge of the membrane as well as reinforcing lines radiating from its base; then joining the framework with the elastomeric membrane using an adhesive cement so as to permanently bond the membrane to the framework. | 5 |
BACKGROUND OF THE INVENTION
The invention relates to analysis of xerographic processes, and more particularly, to the precise determination of failed parts within the xerographic process.
As reproduction machines such as copiers and printers become more complex and versatile, the interface between the machine and the service representative must necessarily be expanded if full and efficient trouble shooting of the machine is to be realized. A suitable interface must not only provide the controls, displays, fault codes, and fault histories necessary to monitor and maintain the machine, but must do so in an efficient, relatively simple, and straightforward way. In addition, the machine must be capable of in depth self analysis and either automatic correction or specific identification of part failure to minimize service time.
Diagnostic methods often require that a service representative perform an analysis of the problem. For example, problems with paper movement in a machine can occur in different locations and occur because of various machine conditions or failure of various components. In the prior art, this analysis by the service representative has been assisted by recording fault histories in the machine control to be available for readout and analysis. For example, U.S. Pat. No. 5,023,817, assigned to the same assignee as the present invention, discloses a method for recording and displaying in a finite buffer, called a last 50 fault list, machine faults as well as fault trends or near fault conditions. This data is helpful in diagnosing a machine. It is also known in the prior art, to provide a much larger data log, known as an occurrence log, to record a variety of machine events.
In addition U.S. Pat. No. 5,023,817, assigned to the same assignee as the present invention, discloses a technique to diagnose a declared machine fault or a suspected machine fault by access to a library of fault analysis information and the option to enter fault codes to display potential machine defects related to the fault codes. It is also known, as disclosed in U.S. Pat. No. 5,533,193 to save data related to given machine events by selectively setting the control to respond to the occurrence of a given machine fault or event, monitoring the operation of the machine for the occurrence of the given machine event, and initiating the transfer of the data in a buffer to a non-volatile memory.
It is also known to be able to monitor the operation of a machine from a remote source by use of a powerful host computer having advanced, high level diagnostic capabilities. These systems have the capability to interact remotely with the machines being monitored to receive automatically initiated or user initiated requests for diagnosis and to interact with the requesting machine to receive stored data to enable higher level diagnostic analysis. Such systems are shown in U.S. Pat. Nos. 5,038,319, and 5,057,866 owned by the assignee of the present invention. These systems employ Remote Interactive Communications to enable transfer of selected machine operating data (referred to as machine physical data) to the remote site at which the host computer is located, through a suitable communication channel. The machine physical data may be transmitted from a monitored document system to the remote site automatically at predetermined times and/or response to a specific request from the host computer.
A difficulty with prior art diagnostic services is the inability to easily and automatically pinpoint the precise parts or subsystems in a machine causing a malfunction or deteriorating condition. It would be much more economical to be able to simply replace a part than to exert significant time and effort trying to correct or repair the part. This is the trend in today's high tech system environment. It would be desirable, therefore, to provide a highly intelligent, automated diagnostic system that provides an indication of the need to replace specific parts or subsystems rather than the need for extensive service troubleshooting to minimize machine downtime.
In copying or printing systems, such as a xerographic copier, laser printer, or ink-jet printer, a common technique for monitoring the quality of prints is to artificially create a "test patch" of a predetermined desired density. The actual density of the printing material (toner or ink) in the test patch can then be optically measured to determine the effectiveness of the printing process in placing this printing material on the print sheet.
In the case of xerographic devices, such as a laser printer, the surface that is typically of most interest in determining the density of printing material thereon is the charge-retentive surface or photoreceptor, on which the electrostatic latent image is formed and subsequently, developed by causing toner particles to adhere to areas thereof that are charged in a particular way. In such a case, the optical device for determining the density of toner on the test patch, which is often referred to as a toner area coverage sensor or "densitometer", is disposed along the path of the photoreceptor, directly downstream of the development of the development unit. There is typically a routine within the operating system of the printer to periodically create test patches of a desired density at predetermined locations on the photoreceptor by deliberately causing the exposure system thereof to charge or discharge as necessary the surface at the location to a predetermined extent.
The test patch is then moved past the developer unit and the toner particles within the developer unit are caused to adhere to the test patch electrostatically. The denser the toner on the test patch, the darker the test patch will appear in optical testing. The developed test patch is moved past a densitometer disposed along the path of the photoreceptor, and the light absorption of the test patch is tested; the more light that is absorbed by the test patch, the denser the toner on the test patch. Xerographic test patches are traditionally printed in the interdocument zones on the photoreceptor. Generally each patch is about an inch square that is printed as a uniform solid half tone or background area. Thus, the traditional method of process controls involves scheduling solid area, uniform halftones or background in a test patch. Some of the high quality printers contain many test patches.
It would be desirable, therefore, to be able to use a simple toner area coverage sensor rather than a complex sensor system to provide machine data to be able to diagnose a machine and identify specific part or subsystem failures or malfunctions. It would also be desirable to provide a systematic, logical test analysis scheme to assess machine operation from a simple sensor system and to be able to pinpoint parts, components, and subsystems needing replacement.
It is an object of the present invention, therefore, to provide a new an improved technique for machine diagnosis, in particular, to be able to identify precise components or parts for replacement to maintain machine operation. It is another object of the present invention to provide a highly intelligent, automated diagnostic system that identifies the need to replace specific parts rather than the need for extensive service troubleshooting to minimize machine downtime. It is still another object of the present invention to provide a systematic, logical test analysis scheme to assess machine operation from a simple sensor system and to be able to pinpoint parts and components needing replacement.
Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.
SUMMARY OF THE INVENTION
The invention includes a highly intelligent, automated diagnostic system that identifies the need to replace specific parts to minimize machine downtime rather than require extensive service troubleshooting. In particular, a systematic, logical test analysis scheme to assess machine operation from a simple sensor system and to be able to pinpoint parts and components needing replacement is provided by a series of first level of tests by the control to monitor components for receiving a first level of data and by a series of second level of tests by the control to monitor components for receiving a second level of data. Each of the first level tests and first level data is capable of identifying a first level of part failure independent of any other test. Each of the second level tests and second level data is a combination of first level tests and first level data or a combination of a first level test and first level data and a third level test and third level data. The second level tests and second level data are capable of identifying second and third levels of part failure. Codes are stored and displayed to manifest specific part failures.
DETAILED DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference may be had to the accompanying drawings wherein the same reference numerals have been applied to like parts and wherein:
FIG. 1 is an elevational view illustrating a typical electronic imaging system incorporating a technique of fault isolation and part replacement in accordance with the present invention;
FIG. 2 illustrates the generation of control test patches for use with a toner area coverage sensor;
FIG. 3 shows a typical developer and toner dispense system;
FIGS. 4 and 5 are a general flow chart illustrating a general technique for fault isolation in accordance with the present invention;
FIGS. 6 and 7 are a more detailed flow chart illustrating actuator performance indicators in accordance with the present invention;
FIG. 8 is a more detailed flow chart illustrating the ROS pixel growth detector in accordance with the present invention;
FIG. 9 illustrates tribo decay recovery in accordance with the present invention;
FIGS. 10, 11, and 12 show seam signature analysis in accordance with the present invention; and
FIG. 13 illustrates outgassing deterioration detection in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will hereinafter be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.
Turning to FIG. 1, the electrophotographic printing machine 1 employs a belt 10 having a photoconductive surface 12 deposited on a conductive substrate 14. By way of example, photoconductive surface 12 may be made from a selenium alloy with conductive substrate 14 being made from an aluminum alloy which is electrically grounded. Other suitable photoconductive surfaces and conductive substrates may also be employed. Belt 10 moves in the direction of arrow 16 to advance successive portions of photoconductive surface 12 through the various processing stations disposed about the path of movement thereof. As shown, belt 10 is entrained about rollers 18, 20, 22, 24. Roller 24 is coupled to motor 26 which drives roller 24 so as to advance belt 10 in the direction of arrow 16. Rollers 18, 20, and 22 are idler rollers which rotate freely as belt 10 moves in the direction of arrow 16.
Initially, a portion of belt 10 passes through charging station A. At charging station A, a corona generating device, indicated generally by the reference numeral 28 charges a portion of photoconductive surface 12 of belt 10 to a relatively high, substantially uniform potential.
Next, the charged portion of photoconductive surface 12 is advanced through exposure station B. At exposure station B, a Raster Input Scanner (RIS) and a Raster Output Scanner (ROS) are used to expose the charged portions of photoconductive surface 12 to record an electrostatic latent image thereon. The RIS (not shown), contains document illumination lamps, optics, a mechanical scanning mechanism and photosensing elements such as charged couple device (CCD) arrays. The RIS captures the entire image from the original document and coverts it to a series of raster scan lines. The raster scan lines are transmitted from the RIS to a ROS 36.
ROS 36 illuminates the charged portion of photoconductive surface 12 with a series of horizontal lines with each line having a specific number of pixels per inch. These lines illuminate the charged portion of the photoconductive surface 12 to selectively discharge the charge thereon. An exemplary ROS 36 has lasers with rotating polygon mirror blocks, solid state modulator bars and mirrors. Still another type of exposure system would merely utilize a ROS 36 with the ROS 36 being controlled by the output from an electronic subsystem (ESS) which prepares and manages the image data flow between a computer and the ROS 36. The ESS (not shown) is the control electronics for the ROS 36 and may be a self-contained, dedicated minicomputer. Thereafter, belt 10 advances the electrostatic latent image recorded on photoconductive surface 12 to development station C.
One skilled in the art will appreciate that a light lens system may be used instead of the RIS/ROS system heretofore described. An original document may be positioned face down upon a transparent platen. Lamps would flash light rays onto the original document. The light rays reflected from original document are transmitted through a lens forming a light image thereof. The lens focuses the light image onto the charged portion of photoconductive surface to selectively dissipate the charge thereon. The records an electrostatic latent image on the photoconductive surface which corresponds to the informational areas contained within the original document disposed upon the transparent platen.
At development station C, magnetic brush developer system, indicated generally by the reference numeral 38, transports developer material comprising carrier granules having toner particles adhering triboelectrically thereto into contact with the electrostatic latent image recorded on photoconductive surface 12. Toner particles are attracted form the carrier granules to the latent image forming a powder image on photoconductive surface 12 of belt 10.
After development, belt 10 advances the toner powder image to transfer station D. At transfer station D a sheet of support material 46 is moved into contact with the toner powder image. Support material 46 is advanced to transfer station D by a sheet feeding apparatus, indicated generally by the reference numeral 48. Preferably, sheet feeding apparatus 48 includes a feedroll 50 contacting the uppermost sheet of a stack of sheets 52. Feed roll 50 rotates to advance the uppermost sheet from stack 50 into sheet chute 54. Chute 54 directs the advancing sheet of support material 46 into a contact with photoconductive surface 12 of belt 10 in a timed sequence so that the toner powder image developed thereon contacts the advancing sheet of support material at transfer station D.
Transfer station D includes a corona generating device 56 which sprays ions onto the backside of sheet 46. This attracts the toner powder image from photoconductive surface 12 to sheet 46. After transfer, the sheet continues to move in the direction of arrow 58 onto a conveyor 60 which moves the sheet to fusing station E.
Fusing station E includes a fuser assembly, indicated generally by the reference numeral 62, which permanently affixes the powder image to sheet 46. Preferably, fuser assembly 62 includes a heated fuser roller 64 driven by a motor and a backup roller 66. Sheet 46 passes between fuser roller 64 and backup roller 66 with the toner powder image contacting fuser roll 64. In this manner, the toner powder image is permanently affixed to sheet 46. After fusing, chute 68 guides the advancing sheet to catch tray 70 for subsequent removal from the printing machine by the operator.
Invariably, after the sheet of support material is separated from photoconductive surface 12 of belt 10, some residual particles remain adhering thereto. These residual particles are removed from photoconductive surface 12 at cleaning station F. Cleaning station F includes a preclean corona generating device (not shown) and a rotatably mounted preclean brush 72 in contact with photoconductive surface 12. The preclean corona generator neutralizes the charge attracting the particles to the photoconductive surface. These particles are cleaned from the photoconductive surface by the rotation of brush 72 in contact therewith. One skilled in the art will appreciate that other cleaning means may be used such as a blade cleaner. Subsequent to cleaning, a discharge lamp (not shown) discharges photoconductive surface 12 with light to dissipate any residual charge remaining thereon prior to the charging thereof for the next successive imaging cycle.
A control system coordinates the operation of the various components. In particular, controller 30 responds to sensor 32 and provides suitable actuator control signals to corona generating device 28, ROS 36, and development system 38 which can be any suitable development system such as hybrid jumping development or a mag brush development system. The actuator control signals include state variables such as charge voltage, developer bias voltage, exposure intensity and toner concentration. The controller 30 includes an expert system 31 including various logic routines to analyze sensed parameters in a systematic manner and reach conclusions on the state of the machine. Changes in output generated by the controller 30, in a preferred embodiment, are measured by a toner area coverage (TAC) sensor 32. TAC sensor 32, which is located after development station C, measures the developed toner mass for difference area coverage patches recorded on the photoconductive surface 12. The manner of operation of the TAC sensor 32, shown in FIG. 1, is described in U.S. Pat. No. 4,553,003 which is hereby incorporated in its entirety into the instant disclosure. TAC sensor 32, is an infrared reflectance type densitometer that measures the density of toner particles developed on the photoconductive surface 12.
Referring to FIG. 2, there is illustrated a typical composite toner test patch 110 imaged in the interdocument area of photoconductive surface 12. The photoconductive surface 12, is illustrated as containing two documents images image 1 and image 2. The test patch 110 is shown in the interdocument space between image 1 and image 2 and in that portion of the photoconductive surface 12 sensed by the TAC sensor 32 to provide the necessary signals for control. The composite patch 110, in a preferred embodiment, measures 15 millimeters, in the process direction, and 45 millimeters, in the cross process direction and provides various halftone level patches such as an 87.5% patch at 118, a 50% halftone patch at 116 and a 12.5% halftone patch at 114.
Before the TAC sensor 32 can provide a meaningful response to the relative reflectance of patch, the TAC sensor 32 must be calibrated by measuring the light reflected from a bare or clean area portion 112 of photoconductive belt surface 12 such as 113 or test patch 110 before development. For calibration purposes, current to the light emitting diode (LED) internal to the TAC sensor 32 is increased until the voltage generated by the TAC sensor 32 in response to light reflected from the bare or clean are 112 is between 3 and 5 volts.
It should be understood that the term TAC sensor or "densitometer" is intended to apply to any device for determining the density of print material on a surface, such as a visible-light densitometer, an infrared densitometer, an electrostatic voltmeter, or any other such device which makes a physical measurement from which the density of print material may be determined.
FIG. 3 shows in greater detail developer unit 38 illustrated in FIG. 1. The developer unit includes a developer 86 which could be any suitable development system, such as hybrid jumping development or mag brush development, for applying toner to a latent image. The developer is generally provided in a developer housing and the rear of the housing usually forms a sump containing a supply of developing material. A (not shown) passive crossmixer in the sump area generally serves to mix the developing material.
The developer 86 is connected to a toner dispense assembly shown as 46 including a toner bottle 88 providing a source of toner particles, an extracting auger 90 for dispensing toner particles from bottle 88, and hopper 92 receiving toner particles from auger 90. Hopper 92 is also connected to delivery auger 96 and delivery auger is rotated by drive motor 98 to convey toner particles from hopper 92 for distribution to developer 86. It should be understood that a developer or toner dispense assembly could be individual replacement units or a combined replacement unit.
With reference to FIGS. 4 and 5, a series of tests, both stand alone and cumulative, logically analyze test results to determine any parts or subsystems needing replacement. These tests are based upon readings of selective test patches by a toner area coverage sensor. The underlying basis of the system is that it is cheaper and quicker to replace a part rather than spending valuable service time trying to correct or repair a part or subsystem at the customer's site. In particular, there is provided a highly intelligent, fully automated xerographic diagnostic routine that has the ability to inform the service representative that a specific part or parts need to be replaced. This task was accomplished by designing a series of individual tests that when performed in a logical manner and their results analyzed according to specific paradigms, the net result would point to the failure of one or more individual subsystems within the xerographic engine.
Some of the tests themselves are and could be used as stand alone diagnostic routines. They consist mainly of reading of various halftone and solid area patches by the process control sensors (BTAC, ESV, etc.) created under specific xerographic conditions usually in a before and after situation. The system analyzes the data using highly sophisticated tools (statistic packages, FFT's, etc.), looks at trends and obtains a result. It then combines this result with the results of various other tests and extracts logical conclusions as to the health of a specific subsystem.
For example: to test the cleaning subsystem, it may be necessary to concatenate the results of tests A, C, D, & F. For this test, A and D may be weighted more than C and F. The final result is that the cleaner test has some value of 60 with a variance of ±8%. The failure mode may be >65 (±5%). In this instance the cleaning subsystem would have failed.
There is an analysis of all the various test combinations for each part that it needs to interrogate and obtains a parts to replace code. This code is then readily available to be accessed by the service rep either over the phone line or through the portable workstation (PWS). When displayed, a corresponding list of part or parts to replace is presented which relates back to the code. This system will run automatically when certain conditions are met within the process control system or can be called by the operator through the UI or the service rep through the PWS.
It should also be noted that the xerographic engine can be instructed from a remote site to run a setup when needed or to run a diagnostic self analysis routine and return via the phone line any pertinent results and/or parts to replace. Upon receiving the remote command, the xerographic subsystem goes off line, runs the appropriate routine and then returns to a ready state and conveys any information back to the calling center.
In modern xerographic print engines, process controls uses a variety of reflective sensors to monitor and control the tone reproduction curve of the xerographic process. One such sensor is the BTAC (Black Toner Area Coverage) sensor. In a final test for proper operation, the BTAC must be calibrated to the bare reflectance (absence of toner) of the photoreceptor. To achieve this, the output of an LED in the sensor is pulsed (stepped) until a certain analog voltage or level of reflectance is attained. This calibration process is continually repeated.
The process control system continuously monitors the state of the xerographic process. Sensors read various halftone patches which are an indication of the quality of the developed image. If the patch quality is not within range, changes are made to various actuators to bring the process back to center. The soundness of the patch is highly effected by the uniform quality of the belt surface. A scratch or defect on the photoreceptor where the patches are produced can change the outcome of a patch read.
Therefore, a second test is to take samples of the entire photoreceptor surface with the Black Toner Area Coverage (BTAC) sensor every 1.5 mm. Using a seam detection algorithm, the seam samples are discarded, and an overall clean belt uniformity measurement is calculated. This value is used as a baseline. Since the seam location was found, the location of each process control patch and its related BTAC readings can be analyzed. The mean and variance are determined for each patch and compared to the baseline value. Through a statistical analysis, the uniformity of each location computed and compared to the baseline. The operator can then be informed to replace the belt if the uniformity was lower than an acceptable level.
Basic xerography is controlled by three subsystems; charge, exposure, and development such as Hybrid Jumping Development. In Discharge Area Development systems, one can develop an image with the absence of charge. This principle makes it possible to devise a logical method for determining certain failure modes of these three actuators.
The first step is to test the charging subsystem. Three different halftone patches (12%, 50%, and 87%) are produced using nominal settings for charge, exposure, and development. The reflectance of each patch is measured with the BTAC sensor. If the level of each patch is within a reasonable range, it is assumed that the charging system is working well. If each patch is measured to be very dark, it is deducted that the charging subsystem is malfunctioning. At this point, the method is halted, and charge is tagged to be faulted.
The second step (if charge is OK) creates a patch by turning off charge and exposure and enabling development. This will create a very dark patch. The level of this patch is measured by the BTAC and based upon the density, development component operability can be determined. The third step creates a patch using nominal charge, nominal development, and a very high exposure setting. This will create a very dark patch. The level of this patch is measured by the BTAC and based upon the density, exposure component operability can be determined.
As prints are produced, the developer subsystem needs to be continuously replenished with toner. This is achieved through a toner dispenser subsystem which consists of a dispense motor and a containment reservoir. This system can become inoperative when the motor fails (electrically loses power or the gears become jammed) or the auger within the containment reservoir becomes impacted with toner and binds up.
With respect to FIGS. 4 and 5, in block 120 the toner area coverage sensor, in this case, a black toner area coverage (BTAC) sensor is calibrated. A first level of determination is whether or not the sensor passes the calibration standard as shown in block 122, and if so, a next level test, a dirt level check is performed as shown in block 126. If the calibration determination in block 122 fails, the machine is stopped as illustrated in block 124.
After the dirt level check, there is a photoreceptor patch uniformity test as illustrated at block 128. In essence, this test checks for defective areas of a xerographic photoreceptor surface. The result of the previous test is to determine if there is an adequate charge provided by the system charging mechanism, as illustrated in block 130. If there is not an adequate charge, the system stops as shown at block 134. If there is adequate charge, as determined at block 132, a ROS beam failure test is conducted as shown in block 136. After the ROS beam failure test, a cleaner test is conducted as illustrated in block 138.
A more comprehensive actuator performance indicator test is illustrated in precharged test block 140 and ROS test 142 and shown in detail in the flow chart in FIGS. 9A and 9B. Following the actuator performance indicator tests, there is provided a background test illustrated in block 144 and a banding test illustrated in block 146. Following these tests as illustrated in block 148, there are provided a series of standard charge tests, exposure tests, grid slope tests, and exposure slope tests as illustrated in blocks 150A, 150B, 150C, and 150D. Upon the completion of these tests there is conducted a ROS pixel size test as illustrated in block 152. Also, there is a toner dispenser test illustrated in block 154. Finally, as illustrated in blocks 156 and 158, there is an analysis of all the test results and a display of failed parts.
FIGS. 6 and 7 illustrate actuator performance indications. In particular, the calibration of the sensor is shown at block 220. Block 222 illustrates the measurement of the relative reflectance of a clean patch. If the relative reflectance of the patch is less than a given threshold, for example, 45, then there is an indication of a charging problem as shown in block 226. It should be noted that the numeral 45 represents a digitized sensor signal in the range of 0-255 and the number selected is a designed decision based upon machine characteristics. A relative reflectance signal less than 45 indicates very dark patches. If the relative reflectance is not less than 45, then as shown in block 228, the charge and exposure systems are turned off and the development unit enabled.
The relative reflectance of special patches are then measured, for example, a 12%, 50%, and 87% half tone patch. The half tone level of each patch is measured by the sensor. If the relative reflectance is greater than 120 as illustrated in block 230, indicating a very light response, then there is indicated a range of problems as illustrated in block 232. On the other hand, if the relative reflectance is less than or equal 120 but greater than 60 as illustrated in decision block 234, indicating a dark to light response, then there is an indication of a set of malfunctions as illustrated in block 236. If the relative reflectance is less than or equal 60 but greater than 35 as illustrated in block 238, indicating a dark response, then another set of problems are indicated as illustrated at block 240. Finally, if the relative reflectance is less than or equal 35 indicating a very dark response, then no malfunction is indicated and the development system is operational as shown in block 242.
The next step is to set the charge and development to nominal to create a patch with a high exposure setting and determine the relative reflectance. As illustrated in block 246, if the relative reflectance digitized signal is greater than 120, indicating a light patch, a video path problem is indicated as shown in block 248. If the relative reflectance is less than or equal 120 but greater than 80 as shown in block 250, indicating a dark to light patch, then there is determined a bad ground as shown in block 252. On the other hand, if the relative reflectance is less than or equal 80 but greater than 40, a dark patch illustrated in block 254, there is an indication of a video cabling problem as shown in block 256. Finally, if the relative reflectance is less than or equal 40, indicating a very dark patch, there is a determination of no malfunction with the ROS system as shown in block 258.
With reference to FIG. 8, there is shown in the flow chart a technique to monitor toner dispense. In particular, three special toner concentration patches are provided on the photoreceptor surface as illustrated in block 276. The details of these three special patches are described in pending U.S. Ser. No. 926,476 (D/97101) filed Sep. 10, 1997, incorporated herein. The patches are read by the BTAC sensor and an average reflectance calculated as shown in block 278. If the reflectance with reference to a clean patch is greater than 15% as illustrated in decision block 280, then there is a determination of a normal toner concentration. However, if the average reflectance is less than or equal 15%, then as illustrated in block 282, the tones dispense is activated for 15 seconds.
It should be noted that 15 seconds is a design choice and in one embodiment is the time for toner to get from a toner bottle dispenser on to the photoreceptor and sensed by the sensor. After activation of the toner dispenses for a given period of time, again three toner concentration patches are provided as illustrated at block 284. Again there is a sensing and calculation of the average reflectance as shown in block 286. If the reflectance is greater than 20 as illustrated in the decision block 288, then the dispenser is determined to be operational as shown in block 292. On the other hand, if the reflectance is 20 or less, there is a determination as shown in block 290 that there is a toner dispense malfunction. Further details of the above technique are described in D/97607 (U.S. Ser. No. 035,129), D/97608 (U.S. Ser. No. 035,137), D/97609 (U.S. Ser. No. 035,124), D/97610 (U.S. Ser. No. 035,126), and D/97614 (U.S. Ser. No. 034,900) incorporated herein.
In modern xerographic print engines, as developer material sits idle for a long period of time (24 hours or more), the charge between the developer material particles (developer and carrier) becomes weak. This weakness is aggravated even more when the humidity increases. The net effect is that the initial copies produced become darker than expected. This results in poor copy quality.
In accordance with this invention, there is a technique to determine when this condition has occurred. This is accomplished by an automatic rest recovery method which would revitalize the material without any operator invention. First the amount of rest time is monitored. The rest time is the time between cycle ups of the xerographic engine. When the rest time reaches a specific threshold, the machine will go off line and cycle up the xerographic subsystem. It then develops two halftone patches (12% and 87%). The reflectance of these two patches is read by the Black Toner Area Coverage (BTAC) sensor and recorded. The difference between the two patches (12%-87%) is calculated. This difference is a good indicator that the patches have become too dark. If the delta is less than a target value, the tribo is considered to be within acceptable range and nothing is done. If the delta is greater than a target value the engine proceeds to perform a special rest recovery setup. This setup initially tones up and tones down the system enough to increase the tribo and rejuvenate the material. It then continues with the regular setup steps of toner concentration setup and electrostatic convergence. Once completed the system goes back on line and is ready to produce good copy quality.
In accordance with another aspect of this invention, it is desirable to rejuvenate the toner component of developer material upon installation of a new developer module. This is a one time procedure that precedes the rest recovery procedure described above. The procedure is as follows: All Xerographic control factors are set to machine nominal. Exposure is increased or decreased until a high density control target relative reflectance value is within a given range. If the target cannot be met and exposure goes out of range a fault is declared. The fault indicates a serious manufacturing or machine assembly problem. When the high density target is achieved a tone down starts. Tone down proceeds for 100 belt pitches at a 25% target area coverage. The tone down reduces the toner concentration by 2.5%.
When tone down is complete, tone up starts. Tone up proceeds at a toner dispenser 30% duty cycle rate for 50 belt pitches. Thru-put is at 5% area coverage. After tone up the procedure is completed. Testing shows that the developer toner tribo is increased in inverse proportion to its starting point. I.E. if the tribo is very low (8 uC/gm) then the break in procedure will increase it to about (16 uC/gm). If the tribo is high (20 uC/gm) then the break in procedure will increase it to (22 uC/gm).
The above procedure is explained in more detail with reference to FIG. 9.
In FIG. 9 a machine cycle out is shown at block 302. Block 304 illustrates the calculation of a difference in measurement in the sensing of a 12% halftone target and an 87% halftone target that was previously done and stored in memory. Block 306 illustrates a decision as to whether or not the machine rest time is greater than 24 hours. If not, then no adjustment is required, as shown at block 308. If the rest time is greater than 24 hours, then at machine cycle up shown at block 310, the target patches are developed on the machine and a calculation of a new difference value shown in block 312. It should be noted that the rest time period of 24 hours is a mere design choice and the density value of the test targets is also a mere design choice and the scope of the present invention is intended to cover any number of suitable choices of parameters and testing devices. A comparison is made of the new difference and the old difference values. If the difference is greater than a suitable level such as 5, then a procedure of tone down or toner purge is activated as shown in block 318. If the comparison is not greater than 5 or some suitable value, then the tribo is considered satisfactory for the making of prints, as shown in block 316. In block 318 for 18 belt revolutions, toner is delivered out of the toner housing and cleaned off the belt to rid the system of old toner.
Then, as illustrated in block 320, toner is dispensed into the system for a period of 18 belt revolutions, again no prints being made during this operation. It should be understood that the number of belt revolutions or the time for tone down or tone up is any suitable design choice. With the completion of the tone up at block 320, the system is then ready to initiate normal xerographic setup procedures as shown in block 322. For materials break-in for a new developer housing, the procedure is similar to the procedure above. A major difference is the number of belt revolutions for tone down and tone up.
In a preferred embodiment, for a new developer material housing break-in, on a given machine, 50 belt revolutions is considered satisfactory.
In modern xerographic print engines, seam detection is a method employed to obtain proper positioning of images on the photoreceptor using an analog process control sensor. The sensor (a Toner Area Coverage Sensor) takes very finely spaced analog samples in the seam area which generates a curve with a given area. The center of moment is then calculated which in reality is the center of the seam. In operation, over the life of the photoreceptor, its surface can become scratched. This scratching can fool the seam detection system by making it appear that there are multiple seams on the belt.
The thrust of this aspect of the invention is to assign a unique identifiable signature to the seam which could easily be discernible from scratches. Since the data for finding the seam is in the shape of a wave form, a Fourier Transform of the wave produces a unique signature for each seam differing from those obtained from scratches.
The procedure first captures this signature when a new photoreceptor is placed into the machine.
In this state, the belt's surface is free of any scratches and the only signal present on the belt is that of the seam. A new belt is detected since the belt is housed in a CRU (Customer Replaceable Unit) equipped with a EPROM that informs the system that it is a new CRU. The seam is then sampled and a FFT, Fast Fourier Transform, is performed on the wave form and the frequency distribution (its signature) is stored in the machine's nonvolatile memory.
Then, if one or more scratches appear as possible seams, a comparison is made between the stored seam signature and the other signatures. A match between the stored signature and a possible seam signature determines which candidate is the actual seam. FIG. 10 illustrates a typical comparison and FIGS. 11 and 12 illustrates the procedure in more detail.
With reference to FIG. 10, there is illustrated the wave forms representing a valid seam, a 2 millimeter surface scratch, and a 1 millimeter surface scratch. The seam is shown as a straight vertical line, the scratches as dashed vertical lines. With reference to FIG. 11, the block 340 is a decision block to determine whether or not the photoreceptor surface is a virgin surface or an older surface. If it is an old surface, then as shown at block 342, no further action is required. However, if it is a new surface, the first step as illustrated in block 344 is to find the seam and perform an FFT on the seam to provide a signature wave form to be stored in memory. Therefore, as shown in FIG. 12, when the machine is in operation, decision block 348 recognizes that the seam of the belt may be unaccounted for. If accounted for, then the belt is registered and the machine operated as shown in block 350. However, if there is confusion as to the location of the surface seam, then as shown in block 352 it is necessary to sample imperfections that may be the seam by performing Fourier Transforms. In block 354 each Fourier Transform is compared to the signature stored in memory. If there is a match as determined by decision block 356, the surface is registered to the seam as indicated by the match and the machine continues operation. If there is no match, indicating possible multiple seams are detected, a fault is declared as illustrated in block 358.
In modern xerographic print engines, the level of toner concentration greatly affects copy quality. As toner is consumed, it must be replenished by the dispense system in the proper proportion to maintain copy quality. Most system use a special magnetic toner control sensor to measure the relative concentration of toner. However, to reduce machine case, the toner concentration sensor is expendable if other methods can be employed.
The thrust of this aspect of the invention is a method to enable a toner concentration control system and thus eliminate a toner concentration sensor. This is accomplished with an abstract pixel counting sensor. The sensor extracts the pixel count (total number of pixels used per image) from the Raster Output Scanner (ROS) hardware and the control calculates the amount of toner consumed by the image. It then determines the amount of time the dispenser needs to run to replenish the used developer material. Also, a process control system monitors the reflectance of an 87% control patch with the Black Toner Area Coverage (BTAC) sensor.
The deviation from a target, a ± error, is calculated and a proportional dispense period is determined based on a gain factor. This ± dispense time is then sent to the toner dispenser subsystem and acted on appropriately. A special toner control patch is also created (mostly used for setup purposes) and developed upon the cycle out of the xerographic engine. This patch is read by the BTAC and acted on in approximately the same way as the 87% patch. The only differences are that the average area coverage of the job run is weighted into the dispense algorithm along with its own gain factor. The ± dispense time is then sent to the toner dispenser subsystem for suitable action.
In modern xerographic print engines which contain a photoreceptor belt, a deletion prone area (loss of development) may occur in the locale of the charge scorotron due to out gassing of nitric oxide. When this occurs, developability is lost and the image can become degraded. In accordance with this aspect of the invention the process control system compares the reflectance uniformity of the suspected area with that of an area where no deletion could exist. Xerographic systems employ many belt parking schemes. But no matter what scheme is used, only certain areas of the belt will be parked under the scorotron and thus be influenced by its out gassing.
The system lays down a 50% halftone patch along the entire length of the belt in the process direction. The patch is sampled by the BTAC sensor in the known parking areas and an area outside the parking locations. The uniformity of these areas are calculated and compared (parked vs. non-parked). If any of the parked areas have a level far below that of the non-parked area it is concluded that a parking deletion exists and a status is displayed that the photoreceptor belt should be replaced.
With reference to FIG. 13, a photoreceptor or photosensitive surface 370 is disposed in a given relationship with respect to a charging device 372, the charging device emits gas that is harmful to that portion of the photosensitive surface disposed within the range of the emitted gasses. A given range is illustrated at 374 outlining a region that is effected by the gasses emitted by the charging device. To determine the degree of deterioration of portions of the photosensitive surface due to the out gasses, a patch or target strip 376 is developed along the length of the photosensitive surface. A portion of the photosensitive surface, illustrated at 378, outside of the region 374 is sensed and compared to a target patch 380 known to be influenced by the charging operation. Based upon the comparison, a determination is made as to whether the degree of deterioration is acceptable or requires a replacement of the photosensitive surface. It should be understood that portions of the photosensitive surface that are positioned or "parked" near the charging device 372 tend to be more seriously effected. The key to the technique is to lay down a target patch 376 that will clearly be within the range of the charging device 374. It should also be understood that one or several target patches 380 can be provided within the boundary 374 to be used to compare with the non-effected target patch 378.
While there has been illustrated and described what is at present considered to be a preferred embodiment of the present invention, it will be appreciated that numerous changes and modifications are likely to occur to those skilled in the art, and it is intended to cover in the appended claims all those changes and modifications which fall within the true spirit and scope of the present invention. | A method to provide a highly intelligent automated diagnostic system that identifies the need to replace specific parts to minimize machine downtime rather than require extensive service troubleshooting. In particular, a systematic, logical test analysis scheme to assess machine operation from a simple sensor system and to be able to pinpoint parts and components needing replacement is provided by a series of first level of tests by the control to monitor components for receiving a first level of data and by a series of second level of tests by the control to monitor components for receiving a second level of data. Each of the first level tests and first level data is capable of identifying a first level of part failure independent of any other test. Each of the second level tests and second level data is a combination of first level tests and first level data or a combination of a first level test and first level data and a third level test and third level data. The second level tests and second level data are capable of identifying second and third levels of part failure. Codes are stored and displayed to manifest specific part failures. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to power conversion, and in particular, to circuits that provide secondary control over synchronous rectifiers with load pre-bias, monotonic start-up, and dead time control.
[0003] 2. Description of the Related Art
[0004] In a conventional power conversion system including an Active Clamp Pulse Width Modification controller that does not provide synchronous rectifier control signals (which is typically the most common arrangement), a self driven control scheme is often chosen. In a self driven control scheme, a self driven rectifier gate voltage varies with an input line voltage such that the self driven rectifier gate voltage may drop to a point where full enhancement of the self driven rectifier is no longer possible which thus impacts efficiency and/or exceeds safe operating limits. For example, in a self driven control scheme, when a needed output voltage is 12 volts or greater, the self driven rectifier gate voltage which is provided by a main transformer secondary winding will be at a level that is beyond safe operating limits of the self driven rectifiers.
[0005] In self driven or control driven schemes, i.e., driven with a Pulse Width Modulation (PWM) controller with secondary control outputs, a pre-bias condition on the output has the potential of creating a short circuit condition forcing the PWM controller into a current limiting protection scheme that the PWM controller will enter into to thereby make it impossible for the output of the power conversion system to ever develop. Additionally, in self driven or control driven schemes, there are no provisions for a monotonic startup. Finally, in a self driven control scheme, there is no dead time control of synchronous rectifiers such that, as an operating temperature of the power conversion system increases, the possibility of cross conduction also increases.
[0006] In an attempt to overcome the above problems, it has been proposed to use a main transformer secondary winding or an additional winding to provide a control signal/drive voltage (i.e., a self driven scheme). However, such an arrangement has a major drawback in which the control signal/drive voltage will vary with an input line voltage, which thereby leads to a possible reduction in efficiency or even a device failure unless specific safeguards are put in place.
[0007] In order to overcome the problems described above, it has also been proposed to keep an input voltage range small, such as a ratio of 2:1, so that the secondary voltage does not vary widely such that the secondary voltage will not exceed the safe operating limit of the synchronous rectifiers or drop below the enhancement level of the synchronous rectifiers. However, such a proposal significantly limits the number and type of applications in which such a power conversion system effectively operates.
[0008] Similarly, using shunt regulators to limit the drive voltage to be maintained within the safe operating limits of the synchronous rectifiers or using an additional winding on the main transformer which has a different turns ratio such that a scaled down drive voltage can be provided have also been proposed. However, both of these proposed arrangements result in an undesirable reduction in overall operating efficiency of the power conversion system.
[0009] Using a secondary controller that includes its own additional bias supply voltage or controlling a rate at which feedback begins its control of the power conversion system has also been proposed. However, this arrangement leads to more complex circuitry and also a corresponding increase in cost. Also, carefully choosing synchronous rectifiers with very fast turn off and very stable temperature characteristics has been proposed. The drawback with this is that it requires more exotic and expensive components with the potential for long lead times.
SUMMARY OF THE INVENTION
[0010] In order to overcome the problems described above, preferred embodiments of the present invention provide a control driven synchronous rectifier in which a controller is arranged to output control signals to at least two switching logic devices, the at least two switching logic devices each being arranged to output timing signals used to drive individual ones of at least two synchronous rectifiers. The control driven synchronous rectifier makes it possible to provide more system control with predictable delays and also to prevent an input range of the voltage input into the control driven synchronous rectifier from influencing the output voltage of the control driven synchronous rectifier.
[0011] A synchronous rectification circuit according to a preferred embodiment of the present invention preferably includes a transformer arranged to receive an input voltage at a primary side and output an output voltage at a secondary side and a controller arranged and programmed to operate independently from the input voltage and the output voltage. The controller is preferably arranged to output control signals to at least two switching logic devices, each of the at least two switching logic devices being arranged to output timing signals used to drive individual ones of at least two synchronous rectifiers included in the secondary side of the transformer.
[0012] The synchronous rectification circuit according to the above described preferred embodiment also preferably includes at least one logic gate arranged to receive the control signals output from the controller and to supply clock signals to the at least two switching logic devices, the clock signals being generated by the at least one logic gate based on the control signal and at least two driving devices arranged to receive the timing signals from a respective one of the at least switching logic devices, the at least two driving devices being arranged to drive the individual ones of the at least two synchronous rectifiers in accordance with the timing signals. The at least two driving devices being, for example, MOSFET drivers.
[0013] Each of the at least two driving devices are preferably arranged to receive timing signals from a same one of the at least two switching logic devices. One of the at least two driving devices is preferably arranged to receive one of the control signals output from the controller. A synchronous rectification circuit according to another preferred embodiment preferably includes a digital isolator arranged between the controller and the two at least switching logic devices, the at least one logic gate, and the at least two driving devices. The digital isolator is arranged to receive the control signals from the controller and then to output the control signals.
[0014] The control signals of a synchronous rectification circuit according to a preferred embodiment of the present invention preferably include a first control signal and a second control signal, the at least one logic gate being arranged to generate one of the clock signals based on the first control signal and the second control signal. Here, at least one logic gate is arranged to generate the one of the clock signals such that a rising edge of the first control signal corresponds to a rising edge of the one of the clock signals and a rising edge of the second control signal corresponds to a falling edge of the one of the clock signals on a first pulse of the one of the clock signals; and on a next clock pulse of the one of the clock signals, falling edges of the first control signal and the second control signal correspond to the next clock pulse. It is preferable that the first control signal is a clamp signal and the second control signal is a primary switching signal, for example.
[0015] Preferably, one of the at least two switching logic devices is arranged to generate a freewheeling signal based on the one of the clock signals, the freewheeling signal being input into one of the at least two driving devices. The one of the at least two switching logic devices which is arranged to generate the freewheeling signal is preferably arranged to generate the freewheeling signal based on one of the first control signal and the second control signal and also based on signals output from the at least one logic gate. The freewheeling signal supplied to the one of the at least two driving devices is preferably delayed due to, for example, a resistor, a diode, and a capacitor connected to an output of the same one of the at least two switching logic devices. Also, the timing signals received by each of the at least two driving devices from the same one of the at least switching logic devices are preferably delayed, this delay preferably being caused by a resistor and a capacitor connected to an output of the same one of the at least two switching logic devices.
[0016] The synchronous rectification circuit according to a preferred embodiment of the present invention may also include a start-up regulator arranged to supply power to the controller.
[0017] Preferably, in various preferred embodiments of the present invention, the at least two switching logic devices are flip-flops, the at least one logic gate includes an exclusive OR gate, and the at least two driving devices are op-amps, for example.
[0018] The above and other features, elements, characteristics, steps and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a circuit diagram showing a power converter in accordance with a preferred embodiment of the present invention.
[0020] FIG. 2 is a circuit diagram showing a power converter in accordance with another preferred embodiment of the present invention.
[0021] FIG. 3 is a timing diagram in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Preferred embodiments of the present invention will be described below with reference to the accompanying drawing.
[0023] A preferred embodiment of a power conversion system in accordance with the present invention preferably includes a synchronous rectifier with an active clamp forward converter. FIG. 1 shows a simplified circuit of an output section of a synchronous rectifier in accordance with a preferred embodiment of the present invention. The synchronous rectifier preferably includes a transformer T 1 , an output filter inductor L 1 , and an output filter capacitor C 3 . The synchronous rectifier also preferably includes a digital isolator U 2 arranged to receive control signals from a host PWM controller (not shown in FIG. 1 ), the control signals preferably including a Clamp signal and a Primary Switch signal. The digital isolator U 2 is arranged to output signals OUT A and OUT B that are needed to create the synchronous rectifier's control signals.
[0024] The output signals OUT A and OUT B of the digital isolator U 2 are input into an exclusive NOR gate U 3 and an inverter U 4 . The exclusive NOR gate U 3 is arranged to create a clock signal for a flip-flop U 5 and the inverter U 4 is arranged to invert the Primary Switch signal output from OUT B of the digital isolator U 2 and then input this inverted signal into the K input of the flip-flop U 5 . The output of the flip-flop U 5 is arranged to provide a secondary control signal used for the synchronous rectifier, where a resistor R 1 , a diode D 1 , and a capacitor C 5 are arranged to provide additional dead time delay to the output of the flip-flop U 5 .
[0025] The power conversion system shown in FIG. 1 further includes a forward synchronous rectifier Q 3 and a freewheeling synchronous rectifier Q 4 . The forward synchronous rectifier Q 3 is preferably driven by a non-inverting driver U 8 which is controlled in part by being connected to the OUT B signal of the digital isolator U 2 . The freewheeling synchronous rectifier Q 4 is preferably driven by an inverting driver U 7 which is controlled in part by being connected to the output of the flip-flop U 5 . Additionally, both of the non-inverting driver U 8 and the inverting driver U 7 are arranged to receive an output from a flip-flop U 6 . The output of the flip-flop U 6 is arranged to slowly charge a capacitor C 4 through a resistor R 2 such that a pre-bias startup delay will occur before the non-inverting driver U 8 and the inverting driver U 7 are enabled. The inverting driver U 7 and the non-inverting driver preferably being provided by, for example, MOSFET drivers.
[0026] Accordingly, by using the above described arrangement, the synchronous rectifier control signals used to drive the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 are created by the Primary Switch control signal from the host PWM controller (not shown in FIG. 1 ) and not from a main transformer, such as transformer T 1 . Thus, it is possible to thereby provide more system control with predictable delays and with far less development effort. Additionally, because the synchronous rectifier drive voltage of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 is derived from an auxiliary bias supply and not from the main transformer, an input range of the voltage input into the power conversion system does not have any influence over the output of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 .
[0027] In addition, both of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 have their outputs fully enhanced such that the synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 will be fully on (which is a state similar to when a transistor becomes saturated), thereby keeping overall efficiency high across the input range of the voltage input into the power conversion system which thereby results in a wider input range that can be used economically. Further, the synchronous rectifier drive voltage is fixed, is derived from an auxiliary bias supply, and is chosen to be in the safe operating range of the synchronous rectifiers to thereby avoid a possibility that the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 will be operated beyond their safe operating limits.
[0028] Finally, because the control signals of the non-inverting driver U 8 and the inverting driver U 7 are delayed for a small amount of time because the output of the flip-flop U 6 is arranged to slowly charge a capacitor C 4 through a resistor R 2 , the resulting pre-bias startup delay to both of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 allow the body diodes of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 to conduct and develop output voltages prior to full synchronous operation. Thus works to prevent the pre-bias voltage from creating a short circuit situation. Similarly, because the control signals of the non-inverting driver U 8 and the inverting driver U 7 have delays introduced, a body diode conduction of the synchronous rectifiers provides a smooth rise of the desired output voltage before enabling full synchronous rectification. The required dead time provided by diode D 1 , resistor R 1 , and capacitor C 1 is added to prevent cross conduction during higher temperatures.
[0029] Another preferred embodiment of a power conversion system in accordance with the present invention will now be described with reference to FIG. 2 . FIG. 2 shows a simplified circuit of a power stage of a power conversion system including a synchronous rectifier with an active clamp forward converter. The preferred embodiment shown in FIG. 2 includes elements similar to those described above with reference to FIG. 1 . For the sake of simplicity, these similar elements include the same reference characters as those described above with reference to FIG. 1 .
[0030] The preferred embodiment of the synchronous rectifier shown in FIG. 2 preferably includes a transformer T 1 , primary side transistors Q 1 and Q 2 , an input filter capacitor C 1 , a capacitor C 2 connected to the collectors of the primary side transistors Q 1 and Q 2 , an output filter inductor L 1 , and an output filter capacitor C 3 . The synchronous rectifier also preferably includes a digital isolator U 2 arranged to receive control signals from a host PWM controller U 1 , which receives power from a Start up Regulator REG 1 . The Start Up Regulator REG 1 is arranged to provide a bias voltage to the host PWM controller U 1 . Start up Regulator REG 1 is preferably a series type regulator that regulates input voltage for the PWM. Once the converter is up and running, an auxiliary voltage is created that will provide slightly higher operating voltage that in a sense shuts off the Start Up Regulator REG 1 . The control signals from the host PWM controller U 1 preferably include a Clamp signal and a Primary Switch signal. The digital isolator U 2 is arranged to output signals OUT A and OUT B that are needed to create the synchronous rectifier's control signals.
[0031] The output signals OUT A and OUT B of the digital isolator U 2 are inputs into an exclusive NOR gate U 3 and an inverter U 4 . The exclusive NOR gate U 3 is arranged to create a clock signal for a flip-flop U 5 and the inverter U 4 is arranged to invert the Primary Switch signal output from OUT B of the digital isolator U 2 and then input this inverted signal into the K input of the flip-flop U 5 . The output of the flip-flop U 5 is arranged to provide a secondary control signal used for the freewheeling synchronous rectifier, where a resistor R 1 , a diode D 1 , and a capacitor C 5 are arranged to provide additional dead time delay to the output of the flip-flop U 5 .
[0032] The power conversion system shown in FIG. 2 further includes a forward synchronous rectifier Q 3 and a freewheeling synchronous rectifier Q 4 . The forward synchronous rectifier Q 3 is preferably driven by a non-inverting driver U 8 which is controlled in part by being connected to the OUT B signal of the digital isolator U 2 . As shown in FIG. 2 , this signal is the isolated Primary Switch control signal, the Primary Switch control signal also controls the primary side transistor Q 1 . The freewheeling synchronous rectifier Q 4 is preferably driven by an inverting driver U 7 which is controlled in part by being connected to the output of the flip-flop U 5 . Additionally, both of the non-inverting driver U 8 and the inverting driver U 7 are arranged to receive an output from a flip-flop U 6 . The output of the flip-flop U 6 is arranged to slowly charge a capacitor C 4 through a resistor R 2 such that a pre-bias startup delay will occur before the non-inverting driver U 8 and the inverting driver U 7 are enabled. The inverting driver U 7 and the non-inverting driver preferably being provided by, for example, MOSFET drivers.
[0033] As discussed above, both of the isolated Primary Switch signal and the isolated Clamp signal from the digital isolator U 2 are sent to the exclusive NOR gate U 3 . The exclusive NOR gate U 3 is arranged to generate a clock signal needed by both the flip-flop U 5 and the flip-flop U 6 as follows; the rising edge of the Clamp signal 1 defines the rising edge of the Clock signal 3 . The rising edge of the Primary Switch signal 2 defines the falling edge of the Clock signal 3 . On the next pulse of the Clock signal 3 , the falling edges of the isolated Clamp signal 1 and the Primary Switch signal 2 are used to create the clock pulse of the Clock signal 3 . This Clock signal 3 is then used to extract the SR freewheeling signal 4 . See the timing diagram shown in FIG. 3 .
[0034] The SR freewheeling signal 4 is extracted as follows: the isolated Clamp signal 1 is supplied to the J input of the flip-flop U 5 and an inverted version of the isolated Primary Switch signal 2 generated by the inverter U 4 is supplied to the K input of the flip-flop U 5 . The flip-flop U 5 processes the signal needed for freewheeling synchronous rectifier Q 4 . The flip-flop U 5 's input clock pin uses the rising edges of the isolated Clamp signal 1 and the Primary Switch signal 2 to extract the necessary edges from both the J and K pins to thereby create the SR freewheel signal 4 . As can be seen in the timing diagram of FIG. 3 , the SR freewheel signal 4 is never on when the Primary Switch signal 2 is on and is in fact delayed by a small amount by the circuit defined by the diode D 1 , the resistor R 1 , and the capacitor C 5 . This small amount of delay is needed to prevent cross conduction between primary and secondary conduction times of the synchronous rectifier.
[0035] The Pre-bias startup delay enable signal 5 is also shown in the timing diagram of FIG. 3 . The Pre-bias startup delay enable signal 5 requires a few cycles from the flip-flop U 6 to charge the capacitor C 4 through the resistor R 2 . This delay holds the enable pins of both non-inverting driver U 8 and the inverting driver U 7 at a low voltage level for a short time, allowing body diode conduction time of the synchronous rectifiers Q 3 and Q 4 to freewheel and thereby preventing any voltage present at the output from creating a short circuit condition on startup. This delay also provides monotonic startup of the output voltage should no Pre-bias condition be present. The Pre-bias startup delay is preferably set to be long enough for body diode conduction of the synchronous rectifiers to provide a smooth rise of the desired output voltage before enabling full synchronous rectification.
[0036] Accordingly, by using the above described arrangement, the synchronous rectifier control signals used to drive the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 are created by the Primary Switch control signal from the host PWM controller (not shown in FIG. 1 ) and not from a main transformer, such as transformer T 1 . Thus, it is possible to thereby provide more system control with predictable delays and with far less development effort. Additionally, because the synchronous rectifier drive voltage of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 is derived from an auxiliary bias supply and not from the main transformer, an input range of the voltage input into the power conversion system does not have any influence over the output of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 .
[0037] Furthermore, both of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 have their outputs fully enhanced such that the synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 will be fully on (which is a state similar to when a transistor becomes saturated), thereby keeping overall efficiency high across the input range of the voltage input into the power conversion system which thereby results in a wider input range that can be used economically. Further, the synchronous rectifier drive voltage is fixed, is derived from an auxiliary bias supply, and is chosen to be in the safe operating range of the synchronous rectifiers to thereby avoiding a possibility that the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 will be operated beyond their safe operating limits.
[0038] Finally, because the control signals of the non-inverting driver U 8 and the inverting driver U 7 are delayed for a small amount of time because the output of the flip-flop U 6 is arranged to slowly charge a capacitor C 4 through a resistor R 2 , the resulting pre-bias startup delay to both of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 allow the body diodes of the forward synchronous rectifier Q 3 and the freewheeling synchronous rectifier Q 4 to conduct and develop output voltages prior to full synchronous operation. This works to block and prevent the pre-bias voltage from creating a short circuit situation. Similarly, because the control signals of the non-inverting driver U 8 and the inverting driver U 7 have delays introduced, body diode conduction of the synchronous rectifiers provide a smooth rise of the desired output voltage before enabling full synchronous rectification. The required dead time provided by the diode D 1 , the resistor R 1 , and the capacitor C 1 is added to prevent cross conduction during higher temperatures.
[0039] It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the appended claims.
[0040] For example, it would be possible to use a signal transformer instead of the digital isolator U 2 described above. Additionally, for non-isolated designs, the digital isolator could be eliminated all together.
[0041] While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims. | A synchronous rectification circuit includes a transformer receiving an input voltage at a primary side and outputting an output voltage at a secondary side and a controller arranged and programmed to operate independently from the input and output voltages. The controller preferably outputs control signals to switching logic devices, the switching logic devices being arranged to output timing signals to drive individual synchronous rectifiers included in the secondary side of the transformer. The synchronous rectification circuit includes at least one logic gate which receives the control signals output from the controller and supplies clock signals to the switching logic devices, the clock signals being generated by the at least one logic gate based on the control signal and driving devices arranged to receive the timing signals from a respective one of the switching logic devices, the driving devices driving the synchronous rectifiers in accordance with the timing signals. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to a textured substrate for growing and forming an epitaxial film of an oxide superconductive material or the like. It particularly relates to a textured substrate for forming an epitaxial film having good crystal orientation with good adhesion.
BACKGROUND ART
[0002] Materials having an epitaxial crystal structure having crystal orientation, such as oxide superconductive materials and solar cell membranes, are used in various fields focusing on their specific properties. Examples of the materials are oxide superconductive materials for forming superconductive conductors, superconductive shields, and the like to be applied to various electrical appliances. Here, materials having an epitaxial crystal structure generally have poor workability and are also sometimes disadvantageous in terms of cost in the production of bulk materials. Therefore, they are normally used as a thin film formed on a predetermined substrate.
[0003] Since a substrate for forming an epitaxial film epitaxially grows crystals having a textured structure, the surface thereof also needs to have a textured structure. As such a substrate, the present inventors found a textured substrate made basically of copper (Patent Document 1). This copper substrate for growing an epitaxial film focuses on the ease of crystal orientation control of copper, and has a {100}<001> cube texture wherein the drift angle Δφ of a crystal axis is as follows: Δφ≦6°. In this substrate, a stainless steel or like metal layer (base material) is cladded to solve the problem of the insufficient strength of copper containing no alloying elements.
[0004] The present inventors made some modifications to the above textured substrate to improve the quality of the epitaxial film formed thereon. For example, the present inventors disclosed the above textured substrate including a copper layer, having an adequate amount of nickel thin film layer laminated on the copper surface to further improve the crystal orientation (Patent Document 2), and the like
RELATED ART DOCUMENT
Patent Documents
[0005] Patent Document 1: JP 2008-266686 A
[0006] Patent Document 2: JP 2009-046734 A
[0007] Suitability of conventional modification examples of substrates for epitaxial film formation is often judged based on quality of the crystal orientation of the substrate itself. The characteristics of an epitaxial film formed on a substrate are greatly dependent on those of the substrate, and thus this judgment standard is not necessarily incorrect. However, in reality, even when a substrate having orientation improved as much as possible is used, the crystal orientation may be disordered upon the formation of an epitaxial film, or, even when an epitaxial film can be formed, its adhesion may be insufficient. Thus, it has been difficult to set film formation conditions.
[0008] Further, as a mode of use of a material using an epitaxial film, such as a superconductive material, a material in an elongated tape shape is often used. For its production, an epitaxial film having crystal orientation is required to be uniformly formed on an elongated textured substrate. However, conventional textured substrates have the problems mentioned above, which makes it difficult to produce elongated materials.
[0009] Further, for conventional textured substrates, it is difficult to cope with recent structural changes in superconductive materials and like materials using an epitaxial film. Specifically, for example, in the formation of a superconductive material by use of a textured substrate, conventionally, rather than direct formation of a film of a superconductive material on the substrate, it is common to form an intermediate layer between the two. Such an intermediate layer was commonly formed by laminating a plurality of layers including a seed layer for mitigating the mismatch between the lattice constant of the composition metal of the substrate and the lattice constant of the superconductive material, a barrier layer for suppressing the diffusion of elements from the superconductive material to the substrate, and the like. However, in recent years, for reducing the number of steps in the production process or improving the characteristics, simplification of the intermediate layer, and particularly elimination of the seed layer, are considered, for example. Then, structural changes resulting from such intermediate layer simplification act to tighten the conditions for epitaxial film formation, which are difficult to cope with by use of a conventional textured substrate.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0010] Thus, the present invention provides a textured substrate for growing an epitaxial thin film, which is capable of forming an epitaxial film having good crystal orientation and high quality with good adhesion; and also a method for producing the same.
Means for Solving the Problems
[0011] The present inventors examined causes for the problems mentioned above, that is, decreases in crystal orientation and adhesion of an epitaxial thin film. As a result, they found that there is an influence of a natural oxide film, which is formed on the substrate surface by just before the formation of an epitaxial thin film.
[0012] The presence of an oxide film on a substrate has not been completely out of consideration. The adverse influence of an oxide on a substrate caused on the subsequent film formation is generally known, and, as a measure therefor, it is recommended to perform a suitable surface treatment, such as ion beam cleaning. However, it is practically impossible to make the substrate surface completely oxygen-free from the completion of the surface treatment to the formation of an epitaxial thin film. Accordingly, at the stage of forming an epitaxial thin film, the substrate surface has an extremely thin natural oxide film formed thereon.
[0013] To suppress the formation of a natural oxide film on the substrate surface, the present inventors examined performing, instead of an external treatment such as cleaning or etching, a modification treatment to make the substrate surface resistant to film formation. As a specific technique therefor, they found the addition of a small amount of palladium on the substrate surface, and thus conceived of the present invention.
[0014] To solve the above problem, the present invention provides a textured substrate for forming an epitaxial film, including a textured metal layer on at least one surface of the layer, the textured metal layer including a copper layer having a cube texture, the textured metal layer having, on a surface of the layer, palladium added in an amount of 10 to 300 ng/mm 2 per unit area, the hydrogen content of the surface of the textured metal layer being 700 to 2000 ppm.
[0015] As mentioned above, in the present invention, palladium is added to a substrate surface having a textured metal layer to suppress the formation of a natural oxide film. As the reason why the formation of a natural oxide film can be suppressed by the addition of palladium like this, although this is not affirmative, the present inventors infer that the hydrogen absorbability of palladium is involved. That is, palladium is known to have higher ability to absorb/store hydrogen as compared with other metals. It is inferred that such absorbed hydrogen acts as a reducing agent, and even when a natural oxide film is formed on the substrate surface, it is immediately reduced.
[0016] Additionally, for the kind of metal added to the substrate surface, other metals than palladium, particularly metals belonging to precious metals like palladium (platinum, gold, silver, ruthenium), also are expected to act in the same manner as palladium for their antioxidative and catalytic characteristics. However, in the examination by the present inventors, as a result of the addition of these precious metals, the natural oxide film cleaning action was not seen. Also from this, it is surmised that the hydrogen absorbability of palladium is associated with the natural oxide film cleaning action.
[0017] Hereinafter, each element of the present invention will be described in further detail. As a premise, the present invention is applied to a textured substrate provided with a copper layer having a cube texture because copper is the best metal in terms of orientation control as mentioned above. The crystal orientation of this copper layer is a face-centered cubic lattice, and thus it has a {100}<001> cube texture. Additionally, needless to say, the copper layer preferably has good crystal orientation. The crystal orientation of the copper layer is preferably such that the drift angle Δφ of a crystal axis of the surface is 6° or less.
[0018] The textured substrate may have a monolayer structure formed only of the textured metal layer. Additionally, a reinforcing material to serve as a base material for reinforcement may also be bonded to the copper layer to serve as the textured metal layer. In this case, the base material used for the textured substrate is preferably made of stainless steel or a nickel alloy (Hastelloy alloy, Inconel alloy, Incoloy alloy, Monel alloy, or the like).
[0019] Additionally, the thickness and shape of the textured substrate are not particularly limited, and a plate shape, a foil shape, a tape shape, or the like according to the intended use can be employed. Further, copper layers may also be bonded to both sides of the base material, and a nickel layer and a nickel oxide layer may be formed thereon, respectively.
[0020] In the present invention, a predetermined amount of palladium is contained on the substrate surface (textured metal layer). The significance of the application of palladium is as mentioned above. Palladium on the substrate surface may form a completely uniform layer covering the crystal orientation improving layer, or may also be scattered over the surface of the crystal orientation improving layer. The action of palladium in the present invention is not like that of a protective film, but is a reducing action caused by absorbed hydrogen, which is similar to a catalytic action. This is because a uniform film needs not to be formed for additives having such a catalytic action.
[0021] The amount of palladium added is specified to be 10 to 300 ng/mm 2 per unit area of the substrate surface. The amount of palladium added is specified to as 300 ng/mm 2 or less per unit area in the present invention because when palladium is added in a larger amount, a thick palladium layer may be formed on the substrate surface, and although there is not the problem of a natural oxide film, this may affect the adhesion or orientation of an epitaxial film formed thereon. Additionally, the lower limit is specified to be 10 ng/mm 2 per unit area because when the amount is less than this, the natural oxide film cleaning action of palladium is not exerted.
[0022] Since the action of palladium described above is exerted with hydrogen being absorbed in palladium, in the textured substrate according to the present invention, it is indispensable that the surface has a high hydrogen content. Specifically, the hydrogen concentration is to be 700 to 2000 ppm. Regarding this hydrogen concentration range, a concentration of less than 700 ppm has no difference from that of conventional textured substrates, and does not have a natural oxide film removal action. Additionally, the upper limit is 2000 ppm because even when palladium has excellent hydrogen absorbability, when the amount of addition mentioned above is considered, it is difficult for the substrate surface to contain hydrogen at a concentration of more than 2000 ppm. Incidentally, such a hydrogen content is achieved in the step of adding palladium to the textured substrate, which will be described below in detail. Although palladium is preferably added to the textured substrate by plating, it is difficult to introduce a suitable amount of hydrogen by general electrolytic plating.
[0023] In the present invention, palladium is added to the textured substrate (textured metal layer) to suppress the formation of a natural oxide film, and the adhesion and uniformity of a subsequently formed epitaxial film is improved; here, it can be said that the crystal orientation of the textured substrate is preferably improved at the same time. That is, as in Patent Document 2, on the textured metal layer, a nickel layer that improves the crystal orientation of the metal layer is formed prior to the addition of palladium, so that an epitaxial thin film with higher quality than on the substrate can be formed. That is, in a more preferred aspect of the present invention, the textured substrate includes a nickel layer on the surface of the textured metal layer, and palladium is added to the surface of the nickel layer.
[0024] Nickel is applied as a crystal orientation improving layer because it has the same crystal structure (face-centered cubic lattice) as copper forming its groundwork, and also because they have similar lattice constants, which results in particularly high effectiveness in improving crystal orientation. The nickel layer preferably has a thickness of 100 to 20000 nm. This is because a thickness of more than this range results in deviation in the growth direction of a subsequently formed epitaxial film, while when the thickness is less than 100 nm, the improving effect on the degree of crystal orientation is not obtained. The nickel layer more preferably has a thickness of 500 to 10000 nm. As a result of the formation of such a nickel layer, the degree of crystal orientation of the substrate surface improves within a range of 0.1 to 3.0° relative to the degree of orientation of the copper layer surface (Δφ).
[0025] Next, the method for producing a textured substrate for forming an epitaxial film according to the present invention will be described. A method for producing a textured substrate for forming an epitaxial film according to the present invention is for producing the textured substrate for forming an epitaxial film, including a step of adding 10 to 300 ng/mm 2 per unit area of palladium to a surface of a copper layer having a cube texture by strike plating.
[0026] In the above production method, the copper layer having a cube texture can be produced according to a conventional method, and a cube texture can be suitably obtained by a thermomechanical treatment.
[0027] Here, as mentioned above, the textured substrate according to the present invention is preferably provided with a nickel layer on the copper layer, to serve as the textured metal layer. When the textured substrate is provided with a nickel layer, the nickel layer is formed after the production of the copper layer. In order to maintain and improve the crystal orientation of the copper layer, the nickel layer is preferably formed by epitaxial growth. Such an epitaxial production method is not particularly limited, and any of various thin film production processes, such as PLD (Pulsed Laser Deposition), CVD (Chemical Vapor Deposition), sputtering, vacuum deposition, ion plating, ion beam deposition, spin coating, MBE (Molecular Beam Epitaxy), and plating can be employed. Plating is particularly preferable.
[0028] Palladium is added onto the textured metal layer of the textured substrate produced as above. Here, for merely adding palladium onto the substrate surface, a general thin film production process such as PLD, CVD, sputtering, vacuum deposition, ion plating, ion beam deposition, spin coating, MBE, or plating can be applied. However, in the present invention, in addition to adding palladium, at least a predetermined amount of hydrogen is also required to be retained on the substrate surface. In order for at least a predetermined amount of hydrogen to be retained on the substrate surface, hydrogen is said to be preferably absorbed in palladium at the same time as the addition of palladium. In this respect, it is difficult to intentionally mix hydrogen into the film by the general thin film production processes mentioned above.
[0029] In the present invention, as a specific method for the addition of palladium, strike plating is employed. Strike plating is a method in which a plating treatment is performed instantaneously at a high current density by use of a plating bath of prescribed composition with the hydrogen ion concentration adjusted, and generally often applied as a groundwork treatment before plating. In strike plating, a large amount of hydrogen gas can be generated from the cathode (textured substrate) during the process, and this hydrogen is absorbed in deposited palladium. Accordingly, the hydrogen content on the substrate surface after the addition of palladium can be increased.
[0030] As conditions for the addition of palladium by strike plating in the present invention, the plating bath is preferably a plating solution with a metal palladium concentration of 0.4 to 0.6 g/L and a pH of 8.5 to 9.5. Additionally, as electrolysis conditions, electrolysis is preferably performed at 35 to 45° C. and 3 to 8 A/dm 2 . Incidentally, the amount of palladium added can be adjusted by the electrolysis conditions.
[0031] The textured substrate after the addition of palladium may be directly subjected to the formation of an epitaxial film, but may also be subjected to a suitable heat treatment. When a heat treatment is performed, the substrate surface can be smoothed at a nano-order level by the migration of a small amount of palladium added to the substrate surface. This heat treatment is preferably performed at a temperature of 400° C. or more. This is because when the temperature is lower than 400° C., the migration of the palladium atom becomes slow. The heat treatment temperature preferably has an upper limit of 1050° C., and when the temperature exceeds that temperature, the copper layer may be soften or melted. The heat treatment time is preferably 10 minutes to 2 hours. This is because when the heat treatment is less than 10 minutes, the atomic migration to smooth the surface is insufficient, while even when the heat treatment is performed for more than 2 hours, this results in no difference in effect will occur.
[0032] Additionally, the present invention is aimed at suppressing the production of a natural oxide film, and thus the heat treatment is required to be performed in a non-oxidizing atmosphere. Preferably, a reducing atmosphere having a hydrogen gas content of 5% or more is employed. For example, a mixed gas atmosphere containing hydrogen gas balanced with an inert gas (argon, and the like) can be mentioned.
[0033] Through the above steps, a textured substrate of the present invention can be produced. Incidentally, the textured substrate according to the present invention is expected to be used with a reinforcing material being bonded to the copper layer. When a textured substrate provided with such a reinforcing material is produced, the timing of the bonding of the reinforcing material is not particularly limited as long as it is after the crystal orientation treatment of the copper layer. Bonding may be performed before or after the formation of a nickel layer, or after the addition of palladium to the nickel layer and after the heat treatment.
[0034] As a method for bonding a reinforcing material to the substrate, surface-activated bonding is preferably applied. Surface-activated bonding is a method of dry etching the bonding surface of a member to be bonded, and oxides or adsorbates on the bonding surface are removed to expose its metal substrate and activate the surface, immediately followed by bonding. In this method, bonding is performed based on the metal atomic force between atoms (molecules) with the surface being completely free of impurities, such as oxides. As a specific technique for the dry etching for surface activation, argon or like ion beam etching, atom beam etching, or plasma etching can be applied. This dry etching needs to be performed in a non-oxidizing atmosphere, particularly preferably in high vacuum.
[0035] Surface-activated bonding allows for bonding with no pressure applied, and materials to be bonded can be bonded by simply stacking together. However, a pressure can also be applied for the position adjustment of the materials or for firmer bonding. Note that the pressure applied in this case should be low enough not to deform the materials, and is preferably 0.01 to 300 MPa. Additionally, surface-activated bonding allows for bonding at normal temperature. Accordingly, it is not necessary to heat the working atmosphere at the time of bonding. Incidentally, also during bonding, the atmosphere is preferably a non-oxidizing atmosphere.
[0036] The textured substrate for forming an epitaxial film according to the present invention described above is suitable for the formation of various kinds of epitaxial films thereon, and is suitable as, for example, a substrate of a superconductive material. The superconductive material includes a superconductor layer formed on the textured metal layer of the textured substrate according to the present invention, and an intermediate layer is usually formed between the substrate and the superconductor layer. This intermediate layer functions as a buffer layer considering the difference in lattice constant between the superconductive material (YBCO, and the like) and the metal forming the substrate, and also acts as a barrier layer for preventing the diffusion of metal elements contained in the substrate. The structure of the intermediate layer may be a three-layer structure including a seed layer, a barrier layer, and a cap layer or a two-layer structure with the seed layer eliminated. Each intermediate layer is preferably made of an oxide, a carbide, or a nitride and has a thickness of 10 to 1000 nm.
[0037] Specific examples of materials forming an intermediate layer include oxides such as cerium oxide and zirconium oxide, composite oxides such as LaMnO, LaZrO, and GdZrO, and nitrides such as TiN. As oxides and composite oxides, perovskite-type and fluorite-type oxides and composite oxides are preferable. Particularly preferably, the seed layer is made of a composite oxide containing a rare earth element oxide or a rare earth element, the barrier layer is made of an oxide containing zirconium oxide, and further the cap layer is made of a composite oxide containing a rare earth element oxide or a rare earth element.
[0038] As a method for producing each oxide to serve as an intermediate layer on the substrate, PLD, CVD, sputtering, ion plating, ion beam deposition, spin coating, MBE, or MOD (Metal Organic Deposition) can be applied. This also applies to the superconductor layer. A stabilization layer is formed by a film formation method such as sputtering or deposition, or may alternatively be formed by formation of a silver layer by such a method, and then bonding of a foil-shaped copper layer thereto by use of a brazing filler metal.
[0039] Additionally, as oxide superconductive materials forming a superconductor layer, RE-based superconductive materials, particularly RE-Ba 2 Cu 3 O x superconductive materials, are preferable (RE is one kind or more kinds of rare earth elements). Specific examples of the material include YBCO, SmBCO, GdBCO, and Y 0.3 Gd 0.7 BCO. Additionally, the superconductor layer may be made only of such a superconductive material, or may alternatively contain an oxide different from these superconductive materials added as an artificial pin to improve the superconducting properties. Incidentally, the superconductor layer preferably has a thickness of 100 nm or more.
Advantageous Effects of the Invention
[0040] As described above, with the textured substrate for forming an epitaxial film according to the present invention, an epitaxial film having good crystal orientation with good adhesion can be formed. The conditions applied for the epitaxial film growth can also be more relaxed than conventional conditions. Besides superconductive materials, the present invention is also suitable as a substrate for producing various materials and devices that apply the characteristics of an epitaxial film, such as solar cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 shows the results of oxygen concentration XPS analysis of the surfaces of the textured substrates of the example and comparative examples.
[0042] FIG. 2 shows the results of X-ray diffraction analysis of epitaxial films formed on the textured substrates of Example 1 and the conventional example.
[0043] FIG. 3 shows X-ray pole figures of epitaxial films formed on the textured substrates of Example 1 and the conventional example.
[0044] FIG. 4 shows X-ray pole figures of an epitaxial film on the textured substrate of Example 1 in the length direction (front end portion, central portion, rear end portion).
[0045] FIG. 5 shows the results of oxygen concentration analysis of the surfaces of textured substrates in the second embodiment, when the treatment conditions for the addition of palladium are varied.
DESCRIPTION OF EMBODIMENTS
[0046] Hereinafter, best modes for carrying out the present invention will be described.
[0047] First Embodiment: In this embodiment, first, various kinds of precious metals were added to the surface of a textured substrate including a copper layer as a textured metal layer, and the effects of the addition of palladium were tested. For the formation of a textured metal layer, a 1000-μm-thick, tape-shaped copper plate was prepared and cold-rolled at room temperature by use of a pressure roll set to have a reduction ratio of 95%, to give a tape material of 50 μm. After rolling is performed, the copper plate was subjected to a heat treatment to orient the crystalline structure to give a {100}<001> cube texture. This heat treatment was performed by the application of heat for 2 hours at a temperature of 750° C. in an atmosphere containing 95% nitrogen gas and 5% hydrogen gas.
[0048] On the crystal-orientation-treated copper layer, a nickel layer to serve as a crystal orientation improving layer was formed by plating. For nickel plating, the substrate was subjected to acid degreasing and electrolytic degreasing, and then to electrolytic plating in a nickel plating bath (Watts's bath). The plating conditions were as follows: temperature: 40° C., current density: 1 A/dm 2 . The plating time was adjusted to give a 1000-nm-thick nickel plating. Incidentally, when a nickel plating is formed as a crystal orientation improving layer, the conditions are preferably set within the following range: current density: 1 to 5 A/dm 2 , bath temperature: 40 to 60° C.
[0049] For the textured substrate formed of a copper layer provided with a nickel layer, various precious metals containing palladium were added to the surface. Precious metals were each added by strike plating. This treatment was performed by use of a plating solution having a metal palladium concentration to 0.5 g/L and a pH of 9 (product name: PALLADEX STRIKE2) as a plating bath at a bath temperature of 35 to 45° C. and a current density 3 to 8 A/dm 2 for a plating time of 20 seconds. In this plating treatment, the amount of addition was set at 60 ng/mm 2 per unit area. After the addition of each precious metal, a heat treatment was performed in a non-oxidizing atmosphere (nitrogen-hydrogen mixed gas) at 700° C. for 1 hour.
[0050] The hydrogen content of the surface of the textured substrate produced as above was analyzed by an inert gas fusion method (analyzer: OHN836, manufactured by LECO Japan). Then, to examine whether a natural oxide film was formed, the oxygen concentration of the substrate surface 180 minutes after production was analyzed by X-ray photoelectron spectroscopy analysis (XPS). The analysis was performed on the outermost surface of the substrate and also near the surface by sputtering. The results are shown in Table 1 (hydrogen content) and FIG. 1 (oxygen concentration).
[0000]
TABLE 1
Added metal
Hydrogen content
Example 1
Pd
783 ppm
Comparative Example 1
Pt
4.8 ppm
Comparative Example 2
Ag
3.2 ppm
Comparative Example 3
Au
3.7 ppm
Comparative Example 4
Ru
3.1 ppm
Conventional example
Not added
3.3 ppm
[0051] Referring to Table 1, the hydrogen content of the textured substrate surface is extremely high in the substrate having palladium added thereto. Referring to the results of the measurement of surface oxygen concentration ( FIG. 1 ), the oxygen concentration of the substrate having palladium added thereto is almost zero even in the outermost surface, and no oxide is confirmed to be produced. In contrast, it is shown that in the conventional example having no metal added thereto, oxygen is present near the outermost surface and also near the surface, which indicates that an oxide was produced. Additionally, regarding the effects of other precious metals, platinum, gold, silver, and ruthenium resulted in lower oxygen concentrations than when no metal is added, which suggests that they are somewhat effective although the mechanism seems to be different from the surface hydrogen content. However, as compared with palladium, the suppressing effect on the formation of an oxide film can be said to be lower. From the above examination results, the addition of palladium was confirmed to be extremely effective to suppress the production of a natural oxide film.
[0052] Next, epitaxial films were formed by use of the textured substrates of Example 1 and the conventional example, and the orientation was evaluated. For the formation of an epitaxial film, a 100-μm-thick, tape-shaped stainless steel (SUS304) plate was bonded to the textured substrate as a reinforcing material. For the bonding of the stainless steel plate, the bonding surfaces of the copper substrate and the stainless steel plate were both surface-activated with a fast atomic beam (argon) by a surface-activated bonding device, and they were bonded together by a pressure roll. The conditions for surface-activated bonding are as follows.
Degree of vacuum: 10 −5 Pa
(Inside the vacuum chamber and etching chamber: argon gas atmosphere)
Applied voltage: 2 kV Etching time: 5 minutes Applied pressure during bonding: 2 MPa
[0057] Additionally, the substrate of the conventional example was subjected to an argon beam treatment before the formation of an epitaxial film to remove the surface oxide film much as possible (the argon beam treatment was not performed in Example 1). For the formation of an epitaxial film, a 100-nm-thick stabilized zirconia (YSZ) thin film was formed by PLD method, and further a 400-nm-thick cerium oxide (CeO 2 ) thin film was formed thereon.
[0058] After the formation of the two-layer epitaxial film, the structure and crystal orientation of the epitaxial film were evaluated. The epitaxial film surface was subjected to X-ray diffraction analysis (XRD), and the crystal orientations of YSZ and CeO 2 forming the epitaxial film were examined by a 2θ-θ method. Then, the crystal orientation was evaluated by a pole figure method (Shultz reflection method).
[0059] FIG. 2 shows the results of X-ray diffraction (2θ-θ method) of the epitaxial films (YSZ/CeO 2 continuous films) formed on the textured substrates of Example 1 and the conventional example. In the epitaxial film of Example 1, only YSZ (002) peak and CeO 2 (200) peak are seen, and it can be observed that each substance grows epitaxially along the crystal orientation of the layer immediately thereunder. Meanwhile, in the epitaxial film of the conventional example, there are only YSZ (101) peak and CeO 2 (111) peak. This indicates that the film grows along the preferred orientation of each substance independently of the orientation of the layer immediately thereunder, which indicates that the function of the textured substrate is not exerted.
[0060] This can be also understood also from the pole figures. FIG. 3 shows X-ray pole figures of the continuous epitaxial films (YSZ/CeO 2 ) formed on the textured substrates of Example 1 and the conventional example. In the epitaxial film of Example 1, YSZ and CeO 2 are shown to have high orientation. In contrast, in the conventional example, it can be observed that YSZ and CeO 2 each grow along its preferred orientation, and, as a result, the CeO 2 crystal orientation is significantly inferior.
[0061] Additionally, FIG. 4 shows X-ray pole figures of the YSZ/CeO 2 continuous film on the textured substrate of Example 1 in the length direction, showing a front end portion, a central portion, a rear end portion. In the epitaxial film of Example 1, the same crystal orientation is seen in every point, and no variation can be observed in the length direction. Accordingly, it was confirmed that even when an elongated epitaxial film was formed, the textured substrate of Example 1 having palladium added thereto allowed for the formation of a film with stable crystal orientation.
[0062] From the above examination results, it was confirmed that when palladium was added to a textured substrate by a suitable treatment while increasing the hydrogen content, such a substrate allowed for the growth of an epitaxial film while maintaining good crystal orientation. This is attributable to the suppressive action on the production of a natural oxide film caused by palladium, and it appears that other metals have no such action. Additionally, the addition of palladium allows for formation of a good epitaxial film even without cleaning the substrate surface before the epitaxial film formation (argon beam treatment), and it can be said that this technique is also excellent in terms of efficiency.
[0063] Second Embodiment: Here, when the treatment conditions for the addition of palladium were varied and a different addition method was applied, it was examined whether there would be any difference in the hydrogen content of the textured substrate surface. Palladium was added under strike plating conditions varied from the first embodiment. Additionally, the treatment was performed by use of general electrolytic plating as a method for adding palladium to produce textured substrates (Comparative Examples 5 and 6). This electrolytic plating was performed by use of a commercially available plating solution (product name: PALLADEX ADP720) at a bath temperature 30 to 50° C. and a current density 0.5 to 1.0 A/dm 2 for a plating time of 1 second. Incidentally, in each case, the amount of addition of palladium was set at 60 ng/mm 2 per unit area.
[0064] Then, the hydrogen content and oxygen concentration of the substrate surface were measured in the same manner as in the first embodiment. The results are shown in Table 2 and FIG. 5 .
[0000]
TABLE 2
Added metal
Hydrogen content
Example 2
Pd
795 ppm
Example 3
751 ppm
Example 4
801 ppm
Comparative Example 5
418 ppm
Comparative Example 6
637 ppm
[0065] From the results of Table 2 and FIG. 5 , it appears that there is correlation between the hydrogen content and oxygen concentration of the substrate surface. However, in order for the effect to be exerted, certain hydrogen content is necessary. Additionally, it can be observed that even though palladium has hydrogen absorbability, it is difficult to introduce a sufficient amount of hydrogen by usual plating, and a treatment in which hydrogen can be forcibly introduced, such as strike plating, is suitable.
INDUSTRIAL APPLICABILITY
[0066] As described above, the textured substrate for forming an epitaxial film according to the present invention ensures crystal orientation and also considers the quality of an epitaxial film formed thereon. The present invention is suitable as a substrate for various materials and devices using an epitaxial film, and is useful as a substrate for forming an oxide thin film for a superconductive material, a solar cell, or the like. | The present invention provides a textured substrate for forming an epitaxial film, including a textured metal layer on at least one surface of the layer, the textured metal layer including a copper layer having a cube texture, the textured metal layer having, on a surface of the layer, palladium added in an amount of 10 to 300 ng/mm 2 per unit area, the hydrogen content of the surface of the textured metal layer being 700 to 2000 ppm. This textured substrate is produced through a step of adding 10 to 300 ng/mm 2 per unit area of palladium by strike plating to a surface of the copper layer having a cube texture. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to (wireless) receivers, and, in particular, to buffer-based methods for generating Orthogonal Variable Spreading Factor (OVSF) codes for the spreading and despreading of data.
2. Description of the Related Art
When a signal travels through a real-world environment, it often reaches a receiver by multiple paths. These paths occur as a result of the signal reflecting, diffracting, and scattering from various elements in the environment, e.g., mountains, trees, and buildings. Multi-path components are essentially time-delayed variants of a single signal. While, in some applications, these multiple components may result in interference, e.g., ghosting on the display of an analog television receiver, Code Division Multiple Access (CDMA) systems intentionally make use of these multiple components.
The basic principle of CDMA systems is orthogonal coding, whereby, instead of assigning specific frequencies or time slots to each user of a system, the users are distinguished from one another by assigning codes. The codes fulfill the same role as frequency or time in frequency- or time-division systems, i.e., to keep the signals for different users from interfering with one another. In orthogonal spreading, a symbol is XOR-multiplied by a defined sequence of bits called a “code sequence” (also called a “code pattern” or simply a “code”). If the code sequence length is n bits, then each symbol is transformed to n so-called chips. The resulting chip rate, i.e., the number of chips per second (e.g., bits per second), is n times the original symbol rate (number of symbols per second). For example, the spreading code sequence 1111 has a length, also called a spreading or spread factor (SF) or Orthogonal Variable Spreading Factor (OVSF), of four. A single 1 will be spread to the sequence 0000 (1 XOR'ed with 1 gives 0), and a single 0 will be spread to the sequence 1111. In general, code sequences are not arbitrarily chosen, but rather, selected according to certain mathematical rules that provide sets of code sequences that are orthogonal to each other. Orthogonal code sequences have no correlation. Consequently, signals spread with code sequences that are orthogonal to each other do not interfere with one another. For a single connection, input data is spread with a particular code sequence at the transmitter end. To recover the data, the same orthogonal code sequence is used at the receiver end to despread the signal.
Implementation of OVSF spreading and/or despreading operations in a transmitter and/or receiver requires the generation of OVSF codes. The most common and widely used solution requires a chip-rate counter to drive an OVSF generation circuit. The OVSF generation circuit performs an XOR operation between the current count from the chip-rate counter and the OVSF code index in reverse order to produce an OVSF sequence bit every cycle.
However, there is a need for an OVSF code generator that is not limited by the constraints imposed by the use of a chip-rate counter (where count values are used in an algorithm for generating OVSF code sequences), e.g., to be able to generate OVSF codes asynchronously with respect to a chip counter.
SUMMARY OF THE INVENTION
The present invention provides buffer-based methods for generating OVSF code sequences without using a chip-rate counter.
In one embodiment, the present invention provides a method of generating a code sequence. The method comprises populating at least one buffer with initial values based on a received spreading factor and desired code index; receiving a timing strobe; changing the values in the at least one buffer upon receipt of the timing strobe based on an algorithm that is independent of any count value associated with the timing strobe; and outputting at least one code sequence value based on the values in the at least one buffer.
In another embodiment, the present invention provides an apparatus for generating a code sequence. The apparatus comprises means for populating at least one buffer with initial values based on a received spreading factor and desired code index; means for receiving a timing strobe; means for changing the values in the at least one buffer upon receipt of the timing strobe based on an algorithm that is independent of any count value associated with the timing strobe; and means for outputting at least one code sequence value based on the values in the at least one buffer.
BRIEF DESCRIPTION OF THE FIGURES
Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which like reference numerals identify similar or identical elements.
FIG. 1 is a portion of a code tree from which OVSF codes for Third-Generation Partnership Project's Universal Mobile Telecommunications System (3GPP/UMTS) applications are selected;
FIG. 2 is a flowchart illustrating an exemplary method for generating OVSF code sequences without the use of a chip-rate counter, in accordance with the present invention;
FIG. 3 is a flowchart illustrating a first exemplary algorithm consistent with the present invention;
FIG. 4 is a set of stack diagrams illustrating graphically the contents of the stack in an exemplary code sequence generation consistent with the flowchart of FIG. 3 ;
FIG. 5 is a hardware diagram illustrating a 4×4 LUT-based 3GPP OVSF code generator employing a second exemplary algorithm consistent with the present invention; and
FIG. 6 is a timing diagram of a hardware code generator embodiment employing multiplexing to generate multiple codes at a time using only a single OVSF code generator consistent with the present invention.
DETAILED DESCRIPTION
FIG. 1 is a portion of a code tree from which OVSF codes for Third-Generation Partnership Project's Universal Mobile Telecommunications System (3GPP/UMTS) applications are selected. While the portion of the tree shown in FIG. 1 shows a pattern of codes for only spread factors 1, 2, and 4, the full tree (not shown) extends to code patterns for a spread factor of up to 512. In the code tree, the codes are uniquely identified as C ch,SF,k , where SF is the spread factor of the code and k is the code index, 0≦k≦SF−1. The 3GPP standard specifies that the code generator should be capable of producing codes with a variable spread factor over the range SF=4 to 512. (It should be understood that the invention may also have utility with non-3GPP applications, i.e., SF can be less than 4 or greater than 512.) Accordingly, in the embodiments described below, a maximum of 9 bits is needed to represent code index (or “code number”) k for all possible spread factors in the range SF=4 to 512. It should be noted that the set of possible code values {−1,1} is sometimes mapped to {1,0} herein to simplify calculation and binary processing.
FIG. 2 is a flowchart 200 illustrating an exemplary method for generating OVSF code sequences without the use of a chip-rate counter, in accordance with the present invention. It should be understood that the broad method of flowchart 200 can be implemented by either the first algorithm or the second algorithm described below. The method of flowchart 200 begins at step 201 . At step 202 , spread factor SF and code index k of the desired OVSF code pattern are received.
At step 203 , an initial timing strobe is received. The timing strobe can be a pulse or other time interval identifier that may include an associated counter value (e.g., as may supplied by a chip-rate counter). However, the timing strobe is not required by the present invention to include an associated counter value (e.g., as may be supplied by a global clock), since the algorithms of the various embodiments of the present invention do not require that the timing strobe include count values. Alternatively, in various embodiments of the present invention, the output of a counter may be used merely for timing purposes, such that the algorithm does not employ the count value itself in generating code sequences.
At step 204 , at least one buffer is populated with certain initial values based on the values of SF and k. At step 205 , another timing strobe is received. At step 206 , the values in the buffer change based on an algorithm, such as the First Algorithm or Second Algorithm described below. At step 207 , a determination is made whether the change in the buffer values results in the generation of an OVSF code sequence value (i.e., a−1 or a+1), in which case the method proceeds to step 208 so that the OVSF code sequence value can be read out of the buffer. If, at step 207 , it is determined that no OVSF code sequence value is generated, then the method returns to step 205 for another timing strobe to be received. At step 209 , a determination is made whether the last OVSF code sequence value in the sequence has been generated, in which case the method ends at step 210 . If, at step 209 , it is determined that the last OVSF code sequence value has not been generated, then the method returns to step 205 for another timing strobe to be received.
Further details of two exemplary algorithms for generating OVSF code patterns without a chip-rate counter, as well as an exemplary time-multiplexed code generator for generating multiple codes at a time using only a single OVSF code generator consistent with the present invention, will now be provided.
First Algorithm
In a first exemplary algorithm consistent with the present invention, OVSF code patterns are generated using a recursive function, such as the function ssf provided in the following pseudo-code:
ssf(n,k) if (n=0) return “1” on chip strobe else ssf(n−1, k/2) if (k is even) ssf(n−1, k/2) else −[ssf(n−1, k/2)] endif endif end
In the above pseudo-code, n is equal to log 2 of the spread factor (where n=0 . . . 9), and k is the desired OVSF code index (where k=0 . . . 2 n −1). The unary operation “−” in the above pseudo-code describes the negation of each element of the entire sequence generated by the second recursive call of the ssf function (in square brackets). The ssf function may be coded in C as follows:
/* n = log2(SF) */ /* k = code index, k= 0..(2{circumflex over ( )}n)−1 */ /* s coding: {−1,1} maps to {1,0} */ int ssf(int n, int k, int s) { if(!n) if(!s)printf(“1”); else printf(“−1”); else { ssf(n−1, k/2, s); if(!(k&01)) ssf(n−1, k/2, s); else ssf(n−1, k/2, (~s)); } }
In the above C code, the sign s of an element in an OVSF sequence is passed on recursively as the third parameter, to offer the same functionality as the unary operator in the above pseudo-code, but in a more convenient fashion for a practical implementation. The value of s in the initial function call is always 0. The operator “˜” describes the inversion of s, i.e., if s is 0, it becomes 1, and if s is 1, it becomes 0.
Turning now to FIG. 3 , a flowchart 300 of an exemplary OVSF code generation method illustrates how the ssf function can be implemented in hardware using a limited-size stack buffer (the “stack”). The term “stack,” as used herein, generally refers to a first-in, last-out (FILO) or a last-in, first-out (LIFO) buffer. In flowchart 300 , the following notation is used:
n is the log 2 of the spread factor, n=0 . . . 9;
k is the code index of the desired OVSF code, k=0 . . . [(2 n )−1], if k=0 then the OVSF code sequence contains all “1”s;
s is the sign of an element in the spreading code sequence, s=+1 or −1;
c is a recursive function call tag indicating the level of recursion, c=0 or 1, for operations corresponding to the first or second recursive ssf call, respectively; and
SP is the stack pointer, SP=0 . . . 9, which points to the top of the stack that holds n, s, and c.
The stack holds parameters n (4 bits), s (1 bit), and c (1 bit) for operations corresponding to each recursive call of the ssf function. In the algorithm shown in flowchart 300 , parameter k (9 bits) is stored on the stack. However, in an alternative embodiment of the algorithm, parameter k could be stored separately from the stack to increase efficiency. For example, the operations of recursively computing k=k/2 (using integer division), storing k on the stack and testing top-of-stack k for being even could be replaced with a single operation of testing the (SP−1) position bit (from the right) of initial k for being “0”. This single operation would replace testing k for being even in step 311 of the flowchart, and the k assignment step k=(k@(SP−1))/2 in step 304 would be removed. The assert operation of step 305 outputs an element of OVSF code sequence, i.e., either +1 or −1, based on whether s is 0 or 1. The coding of s is mapped as follows: +1 is coded as 0, and −1 is coded as 1, to be consistent with the ssf function above.
The method of flowchart 300 begins at step 301 , wherein a stack containing variables n, k, s, c, and SP is initialized, and s, c, and SP are set to 0. The values for variables n (log 2 of spread factor SF) and k (the OVSF code index of the desired sequence) are received and stored on the top of the stack. At step 302 , a determination is made whether top-of-stack n is equal to 0. If top-of-stack n is not equal to 0, then the method proceeds to step 303 , wherein SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , n at stack location SP−1 is decremented by 1 and the result stored as top-of-stack n, k at stack location SP−1 is divided by 2 and the result stored as top-of-stack k, top-of-stack c is set to 0, and top-of-stack s is set to the value of s at stack location SP−1, after which the method returns to step 302 . If, at step 302 , it is determined that top-of-stack n is equal to 0, then the method proceeds to step 305 , wherein the assert function is called for top-of-stack s to output a +1 if top-of-stack s is equal to 0, or a −1 if top-of-stack s is equal to 1. Next, at step 306 , a determination is made whether SP is equal to 0, in which case the code generation is complete, and the method terminates at step 307 . If, at step 306 , it is determined that SP is not equal to 0, then the method proceeds to step 308 . At step 308 , a determination is made whether top-of-stack c is equal to 0. If top-of-stack c is not equal to 0, then the method proceeds to step 309 , wherein SP is decremented by 1, after which the method returns to step 306 . If, at step 308 , it is determined that top-of-stack c is not equal to 0, then the method proceeds to step 310 , wherein top-of-stack c is set to 1. Next, at step 311 , a determination is made whether k at stack location SP−1 is even, in which case the method proceeds to step 312 . At step 312 , top-of-stack s is set to the value of s at stack location SP−1, after which the method returns to step 302 . If, at step 311 , it is determined that k at stack location SP−1 is not even, then the method proceeds to step 213 . At step 213 , top-of-stack s is set to the inverse of the value of s at stack location SP−1, after which the method proceeds to step 302 .
FIG. 4 is a set of stack diagrams illustrating graphically the contents of the stack in an exemplary code sequence generation, to illustrate the operation of flowchart 300 . In this example, the spread factor is SF=16 (hence, n=4), and the sequence for OVSF code index 9 is requested. Thus, variables n and k in the initial row of the stack will be initialized to the values n=4 and k=9. The corresponding OVSF codes for SF=16 are shown in the following Table I:
TABLE I OVSF Code Number OVSF code 0 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 1 1, 1, 1, 1, 1, 1, 1, 1, −1, −1, −1, −1, −1, −1, −1, −1 2 1, 1, 1, 1, −1, −1, −1, −1, 1, 1, 1, 1, −1, −1, −1, −1 3 1, 1, 1, 1, −1, −1, −1, −1, −1, −1, −1, −1, 1, 1, 1, 1 4 1, 1, −1, −1, 1, 1, −1, −1, 1, 1, −1, −1, 1, 1, −1, −1 5 1, 1, −1, −1, 1, 1, −1, −1, −1, −1, 1, 1, −1, −1, 1, 1 6 1, 1, −1, −1, −1, −1, 1, 1, 1, 1, −1, −1, −1, −1, 1, 1 7 1, 1, −1, −1, −1, −1, 1, 1, −1, −1, 1, 1, 1, 1, −1, −1 8 1, −1, 1, −1, 1, −1, 1, −1, 1, −1, 1, −1, 1, −1, 1, −1 9 1, −1, 1, −1, 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1 10 1, −1, 1, −1, −1, 1, −1, 1, 1, −1, 1, −1, −1, 1, −1, 1 11 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1, 1, −1, 1, −1 12 1, −1, −1, 1, 1, −1, −1, 1, 1, −1, −1, 1, 1, −1, −1, 1 13 1, −1, −1, 1, 1, −1, −1, 1, −1, 1, 1, −1, −1, 1, 1, −1 14 1, −1, −1, 1, −1, 1, 1, −1, 1, −1, −1, 1, −1, 1, 1, −1 15 1, −1, −1, 1, −1, 1, 1, −1, −1, 1, 1, −1, 1, −1, −1, 1
The desired OVSF sequence in this example is the one corresponding to OVSF code index 9 , which is: {1, −1, 1, −1, 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1}. To arrive at this sequence, the following steps take place (the “iterations” set forth below are provided for ease of reference and merely refer to instances of updating one or more stack variables; the “iterations” do not necessarily correspond to any particular steps or substeps within flowchart 300 ):
At iteration 1 , the stack containing variables n, k, s, c, and SP is initialized at step 301 , and s, c, and SP are set to 0. The value for n is set to 4 (for a spread factor SF=16) and the value fork is set to 9 for OVSF code index 9 . It is determined at step 302 that top-of-stack n is not equal to 0, and so the method proceeds to step 303 .
At iteration 2 , the value 0 of SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , the value 4 for n at stack location SP−1 is decremented by 1, and the result 3 is stored as top-of-stack n. The value 9 for k at stack location SP−1 is divided by 2, and the result 4 is stored as top-of-stack k. The value for top-of-stack c is set to 0. The value for top-of-stack s is set to 0, i.e., the value of s at stack location SP−1, and the method returns to step 302 . It is determined at step 302 that top-of-stack n is not equal to 0, and so the method proceeds to step 303 .
At iteration 3 , the value 1 of SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , the value 3 for n at stack location SP−1 is decremented by 1, and the result 2 is stored as top-of-stack n. The value 4 for k at stack location SP−1 is divided by 2, and the result 2 is stored as top-of-stack k. The value for top-of-stack c is set to 0. The value for top-of-stack s is set to 0, i.e., the value of s at stack location SP−1, and the method returns to step 302 . It is determined at step 302 that top-of-stack n is not equal to 0, and so the method proceeds to step 303 .
At iteration 4 , the value 2 of SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , the value 2 for n at stack location SP−1 is decremented by 1, and the result 1 is stored as top-of-stack n. The value 2 for k at stack location SP−1 is divided by 2, and the result 1 is stored as top-of-stack k. The value for top-of-stack c is set to 0. The value for top-of-stack s is set to 0, i.e., the value of s at stack location SP−1, and the method returns to step 302 . It is determined at step 302 that top-of-stack n is not equal to 0, and so the method proceeds to step 303 .
At iteration 5 , the value 3 of SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , the value 1 for n at stack location SP−1 is decremented by 1, and the result 0 is stored as top-of-stack n. The value 1 for k at stack location SP−1 is divided by 2, and the result 0 is stored as top-of-stack k. The value for top-of-stack c is set to 0. The value for top-of-stack s is set to 0, i.e., the value of s at stack location SP−1, and the method returns to step 302 . Since top-of-stack n is equal to 0, the method proceeds to step 305 , wherein the assert function is called. The assert function outputs a value of +1 because top-of-stack s is equal to 0. At step 306 , it is determined that SP is not equal to 0, and the method proceeds to step 308 . At step 308 , it is determined that top-of-stack c is equal to 0.
At iteration 6 , the value for top-of-stack c is set to 1 at step 310 . At step 311 , it is determined that the value 1 for k at stack location SP−1 is not even. At step 213 , the value for top-of-stack s is set to 1, which is the inverse of the value 1 of s at stack location SP−1. The method proceeds to step 302 .
At iteration 7 , since top-of-stack n is equal to 0, the method proceeds to step 305 , wherein the assert function is called. The assert function outputs a value of −1 because top-of-stack s is equal to 1. At step 306 , it is determined that SP is not equal to 0, and the method proceeds to step 308 .
At iteration 8 , at step 308 , it is determined that top-of-stack c is not equal to 0, and so, at step 309 , SP is decremented by 1, removing the top row from the stack. At step 306 , it is determined that SP is not equal to 0, and the method proceeds to step 308 . At step 308 , it is determined that top-of-stack c is equal to 0, and the method proceeds to step 310 , wherein top-of-stack c is set to 1. It is determined at step 311 that the value 2 for k at stack location SP−1 is even. At step 312 , the value for top-of-stack s is set to 0, which is the value of s at stack location SP-1.
At iteration 9 , the method proceeds to step 302 . Since top-of-stack n is not equal to 0, the method proceeds to step 303 , wherein the value 3 of SP is incremented by 1, creating a new, empty top-of-stack row. Next, at step 304 , the value 1 for n at stack location SP−1 is decremented by 1, and the result 0 is stored as top-of-stack n. The value 1 for k at stack location SP−1 is divided by 2, and the result 0 is stored as top-of-stack k. The value for top-of-stack c is set to 0. The value for top-of-stack s is set to 0, i.e., the value of s at stack location SP−1, and the method returns to step 302 . Since top-of-stack n is equal to 0, the method proceeds to step 305 , wherein the assert function is called. The assert function outputs a value of +1 because top-of-stack s is equal to 0. At step 306 , it is determined that SP is not equal to 0, and the method proceeds to step 308 .
The method continues to follow flowchart 300 until step 307 is reached and the method ends, as shown in Iterations 10 through 64 of FIG. 4 . By the end of this process, the entire sequence corresponding to OVSF code index 9 , i.e., {1, −1, 1, −1, 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1} will have been generated efficiently, without the use of a chip-rate counter.
Second Algorithm
In a second exemplary algorithm consistent with the present invention, the OVSF codes are generated using a look-up table (LUT), such as the following Table II, which provides the OVSF codes for a spread factor of 4:
TABLE II k OVSF bit for SF 4 0 (00) 0 0 0 0 1 (01) 0 0 1 1 2 (10) 0 1 0 1 3 (11) 0 1 1 0
In Table II and in the description below, the set of possible code values {−1,1} is mapped to {1,0} to simplify calculations, as in the first algorithm described above.
With reference now to FIG. 5 , a hardware diagram illustrates a 4×4 LUT-based 3GPP OVSF code generator 500 employing a second algorithm consistent with the present invention. As shown, the code generator comprises a controller 501 , a desired OVSF code register 502 , LUT 503 , a pattern buffer 504 , a path buffer 505 , and a decision block 506 .
As shown in FIG. 5 , controller 501 coordinates the reading and writing of values stored in desired OVSF code register 502 , LUT 503 , pattern buffer 504 , and path buffer 505 and also controls the operation of decision block 506 . Controller 501 receives a timing strobe (from an external source) that governs the timing of its operations. The arrows between desired OVSF code register 502 , LUT 503 , pattern buffer 504 , path buffer 505 , and decision block 506 are provided merely to illustrate data flow between these components, which may occur directly, via controller 501 , or via other components, and do not necessarily represent direct connections between these components.
Desired OVSF code register 502 is a 9-bit register with memory locations N[ 8 : 0 ]. Initially, controller 501 stores the desired OVSF code sequence corresponding to code index k in register 502 by populating the MSB bits of memory locations N[ 8 : 0 ] with the binary representation of the desired OVSF code index k (received from an external source), with the LSB bits of memory locations N[ 8 : 0 ] filled with zero values, i.e., k[MSB], k[MSB-1], . . . , k[LSB], 0, . . . , 0. For example, if k is 9, then desired OVSF code register 502 is filled with the following values: 100100000. While in the example of FIG. 5 , the buffer sizes (of desired OVSF code register 502 , pattern buffer 504 , and path buffer 505 ) are sized to support a spreading factor of up to 512, other buffer sizes are possible. It should be understood that the number of memory locations N should be equal to or greater than log 2 (SF) to have sufficient storage for a binary representation of k. If the number of memory locations N is equal to log 2 (SF), then memory locations [log 2 (SF)−1:0] will contain a binary representation of k. If the number of memory locations is greater than log 2 (SF), then the MSB bits of memory locations [log 2 (SF)−1:0] contain a binary representation of k, and the LSB bits of memory locations [log 2 (SF)−1: 0 ] contain zero values.
LUT 503 is a 4×4 look-up table populated with the OVSF codes shown in Table II above. The values in LUT 503 remain constant and can either be stored permanently in LUT 503 or initialized (e.g., using controller 501 ) at the beginning of the code generation process to contain the correct values.
As shown in FIG. 5 , pattern buffer 504 contains bits b 0 through b 17 stored across 5 levels. The bottom 4 levels (P 0 through P 3 ) each have 4 bits (P 0 contains bits b 0 through b 3 , P 1 contains bits b 4 through b 7 , P 2 contains bits b 8 through b 11 , and P 3 contains bits b 12 through b 15 ). The top level (P 4 ) has 2 bits (bits b 16 and b 17 ).
For each level of pattern buffer 504 , controller 501 looks up content in LUT 503 using a specified two-bit sequence and stores in the level of pattern buffer 504 the values read from LUT 503 (i.e., the 4-bit row contents) that correspond to the two-bit sequence provided by desired OVSF code register 502 , as follows: The values stored in memory locations N[ 8 : 7 ] are used to look up content for level P 0 (bits b 0 -b 3 ) in LUT 503 to populate pattern buffer 504 . The values stored in memory locations N[ 6 : 5 ] are used to look up content for level P 1 (bits b 4 -b 7 ) in LUT 503 to populate pattern buffer 504 . The values stored in memory locations N[ 4 : 3 ] are used to look up content for level P 2 (bits b 8 -b 11 ) in LUT 503 to populate pattern buffer 504 . The values stored in memory locations N[ 2 : 1 ] are used to look up content for level P 3 (bits b 12 -b 15 ) in LUT 503 to populate pattern buffer 504 . The value stored in memory location N[ 0 ] concatenated with the value “0” are used to look up content for level P 4 (bits b 16 and b 17 ) in LUT 503 to populate pattern buffer 504 .
For example, given a spread factor of SF=256, if the desired OVSF code index is k=169, then controller 501 fills desired OVSF code register 502 with the sequence 10101001;0, which sequence will be used as the LUT index. Next, controller 501 fills pattern buffer 504 with the content shown in the following Table III:
TABLE III
LUT index
Pattern Buffer Content
Level P0
10
0
1
0
1
Level P1
10
0
1
0
1
Level P2
10
0
1
0
1
Level P3
01
0
0
1
1
Level P4
00
0
0
Path buffer 505 has 5 levels, which permits code generator 500 to support a spread factor of up to SF=512. As with pattern buffer 504 , the bottom four levels each have 4 bits, and the top level has 2 bits. Controller 501 initializes path buffer 505 to contain the values in the following Table IV:
TABLE IV Level L0 1 0 0 0 Level L1 1 0 0 0 Level L2 1 0 0 0 Level L3 1 0 0 0 Level L4 1 0
At each assertion of the timing strobe (i.e., each clock cycle) during the code generation process, controller 501 performs a “walking ones” operation to right-shift circularly (i.e., from left to right in a circular manner) the position of one or more of the “1” bits in path buffer 505 , as follows: Level L 0 will be shifted one bit to the right, such that the LSB bit is shifted to become the MSB. Level L 1 will be shifted one bit to the right only when the LSB of Level L 0 turns to “0” from “1”. Similarly, Level L 2 has dependency on Level L 1 so as to shift one bit to the right only when the LSB of Level L 1 turns from “0” to “1”; Level L 3 has dependency on Level L 2 so as to shift one bit to the right only when the LSB of Level L 2 turns from “0” to “1”; and Level L 4 has dependency on Level L 3 so as to shift one bit to the right only when the LSB of Level L 3 turns from “0” to “1”.
Next, for each level of path buffer 505 , controller 501 selects a bit in the corresponding level of pattern buffer 504 to send to decision block 506 . Controller 501 determines this bit selection by the position of the “1” bit in the corresponding level of path buffer 505 . In other words, one bit from each level of pattern buffer 504 at a time is sent to decision block 506 , for a total of 5 bits: p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n].
Decision block 506 performs an XOR operation (or other decision method) among the 5 selected bits p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] from pattern buffer 504 to decide the OVSF code. Following the XOR operation, controller 501 performs another “walking ones” operation on the bits of path buffer 505 , controller 501 selects another bit from each of the five levels of pattern buffer 504 to send to decision block 506 , and decision block 506 performs another XOR operation, and so forth. This process continues until the entire OVSF code sequence has been generated and may be repeated subsequently for one or more additional OVSF code sequences.
With reference to the following Tables V-VIII, the steps of an exemplary code sequence generation will now be provided to illustrate the operation of code generator 500 . In this example, the spread factor is SF=16, and the sequence for OVSF code index 9 is requested. Thus, the values SF=16 and k=9 will be provided to controller 501 . The corresponding OVSF codes for SF=16 are shown in Table I above. The desired OVSF sequence in this example is the one corresponding to OVSF code index 9 , which is: {1, −1, 1, −1, 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1}. Mapping the code values {−1,1} to {1,0}, the desired OVSF sequence becomes {0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0}. To arrive at this sequence, the following steps take place:
Controller 501 receives the spread factor of 16 and assigns this value to SF. Controller 501 receives the value of the desired OVSF code index, i.e., 9 , or { 1001 } and assigns this value to k. Controller 501 fills desired OVSF code register 502 with the following values: {k[3], k[2], k[1], k[0], k[0], 0, 0, 0, 0}, i.e. {10, 01, 00, 00, 0}.
Pattern buffer 504 is initialized based on the contents of register 502 , as follows: For Level P 0 of pattern buffer 504 , controller 501 looks up content in LUT 503 using the specified two-bit sequence N[ 8 : 7 ] stored in desired OVSF code register 502 (which contains the values “10”), and reads the 4-bit row contents in LUT 503 that correspond to the sequence “10”, i.e., “0101”. Controller 501 then stores the retrieved sequence “0101” in level P 0 of pattern buffer 504 . For Level P 1 of pattern buffer 504 , controller 501 looks up content in LUT 503 using the specified two-bit sequence N[6:5] stored in desired OVSF code register 502 (which contains the values “01”), and reads the 4-bit row contents in LUT 503 that correspond to the sequence “01”, i.e., “0011”. Controller 501 then stores the retrieved sequence “0011” in level P 1 of pattern buffer 504 . For Level P 2 of pattern buffer 504 , controller 501 looks up content in LUT 503 using the specified two-bit sequence N[ 4 : 3 ] stored in desired OVSF code register 502 (which contains the values “00”), and reads the 4-bit row contents in LUT 503 that correspond to the sequence “00”, i.e., “0000”. Controller 501 then stores the retrieved sequence “0000” in level P 2 of pattern buffer 504 . For Level P 3 of pattern buffer 504 , controller 501 looks up content in LUT 503 using the specified two-bit sequence N[ 2 : 1 ] stored in desired OVSF code register 502 (which contains the values “00”), and reads the 4-bit row contents in LUT 503 that correspond to the sequence “00”, i.e., “0000”. Controller 501 then stores the retrieved sequence “0000” in level P 3 of pattern buffer 504 . For Level P 4 of pattern buffer 504 , controller 501 looks up content in LUT 503 using the specified one-bit value N[0] stored in desired OVSF code register 502 and concatenates the value of N[0] (which contains the value “0”) with the value “0”. Controller 501 then reads the 4-bit row contents in LUT 503 that correspond to the sequence “00”, i.e., “0000”. Controller 501 then stores the retrieved sequence “00” in level P 4 of pattern buffer 504 . It is noted that the last two bits of the sequence “0000” are simply ignored, since Level P 4 of pattern buffer 504 has storage for only 2 bits. After the foregoing steps for populating pattern buffer 504 , the contents of pattern buffer 504 are as shown in the following Table V:
TABLE V Level P0 0 1 0 1 Level P1 0 0 1 1 Level P2 0 0 0 0 Level P3 0 0 0 0 Level P4 0 0
Path buffer 505 has already been prepopulated with the values shown in the following Table VI:
TABLE VI
Level L0
1
0
0
0
Level L1
1
0
0
0
Level L2
1
0
0
0
Level L3
1
0
0
0
Level L4
1
0
Now, generation of the first bit of the OVSF sequence begins. Controller 501 reads the position of the “1” in Level L 0 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 0 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 1 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 1 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 2 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 2 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 3 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 3 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 4 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 4 of pattern buffer 504 , which is a “0”. Controller 501 causes the 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from pattern buffer 504 , i.e., “00000”, to be provided to decision block 506 .
Decision block 506 performs an XOR operation on the values p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] ({0, 0, 0, 0, 0}) of the received sequence “00000” and returns a “0”, which is the first OVSF code bit in the desired sequence corresponding to OVSF code index 9 .
After completing the generation of the first OVSF code bit, the contents of Level L 0 of path buffer 505 are circularly right-shifted by one bit, so that path buffer 505 now contains the values shown in the following Table VII:
TABLE VII
Level L0
0
1
0
0
Level L1
1
0
0
0
Level L2
1
0
0
0
Level L3
1
0
0
0
Level L4
1
0
Now, generation of the second bit of the OVSF sequence begins. Controller 501 reads the position of the “1” in Level L 0 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 0 of pattern buffer 504 , which is a “1”. Next, controller 501 reads the position of the “1” in Level L 1 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 1 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 2 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 2 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 3 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 3 of pattern buffer 504 , which is a “0”. Next, controller 501 reads the position of the “1” in Level L 4 of path buffer 505 and uses this position as an index to read the value that has the same position in Level P 4 of pattern buffer 504 , which is a “0”. Controller 501 causes the 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from pattern buffer 504 , i.e., “10000”, to be provided to decision block 506 .
Decision block 506 performs an XOR operation on the values p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] ({1, 0, 0, 0, 0}) of the received sequence “10000” and returns a “1”, which is the second OVSF code bit in the desired sequence corresponding to OVSF code index 9 .
After completing the generation of the second OVSF code bit, the contents of Level L 0 of path buffer 505 are circularly right-shifted by one bit, so that path buffer 505 now contains the values shown in the following Table VIII:
TABLE VIII
Level L0
0
0
1
0
Level L1
1
0
0
0
Level L2
1
0
0
0
Level L3
1
0
0
0
Level L4
1
0
Generation of the third bit of the OVSF sequence now takes place, and the foregoing process continues in this manner, until the “1” in Level L 0 is shifted back into its initial position, at which point the “1” in Level L 1 starts to right-shift circularly by one bit. Once the “1” in Level 1 is shifted back into its initial position, the “1” in Level L 2 starts to right-shift circularly by one bit, and so forth. When this process is complete, the entire OVSF sequence for OVSF code index 9 {0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0}, i.e., {1, −1, 1, −1, 1, −1, 1, −1, −1, 1, −1, 1, −1, 1, −1, 1}, will have been generated efficiently, without the use of a chip-rate counter.
It is noted that the contents of pattern buffer 504 remain unchanged during this entire process and only change if a new OVSF code sequence with a different OVSF code index is requested.
Time-Multiplexed Code Generator
FIG. D illustrates the processing flow and timing of an exemplary time-multiplexed code generator for generating four codes at a time using only a single OVSF code generator consistent with the present invention. In this embodiment, the code generator contains similar hardware components as code generator 500 of FIG. 5 , with several additional signals provided to the controller to govern the time-multiplexing. In this four-code embodiment, there are four desired OVSF code indices k 1 , k 2 , k 3 , and k 4 . Other embodiments with other numbers of (i.e., 2 or more) OVSF code indices may alternatively be employed. Path buffer 505 is common to all four code indices and is shifted once every chip period, i.e., after an OVSF sequence bit has been generated for all four code indices, pattern buffer 504 is reloaded to generate an OVSF sequence bit for each code of the four code indices during every chip period.
Path buffer 505 is reset to its initial values when a reset signal is asserted. As shown, desired OVSF code register 502 (reg_N) is loaded serially with the corresponding desired OVSF code indices k 1 , k 2 , k 3 , and k 4 , respectively, at a plurality of instances at which a load_k signal is asserted. Pattern buffer 504 is filled serially with the patterns from LUT 503 based on the current contents of the desired OVSF code register, first with the pattern corresponding to OVSF code index k 1 , then with the pattern corresponding to OVSF code index k 2 , then with the pattern corresponding to OVSF code index k 3 , and then with the pattern corresponding to OVSF code index k 4 .
Based on the pattern buffer contents corresponding to code index k 1 and the contents of the path buffer (which will remain the same for all four code indices), a 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from the pattern buffer is provided to decision block 506 to obtain the first bit for code index k 1 . Next, based on the pattern buffer contents corresponding to code index k 2 and the contents of the path buffer, a 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from the pattern buffer is provided to the decision block to obtain the first bit for code index k 2 . Next, based on the pattern buffer contents corresponding to code index k 3 and the contents of the path buffer, a 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from the pattern buffer is provided to the decision block to obtain the first bit for code index k 3 . Next, based on the pattern buffer contents corresponding to code index k 4 and the contents of the path buffer, a 5-bit sequence p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] containing the values read from the pattern buffer is provided to the decision block to obtain the first bit for code index k 4 . Additional temporary storage for the 5-bit sequence values p 0 [i], p 1 [j], p 2 [k], p 3 [m], and p 4 [n] may be provided but is not necessary if the OVSF bits are being generated on the fly.
Once a first bit has been obtained for each of OVSF code indices k 1 , k 2 , k 3 , and k 4 , a path_shift signal is asserted to cause a “walking ones” shift in the values in the path buffer. The foregoing process then repeats for the remaining bits for OVSF code indices k 1 , k 2 , k 3 , and k 4 , until the entire OVSF sequence for OVSF code indices k 1 , k 2 , k 3 , and k 4 have been generated. Thus, by time-multiplexing a single OVSF code generator, multiple OVSF codes can be generated at the same time without the use of a plurality of OVSF code generators.
It should be recognized that the process steps of the embodiments described herein may be implemented using many different hardware and/or software devices, and that the hardware configurations described herein are merely exemplary.
While certain embodiments of the present invention disclosed herein relate to 3GPP and UMTS applications, the present invention may have utility in other non-3GPP and non-UMTS contexts, as well.
It should also be recognized that the present invention may be implemented in code generation for despreading in contexts other than OVSF, as well as for descrambling, and that code sequences other than those described herein, consistent with various embodiments of the present invention, are possible.
While the exemplary embodiments of the present invention have been described with respect to processes of circuits, including possible implementation as a single integrated circuit, a multi-chip module, a single card, or a multi-card circuit pack, the present invention is not so limited. As would be apparent to one skilled in the art, various functions of circuit elements may also be implemented as processing steps in a software program. Such software may be employed in, for example, a digital signal processor, micro-controller, or general purpose computer.
The present invention can be embodied in the form of methods and apparatuses for practicing those methods. The present invention can also be embodied in the form of program code embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. The present invention can also be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium or carrier, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a unique device that operates analogously to specific logic circuits.
It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims.
Although the steps in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those steps, those steps are not necessarily intended to be limited to being implemented in that particular sequence. | A method of generating a code sequence comprises populating at least one buffer with initial values based on a received spreading factor and desired code index; receiving a timing strobe; changing the values in the at least one buffer upon receipt of the timing strobe based on an algorithm that is independent of any count value associated with the timing strobe; and outputting at least one code sequence value based on the values in the at least one buffer. An apparatus for generating a code sequence comprises means for populating at least one buffer with initial values based on a received spreading factor and desired code index; means for receiving a timing strobe; means for changing the values in the at least one buffer upon receipt of the timing strobe based on an algorithm that is independent of any count value associated with the timing strobe; and means for outputting at least one code sequence value based on the values in the at least one buffer. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent Application Number 10-2008-0116420 filed on Nov. 21, 2008, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a diesel oxidation catalyst and an exhaust system provided with the same. More particularly, the present invention relates to a diesel oxidation catalyst and an exhaust system provided with the same that releases sulphur absorbed at an oxidation catalyst in high temperature by using hydrocarbon (HC) absorbed in low temperature.
[0004] 2. Description of Related Art
[0005] Generally, exhaust gas flowing out through an exhaust manifold from an engine is driven into a catalytic converter mounted at an exhaust pipe and is purified therein. After that, the noise of the exhaust gas is decreased while passing through a muffler and then the exhaust gas is emitted into the air through a tail pipe. The catalytic converter is a type of diesel particulate filter (DPF) and purifies pollutants contained in the exhaust gas. A catalytic carrier for trapping particulate material (PM) contained in the exhaust gas is in the catalytic converter, and the exhaust gas flowing out from the engine is purified through a chemical reaction therein.
[0006] One type of catalytic converters is a diesel oxidation catalyst (DOC). The DOC oxidizes HC and CO contained in the exhaust gas.
[0007] Meanwhile, since sulphur contained in a fuel deteriorates performance of the oxidation catalyst, a noble metal including platinum (Pt) that has high sulphur tolerance is mainly used for the DOC. However, since platinum is expensive, manufacturing cost of the DOC becomes expensive. Therefore, the oxidation catalyst including platinum and palladium (Pd) is mainly used. In this case, deterioration in activity of the oxidation catalyst caused by sulphur is a major concern.
[0008] Particularly, deterioration in activity of the oxidation catalyst caused by sulphur is extremely large when temperature of the exhaust gas is low.
[0009] FIG. 6 is a graph showing relations between a temperature of an exhaust gas and a time required for recovering activity of an oxidation catalyst after poisoning of sulphur. As shown in FIG. 6 , 5 minute is required for recovering activity of the oxidation catalyst in a case that the temperature of the exhaust gas is 400° C., 1 minute is required for recovering activity of the oxidation catalyst in a case that the temperature of the exhaust gas is 450° C., and 10 second is required for recovering activity of the oxidation catalyst in a case that the temperature of the exhaust gas is 500° C. Therefore, in order to use the oxidation catalyst including the platinum and the palladium, the temperature of the exhaust gas must be maintained higher than 450° C., but it is very difficult.
[0010] The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY OF THE INVENTION
[0011] Various aspects of the present invention are directed to provide a diesel oxidation catalyst and an exhaust system provided with the same having advantages of recovering activity of an oxidation catalyst as a consequence of releasing sulphur absorbed at the oxidation catalyst by using oxidation heat of hydrocarbon contained in an exhaust gas.
[0012] In an aspect of the present invention, the diesel oxidation catalyst mounted on an exhaust pipe that exhausts an exhaust gas generated in an engine to the exterior, may include a first portion having a hydrocarbon trap (HC trap) coated thereon, the HC trap absorbing or releasing a hydrocarbon (HC) depending on whether or not a predetermined condition is satisfied, and a second portion having an oxidation catalyst coated thereon, the oxidation catalyst oxidizing the hydrocarbon (HC) and a carbon monoxide (CO) in the exhaust gas, wherein the second portion performs oxidation reaction with the HC released from the first portion and releases sulphur absorbed at the oxidation catalyst by using oxidation heat generated in the oxidation reaction thereof.
[0013] The first portion may be coated on a carrier and the second portion is coated on the first portion, wherein the exhaust gas is configured to contact the second portion at first.
[0014] The first portion may be coated on a carrier and the second portion is coated on the carrier, wherein the first portion and the second portion are aligned in sequence along a flowing direction of the exhaust gas such that the exhaust gas contacts the first portion at first.
[0015] The first portion may be coated on a carrier at a front portion of the diesel oxidation catalyst, and the second portion is coated on the carrier at a rear portion of the diesel oxidation catalyst.
[0016] The predetermined condition may be satisfied when temperature of the exhaust gas is higher than a predetermined temperature.
[0017] The hydrocarbon trap may be a beta zeolite, wherein the beta zeolite has a structure of twelve rings and ratio of silica SiO 2 to aluminum oxide Al 2 O 3 is 24-38.
[0018] The hydrocarbon trap may be between approximately 30% and approximately 50% of entire washcoat in the first portion.
[0019] A noble metal including platinum (Pt) and palladium (Pd) may be used for the oxidation catalyst.
[0020] In another aspect of the present invention, an exhaust system is mounted on an exhaust pipe through which an exhaust gas generated in an engine passes and purifies noxious materials contained in the exhaust gas, wherein the exhaust system may include a diesel oxidation catalyst oxidizing HC and CO, and wherein the diesel oxidation catalyst is a diesel oxidation catalyst.
[0021] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic diagram of an exhaust system provided with an exemplary diesel oxidation catalyst according to the present invention.
[0023] FIG. 2 is a schematic diagram of an exemplary diesel oxidation catalyst according to the present invention.
[0024] FIG. 3 is a schematic diagram of another exemplary diesel oxidation catalyst according to the present invention.
[0025] FIG. 4 is a graph showing concentration of sulphur and temperature at a rear end of a diesel oxidation catalyst when temperature of an exhaust gas is increased to a predetermined temperature after an engine provided with an exhaust system according to exemplary embodiments of the present invention is driven at an idle state during a predetermined time.
[0026] FIG. 5 is a graph showing concentration of HC and CO in a case that an engine provided with exhaust systems according to conventional arts and according to exemplary embodiments of the present invention, respectively.
[0027] FIG. 6 is a graph showing relations between a temperature of an exhaust gas and a time required for recovering activity of an oxidation catalyst after poisoning of sulphur.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0029] FIG. 1 is a schematic diagram of an exhaust system provided with a diesel oxidation catalyst according to various embodiments of the present invention. One type of exhaust systems provided with a diesel oxidation catalyst according to various embodiments of the present invention will be exemplarily described, but the sprit of the present invention cannot be limited to the embodiments exemplified herein.
[0030] As shown in FIG. 1 , an exhaust gas generated in an engine 10 passes sequentially through a turbo charger 20 , a catalyzed particulate filter (CPF) 30 , a diesel oxidation catalyst (DOC) 40 , an injection nozzle 50 , and a selective catalytic reduction (SCR) apparatus 60 , and noxious materials contained in the exhaust gas are purified in this process. The turbo charger 20 , the CPF 30 , the DOC 40 , the injection nozzle 50 , and the SCR apparatus 60 are mounted on an exhaust pipe 70 .
[0031] The engine 10 includes a plurality of cylinders (not shown) for burning an air-fuel mixture. The cylinder is connected to an intake manifold (not shown) so as to receive the air-fuel mixture, and the intake manifold is connected to an intake pipe (not shown) so as to receive an air.
[0032] In addition, the cylinder is connected to an exhaust manifold (not shown), and the exhaust gas generated in a combustion process is gathered in the exhaust manifold. The exhaust manifold is connected to the exhaust pipe 70 .
[0033] The turbo charger 20 rotates a turbine (not shown) by using energy of the exhaust gas so as to increase intake amount of the air.
[0034] The CPF 30 is mounted downstream of the turbo charger 20 . The CPF 30 traps PM contained in the exhaust gas and regenerates the trapped PM (i.e., soot). Regeneration of the soot, generally, starts when pressure difference between inlet and outlet of the CPF is greater than a predetermined pressure (about, 20-30 kpa).
[0035] The DOC 40 is mounted downstream of the CPF 30 and receives from the CPF 30 the exhaust gas in which the PM is removed. The DOC 40 oxidizes hydrocarbon (HC) and carbon monoxide (CO) contained in the exhaust gas into carbon dioxide (CO 2 ).
[0036] The injection nozzle 50 is mounted between the DOC 40 and the SCR apparatus 60 and doses a reducing agent to the exhaust gas in which the HC and the CO is removed at the DOC 40 . The reducing agent may be ammonia. Generally, urea is dosed into the exhaust gas by the injection nozzle 50 and the urea is decomposed into ammonia.
[0037] The exhaust gas mixed with the reducing agent is supplied to the SCR apparatus 60 .
[0038] The SCR 60 is mounted downstream of the injection nozzle 50 and includes a zeolite-catalyst where transition elements are ion-exchanged. The transition elements may be copper or iron so as to effectively reduce NO x . The SCR 60 reduces NO x contained in the exhaust gas into nitrogen gas (N 2 ) by using the reducing agent so as to remove NO x in the exhaust gas.
[0039] Hereinafter, the diesel oxidation catalyst according to various embodiments of the present invention will be described in detail.
[0040] As shown in FIG. 2 , the DOC 40 according to various embodiments of the present invention includes a carrier 42 , a first portion 44 , and a second portion 46 .
[0041] The first portion 44 is washcoat including hydrocarbon trap (HC trap) and is coated on the carrier 42 . A beta zeolite is used for the HC trap in order to effectively absorb the hydrocarbon. Particularly, the beta zeolite has a structure of twelve rings and ratio of silica SiO 2 to aluminum oxide Al 2 O 3 is 24-38. In addition, the beta zeolite is 30-50% of entire washcoat in the first portion 44 .
[0042] Generally, the beta zeolite absorbs the HC when temperature of the exhaust gas is lower than or equal to 250° C. and releases the absorbed HC when the temperature of the exhaust gas is higher than 250° C. Therefore, the first portion 44 absorbs the HC when the temperature of the exhaust gas is lower than or equal to a predetermined temperature and releases the HC when the temperature of the exhaust gas is higher than the predetermined temperature.
[0043] The second portion 46 is washcoat including an oxidation catalyst of platinum and palladium, and is coated on the first portion 44 . The second portion 44 oxidizes the HC and the CO contained in the exhaust gas. In addition, the second portion 46 oxidizes the HC released from the first portion 44 . In this case, temperature of the DOC 40 rises quickly such that the temperature of DOC 40 is larger than or equal to 500° C. because of oxidation heat of the HC, and accordingly, sulphur absorbed at the DOC 40 is released.
[0044] As shown in FIG. 3 , the DOC 40 according to other exemplary embodiments of the present invention is the same as that 40 except coating structure of the DOC 40 .
[0045] The DOC 40 according to various embodiments of the present invention includes the carrier 42 , the first portion 44 , and the second portion 46 .
[0046] The first portion 44 is coated on the carrier 42 at a front portion of the DOC 40 , and the second portion 46 is coated on the carrier 42 at a rear portion of the DOC 40 .
[0047] FIG. 4 is a graph showing concentration of sulphur and temperature at a rear end of a diesel oxidation catalyst when temperature of an exhaust gas is increased to a predetermined temperature after an engine provided with an exhaust system according to exemplary embodiments of the present invention is driven at an idle state during a predetermined time.
[0048] In a case that the engine 10 is driven by using fuel containing 50 ppm sulphur at an idle state during 10 minute, a little amount of the oxidation heat is generated even if the temperature of the exhaust gas is raised to the predetermined temperature (about 350° C.) since a little amount of the HC is absorbed at the first portion 44 . Therefore, only 5 ppm sulphur may be released.
[0049] On the contrary, the engine 10 is driven by using fuel containing 50 ppm sulphur at the idle state during 120 minute, a large amount of the oxidation heat is generated since a large amount of the HC is absorbed at the first portion 44 . Therefore, 32 ppm sulphur may be released.
[0050] Therefore, the HC absorbed at the first portion 44 is very effective for releasing the sulphur absorbed at the second portion 46 .
[0051] FIG. 5 is a graph showing concentration of HC and CO in a case that an engine provided with exhaust systems according to conventional arts and according to exemplary embodiments of the present invention, respectively. 30% and 50% in the drawings means that the HC trap is 30% and 50% of the washcoat in the first portion 44 , respectively.
[0052] As shown in FIG. 5 , oxidation capability of the HC and the CO is deteriorated when the exhaust system according to the prior arts is driven at the idle state during 20 minute. In this case, the diesel oxidation catalyst is regenerated at 500° C. in order to recover its oxidation capability.
[0053] However, the exhaust system according to exemplary embodiments of the present invention may have sufficient oxidation capability of the HC and the CO without regeneration of the diesel oxidation catalyst. Particularly, in a case that the HC trap is 50% of the washcoat in the first portion 44 , the exhaust system according to exemplary embodiments of the present invention has similar oxidation capability of the HC and the CO to the exhaust system according to the prior arts where the oxidation catalyst is regenerated.
[0054] According to the present invention as described above, stable purifying performance of hydrocarbon may be attained as a consequence that the hydrocarbon contained in an exhaust gas is absorbed in a low temperature and activity of an oxidation catalyst is recovered in a high temperature by using oxidation heat of the absorbed hydrocarbon.
[0055] In addition, since the oxidation catalyst including platinum and palladium is used, manufacturing cost may be reduced.
[0056] For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “front”, and “rear” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0057] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A diesel oxidation catalyst mounted on an exhaust pipe that exhausts an exhaust gas generated in an engine to the exterior may include a first portion having a hydrocarbon trap (HC trap) coated thereon, the HC trap absorbing or releasing a hydrocarbon (HC) depending on whether or not a predetermined condition is satisfied, and a second portion having an oxidation catalyst coated thereon, the oxidation catalyst oxidizing the hydrocarbon (HC) and a carbon monoxide (CO) in the exhaust gas, wherein the second portion performs oxidation reaction with the HC released from the first portion and releases sulphur absorbed at the oxidation catalyst by using oxidation heat generated in the oxidation reaction thereof. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Japanese Patent Application No. 2010-015629 filed on Jan. 27, 2010 and U.S. Provisional Application Ser. No. 61/282,665 filed on Mar. 15, 2010, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates to an evaluation device and an evaluation method for a substrate mounting apparatus used for holding a target substrate such as a silicon wafer in a semiconductor manufacturing process and controlling a temperature of the target substrate. More particularly, the present disclosure relates to a device and a method for easily evaluating a function, especially, a temperature control function, of a substrate mounting apparatus when a target substrate is heated from the outside in a plasma process or the like.
BACKGROUND OF THE INVENTION
[0003] In a semiconductor manufacture field, there has often been used a plasma processing apparatus which performs an etching process or a film forming process by applying plasma to a target substrate (hereinafter, referred to as “substrate”) such as a silicon wafer. Since such a plasma process has been performed under a depressurized pressure, a vacuum chuck cannot be used to hold the substrate. Thus, there has generally been used a substrate mounting apparatus such as a mechanical clamp or an electrostatic chuck using electrostatic force.
[0004] The electrostatic chuck may include a substrate mounting surface made of an insulator having therein an embedded sheet electrode. If a high potential is applied to the sheet electrode, Coulomb force or Johnsen-Rahbek force is generated by static electricity distributed in the insulator and polarized and electrified charges in the substrate. Accordingly, the substrate can be held onto the substrate mounting surface by the Coulomb force or the Johnsen-Rahbek force.
[0005] A basic function of the electrostatic chuck is to adsorptively hold the substrate, but recently, the electrostatic chuck has generally been used for controlling a temperature of the silicon wafer during a process. By way of example, the electrostatic chuck may be used for cooling the silicon wafer by flowing an inert gas such as helium between the silicon wafer and the electrostatic chuck, or the electrostatic chuck may be used for heating the silicon wafer in combination with a heater. This is because the temperature of the substrate is closely related with a rate of an etching process or a film forming process and a quality of a processing result.
[0006] For this reason, in evaluation of the electrostatic chuck, there has been considered the temperature control function of the silicon wafer and uniformity of temperature distribution during a film forming process and an etching process onto the silicon wafer as very important evaluation factors in addition to a mechanical characteristic, a decrease of particles, improvement in purity, plasma resistance, and chemical resistance.
[0007] Generally, the temperature of the substrate during a plasma process may depend on heat inputted to the substrate or a mounting table from the outside. Therefore, the temperature control function of the substrate mounting apparatus may be influenced by heat from the outside.
[0008] Therefore, performance evaluation for the electrostatic chuck used in the plasma processing apparatus needs to consider heat inputted to the substrate or the mounting table from plasma. If a thermal condition in the performance evaluation is different from a thermal condition in an actual plasma process, results of the performance evaluation may be greatly different from results of the actual plasma process.
[0009] If characteristics of the electrostatic chuck are measured by using the plasma processing apparatus under the same condition as a process such as an actual etching process, the performance evaluation can be conducted accurately. However, it costs a lot to use a high-priced and complicated plasma processing apparatus for this evaluation. Further, there is a problem in that it takes a lot of effort and time required for the evaluation.
[0010] For this reason, disclosed in Patent Document 1 are an evaluation device and an evaluation method for an electrostatic chuck. In Patent Document 1, performance of an electrostatic chuck is evaluated by providing the electrostatic chuck in an evacuable airtight chamber and heating a substrate by a lamp heater positioned above the electrostatic chuck to simulate a thermal condition in a plasma processing apparatus.
[0011] Meanwhile, disclosed in Patent Document 2 are an evaluation device and an evaluation method for simply evaluating a substrate mounting apparatus by simulating a thermal status corresponding to an actual plasma processing apparatus.
[0012] Patent Document 1: Japanese Patent Laid-open Publication No. 2006-86301
Patent Document 2: Japanese Patent Laid-open Publication No. 2008-108938
[0013] As disclosed in Patent Document 1, the evaluation method for the electrostatic chuck is conducted in the evaluation device which simulates the thermal condition by using the lamp heater (halogen lamp) as an external heating source instead of plasma. Accordingly, the performance for the electrostatic chuck can be simply evaluated.
[0014] However, upon review of this method, the present inventor has found that it is difficult to simulate the thermal condition using plasma by the evaluation method for the electrostatic chuck disclosed in Patent Document 1.
[0015] The reason for that is a difference in a heat transfer mechanism between heat transfer from plasma and heat transfer from a conventional heating lamp or heater. Generally, it is deemed that the heat transfer from plasma of high temperature is mainly caused by contact heat transfer by molecules excited into plasma.
[0016] Meanwhile, the heat transfer from the heating lamp occurs in such a way that resonance absorption of an infrared light irradiated from a heating source occurs on a substrate, and such energy brings about motion (vibration) of molecules, and, thus, friction between vibrated materials generates heat.
[0017] Here, the infrared light irradiated from the heating lamp may mainly include a near infrared ray (about 0.78 μm to about 2 μm) and an infrared ray (about 2 μm to about 4 μm). A silicon wafer serving as the substrate mostly transmits the infrared ray (infrared light) of a wavelength in the range of from about 1 μm to about 5 μm. For this reason, the silicon wafer is hardly heated by an infrared lamp, and the infrared light penetrates the silicon wafer and entirely heats a surface (mounting surface) of the electrostatic chuck underneath the silicon wafer.
[0018] Here, in a microscopic view, there exist freaks on surfaces of the electrostatic chuck and the silicon wafer. For this reason, contact surfaces between the electrostatic chuck and the silicon wafer have some areas where the surfaces are in close contact with each other and some areas where a gap exists between the surfaces. In this status, the irradiation light (infrared light) from the infrared lamp mostly penetrates the silicon wafer. Accordingly, only the surface of the electrostatic chuck is heated at the areas where the gap exists between the surfaces, whereas the contact surface of the silicon wafer with the electrostatic chuck is heated at the areas where the surfaces are in close contact with each other. Consequently, the heat is sufficiently transferred to the silicon wafer at the areas where the surfaces are in close contact with each other. Meanwhile, the heat is not sufficiently transferred into the silicon wafer at the areas where the gap exists between the surfaces (where the surfaces are not in close contact with each other).
[0019] Meanwhile, in an actual process using plasma, it is deemed that heat is mainly transferred by contact heat transfer of molecules when molecules exited into plasma of high temperature when the molecules are brought into contact with the silicon wafer. For this reason, the entire surface of the silicon wafer can be uniformly heated.
[0020] Therefore, it is deemed that a thermal status of the electrostatic chuck and the silicon wafer in the simulation device using the infrared light is different from that in the actual plasma processing apparatus.
[0021] In order to solve this problem, disclosed in Patent Document 2 is the evaluation device for evaluating the performance of the substrate mounting apparatus by using the infrared heater as the heating source. In this evaluation device, to simulate the thermal status corresponding to the actual plasma processing apparatus, the thermal status of the plasma processing apparatus can be simply simulated by using a substrate made of silicon carbide which absorbs the infrared light instead of a substrate made of silicon.
[0022] However, the evaluation device disclosed in Patent Document 2 needs to additionally include the infrared heater or the lamp as the heating source like the evaluation device disclosed in Patent Document 1. For this reason, there is a problem in that the evaluation device becomes larger and expensive.
[0023] Further, since the heating source such as the infrared heater is positioned above the substrate, when temperature distribution of an entire substrate is measured by, for example, a non-contact radiation thermometer, the measurement may be influenced by the heating source such as the infrared heater. Meanwhile, it may be possible to use a temperature probe as a thermocouple element, but it is very difficult to arrange temperature probes as thermocouple elements on the entire substrate. If the temperature probes as thermocouple elements are arranged, areas where they are positioned have thermal characteristics that are different from other areas. For this reason, if a multiple number of such areas having thermal characteristics different from the other areas exist on the substrate for evaluation, a thermal status thereof becomes different from an actual thermal status. Accordingly, there is a problem in that performance evaluation of the electrostatic chuck cannot be simply conducted on its entire surface with high precision according to the technologies disclosed in Patent Documents 1 and 2.
[0024] Meanwhile, when a temperature control function of an electrostatic chuck serving as a substrate mounting table is evaluated, it is not necessary to uniformly evaluate an entire surface of a substrate mounting surface. According to research by the present inventor until now, it has been found that it is possible to specify some areas which should not be excluded from evaluation of characteristics of the electrostatic chuck. By way of example, there is formed a flow path for coolant used for a temperature control in the electrostatic chuck and the coolant flows into and out from the flow path. For this reason, it is difficult to control temperatures at an inlet and outlet of the coolant flow path as compared to temperatures in the other areas. Further, an area near a high voltage power supply unit where the coolant flow path cannot be formed or an area near lift pins for moving the substrate up and down have the same problem. Furthermore, an outer periphery in a circumferential direction of the substrate has a plasma density distribution problem or electric field distribution problem and needs more delicate temperature control than any other areas.
[0025] In the conventional methods, it is possible to measure and evaluate temperature characteristics on the entire surface of the substrate mounting table at a time, but it is very difficult to uniformly heat the entire substrate. Further, it costs a lot to conduct the measurement and evaluation.
[0026] With regard to this problem, the present inventor has conceived that a self-heating type evaluation substrate can be used as a dedicated substrate (hereinafter, referred to as “evaluation substrate”) to evaluate characteristics of a substrate mounting apparatus such as an electrostatic chuck. According to this, it is possible to evaluate performance of an electrostatic chuck made of, for example, silicon which transmits the infrared light. Further, if the self-heating type evaluation substrate is used, the heating source such as the infrared heater is not needed, and, thus, a non-contact thermometer can be provided thereabove. With this configuration, it is possible to measure temperature distribution of an entire surface of the evaluation substrate with high accuracy. The present inventor has derived the present disclosure in view of the foregoing description.
[0027] Accordingly, the present disclosure provides an evaluation device and an evaluation method for a substrate mounting apparatus capable of simply evaluating a temperature control function of the substrate mounting apparatus under preset evaluation conditions or circumstances, and an evaluation substrate used for the same.
BRIEF SUMMARY OF THE INVENTION
[0028] In accordance with one aspect of the present disclosure, there is provided an evaluation device for a substrate mounting apparatus which holds a target substrate mounted on a mounting surface and controls a temperature of the target substrate. The evaluation device includes an evacuable airtight chamber in which the substrate mounting apparatus is provided; an evaluation substrate which is mounted on the mounting surface instead of the target substrate and includes a self-heating resistance heater; and a temperature measurement unit which measures a temperature of the evaluation substrate.
[0029] In the evaluation device, the resistance heater may be provided within the evaluation substrate and/or on all or a part of a surface of the evaluation substrate.
[0030] In the evaluation device, the evaluation substrate may have substantially same size and shape as the target substrate.
[0031] In the evaluation device, the evaluation substrate may have an enough size to measure temperatures of measurement target areas on the mounting surface.
[0032] In the evaluation device, the temperature measurement unit may be a temperature probe as a thermocouple element.
[0033] In the evaluation device, temperature probe as a thermocouple element may be provided in an opening formed in the resistance heater so as to be brought into contact with the evaluation substrate.
[0034] In the evaluation device, the temperature measurement unit may be a non-contact thermometer which is not in contact with the evaluation substrate.
[0035] In the evaluation device, the resistance heater may have therein an opening through which infrared light of the evaluation substrate radiated.
[0036] In the evaluation device, the non-contact thermometer may be provided outside the airtight chamber so as to receive the infrared light via an observation window provided in the airtight chamber.
[0037] In the evaluation device, the substrate mounting apparatus may be an electrostatic chuck.
[0038] In accordance with another aspect of the present disclosure, there is provided an evaluation substrate used in an evaluation device for a substrate mounting apparatus which holds a target substrate mounted on a mounting surface and controls a temperature of the target substrate. The evaluation substrate includes a resistance heater which increases a temperature of the evaluation substrate to a required level in a substantially uniform manner; and a temperature measurement unit which measures a temperature of the evaluation substrate.
[0039] In the evaluation substrate, the evaluation substrate may have substantially same size and shape as the target substrate.
[0040] In the evaluation substrate, the evaluation substrate may have an enough size to measure temperatures of measurement target areas on the mounting surface.
[0041] In the evaluation substrate, the resistance heater may be provided on all or a part of a surface of the evaluation substrate.
[0042] In the evaluation substrate, the temperature measurement unit may be a temperature probe as a thermocouple element.
[0043] In the evaluation substrate, the temperature probe as a thermocouple element may be provided in an opening formed in the resistance heater so as to be brought into contact with the evaluation substrate.
[0044] In the evaluation substrate, the temperature measurement unit may be a thermometer which is not in contact with the evaluation substrate.
[0045] In the evaluation substrate, an opening through which infrared light of the evaluation substrate are radiated may be formed in the resistance heater provided on the evaluation substrate.
[0046] In accordance with still another aspect of the present disclosure, there is provided an evaluation method for a substrate mounting apparatus includes providing the substrate mounting apparatus which holds a target substrate mounted on a mounting surface and includes a temperature control unit for controlling a temperature of the target substrate in a depressurizable airtight chamber; mounting an evaluation substrate having a self-heating resistance heater on the substrate mounting apparatus; measuring temperature distribution of the evaluation substrate by adjusting a temperature of the evaluation substrate to a required level by the temperature control unit and the resistance heater; and evaluating a function of the substrate mounting apparatus based on the temperature distribution of the evaluation substrate.
[0047] In the evaluation method, the evaluation substrate may be self-heated by the resistance heater provided within the evaluation substrate and/or on all or a part of a surface of the evaluation substrate.
[0048] In the evaluation method, the function of the substrate mounting apparatus may be evaluated by using the evaluation substrate having substantially same size and shape as the target substrate.
[0049] In the evaluation method, characteristics of measurement target areas on the mounting surface may be evaluated by using the evaluation substrate having an enough size to measure temperatures of the measurement target areas.
[0050] In the evaluation method, the temperature distribution of the evaluation substrate may be measured by a temperature probe as a thermocouple element.
[0051] In the evaluation method, the temperature probe as a thermocouple element may be provided so as to be brought into contact with the evaluation substrate.
[0052] In the evaluation method, the temperature distribution of the evaluation substrate may be measured by a thermometer which is not in contact with the evaluation substrate.
[0053] In the evaluation method, an opening may be formed in the resistance heater, and the temperature distribution of the evaluation substrate may be measured by using an opening through which infrared light is radiated from the evaluation substrate.
[0054] In the evaluation method, the temperature distribution of the evaluation substrate may be measured via an observation window provided in the airtight chamber by a unit outside the airtight chamber.
[0055] In the evaluation method, the substrate mounting apparatus may be an electrostatic chuck.
[0056] In accordance with the present disclosure, it is possible to provide an evaluation device and an evaluation method for a substrate mounting apparatus capable of simply evaluating a temperature control function of the substrate mounting apparatus depending on evaluation conditions or circumstances and an evaluation substrate used for the same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] Non-limiting and non-exhaustive embodiments will be described in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be intended to limit its scope, the disclosure will be described with specificity and detail through use of the accompanying drawings, in which:
[0058] FIG. 1 is a schematic cross-sectional view of an evaluation device for a substrate mounting apparatus in accordance with an embodiment of the present disclosure;
[0059] FIGS. 2A and 2B show a chip-type evaluation substrate in accordance with an embodiment of the present disclosure;
[0060] FIGS. 3A and 3B show a chip-type evaluation substrate in accordance with an embodiment of the present disclosure;
[0061] FIG. 4 shows an evaluation device for a substrate mounting apparatus in case of measuring a temperature of an evaluation substrate by a radiation thermometer;
[0062] FIG. 5 shows an evaluation device for a substrate mounting apparatus in case of measuring a temperature of an evaluation substrate by a radiation thermometer;
[0063] FIG. 6 is a plane view of an evaluation substrate in which a resistance heater is positioned so as to surround a temperature probe as a thermocouple element;
[0064] FIG. 7 is a plane view of an evaluation substrate in which temperature probes as thermocouple elements are provided inside clip-shaped resistance heaters;
[0065] FIG. 8 is a plane view of an evaluation substrate in accordance with another embodiment of the present disclosure, and the evaluation substrate is capable of evaluating an outer periphery of a wafer in a circumferential direction thereof;
[0066] FIG. 9 is a plane view of an evaluation substrate in which openings are formed inside the clip-shaped resistance heaters;
[0067] FIG. 10 is a plane view of an evaluation substrate in which temperature probes as thermocouple elements are removed and openings are formed;
[0068] FIG. 11 is a plane view of an evaluation substrate in which a ring-shaped resistance heater is provided at an outer periphery in a circumferential direction and a plurality of openings is formed in the resistance heater; and
[0069] FIG. 12 is a plane view of an evaluation substrate in which a spiral-shaped resistance heater is provided and a plurality of openings is formed in the resistance heater.
DETAILED DESCRIPTION OF THE INVENTION
[0070] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings, but the present disclosure is not limited thereto. FIG. 1 is a schematic cross-sectional view of an evaluation device for a substrate mounting apparatus in accordance with an embodiment of the present disclosure. This evaluation device may include an airtight chamber 1 ; a vacuum pump 6 which evacuates the inside of the chamber 1 ; an electrostatic chuck 2 provided in the chamber 1 ; an evaluation substrate 4 mounted on a mounting surface 3 of the electrostatic chuck 2 ; a self-heating type resistance heater 5 (see FIGS. 2A and 2B ) provided on the evaluation substrate 4 ; an AC power supply 13 which supplies a power to the resistance heater 5 ; temperature probes 14 as thermocouple elements buried in the evaluation substrate 4 ; and a thermocouple main body 15 connected thereto.
[0071] A type of the electrostatic chuck 2 as an evaluation target in the present disclosure is not specially limited. By way of example, an insulation body 7 may be any one of a ceramic body formed by thermal spraying or sintering or insulating resin body such as a polyimide film. An electrode 8 may be formed into any one of a film shape, a plate shape, and a spiral coil shape as long as a voltage can be applied substantially uniformly onto an entire surface of a target substrate.
[0072] The electrostatic chuck 2 may have a configuration in which the electrode 8 is buried in the insulation body 7 constituting the mounting surface 3 , and the insulation body 7 is fixed on a cooling plate 9 . In the cooling plate 9 , a coolant path is formed and coolant flows therein through an inlet line and an outlet line. Further, the electrode 8 is supplied with a high voltage from a DC power supply 10 .
[0073] Provided at a ceiling of the chamber 1 is a heat insulating plate 12 via an insulating post 11 in order to prevent overheating of the ceiling. Here, the heat insulating plate 12 can be omitted depending on an upper limit of a temperature increased by the resistance heater 5 . The resistance heater 5 is supplied with a power from the AC power supply 13 outside the chamber 1 , so that the evaluation substrate 4 is self-heated. The power is controlled by a controller (not shown) to an appropriate value.
[0074] Further, desirably, the cooling plate 9 and the insulation body 7 may adhere to each other as one body in order to improve heat conductivity and the cooling plate 9 may be made of a material of high heat conductivity.
[0075] Meanwhile, a cooling medium such as a He gas can be introduced between the evaluation substrate 4 and the insulation body 7 in order to directly cool the evaluation substrate. Alternatively, a heater may be provided in the cooling plate 9 and the cooling plate 9 may be used as not a heat sink but a heat source.
[0076] Desirably, by evacuating the inside of the camber 1 by the vacuum pump, the chamber 1 may have a vacuum level lower than several Torr, and specifically equal to a vacuum level of various kinds of plasma processing apparatuses. However, any vacuum level is possible as long as the evaluation substrate 4 is maintained in a thermally isolated state from its surroundings. If air flow and convection do not occur, the chamber 1 may be in the atmospheric atmosphere.
[0077] Herein, a feature of the prevent disclosure is that the resistance heater 5 (see FIGS. 2A and 2B ) is provided on the evaluation substrate 4 . Since the resistance heater 5 is provided on the evaluation substrate 4 , heat can be transferred directly to the evaluation substrate 4 . For this reason, a material, which is not heated due to transmission of infrared lights from an infrared lamp or an infrared heater, can be heated. Further, since the evaluation substrate 4 is self-heated, an external heating source such as an infrared heater or a lamp is unnecessary.
[0078] Hereinafter, there will be explained a size of the evaluation substrate 4 including the resistance heater 5 . The present inventor found out that when performance evaluation for the electrostatic chuck 2 is conducted, temperature distribution on its entire surface needs not be measured at a time. That is because it is possible to specify areas to be measured after evaluation of a temperature control function of the electrostatic chuck 2 is completed. By way of example, areas corresponding to an inlet and an outlet of the coolant path or a high voltage power supply unit, areas near lift pins, and an outer periphery of the target substrate in a circumferential direction thereof are important places for the evaluation.
[0079] In view of the foregoing, desirably, the evaluation substrate 4 may be large enough such that temperatures can be measured at areas to be evaluated, and such an evaluation substrate 4 will be referred to as “chip-type evaluation substrate” herein. It is easy to uniformly heat the entire chip-type evaluation substrate 4 including the resistance heater 5 . Depending on an arrangement of the resistance heater 5 , the evaluation substrate 4 may have the same size and shape as an actual target substrate such as a silicon wafer of about 300φ.
[0080] Hereinafter, there will be explained a principle of measurement of a heat flow rate by using the evaluation substrate 4 of the present disclosure. The evaluation substrate 4 is maintained in a thermally isolated state from the outside. By way of example, the vacuum chamber 1 may have a vacuum level in the range of from about 1 Pa to about 100 Pa and a current may flow into the resistance heater 5 . A power applied to the resistance heater 5 may be in the range of from about 1 kW/m 2 to about 100 kW/m 2, and, desirably, in the range of from about 20 kW/m 2 to about 40 kW/m 2 . By way of example, if a silicon evaluation substrate having a size of about 300φ heated from the normal temperature to about 100°C., it is desirable to apply a power in the range of from about 2 kW to about 4 kW.
[0081] In this case, if the applied voltage is about 100 V, resistance is in the range of from about 2Ω to about 5Ω, and if the applied voltage is about 200 V, resistance is in the range of from about 10Ω to about 20Ω.When such a power is applied to the resistance heater 5 , an hourly change in temperature of the evaluation substrate 4 is set as a reference temperature characteristic.
[0082] Subsequently, the evaluation substrate 4 is mounted on the electrostatic chuck 2 , the same power is applied to the resistance heater 5 , and a temperature of the evaluation substrate 4 which is temperature-controlled by the electrostatic chuck 2 is measured every hour. This is the same as a measurement of a heat loss (calories lost by the evaluation substrate 4 ) at a contact area between the electrostatic chuck 2 and the evaluation substrate 4 . Further, by comparing the measured heat loss value with a theoretical heat loss value, a function of the electrostatic chuck 2 is evaluated.
[0083] Herein, the temperature of the evaluation substrate 4 can be measured directly by, for example, the temperature probe 14 as a thermocouple element. Alternatively, the temperature of the evaluation substrate 4 can be measured by, for example, a radiation thermometer as a non-contact temperature measuring device. Hereinafter, there will be explained each temperature measuring method in case of using the chip-type evaluation substrate 4 and in case of using the evaluation substrate having the same size and shape as the target substrate.
[0084] FIGS. 2A and 2B show the chip-type evaluation substrate 4 in accordance with an embodiment of the present disclosure. The evaluation substrate 4 may evaluate characteristics of the electrostatic chuck 2 at each area. FIG. 2A is a perspective view of the evaluation substrate 4 , and FIG. 2B is a cross-sectional view thereof. As depicted in FIGS. 2A and 2B , the resistance heater 5 is provided on a surface of the evaluation substrate 4 via an adhesion layer such as an adhesive. Alternatively, the resistance heater 5 may be provided on the evaluation substrate 4 by heat-pressing adhesion, vapor deposition, thermal spraying, coating, and printing other than by using the adhesive.
[0085] Herein, it is illustrated that the resistance heater is provided on the surface, i.e., a base 41 , of the evaluation substrate 4 , but the resistance heater 5 may be provided within the base 41 . By way of example, the resistance heater 5 may be embedded in the base 41 . Further, the resistance heater 5 may be buried when the evaluation substrate 4 is fabricated.
[0086] A material of the resistance heater 5 is not specifically limited, but in general, any material such as a metal heating wire, graphite, or conductive ceramic can be used as long as it generates heat when a current flows. Further, any shape or any arrangement of the resistance heater 5 is possible as long as the entire evaluation substrate 4 can be uniformly heated.
[0087] As depicted in FIGS. 2A and 2B , a plurality of the temperature probes 14 as thermocouple elements is connected to the resistance heater 5 . An electromotive power from the temperature probes 14 as thermocouple elements is transmitted to the external thermocouple main body 15 via a connection terminal provided at an inner wall of the chamber 1 , and, thus, a temperature of the evaluation substrate 4 is measured.
[0088] Front ends of the temperature probes 14 as thermocouple elements are closely connected and fixed to the evaluation substrate 4 by an adhesive or the like. It is important that a total amount of the adhesive covering the front ends is uniform and there is no gap in a contact interface and also, air bubbles are not entered therein.
[0089] A temperature of the evaluation substrate 4 may be measured by a non-contact thermometer such as a radiation thermometer instead of the temperature probes 14 as thermocouple elements. FIGS. 3A and 3B show the chip-type evaluation substrate 4 in accordance with an embodiment of the present disclosure. As depicted in FIGS. 3A and 3B , the temperature probes 14 as thermocouple elements in the resistance heater 5 of the evaluation substrate 4 illustrated in FIGS. 2A and 2B are removed. A surface of the base 41 can be seen through openings 42 to which the temperature probes 14 as thermocouple elements were attached.
[0090] With this configuration, it is possible to measure infrared light radiated through the openings 42 of the resistance heater 5 and the temperature of the evaluation substrate 4 can be measured by measuring the infrared light.
[0091] Hereinafter, there will be explained a temperature measurement method of the evaluation substrate 4 using a radiation thermometer. As described above, various materials may be considered for a material of the evaluation substrate 4 . In this case, emissivity may be varied depending on a material of the evaluation substrate 4 and a displayed temperature of the radiation thermometer may be affected accordingly. Therefore, for example, a thermostat furnace may be used and a difference between a temperature of the thermostat furnace (i.e., a temperature of the evaluation substrate 4 ) and the displayed temperature of the radiation thermometer may be corrected in advance. By making such a correction in advance, a temperature of the evaluation substrate 4 can be measured with high accuracy regardless of a material of the evaluation substrate 4 .
[0092] FIG. 4 shows an evaluation device for a substrate mounting apparatus in case that a temperature of the evaluation substrate 4 is measured by a radiation thermometer. As depicted in FIG. 4 , the radiation thermometer 16 may be provided in the airtight chamber 1 .
[0093] In the evaluation device depicted in FIG. 4 , the radiation thermometer 16 is provided at the heat insulating plate 12 via the insulating post 11 in the airtight chamber 1 in order to prevent overheating of the ceiling. With this radiation thermometer 16 , it is possible to measure a temperature by using infrared light radiated from the openings 42 of the evaluation substrate 4 . Further, in the present embodiment, temperature distribution of the entire surface of the evaluation substrate 4 is measured by a single radiation thermometer 16 . However, the present disclosure is not limited thereto, and, by way of example, another radiation thermometer 16 may be further provided in order to measure a temperature of the outer periphery of the evaluation substrate 4 .
[0094] FIG. 5 illustrates an evaluation device in which the radiation thermometer 16 is provided outside the airtight chamber 1 . When the radiation thermometer 16 is provided outside the airtight chamber 1 , an observation window 18 may be provided at an upper part of the chamber 1 and a hole may be formed at a position corresponding to the observation window 18 in the heat insulating plate 12 . With this observation window 18 , it is possible to measure the infrared light radiated through the openings 42 of the evaluation substrate 4 , and, thus, a temperature of the evaluation substrate 4 can be measured. Since the radiation thermometer 16 is provided outside the airtight chamber 1 , a design of the evaluation device becomes easier.
[0095] Hereinafter, there will be explained the evaluation substrate 4 having the same size and shape as the target substrate. FIG. 6 is a plane view of an evaluation substrate 4 - 1 , and the evaluation substrate 4 - 1 may include a base 41 as a silicon wafer which is used in an actual plasma process; a temperature probe 14 as a thermocouple element embedded in a central portion of the base 41 ; and a resistance heater 5 positioned so as to surround the temperature probe 14 as a thermocouple element.
[0096] As described above, a power supply unit for supplying a high voltage to the electrode 8 is positioned at a central area of the electrostatic chuck 2 , and, thus, a coolant path cannot be formed. For this reason, evaluation of a temperature at the central area is very important and the evaluation substrate 4 - 1 is used therefor.
[0097] FIG. 7 is a plane view of an evaluation substrate 4 - 2 , and the evaluation substrate 4 - 2 may include a base 41 as a silicon wafer; clip-shaped resistance heating bodies 5 provided at eight (8) areas on the outer periphery in the circumferential direction; and temperature probes 14 as thermocouple elements provided in the resistance heating bodies 5 . As described above, during a plasma process, the outer periphery of the wafer in the circumferential direction has a problem with non-uniformity in plasma density distribution or electric field distribution. For this reason, the outer periphery is a very important area in evaluation of functions of the electrostatic chuck 2 . Accordingly, with the evaluation substrate 4 - 2 , it is possible to evaluate the outer periphery of the wafer in the circumferential direction as well as the central area thereof.
[0098] FIG. 8 is a modification example of FIG. 7 and shows a plane view of an evaluation substrate 4 - 3 in accordance with another embodiment of the present disclosure. The evaluation substrate 4 - 3 can measure a temperature of the central area and the circumferential periphery of the wafer. In the evaluation substrate 4 - 2 illustrated in FIG. 7 , the areas surrounded by the resistance heating bodies 5 are heated and temperatures of the areas are measured by the temperature probes 14 as thermocouple elements, whereas in the evaluation substrate 4 - 3 illustrated in FIG. 8 , temperatures of the outer periphery in the circumferential direction and the central area can be measured while the entire wafer is uniformly heated.
[0099] Hereinafter, there will be explained a case where a temperature of the evaluation substrate 4 is measured by using the radiation thermometer 16 . FIG. 9 is a plane view of an evaluation substrate 4 - 4 , and the evaluation substrate 4 - 4 may include a base 41 as a silicon wafer; clip-shaped resistance heating bodies 5 provided at eight (8) areas in the outer periphery in the circumferential direction; and openings 42 provided in the resistance heating bodies 5 . By measuring infrared light radiated through the openings 42 by the radiation thermometer 16 , a temperature of the outer periphery of the evaluation substrate 4 in the circumferential direction can be measured.
[0100] FIG. 10 is a plane view of an evaluation substrate 4 - 5 in which temperature probes 14 as thermocouple elements provided in the evaluation substrate 4 - 3 shown in FIG. 8 are removed and the openings 42 are opened. By measuring infrared light radiated through the openings 42 by the radiation thermometer 16 , temperatures of the outer periphery in the circumferential direction and the central area in the evaluation substrate 4 can be measured.
[0101] FIG. 11 is a plane view of an evaluation substrate 4 - 6 , and the evaluation substrate 4 - 6 may include a base 41 as a silicon wafer; a ring-shaped resistance heater 5 provided in the outer periphery in its circumferential direction; and a plurality of the openings 42 formed in the resistance heater 5 . Further, FIG. 12 is a plane view of an evaluation substrate 4 - 7 , and the evaluation substrate 4 - 7 may include a base 41 as a silicon wafer; a spiral-shaped resistance heater 5 provided in order to uniformly heat the entire base 41 ; and a plurality of the openings 42 formed in the resistance heater 5 . With the evaluation substrate 4 - 6 , a temperature of the outer periphery in the circumferential direction can be measured by measuring infrared light radiated through the openings 42 . Furthermore, with the evaluation substrate 4 - 7 , temperature distribution of the entire wafer can be measured. | There are provided an evaluation device and an evaluation method for a substrate mounting apparatus capable of simply evaluating a temperature control function of the substrate mounting apparatus depending on evaluation conditions or circumstances and an evaluation substrate used for the same. The substrate mounting apparatus holds a target substrate mounted on a mounting surface and controls a temperature of the target substrate. The evaluation device includes an evacuable airtight chamber in which the substrate mounting apparatus is provided; an evaluation substrate which is mounted on the mounting surface instead of the target substrate and includes a self-heating resistance heater; and a temperature measurement unit which measures a temperature of the evaluation substrate. | 7 |
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of diabetes and pancreatic islets and more particularly relates to endocrine progenitor/precursor cells from pancreatic islet cells that have the potential to be differentiated into functioning insulin-producing beta-cells.
BACKGROUND OF THE INVENTION
[0002] Diabetes mellitus is a significant health problem, affecting approximately 16 million people in the United States. Loss of sufficient insulin production by the pancreatic islet beta cell is a hallmark of both type I and type II diabetes. Replacement of these cells through regeneration or transplantation could offer lifelong treatment for diabetics. However, a major problem in implementing treatment is the lack of sufficient islet cell tissue for transplantation. It has been reported that in the U.S. only about 3,000 human donor pancreases are available each year, yet over 35,000 new cases of type I diabetes are diagnosed each year. There is a continuing need for a method of treating a diabetic patient by transplantation of cells that will function as insulin-producing pancreatic islet cells.
SUMMARY OF THE INVENTION
[0003] The invention is a cell composition comprising endocrine progenitor/precursor cells from a mammalian pancreas, preferably a human pancreas, and typically an adult pancreas, that have been cultured in serial passages in a defined culture medium and that express islet progenitor markers pdx1 and nestin. The endocrine progenitor/precursor cells are cultured in a defined culture medium over multiple passages to expand cell numbers. As the cells expand, they become more proliferative and less differentiated. When a sufficient number of cells are obtained, the cell composition of the invention comprising the endocrine progenitor/precursor cells may be used to make living cell implants to treat one or more patients with insulin deficient diabetes.
BRIEF DESCRIPTION OF THE FIGURES
[0004] FIG. 1 shows the table and graph of cumulative population doubling of human islet-derived cells H297.
[0005] FIG. 2 shows RT-PCR analysis of pdx1, nestin and insulin expression in human islet-derived cells H297.
DETAILED DESCRIPTION
[0006] One feature of the invention is a cell composition of endocrine progenitor/precursor cells from mammalian pancreatic islets, typically adult pancreas islet cells, characterized by less differentiation than the initial derived cells prior to culturing in serial passages in defined medium.
[0007] Another feature of the invention is a defined culture medium formulation for the culture of endocrine precursor cells.
[0008] A further feature of the invention is a method for culturing cells from mammalian pancreatic islets in serial passages resulting in endocrine progenitor/precursor cells that are less differentiated than the initial cells of the culture.
[0009] The cells used to initiate the cell composition of the invention are derived from mammalian pancreatic islets, preferably human pancreatic islets, and typically adult pancreas islet cells. Following the described culturing methods of the invention, these initial pancreatic islet cells are cultured in defined culture medium and expanded through serial passages in defined culture medium, resulting in less differentiated endocrine progenitor/precursor cells that express islet progenitor markers pdx- 1 and nestin. The endocrine progenitor/precursor cells have the potential to be differentiated into functioning insulin-producing beta-cells. As used herein, “endocrine progenitor/precursor cells,” “endocrine progenitor cells,” and “endocrine precursor cells” are all intended to refer to cells derived from mammalian pancreatic islets that are capable of serial passages in defined culture medium, are less differentiated than the initial cells prior to culturing, and that express markers pdx1 and nestin. In the cell composition of the invention, the endocrine progenitor cells differentiate into functioning insulin-producing beta cells when implanted into a patient to treat insulin deficient diabetes.
[0010] The medium used to culture the initial pancreatic cells and serial passage into endocrine precursor cells is chemically defined, meaning that it contains no serum or. organ extracts. The medium is able to culture and maintain endocrine precursor cells over several passages to expand the cell numbers of the population. The ability to expand the cell numbers is beneficial where human pancreatic tissue is limited. An additional benefit is that a number of therapeutic cell compositions can be produced from a single pancreas.
[0011] The defined culture medium is comprised of a nutrient base usually further supplemented with other components. The skilled artisan can determine appropriate nutrient bases in the art of animal cell culture with reasonable expectations for successfully producing a tissue construct of the invention. Many commercially available nutrient sources are useful on the practice of the present invention. These include commercially available nutrient sources which supply inorganic salts, an energy source, amino acids, and B-vitamins such as Dulbecco's Modified Eagle's Medium (DMEM); Minimal Essential Medium (MEM); M199; RPMI 1640; Iscove's Modified Dulbecco's Medium (EDMEM). Minimal Essential Medium (MEM) and M199 require additional supplementation with phospholipid precursors and non-essential amino acids. Commercially available vitamin-rich mixtures that supply additional amino acids, nucleic acids, enzyme cofactors, phospholipid precursors, and inorganic salts include Ham's F-12, Ham's F-10, NCTC 109, and NCTC 135. Albeit in varying concentrations, all basal media provide a basic nutrient source for cells in the form of glucose, amino acids, vitamins, and inorganic ions, together with other basic media components.
[0012] The preferred base medium of the invention comprises a nutrient base of either calcium-free or low calcium Dulbecco's Modified Eagle's Medium (DMEM), without glucose, magnesium, and with L-glutamine at 4.0 mM, without sodium pyruvate, and with Ham's F-12 (with 5 mM glucose) in a 3-to-1 ratio. The final glucose concentration of the base is adjusted to between about 2 mM to about 8 mM, more preferably between about 3 mM to about 7 mM, and most preferably at about 5 mM.
[0013] The base medium is supplemented with components such as amino acids, growth factors, and hormones. Defined culture media for the culture of cells of the invention are described in U.S. Pat. No. 5,712,163 to Parenteau and in International PCT Publication No. WO 95/31473, the disclosures of which are incorporated herein by reference. Other media are known in the art such as those disclosed in Ham and McKeehan, Methods in Enzymology, 58:4493 (1979), or for other appropriate chemically defined media, in Bottenstein et al., Methods in Enzymology, 58:94109 (1979).
[0014] In the preferred embodiment, the base medium is supplemented with the following components known to the skilled artisan in animal cell culture: insulin, transferrin, triiodothyronine (T3), either or both ethanolamine and o-phosphoryl-ethanolamine, epidermal growth factor, hydrocortisone, selenium, adenine, strontium chloride, sodium pyruvate, non-essential amino acids, soybean trypsin inhibitor (SBTI), and glucose. Concentrations and substitutions for the supplements may be determined by the skilled artisan by carrying out titration experiments.
[0015] Insulin is a polypeptide hormone that promotes the uptake of glucose and amino acids to provide long term benefits over multiple passages. Supplementation of insulin or insulin-like growth factor (IGF) is necessary for long term culture as there will be eventual depletion of the cells' ability to uptake glucose and amino acids as well as possible degradation of the cell phenotype. Insulin supplementation is advisable for serial cultivation and is provided to the media at a concentration range of preferably between about 0.5 μg/ml to about 50 μg/ml, more preferably between about 5 μg/ml to about 15 μg/ml, and most preferably at about 10 μg/ml. Appropriate concentrations for the supplementation of insulin-like growth factor, such as IGF-1 or IGF-2, used in place of insulin may be easily determined by one of skill in the art by carrying out a simple titration experiment for the cell types chosen for culture.
[0016] Transferrin is in the medium for iron transport regulation. Iron is an essential trace element found in serum. As iron can be toxic to cells in its free form, in serum it is supplied to cells bound to transferrin at a concentration range of preferably between about 0.05 μg/ml to about 50 μg/ml, more preferably between about 5 μg/ml to about 15 μg/ml, and most preferably at about 5 μg/ml.
[0017] Triiodothyronine (T3) is a basic component and is the active form of thyroid hormone that is included in the medium to maintain rates of cell metabolism Triiodothyronine is supplemented to the medium at a concentration range between about 0 to about 400 ρM, more preferably between about 2 ρM to about 200 ρM, and most preferably at about 20 ρM.
[0018] Either or both ethanolamine and o-phosphoryl-ethanolamine, which are phospholipids, are added whose function is an important precursor in the inositol pathway and fatty acid metabolism. Supplementation of lipids that are normally found in serum is necessary in a serum-free medium. Ethanolamine or o-phosphoryl-ethanolamine, or both, are provided to media at a concentration range between about 10 −6 M to about 10 −2 M, more preferably at about 1×10 −4 M.
[0019] Hydrocortisone has been shown to have benefits when culturing other epithelial cell types, to promote phenotype and therefore enhance differentiated characteristics (Rubin et al., J. Cell Physiol., 138:208-214 (1986)). Hydrocortisone may be provided at a concentration range of about 0.04 μg/ml to about 4.0 μg/ml, preferably at about 0.4 μg/ml.
[0020] Selenium is added to serum-free media to resupplement the trace elements of selenium normally provided by serum. Selenium may be provided at a concentration range of about 10 −9 M to about 10 −7 M; most preferably at about 5.3×10 −8 M.
[0021] The amino acid L-glutamine is present in some nutrient bases and may be added in cases where there is none or insufficient amounts present. L-glutamine may also be provided in stable form such as that sold under the mark, GlutaMAX-1™ (Gibco BRL, Grand Island, N.Y.). GlutaMAX-1™ is the stable dipeptide form of L-alanyl-L-glutamine and may be used interchangeably with L-glutamine and is provided in equimolar concentrations as a substitute to L-glutamine. The dipeptide provides stability to L-glutamine to protect it from degradation over time in storage and during incubation that can lead to uncertainty in the effective concentration of L-glutamine in medium. Typically, the base medium is supplemented with glutamine at a concentration preferably between about 1 mM to about 10 mM, more preferably between about 2 mM to about 8 mM, and most preferably 6 mM L-glutamine.
[0022] Growth factors such as epidermal growth factor (EGF) may also be added to the medium to aid in the establishment of the cultures through cell scale-up and seeding. EGF in native form or recombinant form may be used Human forms, native or recombinant, of EGF are preferred for use in the medium when fabricating a skin equivalent containing no non-human biological components. EGF is an optional component and may be provided at a concentration between about 1 to 15 ng/mL, more preferably between about 5 to 10 ng/mL.
[0023] The defined medium described above is typically prepared as set forth below. However, it should be understood that the components of the defined medium may be prepared and assembled using any conventional methodology compatible with their physical properties. It is well known in the art to substitute certain components with an appropriate analogue or functionally equivalent acting agent for the purposes of availability or economy and arrive at a similar result Naturally occurring growth factors may be substituted with recombinant or synthetic growth factors that have similar qualities and results when used in culturing. The optimal concentration for the supplements may have to be adjusted slightly for cells derived from different mammalian species and cell lines from different donors will vary in their performance due to its age, size, and health. Titration experiments are performed with varying concentrations of a component to arrive at the optimal concentration for that component.
[0024] Media in accordance with the present invention are sterile. Sterile components are bought or rendered sterile by conventional procedures, such as filtration, after preparation. Proper aseptic procedures were used throughout the following Examples. DMEM and F-12 are combined and the individual components are then added to complete the medium. Stock solutions of all components can be stored at −20° C., with the exception of nutrient source that can be stored at 4° C. All stock solutions are prepared at 500× final concentrations listed above. A stock solution of insulin, transferrin and triiodothyronine (all from Sigma) is prepared as follows: triiodothyronine is initially dissolved in absolute ethanol in 1N hydrochloric acid (HCl) at a 2:1 ratio. Insulin is dissolved in dilute HCl (approximately 0.1N) and transferrin is dissolved in water. The three are then mixed and diluted in water to a 500× concentration. Ethanolamine and o-phosphoryl-ethanolamine are dissolved in water to 500× concentration and are filter sterilized. Hydrocortisone is dissolved in absolute ethanol and diluted in phosphate buffered saline (PBS). Selenium is dissolved in water to 500× concentration and filter sterilized. EGF is purchased sterile and is dissolved in PBS. Adenine is difficult to dissolve but may be dissolved by any number of methods known to those skilled in the art. Human serum albumin (HSA) or bovine serum albumin (BSA) may be added for prolonged storage to maintain the activity of the EGF stock solutions. The medium can be either used immediately after preparation or, stored at 4° C. If stored, EGF should not be added until the time of use.
[0025] A more preferred culture medium formulation for serial culture of the endocrine precursor cells of the invention comprises: a base 3:1 mixture of Dulbecco's Modified Eagle's Medium (DMEM) (no glucose, no calcium, with 4 mM L-glutamine) and Hams F-12 medium, and the base is supplemented with the following components with the final concentration of each component indicated. 6 mM L-glutamine (or equivalent), 10 ng/ml epidermal growth factor, 0.4 μg/ml hydrocortisone, 1×10 −4 M ethanolamine, 1×10 −4 M o-phosphorylthanolainine, 5 μg/ml insulin, 5 μg/mL transferrin, 20 ρM trijodothyronine, 6.78 ng/ml selenium, 24.4 μg/mL adenine, 266.6 μg/mL strontium chloride, 100 mM sodium pyruvate, 10 mM non-essential amino acids, 12.5 mg/mL soybean trypsin inhibitor (SBTI), and 5 mM glucose
[0026] The endocrine precursor cells are cultured in a vessel suitable for animal cell or tissue culture, such as a culture dish, flask, or roller-bottle, which allows for the formation of a three-dimensional tissue-like structure. Suitable cell growth surfaces on which the cells can be grown can be any biologically compatible material to which the cells can adhere and-provide an anchoring means for the cell-matrix construct to form. Materials such as glass, stainless steel, polymers, including polycarbonate, polystyrene, polyvinyl chloride, polyvinylidene, polydimethylsiloxane, fluoropolymers, and fluorinated ethylene propylene; and silicon substrates, including fused silica, polysilicon, or silicon crystals may be used as a cell growth surfaces. The cell growth surface material may be chemically treated or modified, electrostatically charged, or coated with biologicals such as with peptides. An example of a peptide coating is RGD peptide.
[0027] While the cells of the invention may be grown on a solid cell growth surface or a cell growth surface with pores, such as a porous membrane, that communicate both top and bottom surfaces of the membrane to allow bilateral contact of the medium to the culture. Bilateral contact allows medium to contact both the top and bottom surfaces of the culture for maximal surface area exposure to the nutrients contained in the medium. The pores in the growth surface allow for the passage of culture media for providing nutrients to the underside of the culture through the membrane, thus allowing the cells to be fed bilaterally. Culture vessels incorporating a porous membrane are known in the art and are preferred for carrying out the invention and are described in a number United States patents in the field, some of which have been made commercially available, including for instance: U.S. Pat. Nos. 5,766,937, 5,466,602, 5,366,893, 5,358,871, 5,215,920, 5,026,649, 4,871,674, 4,608,342, the disclosures of which are incorporated herein by reference. A preferred pore size is one that is small enough that it does not allow for the growth of cells through the membrane, yet large enough to allow for free passage of nutrients contained in culture medium to the bottom surface of the cell culture, such as by capillary action. Preferred pore sizes are about less than 3 microns but range between about 0.1 microns to about 3 microns, more preferably between about 0.2 microns to about 1 micron and most preferably about 0.4 micron to about 0.6 micron sized pores are employed.
[0028] The cultures are maintained in an incubator to ensure sufficient environmental conditions of controlled temperature, humidity, and gas mixture for the culture of cells. Preferred conditions are between about 34° C. to about 38° C., more preferably 37±1° C. with an atmosphere between about 5-10±1% CO 2 and a relative humidity (Rh) between about 80-90%.
[0029] The defined culture medium allows for establishing primary cultures and serial passaging of the cultures, thus providing for an expanded number of cells for using the cells for testing or as a therapeutic. One of the hurdles in human islet cell culture is fibroblast overgrowth that could overshadow the growth of the targeted epithelial cells, a sub-population with characteristics of islet progenitor/precursor cells. Culturing the cells with the defined medium has overcome this problem The cells grown from human islets using this defined medium have shown predominantly epitheloid-like morphology and expressed the cytokeratin epithelial marker.
[0030] At each passage of the cells, the markers specific to both progenitor cells and endocrine precursor cells continue to be exhibited by the cells, including pdx1 and nestin. The cultured cells exhibit a decrease in the expression of islet cell markers indicating the cells may dedifferentiate with each passage; however, the cells maintain progenitor phenotype throughout each passage.
[0031] Pdx1, a transcription factor also known as IDX-1, is a known marker of pancreatic differentiation and regulator of pancreatic development. (Jonsson et al. Nature 371:606 (1994) and Offield et al. Development 122:983 (1996)).
[0032] Nestin is a cellular marker for developing pancreatic islet cells. (Lendahl, et al. Cell 60:585-595 (1990) and Zulewski et al. Diabetes. March 2001;50(3):521-33.)
[0033] The endocrine precursor cells may be induced to differentiate using chemical or physical means, such as by supplementing the culture medium with an agent that promotes differentiation to insulin-producing beta cells or by way of forming cell clusters in a matrix, such as an extracellular matrix. Inplant-induced differentiation (in vivo) of the cells in the right environment will induce the cells to differentiate. The cells may be implanted subcutaneously, in the submucosa of the small intestine, or under the kidney capsule.
[0034] The following examples are provided to better explain the practice of the present invention and should not be interpreted in any way to limit the scope of the present invention. Those skilled in the art will recognize that various modifications can be made to the methods described herein while not departing from the spirit and scope of the present invention.
EXAMPLES
Example 1
Isolation of Pancreatic Small Cells from Cadaveric Human Pancreata
[0035] Human pancreatic islet isolation was performed by the semi-automated method originally proposed by Ricordi (Ricordi C, Lacy P E, Finke E H, et al. Automated method for isolation of human pancreatic islets. Diabetes 1988 37:413-420). Procured pancreases were distended by intra-ductal infusion of a Liberase HI (Roche Molecular Biochemicals, Indianapolis, Ind.) or Serva Collagenase (Cresent Chemical, Brooklyn, N.Y.) (linetsky E, Bottno R, Ehmann R, et al. Improved human islet isolation using a new enzyme blend, Liberase. Diabetes 1997 46:1120-1123), and then dissociated using the automated method (Ricordi C, Lacy P E, Finke E H, et. Al. Automated method for isolation of human pancreatic islets. Diabetes 1988 37:413-420). The separation occurs during a process of continuous digestion lasting approximately 12-30 minutes, after which the digestion circuit was cooled and the tissue collected into approximately 8 liters of cold Hanks solution and washed. Liberated islets were separated from non-islet tissue on a continuous gradient of Euroficoll in a Cobe 2991 cell separator.
[0036] Preparations of partially purified islets from the Cobe cell separator were then passed through a series of different size steel mesh screens (100 to 25μpores), and the tissue that is retrieved was placed into culture directly on plastic in culture medium and permitted to spread out.
Example 2
Isolation of Porcine Islet Cells
[0037] Pancreatic islet cells were isolated from a porcine donor and plated using the defined medium to obtain a culture with an epithelial-like phenotyye. The isolation of porcine islet cells procedure is as follows. Two Nalgene containers, several 50 mL round bottom centrifuge tubes, trays, and screens were autoclaved. Two solutions were prepared, UW-D organ preservation solution and three concentrations, 27%, 24.6%, and 11%, of FICOLL solution.
[0038] The UW-D organ preservation solution was made according to the specifications given by Sumimoto et al (Transplantation July 1989; 48(1): 1-5). One liter of 1× UW-D organ preservation solution consisted of 35.83 g of lactobionic acid (Aldrich, Milwaukee, Wis.), 17.83 g raffinose (Sigma, St. Louis, Mo.), 1.23 g MgSO 4 (Sigma, St. Louis, Mo.), 0.92 g glutathione (Sigma, St. Louis, Mo.), 0.136 g allopurinol (Sigma, St. Louis, Mo.), and 3.40 g monobasic potassium phosphate (Sigma, St. Louis, Mo.) and double-distilled water. This solution was then filter-sterilized using a 0.2 u filter and stored at 4° C. until needed.
[0039] The FICOLL solutions were prepared from a Eurocollins base. Eurocollins base solution (pH 7.3) consisted of 4.1 g monobasic potassium phosphate (Sigma, St. Louis, Mo.), 14.8 g dibasic potassium phosphate (Sigma, St. Louis, Mo.), 2.24 g potassium chloride (Sigma, St. Louis, Mo.), 1.68 g sodium bicarbonate (Sigma, St. Louis, Mo.), 70 g-D-Glucose (Sigma, St. Louis, Mo.) and an adequate amount of double-distilled water to bring it up to 2 liters. One liter of Eurocoliins base solution was added to 500 g of FICOLL (Sigma, St. Louis, Mo.). The FICOLL was allowed to go into solution, a process that took about 2 hours. Another 500 mL of Eurocollins was added. The solution was analyzed for BRIX and Refractive index ranges, 28-28.4 and 1.3774-1.3779n 0 respectively. Additional Eurocollins base was added as needed. The FICOLL solution was then filtered sterilized using a MILLIPORE-MLLIPACK (Millipore, Bedford, Mass.) and distributed into sterile IL bottles. To prepare the 24.6% FICOLL solution, 456 mL of the stock (27%) FICOLL was diluted with 44 mL Eurocollins solution. To create the 11% FICOLL solution, 204 mL stock FICOLL was diluted with 296 mL Eurocollins. The FICOLL solutions were stored at 5° C. until needed.
[0040] The pancreas was obtained from a mixed breed pig weighing more than 40 pounds (≅20 kg). The pig had been fed a normal diet and was fasted for 24 hours prior to surgery. A cooler filled with ice, 500 mL of cold UW solution, 10 and 30 c.c. syringes, and 20-gauge angiocatheters were used in the harvest and transport of the pancreas. Once the pancreas was removed, it was perfused with cold UW solution until swollen. It was then placed in a 250 mL Nalgene container and put on ice.
[0041] During collection of the pancreas, a water bath was heated to 41° C. and a filter-sterilized Liberase PI solution (Roche Molecular Biochemicals, Indianapolis, Ind.) prepared. In order to facilitate the liberase infusion of the pancreas, dissection trays, large and small forceps, extra angiocaths, 30 and 60 c.c. syringes, and Nalgene containers were placed in the sterile field of the biological safety cabinet The organ was then removed from the ice and put onto the dissection tray. Liberase PI solution was perfused into the organ. This step was done slowly to avoid disturbing the cannulae placed there during surgery and also to prevent backflow. Once the organ was full, it was placed into another Nalgene container with some additional Liberase solution. The container was sealed and placed in the 41° C. water bath to incubate.
[0042] The pancreas was then digested until it appeared to begin separating, a process that took between 15-30 minutes. Before returning the organ to the sterile biological safety cabinet, the Nalgene container was sprayed with ethyl alcohol to insure sterility. The organ was then placed on the separating screen and gently scraped with cell scrapers for 5-10 minutes. Wash media was frequently added to facilitate the dissociation of the tissue. The wash media consisted of modified Hank's balanced salt solution (HBSS) (with calcium and magnesium, no phenol red) (JRH Biosciences, Lenexa, Kans.), donor herd horse serum (JRH Biosciences, Lenexa, Kans.), streptomycin 10,000 ug/mL (Invitrogen Life Technologies, Carlsbad, Calif.), gentamycin sulfate 50 mg/mL (OI P/N 100-50), fungizone 250 mg/mL (Invitrogen Life Technologies Carlsbad, Calif.), Amphotericin B (Invitrogen Life Technologies, Carlsbad, Calif.), and sodium desoxycholate 205 mg/mL (Invitrogen Life Technologies, Carlsbad, Calif.).
[0043] The underside of the screen was scraped to ensure that no islet cells were left behind. The wash/cell solution was then placed in large centrifuge bottles and then spun down at 700 rpms for a minute and a half. The supernatant was then carefully aspirated off. The content of each bottle was resuspended using wash media that was consolidated into one centrifuge bottle. Wash media was added until the bottle was full and then centrifuged again. The supernatant was then aspirated off and the volume of tissue determined.
[0044] To begin the density separation, 5 mL of 24.6% FICOLL was added for each mL tissue. The suspension was then mixed well and added to a 50 mL round bottom tube. In each tube, there should be no more than 12 mL of this suspension. A second layer of 27% FICOLL was added to the top of the suspension. A third layer of 11% FICOLL was added to the top of the gradient. Special care was taken to ensure that the layers did not mix. The tubes were then loaded into a centrifuge and spun down at 1700 rpms for 18 minutes. In order to maintain the gradient, the acceleration of the centrifuge was slowed and the brake disengaged.
[0045] To collect the islet cells, the 11-24.6% interface layer was removed. The islet cells and wash media were added to a wash tube and spun down for 5 minutes at 1000 rpm. The supernatant was removed and the islet cells resuspended with more wash media. This resuspension and centrifugation was repeated three times. The islet cells were then resuspended with culture media and plated.
Example 3
Islet Cell Culture
[0046] The islets cells acquired by the method of Example 1 were then plated to 60 mm tissue-culture treated culture dishes. The medium used in this example included the following: a base 3:1 mixture of Dulbecco's Modified Eagle's Medium (DMEM) (no glucose, no calcium, with 4 mM L-glutamine) and Hams F-12 medium, and the base is supplemented with the following components with the final concentration of each component indicated: 2 mM L-glutamine (or equivalent), 10 ng/ml epidermal growth factor, 0.4 μg/ml hydrocortisone, 1×10 −4 M ethanolamine, 1×10 −4 M o-phosphoryl-ethanolamine, 5 μg/ml insulin, 5 μg/ml transferrin, 20 ρM triiodothyronine, 6.78 ng/ml selenium, 24.4 μg/mL adenine, 266.6 μg/mL strontium chloride, 100 mM sodium pyruvate, 10 mM non-essential amino acids, 12.5 mg/mL soybean trypsin inhibitor (SBTI), and 5 mM glucose.
[0047] Human islet cells were cultured from primary cultures derived from the pancreatic tissue as described in Example 1 and passaged to passage 8 in the defined culture medium (identified as “H297” in the Figures). FIG. 1 shows the cumulative population doublings for each passage.
[0048] Human islet cells were plated to the culture dishes (previously coated with 0.05 mg/mL collagen for 30 minutes) and spread out from the islet clusters as early as day 1 after the plating, and grew slowly during the first week. Around day 10, small, mitotically active cells started to emerge and form colonies. These colonies expanded quickly and eventually merged together to form a population with epithelial morphology within 3-4 days. After splitting the cell culture and passing them to new culture dishes, the sub-cultured cells proliferated very fast with doubling time around 30 hours. These cells maintained proliferative capability for at least 7 passages, and the total population doubling reached up to 9.
Example 4
Characterization Studies
[0049] To characterize the expanded cell population, the expression of islet stem/progenitor markers pdx1 and nestin as well as islet hormone insulin was examined by RT-PCR, as shown in FIG. 2 . H297 cells from passages 0, 2, 4, and 8 were all positive for pdx1 expression. The level of pdx1 expression seems to be relatively constant throughout the culture period. Similar expression pattern of nestin has also been detected in the cells from all these passages. The continued expression of both pdx1 and nestin in the expanded cells suggests the possibility of existence of islet stem/progenitor cells in the culture, and indicates the potential of the expansion strategy for cell based therapy. The expression of insulin, as expected, can only be detected from the cells from early passages. At passage 4, virtally no insulin mRNA signal can be detected. This result is consistent with the immunfluorescence result in which few insulin-positive cells were observed in cells from passage 4 (data not shown). The decrease of insulin signal suggests that the expanding cells are more proliferative and less differentiated. | A cell composition of endocrine progenitor cells derived from mammalian pancreatic islet cells that can be trans-planted planted into a diabetic patient such t the cells of the cell composition differentiates into functioning insulin-producing beta cells. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to wastewater treatment systems, and particularly to a circular clarifier cleaning system that can clean and prevent the development of algae and solids accumulation on the surfaces of a circular clarifier in a wastewater treatment plant.
[0003] 2. Description of the Related Art
[0004] Clarifiers are well known in the prior art for separating suspended solids from clarified liquids. Most clarifiers operate by sedimentation of solids, i.e., solids sink and are collected from a bottom portion of the clarification vessel, or by flotation, i.e., solids are caused to float and are removed as a flotation blanket from the surface of the clarification vessel.
[0005] In a typical conventional activated sludge sewage treatment process, a considerable volume of scum and other gross floatables enters with the influent feed into the clarifier basin. This is distinct from biological scum, which arises from biological processes occurring in the basin. In conventional clarifiers, the influent scum and other floatables are often moved out of the influent well to be collected along with biological scum over the entire clarifier surface or at the periphery of the clarifier. The two types of scum typically are commingled and discharged together, and where influent well scum and floatables are collected, they are delivered to the periphery of the clarifier and commingled with biological scum.
[0006] Most prior art clarifiers exhibit shortcomings in that they allow algae, sludge and scum accumulation on the surfaces of the baffles, weirs, launders, and troughs. This build-up leads to operator maintenance.
[0007] Circular clarifiers can exhibit significant process advantages, especially when built on a large scale (e.g., sixty feet in diameter or more). In circular clarifiers, beaches are typically deployed radially to provide a surface for floatable solids collection. Also, in circular clarifiers, the influent feed may be introduced from a central, inner portion of the clarifier, and effluent may be removed from the outer perimeter under relatively quiescent conditions. Nevertheless, the problem of algae buildup remains.
[0008] Thus, a circular clarifier cleaning system solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0009] The circular clarifier cleaning system includes a mainframe attached to a skimmer arm of a circular clarifier having an influent feed well and an effluent trough. Various components are attached to the mainframe for the prevention of growth and accumulation of algae and debris from surfaces of the circular clarifier. The components within the system include gravity-driven drag sweeping chains, vertically suspended rotating chains, and a chain disposed in a hanging V-formation, the chains being disposed at various orientations in relation to the clarifier surfaces. In this manner, the trough, inner and outer trough wall, V-notch weirs, baffle plate wall, and inner baffle plate wall are all cleaned as the skimmer arm rotates around the clarifier. Two main drag chain assemblies are used to clean the effluent trough and overflow in an overflow wall after a V-notch weir structure of the circular clarifier. An individual chain is utilized as a “garland” to remove trapped solids on the V-notch weirs at the overflow. The clarifier cleaning system is driven by an existing skimmer arm generally found on secondary clarifiers. The attachment could be as simple as drilling two holes in the existing steel arm and bolting up.
[0010] Municipalities throughout the United States utilize either rectangular, circular, or other types of clarification, depending on the engineering concept. This also applies to Industries that produce waste at their production facilities. The circular clarifier cleaning system applies to circular clarifier installations. The system eliminates the necessity of extensive and frequent manual cleaning of those clarifier components by utilizing sweeping drag chains and non-motorized rotating chains that impinge clarifier wall surfaces to allow the process water to flow unabated while preventing algae growth and material matting in the clarifier components.
[0011] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a partial environmental, perspective view of a circular clarifier cleaning system according to the present invention.
[0013] FIG. 2 is a partial environmental perspective view of the circular clarifier cleaning system of FIG. 1 , showing the garland chain engaging the V-notch weir gap.
[0014] FIG. 3 is a partial diagrammatic side view of the circular clarifier cleaning system of FIG. 1 , showing further details thereof.
[0015] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] As shown in FIGS. 1 through 3 , the circular clarifier cleaning system 10 attaches to an existing clarifier's scum skimmer arm 2 a . The circular clarifier cleaning system 10 is designed for new or existing circular clarifiers at municipal or industrial wastewater treatment plants. Such circular clarifiers have a clarifier skimmer arm 2 a and scum scraper blade 2 b , which extend radially across an influent basin 120 to a location proximate the inside wall of the circular clarifier scum baffle B. The arm 2 a and blade 2 b are connected to a motor at the center of the circular clarifier to provide rotation of the arm 2 a and blade 2 b around the inside periphery of the clarifier scum baffle B. Thus, the circular clarifier cleaning system 10 is driven by an existing skimmer arm 2 a generally found on secondary clarifiers. The method of attachment could be as simple as drilling two holes in the existing steel arm 2 a and bolting up an elongate mainframe member 3 a of the clarifier cleaning system 10 . When attached in this manner, the circular clarifier cleaning system 10 has a low profile, and is also easily accessible.
[0017] The elongate mainframe member 3 a of the circular clarifier cleaning system 10 is rigidly attached to, and projects radially from, the scum skimmer arm 2 a in order to extend the cleaning system's reach over the clear effluent section of the clarifier to a point proximate the inner circumferential portion of the effluent trough wall 17 .
[0018] A baffle wheel positioning member 3 b is pivotally secured to the mainframe member 3 a by a bracket assembly 35 . The baffle wheel positioning member 3 b is constrained to pivot in a plane parallel to the plane defined by rotational sweeping motion of the scum skimmer arm 2 a and the rigidly attached mainframe member 3 a . Preferably, all pivoting components of the clarifier cleaning system 10 have self-lubricating bearings at their pivot points.
[0019] A spring 5 is attached to the mainframe member 3 a and to the baffle wheel positioning member 3 b to bias the pivot direction of the positioning member 3 b towards the wall of the baffle B. There is one such combination of spring 5 and baffle wheel positioning member 3 b arranged to bias a positioning member 3 b towards the inside wall of baffle B, and an opposing such combination of spring 5 and an identical baffle wheel positioning member 3 b arranged to bias the identical positioning member 3 b towards the outside wall of baffle B. A planar extension member 30 is attached to and extends downward from one end of the positioning member 3 b on the side that is biased towards the wall. An L-shaped baffle wheel support member 37 a is attached to and extends downward from the planar extension member 30 . A wheel 9 having a vertically aligned spin axis is attached to the short leg of the L-shaped baffle wheel support member 37 a and, due to the pivot bias of the positioning member 3 b , contacts the wall of the baffle B. A plurality of chains 50 are attached to the bottom face of the wheel 9 and are suspended from the wheel 9 at predetermined radial displacements along the bottom face of the wheel 9 , thus allowing the chains 50 to hang down vertically from the wheel 9 . Preferably, all chains utilized in the cleaning system 10 are stainless steel.
[0020] Rotation of the skimmer arm 2 a causes the wheel 9 in con t act with the wall of the baffle B to turn, thus imparting rotational beating motion in the vertically hanging chains 50 against the baffle wall, which dislodges any debris, algae, or the like from the wall of the baffle B. It should be understood that the vertically hanging chain wall beating members 50 are exemplary, and do not preclude the use of other wall beating members, such as brushes, that may be attached to the wheel 9 . Each wheel 9 of the circular clarifier cleaning system 10 is capable of controlling cleaning elements, such as chains, brushes, squeegees, or a combination thereof, by maintaining a predetermined cleaning tolerance on rough, misshapen, and/or irregular surfaces often found in the walls of a clarifier. The wheels 9 may also control chains, squeegees, or brushes, independently, depending upon the existing conditions at a particular clarifier installation.
[0021] Similar to the baffle cleaning arrangement, a wheel 9 contacts the inside portion of the weir wall 21 and has vertically hanging rotational beating chains 50 , which contact the inner wall of the spillway to dislodge debris therefrom. The wheel 9 in contact with the weir wall 21 is suspended from, and contact-biased by, an L-shaped weir wheel support bracket 7 , which is attached to a weir wheel positioning member 3 c . The weir wheel positioning member 3 c is attached to the mainframe 3 a using attachment brackets 35 . A spring 5 is connected to the mainframe 3 a and the positioning member 3 c to form the bias of the wheel assembly 9 towards contact with the weir wall 21 .
[0022] Moreover, a similar arrangement of a wheel 9 and vertically disposed rotational beating chains 50 contacts the inner portion of the outer effluent trough wall 17 to dislodge debris therefrom. For example, as most clearly shown in FIG. 1 , the wheel 9 in contact with the outer effluent trough wall 17 is suspended from, and contact-biased by, an outer effluent trough wheel support bracket 37 c , which is attached to an outer trough wall wheel positioning member 3 d . The outer trough wall wheel positioning member 3 d is attached to the mainframe 3 a using attachment brackets 35 . A spring 5 is connected to the mainframe 3 a and the positioning member 3 d to form the bias of wheel assembly 9 towards contact with the outer trough wall 17 .
[0023] An individual chain 16 is utilized as a “garland” to clean the V-notch weirs 22 at the overflow. As shown in FIG. 2 , opposite ends of the chain 16 are suspended from the mainframe 3 a so that the chain 16 forms a V-shaped span, the tip region of garland V chain 16 dipping into and cleaning the V-notched weirs 22 as the clarifier scum skimmer arm 2 a rotates.
[0024] As shown in FIG. 3 , the circular clarifier cleaning system 10 also includes a horizontal effluent trough drag chain curtain 52 and a horizontal spillway drag chain curtain 100 , which are used to clean the effluent trough 20 a and the upper horizontal portion 20 b of the spillway wall 19 , respectively. The effluent trough drag chain curtain 52 is suspended from the mainframe 3 a by two rods 62 or cables attached at two distinct points along the first row of the drag chain curtain 52 and corresponding attachment points along the mainframe 3 a , the corresponding attachments being secured by eyebolts 60 inserted into the mainframe 3 a . The first row of drag chain curtain 52 is maintained in a rigid horizontal row configuration by a series of welds between each of the chain links and is suspended from the mainframe 3 a so that columns of links in the drag chain curtain 52 are arranged along a portion of a radial line extending from the center of the clarifier. The drag chain curtain 100 has a similarly configured first row, which is maintained by a series of welds between each of the chain links in the first row, and the curtain's columns are also arranged along a portion of a radial line extending from the center of the clarifier. A rigid spillway chain attachment member 37 d is vertically and pivotally attached to the end of the weir wheel positioning member 3 c distal from the mainframe 3 a . A pair of rods or cables is pivotally attached to the end of the spillway chain attachment member 37 d distal from the weir wheel positioning member 3 c . The rod/cable pair is then attached to the drag chain curtain 100 at the top horizontal row of its chain links, thereby pivotally securing the drag chain curtain 100 to the spillway chain attachment member 37 d and allowing the drag chain curtain 100 to slide across the upper horizontal portion 20 b of the spillway 19 to dislodge debris and algae therefrom as the clarifier scum skimmer arm 2 a rotates.
[0025] An inner trough wall drag chain 54 is pivotally attached to the end of the top row of the spillway horizontal drag chain curtain 100 closest to the inner trough wall 20 c , thereby allowing the inner trough wall drag chain 54 to slide across the slanted inner trough wall 20 c to dislodge debris and algae therefrom as the clarifier scum skimmer arm 2 a rotates.
[0026] The circular clarifier cleaning system 10 may be provided as a custom-fitted kit for a specific circular clarifier. An exemplary embodiment of the kit includes an elongate mainframe member 3 a having drilled holes and associated hardware adapted for attachment of the mainframe 3 a as a radial extension to the scum skimmer arm 2 a of the circular clarifier. A positioning member 3 b is provided and exemplifies a typical attachment to the elongate mainframe member 3 a . A spring 5 attachable to the mainframe 3 a and positioning member 3 b is provided to pivotally bias positioning member 3 b along a horizontal plane. A wheel 9 having its axis of rotation vertically aligned is provided for attachment to the positioning member 3 b . A plurality of vertically extending chains 50 attachable to the wheel 9 is provided. A plurality of positioning member and wheel assembly combinations attachable to the mainframe 3 a may be included in the kit to provide the capability of cleaning all of the circular walls of the clarifier.
[0027] Additional kit components may include an effluent trough drag chain curtain 52 , which can be suspended from the mainframe 3 a , and a spillway surface drag chain curtain 100 , which is also suspendable from the mainframe 3 a . A length of chain 16 suspendable form the mainframe 3 a to form a V shape garland is also provided in the kit.
[0028] It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | The circular clarifier cleaning system includes a mainframe to which all various components are attached for the prevention of growth and accumulation of the algae and debris. The components within the system include gravity-driven, horizontal and vertical sweeping chains. The outer trough wall, V-notch weirs, baffle plate wall, and inner baffle plate wall are all cleaned utilizing a rotating chain system device. Two main drag chains are used to clean the effluent trough and the overflow in the overflow wall after the V-notch weirs. An individual chain is utilized as a “garland” to clean the V-notch weirs at the overflow. The circular clarifier cleaning system is driven by an existing skimmer arm found on all secondary clarifiers. | 1 |
This is a continuation-in-part of AN APPARATUS AND METHOD FOR PROVIDING REMOTE PCI SLOT EXPANSION, Ser. No. 08/490,778 filed Jun. 16, 1995, now U.S. Pat. No. 5,696,949.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to booting a processor. More specifically, the invention relates to booting a processor from a remote memory.
2. Related Art
Intelligent input/output (I/O) processing has become increasingly common. An intelligent I/O system implies that in addition to a host processor, a lesser I/O processor is also provided to handle various I/O tasks, thereby facilitating the speed and efficiency of I/O operations. The I/O processor is typically much lower in cost and processing power than the host processor and is associated with a local memory which is typically at least partially composed of read only memory (ROM) in which the boot code for booting and initializing the I/O processor is maintained. Among the processors used as I/O processors is the JF80960 manufactured by Intel Corporation of Santa Clara, Calif. The JF80960 responds to a reset signal by placing the local ROM address of its boot code on the local bus. In response, the boot code is returned from the ROM and the JF8960 initializes itself and configures the local I/O environment. The processor and its local memory are typically provided on an I/O card for insertion into an I/O bus slot. Unfortunately, providing the local memory on the I/O card significantly increases the cost of the card. This is a concern as the market becomes increasingly cost sensitive.
The peripheral component interconnect (PCI) bus is a high performance low latency I/O bus architected to minimize system cost. PCI has quickly gained wide acceptance in the computer industry. The PCI bus standard provides for a high bandwidth and a flexibility that is independent of new processor technologies and increased processor speed. At this time, computer system architects are primarily designing speed sensitive peripherals such as graphics accelerators and small computer systems interface (SCSI) drive controllers to be utilized with the PCI bus.
The PCI specification is well defined. See particularly, PCI Local Bus Specification, rev. 2.0, Apr. 30, 1993. The specification reflects that PCI is capable of running at any frequency up to 33 MHz. This high level of possible throughput makes PCI an ideal choice for volume servers. Unfortunately, at such speed, the PCI bus can only support 3-4 slots along a single bus segment This number of slots is unacceptably low for a practical application in the volume server market. Some prior systems have addressed this problem by cascading PCI buses on the host mother board. Unfortunately, such cascading increases the cost of the basic system and still fails to provide a level of slot expansion necessary in volume servers. Moreover, such single chassis systems are not readily expandable as the user's needs change.
The volume server market has yielded another limitation not readily addressed by a single chassis system, specifically, physical space. Stated differently, current processors have enough processing power that a single processor can satisfy the processing requirements of more, for example, SCSI drives than will fit within any single chassis. Any time the number of drives exceeds this physical limitation, it will clearly be necessary to expand out of the chassis. As a practical matter, since each chassis is likely to be provided with its own I/O processor, the cost of the system could be significantly reduced if it were possible to eliminate the local memory associated with at least some of the I/O processors.
It is therefore desirable to be able to boot an I/O processor from a remote memory, thereby allowing the elimination of that I/O processor's local memory which in prior art systems would have contained the processor's boot code. It is further desirable to provide an apparatus which allows PCI slot expansion without unnecessarily increasing the cost of the host system. The performance of an expanded slot must be maintained at an acceptably high level, and the system should be readily expandable to meet the demands of increasing processor power.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system employing one embodiment of the invention.
FIG. 2 is a table of relevant PCI signals for one embodiment of the invention.
FIG. 3 is a block diagram of the primary and secondary expansion bridges of one embodiment of the invention.
FIG. 4 is a diagram of memory mapping for one embodiment of the invention.
SUMMARY OF THE INVENTION
A method and system for booting a first processor from a remote memory is disclosed. In response to a reset signal, a processor which has no associated local memory is prevented from executing code and particularly its boot sequence. Because the first processor is prevented from initializing its environment, configuration cycles from a host processor should be prevented from configuring that environment until the first processor has booted. By preventing the host processor from configuring, the first processor environment's integrity is protected. Because the first processor has no local memory, address cycles generated to access local memory would normally go unclaimed on a local bus. An interface between the local bus and the remote memory is configured to claim the local memory address range from the local bus. Once the first processor is enabled, the local memory addresses are used to access the remote memory to return the necessary boot code.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method and apparatus booting a processor from a remote memory. For the purpose of explanation, specific details are set forth to provide a thorough understanding of the present invention. Notably, the invention is described in the context of PCI buses, however, the invention could also be employed in the context of other bus structures. It will be understood by one skilled in the art that the invention may be practiced without these details. Moreover, well known elements devices, process steps and the like are not set forth in order to avoid obscuring the invention.
FIG. 1 shows a block diagram of a system incorporating the instant invention. The host system resides within a host chassis 1 and includes a host mother board 3. The host mother board has a central processing unit (CPU) 5 connected to a memory 6 by a system bus 7. A bridge 8 is provided on the mother board to bridge between the system bus 7 and a host PCI bus 9. At 33 MHz, the PCI specification only permits 3-4 slots 10 along a single bus segment. By installing an expansion card 11 in at least one of the slots 10 on the host PCI bus 9, it is possible to expand the number of slots of the system as a whole.
The expansion card 11 has a primary expansion bridge (PEB) 12 described more fully with reference to FIG. 3 below, and a cable connector 15. In an exemplary embodiment, a 100 pin cable connector is used. This allows for sufficient signal conductors to accommodate parallel transmission of all PCI required signals and adequate grounding. The expansion card also provides an optional advanced programmable interrupt controller (APIC) connector 14 to allow the card 11 to be connected to the APIC bus (not shown) on the host mother board 3. FIG. 2 is a table of the relevant PCI signals. The cable 16 is selected based on propagation speed down the cable 16 and cable slewing. It is desirable to choose a cable 16 with minimal slewing and with maximum propagation speed. The cable 16 functions as a point to point PCI bus between the expansion side of the PEB 12 and the secondary expansion bridge (SEB) 19 which is described more fully below. The cable 16 should be well terminated at either end with impedances approximately equal to the characteristic impedance in the cable. In an exemplary embodiment, a six foot high performance parallel interface (HIPPI) cable with a characteristic impedance of 88±5 ohms is used. HIPPI cable meets American National Standards Institute (ANSI) standards and includes 50 twisted pairs, thereby providing an adequate number of signal lines. It would be possible to use a smaller cable and lower pin count connector but such would limit possible functionality somewhat.
The expansion chassis 2 contains an expansion mother board 4 to which the cable 16 connects via connector 17. A PCI bus runs from the connector to the SEB 19. The clocking in the expansion system is provided by a clock generator 18 which is asynchronous with and independent of the host clock (not shown). The number of slots 21 available on the secondary PCI bus (SPB) 20 is determined by the speed of the clock signal generated. At 25 MHz, 8-12 slots are available, while at 33 MHz, only 3-4 slots would be available. It is possible and contemplated as within the scope of this invention that multiple expansion modules could be coupled to a single host (one card per available PCI slot). It is also within the scope of the invention to cascade an expansion module off an expansion module.
FIG. 3 shows a block diagram of PEB 12 as coupled to the SEB 19 of the instant invention. Local processor 30 is coupled to local bus 34 which is also coupled to primary address translation unit (ATU) 39 and secondary ATU 31. A primary ATU 39 is also coupled to the primary PCI bus 38. The secondary ATU 31 is coupled to the secondary PCI bus 35. Secondary ATU 31 contains programmable bit 56 which can provide a control signal to cause the ATU 37 to change the address range claim from the local bus. Bridge 32 provides a PCI to PCI bridge between primary PCI bus 38 and secondary PCI bus 35. The bridge 32 issues local bus reset (not shown) which resets the devices on the local bus 34.
Primary reset 37 operates as an input signal to the bridge 32 which is passed through to become secondary reset 36 which is cabled over cabled bus 16 to become primary reset 47. Cabled bus 16 also connects secondary PCI bus 35 with primary PCI bus 48. SEB 19 has the same basic structure as PEB 12. Local processor 40 is connected to local bus 44 which in turn is connected to primary and secondary ATUs 49 and 41, respectively. The bridge unit 42 bridges between primary PCI bus 48 and secondary PCI bus 45 and provides the local bus reset 43 to the devices on the local bus. In one exemplary embodiment, local bus 44 is also coupled to a local memory 50. Local memory 50 includes at least some ROM containing initialization code for local processor 40. Local processor 40 initializes itself from the code in local memory and then initializes the components on the local bus 44 in the usual way.
Two programmable bits 54 and 55 are programmed responsive to primary reset 37 by sampling each of two strapping pins while primary reset 37 is asserted. These bits are set and cleared in memory cycles. A retry pin 51 programs the programmable bit 54 to indicate a retry condition to the host until bit 54 is cleared. Core reset pin 52 programs programmable bit 55 to hold the local processor 30 in reset until cleared. It will be recognized by one of ordinary skill in the art that the decision of whether to set/clear to indicate, e.g., retry/no retry, the programmable bits is a design decision and the inverse is within the scope of the invention. Significantly, because the retry pin 51 and the core reset pin 52 are only sampled when primary reset 37 is asserted, these pins can be multiplexed and used for other functions the rest of the time. Since many integrated circuits are pin limited, this pin "saving" is important.
In response to an assertion and deassertion of a reset signal along primary reset line 37, the bridge 32 asserts and deasserts secondary reset signal 36 which corresponds to an assertion and deassertion of primary reset signal 47 and to bridge 42. Additionally, the bridge asserts local bus reset (not shown) which resets all devices on the local bus. However, to prevent the local processor 30 from beginning its initialization cycles, core processor reset 33 is maintained asserted because bit 55 remains set. Local processor 40 begins initialization responsive to deassertion of local bus reset signal 43. Thus, when reset signal 43 is deasserted, local processor 40 will place the address of its initialization code as located in local memory 50 onto the local bus 44. Local memory 50 will then provide the necessary initialization routines across local bus 44 to processor 40 and local processor 40 will initialize the other units on local bus 44.
The host processor will try to configure the PEB 12 and SEB 19 by sending configuration cycles through the primary interface of the PEB. The bridge 32 forwards the configuration cycles directed to the primary PCI 48 of the SEB 19. Configuration cycles in PCI are permitted only when an ID select (IDSEL) signal is asserted. The IDSEL signal is typically tied to particular address lines of the PCI bus which ensure that it will be asserted if the cycle is a configuration cycle. Primary IDSELs 58 and 68 are asserted for configuration cycles within the PEB 12 and SEB 19, respectively.
With programmable bit 54 set, host processor configuration cycles are prevented from entering the PEB 12. Specifically, when host configuration cycles appear on primary PCI bus 38, the bridge 32 asserts a retry signal. The retry signal indicates that the target (in this case the PEB 12) is not ready to receive the cycles from the host processor. As a result, the host processor releases the primary PCI bus 38 for a period of time and then comes back and attempts drive configuration cycles into the PEB 12. The retry signal requires the host to come back, but there is no limit to the number of times the host processor can be forced to retry. Thus, programmable bit 54 causes the host processor to be retried indefinitely until programmable bit 54 is cleared.
Once the local processor 40 of SEB 19 has initialized the local bus 44, it sets programmable bit 56 in secondary ATU 31 to claim a new address range from local bus 34. This setting is performed by a configuration cycle through the secondary PCI bus 35 of the PEB 12. To allow configuration cycles along the PEB's secondary PCI bus 35, a secondary IDSEL signal 57 is provided. The secondary IDSEL is asserted to allow the setting or clearing of programmable bit 56. The SEB 19 is shown with a secondary IDSEL 67 which is unused in the configuration shown.
Claiming of the new address range is discussed more fully below with reference to FIG. 4. Once bit 56 is set, SEB local processor 40 clears programmable bit 55 via a memory cycle, which causes the reset of local processor 30 to be deasserted. Local processor 30 puts out initialization cycles on local bus 34 which are claimed by secondary ATU 31 because programmable bit 56 is set. The secondary ATU 31 converts these local bus addresses to PCI addresses and forwards them on secondary PCI bus 35. Primary ATU 49 claims these PCI addresses and translates them to the local bus 44 where they are claimed by local memory 50. Local memory 50 then forwards the necessary initialization code to local processor 30 in the PEB 12. Once local processor 30 has booted and initializes the components local bus 34, SEB local processor 40 clears programmable bit 56 returning secondary ATU 31 to claiming its normal address range. PEB local processor 30 then clear programmable bit 54 so that on the next attempt, host configuration cycles will be allowed to enter the PEB.
While FIG. 3 shows the PEB and the SEB having the same architecture, the invention is not so limited. For example, a local memory and processor could be provided on the SEB primary PCI bus, thereby obviating the need for the SEB primary ATU in this invention. If the PEB were provided with an additional strapping pin to program programmable bit 56, the PEB local processor could boot from a remote memory in the SEB without the aid of an SEB local processor. Thus, with such additional strapping pin, the PEB processor could boot from a memory on the SEB primary PCI bus without additional support from other SEB components. It is also possible for additional devices to reside on either the local bus, one of the PCI buses, or both without departing from the scope and contemplation of the invention. Notably, it is envisioned that the invention can be used with the architecture described in i960® RP Microprocessors Users Manual available from Intel Corporation publications division.
FIG. 4 shows a local bus address space for one embodiment of the invention. The outbound translation windows 104 have been shown in an exploded view. The local bus address space is divided in seven functional regional and two reserved regions 101, 107. The functional regions include internal data RAM 100, peripheral memory mapped registers 102, ATU outbound direct addressing 103, ATU translation 104, external memory code and data 105, initialization boot record 106, and 80960 JX processor memory mapped register space 108.
The invention deals primarily with the ATU outbound translation windows 104, and the secondary boot translation window 121. There are six outbound ATU translation windows, three each corresponding to the primary and secondary ATU's. The six windows are Primary Memory Window 109, Primary Dual Address Cycle (DAC) window 110, primary I/O window 113 and corresponding secondary windows 111, 112, and 114, respectively.
In one embodiment of the instant invention, the address range claimed for ATU translation is modified to allow the secondary ATU to claim and translate addresses in the secondary boot translation window 121.
Addresses falling within the outbound translation windows 111, 112, and 114 are claimed by the secondary ATU in the course of normal operation and translated to a PCI address in a standard way. However, when bit 56 in the secondary ATU is set, the secondary ATU also claims an additional window 121. The additional window 121 claimed includes a portion of external memory code/data 105, the initialization boot record 106, reserved block 107, and the memory mapped register space 108 at FE00.0000 through FEFF.FFFFF. Unless this programmable bit 56 is set, addresses within the initialization boot record 106 and external memory window 120 placed on the local bus would go unclaimed as there is no local memory which would normally respond to this address range. It is not necessary to claim windows 107 and 108 and the ATU could be configured to claim all of external memory code/data window 105. But establishing the secondary boot window 121 as discussed above simplifies decoding and implementation as 1) any address above FE000000 is claimed, thus obviating the need to check for an upper end, and 2) the number of address bits decoded is reduced over claiming the expanded range. Nevertheless, embodiments claiming a larger window and those with an upper end limit are within the scope and contemplation of the invention. Once the secondary ATU claims an address of this secondary boot translation window 121, that address is translated to a PCI address and forwarded over the cabled bus to the SEB and appropriate initialization information will be returned as discussed previously.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will however be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly, to be regarded in an illustrative rather than a restrictive sense. Therefore, the scope of the invention should be limited only by the appended claims. | A method and system for booting a first processor from a remote memory. In response to a reset signal, a processor which has no associated local memory is prevented from executing code and particularly its boot sequence. Because the first processor is prevented from initializing its environment, configuration cycles from a host processor should be prevented from configuring that environment until the first processor has booted. By preventing the host processor from configuring, the first processor environment's integrity is protected. Because the first processor has no local memory, address cycles generated to access local memory would normally go unclaimed on a local bus. An interface between the local bus and the remote memory is configured to claim the local memory address range from the local bus. Once the first processor is enabled, the local memory addresses are used to access the remote memory to return the necessary boot code. | 6 |
TECHNICAL FIELD
The present invention relates to a logic circuit using a two terminal switching device having two stable resistivity values against an applied voltage.
BACKGROUND ART
In recent years, the development of characteristics of an electronic device using an organic electronic material has been remarkable. For example, in organic EL displays or organic LED displays, since each pixel individually emits light (or more specifically, spontaneously emits light), they have a number of advantages, such as an advantage that they have a wide viewing angle that a color filter is not necessary; an advantage that a backlight is not necessary so that thinning is possible; and an advantage that they can be formed on a flexible substrate such as plastic, as compared with conventional liquid crystals.
Also, in a circuit system for driving an electronic device of this kind, the use of an organic material is studied. If this is possible, it is expected that an electronic device in which a substrate can be deformed, such as a wearable PC and a flexible display, is realized.
In addition, in RFID (radio frequency identification) technology, which has been eagerly utilized in recent years, the utilization of an organic electronic device is studied. In this RFID technology, data is stored or read out in a medium in a card form or tag form by using a radio wave, and the foregoing data is recognized by communication via an antenna. That is, the data is exchanged by radio between a small-sized medium such as a tag and a device designated as a reader.
Since RFID is convenient in that it is not necessary to bring the tag or the like into contact with the reader if they are in communication range, its application tends to spread. However, since the unit price of a current tag is several tens of yen or more, a problem arises in that it is too expensive to attach to a commodity with a low price.
At present, while IC using a silicon chip is used in a tag, for the purpose of solving the foregoing problem, the use of a tag made of an organic electronic device is studied.
As one example of the foregoing organic electronic device, a CMOS circuit that is configured to have a transistor made of an organic electronic material is proposed. This can be suitably used as a so-called “combination logic circuit” (see, for example, JP 09-199732 A, JP 2001-177109 A, JP 2001-203364 A or JP 2002-324931 A).
The foregoing organic electronic material is formed as a thin film on a substrate. This thin film made of an organic electronic material is formed so as to have a film thickness in the range of from approximately several tens to several hundreds nm by a measure such as vacuum vapor deposition and solution coating (for example, a spin coating method and an inkjet method).
Glass, silicon, and plastics are frequently used as the material of the foregoing substrate. On this substrate, a metal electrode, an electrode made of an oxide such as ITO, an insulating film, and so on are formed by employing a measure such as vacuum vapor deposition, solution coating (for example, a spin coating method and an inkjet method), sputtering, CVD, and PVD as the need arises.
In the foregoing, in particular, the use of an organic material as the electronic material brings such merits that the manufacturing costs are low; that the processing temperature is low; and that flexible electric appliances can be manufactured by using a plastic substrate.
DISCLOSURE OF THE INVENTION
However, a concrete proposal has not yet been made to configure a flip-flop circuit (bistable circuit), which is necessary for a “sequential logic circuit”, as opposed to a “combination logic circuit”, by using an organic electronic material device. Here, in the “combination logic circuit”, an output value is determined by a combination of input logic values at the present point in time; and in the “sequential logic circuit”, an output value is determined by a time series of input logic values to the present point in time.
Generally, when using conventional silicon devices, a sequential logic circuit made of a combination of plural transistors and rectifying devices is employed. However, in sequential logic circuits using silicon devices, preparing an organic transistor is complicated. Thus, a problem has arisen that characteristics are so widely scattered that the yield rate is low.
Now, under the foregoing circumstances, an object of the invention is to realize a logic circuit employing an organic electronic material in a simple and easy configuration of a flip-flop circuit (bistable circuit), which is necessary for the “sequential logic circuit”.
In order to attain the foregoing object, a logic circuit according to the invention includes a two terminal switching device having two stable resistivity values against each applied voltage value, which when a voltage of not more than a prescribed first threshold voltage is applied thereto, becomes in a first state having a higher resistivity value of the foregoing respective resistivity values, whereas when a voltage of a prescribed second threshold voltage or more that is larger than the foregoing first threshold voltage is applied thereto, becomes in a second state having a lower resistivity value of the foregoing respective resistivity values; a resistance device connected in series to the foregoing two terminal switching device; a terminal for applying a prescribed bias voltage to both ends of a series circuit of the foregoing switching device and resistance device; a first pulse inputting terminal for inputting a first pulse of a prescribed voltage to one end of the foregoing switching device; and a second pulse inputting terminal for inputting a second pulse of a prescribed voltage to a connection between the other end of the foregoing switching device and the foregoing resistance device, with the foregoing first and second states being selectively generated in the foregoing switching device by a combination of inputs of the foregoing first and second pulses.
In one embodiment, the foregoing switching device is configured to have a lower electrode layer and an upper electrode layer each of which is made of a thin film and an organic bistable layer, which is made of a thin film mediated between the foregoing lower electrode layer and upper electrode layer.
In this case, for example, aluminum can be used as a material of the foregoing lower electrode layer and upper electrode layer, and aminoimidazole dicyanate can be used as a material of the foregoing organic bistable layer.
As a concrete example, the foregoing lower electrode layer and upper electrode layer are formed such that they are each in a stripe form and that their longitudinal axial lines are orthogonal to each other; and the foregoing organic bistable layer is formed so as to cover an intersection point between the foregoing lower electrode layer and upper electrode layer.
Also, a logic circuit according to the invention includes a first two terminal switching device having two stable resistivity values against each applied voltage value, which when a voltage of not more than a prescribed first threshold voltage is applied thereto, becomes in a first state having a higher resistivity value of the foregoing respective resistivity values, whereas when a voltage of a prescribed second threshold voltage or more that is larger than the foregoing first threshold voltage is applied thereto, becomes in a second state having a lower resistivity value of the foregoing respective resistivity values; a second two terminal switching device having electric characteristics the same as in the foregoing first switching device and being connected in series in a direction with uniformpolarity to the foregoing first two terminal switching device; a terminal for applying a prescribed bias voltage to both ends of a series circuit of the foregoing first and second switching devices; a first pulse inputting terminal for inputting a first pulse of a prescribed voltage to one end of the series circuit of the foregoing first and second switching devices; a second pulse inputting terminal for inputting a second pulse of a prescribed voltage to a connection between the foregoing first and second switching devices; and a third pulse inputting terminal for inputting a third pulse of a prescribed voltage to the other end of the series circuit of the foregoing first and second switching devices, with the foregoing first and second states being selectively generated in the foregoing first and second switching devices by a combination of inputs of the foregoing first, second and third pulses.
In addition, a logic circuit according to the invention includes a first two terminal switching device having two stable resistivity values against each applied voltage value, which when a voltage of not more than a prescribed first threshold voltage is applied thereto, becomes in a first state having a higher resistivity value of the foregoing respective resistivity values, whereas when a voltage of a prescribed second threshold voltage or more that is larger than the foregoing first threshold voltage is applied thereto, becomes in a second state having a lower resistivity value of the foregoing respective resistivity values; a second two terminal switching device having electric characteristics the same as in the foregoing first switching device and being connected in series in a direction with uniform polarity to the foregoing first two terminal switching device; a terminal for applying a prescribed bias voltage to both ends of a series circuit of the foregoing first and second switching devices; a first pulse inputting terminal for inputting a first pulse of a prescribed voltage to both ends of the series circuit of the foregoing first and second switching devices; and a second pulse inputting terminal for inputting a second pulse of a prescribed voltage to a connection between the foregoing first and second switching devices, with the foregoing first and second states being selectively generated in the foregoing first and second switching devices by a combination of inputs of the foregoing first and second pulses.
In one embodiment, the foregoing first and second switching devices are each configured to have a lower electrode layer and an upper electrode layer each of which is made of a thin film and an organic bistable layer, which is made of a thin film mediated between the foregoing lower electrode layer and upper electrode layer.
In this case, aluminum can be used as a material of the foregoing lower electrode layer; gold can be used as a material of the foregoing upper electrode layer; and bisquinomethane can be used as a material of the foregoing organic bistable layer.
As a concrete example, the foregoing lower electrode layer and upper electrode layer are formed such that they are each in a stripe form and that their longitudinal axial lines are orthogonal to each other; and the foregoing organic bistable layer is formed so as to cover an intersection point between the foregoing lower electrode layer and upper electrode layer.
According to the invention, since a two terminal switching device having two stable resistivity values against each applied voltage value, which when a voltage of not more than a prescribed first threshold voltage is applied thereto, becomes in a first state having a higher resistivity value of the foregoing respective resistivity values, whereas when a voltage of a prescribed second threshold voltage or more that is larger than the foregoing first threshold voltage is applied thereto, becomes in a second state having a lower resistivity value of the foregoing respective resistivity values is used, it becomes possible to realize a flip-flop circuit (bistable circuit), which is necessary for a sequential logic circuit, by a simple and easy configuration.
Also, according to the invention, by configuring the foregoing two terminal switching device by using an organic electronic material, it becomes possible to more reduce the manufacturing costs and to manufacture flexible electric appliances.
Incidentally, it should not be construed that the two terminal switching device of the invention is limited to one using an organic electronic material. That is, the invention also applies to two terminal switching devices formed of an inorganic electronic material so far as they have the foregoing electric characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram to show a first embodiment of a logic circuit according to the invention.
FIG. 2 is a graph to illustrate electric characteristics and operating points of a two terminal switching device, which is used in the logic circuit of FIG. 1 .
FIG. 3 is a circuit diagram to show a second embodiment of a logic circuit according to the invention.
FIG. 4 is a graph to illustrate electric characteristics and operating points of a two terminal switching device, which is used in the logic circuit of FIG. 1 .
FIG. 5( a ) shows one example of a pulse inputting circuit; and FIG. 5( b ) shows one example of a waveform of a pulse, which is formed by this inputting circuit.
FIG. 6 is a cross-sectional view to conceptually show a configuration of a two terminal switching device according to Examples 1, 2 and 3.
FIG. 7 is a plan view showing a configuration of a logic circuit according to Examples 1 and 2.
FIG. 8 is a pan view showing a configuration of a logic circuit according to Example 3.
FIG. 9 is a graph showing characteristics of a two terminal switching device in a logic circuit according to Example 1.
FIG. 10 is a graph showing characteristics of a two terminal switching device in a logic circuit according to Examples 2 and 3.
DETAILED DESCRIPTION
FIG. 1 shows an embodiment of a logic circuit having the simplest and easiest configuration according to the invention. This logic circuit has a configuration that a resistance 2 is connected in series to a two terminal switching device 1 .
The foregoing two terminal switching device 1 has electric characteristics (current-voltage characteristics) as illustrated in FIG. 2 , namely electric characteristics such that it exhibits two stable resistivity values against each applied voltage value; that when a voltage of not more than a threshold voltage Vth 1 is applied, it becomes in a high resistance state (a state to show current-voltage characteristics as illustrated by a reference numeral 11 ); and that when a voltage of a threshold voltage Vth 2 or more is applied, it becomes in a low resistance state (a state to show current-voltage characteristics as illustrated by a reference numeral 12 ). Incidentally, a reference numeral 13 illustrates electric characteristics of the resistance 2 .
In this logic circuit, when a voltage Vt is applied as a direct current bias, two operating points are present corresponding to the foregoing two states of the two terminal switching device 1 . In FIG. 2 , a voltage of each of the operating points at the time when the two terminal switching device 1 becomes in a low resistance state and in a high resistance state is shown as Von and Voff, respectively.
In the low resistance state, when a pulse of (Von−Vth 1 ) is inputted in a pulse inputting R terminal which is present in a connection between the other end of the two terminal switching device 1 and the resistance 2 , the two terminal switching device 1 transits into the high resistance state, whereby a potential of an outputting Q terminal which is present in the foregoing connection changes from (Vt−Von) to (Vt−Voff).
On the other hand, in the high resistance state, when a pulse of (Vth 2 −Voff) is inputted in a pulse inputting S terminal which is present in one end (application point of direct current bias voltage Vt) of the two terminal switching device 1 , the two terminal switching device 1 transits into the low resistance state, and as a result, a potential of the Q terminal changes from (Vt−Voff) to (Vt−Von).
In the case where the both pulses are not inputted, the state of the outputting Q terminal does not change. Furthermore, in the case where the foregoing pulses are inputted in the inputting R and S terminals at the same time, since the both pulses negate each other, the state of the Q terminal does not change, too. Accordingly, when inputs of pulses in the inputting R and S terminals are defined as 1, a non-input is defined as 0, a state value of the current outputting Q terminal is defined as Q n and a state value of the Q terminal immediately after inputting the pulse is defined as Q n+1 , a voltage of the Q terminal changes as shown in Table 1 corresponding to a combination of the input and the non-input of the pulses in the R and S terminals.
Incidentally, with respect to the pulses which are inputted in the R and S terminals, pulses having the same height can be used so far as they meet the respective requirements at the same time.
TABLE 1
S
R
Q n+1
Remark
0
0
Q n
Not changed
1
0
Vt − Von
Set
0
1
Vt − Voff
Reset
1
1
Q n
Not changed
Now, the flip-flop circuit is classified into an RS (reset/set) flip-flop circuit, a JK flip-flop circuit, a T (trigger) flip-flop circuit, and a D (delay) flip-flop circuit depending upon its function (see, for example, Takeo Miyata, Sokkai Logic Circuit , Corona Publishing Co., Ltd. (1998)).
A logical table of the RS flip-flop circuit that is the most basic among them is one as shown in Table 2.
TABLE 2
S
R
Q n+1
Remark
0
0
Q n
Not changed
1
0
1
Set
0
1
0
Reset
1
1
—
Inhibited
In the foregoing Table 1, assuming that the time when the value of the outputting Q terminal is (Vt−Von) is defined as a set state and the time when it is (Vt−Voff) is defined as a reset state, it is clear that the logic circuit of FIG. 1 exhibits the operation of Table 2. At this time, an input of S=R=1 is inhibited.
Incidentally, flip-flop circuits of other types can be configured in combination with a device of other kind based on the RS flip-flop circuit (see the foregoing document).
FIG. 3 shows other embodiment of the logic circuit according to the invention.
The logic circuit as shown in FIG. 3 has a configuration that two terminal switching devices 1 A and 1 B having the electric characteristics of FIG. 2 are connected in series. Logic when, for example, a direct current bias voltage of Vt=(Vth 1 +Vth 2 ) is applied to both ends of this logic circuit and a positive pulse of sufficient voltage is selectively inputted in a pulse inputting S terminal which is present in one end (application point of bias voltage Vt) of the two terminal switching device 1 A, a pulse inputting R terminal which is present in a series connection between the two terminal switching devices 1 A and 1 B and a pulse inputting T terminal which is present in a grounding point is one as shown in Table 3. In this Table 3, states 0 and 1 of the switching devices 1 A and 1 B represent a high resistance state and a low resistance state of those devices, respectively.
TABLE 3
S
R
T
A
B
Q n+1
Remark
0
0
0
Not changed
Not changed
Q n
Not changed
0
0
1
Not changed
0
0
1
0
0
1
1
Reset
0
1
1
0
Not changed
1
0
0
1
Not changed
1
0
1
1
0
0
Set
1
1
0
Not changed
1
1
1
1
Not changed
Not changed
Q n
Not changed
Now, in the case where the same pulse is inputted in the T terminal and the S terminal as shown in FIG. 3 at the same time, this logic circuit exhibits a logical operation as shown in Table 4. The operation of Table 4 is coincident with the operation of Table 1. This demonstrates that the logic circuit of FIG. 3 has a function as the RS flip-flop circuit, too.
TABLE 4
S
R
Q n+1
Remark
0
0
Q n
Not changed
1
0
Vt − Von
Set
0
1
Vt − Voff
Reset
1
1
Q n
Not changed
In the case of this logic circuit, an operating point of the respective switching devices 1 A and 1 B is one as shown in FIG. 4 . As is clear from the comparison between FIG. 2 and FIG. 4 , in the case where the same pulse is inputted in the T terminal and the S terminal of the logic circuit as shown in FIG. 3 at the same time, either one of the switching devices 1 A and 1 B becomes in a high resistance state in all of the set and reset states. Thus, according to this logic circuit, a characteristic feature that a current value is controlled is obtained.
As the two terminal switching devices 1 , 1 A and 1 B related to the invention, a number of devices can be used so far as they have the foregoing functions. For example, there have hitherto been reported Schottky diodes configured of a ferroelectric semiconductor (for example, ZnCdS and SrTiO 3 (doped with 0.2% of Cr)) and metal electrodes and two terminal devices resulting from interposing an organic material of every kind (for example, charge transfer complexes containing CuTCNQ, aminoimidazole based materials, and bisquinomethane based materials) by metal electrodes, and these materials are all useful.
Of these, materials using an inorganic material are easy for integration. Furthermore, since materials using an organic material employ a low-temperature process, they are low in costs, and a plastic substrate can be used. In particular, in order to produce cheap IC tags, merits of the latter are large.
Furthermore, with respect to a wiring between the two terminal switching devices 1 A and 1 B, vapor deposition films with a metal such as aluminum can be used. Furthermore, the foregoing wiring can also be applied by coating or printing of a carbon based conductive material.
As a substrate for forming the switching devices 1 , 1 A and 1 B according to the invention, high molecular weight plastic films such as of polyimides, polyetherimides, polysulfones, polyethersulfones, polyphenylene sulfides, para-type aramids, polyetherketones, polyesters, polycarbonates, amorphous polyolefins, epoxy resins, and fluorine resins can be used as a flexible substrate.
Of these, polyesters or polycarbonates are preferable in view of strength, and polyesters such as polyethylene terephthalate are especially preferable. A thickness of the substrate is preferably from 0.05 mm to 2 mm, and more preferably from 0.1 mm to 1 mm. Furthermore, a non-glass substrate or a silicon substrate can also be used as the flexible substrate.
As a method of forming the organic thin film that configures the two terminal switching devices 1 , 1 A and 1 B, besides vacuum vapor deposition, a coating method can be employed, too. Examples of the coating method include screen printing, casting, and dipping in addition to spin coating and blade coating. Furthermore, there is also enumerated a method in which a thin film is formed by the foregoing appropriate method using a desired low molecular weight precursor or a desired high molecular weight precursor, which is then converted into a desired organic semiconductor layer by a heat treatment or the like.
A coating solution that is used in the foregoing coating method can be prepared by dissolving or dispersing an organic material in a suitable solvent. Though the solvent can be properly selected depending upon the kind of the organic material, for example, THF (tetrahydrofuran) and DCM (dichloromethane) are suitable because they are able to dissolve a number of organic materials therein. Besides, acetonitrile, benzene, butanol, cyclohexane, dichloroethane, ethanol, ethyl acetate, and so on can be used. However, it should not be construed that the solvent is limited thereto.
Furthermore, in the foregoing respective embodiments, an inputting pulse is superimposed on the bias voltage Vt, and a number of methods can be employed for this. For example, when a bilaterally asymmetric pulse 22 as shown in a left side of FIG. 5( b ) is inputted via a series circuit of a resistance 20 and a capacitor 21 with appropriate capacity as shown in FIG. 5( a ), since a displacement current flows in the capacitor 21 corresponding to its asymmetry, it is possible to superimpose a positive or negative pulse 23 as shown in a right side of FIG. 5( b ) on the foregoing bias voltage Vt.
Here, the range of the bias voltage Vt is described. The range of the bias voltage Vt is expressed below based on the relations of (Vt=Von+Voff) and (Vth 1 <Von<Voff<Vth 2 ).
2 Vth 1<( V on+ V off= Vt )< Vth 2
Though a value of the bias voltage Vt can be properly selected within the foregoing range, in general, it is desired to set up its value as small as possible. This is because the smaller the value of the bias voltage Vt, the smaller the current flowing in the logic circuit, resulting in reducing the consumed electricity.
Examples of the invention will be hereunder described in detail.
EXAMPLE 1
A two terminal switching device having a configuration as shown in FIG. 6 was prepared according to the following procedures.
That is, this switching device is configured by successively forming a lower electrode layer 41 , an organic bistable layer 42 and an upper electrode layer 43 , each of which is made of a thin film, on a substrate 40 made of glass.
The lower electrode layer 41 was formed by film forming aluminum on a surface of the substrate; the organic bistable layer 42 was formed by film forming aminoimidazole dicyanate represented by the following chemical formula on the lower electrode layer 41 ; and the upper electrode layer 43 was formed by film forming aluminum on the organic bistable layer 42 , respectively.
The lower electrode layer 41 , the organic bistable layer 42 and the upper electrode layer 43 were film formed so as to have a thickness of about 100 nm, 80 nm and 100 nm, respectively. As a method of this film formation, in the case of employing a vacuum vapor deposition method, a degree of vacuum of a vapor deposition device was set up at approximately 3×10 −6 torr by exhaustion by a diffusion pump.
The vapor deposition of aluminum was carried out at a film formation rate of 3 angstroms/sec by an ohmic heating system; and the vapor deposition of aminoimidazole dicyanate was carried out at a film formation rate of 2 angstroms/sec by an ohmic heating system. At this time, the lower electrode layer 41 and the upper electrode layer 43 were formed such that they were each in a stripe form with a width of about 0.5 mm and that their longitudinal axial lines were orthogonal to each other; and the organic bistable layer 42 was formed so as to cover an intersection point between the lower electrode layer 41 and the upper electrode layer 43 (see FIG. 7 ). Accordingly, an effective area of the two terminal switching device according to this Example 1 is about 0.5×0.5=0.25 mm 2 .
Thereafter, a bias applying electrode 44 and a pulse inputting S terminal 45 were connected to the upper electrode layer 43 ; and a pulse inputting R terminal 46 , a resistance terminal 47 and an outputting Q terminal 48 were connected to the lower electrode layer 41 . A non-illustrated resistance (corresponding to the resistance 2 of FIG. 1 ) is connected to the resistance terminal 47 . In this resistance, its value is set up at, for example, 0.8 MΩ, and its other end is grounded. There was thus obtained a logic circuit of Example 1. An equivalent circuit to this logic circuit is one as shown in FIG. 1 .
EXAMPLE 2
A logic circuit according to this Example 2 is the same as the logic circuit of Example 1, except that a bisquinomethane based compound represented by the following chemical formula was used as the material of the foregoing organic bistable layer 42 and that gold was used as the material of the upper electrode layer 43 .
EXAMPLE 3
As shown in FIG. 8 , a logic circuit according to this Example 3 is provided with two terminal switching devices.
In the respective two terminal switching devices, aluminum is used as a material of each of their lower electrode layers 41 and 411 ; the foregoing bisquinomethane based compound is used as a material of each of their organic bistable layers 42 and 421 ; gold is used as a material of each of their upper electrode layers 43 and 431 , respectively.
In this Example, first of all, the materials for forming the lower electrode layer 41 , the organic bistable layer 42 and the upper electrode layer 43 were successively film formed so as to have a thickness of about 100 nm, 80 nm and 100 nm, respectively, thereby forming a one-sided two terminal switching device.
Thereafter, the lower electrode layer 411 was formed on the upper electrode layer 43 of the foregoing one-sided two terminal switching device (its forming position is deviated towards a right side in FIG. 8 from the position of the lower electrode layer 41 of the one-sided two terminal switching device); and the organic bistable layer 421 and the upper electrode layer 431 corresponding to the foregoing organic bistable layer 42 and the upper electrode layer 43 were further successively formed on this lower electrode layer 411 , thereby forming the other two terminal switching device.]
Incidentally, the materials for forming the lower electrode layer 411 , the organic bistable layer 421 and the upper electrode layer 431 are also film formed so as to have a thickness of about 100 nm, 80 nm and 100 nm, respectively.
The electrode layers 41 and 43 of the foregoing one-sided two terminal switching device are formed such that they were each in a stripe form with a width of about 0.5 mm and that their longitudinal axial lines are orthogonal to each other; and the electrode layers 411 and 431 of the other two terminal switching device are formed in the same form. Furthermore, the organic bistable layer 42 is formed so as to cover an intersection point between the electrode layers 41 and 43 ; and similarly, the organic bistable layer 421 is formed so as to cover an intersection point between the electrode layers 411 and 431 . Accordingly, an effective area of each of the foregoing two terminal switching devices is about 0.5×0.5=0.25 mm 2 .
After forming the foregoing respective two terminal switching devices, a bias applying electrode 44 and a pulse inputting S terminal 45 were connected to the upper electrode layer 431 ; a pulse inputting R terminal 46 and an outputting Q terminal 48 were connected to the lower electrode layer 411 ; and a grounding terminal 50 and a pulse inputting T terminal 49 were connected to the lower electrode layer 41 . Incidentally, the grounding terminal 50 is grounded.
An equivalent circuit to the thus formed logic circuit is one as shown in FIG. 3 .
TEST EXAMPLE 1
Characteristics of the switching device 1 as obtained in the foregoing Example 1 were those as shown in FIG. 9 ; and characteristics of the switching device 1 as obtained in the foregoing Example 2 and characteristics of the respective switching devices as obtained in the foregoing Example 3 were respectively those as shown in FIG. 10 . Incidentally, a bias voltage and a pulse input were given from an external circuit.
One example of a drive condition of the logic circuits according to the foregoing Examples 1, 2 and 3 and values of operating point voltages Von and Voff of the respective logic circuits under this condition were summarized in Table 5. As is clear from this Table 5, it was confirmed that all of the logic circuits according to the Examples exhibited a satisfactory operation as an RS flip-flop circuit.
TABLE 5
(unit: V)
Bias
Pulse
Pulse
Vth/1
Vth2
voltage
voltage S
voltage R
Von
Voff
Example 1
0.5
2.4
2.4
0.7
0.7
1.1
2.0
Example 2
0.5
6.0
3.0
0.7
0.7
1.5
2.5
Example 3
0.5
6.0
3.3
1.0
1.0
0.7
5.2
In the light of above, while preferred embodiments and examples of the invention have been described, it is evident that the technical scope of the invention is not limited by them. | The invention includes a two terminal switching device having two stable resistivity values for each applied voltage, which when a voltage of not more than a first threshold voltage (Vth 1 ) is applied, becomes in a first state having a higher resistivity, whereas when a larger second threshold voltage (Vth 2 ) or more is applied, becomes in a second state having a lower resistivity; a resistance connected in series to the switching device; a terminal for applying a bias voltage (Vt) to both ends of a series circuit of the switching device and the resistance; a first pulse inputting terminal; and a second pulse inputting terminal. The invention provides a simple realization of a flip-flop circuit for a sequential logic circuit. | 7 |
FEDERALLY SPONSORED RESEARCH
[0001] Not Applicable
SEQUENCE LISTING
[0002] Not Applicable
BACKGROUND
[0003] 1. Field of Invention
[0004] This invention relates to trigger systems for rifles, specifically, such systems which are used in lever action or single shot rifles with trigger block safeties.
[0005] 2. Description of Prior Art
[0006] Historically and through the present time, in simplest form, the fire control mechanism of firearms has consisted of a hammer mechanism powered by a spring which serves to strike the igniting charge, together with a trigger mechanism, which releases the hammer. Illustrative examples of the traditional hammer/trigger mechanism in lever action repeating rifles are found in Hepburn, U.S. Pat. Nos. 298,377, 371,455 and 502,489. As can be seen from the foregoing designs, the trigger itself is a one piece unit that pivots back and forth on a pin and is held in place against the hammer cocking surfaces by a spring resting on a flat on the upper backside of the trigger. When the hammer is in the fired or uncocked position, the trigger nose rests on the cocking surfaces of the hammer. As the hammer is cocked, the trigger nose presses itself against the hammer surface via spring pressure against the trigger. The trigger nose continues riding past the safety or half cock notch on the cocking surfaces of the hammer until it reaches the full cock notch. At that time the trigger nose locks into place by spring pressure on the trigger. When the trigger is pulled, the trigger nose slides out of the full cock notch, the hammer drops, and the spring pressure on the trigger causes the trigger to rest again against the hammer cocking surfaces.
[0007] The foregoing trigger/hammer mechanism was improved by Hepburn in U.S. Pat. No. 434,062. The improvement, commonly known as a “trigger block safety” changed the one piece trigger into a combination of a separate trigger and a separate trigger nose, which part is commonly known as a sear. The trigger has a flat on the upper backside with an extension connection on the upper portion that allows the sear to be fitted by way of a slot in the sear body. Both parts fitted together pivot on a pin, so that when the hammer is in the fired or uncocked position, the sear rides against the cocking surfaces of the hammer by way of the pressure from the trigger derived from the trigger spring. As the hammer is cocked, the sear continues to ride against the cocking surfaces of the hammer, held in place by trigger pressure, until the full cock notch is reached. At that time the sear rests in the full cock notch until the trigger is pulled, which drops the sear from the notch causing the hammer to fall. The separate trigger permits a block to be fitted so as to prevent full travel of the trigger and concomitant actuation of the sear against the hammer until such time as the lever actuation mechanism and breech block are fully closed, thereby moving the safety block into a position allowing full travel of the trigger.
[0008] Hepburn's lever action repeating rifles with trigger block safeties continue to be manufactured today. While such triggers provide a means to ensure that the rifle is not fired until the breech is closed and the action fully locked they suffer from a number of disadvantages, specifically:
[0009] a. excessive side play or movement of the trigger in the trigger/sear combination;
[0010] b. excessive movement fore and aft of the trigger in the trigger/ sear combination;
[0011] c. excessive movement of the trigger prior to firing (creep);
[0012] d. excessive pressure on the trigger necessary to disengage the sear.
OBJECTS AND ADVANTAGES
[0013] The objects and advantages of the present invention are:
[0014] a. to provide a trigger mechanism which allows use of the trigger block safety and eliminates excessive side to side play of the trigger in the firearm;
[0015] b. provide a trigger mechanism which allows use of the trigger block safety and eliminates excessive trigger movement fore and aft;
[0016] c. to provide a trigger mechanism which allows use of the trigger block safety while eliminating excessive creep;
[0017] d. to provide a trigger mechanism which allows use of the trigger block safety while eliminating the excessive pressure necessary to disengage the sear.
[0018] Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
DRAWINGS
Drawing Figure
[0019] FIGS. 1 , 1 -A to 1 -C shows the various views of the trigger portion of the trigger system
[0020] FIGS. 2 , 2 -A to 2 -C shows the various views of the bushing portion of the trigger system.
[0021] FIGS. 3 , 3 -A to 3 -C shows the various views of the sear portion of the trigger system
[0022] [0022]FIG. 4 shows the sear placement spring portion of the trigger system.
[0023] [0023]FIG. 5 shows the assembled trigger system, referenced to the hammer.
[0024] [0024]FIG. 6 shows the assembled trigger system installed in the firearm.
Reference Numerals in Drawings
[0025] [0025] 8 Trigger 10 Trigger/Sear connector 12 Trigger through hole 14 Bushing through hole 16 Sear through hole 18 Sear connector slot 20 Bushing surface 22 Sear body 24 Trigger flat 26a Sear placement spring hole 26b Sear placement spring hole
DETAILED DESCRIPTION
[0026] The trigger system is manufactured from any high quality steel in three separate parts. The three are the Trigger, shown in various views in FIGS. 1 , 1 -A through 1 -C; the Bushing, shown in various views in FIGS. 2 , 2 -A through 2 -C: and the Sear, shown in various views in FIGS. 3 , 3 -A through 3 -C.
[0027] The trigger body 8 itself in FIG. 1-A side view and FIGS. 1 -B and 1 -C front and back view is of traditional curved design to permit rearward manipulation by the shooting finger. The trigger body is designed to accept the bushing at 12 , the trigger through hole, which is precision machined through 10 , the trigger sear connector, to accommodate the bushing via a press fit. The trigger/sear connector 10 is beveled or rounded to the same dimensions as the top of the sear body 22 , as in FIGS. 1 -A and 3 -A. The bushing surface 20 in FIGS. 2 and 2-B side view is machined to precisely fit into the trigger through hole 12 and the sear through hole 16 when assembled. The bushing through hole 14 in FIG. 2-B front view is machined to permit insertion of a pin to hold the entire assembly in place.
[0028] The sear body 22 in FIG. 3-A side view has a machined sear through hole 16 . The sear connector slot 18 in FIG. 3-B top view and 3 -C bottom view is machined to accept the trigger/sear connector. Sear body placement spring holes 26 a and 26 b in bottom view FIG. 3-C are machined to accept the sear placement spring, FIG. 4.
[0029] To assemble the system, the sear placement springs FIG. 4 fit into the sear placement spring holes 26 a and 26 b in the sear body 22 . The sear connector 10 on the trigger body 8 is fitted inside the sear body 22 by means of the sear connector slot 18 , so that the sear placement springs are exerting pressure on both the trigger body 8 and the sear body 22 at the trigger flat 24 . The parts as thus assembled are held in place as one unit when the FIG. 2 bushing is pressed through the trigger through hole 12 , which is riding inside the sear through hole 16 . The assembled mechanism is shown in perspective to the hammer in FIG. 5.
Advantages
[0030] From the description, above, a number of advantages of the present invention become evident.
[0031] 1. The rounding of the trigger/sear connector to the same dimensions of the sear body allows more precise alignment of the trigger system parts when assembled and eliminates any drag or interference on the hammer of the firearm while the mechanism goes through the cocking/firing cycle.
[0032] 2. The use of a bushing to hold all parts in place allows for precision assembly of the separate trigger and sear thereby eliminating side play, vertical play, looseness and binding or drag on the sear.
[0033] 3. The close fit of parts that is made possible by use of a separate bushing eliminates creep and excessive pressure necessary to release the hammer.
[0034] 4. The use of the placement springs provides upward and downward spring pressure on the sear and trigger thereby eliminating uncontrolled fore and aft trigger movement
Operation
[0035] The operation of the trigger system designed here is similar to those presently in use and accordingly, can be used to replace the systems presently in use without modification to the firearm merely by removing the old system and reinstalling the new system on an existing trigger/sear pin. Rearward pressure on the trigger body 8 causes the sear body 22 to pivot forward around the trigger/sear pin thereby moving the sear out of the full cock notch, allowing the hammer to go forward. Unlike present systems, the sear body 22 pivots while assembled into the trigger body 8 via the trigger through hole 16 and the bushing, so that the sear body and the bushing move as one unit.
Conclusion, Ramification and Scope
[0036] Accordingly, the reader will see that the Safety Precision Trigger System is easily installed into currently produced firearms that utilize the trigger block safety as designed by Hepburn in U.S. Pat. No. 434,062. The Safety Precision Trigger System allows use of the trigger safety while controlling fore and aft play of the trigger body, with the added advantage that trigger creep and trigger pull are reduced.
[0037] Although the description above contains many specificities, these should not be construed as limiting the scope of the invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | An improved trigger system for lever action rifles that utilize a trigger block safety, comprising a trigger, sear, bushing and springs. The trigger, sear, bushing and springs are assembled as one unit permitting the user to fit the trigger system into an existing rifle without modification. The system eliminates looseness, play, creep and drag found in existing systems. | 5 |
TECHNICAL FIELD
[0001] This disclosure relates to the engineering of phototrophic microorganisms for conversion of alkanes into high-value products. In particular, this disclosure relates to the production of alcohols such as butanols from methane using recombinant phototrophic organisms such as cyanobacteria.
BACKGROUND
[0002] The increasing reserves of natural gas combined with its availability in different geographical locations have generated a great interest in development of processes for its economical transformation into energy-dense liquid transportation fuel and products. Methane is the principal component of natural gas and thus development of economical and sustainable strategies for utilization of methane is of significance. A well-recognized process is oxidative transformation of methane into methanol. Partial oxidation of methane to synthesis gas followed by the Fischer-Tropsch chemistry is a well established chemical transformation process. However, it involves multiple components which results in high capital costs and the conversion efficiency is generally poor. This limits its utility only in geographical locations with large natural gas reserves.
[0003] Although methanotrophs belonging to alpha- and gamma-proteobacteria are known to utilize methane as a sole source of carbon and energy, there are many challenges in the use of methanotrophs based bioprocess technology for production of high-value products from methane. These organisms obtain the necessary energy for metabolic activities including the initial oxidation of methane by converting a large amount of methane into CO 2 which results in loss of methane and generation of greenhouse gas. Therefore, there are great challenges in leveraging these organisms for commercial applications to convert natural gas into products useful in petrochemical, material and energy industries.
SUMMARY
[0004] Provided herein are recombinant phototrophic microorganisms, comprising one or more alkane oxidation genes whose expression results in oxidation of alkanes and assimilation of the resulting products into the central metabolic pathways in phototrophic organisms such as cyanobacteria. The one or more alkane oxidation genes can be an alkane monooxygenase, an alcohol dehydrogenase or an aldehyde assimilatory gene. The recombinant photosynthetic organism converts the entire feed of alkane into the targeted product because it uses sunlight to provide energy and oxygen needed for oxidation of alkanes. Having the ability to couple oxidation of alkanes such as methane with sunlight in the recombinant phototrophic organism and energy can allow molecules of interest (e.g., butanol) to be produced biologically from natural gas in an efficient and cost effective manner. Because the recombinant phototrophic organism converts alkanes into metabolic products that are natively part of central metabolic pathway of all living organisms, the recombinant photosynthetic microorganisms or organisms provided herein can be further genetically modified with previously known polypeptides in the art whose expression converts metabolites from central metabolic pathways into several molecules including, but not limited to, amino acids, alcohols, dicarboxylic acids, fatty acids, energy-dense molecules and other molecules useful in petrochemical, material and energy industries efficiently and at high levels. Production processes involving phototrophic microorganisms are carried out under moderate conditions, use simpler and potentially more selective reactions, and have the potential to be operationally implemented at different scales for economical production of energy-dense transportation fuels at different geographical locations.
[0005] In one aspect, provided herein is a recombinant phototrophic microorganism, comprising one or more genes encoding a methane monooxygenase (MMO). The MMO can be a particulate MMO, and the one or more genes can comprise coding sequences for polypeptides having the amino acid sequences of Methylococcus capsulatus Bath PmoA, PmoB, and PmoC. The MMO can be a soluble MMO and the one or more genes can comprise coding sequences for an MmoX polypeptide; an MmoY polypeptide, an MmoB polypeptide, an MmoZ polypeptide, an MmoD, and an MmoC polypeptide. The expression of said one or more genes in the recombinant microorganism can result in the production of methanol; ethanol; propanol, or n-butanol, when the microorganism is grown in the presence of light and O 2 in a medium comprising methane, ethane, propane or butane, respectively.
[0006] The recombinant microorganism can further include a methanol dehydrogenase or a human class I alcohol dehydrogenase; a hexulose-6-phosphate synthase and a 6-phosphate-3-hexuloisomerase; and recombinant genes encoding an acetyl-CoA acetyltransferase polypeptide; a 3-hydroxybutyryl-CoA dehydrogenase polypeptide; a 3-hydroxybutyryl-CoA dehydratase (crotonase) polypeptide; an aldehyde/alcohol dehydrogenase polypeptide; and a trans-enoyl-CoA reductase polypeptide. Expression of these genes in the microorganism can result in the production of n-butanol when the microorganism is grown in the presence of light and 02 in a medium comprising methane.
[0007] In another aspect, also provided herein is a recombinant phototrophic microorganism, comprising one or more genes encoding a methanol dehydrogenase (MDH) or a human class I alcohol dehydrogenase. The one or more genes can be a gene encoding a human class I ADH1A, ADH1B, and ADH1C alcohol dehydrogenase. The recombinant microorganism can be a strain of cyanobacterium or algae, e.g., a Synechocystis species. The one or more genes can comprise a gene encoding a polypeptide having the amino acid sequence of an NAD-dependent MDH from methylotrophic Bacillus methanolicus . The recombinant microorganism can further include a gene encoding a hexulose-6-phosphate synthase (HPS) and a gene encoding a 6-phosphate-3-hexuloisomerase (PHI), and be capable of growth in media containing 2% (v/v) methanol. In addition to a gene encoding a hexulose-6-phosphate synthase and a gene encoding a 6-phosphate-3-hexuloisomerase, such a recombinant microorganism can further include recombinant genes encoding an acetyl-CoA acetyltransferase polypeptide; a 3-hydroxybutyryl-CoA dehydrogenase polypeptide; a 3-hydroxybutyryl-CoA dehydratase (crotonase) polypeptide; an aldehyde/alcohol dehydrogenase polypeptide; and a trans-enoyl-CoA reductase polypeptide. Expression of such genes in the microorganism can result in the production of n-butanol when the microorganism is grown in the presence of light and O 2 in a medium comprising methanol.
[0008] In another aspect, also provided herein is a recombinant phototrophic microorganism, comprising one or more genes encoding a hexulose-6-phosphate synthase (HPS) or a 6-phosphate-3-hexuloisomerase (PHI). At least one of the HPS and PHI genes can encode a polypeptide having the amino acid sequence of an HPS or PHI from Methylococcus capsulatus, Bacillus methanolicus , or Pyrococcus horikoshii . The recombinant phototrophic microorganism can be capable of growth in media containing 15 mM formaldehyde. The rate of growth of the microorganism in media containing 15 mM formaldehyde can be about 88% or more, relative to the rate of growth of the microorganism in corresponding media containing no added formaldehyde. The amount of formaldehyde in supernatant from media in which the microorganism has been cultured can be about 4-fold less than the amount of formaldehyde in supernatant from media in which isogenic control cells have been cultured. The recombinant microorganism can further comprise a gene encoding a phosphoribulokinase, and/or can further comprise one or more genes encoding a phosphoribulokinase; a transketolase, a transaldolase, and/or a sedoheptulose-1,7-bisphosphatase. The microorganism can be a strain of cyanobacterium or alga, such as a Synechocystis species.
[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a bar graph showing the optical density of Synechocystis cultures at 0 days and at 7 days of growth after 7 days of growth at 30° C. in media containing different concentrations of methanol. Optical density was monitored by measuring absorbance at 730 nm. WT=wild type Synechocystis strain lacking MDH and ACT genes; BM-mdh= Synechocystis strain expressing MDH gene; BM-mdh-act Synechocystis strain expressing MDH and ACT genes.
[0011] FIG. 2 is a bar graph showing the formaldehyde concentration (as measured by absorbance at 412 nm) in supernatants of Synechocystis cultures after 1 day of growth at 30° C. in media containing formaldehyde. C=no cells; WT=wild type Synechocystis cells; MSI=cells of a recombinant Synechocystis strain expressing Methylococcus capsulatus HPS and PHI genes.
DESCRIPTION OF THE SEQUENCE LISTING
[0012]
[0000]
Genbank No.
Species
SEQ ID NO:
GI: 53804130
Methylococcus capsulatus
1
GI: 7188931
Methylosinus trichosporium
2
GI: 427190913
Methylohalobius crimeensis
3
GI 357403888
Methylomicrobium alcaliphilum
4
GI: 402774099
Methylocystis sp.
5
GI: 223717937
Methylococcaceae bacterium
6
GI: 224967033
Methylomarinum vadi
7
GI: 7188938
Methylocystis sp.
8
GI: 7188933
Methylosinus trichosporium
9
GI: 83308654
uncultured bacterium
10
GI: 189219600
Methylacidiphilum infernorum
11
GI: 83308708
Methylocapsa acidiphila
12
GI:53804139
Methylococcus capsulatus
13
GI 7188932
Methylosinus trichosporium
14
GI 189219602
Methylacidiphilum infernorum
15
GI 83308706
Methylocapsa acidiphila
16
GI 357403887
Methylomicrobium alcaliphilum
17
GI 402774098
Methylocystis sp.
18
GI 6013166
Methylocystis sp.
19
GI 53758445
Methylococcus capsulatus
20
GI 73745618
Methylosinus trichosporium
21
GI 89572582
Methylomicrobium japanense
22
GI 74381909
Methylocella silvestris
23
GI 5102756
Methylosinus trichosporium
24
GI 88656492
Methylosinus sporium
25
GI 6013167
Methylocystis sp.
26
GI 53804675
Methylococcus capsulatus
27
GI 306921972
Methylovulum miyakonense
28
GI 73745619
Methylosinus trichosporium
29
GI 2098696
Methylocystis sp.
30
GI 88656493
Methylosinus sporium
31
GI 6013168
Methylocystis sp.
32
GI 6002406
Methylomonas sp.
33
GI 7770068
Methylococcus capsulatus
34
GI 89572584
Methylomicrobium japanense
35
GI 53804674
Methylococcus capsulatus
36
GI 306921973
Methylovulum miyakonense
37
GI 73745620
Methylosinus trichosporium
38
GI 88656494
Methylosinus sporium
39
GI 6013169
Methylocystis sp.
40
GI 7770067
Methylococcus capsulatus
41
GI 53804672
Methylococcus capsulatus
42
GI 19855848
Methylococcus capsulatus
43
GI 306921974
Methylovulum miyakonense
44
GI 73745621
Methylosinus trichosporium
45
GI 88656496
Methylosinus sporium
46
GI 6013171
Methylocystis sp.
47
GI 21362649
Methylosinus trichosporium
48
GI 18266834
Methylococcus capsulatus
49
GI 245216
Methylosinus trichosporium
50
GI 7770065
Methylococcus capsulatus
51
GI 53804670
Methylococcus capsulatus
52
GI 73745623
Methylosinus trichosporium
53
GI 88656495
Methylosinus sporium
54
GI 141050
Methylococcus capsulatus
55
GI 21362648
Methylosinus trichosporium
56
GI 53804671
Methylococcus capsulatus
57
GI 53758432
Methylococcus capsulatus
58
GI 74381913
Methylocella silvestris
59
GI 462590
Bacillus methanolicus
60
GI 41057056
Bacillus methanolicus
61
GI 387585284
Bacillus methanolicus
62
GI 143175
Bacillus sp.
63
GI 22654852
Bacillus methanolicus
64
GI 4501929
Homo sapiens
65
GI 50960621
Homo sapiens
66
GI 34577061
Homo sapiens
67
GI 4501933
Homo sapiens
68
GI 53802837
Methylococcus capsulatus
69
GI 170781838
Clavibacter michiganensis subsp.
70
GI 53756598
Methylococcus capsulatus str.
71
GI 169156406
Clavibacter michiganensis subsp.
72
GI 49482799
Staphylococcus aureus subsp.
73
GI 15923560
Staphylococcus aureus subsp.
74
GI 56416177
Salmonella enterica subsp.
75
GI 56415567
Salmonella enterica subsp.
76
GI 89089643
Bacillus sp.
77
GI 40074227
Bacillus methanolicus
78
GI 333985721
Methylomonas methanica
79
GI 53756597
Methylococcus capsulatus str.
80
GI 390191152
Desulfurococcus fermentans
81
GI 327400808
Archaeoglobus veneficus
82
GI 373906366
Methanoplanus limicola
83
GI 544229974
Lactobacillus brevis
84
GI 410600419
Methanobacterium sp.
85
GI 18976592
Pyrococcus furiosus
86
GI 20905670
Methanosarcina mazei
87
GI 124363810
Methanocorpusculum labreanum
88
GI 124363357
Methanocorpusculum labreanum
89
GI 351717933
Methylomicrobium alcaliphilum
90
GI 18892157
Methylomicrobium alcaliphilum
91
GI 387585261
Bacillus methanolicus
92
GI 387587408
Bacillus methanolicus
93
GI 14591680
Pyrococcus horikoshii
94
GI 387587407
Bacillus methanolicus
95
DETAILED DESCRIPTION
[0013] This document provides methods and materials to metabolically engineer photosynthetic organisms such as cyanobacteria, such that oxidation of alkanes is coupled with energy derived from sunlight for cost-effective biological conversion of such alkanes into high-value products (e.g., butanol). The ability of the engineered microorganism to utilize sunlight as the source of energy for metabolic activities provides a method to convert the entire feed of alkane into targeted product while ability of the recombinant phototrophic organism to provide photosynthetically produced oxygen from water as an in situ generated substrate for the activation of alkane reduces the equipment cost.
[0014] This document provides methods and materials for using recombinant phototrophic organisms (e.g., cyanobacteria such as a Synechocystis species) designed to express a polypeptide having alkane monooxygenase activity that is localized to either the cytoplasmic membrane or in soluble form that converts alkanes into their respective alcohols (e.g., methane into methanol) or both i.e., a recombinant organism can carry both forms of alkane monooxygenase activity. As described herein, polypeptides (e.g., polypeptides having enzymatic activity) can be designed to include a membrane-targeting sequence that allows the polypeptide to be localized to a membrane. Similarly, a polypeptide having alcohol dehydrogenase activity can be expressed that converts alcohols into their respective aldehydes (e.g., methanol to formaldehyde), and a polypeptide having aldehyde assimilation activity that converts an aldehyde into a metabolite of central metabolic pathways (e.g., formaldehyde into 3-phosphoglycerate). The ability of the engineered phototrophic organisms to convert alkanes such as methane into intermediates of a central metabolic pathway allows one to produce any products including, but not limited to, amino acids, alcohols, dicarboxylic acids, fatty acids, and energy-dense molecules from the alkanes efficiently and at high levels.
[0015] As used herein, the term recombinant microorganism refers to a microorganism, the genome of which has been augmented by at least one incorporated DNA sequence. Such DNA sequences include but are not limited to genes that are not naturally present, DNA sequences that are not normally transcribed into RNA or translated into a protein (“expressed”), and other genes or DNA sequences which one desires to introduce into the non-recombinant microorganism. It will be appreciated that typically the genome of a recombinant microorganism described herein is augmented through the stable introduction of one or more recombinant genes that are not originally resident in the microorganism that is the recipient of the DNA. However, it is within the scope of the invention to isolate a DNA segment from a given microorganism, and to subsequently introduce one or more additional copies of that DNA back into the same microorganism, e.g., to enhance production of the product of a gene or alter the expression pattern of a gene. In some instances, the introduced DNA will modify or even replace an endogenous gene or DNA sequence by, e.g., homologous recombination or site-directed mutagenesis.
[0016] The term “recombinant gene” refers to a gene or DNA sequence that is introduced into a recipient microorganism, regardless of whether the same or a similar gene may already be present in such a microorganism. “Introduced,” or “augmented” in this context, is known in the art to mean introduced or augmented by the hand of man. Thus, a recombinant gene may be a DNA sequence from another species, or may be a DNA sequence that originated from or is present in the same species, but has been incorporated into a microorganism by genetic engineering methods to form a recombinant microorganism. It will be appreciated that a recombinant gene that is introduced into a microorganism can be identical to a DNA sequence that is normally present in the microorganism being transformed, and is introduced to provide one or more additional copies of the DNA to thereby permit overexpression or modified expression of the gene product of that DNA. Recombinant genes typically encode one or more polypeptides.
[0017] It will be appreciated that functional homologs of the said polypeptides are also suitable for use in generation of the said recombinant microorganism. A functional homolog is a polypeptide that has sequence similarity to a reference polypeptide, and that carries out one or more of the biochemical or physiological function(s) of the reference polypeptide. A functional homolog and the reference polypeptide may be natural occurring polypeptides, and the sequence similarity may be due to convergent or divergent evolutionary events. As such, functional homologs are sometimes designated in the literature as homologs, or orthologs, or paralogs. Variants of a naturally occurring functional homolog, such as polypeptides encoded by mutants of a wild type coding sequence, may themselves be functional homologs. Functional homologs can also be created via site-directed mutagenesis of the coding sequence for a polypeptide, or by combining domains from the coding sequences for different naturally-occurring polypeptides (“domain swapping”). Functional homologs can also be created via site-directed mutagenesis of the coding sequence for a naturally occurring polypeptide, or by combining domains from the coding sequences for different naturally-occurring polypeptides (“domain swapping”). Techniques for modifying genes encoding functional polypeptides described herein are known and include, inter alia, directed evolution techniques, site-directed mutagenesis techniques and random mutagenesis techniques, and can be useful to increase specific activity of a polypeptide, alter substrate specificity, alter expression levels, alter subcellular location, or modify polypeptide:polypeptide interactions in a desired manner. Such modified polypeptides are considered functional homologs. The term “functional homolog” is sometimes applied to the nucleic acid that encodes a functionally homologous polypeptide.
[0018] Functional homologs can be identified by analysis of nucleotide and polypeptide sequence alignments. For example, performing a query on a database of nucleotide or polypeptide sequences can identify homologs of the said polypeptides such as alkane monooxygenase. Sequence analysis can involve BLAST, Reciprocal BLAST, or PSI-BLAST analysis of nonredundant databases using an alkane monooxygenase polypeptide amino acid sequence as the reference sequence. Amino acid sequence is, in some instances, deduced from the nucleotide sequence. Those polypeptides in the database that have greater than 40% sequence identity are candidates for further evaluation for suitability as a polypeptide representing specific function described in this invention. Amino acid sequence similarity allows for conservative amino acid substitutions, such as substitution of one hydrophobic residue for another or substitution of one polar residue for another. If desired, manual inspection of such candidates can be carried out in order to narrow the number of candidates to be further evaluated. Manual inspection can be performed by selecting those candidates that appear to have domains present in the said polypeptides, e.g., conserved functional domains.
[0019] Conserved regions can be identified by locating a region within the primary amino acid sequence of the said polypeptide that is a repeated sequence, forms some secondary structure (e.g., helices and beta sheets), establishes positively or negatively charged domains, or represents a protein motif or domain. See, e.g., the Pfam web site describing consensus sequences for a variety of protein motifs and domains on the World Wide Web at sanger.ac.uk/Software/Pfam/ and pfam.janelia.org/. A description of the information included at the Pfam database is described in Sonnhammer et al., Nucl. Acids Res., 26:320-322 (1998); Sonnhammer et al., Proteins, 28:405-420 (1997); and Bateman et al., Nucl. Acids Res., 27:260-262 (1999). Conserved regions also can be determined by aligning sequences of the same or related polypeptides from closely related species. Closely related species preferably are from the same family. In some embodiments, alignment of sequences from two different species is adequate.
[0020] Typically, polypeptides that exhibit at least about 40% amino acid sequence identity are useful to identify conserved regions. Conserved regions of related polypeptides exhibit at least 45% amino acid sequence identity (e.g., at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% amino acid sequence identity). In some embodiments, a conserved region exhibits at least 92%, 94%, 96%, 98%, or 99% amino acid sequence identity.
[0021] It will be appreciated that functional homologs of the polypeptides described below are also suitable for use in generation of a recombinant microorganism in which functional expression of the said polypeptides enables the recombinant microorganism to utilize alkane as a sole source of carbon and energy.
Alkane Oxidation Polypeptides
[0022] Alkanes can be oxidized by a number of enzymes including methane monooxygenase (MMO), alkene monooxygenase and cytochrome P450s. There are two known forms of MMO: a cytoplasmic membrane localized form known as particulate MMO (pMMO) (EC 1.14.18.3) and a cytoplasmic soluble form known as soluble MMO (sMMO) (EC 1.14.13.25). Both MMOs are able to break the C—H bonds present in alkanes, although their structure, subunit composition and catalytic mechanism are different. Most methanotrophs contain only pMMO but some also have both pMMO and sMMO.
[0023] pMMOs are generally more selective in their ability to react with various substrates whereas sMMOs generally are able to react with a broader range of substrates. sMMOs typically can utilize hydrocarbons up to C8 as substrates, including aromatic and chlorinated hydrocarbons. pMMO is composed of three polypeptides (PmoA, PmoB and PmoC) and the active form of the enzyme is in a (αβγ) 3 configuration. The nucleic acids encoding pMMO subunits typically are part of a conserved operon among methanotrophs. Some methanotrophs contain a single copy of the operon whereas others contain multiple copies. Multiple pmo operon clusters in a single methanotroph often encode divergent pMMO enzymes that have varying reaction rates for oxidation of methane into methanol.
[0024] It have been suggested that the active site of pMMO may contain either diiron, tricopper or dicopper centers depending on the methanotrophic organism. Recent crystal structures of certain pMMOs indicate that a dicopper center in the soluble cupridoxin domains in PmoB is involved in methane hydroxylation. The soluble domain of PmoB expressed in E. coli can catalyze propylene epoxidation and methane oxidation. PmoA and PmoC also contain metals (zinc in PmoA and PmoC subunits from Methylococcus capsulatus Bath and iron in PmoA and PmoC subunits from Methylosinus trichosporium OB3b).
[0025] Methanotrophs have developed specialized mechanisms to mobilize and acquire copper from their environment for pMMO function. A small chromopeptide known as methanobactin is involved in copper delivery to pMMO. Thus, in some embodiments, the open reading frames in the methanobactin biosynthetic gene cluster can be codon optimized for a desired phototrophic microorganism, and the optimized sequences introduced into and expressed in that microorganism, thereby facilitating copper acquisition for pMMO activity. Although the involvement of copper in function of pMMO has been universally recognized, not all methanotrophs appear to have methanobactin. This suggests that alternate systems can be utilized to acquire and deliver copper to pMMO.
[0026] PmoA is one of the three polypeptides of pMMO and has been suggested to be involved in stabilization of pMMO as well as a role in electron transfer from electron carrier to the active site. Examples of the pmoA sequences can be found under the following GenBank accession numbers: YP — 114235.1 (GI: 53804130), AAA87220.2 (GI: 7188931), BAM71040.1 (GI: 427190913), YP — 004915812.1 (GI: 357403888), YP — 006593636.1 (GI: 402774099), BAH22845.1 (GI: 223717937), BAF62077.2 (GI: 224967033).
[0027] PmoB is another of the three polypeptides of pMMO. This polypeptide contains the active center where actual methane hydroxylation takes place. Various pmoB sequences can be found under the following GenBank accession numbers: AAF37897.1 (GI: 7188938), AAF37894.1 (GI: 7188933), CAJ01562.1 (GI: 83308654), YP — 001940241.1 (GI: 189219600), CAJ01618.1 (GI: 83308708), YP — 114234.1 (GI: 53804139).
[0028] PmoC is the third of the three polypeptides of pMMO. It has been suggested that PmoC is involved in stabilization of pMMO as well as having a role with electron transfer. Various pmoC sequences can be found under the following GenBank accession numbers: AAF37893.1 (GI: 7188932), YP — 001940243.1 (GI: 189219602), CAJ01616.1 (GI: 83308706), YP — 004915811.1 (GI: 357403887), YP — 006593635.1 (GI: 402774098).
[0029] sMMO (EC 1.14.13.25) is a multi-component enzyme containing a hydroxylase component, a reductase component and a regulatory component. The hydroxylase component is composed of three subunits in a (αβγ) 2 configuration. The catalytic site of sMMO resides on a subunit of the hydroxylase component and contains a carboxylate-bridged diiron center. The reductase component contains an FAD and [2Fe-2S] ferredoxin domains and provides electrons to hydroxylase by oxidizing NADH to NAD + . The regulatory component has been suggested to be involved in regulation of electron flow from the reductase component to the hydroxylase component.
[0030] Coding sequences for sMMO are organized in a conserved cluster and contain the following genetic loci: mmoX (encodes a subunit of hydroxylase component), mmoY (encodes β subunit of hydroxylase component), mmoB (encodes regulatory component), mmoZ (encodes γ subunit of hydroxylase component), mmoD (encodes a polypeptide of unknown function), and mmoC (encodes the reductase component).
[0031] The MmoX polypeptide is one of the subunits of the hydroxylase component of sMMO. It contains the active center which lies in a four-helix bundle. Examples of the mmoX sequences can be found under the following GenBank accession numbers: AAF01268.1 (GI: 6013166), AAU92736.1 (GI: 53758445), AAZ81968.1 (GI: 73745618), BAE86875.1 (GI: 89572582), CAJ26291.1 (GI: 74381909), CAA39068.2 (GI: 5102756).
[0032] The MmoY polypeptide is another of the subunits of the hydroxylase component of sMMO. Various mmoY sequences can be found under the following GenBank accession numbers: ABD46893.1 (GI: 88656492), AAF01269.1 (GI: 6013167), YP — 113660.1 (GI: 53804675), BAJ17646.1 (GI: 306921972), AAZ81969.1 (GI: 73745619), AAC45290.1(GI: 2098696).
[0033] The MmoB polypeptide is the regulatory component. It regulates transfer of electrons from component C to the hydroxylase component. Various mmoB sequences can be found under the following GenBank accession numbers: ABD46894.1 (GI: 88656493), AAF01270.1 (GI: 6013168), BAA84759.1 (GI: 6002406), AAF04158.2 (GI: 7770068), BAE86877.1 (GI: 89572584), YP — 113661.1 (GI: 53804674), BAJ17647.1 (GI: 306921973), AAZ81970.1 (GI: 73745620).
[0034] The MmoZ polypeptide is the third of the subunits of the hydroxylase component of sMMO. Various mmoZ sequences can be found under the following GenBank accession numbers: ABD46895.1 (GI: 88656494), AAF01271.1 (GI: 6013169), AAF04157.2 (GI: 7770067), YP — 113663.1 (GI: 53804672), P11987.4 (GI: 19855848), BAJ17648.1 (GI: 306921974), AAZ81971.1 (GI: 73745621).
[0035] The MmoC polypeptide is the reductase component. It contains FAD and a [2Fe-2S] cluster and is involved in transfer of electrons from NADH to the hydroxylase component. Various mmoC sequences can be found under the following GenBank accession numbers: ABD46897.1 (GI: 88656496), AAF01273.1 (GI: 6013171), Q53563.1 (GI: 21362649), P22868.2 (GI: 18266834), AAB21393.1 (GI: 245216), AAB62391.2 (GI: 7770065), YP — 113665.1 (GI: 53804670), AAZ81973.1 (GI: 73745623).
[0036] The MmoD polypeptide is suggested to be involved in regulation of sMMO by sensing the availability of copper. Various mmoD sequences can be found under the following GenBank accession numbers: ABD46896.1 (GI: 88656495), P22867.1 (GI: 141050), Q53562.1 (GI: 21362648), YP — 113664.1 (GI: 53804671), AAU92723.1 (GI: 53758432), CAJ26295.1 (GI: 74381913).
Methanol Dehydrogenase
[0037] Conversion of methanol into formaldehyde can be accomplished by methanol dehydrogenase (MDH). Multiple classes of methanol dehydrogenases are known including pyrroloquinoline quinone (PQQ) dependent MDH found in the Gram negative methanotrophs and methylotrophs, NAD-dependent MDH in methylotrophic Bacillus strains, and class I alcohol dehydrogenase (ADH) in human and other animals. In methylotrophic yeast, oxidation of methanol is carried out by alcohol oxidase along with catalase in peroxisomes. Alcohol oxidase consists of eight identical subunits with each subunit containing one FAD as prosthetic group. PQQ-MDH is localized in periplasm and contains two subunits forming α 2 β 2 structure. The entire biosynthetic pathway for synthesis of PQQ and MDH subunits is part of a large cluster containing at least 10 genes.
[0038] Methylotrophic Bacillus strains contain an NAD-dependent MDH enzyme which consists of 10 subunits of an identical polypeptide. Class I ADH is another diverse group of enzymes that can catalyze conversion of methanol into formaldehyde using NAD as cofactor. Human class I ADH enzymes can exist in either the homodimer or the heterodimer form of α, β, and γ subunits encoded by ADH1A, ADH1B and ADH1C genes.
[0039] Methanol dehydrogenase or alcohol dehydrogenase genes encode polypeptides that convert methanol into formaldehyde. Various mdh or adh sequences can be found under the following GenBank accession numbers: P31005.3 (GI: 462590), NP — 957659.1 (GI: 41057056), EIJ77618.1 (GI: 387585284), AAA22593.1 (GI: 143175). Additional polypeptides that provide a regulatory function can also be included if desired. Sequences for such polypeptides can be found under the following GenBank accession numbers: AAM98772.1 (GI: 22654852) Various class I adh sequences can be found under the following GenBank accession numbers: NP — 000658.1 (GI: 4501929), AAH74738.1 (GI: 50960621), NP — 000659.2 (GI: 34577061), NP — 000660.1 (GI: 4501933).
Assimilation of Formaldehyde
[0040] Assimilation of formaldehyde in methanotrophic and methylotrophic organisms is accomplished primarily by two pathways: the serine pathway and the RuMP pathway. In the serine pathway, formaldehyde reacts with glycine to form serine. It goes through a series of cyclic reactions leading to the production of 3-phosphoglycerate. The net balance of serine cycle is the fixation of two molecules of formaldehyde and 1 molecule of CO 2 into 1 molecule of 3-phosphoglycerate using 2 molecules each of ATP and NAD(P)H.
[0041] In the RuMP pathway, formaldehyde is condensed with D-ribulose 5-phosphate by hexulose-6-phosphate synthase (HPS) to form hexulose 6-phosphate which is then isomerized by 6-phosphate-3-hexuloisomerase (PHI) to form D-fructose 6-phosphate. The product of PHI is fed into the central metabolic pathway via the reductive pentose phosphate pathway. HPS and PHI are mostly unique to methanotrophs. The overall reaction is the fixation of three molecules of formaldehyde into 1 molecule of 3-phosphoglycerate using 1 molecule of ATP.
[0042] Various hps sequences can be found under the following GenBank accession numbers: YP — 115430.1 (GI: 53802837), YP — 001710170.1 (GI: 170781838), AAU90889.1 (GI: 53756598), CAQ01554.1 (GI: 169156406), YP — 040023.1 (GI: 49482799), NP — 371094.1 (GI: 15923560), YP — 153252.1 (GI: 56416177), YP — 152642.1 (GI: 56415567), EAR68750.1 (GI: 89089643), AAR39392.1 (GI: 40074227).
[0043] Various phi sequences can be found under the following GenBank accession numbers: YP — 004514931.1 (GI: 333985721), AAU90888.1 (GI: 53756597), AFL66208.1 (GI: 390191152), YP — 004341647.1 (GI: 327400808), EHQ34470.1 (GI: 373906366), ERK43186.1 (GI: 544229974), EKQ54947.1 (GI: 410600419).
[0044] In some cases, HPS and PHI enzymatic activities are present in a single polypeptide. Various hps-phi sequences can be found under the following GenBank accession numbers: NP — 577949.1 (GI: 18976592), AAM30911.1 (GI: 20905670), ABN07618.1 (GI: 124363810), ABN07165.1 (GI: 124363357), CCE23598.1 (GI: 351717933), AAL80344.1 (GI: 18892157).
[0045] The RuMP pathway is energetically more efficient compared to the serine pathway. This is also reflected in the growth yield experimentally established for organisms utilizing either RuMP pathway (˜0.55 CDW/g methanol) or serine pathway (˜0.4 g CDW/g methanol). Most methanotrophs contain separate genes for HPS and PHI, however, Archaeon Pyrococcus horikoshii contains a single gene encoding both functions.
Genes
[0046] A gene encoding a polypeptide described herein comprises the coding sequence for that polypeptide, operably linked in sense orientation to one or more regulatory regions suitable for expressing the polypeptide. Because many microorganisms are known to encode multiple proteins of a pathway in a polycistronic unit, multiple polypeptides can be expressed under the control of a single regulatory region for those microorganisms, if desired. A coding sequence and a regulatory region are considered to be operably linked when the regulatory region and coding sequence are positioned so that the regulatory region is effective for regulating transcription or translation of the sequence. Typically, the translation initiation site of the translational reading frame of the coding sequence is positioned between one and about fifty nucleotides downstream of the regulatory region for a monocistronic gene.
[0047] “Regulatory region” refers to a nucleic acid having nucleotide sequences that influence transcription or translation initiation and rate, and stability and/or mobility of a transcription or translation product. Regulatory regions include, without limitation, promoter sequences, enhancer sequences, response elements, protein recognition sites, inducible elements, protein binding sequences, 5′ and 3′ untranslated regions (UTRs), transcriptional start sites, termination sequences, polyadenylation sequences, introns, and combinations thereof. A regulatory region typically comprises at least a core (basal) promoter. A regulatory region also may include at least one control element, such as an enhancer sequence, an upstream element or an upstream activation region (UAR).
[0048] The choice of regulatory regions to be included depends upon several factors, including, but not limited to, efficiency, selectability, inducibility, desired expression level, and preferential expression during certain culture stages. It is a routine matter for one of skill in the art to modulate the expression of a coding sequence by appropriately selecting and positioning regulatory regions relative to the coding sequence. It will be understood that more than one regulatory region may be present, e.g., introns, enhancers, upstream activation regions, transcription terminators, and inducible elements.
[0049] It will be appreciated that it may be desirable to remove or replace certain regulatory regions in order to increase expression levels. For example, it may be desirable to remove regions of genes encoding sMMO polypeptides so that expression of these polypeptides is not under the control of the presence of copper and that it can be expressed simultaneously with membrane localized pMMO polypeptides.
[0050] One or more genes can be combined in a recombinant nucleic acid construct in “modules” useful for a discrete aspect of generation of recombinant phototrophic organism. Combining a plurality of genes in a module, particularly a polycistronic module, facilitates the use of the module in a variety of species. For example, an alkane oxidation gene cluster, an alcohol dehydrogenase gene and an aldehyde assimilatory gene can be combined in a polycistronic module such that, after insertion of a suitable regulatory region, the module can be introduced into a wide variety of industrial microorganisms. In addition to genes useful for oxidation of alkanes and its assimilation into the central metabolic pathways, a recombinant construct typically also contains an origin of replication, and one or more selectable markers for maintenance of the construct in appropriate species.
[0051] It will be appreciated that because of the degeneracy of the genetic code, a number of nucleic acids can encode a particular polypeptide; i.e., for many amino acids, there is more than one nucleotide triplet that serves as the codon for the amino acid. Thus, codons in the coding sequence for a given polypeptide can be modified such that optimal expression in a particular microorganism is obtained, using appropriate codon bias tables for that microorganism, and codon-optimized nucleic acids are typically used when the polypeptide to be expressed is heterologous for that microorganism. In some cases, it is desirable to inhibit one or more functions of an endogenous polypeptide. For example, it may be desirable to inhibit or reduce conversion of ribulose 5-monophosphate to ribulose 1-5-bisphosphate using recombinant techniques. In such cases, a nucleic acid that inhibits or suppresses expression of a protein involved in conversion may be included in a recombinant construct that is then transformed into the strain.
[0052] Microorganisms
[0053] A number of prokaryotes and eukaryotes are suitable for use in constructing the recombinant microorganisms described herein, e.g., cyanobacteria and algae, such as oxygenic phototrophic cyanobacteria and algae. In some embodiments, non-phototrophic organisms such as yeast and fungi can also be used to express the polypeptide to achieve the oxidation of alkanes. Typically, a species and strain selected for oxidation of alkanes is first analysed to determine which needed genes are endogenous to the strain and which needed genes are not present. Genes for which an endogenous counterpart is not present in the strain are assembled in one or more recombinant constructs, which are then transformed into the strain in order to supply the missing function(s). Genes for which an endogenous counterpart is present in the strain can, if desired, be modified as described above or supplemented with one or more recombinant genes in order to enhance flux in the strain through particular pathways or particular steps.
[0054] Examples of algae that can be engineered to include one or more polypeptides designed to oxidize alkanes into central metabolic pathway intermediates include, without limitation, green algae (Chlorophyceae), red algae (Rhodophyceae), and dinoflagellates (Dinophyta). In some embodiments, a suitable alga is from a genus of Chlorophyta such as Chlamydomonas, Dunaliella, Scenedesmus, Chlorella, Prototheca, Botryococcus, Haematococcus, Isochrysis, Tetraselmis, Skeletonema, Thalassiosira, Phaeodactylum, Chaetoceros, Cylindrotheca, Bellerochea, Actinocyclus, Nitzchia, Cyclotella, Isochrysis, Pseudoisochrysis, Dicrateria, Monochrysis, Tetraselmis, Pyramimonas, Micromonas, Chroomonas, Cryptomonas, Rhodomonas, Olisthodiscus , and Carteria.
[0055] Examples of photosynthetic organisms such as cyanobacteria that can be engineered to include one or more polypeptides designed to oxidize alkanes into central metabolic pathway intermediates include, without limitation, cyanobacteria from a genus such as Chamaesiphon, Chroococcus, Cyanobacterium, Cyanobium, Dactylococcopsis, Gloeobacter, Gloeocapsa, Gloeothece, Microcystis, Prochlorococcus, Prochloron, Synechococcus, Synechocystis, Chroococcidiopsis, Cyanocystis, Dermocarpella, Myxosarcina, Pleurocapsis, Stanieria, Xenococcus, Arthrospira, Borzia, Crinalium, Geitlerinema, Halospirulina, Leptolyngbya, Limnothrix, Lyngbya, Microcoleus, Oscillatoria, Planktothrix, Prochlorothrix, Pseudanabaena, Spirulina, Starria, Symploca, Trichodesmium, Tychonema, Anabaena, Anabaenopsis, Aphanizomenon, Calothrix, Cyanospira, Cylindrospermopsis, Cylindrospermum, Nodularia, Nostoc, Chlorogloeopsis, Fischerella, Geitleria, Nostochopsis, Iyengariella, Stigonema, Rivularia, Scytonema , and Tolypothri.
[0056] For example, cyanobacteria such as members of a Synechocystis species can be engineered to include one or more polypeptides designed to convert alkanes such as methane into methanol by functional expression of methane monooxygenase. The resulting methanol is converted into formaldehyde by the functional expression of methanol dehydrogenase. The resulting formaldehyde is then assimilated into 3-phosphoglycerate by the functional expression of formaldehyde assimilating polypeptides. It will be appreciated that 3-phosphoglycerate is a naturally occurring metabolite of central metabolic pathways found in all living organisms. Thus, the ability of the recombinant phototrophic organism to convert methane into a common metabolite of central metabolic pathways allows one to generate molecules of interest using the known arts of recombinant DNA technology. Such molecules, without limitation, may include amino acids, alcohols, dicarboxylic acids and any molecules currently useful in the chemical, material and energy industries.
[0057] Phototrophic microorganisms expressing recombinant genes described herein can be engineered such that methanol rather than methane can be the substrate for conversion into end products. For example, a recombinant phototrophic microorganism can be made that expresses MDH, HPS and PHI polypeptides and produces metabolic pathway intermediates such as acetyl CoA and 3-phosphoglycerate. When such a microorganism also expresses genes encoding enzymes that convert these intermediates into n-butanol, growing the microorganism on media containing methanol results in the production of n-butanol. Such a microorganism can be an oxygenic phototroph or an anoxygenic phototroph.
Methods of Producing N-Butanol
[0058] Recombinant hosts described herein can be used in methods to produce n-butanol, methanol or other desired products. For example, the method can include growing the recombinant microorganism in a culture medium under conditions in which MMO, MDH and/or formaldehyde assimilation genes are expressed. Typically, the recombinant microorganism is grown in a fermentor at a defined temperature(s) for a desired period of time. Depending on the particular microorganism used in the method, other recombinant genes such as genes for conversion of acetyl CoA to n-butanol may also be present and expressed. Levels of substrates, intermediates and/or final products can be determined by extracting samples from the culture media for analysis.
[0059] A number of different liquid media are suitable for growing recombinant phototrophic organisms in order to produce products such as n-butanol. For example, recombinant Synechocystis cells can be grown in shake flasks with constant shaking (120 rpm) in a minimal medium containing 1.5 g/L NaNO 3 , 0.04 g/L K 2 HPO 4 , 0.075 g/L MgSO 4 .7H 2 O, 0.036 g/L CaCl 2 .2H 2 O, 0.006 g/L Citric acid, 0.006 g/L Ferric ammonium citrate, 0.001 g/L EDTA (disodium salt), 0.02 g/L Na 2 CO 3 and 1 ml/L trace metal mix. Trace metal mix contains 2.86 g/L H 3 BO 3 , 1.81 g/L, MnCl 2 .4H 2 O, 0.222 g/L ZnSO 4 .7H 2 O, 0.39 g/L NaMoO 4 .2H 2 O, 0.079 g/L CuSO 4 .5H 2 O and 0.0494 g/L Co(NO 3 ) 2 .6H 2 O.
[0060] Cells typically are grown in fermentation vessels under illumination, e.g., illuminated with cool white fluorescent light at a light intensity of about 20 μmol of photons m −2 s −1 at a temperature of about 32° C. The light intensity can be from about 1 to about 200 μmol of photons m −2 s −1 , e.g., from about 20 to about 30 μmol of photons m −2 s −1 . Once cells are in the logarithmic phase, methane is fed into the vessel, the vessel is sealed air-tight, and cell growth is continued under the same culture conditions. The amount of methane converted into butanol is determined by measuring the cell density and the butanol concentration in the vessel at various times during culture. Similarly, when methanol is the substrate, the amount of methanol converted into butanol is determined by measuring the cell density and the butanol concentration in the vessel at various times during culture. In those embodiments in which methanol is the desired end product, the amount of methane converted into methanol is determined by measuring the cell density and the methanol concentration in the vessel at various times during culture.
[0061] The recombinant microorganism may be grown in a fed batch or continuous process. In the continuous mode, methane or methanol is fed into the vessel after cells have reached logarithmic phase, at a rate constant at which the cells are able to convert the substrate into intermediates and to produce the final n-butanol product.
Separation of Final Product
[0062] After the recombinant microorganism has been grown in culture for the desired period of time, the product of interest can then be recovered from the culture using various techniques. For example, n-butanol can be separated from the headspace of a fermentation vessel using distillation or pervaporation using various membranes, gas stripping, or a combination of these techniques. If n-butanol production is carried out in continuous mode, the butanol product is continuously removed by the use of extraction methods.
[0063] Purified n-butanol can then be provided to the transportation fuel industry for drop-in use in a gasoline blend. N-butanol is compatible with existing storage and distribution infrastructure, can be blended at high capacity with gasoline, and possesses fuel characteristics that are often superior to other types of biofuel. Because of these features, n-butanol can be used with minimal modifications and cost to the existing infrastructure of storage and distribution. The purified product can also be used in chemical conversion processes to make butylene, which can be used to produce specialty and commodity products as well as C12/C16 hydrocarbons for use in jet fuel.
[0064] Purified methanol can also be provided to the transportation fuel industry for drop-in use in a gasoline blend, or can be used in chemical conversion processes to make various industrial chemicals.
EXAMPLES
[0065] The invention will be further described in the following examples, which do not limit the scope of the invention described in the claims.
Example 1
Expression of Methane Monooxygenase in a Phototrophic Microorganism
[0066] Expression of methane monooxygenase in a phototrophic microorganism is accomplished via introduction of coding sequences for polypeptide subunits for either pMMO or sMMO. A number of pMMO and sMMO sequences are available from different methanotrophic organisms. For example, nucleic acids encoding the pmoCAB gene cluster (MCA1796, MCA1797 and MCA1798) or the sMMO gene cluster (MCA1194, MCA1195, MCA1196, MCA1198, MCA1199 and MCA1200) from Methylococcus capsulatus Bath can be operably linked to suitable promoters and introduced into Synechocystis sp. PCC 6803 (hereafter Synechocystis ) to create a recombinant phototropic microorganism expressing a functional MMO. Given the different GC percent, codon utilization and differences in the regulatory sequences involved in expression and stability of messenger RNA, codon optimized genes are used for expression in Synechocystis and other phototropic microorganisms. Typically, such codon optimized genes are operably linked to a strong constitutive promoter.
[0067] MMO genes are transcribed polycistronically in Methylococcus capsulatus Bath. Therefore, these gene clusters can be assembled as polycistronic units and stably integrated in the genome of the phototrophic microorganism or can be maintained on a stably replicated plasmid. In other cases, the coding sequence for each MMO polypeptide subunit is expressed monocistronically. The use of monocistronic nucleic acids allows one to drive expression of each gene by a suitable promoter and ribosome binding site, and thus to manipulate expression of each gene individually.
[0068] The amino-terminal 32 residues of the PmoB polypeptide contain a signal peptide and in some cases it may be desirable to replace the Methylococcus signal peptide with, for example, a Synechocystis signal peptide for more efficient targeting to membranes. The initial assembly of MMO polypeptide coding sequences usually is carried out in E. coli such that the sequences can be targeted into the phototrophic microorganism at a single locus as previously described.
[0069] Typically, a nucleic acid construct carrying MMO coding sequences also includes an antibiotic cassette for selection of transformants carrying the MMO coding sequences. Additional coding sequences, such as coding sequences for methanobactin biosynthesis, may also be included in the recombinant construct. The recombinant construct typically is introduced into the phototrophic microorganism by transformation and targeted to a neutral site via double homologous recombination.
[0070] For Synechocystis , after colonies of transformants expressing mmo genes are obtained, the presence of these genes is confirmed by isolating genomic DNA and performing polymerase chain reaction using gene specific primers. Synechocystis can be restreaked as necessary in order to obtain isogenic lines with respect to introduced mmo genes. The steady state transcript level of each mmo gene can be determined by isolating total RNA and measuring expression of each mmo gene by real time polymerase chain reaction. Functional expression of MMO polypeptides can be determined using polyclonal antibodies against each subunit of MMOs to quantitatively measure the amount of MMO subunits in Synechocystis.
[0071] The enzymatic activity of MMO in the recombinant organism is measured using either methane or propylene as substrate and using gas chromatography as previously described. Because it is known that the enzymatic activity of pMMO and sMMO can be dependent on the presence of copper, the recombinant strains are grown in the presence of different concentrations of copper, and MMO activity is measured as described above. In some embodiments, coding sequences for MMO polypeptides are operably linked to copper regulated promoters so that MMO expression is coordinated with copper availability. Copper regulated promoters include those driving expression of plastocyanin and Cyt c553, two electron carriers that can carry electrons from the cytochrome bf complex to photosystem I.
Example 2
Identification of MMO Accessory Genes by Complementation of Recombinant Synechocystis
[0072] It may be useful to express additional polypeptides in a recombinant phototroph. To identify such proteins, a reverse approach involving complementation studies can be used to establish functional expression of MMOs in Synechocystis . For this, a recombinant Synechocystis strain is generated that expresses pMMO or sMMO polypeptides, methanol dehydrogenase polypeptides and two polypeptides that assimilate formaldehyde into 3-phosphoglycerate. The recombinant microorganism can utilize methanol as a sole source of carbon and energy. The microorganism can then be used to carry out complementation studies to identify methanotroph genes that facilitate assembly and function of MMOs in Synechocystis.
[0073] The complementation assay utilizes genomic DNA isolated from Methylococcus capsulatus Bath. Genomic DNA is partially digested with Sau3A1 to generate fragments of ˜5 kb which are then cloned in a BamH1-digested plasmid that stably replicates in Synechocystis . The resulting library is transformed into the Synechocystis strain described above. Transformed cells are then selected on solid media plates for their ability to utilize methane as a sole source of carbon and energy. The Sau3A1 insert that is present in those colonies having increased methane utilization relative to a control organism is sequenced. The coding sequence(s) found in the insert can be codon optimized for Synechocystis and their effect on methane utilization determined. Any such coding sequences that confer increased methane utilization can then be introduced and expressed in a Synechocystis strain containing coding sequences for MMO polypeptides. MMO activity in the resulting strain is measured by functional assays as described previously, as well as by ability of the engineered strain to grow on methane as a sole source of energy and carbon.
Example 3
Expression of Methanol Dehydrogenase
[0074] Conversion of methanol into formaldehyde in a phototrophic microorganism can be accomplished by the expression of NAD-dependent MDH or class I ADH from humans. NAD-dependent MDHs do not require a specialized cofactor. Alternatively, MDHs from methanotrophs can be used. However, methanotroph MDHs utilize a specialized cofactor PQQ, and the expression of PQQ-MDH polypeptides and regulation of PQQ-MDH activity involves about 10 genes. Suitable NAD-dependent MDHs include those from methylotrophic Bacillus methanolicus.
[0075] Coding sequences are codon-optimized, synthesized, and expressed in Synechocystis behind a strong constitutive promoter and enzymatic function of MDH in the recombinant Synechocystis is measured using crude extracts and/or intact cells as previously described. It may be useful to express additional polypeptides. For example, regulation of Bacillus methanolicus MDH activity involves an activator protein, and it may be desirable to introduce and express coding sequences for the activator protein from Bacillus methanolicus in Synechocystis . Similarly, class I ADH enzymes from human exist in homodimeric or heterodimeric form and each form has different kinetic properties for different alcohols. Coding sequences (ADH1A, ADH1B and ADH1C) encoding class I ADH polypeptides, either as homodimeric or heterodimeric forms, can be expressed in various combinations and thereby identify suitable enzyme systems for specific oxidation of methanol in Synechocystis.
Example 4
Formaldehyde Assimilation by Recombinant Synechocystis
[0076] Formaldehyde in an engineered Synechocystis strain can be assimilated into central metabolic pathways via enzymes of the ribulose monophosphate pathway. Sequences encoding suitable RuMP pathway polypeptides include: i) hps and phi genes from Methylococcus capsulatus Bath; ii) hps and phi genes from Bacillus methanolicus ; and iii) hps and phi genes from Pyrococcus horikoshii . In the first two cases, each polypeptide is encoded by a separate sequence, whereas a single coding sequence encodes both polypeptides in the third case. These sequences can be codon-optimized, synthesized and expressed in Synechocystis behind a strong constitutive promoter. After suitable expression is established by real time polymerase chain reaction and LC-MS, enzymatic activity in the engineered Synechocystis strain is measured as previously described.
Example 5
Ribulose Bisphosphate and Ribulose Monophosphate Regeneration
[0077] Synechocystis contains a highly active reductive pentose phosphate pathway. It plays a central role in coupling light energy to CO 2 fixation by regenerating ribulose bisphosphate for carboxylation reaction and channeling the fixed carbon to central metabolic pathways. In order to establish efficient assimilation of formaldehyde and capture of CO 2 in the recombinant Synechocystis , regeneration of both ribulose monophosphate and ribulose bisphosphate is balanced by the reductive pentose phosphate pathway. This is achieved first by biochemical studies using a Synechocystis strain expressing hps and phi genes to determine if the assimilation of formaldehyde is limited by the availability of ribulose monophosphate. This is carried out by incubation of intact cells with different concentrations of ribulose monophosphate. If it is determined that the rate of formaldehyde assimilation is limited by the availability of ribulose monophosphate then a coding sequence for phosphoribulokinase, an enzyme that converts ribulose monophosphate into ribulose bisphosphate, can be introduced and expressed in Synechocystis to achieve balanced regeneration of ribulose monophosphate and ribulose bisphosphate. The level of expression from the phosphoribulokinase coding sequence can be controlled by the type of promoter used to drive transcription, e.g., using a weak promoter, or using a copper regulated promoter. In Synechocystis , suitable copper regulated promoters include those driving expression of plastocyanin and Cyt c553, two electron carriers that can carry electrons from the cytochrome bf complex to photosystem I.
[0078] Similarly, a suitable level of expression can be determined for other enzymes involved in the reductive pentose phosphate pathway, including transketolase, transaldolase, and sedoheptulose-1,7-bisphosphatase, in order to achieve balanced regeneration of ribulose monophosphate and ribulose bisphosphate. If it is determined that certain enzymes involved in regeneration of ribulose monophosphate are limiting in recombinant organism, then a functionally homologous polypeptide from another cyanobacterial strain can be introduced into and expressed to overcome that limitation.
Example 6
Production of n-Butanol from Metabolic Pathway Intermediates
[0079] Recombinant phototrophic microorganisms can be generated that convert intermediates of the central metabolic pathways into a useful product (e.g. butanol). For example, nucleic acids encoding enzymes involved in the conversion of acetyl-CoA into n-butanol can expressed in a recombinant Synechocystis microorganism. Sequences suitable for introduction and expression in Synechocystis include the atoB gene from E. coli ; hbd, crt and adhE2 genes from Clostridium acetobutylicum ; and the ter gene from Treponema denticola . These sequences are codon optimized, introduced into and overexpressed in Synechocystis in order to confer the capability of producing n-butanol from acetyl-CoA.
Example 7
Biosynthesis of n-Butanol from Methane
[0080] A phototrophic microorganism can be produced that includes recombinant genes encoding and expressing: pMMO and/or sMMO polypeptides; an NAD-dependent MDH polypeptide and/or a human class I ADH polypeptide; an HPS polypeptide; an PHI polypeptide; an acetyl-CoA acetyltransferase polypeptide; a 3-hydroxybutyryl-CoA dehydrogenase polypeptide; a crotonase polypeptide; an aldehyde/alcohol dehydrogenase polypeptide; and a trans-enoyl-CoA reductase polypeptide. For example, a Synechocystis microorganism can contain codon optimized sequences encoding: pMMO and/or sMMO polypeptides described above, an NAD-dependent MDH polypeptide or a human class I ADH1A, ADH1B and/or ADH1C polypeptide described above; an HPS polypeptide described above; an PHI polypeptide described above; an acetyl-CoA acetyltransferase polypeptide described above; a 3-hydroxybutyryl-CoA dehydrogenase polypeptide described above; a crotonase polypeptide described above; an aldehyde/alcohol dehydrogenase polypeptide described above; and a trans-enoyl-CoA reductase polypeptide described above.
[0081] In some embodiments, such a microorganism further includes genes encoding peptides of the methanobactin gene cluster and/or one or more of the following polypeptides: phosphoribulokinase; transketolase, transaldolase, and sedoheptulose-1,7-bisphosphatase. A Synechocystis strain containing such recombinant genes can convert methane into a useful product (e.g. n-butanol).
Example 8
Recombinant Synechocystis Strains Capable of Oxidizing Methanol
[0082] Genes coding for alcohol dehydrogenase were obtained from Bacillus methanolicus MGA3 (locus: MGA3 — 17392; GI:387585261) and Homo sapiens [ADH1A (P07327.2); ADH1B (P00325.2), and ADH1C (NP — 000660.1)]. An additional gene that acts as activator to methanol dehydrogenase in Bacillus methanolicus MGA3 (EIJ83380.1) was also obtained. They were codon-optimized for Synechocystis and synthesized. Two restriction sites (NdeI and HpaI) were introduced in each gene to facilitate cloning and subsequent recombination in Synechocystis . These genes were cloned behind the psbA2 promoter using the NdeI and HpaI sites and then introduced into a neutral locus in Synechocystis . Such neutral loci in Synechocystis are known in art and combinations of these loci can be used for this purpose if desired. A chloramphenicol acetyltransferase gene was also introduced into Synechocystis for selection of the recombinant strain using chloramphenicol as the selection agent. Genes that confer resistance to kanamycin, gentamicin, spectinomycin, or other similar antibiotics to which Synechocystis is sensitive can also be used for selection of recombinant strains.
[0083] A total of eight different isogenic recombinant Synechocystis strains were generated (see Table 1). Since the functional form of alcohol dehydrogenase in Homo sapiens can be either a homodimer or a heterodimer, some of the recombinant Synechocystis strains have two adh genes. The presence of the desired alcohol dehydrogenase gene(s) was confirmed by polymerase chain reaction assay, and expression was confirmed by RT-PCR.
[0084] Alcohol dehydrogenase enzymatic activity in the recombinant Synechocystis was measured using crude extracts and/or intact cells. Crude extract was isolated by first treating the Synechocystis cells with lysozyme in a buffer containing 50 mM Tris, PH 8.0, 10% glycerol, 0.1% Triton X-100 and incubating at 37° C. for 30 min. The treated cells were harvested by centrifugation at 4000×g for 5 min at 4° C. and resuspended in a buffer containing 50 mM Tris, PH 8.0, 10% glycerol, 0.1% Triton X-100 and protease inhibitor cocktail (Sigma). Cells were lysed by sonication using a Misonix S3000 Sonicator (power setting: 3 for a 4-5 cycles with each cycle lasting for 20 seconds). The crude extracts was clarified by centrifugation at 12,000×g for 5 min at 4° C. and the clarified supernatant containing was used to measure methanol dehydrogenase activity at 340 nm following NAD + reduction in a reaction mixture containing 500 mM (˜2%) methanol, 100 mM glycine-KOH buffer (pH 9.5), 5 mM MgSO 4 , 5 mM 2-mercaptoethanol, 1 mM NAD + and 10 μl of extract. The methanol dehydrogenase activity observed in the recombinant Synechocystis extracts is shown in Table 1. The results indicate that methanol dehydrogenase activity was observed in all strains except for MGC0460. Extracts of many of the strains also exhibited activity with ethanol, propanol or butanol as the substrate.
[0000]
TABLE 1
Recombinant Synechocystis containing alcohol dehydrogenase genes
Specific Activity (nmol
Strain Name
Gene
NADPH/min/mg protein)
MGC0416
MDH
0.0042
MGC0440
MDH and ACT
0.0021
MGC0428
ADH1A
0.0075
MGC0443
ADH1B
0.0034
MGC0452
ADH1C
0.0047
MGC0448
ADH1A and ADH1B
0.0028
MGC0460
ADH1A and ADH1C
0.0000
MGC0461
ADH1B and ADH1C
0.0039
[0085] The effect of dehydrogenase expression on growth of recombinant Synechocystis strains was determined by measuring the optical density at 730 nm of strains cultured at 30° C. under a 30 μE m −2 s −1 light regimen and ambient air on media containing din the presence of light and ambient air in media containing different concentrations of methanol. The medium contained 1.5 g/L NaNO 3 , 0.04 g/L K 2 HPO 4 , 0.075 g/L MgSO 4 .7H 2 O, 0.036 g/L CaCl 2 .2H 2 O, 0.006 g/L Citric acid, 0.006 g/L Ferric ammonium citrate, 0.001 g/L EDTA (disodium salt), 0.02 g/L Na 2 CO 3 and 1 ml/L trace metal mix. Trace metal mix contained 2.86 g/L H 3 BO 3 , 1.81 g/L, MnCl 2 .4H 2 O, 0.222 g/L ZnSO 4 .7H 2 O, 0.39 g/L NaMoO 4 .2H 2 O, 0.079 g/L CuSO 4 .5H 2 O and 0.0494 g/L Co(NO 3 ) 2 .6H 2 O.
[0086] Results are shown in FIG. 1 , and indicate that recombinant Synechocystis strains containing and expressing an MDH, or MDH and ACT, can grow on media containing up to 2% methanol, despite the likely accumulation in the media of formaldehyde, the product of the dehydrogenase activity.
Example 9
A Recombinant Synechocystis Strain Capable of Assimilating Formaldehyde
[0087] Genes coding for 3-Hexulose-6-phosphate synthase (HPS) were obtained from Methylococcus capsulatus Bath (locus: MCA3043; GI:53756598), Bacillus methanolicus MGA3 (locus: MGA3 — 15306; GI:387587408) and Pyrococcus horikoshii OT3 (locus: PH1938; GI:14591680); and phospho-3-hexuloisomerase (PHI) from Methylococcus capsulatus Bath (locus: MCA3044; GI:53756597), Bacillus methanolicus MGA3 (locus: MGA3 — 15301; GI:387587407) and Pyrococcus horikoshii (locus: PH1938; GI:14591680). They were codon-optimized for expression in Synechocystis and synthesized. Two restriction sites (NdeI and HpaI) were introduced in each gene to facilitate cloning and subsequent recombination in Synechocystis . These genes were cloned behind the psbA2 promoter using the NdeI and HpaI sites and then introduced into a neutral locus in Synechocystis . A chloramphenicol acetyltransferase gene was also introduced into Synechocystis for selection of the recombinant strain using chloramphenicol as the selection agent.
[0088] Three different isogenic recombinant Synechocystis strains are generated, one containing HPS and PHI sequences from Methylococcus capsulatus Bath, one containing HPS and PHI sequences from Bacillus methanolicus , and one containing HPS and PHI sequences from Pyrococcus horikoshii OT3. The presence of the desired HPS and PHI genes is confirmed by polymerase chain reaction assay, and expression is confirmed by RT-PCR.
[0089] Enzymatic activity in the recombinant Synechocystis strains was measured using crude extracts and/or intact cells. Crude extracts were prepared as described in Example 8. HPS and PHI activities were measured by following NADP reduction at 340 nm in a 1 ml reaction mixture containing 50 mM potassium phosphate buffer pH 7.0, 5 mM magnesium chloride, 1 unit each of glucose-6-phosphate dehydrogenase (Sigma) and glucose-6-phosphate isomerase (Sigma), 0.4 mM NADP, 2.5 units of phosphoriboisomerase (Sigma), and 100 μl extract. After temperature equilibration to 30° C., 5 mM ribose-5-phosphate was added. After 1 min of further preincubation, the reaction was started by the addition of 5 mM formaldehyde. The specific activity of the Methylococcus HPS and PHI enzymes in Synechocystis crude extracts was 1086 nmol NADPH/min/mg protein. The results also indicated that expression of the HPS and PHI genes from Methylococcus capsulatus Bath conferred more formaldehyde assimilation activity on Synechocystis crude extracts than did the genes from Pyrococcus or Bacillus.
[0090] The effect of HPS and PHI expression on growth of wild type and recombinant Synechocystis strains was determined by measuring the growth of the MSI strain under a a 30 μE m −2 s −1 light regimen and in the presence of ambient air on media containing different concentrations of formaldehyde. The results are shown in Table 2, and indicate that wild type growth is inhibited at 5 mM formaldehyde whereas a Synechocystis strain expressing Methylococcus HPS and PHI can grow at concentrations up to 15 mM formaldehyde. The results in Table 2 also indicate that the rate of growth of recombinant Synechocystis cells in media containing 5 to 15 mM formaldehyde is about 88% to about 100% of the rate observed for recombinant Synechocystis cells grown in media having no added formaldehyde.
[0000]
TABLE 2
Growth of wild type and recombinant Synechocystis strains in the presence
of different concentrations of formaldehyde.
Formaldehyde
OD730
OD730 after 6 days
concentration
after 6 days
Recombinant
(mM)
Wild Type cells
Synechocystis cells
0
1.316
1.292
5
0.728
1.244
10
0.064
1.136
15
0.06
1.288
20
0.096
0.032
[0091] The amount of formaldehyde present in the culture supernatant of a Synechocystis strain expressing HPS and PHI was determined after growth for 1 day at 30° C. in media containing from various concentrations of formaldehyde, from 20 μM to 200 μM. The amount of formaldehyde in the supernatant was measured using a colorimetric assay based on the Hantzsch reaction. Nash, Biochem. J. 55: 416-421 (1953). The results are shown in FIG. 2 , and indicate that formaldehyde in culture supernatants from Synechocystis cells expressing HPS and PHI is depleted to a much greater extent than in the supernatant from wild type control Synechocystis cells that lack these two genes. The amount of formaldehyde in supernatant from Synechocystis cells expressing HPS and PHI is about 4-fold less than the amount in supernatant from the isogenic wild type Synechocystis cells. | This disclosure relates to the engineering of phototrophic microorganisms for conversion of alkanes into higher-value products. Recombinant phototrophic organisms such as cyanobacteria can be engineered, optionally in a modular format, to express enzymes involved in converting methane to methanol, methanol to formaldehyde, formaldehyde to central metabolic pathway intermediates, and such intermediates to n-butanol. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of working metal foils and, more particularly, to corrugating metal foils that exhibit low room temperature ductility, such as gamma-titanium aluminide (γ-TiAl) foils.
2. Background Information
Because of the light weight and desirable mechanical properties at elevated temperatures of γ-TiAl, significant research has been conducted regarding fabrication and producibility of honeycomb sandwich panels for use in high temperature aerospace applications. In order to produce γ-TiAl core sections for use in honeycomb panel construction, forming/corrugating thin foil strip is required. A significant problem with γ-TiAl is that it exhibits low room temperature ductility, which presents difficulties in forming it at room temperature. Moreover, γ-TiAl becomes more susceptible to surface oxidation when heated to high temperatures (>1400° F.). In addition, when hot forming thin foils of any metal, rapid heat loss in the foil may occur during the forming process when the foil comes into contact with the machine forming tool faying surfaces (e.g., forming gears). This situation exacerbates the difficulties of consistently producing an end product that has the desired shape and is free of defects (e.g., cracks and altered surface grain structure). Furthermore, the environment around the forming tool area also may add to the foil forming/corrugation difficulties in regards to surface interstitial diffusion.
For the foregoing and other reasons, there is, accordingly, a need for a machine for, and a method of, corrugating metal foils that exhibit low room temperature ductility. In particular, there is a need for a machine, and a method, for corrugating such metal foils under conditions that ensure reliable production of a corrugated foil that is free of defects and has a desired end geometry.
SUMMARY OF THE INVENTION
The foregoing need is fulfilled, in accordance with the present invention, by a machine for corrugating metal foil strip lengths that includes an enclosure defining a chamber and a controllable heat source for heating the chamber. A gas or combination of gases may or may not be introduced into the chamber. At least one corrugation-forming tool set located in the chamber forms corrugations into the metal foil strip. Foil entrance feeder elements supply and guide the metal foil strip from outside the chamber into the chamber and to the tool set. A drive for the tool set is mounted outside the chamber and coupled to the tool set to actuate the tool set. Foil exit delivery elements guide the strip from the tool set and out of the chamber.
The heat source for the chamber maintains—by using convection or radiation heating, or a combination thereof—a quasi isothermal temperature of the tool set and also heats the foil strip as it is guided to the tool set, such that when it is worked by the tool set it has sufficient ductility to be formed without cracking. Moreover, the heated tool set precludes any heat loss from the foil strip at the time of working that might alter its mechanical properties. The drives for the tool set are located outside the chamber where they are protected from the heat.
In some cases, the foil strip can be corrugated without heating the chamber to a temperature sufficiently high to oxidize the tool set, the foil strip, or both. When the machine and method involve temperatures in the chamber high enough to oxidize the tool set or foil strip, or both, a source supplying an inert gas to the chamber at a controlled gas flow rate may be used.
As explained more fully below, there are inherently significant gradients of heat along the length of the foil strip that resides at any given time between a supply roll of the foil stock and the delivery point of the corrugated foil strip after it leaves the heated chamber. On the incoming side of the chamber immediately outside of an opening in a wall of the chamber through which the strip enters the chamber, the cool incoming part of the strip is not heated enough to be subject to oxidation. While in the chamber, the inert gas prevents oxidation of the strip. The portion of the strip between the tool set and an exit opening from the chamber is progressively cooler near the exit opening, due to both heat loss by conduction along the strip to the cooler part of the strip outside of the chamber and to the cooler gases that are present near the walls of the chamber. Accordingly, when the strip leaves the chamber, it is no longer hot enough to be oxidized by the ambient air.
In preferred embodiments, the enclosure is double-walled and liquid-cooled so as to provide a large temperature gradient through the gas environment near the enclosure chamber walls (as well as through the chamber double walls). Those temperature gradients allow portions of the strip outside the chamber to remain at sufficiently low temperatures to avoid oxidation and to keep the outside of the enclosure at a relatively low temperature.
The enclosure may include partition walls forming a medial chamber and end sub-chambers on opposite ends of the medial sub-chamber and openings between the medial chamber and each sub-chamber through which the foil strip passes between the sub-chambers. This geometric arrangement of the entire chamber allows a foil strip to enter the medial sub-chamber from one end sub-chamber and to pass into the other end sub-chamber from the medial sub-chamber. The partition walls may be cooled with internal “water jackets.” The tool set and the heating elements for heating the gas are located in the medial sub-chamber. The inert gas is supplied to the medial chamber. The partition walls of the medial chamber establish a temperature gradient between the inside of the medial chamber and the insides of the end sub-chambers. The inert gas passes from the medial sub-chamber through the openings in the partition walls into the end sub-chambers. The foil feeder elements and foil exit delivery elements guide the strip through the sub-chambers and/or through the medial chamber.
The foil feeder elements may include guide members within the chamber that form a serpentine delivery path for the strip so as to permit the strip to be heated before it reaches the tool set. Other suitable feeder elements include a guide chute supporting the strip along a path from the supply opening in a wall of the enclosure to the tool set. The guide chute provides a path for heat conduction along its length, so that the chute is relatively cool adjacent the wall of the enclosure and relatively hot near the tool set. The chute can be designed to establish a desired temperature gradient along its length. The foil strip, being in contact with the chute, exchanges heat with the chute and possesses a temperature—and temperature gradient—close to that of the chute. Likewise, and with similar effect, the delivery elements may include—or consist of—a guide chute supporting the strip along a path from the tool set to the exit opening in a wall of the enclosure.
The tooling in the enclosure may include a pre-form tool set that partially forms corrugations and a final tool set that fully forms the corrugations. Forming corrugations in two (or more) stages will affect the amount of foil springback. Given a similar final foil corrugation geometry, the strain rate during forming in each stage of a two-stage forming process will be less (for any given machine throughput) than if only a single-stage forming process is employed.
Various tool sets may be used in a machine according to the invention, such as:
1) A driven form gear having forming teeth and an idler form gear having forming teeth meshing with the forming teeth of the driven form gear and driven by the driven form gear.
2) A driven form gear having forming teeth, an idler pre-form gear having forming teeth meshing with the forming teeth of the driven form gear at a first location along the perimeter of the driven form gear and driven by the driven form gear, and an idler final form gear having forming teeth meshing with the forming teeth of the driven form gear at a second location along the perimeter of the driven form gear spaced apart from the first location and driven by the driven form gear.
3) A driven form gear having forming teeth, an idler form gear having forming teeth meshing with the forming teeth of the driven form gear, and a gear train coupling the driven form gear and the idler form gear so that both the driven and idler form gears are driven in rotation;
4) A pre-form tool set and a separate final tool set, each having a driven form gear having forming teeth, an idler form gear having forming teeth meshing with the forming teeth of the driven form gear, and a gear train coupling the driven form gear and the idler form gear so that both the driven and idler form gears are driven in rotation; the driven form gear of one of the tool sets is driven by the driven form gear of the other tool set.
5) A driven form gear having teeth defining cavities and a punch having a tooth substantially complementary in shape to the shape of the cavities. With a form gear/punch tool set, the drive includes a rotary drive that rotates the driven form gear and a reciprocating linear actuator driving the punch radially of the form gear. Preferably, the rotary drive rotates the form gear intermittently with a dwell period during which the punch forms a corrugation in the strip by deforming the strip into a cavity of the form gear. The punch may include a holder foot that engages an outgoing loop of a corrugation of the strip against the tip of the tooth of the form gear on the outgoing side of the cavity on each forming stroke of the tooth of the punch.
6) A pre-form tool set and a final tool set, both tool sets sharing a driven form gear having teeth defining cavities. The pre-form tool set includes a pre-form punch having a tooth partially complementary in shape to the shape of the cavities. The final pre-form tool set includes a final punch having a tooth substantially complementary in shape to the shape of the cavities. The final punch is spaced apart circumferentially of the form gear from the pre-form punch. The drive includes a rotary drive, preferably driven intermittently with a dwell period during actuation of the punches, rotating the driven form gear and a reciprocating linear actuator driving each punch radially of the form gear. Each punch may have a holder foot that engages an outgoing loop of a corrugation of the strip against the tip of the tooth of the form gear on the outgoing side of the cavity on each forming stroke of the tooth of the punch.
The foregoing description has outlined rather broadly some features and advantages of the present invention. The detailed description of embodiments of the invention that follows will enable the present invention to be better understood and the present contribution to the art to be more fully appreciated. Those skilled in the art will recognize that the embodiments may be readily utilized as a basis for modifying or designing other structures and methods for carrying out the purposes of the present invention. All such structures and methods are intended to be included within the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally schematic front elevational view of a first embodiment;
FIG. 2 is a generally schematic front elevational view of a second embodiment;
FIG. 3 is a generally schematic front elevational view of a third embodiment;
FIG. 4 is a generally schematic front elevational view of a fourth embodiment;
FIG. 5 is a generally schematic front elevational view of a fifth embodiment;
FIG. 6 is a generally schematic detail front elevational view of the punch and gear form tools of the fifth embodiment; and
FIG. 7 is a generally schematic front elevational view of a sixth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the machine shown therein has a double-walled enclosure 10 , which is subdivided by partition walls 12 and 14 to provide a medial sub-chamber 16 and end sub-chambers 18 and 20 . The inner wall of the enclosure 10 is insulated. A coolant, which may be water, is continuously circulated through the jacket between the inner and outer walls of the enclosure 10 from a coolant source 22 to a coolant outlet 24 . In practice, the coolant is circulated separately through each double-wall panel (top, bottom, ends and rear) that forms the enclosure and through a hinged access door on the front of the enclosure.
When needed to prevent oxidation of the tool set or the foil strip, an inert gas, such as argon, is supplied from an inert gas source 26 to the medial sub-chamber at a controlled gas flow rate and is exhausted through an exhaust outlet 28 , which is connected by pipes 28 p to the end sub-chambers. The inert gas fills the enclosure 10 and is replenished continuously so as to purge substantially all oxygen from the sub-chambers, including any oxygen that is released from the walls of the enclosure and parts of the machine within the chamber. The inert gas in the chamber is heated by heating elements 30 located in the medial sub-chamber. The temperature of the inert gas in the chamber is, of course, suitably controlled.
The foil strip S that is to be corrugated in the machine is supplied from a roll R, is admitted into the end sub-chamber 18 through a slot in the bottom wall of the enclosure, and is guided along a tortuous path formed by guides 34 to a tool set 36 (described below) that forms corrugations in the foil strip. The corrugated strip is guided away from the tool set along a chute 38 and after passing through the end sub-chamber 20 exits the enclosure through a slot. The strip passes from the end sub-chamber 18 into the medial sub-chamber 16 through an opening 13 at the upper edge of the wall 12 and passes from the medial sub-chamber 16 into the end sub-chamber 20 through an opening 15 at the upper edge of the wall 14 . The openings allow the inert gas that enters the medial sub-chamber 16 from the source 26 to flow from the medial sub-chamber 16 into the end sub-chambers 18 and 20 and thence to the exhaust pipes 28 p . Because the inert gas in the chamber formed by the enclosure 10 is at a pressure above atmospheric, gas leakage from the chamber to the outside of the enclosure through the slots through which the foil strip enters and leaves the chamber is acceptable.
There are relatively large temperature gradients within the medial and end sub-chambers and between the medial sub-chamber and the end sub-chambers. Therefore, the foil strip S, which is thin and thus transfers heat readily in the thickness direction, is subject to gradients of temperatures as it passes into, through and out of the sub-chambers in the enclosure 10 . The coolest regions of the chamber are the lowest portions of the end sub-chambers 18 and 20 . As the inert gas flows from the openings 13 and 15 , it gives up heat to the top and end walls of the enclosure. Heat is also given up to the relatively cool incoming foil strip S. The highest temperatures in the chamber formed by the enclosure 10 are in the center region of the medial sub-chamber 16 , which is remote from the cooled walls of the enclosure and in proximity to the heating elements 30 . The guides 34 and the tool set 36 within the medial sub-chamber 16 , which contact the foil strip, are kept heated by the inert gas, so heat exchange between those components and the foil strip is minimal. The guides 34 may be of a ceramic or other material with a low heat conductivity. The tortuous path for the foil strip S enables the strip to reside in the hot medial sub-chamber 16 for a sufficient time to be highly heated before it is worked by the tool set 36 . The inert gas prevents the foil strip and the tool set from being oxidized at the high temperature ranges to which the foil will in most uses of the machine be heated for forming/corrugation. In some cases, the machine can be used without activating the inert gas supply.
After being corrugated by the tool set 36 , the strip S is guided along the chute 38 through the opening 15 , passes down through the end sub-chamber 20 and out of the chamber of the enclosure 10 through a slot in the bottom wall. The chute 38 is designed to receive heat from the now-corrugated strip by conduction—the chute 38 is of a material that conducts heat and is fastened to the relatively cool rear wall of the enclosure 10 so that it is at a significantly lower temperature than that of the gas in the medial sub-chamber 16 . The strip S continues to cool as it passes through the end sub-chamber 20 . By the time the strip leaves the enclosure 10 , it has cooled sufficiently to be able to enter the air without a risk of oxidizing.
The then-corrugated strip is conducted through and between sizing rolls 40 , which are smooth circumferential tool rolls that perform an additional adjustment to the as-corrugated foil formed shape (specifically, the pitch), to accommodate any changes due to non-uniform springback.
The tool set 36 of the embodiment shown in FIG. 1 consists of a driven form gear 42 and an idler form gear 44 . The shaft of the driven form gear 42 is supported by bearings located outside the enclosure and is driven in rotation by a rotary drive 46 that is also located outside of the enclosure. Each form gear has teeth that mesh with the teeth of the other form gear, the teeth and cavities between the teeth of the form gear pair being shaped to form corrugations in the strip S of the desired shape. Corrugating very thin foils, which may be from about 0.002″ to about 0.006″ thick, requires setting the form gears very precisely. To that end, the idler form roll 44 is mounted in bearings outside the enclosure that are carried by an adjustable mount, which is indicated schematically in FIG. 1 by the crank 48 .
The second to sixth embodiments of machines according to the present invention, which are shown in FIGS. 2 to 7 ) are similar in many respects to the first embodiment. Accordingly, much of the description set forth above of the first embodiment is applicable to many aspects of the second to sixth embodiments and is not repeated in the descriptions below of the second to sixth embodiments. Also, the reference numerals applied to the elements of the second to the sixth embodiments in the drawings have the same last two digits as the corresponding elements of the first embodiment. The first digits of the reference numerals applied to the elements of the second to the sixth embodiments correspond to the number of the embodiment. For example, the first digit of the reference numerals applied to the second embodiment is 2 , the first digit of the reference numerals applied to the third embodiment is 3 , etc.
As shown in FIG. 1, the tool set 36 of the first embodiment—a single pair of meshing form gears 42 and 44 fully forms each corrugation in the strip in a single stage of working, in which each corrugation is formed by progressive elongation and bending of a segment of the strip as a tooth of one form gear pushes the segment into a cavity of the other form gear. In the second embodiment (FIG. 2 ), the tool set 236 consists of a driven form gear 242 , an idler form gear 244 , and an idler pre-form gear 250 . The pre-form gear 250 has teeth that seriatim push segments of the strip S partway into the cavities of the driven form gear 242 , thus partially forming the corrugations. The teeth of the idler form gear 244 complete the partially formed corrugations by pushing them seriatim more deeply into the cavities of the drive form gear 242 . The pre-form gear 250 forms a partial corrugation by pulling an incoming segment of the strip into the cavity with little or no axial stretching. Since the strip arrives at the idler form gear 244 with partially formed corrugations tucked into the cavities of the driven form gear 242 , the pushing of each partially formed corrugation more deeply into a cavity of the driven form gear 242 stretches the corrugation lengthwise of the strip.
In the third embodiment (FIG. 3 ), the tool set 336 includes a pre-form gear pair 352 and 354 , which partially form corrugations in the strip S, and a final form gear pair 356 and 358 , which complete the formation of the corrugations. One form gear 356 of the final form gear pair is driven by a rotary drive (not shown). The driven form gear 356 drives the pre-form gear 352 through a belt 360 and drives the final form gear 358 . The pre-form gear 352 drives the pre-form gear 354 , which is an idler.
FIG. 4 shows additional elements of the fourth embodiment and contains a more detailed schematic depiction. The enclosure 410 has a double-walled, liquid-cooled main casing 410 m with an opening at the front that is framed by a flange 410 f . A double wall front cover (not shown) is coupled by a pair of hinges, one leaf 410 h of each of which is shown, to the main casing 410 m . The chamber casing is lined with at least one layer (shown in FIG. 4 as a double layer) of ceramic insulator panels 410 p , the front edges of which are stepped so that they will mate with insulator panels having stepped edges on the front panel. Alternatively, more than two layers, say three layers, of ceramic insulator may be used in other embodiments of this invention. The front panel is normally bolted to the main casing by a mating flange on the front cover but can be opened for maintenance or replacement (e.g., to change the forming tools) of components within the enclosure by removing the bolts and swinging the cover open on the hinges. The enclosure 410 is not subdivided into sub-chambers, and there is no dedicated gas exhaust system (compare FIG. 4 with FIG. 1 ). In FIG. 4, the gas escapes through predetermined openings (e.g. gaps around the entry and exit foil feeders) through the chamber. The foil strip S is conducted through the enclosure along a horizontal, straight path, entering through a slot in the right (in the drawing) side wall and exiting through a slot in the left side wall. A guide 434 on the incoming side of the tool set 436 supports the strip and is configured to afford rapid heat transfer to the strip so that it arrives at the tool set at a high temperature for working. On the other hand, the guide 434 does not “feed” heat from within the chamber back to the part of the strip that is still outside the enclosure (and in the air) to an extent that the part that has not entered the enclosure might be oxidized. The outgoing part of the then corrugated strip S is supported along its exit path from the tool set by a guide 438 , which is designed to cool the strip so that it leaves the enclosure at a temperature below that at which it is subject to oxidation. The guide 438 is also designed to prevent “pulling” heat away from the part of the strip that—at any point in time—is being corrugated by the tool set.
The tool set 436 consists of a driven form gear 442 and an idler form gear 444 , the same type of tool set as in the first embodiment (FIG. 1 ). FIG. 4 shows the upper part of an adjustable support tower 448 for the idler form gear. One can observe an adjustable compression spring 448 s , which biases the idler form gear 444 into engagement with the driven form gear 442 such as to form the corrugations under a predetermined “nip pressure” between the form gears. The spring 448 s allows the gears to disengage in the event of over pressure of the gear tool set or a malfunction that causes a build up of strip in the tool set.
The fourth embodiment does not have an exhaust system as such for conducting inert gas from the chamber within the enclosure 410 . Instead, the slots through which the foil strip enters and leaves the chamber (as well as other openings in the enclosure walls) are sized to allow leakage of the inert gas from the chamber at a suitable rate to ensure that the inert gas supplied to the chamber flows through the chamber and sweeps out oxygen.
The tool set 536 of the fifth embodiment (FIG. 5) consists of a rotating form gear 542 and a reciprocating punch 544 . The form gear 542 is driven in rotation by a drive (not shown) intermittently to move each cavity seriatim into a position immediately below the punch 544 and then dwell while the punch 544 makes a cycle of a down movement and an up movement. The punch has a single forming tooth 544 t (FIG. 6) that moves into the then-waiting cavity 542 c of the form gear. The punch also has a spring-biased holding foot 544 f located abreast of the forming tooth. On each down-stroke of the punch, which is actuated by a linear drive 536 d , the holding foot 544 f engages the segment of the foil strip that overlies the tooth of the forming gear immediately on the outgoing side of the cavity 542 c into which the forming tooth is about to move on its down-stroke. The engagement occurs before the forming tooth engages the foil to begin forming the next corrugation, so that the outgoing corrugation of the foil strip is engaged and clamped by the holding foot against the tip of the outgoing tooth flanking the segment of the foil strip that will form the next corrugation to be formed before it is formed by a down-stroke of the punch. The clamping of the immediately outgoing corrugation while the next corrugation is formed ensures that the shape of each outgoing corrugation is retained rather than possibly being pulled partly back as the immediately following corrugation is formed. Each corrugation is formed of material from the incoming part of the foil strip, which is pulled into the cavity on the down-stroke of the punch. The rotary drive of the form gear and the linear actuator of the punch are computer/servo-controlled so as to time the rotations and dwell periods of the form gear and the dwell periods and strokes of the punch very precisely. Even though each corrugation in the foil strip is formed individually with an overall operating cycle that includes dwell periods for both the form gear and the punch, a well-designed machine according to FIG. 5 can be run at a speed that will produce up to several corrugations per second.
The sixth embodiment (FIG. 7 ), has a tool set 636 consisting of a form gear 642 that is rotated intermittently with a dwell period between each increment of rotation in which it remains stationary while a pre-form punch 644 P partially forms a corrugation in one cavity and a final form punch 644 F located circumferentially spaced apart from the pre-form punch in the direction of rotation of the form gear completes the formation of a partially formed corrugation previously started by the preform punch. The two punches 644 P and 644 F are identical except for the shapes of the forming tooth on each punch. Furthermore, punch 644 F is identical to punch 544 of FIGS. 5 and 6, and punch 644 P is identical to punch 544 except for the shape of the forming tooth on each punch. The machine is timed, of course, so that the cycles of the punches coincide and both punches dwell while the form gear rotates a distance equal to the pitch distance of the forming cavities.
The tool sets of the embodiments shown in FIGS. 5 to 7 are described and shown in U.S. patent application Ser. No. 09/970,571 filed concurrently herewith, which is incorporated by reference herein for all purposes. | A machine and method for corrugating a metal foil strip utilizes an enclosure defining a chamber and a controllable heat source for heating the chamber. The chamber may optionally include at least one gas that is also heated by the heat source. At least one tool set received in the chamber forms corrugations in the metal foil strip. Foil entry feeder elements supply and guide the metal foil strip from outside the chamber into the chamber and to the tool set. A drive for the tool set is mounted outside the chamber and coupled to the tool set to actuate the tool set. Foil exit delivery elements guide the strip from the tool set and out of the chamber. Where required to prevent oxidation of the foil strip, a source supplying an inert gas to the chamber at a controlled rate is used. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a device for protecting securities such as shares, bonds, bank notes and the like whereby this device consists of a unit which can be closed, and which is divided in at least two spaces, whereby the first space is designed to hold the papers to be protected, whereas pyrotechnical means are provided in the second space which, when the device is manipulated in an unwanted manner, make the above-mentioned papers worthless.
In particular, the present invention concerns a device of the type which is mounted in a fixed or portable manner in a private or public building, in a bank, in a means of transport or the like.
2. Brief Description of the Related Art
Devices of this type are already known which, when they are used in the wrong manner, for example in case of a burglary, or when the latter or similar devices are opened in an unwanted manner, the content is exposed to ink, smoke or another material so as to damage or destroy the securities.
However, it was found that when the papers provided in these known devices so as to protect them are not always entirely damaged and/or destroyed after somebody has attempted to open the device in an unwanted manner or after somebody has entered the wrong code in case of combination locks or such.
It was found that in those cases, a relatively large number of securities remains nevertheless undamaged, such that it is still worth while to force these devices.
Another type of device for protecting securities is known from U.S. Pat. No. 4,236,463. This known device consists of a case which is divided in at least two spaces, whereby the first space can hold the papers to be protected, whereas the second space is entirely filled with a non-explosive thermite load which closes off the first space and which, when the device is manipulated in an unwanted manner, will become overheated up to over 1649° C. as a result of a chemical reaction, as a result of which the papers contained in the first space will carbonize.
SUMMARY OF THE INVENTION
The present invention aims a device for protecting securities, in particular a device which makes these papers completely useless when the device is opened in an unwanted manner or when the device is manipulated by someone who does not know the code, but in such a manner that data provided on these papers, such as identification numbers or such remain intact.
To this aim, according to the present invention, the pyrotechnical means which are situated in the second space are capsules which each contain a pyrotechnical mixture which, when the device is manipulated in an unwanted manner as mentioned above, will inflame so as to produce a flame which transpierces the papers contained in the first space.
According to a preferred embodiment, the device according to the present invention will be equipped with at least one maze or labyrinth through which the produced gases can escape, such that flames nor gases under pressure can in no way whatsoever escape from the device when the security system is activated.
In a similar manner, retardation mechanisms can be provided on the means causing the destruction of the securities, such that the latter are destroyed at short intervals, so as to avoid that the destruction is too brutal at a given moment and that flames and/or gases under pressure escape from the device.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to better explain the characteristics of the invention, the following two devices according to the invention are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:
FIG. 1 shows a view in perspective of a device according to the invention, made in this case in the shape of a portable briefcase;
FIG. 2 shows a section according to line II—II in FIG. 1 to a larger scale;
FIGS. 3, 4 , 5 and 6 respectively show sections according to lines III—III, IV—IV, V—V and VI—VI in FIG. 2;
FIG. 7 shows a connection diagram of the ignition device according to the invention;
FIG. 8 shows a connection diagram of the same type as in FIG. 7, but for another embodiment;
FIG. 9 shows a cross section of an ignition capsule as used in the device according to the invention;
FIG. 10 represents a table of possible pyrotechnical mixtures;
FIG. 11 shows a front view of a device according to the invention, but in relation to another embodiment, namely in the shape of a safety box;
FIG. 12 shows a section according to lines XII—XII in FIG. 11;
FIGS. 13 and 14 show sections according to lines XIII—XIII and XIV—XIV in FIG. 12;
FIG. 15 shows the part indicated by F 15 in FIG. 13 to a larger scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although by a device is understood a portable briefcase or safety box in the examples described hereafter, it is clear that the present invention may also apply to fixed as well as moveable devices such as for example a safe or such.
A portable briefcase 1 is represented in FIGS. 1 to 6 which mainly consists of a base 2 and a lid 3 which is connected to the base 2 by means of appropriate hinges and locks 4 - 5 which are not represented here, and whose base is equipped with a handle 6 .
This portable briefcase 1 can be made in any material whatsoever.
In general, the volume of the portable briefcase 1 is subdivided in three separate spaces, namely a first space 7 in which the securities 8 , for example banknotes, can be safeguarded, a second space 9 in which the ignition and fire destruction mechanism 10 is mounted and a third space 11 in which one or several flues forming a labyrinth shaped path are provided through which the flames or gases which are released during the ignition or destruction by the fire, provoked by the ignition and fire destruction mechanism 10 , are diminished before leaving the device.
The above-mentioned spaces 7 and 9 are separated from one another by means of a first partition comprising a metal plate 12 , for example made of aluminium, in which a small hole 13 is provided on the spot where a wad of securities 8 , for example banknotes, will be placed, whereby a capsule 14 is provided in the space 9 opposite each small hole 13 , each filled with a pyrotechnical mixture.
All the capsules 14 are electrically connected to an electronic security system which, as represented in FIG. 7, can be built as follows:
Each capsule 14 is electrically connected to the ground consisting in this case of the first partition 12 , and it is further connected to an electronic switching mechanism 15 which is placed in the electric circuit of a battery 16 situated between the switching mechanism 15 and the first partition, whereby a reversing switch 17 is provided in the above-mentioned electric circuit which makes it possible to put the security device under tension.
The third space 11 of the portable briefcase 1 is in this case confined by a second partition comprising a metal plate 18 forming a division between said third space 11 and the first space 7 , whereby, relatively large holes 19 are provided in said second partition plate 18 , opposite each wad of papers 8 , in particular coaxially in relation to the holes 13 provided in the first partition 12 .
Moreover, the third space 11 is subdivided in one or several flues, in this case one flue having a labyrinth shaped path 20 per capsule 14 , whereby these flues 20 open into the atmosphere via a passage 21 provided to this end in the external wall of the third space 11 and in the adjacent walls of the base 2 and the lid 3 .
FIG. 8 shows a variant of the diagram according to FIG. 7, whereby, in this case, certain capsules 14 are equipped with what is called a retardation device 22 which forms a barrier between the ignition mechanism 23 and the pyrotechnical mixture of the capsule 14 so as to obtain a retarded ignition of the pyrotechnical mixture. These retardation devices may be identical to one another or they may be divided in groups or they may also be all different so as to obtain discharges going off at different moments.
Naturally, also other embodiments of the electronic security system are possible.
Thus, FIG. 9 represents a capsule 14 made of steel, whereby this capsule 14 is coupled to the retarding mechanism 22 via an opening 24 , to the ignition mechanism 23 respectively, and whereby a pyrotechnical mixture is put in said capsule 14 consisting of what are called pyrotechnical charges, in this case an ignition charge 25 and three fire destruction charges 26 , 27 and 28 which may have an appropriate composition, the whole being sealed by a small plate 29 made of nonflammable material.
The pyrotechnical mixture may have any composition whatsoever; as an example only, a table of materials which can be used in any combination whatsoever, in compliance with the indicated proportions, in order to form an ignition charge 25 , a fire destruction charge 26 - 27 - 28 respectively, is represented in FIG. 10 .
The ignition charge may consist of magnesium, strontium peroxides and bonding materials, whereas the pyrotechnical mixture may consist of iron oxides, magnesium, aluminium, barium nitrate, graphite and synthetic phenol resin.
The use and working of the device according to the invention is very simple and as described below.
When a certain number of securities 8 , for example bank notes, are put in a portable briefcase 1 according to the invention, for example in order to transport papers of this sort, these papers are placed exactly over the holes 13 provided in the first partition 12 , in the first space 7 whose dimensions preferably correspond to those of the papers.
Then, the device 1 is closed such that the papers 8 are perfectly protected, whereby the reversing switch 17 is switched off in an appropriate manner as the briefcase is closed.
The reversing switch 17 can be provided at any place whatsoever, for example between the base 2 and the lid 3 , in either of the locks 4 - 5 , combined with a combination lock or combined with a keyboard for entering a code or via which one has to enter a code at regular intervals so as to switch off the reversing switch 17 .
The reversing switch 17 or the electronic security system may also be remotely controlled, in which case the tripping of the security system does not need to coincide with the portable briefcase 1 being closed.
When someone wants to break into a portable briefcase 1 of this type, either by twisting the lid 3 or by distorting the locks 4 or 5 , or also, in the case of a keyboard, by damaging this keyboard or by entering the wrong code, the reversing switch 17 will be switched on in the appropriate manner and, via the electronic switching mechanism 15 , it will send a message to the capsules 14 ordering the ignition mechanism 23 to provoke the ignition of the ignition charge 25 , and consequently of the fire destruction charges 26 - 27 - 28 , such that, through the holes 13 provided in the first partition 12 , a flame is lit transpiercing the wads of papers 8 , whereby this flame and the produced gases are then led through a flue 20 , where they are diminished before leaving the portable briefcase 1 , such that flames and/or gases under pressure can by no means escape from the portable briefcase 1 .
The thus realised piercing of the papers 8 may cause a conical, flattened burn hole in the wad of papers 8 , having a diameter of about 3 to 4 cm in the base and of about 1 cm at the top, with a total height of at least 5 cm.
In this way, the papers 8 are made useless, but they remain as such, such that they can still be examined in one way or the other.
FIG. 8 shows another connection diagram in which is applied a retarding device 22 on certain capsules 14 so as to program the discharge of the capsules 14 such that, for example in the example represented in FIG. 8, three capsules 14 will flare up together, igniting a second series of three capsules 14 a few seconds later and finally igniting a third series of capsules 14 after another few seconds, such that the force of the ignition is spread in time.
FIGS. 11 to 15 represent another embodiment of the invention in which the device is made in the shape of a security box 30 .
The construction is analogous to that of the portable briefcase 1 , but the lid 3 is replaced by a flap 31 in a narrow side wall of the security box 30 , whereas the third space 11 , in which are provided one or several flues having a labyrinth shaped path 20 , is made in the shape of a revolving shutter 32 .
FIGS. 11 to 15 represent identical or analogous elements or spaces having the same reference numbers as used in FIGS. 1 to 6 .
In this embodiment, the first partition 12 forms a tray, such that the second space 9 in which is mounted the ignition and fire destruction mechanism 10 extends all around the first space 7 , with the exception of the front side where the flap 31 is provided.
The flap 31 can be bolted by means of a lock 5 with an electronic key.
The third space 11 which forms one or several flues 20 is not provided directly against the flap 31 , but it is provided against the inside at a certain distance of the latter in the revolving shutter 32 which can glide over guides 33 in the second space 9 .
The slats 32 ′ of the revolving shutter 32 are double-walled and are made of metal, and they each have an opening 34 near one end. Said slat 32 ′ is divided in two in its longitudinal direction by means of a partition 35 which is connected at one end to the far end of the slat 32 ′ alongside which the openings 34 are provided, whereby the other end remains at a short distance from the other far end of the slat 32 ′.
Thus, a flue 20 is formed in each slat 32 ′ through which the ignition gases coming in via the opening 34 must cover a long distance before they come out of the opening 34 against the outer side of the slat 32 ′ in the space provided between the revolving shutter 32 and the flap 31 . From this space they can escape into the atmosphere through the clearance of the flap 31 .
Successive slats 32 ′ of the revolving shutter 32 are provided such that the openings 34 are provided alternately on either side of the revolving shutter 32 .
By closing the flap 31 or after it has been closed via a remote control, the reversing switch 17 is switched off or the security system is activated in one way or another.
In case of violation, the security box 31 works in the same manner as described above for the portable briefcase 1 .
Thanks to the design of the revolving shutter 32 described above, neither flames nor gases under pressure can escape from this security box 30 .
It is clear that the present invention is in noway limited to the embodiments described as example and shown in the annexed drawings; a device according to the invention may be realised in all sorts of shapes and dimensions without falling outside the scope of the invention. | The invention concerns a protective device for valuable documents, including a volume capable of being closed and divided into two compartments, one of the compartments being used to receive the documents to be protected while in the second compartment caps contain a pyrotechnic mixture which, when the device is wrongly manipulated, will burst into a flame which will penetrate the documents in the first mentioned compartment. | 4 |
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a developing apparatus, a process cartridge, and an electrophotographic image forming apparatus which uses a process cartridge.
[0002] Here, an electrophotographic image forming apparatus means an apparatus which forms an image on recording medium with the use of an electrophotographic image forming method. Examples of an electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, laser beam printer, LED printer, etc.), a facsimile apparatus, a wordprocessor, etc.
[0003] A process cartridge means a cartridge in which an electrophotographic photosensitive drum and one or more processing apparatuses, that is, a charging means, a developing means, and a cleaning means, are integrally disposed, and which is removably mountable in the main assembly of an electrophotographic image forming apparatus. More specifically, a process cartridge means a cartridge in which an electrophotographic photosensitive drum, a charging means, and a developing means or cleaning means, are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus. It also means a cartridge in which an electrophotographic photosensitive drum, and at least one among a charging means, a developing means, and a cleaning means, are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus. Further, it also means a cartridge in which an electrophotographic photosensitive drum and a developing means are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus.
[0004] In the field of an electrophotographic image forming apparatus which uses an electrophotographic image formation process, it has been common practice to employ a process cartridge system, which integrally disposes an electrophotographic photosensitive drum and one or more means for processing the electrophotographic photosensitive drum in a cartridge so that they can be removably mountable in the main assembly of an image forming apparatus. A process cartridge system enables in effect a user to maintain an electrophotographic image forming apparatus by himself or herself, that is, without relying on a service person. Thus, it can drastically improve an electrophotographic image forming apparatus in operational efficiency. Therefore, a process cartridge system is widely in used in the field of an electrophotographic image forming apparatus.
[0005] An electrophotographic image forming apparatus forms an electrostatic latent image on its photosensitive drum by projecting a beam of light emitted by a laser, an LED, an ordinary lamp, or the like, while modulating the beam of light with the information regarding an image to be formed.
[0006] Then, it develops the electrostatic latent image on the photosensitive drum into a toner image. More specifically, it applies a development bias to the development roller with which its developing apparatus is provided. As a result, the electrostatic latent image on the photosensitive drum is developed into a toner image with the toner on the development roller. Then, it transfers the toner image on the photosensitive drum onto recording medium.
[0007] Thus, the development unit 4 is provided with electrical contacts for applying bias voltage to the development roller, etc. The electrical contacts are formed of electrically conductive plate or the like. Thus, it is common practice to structure an electrophotographic image forming apparatus so that as a developing apparatus or a process cartridge is mounted into the main assembly of the image forming apparatus, its electrical contacts come into contact with the counterparts of the main assembly of the image forming apparatus.
[0008] As one of the means for driving the development roller in a process cartridge, such as the one described above, the driving means disclosed in Japanese Laid-open Patent Application 2004-12523 has been well-known. In the case of this development roller driving means, one of the lengthwise ends of the shaft of the development roller, which is to be fitted with a driving force transmitting (receiving) member, for example, a helical gear, is given such a cross-sectional shape (for example, D-shaped or H-shaped) that prevents the driving force transmitting member from slipping relative to the shaft in terms of the rotational direction.
[0009] More specifically, in terms of the direction of the teeth of the helical gear, the helical gear is structured so that as driving force is applied (transmitted) to the helical gear from the main assembly of the image forming apparatus, thrust is generated in the direction to push the development roller in the lengthwise direction of the development roller. Further, the electrical contacts for supplying the development roller with the development bias are disposed so that they contact the opposite lengthwise end of the shaft of the development roller from the helical gear in terms of the lengthwise direction of the axial line of the development roller.
[0010] There is another well-known means for driving the development roller, which is disclosed in Japanese Laid-open Patent Application H11-338211. In the case of this development roller driving means, an Oldham's coupling is used as the member for transmitting driving force to the developing device. The usage of the Oldham's coupling makes it possible to ensure that even if the rotational axis of the driving force output shaft (driving shaft of main assembly) becomes misaligned with the rotational axis of the driving force input shaft (drive shaft of developing device), the development roller driving force is reliably transmitted to the development roller.
[0011] In the case of a developing apparatus an electrophotographic image forming apparatus structured so that its developing apparatus is mounted into its main assembly in the direction parallel to the axial line of the development roller, it is also structured so that the developing apparatus receives the development roller driving force through its leading end (downstream end) in terms of the developing apparatus insertion direction, and further, so that the electrical contacts of the developing apparatus, which are for supplying the development roller with development bias, make contact with the counterparts of the main assembly of the image forming apparatus, also at the leading end.
[0012] Thus, conventional image forming apparatuses require a large amount of space for routing wiring for the bias contacts.
[0013] Further, in a case where an Oldham's coupling is used as the member for the developing apparatus to receive the mechanical force from the main assembly of an image forming apparatus, the thrust generated by the transmission of the driving force is not as large as the thrust generated in a case where a helical gear is used as the member for the developing apparatus to receive the mechanical force from the main assembly of the image forming apparatus. Thus, in the case where an Oldham's coupling is used, it becomes a serious concern how to make the bias contact precisely (reliably) contact, and remain in contact, with the development roller.
SUMMARY OF THE INVENTION
[0014] The present invention was made in consideration of the above described concern. Thus, its primary object is to provide a developing apparatus, a process cartridge, and an electrophotographic image forming apparatus, which are characterized in that the electrical contact for the development roller precisely (reliably) contact, and remain in contact, with the development roller.
[0015] According to an aspect of the present invention, there is provided a developing apparatus including a developing roller for developing an electrostatic latent image formed on a photosensitive member, wherein said developing apparatus is detachably mountable to a main assembly of an electrophotographic image forming apparatus in an axial direction of said developing roller, said developing apparatus comprising a drive transmission member, provided at one end of said developing roller, for receiving a driving force from the main assembly and transmitting the driving force to said developing roller; an urging member, provided at other end, for urging said developing roller in the axial direction; an abutting portion, provided adjacent said one end, for being abutted by said shaft of said developing roller by an urging force of said urging member to position said developing roller with respect to the axial direction; and a contact member contactable to a main assembly contact provided in the main assembly when said developing apparatus is mounted to the main assembly, wherein said contact member contacts to a peripheral surface of said shaft of said developing roller adjacent said one end to apply a voltage to said developing roller.
[0016] According to another aspect of the present invention, there is provided a process cartridge including a photosensitive member, a developing roller for developing an electrostatic latent image formed on said photosensitive member, wherein said process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus in an axial direction of said developing roller, said process cartridge comprising a drive transmission member, provided at one end of said developing roller, for receiving a driving force from the main assembly and transmitting the driving force to said developing roller; an urging member, provided at other end, for urging said developing roller in the axial direction; an abutting portion, provided adjacent said one end, for being abutted by said shaft of said developing roller by an urging force of said urging member to position said developing roller with respect to the axial direction; and a contact member contactable to a main assembly contact provided in the main assembly when said process cartridge is mounted to the main assembly, wherein said contact member contacts to a peripheral surface of said shaft of said developing roller adjacent said one end to apply a voltage to said developing roller.
[0017] According to a further aspect of the present invention, there is provided an electrophotographic image forming apparatus for forming an image on a recording material, said apparatus comprising (i) a photosensitive member; (ii) a developing device including a developing roller for developing an electrostatic latent image formed on a photosensitive member, wherein said developing device is mounted to a main assembly of an electrophotographic image forming apparatus in an axial direction of said developing roller, said developing device further including a drive transmission member, provided at one end of said developing roller, for receiving a driving force from the main assembly and transmitting the driving force to said developing roller, an urging member, provided at other end, for urging said developing roller in the axial direction, an abutting portion, provided adjacent said one end, for being abutted by said shaft of said developing roller by an urging force of said urging member to position said developing roller with respect to the axial direction, and a contact member contactable to a main assembly contact provided in the main assembly when said developing apparatus is mounted to the main assembly, wherein said contact member contacts to a peripheral surface of said shaft of said developing roller adjacent said one end to apply a voltage to said developing roller; (iii) mounting means for detachably mounting said developing apparatus; and (iv) feeding means for feeding the recording material.
[0018] According to a further aspect of the present invention, there is provided an electrophotographic image forming apparatus for forming an image on a recording material, said apparatus comprising (i) a process cartridge including a photosensitive member, a developing roller for developing an electrostatic latent image formed on said photosensitive member, wherein said process cartridge is mounted to a main assembly of an electrophotographic image forming apparatus in an axial direction of said developing roller, said process cartridge further including a drive transmission member, provided at one end of said developing roller, for receiving a driving force from the main assembly and transmitting the driving force to said developing roller, an urging member, provided at other end, for urging said developing roller in the axial direction, an abutting portion, provided adjacent said one end, for being abutted by said shaft of said developing roller by an urging force of said urging member to position said developing roller with respect to the axial direction, and a contact member contactable to a main assembly contact provided in the main assembly when said process cartridge is mounted to the main assembly, wherein said contact member contacts to a peripheral surface of said shaft of said developing roller adjacent said one end to apply a voltage to said developing roller; (ii) mounting means for detachably mounting said process cartridge; and (iii) feeding means for feeding the recording material.
[0019] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic sectional view of the electrophotographic color image forming apparatus in the first preferred embodiment of the present invention, which depicts the general structure of the apparatus.
[0021] FIG. 2 is a schematic sectional view of the cartridge for the image forming apparatus shown in FIG. 1 .
[0022] FIG. 3 is a perspective view of the image forming apparatus in FIG. 1 prior to the mounting of the cartridge into the main assembly of the image forming apparatus.
[0023] FIG. 4 is a top plan view of the cartridge, which shows the general structure of the cartridge.
[0024] FIG. 5 is a side view of the cartridge, as seen from the leading side of the cartridge in terms of the direction in which the cartridge is mounted into the main assembly of the image forming apparatus, which also depicts the structure of the cartridge.
[0025] FIGS. 6( a ) and 6 ( b ) are schematic sectional views of the lengthwise end portion of the development roller, from which the development roller is driven.
[0026] FIGS. 7( a ) and 7 ( b ) are sectional views of the lengthwise end portion of the development roller, in another embodiment of the present invention, from which the development roller is driven.
[0027] FIG. 8 is a perspective view of the lengthwise end portion of the development roller, in the first preferred embodiment, by which the development roller is driven.
[0028] FIG. 9 is a perspective view of the lengthwise end portion of the development roller, in another preferred embodiment, from which the development roller is driven.
[0029] FIG. 10 is a schematic, perspective, and exploded view of one of the lengthwise end portion of the development roller pressing member, and its adjacencies, from which the developing apparatus is not driven, which is for describing the structure of the pressing member.
[0030] FIG. 11 is a side view of the development unit in the first preferred embodiment, as seen from the deepest end of the apparatus main assembly in terms of the cartridge insertion direction, with the Oldham's coupling 40 removed.
[0031] FIG. 12 is a side view of the development unit 4 in another embodiment, as seen from the deepest end of the apparatus main assembly in terms of the cartridge insertion direction, with the Oldham's coupling 40 removed.
[0032] FIG. 13 is an exploded perspective view of the Oldham's coupling, which is for describing the structure of the coupling.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] In the following descriptions of the preferred embodiments of the present invention, the electrical contacts and driving force transmitting member disclosed in the claim portion of this application will be referred to as development roller contacts and Oldham's coupling, respectively. Further, the surface of the main assembly of the image forming apparatus, upon which the development roller is kept pressed, will be referred as regulating surface.
Embodiment 1
[0034] Next, the process cartridge (which hereafter will be referred to simply as cartridge) and electrophotographic image forming apparatus (which hereafter will be referred simply as image forming apparatus) in the first preferred embodiment of the present invention will be described with reference to the appended drawings.
(General Structure of Image Forming Apparatus)
[0035] First, referring to FIGS. 1 and 3 , the image forming apparatus in this embodiment will be described regarding its general structure. The image forming apparatus 100 , shown in FIG. 1 , has four cartridge chambers 22 ( 22 a - 22 d ), where four cartridges are mounted one for one), which are placed in tandem at a preset angle relative to the horizontal direction ( FIG. 3 ). The four cartridges 7 ( 7 a - 7 d ) in the four cartridge chambers ( 22 a - 22 d ) are provided with four electrophotographic photosensitive drums 1 ( 1 a - 1 d ), respectively.
[0036] The electrophotographic photosensitive drum 1 (which hereafter will be referred to simply as photosensitive drum 1 ) is rotated by a driving member (unshown) in the clockwise direction, shown in FIG. 1 . In the adjacencies of the peripheral surface of the photosensitive drum 1 , multiple means for processing the photosensitive drum 1 are disposed. More specifically, a cleaning member 6 ( 6 a - 6 d ), a charge roller 2 ( 2 a - 2 d ), and a development unit 4 ( 4 a - 4 d ) are disposed in the listed order. The cleaning member 6 is for removing the developer (which hereafter may be referred to as toner) remaining on the peripheral surface of the photosensitive drum 1 after the abovementioned transfer of the toner image from the photosensitive drum 1 . The charge roller 2 is for uniformly charging the photosensitive drum 1 ( 1 a - 1 d ), respectively, across their peripheral surfaces. The development unit 4 is for developing the abovementioned electrostatic latent image on the photosensitive drum 1 with the use of the toner. As for the main assembly of the image forming apparatus, it is provided with a scanner unit 3 and an intermediary transfer belt 5 . The scanner unit 3 forms an electrostatic latent image on the photosensitive drum 1 by projecting a beam of light on the photosensitive drum 1 while modulating the beam with the information regarding the image to be formed. The intermediary transfer belt 5 is the belt onto which four monochromatic toner images, different in color, are sequentially transferred in layers from the four photosensitive drums 1 . The photosensitive drum 1 , cleaning member 6 , charge roller 2 , and development unit 4 are integrally disposed in a cartridge 7 , which can be removably mountable in the main assembly 100 a of the image forming apparatus 100 by a user.
[0037] The intermediary transfer belt 5 is suspended by a driver roller 10 and a tension roller 11 . Further, the main assembly 100 a of the image forming apparatus 100 (which hereafter will be referred to simply as apparatus main assembly 100 a ) is provided with four primary transfer rollers 12 ( 12 a - 12 d ), which are disposed in the loop which the intermediary transfer belt 5 forms. To the intermediary transfer belt 5 , a transfer bias is applied by a bias applying means (unshown).
[0038] After the formation of a toner image on the photosensitive drum 1 , the toner image is carried by the photosensitive drum 1 in the direction indicated by an arrow mark Q, while the intermediary transfer belt 5 is circularly rotated in the direction indicated by an arrow mark R, and a positive bias is applied to the primary transfer rollers 12 . As a result, the four monochromatic toner images, different in color, are sequentially transferred (primary transfer) in layers onto the intermediary transfer belt 5 . Then, the four monochromatic toner images layered on the intermediary transfer belt 5 are conveyed by the intermediary transfer belt 5 to a secondary transfer portion 15 while remaining layered.
[0039] Meanwhile, a sheet S of recording medium (which hereafter will be referred to simply as sheet S) is conveyed to the secondary transfer portion 15 by a recording medium feeding apparatus 13 , a pair of registration rollers 17 , etc., in synchronism with the progression of the above described image forming operation. The recording medium feeding apparatus 13 has: a recording medium feeder cassette 24 , in which multiple sheets S of recording medium are stored; a feeder roller 8 for feeding recording mediums into the apparatus main assembly 100 a ; and a pair of conveyer rollers 16 for conveying further the fed sheet S. The feeder cassette 24 can be pulled out of the apparatus main assembly 3 in the frontward direction. The recording sheets S in the feeder cassette 24 are kept pressed against the feeder roller 8 so that the top sheet S is kept pressed on the feeder roller 8 . They are fed into the apparatus main assembly 100 a by a separation pad 9 in such a manner that only the top sheet S is fed into the apparatus main assembly 100 a while being separated from the other recording mediums S in the feeder cassette 24 (separating system based on friction).
[0040] After being fed into the apparatus main assembly 100 a from the recording medium feeding apparatus 13 , each sheet S is conveyed to the secondary transfer portion 15 by the pair of registration rollers 17 . In the secondary transfer portion 15 , a positive bias is applied to a secondary transfer roller 18 . Thus, the four monochromatic toner images, different in color, on the intermediary transfer belt 5 are transferred together (secondary transfer) onto the sheet S while the four toner images and the sheet S are conveyed through the secondary transfer portion 15 .
[0041] A fixing portion 14 , which is a fixing means, is a portion for fixing an unfixed color toner image on the sheet S, to the sheet S by applying heat and pressure to the sheet S and the unfixed toner image thereon after the transfer of the color toner image onto the sheet S. The fixation belt 14 a is cylindrical, and is guided by a belt guiding member (unshown) having heating means, such as a heater, bonded to the belt guiding member. The fixation belt 14 a and a pressure roller 14 b are kept pressed upon each other by a preset amount of pressure to form a fixation nip between the belt 14 a and roller 14 b.
[0042] After the formation of an unfixed toner image on the sheet S in the image forming portion, the sheet S is conveyed from the image forming portion to the fixing portion 14 , and then, is conveyed through the fixation nip, which is the interface between the fixation belt 14 a and pressure roller 14 b . While the sheet S is conveyed through the fixation nip, the sheet S and the multicolor toner images thereon are subjected to heat and pressure. As a result, the unfixed multicolor toner image becomes fixed to the sheet S. Thereafter, the sheet S, that is, the sheet to which the multicolor toner images has just been fixed, is discharged into a delivery tray 20 by a pair of discharge rollers 19 .
[0043] Meanwhile, the toner remaining on the peripheral surface of each of the photosensitive drums 1 after the primary transfer of the toner image, is removed by the cleaning member 6 . The removed toner is recovered into a toner chamber with which the latent image formation units 26 ( 26 a - 26 d ) are provided.
[0044] The toner remaining on the intermediary transfer belt 5 after the transfer (secondary transfer) of the multicolor toner image onto the sheet S is removed by a transfer belt cleaning apparatus 23 . The removed toner is recovered into a waste toner recovery container disposed in the rear end portion of the apparatus main assembly 100 a.
(Cartridge)
[0045] Next, referring to FIG. 2 , the cartridge in this embodiment will be described. FIG. 2 is a schematic section view of the cartridge 7 , which contains toner t, at a plane perpendicular to the lengthwise direction of the cartridge 7 . Incidentally, the cartridge for storing yellow toner t is referred to as cartridge 7 a , and the cartridge for storing magenta toner t is referred to as cartridge 7 b . Further, the cartridge for storing cyan toner t is referred to as cartridge 7 c , and the cartridge for storing black toner t is referred to as cartridge 7 d . The four cartridges 7 a - 7 d are the same in structure.
[0046] Each cartridge 7 is made up of a latent image formation unit 26 and a development unit 4 . The latent image formation unit 26 is provided with the photosensitive drum 1 , charge roller 2 (charging means), and cleaning member 6 (cleaning means). The development unit 4 has the development roller 25 (developing means).
[0047] The photosensitive drum 1 is rotatably attached to the cleaning means frame portion 27 of the latent image formation unit 26 , with the bearings (which will be described later) disposed between the cleaning means frame portion 27 and the photosensitive drum 1 . During an image forming operation, the photosensitive drum 1 is rotated by transmitting driving force to the photosensitive drum 1 from a motor (unshown) for driving the latent image formation unit 26 . There are the charge roller 2 and cleaning member 6 in the adjacencies of the peripheral surface of each photosensitive drum 1 as described above. As the transfer residual toner, more specifically, the toner remaining on the peripheral surface of the photosensitive drum 1 is removed by the cleaning member 6 , it falls into the removed toner storage chamber 27 a . A pair of charge roller bearings 28 are attached to the cleaning means frame portion 27 in such a manner that they can be moved in the direction indicated by an arrow mark D which coincides with the axial line of the photosensitive drum 1 and the axial line of the charge roller 2 . The shaft 2 j (rotational axle) of the charge roller 2 is rotatably supported by the pair of charge roller bearings 28 . Further, the charge roller bearings 28 are kept pressed toward the photosensitive drum 1 by a pair of charge roller pressing members 46 .
[0048] The development unit 4 has a development roller 25 and a development unit frame 31 . The development roller 25 rotates in contact with the photosensitive drum 1 in the direction indicated by an arrow mark B. The development roller 25 is rotatably supported by the development unit frame 31 with a pair of bearings 32 ( 32 R and 32 L) disposed between the lengthwise end portions (in terms of direction parallel to axial line of development roller 25 ) and the right and left walls of the development unit frame 31 , respectively. Further, the development unit 4 is provided with a toner supply roller 34 and a development blade 35 , which are disposed in the adjacencies the peripheral surface of the development roller 25 . The toner supply roller 34 rotates in contact with the development roller 25 in the direction indicated by an arrow mark C. The development blade 35 is for regulating in thickness the layer of toner on the peripheral surface of the development roller 25 . Further, the development unit 4 is provided with a toner conveying member 36 for conveying the toner in the development unit 4 to the abovementioned toner supply roller 34 while stirring the toner. The toner conveying member 36 is disposed in the toner storage portion 31 a of the development unit frame 31 .
[0049] The development unit 4 is connected to the latent image formation unit 26 with the use of a pair of shafts 37 ( 37 R and 37 L) put through the holes 32 R and 32 L with which the bearings 32 R and 32 L are provided, respectively, in such a manner that the two units 4 and 26 are enabled to rotationally move relative to each other about the pair of shafts 37 . The development unit 4 is kept under the pressure by a pair of compression springs 38 . Thus, as the cartridge 7 is mounted into the apparatus main assembly 100 a , the development unit 4 rotates about the pair of shafts 37 in the direction indicted by an arrow mark A, causing the development roller 25 to come into contact with the photosensitive drum 1 , and ensures that the development roller 25 remains in contact with the photosensitive drum 1 during image formation.
(Structure of Oldham's Coupling)
[0050] Next, referring to FIG. 13 , the driving force transmitting member (which hereafter may be referred to as Oldham's coupling) in this embodiment will be described. FIG. 13 is a perspective and exploded view of the Oldham's coupling. The Oldham's coupling 40 is attached to one of the lengthwise ends of the shaft 25 b of the development roller 25 in terms of the direction parallel to the axial line of the development roller 25 . The Oldham's coupling 40 is made up of a driving force receiving portion 40 a , a center portion 40 b , and a driving force transmitting portion 40 c . The engaging portion 40 a 2 of the driving force receiving portion 40 a receives the development roller driving force from the apparatus main assembly 100 a by engaging with a coupling 100 b ( FIG. 6 ) of the apparatus main assembly 100 a , which is connected to the drive shaft of the apparatus main assembly 100 a . Incidentally, the development roller shaft 25 b is rotatably supported by the bearing 32 R ( FIG. 6( b )), which is solidly fixed to the development unit frame (unshown).
[0051] The driving force transmitting portion 40 c is solidly fixed to the development roller shaft 25 b in such a manner that their axes coincide. The driving force transmitting portion 40 c has a rib 40 c 1 , which is an integrally formed part of the driving force transmitting portion 40 c . The driving force receiving portion 40 a has three engaging portions 40 a 2 and a rib 40 a 1 , which are integrally formed parts of the driving force receiving portion 40 a . The center portion 40 b has a groove 40 b 2 into which the rib 40 c 1 of the driving force transmitting portion 40 c fits. It has also a groove 40 b 1 into which the rib 40 a 1 of the driving force receiving portion 40 a fits.
[0000] (Structural Arrangement for Keeping Development Roller Contact in Contact with Development Roller Shaft)
[0052] Next, referring to FIGS. 4 , 5 , 6 , 8 , 10 , 11 , and 13 , the relationship between the electrical contact for the development roller 25 , and the development roller shaft, will be described.
[0053] FIG. 4 is a top view of the cartridge 7 . A referential letter W in FIG. 4 indicates the side from which the cartridge 7 is driven, in terms of the lengthwise direction of the cartridge 7 . FIG. 5 is a side view of the cartridge 7 as seen from the cartridge driving side W. FIG. 6 is a combination of enlarged sectional views of the lengthwise end portions of the development unit 4 , from which the development unit 4 is driven. More specifically, FIGS. 6( a ) and 6 ( b ) are enlarged sectional views of the lengthwise end portion of the development unit 4 prior to and after, respectively, the attachment of the development roller 25 to the development unit frame. Designated by a referential number 45 is the electrical contact (which hereafter will be referred to simply as development roller contact), which is on the reader's side of the plane of FIG. 6 . FIG. 8 is a perspective view of the lengthwise end portion of the development roller shaft 25 b , which is on the side from which the development roller 25 is driven. FIG. 10 is a perspective exploded view of the a pressure applying member 41 , which is at the lengthwise end of the development roller shaft 25 b , from which development roller 25 is not driven. FIG. 8 shows the structure of the pressure applying member 41 . FIG. 11 is a side view of the development unit 4 , as seen from the driving side W ( FIG. 10) , with the Oldham's coupling 40 removed.
[0054] Referring to FIGS. 4 and 6 , the Oldham's coupling 40 (male coupling) is attached to the lengthwise end of the development roller shaft 25 b , on the side from which the development roller 25 is driven. As the cartridge 7 is mounted into the apparatus main assembly 100 a of the image forming apparatus 100 , the driving force receiving portion 40 a of the Oldham's coupling 40 engages with the coupling (female coupling) 100 b ( FIG. 6( b )), which is the driving force transmitting member of the apparatus main assembly 100 a , making it possible for the development roller driving force to be transmitted from the apparatus main assembly 100 a to the development roller 25 . Next, referring to FIG. 5 , also as the cartridge 7 is mounted into the apparatus main assembly 100 a , the contact point 45 c of the development roller contact 45 comes into contact with the electrical contact 100 c with which the apparatus main assembly 100 a is provided, making it possible for the bias voltage to be applied to the development roller 25 from the apparatus main assembly 100 a through the development roller contact 45 .
[0055] Further, the development unit 4 is provided with the pressure applying member 41 , which is at the opposite lengthwise end of development unit 4 from the lengthwise end from which the development unit 4 is driven. Referring to FIG. 10 , the pressure applying member 41 is made up of a nonelastic member 41 a and an elastic member 41 b . The elastic member 41 b applies pressure to the development roller shaft 25 b through the nonelastic member 41 a , keeping thereby the development roller 25 pressured toward the driving side W.
[0056] Next, referring to FIG. 8 , the lengthwise end portion of the development roller shaft 25 b , which is on the driving side W, is reduced in diameter relative to the rest of the development roller shaft 25 b , providing thereby the development roller shaft 25 b with a pressure taking surface 25 c . Next, referring to FIG. 6( a ), the bearing 32 R is provided with a roller shaft accommodating hole 32 Rd and a development roller shaft catching surface 32 Ra (which hereafter may be referred to as regulating surface 32 Ra). More specifically, the bearing 32 R is provided with a pair of development roller shaft catching portions, which extend from the main portion of the bearing 32 R toward the Oldham's coupling 40 . That is, the development roller shaft catching surface 32 Ra is the surface of the development roller shaft catching portion, which faces toward the development roller 25 . Further, the abovementioned development roller contact 45 , which is for applying the bias voltage to the development roller 25 , is attached to the electrical contact placement surface 32 Rc of the bearing 32 R. During the assembly of the development unit 4 , the shaft 25 b of the development roller 25 is inserted into the bearing 32 R in the direction indicated by an arrow mark F in FIG. 6( a ). Next, referring to FIG. 6( b ), the development roller 25 is kept pressured toward the driving side W by the pressure applying member 41 ( FIG. 10) , which is located at the lengthwise end of the development roller 25 , from which the development roller 25 is not driven. Thus, the pressure taking surface 25 c of the development roller shaft 25 b is kept in contact with the regulating surface 32 Ra of the bearing 32 R; in other words, the development roller 25 is kept precisely positioned in terms of its lengthwise direction. Further, the development roller contact 45 is kept in contact with the development roller shaft 25 b , between the regulating surface 32 Ra and contact placement surface 32 Rc. More specifically, referring to FIG. 11 , the development roller contact 45 contacts the peripheral surface of the development roller shaft 25 b by its contact points 45 a and 45 b.
[0057] Even in a case where the combination of the Oldham's coupling 40 and pressure applying member 41 is used as it is in this embodiment, the space necessary for connecting the cartridge 7 to the apparatus main assembly 100 a in mechanical and electrical terms can be significantly reduced (smallest possible without sacrificing function) by structuring an image forming apparatus so that the development roller contact 45 contacts the peripheral surface of the development roller shaft 25 b on the side from which the development roller 25 is driven, instead of structuring an image forming apparatus so that the development roller contact 45 contacts the lengthwise end surface of the development roller shaft 25 b on the side from which the development roller 25 is not driven. Further, because the development roller 25 is kept pressured toward the driven side W, the position of the contact between the development roller contact 45 and development roller shaft 25 b is significantly closer to the referential point of contact between the cartridge 7 and apparatus main assembly 100 a , compared to the position of the contact between the development roller contact ( 45 ) and development roller shaft ( 25 b ) in a conventional image forming apparatus. Therefore, this structural design makes the image forming apparatus 100 , more specifically, the cartridge 7 and apparatus main assembly 100 a , less likely to be adversely affected by the tolerance of the components of the cartridge 7 and apparatus main assembly 100 a , making it possible to reduce in size the spaces to be provided in anticipation of the effects (rattling or the like) attributable to the tolerance. Thus, the structural design of the image forming apparatus in this embodiment can reduce in size the cartridge 7 by reducing in length the cartridge 7 . Further, the cartridge 7 and apparatus main assembly 100 a in this embodiment are structured so that the development roller contact 45 and pressure taking surface 25 c are positioned on the outward side of the hole 32 Rd of the bearing 32 R. Therefore, the portion of the development roller shaft 25 a , which is on the inward side of the bearing 32 R, and the portion of the development roller shaft 25 b , which fits in the hole 32 Rd of the bearing 32 R, can be formed continuous and the same in diameter. Therefore, it is unnecessary to take into consideration the geometrical tolerance regarding coaxially or the like, unlike the case where the portion of the development roller shaft 25 b , which is on the inward side of the bearing 32 R and the portion of the development roller shaft 25 b , which is on the outward side of the bearing 32 R, are different in diameter. Thus, the structural design for the image forming apparatus in this embodiment can reduces in amount the tolerance of the components of an image forming apparatus. Further, the portions by which the development roller 25 is supported, and the elastic portion 25 a of the development roller 25 , which contacts the photosensitive drum 1 , are coaxial. Therefore, the development roller 25 is stable in rotation, ensuring that the image forming apparatus 100 remains stable in image quality.
Embodiment 2
[0058] (Structural Arrangement for Keeping Development Roller Contact in Contact with Development Roller Shaft)
[0059] Next, referring to FIGS. 4 , 5 , 7 , 9 , 10 , 12 , and 13 , the relationship between the development roller contact and development roller shaft in the second preferred embodiment of the present invention will be described.
[0060] FIG. 4 is a top plan view of the cartridge 7 . A letter W in FIG. 4 indicates the side from which the cartridge 7 is driven. FIG. 5 is a side view of the cartridge 7 as seen from the driving side W. FIG. 7 is a combination of enlarged sectional views of the lengthwise end of the development unit 4 , from which the development unit 4 is driven, and the bearing 32 R, in the second embodiment of the present invention. More specifically, FIGS. 7( a ) and 7 ( b ) are enlarged sectional views of the lengthwise end portion of the development unit 4 , from which the development unit 4 is driven, prior to and after, respectively, the attachment of the development roller 25 to the frame (bearing) of the development unit. Designated by a referential number 45 in FIG. 7 is the development roller contact, which is on the reader's side of the plane of FIG. 7 . FIG. 9 is a perspective view of the lengthwise end portion of the development roller shaft 25 b , from which the development roller 25 is driven. FIG. 10 is a perspective view of the a pressure applying member 41 , which is at the lengthwise end of the development roller shaft 25 b , from which development roller 25 is not driven, and shows the structure of the pressure applying member 41 . FIG. 12 is a side view of the development unit 4 , as seen from the driving side W ( FIG. 10) , that is, the side from which the development roller 25 is driven, with the Oldham's coupling 40 removed.
[0061] Referring to FIGS. 4 and 7 , the Oldham's coupling 40 (male coupling) is attached to the lengthwise end of the development roller shaft 25 b , on the side from which the development roller 25 is driven. As the cartridge 7 is mounted into the apparatus main assembly 100 a of the image forming apparatus 100 , the driving force receiving portion 40 a of the Oldham's coupling 40 engages with the coupling 100 b ( FIG. 7( b )), which is the driving force transmitting member of the apparatus main assembly 100 a , making it possible for the development roller driving force to be transmitted from the apparatus main assembly 100 a to the development roller shaft 25 b.
[0062] Further, the development unit 4 is provided with the pressure applying member 41 , which is at the opposite lengthwise end of development unit 4 from the lengthwise end from which the development unit 4 is driven. Referring to FIG. 10 , the pressure applying member 41 is made up of a nonelastic member 41 a and an elastic member 41 b . The elastic member 41 b applies pressure to the development roller shaft 25 b through the nonelastic member 41 a , keeping thereby the development roller 25 pressured toward the driving side W.
[0063] Next, referring to FIG. 9 , the lengthwise end portion of the development roller shaft 25 b on the driving side W is reduced in diameter relative to the rest of the development roller shaft 25 b , providing thereby the development roller shaft 25 b with a pressure taking surface 56 c . Next, referring to FIG. 7( a ), the bearing 32 R is provided with a roller shaft accommodating hole 32 Rd and a regulating surface 53 Ra. More specifically, the bearing 32 R is provided with a pair of development roller shaft catching portions, which slightly protrude from the main portion of the bearing 32 R toward the direction from which the development roller shaft 25 d is inserted into the bearing 32 R. The regulating surface 53 Ra is the surface of the development roller shaft catching portion, which faces toward the development roller 25 . Further, the abovementioned development roller contact 45 is attached to the electrical contact placement surface 32 Rc of the bearing 32 R. During the assembly of the development unit 4 , the shaft 25 b of the development roller 25 is inserted into the bearing 32 R in the direction indicated by an arrow mark F in FIG. 7( a ). Next, referring to FIG. 7( b ), the development roller 25 is kept pressured toward the driving side W by the pressure applying member 41 ( FIG. 10) , which is located at the lengthwise end of the development roller 25 , from which the development roller 25 is not driven. Thus, the pressure taking surface 56 c of the development roller shaft 25 b is kept in contact with the regulating surface 53 Ra of the bearing 32 R; in other words, the development roller 25 is kept precisely positioned in terms of its lengthwise direction. Further, the development roller contact 45 is kept in contact with the development roller shaft 25 b , between the Oldham's coupling 40 and contact placement surface 32 Rc. That is, the development roller contact 45 contacts the peripheral surface of the development roller shaft 25 b by its contact points 45 a and 45 b as shown in FIG. 12 .
[0064] Even in a case where the combination of the Oldham's coupling 40 and pressure applying member 41 is used as it is in this embodiment, the space necessary for connecting the cartridge 7 to the apparatus main assembly 100 a in mechanical and electrical terms can be significantly reduced (smallest possible without sacrificing function) by structuring an image forming apparatus so that the development roller contact 45 contacts the peripheral surface of the development roller shaft 25 b , on the side from which the development roller 25 is driven, instead of structuring an image forming apparatus so that the development roller contact 45 contacts the lengthwise end surface of the development roller shaft 25 b , on the side from which the development roller 25 is not driven. Further, because the development roller 25 is kept pressured toward the driven side W, with the use of the pressure applying member 41 , the position of the contact between the development roller contact 45 and development roller shaft 25 b is significantly closer to the referential point of contact between the cartridge 7 and apparatus main assembly 100 a , compared to the position of the contact between the development roller contact ( 45 ) and development roller shaft ( 25 b ) in a conventional image forming apparatus. Therefore, this structural design makes the image forming apparatus 100 , more specifically, the cartridge 7 and apparatus main assembly 100 a , less likely to be adversely affected by the tolerance of the components of the cartridge 7 and apparatus main assembly 100 a , making it possible to reduce in size the spaces to be provided in anticipation of the effects (rattling or the like) attributable to the tolerance. Thus, the structural design of the image forming apparatus in this embodiment can reduce in size the cartridge 7 by reducing in length the cartridge 7 . Further, the cartridge 7 and apparatus main assembly 100 a are structured so that the development roller contact 45 and pressure taking surface 25 c are positioned at the hole 32 Rd of the bearing 32 R (more specifically, on the upstream side as seen from side from which development roller shaft 25 b is inserted into bearing 32 R). Therefore, it is possible to utilize a conventional bearing ( 32 ) without modifying it in shape and/or providing it with the space for mechanical and electrical connection. In other words, the present invention can reduce in size an image forming apparatus by simplifying in structure the bearings for supporting the development roller shaft.
[0065] As described above, according to the present invention, both the member for transmitting mechanical driving force to the development roller, and the electrical contact for transmitting electrical power to the development roller, are positioned at one of the lengthwise ends of the development roller shaft (same lengthwise end), and therefore, it is unnecessary for the space for the electrical contact to be provided at the other lengthwise end. In other words, the present invention can reduce in size a developing apparatus and a process cartridge. Further, according to the present invention, a development roller is kept under pressure so that one of its lengthwise ends remains in contact with the surface of the corresponding development roller bearing. Therefore, it is ensured that the electrical contact for the development roller remains precisely positioned relative to the development roller shaft.
[0066] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
[0067] This application claims priority from Japanese Patent Applications Nos. 138040/2008 and 107877/2009 filed May 27, 2008 and Apr. 27, 2009, respectively which are hereby incorporated by reference. | A developing apparatus including a developing roller for developing an electrostatic latent image formed on a photosensitive member, wherein the developing apparatus is detachably mountable to a main assembly of an electrophotographic image forming apparatus in an axial direction of the developing roller, the developing apparatus includes a drive transmission member, provided at one end of the developing roller, for receiving a driving force from the main assembly and transmitting the driving force to the developing roller; an urging member, provided at other end, for urging the developing roller in the axial direction; an abutting portion, provided adjacent the one end, for being abutted by the shaft of the developing roller by an urging force of the urging member to position the developing roller with respect to the axial direction; and a contact member contactable to a main assembly contact provided in the main assembly when the developing apparatus is mounted to the main assembly, wherein the contact member contacts to a peripheral surface of the shaft of the developing roller adjacent the one end to apply a voltage to the developing roller. | 6 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional applications 61/756,857 filed Jan. 25, 2013 and 61/757,900 filed Jan. 29, 2013; the contents of each are herein incorporated in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates generally to the field of cell culture and more specifically to the field of determining cell type.
BACKGROUND
[0003] Brown adipose tissue (BAT) plays a key role in the evolutionarily conserved mechanisms underlying energy homeostasis in mammals. It is characterized by fat vacuoles 5-10 microns in diameter and expression of uncoupling protein 1 (UCP1), central to the regulation of thermogenesis. In the human newborn, depots of BAT are typically grouped around the vasculature and solid organs. These depots maintain body temperature during cold exposure by warming the blood before its distribution to the periphery. They also ensure an optimal temperature for biochemical reactions within solid organs. BAT had been thought to involute throughout childhood and adolescence. Recent studies, however, have confirmed the presence of active brown adipose tissue in adult humans with depots residing in cervical, supraclavicular, mediastinal, paravertebral and suprarenal regions. While human pluripotent stem cells have been differentiated into functional brown adipocytes in vitro and inducible brown adipocyte progenitor cells have been identified in murine skeletal muscle and white adipose tissue, metabolically active brown adipose tissue derived stem cells have not been identified in adult humans to date.
[0004] The present invention addresses this issue.
SUMMARY OF THE INVENTION
[0005] In one aspect the invention relates to a method of distinguishing a brown adipose cell from a white adipose cell. In one embodiment the method includes measuring the expression level of one or more genes in an adipose cell; comparing the measured expression levels to a control, and correlating the expression level of the one or more genes to an identity as a white adipose cell or a brown adipose cell. In one embodiment the one or more genes are selected from the genes listed in FIG. 4C . In another embodiment an increase in expression of one or more of the following genes as compared to the control is indicative that the adipose cell is a brown adipose cell: ACACB, ADRB2, FGF10, KLF15, LIPE, NR1H3, CIDEC, ELOVL3, INHBB, PPARGC1A, and UCP1. In yet another embodiment an increase in expression of LEP as compared to the control is indicative that the adipose cell is a white adipose cell. In still yet another embodiment the method measures the expression level by quantifying transcript levels.
[0006] In one embodiment the method measures the levels of at least two, at least three, at least four, at least five, at least 6, at least 7, at least 8, at least 9, at least 10, or at least 11 genes. In another embodiment the method measures the levels of any one of ELOVL3, INHBB, PPARGC1A, or UCP1. In yet another embodiment the method measures the levels of any two of ELOVL3, INHBB, PPARGC1A, or UCP1. In still yet another embodiment the method measures the levels of any three of ELOVL3, INHBB, PPARGC1A, or UCP1. In one embodiment the method measures the levels of ELOVL3, INHBB, PPARGC1A, and UCP1.
[0007] In another aspect the invention relates to a method of differentiating an adipose stem cell. In one embodiment the method includes inducing differentiation of an adipose stem cell in vitro; and distinguishing the differentiated stem cell. In another embodiment the inducing is performed by contacting the adipose stem cell with a brown adipose cell differentiation media. In yet another embodiment the inducing is performed by contacting the adipose stem cell with FNDC5.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. The present teachings described herein will be more fully understood from the following description of various illustrative embodiments, when read together with the accompanying drawings. It should be understood that the drawings described below are for illustration purposes only and are not intended to limit the scope of the present teachings in anyway.
[0009] FIG. 1(A) is a series of diagrams of flow cytometry results of undifferentiated brown adipose derived stem cells;
[0010] FIG. 1(B) is a photomicrograph of biopsied mediastinal brown adipose depots that demonstrate multiocular lipid morphology and UCP1 staining specific to brown adipose tissue;
[0011] FIG. 1(C) is a karyotype analysis of passage 10 brown adipose derived stem cells;
[0012] FIG. 2 is a set of flow cytometry results of TMEM26 and CD137 of brown and white adipose derived stem cells;
[0013] FIG. 3(A) is a Western blot of cells 21 days post FNDC5 induction;
[0014] FIG. 3(B) is a photomicrograph of Alcian blue stained brown adipose derived stem cells directionally differentiated into chondrocytes;
[0015] FIG. 3(C) is a photomicrograph of fatty acid binding protein 4 (FABP4) immunocytochemistry of brown adipose derived stem cells induced to undergo white adipogenesis;
[0016] FIG. 3(D) is a photomicrograph of Alizarian red stained brown adipose derived stem cells induced to undergo osteogenesis;
[0017] FIG. 4(A) is a SEM of brown adipose derived stem cells cultured on porous extracellular matrix scaffolds;
[0018] FIG. 4(B) is a SEM of directionally differentiated brown adipocytes on scaffolds;
[0019] FIG. 4(C) is a transcriptional profile of brown adipose derived stem cells differentiated into brown and white adipocytes;
[0020] FIG. 4(D) is a measure of fatty acid uptake of brown fat differentiated brown adipose derived stem cells at 7, 14 and 21 days post differentiation;
[0021] FIG. 4(E) is a measure of functional mitochondrial respiration assay of brown adipose derived stem cells differentiated into brown adipocytes at 7, 14 and 21 days post differentiation;
[0022] FIG. 5(A) is a graph of expression levels of MSC associated genes;
[0023] FIG. 5(B) is a graph of expression levels of MSC specific genes; and
[0024] FIG. 5(C) is a graph of expression levels of sternness genes.
DETAILED DESCRIPTION
[0025] Briefly, for this study, human adipose tissues were biopsied and analyzed with immunohistochemistry and primary cell isolation. Primary cells isolated from adipose explants were expanded and their growth kinetics, karyotyping, flow cytometry and immunocytochemistry were determined. Passage-2 cells were directionally differentiated into osteogenic, chondrogenic, white adipogenic and brown adipogenic lineages on plastic and also differentiated into brown adipocytes on porous extracellular matrix scaffolds. Differentiation was confirmed by Western blot, immunohistochemistry, cytochemistry, scanning electron microscopy (SEM), and quantitative real-time PCR. Functional brown fat differentiation was confirmed by fatty acid uptake and mitochondrial respiration, as measured by the oxygen consumption rate (OCR).
Methods
Mediastinal Adipose Tissue Procurement
[0026] Mediastinal adipose tissues were obtained from 54 patients undergoing cardiac surgery. The group included 44 males and 10 females and had a mean ±SE age 72.4±12 yr. (range 28-84 yr.).
Derivation of Mediastinal Adipose Derived MSCs
[0027] The excised tissue was cut into 3 mm pieces and explanted onto a 6 well dish and grown in DMEM low glucose, 10% XcytePL™ Supplement (JadiCell, Phoenix, Ariz.), 1X Glutamax, and 1X MEM-NEAA (Life Technologies, Carlsbad, Calif.) and cultured in 5% CO 2 /37° C.
RNA Analysis
[0028] RNA was isolated and DNaseI treated using the RNAqueous-4PCR Kit (Life Technologies AM1914 (Life Technologies, Carlsbad, Calif.)) per manufacturer's protocol.
[0029] First strand cDNA was synthesized using the RI' First Strand Kit (SABiosciences 330401) (SABiosciences, Valencia, Calif.) per manufacturer's protocol.
[0030] PCR was carried out on RT 2 Profiler PCR Arrays using RT 2 SYBR Green qPCR Mastermix (SABiosciences 330521) in an Eppendorf Mastercycler ep realplex 4 pcr machine (Eppendorf, Hauppauge, N.Y.) per manufacturer's protocol.
[0031] The following RT 2 Profiler PCR Arrays and individual gene primers were used:
Human Adipogenesis (SABiosciences PAHS-049A) Human Mesenchymal Stem Cells (SABiosciences PAHS-082A) RT 2 qPCR Primer Assay for CIDEC(SABiosciences PPH18299E) RT 2 qPCR Primer Assay for COX8A (SABiosciences PPH20233A) RT 2 qPCR Primer Assay for CYC1(SABiosciences PPH00724A) RT 2 qPCR Primer Assay for CYFIP2 (SABiosciences PPH14474E) RT 2 qPCR Primer Assay for DPT (SABiosciences PPH10191A) RT 2 qPCR Primer Assay for ELOVL3(SABiosciences PPH16532A) RT 2 qPCR Primer Assay for INHBB(SABiosciences PPH01917A) RT 2 qPCR Primer Assay for LHX8(SABiosciences PPH19135A) RT 2 qPCR Primer Assay for NDUFA11(SABiosciences PPH19207A) RT 2 qPCR Primer Assay for NDUFA13(SABiosciences PPH60028A) RT 2 qPCR Primer Assay for PMP22(SABiosciences PPH02152E) RT 2 qPCR Primer Assay for GJA1(SABiosciences PPH02781E) RT 2 qPCR Primer Assay for MYH7(SABiosciences PPH00044E) RT 2 qPCR Primer Assay for NKX2-5(SABiosciences PPH02462A) RT 2 qPCR Primer Assay for TNNT2(SABiosciences PPH02619A) RT 2 qPCR Primer Assay for B2M(SABiosciences PPH01094E) RT 2 qPCR Primer Assay for HPRT1(SABiosciences PPH01018B) RT 2 qPCR Primer Assay for RPL13A(SABiosciences PPH01020B)
[0052] Delta delta (ΔA) Ct based fold-change calculations were performed using the RT 2 Profiler PCR Array Data Analysis Web Portal version 3.5 provided by SABiosciences at: http://pcrdataanalysis.sabiosciences.com/pcr/arrayanalysis.php
[0053] Total RNA was purified and DNase-treated from individual wells of 24-well plates using the RNAqueous-Micro kit (Ambion AM1931(Life Technologies, Carlsbad, Calif.)) per manufacturer's protocol. 100 ng of each sample was reverse transcribed and pre-amplified using the RT 2 PreAMP cDNA Synthesis Kit (SABiosciences 330241) (SABiosciences, Valencia, Calif.). The preamplified product was then amplified using the RT 2 SYBR Green/ROX qPCR Master Mix (SABiosciences PA-012) (SABiosciences, Valencia, Calif.). Experiments were done in triplicate and data was analysed by the delta delta (ΔA) Ct method. The control gene used was HPRT1.
Immunocytochemistry
[0054] Cells were fixed with 4% paraformaldehyde. After blocking, cells were incubated with primary antibody diluted in 5% donkey serum. After washing cells were incubated with secondary antibody and counterstained with DAPI (Molecular Probes (Life Technologies, Carlsbad, Calif.)). For negative controls, incubation without primary antibody and with corresponding specific non-immune immunoglobulin (EMD Millipore, Billerica, Mass.) was used.
Flow Cytometry
[0055] Directly conjugated antibodies used: HLA-DP DQ DR (BD Biosciences,), CD90, LIN, CD166, STRO-1, SSEA-4, CD44, CD106, CD73, CD117, CD105, HLA-ABC, CD86, CD63, CD9, CD80 (Biolegend, San Diego, Calif.), CD45, CD133, and CD34 (Miltenyi Biotech, Bergisch Gladbach, Germany). After staining, the cells were fixed and analyzed using a FACSCanto II analyzer (BD Biosciences, Franklin Lakes, N.J.).
Adipogenic Differentiation
[0056] Cells were plated in 6-well dishes at a density of 50,000 cells/well. White or brown adipogenesis differentiation medium was added. For brown adipogenesis, FNDC5 was added 6 days post induction. Fatty acid binding protein 4 (FABP4) immunocytochemistry and 0.3% Oil Red O (Sigma Aldrich, St. Louis, Mo.) was used for staining to detect intracellular lipid accumulation (Data not shown).
Osteogenic Differentiation
[0057] Cells were plated in 6 well dishes at a density of 50,000 cells/well. StemPro® Osteogenesis Differentiation medium ((Life Technologies, Carlsbad, Calif.)) was added. 2% Alizarian Red S (Sigma Aldrich, St. Louis, Mo.) was used for staining to detect de novo formation of bone matrix.
Chondrogenic Differentiation
[0058] 500,000 cells/15 ml tube were pelleted and induced with StemPro® Chondrogenesis Differentiation medium ((Life Technologies, Carlsbad, Calif.)). 1% Alcian Blue (Sigma Aldrich, St. Louis, Mo.) was used to detect sulfated glycosaminoglycans.
Fatty Acid Uptake Analysis
[0059] Analysis began with the replacement of growth media with HBSS Buffer with 20 mM HEPES and 0.2% fatty free BSA. Cells were placed in the incubator for 1.5 h, QBT Fatty Acid Uptake (Molecular Devices, Sunnyvale, Calif.) media was added to the wells and fluorescence was analyzed every minute in a Bio-Tek Synergy HT (Bio Tek, Winooski, Vt.).
Cellular Respiration and Glycolysis Analysis
[0060] The oxygen consumption rate (OCR) was performed using a Seahorse Bioscience XF-24 instrument (Seahorse Bioscience, Billerica, Mass.). Analysis was performed by replacing the growth media with XF assay media and incubating in a CO 2 free chamber for 1 h. The XF Cell Mito Stress Test simultaneously analyzed basal respiration, ATP turnover, proton leak, spare respiratory capacity and glycolysis.
Transmission Electron Microscopy
[0061] Samples were fixed and embedded for routine TEM. They were then examined on an FEI Tecnai T-12 (FEI Hillsboro, Oreg.) at 120 KV.
Scanning Electron Microscopy
[0062] Scaffolds were fixed and post fixed in 2% osmium tetroxide, dehydrated through a series of ethanol washes, dried with hexamethyldisilazane. Scaffolds were then sputter coated with gold and imaged with a scanning electron microscope under high vacuum.
Results
[0063] FIG. 1(A) shows flow cytometry of undifferentiated brown adipose derived stem cells. The cells expressed CD44, CD105, CD166, and CD90 and were negative for hematopoietic markers CD34, CD45, and HLA-DR. FIG. 1(B) is a photomicrograph of biopsied mediastinal brown adipose depots demonstrate multiocular lipid morphology and UCP1 staining specific to brown adipose tissue. FIG. 1(C) is a karyotype analysis of passage 10 brown adipose derived stem cells.
[0064] FIG. 2 depicts the flow cytometry results of TMEM26 and CD 137 of brown and white adipose derived stem cells. Brown adipose derived stem cells express higher levels of TMEM26 and CD137.
[0065] FIG. 3(A) is a Western blot 21 days post FNDC5 induction. Lane 1 holds brown adipose derived stem cells directionally differentiated into brown adipocytes. Lane 2 holds undifferentiated brown adipose derived stem cells. FIG. 3(B) is a photomicrograph of Alcian blue stained brown adipose derived stem cells directionally differentiated into chondrocytes. FIG. 3(C) is a photomicrograph of the fatty acid binding protein 4 (FABP4) immunocytochemistry of brown adipose derived stem cells induced to undergo white adipogenesis. FIG. 3(D) is a photomicrograph of Alizarin red stained brown adipose derived stem cells induced to undergo osteogenesis.
[0066] FIG. 4(A) is a SEM of brown adipose derived stem cells cultured on porous extracellular matrix scaffolds. FIG. 4(B) SEM of directionally differentiated brown adipocytes on scaffolds. FIG. 4(C) is a transcriptional profile of brown adipose derived stem cells differentiated into brown and white adipocytes. FIG. 4(D) is a graph of fatty acid uptake of brown fat differentiated brown adipose derived stem cells at 7, 14 and 21 days post differentiation. FIG. 4(E) is a graph of the results of a functional mitochondrial respiration assay of brown adipose derived stem cells differentiated into brown adipocytes at 7, 14 and 21 days post differentiation.
[0067] In FIG. 4(C) , profiled genes are listed according to their standard abbreviation (NCBI gene profile):
ACACB: acetyl-CoA carboxylase beta ADIG: adipogenin ADIPOQ: Adiponectin ADRB2: adrenoceptor beta 2, surface AGT: angiotensinogen BMP4: bone morphogenetic protein 4 CCND1: cyclin D1 CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha CFD: complement factor D (adipsin) DKK1: Dickkopf1 DLK1: delta-like 1 homolog E2F1: E2F transcription factor 1 FABP4: fatty acid binding protein 4 FASN: Fatty acid synthase FGF1: fibroblast growth factor 1 FGF10: fibroblast growth factor 10 FGF2: fibroblast growth factor 2 FOXO1: forkhead box O1 GATA2: GATA binding protein 2 HES1: hairy and enhancer of split 1 IRS2: insulin receptor substrate 2 KLF15: Kruppel-like factor 15 KLF2: Kruppel-like factor 2 LEP: Leptin LIPE: hormone-sensitive lipase LMNA: lamin A/C LPL: lipoprotein lipase NR1H3: nuclear receptor subfamily 1, group H, member 3 PPARG: peroxisome proliferative activated receptor, gamma SLC2A4: solute carrier family 2 (facilitated glucose transporter) SREBF1: sterol regulatory element binding transcription factor 1 TSC22D3: TSC22 domain family, member 3 VDR: Vitamin D3 receptor WNT10B: wingless-type MMTV integration site family, member 10B WNT5B: wingless-type MMTV integration site family, member 5b CIDEC: cell death-inducing DFFA-like effector c CYFIP2: Cytoplasmic FMR1-interacting protein 2 DIO2: deiodinase, iodothyronine, type II DPT: Dermatopontin ELOVL3: Elongation of very long chain fatty acids protein 3 FOXC2: forkhead box C2 INHBB: inhibin, beta B INSR: insulin receptor PPARGC1A: peroxisome proliferative activated receptor, gamma, coactivator 1 UCP1: uncoupling protein 1.
[0113] Table 1 is a list of genes expressed by brown and white MSC as measured against a standard along with a measure of their expression relative to the standard. Thus for example The expression of the gene ANXA5 is 1.178 fold higher in brown than in the standard.
[0000]
TABLE 1
Gene
Brown
White
ANXA5
1.178
0.150
BDNF
2.573
0.555
BGLAP
1.214
0.180
BMP7
−1.192
0.421
COL1A1
−1.206
0.203
CSF2
−1.019
0.315
CSF3
−1.143
0.523
CTNNB1
1.243
0.190
EGF
1.240
0.510
FUT1
5.110
2.330
GTF3A
1.275
0.195
HGF
1.613
0.295
ICAM1
−3.211
0.360
IFNG
−1.059
0.239
IGF1
−2.822
3.061
IL10
−1.982
4.268
IL1B
4.532
0.720
IL6
13.056
2.485
ITGB1
1.200
0.190
KITLG
−1.248
0.290
MITF
1.050
0.220
MMP2
−1.709
0.252
NES
2.346
0.455
NUDT6
1.643
0.120
PIGS
1.067
0.095
PTPRC
1.347
0.805
SLC17A5
1.257
0.215
TGFB3
−1.125
0.141
TNF
1.729
0.970
VEGFA
1.502
0.320
VIM
−1.347
0.292
VWF
−1.382
0.891
ALCAM
4.327
0.665
ANPEP
−1.228
0.125
BMP2
1.035
0.125
CASP3
1.879
0.150
CD44
1.866
0.305
ENG
1.454
0.145
ERBB2
1.228
0.250
FUT4
1.272
0.205
FZD9
1.329
0.650
ITGA6
12.524
2.395
ITGAV
1.206
0.165
KDR
14.254
5.895
MCAM
1.431
0.260
NGFR
−1.102
0.440
NT5E
1.725
0.225
PDGFRB
−2.139
0.100
PROM1
0.010
0.000
THY1
−1.082
0.115
VCAM1
15.780
9.470
FGF2
1.643
0.275
INS
0.000
0.000
LIF
3.855
0.805
POU5F1
3.767
0.925
SOX2
0.000
0.000
TERT
0.000
0.000
WNT3A
0.000
0.000
ZFP42
2.240
0.670
[0114] FIG. 5 is a graph of the expression of MSC associated genes. MSC associated genes are genes that are generally found in all mesenchymal stem cells to some degree. FIG. 6 is a graph of the expression of MSC specific genes. These genes are generally unique to mesenchymal stem cells. FIG. 7 is a graph of the expression of Sternness genes. These genes generally are found in cells with more differentiation potential such as embryonic stem cells
[0115] These results uniquely demonstrate a resident stem cell population within depots of brown adipose tissue from adult human mediastinum. Cells from this tissue exhibit multi-lineage potential with capacities to undergo osteogenesis, chondrogenesis and both brown and white adipogenesis. Directionally differentiated brown adipocytes exhibit a distinct morphology and gene expression profile, with functional properties characteristic of brown adipose tissue in vivo. These brown adipose-derived stem cells may offer a new target to activate and restore energy homeostasis in vivo for the treatment of obesity and related metabolic disorders.
[0116] It is to be understood that while the disclosure has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims. | A method of distinguishing a brown adipose cell from a white adipose cell. In one embodiment the method includes measuring the expression level of one or more genes in an adipose cell; comparing the measured expression levels to a control, and correlating the expression level of the one or more genes to an identity as a white adipose cell or a brown adipose cell. In one embodiment the one or more genes are selected from the genes listed in FIG. 4 C. In another aspect the invention relates to a method of differentiating an adipose stem cell. In one embodiment the method includes inducing differentiation of an adipose stem cell in vitro; and distinguishing the differentiated stem cell. In another embodiment the inducing is performed by contacting the adipose stem cell with a brown adipose cell differentiation media. | 2 |
CROSS-REFERENCED TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 099139575 filed on Nov. 17, 2010 Republic of China, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates a thermoelectric material with low electrical resistivity in comparison with a conventional metal or semiconductor.
BACKGROUND OF THE INVENTION
[0003] The thermoelectric material is a solid material which can convert thermal energy into electrical energy or use electrical energy to move heat. In 1821, Thomas Johann Seebeck found that a circuit made from two dissimilar metals (Cu and Bi), with junctions at different temperatures (ΔT) would generate an electric potential (ΔV), which is defined as Seebeck coefficient (S=ΔV/ΔT), and used as a principle for the thermoelectric generator and thermocouple. In 1835, Jean Charles Athanase Peltier found that an electrical current would produce heating or cooling at the junction of two dissimilar metals, and this principle was used for thermoelectric cooler. Twenty years later, William Thomson established the base of thermoelectric theory and predicted a third thermoelectric effect, now known as the Thomson effect. In the Thomson effect, heat is absorbed or produced when current flows in a material with a temperature gradient. The heat is proportional to both the electric current and the temperature gradient.
[0004] The thermoelectric material has been developed more than one hundred years so far. How to obtain better thermoelectric conversion efficiency was the most important goal for its applicability. Until 1954, Goldsmid and Douglas etc. applied semiconductor materials to thermoelectric coolers and successfully lowered down cooling temperature to 0° C., this huge progress induced a studying heat in 1960. However, for the past 30 years, this field has fallen in a difficult position. Until 1990, various novel materials have been developed so as to inspire studies in this field. Thermoelectric materials often involve the multi-component system, and complex composition and synthesis condition limit its utility. At present, it is a major object to develop novel thermoelectric materials and thermoelectric components.
[0005] In thermoelectric material developments, thermoelectric figure of merit (z=S 2 /κρ; S: Seebeck coefficient; κ=thermal conductivity, ρ=electrical resistivity) is an important indicator for developments. Nowadays the most popular commercial thermoelectric material is p-type semiconductor Bi 2 Te 3 , whose thermoelectric figure of merit is 1. Hsu etc. (Science, Vol. 303, pp. 818-821, 2004) has published a paper about high-performance thermoelectric material AgPb m SbTe 2+m , which indicated that nano structure could help its thermoelectric conversion efficiency and its thermoelectric figure of merit reached 2.2 at 800 K. Therefore, how to obtain better thermoelectric conversion efficiency has become a crucial object.
SUMMARY OF THE INVENTION
[0006] Ag—Sb—Te is a material system deserved to study. AgSbTe 2 is an existed ternary compound and also a p-type semiconductor having low thermal conductivity and high thermoelectric conversion efficiency (thermoelectric figure of merit is approximately 1.4). However, its high resistivity and fragile characteristic significantly influence its applicability.
[0007] It is an object of the present invention to provide a thermoelectric material Ag—Sb—Te having low resistivity.
[0008] In one aspect of the present invention, thermoelectric material with low electrical resistivity comprising: at least Ag, Sb and Te, in a molar ratio of 1:2.43˜3.29:2.18˜2.96, wherein the electrical resistivity of the thermoelectric material is less than 0.1 Ωcm at room temperature.
[0009] Preferably, Ag, Sb and Te are constituted in a molar ratio of 1:2.55˜3.15:2.31˜2.83.
[0010] Preferably, the average crystal grain size of the thermoelectric material is preferably less than 1000 nm.
[0011] Preferably, the average crystal grain size of the thermoelectric material is preferably less than 500 nm.
[0012] Preferably, Ag, Sb and Te are constituted in a total weight ratio of 90% or more.
[0013] Preferably, the electrical resistivity of the thermoelectric material is preferably less than 0.01 Ωcm at room temperature.
[0014] In another aspect of the present invention, manufacture of preparing a thermoelectric material with low electrical resistivity, comprising the steps of: (A) providing a initial material comprising Ag, Sb and Te in a molar ratio of 1:2.43˜3.29:2.18˜2.96; (B) melting the initial material in vacuum with a temperature of at least 500° C. for a predetermined period; and (C) quenching the initial material for a predetermined period to form the thermoelectric material; wherein the thermoelectric material is less than 0.1 Ωcm at room temperature.
[0015] Preferably, the initial material in step (B) is melted for 24 hours.
[0016] Preferably, the initial material in step (C) is firstly quenched to 550° C. with a rate of 1° C./min, secondly quenched at this temperature for 120 hours, and finally quenched again by cool water.
[0017] Preferably, the initial material in step (C) is rapidly quenched in first, secondly quenched at 650° C. in a furnace for 120 hours, and finally quenched by cool water.
[0018] Resistivity of the thermoelectric material of the present invention is 8.4*10 −4 Ωcm measured by four point probe method at room temperature, and it is one-tenth of that in ternary compound AgSbTe 2 . According to following analysis and material, the phase formation is proved to be AgSbTe 2 , δ phase (Sb 2 Te) and 200-400 nm Ag 2 Te phase. These results prove that it is an ideal thermoelectric material which is suitable to be applied to modules of thermoelectric generators, industry thermal recycling, and combination with other energy materials such as solar cells. As expected, in the future, new energy materials developed by the thermoelectric material with low resistivity of the present invention may play a crucial role in new energy technology developments.
[0019] The embodiments of the present invention are further described through below detailed examples and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic diagram showing the manufacture of the present invention.
[0021] FIG. 2 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at low magnification.
[0022] FIG. 3 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at high magnification.
[0023] FIG. 4 is a diagram showing electrical resistivities of the material of the present invention in comparison with other high efficiency thermoelectric materials.
[0024] FIG. 5 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at low magnification.
[0025] FIG. 6 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at high magnification.
[0026] FIG. 7 is a diagram showing electrical resistivities of the material of the present invention in comparison with other high efficiency thermoelectric materials.
[0027] FIG. 8 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at low magnification.
[0028] FIG. 9 is a metallographic diagram showing the material of Ag-40.0 at % Sb-36.0 at % Te at high magnification.
[0029] FIG. 10 is a diagram showing electrical resistivities of the material of the present invention in comparison with other high efficiency thermoelectric materials.
DETAILED DESCRIPTION
[0030] A thermoelectric material with low electrical resistivity and manufacture thereof are described with reference to the preferred embodiments below, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.
DEFINITION
[0031] The formula “Ag-40.0 at % Sb-36.0 at % Te” wherein at % represents the atomic percent of each element in that alloy.
[0032] The compositional range of Ag-40.0 at % Sb-36.0 at % Te is determined by the liquidus projection constructed by experiments. During the cooling process, melts with nominal compositions located in that compositional range (Ag, Sb and Te in a molar ration of 1:2.43˜3.29:2.18˜2.96) will pass through the ternary eutectic point (Ag-40.0 at % Sb-36.0 at % Te), and solidify large amount of nano-sized phase.
[0033] The compositional range is indicated by a square. Alloys within that square area will exhibit large amount of the eutectic phase (Ag-40.0 at % Sb-36.0 at % Te) in their solidification microstructures. (as show in FIG. 11 ) The compositions of points 1, 2, 3 and 4 are: (1) Ag-38.0 at % Sb-47.0 at % Te (Ag:Sb:Te=1:2.43:2.96 in molar ration), (2) Ag-43.3 at % Sb-38.8 at % Te (Ag:Sb:Te=1:2.43:2.18 in molar ration), (3) Ag-45.3 at % Sb-40.8 at % Te (Ag:Sb:Te=1:3.29:2.96 in molar ration), (4) Ag-50.8 at % Sb-33.7 at % Te (Ag:Sb:Te=1:3.29:2.18 in molar ration). The specific compositional range as stated in the claim 1 (Ag, Sb and Te in a molar ratio of 1:2.43˜3.29:2.18˜2.96) is determined thereby.
Embodiment 1
[0034] (i) Metallographic and Composition Analysis
[0035] With reference to FIG. 1 , it demonstrates the manufacture of the present invention. A predetermined amount of silver (Ag), antimony (Sb), and Tellurium (Te) in high purity was weighted by the electronic scale (Mettler, Ae200, USA) to prepare an alloy in a ratio of Ag-40.0 at % Sb-36.0 at % Te, and the prepared alloy was placed in a 6 mm×8 mm quartz tube. In order to prevent oxidation of the alloy, it was sealed by an oxygen-gas torch gun in a vacuum of 2×10 −5 bar. The alloy was placed in a furnace at 800° C. to melt for 24 hours, and then quenched by cool water to prevent generation of low-temperature solid phase. Then the alloy was cold mount by resin to perform metallographic and composition analysis. The alloy was ground by the sandpapers of #1200, #2400, and #4000, and was polished by aluminum oxide powder of 1.0 μm and 0.3 μm to. Until a mirror surface was shown, residual powder was removed by a sonicator. An optical microscope (OM, Olympus, BH, Japan) was used for initial observation, and then an scanning electronic microscope (SEM, Hitachi, S-2500, Japan) and an electron probe microanalyzer (Electron Probe Microanalysis, EPMA; JEOL, JXA-8600 SX, Japan) were used for the composition analysis. The results were shown in FIGS. 2 and 3 , which were metallographic diagrams showing the material of Ag-40.0 at % Sb-36.0 at % Te at different magnification. In FIG. 2 , there was no distinguished phase. In FIG. 3 , the dotted phase in a grain size of 200-400 nm was uniformly distributed in the alloy, and this nano-size microstructure was a characteristic of the present invention.
[0036] (ii) Electrical Property Measurement
[0037] The composition and manufacture of the alloy were described as (i), the quenched alloy cylinder was cut by a diamond sawing blade (BUEHLER® IsoMet®, U.S.A) to form a round ingot of 1 mm thickness and 6 mm diameter, and resistivity (Ωcm) of the ingot was then measured by Van der Pauw and four point probe method at room temperature. The 20W Model 2400 SourceMeter® instrument was used, 1 A of input was selected and resistance (Ω) was measured and displayed. By proper calibration and calculation, measured resistivity (ρ) was 7.72*10 −4 (Ωcm). FIG. 4 was a diagram showing electrical resistivity of the material of the present invention in comparison with other high efficiency thermoelectric materials. As compared in FIG. 4 , the thermoelectric material of the present invention had an extremely low resistivity.
Embodiment 2
[0038] (i) Metallographic and Composition Analysis
[0039] In this embodiment, most of the steps are similar with embodiment 1. At first, a predetermined amount of silver (Ag), antimony (Sb), and Tellurium (Te) in high purity was weighted by the electronic scale (Mettler, Ae200, USA) to prepare an alloy in a ratio of Ag-40.0 at % Sb-36.0 at % Te, and the prepared alloy was placed in a 6 mm×8 mm quartz tube. In order to prevent oxidation of the alloy, it was sealed by an oxygen-gas torch gun in a vacuum of 2×10 −5 bar. The alloy was placed in a furnace at 800° C. to melt for 24 hours, and the alloy was firstly quenched to 550° C. with a rate of 1° C./min, secondly quenched at this temperature for 120 hours, and finally quenched again by cool water. Then the alloy was cold mount by resin to perform metallographic and composition analysis. The following steps were the same as described in embodiment 1 and not repeated herein. The results were shown in FIGS. 5 and 6 , which were metallographic diagrams showing the material of Ag-40.0 at % Sb-36.0 at % Te at different magnification. In FIG. 5 , there was no distinguished phase. In FIG. 6 , the dotted phase in a grain size of 200-400 nm was uniformly distributed in the alloy, and this nano-size microstructure was a characteristic of the present invention.
[0040] (ii) Electrical Property Measurement
[0041] The composition and manufacture of the alloy were described as (i), the quenched alloy cylinder was cut by a diamond sawing blade (BUEHLER® IsoMet®, U.S.A) to form a round ingot of 1 mm thickness and 6 mm diameter, and resistivity (Ωcm) of the ingot was then measured by Van der Pauw and four point probe method at room temperature. The 20W Model 2400 SourceMeter® instrument was used, 1 A of input was selected and resistance (Ω) was measured and displayed. By proper calibration and calculation, measured resistivity (ρ) was 8.33*10 −4 (Ωcm). FIG. 7 was a diagram showing electrical resistivity of the material of the present invention in comparison with other high efficiency thermoelectric materials. As compared in FIG. 7 , the thermoelectric material of the present invention had an extremely low resistivity.
Embodiment 3
[0042] (i) Metallographic and Composition Analysis
[0043] In this embodiment, most of the steps are similar with embodiment 1. At first, a predetermined amount of silver (Ag), antimony (Sb), and Tellurium (Te) in high purity was weighted by the electronic scale (Mettler, Ae200, USA) to prepare an alloy in a ratio of Ag-40.0 at % Sb-36.0 at % Te, and the prepared alloy was placed in a 6 mm×8 mm quartz tube. In order to prevent oxidation of the alloy, it was sealed by an oxygen-gas torch gun in a vacuum of 2×10 −5 bar. The alloy was placed in a furnace at 800° C. to melt for 24 hours. After rapid cooling, the alloy was quenched at 650° C. for 120 hours, and then quenched again by cool water. Then the alloy was cold mount by resin to perform metallographic and composition analysis. The following steps were the same as described in embodiment 1 and not repeated herein. The results were shown in FIGS. 8 and 9 , which were metallographic diagrams showing the material of Ag-40.0 at % Sb-36.0 at % Te at different magnification. In FIG. 8 , there was no distinguished phase. In FIG. 9 , the dotted phase in a grain size of 200-400 nm was uniformly distributed in the alloy, and this nano-size microstructure was a characteristic of the present invention.
[0044] (ii) Electrical Property Measurement The composition and manufacture of the alloy were described as (i), the quenched alloy cylinder was cut by a diamond sawing blade (BUEHLER® IsoMet®, U.S.A) to form a round ingot of 1 mm thickness and 6 mm diameter, and resistivity (Ωcm) of the ingot was then measured by Van der Pauw and four point probe method at room temperature. The 20W Model 2400 SourceMeter® instrument was used, 1 A of input was selected and resistance (Ω) was measured and displayed. By proper calibration and calculation, measured resistivity (ρ) was 9.33*10 −4 (Ωcm). FIG. 10 was a diagram showing electrical resistivity of the material of the present invention in comparison with other high efficiency thermoelectric materials. As compared in FIG. 10 , the thermoelectric material of the present invention had an extremely low resistivity.
[0045] As depicted in the above embodiments, the thermoelectric material of the present invention had a uniformly nano-size microstructure, and its average resistivity was about 8.46*10 −4 Ωcm. Other high efficiency thermoelectric materials in the previous documents were listed in table. 1. According to table. 1, resistivity of the thermoelectric material of the present invention was lower than those in other thermoelectric materials, such as Bi 2 Te 3 , AgSbTe 2 , (AgSbTe 2 ) 0.8 , (Ag 2 Te) 0.2 (Ag 2 Te) 0.2 and TAGS-75, which proved it was a ideal thermoelectric material.
[0000]
TABLE 1
Average resistivity of the thermomaterial of the present invention
in comparison with those in other materials in previous documents.
ρ(Ωcm)
at room
temperature
Reference
Ag - 40.0 wt %
8.4 × 10 −4
the persent invention
Sb - 36.0 wt %
Te
Bi 2 Te 3
1.5 × 10 −3
Ji et al., J. Appl. Phys., 104,
034907, (2008).
AgSbTe 2
7.5 × 10 −3
V. Jovovic and J. P. Heremans
PHYSICAL REVIEW B,
77, 245204, (2008).
AgPb m SbTe 2m
5.7 × 10 −4
K. F. Hsu et al., Science, 6, 818,
303, (2004).
(AgSbTe 2 ) 0.8 (Ag 2 Te) 0.2
3.0 × 10 −3
T. Su et al., Materials Letters, 62,
3269, (2008).
TAGS-75
1.6 × 10 −3
S. H. Yang et al., Nanotechnology,
TAGS-80
8.0 × 10 −4
19, 245707, (2008).
[0046] New energy material belongs to one of the top five development fields. To correspond flourish developments in energy industry, the present invention provides a thermoelectric material which has low resistivity and uniform nano size microstructure, and it can be produced by a simple manufacture. The present invention clearly discloses the embodiments of thermoelectric material, which can be applied to modules of thermoelectric generators, industry thermal recycling, and combination with other energy materials such as solar cells. Therefore, the present invention meets the requirement of utility. The thermoelectric material and its manufacture of the present invention can be used as a critical material required in developments of new energy materials. Further, there was no application about Ag—Sb—Te thermoelectric material with low resistivity and uniform nano size microstructure in the past. Therefore, the present invention also meets the requirements of novelty and unobvious.
[0047] According to the report of BBC Research & Consulting company, the market of new energy equipment and materials in 2009 is estimated as 116 hundred million dollars, and it is expected to increase to 116 hundred million dollars until 2014. Compound Annual Growth Rate (CAGR) has reached 7.8% in the resent five years, and the photothermal material possesses the highest ratio. Its market cost 83 hundred million dollars in 2009, and its CAGR reached 9.8%. Therefore, the invention can meet the requirement of this growing market.
[0048] Although the present invention is described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. | Thermoelectric material has attracted more attentions as a promising energy material in recent years. Research nowadays are devoted to improvement of figure-of-merit (zT=S 2 T/ρκ). Motivated by p-type AgSbTe 2 compound, ternary Ag—Sb—Te has been reported as an important thermoelectric system. Although ternary AgSbTe 2 compound has been considered as a candidate for thermoelectric materials with the advantages of low thermal conductivity (κ p =0.6 WK −1 m −1 ), the relatively high electrical resistivity (ρ=7.5*10 −3 Ωcm) has limited its applications. This invention disclosed brand-new Ag—Sb—Te bulk materials with very fine microstructures that nanoscale Ag 2 Te phase precipitate uniformly in the multi-phase matrix through class I reaction, liquid=Ag 2 Te+AgSbTe 2 +δ. Moreover, the electrical resistivity (ρ) measured by four-probe method is as low as 8.4*10 −4 (Ωcm) at room temperature, which guarantees the promise of those ternary bulk materials. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit under 35 U.S.C. § 119 of Japanese Patent Application No. 350477/2004, filed Dec. 2, 2004, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates to coated printing papers having good printability, good color print quality and air cleaning effect, especially those on which news ink is used.
Against the background of growing demands for removing harmful substances in daily life such as offensive odors, along with a growing awareness of the need to protect the environment, titanium oxides are drawing attention. Such oxides have been conventionally used as pigments for papermaking on account of their good opacity; and techniques for supporting fine titanium oxides on paper are under development in order to effectively utilize their known ability to induce redox reactions by using light energy to decompose various harmful substances in the atmosphere. For example, a photocatalytic paper internally containing a water-soluble polymer and a photocatalytic material such as a titanium oxide has been disclosed (see patent document 1), but the inclusion of a photocatalytic material within paper layers is neither efficient nor sufficiently effective because it produces its catalytic effect by exposure to light. In order to increase catalytic efficiency, it is thought that a photocatalytic material should be supported as close as possible to a paper surface; or most effectively, paper should be coated with the material. For example, a method has been disclosed by which fine titanium oxide are bonded to an inorganic binder such as colloidal silica and bonded around it by an organic adhesive (see patent document 2). However, such paper is not common and there is limited incentive to use them in view of current environmental awareness. Photocatalytic technologies would be most effectively utilized if they could be applied to e.g., the cover pages of newspapers because currently the most common papers are printing papers, and especially newspapers are published everyday.
Recently, with the growth of various printing technologies there is a growing trend in employing multicolor printing and using printing press with greatly improved printing speed. This tendency is also seen in newspaper printing. Multicolor printing of newsprint paper takes place under conventional printing conditions, i.e. penetration drying type inks are used for printing on conventional newsprint by high-speed coldset rotary presses to meet the need for immediate mass printing typical of newspaper printing and for cost-related reasons. However, when paper is coated by conventional methods, the ink drying properties of the paper are very poor. Therefore, when using penetration drying type inks on such paper printed by high-speed coldset rotary presses, there remains some undried ink which is deposited on guide rolls and transferred to the paper which will cause the final quality to deteriorate.
REFERENCES
Patent document 1: JPA HEI 10-226983.
Patent document 2: JPA 2000-129595.
Under such circumstances, an object of the present invention is to provide coated printing papers having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially when using penetration drying type news inks.
SUMMARY OF THE INVENTION
As a result of careful studies to achieve the above object, we found that a coated printing paper having good ink drying properties of prints, little stickiness, good printability, and good reproducibility and sharpness of color printed images, as well as having the effect of decomposing harmful substances by exposure to light can be obtained by providing a coated paper comprising a coating layer containing a pigment and an adhesive on a base paper wherein a fine titanium oxide having a photocatalytic effect is contained in the coating layer and the coated paper has an oil absorbency of 20 g/m 2 or more under pressure and a Bekk smoothness of 75 seconds or less. It is thought that retransfer to rolls of printing press or the like or the resulting stain on the surface of printing can be reduced by adjusting the coated paper at an oil absorbency under pressure of 20 g/m 2 or more and a Bekk smoothness of 75 seconds or less because news inks or the like moderately penetrate the coated paper during printing to contribute to good ink receptivity and ink drying properties and reduced stickiness and inks are deposited on the surface of the coated paper having low smoothness. In the present invention, the base paper preferably contains an organic compound having the effect of inhibiting interfiber binding of pulp. Preferably, the fine titanium oxide is contained at 5 parts by weight or more and the fine titanium oxide and calcium carbonate are contained at 30 parts by weight or more per 100 parts by weight of the pigment.
ADVANTAGES OF THE INVENTION
According to the present invention, coated printing papers can be obtained having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially in printing using penetration drying type news inks.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, coated printing paper having defined smoothness and oil absorbency are obtained by coating a specific pigment on a base paper.
It is important that the coated printing paper of the present invention has a Bekk smoothness of 75 seconds or less. If the Bekk smoothness is more than 75 seconds, the paper surface becomes stained, resulting in poor printability. This is probably because the inks supplied to the paper surface during printing may be retransferred to rolls of printing press or the like once they have been transferred to the printing paper and thereby the paper surface is more likely to be stained in the case of paper with high smoothness in contrast to papers with low smoothness in which inks are less likely to be transferred. More preferably, the Bekk smoothness is 10 seconds or more and 60 seconds or less.
It is also important that the coated printing paper of the present invention has an oil absorbency of 20 g/m 2 or more under pressure. The method for measuring the oil absorbency under pressure in the present invention uses AA-GWR Water Retention Meter from KALTEC. A coated paper test sample, a membrane filter (pore size 5.0 μm), and the accessory cup are placed in the instrument, and 1 ml of soybean oil is added from the top, and then the cup is tightly closed under a constant pressure (50 kPa) for a determined period (20 seconds), and then the amount of oil adsorbed into coated paper is measured. Normally, ink drying properties, i.e., the oil absorbency of papers is typically evaluated from the oil drop absorbency measured at normal pressures. However, actual printing conditions were not simulated and no definite correlation with printability such as paper surface stain or stickiness was observed by the oil drop absorbency measured at normal pressures because the inks on the blanket in offset rotary presses in fact set on paper under pressure between upper and lower cylinders. No correlation with printability is observed again according to JIS P 8130 defining a pressure set type oil absorbency test method. It was found that high correlation with printability is obtained by using the method of the present invention as described above. If the oil absorbency under pressure is less than 20 g/m 2 , news inks are less likely to penetrate the coated paper during printing, resulting in poor ink receptivity on one side of the coated paper and poor ink drying properties to cause staining on the printed surface or stickiness. If the oil absorbency under pressure is too high, inks excessively penetrate the coated paper, resulting in decreased ink receptivity and poor reproducibility and sharpness of prints. The coated papers preferably have an oil absorbency of 25 g/m 2 or more and 250 g/m 2 or less under pressure.
The base paper in the present invention comprises pulp, fillers and various additives. Chemical pulp, mechanical pulp, de-inked pulp and the like can be used, but mechanical pulp and waste paper pulp derived from mechanical pulp are preferably contained at 60% by weight or less, most preferably not contained because they deteriorate and discolor upon exposure to light when they are excessively used.
In the base paper of the present invention, a bulking agent (density reducing agent) such as a surfactant is preferably used as an organic compound having the effect of inhibiting interfiber binding of pulp to reduce the density of the base paper and to balance oil absorbency and smoothness. The organic compound having the effect of inhibiting interfiber binding of pulp (hereinafter simply referred to as binding inhibitor) means a compound having a hydrophobic group and a hydrophilic group, and suitable binding inhibitors for the present invention are density reducing agents (or bulking agents) recently introduced on the market to increase the bulk of paper for papermaking, including e.g., compounds disclosed in WO98/03730, JPA HEI 11-200284, JPA HEI 11-350380, JPA 2003-96694, JPA 2003-96695, etc. Specifically, ethylene and/or propylene oxide adducts of higher alcohols, polyvalent alcohol-type nonionic surfactants, ethylene oxide adducts of higher fatty acids, ester compounds of polyvalent alcohols and fatty acids, ethylene oxide adducts of ester compounds of polyvalent alcohols and fatty acids, or fatty acid polyamide amines, fatty acid diamide amines, fatty acid monoamides, or condensation products of polyalkylene polyamine/fatty acid/epichlorohydrin can be used alone or as a combination of two or more of them. Ester compounds of polyvalent alcohols and fatty acids, fatty acid diamide amines, fatty acid monoamides, condensation products of polyalkylene polyamine/fatty acid/epichlorohydrin or the like are preferred. Commercially available bulking agents include Sursol VL from BASF; Bayvolume P Liquid from Bayer; KB-08T, 08W, KB110, 115 from Kao Corporation; Reactopaque from Sansho Co., Ltd.; PT-205 from Japan PMC Corporation; DZ2220, DU3605 from NOF Corporation; R21001 from Arakawa Chemical industries, Ltd., and these can be used alone or as a combination of two or more of them. The coated papers of the present invention preferably contain 0.1-10 parts by weight, especially 0.2-1.0 parts by weight of an inhibitor of interfiber binding of pulp per 100 parts by weight of the base paper to improve air permeability of the base paper.
In the present invention, known fillers such as amorphous silicates, amorphous silica, talc, kaolin, clay, precipitated calcium carbonate, ground calcium carbonate, titanium oxides and synthetic resin fillers can be used in an amount of about 3-20% by weight of pulp in the base paper. These fillers can be used alone or as a combination of two or more of them for the purpose of controlling papermaking suitability of stock or strength characteristics.
These stock can be added to with chemicals commonly used during papermaking processes, such as paper strength enhancers, sizing agents, antifoaming agents, colorants, softening agents or the like as needed in the range not inhibiting the effects of the present invention.
The base paper may be prepared by any process for papermaking acidic, neutral or basic papers using a Fourdrinier paper machine including a top wire or the like, a cylinder paper machine, a combination machine of both or a Yankee dryer machine or the like and may also be a mechanical base paper containing recycled paper pulp obtained from old newspapers. Base papers precoated with starch or polyvinyl alcohol using a size press, bill blade, gate roll coater, premetering size press or the like may also be used. Base papers having a basis weight of about 30-400 g/m 2 used for normal coated papers can be used as coating base papers, but preferably about 30-100 g/m 2 because the present invention relates to coated printing papers, especially coated papers suitable for use in rotary newspaper presses. In the present invention, the base paper preferably has a density of 0.3 g/cm 3 or more and 0.8 g/cm 3 or less, more preferably a density of 0.3 g/cm 3 or more and 0.6 g/cm 3 or less.
In the present invention, the ability to decompose harmful substances in the atmosphere by exposure to light can be conferred by using a fine titanium dioxide as a pigment. It is preferably contained in an amount of 5 parts by weight or more, more preferably 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the pigment. The titanium oxide in the present invention can be prepared from not only titanium oxides but also any titanium oxide or hydroxide called wet titanium oxides, hydrated titanium oxides, metatitanic acid, orthotitanic acid, and titanium hydroxide. The titanium oxide used in the present invention preferably has a primary particle size of 2-150 nm. It preferably has a specific surface area of 10-350 m 2 /g.
In the present invention, a mixture of a fine titanium dioxide and colloidal silica or alumina in a ratio of 5:1-1:5 is preferably used as a pigment in the coating color. Thus, coexisting organic adhesives can be inhibited from being decomposed. Preferably, a fine titanium oxide and a colloidal solution of silica or alumina are added in certain proportions, and after stirring for a given period, other pigments or additives are added.
In addition to the pigment as mentioned above, inorganic pigments such as precipitated calcium carbonate, ground calcium carbonate, clay, kaolin, engineered kaolin, delaminated clay, talc, calcium sulfate, titanium dioxide used for conventional papermaking, barium sulfate, zinc oxide, silicic acid, silicic acid salts, satin white; or organic pigments such as plastic pigments can also be used in the present invention. In the present invention, it is preferable to use calcium carbonate, especially ground calcium carbonate in terms of production costs and improvements in ink drying properties. Preferably, 30 parts by weight or more, more preferably 50 parts by weight or more of a mixture of calcium carbonate and titanium oxide is contained per 100 parts by weight of the pigment.
Adhesives used in the present invention can be selected as appropriate from one or more of conventional adhesives for coated papers, e.g., synthetic adhesives such as styrene-butadiene copolymers, styrene-acrylic copolymers, ethylene-vinyl acetate copolymers, butadiene-methyl methacrylate copolymers, vinyl acetate-butyl acrylate copolymers, or polyvinyl alcohols, maleic anhydride copolymers and acrylic-methyl methacrylate copolymers; proteins such as casein, soybean protein and synthetic proteins; starches such as oxidized starches, cationized starches, urea phosphate-esterified starches, hydroxyethyl etherified starches; and cellulose derivatives such as carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose. These adhesives are preferably used in a range of 5-50 parts by weight, more preferably 10-40 parts by weight per 100 parts by weight of the pigment. More than 50 parts by weight is not preferred because of disadvantage in runnability or the like, e.g., the resulting coatings becoming too viscous to readily pass through piping or screens. Less than 5 parts by weight is not preferred because of insufficient surface strength.
The coating color of the present invention may contain various conventional auxiliaries such as dispersants, thickeners, water-retention agents, antifoamers, water insolubilizers, dyes, optical brighting agents, etc.
The coating color prepared is applied in one or more layers on one or both sides of the base paper using a blade coater, bar coater, roll coater, air knife coater, reverse roll coater, curtain coater, size press coater, gate roll coater or the like. The range of the coat weight in which the present invention is effective is preferably 3 g/m 2 or more and 12 g/m 2 or less, more preferably 4 g/m 2 or more and 8 g/m 2 or less per side.
The wet coating layer is dried by using conventional means such as a steam heater, gas heater, infrared heater, electric heater, hot air dryer, microwave, cylinder dryer, for example.
After drying, the paper can be post-processed as needed to confer smoothness by carrying out finishing processes using a supercalender, a hot soft nip calender or the like. However, it can be processed by any calender or uncalendered so far as a coated paper of a desired quality can be obtained. Any other conventional paper processing means can also be applied.
EXAMPLES
The following examples specifically illustrate the present invention without, however, limiting the invention thereto as a matter of course. Unless otherwise specified, parts and % in the examples mean parts by weight and % by weight, respectively. Coating color and the obtained coated printing papers were tested by the following evaluation methods.
(Evaluation Methods)
(1) Oil absorbency under pressure: The oil absorbency under pressure as defined herein was determined using AA-GWR Water Retention Meter from KALTEC. First, six pieces of each coated paper test sample (5 cm×5 cm) (or any number of pieces adjusted as appropriate if the sample is highly absorbent) and a piece of a membrane filter (from KALTEC; pore size 5.0 μm) are laid on the supplied rubber mat and the supplied cup is placed thereon, and the assembly is inserted into the instrument. The assembly is raised by the clamp to come into close contact with the top of the instrument, and then 1 ml of soybean oil (from Wako Pure Chemical Industries, Ltd., Wako first-class quality) is injected via the liquid inlet at the top, and immediately the supplied cap is put on the cup to start measurements. After maintaining the pressure in the cup at 50 kPa for 20 seconds, the cup was opened and the weight of the coated paper sample was measured. The area measured is 8 cm 2 . The weight gain corresponds to the weight of soybean oil absorbed by each paper under pressure and the weight of oil absorbed per m 2 was determined as oil absorbency under pressure herein.
Oil absorbency under pressure(g/m 2 )=(paper weight
after measurement(g)−paper weight before measurement
(g))/(0.0008(m 2 ))
(2) Bekk smoothness: determined according to JIS P 8119.
(3) Ink receptivity: Printing was performed using an offset rotary press (4 colors) from Toshiba Machine Co., Ltd. with penetration drying type news inks for offset printing (Vantean Eco from Toyo Ink Mfg. Co., Ltd.) at a printing speed of 500 rpm, and the ink receptivity of the resulting print (solid print in three colors consisting of cyan, magenta and yellow) was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
(4) Ink drying properties: Immediately after printing using an RI press with a penetration drying type news ink for offset printing (Vantean Eco from Toyo Ink Mfg. Co., Ltd.), the resulting print (solid print in magenta simply) was transferred to a woodfree paper and the cleanness of the woodfree paper was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
(5) Print sharpness: Sharpness of the print in offset printing was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
(6) Stickiness: Stickiness of the print in offset printing was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
(7) Photocatalytic effect: A sheet was cut into 10 cm×15 cm and placed in a 5-liter quartz glass sealed vessel, and acetaldehyde gas was injected via a microsyringe to a concentration of 100 ppm in the vessel. The vessel was irradiated with UV rays using three 15-W black lights at a dose of 5.0 mW/cm 2 on the sheet surface. After 1 hr, the gas concentration in the vessel was measured by a Kitagawa gas detector tube to determine the decomposition rate (%), from which the photocatalytic effect was evaluated.
Example 1
In a Cellier mixer, 15 parts (solids) of a slurry of titanium oxide microparticles (CSB-M from Sakai Chemical Industry, Co., Ltd.) and 24 parts of colloidal silica (Snowtex 40 from Nissan Chemical Industries, Ltd.) were stirred for 1 hr. Into this mixed slurry was added a pigment slurry prepared by dispersing a pigment consisting of 40 parts of ground calcium carbonate (FMT-90 from Fimatec Ltd.) and 21 parts of fine clay (JapanGloss from HUBER) with a dispersant consisting of sodium polyacrylate (0.2 parts based on the inorganic pigment) in a Cellier mixer to prepare a pigment slurry having a solids content of 63%. To thus obtained pigment slurry were added 13 parts of a styrene/butadiene copolymer latex (glass transition temperature 20° C., gel content 85%) and 26 parts of a hydroxyethyl-etherified starch (PG295 from Penford Corporation) and water was further added to give a coating color having a solids content of 58%.
The base paper to be coated was a medium quality paper having a basis weight of 50 g/m 2 prepared from papermaking pulp consisting of 30% mechanical pulp and 70% chemical pulp and containing 7%, on the basis of the weight of the base paper, of light calcium carbonate as a filler and 0.3%, on the basis of the weight of the base paper, of an ester compound of a polyvalent alcohol and a fatty acid (KB-110 from Kao Corporation) as an organic compound having the effect of inhibiting interfiber binding of pulp.
The base paper was coated with the coating color on both sides at a coating mass of 5 g/m 2 per side using a blade coater at a coating speed of 700 m/min and dried to a moisture content of 5% in coated paper to give a coated printing paper.
Example 2
A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 16 parts of colloidal silica, 50 parts of ground calcium carbonate, and 24 parts of fine clay.
Example 3
A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 5 parts (solids) of the slurry of titanium oxide microparticles, 8 parts of colloidal silica, 60 parts of ground calcium carbonate, and 27 parts of fine clay.
Example 4
A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 16 parts of colloidal silica, and 74 of ground calcium carbonate.
Example 5
A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 66 parts of ground calcium carbonate, and 24 parts of fine clay.
Example 6
A coated printing paper was obtained by the same procedure as in Example 1 except that the ester compound of a polyvalent alcohol and a fatty acid (KB-110 from Kao Corporation) was not used as an organic compound having the effect of inhibiting interfiber binding of pulp in the base paper in Example 1.
Comparative Example 1
A coated printing paper was obtained by the same procedure as in Example 1 except that the coated paper was treated in a hot soft nip calender with 2 nips at a metal roll surface temperature of 100° C., a paper feed speed of 1200 m/min, and a linear load of 300 kN/m after it was dried in Example 1.
Comparative Example 2
A coated printing paper was obtained by the same procedure as in Example 6 except that the coated paper was treated in a hot soft nip calender with 2 nips at a metal roll surface temperature of 100° C., a paper feed speed of 1200 m/min, and a linear load of 300 kN/m after it was dried in Example 6.
Comparative Examples 3
A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 70 parts of ground calcium carbonate and 30 parts of fine clay.
The evaluation results are shown in Table 1.
TABLE 1
Oil
absorbency
under
Bekk
Print
pressure
smoothness
Ink
Ink drying
surface
Photocatalytic
(g/m 2 )
(sec)
receptivity
properties
sharpness
Stickiness
effect (%)
Example 1
56
31
⊚
⊚
⊚
⊚
64
Example 2
70
33
⊚
⊚
⊚
⊚
32
Example 3
74
35
⊚
⊚
⊚
⊚
18
Example 4
90
25
◯
⊚
⊚
⊚
30
Example 5
71
35
⊚
⊚
⊚
⊚
29
Example 6
30
62
⊚
◯
⊚
◯
65
Comparative
30
90
⊚
X
⊚
Δ
65
example 1
Comparative
18
90
⊚
X
⊚
X
65
example 2
Comparative
60
30
⊚
⊚
⊚
⊚
0
example 3 | The present invention aims to provide coated printing papers having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially when using penetration drying type news inks.
A coated printing paper is provided, comprising a coating layer containing a pigment and an adhesive on a base paper, characterized in that a fine titanium oxide powder having a photocatalytic effect is contained in the coating layer and that the coated paper has an oil absorbency of 20 g/m 2 or more under pressure and a Bekk smoothness of 75 seconds or less. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a process for producing krypton and xenon in which liquid oxygen obtained under rectification by means of an air separation plant is concentrated, and in which krypton and xenon contained in the thus concentrated liquid are recovered safely and efficiently.
In recovering industrially krypton and xenon contained in air, it is a common practice to rectify liquid oxygen which has been separated in a main condenser evaporator of the air separation plant, to concentrate krypton and xenon contained in the rectified liquid to obtain a gas mixture of krypton and xenon, and then to purify and separate the gas mixture, whereby pure krypton and xenon are separately produced. Hydrocarbons included in air are also carried into the liquid oxygen, and are hence concentrated during the concentrating process of krytpon and xenon. The enrichment of the liquid with hydrocarbons, particularly methane is liable to cause explosion. To avoid this explosion hazard, removal of hydrocarbons by adsorption or replacement of oxygen by inert gases such as argon is conventionally carried out. It is however difficult to completely remove hydrocarbons by adsorption. Also, it is insufficient to remove hydrocarbons by using the method of catalitic combustion and adsorption of water and carbon dioxide which are combustion products thereby to eliminate the danger of the explosion of hydrocarbons, because the ratio of the supplied liquid oxygen to the concentrated liquid in the concentrating step should be kept under range of the methane 150-180 in view of explosion limit concentration. In the process replacing oxygen by inert gases such as argon gas, there are disadvantages that an argon extraction system must be provided in the air separation plant, and further that expensive argon is consumed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a process for producing krypton and xenon in which krypton and xenon are concentrated without raising hydrocarbon concentration too high, whereby safety can be greatly enhanced.
It is a further object of the invention to provide a process for producing krypton and xenon in which the concentration of xenon which is valuable for industrial purposes is highly raise thereby to increase the yield of xenon.
It is another object of the invention to provide a process for producing krypton and xenon in which the concentration of methane contained in the liquid oxygen is maintained low during the concentration process compared to the prior art, so that krypton and xenon can be concentrated to a high degree and the amount of treatment gas to be processed in the later stages becomes relatively small which enables the combustion and absorption of methane gas to be easily performed, and which allows units used for such steps to be made compact.
These and other objects of the invention are achieved by a process for producing krypton and xenon in which concentrations of krypton and xenon contained in the liquid oxygen are not highly increased in the concentrating column to produce concentrated liquid having a low concentration of methane, which is stripped of methane by contact with oxygen gas in a methane purging column to reduce the methane concentration and the methane-purged liquid is then concentrated at the lower part of the purging column.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is a flowsheet of one embodiment of the process according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the FIGURE, reference numeral 1 designates a main condenser of an air separation plant, from which liquid oxygen containing small concentrations of krypton, xenon and hydrocarbons is extracted and is supplied through a line 2 to the top of a first concentrating column 3. On the other hand, nitrogen gas for heating is fed from the air separation plant through a line 4 to the bottom of the column 3. The liquid oxygen fed to the top of the concentrating column 3 is rectified and concentrated in the column 3. As a result, a concentrated liquid containing krypton, xenon, and hydrocarbons flows out of a condensed section at the bottom of the concentrating column 3 through a line 5 while oxygen gas containing methane issues from a line 6. The nitrogen gas which was supplied for heating through pipe 4 is liquefied and accumulated in the bottom of the concentrating column 3 and is then returned back through a pipe 7 to the air separation plant.
The concentrated liquid flowed out through the line 5 is fed to the top portion of a first methane purging column 8 of a conventional type, for example, a rectification column. On the other hand, the bulk of the reduced methane-concentration oxygen gas flowed out through the line 6 is injected through a line 9 into a middle portion of the purging column 8 and moved upwards accompanying with methane contained in the concentrated liquid which is fed in the top of the column 8 and fallen in it, and then is discharged through a pipe 10 with an increased concentration of methane gas. This purging lowers greatly the concentration of the methane contained in the concentrated liquid, but the liquid is re-concentrated and at the bottom of the column 8 becomes substantially the same in the concentration of methane as the liquid at the top of the column. Simultaneously, krypton and xenon in the liquid are also concentrated. Thus-methane-purged concentrated liquid is extracted through a line 11, is fed into a top portion of a second methane purging column 12 of a well-known type, and is then methane purged as in the column 8 by the remaining oxygen gas derived from the top of the concentrating column 3 and then injected through a line 13 into a middle portion of the column 12. As a result, oxygen-rich liquid containing considerable concentrations of krypton and xenon relatively small concentrations of methane and other hydrocarbons is flowed out of the bottom of the second methane purging column 12 through a line 14, while the oxygen-rich gas carrying the methane gas is discharged from the top of the column 12 through a line 15 and is returned back through a line 16 to the air separation plant together with the oxygen-rich gas flowing out through the line 10 of the first methane purging column 8. At the bottom portions of the methane purging column 8 and 12, there are respectively provided heating means 17 and 18 such as heater for generating heat necessary for rectification.
The concentrated liquid extracted through the line 14 is introduced into and evaporated by a heater 19 and then enters through a line 20 a catalytic combustion cylinder or reactor 21, where the bulk of hydrocarbons contained in the evavopated liquid is burnt to generate water and carbon dioxide, which are thereafter introduced through a line 22 into one of adsorption units 23 which can be switched over to the other, where the water and carbon dioxide are adsorbed and removed. The hydrocarbon-purged or purified gas enters through a line 24 a heat exchanger 25 for cooling and is then fed through a line 26 to the middle portion of second concentrating column 27 of a conventional type where rectification is carried out by supplying liquid oxygen through a line 28 to the condensation section at the top of the column 27 and by providing oxygen gas or air through a line 29 to a heating section at the bottom of the column 27 from the air separation plant. Consequently, a liquid mixture of krypton and xenon is accumulated at the bottom of the second concentrating column 27, and oxygen gas issues through a line 30 from the top of the condensation section. The oxygen gas cools at the heat exchanger 25 the gas mixture to be fed to the column 27 and then flows out through a line 31. On the other hand, the liquid mixture of krypton and xenon is drawn through a line 32 and then undergoes well-known purifying steps such as combustion, absorption, etc, after which the purified gases are rectified and separated into pure krypton gas and xenon gas. The vaporized part of the liquid oxygen for cooling which has been supplied through the line 28 issues out of a line 33, and is returned back to the air separation plant as well as the oxygen gas flowing out of the lines 29 and 31.
In the above embodiment, the methane purging is performed in two stages by the use of two methane purging columns, but it may be carried out in a single or more than two stages. Also, only methane purging may be carried out without reconcentration of the concentrated liquid in the first methane purging column and/or the second methane purging column. The oxygen gas for stripping methane in the methane purging column is not limited to the oxygen gas obtained from the top of the concentration column, but oxygen gas, from whatever oxygen source it may be obtained, can be used for the methane purging process, if it contains a small amount of methane. The nitrogen gas supplied from the air separation plant for the purpose of heating the concentrating column may be substituted by air, oxygen gas, or argon gas provided from the plant, or by the oxygen gas under pressure which has been stripped of methane in the methane purging column. Further, these heating air, nitrogen gas, argon gas, etc. may be recycled by a recycle compressor, so that the present krypton and xenon recovering system is supplied only with liquid oxygen as raw material from the air separation plant thereby to achieve stabilization of the operation of the plant. Instead of this recycle method for heating the concentrating column, the oxygen gas discharged from the top of the concentrating column may be used as a heating gas after being heated, compressed, and cooled.
EXAMPLE
A plant for recovering krypton and xenon of the type illustrated in the FIGURE was built and tested. Liquid oxygen containing 80 ppm of krypton, 25 ppm of xenon, 55 ppm of methane and a trace amount of other hydrocarbons was fed from an air separation plant through the line 2 to the concentration column 3 at a rate of 100 Nm 3 /h. As a result of the rectification process in the concentration column 3, concentrated liquid containing 500 ppm of xenon, 1000 ppm of methane, etc. was flowed out through the line 5 at a rate of 5 Nm 3 /h, and an oxygen gas containing 7 ppm of methane issued through the line 6 at a rate of 95 Nm 3 /h. The oxygen gas was injected into the first methane purging column 8 through the line 9 at a rate of 87 Nm 3 /h. This purging process caused oxygen gas containing 55 ppm of methane to be discharged through the line 10 and also caused concentrated liquid 6000 ppm (0.6%) of xenon and 1,000 ppm of methane to be flowed out through the line 11 at a rate of 0.42 Nm 3 /h. The concentrated liquid was introduced into the second methane purging column 12. The remaining oxygen gas injected through the line 13 into the second methane purging column 12 at a rate of 8 Nm 3 /h. As a result, a liquid mixture containing 5.3% of krypton, 3.3% of xenon, 500 ppm of methane, 300 to 400 ppm of the other hydrocarbons, and the remaining part of oxygen was obtained from the line 14 at a rate 0.07 Nm 3 /h. It is to be noted that the concentration of methane contained in the concentrated liquid reaches according to the prior process about 8000 to 10000 ppm (0.8-1%), but is according to the present invention about 1/10 of that level even in the case of maximum concentration. | A process for producing krypton and xenon. The concentrations of krypton and xenon contained in liquid oxygen are not highly increased in a concentrating column to produce concentrated liquid having a relatively low concentration of methane, which is stripped of methane by contact with oxygen gas in a methane purging column to reduce the methane concentration and the methane-purged liquid is then concentrated at the lower part of the purging column. Then, the concentrated liquid is vaporized and purified by catalitic combustion and adsorption, and thereafter a mixture of krypton and xenon is separated from the purified gas in a second concentrating column. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a device for controlling an internal combustion engine. In devices for controlling an internal combustion engine of a motor vehicle, particularly for controlling the ignition and the like, it is known to use sensor systems for detecting an angular position of a shaft of the internal combustion engine, particularly the crankshaft or the camshaft.
Such systems are constructed e.g. as segment systems in and transmitter disks rotate with the shaft, which are provided at their circumference with a plurality of segments, i.e. elongated marked areas, proportional to the number of cylinders of the internal combustion engine. In the detection of the angular position of the crankshaft, the number of segments amounts to one half of the number of cylinders. In the detection of the angular position of the camshaft the number of segments is identical to the number of cylinders, since the crankshaft rotates at twice the speed of the camshaft, as is known. Every segment is assigned to a cylinder (n) of the internal combustion engine (two cylinders in the detection of the angular position of the crankshaft), and every ignition process is controlled as a function of the passage of a respective segment. In a stationary receiving element, the leading edge of the segment is detected, and the control processes for the internal combustion engine are triggered by a suitable time control over the entire length of the segment. On the other hand, segment systems with segments of equal dimensions have the disadvantage that an assignment, which is sufficient for a high-voltage distribution without the use of a distributor or for a dual-circuit (e.g. eight-cylinder engine) high-voltage distribution, is not possible.
In addition, segment systems are known in which individual segments are divided by a number of teeth and tooth spaces and the signals produced by the teeth and tooth spaces, respectively, are fed to a control circuit. In so doing, the angular position of the shaft is determined by counting the passing teeth and tooth spaces, respectively. This method is costly and requires an additional counting device.
In addition, if only a single tooth space is formed in a segment, there is the risk that the additional trailing edge will trigger an additional ignition.
In all devices mentioned here, at least one revolution is required when starting the internal combustion engine in order to detect an accurate assignment of the marking.
SUMMARY OF THE INVENTION
The object of the invention is a device in which it is possible to assign the ignition pulses for a high-voltage distribution without the use of a distributor or for a dual-circuit high-voltage distribution with a single transmitter while maintaining the two electrical marks at the beginning and end of the segment. The object of the invention is achieved by assigning a permanent magnet to at least one segment as a mark which generates a signal which can be fed to a control circuit. Because of the resulting electric signals (markings), the cylinder groups can be clearly assigned in a high-voltage distribution without the use of a distributor. It is not necessary to change the profile of the segments, so that no cracks can occur as a result of of stresses particularly at high engine output moments.
The total length of the segment having the permanent magnet thereon is equal to that of other segments.
The present invention as to its construction so to its method of operation, together with additional objects and advatnages thereof, will be best understood from the following description of the preferred embodiment with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a basic view of a transmitter disk of the device according to the present invention;
FIGS. 2a, 2b, and 2c show a pulse diagram; and
FIG. 3 shows a circuit diagram according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, a transmitter disk designated by 1, 1 rotates with a crankshaft or a camshaft of an internal combustion engine. At its circumference, the transmitter disk 10 comprises segments 11, 12 and spaces 13, 14 located between the latter. If two segments and two gaps, respectively, are provided, as in FIG. 1, and the transmitter disk 10 is fastened at the crankshaft of the internal combustion engine, it is suitable for devices for controlling four-cylinder engines. The segments 11, 12 have equal lengths the same angle of rotation and are located diametrically opposite one another. A permanent magnet 15, whose polarity is formed in the radial direction of the transmitter disk 10, is arranged at the end of the segment 11. The height of the permanent magnet 15 corresponds to the height of the segment 11 and is adpated to the surface curvature of the segment 11. The segment 11, including the permanent magnet 15, corresponds in length to the segment 12. Accordingly, the segment 11 is to be shortened, e.g. by milling, by an amount corresponding to the width of the permanent magnet 15 during production.
A stationary receiving element 20, which is, in turn, in a operative connection with a control circuit 21 and, is located in the vicinity of the circumference of the transmitter disk 10. The type of interaction betweenn the transmitter disk 10 and receiving element 20 can vary to a great extent. To provide for magnetic interaction, the transmitter disk 10 can be punched out from a ferromagnetic sheet metal and an inductive sensor, which already has a magnetic flux in the rest state, is used as a receiving element 20. The receiving element 20 shown in FIG. 1 comprises a permanent magnet 22 and a coil 23.
If the transmitter disk 10, as shown in FIG. 1, rotates in the clockwise direction, the receiving element 20 detects-e.g. in segment 12 the leading edge of the segment 12. The ignition process can then be triggered e.g. at the end of the segment 12 at an angular position corresponding to the trailing edge of the segment 12.
In order to illustrate the manner of operation of the device shown in FIG. 1, FIG. 2 shows the time characteristic of signals generated by the segments 11, 12 and the spaces 13, 14, respectively, and by the permanent magnet 15. FIG. 2a shows a transmission of the rotational movement of the crankshaft (Δ CS) to the rotation of the transmitter disk 10 as a function of the angle of rotation (α) of the transmitter disk. In FIG. 2b, the magnetic flux (ΔΦ) produced in the receiving element 20 is shown as a function of the angle of rotation (α) of the transmitter disk 10. If the transmitter disk 10 moves in the clockwise direction, a change in the magnetic flux is produced at the leading edge of the segment 11, i.e. at the angular position α 1 , in the receiving element 20. The magnetic flux runs at the same height, while the segment 11 passes the receiving element 20; consequently, no voltage is induced. When the receiving element 20 reaches the permanent magnet 15, i.e. the transmitter disk 10 is located in the angular position α.sub. 2, the magnetic flux increases again. When the receiving element 20 reaches the end of the permanent magnet 15, i.e. the leading edge of the segment 11 and angular position α 3 , respectively, the magnetic flux decreases. While the space 13 now passes the receiving element 20, no substantial magnetic flux is generated. In a manner analogous to segment 11, a change in the magnetic flux is now produced also by segment 12 at its leading edge as well as at its trailing edge, i.e. at the angular position α 4 and α 5 .
FIG. 2c shows the pulses generated in the receiving element 20. A negative pulse is generated in each instance at the leading edge of the segments 11, 12, i.e. at the angular position α 1 and α 4 . The pulse is dependent on the polarity of the receiving element 20. When the receiving element 20 reaches the permanent magnet in angular position α 2 , another negative pulse is produced. When the receiving element 20 reaches the rear flank of the segments 11, 12, i.e. the transmitter disk 10 is located at angular position α 3 and α 5 , a positive pulse is produced. Due to the magnetic field of the permanent magnet 15, the positive pulse at position α 3 is greater than the pulse in position α 5 . The additional pulse produced in position α 2 , and the different pulse height at position α 3 , respectively, can now be used as a mark.
The voltages produced in the receiving element 20 at the edges of the segments 11 and 12, respectively, and in position α 2 by the permanent magnet 15, are fed to two input terminals E1 and E2 of the control circuit shown in the basic diagram in FIG. 3 via two Schmitt triggers having different switching thresholds. An inverter 27 is connected to the input terminal E1, to which the voltage U - is applied. On the other hand, a non-inverting driver stage 28 is connected to the input terminal E2 to which the voltage U + is applied. The output of the inverter 27 is connected with the inverting reset input of a flip-flop 29. The output of the driver stage 28 is connected to its inverting set input. A line leads from the output Q of the flip-flop 29 to the clear-enable input of a counter 30. The inverting clear enable input of the counter 30 is connected with the output of the driver stage 28. In addition, the voltage U - tapped prior to the inverter 27 is applied to the counter input of the counter 30. Lines lead from the two outputs of the counter 30 to the two cylinder groups of a four-cylinder engine. This circuit serves to achieve a synchronous pulse in order to enable an accurate assignment of the position of the transmitter disc relative to the respective rotation of the shaft already when starting the internal combustion engine. Of course, this principle of control is applicable to all engines with an even number of cylinders. In asymmetrical engines, it must be ensured that the asymmetry occurs within a crankshaft revolution.
While the invention has been illustrated and described as embodied in a device for controlling an internal combustion engine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A device for controlling an internal combustion engine of a motor vehicle and comprising a transmitter disk which rotates with a shaft of the internal combustion engine relative an opposite stationary receiving element, the transmitter disk being provided at its circumference with a plurality of segments proportional to the number of cylinders, and a permanent magnet assigned to at least one of the segments for generating a marking signal to be fed to a control circuit for the ignition, injection and the like of the motor vehicle via the receiving element. | 5 |
BACKGROUND
[0001] 1. Field of the Disclosure
[0002] The embodiments described herein relate to a method and apparatus for a downhole device connected to coiled tubing to obtain diagnostic information of a wellbore. The downhole device may be connected to the interior of the coiled tubing. Alternatively, the downhole device may be connected to an exterior carrier portion of the coiled tubing.
[0003] 2. Description of the Related Art
[0004] Natural resources such as gas and oil may be recovered from subterranean formations using well-known techniques. For example, a horizontal wellbore may be drilled within the subterranean formation. After formation of the horizontal wellbore, a string of pipe, e.g., casing, may be run or cemented into the well bore. Hydrocarbons may then be produced from the horizontal wellbore.
[0005] In an attempt to increase the production of hydrocarbons from the wellbore, the casing may be perforated and fracturing fluid may be pumped into the wellbore to fracture the subterranean formation. The fracturing fluid is pumped into the well bore at a rate and a pressure sufficient to form fractures that extend into the subterranean formation, providing additional pathways through which fluids being produced can flow into the well bores. The fracturing fluid typically includes particulate matter known as a proppant, e.g., graded sand, bauxite, or resin coated sand, that may be suspended in the fracturing fluid. The proppant becomes deposited into the fractures and thus holds the fractures open after the pressure exerted on the fracturing fluid has been released.
[0006] A production zone within a wellbore may have been previously fractured, but the prior fracturing may not have adequately fractured the formation leading to inadequate production from the production zone. Even if the formation was adequately fractured, the production zone may no longer be producing at adequate levels. Over an extended period of time, the production from a previously fractured horizontal wellbore may decrease below a minimum threshold level. One technique in attempting to increase the hydrocarbon production from the wellbore may be the re-fracturing of some of the previously fractured locations of the horizontal wellbore. However, it may not be beneficial to re-fracture every previously fractured location. It may be beneficial to use a diagnostic tool to analyze the production zones in a horizontal wellbore to determine which zones should be re-fractured.
[0007] FIG. 8 shows a prior art diagnostic tool 22 conveyed into a wellbore 10 on coiled tubing 40 via a wellhead 16 . The coiled tubing 40 moves the diagnostic tool 22 down the wellbore 10 along the casing 18 until the diagnostic tool 22 is positioned at a desired location. The diagnostic tool 22 is connected to the surface via a cable 14 , which transmits diagnostic information obtained from the device 22 . The cable 14 and diagnostic tool 22 are connected to the end of the coiled tubing 40 via a cable head 20 and connector 21 . Prior to running the diagnostic tool 22 into the wellbore 10 , coiled tubing 40 may be run into the wellbore 10 to conduct a clean-out procedure. The coiled tubing 40 is then tripped out of the wellhead 16 and the diagnostic tool 22 and cable 14 may be connected to the coiled tubing 40 for a second trip into the wellbore 10 with the coiled tubing 40 . The positioning of the cable 14 outside of the coiled tubing 40 as well as the diagnostic tool 22 being connected to end of the coiled tubing 40 may present an increased chance the coiled tubing 40 becomes stuck within the wellbore 10 . It may also be beneficial to permit a cleanout procedure and conveyance of a diagnostic tool 22 into a wellbore in a single trip of coiled tubing 40 .
SUMMARY
[0008] The present disclosure is directed to a downhole device connected to coiled tubing that substantially overcomes some of the problems and disadvantages discussed above.
[0009] One embodiment is a method of determining information about the production from a zone of a wellbore comprising running a downhole device into a wellbore. The device comprises an electronic device positioned inside of a housing within an interior of coiled tubing. The method includes positioning the downhole device adjacent a first zone of the wellbore, determining diagnostic information of the first zone of the wellbore, and storing the determined diagnostic information of the first zone in a memory device.
[0010] The method may include connecting the housing to the interior of coiled tubing. The method may include pumping fluid down the interior of the coiled tubing past the downhole device while determining diagnostic information of the first zone. The method may include positioning the downhole device adjacent a second zone of the wellbore, determining diagnostic information of the second zone of the wellbore, and storing the determined diagnostic information of the second zone in the memory device. The electronic device may be a logging tool. The method may include pulling the downhole device out of the wellbore and analyzing the diagnostic information of the first zone stored in the memory device.
[0011] One embodiment is a method of determining information about the production from a zone of a wellbore comprising running a downhole device into a wellbore. The downhole device comprises an electronic device positioned inside of a housing connected to a recess in an exterior of coiled tubing. The method includes positioning the downhole device adjacent a first zone of the wellbore, determining diagnostic information concerning the first zone of the wellbore, and storing the determined diagnostic information of the first zone in a memory device.
[0012] The electronic device may be a logging tool. The method may further comprise positioning the downhole device adjacent a second zone of the wellbore, determining diagnostic information of the second zone of the wellbore, and storing the determined diagnostic information of the second zone in the memory device. The method may include pulling the downhole device out of the wellbore and analyzing the diagnostic information of the first zone stored in the memory device.
[0013] One embodiment is a system to monitor a zone of a wellbore. The system comprises a string of coiled tubing and a housing having a first end and a second end. The housing is closed at the first end and is closed at the second end and at least one of the ends being selectively closed to permit access into the housing. The system includes an electronic device positioned within the housing. The electronic device is configured to obtain diagnostic information of a wellbore. The housing is connected to a portion of an interior of the string of coiled tubing with a flow path between the housing and the interior of the string of coiled tubing.
[0014] The electronic device may be a logging tool. The system may include a memory storage device connected to the electronic device. The housing may be welded to the interior of the string of coiled tubing. The housing may be positioned between an end of the string of coiled tubing and a location ten feet from the end of the string of coiled tubing, the location being along the string of coiled tubing.
[0015] One embodiment is a system to monitor a zone of a wellbore. The system comprises a string of coiled tubing and a housing having a first end and a second end. The housing is closed at the first end and is closed at the second end and at least one of the ends being selectively closed to permit access into the housing. The system includes an electronic device positioned within the housing. The electronic device is configured to obtain diagnostic information of a wellbore. The housing is connected to a recess in a portion of an exterior of the string of coiled tubing with a flow path in an interior of the string of coiled tubing past the recess.
[0016] The electronic device may be a logging tool. The system may include a memory storage device connected to the electronic device. The housing may be welded to the exterior of the string of coiled tubing. The housing may be positioned between an end of the string of coiled tubing and a location ten feet from the end of the string of coiled tubing, the location being along the string of coiled tubing.
[0017] One embodiment is a system to monitor a wellbore. The system comprises a string of coiled tubing and a housing having a first end, a second end, at least one inner wall forming a cavity, and a flow path from the first end to the second end. The cavity is selectively sealed from the flow path. The housing is connected to an end of the string of coiled tubing. The system includes an electronic device positioned within the selectively sealed cavity of the housing. The electronic device is configured to obtain diagnostic information of a wellbore. The system includes a memory storage device connected to the electronic device. The memory storage device is positioned within the selectively sealed cavity of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows an embodiment of a downhole device positioned within a housing inside of coiled tubing;
[0019] FIG. 2 shows an end cross-section view of an embodiment of a downhole device positioned within a housing inside of coiled tubing;
[0020] FIG. 3 shows an end cross-section view of an embodiment of a downhole device positioned within a housing inside of coiled tubing within casing;
[0021] FIG. 4 shows an embodiment of a downhole device positioned adjacent a first zone of a wellbore;
[0022] FIG. 5 shows an embodiment of a downhole device positioned adjacent a second zone of a wellbore;
[0023] FIG. 6 shows an embodiment of a downhole device positioned within a housing connected to the outside of coiled tubing;
[0024] FIG. 7 shows an embodiment of a downhole device that may be connected to the end of coiled tubing; and
[0025] FIG. 8 shows a prior art downhole device connected to coiled tubing.
[0026] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0027] FIG. 1 shows an embodiment of a downhole device 100 that may be connected to the interior of coiled tubing 40 . The downhole device 100 may include a housing 50 that is connected to the inside of the coiled tubing 40 . The housing 50 may be connected to the inside of the coiled tubing 40 by various mechanisms such as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. For example, the housing 50 could be welded to the interior of the coiled tubing 40 . An electronic device 60 configured to monitor various aspects of a production zone (e.g. 30 a or 30 b shown in FIG. 4 and FIG. 5 ) of a wellbore 10 is positioned within the housing 50 . The coiled tubing 40 is used to run the device 100 down a wellbore 10 within casing or tubing 18 and position the electronic device 60 of the downhole device 100 at a desired location within the wellbore 10 . The ends of the housing 50 are closed so that fluid flows around the housing through a flow area 45 (shown in FIG. 2 ) between the housing 50 and the coiled tubing 40 as shown by arrows 41 in FIG. 1 . The positioning of the downhole device 100 inside of the coiled tubing 40 may permit the attachment of a bottom hole assembly to the bottom of the coiled tubing 40 that is adapted for other purposes. A conventional logging tool connected to the bottom of the coiled tubing 40 may prevent the connection of an additional bottom hole assembly to the coiled tubing 40 .
[0028] The downhole device 100 is preferably connected to the interior of the coiled tubing 40 near the downhole end of the coiled tubing. For example, the downhole device 100 may be positioned flush with the end of the coil or between the end of the coiled and ten (10) feet from the end of the coiled tubing 40 . FIG. 1 shows a distance, D, from the end of the coiled tubing 40 within which the downhole device 100 is preferably positioned within. The distance, D, may be various lengths. For example, D may be two (2) feet, which is approximately shown in FIG. 1 . However, this distance is for illustrative purposes only and may be varied as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. Preferably, the distance D may be approximately ten (10) feet. Coiled tubing 40 is often inserted into a wellbore 10 to perform a cleaning operation prior to other wellbore operations. The insertion of the downhole device 100 inside of the coiled tubing 40 permits the transmittal of an electronic device 60 , which may be a diagnostic tool, into the wellbore 10 during the cleaning trip into the wellbore 10 . The housing 100 connected inside of the coiled tubing 40 may provide added protection as the electronic device 60 , which may be fragile, is tripped in and out of the wellbore 10 . The addition of the housing 50 to the end of the coiled tubing string 40 may provide higher rigidity at the end of the coiled tubing string 40 , which may aid in the insertion of the coiled tubing string 40 into a wellbore 10 , in particular if the wellbore 10 is a horizontal wellbore.
[0029] FIG. 2 shows an end cross-section view of the downhole device 100 connected to an interior portion of the coiled tubing 40 creating a flow path 45 between the housing 50 of the device 100 and the rest of the interior of the coiled tubing 40 that is not connected to the housing 50 . The outer diameter of the housing 50 may be configured to permit an adequate flow path past the housing 50 . The housing 50 encloses an electronic device 60 that may be used to analyze the condition of the wellbore 10 and its surroundings. For example, the electronic device 60 may be a logging tool also referred to as a diagnostic tool. The diagnostic information gathered from the electronic device 60 may be stored on a memory device 70 also positioned within the housing 50 . The diagnostic information stored on the memory device 70 may then be analyzed after the device 100 is removed from the wellbore 10 . FIG. 3 shows an end cross-section view of a downhole device 100 connected to coiled tubing 40 positioned within casing, or tubing, 18 of a wellbore. The device creates a flow area 45 between the housing 50 of the device 100 and the coiled tubing 40 . Likewise, the coiled tubing 40 creates a flow area 25 between the exterior of the coiled tubing 40 and the casing 18 . The flow area 45 between the housing 50 and the coiled tubing 40 may permit the pumping of fluid down the coiled tubing 40 during the capturing of diagnostic information from the electronic device 60 . The housing 50 may also act as a fluid displacer, which may enhance the response on neutralizing wellbore fluids.
[0030] FIG. 4 shows the downhole device 100 connected to coiled tubing 40 being positioned adjacent a first zone 30 a of a wellbore 10 . The electronic device 60 of the downhole device may be used to determine whether the first zone 30 a should be re-fractured during a re-fracturing procedure. For example, the downhole device 100 may be run into the wellbore 10 to determine which locations of the wellbore should be re-fractured by the process disclosed in related and commonly owned U.S. patent application Ser. No. 14/091,677 filed on Nov. 27, 2013 entitled System and Method for Re-fracturing Multizone Horizontal Wellbore, which is incorporated by reference herein in its entirety.
[0031] The electronic device 60 of the downhole device may be adapted to obtain various information about a desired location of a wellbore 10 . The diagnostic device 60 of the downhole device 100 may provide information concerning the temperature, pressure, fluid flow, and formation. The electronic device 60 may use various mechanisms to obtain diagnostic information as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. For instance, the device 60 may generate pulsed neutrons that penetrate the housing 50 and reflect off the wellbore fluid as well as the wellbore 10 and surrounding formation measuring its activity. All of the diagnostic information gathered by the electronic device 60 may be stored in the memory device 70 for later analysis.
[0032] The coiled tubing 40 may be used to position the downhole device 100 adjacent a first zone 30 a of a wellbore 10 so that the electronic device 60 may obtain diagnostic information concerning the first zone 30 a . This diagnostic information is stored in the memory device 70 and may be used later to determine whether it would be beneficial to re-fracture the first zone 30 a during a re-fracturing process. After storing the diagnostic information for the first zone 30 a , the coiled tubing 40 may be used to position the downhole device 100 adjacent a second zone 30 b of the wellbore 10 as shown in FIG. 5 . The electronic device 60 may then obtain diagnostic information concerning the second zone 30 b , which may be stored in the memory device 70 . This process may be repeated until all desired locations within the wellbore 10 have been analyzed by the electronic device 60 .
[0033] FIG. 6 shows an end cross-section view of an embodiment of a downhole device 100 connected to the exterior of coiled tubing 140 . The coiled tubing 140 includes a carrier portion 141 , which is a concave portion that creates a recess for the placement of downhole device 100 . The housing 50 of the downhole device 100 may be connected to the recess in the coiled tubing 140 by various means. For example, the housing 50 may be welded to the carrier portion 141 of the coiled tubing 140 . The carrier portion 141 may be connected to coiled tubing 140 at connection points 142 . For example, the carrier portion 141 may be welded to the coiled tubing at connection points 142 . The carrier portion 141 may be formed from crimping the coiled tubing 140 to form bends at connection points 142 forming a recess for the positioning of the downhole device 100 . The coiled tubing 140 includes a flow path 145 between the interior of the coiled tubing 140 and the carrier portion 141 . The downhole device 100 includes an electronic device 60 used to diagnose conditions of the wellbore 10 and memory device 70 protected by housing 50 . The coiled tubing 140 may be used to positioned the downhole device 100 at desired locations within the wellbore 10 to obtain diagnostic information as detailed herein. As shown in FIG. 6 , the addition of the downhole device 100 to the coiled tubing 140 may result in substantially the same outer diameter of the coiled tubing 140 if it did not contain the carrier portion 141 .
[0034] FIG. 7 shows an exploded view of an embodiment of a downhole device 200 that may be connected to the end of a coiled tubing string 240 by a connector 270 . The downhole device 200 includes an electronic device 60 that is configured as a wellbore diagnostic tool and a memory device 70 positioned within a cavity 205 within the downhole device 200 . As disclosed herein, the electronic device 60 may be positioned at various locations within the wellbore to obtain information concerning the wellbore 10 that may be stored in the memory device 70 for later analysis. The downhole device 200 may be formed by machining a housing 201 that includes an flow path 245 that is in communication with the interior of the coiled tubing 240 and a cavity that is formed by inner wall 202 and end caps 210 and 215 . End caps 210 and 215 seal the cavity 205 from fluids flowing through the flow path 245 of the downhole device. One or both of the end caps 210 and 215 may be selectively disconnected form the cavity 205 to permit access to the cavity 205 as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. The end caps 210 and 215 may be connected to the cavity 205 by various mechanisms as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. Various mechanisms may be used to selectively seal the chamber 205 from the flow path 245 within the device 200 . For example, one end may be permanently closed with the other including a removable plugging element.
[0035] Although this invention has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the features and advantages set forth herein, are also within the scope of this invention. Accordingly, the scope of the present invention is defined only by reference to the appended claims and equivalents thereof. | A method and system for determining information about a wellbore with coiled tubing. A downhole device may be positioned within coiled tubing and run down the wellbore to determine diagnostic information about a location with the wellbore. The downhole device may store diagnostic information in a storage device that may be analyzed when the device is returned to the surface. A downhole device may be connected to the end of a string of coiled tubing that includes a diagnostic device and memory sealed in a chamber. A flow path past the chamber is in communication with the coiled tubing string permitting the flow of fluid past the chamber. A downhole device including a diagnostic device may be connected to a recess in an exterior of a coiled tubing string. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 10/351,495 filed Jan. 23, 2003 now U.S. Pat. No. 6,776,727 and claims the benefit thereof.
FIELD OF INVENTION
This invention relates to putters that can be used for practice and play, with either a right or left-handed stroke. Specifically, this invention is a putter rotatable from a first position to strike a golf ball with a practice face of a clubhead to a second position to strike a golf ball with a play face of the clubhead.
BACKGROUND
Golf is governed by The Rules of Golf as approved by the United States Golf Association and the Royal and Ancient Golf Club of St. Andrews, Scotland, referred to herein as the USGA Rules. The most current rules are available from www.USGA.org. A typical game of golf is played on a course having 18 holes and a golfer may carry up to 14 clubs with him during play. An average golfer uses over 80 strokes to complete the game, and typically half of those stokes are putts. Therefore, the putter is by far the most important of the regulation 14 golf clubs in a golfer's bag, and improved putting will improve a player's score more than improvement in any other stroke.
Consequently, thousands of devices and methods have been devised to help a golfer improve his putting, ranging from the practical to the absurd. Most of these devices do not conform to the design of clubs specified by the USGA Rules, however, and therefore are used during practice only. The golfer must switch putters to play a round of golf, thus changing the primary tool with which he perfected his stroke. As a result, the putt stokes during play are seldom as good as during practice. It would be advantageous, then, to provide a dual-purpose putter that conforms to the Rules of Golf so that the golfer can use the same putter in practice as in play.
Under the USGA Rules, the putter shall have a shaft and a head, fixed to form one unit. When the golf club is in its normal position to address the ball, the shaft shall be aligned so that the projection of the straight part of the shaft onto the vertical plane through the toe and heel shall diverge from the vertical by at least 10 degrees. Further, the projection of the straight part of the shaft onto the vertical plane along the intended line of play shall not diverge from the vertical by more than 20 degrees. The USGA Rules further require that the clubhead meet specific criteria. For example, the distance from the heel to the toe of a putter shall be greater than the distance from the play face to the back. These rules limit the orientation of the shaft to the clubhead, and therefore the balance of the putter, a major factor in aligning the ball and in putting consistently.
The penalty for playing a game of golf with a putter that does not conform to the USGA Rules is disqualification from the game. However, with the many rules pertaining to the design of putters, it is difficult to design a club that provides quality training features for practicing and yet can be used for play. It is desirable to provide a single putter that can be converted from a practice putter to a play putter that conforms to USGA Rules.
Therefore, it is an object of this invention to provide a putter that enables the golfer to determine which strokes are the best during practice so that he may practice those strokes repeatedly and learn to stroke the ball consistently in play. It is another object of this invention to provide a single putter that can be used for both practice and play. It is another object to provide a single putter that can be converted from a practice putter to a play putter that conforms to the USGA Rules. It is an object of this invention to provide a putter in which the shaft always diverges at least 10 degrees from the sole of the clubhead, regardless which orientation the golfer holds the putter when addressing the ball.
SUMMARY OF THE INVENTION
The present invention is an improved putter that combines several features to provide a balanced putter, which assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The shaft is attached to the clubhead such that it can swivel from a practice configuration to a play configuration. The clubhead has tapered top and bottom surfaces such that the angle of the shaft relative to the sole of the putter is no more than 80 degrees. The clubhead has a playing surface on one face that is parabolic and can be flat in the extreme. The clubhead has a practice surface on the other face that is curved, preferably elliptical, to assist the golfer in learning the proper stroke. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for either a right- or left-handed stroke.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1( a ) is a perspective view of the practice face of the clubhead with the shaft in position for a right-handed golfer.
FIG. 1( b ) is a perspective view of the play face of the clubhead, with the shaft in position for a right-handed golfer.
FIG. 2( a ) is a top view of the clubhead.
FIG. 2( b ) is a bottom view of the clubhead.
FIG. 2( c ) is a cross-section view of the clubhead 11 along line c—c of FIG. 2( a ).
FIG. 2( d ) is an end view of the clubhead; each end is symmetric to the other.
FIG. 3 is an exploded, perspective view of the clubhead with a curved practice face and a flat play face.
FIG. 4 illustrates an exploded view of the clubhead, illustrating the hosel and its alignment with the receiving holes.
FIG. 5( a ) illustrates the angle of the shaft to the sole of the putter when the putter is standing upright.
FIG. 5( b ) illustrates the angle of the shaft to the sole of the putter for a right-handed stroke.
FIG. 5( c ) illustrates the angle of the shaft to the sole of the putter for a left-handed stroke.
FIG. 6 is a perspective schematic view of the clubhead, indicating the sides and faces of the preferred embodiment.
FIG. 7 illustrates the center of the clubhead aligned with the center of the golf ball at the instant the clubhead strikes the golf ball during a putt stroke.
FIG. 8( a ) is a plan view of the practice face of the preferred embodiment, having a convex practice insert.
FIG. 8( b ) is a plan view of the play face of the preferred embodiment, having a flat play insert.
FIG. 9( a ) is a plan view of the practice face of an alternate embodiment, having a convex practice insert.
FIG. 9( b ) is a plan view of the play face of an alternate embodiment having a parabolic, concave play insert.
FIG. 9( c ) is a side view of the alternate embodiment, showing a convex practice face and a concave play face.
FIG. 10( a ) illustrates a golfer playing a left-handed putt stroke with the play face.
FIG. 10( b ) illustrates a golfer practicing a left-handed putt stroke with the practice face.
DETAILED DESCRIPTION OF THE INVENTION
A clubhead 11 of an improved putter 10 is attached to a shaft 12 with a hosel 13 . The present device may be used with shafts of any length. The clubhead 11 has two faces, a practice face 14 and a play face 15 . Only the play face is used as a striking surface during play, thereby conforming with a USGA Rule that a clubhead have only one striking face. The shaft is attached to the clubhead in such a way that the clubhead can swivel from a practice position to a play position, keeping the shaft in the same position relative to the golfer. See FIG. 1 a which shows the clubhead in the practice position for a right handed golfer and FIG. 1 b which shows the clubhead after it has been swiveled into the play position.
In the preferred embodiment, the shaft is affixed to the hosel or integral with it. The hosel 13 is attached to a spring 9 that is biased to keep the hosel substantially flush with the top surface of the clubhead. See FIG. 2 c . The clubhead is switched from a practice position to a play position by pulling the shaft away from the clubhead, thereby extending the spring 9 . Once the hosel is free of its seated position in the clubhead, the clubhead is rotated 180 degrees relative to the shaft. The shaft is released, thereby allowing the hosel to be drawn back to the clubhead again as the spring 9 contracts. See FIG. 4 . The hosel is guided to its seated position and the playface is now facing the ball.
In the preferred embodiment, the hosel has two pins 7 that extend toward the clubhead that rest inside two receiving holes 8 . The hosel can be firmly seated in the clubhead in other ways, for example using a detente system having hemispherical projections and mated recesses.
The practice face 14 has a substantially circular insert, referred to as a practice insert 16 . The practice insert 16 is convex relative to the practice face 14 , as best illustrated in FIGS. 2 a–d , and the practice face shape ranges from elliptical to spherical. The curved shape limits the number of points at which the practice face can strike a golf ball in order for the golf ball to move in a straight line perpendicular to the practice face, referred to as the line of putt. Hitting the center of the golf ball with the center of the practice face will cause the golf ball to move on the perpendicular line. However, if the golfer hits the golf ball with any part of the practice face other than the center of the practice insert, the golf ball will veer off the perpendicular line. The farther away from the center of the practice insert, the worse the veer angle will be.
Preferably the practice insert 16 is an ellipse. With an elliptically curved practice insert, the veer is relatively small at short radii from its center, thereby being somewhat forgiving to a less-than-perfect stroke. This approximates the amount of forgiveness of putts in play, because slight deviations for a perfect line of putt will not prevent the golf ball from falling in the hole. However, as the veer angle grows increasingly larger farther away from the center of the practice face, the “penalty” for a bad stroke increases as the stokes become increasingly off-center. A spherical practice insert may also be used; it provides a less forgiving center, but a more forgiving perimeter, as the veer angle changes relatively less than at the perimeter of an elliptical practice insert. The “penalty” for a bad stroke is constant regardless of how off-center the stroke is. It is likely that a better golfer will use the spherical practice insert to fine tune his putt stroke.
In addition to the curvature of the practice insert, the present invention includes alignment apertures for assisting the golfer in visualizing a straight line to the ball or other desired point. Each alignment aperture is made in the clubhead 11 to receive a lightweight post 30 that extends substantially perpendicularly from the practice face 14 . A conventional drinking straw is suitable for the post, as is it extremely lightweight and most convenient to obtain at a golf course. Preferably, therefore, the diameter of each aperture is made to enable a drinking straw to be inserted and held in place snugly simply by friction. A post can be inserted in any one or more of the alignment apertures, in whichever placement the golfer finds it assists his alignment the best. In the preferred embodiment, the practice face 14 has two alignment apertures, 18 and 20 , however more are acceptable, as indicated by aperture 21 and the aperture into which post 30 is inserted.
The play face 15 also has a substantially circular insert, referred to as a play insert 17 . The play insert 17 is inwardly parabolic relative to the play face 15 , ranging from flat to concave. A flat striking face is required under USGA Rules, so a flat play insert should be used when playing a round of golf.
A parabolic-shaped play insert is self-correcting to some degree, because the curve of the insert will urge the golf ball to the center of the parabola before redirecting the ball away from the play face. A parabola is the set of all points in a plane equidistant from a fixed point (called the focus) and a fixed line (called the directrix). The formula for a parabola is generally:
y = x 2 4 p
Thus, when p is large, the curvature of the play insert is great and the ball is strongly urged to the center of the parabola. As the parabola flattens out, that is, as p becomes small, the play insert provides less assistance in getting the ball to travel on the putt line perpendicular to the play face. When the parabola is flat, that is, when y is constant, the striking face is flat, and the putter provides no self-correcting assistance to the golfer. Preferably, the play insert 17 is flat so that the putter conforms to USGA Rules.
FIG. 3 illustrates a preferred embodiment of the clubhead having a core 91 , curved practice insert 92 and flat play insert 93 . The top and the bottom of the clubhead are substantially v-shaped with flattened apexes, the tapered sides serving to position the shaft at an appropriate angle to the ground during practice and play, as described in more detail below. The clubhead is operable with sharp edges where the various faces meet, but preferably the edges are rounded. Preferably the clubhead 11 is manufactured as a core having apertures into which the hosel and shaft assembly, practice insert and play insert are inserted to form an integral unit. The inserts must be firmly fixed so that there is little likelihood of them working loose during a round of golf. The inserts may be integral with the core 91 of the clubhead 11 , or may be separate pieces that are attached to the core or face of the clubhead, with adhesive or friction fit. Preferably the practice inserts and play inserts are changeable to accommodate the needs of the golfer and preferably the insets are threaded to mate with a threaded aperture in the core 91 . They also may be attached in other ways, such as friction fit.
The core is made of any durable material, and preferably metal such as aluminum, brass or steel. The practice insert is also made of a durable material, but preferably a hard composite material such as a polymer that provides for a satisfying “thunk,” such as Surlyn® thermoplastic resin sold by the E.I. DuPont De Nemours and Company, which was the first and most durable cover material that revolutionized the construction of the golf ball when it was introduced in the 1980s. The play insert is made of durable materials, metal or composite, and preferably the same material as the practice insert so that the feel of the practice stroke is the same as the stroke during play.
For aligning the ball and for putting consistently, it is advantageous to have a puffer that is balanced in as many dimensions as possible. One USGA Rule requires that the projection of the straight part of the shaft onto the vertical plane through the toe and heel shall diverge from the vertical by at least 10 degrees. In other words, the angle between the shaft and the sole of the club must be less than 80 degrees. To achieve both a balanced clubhead and this angle, the bottom of the clubhead is tapered in a V, upward from the midpoint of the bottom to the toe and heel. When putting, one side of the bottom of the club will be resting on or parallel to the playing surface. This portion of the bottom becomes the sole of the club. Due to the taper and the shaft's orientation to the clubhead, the shaft is then atways tilted at least 10 degrees from vertical. The clubhead can be rotated to accommodate for either a right-handed or left-handed golfer. FIG. 5 illustrates the resultant effect, where α is the angle between the vertical and the shaft. In FIG. 5( a ), the putter is shown in its upright position with the shaft 12 perpendicular to the playing surface 60 . FIG. 5( b ) illustrates the putter in the position as a right-handed golfer addresses the ball. Note that α is at least 10 degrees, making the shaft 12 at least 10 degrees off vertical; in other words, the angle between the shaft and the sole 31 of the club is less than 80 degrees. FIG. 5( c ) illustrates the putter in the position as a left-handed golfer addresses the ball. Note again that the shaft 12 is at least 10 degrees off vertical, so that the angle between the shaft 12 and the sole 32 is less than 80 degrees. Since the clubhead is tapered by at least 10 degrees, the shaft will always diverge at least 10 degrees from the plane through the toe and heel, regardless of which orientation the golfer uses to address the ball. To maintain symmetry and weight balance in the clubhead, the top should be similarly tapered. That is, the top of the clubhead is tapered in a V, downward from the midpoint of the top to the toe and heel.
The clubhead 11 is a polyhedron. Preferably the perimeter of the practice face 16 and play face 17 are octagons as shown in FIG. 6 . The perimeter of the practice face has sides a, b, d, c, e, f, g and h. The perimeter of the play face has sides i, j, k, l, m, n, o and p. The practice face and play face are substantially parallel to each other, and connected to each other with a top and a bottom. The top of the polyhedron has three faces, P, Q and R that are attached to sides of the practice face a, b, c and the play face i, j, and k, respectively. The bottom has three faces, S, T and U that are attached to sides of the practice face e, f, g and play face m, n and o, respectively. The ends of the clubhead 11 are parallel to each other and perpendicular to face Q and face T of the bottom. The taper of the clubhead is the effect of the relationship of the sides to the top and bottom. In FIG. 6 , the taper is therefore indicated by angle β. The angles between sides a and b, b and c, d and e, e and f, are equal and no more than 170 degrees, and the angles between sides i and j, j and k, m and n, n and o, are equal and no more than 170 degrees.
To best control and eliminate spin on the golf ball, it is desirable to be able to strike the ball along the horizontal plane bisecting the center of the ball. FIG. 7 illustrates the centerline l—l of the play face 15 aligned with the center of a golf ball 79 upon impact with the golf ball. Consistent with good clubhead balance, preferably the practice and play faces are centered along the horizontal centerline of the clubhead 11 . For good visual alignment, the practice and play faces are preferably about the same size as a golf ball. Preferably, therefore, the practice and play faces are centered on the clubhead so that the center of the practice and play faces meet the centerline of the ball when it is struck. The actual dimensions of the clubhead can be customized to take into account various factors including the player's stroke, the lay of the ball on the putting surface, and the length of the nap of the grass.
Many combinations of the shapes of the clubhead, play and practice faces are possible while still achieving the objective of this invention, as illustrated in FIGS. 8 and 9 . FIG. 8 illustrates the preferred embodiment, wherein the practice face 50 ( FIG. 8( a )) and play face 51 ( FIG. 8( b )) are octagons and the taper angle α is about 10 degrees. The practice insert 52 is outwardly convex in an elliptical curve. The play insert 53 is flat. FIG. 9 illustrates an alternate embodiment, wherein the practice face 70 ( FIG. 9( a )) and play face 71 ( FIG. 9( b )) are octagons, but the taper angle α has been increased to about 20 degrees. The practice insert 72 is outwardly convex in a spherical curve and the play insert 73 is convex in a parabolic curve. FIG. 9( c ) is a side view illustrating a convex practice face and a concave play face.
FIG. 10( a ) illustrates a golfer 80 practicing a left-handed putt stroke into hole 83 . The golfer uses the practice face 81 to hit the ball and improve his aim. By rotating the putter 180 degrees in his hands, the golfer can use the same putter and the same stance to putt in play. FIG. 10( b ) illustrates the same golfer putting in play, using the play face 82 as the striking face.
While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. | The present invention is an improved putter that combines several features to provide a balanced putter, which assists a player in perfecting a putt stroke during practice and repeating it with the same club during play. The shaft is attached to the clubhead such that it can swivel from a practice configuration to a play configuration. The clubhead has tapered top and bottom surfaces such that the angle of the shaft relative to the sole of the putter is no more than 80 degrees. The clubhead has a playing surface on one face that is parabolic and can be flat in the extreme. The clubhead has a practice surface on the other face that is curved, preferably elliptical, to assist the golfer in learning the proper stroke. The putter conforms to the Rules of Golf so that the player does not have to change clubs between practice and play. The club may be used for either a right- or left-handed stroke. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to active monolithic crystalline doped media for blue laser luminescence which are tunable continuously over a broad band of wavelengths. Known monolithic laser cavities produce only a single wavelength or a very restricted band of frequencies and they have low frequency doubling efficiency of less than 10% and they generate noise levels greater than a standard deviation of 10%.
Dixon et al. in an article entitled: "Efficient blue emission from an intracavity-doubled 946 nm Nd:YAG laser" appearing in Optics Letters, Vol.13, pg. 137-139 (1988) discloses coherent emission at 473 nm from an intercavity-doubled Nd:YAG microlaser. However, the output power was only 5 mW, and the frequency doubling efficiency was only 2%.
It has been shown that KNbO 3 is an effective electro-optic frequency doubling crystal to produce blue coherent light in a U.S. Pat. No. 4,809,291 to Byer et al. A thermoelectric heat exchanger is also disclosed which is coupled to the laser crystals to phase match to the pumping laser radiation. But, the laser crystal, Nd:YAG, is shown to be separate from the doubler crystal, and it is taught that both power and amplitude stability are increased by this decoupling. This teaches away from the monolithic microchip microlaser of the present invention.
A diode pumped 473 nm Nd:YAG/KNbO 3 microchip laser is disclosed by Matthews et al. in an article entitled "Diode pumping of a blue (473 nm) Nd:YAG/KNbO 3 microchip laser" in CLEO'96 Vol.9, pgs 174-175 (1996) as a monolithic micro chip. However, the maximum blue output power was only 26.5 mW with blue intensity noise of plus or minus 7% to 20%.
A bonded microchip laser whose temperature is controlled by a Peltier cooler in thermal contact with the microchip is disclosed by Tatsuno et al. in U.S. Pat. No. 5,377,212. However, there is a separate mirror, so the entire structure is not monolithic, and the crystalline composition is entirely different from the present invention. Furthermore, the device is not tunable.
None of the above disclosures include tunability of the output wavelength.
It is taught by Convoy et al. in an article entitled "Gain guiding and thermal distortion in diode pumped Nd:YVO 4 microchip lasers", in CLEO'96, Vol.9, pgs 175-176 (1996) that heating and deformation of the single Nd:YVO 4 crystal result in a tuning rate of 1.4 GHz per degree centigrade change in crystal temperature. Aspherical focusing and collimating lenses are disclosed. However, the heat was applied by the pumping laser and there is no frequency doubling crystal and there is no thermoelectric device external to the crystal. Further, the tuning band was only 600 GHz for the 1064 nm line.
It is known to change the wavelength of a laser beam by wavefront conversion with the use of lenses, mirrors and crystals with conical surfaces as disclosed by Tanuma in U.S. Pat. Nos. 5,355,246 and 5,173,799, however, this is not applied to any tunable lasers.
A continuously tunable UV Ce:LiSAF laser is disclosed in U.S. Pat. No. 5,487,079 to Esterowitz et al. However, tuning is achieved by a motor attached to a birefringent tuning plate, grating or prism which is placed between the laser crystal and the output mirror. The efficiency was only 14% and the device has many moving components and is complicated and costly to build.
A tunable Sc 2+ based UV to visible spectral range laser is disclosed in U.S. Pat. No. 5,471,493 to Mirov et al. However, the base crystal must be changed in composition in order to change the output wavelength and there is a motor unit which rotates a diffraction grating.
A composite cavity microchip laser having four spaced, parallel, dielectrically coated surfaces on the gain medium and doubling medium crystal surfaces, and small annular shaped dielectric spacers between the lasing medium and the doubling crystal preferably 50-500 microns wide are disclosed in U.S. Pat. No. 5,574,740 to Hargis et al. However, the present invention includes only two dielectric coatings instead of four. Furthermore, the present invention does not require any spacer, dielectric, nor epoxy in the interface between the two crystal media. Therefore the prior art involves the extra fabrication steps of creating these dielectric spacers with bonding agents which is not required in the present invention.
The goal of the present invention is to satisfy the need to develop a practical, simple, powerful, highly efficient, continuously tunable microchip laser which has low noise and which can be produced at low cost.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a single monolithic cavity laser out of at least two different laser crystals for the purpose of generating coherent blue light efficiently and with low noise. It is a further object to provide continuous tunability over a broad wavelength range without any moving parts or complex components, and without the requirement to alter the crystal composition.
These and other objects are achieved according to the present invention by a monolithic cavity made of at least two different solid state crystals bonded to each other with a small gap in such a way as to obtain maximum power stability. The input crystal is pumped by a semiconductor pumping laser and there is an aspherical lens system positioned between the pumping laser and the microchip laser media to focus and collimate the pumping laser beam designed to maximize the power of the output laser beam.
Tunability over a wide band from 430 nm to 480 nm is achieved by a thermoelectric heat exchanger affixed in thermal contact with the laser microchip which continuously tunes the index of refraction by heating or cooling the crystal laser media.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a Cr:LISAF/KNbO 3 monolithic microchip continuously tunable laser.
FIG. 2 is a Nd:YAG/KNbO 3 /LBO monolithic microchip UV laser.
FIG. 3 is a Nd:YVO 4 /KNbO 3 monolithic microchip blue laser.
FIG. 4 is a Nd:YAG/KTP/KNbO 3 monolithic microchip tunable optical parametric oscillator.
FIG. 5 is a Nd:YAG/Cr:Mg 2 SiO 4 /KNbO 3 monolithic microchip continuously tunable laser.
FIG. 6 is a Nd:YVO 4 /KNbO 3 monolithic microchip green laser.
FIG. 7 is a Nd:YAG/KNbO 3 monolithic microchip blue laser.
DESCRIPTION OF PREFERRED EMBODIMENTS
The main feature of the present invention which contributes to the achievement of the objects of the invention is the crystal bonding of different laser media with the inclusion of a small wedge shaped gap 1, which is at least 0.5 micron to at most 3 microns in thickness, to obtain a single axial mode which gives rise to improved power stability. There is no requirement for any dielectric, air, nor any bonding agent in the wedge shaped gap 1. This increases power generation and improves frequency doubling efficiency to 20%. The noise level is reduced to at most a standard deviation of 0.1%. These results are surprising and completely unexpected in view of the prior art. Another feature common to all of the embodiments and FIGS. 1-7 is a thermo-electric heating and cooling heat exchanger 2 affixed to the microchip holder 3 to fine tune the output wavelength by changing and controlling the index of refraction of the laser media in a continuous way. Another common feature in all the embodiments and FIGS. 1-7 is an aspherical microlens 4 and a gradient index lens 5 which are positioned between a semiconductor pumping laser 6 and the first crystal 7 of the lasing media. The external surfaces both closest and furthest away from the pumping laser are both coated with a dielectric thin film coating 8.
In the first embodiment, shown in FIG. 1, the laser media are two crystals. The first crystal 7 is Cr:LiSAF and the second crystal 9 is KNbO 3 . Upon pumping by the semiconductor laser 6 the first crystal 7 lases at a wavelength of at least 860 nm and at most 960 nm, and the second crystal 9 frequency doubles at a continuously tunable output wavelength of at least 430 nm and at most 480 nm. The power of the pumping laser 6 is at least 30 m Watt and the output power of the second crystal is at least 10 micro Watts.
In the second embodiment, shown in FIG. 2, there are three crystals which make up the laser media. The first crystal 7 is Nd:YAG, the second crystal 9 is KNbO 3 , and the third crystal 10 is LBO. The output wavelength emitted by the third crystal 10 is controlled to at least 354 nm and at most 356 nm. The power of the pumping laser 6 is at least 1 Watt and the output power of the third crystal 10 is at least 10 m Watts. Both the second crystal 9 and the third crystal 10 are frequency doubling laser media.
In the third embodiment, shown in FIG. 3, there are two crystals which make up the laser media. The first crystal 7 is Nd:YVO 4 and the second crystal 9 is KNbO 3 . Upon pumping by the semiconductor laser 6 the first crystal 7 lases at a wavelength of at least 912 nm and at most 918 nm, the second crystal 9 frequency doubles at a controlled output wavelength of at least 456 nm and at most 459 nm. The power of the pumping laser 6 is at least 1 Watt, and the output power of the second crystal is at least 50 m Watts.
In the fourth embodiment, shown in FIG. 4, a continuously tuning optical parametric oscillator is shown. There are three crystals which make up the laser media. The first crystal 7 is Nd:YAG, the second crystal 9 is KTP, and the third crystal is KNbO 3 . Upon pumping by the semiconductor laser 6 the third crystal 10 emits a continuously tunable range of wavelengths of at least 2000 nm and at most 4500 nm. Both the second crystal 9 and the third crystal 10 are frequency doubling laser media.
In the fifth embodiment, shown in FIG. 5, there are three crystals which make up the laser media. The first crystal 7 is Nd:YAG, the second crystal 9 is Cr:Mg 2 SiO 4 , and the third crystal 10 is KNbO 3 . Upon pumping by the semiconductor laser 6 the third crystal 10 emits a continuously tunable output range of wavelengths of at least 565 nm and at most 684 nm. Both the first crystal 7 and the second crystal 9 are laser gain media.
In the sixth embodiment, shown in FIG. 6, there are two crystals which make up the laser media. The first crystal 7 is Nd:YVO 4 and the second crystal 9 is KNbO 3 . Upon pumping by the semiconductor laser 6 the first crystal 7 lases at a controlled wavelength of at least 1062 nm and at most 1066 nm, and the second crystal 9 frequency doubles at a controlled output wavelength of at least 531 nm and at most 533 nm.
In the seventh embodiment, shown in FIG. 7, there are two crystals which make up the laser media. The first crystal 7 is Nd:YAG and the second crystal 9 is KNbO 3 . Upon pumping by the semiconductor laser 6 the first crystal 7 lases at a wavelength of at least 944 nm and at most 948 nm, and the second crystal frequency doubles at a controlled output wavelength of at least 472 nm and at most 474 nm. The power of the pumping laser 6 is at least 1 Watt and the power emitted by the second crystal 9 is at least 50 m Watts.
The monolithic structure specially bonded microchip laser, wedge shaped gap in the optical contact, mirror, focusing and collimating lens configuration are all novel futures of the present invention, however, the instant invention is also the combination of these features and the relative orientation of each of these components in a single unit construction of the continuously tunable laser. It is this combination which provides a highly efficient, low cost, low noise micro laser which is continuously tunable over a wide band of output wavelengths. Accordingly for all these reasons set fourth, it is seen that the micro laser of the present invention represents a significant advancement in the art of microchip lasers and has substantial commercial merit.
While there is shown and described herein certain specific structures embodying the invention, it will be manifest to those skilled in the art that modifications may be made without departing from the spirit and the scope of the underlying inventive concept. The present invention shall not be limited to the particular forms herein shown and described except by the scope of the appended claims. | Second Harmonic microchip laser producing coherent blue wavelengths tunable from 430 nm to 480 nm is disclosed. The microchip laser is formed by an optical contact of two crystal surfaces with a small gap, which provides a stable laser performance. The same technology is also applied to generate other blue, UV, and infrared lasers. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a driver assistance system for motor vehicles, having a sensor mechanism for acquiring the surrounding traffic environment, a prediction device for predicting a travel route envelope that the vehicle is expected to follow, and an assistance function that makes use of the predicted travel route envelope.
[0003] 2. Description of Related Art
[0004] In driver assistance systems that support the driver in the driving of the vehicle, warn the driver of acute danger situations, introduce automatic measures for avoiding a threatened collision, or activate safety systems in preparation for a collision, it is often necessary to predict the course that the home vehicle is expected to follow. A typical example of such a driver assistance system is a dynamic speed regulator, or ACC (adaptive cruise control) system, which regulates the speed of the home vehicle automatically to the speed of a vehicle traveling in front of the home vehicle that has been located using a radar or lidar sensor system. The travel route envelope prediction is then used primarily in order to decide whether an acquired object is to be selected as target object for the distance regulation, or whether this object is an irrelevant object, e.g., a vehicle in an adjacent lane. The travel route envelope is represented for example by a geometrical object defined by a center line, corresponding to the trajectory of the vehicle, and a particular travel route envelope width. The selection of a target object then takes place under the premise that only vehicles within the travel route envelope are relevant for the distance or speed regulation.
[0005] Such ACC systems are already in use, but their area of application has up to now been limited mainly to driving on highways or on well-constructed rural roads. In these situations, the analysis of the traffic environment can be limited to moving objects, for example vehicles traveling in front of the home vehicle, while stationary objects, for example objects at the edge of the roadway, can be ignored. In order to predict the travel route envelope, in such systems first of all the current speed of the home vehicle and the yaw rate of the home vehicle are taken into account. On the basis of these data, a travel route envelope hypothesis is produced by mathematically describing the center line of the travel route envelope as a parabola whose curvature is given by the ratio of the yaw rate and the vehicle speed.
[0006] Efforts are being made to expand the area of application of ACC systems to other traffic situations, e.g., stop-and-go situations on highways (traffic jam assistants), travel on rural roads, and also travel in city traffic. In these situations, in which in general stationary objects must also be taken into account, making the selection of valid target objects and the recognition of obstacles significantly more complex, higher demands are also made on the precision of the travel route envelope prediction.
[0007] For travel route envelope prediction, it has already been proposed to additionally use data from other information sources, e.g., the collective movements of other vehicles, which can be acquired using the radar system, data from a navigation system, location data of stationary objects at the edge of the roadway, or information supplied by a mono or stereo video system, permitting a determination of the available driving space.
[0008] In addition, the results of the travel route envelope prediction are capable of being used not only in conventional ACC systems and advanced ACC systems having expanded functionality, but also in other assistance systems, for example warning and/or safety systems, in which an impending collision of the home vehicle with an obstacle must be recognized.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention offers the advantage that different demands, possibly changing in accordance with the particular situation, on the travel route envelope prediction can be taken into account better and more quickly.
[0010] This is achieved in that the projection device is fashioned so as to follow a plurality of travel route envelope hypotheses simultaneously and to make them available to the assistance function.
[0011] From the plurality of travel route envelope hypotheses, the subsequently connected assistance function can then select as the predicted travel route envelope the one that best corresponds to the indicated functional purpose and/or the given situation. This not only facilitates control over ambiguous situations, e.g., at intersections or forks in the road, but above all also makes it possible to adapt the various travel route envelope hypotheses more precisely to the respective functional purpose, or to various characteristic situations, e.g., by using, for each of the parallel travel route envelope hypotheses, different sources of information, different rules for interpreting the information, and/or different rules for constructing the travel route envelope. The subsequent assistance function then selects the best-suited travel route envelope hypothesis in accordance with the situation or functional purpose, and can quickly change over to a different hypothesis if the situation or the operating mode of the assistance function changes.
[0012] In addition, it is possible to accommodate a plurality of different assistance functions on a common sensor mechanism and a common information base, the prediction device making available to each assistance function one or more travel route envelope hypotheses that are determined specifically for this function.
[0013] In an example embodiment, the various travel route envelope hypotheses are each constructed so as to correspond to the different conceivable behaviors of the driver, and the selection of the predicted travel route envelope then takes place on the basis of a recognition and analysis of the driver's reactions that permit conclusions as to his intentions, e.g., driving actions, settings of the travel direction indicator, etc.
[0014] For example, in the context of an expanded ACC function that is also suitable for city driving, besides a standard operating mode, a special operating mode is also conceivable that is activated automatically or by driver command when obstacles that are blocking only a part of the home lane, e.g., bicyclists or stationary vehicles on the edge of the roadway, are to be overtaken or driven around. In this case, the travel route envelope is constructed in such a way that it takes into account the evasive maneuver to be expected on the part of the driver. This operating mode can therefore also be referred to as “ACC travel in the available driving space.” The travel route envelope hypothesis prepared by the prediction device for ACC travel in the available driving space can be also be used, in identical or similar form, for a traffic jam assistant implemented in the same assistance system. It is also conceivable that, parallel to the assistance function or to the traffic jam assistant, another warning or safety function is running; for example, this could be what is known as a pre-crash function, which also makes use of the travel route envelope hypothesis for ACC travel in the available driving space, or makes use of a slightly modified travel route envelope hypothesis.
[0015] According to the present invention, not only are parallel travel route envelope hypotheses prepared, but the further evaluation may also take place largely in parallel fashion. For example, in an ACC system the plausibilization of the objects, the allocation of the objects to the travel route envelope, and the selection of the target object, as well as, if warranted, the production of a corresponding rule proposal for the distance regulation according to travel route envelope hypotheses, can be carried out separately and in parallel, so that the decision in favor of one hypothesis or another is not made until the rule proposal has been implemented. This has the advantage that the rule system is, as it were, always prepared for all eventualities.
[0016] The parallel prosecution of a plurality of travel route envelope hypotheses is particularly useful in cases in which the production of these hypotheses is based on information relating to past procedures. Thus, for example in the context of an ACC function, the trajectories of the located objects are followed over a longer period of time. Under the assumption that in an area where another vehicle has moved there must also exist a possible travel route envelope for the home vehicle, the trajectories followed in this way can be used in order to create travel route envelope hypotheses. However, this presupposes that the trajectory has already been followed for a certain period of time. If a plurality of travel route envelope hypotheses are maintained in parallel, the advantage thus results that the required information is immediately available when needed. This holds not only for the prosecution of trajectories, but also for example for the interpretation of other infrastructure data, e.g., roadway markings located using a video system and the like. In the interpretation and plausibilization of such objects as well, recourse is often had to the history, e.g., in order to enable the stability of the object location to be evaluated.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1 shows a block diagram of a driver assistance system.
[0018] FIGS. 2 and 3 show diagrams illustrating two different travel route envelope hypotheses applied by the present system.
[0019] FIG. 4 shows a flow-chart illustrating exemplary method steps of the application of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 shows a driver assistance system in which different assistance functions 10 a , 10 b , and 10 c are implemented, e.g., an URBAN-ACC function, a traffic jam assistant, and a warning and safety system. The expression “URBAN ACC” indicates that the system is intended also to be suitable for city driving. Driver assistance system 10 is formed by one or more microcomputers and associated software, and is therefore represented only schematically as a block. The associated sensor system is also not shown in more detail in FIG. 1 . Only the functions of the system that relate to travel route envelope prediction are indicated as a separate block 12 .
[0021] For travel route envelope prediction, in the depicted example the following information sources are available: a navigation system 14 , which supplies for example information concerning roadway curves, intersections, and the like, a video system 16 , and a radar system 18 , which also provides the data for the distance regulation in the context of the ACC function. Radar system 18 locates both stationary objects 20 and also moving objects 22 . The corresponding location data are evaluated in different ways, so that the stationary objects and the moving objects are here treated as different information sources.
[0022] From the four sources of information, raw data 24 are extracted. These raw data 24 are represented mathematically as geometrical objects in a unified two-dimensional coordinate system. These objects are designated NO, VO, SO, BO, in accordance with the information source. In a method stage 26 , designated “matching/object fusion,” the raw data are interpreted and adapted to one another in order to determine possible contradictions and remove them to the greatest possible extent, and to correct imprecisions resulting from the nature of the respective information source. Here, for example individual objects recognized by the video system can also be identified with corresponding radar targets (object fusion). In addition, there takes place here a plausibilization of the recognized objects, generally making use of the history, i.e., earlier data allocated to the same object. In this way, consolidated raw data 28 are obtained, designated KNO, KVO, KSO, and KBO. Typically, these data represent line objects, such as for example the course of center stripes and edge marking lines on the roadway (KVO, derived from the video data), roadway edges derived from series of stationary objects (KSO, obtained through the fusion of radar and video data), and vehicle trajectories (KBO, derived from radar and possibly video data).
[0023] In a step 30 , “lane fusion,” the raw data for mutually corresponding line objects are combined by generating new synthetic line objects from the parameters and coefficients that describe the individual line objects; each of these new line objects corresponds to a travel route envelope hypothesis 32 , 34 . In the depicted example, for the sake of simplicity only two travel route envelope hypotheses are shown, but their number can also be greater than two.
[0024] During the matching and in the interpretation of the raw data, and in the fusion of these data, different criteria and rules are used for each of the two travel route envelope hypotheses 32 and 34 , adapted specifically to their respective functional purpose.
[0025] The rules for travel route envelope hypothesis 32 correspond to a standard ACC function (assistance function 10 a ), and are based on the assumption that the travel route envelope corresponds approximately to the overall width of the roadway lane in which the home vehicle is currently traveling or is expected to travel.
[0026] The rules for travel route envelope hypothesis 34 are adapted to ACC travel in the available driving space, and are accordingly based on the assumption that in the case of obstacles that do not completely block the current or expected lane, but rather merely narrow it somewhat, the travel route envelope will be displaced and possibly narrowed so as to correspond to a circumvention of the obstacle within the home lane. This travel route envelope hypothesis 34 is made available to all three assistance functions 10 a , 10 b , and 10 c . Assistance function 10 a , “Urban ACC,” is thus provided with two travel route envelope hypotheses 32 and 34 for selection. For standard ACC travel, the assumption is made that the driver wishes to be supported during forward driving of the vehicle, i.e. during acceleration and/or braking, and that accordingly the home vehicle must be comfortably regulated in the forward direction. The driver will engage in transverse driving of the vehicle only in order to maintain the lane and for lane change maneuvers.
[0027] In contrast, for traffic jam assistant 10 b , which is activated automatically or by the driver when there is a traffic jam on a highway, the assumption is made that the driver would like to be guided rapidly and comfortably through the traffic jam, so that the driver is also prepared to execute passing maneuvers within the home lane given vehicles traveling in a staggered pattern. The same also holds in specific situations for the urban ACC function, for example given vehicles traveling in a staggered pattern on the right edge of the roadway (e.g. bicyclists), which are preferably to be overtaken within the city. In such cases, the driver expects that the urban ACC system, or the traffic jam assistant, will not react to the staggered vehicles, as long as sufficient driving space is available for comfortable passing or circumvention.
[0028] The various driver expectations and travel route envelope constructions are illustrated in FIGS. 2 and 3 .
[0029] FIG. 2 shows the home (i.e., controlled) vehicle 36 , equipped with driver assistance system 10 and with an associated sensor mechanism in the form of a video camera and a radar sensor, situated on the center lane of a three-lane roadway 38 . In the context of the standard ACC function, a vehicle 40 driving in front of the home vehicle is being followed. Consequently, the prediction of a travel route envelope 42 takes place on the basis of travel route envelope hypothesis 32 . Travel route envelope 32 extends at least over the entire width of the lane in which home vehicle 36 is situated, and therefore also includes a vehicle 44 situated at the right edge of the roadway and extending partially into the center lane. The ACC function will therefore locate vehicle 44 as a relevant object, and will initiate a corresponding delay, and, if necessary, a stopping, of home vehicle 36 .
[0030] For comparison, FIG. 3 illustrates the construction of a travel route envelope 46 that is based on travel route envelope hypothesis 34 and is provided for ACC travel in the available traffic space. Travel route envelope 46 is limited in such a way that vehicle 44 is now situated completely outside this travel route envelope, and is no longer treated as a relevant object. This corresponds to the expectation that the driver intends to drive around vehicle 44 without significantly departing from the home lane. In a traffic jam situation, this would be an appropriate reaction.
[0031] In city traffic, i.e., given an active urban ACC, the circumvention of obstacles within the home lane can sometimes be an appropriate reaction, e.g., when overtaking a bicyclist, but in other situations may not be appropriate, for example when approaching a motorcyclist at the end of a line at a traffic light. In the context of assistance function 10 a , it must therefore be decided at an appropriate point in time which of the two travel route envelope hypotheses 32 , 34 will be used as the basis of the regulation. A flow diagram for this is shown in FIG. 4 .
[0032] In step S 1 , the available driving space is determined on the basis of the data from navigation system 14 , video system 16 , and radar system 18 , and the probability is determined that the home vehicle will follow one or another of the available routes. In steps S 2 a and S 2 b , the two travel route envelope hypotheses 32 and 34 are then calculated and pursued in parallel. In steps S 3 a and S 3 b , for each travel route envelope hypothesis the located objects are tested for plausibility, i.e., in each case it is decided which objects are situated within the travel route envelope. In steps S 3 a and S 3 b , a target object is then selected in each case from the located objects, and, dependent on the location data of this target object, in steps S 4 a and S 4 b two alternative rule proposals are calculated. In the meantime, in step S 5 the hypotheses concerning the expected behavior of the driver are compared with reality. For example, for this purpose on the basis of the yaw rate of the home vehicle it is determined whether or not the driver is initiating a driving maneuver in order to drive around the object. If necessary, other criteria can also be taken into account, such as the presence and/or trajectories of other objects, e.g., a passenger vehicle situated in front of the motorcyclist stopped at the end of the line at the traffic light. On this basis, in step S 6 a decision is then made in favor of one rule proposal or the other, and in step S 7 the corresponding control process is introduced. Step S 6 here operates with a certain degree of hysteresis, so that in case of doubt a rapid change between opposed decisions is avoided. | A driver assistance system for motor vehicles, having a sensor system ( 16, 18 ) for acquiring the surrounding traffic environment, a prediction device ( 12 ) for predicting a travel route envelope ( 42, 46 ) that the vehicle ( 36 ) is expected to travel, and an assistance function ( 10 a , 10 b, 10 c ) that makes use of the predicted travel route envelope,
wherein the prediction device ( 12 ) is fashioned so as to simultaneously pursue a plurality of travel route envelope hypotheses ( 32, 34 ) and to make them available to the assistance function ( 10 a , 10 b, 10 c ). | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of the Taiwan Patent Application Serial Number 100124615, filed on Jul. 12, 2011, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a zinc finger-like peptide for treating cancer, a pharmaceutical composition containing the zinc finger-like peptide and a method for treating cancer.
[0004] 2. Description of Related Art
[0005] Foods or food additives, and environmental pollutions have been a source of contention as a cause or catalyst for promoting cancer in recent years. Not coincidentally, the same event is happening as well in the developed countries and around the world, positing as an alarming sign that the incidence rates of cancers are quite high. According to the data published by the American Cancer Society, cancer is being proved to be the most significant threat to public health.
[0006] The general methods for treating cancer include surgery, radiotherapy, chemotherapy and immune therapy. In recent years, the development of several therapeutic agents has lead to cancer treatments through new anti-cancer mechanisms, and it has been proven that the survival rate of patients can be increased by treating them with these therapeutic agents. Generally, the therapeutic agents can treat cancers through inhibition of cell cycle progression, angiogenesis, farnesyl transferase, and tyrosine kinases.
[0007] Although it is known that certain agents exhibit therapeutic effects on cancer, these agents do have their limitations. For example, “Gefitinib” is a drug for inhibiting non-small cell lung cancer, but it fails to cure in most cases. Also, it has no effects on blocking the progression of breast and colorectal cancers. In addition, the therapeutic effects of the anti-cancer drugs also depend on the locations of tumor cells, genetic variations of patients, and the side effects of drugs. Furthermore, cancer cells may become malignant and spread from its original sites to target organs via the lymphatic system or bloodstream, thereby establishing metastatic cancers.
[0008] Since the risk of developing cancer generally increases with age, the occurrence rates of cancer go up as more people live to an old age and as mass lifestyle changes. Hence, there is a long unfulfilled need to provide new agents for cancer treatment and prevention.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide a zinc finger-like peptide, a pharmaceutical composition containing the zinc finger-like peptide and a method for treating cancer, which can be used to treat cancer.
[0010] Another object of the present invention is to provide a zinc finger-like peptide expression plasmid, a pharmaceutical composition containing the zinc finger-like peptide and a method for treating cancer, wherein the zinc finger-like peptide expression plasmid can express a zinc finger-like peptide for treating cancer.
[0011] To achieve the object, the zinc finger-like peptide for treating cancer comprises: at least seven amino acids, wherein the sequence of the at least seven amino acids has 85-100% similarity to a sequence represented by SEQ ID NO: 1.
[0012] In addition, the zinc finger-like peptide expression plasmid for treating cancer comprises: a DNA sequence for expressing the aforementioned zinc finger-like peptide.
[0013] To achieve the object, the zinc finger-like peptide for treating cancer comprises: at least seven amino acids, wherein the sequence of the at least seven amino acids has 50-100% similarity to a sequence represented by SEQ ID NO: 1 (RRSSSCK).
[0014] In addition, the zinc finger-like peptide expression plasmid for treating cancer comprises: a DNA sequence for expressing the aforementioned zinc finger-like peptide, which has 70-100% identity to a sequence represented by SEQ ID NO: 3 (agaaggtcgt cttcttgtaa a).
[0015] The present invention provides a zinc finger-like peptide, which is a small molecule peptide similar to a zinc finger motif. The amino-acid length of the peptide is not particularly limited, and the peptide can be constituted of 4-200 amino acids. Preferably, the peptide contains 4-100 amino acids. More preferably, the peptide contains 5-70 amino acids. Most preferably, the peptide contains 6-45 amino acids. Particularly preferably, the peptide contains 7-15 amino acids. The zinc finger-like peptide for treating cancer comprises at least seven amino acids, wherein the sequence of the at least seven amino acids may have 50-100% similarity to a sequence represented by SEQ ID NO: 1. Preferably, the sequence of the at least seven amino acids has 70-100% similarity to a sequence represented by SEQ ID NO: 1. More preferably, the sequence of the at least seven amino acids has 85-100% similarity to a sequence represented by SEQ ID NO: 1. In addition, the sequence of the at least seven amino acids may have 50-100% identity to a sequence represented by SEQ ID NO: 1. Preferably, the sequence of the at least seven amino acids has 70-100% identity to a sequence represented by SEQ ID NO: 1. More preferably, the sequence of the at least seven amino acids has 85-100% identity to a sequence represented by SEQ ID NO: 1. Most preferably, the sequence of the zinc finger-like peptide is SEQ ID NO: 1.
[0016] The zinc finger-like peptide of the present invention may have 50-100% similarity to a sequence represented by SEQ ID NO: 2 (MSSRRSSSCKYCEQDFRAHTQKNAATPFLAN). Preferably, the zinc finger-like peptide has 70-100% similarity to a sequence represented by SEQ ID NO: 2. More preferably, the zinc finger-like peptide has 80-100% similarity to a sequence represented by SEQ ID NO: 2. In addition, the zinc finger-like peptide may have 50-100% identity to a sequence represented by SEQ ID NO: 2. Preferably, the zinc finger-like peptide has 70-100% identity to a sequence represented by SEQ ID NO: 2. Most preferably, the zinc finger-like peptide has 80-100% identity to a sequence represented by SEQ ID NO: 2.
[0017] The DNA sequences shown in SEQ ID NOs: 3 and 4 are respectively coded into the amino acid sequences shown in SEQ ID NOs: 1 and 2. The DNA sequences shown in SEQ ID NO 4 is listed as the following: atgagcagca gaaggtcgtc ttcttgtaaa tattgtgaac aggacttccg agcacacaca cagaagaatg cggccacacc cttcctagcc aac. In the present invention, cDNA having DNA sequences shown in SEQ ID NO: 3 or 4 can be inserted into a vector to obtain the zinc finger-like peptide expression plasmid, which can express peptide having amino acid sequence shown in SEQ ID NO: 1 or 2 in vitro or in vivo.
[0018] The sequence of the aforementioned zinc finger-like peptide can be derived from any zinc finger-like peptide of different species. Preferably, the zinc finger-like peptide of the present invention is derived from human or mouse. In addition, the zinc finger-like peptide may be obtained through peptide synthesis, or expression of cDNA of zinc finger-like peptide from human or mouse. In one aspect of the present invention, the zinc finger-like peptide of the present invention is obtained through peptide synthesis.
[0019] The expression plasmid of the present invention can be any plasmid capable of expressing the zinc finger-like peptide of the present invention. Preferably, the expression plasmid used in the present invention is pCR3.1 (available from Invitrogen) or pEGFPC1 (available from Clontech). The host for the zinc finger-like peptide of the present invention is not particularly limited, as long as it can express the cDNA inserted into the vector. Examples of the host may include: bacteria, mammalian cells or tumor cells. Preferably, the zinc finger-like peptide expression plasmid of the present invention is transfected into mammalian cells or tumor cells to express the zinc finger-like peptide.
[0020] In addition, the zinc finger-like peptide of the present invention may have 50-100% similarity to a sequence represented by SEQ ID NO: 8 (MSSRRSSSCKYCEQD). Preferably, the zinc finger-like peptide has 70-100% similarity to a sequence represented by SEQ ID NO: 8. More preferably, the zinc finger-like peptide has 80-100% similarity to a sequence represented by SEQ ID NO: 8. In addition, the zinc finger-like peptide may have 50-100% identity to a sequence represented by SEQ ID NO: 8. Preferably, the zinc finger-like peptide has 70-100% identity to a sequence represented by SEQ ID NO: 8. Most preferably, the zinc finger-like peptide has 80-100% identity to a sequence represented by SEQ ID NO: 8. Most preferably, the sequence of the zinc finger-like peptide is SEQ ID NO: 8.
[0021] Furthermore, the zinc finger-like peptide of the present invention may have 50-100% similarity to a sequence represented by SEQ ID NO: 9 (FRAHTQKNAATPFLAN). Preferably, the zinc finger-like peptide has 70-100% similarity to a sequence represented by SEQ ID NO: 9. More preferably, the zinc finger-like peptide has 80-100% similarity to a sequence represented by SEQ ID NO: 9. In addition, the zinc finger-like peptide may have 50-100% identity to a sequence represented by SEQ ID NO: 9. Preferably, the zinc finger-like peptide has 70-100% identity to a sequence represented by SEQ ID NO: 9. Most preferably, the zinc finger-like peptide has 80-100% identity to a sequence represented by SEQ ID NO: 9. Most preferably, the sequence of the zinc finger-like peptide is SEQ ID NO: 9.
[0022] In the present invention, the term “similarity” refers to the percentage of the similar amino acid residues between two sequences, which is defined by the chemical similarity of amino acids. For example, alanine, valine, leucine and isoleucine are similar amino acid residues with saturated hydrocarbon groups; phenylalanine, tyrosine, tryptophan and histidine are similar amino acid residues with aromatic groups; aspartic acid, asparagine, glutamic acid and glutamine are similar amino acid residues with carboxyl groups and amide groups; lysine and arginine are similar amino acid residues with amino groups; serine and threonine are similar amino acid residues with alcoholic groups; and methionine and cysteine are similar amino acid residues with thio-groups. In addition, the term “identity” refers to the percentage of the identical amino acid residues between two sequences.
[0023] In the zinc finger-like peptide containing at least seven amino acids of the present invention, the sequence thereof may contain at least two duplicate amino acid residues with similar chemical properties. For example, the sequence thereof may contain at least two duplicate hydrophilic amino acid residues such as aspartic acid, glutamine, serine, threonine, or cysteine; at least two duplicate amino acid residues with alcoholic groups, such as threonine, serine or tyrosine; or at least two duplicate amino acid residues with thio-groups such as cysteine. In the present invention, the zinc finger-like peptide at least contains two cysteine and one histidine to form a zinc finger-like peptide with C2H2 motif.
[0024] In addition, the zinc finger-like peptide expression plasmid of the present invention may further comprise a vector connecting to the DNA sequence for expressing the zinc finger-like peptide of the present invention. The type of the vector is not particularly limited by number, and can be any vector generally used in the art. For example, the vector may be derived from pEGFP or pECFP, which is generally used to transfect into mammalian cells such as human cell lines for expressing inserted cDNAs.
[0025] Furthermore, the zinc finger-like peptide or the expression plasmid of the present invention may be encapsulated into liposome. Preferably, the expression plasmid is co-transfected into hosts with liposome to express the zinc finger-like peptide.
[0026] The zinc finger-like peptide of the present invention has similar structure to zinc-finger motif. In addition, the peptide of the present invention may selectively contain several duplicate amino acid residues with similar chemical properties or several duplicate identical amino acid residues to form a peptide motif with specific bondings. Furthermore, the zinc finger-like peptide can self-polymerize without adding any catalytic agents. The zinc finger-like peptide of the present invention also can bind to proteins related to apoptosis. Hence, it can inhibit the growth of tumor cells, and can be used to treat or prevent cancers.
[0027] The present invention further provides a pharmaceutical composition for treating cancer, which comprises: an effective amount of the aforementioned zinc finger-like peptide or zinc finger-like peptide expression plasmid; and a pharmaceutically acceptable carrier.
[0028] In addition, the present invention also provides a method for treating cancer, which comprises: administering the aforementioned zinc finger-like peptide, the aforementioned zinc finger-like peptide expression plasmid, or the aforementioned pharmaceutical composition to a subject in need thereof.
[0029] The zinc finger-like peptide of the present invention may be applied to various cancers, such as bladder cancer, bone cancer, brain cancer, breast cancer, cervical caner, colon cancer, endometrial cancer, esophageal cancer, leukemia, liver cancer, lymphoma, kidney cancer, osteosarcoma, ovarian cancer, pancreatic cancer, prostate cancer, skin cancer including basal and squamous cell carcinoma and melanoma, small intestine cancer, stomach cancer, thymus cancer and thyroid cancer, but the scope of applicability of the present invention is not limited thereto. Preferably, the zinc finger-like peptide of the present invention is used to treat breast cancer, colon cancer, esophageal cancer, leukemia, lymphoma, liver cancer, lung cancer, ovarian cancer, pancreatic cancer, prostate cancer, skin cancer, stomach cancer or thyroid cancer. More preferably, the zinc finger-like peptide of the present invention is used to treat breast cancer, colon cancer, lung cancer, lymphoma, prostate cancer or skin cancer. Most preferably, the zinc finger-like peptide of the present invention is used to treat brain cancer, breast cancer, prostate cancer or skin cancer.
[0030] The zinc finger-like peptide of the present invention can inhibit proliferation, growth, invasion and metastasis of tumor cells.
[0031] The zinc finger-like peptide and the pharmaceutical composition for treating cancer of the present invention can be administered via parenteral, inhalation, local, rectal, nasal, sublingual, or vaginal delivery, or implanted reservoir. Herein, the term “parenteral delivery” includes subcutaneous, intradermic, intravenous, intra-articular, intra-arterial, synovial, intrapleural, intrathecal, local, and intracranial injections.
[0032] According to the pharmaceutical composition of the present invention, the term “pharmaceutically acceptable carrier” means that the carrier must be compatible with the active ingredients (and preferably, capable of stabilizing the active ingredients) and not be deleterious to the subject to be treated. The carrier may be at least one selected from the group consisting of active agents, adjuvants, dispersants, wetting agents and suspending agents. The example of the carrier may be microcrystalline cellulose, mannitol, glucose, non-fat milk powder, polyethylene, polyvinylprrolidone, starch or a combination thereof.
[0033] In addition, the term “treating” used in the present invention refers to the application or administration of the zinc finger-like peptide or the pharmaceutical composition containing the zinc finger-like peptide to a subject with symptoms or tendencies of suffering from cancer in order to cure, heal, alleviate, relieve, alter, remedy, ameliorate, improve, prevent or affect the symptoms or tendencies of cancers. Furthermore, “an effective amount” used herein refers to the amount of each active ingredients such as the zinc finger-like peptide required to confer therapeutic effect on the subject. The effective amount may vary according to the route of administration, excipient usage, and co-usage with other active ingredients.
[0034] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1A is a curve representing the tumor volumes of mice in the experimental group according to Example 1 of the present invention;
[0036] FIG. 1B is a curve representing the tumor volumes of mice in the control group according to Example 1 of the present invention;
[0037] FIG. 2 shows curves representing the tumor volumes of mice according to Example 2 of the present invention;
[0038] FIG. 3A is a curve representing the tumor volumes of mice in the experimental group according to Example 3 of the present invention;
[0039] FIG. 3B is a curve representing the tumor volumes of mice in the control group according to Example 3 of the present invention;
[0040] FIG. 4 shows curves representing the tumor volumes of mice according to Example 4 of the present invention;
[0041] FIG. 5 shows curves representing the tumor volumes of mice according to Example 5 of the present invention;
[0042] FIG. 6A is a curve representing the tumor volumes of mice in the experimental group according to Example 6 of the present invention;
[0043] FIG. 6B is a curve representing the tumor volumes of mice in the control group according to Example 6 of the present invention;
[0044] FIG. 7A is a curve representing the tumor volumes of mice in the experimental group according to Example 7 of the present invention;
[0045] FIG. 7B is a curve representing the tumor volumes of mice in the control group according to Example 7 of the present invention;
[0046] FIG. 8 shows curves representing the tumor volumes of mice according to Example 8 of the present invention;
[0047] FIG. 9A is a curve representing the tumor volumes of mice in the experimental group according to Example 9 of the present invention;
[0048] FIG. 9B is a curve representing the tumor volumes of mice in the control group according to Example 9 of the present invention;
[0049] FIG. 10A is a curve representing the tumor volumes of mice in the experimental group according to Example 10 of the present invention;
[0050] FIG. 10B is a curve representing the tumor volumes of mice in the control group according to Example 10 of the present invention;
[0051] FIG. 11A is a curve representing the tumor volumes of mice in the control group according to Example 11 of the present invention;
[0052] FIG. 11B is a curve representing the tumor volumes of mice in the experimental group 1 according to Example 11 of the present invention; and
[0053] FIG. 11C is a curve representing the tumor volumes of mice in the experimental group 1 according to Example 11 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0054] The DNA sequence and the amino acid sequence of the zinc finger-like peptide used in the following examples are listed in the following table 1.
[0000]
TABLE 1
SEQ ID NO:
DNA/amino acid sequence
SEQ ID NO: 1
RRSSSCK
SEQ ID NO: 2
MSSRRSSSCKYCEQDFRAHTQKNAATPFLAN
SEQ ID NO: 3
agaaggtcgt cttcttgtaa a
SEQ ID NO: 4
atgagcagca gaaggtcgtc ttcttgtaaa tattgtgaac aggacttccg
agcacacaca cagaagaatg cggccacacc cttcctagcc aac
SEQ ID NO: 5
MSSRRSS G CKYCEQD (serine mutation)
SEQ ID NO: 6
RSSSCK (cysteine deletion)
SEQ ID NO: 7
atgagcagca gaaggtcgtc tggctgtaaa tattgtgaac aggacttccg
agcacacaca cagaagaatg cggccacacc cttcctagcc aac
SEQ ID NO: 8
MSSRRSSSCKYCEQD
SEQ ID NO: 9
FRAHTQKNAATPFLAN
[0055] In the following examples, 8-week nude mice were used as host subjects to perform in vivo experiments. The nude mice were placed in room temperature and suitable humidity, and supplied with sterile water and standard food for 2 consecutive weeks before performing experiments. Then, the nude mice were injected with zinc finger-like peptide and tumor cells. The detailed processes for the experiments are described as follows.
[0056] First, manually synthesized zinc finger-like peptide (Genemed Synthesis Inc., San Antonio, Tex., USA) was resuspended in degassed purified water to obtain 1-5 mM of zinc finger-like peptide solution (100 μl). Herein, the solution for suspending the zinc finger-like peptide is not particularly limited. Preferably, the zinc finger-like peptide is resuspended in degassed purified water, in order to prevent the self-polymerization of the zinc finger-like peptide and loss its ability to inhibit tumor cell growth.
EXAMPLE 1
Experimental Group
[0057] Herein, zinc finger-like peptide with sequence shown in SEQ ID NO: 2 was injected into nude mice.
[0058] In particularly, nude mice were injected with an intravenous injection of peptide (2 mM, 100 μl phosphate-buffered saline or PBS) via tail veins per week for 3 consecutive weeks, followed by inoculating basal cell carcinoma (BCC) cells (2 million cells/100 μl PBS) at both the right and left flanks. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 1A , which is a curve representing the tumor volumes of mice.
Control Group
[0059] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with PBS buffer (100 μl) in the present control group. The result is shown in FIG. 1B , which is a curve representing the tumor volumes of mice.
[0060] As shown in FIG. 1A and FIG. 1B , the zinc finger-like peptide inhibited the growth of skin cancer cell on nude mice when the mice were pre-injected with zinc finger-like peptide (experimental group). However, the tumor volumes of mice without injection of zinc finger-like peptide (control group) were much larger than those of the experimental group. These results indicate that the zinc finger-like peptide is effective on treating and preventing skin basal cell carcinoma.
EXAMPLE 2
Experimental Group 1
[0061] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
[0062] Nude mice were injected with an intravenous injection of peptide (2 mM, 100 μl PBS) via tail veins per week for 3 consecutive weeks, followed by inoculating BCC cells (2 million cells/100 μl PBS) at both the right and left flanks. 2 months later, boost injection of peptide was carried out per week for 3 consecutive weeks. The tumor volumes (mm 3 ) were daily observed during the whole experiment.
Experimental Group 2
[0063] The process of the present experimental group was the same as that of the experimental group 1, except that the zinc finger-like peptide with sequence shown in SEQ ID NO: 1 of the experimental group 1 was substituted with zinc finger-like peptide with sequence shown in SEQ ID NO: 5 in the present experimental group.
Control Group
[0064] The process of the present control group was the same as that of the experimental group 1, except that the zinc finger-like peptide of the experimental group 1 was substituted with H 2 O (100 μl) in the present control group.
[0065] The results of the present example are shown in FIG. 2 , which shows curves representing the tumor volumes of mice of the experimental group 1, the experimental group 2 and the control group of the present example. As shown in FIG. 2 , the zinc finger-like peptide with sequence shown in SEQ ID NO: 1 (experimental group 1) can prevent and inhibit the growth of cancer cell, and has effect on skin cancer treatment. However, when the fifth amino acid, serine of SEQ ID NO: 1 is replaced with glycine (i.e. the zinc finger-like peptide with sequence shown in SEQ ID NO: 5), the therapeutic effect of the zinc finger-like peptide is decreased. However, the zinc finger-like peptide used in the experimental group 2 still has better treatment effect than H 2 O used in the control group.
EXAMPLE 3
Experimental Group
[0066] Herein, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 is injected into nude mice.
[0067] With this experimental group, nude mice received an intravenous injection of peptide (2 mM, 100 μl sterile water) via tail veins per week for 3 consecutive weeks, followed by inoculation of malignant melanoma B16F10 (2 million cells/100 μl PBS) at both the right and left flanks. The tumor volumes (mm 3 ) were observed daily during the whole experiment. Shown in FIG. 3A is the result representing the tumor volumes of mice of the present experimental group.
Control Group
[0068] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 3B , which is a curve representing the tumor volumes of mice of the present control group.
[0069] As shown in FIG. 3A and FIG. 3B , the zinc finger-like peptide can inhibit the growth of skin melanoma on nude mice when the mice were pre-injected with zinc finger-like peptide (experimental group). However, the tumor volumes of mice without injection of zinc finger-like peptide (control group) were much larger than those of the experimental group. These results indicate that the zinc finger-like peptide exhibit dramatic effects on treating and preventing malignant melanoma.
EXAMPLE 4
[0070] Nude mice received an intravenous injection of peptide (2 mM, 100 μl) via tail veins per week for 2 consecutive weeks, followed by inoculating malignant melanoma B 16F10 (2 million cells/100 μl PBS) at both the right and left flanks. The tumor volumes (mm 3 ) were observed daily during the whole experiment.
Experimental Group 1
[0071] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
Experimental Group 2
[0072] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1, in which the fifth amino acid, serine was phosphorylated, and injected into nude mice.
Experimental Group 3
[0073] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 6 was injected into nude mice.
Experimental Group 4
[0074] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 6, in which the fourth amino acid serine was phosphorylated, and injected nude mice.
Control Group
[0075] In the control group, H 2 O (100 μl) was injected into nude mice.
[0076] The results of the present example are shown in FIG. 4 , which shows curves representing the tumor volumes of mice of the experimental groups 1-4 and the control group of the present example. As shown in FIG. 4 , the nude mice of the experimental group 3 died on 31 st day, and those of the experimental groups 2 and 4 died on 35 th day. These results indicate that the zinc finger-like peptide with sequence shown in SEQ ID NO: 1 (the experimental group 1) can effectively inhibit the growth of tumor cells. In addition, the skin cancer was completely cured after 115 days, and therefore the zinc finger-like peptide with sequence shown in SEQ ID NO: 1 has effect on skin cancer treatment. Furthermore, according to the results of the experimental groups 2-4, the activities of the zinc finger-like peptide on skin cancer treatment were reduced by phosphorylation of serine or deletion of cyctine of zinc finger-like peptide.
EXAMPLE 5
[0077] The cDNA of zinc finger-like peptide was inserted into vector pCR3.1/CMV to form a zinc finger-like peptide expression plasmid, wherein the zinc finger-like peptide was connected to the c-terminal of EGFP.
Experimental Group
[0078] In the present experimental group, the zinc finger-like peptide expression plasmid containing DNA sequence for expressing the zinc finger-like peptide (SEQ ID NO: 4) (100 μl) was injected into nude mice via tail veins per week for 2 consecutive weeks, to express zinc finger-like peptide. Then, BCC cells (2 million cells/100 μl medium) were inoculated into nude mice at both the right and left flanks. The tumor volumes (mm 3 ) were observed daily during the whole experiment.
Experimental Group 2
[0079] The process of the present experimental group was the same as that of the experimental group 1, except that the DNA sequence shown in SEQ ID NO: 4 was substituted with DNA sequence shown in SEQ ID NO: 7.
Control Group
[0080] The process of the present control group was the same as that of the experimental group 1, except that the zinc finger-like peptide expression plasmid was substituted with vector containing EGFP only.
[0081] The results of the present example are shown in FIG. 5 , which shows curves representing the tumor volumes of mice of the experimental groups 1-2 and the control group of the present example. As shown in FIG. 5 , the growth of tumor cells can be inhibited and the volume thereof can be reduced, when the zinc finger-like peptide expression plasmid containing DNA sequence shown in SEQ ID NO: 4 (experimental group 1) was injected into nude mice. Hence, the zinc finger-like peptide expression plasmid exhibits ability to treat skin cancer. Although the zinc finger-like peptide expression plasmid containing DNA sequence shown in SEQ ID NO: 7 (experimental group 2) cannot effectively terminate the growth of tumor cells, it can slightly inhibit the growth of the tumor cells. These results indicate that serine in the zinc finger-like peptide plays an important role on the cancer treatment.
EXAMPLE 6
Experimental Group
[0082] In the present experimental group, zinc finger-like peptide with sequences shown in SEQ ID NO: 8 and 9 was injected into nude mice.
[0083] Nude mice received an intravenous injection of peptide (2 mM, 100 μl ) via tail veins per week for 4 consecutive weeks, followed by inoculating breast adenocarcinoma MDA-MB-231 (2 million cells/100 μl medium) at both the right and left flanks on 40 th day and 85 th day. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 6A , which is a curve representing the tumor volumes of mice.
Control Group
[0084] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 6B , which is a curve representing the tumor volumes of mice.
[0085] As shown in FIG. 6A , when the nude mice were injected with peptide and followed by inoculating breast tumor cells (experimental group), the growth and proliferation of tumor cells were not observed at both the left and right flanks. However, as shown in FIG. 6B , the tumor volumes of the nude mice in the control group were increased to 1000 times at both the left and right flanks on the 161st day. These results indicate that the zinc finger-like peptide exhibit effects on treating and preventing breast adenocarcinoma.
[0086] In addition, there are no side effects on the nude mice injected with the zinc finger-like peptide 1.5 years layer. Hence, the zinc finger-like peptide exhibits low side effect and has ability to prevent the growth of breast tumor cells.
EXAMPLE 7
Experimental Group
[0087] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
[0088] Nude mice were injected with an intravenous injection of peptide (3 mM, 100 μl) via tail veins per week for 3 consecutive weeks, followed by inoculating breast carcinoma MDA-MB-468 (2 million cells/100 μl medium) at both the right and left flanks. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 7A , which is a curve representing the tumor volumes of mice.
Control Group
[0089] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group as substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 7B , which is a curve representing the tumor volumes of mice.
[0090] As shown in FIG. 7A , when the nude mice were injected with peptide and followed by inoculating breast tumor cells (experimental group), the growth and proliferation of tumor cells were not observed at both the left and right flanks. However, as shown in FIG. 7B , the tumor volumes of the nude mice in the control group were increased to 200-500 times at both the left and right flanks on the 91 st day. These results indicate that the zinc finger-like peptide exhibit effects on treating and preventing breast carcinoma.
EXAMPLE 8
Experimental Group
[0091] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 2 was injected subcutaneously into nude mice.
[0092] Nude mice received an injection of breast carcinoma MDA-MB-435s (2 million cells/100 μl PBS) via tail veins at both the right and left flanks on the P t day, followed by injecting peptide (2 mM, 100 μl) per week for 4 consecutive weeks from the 70 th day. The tumor volumes (mm 3 ) were observed daily during the whole experiment.
Control Group
[0093] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with PBS buffer (100 μl) in the present control group.
[0094] The results of the present example are shown in FIG. 8 , which shows curves representing the tumor volumes of mice of the experimental groups 1-2 and the control group of the present example. The tumor volumes in the experimental group were significantly increased from the 89 th day, and the maximum tumor volumes were observed on the 100 th day (1000 mm 3 ). Then, the tumor volumes were reduced to 50% on the 113 th day. However, the tumor volumes in the control group were significantly increased from the 80 th day, and increased to 4000 times (4000 mm 3 ) on the 105 th day. Although the tumor volumes in the experimental group were increased, the zinc finger-like peptide used therein can still terminate 75% tumor cell growth compared to the control group. Hence, the zinc finger-like peptide can be used to treat breast cancer.
EXAMPLE 9
Experimental Group
[0095] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
[0096] Nude mice were injected with an intravenous injection of peptide (2 mM, 100 μl) via tail veins per week for 3 consecutive weeks, followed by inoculating malignant prostate cancer DU145 cells (2 million cells/100 μl medium) at both the right and left flanks three months later. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 9A , which is a curve representing the tumor volumes of mice.
Control Group
[0097] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 9B , which is a curve representing the tumor volumes of mice.
[0098] As shown in FIG. 9A , when the nude mice were injected with peptide and followed by incoluation of prostate tumor cells (experimental group), the growth and proliferation of tumor cells were not observed at both the left and right flanks. In addition, there is a 3-month resting period after peptide treatment prior to challenge with tumor cells, suggesting that zinc finger-like peptide could provide a long-term protection against cancer.
[0099] However, as shown in FIG. 9A and FIG. 9B , the implanted tumor cells in the control group without peptide injection proliferated at both the right and left flanks, and the tumor volumes of the control group were much lager than those of the experimental group.
EXAMPLE 10
Experimental Group
[0100] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
[0101] Nude mice were injected with an intravenous injection of peptide (2 mM, 100 μl) via tail veins per week for 3 consecutive weeks, followed by inoculating prostatic epithelial cells PZ-HPV-7 (2 million cells/100 μl medium) at both the right and left flanks on the 20 th day and the 90 th day. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 10A , which is a curve representing the tumor volumes of mice.
Control Group
[0102] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 10B , which is a curve representing the tumor volumes of mice.
[0103] As shown in FIG. 10A , when the nude mice were injected with peptide and followed by inoculating prostate tumor cells (experimental group), the growth and proliferation of tumor cells were not observed at both the left and right flanks However, as shown in FIG. 10B , the implanted tumor cells in the control group without peptide injection were proliferated at both the right and left flanks.
[0104] Hence, the zinc finger-like peptide can be used to treat prostate cancer, terminate the growth of tumor cells, and obtain the purpose of cancer prevention.
EXAMPLE 11
Control Group
[0105] The process of the present control group was the same as that of the experimental group, except that the zinc finger-like peptide of the experimental group was substituted with H 2 O (100 μl) in the present control group. The result is shown in FIG. 11A , which is a curve representing the tumor volumes of mice.
Experimental Group 1
[0106] In the present experimental group, zinc finger-like peptide with sequence shown in SEQ ID NO: 1 was injected into nude mice.
[0107] Nude mice were injected with an intravenous injection of peptide (2 mM, 100 μl) via tail veins per week for 3 consecutive weeks, followed by inoculating malignant glioma U87-MG cells (2 million cells/100 μl medium) at both the right and left flanks 1 month later. The tumor volumes (mm 3 ) were observed daily during the whole experiment. The result is shown in FIG. 11B , which is a curve representing the tumor volumes of mice.
Experimental Group 2
[0108] The process of the present control group was the same as that of the experimental group 1, except that the concentration of the zinc finger-like peptide is 4 mM. The result is shown in FIG. 11C , which is a curve representing the tumor volumes of mice.
[0109] As shown in FIG. 11A to FIG. 11C , when the nude mice were injected with peptide and followed by inoculating brain tumor cells (experimental groups 1 and 2), the growth and proliferation of tumor cells were slower than that observed in the control group. In addition, the suppression on tumor cell growth was getting significant as the concentration of the zinc finger-like peptide increased.
[0110] The aforementioned results indicate that the zinc finger-like peptide or the zinc finger-like peptide expression plasmid can inhibit the growth and the proliferation of tumor cells, and thus has potential for cancer treatment and prevention.
[0111] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | A zinc finger-like peptide for treating cancer, a pharmaceutical composition containing the zinc finger-like peptide and a method for treating cancer are disclosed. In the present invention, the zinc finger-like peptide for treating cancer comprises: at least seven amino acids, wherein the sequence of the at least seven amino acids has 85-100% similarity to a sequence represented by SEQ ID NO: 1. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of co-pending application Ser. No. 13/814,424 filed on Mar. 4, 2013, which is a National Phase of PCT International Application No. PCT/JP2011/066740 filed on Jul. 22, 2011, which claims priority under 35 U.S.C. §119(a) to Patent Application No. 2010-177918 filed in Japan on Aug. 6, 2010. All of the above applications are hereby expressly incorporated by reference into the present application.
TECHNICAL FIELD
[0002] The present invention relates to a base station apparatus, a mobile station apparatus, a mobile communication system, a communication method, a control program, and an integrated circuit that are used for efficiently executing random access.
BACKGROUND ART
[0003] In 3GPP (3rd Generation Partnership Project), the W-CDMA scheme has been standardized as a 3rd generation cellular mobile communication scheme, and the services thereof have sequentially been available. Also, HSDPA with higher communication speed has been standardized, and the services thereof have been available.
[0004] Also, in 3GPP, standardization of evolved 3rd generation radio access (Evolved Universal Terrestrial Radio Access, hereinafter referred to as “EUTRA”) is progressing. As a downlink communication scheme of EUTRA, the OFDM (Orthogonal Frequency Division Multiplexing) scheme, which is resistant to multipath interference and is suitable for high-speed transmission, is employed. As an uplink communication scheme, the DFT (Discrete Fourier Transform)-spread OFDM scheme of the SC-FDMA (Single Carrier-Frequency Division Multiple Access) scheme, in which the PAPR (Peak to Average Power Ratio) of a transmission signal can be decreased, is employed in view of the cost and power consumption of mobile station apparatuses.
[0005] In 3GPP, discussions over Advanced-EUTRA, which is a further development of EUTRA, have begun. Advanced-EUTRA is based on the assumption that a band with a bandwidth of up to 100 MHz is used in each of uplink and downlink, and that communication is performed at transmission rates of up to 1 Gbps or more in downlink and up to 500 Mbps or more in uplink.
[0006] Advanced-EUTRA is directed to realizing a 100 MHz band at a maximum by combining a plurality of EUTRA bands, each having a bandwidth of 20 MHz or less, so as to be compatible with EUTRA mobile station apparatuses. In Advanced-EUTRA, each EUTRA band of 20 MHz or less is called a component carrier (CC) (NPL 3). A combination of one downlink component carrier and one uplink component carrier constitutes one cell. Also, only one downlink component carrier may constitute one cell.
CITATION LIST
Non Patent Literature
[0000]
NPL 1: 3GPP TS (Technical Specification) 36.300, V9.30 (2010-03), Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN), Overall description Stage 2
NPL 2: 3GPP TS (Technical Specification) 36.321, V9.20 (2010-03), Evolved Universal Terrestrial Radio Access (E-UTRA) Medium Access Control (MAC) protocol specification
NPL 3: 3GPP TS (Technical Report) 36.814, V9.00 (2010-03), Evolved Universal Terrestrial Radio Access (E-UTRA) Further advancements for E-UTRA physical layer aspects
SUMMARY OF INVENTION
Technical Problem
[0010] In a case where a mobile station apparatus communicates with a base station apparatus by using a plurality of cells, the mobile station apparatus may connect to the base station apparatus via a repeater or the like. In such a case, the reception timing of each downlink component carrier in the mobile station apparatus may vary among individual cells. Furthermore, a transmission timing for the base station apparatus may vary among individual uplink component carriers of individual cells. Thus, it is necessary to adjust transmission timings in individual uplink component carriers of individual cells.
[0011] However, in a case where it is necessary to adjust transmission timings in individual cells, if uplink synchronization is lost, such as at the time of initial access or handover, random access processing is necessary for individual cells. In a case where each mobile station apparatus is allocated with a plurality of cells and where a plurality of random access processing operations are simultaneously executed in the individual cells, the processing executed in the mobile station apparatus becomes complicated. In addition, since each mobile station apparatus executes a plurality of random access processing operations, collisions of random access preambles among the mobile station apparatuses increase.
[0012] The present invention has been made in view of these circumstances, and an object of the invention is to provide a base station apparatus, a mobile station apparatus, a mobile communication system, a communication method, a control program, and an integrated circuit that enable efficient random access in a case where transmission timings on the side of mobile station apparatuses vary among individual cells.
Solution to Problem
[0013] (1) In order to achieve the above-described object, an embodiment of the present invention takes the following measures. That is, a base station apparatus of an embodiment of the present invention is a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The base station apparatus allocates a plurality of cells to the mobile station apparatus, groups the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, notifies the mobile station apparatus of transmission timings determined for the individual groups, permits the mobile station apparatus to execute random access using any one of the cells included in the groups, and notifies the mobile station apparatus of random access execution information about the cell for which random access is permitted.
[0014] (2) The base station apparatus of an embodiment of the present invention permits both of contention based random access and non-contention based random access, or only non-contention based random access for the cell for which random access is permitted.
[0015] (3) The base station apparatus of an embodiment of the present invention permits both of contention based random access and non-contention based random access for any one of the cells for which random access is permitted, and permits non-contention based random access for another one of the cells for which random access is permitted.
[0016] (4) In a case where the cell for which random access is permitted is changed, the base station apparatus of an embodiment of the present invention notifies the mobile station apparatus of random access execution information about a cell for which random access is newly permitted.
[0017] (5) A base station apparatus of an embodiment of the present invention is a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The base station apparatus allocates a plurality of cells to the mobile station apparatus, groups the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, and notifies the mobile station apparatus of transmission timings determined for the individual groups. Also, the base station apparatus sets, for the mobile station apparatus, any one of the cells included in any one of the groups as a first cell, any one of the cells included in another one of the groups as a second cell, and cells other than the first cell and the second cell as third cells, and notifies the mobile station apparatus of system information and setting information about the cells.
[0018] (6) In the base station apparatus of an embodiment of the present invention, system information about the first cell and the second cell includes random access execution information, and system information about the third cells does not include random access execution information.
[0019] (7) The base station apparatus of an embodiment of the present invention permits contention based random access and non-contention based random access for the first cell, and permits non-contention based random access for the second cell.
[0020] (8) A mobile station apparatus of an embodiment of the present invention is a mobile station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The mobile station apparatus receives, from the base station apparatus, allocation information about a plurality of cells, information about grouping of the cells into groups in each of which cells have an identical transmission timing, and random access execution information about one cell in each of the groups, and transmits a random access preamble for only a cell to which the random access execution information is set.
[0021] (9) In a case where the mobile station apparatus of an embodiment of the present invention newly receives random access execution information from the base station apparatus after the cell for which random access is permitted has been changed by the base station apparatus, the mobile station apparatus discards random access execution information that has already been obtained.
[0022] (10) In a case where the number of transmissions of a random access preamble for the cell for which both of contention based random access and non-contention based random access are permitted by the base station apparatus exceeds a maximum number of retransmissions, the mobile station apparatus of an embodiment of the present invention determines that random access has failed, and, in a case where the number of transmissions of a random access preamble for the cell for which only non-contention based random access is permitted exceeds the maximum number of retransmissions, the mobile station apparatus determines that random access has not failed.
[0023] (11) In a case where the mobile station apparatus of an embodiment of the present invention receives random access instruction information about the cell for which only non-contention based random access is permitted by the base station apparatus and where the random access instruction information indicates contention based random access, the mobile station apparatus discards the received random access instruction information.
[0024] (12) In a case where the mobile station apparatus of an embodiment of the present invention receives random access instruction information about a cell other than the cell for which random access is permitted by the base station apparatus, the mobile station apparatus discards the received random access instruction information.
[0025] (13) A mobile station apparatus of an embodiment of the present invention is a mobile station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. In the base station apparatus, cells are grouped into groups in each of which cells have an identical transmission timing, any one of the cells included in any one of the groups is set as a first cell, any one of the cells included in another one of the groups is set as a second cell, cells other than the first cell and the second cell are set as third cells, and the mobile station apparatus receives system information and setting information about the cells from the base station apparatus, and sets, for the individual cells, the received system information and setting information about the cells.
[0026] (14) The mobile station apparatus of an embodiment of the present invention transmits a random access preamble only for the first cell and the second cell.
[0027] (15) In a case where the mobile station apparatus of an embodiment of the present invention receives change instruction information for changing the first cell or the second cell from the base station apparatus, the mobile station apparatus discards random access execution information about the first cell before change or the second cell before change.
[0028] (16) In a case where the number of transmissions of a random access preamble for the second cell exceeds a maximum number of retransmissions, the mobile station apparatus of an embodiment of the present invention determines that random access has not failed.
[0029] (17) In a case where the mobile station apparatus of an embodiment of the present invention receives random access instruction information about the second cell from the base station apparatus and where the received random access instruction information indicates contention based random access, the mobile station apparatus discards the received random access instruction information.
[0030] (18) In a case where the mobile station apparatus of an embodiment of the present invention receives random access instruction information about the third cells from the base station apparatus, the mobile station apparatus discards the received random access instruction information.
[0031] (19) A mobile communication system of an embodiment of the present invention includes the base station apparatus according to (1) and the mobile station apparatus according to (8), or the base station apparatus according to (5) and the mobile station apparatus according to (13).
[0032] (20) A communication method of an embodiment of the present invention is a communication method for a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The communication method includes allocating a plurality of cells to the mobile station apparatus, grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, notifying the mobile station apparatus of transmission timings determined for the individual groups, permitting the mobile station apparatus to execute random access using any one of the cells included in the groups, and notifying the mobile station apparatus of random access execution information about the cell for which random access is permitted.
[0033] (21) A communication method of an embodiment of the present invention is a communication method for a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The communication method includes allocating a plurality of cells to the mobile station apparatus, grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, notifying the mobile station apparatus of transmission timings determined for the individual groups, setting, for the mobile station apparatus, any one of the cells included in any one of the groups as a first cell, any one of the cells included in another one of the groups as a second cell, and cells other than the first cell and the second cell as third cells, and notifying the mobile station apparatus of system information and setting information about the cells.
[0034] (22) A control program of an embodiment of the present invention is a control program for a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The control program includes commands to cause a computer to be able to read and execute a series of processes. The series of processes include a process of allocating a plurality of cells to the mobile station apparatus, a process of grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, and notifying the mobile station apparatus of transmission timings determined for the individual groups, and a process of permitting the mobile station apparatus to execute random access using any one of the cells included in the groups, and notifying the mobile station apparatus of random access execution information about the cell for which random access is permitted.
[0035] (23) A control program of an embodiment of the present invention is a control program for a base station apparatus applied to a mobile communication system in which random access from a mobile station apparatus to a base station apparatus is executed. The control program includes commands to cause a computer to be able to read and execute a series of processes. The series of processes include a process of allocating a plurality of cells to the mobile station apparatus, a process of grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, and notifying the mobile station apparatus of transmission timings determined for the individual groups, a process of setting, for the mobile station apparatus, any one of the cells included in any one of the groups as a first cell, a process of setting any one of the cells included in another one of the groups as a second cell, a process of setting cells other than the first cell and the second cell as third cells, and a process of notifying the mobile station apparatus of system information and setting information about the cells.
[0036] (24) An integrated circuit of an embodiment of the present invention is an integrated circuit that is mounted in a base station apparatus to cause the base station apparatus to implement a plurality of functions. The integrated circuit causes the base station apparatus to implement a series of functions. The series of functions includes a function of allocating a plurality of cells to the mobile station apparatus, a function of grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, and notifying the mobile station apparatus of transmission timings determined for the individual groups, and a function of permitting the mobile station apparatus to execute random access using any one of the cells included in the groups, and notifying the mobile station apparatus of random access execution information about the cell for which random access is permitted.
[0037] (25) An integrated circuit of an embodiment of the present invention is an integrated circuit that is mounted in a base station apparatus to cause the base station apparatus to implement a plurality of functions. The integrated circuit causes the base station apparatus to implement a series of functions. The series of functions includes a function of allocating a plurality of cells to the mobile station apparatus, a function of grouping the cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus, and notifying the mobile station apparatus of transmission timings determined for the individual groups, a function of setting, for the mobile station apparatus, any one of the cells included in any one of the groups as a first cell, a function of setting any one of the cells included in another one of the groups as a second cell, a function of setting cells other than the first cell and the second cell as third cells, and a function of notifying the mobile station apparatus of system information and setting information about the cells.
Advantageous Effects of Invention
[0038] According to the present invention, unnecessary random access processing does not occur even in a case where a plurality of component carriers are allocated to one mobile station apparatus in an Advanced-SUTRA system. This enables efficient random access.
BRIEF DESCRIPTION OF DRAWINGS
[0039] FIG. 1 is a block diagram illustrating the configuration of a mobile station apparatus according to a first embodiment of the present invention.
[0040] FIG. 2 is a block diagram illustrating the configuration of a base station apparatus according to the first embodiment of the present invention.
[0041] FIG. 3A is a diagram illustrating an example configuration of cells according to the first embodiment of the present invention.
[0042] FIG. 3B is a diagram illustrating an example configuration of cells according to the first embodiment of the present invention.
[0043] FIG. 4A is a diagram illustrating an example configuration of cells according to a second embodiment of the present invention.
[0044] FIG. 4B is a diagram illustrating an example configuration of cells according to the second embodiment of the present invention.
[0045] FIG. 5 is a diagram illustrating a channel configuration in EUTRA.
[0046] FIG. 6 is a diagram illustrating the configuration of uplink in EUTRA.
[0047] FIG. 7 is a sequence chart illustrating a contention based random access procedure.
[0048] FIG. 8 is a sequence chart illustrating a non-contention based random access procedure.
[0049] FIG. 9 is a diagram illustrating an example of a sequence group in EUTRA.
[0050] FIG. 10 is an explanatory diagram of downlink component carriers in Advanced-EUTRA.
[0051] FIG. 11 is an explanatory diagram of uplink component carriers in Advanced-EUTRA.
[0052] FIG. 12 is a diagram illustrating an example in which a base station apparatus and a mobile station apparatus communicate with each other via repeaters.
DESCRIPTION OF EMBODIMENTS
[0053] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The downlink of EUTRA is constituted by a downlink pilot channel DPiCH, a downlink synchronization channel DSCH, a physical downlink shared channel PDSCH, a physical downlink control channel PDCCH, and a physical broadcast channel PBCH.
[0054] The uplink of EUTRA is constituted by an uplink pilot channel UPiCH, a random access channel RACH, a physical uplink shared channel PUSCH, and a physical uplink control channel PUCCH.
[0055] FIG. 5 is a diagram illustrating a channel configuration in EUTRA, and FIG. 6 is a diagram illustrating the configuration of uplink in EUTRA. One block is constituted by twelve sub-carriers and seven OFDM symbols. Two blocks constitute one resource block. Regarding the random access channel RACH, one random access channel is provided in one sub-frame, so that accesses from many mobile station apparatuses, for example, mobile station apparatuses 1 - 1 to 1 - 3 (hereinafter the mobile station apparatuses 1 - 1 to 1 - 3 are collectively referred to as mobile station apparatuses 1 ), can be dealt with.
[0056] The arrangement configuration (frequency positions and time positions) of random access channels RACH is notified from a base station apparatus 3 to the mobile station apparatuses 1 , as a part of system information about the base station apparatus 3 . The random access channels RACH are arranged at certain intervals. The random access channels RACH, the region of the physical uplink shared channel PUSCH, and the region of the physical uplink control channel PUCCH are separated as illustrated in FIG. 6 . One random access channel RACH is constituted by using six resource blocks. The random access channel is used for, in uplink, achieving uplink synchronization between the mobile station apparatus 1 and the base station apparatus 3 (adjusting a timing of transmission from the mobile station apparatus 1 to the base station apparatus 3 ).
[0057] A random access procedure has two variants, namely contention based random access and non-contention based random access (NPL 1).
[0058] FIG. 7 is a diagram illustrating a procedure of contention based random access. Contention based random access is random access in which collision is likely to occur among the mobile station apparatuses 1 . Contention based random access is performed, for example, at the time of initial access in a state where connection to (communication with) the base station apparatus 3 has not been established, or at the time of sending a scheduling request when uplink data transmission occurs in the mobile station apparatus 1 in a state where connection to the base station apparatus 3 has been established but uplink synchronization is lost.
[0059] FIG. 8 is a diagram illustrating a procedure of non-contention based random access. Non-contention based random access is random access in which collision does not occur among the mobile station apparatuses 1 . In non-contention based random access, the mobile station apparatus 1 starts random access in response to an instruction from the base station apparatus 3 in a special case, for example, at the time of handover or in a case where the transmission timing of the mobile station apparatus 1 is not valid, in order to quickly achieve uplink synchronization between the mobile station apparatus 1 and the base station apparatus 3 when the connection between the base station apparatus 3 and the mobile station apparatus 1 has been established but uplink synchronization therebetween is lost (NPL 1). Non-contention based random access is instructed by a message of an RRC layer (Radio Resource Control: Layer 3) and control data of the physical downlink control channel PDCCH.
[0060] In the case of accessing a random access channel RACH, the mobile station apparatus 1 transmits only a random access preamble. The random access preamble is constituted by a preamble portion and a CP (Cyclic prefix) portion. In the preamble portion, a CAZAC (Constant Amplitude Zero Auto-Correlation Zone Code) sequence serving as a signal pattern representing information is used. Sixty-four types of sequences are prepared and six-bit information is expressed.
[0061] As illustrated in FIG. 9 , CAZAC sequences used for a random access preamble are roughly classified into a sequence used for contention based random access (random sequence or random preamble) and a sequence used for non-contention based random access (dedicated sequence or dedicated preamble). Information about generation of the random access preamble is notified as system information from the base station apparatus 3 to the mobile station apparatus 1 . Also, random access information included in the system information notified from the base station apparatus 3 includes information about the maximum number of transmissions of a random access preamble and the transmission power for the random access preamble.
[0062] A contention based random access procedure will be briefly described with reference to FIG. 7 . First, a mobile station apparatus 1 among the mobile station apparatuses 1 transmits a random access preamble to the base station apparatus 3 (message 1 ( 1 ), step S 1 ). Then, the base station apparatus 3 receives the random access preamble and transmits a response to the random access preamble (random access response) to the mobile station apparatus 1 (message 2 ( 2 ), step S 2 ). The mobile station apparatus 1 transmits a message of an upper layer (Layer 2/Layer 3) on the basis of scheduling information included in the random access response (message 3 ( 3 ), step S 3 ). The base station apparatus 3 transmits a collision confirmation message to the mobile station apparatus 1 which has received the upper layer message of ( 3 ) (message 4 ( 4 ), step S 4 ). Note that contention based random access is also referred to as random preamble transmission.
[0063] A non-contention based random access procedure will be briefly described with reference to FIG. 8 . First, the base station apparatus 3 notifies the mobile station apparatus 1 of a preamble number (or a sequence number) and a random access channel number to be used (message 0 ( 1 ′), step S 11 ). The mobile station apparatus 1 transmits a random access preamble of the specified preamble number to the specified random access channel RACH (message 1 ( 2 ′), step S 12 ). Then, the base station apparatus 3 receives the random access preamble and transmits a response to the random access preamble (random access response) to the mobile station apparatus 1 (message 2 ( 3 ′), step S 13 ). If the value of the notified preamble number is 0, contention based random access is performed. Note that non-contention based random access is also referred to as dedicated preamble transmission.
[0064] Referring to FIG. 7 , the contention based random access procedure will be described in detail. First, the mobile station apparatus 1 selects one random sequence from a random sequence group on the basis of a downlink radio channel condition (path-loss) and the size of message 3 , generates a random access preamble on the basis of the selected random sequence, and transmits the random access preamble by using a random access channel RACH (message 1 ( 1 )).
[0065] The base station apparatus 3 detects the random access preamble transmitted from the mobile station apparatus 1 , and then calculates an amount of difference in transmission timing between the mobile station apparatus 1 and the base station apparatus 3 by using the random access preamble, performs scheduling for transmitting an L2/L3 message (specifies the position of an uplink radio resource and a transmission format (message size)), allocates Temporary C-RNTI (Cell-Radio Network Temporary Identity: mobile station apparatus identification information), arranges RA-RNTI, which represents a response (random access response) addressed to the mobile station apparatus 1 which has transmitted the random access preamble using the random access channel RACH, to the physical downlink control channel PDCCH, and transmits the random access response, which includes transmission timing information, scheduling information, Temporary C-RNTI, and the preamble number (sequence number) of the received preamble, to the physical downlink shared channel PDSCH (message 2 ( 2 )).
[0066] The mobile station apparatus 1 detects the RA-RNTI in the physical downlink control channel PDCCH, and then determines the content of the random access response message arranged in the physical downlink shared channel PDSCH. If the random access response message includes the preamble number corresponding to the transmitted random access preamble, the mobile station apparatus 1 adjusts the transmission timing in accordance with the transmission timing information, and transmits an L2/L3 message which includes information identifying the mobile station apparatus 1 , such as C-RNTI (or Temporary C-RNTI) or IMSI (International Mobile Subscriber Identity), by using the scheduled radio resource and transmission format (message 3 ( 3 )). After adjusting the transmission timing, the mobile station apparatus 1 starts a transmission timing timer in which the adjusted transmission timing is valid. The transmission timing becomes invalid when timeout occurs. While the transmission timing is valid, the mobile station apparatus 1 is capable of transmitting data to the base station apparatus 3 . When the transmission timing is invalid, the mobile station apparatus 1 is capable of transmitting only a random access preamble.
[0067] The mobile station apparatus 1 waits for a random access response message from the base station apparatus 3 for a certain period. If the mobile station apparatus 1 does not receive a random access response message which includes the preamble number of the transmitted random access preamble, the mobile station apparatus 1 retransmits the random access preamble.
[0068] The base station apparatus 3 receives the L2/L3 message from the mobile station apparatus 1 , and then transmits a collision confirmation (contention resolution) message for determining whether or not collision is being occurred among the mobile station apparatuses 1 - 1 to 1 - 3 to the mobile station apparatus 1 by using C-RNTI (or Temporary C-RNTI) or IMSI included in the received L2/L3 message (message 4 ( 4 )).
[0069] If the mobile station apparatus 1 does not detect a random access response message which includes the preamble number corresponding to the transmitted random access preamble within a certain period, or fails to transmit the message 3 , or does not detect identification information about the mobile station apparatus 1 itself in the collision confirmation message within a certain period, the mobile station apparatus 1 retransmits the random access preamble (message 1 ( 1 )) (NPL 2). If the number of transmissions of the random access preamble exceeds the maximum number of transmissions of the random access preamble indicated by the system information, the mobile station apparatus 1 determines that random access has failed, and stops the communication with the base station apparatus 3 . If the random access procedure has been successfully completed, transmission and reception of control data for establishing connection are performed between the base station apparatus 3 and the mobile station apparatus 1 .
[0070] After the random access procedure, the transmission timing is updated in the following manner: the base station apparatus 3 measures the uplink pilot channel UPiCH transmitted from the mobile station apparatus 1 , calculates timing information, and notifies the mobile station apparatus 1 of the calculated transmission timing.
[0071] In 3GPP, discussions over Advanced-EUTRA, which is a further development of EUTRA, have begun. Advanced-EUTRA is based on the assumption that a band with a bandwidth of up to 100 MHz is used in each of uplink and downlink, and that communication is performed at transmission rates of up to 1 Gbps or more in downlink and up to 500 Mbps or more in uplink.
[0072] FIG. 10 is an explanatory diagram of downlink component carriers in Advanced-EUTRA. FIG. 11 is an explanatory diagram of uplink component carriers in Advanced-EUTRA.
[0073] Advanced-EUTRA is directed to realizing a 100 MHz band at a maximum by combining a plurality of EUTRA bands, each having a bandwidth of 20 MHz or less, so as to be compatible with EUTRA mobile station apparatuses 1 . In Advanced-EUTRA, each EUTRA band of 20 MHz or less is called a component carrier (CC) (NPL 3). A combination of one downlink component carrier and one uplink component carrier constitutes one cell. Also, only one downlink component carrier may constitute one cell.
[0074] The base station apparatus 3 allocates, among a plurality of cells, one or more cells suitable for the communication capacity and communication condition of the mobile station apparatus 1 . The mobile station apparatus 1 transmits and receives data by using the allocated cell or cells. In a case where the mobile station apparatus 1 communicates with the base station apparatus 3 by using a plurality of cells, the mobile station apparatus 1 may connect to the base station apparatus 3 via a repeater or the like, as illustrated in FIG. 12 . In such a case, the reception timing of each downlink component carrier in the mobile station apparatus 1 and/or the transmission timing of each uplink component carrier for the base station apparatus 3 may vary among individual cells. Particularly, if the transmission timing of each uplink component carrier for the base station apparatus 3 varies, it is necessary for the mobile station apparatus 1 to adjust transmission timings in individual uplink component carriers of individual cells.
First Embodiment
Description of Configuration
[0075] FIG. 1 is a diagram illustrating the configuration of the mobile station apparatus 1 according to an embodiment of the present invention. The mobile station apparatus 1 includes a radio unit 101 , transmission processing units 103 - 1 to 103 - 5 (hereinafter, the transmission processing units 103 - 1 to 103 - 5 are collectively referred to as transmission processing units 103 ), reception processing units 105 - 1 to 105 - 5 (hereinafter, the reception processing units 105 - 1 to 105 - 5 are collectively referred to as reception processing units 105 ), a transmission data control unit 107 , a control data extracting unit 109 , a random access preamble generating unit 111 , transmission timing adjusting units 113 - 1 to 113 - 5 (hereinafter, the transmission timing adjusting units 113 - 1 to 113 - 5 are collectively referred to as transmission timing adjusting units 113 ), a control unit 115 , and a scheduling unit 117 . The scheduling unit 117 includes a control data analyzing unit 119 , a UL scheduling unit 121 , a control data creating unit 123 , and a cell management unit 125 . In this embodiment, in order to describe an example in which the mobile station apparatus 1 - 1 is capable of receiving signals using five cells, five transmission processing units 103 , five reception processing units 105 , and five transmission timing adjusting units 113 are provided.
[0076] User data and control data are input to the transmission data control unit 107 . The transmission data control unit 107 allocates individual pieces of data to individual channels of uplink component carriers of individual cells, and transmits the pieces of data to the transmission processing units 103 - 1 to 103 - 5 , in response to an instruction from the control unit 115 . The transmission processing units 103 - 1 to 103 - 5 modulate and encode the pieces of data received from the transmission data control unit 107 , perform series/parallel conversion on input signals, perform DFT-IFFT (Inverse Fast Fourier Transform), and also perform OFDM signal processing such as insertion of CP, thereby generating OFDM signals. The transmission timing adjusting units 113 - 1 to 113 - 5 adjust transmission timings of signals to be output using individual uplink component carriers of individual cells, in accordance with transmission timing information received from the control unit 115 . After the adjustment of transmission timings, the signals are up-converted to a radio frequency by the radio unit 101 and are transmitted from a transmission antenna. Note that a random access preamble is transmitted without the transmission timing thereof being adjusted, even if a transmission timing is set.
[0077] The radio unit 101 down-converts radio signals received from the antenna and supplies the radio signals to the reception processing units 105 . The reception processing units 105 - 1 to 105 - 5 perform FFT (Fast Fourier Transform) processing, decoding, demodulation processing, and so forth on the signals received from the radio unit 101 , and supply demodulated data to the control data extracting unit 109 . Also, the reception processing units 105 - 1 to 105 - 5 measure radio channel characteristics of the downlink component carriers of the individual cells, and supply measurement results to the scheduling unit 117 .
[0078] The control data extracting unit 109 refers to C-RNTI (mobile station apparatus identification information) which is arranged in the physical downlink control channels PDCCH of the individual cells and downlink scheduling information in the input data, and determines whether or not the input data is addressed to the own mobile station apparatus. If the input data is addressed to the own mobile station apparatus, the control data extracting unit 109 divides the data in the physical downlink shared channels PDSCH modulated by the reception processing units 105 - 1 to 105 - 5 into control data and user data. Then, the control data extracting unit 109 supplies the control data to the scheduling unit 117 , and supplies the user data to an upper layer. Also, the control data extracting unit 109 supplies uplink scheduling information included in the physical downlink control channels PDCCH to the scheduling unit 117 . Also, in a case where the control data extracting unit 109 detects RA-RNTI (Random Access-Radio Network Temporary Identity) after transmitting a random access preamble, the control data extracting unit 109 supplies a random access response message to the scheduling unit 117 . Also, the control data extracting unit 109 instructs the scheduling unit 117 to respond to the received data. The control unit 115 controls the radio unit 101 , the transmission processing units 103 - 1 to 103 - 5 , the reception processing units 105 - 1 to 105 - 5 , the transmission data control unit 107 , and the control data extracting unit 109 , in response to instructions from the scheduling unit 113 .
[0079] The scheduling unit 117 includes the control data analyzing unit 119 , the UL scheduling unit 121 , the control data creating unit 123 , and the cell management unit 125 . The control data creating unit 123 creates control data, and creates a response to downlink data received by the control data extracting unit 109 . The control data analyzing unit 119 analyzes the control data received from the control data extracting unit 109 . The control data analyzing unit 119 supplies system information about the cells, allocation information about the cells, a random access response message, and random access instruction information which are received from the base station apparatus 3 to the cell management unit 125 , and supplies random access information included in the system information to the random access preamble generating unit 111 .
[0080] The UL scheduling unit 121 controls the transmission data control unit 107 on the basis of scheduling information about uplink data. Also, the UL scheduling unit 121 instructs the cell management unit 125 to execute random access on the basis of control information received from an upper layer.
[0081] The cell management unit 125 manages the cells which are set by the base station apparatus 3 , and manages system information notified from the base station apparatus 3 , such as the configuration of physical channels of the individual cells, transmission power information, and random access information. In a case where random access to the base station apparatus 3 is executed, the cell management unit 125 determines a cell with which a random access preamble is to be transmitted, randomly selects a sequence to be used on the basis of the downlink radio channel characteristic information received from the reception processing units 105 - 1 to 105 - 5 and the transmission data size of the message 3 by using random access information about the cell to be used for random access, and notifies the random access preamble generating unit 111 of information about the selected cell and a sequence number (preamble number). The details of random access will be described below.
[0082] Also, the cell management unit 125 determines the content of the random access response received from the control data analyzing unit 119 . When the cell management unit 125 detects the preamble number of the transmitted random access preamble, the cell management unit 125 supplies transmission timing information to any of the transmission timing adjusting units 113 - 1 to 113 - 5 related to the cell used for random access, and supplies allocated radio resource information to the UL scheduling unit 121 . After determining a contention resolution message, the cell management unit 125 ends the random access procedure. Also, the cell management unit 125 extracts a sequence number (preamble number) and a random access channel number from the random access instruction information received from the control data analyzing unit 119 , and supplies the cell information, the sequence number (preamble number), and the random access channel number to the random access preamble generating unit 111 .
[0083] The sequence selected by the mobile station apparatus 1 is referred to as a random sequence (random preamble), and the sequence specified by the base station apparatus 3 is referred to as a dedicated sequence (dedicated preamble). In a case where a cell to be used is not specified by the base station apparatus 3 , the mobile station apparatus 1 executes random access by using the uplink component carrier of the cell with which the random access instruction information has been received. Also, in a case where a sequence to be used is not specified, the mobile station apparatus 1 selects a sequence from among random sequences.
[0084] In a case where the random access preamble generating unit 111 is notified of cell information and a sequence number from the scheduling unit 117 , the random access preamble generating unit 111 creates a preamble portion and a CP portion on the basis of the random access information about the specified cell and the sequence number, and thereby generates a random access preamble. Also, the random access preamble generating unit 111 selects a random access channel position to be used on the basis of the random access information about the specified cell, and allocates the generated random access preamble to the selected random access channel position. In a case where the random access preamble generating unit 111 is notified of a cell number, a sequence number, and a random access channel number from the scheduling unit 117 , the random access preamble generating unit 111 creates a preamble portion and a CP portion on the basis of the random access information about the specified component carrier and the sequence number, and thereby generates a random access preamble. Also, the random access preamble generating unit 111 selects a random access channel position to be used on the basis of the random access information about the specified cell and a random access number. Then, the random access preamble generating unit 111 allocates the generated random access preamble to the selected random access channel position in the specified component carrier.
[0085] FIG. 2 illustrates a configuration diagram of the base station apparatus 3 according to an embodiment of the present invention. The base station apparatus 3 includes a radio unit 201 , transmission processing units 203 - 1 to 203 - 5 (hereinafter, the transmission processing units 203 - 1 to 203 - 5 are collectively referred to as transmission processing units 203 ), reception processing units 205 - 1 to 205 - 5 (hereinafter, the reception processing units 205 - 1 to 205 - 5 are collectively referred to as reception processing units 205 ), a transmission data control unit 207 , a control data extracting unit 209 , preamble detecting units 211 - 1 to 211 - 5 (hereinafter, the preamble detecting units 211 - 1 to 211 - 5 are collectively referred to as preamble detecting units 211 ), a control unit 213 , and a scheduling unit 215 (base-station-side scheduling unit). The scheduling unit 215 includes a DL scheduling unit 217 , a UL scheduling unit 219 , a control data creating unit 221 , and a cell management unit 223 . In this embodiment, an example of a case where the base station apparatus 3 has five cells is described, and thus five transmission processing units 203 , five reception processing units 205 , and five preamble detecting units 211 are provided.
[0086] In accordance with an instruction from the control unit 213 , the transmission data control unit 207 maps user data and control data, that is, maps control data to the physical downlink control channels PDCCH, the downlink synchronization channels DSCH, the downlink pilot channels DPiCH, the physical broadcast channels PBCH, and the physical downlink shared channels PDSCH of the downlink component carriers of the individual cells, and maps the data to be transmitted to the individual mobile station apparatuses 1 to the physical downlink shared channels PDSCH.
[0087] The transmission processing units 203 - 1 to 203 - 5 modulate and encode the data to be transmitted, perform series/parallel conversion on input signals, and perform OFDM signal processing such as IFFT transform, insertion of CP, and filtering, thereby generating OFDM signals. The radio unit 201 up-converts the OFDM-modulated data to a radio frequency, and transmits the data to the mobile station apparatuses 1 . Also, the radio unit 201 receives uplink data from the mobile station apparatuses 1 , down-converts the data to baseband signals, and supplies the received signals to the reception processing units 205 - 1 to 205 - 5 or the preamble detecting units 211 - 1 to 211 - 5 . The reception processing units 205 - 1 to 205 - 5 perform demodulation processing by using the uplink scheduling information received from the control unit 213 in view of the transmission processing executed by the mobile station apparatuses 1 , so as to demodulate data. Also, the reception processing units 205 - 1 to 205 - 5 measure radio channel characteristics by using the uplink pilot channels UPiCH, and supply the results to the scheduling unit 215 . It is assumed that a single carrier scheme, such as DFT-spread OFDM, is used as an uplink communication scheme. However, a multi-carrier scheme such as an OFDM scheme may be used.
[0088] The control data extracting unit 209 determines whether or not received data is correct or incorrect, and notifies the scheduling unit 215 of a determination result. If the received data is correct, the control data extracting unit 209 divides the received data into user data and control data. The control unit 213 controls the radio unit 201 , the transmission processing units 203 - 1 to 203 - 5 , the reception processing units 205 - 1 to 205 - 5 , the transmission data control unit 207 , and the control data extracting unit 209 , on the basis of instructions from the scheduling unit 215 .
[0089] The scheduling unit 215 includes the DL scheduling unit 217 which performs downlink scheduling, the UL scheduling unit 219 which performs uplink scheduling, the control data creating unit 221 , and the cell management unit 223 . The DL scheduling unit 217 performs scheduling for mapping user data and control data to individual downlink channels, on the basis of the downlink radio channel information notified from the mobile station apparatuses 1 , data information about individual users notified from an upper layer, and the control data created by the control data creating unit 221 . The UL scheduling unit 219 performs scheduling for mapping user data to individual uplink channels, on the basis of the uplink radio channel estimation result received from the reception processing units 205 - 1 to 205 - 5 and radio resource allocation requests from the mobile station apparatuses 1 , and supplies a scheduling result to the control unit 213 . In a case where the UL scheduling unit 219 is notified from the preamble detecting units 211 that a random access preamble has been detected, the UL scheduling unit 219 allocates the physical uplink shared channel PUSCH, and notifies the control data creating unit 221 of the allocated physical uplink shared channel PUSCH and a preamble number (sequence number).
[0090] The cell management unit 223 manages individual cells and system information about the cells (for example, configuration information about physical channels, transmission power information about individual channels, and random access information). Also, the cell management unit 223 allocates cells to the mobile station apparatus 1 , and determines a cell for which random access is permitted among the allocated cells. Then, the cell management unit 223 supplies system information to the control data creating unit 221 to notify the control data creating unit 221 of the system information about the allocated cells. The system information about the cell for which random access is permitted includes random access information (arrangement information about random access channels RACH, random access preamble generation information, and transmission information about a random access preamble, such as the maximum number of transmissions of a random access preamble and transmission power for the random access preamble). The system information about the cell for which random access is not permitted does not include random access information. Also, in the case of allowing the mobile station apparatus 1 to execute random access, the cell management unit 223 selects a dedicated sequence (dedicated preamble) and the position of a random access channel RACH, and supplies the selected dedicated sequence number and random access channel number to the control data creating unit 221 .
[0091] The control data creating unit 221 creates control data to be set to the physical downlink control channel PDCCH and control data to be set to the physical downlink shared channel PDSCH. The control data creating unit 221 creates control data, such as a control message including scheduling information; ACK/NACK of uplink data; a system information message including configuration information about physical channels, transmission power information about individual channels, and random access information; an initial setting message including setting information about a cell to be used (including random access information); a random access response message including a preamble number, transmission timing information, and scheduling information; a contention resolution message; and a message including a dedicated sequence number, a random access channel number, and a random access instruction.
[0092] In a case where the preamble detecting units 211 - 1 to 211 - 5 detect a random access preamble in a random access channel RACH, the preamble detecting units 211 - 1 to 211 - 5 calculate an amount of difference in transmission timing on the basis of the detected random access preamble, and notify the scheduling unit 215 of the cell in which the random access preamble has been detected, a detected preamble number (sequence number), and the amount of difference in transmission timing.
[Description of Operation]
[0093] A radio communication system which uses the random access procedures illustrated in FIGS. 7 and 8 is assumed. Also, a radio communication system in which the base station apparatus 3 and the mobile station apparatus 1 communicate with each other by using a plurality of cells among which the transmission timing in the mobile station apparatus 1 varies, as illustrated in FIGS. 10 , 11 , and 12 , is assumed.
[0094] In Advanced-EUTRA, the base station apparatus 3 allocates one or more cells of different frequencies suitable for the communication capacity and communication condition of the mobile station apparatus 1 among a plurality of cells for each frequency, and the mobile station apparatus 1 transmits and receives data by using the allocated cell or cells. In a case where the mobile station apparatus 1 communicates with the base station apparatus 3 by using a plurality of cells, the mobile station apparatus 1 may connect to the base station apparatus 3 via a repeater or the like, as illustrated in FIG. 12 . In such a case, the reception timing of a downlink component carrier in the mobile station apparatus 1 may vary among individual cells. Furthermore, the transmission timing for the base station apparatus 3 may vary among individual uplink component carriers of individual cells. If the transmission timing of each uplink component carrier for the base station apparatus 3 varies, it is necessary for the mobile station apparatus 1 to adjust transmission timings in individual uplink component carriers of individual cells.
[0095] However, in a case where it is necessary to adjust the transmission timing in the mobile station apparatus 1 in individual cells, if uplink synchronization is lost, for example, at the time of initial access or handover, random access processing is required for each cell. In a case where each mobile station apparatus 1 is allocated with a plurality of cells and where random access processing operations are simultaneously executed in the individual cells, the processing executed in the mobile station apparatus 1 becomes complicated. In addition, since each mobile station apparatus 1 executes a plurality of random access processing operations, the probability of the occurrence of collision of random access preambles among the mobile station apparatuses 1 increases, and the occurrence of collision of random access preambles in the entire cells increases. Thus, the opportunities of transmitting an unnecessary random access preamble are decreased by restricting execution of random access by the mobile station apparatuses 1 .
[0096] The base station apparatus 3 groups cells into groups in each of which cells have an identical transmission timing in the mobile station apparatus 1 (hereinafter referred to as transmission timing cell groups). The base station apparatus 3 permits random access for one cell in each transmission timing cell group. The base station apparatus notifies the mobile station apparatus 1 of system information about only the cell for which random access is permitted, the system information including random access information (arrangement information about random access channels RACH, random access preamble generation information, the maximum number of transmissions of a random access preamble, transmission power information about a random access preamble, and so forth). Accordingly, the mobile station apparatus 1 is incapable of executing random access using a cell whose random access information is not available, and thus execution of random access can be restricted, and unnecessary random access can be prevented. Note that the system information is information constituting a cell, such as configuration information about uplink/downlink physical channels and transmission information about uplink/downlink physical channels. The random access information is information that is necessary for executing a random access procedure related to transmission of a random access preamble, such as arrangement information about random access channels RACH, information for generating a random access preamble, and information about the maximum number of transmissions of a random access preamble and transmission power.
[0097] Furthermore, the base station apparatus 3 permits both of contention based random access and non-contention based random access for one of the cells for which random access by the mobile station apparatus 1 is permitted, and permits non-contention based random access for the other cells for which random access is permitted. Accordingly, the mobile station apparatus 1 is incapable of executing random access using a cell for which only non-contention based random access is permitted, as long as an instruction is not provided from the base station apparatus 3 , and thus execution of random access can be restricted.
[0098] Alternatively, the random access to be permitted may be specified for each transmission timing cell group. That is, the base station apparatus 3 is capable of restricting execution of random access from the mobile station apparatus 1 by permitting both of contention based random access and non-contention based random access, or non-contention based random access for each of the cells for which random access is permitted. Alternatively, the base station apparatus 3 may enable selection of only contention based random access.
[0099] The operations of the mobile station apparatus 1 - 1 and the base station apparatus 3 will be described. The base station apparatus 3 is constituted by, for example, cells # 1 to # 5 , as illustrated in FIG. 3A . Cells # 1 to # 3 form a cell group of an identical transmission timing, and cells # 4 and # 5 form another cell group of an identical transmission timing.
[0100] The mobile station apparatus 1 - 1 executes cell search, and finds one of the cells of the base station apparatus 3 . Here, it is assumed that the mobile station apparatus 1 - 1 finds cell # 1 . The mobile station apparatus 1 - 1 obtains system information about cell # 1 (physical channel configuration of the cell, transmission power information, random access information, etc.) from the physical broadcast channel PBCH of cell # 1 . Then, by using the random access information included in the system information, the mobile station apparatus 1 - 1 transmits a random access preamble to the random access channel RACH of cell # 1 for initial access. Then, the mobile station apparatus 1 - 1 obtains random access response information including transmission timing information about cell # 1 from the base station apparatus 3 , sets a transmission timing of an uplink component carrier for cell # 1 , and starts a transmission timing timer. The mobile station apparatus 1 - 1 transmits a message 3 to the base station apparatus 3 via cell # 1 . The message 3 includes the content representing initial access. Upon receiving a contention resolution from the base station apparatus 3 , the mobile station apparatus 1 - 1 ends the contention based random access procedure.
[0101] After the random access procedure has been completed, the base station apparatus 3 allocates the cells to be used by the mobile station apparatus 1 - 1 , and notifies the mobile station apparatus 1 - 1 of the system information about the cells to be used by the mobile station apparatus 1 - 1 . Here, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 by including, in the system information, random access information about only the cells for which random access is permitted in individual transmission timing cell groups. The mobile station apparatus 1 - 1 recognizes that random access is permitted for the cells whose random access information is included in the system information among the allocated cells. Also, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of information indicating that both of contention based random access and non-contention based random access are permitted for the cells for which random access is permitted, or information indicating that non-contention based random access is permitted. Alternatively, the base station apparatus 3 may notify the mobile station apparatus 1 - 1 of only information indicating that both of contention based random access and non-contention based random access are permitted for one of the cells for which random access is permitted, so that the mobile station apparatus 1 - 1 recognizes that only non-contention based random access is permitted for the other cells for which random access is permitted.
[0102] Here, as illustrated in FIG. 3B , the base station apparatus 3 allocates cells # 1 to # 5 to the mobile station apparatus 1 - 1 , and permits contention based random access and non-contention based random access for cell # 1 , and permits non-contention based random access for cell # 5 . The base station apparatus 3 notifies the mobile station apparatus 1 - 1 of setting information, such as the system information about the allocated cells and group information about the transmission timing cell groups. Here, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 without including random access information in the system information about cells for which random access is not permitted. Here, the base station apparatus 3 does not notify the mobile station apparatus 1 - 1 of random access information about cells # 2 , # 3 , and # 4 . The mobile station apparatus 1 - 1 recognizes that random access is not permitted for the cells whose random access information is not included in the system information among the allocated cells.
[0103] After obtaining the allocated system information and the group information about the transmission timing cell groups, the mobile station apparatus 1 - 1 sets the transmission timing of cell # 1 as the uplink transmission timings of cells # 2 and # 3 , which are in the same transmission timing cell group as cell # 1 . After that, data is transmitted and received between the mobile station apparatus 1 - 1 and the base station apparatus 3 via the downlink component carriers of cells # 1 to # 5 and the uplink component carriers of cells # 1 to # 3 .
[0104] In a case where the amount of data transmitted from the mobile station apparatus 1 - 1 increases and where there is a cell which is not used by the mobile station apparatus 1 - 1 , the base station apparatus 3 notifies, by using the physical downlink control channel PDCCH, the mobile station apparatus 1 - 1 of random access instruction information for providing an instruction to execute non-contention based random access using the cell for which random access is permitted. Here, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of the random access instruction information about cell # 5 . The random access instruction information includes a preamble number and a random access channel number. The mobile station apparatus 1 - 1 determines the preamble number, and, if the preamble number indicates non-contention based random access, the mobile station apparatus 1 - 1 transmits a random access preamble to the random access channel RACH of cell # 5 by using the preamble and random access channel specified by the base station apparatus 3 . The base station apparatus 3 notifies the mobile station apparatus 1 - 1 of the random access instruction information by using the downlink component carrier of the cell which is a target of random access.
[0105] Upon detecting the random access preamble, the base station apparatus 3 calculates a transmission timing on the basis of the random access preamble, and transmits a random access response including transmission timing information to the mobile station apparatus 1 - 1 via the downlink component carrier of cell # 5 . Upon receiving the random access response, the mobile station apparatus 1 - 1 sets the transmission timing included in the random access response as the transmission timing of the uplink of cell # 5 and as the transmission timing of the uplink of cell # 4 in the same transmission timing cell group, and starts a transmission timing timer. Then, the mobile station apparatus 1 - 1 completes the non-contention based random access procedure. After that, data is transmitted and received between the mobile station apparatus 1 - 1 and the base station apparatus 3 also by using the uplink component carriers of cells # 4 and # 5 .
[0106] The mobile station apparatus 1 - 1 has one transmission timing timer for each transmission timing cell group, and starts or restarts the transmission timing timer upon receiving transmission timing information. While the transmission timing timer is running, uplink synchronization is achieved (transmission timing is valid), and uplink transmission on the uplink component carriers of a target transmission timing cell group is possible. While the timer is stopped, uplink synchronization is lost (transmission timing is invalid), and uplink data transmission on the uplink component carriers of a target transmission timing cell group is impossible, except for transmission of a random access preamble.
[0107] The mobile station apparatus 1 - 1 does not execute a random access procedure when receiving random access instruction information regarding a cell other than a cell for which random access is permitted. Also, the mobile station apparatus 1 - 1 does not execute a random access procedure when receiving random access instruction information for providing an instruction to execute contention based random access regarding a cell for which only non-contention based random access is permitted.
[0108] In a case where uplink transmission data is newly generated in a state where there is no allocation of a physical uplink shared channel PUSCH from the base station apparatus 3 and where uplink synchronization is achieved (transmission timing is valid) or is not achieved (transmission timing is invalid), the mobile station apparatus 1 - 1 executes contention based random access as a scheduling request. At this time, the mobile station apparatus 1 - 1 selects a cell for which contention based random access is permitted for the uplink component carrier of the cell used in random access. Here, the mobile station apparatus 1 - 1 selects cell # 1 . Then, the mobile station apparatus 1 - 1 selects one random sequence by using random access information about the cell for which contention based random access is permitted, generates a random access preamble, and transmits the random access preamble to the random access channel RACH of cell # 1 .
[0109] Upon receiving a random access response from the base station apparatus 3 via the downlink component carrier of cell # 1 , the mobile station apparatus 1 - 1 sets obtained transmission timing information as an uplink transmission timing of cell # 1 and as uplink transmission timings of cells # 2 and # 3 in the same transmission timing group, and starts a transmission timing timer. Then, the mobile station apparatus 1 - 1 includes transmission buffer status information about the mobile station apparatus 1 - 1 in a message 3 , and notifies the base station apparatus 3 of the message 3 . The mobile station apparatus 1 - 1 ends contention based random access upon receiving a contention resolution from the base station apparatus 3 .
[0110] The base station apparatus 3 may change the cell for which random access is permitted, in accordance with an access status of the random access channel RACH. In the case of changing the cell for which random access is permitted, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of random access information about the cell for which random access is newly permitted. The mobile station apparatus 1 - 1 sets the obtained random access information, and deletes old random access information.
[0111] For example, in the case of changing cell # 5 for which non-contention based random access is permitted to cell # 4 , the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of random access information about cell # 4 . Upon receiving the random access information about cell # 4 , the mobile station apparatus 1 - 1 sets the random access information about cell # 4 , and deletes the random access information about cell # 5 . At this time, the mobile station apparatus 1 - 1 recognizes that the cell for which random access is permitted has changed within the same transmission timing cell group, and performs setting under the assumption that the random access which is permitted for cell # 4 is non-contention based random access. The mobile station apparatus 1 - 1 does not change the setting of a cell for which random access is permitted in different transmission timing cell groups. Additionally, in the case of changing a permitted random access procedure, information indicating the permitted random access procedure is also notified.
[0112] In a case where the mobile station apparatus 1 - 1 receives, from the base station apparatus 3 , random access instruction information about a cell for which non-contention based random access is permitted during processing of a contention based random access procedure, the mobile station apparatus 1 - 1 continues the contention based random access processing which is being executed and ignores the ransom access instruction information from the base station apparatus 3 , or stops the contention based random access processing which is being executed and performs random access using the cell specified in accordance with the random access instruction information received from the base station apparatus 3 . In a case where the mobile station apparatus 1 - 1 receives random access instruction information about a cell during random access processing which is based on random access instruction information from the base station apparatus 3 , the mobile station apparatus 1 - 1 places priority on the first random access instruction and ignores the subsequent random access instruction information. In this way, the mobile station apparatus 1 - 1 does not simultaneously execute a plurality of random access processing operations.
[0113] Also, regarding random access using a cell for which both of contention based random access and non-contention based random access are permitted, if the number of transmissions of a random access preamble exceeds the maximum number of transmissions, the base station apparatus 1 - 1 determines that random access has failed. However, regarding random access using a cell for which non-contention based random access is permitted, the mobile station apparatus 1 - 1 does not determine that random access has failed even if the number of transmissions of a random access preamble exceeds the maximum number of transmissions. With this configuration, the occurrence of random access failure can be suppressed.
[0114] In the above-described embodiment, description has been given of a method for restricting random accesses by permitting contention based random access and non-contention based random access for one cell in one transmission timing cell group and by permitting non-contention based random access for one cell in each of the other transmission timing cell groups. Alternatively, contention based random access may be random access which is based on a scheduling request, and non-contention based random access may be random access which is based on random access instruction information. That is, random accesses can be restricted by permitting random access which is based on a scheduling request and random access which is based on random access instruction information for one cell in one transmission timing cell group and by permitting random access which is based on random access instruction information for one cell in each of the other transmission timing cell groups.
[0115] Accordingly, unnecessary random access does not occur. Also, the mobile station apparatuses 1 do not need to simultaneously execute random access processing, and thus random access processing in the mobile station apparatuses 1 can be prevented from being complicated.
Second Embodiment
Description of Configuration
[0116] The configuration of the mobile station apparatus 1 according to a second embodiment of the present invention is the same as that in FIG. 1 . The mobile station apparatus 1 includes the radio unit 101 , the transmission processing units 103 - 1 to 103 - 5 , the reception processing units 105 - 1 to 105 - 5 , the transmission data control unit 107 , the control data extracting unit 109 , the random access preamble generating unit 111 , the transmission timing adjusting units 113 - 1 to 113 - 5 , the control unit 115 , and the scheduling unit 117 . The scheduling unit 117 includes the control data analyzing unit 119 , the UL scheduling unit 121 , the control data creating unit 123 , and the cell management unit 125 . In this embodiment, in order to describe an example in which the mobile station apparatus 1 is capable of receiving signals using five cells, five transmission processing units 103 , five reception processing units 105 , and five transmission timing adjusting units 113 are provided.
[0117] The operations of the radio unit 101 , the transmission processing units 103 - 1 to 103 - 5 , the reception processing units 105 - 1 to 105 - 5 , the transmission data control unit 107 , the control data extracting unit 109 , the random access preamble generating unit 111 , the transmission timing adjusting units 113 - 1 to 113 - 5 , and the control unit 115 are the same as the operations described above with reference to FIG. 1 , and thus the description thereof is omitted.
[0118] The scheduling unit 117 includes the control data analyzing unit 119 , the UL scheduling unit 121 , the control data creating unit 123 , and the cell management unit 125 . The control data creating unit 123 creates control data, and creates a response to downlink data received by the control data extracting unit 109 . The control data analyzing unit 119 analyzes the control data received from the control data extracting unit 109 . The control data analyzing unit 119 supplies system information about the cells, allocation information about the cells, a random access response message, and random access instruction information which are received from the base station apparatus 3 to the cell management unit 125 , and supplies random access information included in the system information to the random access preamble generating unit 111 .
[0119] The UL scheduling unit 121 controls the transmission data control unit 107 on the basis of scheduling information about uplink data. Also, the UL scheduling unit 121 instructs the cell management unit 125 to execute random access on the basis of control information received from an upper layer.
[0120] The cell management unit 125 manages the cells which are set by the base station apparatus 3 , and manages system information notified from the base station apparatus 3 , such as the configuration of physical channels of the individual cells, transmission power information, and random access information. Also, the cell management unit 125 manages the operations of the mobile station apparatus 1 for each of a first cell, second cell, and third cell. In a case where random access to the base station apparatus 3 is executed, the cell management unit 125 determines a cell with which a random access preamble is to be transmitted, randomly selects a sequence to be used on the basis of the downlink radio channel characteristic information received from the reception processing units 105 - 1 to 105 - 5 and the transmission data size of the message 3 by using random access information about the cell to be used for random access, and notifies the random access preamble generating unit 111 of information about the selected cell and a sequence number (preamble number). The details of random access will be described below.
[0121] Also, the cell management unit 125 determines the content of the random access response received from the control data analyzing unit 119 . When the cell management unit 125 detects the preamble number of the transmitted random access preamble, the cell management unit 125 supplies transmission timing information to any of the transmission timing adjusting units 113 - 1 to 113 - 5 related to the cell used for random access, and supplies allocated radio resource information to the UL scheduling unit 121 . After determining a contention resolution message, the cell management unit 125 ends the random access procedure. Also, the cell management unit 125 extracts a sequence number (preamble number) and a random access channel number from the random access instruction information received from the control data analyzing unit 119 , and supplies the cell information, the sequence number (preamble number), and the random access channel number to the random access preamble generating unit 111 .
[0122] The sequence selected by the mobile station apparatus 1 is referred to as a random sequence (random preamble), and the sequence specified by the base station apparatus 3 is referred to as a dedicated sequence (dedicated preamble). In a case where a cell to be used is not specified by the base station apparatus 3 , the mobile station apparatus 1 executes random access by using the uplink component carrier of the cell with which the random access instruction information has been received. Also, in a case where a sequence to be used is not specified, the mobile station apparatus 1 selects a sequence from among random sequences.
[0123] The configuration of the base station apparatus 3 according to the second embodiment of the present invention is the same as that illustrated in FIG. 2 . The base station apparatus 3 includes the radio unit 201 , the transmission processing units 203 - 1 to 203 - 5 , the reception processing units 205 - 1 to 205 - 5 , the transmission data control unit 207 , the control data extracting unit 209 , the preamble detecting units 211 - 1 to 211 - 5 , the control unit 213 , and the scheduling unit 215 (base-station-side scheduling unit). The scheduling unit 215 includes the DL scheduling unit 217 , the UL scheduling unit 219 , the control data creating unit 221 , and the cell management unit 223 . In this embodiment, an example of a case where the base station apparatus 3 has five cells is described, and thus five transmission processing units 203 , five reception processing units 205 , and five preamble detecting units 211 are provided.
[0124] The operations of the radio unit 201 , the transmission processing units 203 - 1 to 203 - 5 , the reception processing units 205 - 1 to 205 - 5 , the transmission data control unit 207 , the control data extracting unit 209 , the preamble detecting units 211 - 1 to 211 - 5 , and the control unit 213 are the same as those described above with reference to FIG. 2 , and thus the description of the operations is omitted.
[0125] The scheduling unit 215 includes the DL scheduling unit 217 which performs downlink scheduling, the UL scheduling unit 219 which performs uplink scheduling, the control data creating unit 221 , and the cell management unit 223 . The DL scheduling unit 217 performs scheduling for mapping user data and control data to individual downlink channels, on the basis of the downlink radio channel information notified from the mobile station apparatuses 1 , data information about individual users notified from an upper layer, and the control data created by the control data creating unit 221 . The UL scheduling unit 219 performs scheduling for mapping user data to individual uplink channels, on the basis of the uplink radio channel estimation result received from the reception processing units 205 - 1 to 205 - 5 and radio resource allocation requests from the mobile station apparatuses 1 , and supplies a scheduling result to the control unit 213 . In a case where the UL scheduling unit 219 is notified from the preamble detecting units 211 that a random access preamble has been detected, the UL scheduling unit 219 allocates the physical uplink shared channel PUSCH, and notifies the control data creating unit 221 of the allocated physical uplink shared channel PUSCH and a preamble number (sequence number).
[0126] The cell management unit 223 manages individual cells and system information about the cells (for example, configuration information about physical channels, transmission power information about individual channels, and random access information). Also, the cell management unit 223 allocates cells to the mobile station apparatus 1 , and determines a first cell, second cell, and third cell among the allocated cells. Then, the cell management unit 223 supplies system information to the control data creating unit 221 to notify the control data creating unit 221 of the system information about the allocated cells. The system information about the first cell and the second cell includes random access information (arrangement information about random access channels RACH, random access preamble generation information, and random access preamble transmission information, such as the maximum number of transmissions of a random access preamble and transmission power for the random access preamble). The system information about the third cell does not include random access information. Also, in the case of allowing the mobile station apparatus 1 to execute random access, the cell management unit 223 selects a dedicated sequence (dedicated preamble) and the position of a random access channel RACH, and supplies the selected dedicated sequence number and random access channel number to the control data creating unit 221 .
[0127] The control data creating unit 221 creates control data to be set to the physical downlink control channel PDCCH and control data to be set to the physical downlink shared channel PDSCH. The control data creating unit 221 creates control data, such as a control message including scheduling information; ACK/NACK of uplink data; a system information message including configuration information about physical channels, transmission power information about individual channels, and random access information; an initial setting message including setting information about a cell to be used (including random access information); a random access response message including a preamble number, transmission timing information, and scheduling information; a contention resolution message; and a message including a dedicated sequence number, a random access channel number, and a random access instruction.
[Description of Operation]
[0128] In this embodiment, description will be given of a cell management method including a random access restriction method. The base station apparatus 3 groups a plurality of cells into a plurality of transmission timing cell groups in each of which cells have an identical transmission timing. In the case of allocating a plurality of cells to the mobile station apparatus 1 , the base station apparatus 3 sets one of the cells in one of the plurality of transmission timing cell groups as a first cell. Also, the base station apparatus 3 sets one of the cells in each of the other transmission timing cell groups as second cells, and sets the cells other than the first and second cells as third cells.
[0129] The base station apparatus 3 is configured to permit contention based random access and non-contention based random access for the first cell. Also, the base station apparatus 3 notifies the base station apparatus 1 of update information of system information about the individual cells via the first cell, and arranges the physical uplink control channel PUCCH to be used by the mobile station apparatus 1 on the physical uplink control channel PUCCH of the first cell. The base station apparatus 3 is configured to permit non-contention based random access for the second cells. Also, the base station apparatus 3 notifies the mobile station apparatus 1 of transmission timing information via the first and second cells. The base station apparatus 3 is configured not to permit random access for the third cells. The mobile station apparatus 1 determines whether of not random access has failed in the first cell, and does not determine whether or not random access has failed in the second cells. Also, the mobile station apparatus 1 determines a radio quality error of downlink in the first cell, and does not determine a radio quality error of downlink in the second and third cells.
[0130] In this way, necessary functions are set in the order of the first cell, second cells, and third cells, and an important function is set to the first cell, so that the cells can be easily managed. Also, with this method, the restriction of random access and the management of random access failure described in the first embodiment can be performed.
[0131] The operations of the mobile station apparatus 1 - 1 and the base station apparatus 3 will be described. For example, it is assumed that the base station apparatus 3 is constituted by cells # 1 to # 5 , as illustrated in FIG. 4A , and that cells # 1 and # 2 are in the cell group of an identical transmission timing (first transmission timing cell group), cells # 3 and # 4 are in the cell group of an identical transmission timing (second transmission timing cell group), and cell # 5 is in the cell group of an identical transmission timing (third transmission timing cell group).
[0132] The mobile station apparatus 1 - 1 executes cell search, and finds one of the cells of the base station apparatus 3 . Here, it is assumed that the mobile station apparatus 1 - 1 finds cell # 2 . The mobile station apparatus 1 - 1 obtains system information about cell # 2 (physical channel configuration of the cell, transmission power information, random access information, etc.) from the physical broadcast channel PBCH of cell # 2 . Then, by using the random access information included in the system information, the mobile station apparatus 1 - 1 transmits a random access preamble to the random access channel RACH of cell # 2 for initial access. Then, the mobile station apparatus 1 - 1 obtains random access response information including transmission timing information about cell # 2 from the base station apparatus 3 , sets a transmission timing of an uplink component carrier for cell # 2 , and starts a transmission timing timer. The mobile station apparatus 1 - 1 transmits a message 3 to the base station apparatus 3 via cell # 2 . The message 3 includes the content representing initial access. Upon receiving a contention resolution from the base station apparatus 3 , the mobile station apparatus 1 - 1 ends the contention based random access procedure.
[0133] After the random access procedure has been completed, the base station apparatus 3 allocates the cells to be used by the mobile station apparatus 1 - 1 , and also sets first, second, and third cells. Here, as illustrated in FIG. 4B , the base station apparatus 3 allocates cells # 1 to # 5 to the mobile station apparatus 1 - 1 , and sets cell # 2 as a first cell, cells # 4 and # 5 as second cells, and cells # 1 and # 3 as third cells. Then, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of setting information, such as system information about the allocated cells and group information about the transmission timing cell groups. The base station apparatus 3 notifies the mobile station apparatus 1 - 1 by including random access information in the system information about the first and second cells, and by not including random access information in the system information about the third cell. That is, the base station apparatus 3 does not notify the mobile station apparatus 1 - 1 of random access information about cells # 1 and # 3 . The setting information about the first cell includes allocation information about the physical uplink control channel PUCCH.
[0134] After obtaining the system information about the individual cells and the group information about the transmission timing cell groups, the mobile station apparatus 1 - 1 sets the transmission timing of the cells in the same transmission timing cell group. Here, the mobile station apparatus 1 - 1 sets the transmission timing of cell # 2 as the uplink transmission timing of cell # 1 . After that, user data is transmitted and received between the mobile station apparatus 1 - 1 and the base station apparatus 3 via the downlink component carriers of cells # 1 to # 5 and the uplink component carriers of cells # 1 and # 2 .
[0135] In a case where the amount data transmitted from the mobile station apparatus 1 - 1 increases, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of random access instruction information for providing an instruction to execute non-contention based random access using the second cell, via the physical downlink control channel PDCCH. Here, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of the random access instruction information about cell # 4 . The random access instruction information includes a preamble number and a random access channel number. The mobile station apparatus 1 - 1 determines the preamble number. If the preamble number indicates non-contention based random access, the mobile station apparatus 1 - 1 transmits a random access preamble to the random access channel RACH of cell # 4 by using the preamble and random access channel specified by the base station apparatus 3 .
[0136] Upon detecting the random access preamble, the base station apparatus 3 calculates a transmission timing on the basis of the random access preamble, and transmits a random access response including transmission timing information to the mobile station apparatus 1 - 1 via the downlink component carrier of cell # 4 . Upon receiving the random access response, the mobile station apparatus 1 - 1 sets the transmission timing included in the random access response as the transmission timing of the uplink of cell # 4 and as the transmission timing of the uplink of cell # 3 in the same transmission timing cell group, and starts a transmission timing timer. Then, the mobile station apparatus 1 - 1 ends the non-contention based random access procedure. After that, data is transmitted and received between the mobile station apparatus 1 - 1 and the base station apparatus 3 also by using the uplink component carriers of cells # 3 and # 4 . In a case where a cell to be used for uplink transmission is further required, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of random access instruction information for providing an instruction to execute non-contention based random access using cell # 5 as the second cell, by using the physical downlink control channel PDCCH of cell # 5 .
[0137] The mobile station apparatus 1 - 1 has one transmission timing timer for each transmission timing cell group, and starts or restarts the transmission timing timer upon receiving transmission timing information. While the transmission timing timer is running, uplink synchronization is achieved (transmission timing is valid), and uplink transmission on the uplink component carriers of a target transmission timing cell group is possible. While the timer is stopped, uplink synchronization is lost (transmission timing is invalid), and uplink data transmission on the uplink component carriers of a target transmission timing cell group is impossible.
[0138] The mobile station apparatus 1 - 1 does not execute a random access procedure when receiving random access instruction information regarding a third cell. Also, the mobile station apparatus 1 - 1 does not execute a random access procedure when receiving random access instruction information for providing an instruction to execute contention based random access regarding a second cell.
[0139] In a case where uplink transmission data is newly generated in a state where there is no allocation of a physical uplink shared channel PUSCH from the base station apparatus 3 and where uplink synchronization is achieved (transmission timing is valid) or is not achieved (transmission timing is invalid), the mobile station apparatus 1 - 1 executes contention based random access as a scheduling request. At this time, the mobile station apparatus 1 - 1 selects the first cell. Here, the mobile station apparatus 1 - 1 selects cell # 2 . Then, the mobile station apparatus 1 - 1 selects one random sequence by using random access information about the first cell, generates a random access preamble, and transmits the random access preamble to the random access channel RACH of the first cell. Then, upon receiving a random access response from the base station apparatus 3 via the downlink component carrier of the first cell, the mobile station apparatus 1 - 1 sets transmission timing information included in the random access response as an uplink transmission timing of the first cell and as an uplink transmission timing of the cell in the same transmission timing group, and starts a transmission timing timer. Then, the mobile station apparatus 1 - 1 includes transmission buffer status information about the mobile station apparatus 1 - 1 in a message 3 , and notifies the base station apparatus 3 of the message 3 . The mobile station apparatus 1 - 1 ends contention based random access upon receiving a contention resolution from the base station apparatus 3 .
[0140] The base station apparatus 3 may change the first cell or second cell, in accordance with a radio channel condition or a communication status. In the case of changing the first cell, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of allocation information about the physical uplink control channel PUCCH for a new first cell and random access information about the new first cell. The mobile station apparatus 1 - 1 sets the obtained allocation information about the physical uplink control channel PUCCH and random access information, releases the radio resource of the uplink PUCCH allocated to the old first cell, and deletes random access information about the old first cell. Also, the mobile station apparatus 1 - 1 recognizes the change of the first cell by being allocated with the physical uplink control channel PUCCH.
[0141] In the case of changing the second cell, the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of random access information about a new second cell. The mobile station apparatus 1 - 1 sets the obtained random access information, and deletes random access information about the old second cell. Also, the mobile station apparatus 1 - 1 recognizes the change of the second cell by not being allocated with the physical uplink control channel PUCCH.
[0142] For example, in the case of changing cell # 2 as the first cell to cell # 1 , the base station apparatus 3 notifies the mobile station apparatus 1 - 1 of the allocation information about the physical uplink control channel PUCCH of cell # 1 and the random access information about cell # 1 . Upon receiving the allocation information about the physical uplink control channel and the random access information about cell # 1 , the mobile station apparatus 1 - 1 sets the random access information about cell # 1 , releases the radio resource of the physical uplink control channel PUCCH which has been allocated to cell # 2 , and deletes the random access information about cell # 2 .
[0143] In a case where the mobile station apparatus 1 - 1 receives random access instruction information about the first cell or second cell from the base station apparatus 3 during processing of a random access procedure, the mobile station apparatus 1 - 1 continues the random access processing which is being executed and ignores the random access instruction information received from the base station apparatus 3 , or stops the random access processing which is being executed and executes random access by using the cell specified in accordance with the random access instruction information received from the base station apparatus 3 . In this way, the mobile station apparatus 1 - 1 does not simultaneously execute a plurality of random access processing operations.
[0144] Also, regarding random access using the first cell, if the number of transmissions of a random access preamble exceeds the maximum number of transmissions, the base station apparatus 1 - 1 determines that random access has failed. However, regarding random access using the second cell, the mobile station apparatus 1 - 1 does not determine that random access has failed even if the number of transmissions of a random access preamble exceeds the maximum number of transmissions. With this configuration, the occurrence of random access failure can be suppressed.
[0145] In the above-described embodiment, description has been given of a method for restricting random accesses by permitting contention based random access and non-contention based random access for the first cell and by permitting non-contention based random access for the second cell. Alternatively, contention based random access may be random access which is based on a scheduling request, and non-contention based random access may be random access which is based on random access instruction information. That is, random accesses can be restricted by permitting random access which is based on a scheduling request and random access which is based on random access instruction information for the first cell and by permitting random access which is based on random access instruction information for the second cell.
[0146] In this way, necessary functions are set in the order of the first cell, second cells, and third cells, and an important function is set to the first cell, so that the cells can be easily managed. Also, with this method, the restriction of random access and the management of random access failure can be performed.
[0147] An embodiment of the present invention has been described in detail with reference to the drawings. The specific configuration is not limited to that described above, and various changes in design can be made without deviating from the gist of the present invention.
[0148] For the convenience of description, the mobile station apparatus 1 - 1 and the base station apparatus 3 according to the embodiment have been described by using functional block diagrams. A program for realizing the functions of the individual units of the mobile station apparatus 1 - 1 and the base station apparatus 3 or part of these functions may be recorded on a computer-readable recording medium, the program recorded on the recording medium may be caused to be read into a computer system so as to be executed, and thereby the mobile station apparatus 1 and the base station apparatus 3 may be controlled. Here, the “computer system” includes hardware, such as an OS and peripheral devices.
[0149] The “computer-readable recording medium” is a portable medium, such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in the computer system. Furthermore, the “computer-readable recording medium” includes a medium which dynamically holds a program for a short time, such as a communication line used for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and a medium which holds a program for a certain period, such as a volatile memory in the computer system serving as a server or a client in that case. The above-described program may be used for realizing part of the above-described function, and may be a program with which the above-described functions can be realized in combination with a program which has already been recorded in the computer system.
[0150] The individual functional blocks used in the above-described embodiments may be realized by an LSI, which is typically an integrated circuit. The individual functional blocks may be individually mounted on chips, or some or all of them may be integrated to be mounted on a chip. A method for integration may be realized by a dedicated circuit or a general-purpose processor, as well as an LSI. In a case where the progress of semiconductor technologies produces an integration technology which replaces an LSI, an integrated circuit according to the technology can be used.
[0151] The embodiments of the present invention have been described in detail with reference to the drawings. Specific configurations are not limited to these embodiments, and design within a scope of the gist of the present invention is included in the claims.
REFERENCE SIGNS LIST
[0000]
1 , 1 - 1 to 1 - 3 mobile station apparatus
3 base station apparatus
5 - 1 , 5 - 2 repeater
101 , 201 radio unit
103 - 1 to 103 - 5 , 203 - 1 to 203 - 5 transmission processing unit
105 - 1 to 105 - 5 , 205 - 1 to 205 - 5 reception processing unit
117 , 215 scheduling unit | A mobile station (MS) obtains a parameter, performs transmission of a preamble, and sets a counter incremented based on transmission of the preamble. The MS is able to indicate a random access problem corresponding to one transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the one transmission timing cell group, where the one transmission timing cell group being one of the plurality of transmission timing cell groups, and the MS is able to not indicate a random access problem corresponding to another transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the another transmission timing cell group, where the another transmission timing cell group being one of the plurality of transmission timing cell groups. | 7 |
This application is a Divisional Application of Ser. No. 08/907,919, filed Aug. 11, 1997, now U.S. Pat. No. 5,879,741 which is itself is a Continuation Application of Ser. No. 08/614,952, filed Mar. 12, 1996, now abandoned, which is itself a Continuation Application of Ser. No. 08/216,311, filed Mar. 23, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention relates to an apparatus and a method of forming a thin film having small residual stress and good adhesion to a substrate having the film thereon.
BACKGROUND OF THE INVENTION
It is conventionally known that as methods of forming a thin film, typically, a sputtering method, an ionized vapor deposition method, etc. are used in the PVD field and a plasma CVD method is employed in the CVD field.
FIG. 1 shows a CVD apparatus using a high-frequency glow discharge of a capacitive coupled type. A high-frequency power system ( 5 ), a high-frequency power supply electrode ( 1 ), an opposed ground electrode ( 2 ), a substrate ( 3 ) having a surface on which a thin film is formed, and a plasma region ( 4 ) generated between the flat electrodes ( 1 ) and ( 2 ) installed in parallel are designated. This manner as shown in FIG. 1 is to form a film using a self bias acting in the side of the substrate ( 3 ) installed in the side of the high-frequency power supply electrode ( 1 ).
Also, FIG. 2 shows an inductive coupled CVD apparatus. In this manner as shown in FIG. 2, a plasma region ( 4 ) is formed by applying an induction energy from a coil ( 6 ) for high-frequency excitation and ions of a material activated in the plasma region are introduced into a filmy substrate ( 3 ) by an electric field from an auxiliary electrode for applying an external bias and a thin film is formed on the flexible substrate ( 3 ). Also, this manner is to move the filmy substrate sequentially by a cylindrical roller and a guide roller and form a thin film sequentially on the substrate ( 3 ).
When a thin film having a large compressive residual stress, typically such as a thin film of diamond-like carbon, is formed using the CVD apparatus as shown in FIG. 1, force by which the formed film is warped with the surface upwardly curved to a protrusion shape is applied to the thin film since the diamond-like carbon thin film has a large compressive stress of the order of 10 10 dyne/cm 2 .
The above condition will be described in FIG. 5 . FIG. 5 (A) shows the condition in which a thin film ( 13 ) having a compressive residual internal stress is formed on a substrate ( 3 ). When the compressive residual internal stress acts on the thin film ( 13 ), the thin film ( 13 ) tends to warp as shown in the drawing. In this case, of course, a stress occurs between the thin film ( 13 ) and the substrate ( 3 ), and thereby problems such as the decrease in adhesion of the thin film ( 13 ) to the substrate ( 3 ) or the cracking or peeling of the film ( 13 ) occur.
When a flexible and filmy substrate is used as the substrate, particularly, the thin film will curl outwardly and the substrate will curl inwardly.
Also, when the CVD apparatus shown in FIG. 2 is used, the compressive residual stress in the longitudinal direction of the movement of the substrate ( 3 ) is canceled by winding the substrate. Though any significant problem does not occur in this case, the substrate will still curl after forming the film thereon due to the compressive residual internal stress in the transverse direction of the substrate ( 3 ).
The compressive residual stress in the transverse direction of the substrate ( 3 ) cannot easily be restored to its original condition even if corrections are performed later. Even if the compressive residual stress be restored to its original condition, now the stress still remains in the interface between the thin film and the substrate, and cracking, peeling, etc. are induced due to the stress. Taking the long view, therefore, the CVD apparatus in FIG. 2 is lacking in the reliability.
The above problems occur more or less in the thin film formed by the CVD (chemical vapor deposition) method.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to solve the problems of the residual stress of the thin film formed by the vapor phase method as described above.
The present invention is summarized in an apparatus of forming a thin film on a substrate by a vapor phase method, characterized in that the substrate is curved in the direction canceling of the internal stress remaining in the thin film after the formation.
In the present invention as above, the vapor phase method designates a sputtering method, an evaporation method and a CVD method. Also, all the well-known thin films such as diamond-like carbon thin film, semiconductor thin film, insulator thin film, a conductive film, etc. may be generally used as a kind of thin film.
Curving the substrate in the direction canceling the internal stress means that the substrate is previously warped in the direction opposite to the direction of the substrate itself warping due to the internal stress remaining in the thin film to be formed thereon. In this manner, when the substrate is warped due to the residual internal stress of the thin film, the previously applied warp of the substrate cancels out the warp of the thin film formed thereon and, as a result, an integrated article composed of the thin film and the substrate with no warp can be obtained.
The function of curving the substrate designates a substrate holding means or substrate carrying means for forcibly curving the substrate, and a means for curving the substrate by moving the substrate along a curved member. The present invention can be applied to all the thin films having a compressive or tensile residual internal stress.
An example of the procedures for carrying out the present invention will be described below.
(a) A residual internal stress of the thin film is formed previously measured or a degree of the curling of the substrate to be generated by forming a thin film thereon is quantitatively examined.
(b) A film is formed while providing the curvature corresponding to the deformation caused by the residual internal stress of the thin film to the substrate.
By adopting the above process, the substrate on which a flat thin film has been formed can be obtained.
The condition of the thin film obtained by utilizing the present invention will be simply indicated in FIG. 5 (B). When a thin film ( 13 ) having a compressive residual internal stress is formed on the surface of a flexible and filmy substrate ( 3 ), the substrate ( 3 ) tends to warp due to the compressive stress as shown in FIG. 5 (A). As illustrated here, warping the substrate in the direction reverse to the condition shown in FIG. 5 (A) during the filming, the stress caused by the warp of the substrate cancels out the compressive residual internal stress of the thin film formed, and the condition as indicated in FIG. 5 (B) can be realized. Further, it is important to use the radius of curvature not inducing wrinkles, flaws, etc. on the film, as the curvature to be previously applied to the substrate, during the filming.
Previously applying the stress capable of canceling the internal stress of the formed thin film to the substrate of which the surface is to be coated with the film, prior to the filming, the internal stress of the thin film can be canceled and thus the deformation of the substrate caused by forming the thin film thereon (that is, the curling phenomenon occurring in a flexible and filmy substrate) can be prevented or reduced beforehand.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects of the invention will be seen by reference to the description taken in connection with the accompanying drawings, in which:
FIG. 1 is a sectional view of the internal structure of a capacitive coupled high-frequency plasma CVD apparatus of a parallel plate type;
FIG. 2 is a schematic illustration of a inductive coupled high-frequency plasma CVD apparatus;
FIG. 3 is a sectional view of the internal structure in the proximity of electrodes of a thin film of diamond-like carbon forming apparatus for carrying out the embodiments of the present invention;
FIG. 4 is a sectional view of the internal structure in the proximity of electrodes of the same diamond-like carbon thin film forming apparatus for carrying out the embodiments of the present invention; and
FIG. 5 is a schematic sectional view comparing the condition of a conventional film (A) with the condition of the film (B) obtained by the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the embodiments described below represent examples in which a thin film of diamond-like carbon is formed on a filmy substrate, it is to be understood that the material of the substrate is not limited as long as a material capable of providing the curvature is used and further the present invention may be utilized in forming a thin film on a substrate, if an internal stress remaining in the thin film formed causes some troubles. Though the embodiments described below represent the examples of forming a thin film having a compressive residual internal stress, the curvature may be applied inversely when a thin film having a tensile residual internal stress is to be formed.
EXAMPLE 1
One embodiment of the present invention will be described with reference to FIGS. 3 and 4.
FIGS. 3 and 4 show a high-frequency plasma CVD apparatus having a parallel plate structure of a roll-to-roll type and capacitive coupled type. FIG. 4 is a sectional view of the apparatus stereographically seen from the oblique direction. FIG. 3 is a sectional view of the apparatus as seen from the direction perpendicular to the direction (indicated by arrow ( 12 )) feeding of a filmy substrate.
Referring to FIGS. 3 and 4, a high-frequency power system ( 5 ) using 13.56 MHz, a filmy flexible substrate ( 3 ), a high-frequency power supply electrode ( 1 ), an opposed ground electrode ( 2 ), a plasma region ( 4 ), and the direction ( 12 ) feeding of substrate are designated.
In this apparatus, the properties of the film to be formed are determined by controlling the self bias acting in the side of the high-frequency power supply electrode ( 1 ), and the apparatus is driven by a simple construction system in which it is not necessary to specially apply a bias etc. from the outside. Of course, another construction in which a DC bias is applied from the outside may be adopted.
In the Example 1, a PET (polyethylene terephthalate) with a thickness of 10 μm, a width of 130 mm and a length of 90 m was used as the filmy substrate ( 3 ).
The high-frequency power supply electrode ( 1 ) has a width of 180 mm, a length of 250 mm and a thickness of 20 mm. As shown in FIG. 3, a radius of curvature of 360 mm is provided in the transverse direction (the horizontal direction of the paper of FIG. 3) of the electrode ( 1 ), and the electrode ( 1 ) is curved.
Also, the opposed ground electrode ( 2 ) has the same size as the high-frequency power supply electrode ( 1 ) and the radius of curvature of 360 mm equal to that of the electrode ( 1 ) is provided in the same direction as the electrode ( 1 ).
A thin film is formed while the filmy substrate ( 3 ) is moved in the direction indicated by the arrow ( 12 ) in FIG. 4 at a speed of 50 m/min. During the filming, the substrate ( 3 ) is curved according to the curvature of the high-frequency power supply electrode ( 1 ) as shown by ( 3 ) in FIG. 3 since the substrate ( 3 ) travels along the high-frequency power supply electrode ( 1 ).
In this manner as stated above, previously curving the substrate in the. direction reverse to the warping direction of the thin film ( 13 ) of FIG. 5 (A) which tends to warp as shown in the same FIG. 5 (A), the residual stress of the thin film ( 13 ) formed can be canceled.
Using the plasma CVD apparatus constructed as described above, a thin film of diamond-like carbon with a thickness of 500 A was formed on the substrate ( 3 ).
The conditions for forming the diamond-like carbon thin film are the same as those for forming the same thin film, but having a compressive residual internal stress of 1.7×10 10 dyne/cm 2 , using the conventional apparatus as shown in FIG. 1 .
Concretely, the conditions for forming the film were as follows:
Input power:
1.5 Kw
Pressure of forming film:
80 Pa
Substrate gap:
15 mm
Substrate temperature:
no heating
Gas for forming film:
C 2 H 6 + H 2 (200 sccm/50 sccm)
As a result of a visual examination of the film recovered by a winding roll, a flat condition before forming the thin film was maintained, and concerning physical properties of the diamond-like carbon thin film, the peeling did not occur at all and the entire uniformity was obtained. Also, with reference to the hardness, though the measurement of the Vickers hardness of the film formed could not be performed due to problems of the substrate and the film thickness. However, there occurred no problem of the durability of the film in the alternative test where a steel ball was moved thereon under pressure. Thus, the film formed was satisfactory.
The reason why the above result was obtained is that when the diamond-like carbon thin film having a compressive stress is formed on the surface of the substrate ( 3 ) traveling along the curvature of the electrode ( 1 ) during the filming, the diamond-like carbon thin film tends to warp in the direction reverse to the warp of the substrate caused by the internal residual stress and as a result, the both warps are canceled out and the condition of little presence of the residual internal stress is realized.
COMPARATIVE EXAMPLE 1
In Comparative Example 1, a thin film of diamond-like carbon with a thickness of 500 Å is formed using a conventionally wellknown high-frequency plasma CVD apparatus as shown in FIG. 1 in the same film forming conditions as in the Example 1. With reference to using a film made of PET as the substrate or the size and shape of the electrodes, Comparative Example 1 is performed in the same conditions as in the Example 1. That is, Comparative Example 1 is the same as Example 1, except that a curvature is not provided to the electrode and the filmy substrate is not curved in the curvature similar to the curvature according to the electrode to which the curvature is provided.
In the thin film of diamond-like carbon obtained by Comparative Example 1, no peeling from the film occurred. However, the film itself curved noticeably and the film had a shape difficult to spontaneously restore to the flat condition if not corrected.
Also, in the durability test where a steel ball is moved on the film under pressure, the film partially peeled at the interface between the film and the substrate.
This means that a large stress occurred between the diamond-like carbon thin film and the substrate.
COMPARATIVE EXAMPLE 2
Comparative Example 2 is performed in the same conditions as in Example 1 except that the radius of curvature of the high-frequency power supply electrode ( 1 ) is 180 mm or the same as the width of the electrode ( 1 ).
In Comparative Example 2, when a thin film of diamond-like carbon was formed at a thickness of 500 Å, a restoring force of the film to which the curvature was forcibly provided was too strong during the formation, and after the formation, microcracks occurred and also the film partially peeled with the lapse of time, and hence the effect of compensating, that is, neutralizing the stress of the thin film formed was not obtained at all.
Comparative Example 2 concluded that in order to cancel the compressive residual internal stress remaining in the diamond-like carbon thin film, too large stress applied by previously curving the substrate prior to the filming caused the problem because of the remaining of the stress applied to the substrate.
Optimum Values of Radius of Curvature
The following Table 1 shows the results of the formation of a thin film of diamond-like carbon on the substrate ( 3 ), varying the curvature applied to the pair of substrates ( 1 ) and ( 2 ) and using the conditions of Example 1.
TABLE 1
Radius of
curvature
(mm)
Result
Condition of coated film
280
poor
Peeling of coated film partially
occurred due to the restoring force of
film.
320
good
Film was substantially flat and no
peeling of coated film occurred.
360
good
Film was substantially flat and no
peeling of coated film occurred.
400
good
Film was substantially flat and no
peeling of coated film occurred.
440
poor
Due to stress of coated film, the film
slightly curled inwardly but no peeling
occurred.
(For electrode width of 180 mm and electrode length of 250 mm)
Table 1 concludes that in the film forming conditions as shown in the Example 1, when the diamond-like carbon thin film having a compressive residual internal stress of about 1.7×10 10 dyne/cm 2 is formed on a PET film substrate, the stress remaining in the diamond-like carbon thin film can be canceled by providing a radius of curvature of about 320 to 400 mm to the PET film substrate (thickness of 10 μm, width of 130 mm and length of 90 m) in the conditions as shown by ( 3 ) in FIG. 3 .
EXAMPLE 2
Example 2 indicates an example in which in the same conditions as in Example 1, expander rolls are additionally located before and after the film forming region formed by parallel plate type electrodes through which the filmy substrate travels. On the substrate is formed a thin film of diamond-like carbon having a thickness of 500 Å.
The expander rolls are an apparatus for removing deflection or wrinkles of the film by applying the tension in the transverse direction of the film.
Example 2 proved that even slight wrinkles were completely removed by expanding the filmy substrate before forming the thin, film thereon by the expander rolls and also the flatness of the filmy substrate on which the thin film was formed could be improved.
Further, physical properties of the diamond-like carbon thin film substantially similar to the above Example 1 were obtained.
When the traveling system of the substrate is long, the use of the expander rolls is extremely effective.
EXAMPLE 3
Example 3 indicates an example in which in the conventional plasma CVD apparatus as shown in FIG. 1, the same curvature of 360 mm as shown in FIG. 3 is provided to the filmy substrate ( 3 ). In the same manner as indicated in FIG. 4, the substrate ( 3 ) was moved so as to pass from one side of the plasma region ( 4 ) to the other side thereof and a thin film was formed.
Example 3 is performed in a manner of forming a thin film by providing the predetermined curvature only to the substrate in the pair of electrodes having a conventionally well-known parallel plate type structure. Example 3 is performed on the premise that a flexible tape is used as the substrate. Further, the tape substrate shall continuously pass between the electrode ( 1 ) and the electrode ( 2 ). In this case, the substrate is curved so that the stress a cts in the transverse direction (perpendicular to the curving direction) of the substrate through a substrate conveyance system and the film is formed, and thereby the effect similar to the Example 1 can be obtained.
Example 3 is characterized in that though it requires the conveyance mechanism for providing the curvature to the substrate ( 3 ), the conventional parallel plate type electrodes can be used as the electrodes.
The condition of the thin film of diamond-like carbon obtained by Example 3 was similar to that of the thin film obtained by Example 1. The thin film formed on the substrate neither peeled from the substrate nor cracked. The substrate thus coated with the thin film did nor warp. Hence, the thin film formed on the substrate was good.
EXAMPLE 4
Example 4 indicates an example in which in the conventionally well-known inductive coupled type plasma CVD apparatus as shown in FIG. 2, the surface of the cylindrical can roller ( 8 ) has been made to be curved inwardly while the surface of the guide roller has been made to be curved outwardly and thereby a certain radius of curvature is provided in the transverse direction of the substrate ( 3 ) in the region in which a thin film of diamond-like carbon is to be formed and the film is formed.
Using the construction of Example 4, the residual compressive internal stress of the thus-formed thin film of diamond-like carbon can be canceled. The thin film formed is flat and is neither peeled from the substrate nor cracked.
Also, when the formed thin film has a tensile stress therein, the above construction may be reversed correspondingly. That is, the surface of the cylindrical can roller ( 8 ) is made to be curved outwardly while the surface of the guide roller is made to be curved inwardly and thereby the internal stress of the thin film can be canceled.
According to the present invention as described above, a flexible substrate is previously processed in such a way that it may have a curvature for generating the stress in the direction canceling the residual stress of a thin film to be formed thereon prior to the filming, and thereby the stress caused by the formation of a thin film on the substrate can be controlled so as to reduce and further neutralize it, that is, so as to approximate as much as possible the interface stress to zero. Hence, a flat thin film can be formed on the substrate, while maintaining the physical properties of the film and also the good adhesiveness thereof with the substrate. | When a thin film is formed on a flexible and filmy substrate by a vapor phase method, the substrate is prevented from warping to be caused by the internal stress remaining in the thin film. When the thin film is formed by the vapor phase method, the substrate is previously curved so that the stress acts in the direction canceling the internal stress remaining in the thin film to be formed prior to the filming. Accordingly, the stress of the curved substrate cancels out the stress remaining in the thin film formed on the substrate. The substrate having a thin film formed thereon is not warped, the stress in the interface between the thin film formed and the substrate is removed, and the thin film has no cracks to be caused by the stress. | 2 |
FIELD OF INVENTION
[0001] The present invention relates to the treatment of peptic ulcers. In particular, the present invention provides methods and compositions for the treatment of peptic ulcers. In addition, the present invention provides a method of reducing gastric acid secretion in a subject.
BACKGROUND
[0002] Peptic ulcers are one of the most prevalent gastrointestinal disorders. They are caused by a number of factors including Heliobacter pylori infection, certain pharmaceuticals such as non-steroidal anti-inflammatory drugs (NSAIDs), stress and diet.
[0003] Typical treatments include administration of antibiotics together with proton pump inhibitors or H 2 -receptor antagonists, which help to raise the gastrointestinal pH level by inhibiting gastric acid secretion. However, existing treatments can have deleterious side effects. Therefore, there remains a need to provide improved methods of treatment and prevention of these conditions.
[0004] Garlic ( Allium sativum ) and onion ( Allium cepa ) are among the oldest of all cultivated plants and have important dietary and medicinal roles (Block, 1985). Khosla and co-workers have shown garlic oil to be protective against ethanol-induced gastric ulcers in rats (Khosla et al., 2004). The protective roles of raw and boiled garlic and onion extracts against ethanol-induced gastric ulcers and gastric acid secretion was previously investigated by the present inventors (Amir et al., 2011).
SUMMARY OF INVENTION
[0005] In a first aspect, the present invention provides a method of treating or preventing peptic ulcers comprising administering to a subject a therapeutically effective amount of at least one of allyl sulphide, allyl disulphide, quercetin and a combination thereof.
[0006] Preferably, the active compound (allyl sulphide, allyl disulphide, quercetin or a combination thereof) is administered alone or in combination with one or more pharmaceutically acceptable carriers or excipients.
[0007] In one preferred embodiment, the active compound is allyl sulphide. In another preferred embodiment, the active compound is allyl disulphide. In yet a further preferred embodiment, the active compound is quercetin.
[0008] Preferably, the subject is a mammal. More preferably, the subject is a human.
[0009] Administration may be carried out by any suitable route. In preferred embodiments, the administration is carried out via the oral route.
[0010] Preferably the therapeutically effective amount ranges from about 10 mg per kg body weight (mg/kg) to about 100 mg/kg, and preferably from about 30 mg/kg to about 80 mg/kg, and more preferably, from about 40 mg/kg to about 60 mg/kg and still more preferably about 50 mg/kg. In certain embodiments, the therapeutically effective amount is 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 mg per kg body weight.
[0011] In a particularly preferred embodiment, allyl sulphide is administered orally at 50 mg per kg body weight. In another particularly preferred embodiment, allyl disulphide is administered orally at 10 mg per kg body weight. In a final particularly preferred embodiment, quercetin is administered orally at 50 mg per kg body weight.
[0012] In a second aspect, the present invention provides method of reducing gastric acid secretion in a subject, the method comprising administering a therapeutically effective amount of at least one of allyl sulphide, allyl disulphide, quercetin and a combination thereof.
[0013] Preferably, the active compound (allyl sulphide, allyl disulphide, quercetin or a combination thereof) is administered alone or in combination with one or more pharmaceutically acceptable carriers or excipients.
[0014] In one preferred embodiment, the active compound is allyl sulphide. In another preferred embodiment, the active compound is allyl disulphide. In yet a further preferred embodiment, the active compound is quercetin.
[0015] Preferably, the subject is a mammal. More preferably, the subject is a human.
[0016] Administration may be carried out by any suitable route. In preferred embodiments, the administration is carried out via the oral route.
[0017] Preferably the therapeutically effective amount ranges from about 10 mg per kg body weight (mg/kg) to about 100 mg/kg, and preferably from about 30 mg/kg to about 80 mg/kg, and more preferably, from about 40 mg/kg to about 60 mg/kg and still more preferably about 50 mg/kg. In certain embodiments, the therapeutically effective amount is 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 mg per kg body weight.
[0018] In a particularly preferred embodiment, allyl sulphide is administered orally at 50 mg per kg body weight. In another particularly preferred embodiment, allyl disulphide is administered orally at 10 mg per kg body weight. In a final particularly preferred embodiment, quercetin is administered orally at 50 mg per kg body weight.
[0019] In a further aspect, there is provided allyl sulphide for use in the treatment of peptic ulcers.
[0020] In yet a further aspect, there is provided allyl disulphide for use in the treatment of peptic ulcers.
[0021] In a still further aspect, there is provided quercetin for use in the treatment of peptic ulcers.
DESCRIPTION OF DRAWINGS
[0022] The present invention will be further understood by reference to the attached drawings, in which:
[0023] FIG. 1 shows the effect of allyl disulfide (onion source) on histamine stimulated gastric acid secretion from rat stomach in vivo.
[0024] FIG. 2 shows the effect of allyl sulfide (garlic source) on histamine stimulated gastric acid secretion from rat stomach in vivo.
[0025] FIG. 3 shows the effect of quercetin (onion source) on histamine stimulated gastric acid secretion from rat stomach in vivo.
[0026] FIG. 4 shows the effect of allyl disulfide (onion source) on gastric ulcer formation in rat stomachs.
[0027] FIG. 5 shows the effect of allyl sulfide (garlic source) on gastric ulcer formation in rat stomachs.
[0028] FIG. 6 shows the effect of quercetin (onion source) on gastric ulcer formation in rat stomachs.
DETAILED DESCRIPTION
[0029] Although onion and garlic extracts have previously been shown by the present inventors to have a protective effect against ethanol-induced gastric ulcers in vivo, the specific active compounds responsible for this effect have not been identified until now. Onion and garlic both contain a host of potentially biologically active compounds, some of which may have undesirable effects, including but not limited to unpleasant odours or tastes. Furthermore, though plant extracts may be safer than synthetic chemicals in certain circumstances, they are not as easily standardized and therefore it may be more difficult to obtain regulatory clearance for such extracts. Administration of specific active compounds at controlled doses is therefore advantageous over the use of plant extracts.
[0030] The present invention provides a method of treating or preventing peptic ulcers comprising administering to a subject a therapeutically effective amount of allyl sulphide, allyl disulphide, quercetin or a combination thereof.
[0031] The term “peptic ulcer” is generally intended to mean any ulcer of the gastrointestinal tract. These may include ulcers of the stomach (also termed gastric ulcers), duodenum, jejunum (also termed middle intestine or mid-gut), ileum or cecum. Ulcers arise due to a number of factors including Heliobacter pylori infection, certain pharmaceuticals such as non-steroidal anti-inflammatory drugs (NSAIDs), stress and diet. In the present application the term peptic ulcer is intended to encompass ulcers due to any cause.
[0032] The present invention also provides a method of reducing gastric acid secretion in a subject, the method comprising administering an effective amount of allyl sulphide, allyl disulphide, quercetin or a combination thereof.
[0033] The phrase “reducing stomach acid secretion” refers to a lowering of acid output by the cells lining the stomach.
[0034] Allyl sulphide, also referred to as allyl sulfide, diallyl sulphide or diallyl sulfide, is an organosulfur compound derived from some members of the Allium family, such as onion ( Allium cepa ). It is commercially available from a number of suppliers.
[0035] Allyl disulphide, also referred to as allyl disulfide, diallyl disulphide or diallyl disulfide, is an organosulfur compound derived from garlic and some other members of the Allium family. It is commercially available from a number of suppliers.
[0036] Quercetin is a plant-derived flavonoid found in a number of different plant groups, including members of the Allium family. It is commercially available from a number of suppliers.
[0037] Preferably, the subject is a mammal. More preferably, the subject is a human.
[0038] In preferred embodiments, the administration is carried out via the oral route. Preferably the therapeutically effective amount ranges from about 10 mg per kg body weight (mg/kg) to about 100 mg/kg, and preferably from about 30 mg/kg to about 80 mg/kg, and more preferably, from about 40 mg/kg to about 60 mg/kg and still more preferably about 50 mg/kg. In certain embodiments, the therapeutically effective amount is 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 mg per kg body weight.
[0039] In a further aspect, there is provided allyl sulphide for use in the treatment of peptic ulcers.
[0040] In yet a further aspect, there is provided allyl disulphide for use in the treatment of peptic ulcers.
[0041] In a still further aspect, there is provided quercetin for use in the treatment of peptic ulcers.
[0042] Allyl sulphide, allyl disulphide, quercetin are all naturally derived compounds and are expected to be well tolerated in vivo, with few or no deleterious side effects.
[0043] The invention will be further understood by reference to the following non-limiting example.
EXAMPLES
Materials and Methods
[0044] Male Wistar rats (weighing 200-225 g) were fasted for 24 hours in wire mesh cages to avoid coprophagy. The rats were obtained from the animal facilities of the Faculty of Medicine and Health Sciences of the United Arab Emirates (UAE) University. Materials
[0045] Onion and garlic compounds (Quercetin, Cat # Q4951,Diallyl sulfide, Cat # A35801, Allyl disulfide, Cat# W202800) were obtained from the from Sigma-Aldrich Chemical Company (Sigma Chemical Co., St. Louis, Mo., USA).Hydrochloric acid (HCl), ethanol, and histamine were obtained from Sigma (St Louis, Mo.).
Example 1
Gastric Acid Secretion Measured In Vivo
[0046] Groups of six rats were used for the experiment. Rats were initially anesthetized with urethane (1.5 g/kg) intraperitoneally. Following general anesthesia, a laparotomy was immediately performed followed by the insertion of a polyethylene tube at the pyloric end of the stomach. This tube was used to collect exudates from the stomach. An orogastric tube was inserted in the stomach via the esophagus. This tube was used to perfuse the stomach with saline (pH 7) at a constant rate of 7 mL/min at 37° C. Following perfusion, effluent samples were collected and titrated against 0.01 M NaOH every 15 minutes for acid secretion. After basal acid output for 1 hour, either saline, quercetin (50 mg/kg,), or diallyl sulfide (50 mg/kg), or allyl disulfide (10 mg/kg) at neutral pH was given orally and 30 minutes later, histamine (2 mg/kg) was administered as a bolus injection. Acid output was monitored continuously for 2 hours thereafter. The acid output was calculated and expressed as μmol (15 min −1 ). This study had an ethical clearance from the Ethical Committee of the UAE University.
Results
[0047] The results of the in vivo gastric acid secretion tests are shown in table 1. FIGS. 1 , 2 and 3 show the effect of allyl disulfide (onion source), allyl sulphide (garlic source) and quercetin (onion source), respectively, on histamine stimulated gastric acid secretion from rat stomach in vivo.
[0048] As can be seen from the figures, rats treated with allyl disulfide, allyl sulphide or quercetin and then challenged with histamine show reduced acid output compared to the histamine control.
[0000]
TABLE 1
Results of in vivo acid secretion test
Time (min)
Group
0
30
45
60
75
90
105
120
135
150
Control
Mean
1.75
2.2
2.45
3.162
4.448
7.891
3.97
1.85
1.362
1.005
N
6
6
6
6
6
6
6
6
6
6
Std.
0.612
0.566
0.903
1.175
1.141
3.584
1.512
0.731
0.428
0.012
Dev.
Std.
0.25
0.231
0.369
0.48
0.466
1.463
0.617
0.298
0.175
0.005
Error
Allyl di
Mean
2.154
3.514
2.458
2.085
2.701
2.77
2.648
1.431
1.286
1.34
sulfide
N
7
7
7
7
7
7
7
7
7
7
10 mg/kg
Std.
0.989
0.871
1.384
0.94
1.811
2.018
3.081
0.294
0.368
0.452
Dev.
Std.
0.374
0.329
0.523
0.355
0.685
0.763
1.165
0.111
0.139
0.171
Error
Allyl
Mean
1.926
3.328
2.023
1.742
1.901
1.627
1.761
1.883
2.301
1.525
sulfide
N
7
7
7
7
7
7
7
7
7
7
50 mg/kg
Std.
1.345
2.491
0.74
0.548
0.796
0.677
1.069
1.11
1.384
0.453
Dev.
Std.
0.508
0.941
0.28
0.207
0.301
0.256
0.404
0.42
0.523
0.171
Error
Quercetin
Mean
1.633
3.323
1.299
5.507
2.579
1.84
1.868
2.213
1.927
1.497
50 mg/kg
N
6
6
6
6
6
6
6
6
6
6
Std.
0.398
1.154
0.467
2.398
1.275
0.718
0.937
0.799
0.644
0.503
Dev.
Std.
0.162
0.471
0.19
0.979
0.521
0.293
0.383
0.326
0.263
0.206
Error
Example 2
Antiulcer Activity
[0049] Rats were divided into groups of six to seven animals for each experiment. Each group received either neutral pH physiologic saline (1 mL) or water extract of either quercetin, diallyl sulfide or allyl disulfide (1 mg/kg, 10 mg/kg, 50 mg/kg or 100 mg/kg; six rats for each dose) by gastric gavage. Two additional comparison groups received either the proton pump inhibitor Lansoprazole (10 mg/kg) or the H 2 -receptor antagonist Ranitidine (20 mg/kg). After 30 minutes of the treatment, 1 mL of acidified ethanol (60% ethanol with 150 mM HCl), an ulcerogenic agent, was administered orally to the animals. The animals were sacrificed 1 hour later by increasing the dose of the anaesthesia. The abdomen was incised, and the stomachs removed, cut open along the greater curvature, and rinsed with saline to remove any adherent particles and mucus. The open stomach was spread on a sheet of cork so as to have a clear view of gastric lesions in the gastric mucosa. The total lengths of hemorrhagic lesions, which were approximately 1 mm in length and formed in the glandular portion of the gastric mucosa, were taken as ulcer index. An observer who was unaware of the drug treatments confirmed the ulcer index. The percentage reduction of the ulcer index in the drug-treated groups was calculated from the saline treated groups. The use of 60% ethanol in 150 mM HCl to produce an ulcerogenic effect was based on earlier observation that ethanol 50% and over provided a reproducible model of gastric damage.
Results
[0050] The results of the antiulcer activity test are shown in table 2. FIGS. 4 , 5 and 6 show the effect of allyl disulfide (onion source), allyl sulphide (garlic source) and quercetin (onion source), respectively, on on gastric ulcer formation in the rat model.
[0051] Rats treated with either quercetin, diallyl sulfide or allyl disulfide show significantly reduced ulcer index compared to the control. The ulcer index is comparable to treatment with Lansoprazole or Ranitidine.
[0000]
TABLE 2
Results of antiulcer test
Ulcer Index
Dose
Std.
Std. Error
Group
(mg/kg)
Mean
N
Deviation
of Mean
Control
0
95.00
7
14.84
5.61
Lansoprazole
10
13.00
6
24.31
9.93
Ranitidine
20
28.50
6
29.06
11.86
Allyl sulfide
1
114.83
6
51.91
21.19
(Garlic Source)
10
72.33
6
21.13
8.62
50
5.50
6
7.48
3.05
100
13.00
6
13.37
5.46
Allyl disulfide
1
11.67
6
9.50
3.88
(Onion Source)
10
0.00
6
0.00
0.00
50
8.33
6
16.02
6.54
100
11.00
6
19.19
7.84
Quercetin
1
34.00
6
14.93
6.09
(Onion Source)
10
34.00
6
25.09
10.24
50
21.83
6
17.15
7.00
100
31.17
6
27.45
11.21
[0052] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Moreover, all embodiments described herein are considered to be broadly applicable and combinable with any and all other consistent embodiments, as appropriate.
[0053] The disclosures of any and all publications cited herein are hereby incorporated by reference in their entireties.
REFERENCES
[0054] Amir N, Al Dhaheri A, Al Jaberi N, Al Marzouqi F, Bastaki S M A. Comparative effect of garlic ( Allium sativum ), onion ( Allium cepa ), and black seed ( Nigella sativa ) on gastric acid secretion and gastric ulcer. Research and Reports in Medicinal Chemistry 2011:1 3-9.
[0055] Block E. The chemistry of garlic and onion. Sci Amer. 1985; 252:114-119.
[0056] Khosla P, Karan R S, Bhargaya V K. Effect of garlic oil on ethanol-induced gastric ulcers in rats. Phytother Res. 2004; 18 (1):87-91. | The present invention relates to the treatment of peptic ulcers. In particular, the present invention provides methods and compositions for the treatment of peptic ulcers. In addition, the present invention provides a method of reducing gastric acid secretion in a subject. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a low temperature, single side, multiple step orientation dependent etching process for the fabrication of three dimensional structures from silicon, and more particularly to the use of this process for the mass production of ink jet printheads.
2. Description of the Related Art
In the manufacture of semiconductor structures, it is frequently desirable to generate large recesses or holes in association with relatively shallow recesses, which may or may not interconnect. For example, an ink jet printhead may be made of a silicon channel plate and a heater plate. Each channel plate has a relatively large ink manifold/reservoir recess or opening and a set of parallel, shallow, elongated channel recesses connected to the reservoir at one end and open at the other end. When aligned and bonded with a heater plate, the recesses in the channel plate become the ink reservoir and the ink channels, as described more fully in U.S. Pat. No. 4,601,777 to Hawkins et al, the disclosure of which is incorporated herein by reference.
In such printheads, it is frequently desirable to form a relatively large or deep reservoir, which is often etched completely through a 10-30 mil thick <1-0-0> wafer, and small or shallow channels, which may be only 1-5 mils deep. One manner of forming such channel plates is by a one step method in which the reservoir and channels are patterned in a single plasma silicon nitride masking layer. The drawback of this method is that the channels are etched for the same length of time as the much larger reservoir and through-etched fill hole. This can result in loss of dimensional control because of the increased probability of the channel intercepting a defect in the wafer crystal. Also, the long etch time can cause the channel width to grow or in crease if the pattern is not accurately aligned with the <1-1-0> plane of the wafer. Another critical drawback of the single step process is the potential for intra-channel width variation resulting from slicing the wafer off the <1-0-0> axis. If there is an off axis condition in the plane of the wafer, long duration etching is likely to form channels wider at one end than the other or non-symmetrical about a centerline.
One method for overcoming the disadvantages of the single step process involves forming the channels and the reservoir in separate etching steps and then subsequently joining them by a variety of methods, such as isotropic etching, machining the silicon material between the reservoir and the channel, or use of a thick film layer on the heater plate that is patterned and etched to form ink flow bypasses. Generally, such a structure is formed by etching a plurality of reservoirs in a <1-0-0> silicon wafer first, and then accurately aligning the channels to the edge of the reservoir in a second lithography step, followed by etch mask delineation and a second short orientation dependent etching (ODE) step, sufficient to etch the depth of the plurality of associated channels. An advantage of such a process is enhanced control of channel dimensioning because the mask defining the channels will be undercut about one-tenth as much as would be the case when the channels and the reservoir are delineated simultaneously. The problem with such a two-step process is that it is difficult to do a second lithography step with an ODE etched wafer because of the large steps and/or etched through holes resulting from the first etching step. The resulting resist mask is nonuniform and this results in a nonuniformity of fine structures, such as the ink jet channels.
There is another two step process for forming the reservoir and the channels in a channel wafer by etching. This process is disclosed in U.S. Pat. No. 4,863,560 to Hawkins, the disclosure of which is incorporated herein by reference. In this process, the reservoir and any necessary throughholes are formed through a coarse silicon nitride mask as the wafer undergoes a relatively a long length etching process. Then the nitride mask is stripped to expose a previously patterned high temperature silicon oxide masking layer that is used in a subsequent, shorter duration, channel etching step. This process avoids the channel width variation problems associated with the previously described single step process, as the channels are formed during a very short etch duration step. The short etch time assures that rotational problems or taper resulting from mask misalignment are not likely to arise. However, the oxide masking layer for channel etching is a high temperature thermal oxide process, usually carried out at temperature of about 1100° C., which can generate a high concentration of oxygen precipitate defects in the wafer and disruption of the crystal lattice. Such defects can cause loss of dimensional control, especially of the channels, and result in unusable channel plates. Also, the oxide layer is subject to considerable erosion in some anisotropic etches, for example, potassium hydroxide.
U.S. Pat. No. 4,063,271 to Bean et al discloses the use of low temperature oxides as a masking material for ODE separation of epitaxial layers forming semiconductor devices but does not disclose the use of such a material in the formation of large and fine structures in a silicon wafer.
U.S. Pat. No. 4,507,853 discloses the use of a low temperature oxide layer, usually in conjunction with a high temperature oxide layer, to insulate an element of a semiconductor from a metal conductor strip. The patent does not disclose formation of large and fine structures in a silicon wafer by such techniques.
U.S. Pat. No. 4,238,683 shows fabrication of gates of a silicon semiconductor by deposition of a silicon nitride layer followed by deposition of a low temperature oxide layer. The oxide and nitride layers are etched to form openings. The oxide layer is then partially removed to bare the nitride layer for subsequent removal. There is no disclosure of formation of fine and large structures in the silicon wafer.
U.S. Pat. No. 4,849,344 discloses the deposition of low temperature oxide for filling shallow grooves or trenches between epitaxial islands. The grooves are lined with a thin, thermally grown isolation oxide layer. The patent does not disclose the formation of fine and large structures by the use of low temperature oxides.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to improve processes for forming fine structures in the surface of silicon wafers by etching processes.
It is another object of this invention to produce both large and fine structures on silicon wafers by etching.
It is a further object of the invention to improve uniformity of channel formation in ink jet channel plates and avoid potential defects arising from high temperature mask formation.
These and other objects are achieved, and the shortcomings discussed above are overcome, by using a single side, two step, process wherein a first pattern incorporating fine structure(s) and large structure(s) are removed from layers of a first fine masking layer and a second, protective, masking layer previously deposited on the wafer. A coarse masking layer is then deposited and a second pattern, within the boundaries of the first pattern is removed therefrom. The applications of the first, second, and third masking layers are carried out at temperatures below the range in which oxygen precipitates are formed in the wafer. The wafer is etched through the second pattern to form a precursor to the large structure. The coarse masking layer, and optionally the protective masking layer, are stripped prior to final etching, during which fine structures are formed in the wafer and the large structure is fully etched. The protective masking layer protects the first masking layer from removal at the time the third masking layer is removed, prior to the final etching step.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein:
FIG. 1 is a partial plan view of a channel plate which has undergone a first etching step;
FIG. 2 is a partial plan view of a channel plate which has undergone a second etching step;
FIG. 3A is a partial cross-sectional view of a wafer to be formed into a channel plate and having first and second masking layers applied;
FIG. 3B is a partial cross-sectional view of a subsequent step in the process showing the removal of portions of the first and second masking layers to form a first pattern incorporating fine and large structures;
FIG. 3C is a partial cross-sectional view of a further step in the process in which a third masking layer is applied to the intermediate fabrication of FIG. 3B;
FIG. 3D is a partial cross-sectional view of a further step in the process in which a second pattern is formed in the third masking layer and a precursor structure of the large structure is formed;
FIG. 3E is a partial cross-sectional view of the wafer after the third masking layer has been removed and the wafer has been subjected to the second etching step;
FIG. 3F is a partial sectional view of the wafer after removal of all masking layers; and
FIG. 4 is a side sectional view of an assembled ink jet printhead subunit utilizing a channel plate made in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is an idealized representation of a step in the process of fabricating an ink jet printer channel plate utilizing the teachings of the present invention. FIG. 1 shows a portion 10 of a planar wafer made from, for example, silicon. As will be discussed more fully hereinafter, the silicon wafer has had first and second masking layers applied to it which have been exposed to known processes for delineating and removing portions thereof to form a first mask pattern 12, which first pattern 12 includes a reservoir portion 14 and a plurality of channels 16. The portions 14 and 16 can form a mask pattern of structures in a final desired form or etch pattern in the wafer. Preferably, the pattern incorporates a separation between reservoir and the channels by a land 28, for purposes hereafter described. The first pattern 12 is shown in phantom view as it has been overlaid with a third masking layer having a second pattern 18, which has been formed in the third masking layer as hereinafter described. The second mask pattern 18 falls within the boundaries of the first mask pattern 12. After formation of the second mask pattern 18, the wafer is subjected to an etching process, such as ODE, to form a precursor structure 20. FIG. 1 illustrates the formation of such a precursor structure 20 after exposure of the wafer to a relatively long duration etching process. The precursor structure coincides with a large or relatively deep structure to be formed in or through the wafer. In the illustrated embodiment, this large portion of the structure is the reservoir portion 14 which, advantageously, extends entirely through the wafer and forms a through hole 22 in the wafer.
FIG. 2 illustrates completion of the formation of a gross structure, such as reservoir 14, and fine structures, such as channels 16, as a result of a second ODE process, to complete formation of the structures in the first pattern 12. FIGS. 1 and 2 are idealized representations of intermediate and finished forms of structures in the wafer portion 10. In a commercial fabrication arrangement, the reservoir would extend in transverse directions of the wafer portion 10 and would include many more channels 16. In addition, auxiliary structures such as locating holes would also be formed in the wafer portion 10. See U.S. Pat. No. 4,601,777. In the two step etching process used, it is common for a step or ledge 21 to be formed in the reservoir as a result of the second etching step.
Referring to FIG. 3A, the channel plate is formed from a substantially planar wafer portion 10 onto which a first masking layer 30 is applied. The preferred material for the masking layer 30 is pyrolitically deposited silicon nitride. The methods of forming such layers are known to those of skill in the art and no further discussion thereof is necessary. Other low temperature methods for depositing the silicon nitride layer can be used, for example chemical vapor deposition (CVD) as disclosed in U.S. Pat. No. 4,601,777. Pyrolytic deposition and CVD are conducted at temperatures of about 800° C. This temperature is below the 1000°-1100° C. range at which a significant amount of oxygen is dissolved within the wafer, with resulting redistribution and agglomeration upon cooling. Thus, this step is unlikely to increase the concentration of oxygen precipitates within the wafer.
A second or protective layer of masking material 32 is formed on the silicon nitride layer masking layer 30. The preferred material for the layer 32 is a low temperature silicon oxide material deposited by chemical vapor deposition techniques. Such materials are known in the art, and are commonly available under the name LOTOX. Application of the layer 32 can be accomplished by either a low temperature oxide deposit or a plasma enhanced chemical vapor deposition. These processes are carried out at temperatures in the range of about 400°-500° C. and, thus, are below the point at which there is any significant redistribution of oxygen within the wafer. The masking layer 32 forms a protecting layer over the first masking layer 30 as will hereinafter be explained.
The deposition of the first and second layers is a double sided process and results in the formation of silicon nitride layer 30, and low temperature oxide layer 32' on the bottom of the wafer. These layers are removed as the corresponding masking layers are removed from the upper surface of the wafer.
After the layer 32 is applied, photo-imagable layer (not shown) is applied over the layer 32 and is patterned by known techniques, such as photolithography, to yield a mask having the pattern for forming the finished configuration of reservoir 14 and channels 16 (FIG. 1). The second masking layer 32 is etched with an appropriate wet etchant, such as a buffered oxide etch. After the second masking layer is etched, the first masking layer 32 is etched, for example by plasma etching. Alternatively the second masking layer and first masking layer are sequentially plasma etched, using appropriate mixtures of gases for removing each layer. As shown in FIG. 3B, after the completion of both etching steps, a full pattern opening 12 for the reservoir 14 and for the channels 16 exists in the masking layers 30 and 32. After completion of the etching of the masking layers 30 and 32, the photo-imagable material is removed.
Referring to FIG. 3C, in the next step in the fabrication of the channel plate, a third masking layer 38, preferably of plasma deposited silicon nitride is formed over the remaining portions of the first and second masking layers and over the exposed surfaces of the wafer formed by the opening 12. A layer 38' is also formed on the bottom of the wafer. A second photoimagable layer (not shown) is applied over the third masking layer 38 and is patterned by known techniques, again such as photolithography, to form a second pattern 18 which is located in the area of the reservoir 14. Referring to FIG. 3D, the second pattern provides an opening 18 in the mask which is smaller than the finished lateral dimensions of the reservoir 14. When the third masking layer 38 is subjected to a plasma etching process, a second mask pattern, having an opening or via 18, is formed in the masking layer 38.
An optional scratch resistant layer, such as polysilicon, can be applied over the LOTOX layer and the third masking lay to prevent scratches in the masks or wafer during subsequent processing. Scratches present opportunities for attack by an etchant in an uncontrolled manner. The polysilicon layer is applied before the photo-imagable layer is applied to the second and third masking layers and can be patterned by wet etching or plasma etching, followed by patterning of the second and third layers. The polysilicon can be removed by using an ODE etchant, such as a KOH, isopropyl alcohol, and water solution. When such a scratch resistant layer is applied to the second masking layer, it is removed prior to the application of the third masking layer.
After formation of opening 18, the channel plate is subjected to a first anisotropic etching step to form a reservoir precursor structure or cavity 20 in the surface of the wafer. Such etching processes are well known in the art and are disclosed in U.S. Pat. No. 4,601,777. Therefore no further discussion of such processes is necessary. The first wafer etching step can be of relatively long duration, for example, four hours, to form a significant portion of the finished reservoir 14.
Referring to FIG. 3E, after the first wafer etching step is terminated, the third masking layer 38 is removed in a suitable manner, such as plasma etching or wet etching in phosphoric acid. When the third masking layer 38 is removed, the first and second masking layers 30, 32 remain on the surface of the wafer. The low temperature oxide masking layer 32 prevents removal of the first masking layer 30 and has, in essence, protected the first masking layer 30 of silicon nitride during removal of the third masking layer 38, also of silicon nitride.
At this stage in the process, the second masking layer 32 can be removed or can be left in place.
The wafer is then exposed to a second anisotropic etching, step through the remaining masking layers 30, 32 (or 30 alone), which, it will be recalled, are in the finished pattern of the reservoir 14 and channels 16. Upon the termination of the second etching process, the reservoir 14 and channels 16 are completely formed and a land 28 separates the channels from the reservoir. This second etchant exposure step can be of relatively short duration, just sufficient to form the channels 16. Thus the channels 16 are not subjected to a relatively long etching process which can adversely affect channel uniformity, as previously described. Alternatively, the second etching step can be an isotropic etch.
After termination of the final etching step, the masking layer 30 and the masking layer 32 (if not previously removed) are removed. The wafer portion 10 now has a fully formed reservoir 14 having a through opening 22 and channels 16. A ridge or land 28 has been formed in the wafer between the reservoir 14 and the channels 16. It is preferred to maintain the land in place on the channel plate and provide for passage of ink from the reservoir to the channels by an ink bypass formed in an associated heater plate, as will hereinafter be described. Forming land 28 is desirable because orientation dependent etching processes produce poor formation of outside angles and this results in variable channel length. If desired, grooves (not shown) are machined through the ridge to provide communication between the channels 16 and the reservoir 14. Suitable machining techniques for forming such grooves are well known. Alternatively, the mask pattern 12 can provide for communication between the channels and the reservoir in the second wafer etch step. Although the foregoing description is in the context of a single channel die, it should be realized that many channel dies are formed simultaneously in this process from a single silicon wafer.
FIG. 4 shows, in cross-section, use of the wafer portion 10 to form a thermal ink jet printhead. The channel recesses 16 have been etched and the reservoir 14 enlarged to its final shape. A heater plate 34 is aligned and bonded onto channel plate wafer 10 by known techniques, such as those disclosed in U.S. Pat. No. 4,601,777. The heater plate 34 includes a polyimide layer 35. A heating element 36 is disposed in a bubble chamber 37 formed in the polyimide layer. A heating element 36 is associated with each channel 16 and each heater element is separately addressable by an electrode arrangement as disclosed in U.S. Pat. No. 4,601,777. 601 777. Further the polyimide layer 35 of heater plate 34 includes an ink bypass 38 for providing for ink flow from the reservoir to the channels over land 28. In order to form nozzles at the end of each channel 16, the joined channel plate 10 and heater plate 34 are separated along line 42, preferably in a dicing operation using a resinoid cutting blade. In this manner, a subunit is made that includes a fully formed reservoir 14 and a plurality of aligned channels 16, each channel having a nozzle at one end thereof and being in communication with the ink reservoir 14 at the other end thereof. The subunit includes a through hole 22 for registration with a means for supplying ink to the reservoir 14.
In summary, this invention relates to batch fabrication of three dimensional silicon structures by a single side, multi-step ODE processing technique. The masks are formed on one side with the coarse mask last and the highest tolerance or finest mask first. Coarse etching is carried out first and fine etching is carried out last. A protective masking layer is utilized to prevent removal of a first applied fine mask when a subsequent coarse mask is removed. After the coarse anisotropic etching is completed, the coarse mask is removed and, preferably, a second anisotropic etch is done. The fabrication of structures having both deep recesses or large through holes and shallow high tolerance recesses can be done much faster by a first fast, less controllable etch and a second slower, more controllable etch. Because the masks are formed at temperatures below the range in which there is substantial redistribution of oxygen within the wafer, the likelihood of creating defects as a result of the formation of oxygen precipitates is substantially eliminated. Using the two silicon nitride layers for two consecutive mask etch processes also avoids the problem of mask layer erosion associated with use of silicon dioxide masking layers in KOH etching processes.
Although the foregoing description illustrates the preferred embodiment as a thermal ink jet printer channel plate, other variations and other three dimensional silicon structures are possible. All such variations and other structures are intended to be included within the scope of this invention as defined by the following claims. | A fabrication process for wafer derived elements such as channel plates for thermal ink jet printers includes formation of a final etchant pattern in first and second masking layers. The second masking layer is a protective layer to prevent removal of the first layer upon removal of a subsequent third masking layer. Preferably, the second masking layer is an oxide applied under low temperature condition to lessen the possibility of inducing formation of oxygen precipitates in the wafer. A third masking layer is formed over the final etchant pattern formed by the first and second masking layers. The third masking layer is patterned to form a precursor structure of a large structure contained in the final etchant pattern. After formation of the precursor structure, the third masking layer is removed and the wafer is subjected to a final etching exposure to form the final etched structures. The process is useful for forming channel plates for thermal ink jet printheads. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to an electrical bicycle shift control device.
[0003] 2. Background Information
[0004] Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle, especially the bicycle control devices for shifting and braking.
[0005] In the past, bicycle shifters were mechanically operated devices that were sometimes located near the brake levers of the bicycle. Thus, an operating force was typically applied by one of the rider's fingers to operate a shift control lever, which in turn transmitted the operating force to the drive component of a bicycle shifting mechanism by a cable that was fixed at one end to the control lever. More recently, electric switches have been used instead of mechanical control levers in order to operate the bicycle shifting mechanism. One example of an electrical shift control device is disclosed in U.S. Pat. No. 5,358,451. This patent discloses a plurality of electric switches may be provided at a plurality of handlebar locations in order to allow for quicker shifts and to enhance responsiveness. Another example of an electrical shift control device is disclosed in U.S. Patent Application Publication No. 2005/0211014. Other examples of electrical shift control devices are disclosed in U.S. Pat. No. 6,073,730 (discloses a pair of electric switches that may be provided in the side of the bracket body; U.S. Pat. No. 6,129,580; U.S. Pat. No. 5,676,021 and U.S. Pat. No. 6,546,827. Two such commercially available systems are “Dura-Ace® Di2 Road” and the “Dura-Ace® Di2 TT/Tri”, both by Shimano.
[0006] Recently, there has been a demand for so-called electronic satellite shifters. These are devices adapted to be fixated on special locations on the bicycle and to function as shifters in conjunction with the commercially available electrical shift control devices. Thus, sprinters might wish to have the electronic switches located in a different place on the handlebar than time-trialers, mountain bikers, recreational riders, road racers, etc. Each type of rider has different shifting patterns and requirements. Thus, there are presently available, satellite shifters configured to be fixated on the top of the handlebars and another type adapted to be located on the brake lever. The electronic gear shifting systems manufactured by Shimano allow for the use of these “satellite” shifters. Shimano currently offers two types of satellite shifters:
[0000] SW-7972: Shifting buttons are mounted on the lower portion of a drop handle bar. This allows for easy gear shifting while the rider is in an aggressive sprinting position.
SW-7970: Mounted on the top portion of a drop handlebar. This allows for easy gear shifting while the rider is in a more relaxed cruising position. The current Shimano offerings are functional. However, they are clunky in appearance and do not offer form, minimal weight, and maximum ergonomics.
[0007] Satellite shifters are equipped with male electric jacks or plugs adapted to fit the female electric sockets in the commercially available electrical shift control devices. At the present time, there are no satellite shifters which are configured to be fixated at any desired location on the bicycle. Thus, satellite shifters adapted to be fixated on top of the handlebar cannot be located elsewhere on the bicycle. Similarly, satellite shifters configured to be located on the brake levers cannot be installed elsewhere on the bicycle. Moreover, the commercially available satellite shifters are not maximally aerodynamic, thereby resulting in a sacrifice in performance.
[0008] In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved satellite electronic shifter which can be installed at any location of the bicycle and which avoids the disadvantages associated with those commercially available. The invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
SUMMARY OF THE INVENTION
[0009] One object of the present invention is to provide a maximally aerodynamic electronic satellite shifter that can be fixated at any location on the bicycle.
[0010] These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed descriptions, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.
[0011] One embodiment of the invention relates to a satellite electrical bicycle shift control device comprising: a mounting portion that is configured to be fixedly or detachably mounted on a bicycle; and a first electrical shift control switch portion fixedly attached to the mounting portion, the electrical shift control switch portion including an operating member arranged and configured to be selectively moved relative to the mounting portion between a neutral position and an actuating position.
[0012] Another embodiment of the invention concerns the above described system further comprising a second electrical shift control switch portion fixedly attached to the mounting portion, the second electrical shift control switch portion also including an operating member arranged and configured to be selectively moved relative to the mounting portion between a neutral position and an actuating position; the second electrical shift control switch being spaced from the first electrical shift control switch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring now to the attached drawings which form a part of this original disclosure:
[0014] FIG. 1 is a side elevational view of a typical bicycle equipped with an electronic derailleur control system.
[0015] FIG. 2 is a side elevational view of a prior art satellite shifter adapted to be installed on the top of a bicycle handlebar.
[0016] FIG. 3 is a top elevational view of an embodiment of the satellite shifter of the invention.
[0017] FIG. 4 is a side elevational view of an embodiment of the satellite shifter of the invention.
[0018] FIG. 5 is an exploded view of the satellite shifters illustrated in FIGS. 3 and 4 .
[0019] FIG. 6 is a rear perspective view of an embodiment of the satellite shifter of the invention installed on the top of a mountain bike handlebar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Selected embodiments of the present invention will now be explained with reference to the drawings where like reference numerals refer to like elements. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0021] Referring initially to FIGS. 1 and 2 , a bicycle 10 with an electronic derailleur control system is illustrated. The bicycle 10 is a road bicycle comprising a diamond-shaped frame 12 , a front fork 14 rotatably mounted to the frame 12 , a drop type bicycle handlebar 16 mounted to the upper part of the front fork 14 , a front wheel 18 rotatably attached to the lower part of the front fork 14 , a rear wheel 20 rotatably attached to the rear of frame 12 , and a drive train or unit 22 . A front wheel brake 24 is provided for applying a braking force to the front wheel 18 , and a rear wheel brake 26 is provided for applying a braking force to the rear wheel 20 . The electronic derailleur control system is configured and arranged so that it can be used with a variety of drive train configurations.
[0022] The bicycle is equipped with a cycle computer 33 , a front electronic derailleur 34 and a rear electronic derailleur 35 . The left and right hand side control devices 31 and 32 are essentially identical in construction and operation, except that they are mirror images. In the illustrated embodiment, the front dual control device 31 that is on the left hand side of the handlebar 16 is electrically connected to the front electronic derailleur 34 , while the rear dual control device 32 that is on the right hand side of the handlebar 16 is electrically connected to the rear electronic derailleur 35 . In any event, when the electronic derailleur control system is used to shift the drive train 22 , the front electronic derailleur 34 selectively moves between two operating positions to switch the chain C between front sprockets using the front control device 31 , while the rear electronic derailleur 35 selectively moves between, typically, ten operating positions to switch the chain C among selected ones of the rear sprockets using the rear control device 32 .
[0023] As seen in FIG. 1 , the drive train 22 basically comprises a chain C, a front crankset FC and a rear cassette RC. Since the parts of the drive train 22 are well known in the art, the parts of the drive train 22 will not be discussed or illustrated in detail herein, except for as they relate to the electronic derailleur control system of the present invention.
[0024] A commercially available electronic satellite shifter 17 fixated on the top of a handlebar 16 is illustrated in FIG. 2 . As is apparent from the construction of the device, it offers a significantly large area to the air encountered when operating the bicycle, thereby increasing drag forces on the bicycle and reducing performance characteristics.
[0025] An embodiment of the satellite shifter of the invention is depicted in FIGS. 3-5 . Two small electronic switches 48 , powered by battery (not shown), and containing actuating buttons 46 are affixed to a flexible band 42 . Each electronic switch 48 is electrically connected via electrical wires 52 to a jack that, in turn, connects to the electronic shifting system (not shown). The unit is encased in a form-fitting, flexible, plastic shrink-tube 44 . The shifter may be wrapped around the handlebar and held in place with small amounts of epoxy or it may be mounted thereon so as to be removable; e.g., by a Velcro fastener system. It will be apparent to those skilled in the art that the satellite shifter of the invention is configured so as to be mountable anywhere on the bicycle; e.g., the handlebar, any portion of the frame or any component mounted thereon.
[0026] The electronic switch 48 and the actuating button 46 are preferably sealed against the elements by the encasing element 44 which is, preferably a shrink-wrapped plastic. The switch 48 is operated by pressing the area of the encasement 44 covering the button 46 , which in turn presses against the button 46 , thereby generating a switching signal to the electronic derailleur control system.
[0027] The band 42 and the encasing element 44 may be constructed of any suitable material that maintains the flexibility of the band 42 (metal, plastic, textile, and the like) and the element-proof nature of the coating 44 (plastic).
[0028] The electrical bicycle shift control device of the invention preferably has a maximum height in the Z axis direction, at its tallest point, is less than about 5 mm. The z-axis height is determined by the nature of the actuator switch and is maintained so as to reduce aerodynamic drag during operation of the bicycle to a minimum | A satellite electrical bicycle shift control device comprising: a mounting portion and a first electrical shift control switch portion attached to the mounting portion, the electrical shift control switch portion including an operating member moveable, relative to the mounting portion, between a neutral position and an actuating position. | 8 |
FIELD OF THE INVENTION
The invention relates to the determination and visualization of the spatial distribution of tissue states in histologic tissue sections on the basis of spatially resolved mass spectrometric signals.
BACKGROUND OF THE INVENTION
The term “tissue state” here means the state of a small subarea of a tissue section with respect to a stress, a pathological change, an infection or other type of change compared with a normal state of this tissue. The tissue state must therefore be identifiable as a concentration pattern of substances which can be detected in this small subarea by a mass spectrometer. The substances can be peptides or proteins which are under- or overexpressed and hence form a pattern, or they can include positranslational modifications of proteins, their breakdown products (metabolites), or collections of other substances in the tissue.
Mass spectrometry with ionization of the samples by matrix-assisted laser desorption and ionization (MALDI) has been used successfully for several years for the determination of molecular weights, and for the identification and structural characterization of proteins. In this case, the protein is usually dissolved and mixed with a solution of a matrix substance such as sinapic acid before being applied to the sample support. The solvent then evaporates and the matrix substance crystallizes, the protein crystallizing with it in the matrix crystals. Bombarding the sample obtained in this way with sufficiently energetic short pulses of laser light leads to the matrix substance absorbing energy and evaporating explosively as a result. The proteins are entrained into the gaseous cloud inside the mass spectrometer and ionized by protonation. The ions are then separated in the mass spectrometer according to their mass-to-charge ratios (m/z) and measured as a mass spectrum. Their mass can be determined from the mass spectrum. Since ionization by matrix-assisted laser desorption essentially provides only singly charged ions, in the following, we will simply refer to “mass determination” and not determination of the mass-to-charge ratios and, correspondingly, just the “mass” of the ions instead of their m/z-ratio.
These analyses can be carried out on biological samples, such as tissue homogenates, lyzed bacteria or biological fluids (urine, blood serum, lymph, spinal fluid, tears, sputum), the samples generally being subjected to sufficient fractionation beforehand by chromatographic or electrophoretic techniques.
For this purpose it is advisable to free the samples from interfering impurities, such as certain buffers, salts or detergents, which reduce the efficiency of the MALDI analyses. The analysis of biological samples usually involves very time-consuming sample preparation, particularly if, at the same time, information concerning the distribution of a protein in different regions of a tissue is to be obtained. “Laser capture microdissection”, for example, can achieve this, but the time-consuming processing described above is still necessary; there is also the difficulty of obtaining sufficient material for this type of analysis.
Imaging mass spectrometry (IMS) makes it unnecessary to go to these lengths. With this method, a microscopic tissue section is produced from a piece of tissue taken from a human or animal organ of interest using a microtome, for example, and laid on a specimen slide. A matrix capable of absorbing laser energy is then applied to the surface of the specimen, for example by pneumatic spraying onto a moving support (U.S. Pat. No. 5,770,272; Biemann et al.). There are two different methods for the subsequent mass spectrometric scan: The raster scan method and stigmatic imaging of the ions of a small region.
The raster scan method produces a one- or two-dimensional intensity profile for individual proteins by scanning a microscopic tissue section with well-focused laser beam pulses in a MALDI mass spectrometer, the proteins being identifiable in the mass spectra (U.S. Pat. No. 5,808,300; Caprioli). Each spot is therefore irradiated at least once with a finely focused pulse of laser light and provides a mass spectrum which can cover a broad range of molecular weights, for example 1 to 30 kilodaltons. Using suitable software, it is then possible to define an ion mass, which represents a peptide or a protein, or a narrow mass range around this mass, in the spectra and to graphically represent its intensity distribution over the surface of the microscopic tissue section. Using this method, it has been possible to correlate the distribution of neuropeptides in the brain of a rat with specific morphological features, for example, or to depict the distribution of amyloid beta peptides in the brains of Alzheimer animal models. It is possible to visualize sections of the brain affected by “Alzheimer plagues” with precise spatial definition (Stoeckli M, Staab D, Staufenbiel M, Wiederhold K H, Signor L, Anal Biochem. 2002, 311, 33-39: Molecular imaging of amyloid beta peptides in mouse brain sections using mass spectrometry).
The method of stigmatic imaging irradiates a defined area of up to 200 by 200 micrometers with the laser pulse. The ions formed over the area are imaged ion-optically, spot by spot on a spatially-resolving detector. So far, it has been possible to scan distribution images of these ion masses by selecting individual ion masses with this method (S. L. Luxembourg et al., Anal. Chem. 2003; 75, 1333-41); it is to be expected, however, that very fast cameras will be able to scan complete mass spectra for every spot of the area.
A considerable disadvantage of both methods is the fact that, until now, only individual features in these types of spectra have been utilized analytically, for example a peptide present in a high concentration, which is particularly typical of certain tissue states within a tissue sample. This procedure has limited the method until now and prevented a broader application for those tissue states which cannot be attributed to the appearance of one single peptide or protein.
Independently of such imaging methods, targeted searching for “markers” has developed as an interesting field of clinically oriented research (W. Pusch et al., Pharmacogenetics 2003; 4, 463-476). Here, bodily fluids such as blood, urine or spinal fluid, but also tissue extracts, are typically processed into coarse fractions with a less complex analyte composition by extracting them with- chromatographic phases, solid phase extraction or other selective methods before they are mass spectrometrically characterized. The mass spectra obtained by this method display a more or less complex pattern which originates from peptides and proteins. By comparing the mass spectra of samples from healthy and sick individuals it is possible, in individual cases, to find single peptides or proteins which are characteristic of the medical condition of the individuals.
However, there is a general opinion that interesting distinguishing features with better statistical evidence can only be discovered when this method is performed on dozens or hundreds of samples from two so-called cohorts of individuals—one cohort serving as a reference and one cohort in which certain peculiarities or deviations in the spectra are expected because a specific clinical picture, such as intestinal cancer or prostate cancer, is present.
This approach has achieved preliminary successes with the discovery of distinct and statistically significant protein signals in the case of samples from ill persons. In the literature, however, a vehement argument is in progress about whether these markers can be used for diagnosis or not since, as yet, it has not been possible to establish whether these markers might simply be indicative of the patient's type of medication or a general stress situation associated with the illness. For the licensing of such markers for general diagnostic purposes, the United States FDA (Food and Drug Administration) now requires, as a minimum, that the protein found as a marker is unambiguously identified and that knowledge of the protein and its function (or its breakdown pathway, if the substance in question is a breakdown product) is used to at least establish the plausibility of a link with the illness concerned.
The objective of these analyses is naturally to make an early prediction about the possible development or proliferation of various diseases in the future of an individual. It is hoped that it will be possible to identify cancer at a very early stage, for example, and therefore to have a much better chance of fighting it.
In general, however, the mass spectra of the various cohorts do not contain any simple features such as a few individual signals whose intensities differ significantly in the cohorts. Complex mathematical-statistical analyses of the mass spectra of the various cohorts must therefore usually be carried out. These analyses can be carried out using a plurality of methods, which analyze whether it is possible to distinguish between the cohorts of healthy patients and sick patients unambiguously and to a statistically significant degree on the basis of groups of features in the mass spectra.
It is, for example, possible for a principal component analysis (PCA) to determine whether cohorts of sick individuals (or, where possible, even several cohorts with several related diseases) can be distinguished from each other and from cohorts of healthy reference individuals. If this is the case, a further mathematical computational method can use the mass spectrometric signals to calculate disease-specific distinguishing characteristics which make it possible to unambiguously identify the state of an individual with respect to a specific disease. Suitable mathematical transformations can, for example, make it possible for the disease-specific distinguishing characteristics to cover the range from minus infinity to plus infinity, for example, where all values less than zero correspond to a healthy state and all values greater than zero to a diseased one. A very simple distinguishing characteristic can be a simple concentration ratio of two proteins, for example, where the range extends from zero to infinity. Alternatively, the distinguishing characteristics are transformed in such a way that they cover the range from zero to one: healthy state close to zero, diseased state close to one. The detailed computational method for calculating the distinguishing characteristics (both the algorithm and the parameter values) is saved and later used for the diagnosis of this disease using mass spectra scanned from this individual's samples.
Genetic algorithms (GA) generate a decision path along which the medical condition of an individual can be determined. A logical expression can be obtained from the decision path which, in turn, can be transformed into a characteristic which distinguishes between different states. This logical computational method is also saved and later used for diagnosis of other samples.
Other methods for analyzing the differentiation have been elucidated, including: linear discriminance analysis (LDA), support vector machines (SVM), neuronal networks (NN), learning vector quantification (LVQ).
From the results of such statistical analyses, it is ultimately possible to obtain detailed computational methods (algorithms plus parameter sets) to calculate distinguishing characteristics that are represented as mathematical or logical expressions, each incorporating several spectra signals. These can also include very weak spectral signals. The distinguishing characteristics also seem to make it possible to represent more subtle differences between samples from different cohorts. However, the number of samples required easily runs into thousands.
It is a considerable problem here that the variation in the ion signals in the individual mass spectra, even within one cohort (patient or healthy), is large, and, for example, the age distribution in a group or the gender-specific distribution can have much more influence than the effect which is to be investigated. One of the reasons for this is the fact that the analysis of bodily fluids only provides a remote—or indirect—picture of the occurrence of the disease at the site of action (for example the tumor or the brain in the case of neuro-degenerative diseases). According to present expectations, the problem of the search for markers could be simplified if it were possible to compare healthy and diseased samples from a single individual. But this is not possible when the samples are bodily fluids because of their homogenization in the body, and can, at best, be determined as a temporal variation over relatively long periods of time.
SUMMARY OF THE INVENTION
The invention provides a method which, on the one hand, can provide a visual representation of the mass spectrometric differentiation of tissue states and, on the other, can formulate characteristics which distinguish between healthy and diseased tissue sections using spatially resolved mass spectrometric signals of the analyzed tissue, and can do this more easily than is the case with samples analyzed on a cohort basis.
The invention first provides a method which is suitable for visualizing the spatial distribution of tissue states of histologic samples. It comprises the following steps:
a) production of at least one histologic sample as a tissue section, b) preparation of the samples for mass spectrometric analyses, c) spatially distributed detection of mass spectrometric signals along one or two dimensions of the samples, d) calculation of localized characteristics which distinguish between different states from at least two mass spectrometric signals, and e) graphic representation of the spatial distribution of these distinguishing characteristics for at least one of the samples.
It is advisable to carry out the calculation on a computer and the tissue imaging on a screen. This makes it possible to lay a microscopic image of the tissue section (or tissue sections) true to position under the image of the distinguishing characteristics. For this, the microscopic image is represented as a color density image (brightness), for example, and the distinguishing characteristics as shades of false color (example: blue tissue is healthy; red is diseased).
For this purpose, the calculation of the localized distinguishing characteristics can utilize detailed computational methods (algorithms and parameter sets) which have been previously obtained from cohorts of healthy and diseased tissue homogenates.
However, since, as shown above, these computational methods are based on widely varying samples from different individuals and can therefore impair clear detectability, a further embodiment of the invention will focus on the differences between healthy and diseased tissue of the same individual. It can be expected that the direct analysis of a tumor tissue and the surrounding healthy tissue in the sample from an individual could reveal differences of far greater specificity between healthy and diseased tissue. Thus, in the image of one or more pieces of tissue on the screen, regions can be indicated which are considered as healthy or diseased. From the mass spectra of these regions it is possible to independently develop (on the computer, by means of predetermined development procedures) computational methods for the characteristics which distinguish between different states. These can then be applied to all spots of the tissue. The distinguishing characteristics are then displayed in the image of the tissue. The computational method can follow a previously determined algorithm, for example, where only the parameter set is optimized. So-called “supervised learning” is one such possibility.
Furthermore, the spatially resolved mass spectra can also be scanned from a copy of the sample, i.e. not from the tissue itself. The peptides or proteins of a tissue section can be transferred onto a blot membrane, for example. Alternatively, they can be transferred onto a surface which is coated with one or more types of antibodies. It is thus also possible to display the spatial distribution of peptides or proteins at very low concentrations. The tissue state characteristics can thus be extended to ratio differences of posttranslational modifications such as phosphorylations or glycosylations, or to breakdown forms of proteins.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which:
FIG. 1A shows a schematic microscopic section of a mouse brain in which two circular areas are defined whose mass spectra, scanned on a spot-by-spot basis, are used to develop the calculation method for the characteristics which distinguish between different states; and
FIG. 1B shows a section like that of FIG. 1A with a characteristic distribution over the whole tissue section.
DETAILED DESCRIPTION
One preferred embodiment begins with the production of a microscopic tissue section, preferably from a deep-frozen piece of tissue, with a microtome. The microscopic tissue section is applied to a suitable support. This support can be a glass specimen slide, for example, whose surface is equipped with a transparent but conductive surface coating for subsequent use in the mass spectrometer. Other supports, for example metal supports or supports made of electrically conductive plastic, can also be used, however. The microscopic tissue section can then be stained in the usual way, although care has to be taken to use a stain which does not interfere with a subsequent mass spectrometric analysis of the tissue constituents. Fluorescence dyeing methods can also be used if they do not restrict the mass spectrometric analysis.
After this, a microscopic image is taken, with transmitted or reflected light, from the microscopic tissue section, and is later used to lay under the result images. Before the image is taken, markings which are recognizable both optically as well as mass spectrometrically can preferably be applied to the support to facilitate subsequent adjustment so as to obtain a true position. Many mass spectrometers are equipped with a viewing unit for the samples, which can likewise be used for the true-to-position adjustment.
The microscopic tissue section is then sprayed with a solution of a suitable matrix substance for ionization by matrix-assisted laser desorption. The spraying can be done on a device which moves the specimen slide under the spray jet so that a uniform sprayed layer is achieved, for example. Care must be taken to ensure that the positional accuracy of the samples is not adversely affected by the sprayed liquid running. During this process, the matrix substance which is crystallizing out absorbs such substances from the microscopic section as can be integrated into the microcrystals themselves or into grain boundaries between the microcrystals during the crystallization.
The choice of matrix substance can greatly influence which biomolecules in the spectra lead to signals. Proteins are prepared for MALDI MS analysis with 2.5 dihydroxybenzoic acid (DHB) or sinapic acid (SA), for example; peptides with α-cyano-4-hydroxycinnamic acid (CCA), nucleic acids with 3-hydroxypicolinic acid (3-HPA) and saccharide-carrying structures with DHB or trihydroxyacetophenone.
In another similarly favorable embodiment, spatially resolved mass spectrometry can be carried out on a copy rather than on the original tissue section. It is thus possible, for example, to bring the moist microscopic tissue section into contact with a blot membrane either before or after the microscopic image is taken. Blot membranes are known from two-dimensional gel electrophoresis; they can bind proteins and peptides by their affinity in a particular way so that they are stationary. The substances can be transferred onto the blot membrane by simple diffusion and also by electrophoresis. Dinitrocellulose membranes are particularly favorable for use as blot membranes for mass spectrometric analyses. These blot membranes are then used instead of the microscopic tissue sections for the mass spectrometric analysis.
A surface which is densely coated with an antibody can be used as the copy medium in place of a blot membrane. This makes it possible to extract various mutants, modification forms and also breakdown forms of a single protein from the tissue and to analyze them with spatial resolution, even if the protein is only present in the tissue at a very low concentration. According to the invention, the ratios of the mutants, modification forms and the breakdown forms can be visualized as tissue state characteristics. It is interesting and extremely informative, for example, to see how a protein occurs mainly in singly phosphorylized form at some sites in the tissue, while at other sites it is triply phosphorylized.
The surface of the copy medium can also be coated with more than one antibody, however, so that several proteins can be fished simultaneously. If the fishing does not take place up to saturation, the ratios of the proteins can again be represented as characteristics which distinguish between different tissue states.
The samples, either the prepared microscopic tissue sections or the prepared copies, are then introduced into the mass spectrometer. The mass spectrometric scans are then carried out using either the raster scan method with a finely focused pulsed beam of laser light or the scanning method with stigmatic imaging of the ions generated over a large area.
The raster scan consists of a spot-by-spot acquisition of the mass spectra, the finely-focused laser beam carrying out one acquisition, or preferably many acquisitions, of mass spectra at each spot of the tissue sample (or blot membrane sample). The mass spectra of the same spot are added together in order to achieve a higher dynamic range of measurement and also to improve the statistics of the mass signals. The diameters of the “spots” correspond roughly to the diameter of the laser focus, or to be more precise, the diameter of the laser beam on the sample, which can be adjusted by focusing. For the purposes of the raster it is usually possible to set diameters of around 10 to 50 micrometers. YAG lasers also permit focus diameters of less than one micrometer, but no applications are known. The sum spectra are stored for every spot of the raster. For a tissue area of one square millimeter there can thus be 400 to 10,000 mass spectra, the normal figure being around 1,000 to 2,000.
The raster is generally made up of measuring spots arranged in a square, a parallelogram or a honeycomb shape, but it can, of course, dispense with this type of pattern and following a specific morphology of the sample, as would be helpful, for example, in the case of an axon of a ganglion several millimeters long. The only important thing is that the separations of the measuring spots are adjusted to match the size of the area irradiated by the laser.
Ions generated from spots by MALDI can be analyzed with different types of mass spectrometers. Time-of-flight mass spectrometers (TOF-MS), with or without ion reflectors, are the usual method. Time-of-flight mass spectrometers with orthogonal ion injection can also be used. Ion traps and Fourier transform ion cyclotron resonance (FT-ICR) are also being used increasingly.
The stigmatic image generates around 100 to 2,000 spatially resolved mass signals from an irradiated surface of around 100 to 200 micrometers in diameter on a spatially-resolving detector. Time-of-flight mass spectrometers with special ion focusing systems for stigmatic imaging are used for this. The current art consists in acquiring only the ion current signal for each laser pulse over a narrow mass range, and masking out the remaining mass ranges, since the time resolution of the detectors permits no other way of measuring. For each of the other mass ranges the measurements must be repeated. The mass ranges are chosen according to those masses which have proven to be significant in previous analyses. It is, however, to be expected that, in future, there will be cameras with better time resolution. It will then be possible to scan the complete mass spectra for a multitude of spots, although the question of the mass resolution power is as yet unanswered. The spatial resolution of this method promises to be better than that of the raster scan. Relatively large areas are scanned one after the other like a mosaic.
After the measurements, complete or partial mass spectra are then available for each tissue spot. From these data it is possible to calculate the characteristics which distinguish between different tissue states for each spot, which is calculated as a mathematical or logical expression from at least two mass signals (usually more) of this tissue spot. This involves the use of the detailed computational methods comprising algorithms and parameter sets obtained in preliminary analyses of cohorts of samples. These tissue state characteristics are then represented graphically—preferably over the microscopic image.
A preferred representation of this tissue image consists in using the microscopic image showing the structure of the tissue for the color density (brightness of the image), and using the tissue state characteristic for the color shade. It is then possible to visualize healthy parts of the tissue in blue, diseased parts in red, and the tissue structures in light-dark shades of the respective color, for example. This type of representation produces a higher resolution of the tissue state characteristics for the eye than is provided by the measurements.
In a further embodiment of the invention, the computational methods for the tissue state characteristics can also be developed, or at least refined, using the mass spectra of the tissue itself (or of two different pieces of tissue). In the tissue image on the screen it is then also possible to indicate regions which are considered to be healthy or diseased ( FIG. 1A ). From the mass spectra of these regions it is then possible to develop computational methods for distinguishing characteristics, independently on the computer using predetermined guidelines. The computational method can follow a previously determined algorithm, for example, where the parameter set is merely optimized. A plurality of learning methods have been elucidated for this type of optimization. It is also possible to develop a new computational method according to a given development scheme, independently on the computer. The improved or newly-developed computational method is then applied to all spots of the tissue, the calculated distinguishing characteristics being represented in the tissue image ( FIG. 1B ).
It can also be interesting to compare more than two groups of spectra with each other. In this case, several group-defining areas are marked in the tissue section, or spread over several tissue sections, and the characteristics are determined in such a way that the groups can be distinguished from each other.
A further embodiment avoids the acquisition of spectra which are not to be used analytically if the regions to be compared are clearly recognizable. In the case of a spatially limited tumor, for example, it can thus be sufficient to mark this and a representative small part of the healthy tissue in the image of the tissue section. Only these two areas, which are to be used for determining the characteristics, are then actually measured.
In further embodiments, three-dimensional images of a tissue, through several layers of microscopic tissue sections, for example, can also be scanned and visualized according to the invention. | The invention relates to the determination and visualization of the spatial distribution of tissue states in histologic tissue sections on the basis of mass spectrometric signals acquired so as to be spatially resolved. The invention provides a method which determines the tissue state for the tissue spots as a state characteristic, which is calculated as a mathematical or logical expression from at least two mass signals of this tissue spot, and which indicates the tissue state as a gray-level or false-color image in one or two dimensions. | 8 |
BACKGROUND OF THE INVENTION
(A) Field of the Invention
The present invention relates to a memory storage device and method for operating the same. More specifically, the present invention relates to a non-volatile memory storage device and method for operating the same.
(B) Description of Related Art
FIG. 1 illustrates an 8-bit flash memory storage device 10 including a flash controller 11 and a flash memory 12 . The flash controller 11 has a flash control circuit 13 which can issue a chip-enable (CE) signal to access the flash memory 12 . An 8-bit flash data bus FD[ 7 : 0 ] is connected between the flash control circuit 13 and the flash memory 12 .
FIG. 2 illustrates a 16-bit flash memory storage device 20 including a flash controller 21 and a flash memory 22 . The flash memory 22 has two flash memory chips 221 and 222 . The flash controller 21 has a flash control circuit 23 that can issue a CE signal to access the flash memory chips 221 and 222 . A 16-bit flash data bus FD[ 15 : 0 ] is connected between the flash control circuit 23 and the flash memory chips 221 and 222 .
FIG. 3 illustrates a flash memory storage device 30 , which is popularly used in current flash memory storage devices or memory card devices, including a flash controller 31 and a flash memory 32 . The flash memory 32 has a plurality of flash memory chips 34 . The flash controller 31 has a flash control circuit 33 that can issue a plurality of CE signals (CE[ 0 ] to CE[ 15 ]) to access the flash memory chips 34 of the flash memory 32 . A 16-bit flash data bus FD[ 15 : 0 ] is connected between the flash control circuit 33 and the flash memory chips 34 .
In order to increase the performance of memory storage devices, it is common to increase the number of data buses, resulting in a need for more flash control circuits. As shown in FIG. 4 , a flash controller 41 of a flash memory storage device 40 needs 64-bit data bus in total. Four control circuits, i.e., Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 , are used, and each controls a 16-bit data bus. Flash Control Circuit 0 generates CE[ 15 : 0 ] to control the flash memory chips 42 at the first two rows, and FD[ 15 : 0 ] is the data bus between the Flash Control Circuit 0 and the flash memory chips 42 . Likewise, Flash Control Circuit 1 generates CE[ 31 : 16 ] to control the flash memory chips 42 at the third and fourth rows, and FD[ 31 : 16 ] is the data bus thereof. Flash Control Circuit 2 generates CE[ 47 : 32 ] to control the flash memory chips 42 at the fifth and sixth rows, and FD[ 47 : 32 ] is the data bus thereof. Flash Control Circuit 3 generates CE[ 63 : 48 ] to control the flash memory chips 42 at the seventh and eighth rows, and FD[ 63 : 48 ] is the data bus thereof. Accordingly, 64 CE pads are needed for the flash controller 41 . However, more CE chip pads would increase the package size and cost.
FIG. 5 illustrates a timing diagram for the flash memory storage device 40 in FIG. 4 . “U” indicates CE update timing, and the CE signals CE[ 0 ], CE[ 16 ], CE[ 32 ] and CE[ 48 ], corresponding to the timings “U” for Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 , are changed from “1” to “0” to access the first column of flash memory chips 42 , respectively. Then, CE[ 0 ], CE[ 16 ], CE[ 32 ], and CE[ 48 ] are changed from “0” to “1” after accessing the first column of flash memory chips 42 , respectively.
FIG. 6 illustrates a timing diagram of the flash memory storage device 40 in which the operation of every two neighboring columns of flash memory chips are interleaved (so-called interleave-2), i.e., they do not operate at the same time. CE[ 0 ] and CE[ 1 ], CE[ 16 ] and CE[ 17 ], CE[ 32 ] and CE[ 33 ], CE[ 48 ] and CE[ 49 ] are interleaved, i.e., CE[ 0 ] and CE[ 1 ] will not be “0” at the same time, CE[ 16 ] and CE[ 17 ] will not be “0” at the same time, CE[ 32 ] and CE[ 33 ] will not be “0” at the same time, and CE[ 48 ] and CE[ 49 ] will not be “0” at the same time. But, CE signals of each flash control circuit work independently, e.g., CE[ 0 ] and CE[ 1 ] do not care CE[ 16 ], CE[ 17 ], CE[ 32 ], CE[ 33 ], CE[ 48 ], and CE[ 49 ]. In another embodiment, the operation of every four neighboring columns of flash memory chips are interleaved (so-called interleave-4). For instance, CE[ 0 ], CE[ 1 ], CE[ 2 ], and CE[ 3 ] are interleaved.
The increase of performance for the flash memory storage devices may incur more power consumption. Peak power demand will grow dramatically when the flash control circuits execute flash commands at the same time. For instance, for the 8-bit memory storage device 10 shown in FIG. 1 , the peak current is approximately 125 mA to 133 mA. For the 16-bit memory storage device 20 shown in FIG. 2 , the peak current is approximately 230 mA to 239 mA. The memory storage devices 10 and 20 each have only one control circuit, and it can be seen that the peak current will increase tremendously as the number of control circuits increases. As shown in FIG. 7 , when the Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 execute flash commands “ 60 ” and “D 0 ” at the same time, a very high peak power consumption occurs at the end of “D 0 ”. There is therefore a challenge to reduce the power consumption of the memory device with high performance.
SUMMARY OF THE INVENTION
The present invention provides a non-volatile memory storage device and the operation method thereof to increase performance of the memory storage device and avoid high peak current when executing commands at the same time.
According to the present invention, a non-volatile memory storage device has a non-volatile memory, e.g., a flash memory, and a controller coupled to the non-volatile memory. The controller comprises a plurality of control circuits and an arbitration circuit. Each control circuit is configured to generate a request to update the CE for the non-volatile memory, and the arbitration circuit configured to determine when the requests are acknowledged. The CE for non-volatile memory is updated when all of the requests are received and acknowledged by arbitration circuit.
In brief, requests to update the CE for non-volatile memory are generated by the control circuits, and then the arbitration circuit determines when the requests are acknowledged. The CE for non-volatile memory will be updated when all of the requests are received and acknowledged.
In an embodiment, the arbitration circuit generates acknowledge signals to the control circuits when all of the requests of the control circuits are received by the arbitration circuit.
In another embodiment, the controller further comprises a command interleaving circuit to interleave timings of acknowledging the requests for the control circuits, so as to avoid peak current when executing commands.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 4 illustrate known flash memory storage devices;
FIGS. 5 to 7 illustrate known operation timing for flash memory storage devices;
FIGS. 8 to 13 illustrate a memory storage device and the operation method thereof in accordance with an embodiment of the present invention; and
FIGS. 14 to 15 illustrate a memory storage device and the operation method thereof in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described with reference to the accompanying drawings. A flash memory device is exemplified but not limited for non-volatile memory of the present invention below.
FIG. 8 illustrates a 64-bit flash memory storage device 50 having a flash controller 51 and a flash memory 52 . The flash memory 52 is a memory array of flash memory chips 54 . The flash controller 51 includes Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 . Chip-enable signals CE[ 0 ], CE[ 1 ], . . . , CE[ 15 ] each control the flash memory chips 54 of the flash memory 52 in the same column. Flash data bus FD[ 15 : 0 ] is between the Flash Control Circuit 0 and the flash memory chips 54 of the first two rows. Flash data bus FD[ 31 : 16 ] is between the Flash Control Circuit 1 and the flash memory chips 54 of the third and fourth rows. Data bus FD[ 47 : 32 ] is between the Flash Control Circuit 2 and the flash memory chips 54 of the fifth and sixth rows. Data bus FD[ 63 : 48 ] is between the Flash Control Circuit 3 and the flash memory chips 54 of the seventh and eighth rows.
In an embodiment, CE[ 15 : 0 ] transmitted to the flash memory chips 54 is determined by a CE arbitration circuit in the flash controller 51 . As shown in FIG. 9 , in addition to Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 , the flash controller 51 further comprises a CE arbitration circuit 55 . Each flash control circuit transmits a CE_UPDATE_REQUEST signal to the CE arbitration circuit 55 , and the CE arbitration circuit 55 acknowledges receipt of the request signal by transmitting a CE_UPDATE_ACK signal to the flash control circuit. After receiving the CE_UPDATE_ACK signal, Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 transmit chip-enable signals ce_ 0 [ 15 : 0 ], ce_ 1 [ 15 : 0 ], ce_ 2 [ 15 : 0 ] and ce_ 3 [ 15 : 0 ] to the CE arbitration circuit 55 , respectively. Then, the CE arbitration circuit 55 transmits CE[ 15 : 0 ] to the flash memory chips 54 .
FIG. 10 illustrates an embodiment of the timing diagram for the flash memory storage device 50 . Each of the flash control circuits may transmit CE_UPDATE_REQUEST signal denoted by “R” to the CE arbitration circuit, and the CE arbitration circuit will not send acknowledge signals CE_UPDATE_ACK denoted by “A” to the flash control circuits until all CE_UPDATE_REQUEST signals are received. The flash control circuits update chip-enable signals in the “U” to the arbitration circuit after receiving CE_UPDATE_ACK signals, thereby causing ce_ 0 [ 0 ], ce_ 1 [ 0 ], ce_ 2 [ 0 ] and ce_ 3 [ 0 ] to switch from “1” to “0” at the same time. In this embodiment, ce_ 0 [ 0 ], ce_ 1 [ 0 ], ce_ 2 [ 0 ], ce_ 3 [ 0 ], and CE[ 0 ] are changed from “1” to “0” at the same time. The CE_UPDATE_REQUEST signals from the flash control circuits may be transmitted to an AND gate to generate a CE_UPDATE_ACK signal as shown in FIG. 11 . CE_UPDATE_ACK will be transmitted to the flash control circuits afterwards.
FIG. 12 illustrates CE update procedures in accordance with the prior art and the present invention. For a prior art, in the flash control circuits, CE for flash memory chips will be updated directly from state A, then change to state B after CE signals are updated. According to the present invention, the flash control circuits transmit CE_UPDATE_REQUEST signals to the CE arbitration circuit when it needs to update CE, and CE for flash memory chips can be only updated until the CE arbitration circuit acknowledges CE_UPDATE_ACK signals to the flash control circuit.
FIG. 13 illustrates a timing diagram for the flash memory storage device 50 in which every two neighboring columns of flash memory chips are interleaved (so-called interleave-2), i.e., they do not operate at the same time. Likewise, each of the flash control circuits may transmit CE_UPDATE_REQUEST signal denoted by “R” to the CE arbitration circuit, and the CE arbitration circuit will send acknowledge signals CE_UPDATE_ACK denoted by “A” to the flash control circuits until all CE_UPDATE_REQUEST signals are received. The flash control circuits change its chip-enable signals denoted by “U” after receiving CE_UPDATE_ACK signals. For ce_ 0 [ 0 ] and ce_ 0 [ 1 ], ce_ 1 [ 0 ] and ce_ 1 [ 1 ], ce_ 2 [ 0 ] and ce_ 2 [ 1 ], ce_ 3 [ 0 ] and ce_ 3 [ 3 ] corresponding to “U” of Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 and Flash Control Circuit 3 , will not be “0” at the same time. CE[ 0 ] is logic AND from ce_ 0 [ 0 ], ce_ 1 [ 0 ], ce_ 2 [ 0 ], and ce_ 3 [ 0 ]. CE[ 1 ] is logic AND from ce_ 0 [ 1 ], ce_ 1 [ 1 ], ce_ 2 [ 1 ], and ce_ 3 [ 1 ]. CE[ 0 ] and CE[ 1 ] will not be “0” at the same time because flash control circuits update its CE signals simultaneously.
The increase of performance for the flash memory storage devices may incur more power consumption. Peak power demand will rise dramatically when the flash control circuits execute flash commands at the same time. According to this invention, the command timings for flash control circuits are interleaved or differentiated to reduce peak current. In FIG. 14 , at time “a”, all flash control circuits request to update CE, Flash Control Circuit 0 receives an acknowledge signal denoted by “A”; however, Flash Control Circuit 1 receives “A” with an interval of “WAIT_CNT” in comparison with Flash Control Circuit 0 . In other words, the generation of acknowledge signal “A” for Flash Control Circuit 1 is postponed with a time period of “WAIT_CNT.” Likewise, the generation of acknowledge signals “A” for Flash Control Circuit 2 and Flash Control Circuit 3 are postponed by the time period “WAIT_CNT” in sequence also. Accordingly, the acknowledge signals for Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 , Flash Control Circuit 3 are generated at time “b”, “c”, “d” and “e”, respectively, i.e., the timings for acknowledgment for the control circuits are interleaved or differentiated. Therefore, the commands “ 60 ” and “D 0 ” will not execute at the same time, thereby reducing the peak power consumption of memory storage device while executing commands. In FIG. 9 , the flash controller 51 can also interleave the acknowledgement of receipt of the requests, thereby preventing commands from executing at the same time to overcome the current peak problem. In an embodiment, the CE arbitration circuit 55 may comprise a command interleaving circuit 56 to interleave the timings of acknowledging the requests.
FIG. 15 illustrates another embodiment, a flash memory storage device 60 having a flash controller 61 and a flash memory 62 . The flash memory 62 includes a memory array of flash memory chips 64 . The flash controller 61 includes Flash Control Circuit 0 , Flash Control Circuit 1 , Flash Control Circuit 2 , Flash Control Circuit 3 , Flash Control Circuit 4 , Flash Control Circuit 5 , Flash Control Circuit 6 , and Flash Control Circuit 7 . Chip enable signals CE[ 0 ], CE[ 1 ], . . . , CE[ 15 ] each control the flash memory chips 64 of the flash memory 62 in the same column. Each flash control circuit has an 8-bit data bus. Flash Control Circuit 0 has data bus FD[ 7 : 0 ]; Flash Control Circuit 1 has data bus F[ 15 : 8 ]; Flash Control Circuit 2 has data bus F[ 23 : 16 ]; Flash Control Circuit 3 has data bus F[ 31 : 24 ]; Flash Control Circuit 4 has data bus F[ 39 : 32 ]; Flash Control Circuit 5 has data bus F[ 47 : 40 ]; Flash Control Circuit 6 has data bus F[ 55 : 48 ]; Flash Control Circuit 7 has data bus F[ 63 : 56 ]. The CE Arbitration Circuit 65 can coordinate CE signals of flash control circuits and interleave the timing of command issue to increase performance and avoid peak current concurrently.
The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims. | A non-volatile memory storage device has a non-volatile memory, e.g., a flash memory, and a controller coupled to the non-volatile memory. The controller comprises a plurality of control circuits and an arbitration circuit. Each control circuit is configured to generate a request to update the chip-enable (CE) signals for non-volatile memory, and the arbitration circuit is configured to determine when the requests are acknowledged. The arbitration circuit generates acknowledge signals to the control circuits when all of the requests of the control circuits have been received by the arbitration circuit. The CE signals for non-volatile memory are updated when requests are acknowledged. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-in-part of U.S. patent application Ser. No. 13/006,813 filed on Jan. 14, 2011 which claims the benefit of priority to U.S. Patent Application No. 61/294,947 filed on Jan. 14, 2010. The disclosures of the above applications are incorporated herein by reference to the extent that such disclosures are not inconsistent with this application.
FIELD
The present disclosure is directed towards looking up words on a display screen and inserting translated words or word combination in a text.
BACKGROUND
Electronic dictionaries are used to look up individual words and word combinations by users who are reading printed texts or texts displayed on a computer screen. Users may interact with electronic dictionaries in different ways.
There are a plethora of electronic devices with display screens capable of displaying text. These devices are suitable for using electronic dictionaries which may be installed locally, i.e. on the user's computer or portable device (such as smartphones, PDAs, cell phones, digital photo or video cameras, e-book readers, and other gadgets), provided on a local area network, or available over the Internet.
Many of the aforesaid devices include advanced displays and associated logic capable of supporting non-keyboard input methods. For example the devices may support pen-based input, or touch-based input.
Many devices, for example, mobile phones, smartphones, pad tablets, or e-books, have small screens, which do not allow a user to open several windows and simultaneously use several applications without frequently switching between them. A small screen makes a text translation process difficult and there is a need to integrate a dictionary with a portable device such that a user may conveniently perform text translation on a small screen.
SUMMARY
The disclosed method and system displays meanings and translations of words and word combinations using electronic dictionaries and enables a user to select and insert an acceptable translation in a text.
In one embodiment, the method comprises: touching a touch screen of an electronic device with a finger, a stylus, or any other suitable object, or aiming a cursor on a word; establishing coordinates of the touch or the cursor location; identifying a word or a word combination chosen by the user; looking up the identified word or the word combination in a dictionary; displaying an abridged version of a relevant dictionary entry, for example, in a balloon or in a pop-up window on the screen of the electronic device; providing a choice to a user of several proposed alternatives of translation including a selection of word forms (such as gender, number, grammatical tense, and other grammatical variations of a word); and inserting a selected alternative of the translation of a word or word combination in the text. While the description refers to translation and provides examples of translation from one language to another, it should be noted that the present disclosure is equally applicable to word look-ups and replacements in the same language. In addition to the foreign language translation, the “translation” words include replacement words in the same language, for example, synonyms.
Electronic dictionaries may comprise a software program and dictionary data. The program may include a shell, which provides a graphical user interface, morphology models to provide inflected forms, context search that uses an index, a teaching module, and other features. The dictionaries may be stored in various locations including on the computer device, such a portable device, or on a server in a local area network (LAN) or a wide area network (WAN), such as the Internet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of displaying a dictionary entry of a word touched by a user on a touch screen of an electronic device.
FIG. 2 shows a flowchart of operations performed by dictionary software during translation of an indicated word or word combination.
FIG. 3A shows an example of displaying alternative translations of a word touched/clicked by a user on a screen of an electronic device.
FIG. 3B shows an example of displaying relevant word forms of a chosen alternative of a translation.
FIG. 4 shows a flowchart of operations performed by dictionary software in connection with inserting a translated word or word combination in the displayed text.
FIG. 5A shows an example of choosing an acceptable word form by touching/clicking it.
FIG. 5B shows a result of an insertion of translated word in the text.
FIG. 6 shows exemplary architecture for implementing the electronic device.
DETAILED DESCRIPTION
The disclosed electronic device allows a user to quickly obtain meanings and translations of words displayed as part of a text from electronic dictionaries and to insert an acceptable alternative of translation of such a word or word combination in the text while reading or translating the text on a display screen of the electronic device. The meanings and translations may be displayed in a balloon, in a pop-up window, as subscript, as superscript, or in any other suitable manner, when the user touches a word on the display screen or aims a cursor at a word.
The disclosed device displays word translations on a screen of an electronic device. FIG. 1 of the drawings illustrates an example of an electronic device 102 , comprising a display screen 104 . The content presented on the display screen or touch screen 104 may be outputted by an application (e.g., Word, Notepad, Adobe, e-book reader, a Web Browser, e-mail, a text message, image display, or another appropriate application) that provides text to the display screen 104 . When the user touches an area on the display screen 104 with a finger, a stylus or with any other suitable object and there is a word or word combination in the area, a balloon with a translation appears displaying an abridged version of the relevant dictionary entry.
The Italian text of FIG. 1 states the following: “Florence is situated in a scenic location: the center of a large amphitheater, surrounded on three sides by the beautiful hills of clay Cercina, slightly above the popular district of Rifredi and Careggi Hospital (in the north), by the hills of Fiesole (in the northeast), Settignano (in the east), and Arcetri, Poggio Imperiale, Bellosguardo (in the south). The plain, where the city towers up, is crossed by the Arno (the city itself is divided by it between Upper Valdarno and Lower Valdarno) and by smaller rivers such as the Mugnone, Terzolle and by the river Greve. Metropolis of Florence—Prato—Pistoia, established by the Regional Council of Tuscany on 29 Mar. 2000, is a very populated, with a population of about 1,500,000 inhabitants, and includes entirely the provinces of Florence, Prato and Pistoia.”
The electronic device 102 may comprise a computer system, such as a general purpose computer, embodied in different configurations such as a desktop personal computer (PC), laptop computer, smartphone, cell phone, digital camera, or another gadget having a display screen. FIG. 6 of the drawings shows exemplary hardware and system architecture for implementing electronic device 102 in accordance with one embodiment.
Electronic device 102 may include a client dictionary application and one or more local dictionaries. Additionally or alternatively to a local dictionary, the application may be able to access one or more remote dictionaries located on a remote server via network connection to the server, e.g. over the Internet.
To look up words and word combinations that appear in non-text files, for example in JPG, TIFF or PDF files, the user's electronic device may include additional Optical Character Recognition (OCR) software which identifies the region on the image where the word or word combination is located and then converts the image in the region into a text format. Optical Character Recognition may also be performed using a remote server, which receives an image and an identified area from the device, applies OCR processing so as to ascertain the word or words at issue, and returns the recognized word or words to the device. The remote server may be accessible via a data path that includes a wireless data path, internet connection, Bluetooth, etc.
FIG. 2 shows a flowchart of operations performed by the device in connection with the dictionary application. When the user reads a text on the display screen 104 of the electronic device 102 and wishes to look up a word or word combination, the user simply points to the word or word combination with a mouse cursor or touches the corresponding region on the display screen 104 with a finger, a stylus or any other suitable object.
The touching or aiming a cursor 210 initiates a process that enables the user to see an abridged dictionary entry for the word or the word combination. Next, the electronic device 102 takes advantage of the screen's ability to establish the coordinates of the area of touching or aiming and matches these coordinates against the image on the screen. In one embodiment, when the touch screen senses the touching of the screen 104 , e.g. by finger, touch coordinate information corresponding to the touching is conveyed to the dictionary software application via the operating system. Techniques that determine coordinates corresponding to the area of touching typically depend on the type of the touch screen which may be resistive, matrix, capacitive, based on surface acoustic waves, infrared, optical imaging, based on dispersive signal technology, acoustic pulse recognition, or another suitable technology. In another embodiment, the touch screen may have a program interface, and the dictionary software application may receive coordinates corresponding to the touching directly from the touch screen through the program interface.
After receiving the coordinates, the dictionary software application determines whether the corresponding point is in a text area ( 220 ) of a currently displayed document. If the coordinates point to a text area, the word region pointed by a user is identified ( 250 ). A word region may contain one word or a word combination. In one embodiment, a word combination relates to one or more words, adjacent to the pointed to word, which, in combination, have a meaning defined in the dictionary. Consequently the system checks for a dictionary meaning not only for the identified word itself but for its combination with adjacent words, if any. The identified word or word combination is passed as a query to the dictionary.
If the coordinates point to an area encoded as an image (e.g. PDF, JPG, TIF, and other picture or image formats where words are not stored as collections of characters), an OCR software is applied. At step 230 , OCR software identifies a rectangular region corresponding to the user input that contains text. To speed up OCR, the OCR software may identify a smallest rectangular image that contains an image of one word or a word string in the area touched by the user. Alternatively, the entire document or its portion may be processed by the OCR software.
At step 240 , the OCR software is applied to the identified rectangular region. The result of the OCR processing is a word or word combination represented by a string of characters. At the OCR step, morphology dictionaries, which include the inflected forms of the words, may also be used, as higher OCR accuracy and error correction are often achieved by comparing the recognition results with word forms in the morphology dictionary. At step 250 , a word or words, selected on the screen and determined, if necessary using OCR processing, are identified as a dictionary query.
At the step 260 , the query is passed to a dictionary or a set of dictionaries that may be preliminarily selected by user. Dictionary software may use default one or more dictionaries or a user may specify a desired dictionary. A default dictionary on a given subject may be selected if the dictionary software determines that the text belongs to a specialized subject. Additionally, the electronic dictionary includes a morphology module, so that the query word or word combination need not be in the base, or “dictionary” form—the morphology module identifies the base form of an inflected form. If more than one base forms are possible, the morphology module identifies the alternatives.
At the step 260 , the morphology of the selected word is analyzed. The morphology analysis returns a set of possible base, or “dictionary,” forms of the word. For the obtained base forms, dictionary meanings/translations are retrieved. If the entry is to be shown in a pop-up window, as subscript or if the screen has a small size as in the case of a mobile device, the most likely (frequent) translation or the translation of the most likely (frequent) part of speech may be selected. Finally, at step 270 , the meaning/translation is displayed on the display screen 104 of the electronic device 102 . The translation may be displayed in a balloon, in a pop-up window, as a subscript, or in any other suitable manner. A translation of a word combination, if found, is also displayed along with the translation of the identified word.
The electronic device 102 may access not only a bilingual dictionary, but also a monolingual dictionary with definitions, or any other reference book, a travel guide, and the like. Additionally the recorded or audio pronunciation of the identified and recognized word and/or its translation may be played back, for example, by selecting this feature preliminarily or also by a touch, which is of value to language learners. Translations may also be obtained from a remote server. The remote server may be accessible via a data path that includes a wireless data path, internet connection, Bluetooth, etc. For example, a dictionary may be an Internet-based resource identified by a user. In this case, the selected word or several words are provide to the dictionary over the Internet and the results of the look up are returned to the device for display.
Although, in the above embodiments, user input was based on finger touches, it is to be understood that in other embodiments, other user input methods based on haptic input methods in general, or other pointing methods, e.g. cursor location or pen/stylus based methods may be used.
The disclosed electronic devices may include any electronic device that has a display screen and application programs to display text or text image on the display screen. As such, the electronic devices may include a mobile phone, a smartphone, a digital camera, a dedicated reading device or e-book reader, a PC, a notebook computer, a tablet PC, or another device. There are a variety of touch screen technologies. The touch screen may be resistive, matrix, capacitive, based on surface acoustic waves, infrared, optical imaging, based on dispersive signal technology or acoustic pulse recognition, etc.
The disclosed dictionary software application provides not only word translations on a screen of an electronic device, but also a capability to perform an insertion of a translated word or a word combination in the text. Such an insertion capability facilities translation of a text displayed on a relatively small screen. It is particularly useful, for example, for users of smartphones or other portable devices. A user may translate a text by inserting translation words and then save the translated text or forward it to another user.
Referring to FIG. 3A of the drawings, and, as discussed in connection with FIG. 1 , the content presented on the display screen or touch screen 104 of an electronic device 102 may be outputted by any application (e.g., Word, Notepad, Adobe, e-book reader, a Web Browser, e-mail, a text message, or another appropriate application) that displays text on the screen 104 . When the user touches an area on the display screen 104 with a finger, a stylus or with any other suitable object or directs a cursor on a word and there is a word or word combination in the area, one or more translation alternatives of the selected word or word combination is displayed as a balloon or a pop-up window, as a subscript or in any other suitable manner.
The German text appearing in FIGS. 3A , 3 B, 5 A, and 5 B is translated as follows: “She knew that the pain in her chest became worse, the cough, sore throat, everything. She was deathly ill, but nobody else but she knew it, doctors just laughed and said that she was perfectly healthy and that no one at her age could be terminally ill. She checked everything: The heart was healthy, the lungs were healthy, the”
In most cases a word can have several meanings and therefore there are several alternative translations into another language. The advantage of the disclosed system is not only in the simplification of word-by-word translation for a user, but also in providing the capability of selecting an appropriate proposed translation alternative. Word forms for a chosen translation alternative can be proposed by the application and selected by a user. Word forms may include tense forms of verbs, singular and plural forms, and other variations of the words if appropriate.
FIG. 4 illustrates a flowchart of operations for insertion of a translated word. When a user wishes to translate a word or word combination, the user simply points to the word or word combination with a mouse, cursor or touches the corresponding region on the display screen 104 with a finger, a stylus or any other suitable object.
The touch or aiming a cursor 410 initiates a process that enables the user to see an abridged dictionary entry for the word or the word combination similarly to step 210 . Next, the electronic device 102 takes advantage of the touch screen's ability to establish the coordinates of a touch and matches these coordinates against the display on the screen, or uses coordinates of a cursor for this purpose.
After receiving the coordinates, the word region and the corresponding word query are identified at the step 420 . A word region may contain one word or a word combination. The identified word or word combination is then passed as a query to a dictionary.
At the step 430 , the query is passed to a dictionary or a set of dictionaries that are used by default or have been preliminarily selected by a user. Dictionaries may be local to the device or remote, e.g. accessible over the Internet. Additionally, a preferred electronic dictionary includes a morphology module so that the query word or word combination need not be in the base, or “dictionary” form—the morphology module identifies the base form of an inflected form. If more than one base forms are possible, the morphology module identifies the possible alternatives.
At step 430 , the morphology of the selected word is analyzed. In one embodiment, the morphology analysis returns a set of possible base forms of the word. For the obtained base forms, dictionary meanings/translations are retrieved. If the entry is to be shown in a pop-up window, as subscript or if the screen has a small size, as in the case of a mobile device, the most likely (frequently occurring) translation(s) or the translation of the most likely (frequently occurring) part of speech may be selected. If there are words adjacent to the selected word, the dictionary is checked for the word combination and, if the translation has been found, it is displayed to the user.
At the step 440 , most likely alternatives of translation of the selected word or words are displayed on the screen 104 of the electronic device 102 . The alternatives of translation may be displayed in a balloon, in a pop-up window, as a subscript, or in any other suitable manner.
At the step 450 , other alternatives of translation may be shown by touching or clicking on a special button or link ( 306 ) displayed, for example, within the translation balloon. Relevant word forms of a translation alternative may be shown by clicking on the selected word. Therefore, at step 430 the morphology module identifies relevant word forms, for example, in accordance with the form of the translated word in the original sentence. At step 460 , a user may touch/click the selected word form of the selected translation alternative. As a result, at the step 470 , a translated word or a word combination is inserted in the original text using the selected word form.
If the original text is in a form of an image as discussed in connection with FIG. 2 , OCR processing is applied to the displayed text and the image is replaced with a collection of characters. OCR processing may be provided as a local application on the device or as a remote server capability. To use remote OCR the image is transmitted to the server, for example, via Internet, and the document or a portion thereof in the text format is returned to the device. The selected word or word combination is translated as discussed above and the user selects the appropriate translation alternative and words form for the selected one or more words. The user selection is then inserted in the version of the original text processed by OCR.
FIG. 3A illustrates the translation from German into English of the verb “wusste.” When the user touches an area on the screen or directs a cursor on this word, a balloon or pop-up window appears displaying the following alternatives of translation: know; realize; and perceive. At this point, an acceptable alternative of the translation may be chosen by the user. If there are no displayed acceptable alternatives among the shown choices of translation, one may get the complete list of translation alternatives, if not all the translations were originally displayed, by pointing at the button 306 .
In one implementation, the capability of displaying not only a translation of a word, but word forms of the word to be translated is provided. Word forms include grammatical modifications of the translated word such as tense forms of verbs and a noun in a plural form. All the appropriate word forms can be shown by clicking or touching on the chosen translation as illustrated in FIG. 3B .
The German verb “wusste” is used in the text in a simple past tense. Therefore word forms in the past tense will be proposed. By clicking on or touching the chosen translation, which is in this example is the verb “know,” several forms in past tense are proposed. For example for the choice “know,” the system displays: “knew, have known, has known.” Similarly, if another alternative of translation were chosen, e.g. “realize,” word forms of this word would be offered.
An insertion of a word or word combination can be performed by clicking on or touching the most acceptable word form. For example, in this case, the past simple tense “knew” is most appropriate. Thus, by clicking or touching on the verb “knew,” as shown in FIG. 5A , this word is inserted in the text ( FIG. 5B ). The place of insertion with respect to a touched word may be selected by the user in advance. The translation may be inserted before, after, or instead of the touched word.
For any word in the pop-up window (for a word being translated or any variant of translation) a user may also obtained through the dictionary software its detailed translation and/or other reference information, such as examples of use, translations from dictionaries on various subjects (e.g. Universal, Computer, Economics, Science, etc.). For example a detailed translation may be requested by a double touch/click on the word of interest, or in any other manner specified for opening an entry with a detailed translation. The detailed and/or specialized information may be provided by dictionary resources stored in the device or accessible over the internet or a combination thereof, depending on applicable design trade-offs.
Also the interface of pop-up windows with alternatives of the translation may be customized. For example, by clicking or touching on the acceptable variant of translation in the pop-up window, in one case, the window may be expanded to include word forms or, in another case, a new window with just the chosen translation variant and its word forms would be displayed. The maximum number of alternatives offered in a pop-up window, vocabularies used during translation, the types of word form and their presentation on the display, and other relevant characteristics may be user-selected as well.
Also the capability of displaying only the most relevant word forms in the pop-up window may be selected by the user. So in the example discussed above, variants of translation will be offered in the following manner: knew, have known, realized, have realized, perceived, have perceived. Thus, a user may choose one of these proposed variants and insert it in the text. Alternatively, a user may request additional reference explanation, such as examples of usage, for any of the proposed variants. Also, the system may be prompted to pronounce any of the translation alternatives.
This method is especially useful for word-by-word translation of a text or for writing a text message in a foreign language. For example, it can be used in connection with Text Document, Word, e-mail, text message, address bar or input string in a browser. The disclosed method reduces time required for translation, since a user does not need to open multiple windows on a screen, switch between applications, remember the correct spelling of the desired word, and input translation in the text. Such advantages are particularly useful in devices with small screen (e.g. mobile devices) for saving space on the screen.
FIG. 6 of the drawings shows hardware and system architecture 600 that may be used to implement the user electronic device 102 in accordance with one embodiment of the invention in order to translate a word or word combination, to display the found translations to the user, to chooses the alternative of the translation and its word form, and to insert the choice in the displayed text. Referring to FIG. 6 , the system 600 typically includes at least one processor 602 coupled to a memory 604 and having touch screen among output devices 608 , which, in this case, is serves also as an input device 606 . The processor 602 may be any commercially available CPU. The processor 602 may represent one or more processors (e.g. microprocessors), and the memory 604 may represent random access memory (RAM) devices comprising a main storage of the system 600 , as well as any supplemental levels of memory, e.g., cache memories, non-volatile or back-up memories (e.g. programmable or flash memories), read-only memories, etc. In addition, the memory 604 may be considered to include memory storage physically located elsewhere in the hardware 600 , e.g. any cache memory in the processor 602 as well as any storage capacity used as a virtual memory, e.g., as stored on a mass storage device 610 .
The system 600 also typically receives a number of inputs and outputs for communicating information externally. For interface with a user or operator, the hardware 600 usually includes one or more user input devices 606 (e.g., a keyboard, a mouse, touch screen, imaging device, scanner, etc.) and a one or more output devices 608 , e.g., a display device and a sound playback device (speaker). The system 600 preferably includes a touch screen device (for example, a touch screen), or an interactive whiteboard, or another device which allows the user to interact with a computer by touching areas on the screen. The keyboard is not obligatory for the embodiments.
For additional storage, the hardware 600 may also include one or more mass storage devices 610 , e.g., a removable drive, a hard disk drive, a Direct Access Storage Device (DASD), an optical drive, e.g. a Compact Disk (CD) drive and a Digital Versatile Disk (DVD) drive. Furthermore, the system 600 may include an interface with one or more networks 612 (e.g., a local area network (LAN), a wide area network (WAN), a wireless network, and/or the Internet among others) to permit the communication of information with other computers coupled to the networks. It should be appreciated that the system 600 typically includes suitable analog and/or digital interfaces between the processor 602 and each of the components 604 , 606 , 608 , and 612 as is well known in the art.
The system 600 operates under the control of an operating system 614 , and executes various computer software applications 616 , components, programs, objects, modules, etc. to implement the techniques described above. In particular, the computer software applications include the client dictionary application and also other installed applications for displaying text and/or text image content such a word processor, dedicated e-book reader etc. Moreover, various applications, components, programs, objects, etc., collectively indicated by reference 616 in FIG. 6 , may also execute on one or more processors in another computer coupled to the system 600 via a network 612 , e.g. in a distributed computing environment, whereby the processing required to implement the functions of a computer program may be allocated to multiple computers over a network.
In general, the routines executed to implement the embodiments of the invention may be implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions referred to as “computer programs.” The computer programs typically comprise one or more instructions set at various times in various memory and storage devices in a computer, and that, when read and executed by one or more processors in a computer, cause the computer to perform operations necessary to execute elements involving the various aspects of the invention. Moreover, while the invention has been described in the context of fully functioning computers and computer systems, those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of computer-readable media used to actually effect the distribution. Examples of computer-readable media include but are not limited to recordable type media such as volatile and non-volatile memory devices, floppy and other removable disks, hard disk drives, optical disks (e.g., Compact Disk Read-Only Memory (CD-ROMs), Digital Versatile Disks (DVDs), flash memory, etc.), among others. Another type of distribution may be implemented as Internet downloads.
While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the broad invention and that this invention is not limited to the specific constructions and arrangements shown and described. | A computer method and an electronic device enable a user to lookup words and insert new words in a text based on the results of the look up. The method executed by the device includes: providing a user with a capability to select at least one word in a text displayed on the screen of the device; performing a dictionary lookup of the identified word so as to determine translation alternatives of the identified word; displaying at least some of the translation alternatives; selecting one of the displayed alternatives; determining its word forms, wherein the word forms consist of gender, number, grammatical tense and grammatical variations of the same word; selecting one of the word forms; and inserting the selected word from in the text. | 6 |
BACKGROUND OF THE INVENTION
Evolution in the design of "clean rooms" has resulted in the general use of modular filter units that can be incorporated into customized or standard plenum structures. The general function of this assembly is to subject all the air coming into a room to the action of high-efficiency filters to remove all airborne particles in excess of a specified size. A completely site-constructed plenum, where parts are all cut from stock and processed at the point of installation, is always expensive, as the use of special machinery and cutting fixtures common in factory operations is not practical. This situation has resulted in the development of larger and larger fully prefabricated filtration modules including the plenum and its structure that supports the filter units. There comes a limit to this line of development, however, and this is due to the problems and cost involved in shipping large units from the factory to the point of installation, and then securing them in place. Widths have a practical maximum of eight feet, due to highway restrictions. Handling a structure this wide, three or four feet high, possibly over twenty feet long and weighing several tons, can easily dissipate the efficiency resulting from factory construction.
It is now clear that this process of design evolution must take a new turn. Other industries, faced with this same problem, have tended to shift over to prefabricated components readily assembled on site without extensive machining or processing. This results in handling components of more reasonable size, and vastly increasing the load density on trucks by removing the need to transport large volumes of the empty space within the modules. The present invention is directed at the formation of a structure capable of this type of construction at a high order of efficiency, while still complying with strict clean air requirements that forbid leakage around the filter units. These modules must be able to accommodate suspension from various ceiling structures, and have a wide range of design flexibility with regard to providing units of different sizes from essentially the same components.
SUMMARY OF THE INVENTION
This filtration module has upper and lower peripheral frames providing facing channels for receiving side panels. The inner flanges of these channels are accessible from the inside for receiving fastenings extending into the panels, and presenting interengaging surfaces that are easily caulked from the same position. Top panels are supported on horizontal shelves integral with the upper peripheral frame, and are similarly accessible to receive fastenings and caulking from the inside. The top panels are strengthened by beams at the junctions of the top panels, and fastenings securing the panels to these beams are also accessible at the inside of the plenum when it is under construction. These beams are independent of the peripheral frames. The filtration units are carried by a grid of beams suspended in part from the top panel beams, and in part supported by the lower peripheral frame. The frames are aligned at the corners by angular members engaging special-purpose channels in the frame extrusions.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a modular plenum involving the present invention.
FIG. 2 is an end view of the structure shown in FIG. 1.
FIG. 3 is a section on the plane 3--3 of FIG. 1.
FIG. 4 is an enlarged fragmentary section showing the structural details of the plenum.
FIG. 5 is a perspective view of one of the corner alignment angles.
FIG. 6 is a horizontal section at the corner of the plenum, showing the engagement of the side panels with a corner extrusion.
FIG. 7 is a section showing the retention of the corner extrusions in the peripheral frames.
FIG. 8 is a fragmentary perspective view showing the junction of the components of the filter-supporting grid frame with the lower peripheral frame of the plenum.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2, and 3, the filtration plenum module indicated generally at 10 may be provided with a blower system shown in dotted lines at 11 for generating a positive pressure within the module relative to the ambient pressure within the room in which the module is installed. Alternatively, a pressure duct (not shown) may be connected to the module as a source of the air pressure. The module includes the upper and lower peripheral frames 12 and 13, respectively, and a group of side panels as shown at 14 and 15 in FIG. 3 forming a closure around the module, and extending between the upper and lower peripheral frames. The module supports a group of standard HEPA filter elements at shown at 16-20 in FIG. 3 through which the air within the plenum is forced. This provides the room below the plenum with the "clean air" required by many industrial and laboratory processes. Optionally, the plenum may also include a group of light fixtures as shown at 21-24, and the sprinkler installation indicated at 25 for the reduction of fire hazards. The top of the plenum is closed off by the rectangular panels 26-30. A suitable opening in a selected one or more of these panels is provided for the air supplied by the blower system 11.
The interior structure of the plenum module is best shown in FIG. 4, which illustrates the junction between the module 10 and a similarly-constructed module 31. The upper peripheral frame is formed by the extrusion 32, and the lower peripheral frame by the extrusion 33. The ends of these extrusions will normally be mitered at the corners of the module, and these corners are secured by angle plates as shown at 34 in FIG. 4. The upper portion of the extrusions 32 is formed by an upwardly-open channel 35 having the inwardly-turned flanges 36 and 37. A terminal block 38 similar to a weldnut is free to slide along the rails provided by the flanges 36 and 37, and is engaged by the bolts 39 securing the corner angles 34. Other terminal blocks similar to the block 38 can be positioned opposite selected components of the ceiling structure of the room to carry the weight of the module. Threaded rods of a length appropriate to the distance from the module up to the ceiling will engage these terminal blocks.
The upper extrusion 32 also has a horizontal shelf 40 supporting the top panel 30, which is secured in place by screws as indicated at 41. The top panels, and the side closure panels as well, are of sheet aluminum, as shown at 42. A layer of fiberglass insulation 43 is bonded to the aluminum 42 to inhibit heat and sound transfer. The opposite edge of the panel 30, at the junction with the panel 29, has an offset flange 43 disposed in a vertical plane set back from the panel junction 44, where the panel is secured to the junction beam 45 by the self-tapping screws 46. The junction beam 45 is preferably a rolled steel member having the in-turned flanges 47 and 48. The beam 45 has a generally U-shaped configuration, and a similar beam 49 is spot-welded along the closed sides of the cross section to provide a downwardly-open channel for receiving the terminal blocks 50. A grid of filter-supporting beams 51 is secured at their junctions by cast members as shown at 52, and these are engaged by the threaded rods 53 extending to the terminal blocks 50. The filter-supporting grid is thus supported primarily by the junction beams formed by the channels 45 and 49, which are secured exclusively to the top panels of the module, and do not need to be secured to the upper peripheral frame. When the top and side panels are in assembled position, they are caulked with a standard sealant to seal off any flow from the interior outward at the various junctions of the components of the module. The caulking is normally done on the inside of the module during assembly, and the module's structure facilitates the application.
The lower peripheral frame 13 formed by the extrusions 33 provides an upwardly-open channel for receiving a sealant indicated at 54. The vertical flange 55 of the frame 56 of the filter unit dips into the sealant 54 to provide a positive seal against any flow of air around the filter mass indicated at 57. The lower peripheral frame also has the parallel flanges 58 and 59 forming an upwardly-open channel vertically opposite the similar channel formed by the flanges 60 and 61 of the upper extrusions 32. These facing channels receive the side panels forming the peripheral closure of the module. These panels are secured by screws and caulked in the same manner as are the top panels.
Referring to FIG. 8, the grid of filter-supporting beams 51 is connected together at the beam intersections by the cross-shaped castings 52, in which the cross configuration is formed by downwardly-open channels that embrace the tops of the beams 51. The spaced flanges 60 and 61 of the beams 51 are serrated on the inner surfaces in a staggered pattern that conforms to the standard thread spacing of bolts as shown at 62 traversing the channels, and engaging the ridges on the inside of the flanges 60 and 61. The central boss 63 of the fitting 52 is threaded internally to receive the rod 53 extending upward to the terminal block in the junction beams secured to the cover panels of the module. The beams 51 may be continuous in any one direction, with the beams perpendicular to it formed by short sections interconnected by the junction fittings 52. At the peripheral frames, T-shaped fittings as shown at 64 and 65 are secured to the horizontal shelves 66. Since the flanges 55 of each of the filter units is continuous around its entire periphery, the channels containing the sealant must be continuous around both the lower peripheral frame and the grid beams. This requires that appropriate notches be made in the flanges forming these sealant channels at these points of intersection. Since this sealant is initially quite flowable, it is advisable to close off any gaps such as occur at the notched-out junctions of the grid beams with the lower frame, and at the bevelled corners of the lower frame members. This can be done by the application of tape, or by special patches that retain the sealant in the troughs until the sealant develops increased viscosity.
At the corner junctions of the side panels of the module, the structure shown in FIG. 6 and 7 is used. A sealable junction of the side panels is provided by the corner extrusion 67, which provides mutually perpendicular channels for receiving the ends of the adjacent side panels 68 and 69. The extrusions 67 enter into the facing channels in the upper and lower peripheral frames, which are wide enough to accept the thickness of the extrusion walls along with the thickness of the panels. Blind rivets as shown at 70 in FIG. 7 traverse appropriate holes in the frame extrusions and in the aluminum sheets of the panels, and are expanded within the panel insulation. On some occasions, the side panels have to be spliced at intermediate points around the periphery of the module, and this is done with a conventional H-shaped extrusion (not shown) entering into the frame channels in the same manner.
Where plenum modules are secured together as shown in FIG. 4 to form a large plenum installation, holes are drilled in the mating sections of the lower peripheral frame on an axis positioned approximately as shown at 71. To seal this juncture properly, gaskets as shown at 72 and 73 are interposed between the lower peripheral frames of the two joined modules, so that the tightening of bolts along the axis of 71 will provide an adequate seal. Where modules are interconnected to form a single large plenum, the abutting end panels are eliminated to form an unobstructed air space.
The assembly procedure for these plenum modules will vary somewhat with the conditions at the point of installation and with the size of the modules. All of the components will be pre-drilled, so that the parts can be put together in the manner of the familiar Erector set. In most cases, the module will be constructed upside down, with the upper peripheral frame resting either on the floor or on appropriate horses that will place the structure at a more convenient working level. The design of the components that have been described is such that all of this work can be done in this position, working from the inside of the plenum. Probably after the installation of the filter-supporting grid, the module is inverted, and hoisted into place. The suspension rods leading to the ceiling structure are installed, and the unit is then ready to receive the standard filter units. Any further special work is easily performed prior to the installation of these units, as the workmen (standing on some form of ladder or platform) can work with head and shoulders extending through the spaces between the grid beams. In most cases it will be possible to completely prefabricate the upper and lower peripheral beams including the application of the sealing material 54, at the factory, these being shipped flat to the point of installation. The side panels and the other structure are then added. During the initial manufacture of the peripheral frames, the frame extrusions are mitered at the corners, and aligned at these junctions with the alignment angles shown in FIG. 5. These are in the configuration of a right angle, and are made from spring steel preferably twenty or thirty thousandths of an inch in thickness. Each of the legs 74 and 75 are lanced to provide projections as shown at 76-79. The legs 74 and 75 enter into alignment channels as shown at 80 in FIG. 4 in the lower frame extrusions, and the presence of the lanced-out portions 76-79 provides a differential force between the insertion and the withdrawal of these members. It is preferable that the channels 80 are proportioned so that the legs 74 and 75 have to be pounded into place. They will normally be inserted with the projections extending downward, as the channels 80 have an opening on the upper side that is necessary in the design of the extrusion dies. Once these angular pieces are firmly in place, the beveled junctions of the frame extrusions are temporarily aligned so that the exterior corner angles can be applied to complete the frame security. It is also preferable to include the dimpled areas 81 and 82 in these alignment angles so that the full depth of the channel 80 is occupied, and thus assure a more effective alignment. The upper of these two installations shown in FIG. 4 is indicated at 83. | A filter plenum module has upper and lower peripheral frame extrusions providing vertically opposite and facing channels receiving side panels secured with fastenings traversing the inner flanges of the channels to engage the panels. Top closure panels are received on horizontal flanges of the top peripheral frame. Fastening and caulking are thus applied all from the inside, as the modules are constructed. Top panels are interconnected by reinforcing beams carried exclusively by the panels. These beams provide the principal support for the grid beams supporting the filter units. The peripheral beams also carry terminals that can be selectively placed to support the plenum assembly, according to the conditions available in the ceiling structure at the point of installation. Angle members are inserted in receptacle channels at the mitered corners of the peripheral beam extrusions for initial alignment. | 5 |
FIELD OF THE INVENTION
This invention relates to diffusers for compressors, and more specifically, to a multiple stage, vaned diffuser for a radial discharge compressor.
BACKGROUND OF THE INVENTION
Diffusers are employed in compressors to convert what may be referred to as a "velocity head" to a "pressure head". It is, of course, highly desirable that this conversion be made with minimal losses since such losses reduce the efficiency of the operation of the machine employing the compressor.
One means of cutting diffuser losses resides in employing a so-called cascade diffuser wherein the vanes are arranged in two or more stages. The vanes in the first stage are located radially inward of the vanes in the second stage with the latter also being downstream of the former in the direction of air flow in the diffuser. Examples of this approach may be found in U.S. Pat. Nos. 3,588,270 issued June 28, 1971 to Boeics and 3,861,826 issued Jan. 21, 1975 to Dean as well as Paper No. 72-GT-39 published by the American Society of Mechanical Engineers and authored by R. C. Pampreen.
Even though these cascade diffusers reduce losses, because transonic velocity occurs in such diffusers, undesirable shock waves may be generated which create losses and otherwise detract from diffuser performance.
The present invention is directed to overcoming the above problem.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a new and improved diffuser for a radial discharge compressor. More specifically, it is an object of the invention to provide a cascade diffuser having plural stages of vanes and wherein the vanes of at least the first stage are configured as supercritical airfoils to minimize losses occurring within the diffuser.
An exemplary embodiment achieves the foregoing object in a radial discharge compressor including a impeller rotatable about an axis and having blades extending from a radially inward position to a radially outward position to terminate in radially outermost discharge ends. An annular collector surrounds the impeller in radially spaced relation with respect thereto and includes at least one compressed gas discharge port. An annular diffuser is disposed between the discharge ends of the impeller vanes and the collector. The diffuser has a radially inner first stage made up of a plurality of radially inner diffuser vanes and a radially outer second stage made up of a plurality of radially outer diffuser vanes, each aligned with a corresponding one of the inner vanes. Each of the vanes has a leading edge and a trailing edge with each trailing edge being radially outward of the leading edge of the associated vane and displaced circumferentially from the leading edge of the associated vane in the direction of rotation of the impeller. According to the invention, at least the vanes of the first stage have cross sections configured as supercritical airfoils.
In a preferred embodiment of the invention, the trailing edges of the vanes of the first stage are separated from the leading edges of the vanes of the second stage in such a way as to define high speed jets.
In a highly preferred embodiment of the invention, the vanes at both of the stages have cross sections configured as supercritical airfoils.
A highly preferred embodiment of the invention contemplates that the leading and trailing edges of the vanes are interconnected by spaced, high and low pressure surfaces and that the airfoils be positioned to have their high pressure surfaces located radially outwardly of their low pressure surfaces.
In addition, the invention contemplates that the leading edges of the vanes of the second stage be in advance of the trailing edges of the corresponding vane of the first stage in the direction of gas flow.
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 a radial discharge compressor made according to the invention; and
FIG. 2 is an enlarged, fragmentary view of two vanes employed in a diffuser.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An exemplary embodiment of a radial discharge, centrifugal compressor is illustrated in FIG. 1 and with reference thereto is seen to include an impeller 10 mounted on a shaft 12 for rotation in the direction of an arrow 14. The shaft 12 is driven by a motor (not shown) and compressor will be provided an inlet for the gas to be compressed that is coaxial with the rotational axis of the shaft 12.
The impeller 10 includes a plurality of vanes or blades 16 which extend radially outward to terminate in outermost discharge ends 18. It is to be particularly noted that the configuration of the vanes 16 and the ends 18 may be conventionally determined and forms no part of the present invention.
An annular collector 20 is located radially outwardly of the impeller 10 in surrounding and spaced relation thereto. The collector 20 may be of conventional configuration and as illustrated in FIG. 1 includes a conventional volute 22 that opens toward the impeller 10 and which terminates in a compressed gas discharge port 24.
Interposed between the impeller 10 and the collector 20 is an annular diffuser, generally designated 26. The diffuser 26 may be comprised of at least one generally circular plate 28 upon which a first stage of diffuser vanes 30 is mounted at a radially inner position adjacent the discharge ends 18 of the impeller vanes 16. The plate 28 also mounts a second stage of diffuser vanes 32 which are located radially outward of the first stage 30 and which are aligned with corresponding ones of the vanes 30 of the first stage.
According to the invention, the vanes 30, and preferably the vanes 32 as well, have cross sections configured as supercritical air foils. The term "supercritical airfoil" is used in a conventional sense and refers to an airfoil that is characterized by very little camber in the forward portion with a severe camber at the rear portion.
The vanes 30 have high pressure sides 34 while the vanes 32 have high pressure sides 36. In addition, the vanes 30 have low pressure sides 38 while the vanes 32 have lower pressure sides 40. As used herein, the low pressure side is that that would be subjected to the least pressure if the vane were employed as a wing. Stated another way, if the vanes were employed as wings, lift in the aerodynamic sense would be operating against the high pressure surfaces 34 and 36.
In any event, according to the invention, the high pressure surfaces 34 and 36 are located radially outwardly of the low pressure surfaces 38 and 40.
Where the surfaces 34 and 38 for the vanes 30 meet, leading edges 42 and trailing edges 44, in relation to the direction of air flow from the impeller 12, are formed. The vanes 32 likewise have leading edges 46 and trailing edges 48 and it will be appreciated from the drawings that the leading edges 46 of the vanes 32 of the second stage are in advance of the trailing edges 44 of the corresponding vanes 30 in the first stage in the direction of gas flow, shown by arrows 50 in FIG. 2. The leading edges 46 are also slightly spaced from the trailing edges 44 and as a consequence, high speed jets 52 for the compressed gas are formed at those locations.
As a result of this construction, the shock waves that are present on the low pressure surfaces of airfoils of conventional construction at transonic velocities are minimized thereby minimizing a source of operational inefficiency. Furthermore, the use of a supercritical airfoil configuration in forming the vanes 30 provides excellent boundary layer control and allows the radial length of the diffuser to be minimized.
The fact that the shock waves are reduced helps maintain the air flow on the surfaces 34, 36, 38, 40 thereby taking advantage of a greater percentage of the surface area of the diffuser vanes 30 and 32 for better efficiency. Similarly, the jets 52 assist in maintaining air flow on the surface of the vanes 32 so that the area of the vanes is more effectively used enabling the previously mentioned relatively short radial length. | Losses in a diffuser 26 for a radial discharge compressor including an impeller 10 with impeller blades 16 terminating in radially outer discharge ends 18 are minimized by means of first and second stages of diffuser vanes 30 and 32, which vanes 30 and 32 have cross sectional shapes configured as supercritical airfoils. | 5 |
This application is a division of application Ser. No. 689,619, filed Jan. 8, 1986, now U.S. Pat. No. 4,670,057.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a primer for the pretreatment of glass surfaces which are to be bonded by standard adhesives to rigid or flexible substrates.
2. Description of Related Art
Glass is a difficult substrate to bond because direct bonding does not produce bonds which satisfy stringent requirements with respect to mechanical strength and durability. Numerous efforts have been made to develop suitable primers. Thus, a primer based on a resin and a silane, such as for example N-2-aminoethyl-2-aminopropyl trimethoxysilane, is proposed for example in U.S. Published patent application No. B 417,014. Although primers such as these provide for bonds which are sufficiently resistant to water and hydrolysis for certain applications, there is nevertheless a need to increase the resistance of glass bonds to water. Thus, waterproof elastomer-glass bonds are for example of interest in the automotive industry.
DESCRIPTION OF THE INVENTION
Accordingly, an object of the present invention is to provide a primer, i.e. a pretreatment agent, for glass by which it is possible to establish hydrolysis-resistant bonds between glass and flexible or rigid substrates, for example elastomers or metals, using known adhesives.
Accordingly, the present invention relates to a primer for the pretreatment of glass in readiness for waterproof bonding, wherein the primer comprises:
A. from about 2 to about 10, preferably from about 3 to about 7% by weight of at least one resin,
B. from about 2.5 to about 25, preferably from about 5 to about 15% by weight of at least one functional silane,
C. from about 0.5 to about 5, preferably from about 1 to about 2% by weight of at least one organosilazane,
D. from about 70 to about 95, preferably from about 80 to about 90% by weight of an organic solvent, and
E. from 0 to about 10, preferably from about 1 to about 6% by weight of one or more of a polyfunctional isocyanate, a prepolymer of a polyhydric alcohol and a molar excess of an aliphatic or aromatic diisocyanate, and an adduct of a polyfunctional epoxide and an aliphatic or aromatic diisocyanate.
The present invention also relates to the use of the above glass primers.
As stated above, the glass primers of the invention contain a resin component, component A. Preferred resins are phenolic resins, particularly reactive phenolic resins. Reactive phenolic resins are understood to be phenolic resins which are not completely crosslinked, i.e. which do not have a three-dimensional lattice-like molecular structure. Reactive phenolic resins such as these are, for example, acid-condensed phenol-formaldehyde or resorcinol-formaldehyde resins which are generally referred to as novolacs. However, it is also possible to use base-condensed phenolic resins which still contain hydroxymethyl groups and which are capable of polycondensation on heating. Thus, it is possible to use phenolic resins in the narrower sense, resorcinol-formaldehyde resins or coumarone-indene resins. In addition to the above resin components, it is also possible to use modified resins, for example, terpene-modified phenolic resins or mixtures thereof with hydrogenated rosin resins. A review of such phenolic resins useful herein can be found in Houben-Weyl, Makromolekulare Stoffe, Part 2 (Vol. 14), Georg Thieme Verlag, Stuttgart, 1963, pages 197 et seq. which is expressly incorporated herein by reference.
In one particularly preferred embodiment of the invention, both novolacs and also resol resins, for example mixtures of novolac and tertiary butyl phenol resol resin, are used herein as component A.
For use in the primers of the invention, it is also preferred to select phenolic resins as component A. which have a viscosity at 25° C. of from about 1000 to about 5000 mPas and an OH-number of from about 300 to about 500. Known products of this type are based on phenol, cresols, tert.-butyl phenol, amyl phenol, resorcinol, or bisphenol A.
The silanes used in the primers of the invention as component B. are known compounds which are generally recommended as so-called adhesion promoters by commercial manufacturers. According to the invention, it is preferred to use products containing at least one reactive group, such as for example vinyl triethoxy silane, vinyl trimethoxy silane, vinyl-tris-(β-methoxyethoxy)silane, γ-methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl-tris-(2-methoxyethoxy)-silane, γ-mercaptopropyl-trimethoxysilane, γ-aminopropyltriethoxysilane or the adduct of acrylic acid with that compound.
The following silanes can also be used: γ-chloropropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, vinyltriacetoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and also N-β-(aminoethyl)-γ-amino-propyltrimethoxysilane or its methacrylic acid adduct in methanol solution.
As stated above, the primers of the invention contain organosilazanes as component C. Organosilazanes are reaction products of organohalogen silanes with ammonia or amines. The reaction products with ammonia are preferred for the purposes of the present invention. Products such as these are not new and their production is described, for example, in German Application No. 28 34 027, which is expressly incorporated herein by reference. By virtue of their Si--N--bonds, organosilazanes are basically hydrolysis-sensitive compounds. These products have hitherto been used as mold release agents in the rubber industry. It is therefore all the more astonishing to those skilled in the art that organosilazanes have now been found to be capable of improving the hydrolysis resistance of glass bonds and, more particularly, the hydrolysis resistance of bonds between glass and elastomers.
The organosilazanes used in accordance with the invention can be produced by the process described in German Application No. 28 34 027, in which solutions of the corresponding organohalogen silanes in inert solvents are reacted with liquid ammonia under pressure and at temperatures in the range of from about 0° to about 50° C.
Suitable organohalogen silanes which can be further processed by this method to form the organosilazanes used in accordance with the invention are diorganodihalogen silanes and/or organotrihalogen silanes or, more precisely, triorganohalogensilanes. The chlorine compounds are preferably used as starting materials, although the bromine compounds can also be used.
The organosilazanes thus produced and used in accordance with the invention contain organic groups which are directly attached to silicon. These organic groups can be alkyl or aryl groups. According to the invention, it is possible to use organosilazanes which contain identical or different carbon residues on the silicon atom.
Suitable Si-bound aromatic radicals are phenyl groups or C 1 -C 6 alkyl substituted phenyl groups while suitable aliphatic radicals preferably contain from 1 to 7 carbon atoms; thus, methyl, ethyl, propyl, isopropyl, butyl, pentyl, neopentyl, hexyl, cyclohexyl or benzyl groups can be attached to the silicon. The latter groups can in turn contain further functional groups providing those groups do not react with the Si--N--bond. Suitable functional groups are, for example, amino or mercapto groups. It is also possible to produce and use organosilazanes containing olefinic double bonds, for example vinyl or allyl groups.
Preferred organosilazanes are the reaction products of methyl trichlorosilane and/or dimethyl dichlorosilane with an excess of ammonia according to German Applcation No. 28 34 027, and also the corresponding propyl compounds.
The organic solvent that is employed herein as component D. can be a single liquid organic solvent or a mixture of two or more such liquid solvents. Such solvents include ketones, esters, aromatic hydrocarbons, aliphatic hydrocarbons and halogenated hydrocarbons. Particularly preferred solvents are methylethyl ketone, alcohol/ketone mixtures, methylene chloride and mixtures thereof with ethylglycol acetate.
As optional component E., the glass primers of the invention can contain a polyfunctional isocyanate. Although not essential, the use of polyfunctional isocyanates is advisable, for example when glass is to be bonded to metals. Suitable polyfunctional isocyanates are primarily diisocyanates, for example aromatic diisocyanates, such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate or technical (more higly condensed) diphenylmethane diisocyanate (functionality of the order of 2.3). Aliphatic diisocyanates, such as isophorone diisocyanate, are also suitable. In addition, prepolymers can be used instead of the diisocyanates. Suitable prepolymers are prepolymers of polyhydric alcohols, particularly diols and triols, such as ethylene glycol, propylene glycol, condensed ethylene and propylene glycols, glycerol, trimethylol ethane, trimethylol propane and/or pentaerythritol, with a distinct excess (more than 20 mole % excess) of the above-mentioned aliphatic and/or aromatic diisocyanates. Prepolymers such as these are used in many industrial fields and are well known to those skilled in the art in adhesives. They can be obtained as such or can be prepared by mixing the raw materials in the appropriate ratio, addition of the hydroxy compound to the diisocyanate being the preferred method of preparation.
Instead of using adducts of diisocyanates with polyhydric alcohols (polyurethane prepolymers), adducts of the above-mentioned aromatic or aliphatic diisocyanates with polyfunctional epoxides can be used. Thus, the reaction product of triglycidyl isocyanurate with diphenylmethane diisocyanate in a molar ratio of 1:3 or the reaction product of the diglycidyl ether of bisphenol A with diphenylmethane diisocyanate in a molar ratio of 1:2 is a suitable additive.
The primers of the invention are easy to use. The solutions are applied to cleaned glass surfaces in the usual way, i.e. by means of spray guns, brushes or coating knives. The solvent is then evaporated and the second substrate applied using a suitable binder.
The glass primers of the invention are particularly suitable when polar and apolar elastomers are to be vulcanized onto glass under vulcanization conditions using standard vulcanization adhesives. Suitable vulcanization adhesives are described, for example, in German Patent Application No. 30 41 841.8. In addition, bonds such as these can also be produced using other standard vulcanization adhesives. The usefulness of the primers of the invention is not confined to vulcanization adhesives. Thus, favorable results are also obtained in cases where glass is to be bonded to other substrates using polyurethane adhesives. This applies in particular to glass-metal bonds, in which case it is preferred to add a polyurethane prepolymer to the primer.
The primers are also useful in cases where they are to be bonded using one- or two-component epoxy adhesives or commercially available acrylate adhesives.
In all the cases mentioned, the particular advantage of the binders of the invention lies in a further increase in the resistance of the bonds to hydrolysis. In this connection, the primers have proved to be particularly suitable for bonds which are exposed to weathering for prolonged periods at highly fluctuating temperatures. Thus, the bonds made using the primers satisfy the requirements of the automotive industry.
The invention will be illustrated but not limited by the following examples.
EXAMPLES
Examples 1-6
Various mixtures were prepared, their compositions being shown in the following Table:
TABLE I______________________________________ % by weight EXAMPLEPrimer composition 1 2 3 4 5 6______________________________________γ-Aminopropyltriethoxy 6 -- -- -- 8 --silaneVinyl triethoxysilane 6 -- 5 5 -- 4γ-Mercaptopropyltrimethoxy 5 -- -- 5 2 6silaneγ-Mercaptopropyltrimethoxy -- 15 10 -- -- --silane/MDI-adduct.sup.(1)Novolac-A -- -- -- 5 3 --t-Butylphenol resin (resol) -- -- -- -- 4 --M.p. = 80-90Polymethylsilazane.sup.(2) -- -- -- 2 1 --Triglycidylisocyanurate/ -- -- 5 -- -- 6MDI-adduct.sup.(1)Solventmethylethyl ketone 48 49 46 47 47 49methylene chloride 35 36 34 36 35 35______________________________________ .sup.(1) MDI = diphenylmethane diisocyanate .sup.(2) Polymethylsilazane prepared according to German Application No. 28 34 027
The above primer compositions were applied as primer to clean glass surfaces by means of spray guns or brushes. After drying of the primer coat, the surfaces were coated with a standard binder from the Chemosil® range (binders produced by Henkel KGaA for vulcanizing rubber onto stable substrates). In the present case, Chemosil®X 4100 was used.
After the film of Chemosil® binder had dried, an EPDM (poly-(ethylene-propylene-diene)) film was extruded onto the coated glass surfaces. Thereafter, the EPDM extrudate was vulcanized for 15 minutes at 170° C. in a hot air cabinet.
Examples 4 and 5 are primers according to the invention and Examples 1-3 and 6 are comparison examples.
The following composition was used as the EPDM mixture.
______________________________________Keltan 812 (EPDM) 100 parts by weightZnO 5 parts by weightStearic acid 2 parts by weightCarbon black FEF 90 parts by weightSillitin N (silica) 55 parts by weightSunpar 2280 (mineral oil) 70 parts by weightCaO (surface-treated with fatty acid) 6 parts by weightVaseline (petroleum jelly) 5 parts by weightRoyalac 133 (a dithiocarbamate/ 1 parts bythiazole mixture) weightVulkacit Mercapto (mercaptobenzthiazole) 1.25 parts by weightDPTT (dipentamethylene thiuram 1 parts bytetrasulfide) weightP extra N (zinc ethylphenyldi- 1.9 parts bythiocarbamate) weightSulfasan R (dithiodimorpholine) 1 parts by weightSulfur 0.5 parts by weight______________________________________
The bonded substrates were adhesion-tested by peeling off the rubber layer. In addition, the substrates were stored in water heated to 90° C. for 20 hours and for 40 hours and then adhesion-tested. Adhesion was assessed by determining the tearing pattern in accordance with the following scheme:
100 R=100% of the bond area, tearing of the rubber.
100 G=100% of the bonded substrates, separation of the primer from the glass surface.
Results are set forth in Table II below.
TABLE II______________________________________ After storage in water at 90° C.Primer Adhesion for 10 hours for 20 hours______________________________________1 80 R 60 R-40 G 20 R-80 G2 100 R 50 R-50 G 20 R-80 G3 100 R 70 R-20 G 50 R-50 G4 100 R 100 R 80 R-20 G5 100 R 100 R 100 R6 100 R 80 R-20 G 80 R-20 G______________________________________
Examples 7-9
Through additions of polyurethane prepolymers of castor oil/MDI.sup.(1) and PPG.sup.(2) -adduct (NCO:OH=1:2) containing terminal OH groups, the resulting primers can be used with PU-adhesives for bonding metals. To this end, the mixtures identified in the following Table III were prepared and, as in Examples 1-6, applied to clean glass surfaces. After drying of the primer coat, the substrates were coated with a commercially available PU-adhesive and, after drying, were bonded to steel. The bonds were press-cured for 30 minutes at 160° C.
The primer compositions are set forth in Table III below.
TABLE III______________________________________ % by weight EXAMPLEPrimer composition 7 8______________________________________γ-Aminopropylene triethoxysilane 8 8γ-Mercaptopropyltrimethoxysilane 2 2Novolac-A 3 3t-butylphenol resin (resol) 4 4M.p. = 80-90Polymethyl silazane -- 1PU-prepolymer (castor oil/MDI- 1 1PPG-adduct)Solventmethylethyl ketone 47 46methylene chloride 35 35______________________________________
The test specimens were adhesion-tested in a tension machine. The results of the adhesion tests are shown in Table IV below. In addition, the test specimens were stored in boiling water and then adhesion-tested in the tension machine.
TABLE IV______________________________________ After storage for 5 hours in water at 90° C.Primer N/mm.sup.2 Adhesion N/mm.sup.2 Adhesion______________________________________0-value 8 100 G 1.5 100 G5 25 glass 18 glass failure failure7 22 glass 20 glass failure failure8 25 glass 20 glass failure failure______________________________________
Tests were carried out as set forth above except that an acrylate adhesive was used, i.e. the tests were carried out with a polyacrylate adhesive.sup.(x) instead of a PU-adhesive. After drying of the primer coat, the substrates were coated with a commercially available acrylate adhesive and bonded to steel. The resin of the adhesive was applied to the glass side and the hardener to the metal side.
The results are shown in the following Table V below.
TABLE V______________________________________ After storage for 5 hours in water at 90° C.Primer N/mm.sup.2 Adhesion N/mm.sup.2 Adhesion______________________________________0-value 2 100 G -- 100 G5 11 100 G 4 100 G7 8 100 G 3 100 G8 12 70 G 6 100 G______________________________________ | The invention relates to a new primer for pretreating glass in readiness for waterproof bonding to other substrates. The primer contains resins, functional silanes, solvents, and organosilazanes and, if desired, polyfunctional isocyanates and other additives. Compared with conventional primers, the resistance of the bond to hydrolysis is significantly improved. | 8 |
BACKGROUND OF THE INVENTION
1. Technical Field
This device relates to blast suppression enclosures that limit or confine the blast effects for safety and health reasons.
2. Description of the Prior Art
Prior art devices of this type have relied on a variety of different structural enclosures to limit blast effects. See for example U.S. Pat. Nos. 4,325,309, 4,248,342 and 3,800,715.
In U.S. Pat. No. 4,325,309, a device is disclosed that comprises a shield system having multiple paneled configurations of alternate layers of steel grating, steel perforated plates and steel louvered panels or wire screening. The shield reduces blast over pressure and heat and will contain flying debris.
U.S. Pat. No. 4,248,342 discloses an improved version of the shield system that was disclosed in U.S. Pat. No. 4,325,309 having almost an identical structural configuration.
In U.S. Pat. No. 3,800,715, a bomb recovery shield apparatus is shown having a support cage covered with rigid high strength material, such as steel, with the ends of the enclosure being open and covered with mesh and a lid to help suppress the blast force directed outwardly from the ends.
SUMMARY OF THE INVENTION
A blast suppression device for use in a confined area provides a yielding structure to absorb and dissipate the blast effects without damage to itself for repeated reuse. The device consists of a rigid support frame with multiple flexible panels movably secured thereto. The device is buried in sand or the like to stabilize and restrict movement of the flexible panels under the force of the blast.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the blast suppression device;
FIG. 2 is a perspective view of flexible flaps removed from the device;
FIG. 3 is an alternate form of the invention;
FIG. 4 is a side elevation of the alternate form of the invention seen in FIG. 3; and
FIG. 5 is an end view of the alternate form of the blast suppression device buried in sand as it would be used.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A blast suppression device for use with explosive hardening techniques that comprises a support frame 10 having a pair of base support tubular members 11 and 12 in spaced parallel relation to one another.
An upper support tubular member 13 is vertically spaced between said support tubular members. Pairs of longitudinally angularly aligned oppositely disposed interconnection member 14 extend between said upper support member 13 and said base support tubular members 11 and 12 respectively forming a generally elongated triangular frame configuration.
An end base tubular connection member 15 is positioned on either end of said support frame 10 removably secured between the free ends of said base support tubular members 11 and 12. A plurality of resilient flap configurations 16 comprised of individual flaps 17, each secured to the base support tubular members 11 and 12 by attachment bars 18 and fasteners F as will be well understood by those skilled in the art.
The resilient flap configurations 16 have a plurality of flaps located on either side of the elongated triangular frame configuration in side to side abutting relationship. Each pair of oppositely disposed flaps 17 overlap their respective free ends 19 on one another equally across the upper support tubular member 13 forming a tent-like enclosure resilient and yieldable in nature.
Referring to FIGS. 2,3 and 4 of the drawings, an alternate form of the invention is disclosed having a plurality of arcuate upstanding plates 20 aligned longitudinally in spaced relation to one another. Each of the plates 20 has a series of radially spaced notches 21 in its outermost edge to receive longitudinally extending interconnecting fastner bands 22 defining a ribbed enclosure 23A. Pairs of oppositely disposed resilient rubber flaps 23 are secured to the lowermost band 22 at 21 by a support plate 24 and multiple fasteners 25. The flaps 23 abut one another in side to side relationship as seen in FIG. 2 of the drawings overlapping their free ends of the oppositvely disposed flap pairs on the ribbed enclosure 23A. The arcuate upstanding plates 20 provide a stable frame for the interconnecting bands 22 and expose only a small edge surface area to the blast force improving durability and reuse factors.
In operation, the blast suppression device is positioned directly over the material to be hardened (M) on a bed of sand (SB). The material to be hardened (M) has been prepared with appropriately placed and configured blasting charges (not shown) positioned as will be well understood by those skilled in the art of blast hardening. The multiple flaps 23 are overlapped on the structure as hereinbefore described. End retainers (R) shown in broken lines in FIG. 4 of the drawings are secured to either end of the support frame. The end retainers (R) can be of any one of a variety of different materials and are used solely to prevent the filling in or the enclosure ends by sand (S) that is used to cover the entire structure to a depth of approximately three to four feet.
Once the blasting charges are fired, the resulting blast force is confined within the blast suppression device which absorbs and dissipates the blast force by flanging back the flaps 17 and 23 under the weight of the sand S.
This unique flexible absorbent action allows such blast hardening to be used in an indoor relatively confined space, unlike blast hardening methods used heretofore that require a large outdoor blast area consisting of many acres.
After the blast, the blast suppression device is removed and reused in tact with only the addition of new end retainers (R).
It will be evident from the above description that the principal object of the invention is to contain and dissipate blast force in a reuseable structure which is most desirable in the blast hardening techniques of metal articles, such as railroad frogs. The ability to contain and dissipate the blast allows use of the blast hardening in confined areas such as indoors where it was heretofore impossible to do allowing blasting on site of production greatly reducing the cost and time consuming factors of shipping material to a blast site. | A blast supression device for use in explosive hardening in a relatively confined enclosed area. The device absorbs and dissipates the explosive force by utilizing a containment frame covered with overlapping multiple flexible resilient flaps that dissipate the explosive force by yielding during the blast within the device. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 62/208,313, titled “ELONGATED L.E.D. LIGHTING SYSTEMS, MANUFACTURING AND METHODS TO CONFIGURE THE SAME”, filed on Aug. 21, 2015. This application is a continuation-in-part of Utility application Ser. No. 14/672,146, titled “LINEAR LIGHTING SYSTEM, MANUFACTURING AND METHODS TO CONFIGURE THE SAME”, filed on Mar. 28, 2015 and U.S. application Ser. No. 14/810,714, titled “ELONGATED L.E.D. LIGHTING SYSTEM, MANUFACTURING AND METHODS TO CONFIGURE THE SAME”, filed on Jul. 28, 2015 and incorporated herein by reference.
BACKGROUND OF INVENTION
[0002] The majority of small form factor elongated lighting fixtures have their drivers in a remote location due to the fact that there is no room for integral drivers in those types of fixtures. These systems have performance losses caused by their long wires and are more difficult to install than integral driver fixtures.
[0003] The remote driver box fixtures are not U.L. approved for battery packs because most of the battery packs should be factory installed not field installed.
[0004] The installer have to drill thru every joist up to the last one near the fixture and route the electrical conduit from the remote driver compartment. This is additional labor and it would considerably increase the overall cost related to this job.
[0005] International residential building code prescribes limitations for notching and bored holes in both interior and exterior walls.
[0006] The decision about the location of the remote driver compartment is left to the installer and he can run into issues when he is limited by the length of the wire due to limitations imposed by manufacturer for power loss in the wire. He has to take extra steps to add up the segments of the wire way path and figure out the total length. In some situations he has to consult other people like the architect, designer, electrical engineer, building owner, contractors, etc. and incur delays due to these complexities.
[0007] For existent construction or remodeling there is a risk to interfere with electrical conduit runs, HVAC ducts or plumbing pipes as these are hidden inside the wall and most initial plans are not available or consulted before the work is started.
[0008] Those fixtures with integral driver compartment are designed as to allow driver access and maintenance, from the room side, but they require cutting and reframing structural members that are intended to support the walls and/or ceiling. This could extend or invalidate the building approvals required by the code or other authority therefore extending the overall lead time unnecessary.
[0009] Traditional shallow elongated recessed fixtures are not usually designed to allow access to replace the light engine while the maintenance of their remote drivers is more difficult than of those fixtures with integral driver.
[0010] The warranty for the L.E.D. driver is usually under 5 years while LEDs could have double that lifetime.
[0011] The power input of these runs is usually at the end of the fixture. Most of the walls and ceilings would have structural joist members at corner or at the end edges therefore these fixtures are not versatile and are not designed for what is mostly needed: end to end, transition corners, etc.
[0012] Most of the other fixtures could not be installed after the planar surface is up, on existent construction. Most of them are for new construction and to be installed before the planar surface is installed.
[0013] Various fixtures have been proposed to secure the light sources to the architectural surfaces. Typically, these fixtures have a relatively large depth profile that necessitates excessive clearance space behind the ceiling, wall, or floor surface. In most cases, it may be necessary to reframe a wall to add sufficient depth for the lighting fixture, which may also require cutting and reframing window sills, headers, and other architectural features for structural continuity.
[0014] Due to its housing depth and because it's installed to the structure with screws, the integral fixture opening is distorted making the opening variable along the length of the fixture which in turn is not accurate enough to install the light diffusing/converting optical elements like: extruded lens,covers, etc. Additional temporary brackets are used to brace and bridge this opening but they don't eliminate completely the effect and/or they don't control the cause of the distortion (deep housing profile, unknown screw torque force applied by the installed in the field).
SUMMARY OF THE INVENTION
[0015] The use of light as an element of design of architectural surfaces is a distinctive trend in modern times. In the near future more and more drivers will be integrated into the L.E.D. board. These are so called IC drivers. We can see that trend in direct line AC L.E.D. boards. These boards are connected directly to main power line without the need of a bulky driver to regulate them. Many consumers will want to convert their fixtures by upgrading their L.E.D. boards and this could eliminate one function of the driver compartment as being the enclosure for an L.E.D. driver but the enclosure will still be needed as storage compartment for the additional L.E.D. tape that is a result of using a tape that is not exactly the length of the concatenated run of fixtures. Also, the enclosure will be needed to contain the wire splices, wire nuts or the electrical connectors used to power the L.E.D. tape. This concept is designed to accommodate both, the current need for a driver compartment and the future upgrade. The future L.E.D. light engines could be housed and be powered directly from the power line integral to the small factor channel housing subject to this design.
[0016] In an exemplary embodiment of this invention, an elongated fixture system is designed to be installed without cutting of the structural joist members and could have any direction along the thin surfaces as well as it can be laid out to create formations of various shapes within these surfaces (for example resembling many if not all the capital letters in the alphabet), geometric figures, etc.
[0017] The applications of these fixtures are expanded to architectural accent lighting, general/ambient lighting for both, commercial and residential buildings.
[0018] The attached driver compartment option is designed to inherit the advantages of the integral fixtures and remove many of their disadvantages. For example a nearby driver would allow short wires between the L.E.D. board and driver therefore reducing considerably the power efficacy loss. The capability to access and replace a faulty driver is another advantage.
[0019] Another reason the traditional fixtures are 3″ to 5″ deep is due to the methods of mixing and diffusing L.E.D. light. The LEDs are oriented directly to the target therefore the point source is visible if it's too close to the lens. Advancements have been done relative to the optics, the diffuser lens are capable to blend the point source into a uniform, glare free, elongated source while allowing smaller distances between the diffuser surface and L.E.D. chips.
[0020] The light source could be remote phosphor style, traditional white L.E.D. or any other electroluminescent diode that is capable of generating radiation in response to an electrical signal. For example, the light source of a remote phosphor style would comprise of L.E.D.s installed on a printed circuit board (P.C.B.), that would emit blue light, namely a “blue pump” L.E.D, with the dominant wavelength ranging from 450 nm to 460 nm. Above the P.C.B., at a certain distance around the LED, there would be a material that contains phosphor that is intended to convert the wavelength of the photons emitted by the blue pump LEDs to white light spectrum. This phosphor material is separate and not packaged into the L.E.D. therefore it's known as “remote phosphor”.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing and other features and aspects of the invention are best understood with reference to the following description of certain exemplary embodiments, when read in conjunction with the accompanying drawings, wherein:
[0022] FIG. 1 illustrates an isometric view, frontal perspective, of a line segment of the embodied lighting system, in accordance with an exemplary embodiment of the present invention;
[0023] FIG. 2 illustrates an isometric view, rear perspective, of a line segment of the embodied lighting system, in accordance with an exemplary embodiment of the present invention;
[0024] FIG. 3 illustrates an isometric view, frontal perspective, of another line segment of the embodied lighting system, in accordance with an exemplary embodiment of the present invention;
[0025] FIG. 4 illustrates an isometric view, rear perspective, of another line segment of the embodied lighting system, in accordance with an exemplary embodiment of the present invention;
[0026] FIG. 5 illustrates a back view of a row of the concatenated run of elongated fixtures having fexible conduit feeding each driver enclosure in that row, in accordance with an exemplary embodiment of the present invention;
[0027] FIG. 6 illustrates a top view of a row of the concatenated run of elongated fixtures having fexible conduit feeding each driver enclosure in that row, in accordance with an exemplary embodiment of the present invention;
[0028] FIG. 7 illustrates a back view of a row of the concatenated run of elongated fixtures having power supply fed to one selected driver enclosure in that row and attached wire chase extrusions 20 to deliver the power from the selected driver enclosure to the remaining driver enclosures, in accordance with an exemplary embodiment of the present invention;
[0029] FIG. 8 illustrates a top view of a row of the concatenated run of elongated fixtures having power supply fed to one selected driver enclosure in that row and attached wire chase extrusions to deliver the power from the selected driver enclosure to the remaining driver enclosures, in accordance with an exemplary embodiment of the present invention;
[0030] FIG. 9 illustrates a back view of a line segment of the concatenated run of elongated fixtures, in accordance with an exemplary embodiment of the present invention;
[0031] FIG. 10 illustrates a top view of a line segment of the concatenated run of elongated fixtures, in accordance with an exemplary embodiment of the present invention;
[0032] FIG. 11 illustrates a front view of a line segment of the concatenated run of elongated fixtures, in accordance with an exemplary embodiment of the present invention;
[0033] FIG. 12 illustrates section view of a line segment of the concatenated run of elongated fixtures taken along section line 12 - 12 as labeled in FIG. 10 , in accordance with an exemplary embodiment of the present invention;
[0034] FIG. 12 -A illustrates section view of a line segment of the concatenated run of elongated fixtures taken along section line 12 -A- 12 -A as labeled in FIG. 10 , in accordance with an exemplary embodiment of the present invention;
[0035] FIG. 13 illustrates section view of a line segment of the concatenated run of elongated fixtures taken along section line 13 - 13 as labeled in FIG. 10 , in accordance with an exemplary embodiment of the present invention;
[0036] FIG. 14 illustrates an exploded view of a line segment of the concatenated run of elongated fixtures to be installed in a planar surface, in accordance with an exemplary embodiment of the present invention;
[0037] FIG. 14 -A illustrates an isometric view of a gap created in a planar surface;
[0038] FIG. 15 illustrates a side view of a line segment of the concatenated run of elongated fixtures installed in a planar surface, in accordance with an exemplary embodiment of the present invention;
[0039] FIG. 16 illustrates another exploded view of a line segment of the concatenated run of elongated fixtures to be installed in a planar surface, in accordance with an exemplary embodiment of the present invention;
[0040] FIG. 16 -A illustrates another isometric view of a gap created in a planar surface;
[0041] FIG. 17 illustrates a side view of a line segment of the concatenated run of elongated fixtures installed in a planar surface, in accordance with an exemplary embodiment of the present invention;
[0042] FIG. 18 illustrates an exploded view of a line segment of the concatenated run of elongated fixtures to be installed in a planar surface along with additional high voltage wireway, in accordance with an exemplary embodiment of the present invention;
[0043] FIG. 18 -A illustrates another isometric view of a gap created in a planar surface;
[0044] FIG. 19 illustrates a side view of another line segment of the concatenated run of elongated fixtures installed in a planar surface along with additional high voltage wireway, in accordance with an exemplary embodiment of the present invention;
[0045] FIG. 20 illustrates a side view of an L.E.D. light source 73 installed on the bottom surface of a light engine housing, component 13 , installed within the spackle flange 86 and assembled with the lens, component 36 , in accordance with an exemplary embodiment of the present invention;
[0046] FIG. 21 illustrates a side view of an L.E.D. light source 73 installed on one side surface of a light engine housing, component 13 , installed within two piece construction spackle flange 83 and 84 , and assembled with the lens, component 36 , in accordance with an exemplary embodiment of the present invention;
[0047] FIG. 22 illustrates a side view of the light engine housing, component 13 , assembled with the extruded lens, component 36 , in accordance with an exemplary embodiment of the present invention;
[0048] FIG. 23 illustrates a side view of other light engine housing, component 91 , assembled with other lens, component 39 , in accordance with an exemplary embodiment of the present invention;
[0049] FIG. 24 illustrates a side view of optical element 36 , in accordance with an exemplary embodiment of the present invention;
[0050] FIG. 25 illustrates a side view of another optical element 39 , in accordance with an exemplary embodiment of the present invention;
[0051] FIG. 26 illustrates an isometric view, frontal perspective, of a tape collector endcap element 87 , in accordance with an exemplary embodiment of the present invention;
[0052] FIG. 27 illustrates an isometric view, rear perspective, of a tape collector endcap element 87 , in accordance with an exemplary embodiment of the present invention;
[0053] FIG. 28 illustrates a side view of a light engine housing, component 13 , in accordance with an exemplary embodiment of the present invention;
[0054] FIG. 29 illustrates a side view of another light engine housing, component 12 , in accordance with an exemplary embodiment of the present invention;
[0055] FIG. 30 illustrates a side view of a light engine housing, component 92 , in accordance with an exemplary embodiment of the present invention;
[0056] FIG. 30 -A illustrates a side view of another light engine housing, component 93 , in accordance with an exemplary embodiment of the present invention;
[0057] FIG. 30 -B illustrates a side view of another light engine housing, component 94 , in accordance with an exemplary embodiment of the present invention;
[0058] FIG. 31 illustrates a side view of a light engine housing, component 95 , in accordance with an exemplary embodiment of the present invention;
[0059] FIG. 31 -A illustrates a side view of another light engine housing, component 96 , in accordance with an exemplary embodiment of the present invention;
[0060] FIG. 31 -B illustrates a side view of another light engine housing, component 97 , in accordance with an exemplary embodiment of the present invention;
[0061] FIG. 32 illustrates a side view of a light engine housing, component 91 , in accordance with an exemplary embodiment of the present invention;
[0062] FIG. 33 illustrates a side view of a light engine housing, component 98 , in accordance with an exemplary embodiment of the present invention;
[0063] FIG. 34 illustrates a side view of a high voltage wire way chase, component 20 , in accordance with an exemplary embodiment of the present invention;
[0064] FIG. 35 illustrates a side view of the spackle flange,one piece construction, component 86 , in accordance with an exemplary embodiment of the present invention;
[0065] FIG. 36 illustrates a side view of the spackle flange, two piece construction, components 83 and 84 , in accordance with an exemplary embodiment of the present invention;
[0066] FIG. 37 illustrates a side view of the spackle flange-one side, component 83 , as if mounted on the left hand side of a fixture, in accordance with an exemplary embodiment of the present invention;
[0067] FIG. 38 illustrates a side view of the spackle flange-one side, component 83 , as if mounted on the right hand side of a fixture, in accordance with an exemplary embodiment of the present invention;
[0068] FIG. 39 illustrates a side view of the spackle flange/cover, component 23 , in accordance with an exemplary embodiment of the present invention;
[0069] FIG. 40 illustrates a top view of component 40 , named ‘L.E.D. driver enclosure’, in accordance with an exemplary embodiment of the present invention;
[0070] FIG. 41 illustrates a front view of component 40 , named ‘L.E.D. driver enclosure’, in accordance with an exemplary embodiment of the present invention;
[0071] FIG. 42 illustrates a back view of component 40 , named ‘L.E.D. driver enclosure’, in accordance with an exemplary embodiment of the present invention;
[0072] FIG. 43 illustrates a section view of component 40 , taken along section line 43 - 43 as labeled in FIG. 40 , in accordance with an exemplary embodiment of the present invention;
[0073] FIG. 44 illustrates an isometric view, rear perspective, of component 40 named ‘L.E.D. driver enclosure’, in accordance with an exemplary embodiment of the present invention;
[0074] FIG. 45 illustrates a top view of component 53 , named ‘power input segment housing for light engine’, in accordance with an exemplary embodiment of the present invention;
[0075] FIG. 46 illustrates a side view of component 53 , named ‘power input segment housing for light engine’, in accordance with an exemplary embodiment of the present invention;
[0076] FIG. 47 illustrates an isometric view of component 55 , named ‘access door’, in accordance with an exemplary embodiment of the present invention;
[0077] FIG. 48 illustrates an isometric view of component 59 , named ‘power access cover’, in accordance with an exemplary embodiment of the present invention;
[0078] FIG. 49 illustrates an isometric view of an acute corner alignment block, component 26 , in accordance with an exemplary embodiment of the present invention;
[0079] FIG. 50 illustrates an isometric view of a normal corner alignment block, component 27 , in accordance with an exemplary embodiment of the present invention;
[0080] FIG. 51 illustrates an isometric view of an obtuse corner alignment block, component 29 , in accordance with an exemplary embodiment of the present invention;
[0081] FIG. 52 illustrates a top view of component 75 , named “internal junction box”, in accordance with an exemplary embodiment of the present invention;
[0082] FIG. 53 illustrates a front view of component 75 , named “internal junction box”, in accordance with an exemplary embodiment of the present invention;
[0083] FIG. 54 illustrates a side view of component 75 , named “internal junction box”, in accordance with an exemplary embodiment of the present invention;
[0084] FIG. 55 illustrates a perspective view of component 75 , named “internal junction box”, in accordance with an exemplary embodiment of the present invention;
[0085] FIG. 56 illustrates a top view of mounting method of component 13 , while component 18 was temporarily hidden in this view, in accordance with an exemplary embodiment of the present invention;
[0086] FIG. 57 illustrates a side view of mounting method of component 13 , in accordance with an exemplary embodiment of the present invention;
[0087] FIG. 58 illustrates a bottom view of another mounting method of component 13 , while components 15 and 18 were temporarily hidden in this view, in accordance with an exemplary embodiment of the present invention;
[0088] FIG. 59 illustrates a side view of another mounting method of component 13 , in accordance with an exemplary embodiment of the present invention;
[0089] FIG. 60 illustrates a perspective view of some geometrical figures that could be created on three dimensional planar surfaces utilizing the lighting system in accordance with an exemplary embodiment of the present invention;
[0090] FIG. 61 illustrates a flow chart 1000 representing a method to assemble the elongated lighting fixtures, in accordance with an exemplary embodiment of the present invention;
[0091] FIG. 62 illustrates a flow chart 1100 representing another method to assemble the elongated lighting fixtures, in accordance with an exemplary embodiment of the present invention;
[0092] It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION OF INVENTION
[0093] The present invention is focused on methods to configure elongated lighting in different interior building spaces. Although the description of exemplary embodiments is provided below in conjunction with interior building structures, alternate embodiments of the invention are applicable to other illuminated open spaces including, but no limited to, transit, tunnels, staircase, sidewalk, landscape, bollards, parking and other outdoor areas. Furthermore, although the invention has been described with reference to specific methods to configure elongated lighting fixtures embedded into interior and exterior architectural surfaces, these descriptions are not meant to be construed in a limiting sense to these applications but a disclosure to apply these concepts to other related applications as recessed lighting applications, cove, surface mount, suspended or track lighting.
[0094] Furthermore, although some embodiments of the invention have been described with reference to specific methods to configure elongated lighting fixtures, it is within the scope of the invention to apply the same concept to any elongated fixture or to a fixture substantially longer than its width. In one embodiment, the invention is an elongated lighting fixture, intended to be installed on a structure without altering the structural members of its framework comprising: an elongated lighting fixture, intended to be installed on a structure without altering the structural members of its framework, comprising: an enclosure, mounted on at least one structural member, wherein said enclosure is sufficiently recessed behind its mounting surface and containing an electrical device used as a power source and control; a channel segment, adjoined said enclosure and mounted on at least one structural member bearing an opening to access said adjoining enclosure; a junction box, adjoined to said channel and located inside said enclosure; a channel housing, abutted to and aligned with said channel segment and mounted on at least one structural member; a wire way chase, mounted on at least one structural member, side by side and in the same direction with said channel; a covering and anchoring surface for said wire way chase; a light source, containing electroluminescent diodes, mounted in said channel, and connected to said electrical device; and, a removable cover, mounted on said channel; wherein said channel would have at least one opening for maintenance access to said power source, after said fixture installation;
[0095] In a variation of the embodiment above, the enclosure is placed anywhere along the gap, between the structural members.
[0096] In another exemplary embodiment, the invention is an elongated light fixture housing comprising: a channel housing, having one or more complementary located flexible locking features; a removable cover, having one or more complementary located flexible locking features; wherein said complementary located flexible locking features engage functioning as a snap-fit cover attachment system for the elongated light fixture.
[0097] In another exemplary embodiment, the invention is an elongated light fixture housing comprising: a channel housing, comprising an outer surface and an inner surface, having at least one indentation integrally formed on its inner surface, in at least one of its side walls; and a removable cover, comprising an outer surface and an inner surface, having at least one complementary indentation integrally formed on its outer surface; wherein said indentation of said channel is for receiving and retaining said complementary indentation of said removable cover and functioning as a snap-fit attachment system of said cover to said channel.
[0098] The term “L.E.D.” is known in the art and relates to Light-Emitting Diode: a semiconductor diode that emits light when an electric current passes thru it as a result of a specific voltage applied to its terminals.
[0099] The term “L.E.D. driver” is known in the art and relates to an electrical device that manages power and controls the current flow to an L.E.D. lighting source. The electrical device is connected to a power source.
[0100] The term “driver enclosure” (abbreviated as D.E. 4 ) is related to the L.E.D. driver enclosure, component 40 in our description, and is known in the art as the electrical enclosure housing the L.E.D. driver and constituting a part of the luminaire intended to:
(a) reduce the risk of contact with live parts; (b) enclose electrical parts and components that can involve a risk of fire; (c) protect internal parts from mechanical damage; and (d) protect internal parts from the environment.
[0105] The term “internal junction box” is an enclosure functioning as a compartment to separate the low voltage wiring circuit from the high voltage branch wiring circuit. The branch wiring compartment must be enclosed in a space with a minimum volume of 6 cubic inches, per U.L. standard 1598.
[0106] The term” opening” should be construed per Underwriters Laboratories (U.L.) definition as “an aperture in an enclosure that is covered or filled by a plug or knockout and that has the potential of becoming an open hole”.
[0107] The term “knockout” (abbreviated as K.O.) relates to a partially cut-out opening that is closed until the precut material is removed. A similar explanation should be related to the term “half-shear” that will be used in our detailed description of the invention embodiment.
[0108] The term “heat sink” should be construed as a material of a particular shape intended to absorb excessive heat from a surface and dissipate that heat thru other surfaces.
[0109] The term “countersink” should be construed as a conical hole cut into a manufactured object.
[0110] The term “plaster” should be construed as “a mixture of lime or gypsum, sand, and water, sometimes with fiber added, that hardens to a smooth solid” and is used for coating walls and ceilings.
[0111] The term “spackle” is a trademark referencing a compound used to fill cracks in plaster and produce a smooth surface.
[0112] The term “spackle flange” is known in the art as that lighting fixture component that is placed in contact with architectural surfaces for the purpose of applying spackle on top of it and bonding the fixture housing to the architectural surface. Alternatively, in another embodiment, the term “covering and anchoring surface” is largely used in reference to the “spackle flange” component but it's not intended to be limited to that particular embodiment.
[0113] The term “elbow fitting” is used in piping and electrical fittings to define a change of direction of an electrical conduit at a specific angle (usually 90 degrees).
[0114] The term “hinge joint” is used in some embodiments of this invention to define an articulation that would allow motion only in one plane.
[0115] For the purpose of this invention, the term “structure” is used in reference to the framework of a building such as an edifice for commercial, residential and industrial space or any other construction establishment.
[0116] The term “stud” is known as a building material that is used to construct the frame of that structure.
[0117] The term “recessed” is used, in this invention, to define a setback position of a component relative to a planar surface or a mounting surface.
[0118] The term “channel” is used to reference an element having an elongated base, a first and a second wall, first wall disposed at a certain distance from the second wall, and extending from the base in a common direction therefore forming a cavity with two open ends.
[0119] The abbreviation “H.V.W.C. 3 ” meaning “High Voltage Wire Channel” is in reference to component 20 of the lighting fixture segment. Alternatively, in another embodiment, the features of component 13 are combined with the features of component 20 to form one piece construction and this new component would be named “channel with integral wire way chase”.
[0120] The abbreviation “P.I.S./H.-L.E.” meaning “Power Input Segment/Housing for Light Engine” is in reference to component 53 of the lighting fixture segment; Alternatively, in another embodiment, the term “channel segment” is used in reference to component 53 , within the scope of the invention, but not limited to that particular embodiment. The abbreviation “T-slot” represents a groove cut into a material, like aluminum, with a tool having the shape of letter ‘T’, like an extrusion tool.
[0121] In an exemplary embodiment, a fastening method is employed to secure at least two components by interlocking their own features (fastening by shape) or by using intermediate fasteners like screws, clips, clasps, glue, etc.
[0122] A “snap-fit” is a mechanical joint system where part-to-part attachment is accomplished with locating and locking features (constraint features) that are homogenous with one or the other of the components being joined. Joining requires the (flexible) locking features to move aside for engagement with the mating part, followed by return of the locking feature toward its original position to accomplish the interference required to latch the components together . . . “— The First Snap - Fit Handbook ”, Bonenberger, 2000 is incorporated herein by reference. Some examples of locking features are: hooks, ridges, grooves, buttons, holes, depressions, indentations, etc.
[0123] Descriptions of snap-fit joints can be found in US patent application no. US20070000922 A1 and U.S. Pat. No. 5,102,253 A incorporated herein by reference. Snap-fits joints advantageously eliminate other joining methods, e.g. screws, clips, and adhesives.
[0124] For the purpose of this invention, the term “groove” is a long, narrow cut or depression, especially one made to guide motion or receive a corresponding ridge.
[0125] For the purpose of this invention, the term “rib” is a long raised piece of stronger or thicker material across a surface or through a structure.
[0126] The term “co-extruded” is used when more than one plastic material is pressed, in the same time, thru the same die, to produce a single piece part;
[0127] For the purpose of defining directionality, a coordinate system needs to be related to an elongated segment of the lighting system having a light emitting surface normal to Z axis of a cartezian coordinate system while its length is defined in the X direction and its width in Y direction.
[0128] In an exemplary embodiment, depicted in FIG. 14 -A, a planar surface could be a wall 80 that is constructed from one or more drywall sheets arranged on a conventional stud frame. A gap of predefined shape could be created by removing a portion or portions from the one or more drywall sheets. Alternatively, the lighting fixture may first be installed on the studs 90 and the wall may be added later. In other embodiments, the wall may be constructed of wallboard, lathing for plaster, wood, or any other material used to construct an architectural surface.
[0129] As illustrated by FIG. 14 -A, the basic shape of the gap for an elongated segment fixture could have two parallel edges 801 and 802 and it might have an end similar to edge 803 . The main components of the slim form factor fixture segment are comprised of: aluminum extruded light engine housing 13 , light diffusing/converting optical element 36 and L.E.D. light engine 73 , as depicted by FIG. 14 . A side view of the main components is illustrated by FIG. 15 , while FIG. 14 is intended to clarify the profile of these components in an exploded view. A similar scenario is depicted by FIG. 16 , except the light engine 73 is installed on the side wall of the light engine housing 13 . A side view of the main components is illustrated by FIG. 17 while FIG. 16 is intended to clarify the profile of these components in an exploded view.
[0130] When a high voltage wire way channel H.V.W.C. 3 is needed between the L.E.D. driver compartments, a “spackle flange/cover” version could be installed, as illustrated by FIG. 18 . The main components of the “spackle flange/cover” fixture segment are comprised of: separate extruded high voltage wireway chase mounted on one side of the LED strips housing, component 20 , spackle flange/cover 23 installed to the planar surface with the screws 18 , aluminum extruded light engine housing 13 , light diffusing/converting optical element 36 , and L.E.D. light engine 73 . A side view of the main components is illustrated by FIG. 19 with the wire 48 installed inside the H.V.W.C. 3 , while FIG. 18 is intended to clarify the profile of these components, in an exploded view.
[0131] In an exemplary embodiment, a gap of predefined shape might be formed in the planar surface similar to a concatenated sequence of “open” line segments with different angles between them. As seen in FIG. 60 , shapes resembling alphabet letters (A,U,C,H,K,L,M,N,T,V,X,Y,Z) could be created on existent architectural surfaces as well as many other geometric figures.
[0132] In an exemplary embodiment, as depicted in FIG. 28 , an important component of the fixture is the aluminum extruded channel/light engine housing 13 . Other variations of an extruded channel/light engine housing could be components 12 depicted in FIG. 29 , or component 91 depicted in FIG. 32 , or component 98 depicted in FIG. 33 , or component 92 depicted in FIG. 30 , or component 93 depicted in FIG. 30 -A, or component 94 depicted in FIG. 30 -B, or component 95 depicted in FIG. 31 , or component 96 depicted in FIG. 31 -A, or component 97 depicted in FIG. 31 -B. The component 20 , depicted in FIG. 34 , it was intended as H.V.W.C. 3 but could be used as a light engine housing. This component and its variations, could be an aluminum extrusion that may or may not be painted depending on certain circumstances. Other preferred materials to manufacture this part are the heat conductive materials and/or materials with electrical insulator properties. Some of its features, as referenced in FIG. 28 or FIG. 30 or FIG. 31 : 131 (and its variations 921 , 951 ) are ‘walls’ intended to be a protective barrier to block particles, like those of the spackle compound 81 , 82 or those of the planar surface 80 illustrated in FIG. 15 , from reaching the lens 36 or the light source 73 .
[0133] The surface 138 or 128 might be exposed or visible surfaces, in some configurations, therefore serving as a decorative surfaces, with a required finish. The protrusions 132 and 134 (respectively 122 and 124 , or 912 and 914 , or 922 and 924 , or 982 and 984 ) could be one or multiple pairs intended to retain the lens 36 or other lens variations 39 , while they are inserted into the channel housing. They are also designed to allow the removal of the lens while a thin object is inserted, between the lens and the housing, and acceptable force is applied on that object. The surface 133 (or 139 ) is a mounting surface for the L.E.D. light source 73 . The top surfaces 131 , 921 or 951 are visible from the room side therefore their alignment is important as they have to be perceived as continuous line independent of the number of fixtures that are in the row. The features 125 , 915 , 925 , 955 or 205 could be described as a ‘T’ slot. This is intended as a receiver slot for corner cleats or alignment plates as those depicted in FIG. 29 thru FIG. 34 . The same slots could be used as screw chase feature designed to receive self tapping screws installed from the end. Those screws are used to secure the end caps of a continuous run. The surface 133 or 139 is also the surface where the installer would drill holes to secure the fixtures to the structure with wood screws. For those channels with ‘T’-slots, as depicted in FIG. 29 thru FIG. 34 , the surface 123 , 913 or 919 could have pre-drilled holes to align and pull the extrusions together with the help of self tapping flat head screws and by using aligner plates- or corner cleats, described in detail in application Ser. No. 14/672,146 incorporated herein by reference. The aligners 26 , 27 or 29 depicted by FIG. 49 , FIG. 50 respectively by FIG. 51 , could each be a guide to align the aluminum extrusions/channels, before the lens 36 are installed. These aligners are to be removed after the extruded channels 13 are secured with screws and before the light engines 73 are laid out. The grooves 136 or 126 , as labeled in FIG. 28 thru FIG. 29 are intended for mounting these extrusions, to the structure, with the help of a few clips, component 15 , as exemplified in FIG. 59 . The ribs 137 or 917 , depicted in FIG. 28 and FIG. 32 , are intended to increase the heat transfer surface on the opposite side of surface 133 , where the light engine is installed, and could be considered as heat sink fins.
[0134] At the ends of the continuous row or on a standalone fixture we would install end caps. One exemplary embodiment, depicted in FIG. 26 and FIG. 27 is component 87 . This could be made out of injection molded plastic materials, metal casting, sheet metal or other manufacturing methods well known in the industry. The end cap could be opaque, translucent or transparent. The feature 873 would match the inside of the light engine housing and would guide and locate the end cap relative to the light engine. The jagged features 875 are intended to help with the attachment of the end cap to the channel, working similar to fastening with ‘hooks’, when the end cap is pressed fit inside the channel, eliminating the need to use screws. If the end cap is opaque, it is recommended that the surface 874 is highly reflective. The top edge 871 is intended to match the outside profile of light diffusing/converting optical elements to avoid visible discontinuity in a row of fixtures. An important role of an end cap is to mitigate the light ‘leakage’ by minimizing the gaps at the end. Another role of the end cap is to mitigate the gaps created due to the thermal expansion/contraction of different materials. The thermal expansion/contraction needs to be taken into consideration between multiple segments of a row.
[0135] Another component of some lighting fixtures, especially those configurations with more than one D.E. 4 in a row, is the high voltage wire way chase, item 20 , as illustrated in FIG. 34 . This component could be made out of extruded aluminum. FIG. 19 illustrates the space where the high voltage wire 48 will be located inside the H.V.W.C 3 . The feature 205 is a T-slot feature intended for alignment plates or corner cleats.
[0136] Another component of the lighting fixtures, exemplified in FIG. 39 and FIG. 18 , is the spackle flange/cover 23 , described in detail in application Ser. No. 14/810,714 incorporated herein by reference. A variation of a spackle flange concept, intended for a recessed light engine without wire way chase, is depicted by FIG. 35 , component 86 , one piece construction. The features 862 are protrusions formed in the component 86 intended to retain the channels 13 or its variations, and working as a snap-fit attachment when put in contact with the grooves 136 of component 13 as depicted by FIG. 20 . Another variation of the spackle flange concept is depicted by FIG. 36 , where two piece construction, component 83 and 84 are assembled to satisfy a symmetrical spackle layout or component 84 could be used alone for an asymmetrical (one side) spackle layout. In another variation, component 83 could be used on one side of the light engine or on both sides.
[0137] Another component of the lighting fixtures, exemplified in FIG. 47 , is the access cover 55 , preferably made of sheet metal (aluminum or steel) but could also be an extruded aluminum component with secondary operations. Similar materials could be used for component 59 power access cover, exemplified in FIG. 48 . Grounding screw 56 needs to be factory installed. This could be pre-installed with grounding wire, eyelet, nut and star washer (not shown). Alternatively, the access covers could be installed directly to the driver enclosure D.E. 4 with screws, thus ensuring the bonding between these components without the need to install additional grounding screws.
[0138] FIG. 24 and FIG. 25 illustrates component 36 respectively 39 , and they materialize the light diffusing/converting optical element. Alternatively, in another embodiment, the term “removable cover” is used in reference to component 36 , within the scope of the invention, but not limited to that particular embodiment. The feature 362 or 392 , representing one or more indents on the side of the lens, is intended to retain the lens to the housing but in the same time allow easy snap in of the lens to the housing, due to their elasticity properties. In one exemplary embodiment of this invention, the feature 362 of component 36 , as depicted by FIG. 24 , is defined as “complementary” to feature 132 of component 13 , as depicted by FIG. 28 , and working as a snap-fit connection, when the two components are put together, as illustrated in FIG. 22 . Some examples of “complementary” located features are groves and ribs or protrusions and indentations. The surface 364 respectively 394 , is the light output surface of the light diffusing/converting optical element. FIG. 24 and FIG. 25 are examples of extruded lens profiles intended for white light L.E.D. sources. The material for these lens or for the removable cover could be made of translucent or transparent plastic materials (i.e. acrylic, polycarbonate, polycarbonate with phosphor) or other light diffusing/converting optical grade materials.
[0139] In another embodiment of this invention, the spackle flange/cover 23 and the light diffusing element 36 could be formed as a single piece component.
[0140] The light source 73 is primarily comprised of multiple L.E.D. The technology could employ blue, white, RGB L.E.D. chips. The electrical circuit could be embedded into soft strips, FR boards, OL.E.D.s or any other electroluminescent diode that is capable of generating radiation in response to an electrical signal.
[0141] FIGS. 40, 41, 42, 43 and 44 illustrates different view angles of an L.E.D. driver enclosure (D.E. 4 ) component 40 . In FIG. 42 , the feature 401 is a knockout intended to be removed if a strain relief device, like an elbow connector 46 depicted in FIG. 5 , FIG. 6 , FIG. 7 or FIG. 8 , would need to be installed to the D.E. 4 to provide power or data wires inside the enclosure. The “depth” of the driver enclosure is limited by the size of the structural elements. In an exemplary embodiment of this invention, an enclosure, mounted on a 2″×4″ (2 inches by 4 inches) structural member, is considered “sufficiently recessed”, if its depth, measured from its mounting surface, is less than 4 inches and its protrusions are less than the thickness of the planar surface into which it is installed.
[0142] The wiring of the L.E.D. driver enclosure (D.E. 4 ) could be done thru any opening on the back of the enclosure (“knockout” holes, access hole and cover plate, etc.) There could be one, two or more K.O. that could receive one, two or more elbow connectors, first being to feed the power wires, a second one to feed the control wires (for example the 0-10V wires). The K.O. could be removed by pushing against the round cap from inside with a screw driver or other object having a diameter smaller than the K.O. diameter and being capable to withstand the force necessary to push the round cap until removed. The D.E. 4 could be made of aluminum sheet metal or steel. The elbow could be an off the shelf item usually made of metals (zinc, steel, etc.).
[0143] Continuing description of features at FIG. 42 , the feature 402 represents an array of half-shear or smaller K.O. features intended for easy removal when a screw and nut needs to be installed either to mount the L.E.D. driver 45 directly or thru an intermediate bracket to the D.E. 4 labeled 40 . The hole 403 ( FIG. 41 ) is intended to receive a self-tapping screw. The screw is mounting the P.I.S./H.-L.E channel segment 53 to D.E. 4 component 40 and ensures electrical bonding of those two components. As illustrated in FIG. 43 , the surface 407 is the back surface of D.E. 4 component 40 that could serve as the mounting surface to L.E.D. driver or mounting brackets 58 , depicted in FIG. 12 or FIG. 13 . Alternatively, 408 or 409 surfaces could be used to support the footprint of the driver or mounting brackets. The installation of the D.E. 4 compartment could be done by using a rotatable bracket 60 ( FIG. 9 and FIG. 12 ).
[0144] On the back side of the driver enclosure we can see a set of small mounting K.O. arranged in any appropriate pattern to match the footprint of a series of L.E.D. drivers intended to be installed for every fixture configuration or by using intermediate mounting bracketing. The mounting of the driver depicted in the exemplary embodiment is not intended to restrict the other options that are not shown here as this driver could be installed on the other adjacent surfaces 408 or 409 of the driver enclosure D.E. 4 , as seen in FIG. 43 . As seen in FIG. 44 , the flange 406 would be capable to be flattened by an operator, at the fixture installation, if a wire way chase is going to be installed adjoined to the driver enclosure. The bend line 405 would be formed on a successive row of holes that are intended to weaken the strength of the flange, at the bend line, and to make it easier for an operator to flatten the flange and eventually remove it by twisting that piece until its material will suffer structural damage at the bend line which would allow the flange 406 to be separated from the electrical enclosure 40 . As shown in FIG. 43 , the tabs 404 are intended to support the access doors while they are shut and to stop them from swinging inside the electrical enclosure 40 .
[0145] The enclosure 40 is considered as being “recessed” and, together with the elbow connector 46 , intended to fit within the “depth” limitation of a particular space, labeled “D 1 ”, described in detail in application Ser. No. 14/810,714 incorporated herein by reference.
[0146] In general, an enclosure is considered “sufficiently recessed” if its depth, measured from its mounting surface, is less than “D 1 ” and its protrusions are equal or less than the thickness of the planar surface “D” plus the thickness of the plaster, if any. The plaster thickness is usually between 1 mm to 6 mm. In general, the materials that are used to manufacture the electrical enclosures and the wire way chase integral to a channel, are: metals (carbon steel, stainless steel, aluminum, etc.), thermoset polyesters (i.e. fiberglass), thermoplastic (i.e. polycarbonate, ABS, etc.), polyesters, fire retardant plastics, etc.
[0147] The power input segment/housing light engine or P.I.S./H.-L.E labeled 53 as illustrated in FIG. 45 thru FIG. 46 could be made out of sheet metal aluminum or steel. Alternate construction could be made out of extruded aluminum but it would require multiple secondary operations. This segment is intended to match the profile of the extruded light engine housing 13 or its variations, and to ensure row continuity along the lens lines. Also, it needs to allow for compliance inspection access, from the room side, to the wire splice compartment. Also, it needs to support the light sources. As illustrated in FIG. 46 , the edges 534 are highly visible and are supposed to match or be accurately aligned with edges 131 of the component 13 as presented in FIG. 28 . As depicted in FIG. 45 , the opening for the access doors, perimeter 537 or 538 is formed as a closed loop shape, while each feature labeled 536 illustrate a countersink hole, which is intended to receive a self-tapping screw, on each side of the housing 53 . The power access cover 59 could be installed either in 537 or 538 opening, depending on where the elbow fitting 46 is installed. While the soft strips 73 are installed on the access doors 55 and 59 , the doors could be opened without removing the strips because the soft strips are flexible light engines. According to U.L. standard, a luminaire shall allow for inspection of branch circuit connections, after installation. Two minimum size openings, in the electrical enclosure, are supposed to allow passage of a rod having a diameter of ⅝″ (16 mm) and these openings are covered by the access doors, in an exemplary embodiment of this invention.
[0148] As illustrated by FIG. 12 , on top of the driver compartment there is a driver access cover 42 (or its alternative 23 ) that could be covered with plaster during the operating time of the fixtures, for aesthetic purpose. This cover could be removed if there is a need to replace the driver inside the D.E. 4 .
[0149] FIG. 52 , FIG. 53 , FIG. 54 and FIG. 55 are illustrating different view angles of the internal junction box, component 75 . In FIG. 55 , the features 751 and 752 are “knockouts”, intended to be removed, as needed, to install a bushing that would allow thru-wires to be safely inserted thru this opening. These wires are to be connected inside the junction box. The feature 753 is a hole intended for a self-tapping screw that would also be installed in a hole punched in the main D.E. 4 , to ensure electrical bonding between the two components. The two flanges, labeled 754 , are intended to cover a larger clearance slot, formed in the component 53 , for removal of the internal junction box while wires are inserted thru 751 and/or 752 . As illustrated by FIG. 12 or FIG. 12 -A, the wiring compartment could be contained by an “internal junction box”, component 75 that is also intended to capture the additional L.E.D. tape, the soft strip connectors, the wire nuts and wires.
[0150] The envelope of the fixture components installed on the framework that is supporting the architectural surface is defined as having the thickness of the respective surface, labeled “D” as illustrated by FIG. 15 . In one exemplary embodiment of this invention, the dimension “D” could take values ranging between ¼ inch to 2 inches. The spackle compound 81 and 82 is applied on the planar surface 80 after the installation of a complete row of fixtures and, in some configurations, before the lens 36 and the light source 73 installation. In other configurations, the light engine 73 and the lens 36 could be installed before the spackle compound is applied. Protective tape is recommended to cover the lens if the last option was chosen. This tape should be removed before the fixture is turned on.
[0151] A section view thru the driver compartment of the lighting system is presented in FIG. 12 and FIG. 12 -A. Most of the components description could be found in previous paragraphs except the wire nuts 47 that are used in the industry to make quick connections between solid copper wires 48 . In FIG. 12 -A we can see the low voltage wires 49 inside the internal junction box 75 .
[0152] The linear fixtures could be installed as semi-recessed configuration, where only the D.E. 4 is recessed while the light engine housings are above the planar surface. Other configuration could be when the light engine housings are surface mounted (for example, using a clip 15 as seen in FIG. 59 ).
[0153] In summary, these are the functions of the main components, or their features, as described previously:
Spackle flange/cover 23 or covering and anchoring surface
a) prevent particle intrusion to the integral wire way compartment of the channel housing; b) support the spackle/plaster compound; c) prevent or reduce plaster cracking;
Spackle flange 86 (or its variations 83 or 84 )
a) support the spackle/plaster compound; b) prevent or reduce plaster cracking;
Internal junction box 75
a) conceal additional L.E.D. tape; b) contains the wire splices, wire nuts;
Electrical enclosure 40
a) contains the L.E.D. driver and driver mounting means (brackets, screw, etc.); b) contains the internal junction box 75 ; c) contains “knockouts” to be removed as needed, to install elbow connector(s);
Channel/light engine housing 13
a) prevent dirt particles to reach the reflective surface, the optical surface or the L.E.D. chips; b) retain the light diffusing or light converting optical element; c) support the L.E.D. light source and transfer the heat out of the light engine;
wire way chase 20 is intended to:
a) protect the high voltage wire according to the safety standards; b) contains T-slots intended to ensure alignment of multiple channels by inserting so-called “cleats” between them; c) allow holes to be drilled for mounting to the structure; d) contains screw chase features to ensure end caps mounting; e) support the spackle flange/cover;
power input segment/housing-light engine 53
a) have an opening for the access doors; b) have mounting holes to attach the electrical enclosure; c) prevent dirt particles to reach the reflective surface, the optical surface or the L.E.D. chips;
light diffusing or light converting optical element 36
a) diffuse and mix the light; b) spread the incident light rays coming from L.E.D. point source to a surface illumination;
[0185] In other exemplary embodiment, depicted by the process Flow chart 1000 of FIG. 61 , we define ( 1001 ) a method of mounting at least one lighting fixture on a structure, without altering the structural members of its framework supporting at least one planar surface, comprising:
a. forming a gap in at least one planar surface ( 1002 ); b. installing at least one electrical enclosure bearing an electrical device attached to a power source, disposed between said structural members, along said gap ( 1003 ); c. mounting at least one channel on said structural members, in the said gap, recessed within the said planar surfaces ( 1004 ); d. attaching at least one covering and anchoring surface to said channel ( 1005 ); e. installing a light source into said channel ( 1006 ); f. connecting said light source to the electrical device ( 1007 ); and g. coupling at least one removable cover to said channel ( 1008 ).
[0193] In another exemplary embodiment, depicted by the process Flow chart 1100 of FIG. 62 , we define ( 1101 ) a method of mounting at least one lighting fixture on a structure, without altering the structural members of its framework supporting at least one planar surface, comprising:
a. forming a gap in at least one planar surface ( 1102 ); b. installing at least one electrical enclosure bearing an electrical device attached to a power source, disposed between said structural members, along said gap ( 1103 ); c. mounting at least one channel on said structural members, in the said gap, recessed within the said planar surfaces ( 1104 ); d. installing a light source into said channel ( 1106 ); e. connecting said light source to the electrical device ( 1107 ); and f. coupling at least one removable cover to said channel ( 1108 ).
[0200] Although each exemplary embodiment has been described in detail, it is to be construed that any features and modifications that are applicable to one embodiment are also applicable to the other embodiments. Furthermore, although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons of ordinary skill in the art upon reference to the description of the exemplary embodiments. It should be appreciated by those of ordinary skill in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or methods for carrying out the same purposes of the invention. It should also be realized by those of ordinary skill in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the scope of the invention. | Elongated lighting fixtures intended to be incorporated into thin architectural surfaces, interconnected and configurable as a continuous run with potential to follow the direction of adjacent planar surface in three dimensional spaces while maintaining the structural integrity of the supporting framework. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel N-benzoyl N'-pyridyloxy phenyl ureas and the process for producing the same and the insecticidal composition containing the same.
2. Description of the Prior Arts
Almost of the conventional insecticides impart neurotoxicity and contact toxicity to all kinds of insects.
And, it has been required to find selective insecticidal compounds without toxicity to useful insects, N-benzoyl N'-phenyl ureas disclosed in U.S. Pat. No. 3,748,356 have such insecticidal properties.
The N-benzoyl N'-pyridyloxyphenyl ureas according to the present invention have a substantially better action than the above described known compounds.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide novel N-benzoyl N'-pyridyloxy phenyl ureas.
It is another object of the present invention to provide a process for producing N-benzoyl N'-pyridyloxy phenyl ureas.
It is the other objects of the present invention to provide selective insecticidal compositions which are remarkably effective to certain injurious insects without affecting useful insects in remarkably low toxicity to animals.
The novel compounds of the present invention are N-benzoyl N'-pyridyloxy phenyl ureas having the formula ##STR2## wherein X 1 represents a halogen atom; X 2 represents hydrogen or halogen atom; X 3 and X 4 respectively represent hydrogen or chlorine atom; X 5 represents hydrogen or halogen atom; and X 6 represents a halogen atom or nitro or trifluoromethyl group.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Suitable compounds having the formula (I) include:
N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-bromopyridyl-2-oxy) phenyl]urea m.p. 196° to 199° C.
N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-nitropyridyl-2-oxy) phenyl]urea m.p. 209° to 212° C.
N-(2-chlorobenzoyl)N'-[4-(3,5-dibromopyridyl-2-oxy) phenyl]urea m.p. 185° to 188° C.
N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dibromopyridyl-2-oxy) phenyl]urea m.p. 223° to 224° C.
N-(2-chlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 216° to 218° C.
N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 225° to 228° C.
N-(2-chlorobenzoyl)N'-[3,5-dichloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 221° to 223° C.
N-(2-chlorobenzoyl)N'-[4-(5-bromopyridyl-2-oxy) phenyl]urea m.p. 179° to 180° C.
N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-chloropyridyl-2-oxy) phenyl]urea m.p. 198° to 200° C.
N-(2-chlorobenzoyl)N'-[3,5-dichloro-4-(5-chloropyridyl-2-oxy) phenyl]urea m.p. 147° to 148° C.
N-(2-chlorobenzoyl)N'-[4-(5-trifluoromethylpyridyl-2-oxy) phenyl]urea
N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-trifluoromethylpyridyl-2-oxy) phenyl]urea
N-(2,6-dichlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 228° to 230° C.
N-(2,6-dichlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 214° to 216° C.
N-(2,6-dichlorobenzoyl)N'-[3,5-dichloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 273° to 275° C.
N-(2,6-difluorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 184° to 185° C.
N-(2,6-difluorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea m.p. 230° to 231° C.
N-(2,6-difluorobenzoyl)N'-[3-chloro-4-(5-chloropyridyl-2-oxy) phenyl]urea m.p. 210° to 212° C.
The N-benzoyl N'-pyridyloxy phenyl ureas having the formula (I) are produced by reacting a compound having the formula ##STR3## wherein X 1 represents a halogen atom; X 2 represents hydrogen or halogen atom; R 1 represents amino or isocyanate group with a compound having the formula ##STR4## wherein X 3 and X 4 are the same and different and respectively represent hydrogen or chlorine atom; X 5 represents hydrogen or halogen atom; X 6 represents halogen atom or nitro or trifluoromethyl group; and R 2 represents an amino or isocyanate group and R 2 is amino group in the case that R 1 is isocyanate group, R 2 is isocyanate group in the case that R 1 is amino group.
More particularly, the compounds having the formula (I) can be produced by the following processes (1) and (2).
(1) The reaction of benzoyl isocyanate having the formula ##STR5## with pyridyloxy aniline having the formula ##STR6## (wherein X 1 , X 2 , X 3 , X 4 , X 5 and X 6 are defined above)
(2) The reaction of benzamide having the formula ##STR7## with pyridyloxy phenyl isocyanate having the formula ##STR8## (wherein X 1 , X 2 , X 3 , X 4 , X 5 , and X 6 are defined above).
The reaction is preferably carried out in the presence of a solvent. Suitable solvents include benzene, toluene, xylene, pyridine etc.
The reaction temperature is usually in a range of 20° to 120° C. and the reaction time is usually in a range of 0.5 to 24 hours. The reaction is preferably carried out at the temperature from 50° C. to a refluxing temperature for 1 to 5 hours.
Certain examples of preparations of the compounds of the present invention will be described.
EXAMPLE 1
Preparation of N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy) phenyl]urea
A solution prepared by dissolving 2.9 g of 3-chloro-4-(3,5-dichloro-pyridyl-2-oxy) aniline in 50 ml of toluene was heated at 80° C. A solution prepared by dissolving 1.8 g of 2-chlorobenzoyl isocyanate in 20 ml of toluene was added dropwise to the former solution under stirring it and the reaction was carried out for 1 hour. After the reaction, the reaction mixture was cooled and the precipitate was filtered and washed with toluene and then with petroleum ether and dried to obtain 3.2 g of N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea (m.p. 225° to 228° C.).
EXAMPLE 2
Preparation of N-(2,6-dichlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy) phenyl]urea
In accordance with the process of Example 1, except using 2.5 g of 4-(3,5-dichloropyridyl-2-oxy) aniline instead of 3-chloro-4-(3,5-dichloropyridyl-2-oxy) aniline and using 2.4 g of 2,6-dichlorobenzoyl isocyanate instead of 2-chlorobenzoyl isocyanate and reacting at 30° C. for 8 hours instead of 80° C. for 1 hour, the process was repeated to obtain 3.8 g of N-(2,6-dichlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy) phenyl]urea (m.p. 228° to 230° C.).
The compounds of the present invention impart excellent selective insecticidal effect as clearly understood from the following experiments.
Most of the conventional insecticides impart quick effect and neurotoxicity and contact toxicity. However, the compounds of the present invention impart the delayed effect that the compounds effect to molting (ecdysis) and metamorphosis of specific insects which orally take the compound with feeds or water whereby the death of the specific insects is caused.
The compounds of the present invention impart remarkable insecticidal effect to larvae of Lepidoptera, Coleoptera, Hymenoptera and Diptera, for example, larvae of the following insects:
diamondback moth (Plutella xylostella), common white (Pieris rapae crucivora), cabbage armyworm (Mamesta brassicae), cabbage looper (Plusia nigrisigma), tobacco cutworm (Prodenia litura), smoller citrus dog (Papilio xuthus), small blackfish cochlid (Seopelodes contracta), fall webworm (Hyphantria cunea), gypsy moth (Lymantria dispar), rice stem borer (Chilo suppressalis), bollworm (Heliothis zea), tobacco budworm (Heliothis virescens), bollweevil (Anthonomus grandis), confused flour beetle (Tribolium confusum), colorado potato beetle (Leptinotarsa decemlineata), sawfly (Neurotoma irdescens), Culex mosquito (Culex pipiens pallens).
The compounds of the present invention do not substantially impart insecticidal effect to adults and are ineffective to natural enemies as predatory insects and impart low toxicity to animals.
When the compounds are used as active ingredients of the insecticidal composition, it is possible to prepare various forms of the compositions such as dust, wettable powder, emulsifiable concentrate, invert emulsion, oil solution, aerosol preparation, etc. with adjuvants as the cases of agricultural compositions. The compositions can be applied with or without diluting them in suitable concentrations.
Suitable adjuvants include powdery carriers such as talc, kaolin, bentonite, diatomaceous earth, silicon dioxide, clay and starch; liquid diluents such as water, xylene, toluene, dimethylsulfoxide, dimethyl formamide, acetonitrile, and alcohol; emulsifiers dispersing agents spreaders etc.
The concentration of the active ingredient in the selective insecticidal composition is usually 5 to 80 wt.% in the case of the oily concentrate; and 0.5 to 30 wt.% in the case of dust; 5 to 60 wt.% in the case of wettable powder.
It is also possible to combine with the other agricultural ingredients such as the other insecticides, miticides, plant growth regulators. Sometimes synergetic effects are found.
The selective insecticides of the present invention are effective for inhibiting various injurious insects and they are usually applied at a concentration of the active ingredients of 5 to 10,000 ppm preferably 20 to 2,000 ppm.
EXPERIMENT 1
The active ingredients were respectively dispersed in water to prepare dispersions having specified concentrations. Leaves of cabbage were dipped into the dispersions for about 10 seconds and taken out and dried under passing air.
A piece of moistened filter paper was put on each Petri dish (diameter 9 cm) and the dried leaves of cabbage were put on the filter paper and larvae of diamondback moth in 2nd or 3rd instar were fed on them and the Petri dishes were covered and kept in constant temperature at 28° C. with lightening. After 8 days from the treatment with the dispersion, the dead larvae were measured and the mortality rates were calculated by the following equation: ##EQU1##
Table 1______________________________________ Mortality Rate (%) (concen- tration) 200 100No. Active ingredient ppm ppm______________________________________1 N-(2-chlorobenzoyl)N'-[3-chloro-4(5-bromo-pyridyl-2-oxy)phenyl]urea 100 1002 N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-nitro-pyridyl-2-oxy)phenyl]urea 100 1003 N-(2-chlorobenzoyl)N'-[4-(3,5-dibromo-pyridyl-2-oxy)phenyl]urea 100 1004 N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dibromopyridyl-2-oxy)phenyl]urea 100 1005 N-(2-chlorobenzoyl)N'-[4-(3,5-dichloro-pyridyl-2-oxy)phenyl]urea 100 1006 N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100 1007 N-(2,6-dichlorobenzoyl)N-[4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100 1008 N-(2,6-dichlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100 1009 N-(2-chlorobenzoyl)N'-[3,5-dichloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100 8010 N-(2,6-dichlorobenzoyl)N'-[3,5-dichloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 80 6011 N-(2,6-difluorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy)phenyl]urea12 10012 N-(2,6-difluorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100 10013 N-(2-chlorobenzoyl)N'-[4-(5-bromo-pyridyl-2-oxy)phenyl]urea 100 10014 N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-chloropyridyl-2-oxy)phenyl]urea 100 10015 N-(2-chlorobenzoyl)N'-[3,5-dichloro-4-(5-chloropyridyl-2-oxy)phenyl]urea 100 6016 N-(2-chlorobenzoyl)N'-[4-(5-trifluoro-methylpyridyl-2-oxy)phenyl]urea 100 8017 N-(2,6-difluorobenzoyl)N'-[3-chloro-4-(5-chloropyridyl-2-oxy)phenyl]urea 100 100______________________________________
EXPERIMENT 2
On radish young seedlings grown in unglazed pots, adults of diamondback moth were fed and kept for 24 hours to blow ova. One day later, aqueous dispersions of the active ingredients (500 ppm) were respectively sprayed on the young seedlings to fall drops of the dispersion and dried and kept in glass greenhouse. After 10 days from the treatment with the dispersion, the dead larvae were measured and the mortality rates were calculated by the equation ##EQU2##
The results are shown in Table 2.
Table 2______________________________________ Mortality rateNO. Active ingredient (%)______________________________________1 N-(2-chlorobenzoyl)N'-[3-chloro-4-(5-nitropyridyl-2-oxy)phenyl]urea 802 N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dibromopyridyl-2-oxy)phenyl]urea 1003 N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 100______________________________________
EXPERIMENT 3
About 20 cc of germinated rice seeds were put into cups (diameter: 9 cm, height: 3 cm) to grow them. When they grew to seedlings having a height of 1 to 2 cm, the aqueous dispersions at specified concentrations were respectively sprayed at a ratio of 2 cc per 1 cup and dried, and larvae of rice stem borer (just hatched) were fed and the cups were covered. After 10 days from the treatment with the dispersion, the dead larvae were measured and the mortality rates were calculated by the equation of Experiment 1. The results are shown in Table 3.
Table 3______________________________________ Mortality rate (%) (concentration)No. Active ingredient 200 ppm 100 ppm______________________________________1 N-(2-chlorobenzoyl)N'-[3-chloro-4- (5-bromopyridyl-2-oxy) phenyl] urea 100 1002 N-(2-chlorobenzoyl)N'-[3-chloro-4- (5-nitropyridyl-2-oxy) phenyl] urea 100 1003 N-(2-chlorobenzoyl)N'-[3-chloro-4- (3,5-dibromopyridyl)-2-oxy) phenyl] urea 100 1004 N-(2-chlorobenzoyl)N'-[3-chloro-4- (3,5-dichloropyridyl-2-oxy) phenyl] urea 100 100______________________________________
EXPERIMENT 4
Young branches of persimmon tree cut in a length of 15 cm from the top, were respectively dipped into the aqueous dispersions of N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea at various concentrations for 10 seconds, and they were dried and put into wide mouth bottles and larvae of gypsy moth in 2nd or 3rd instar were fed into them. The bottles were covered with gauze and kept in a constant temperature at 28° C. with lightening. After 7 days and 15 days from the treatment with the dispersion, the dead larvae were measured and the mortality rates and the abnormal rates were calculated. The results are shown in Table 4.
Table 4______________________________________ Mortality rate (%) (concentration)Observation 400 ppm 200 ppm 100 ppm______________________________________After 7 days 100 90 (10)* 40 (30)*After 15 days 100 100 90 (10)*______________________________________ *abnormal rate
EXPERIMENT 5
N-(2-chlorobenzoyl)N'-[4-(3,5-dibromopyridyl-2-oxy)phenyl]urea was used to prepare the aqueous dispersions at specified concentrations. The effects of the dispersions to various insects were tested. The mortality rates after 10 days from the treatments were obtained in accordance with the process of Experiment 1.
The results are shown in Table 5.
Table 5______________________________________ Concent- ration MortalityInsects Treatment (ppm) rate______________________________________cabbage armyworm: cabbage leaf2nd instar larvae dipping 50 100(Lepidoptera)confused flour beetle: wheat flour2nd larval instar larvae blending 200 100(Coleoptera)1 sp. of sawfly cherry branch3rd instar larvae spraying 250 100(Hymenoptera)______________________________________
EXPERIMENT 6
200 ml of the aqueous dispersions at specified concentrations were respectively placed in glass containers with a capacity of 450 cc. 20 larvae of third instar of the mosquito (Culex pipiens pallens) were placed in each container and the containers were hold at 26°-28° C. with lightening. The mortality rates after 10 days from the treatments were obtained in accordance with the process of Experiment 1.
The results are shown in Table 6.
Table 6______________________________________ Mortality rate (%)No. Active ingredient 0.1 ppm 0.01 ppm______________________________________1 N-(2-chlorobenzoyl)N'-[4-(3,5-dibromopyridyl-2-oxy)phenyl] urea 100 1002 N-(2,6-difluorobenzoyl)N'-[4-(3,5-dichloropyridy-2-oxy)phenyl] urea 100 1003 N-(2-chlorobenzoyl)N'-[4-(5-bromo-pyridyl)-2-oxy)phenyl] urea 100 100______________________________________
COMPOSITION 1
______________________________________(a) N-(2-chlorobenzoyl)N'-[3-chloro-4-(3,5-dichloropyridyl-2-oxy)phenyl]urea 20 wt. parts(b) Dimethyl sulfoxide 70 wt. parts(c) Polyoxyethylenealkylphenyl ether 10 wt. parts______________________________________
The components were uniformly blended to dissolve the ingredient to prepare an emulsifiable concentrate.
COMPOSITION 2
______________________________________(a) N-(2-chlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy)phenyl] urea 5 wt. parts(b) Talc 92 wt. parts(c) Sodium naphthalene sulfonate formaldehyde condensate 3 wt. parts______________________________________
The mixture was pulverized to uniformly mix them to prepare dust.
COMPOSITION 3
______________________________________(a) N-(2,6-dichlorobenzoyl)N'-[4-(3,5-dichloropyridyl-2-oxy phenyl]urea 50 wt. parts(b) Jeeklite (fine divided clay) 45 wt. parts(d) Sodium ligninsulfonate 5 wt. parts______________________________________
The components were pulverized to uniformly mix them to prepare a wettable powder. | N-benzoyl N'-pyridyloxy phenyl urea having the formula ##STR1## wherein X 1 represents a halogen atom; X 2 represents hydrogen or halogen atom; X 3 and X 4 respectively represent hydrogen or chlorine atom; X 5 represents hydrogen or halogen atom; and X 6 represents a halogen atom or nitro or trifluoromethyl group are novel compounds.
The compositions containing the compound as the active ingredient are effective as the insecticide for extinction of injurious insects with high safety in agricultural, forestry and hygienic applications. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a tandem master cylinder for a hydraulic brake unit with slip control. In the housing of the brake unit a primary piston preloaded by a second return spring define a primary and a secondary pressure chamber within a longitudinal bore. The pressure chambers are connected to a fluid reservoir through intake chambers and nonreturn valves and are associated with a first and a second control valve which release or shut off a second connection between the pressure chambers and the fluid reservoir depending on an actuating force.
A tandem master cylinder of this type is described, for example, in the published German patent application No. 3627000 in conjunction with a slip-controlled brake unit. The particular feature of this tandem master cylinder is that its pistons are furnished with central control valves. Brake lines associated with the two pressure chambers communicate through intake lines with nonreturn valves incorporated therein, with motor-driven pumps whose suction connections are linked by way of a suction line to the fluid reservoir. In this manner, the central control valves operate as pressure limiting valves which are controlled depending on the pedal force and which limit the hydraulic pressure built up by the two pumps by releasing hydraulic fluid connections between the pressure chambers and the fluid reservoir depending on the foot force acting on the pedal. On brake operation and also in the event of a brake pressure control action, the hydraulic fluid flows through a small number of valves and on each slip control action, the two master cylinder pistons are completely restored in order to safeguard a maximum reserve for braking in the event of a failure of the pumps. In these known brake units it is a disadvantage that the master cylinder presents a considerable overall axial length which has a negative effect particularly when mounting the brake pressure transmitted in the engine compartment of an automotive vehicle.
It is, therefore, the object of the present invention to improve a tandem master cylinder of this type by reducing its overall axial length without impairing its functional reliability.
SUMMARY OF THE INVENTION
According to the present invention, this object is attained in that the control valves are arranged outside the pistons and are linearly controlled by the pistons. The control valves are accommodated in a valve body which preferably has an axially symmetrical configuration and is stationarily supported within a section of larger diameter of the longitudinal bore.
According to a particularly compact design of the present invention, the intake chambers of the primary, and the secondary pressure chamber are arranged outside the longitudinal bore in the housing in its cylindrical recesses and are separated from the fluid reservoir by means of nonreturn valves. The nonreturn valves are formed by flow interceptor cups which are located at retaining elements accommodated in the cylindrical recesses and provided with hydraulic fluid ducts.
In a further embodiment of the present invention a radial recess is provided in the wall of the axial bore of the valve body which forms an annular chamber in conjunction with the surface of the secondary piston. The annular chamber communicates with the fluid reservoir and is separated from the primary pressure chamber by means of a first sealing ring, and from the secondary pressure chamber by means of a second sealing ring. This provision affords the driver recognition of an untightness of one of the two sealing rings directly at the brake pedal.
BRIEF DESCRIPTION OF THE DRAWING
Further characteristics and advantages of the present invention are set forth in the following detailed description of one embodiment, taken in conjunction with the accompanying drawing, wherein:
FIG. 1 shows a tandem master cylinder in accordance with the present invention in axial section;
FIG. 2 shows a first embodiment of the control valve in accordance with the present invention which is also illustrated in axial section; and,
FIG. 3 shows in axial section a second embodiment of the control valve.
DETAILED DESCRIPTION
The tandem master cylinder of the present invention as shown in FIG. 1 comprises a housing 2 in whose longitudinal bore 4 is a primary piston 6 and a secondary piston 7 define a primary pressure chamber 8 and a secondary pressure chamber 9. The longitudinal bore 4 which presents a section 35 of larger diameter is closed by a sealing element 3 at which a first return spring 18 is support to pre-load the primary piston 6. The sealing element 3, within which the primary piston 6 is sealed off by means of a sealing cup 21 is guided, partly surrounds a valve body 5. The valve body is incorporated in section 35 and preferably presents an axially symmetrical configuration in whose axial bore 71 forming the primary pressure chamber 8 the primary piston 7 which is arranged as a plunger piston is additionally guided axially by means of a guide collar 28 furnished with a plurality of bores 29. In this configuration section 35 is provided as a stepped bore whose steps in conjunction with annular surfaces of smaller diameters provided at the valve body 5 define two annular chambers 25, 26 communicating with the primary pressure chamber 8. The function of the annular chambers 25, 26 are described in the following. Sealing of the valve body 5 with respect to the sealing element 3 and to the section 35, respectively is carried out by means of four sealing rings 38, 39, 40 and 41 inserted into radial grooves of the valve body 5. The end of valve body 5 facing away from the primary piston 6 serves as a stop for the secondary piston 7 guided therein. The secondary piston 7 is formed with a radial collar 70 for this purpose. In this context, secondary piston 7 interacts with a first sealing ring 22 and with a second sealing ring 23 which are arranged in radial grooves of the valve body 5 and which separate an annular chamber 73 defined by a radial recess 72 in the valve body 5 and the surface of the secondary piston 7 from the primary pressure chamber 8, respectively, from the secondary pressure chamber 9. Between the bottom of longitudinal bore 4 and secondary piston 7 there is arranged a second return spring 19 which pre-loads the secondary piston 7 in the direction toward the valve body 5.
In order to suck hydraulic fluid from a fluid reservoir 20 in the event of return movements of the two pistons 6, 7, cylindrical recesses 31, 32 are provided in the housing 2 which from a first and a second intake chamber 14, 15 which are sealed off by means of nonreturn valves in the shape of flow interceptor cups 12, 13.
The flow interceptor cups 12, 13 are preferably arranged at retaining elements 33, 34 inserted in the cylindrical recesses 31, 32. The retaining elements 33, 34 are furnished with hydraulic fluid ducts 64, 65, 66 and preceded by two filters 68, 69 in the direction of flow of the hydraulic fluid from fluid reservoir 20 into the inner space of the housing 2. In this configuration, the intake chambers 14, 15 are associated to the individual pressure chambers 8, 9 in such a manner that while the first intake chamber 14 communicates with the primary pressure chamber 8 by means of a first intake duct 16 by way of the first annular chamber 25, the connection of the second intake chamber 15 to the secondary pressure chamber 9 is carried out through a second intake duct 17 directly.
In addition to the first hydraulic fluid connection described above, that is, between the pressure chambers 8, 9 and the fluid reservoir 20, a second connection is provided which is shut of by mean of a first control valve 10 and a second control valve 11 arranged within bores provided in the valve body 5. The second connection between the primary pressure chamber 8 and the fluid reservoir 20 is routed by way of a slot 30 formed in the valve body 5, by way of the open valve seat 46 (FIG. 2) of the first control valve 10, by way of a radial hydraulic fluid passage 47 in valve body 5, by way of the second annular chamber 26, by way of a hydraulic fluid duct 36 in the housing 2, and by way of the central bore 64 in the first retaining element 33. The second connection between the fluid reservoir 20 and the secondary pressure chamber 9 leads through the open valve seat 57 (FIG. 3) of the second control valve 11, through an annular chamber 59, described more fully hereinafter, through a radial hydraulic fluid duct 60 in the valve body 5, through a hydraulic fluid duct 37 provided in the housing 2, and through the central bore 66 of the second retaining element 34. The manner in which the two control valves 10, 11 are actuated by the guide collar 28 provided at the primary piston 6, respectively, by an actuating plate 24 located at the secondary piston 7 is described in greater detail in connection with FIGS. 2 and 3.
As is illustrated in FIG. 2, the first control valve 10 comprises ah actuating element 43 axially slidably supported within a bore 42 of the valve body 5 and, furnished with a filter 44, bearing a hemispherical closing element 45 which interacts with the valve seat identified by the reference numeral 46. At its end facing away from the closing element 45, actuating element 43 is formed with a nose 27 which catches behind the guide collar 28 (not shown) of the primary piston 6 so that the actuating element 43 comes to rest against the sealing element 3 contrasting the action of a compression spring 49 disposed in its bore 48. Compression spring 49 takes support in this configuration at the sealing element 3. A supporting element 50 is interposed which is secured within a section of larger diameter of the bore 48 by means of a circlip 51. Due to the initial tension of the compression spring 49, the actuating element 43 will be slid in the direction of the valve seat 46 on compression spring 49 being relieved (shift of the primary piston 6 in the direction of actuation), so that the control valve 10 is closed and the second connection between the primary pressure chamber 8 and the fluid reservoir 20 is interrupted.
The second control valve 11 which is illustrated in FIG. 3 is comprised of a valve bushing 52 being stationarily supported within an axial bore 56 of the valve body 5 and guiding an actuating plunger 53 which bears a spherical segment-shaped losing element 58 and is furnished with two bores 63, 54 arranged vertically relative to each other. Actuating plunger 53 which is biased by means of a compression spring 62 interacts with the actuating plate 24 located at the secondary piston 7. The second connection between the secondary pressure chamber 9 and the pressureless fluid reservoir 20 leading by way of a filter 55 is being provided in the valve bushing 52, by way of the two bores 63, 54 of the actuating plunger 53, by way of the open valve seat 57, by way of a passage 61 configurated in the valve bushing 52, and by way of the annular chamber 59 defined by a radial recess 74 of valve bushing 52. On actuation of the master cylinder, the compression spring 62 will be relieved by the sliding of the secondary piston 7 so that the spherical segment-shaped closing element 58 will close the valve seat 57 and the second connection between the secondary pressure chamber 9 and the fluid reservoir 20 will be interrupted. | A tandem master cylinder for a hydraulic brake unit with slip control. In the housing of the brake unit a primary piston pre-loaded by a first return spring and a secondary piston pre-loaded by a second return spring define a primary and a secondary pressure chamber within a longitudinal bore. The pressure chambers are connected to a fluid reservoir and are associated with a first and a second control valve which release or shut off a second connection between the pressure chambers and the fluid reservoir depending on an actuating force. In order to reduce the overall axial length of the tandem master cylinder, the control valves (10, 11) are arranged outside the pistons (6, 7) and are actuated linearly by the pistons (6, 7). | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a semiconductor device constituting a monolithic semiconductor IC device including a plurality of bipolar transistors formed in a single semiconductor substrate, and a monolithic semiconductor IC device including a bipolar transistor and a MOS transistor in a single semiconductor substrate.
Conventionally, in a Bi-CMOS LSI device (a large scale integrated circuit device including bipolar transistors and complementary metal-oxide-semiconductor field effect transistors), the performance of the constituent bipolar transistors (cutoff frequency f T and breakdown voltage) is the same throughout the LSI chip. This performance is determined by such a transistor which needs the highest breakdown voltage. The breakdown voltage and the cutoff frequency of a transistor are in the relation of trade-off to each other.
With respect to IC devices which include bipolar transistors other than Bi-CMOS LSI devices, there is a concept, as proposed in JP-A-57-157539, of partially differentiating the thickness of the epitaxial layer to constitute a circuit with bipolar transistors of different operation speed (cutoff frequency) and different breakdown voltage. In this case, the breakdown voltage is made different between bipolar transistors constituting the logic circuit provided with memory portion and bipolar transistors constituting the output linear circuit. In other words, the breakdown voltage is the same for all the bipolar transistors constituting the logic circuit.
The breakdown voltage needed for a bipolar transistor in a monolithic semiconductor IC device differs depending on what part or block of executing various functions the bipolar transistor under interest constitutes.
For example, a monolithic semiconductor IC device constituting a DRAM device may be a Bi-CMOS LSI device including such blocks as disposed as schematically shown in FIG. 1. Namely, the DRAM device includes an input circuit block 15, a decoder block 16, a word line driver block 17, a memory cell block 18, a sense amplifier block 19, and an output circuit block 20.
In the DRAM device constructed as above, the input circuit block 15 and the output circuit block 20 are formed only of those bipolar transistors which operate in the small signal region (the small signal being, for example, a voltage signal having an amplitude of about 1 V or lower) in order to improve the operation speed. The decoder block 16, the word line driver block 17 and the memory cell block 18 have circuit structures including CMOS transistors in order to reduce the power consumption and to increase the degree of integration. Here, however, the decoder block 16 and the word line driver block 17 also include bipolar transistors operating in the large signal region (the large signal being, for example, a voltage signal having an amplitude corresponding to about 0.8 to 1.2 times the supply voltage to the device) because there is a necessity to drive a multiplicity of memory cells at a high speed. The sense amplifier block 19 may also include bipolar transistors operating in the large signal region.
Now, a specific structure of the DRAM device having the structure as described above will be described referring to FIG. 2.
In the figure, numeral 11 denotes a bipolar transistor, 12 a p type MOSFET (hereinafter, referred to as PMOS), 13 an n type MOSFET (hereinafter, referred to as NMOS), and 14 a memory cell.
The bipolar transistor 11 is particularly that transistor which constitutes an input/output circuit for the memory cell, and operates in the small signal region (i.e. handles small amplitude signals). The PMOS 12 and the NMOS 13 constitute a CMOS by connecting one of their drain terminals with one of their source terminals.
Numeral 6 denotes a p type semiconductor substrate in the surface of which an n + type embedded layer 7 and a p + type embedded layer 9 are formed by the conventional technique such as ion implantation or diffusion.
On the embedded layers, an n type well region 8-1 (n type epitaxial layer) which constitutes a collector region of a bipolar transistor, an n type well region 8-2 (n type epitaxial layer) which constitutes a channel layer of the PMOS, and a p type well 10 (p type epitaxial layer) are formed by the technology of the epitaxial growth.
On the n type wells 8-1, 8-2 and the p type well 10, semiconductor regions 71, 72, 73, 74, 75, 76 and 77 are formed through ion implantation or diffusion.
A field insulating film 31 for isolating the elements from one another is formed for example of SiO 2 by selective thermal oxidation.
Numeral 33 denotes electrodes for the respective elements, which electrodes are formed by applying an inter-layer insulator film 32 on the whole surface, then opening windows for contacting electrodes by dry etching, vacuum-depositing a thin film of metal such as aluminum (Al), and removing those portions of the aluminum thin film by etching which are between the elements.
Here, in the conventional Bi-CMOS LSI device as described above, the n type well regions 8-1 which constitute the collector regions of the bipolar transistors 11, are formed under the same conditions and have the same thickness and the impurity concentration, regardless of whether the transistor should operate in the small signal region or in the large signal region. Further, the conditions for forming the n type well region 8-1 are also the same as those for forming the n type well region 8-2 which constitutes the channel layer of the PMOS 12. Thus in the LSI, the impurity concentration in the n type well region 8-1 is the same as that in the n type well region 8-2.
Now, referring back to FIG. 1 again, the breakdown voltage required for the respective blocks will be described. For example, the bipolar transistors in the circuit blocks 17 and 19 directly connected to the memory cell block 18 should have a breakdown voltage of 8 volts or more. The bipolar transistors in the indirect peripheral circuit block 16 need a breakdown voltage of 5 volts or more. The bipolar transistors in the ECL (emitter coupled logic) circuit block included in the IC device should have a breakdown voltage of around 3-4 volts. As stated above, the cutoff frequency f T which is a measure of the high speed operation and the breakdown voltage in a bipolar transistor are in the mutual relation of trade-off. To make the breakdown voltage of a bipolar transistor high is to put a disturbance for making the operation speed of the bipolar transistor high (i.e. the cutoff frequency cannot be made high). Therefore, to make the breakdown voltages of all the bipolar transistors in a single LSI chip uniform constitutes a burden for increasing the operation speed of the monolithic IC device.
Also, as the impurity concentration of the collector region of a bipolar transistor is made higher, the larger becomes the possibility of increasing the operation speed thereof. As will be stated later, however, the operation speed of the monolithic IC device including the bipolar transistor is not necessarily improved.
SUMMARY OF THE INVENTION
An object of this invention is, in a monolithic semiconductor IC device having a plurality of blocks formed in a single semiconductor substrate and having different functions, to give an appropriate operation speed and an appropriate breakdown voltage to each block, which are required in correspondence to the function of the respective block, thereby improving the operation speed of the IC device.
Another object of this invention is to provide a technique of varying the breakdown voltages of the bipolar transistors in a single chip according to the location, thereby enabling to fully extract the high speed operability of the bipolar transistors.
According to a main aspect of this invention, in a monolitic semiconductor IC device having a plurality of blocks formed in a single semiconductor substrate and having mutually different functions, at least one of the bipolar transistors contained in at least one of the above-mentioned blocks has a different resistance value of its collector region from the resistance value of the collector region of the bipolar transistor contained in another block, the collectors of the bipolar transistors having identical cross-sections through which carriers flow. By so designing, a plurality of blocks in a single semiconductor substrate will have the operation speeds and the breakdown voltages required in accordance with their functions.
Variation of the resistance of the collector regions of the bipolar transistors in respective blocks in order to give different operation speeds and breakdown voltages to different blocks contained in a monolithic semiconductor IC device may be achieved by controllably adjusting (determining) the length (thickness) of the collector region in the transport direction of carriers contributable to the conduction of the bipolar transistor, or the impurity concentration in the collector region.
Now, description will be made on the study and investigation by the present inventors, which have formed the basis for obtaining the above-mentioned technical feature.
FIG. 3 shows a cross-sectional structure of an npn bipolar transistor isolated by a silicon oxide (SiO 2 ) layer 31. The thickness of the lightly doped collector layer (collector region) 8 of a bipolar transistor is determined by the thickness of a lightly doped silicon (Si) layer 10 formed on an n + type embedded layer (heavily doped region) 7 and including the lightly doped collector layer 8, provided that the conditions for forming an emitter layer (emitter region) 71 and a base layer (base region) 72 are kept constant. The breakdown voltage of a bipolar transistor is mainly determined by the width (thickness) and the concentration of the lightly doped collector layer 8. In a bipolar transistor which requires a large breakdown voltage, the width of the collector lightly doped layer 8 may be made large. Then, the cutoff frequency, however, becomes smaller. A bipolar transistor which requires only a small breakdown voltage may have a reduced width of the collector lightly doped layer 8, thereby increasing the cutoff frequency f T (making the operation speed high).
Taking the above analysis into consideration, an embodiment of this invention adopts varying the thickness or width of the collector lightly doped layers 8 along the transport direction of carriers contributing to the conduction of the bipolar transistor, in a single chip.
An example of a Bi-CMOS DRAM device will be described referring to FIG. 4. In a p type silicon substrate 6, the depths of n + type embedded layers 42 are changed. In other words, the thicknesses of lightly doped layers 43 which constitute the collector lightly doped layers of bipolar transistors are changed to vary the breakdown voltages (and the cutoff frequencies). The width of the lightly doped layer 43 is made largest in a word line driver circuit block 17 which requires the highest breakdown voltage, and is gradually decreased from the word line driver block 17, through the decoder block 16 to the input circuit block 15. Therefore, the breakdown voltages and the cutoff frequencies f T in the blocks A, B, C, D and E shown in FIG. 4 are in the following unequality relations.
breakdown voltage: block C>blocks B, D>blocks A, E
f T : blocks A, E>blocks B, D>block C
As described above, a Bi-CMOS LSI device fully exhibiting the features of the bipolar transistor is realized by changing the breakdown voltages and the cutoff frequencies of the bipolar transistors in a single semiconductor chip.
Thus, in a single semiconductor chip including a plurality of blocks, the widths of the collector regions of the bipolar transistors in respective blocks along the transport direction of carriers contributing to the conduction of the transistor are changed according to whether the transistor is in a directly connected peripheral circuit block, or in an indirectly connected peripheral circuit block or in an input/output circuit block, to form bipolar transistors which have different breakdown voltages (different high speed operabilities) in different circuit blocks. Namely, the breakdown voltage of the bipolar transistor is varied in the unit of a circuit block. Then, the operation speed of the LSI device can be made higher as shown in FIG. 5, while maintaining the breakdown voltage of the LSI device as required. In the prior art, the breakdown voltage and the cutoff frequency f T of bipolar transistors are determined by the conditions for the directly connected peripheral circuit block which needs the highest breakdown voltage (for example, the word line driver block). In contrast to such prior art, the cutoff frequency f T is made higher as the required breakdown voltage becomes smaller when the transistor is located in the indirectly connected peripheral circuit block (decoder or sense amplifier block), and further in the input/output circuit block. Thus, as shown in FIG. 5, the delay times of the directly connected peripheral circuit block and the input/output circuit block can be shortened compared to the prior art.
Further, when improvement in the operation speed of A Bi-CMOS LSI device is intended, the base width of the bipolar transistor may be reduced to improve the cutoff frequency f T . It is difficult, however, to reduce the base width to a large extent, because the reduction is limited by the conditions of the manufacturing processes such as the annealing time and the annealing temperature. The cutoff frequency f T can be increased also by increasing the impurity concentration of the collector lightly doped region (hereinafter, referred to as collector impurity concentration).
FIG. 6 is a graph showing a relation between the collector impurity concentration of the bipolar transistor acting in the small signal range and the cutoff frequency f T . Here, the thickness of the n type well (and the p type well) formed in the epitaxial layer was set at about 1.0 μm, the emitter width was set not larger than 0.1 μm and the base width was set not larger than 0.1 μm.
It can be seen from FIG. 6 that the cutoff frequency f T increases from about 8 GHz to about 12 GHz when the collector impurity concentration is raised from 10 16 cm -3 to 10 17 cm -3 .
In short, when only the improvement in the operation speed of the bipolar transistor acting in the small signal range is considered, the impurity concentration of the n type well which determines the collector impurity concentration is higher, the better.
Therefore, for improving the operation speed of the Bi-CMOS LSI device, it can be considered to increase the quantity of impurity to be introduced in the well.
When the impurity concentration of n type wells, e.g. in the structure of FIG. 2, is simply increased, the junction capacitance between the n type well 8-2 and the source/drain regions 173 of the PMOS transistor 12 should increase. Thus, the operation speed of the PMOS transistor may be lowered.
Namely, when the impurity concentration of the n type wells is raised, the operation speed of the input circuit block, and the output circuit block, etc. of the Bi-CMOS LSI device which are formed solely of bipolar transistors becomes faster, but the operation speed of those circuit blocks of the Bi-CMOS LSI device which are constituted by CMOS transistors including a PMOS transistor may be lowered, on the contrary to the above.
Further, it has been experimentally confirmed by the present inventors that the cutoff frequency f T of a bipolar transistor acting in the large signal range is not so improved by the increase in the collector impurity concentration as in the small signal range, even though it is also a bipolar transistor.
When the collector impurity concentration is raised, the depletion region grows more into the base region to reduce the effective base width W b . This may be accompanied with a problem that the withstand voltage between the collector and the emitter may be lowered.
According to another embodiment of this invention, in a monolithic semiconductor IC device having bipolar transistors and insulated-gate field-effect transistors or MOS transistors on a single semiconductor substrate, the collector impurity concentration of a bipolar transistor is made higher than the impurity concentration in the channel region of a MOS transistor.
According to a further embodiment of this invention, in a monolithic semiconductor IC device having a plurality of bipolar transistors on a single semiconductor substrate, the impurity concentration in the collector region of a bipolar transistor acting in the small signal range is made higher than the impurity concentration in the collector region of a bipolar transistor acting in the large signal range.
The cutoff frequency f T of a bipolar transistor can be expressed, using the time for charging the emitter-base junction capacitance T1, the transit time of carriers in the effective base region T2, the time for charging the base-collector junction capacitance T3, and the transit time of carriers in the collector depletion region T4, as follows,
f.sub.T =1/2 π(T1+T2+T3+T4).
Among the four factors, the largest contribution is given by the effective base transit time T2. This factor T2 becomes smaller as the effective base width W b becomes smaller. When the collector impurity concentration in the bipolar transistor is raised, the extent of the effective base is limited and the depletion region extends more into the base region, thereby reducing the effective base width W b .
FIG. 7 schematically shows how the effective base width W b is narrowed by an increase in the collector impurity concentration. In the figure, reference numeral 71 represents an emitter region, 72 a base region, 73 a collector region, 712 an emitter-base depletion region, 720 and 720' effective base regions, 723 and 723' base-collector depletion regions.
In part (a) of the figure, which illustrates the case of the low impurity concentration collector wherein the collector impurity concentration is sufficiently low compared to the base impurity concentration, the base-collector depletion region 723 mainly extends into the collector region 73. Since the extent of the depletion region 723 into the base region 72 is small, the effective base width W b remains wide.
In part (b) of FIG. 7, the collector impurity concentration is raised. Along with the increase in the collector impurity concentration, the extention of the base-collector depletion region 723' into the base region 72 becomes larger and hence the effective base width W b is narrowed as shown at 720'.
As described above, by an increase in the collector impurity concentration, the effective base width W b is reduced and the cutoff frequency f T is improved.
Namely, in a semiconductor monolithic IC device including bipolar transistors of the above-described structure, the operation speed of those portions which are constituted only of bipolar transistors can be improved. When the entire Bi-CMOS LSI device is considered, the operation speed of the Bi-CMOS LSI can be improved by the increment in the operation speed of the bipolar transistors.
In an LSI device having bipolar transistors acting in the small signal range and bipolar transistors acting in the large signal range, which are formed in a same semiconductor substrate, the operation speed of the bipolar transistors acting in the small signal range can be improved. Seeing the LSI device as a whole, the operation speed of the LSI device can be improved by the improvement of the small signal bipolar transistors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a model diagram of a DRAM device.
FIG. 2 is a cross-section of a part of a specific structure example of a DRAM device.
FIG. 3 is a cross-section of a vertical bipolar transistor.
FIG. 4 is a model diagram of a Bi-CMOS DRAM device according to an embodiment of this invention.
FIG. 5 is a diagram illustrating an effect of the effective base width narrowing according to an embodiment of this invention.
FIG. 6 is a graph showing the relation between the cutoff frequency of the vertical bipolar transistor and the impurity concentration in the collector region of the transistor.
FIG. 7a-b is a model diagram illustrating how the effective base width in the vertical bipolar transistor is reduced by an increase in the impurity concentration in the collector region.
FIGS. 8 and 9 are partial cross-sections of a Bi-CMOS DRAM device according to an embodiment of this invention.
FIGS. 10a and 10b are partial cross-sections of a semiconductor substrate, illustrating the ion implantation to be achieved in an embodiment of this invention.
FIGS. 11a and 11b are graphs illustrating concentration profiles of the implanted impurity ion.
FIG. 12 is a schematic diagram for illustrating the manufacture of a Bi-CMOS device, employing the ion implantation as shown in FIGS. 10a and 10b.
FIG. 13 is a graph showing the impurity concentration profiles in the bipolar transistors according to an embodiment of this invention.
FIG. 14 is a cross-section of a p channel MOS transistor.
FIGS. 15a to 15c are partial cross-sections of a semiconductor substrate, illustrating the ion implantation to be achieved in an embodiment of this invention.
FIG. 16(a) to (c) show partial cross-sections of a semiconductor substrate, illustrating the ion implantation and epitaxial growth to be achieved in an embodiment of this invention.
FIGS. 17a to 17c are partial cross-sections of a semiconductor substrate, illustrating various steps in the manufacture of a Bi-CMOS LSI device according to an embodiment of this invention.
FIG. 18 is a graph showing the impurity concentration profiles in the bipolar transistor and in the MOS transistor according to an embodiment of this invention.
FIG. 19 is a graph showing the impurity concentration profiles in the bipolar transistors according to an embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 8 shows an example of a partial cross-section of a Bi-CMOS DRAM device structure, in which a plurality of vertical bipolar transistors as shown in FIG. 3 are formed in a silicon substrate having n + type embedded layers as shown in FIG. 4.
In FIG. 8, blocks A and E, blocks B and D, and a block C include respective bipolar transistors, each having an emitter region 85, a base region 86, and a collector region (i.e. collector lightly doped region) 87. The depth of the n + type embedded region or layer 42, and hence the breakdown voltage becomes large in the order of the blocks A and E, the blocks B and D, and the block C. The operation speed, on the contrary, decreases in this order. The thickness of the collector region 87 defined by the depth of the embedded layer 42 is the length of the region 87 along the moving direction of carriers contributing to the conduction of the transistor. Reference numeral 42' denotes a p + type embedded region or layer. Reference numeral 84 denotes an SiO 2 isolation region.
Regarding the bipolar transistor, the vertical npn bipolar transistor having an n + type embedded layer has been described. The concept of the above embodiment holds in completely similar way in other bipolar transistors, e.g. lateral bipolar transistor.
FIG. 9 shows a Bi-CMOS DRAM device in which the vertical npn bipolar transistors in the Bi-CMOS DRAM device of FIG. 8 are substituted with lateral bipolar transistors, each having an emitter region 95, a base region 96 and a collector region 97. The collector region 97 is formed of a surface portion of an n type well 95' formed in a p type substrate 1'. The width of the collector lightly doped region 97 is shown at W c1 , W c2 and W c3 , which are the lengths of the respective regions 97 along the moving direction of carriers contributing to the conduction of the transistor. For establishing an unequality relation of the breakdown voltage of the transistors as represented by
A, E<B, D<C,
the widths of the collector lightly doped regions W c1 , W c2 and W c3 are set to satisfy
W.sub.c3 <W.sub.c2 <W.sub.c1.
A semiconductor substrate having a structure as shown in FIG. 4 can be produced by forming n + type embedded layers 42 e.g. through high energy ion implantation. An example of forming an n + type embedded layer 42 in a silicon substrate 6 will be described referring to FIGS. 10a and 10b. First, as shown in FIG. 10a, an SiO 2 (or Si 3 N 4 ) layer 4 having a stepwisely changing thickness is formed partially on a silicon substrate 1. The film thickness of the oxide layer 4 is so selected that it is thicker in the block I than in the block II. Then, arsenic ions As + (or phosphorus ions P + ) are ion-implanted into the substrate 1 through the oxide mask 4 at an acceleration energy of around 3-5 MeV. As the result, n + type embedded layers are formed deep in the silicon substrate. The depth of the embedded layer becomes deeper in the order of the block I with the thick oxide--the block II with the thin oxide--the block III without any oxide layer. Therefore, the width of the lightly doped layers 3 becomes thicker in the order of the block I--the block II--the block III as shown in FIG. 10b. In this way, a substrate which enables varying the breakdown voltage and the cutoff frequency f T in a same chip and fully extracting the high speed operability of the LSI device, can be manufactured.
Function of the arsenic ion implantation through the oxide mask layer 4 in the process of FIGS. 10a and 10b will be described hereinbelow.
When n type impurity ions are implanted at a high acceleration energy into a bare silicon substrate without an oxide layer to form an embedded n + type layer 2, the n type impurity ions or atoms will distribute in a Gaussian distribution D with a mean implantation depth R p and a standard deviation σ as shown in FIG. 11a, being similar to the case of low acceleration energy (300-500 KeV). For example, when arsenic ions As + are implanted into a silicon substrate at an acceleration energy of 3 MeV, the mean implantation depth R p is about 2 μm and the standard deviation σ is about 0.4 μm.
When ions are implanted into a silicon substrate covered with a silicon oxide layer, the silicon oxide layer serves to block the ions similar to silicon. Then, the distribution of the ions D' in the silicon substrate will be shifted towards the surface of the silicon substrate compared to the case of having no silicon oxide layer, as shown in FIG. 11b. In FIG. 11b, the mean implantation depth R p ' is smaller than R p of FIG. 11a.
When arsenic ions are ion-implanted at an acceleration energy of 3 MeV into a silicon substrate covered with a silicon oxide layer having a thickness of 0.2 μm, the mean implantation depth R p ' becomes about 1.75 μm. That is, an n + type embedded layer is formed shallower by about 0.25 μm, compared to 2 μm in the case of no oxide layer.
As described above, the depth of the n + type embedded layer can be controlled by an SiO 2 layer, the thickness of which can be varied to control the depth. Namely, the width of the collector layer can be controlled according to the location in the substrate.
According to this embodiment, there may be no step of forming an epitaxial layer on a substrate for embedding an n + type layer. Thus, the manufacturing cost of a substrate can be reduced.
An embodiment of manufacturing bipolar transistors by forming a p type silicon substrate 1 having a structure as shown in FIG. 4 through high energy ion implantation as shown in FIGS. 10a and 10b will be described hereinbelow. For forming the n + type embedded layers 42 as shown in FIG. 4, an SiO 2 layer 4 having a thickness distribution on the respective blocks as shown in FIG. 12 is formed. The thickness of the oxide layer 4 is set at 0.4 μm on the input circuit block A and the output circuit block E, and is set at 0.2 μm on the decoder block B and the sense amplifier block D. Arsenic ions are implanted into the silicon substrate 1 through the mask 4 at an acceleration energy of 3 MeV and a dose of 1.7×10 15 /cm 2 to form n + type embedded layers 2.
Then, bipolar transistors as shown in FIG. 8 are made as follows. First, ion implantation of phosphorus ions (P + ) at an acceleration energy of 125 KeV and at a dose of 1.7×10 13 /cm 2 is carried out to form collector lightly doped layers 87. After the ion implantation, field oxide films made of SiO 2 and having a thickness of 5000 Å are formed by steam oxidization at 1000° C. for 90 minutes, to isolate the respective elements. Base layers 86 are formed by ion implantation of boron ions (B + ) at an acceleration energy of 30 KeV and at a dose of 1.3×10 14 cm 2 . After emitter apertures are formed, emitter 20 layers 85 are formed by ion implantation of arsenic ions (As + ) at an acceleration energy of 80 KeV and at a dose of 6×10 15 /cm 2 . After the base ion implantation for forming the base regions 86, heat treatment at 950° C. for 50 minutes is done, which determines the impurity distribution.
The impurity concentration profiles in a bipolar transistor manufactured as above including the profile in the n + type embedded layer 2 are shown in FIG. 13.
Following values are obtained for the cutoff frequency f T and the collector-emitter breakdown voltage BV CEO of the transistors in the blocks A to E disposed as shown in FIGS. 4 and 12. This breakdown voltage determines the breakdown voltage of the transistor.
______________________________________ Block A B C D E______________________________________BV.sub.CEO (volts) 4 7 10 7 4f.sub.T (GHz) 16 10 6 10 16Distance between 0.5 0.7 0.8 0.7 0.5substrate surfaceand embeddedlayers (μm)______________________________________
According to the prior art, the breakdown voltage should be the same all over the chip. Then, all the blocks should have, for example, BV CEO =10 volts and f T =6 GHz. The possible high speed operability of the DRAM device has not fully extracted.
As shown in the above embodiment, the breakdown voltage BV CEO and the cutoff frequency f T of the respective blocks could be varied and a significant improvement in the operation speed of the DRAM device could be achieved. The access time of the DRAM device manufactured according to this embodiment was 25 ns, while a similar DRAM according to the prior art has an access time of 35 ns.
Although reference has been made to npn transistors in the above description, it is also applicable to pnp transistors. The same is true in the following description.
The technique of forming a heavily doped embedded layer by high energy ion implantation can also be applied to the MOS transistor. FIG. 14 shows a structure of a p channel transistor having a p + type embedded layer 52. A pair of n + type regions 49 and 51 constitute a source and a drain or a drain and a source. A gate insulator film 50 formed of an SiO 2 film is disposed on the surface between the source 49 and the drain 51. A gate electrode 53 is formed on the gate insulator film 50. By this technique, the depth of the p + type embedded layer 52 can be controlled. By controlling the depth of p + type embedded layer 52, such effects can be obtained as that the resistance to the soft errors by α particle radiation can be changed.
In the above embodiments utilizing the mask effect illustrated in FIGS. 11a and 11b, the mask layer formed on the silicon substrate was made only of SiO 2 . The material is not limited to SiO 2 . Various structures can be employed such as a combination of a photoresist layer 63 and an SiO 2 layer 4 as shown in FIG. 15a, an Si 3 N 4 layer 64 having stepwisely changing film thickness as shown in FIG. 15b, and a combination of a photoresist layer 63 and an Si 3 N 4 layer 67.
Another embodiment of the method of manufacturing a substrate having the structure as shown in FIG. 4 is illustrated in FIG. 16. As shown in part (a) of FIG. 16, arsenic ions As + of 360 KeV and antimony ions Sb + of 20 KeV are successively and separately ion-implanted into a p type silicon substrate 101 at the respective doses of 1×10 15 /cm 2 . Then, n + type embedded layers 102 are formed as shown in part (b) of FIG. 16, with the depth of the As-doped layer being deeper than the depth of the Sb-doped layer. More specifically, the Sb-doped layer is formed in the vicinity of the substrate surface, while the As-doped layer is formed in the vicinity of depth 0.2 μm.
Then, as shown in part (c) of FIG. 16, an epitaxial layer 116 is formed on the substrate 101 by epitaxial growth. Through the above processes, n + type embedded layers 102 the depth of which is different by 0.2 μm according to the location.
The impurity for forming the n + type embedded layer 102 is not limited to As and Sb, and may also be P, etc. Considering the impurity diffusion during the epitaxial growth process, it is desirable that the impurity for forming the deep embedded layer has a smaller diffusion constant than the impurity for forming the shallow embedded layer.
As shown in the above embodiments, the thickness of the collector region of the bipolar transistors, which has been uniformly determined by the largest value of the required breakdown voltages, can be varied according to the required breakdown voltage. Hence, the cutoff frequency can also be varied.
As the method for manufacturing such a structure, application of high energy ion implantation is raised. An oxide layer having a different film thickness on different blocks in a single chip is formed. Impurity ions are implanted at a high energy. Because the ability of the oxide layer of blocking the ions varies according to the position on the substrate, there is generated a difference in the depth of the impurity distribution implanted in the silicon substrate. Therefore, the depth of the heavily doped embedded layer can be easily adjusted.
According to the above embodiments, the width of the collector layer of bipolar transistors can be controlled by varying the depth of the highly doped embedded layer in a same chip. Therefore, the breakdown voltage and the cutoff frequency f T , which is a measure of the high speed operability, of the bipolar transistor can be varied in a same chip, to produce high speed operation in the LSI device.
FIGS. 17a to 17c are cross-sections of a semiconductor substrate for illustrating the method for manufacturing a Bi-CMOS LSI device according to another embodiment of this invention. In the figures, reference numeral 51 denotes a block where bipolar transistors acting in the small signal range (dealing with small amplitude signals) are formed, 52 a block where bipolar transistors acting in the large signal range (dealing with large amplitude signals) are formed, and 53 a block where PMOS transistors are formed.
In the figures, n + type embedded layers 7 are formed on the surface of a p type semiconductor substrate 6, and silicon single crystal is epitaxially grown thereon to form epitaxial layers 54 having a thickness of 1.7 μm.
Then, for forming n type wells which form collector regions of the bipolar transistors and channel layers of PMOS transistors, phosphorus ions are implanted into the epitaxial layers 54 at an acceleration energy of 125 KeV and at a dose of 2×10 12 /cm 2 , to form n type wells 8-3 which constitute the collector regions of the bipolar transistors and n type wells 8-4 which constitute channel layers of the PMOS transistors (see FIG. 17a).
Then, for increasing only the collector impurity concentration of the bipolar transistor 51 acting in the small signal range, the regions for the bipolar transistor 52 acting in the large signal range and the PMOS transistor 53 are covered with photo-resist layers 55, and phosphorus ions are implanted into the epitaxial layer 54 at an acceleration energy of 125 KeV and at a dose of 1.8×10 13 /cm 2 to form an n type well 8-5 of a high impurity concentration (see FIG. 17b).
The above is the conditions of ion implantation for the n type well which determines the collector impurity concentration.
Then, steam oxidization at 1000° C. for 90 minutes is performed to grow field oxide films 31 to a thickness of 5000 Å to achieve the element isolation. Base regions 63 are formed by boron ion implantation at an acceleration energy of 30 KeV and at a dose of 1.5×10 14 /cm 2 . Emitter regions 62 are formed, after opening the emitter apertures, by arsenic ion implantation at an acceleration energy of 80 KeV and at a dose of 5×10 15 /cm 2 . The heat treatment for adjusting the impurity distribution after the ion implantation for forming the base regions 63 is performed under the conditions of 950° C. and 40 minutes (see FIG. 17c).
Following data are obtained for the collector-emitter breakdown voltage BV CEO and the cutoff frequency f T of the transistors in blocks A to E (blocks 15 to 17, 19, 20) disposed as shown in FIG. 1 or FIG. 4 with respect to various impurity concentration of n wells.
______________________________________BlockA(15) B(16) C(17) D(19) E(20)______________________________________BV.sub.CEO.sup.(V) 4 10 10 10 4f.sub.T (GHz) 16 16 6 6 16n well 1 × 10.sup.17 1 × 10.sup.16 1 × 10.sup.16 1 × 10.sup.16 1 × 10.sup.17impurityconcen-tration(cm.sup.-3)______________________________________
In this way, the collector region of the bipolar transistor 51 and the channel layer of the MOS transistor 53, which has the same conductivity type as that of the collector region of said bipolar transistor 51, are formed under different conditions, while they have been formed under the same conditions by the prior art. The impurity concentration of the collector region of the bipolar transistor 51 is made higher than the impurity concentration of the channel layer. Thus, the operation speed of the Bi-CMOS LSI device can be improved.
Further, among the bipolar transistors, the collector impurity concentration of the bipolar transistor 51 acting in the small signal range is set separately from and higher than the collector impurity concentration in the bipolar transistor 52 acting in the large signal range. Then, the operation speed of the Bi-CMOS LSI device can be improved without degrading the collector-emitter breakdown voltage.
FIG. 18 shows the impurity distributions in a bipolar transistor manufactured under the above-described manufacturing conditions.
In the figure, a dotted curve represents an impurity concentration distribution in the bipolar transistor having a raised collector impurity concentration and a solid curve represents an impurity concentration distribution in the bipolar transistor having the ordinary collector impurity concentration. More specifically, numeral 41 denotes the distribution in the emitter region, 42 the distribution in the base region, 43 the distribution in the collector region of the bipolar transistor having the raised collector impurity concentration, and 44 the distribution in the channel layer and in the collector region of the bipolar transistor having the ordinary collector impurity concentration.
As can be seen from the figure, the collector impurity concentration of the bipolar transistor acting in the small signal region was about 1×10 17 /cm 3 , and the impurity concentration in the collector region of the bipolar transistor acting in the large signal region and in the channel region of the MOS transistor was about 1×10 16 /cm 3 .
Further, the cutoff frequency f T of these bipolar transistors made under the above-described manufacturing conditions was measured. While the cutoff frequency of the bipolar transistor acting in the large signal region was 5 GHz, the cutoff frequency of the bipolar transistor acting in the small signal region was improved to 8 GHz, by an increment of about 60%.
Further, when such transistors were incorporated in a DRAM LSI device, the access time of the DRAM could be reduced from 35 nano-seconds to 28 nano-seconds.
As has been described above, the operation speed of the Bi-CMOS LSI device can be made faster by selecting the impurity concentration in the collector region of the bipolar transistor to be higher than the impurity concentration in the channel region of the MOS transistor.
Further, in an IC device having bipolar transistors acting in the small signal range and bipolar transistors acting in the large signal range, formed in a same substrate, when only the collector impurity concentration of the bipolar transistors acting in the small signal range is made higher the operation speed of the IC device can be improved without degrading the collector-emitter breakdown voltage.
In the above-described embodiments, use is made of high energy ion implantation technique. In the following embodiment in order to provide different effective widths for collector regions of bipolar transistors in different blocks as shown in FIG. 4, for example, use is made of ion implantation into a substrate surface, formation of an epitaxial layer of a uniform thickness on the substrate and heat treatment for the formation of base and emitter regions.
Conventionally, in order to form an n + buried layer, Sb ions are implanted into that portion of a Si substrate surface in which the n + buried layer is to be formed, or otherwise, Sb is deposited and diffused into such portion of the substrate surface, and thereafter an epitaxial layer is formed on the substrate.
In this embodiment, for block C (FIG. 4) expected to have a relatively higher breakdown voltage, only Sb (antimony) ions were implanted at a dose of 1×10 15 /cm 2 , for blocks B and D expected to have next higher breakdown voltages, Sb ions were implanted at 1×10 15 /cm 2 and additionally P (phosphorus) ions having a diffusion coefficient two order of magnitudes larger than that of Sb ions were implanted at 2×10 14 /cm 2 and for blocks A and E expected to have relatively lower breakdown voltages, Sb ions were implanted at 1×10 15 /cm 2 and additionally P ions were implanted at 4×10 14 /cm 2 . After the resulting substrate was annealed, an epitaxial layer was formed thereon to a thickness of 1.1 μm. Using the thus obtained structure, a Bi-CMOS memory was fabricated according to a process similar to that employed in the above-described embodiments. During the process, for formation of bipolar transistors for the various blocks, heat treatments were effected to form their base and emitter regions, when the Sb ions and P ions having been implanted into the substrate surface were further diffused toward the substrate surface, i.e., shallower with energy of the heat treatments, depending on the implantation dose and the diffusion coefficient of the impurity ions, to different depths.
The profile of impurity concentration distribution in the resulting transistor portions is shown in FIG. 19, from which it can be seen that the effective thickness of the epitaxial layer (collector region) is made different among the different blocks as in the above-described embodiments using high energy ion implantation technique to provide the same effects. | A monolithic semiconductor integrated circuit device includes bipolar transistors and MOS transistors constituting plural blocks formed in a single semiconductor substrate and capable of performing different functions. The bipolar transistors in the blocks have different breakdown voltages and different operation speeds due to the selection of different resistances of their collector regions. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention provides a cam tube support for a drum brake assembly that can adjust to an outer cam tube diameter so that good contact is always provided between the support and the cam tube.
2. Description of Related Art
Various drum brake cam tube support arrangements are in use today. However, with typical arrangements, it is often difficult to maintain consistent contact with cam tubes when using supports designed to accommodate variations in drum brake cam tube locations. Conversely, supports that maintain consistent contact with cam tubes typically fail to permit variations in support locations.
U.S. Pat. No. 3,076,531 to Hanley et al. shows a single tubular brake support that is adjustably secured within a brake spider. The mounting is rotatable around splines of the brake spider.
U.S. Pat. No. 5,174,680 to Nakamura et al. discloses a pair of rings brought together by bolts so as to ramp together between a shaft and a wheel and provide torque transfer. Guide portions on the shaft are unnecessary, but the ramp action is strictly limited by the sizes of the shaft and the hole in the wheel.
U.S. Pat. No. 5,649,685 to Keller shows a muffler support apparatus including two members that surround a muffler tube and are clamped together. The muffler support apparatus surrounds the tube and bolts vertically.
U.S. Pat. No. 6,240,806 to Morris et al. shows a non-welded cam tube support assembly. The tube includes a support plate that resists torsional loading and provides for either inboard or outboard mountings. An inner hole of the plate is irregularly shaped to tightly engage the cam tube.
U.S. Pat. No. 7,537,224 to Morris et al. shows a cam shaft support enclosure that has a two-piece, non-welded assembly. Two brackets mate with each other by sliding over a cam tube such that movement of the cam tube is minimized. Contact with the cam tube is maintained by tabs around an opening of the assembly. The overall fastener is movable along the length of the cam tube.
U.S. Patent Application Publication 2006/0021834 to Kwasniewski shows a cam washer that cooperates with a cam tube seal lug to reduce vibration, prevent corrosion, and hold a seal in place.
SUMMARY OF THE INVENTION
Introduction of wide-based tires has resulted in increased vibration and subsequent damage to drum brake cam tube assemblies. The present invention is intended to support drum brake cam tubes in such a way as to reduce vibration that can result in this sort of damage to the cam tube assemblies, and provides an improvement over an existing part that was first designed over 30 years ago. A support according to this invention can be attached to a welded or bolted frame member, may be used either in production or as a retrofit in the field, and can be installed independent of the cam tube assembly process. The present cam tube support serves to withstand the cantilevered load of an air chamber tube assembly while accommodating a variety of tube diameters via support jaw camming. Separate tube support pieces that do not rely on splines for changing the orientation around the cam tube are used, and form a three-piece assembly that move together to improve holding of cam tubes having different diameters at different locations along those cam tubes.
According to one embodiment of the invention, a support arrangement operable to clamp a tube for a brake assembly in position relative to an adjacent vehicle component includes a first jaw having a first pair of arms, each of which has an one opening in an inclined end section, a second jaw having a second pair of arms, each of which has an opening in an inclined end section, and a base associated with the vehicle component and having a third pair of arms. Each of the third pair of arms also has an opening in its end section. Bolts or other such fastener elements are receivable within aligned sets of openings in the first, second, and third pairs of arms, permitting displacement of the first and second jaws relative to the base upon adjustment of the fasteners so that the jaws grip the tube and clamp the tube in its proper position. A clamping process is also described.
In certain embodiments of the invention, the jaws have respective solid central recurved portions interconnecting the arms of the jaws and forming part-elliptical or part-circular recesses between the jaw arms. The inclined end sections of the jaws are bent relative to these central portions to provide the jaws with a camming action as the fasteners are tightened. The openings in the jaws and the base are preferably configured as oblong slots, and, when the arrangement is assembled, the oblong jaw slots have longer dimensions extending in directions that are not the same as directions in which longer dimensions of the oblong base slots extend.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a cam tube support fully clamping a partially illustrated cam tube in position relative to an associated vehicle component.
FIG. 2 is a front exploded view of certain components of the support shown in FIG. 1 .
FIG. 3 is a side view of the components shown in FIG. 2 .
FIG. 4 is a more comprehensive, perspective view of the cam tube and certain associated parts.
FIG. 5 is a side view of the structure shown in FIG. 4 .
FIG. 6 is a perspective view similar to FIG. 4 , but showing certain components of the cam tube support in alternative positions.
FIG. 7 is an enlarged plan view of the base of a cam tube support according to the invention.
FIG. 8 is an enlarged plan view of a jaw of the cam tube support according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The side view provided by FIG. 1 shows a partially illustrated cam tube 10 as fully clamped in position relative to an axle tube or other such unsprung vehicle component 12 , such as a suspension arm or other linkage, by a clamping cam tube support 14 . In one preferred configuration of the invention, when the cam tube 10 is mounted in position in a car, truck, or other such vehicle, a rotatable cam shaft (not shown) extends through the cam tube 10 to interconnect a fluid brake actuator and slack adjuster arrangement with a drum brake cam, which is operable to expand drum brake shoes apart in a known manner. Such cam shafts are disclosed, for example, in the Hanley et al. ('531), Morris et al. ('806), and Morris et al. ('224) patents mentioned above as well as the Kwasniewski ('834) publication mentioned above. The entire disclosure of each of the Hanley et al. ('531), Morris et al. ('806), and Morris et al. ('224) patents mentioned above, and the entire disclosure of the Kwasniewski ('834) publication mentioned above, are incorporated herein by reference as non-essential subject matter.
The clamping cam tube support 14 is composed of three primary parts, including a base 16 secured by welds 18 or in any other suitable manner to the unsprung vehicle component 12 , an approximately U-shaped lower jaw 20 , and an approximately U-shaped upper jaw 22 . As illustrated in the exploded plan view of FIG. 2 , the base 16 has an approximately Y-shaped configuration, but the base 16 could take other forms, and could be U-shaped as well. When the clamping cam tube support 14 is in use, a pair of threaded bolts 24 may pass through aligned slots in the legs of the base 16 and the jaws 20 and 22 . Cooperating nuts 26 may be tightened onto the ends of the bolts 24 to secure the base 16 and jaws 20 and 22 together, thereby fastening the cam tube 10 to the vehicle component 12 .
FIG. 2 provides an illustration of the base 16 and the jaws 20 and 22 in an exploded plan view. The base 16 is shown as having a central section 29 with a mounting surface 30 , adapted to be secured on a corresponding surface of the component 12 by the welds 18 . The base 16 , of course, could be attached to the component 12 in another suitable way or integrally formed with that component. The base 16 also has a pair of upstanding extensions defining arms 32 . Each arm is provided with an oblong slot opening 34 , with the longer dimension of the opening oriented roughly vertically. The term “vertically” is used here and elsewhere in this specification in a non-limiting manner, and, here, refers to a direction in which the arms 32 extend away from the central section 29 . A recess 36 defined between the arms 32 of the base has a circumferential wall 38 with a contour matching the contour of the outer surface of the cam tube 10 .
The lower jaw 20 is shown in FIG. 2 as having a solid central recurved portion 40 and a pair of arms 42 . Each arm 42 , near its end 43 distal the central portion 40 , has an oblong slot opening 44 , with the longer dimension of the opening oriented roughly horizontally. The term “horizontally” is used here and elsewhere in this specification in a non-limiting manner, and, here, refers to a direction approximately perpendicular to the direction in which the arms 42 extend away from the central portion 40 .
The upper jaw 22 has a configuration that is similar to that of the lower jaw 20 , and has a solid central recurved portion 46 and a pair of arms 48 . Each arm 48 , near its end 49 distal the central portion 46 , has an oblong slot opening 50 , with the longer dimension of the opening oriented roughly horizontally, similarly to slot openings 44 . When the clamping cam tube support 14 is in use, the jaws 20 and 22 are oriented such that each arm end 43 is adjacent a corresponding arm end 49 , and the central portions 40 and 46 are located away from each other. A recess 52 defined between the lower jaw arms 42 is surrounded by a circumferential wall with a contour matching the contour of the outer surface of the cam tube 10 , while a recess 54 defined between the upper jaw arms 48 , similarly, is surrounded by a circumferential wall with a contour matching the contour of the cam tube outer surface.
The base 16 and the jaws 20 and 22 are shown in FIG. 3 in an exploded side view. It is apparent from FIG. 3 that each lower jaw arm 42 has an inclined or canted section 45 adjacent its end 43 , and that each of the openings 44 is disposed in one of the inclined or canted sections. Each upper jaw arm 48 , similarly, has an inclined or canted section 47 adjacent its end 49 , with each of the openings 50 disposed in one of the inclined or canted sections 47 . The sections 45 and 47 , as shown, are inclined at approximately 15-20 degrees relative to the remainder of the respective jaw arm, but the amount of inclination shown is not to be considered limiting in any way. Although “camming” would be produced at any inclination angle in the 1-89 degree range, the range of preferred inclination angles is important due to load. Increasing the sizes of the openings 34 , 44 , and 50 would allow a wider range of angles.
The amount of inclination provided to sections 47 can be varied as required to provide more, or less, clamping force to the barrel of the cam tube 10 . In conjunction, as the angle of inclination increases, so must the size of the openings 44 and 50 be varied to accommodate insertion of the bolts 24 when the jaws are in a vertical position while remaining small enough to prevent the head of the bolt 24 and the nut 26 from passing through the openings when tightened. The clearance of the jaws 20 and 22 relative to the tube 10 will determine the travel of the jaws to the clamping position and, in combination with the angle of inclination, will determine the amount of clamp force that is developed.
When different cam brackets are installed, they will always be in slightly different locations because of common variations in the manufacturing process. The two-direction slots allow the clamping tube support to function even with this variation in tube locations. The horizontal slots in jaws 20 and 22 accommodate variation in the horizontal direction, while the vertical slots in the base 16 accommodate variation in the vertical direction. When assembly of the three parts comes together with bolts, the sets of slots allow the support to always “center-up” on the cam tube and achieve a good clamp. The support can also be disassembled and re-used as many times as necessary, avoiding the need to cut known support arrangements off the axle and the associated need for re-welding when a new cam bracket is installed.
FIG. 4 is a more comprehensive view of the cam tube 10 and certain parts associated therewith. FIG. 4 shows the tube 10 in a clamped condition, after the support 14 has been securely clamped onto the outer surface of the cam tube in a manner to be described. It is to be understood that the base 16 must be welded to the relevant vehicle component 12 (not shown in FIG. 4 ) before clamping can take place. The cam tube 10 shown in FIG. 4 extends from a bracket 56 , securable to an axle housing or other unsprung vehicle structure by bolts receivable in holes 60 , to an attachment flange 58 , securable to a drum brake spider, backing plate, or other such element. The rotatable cam shaft (not shown) protrudes in a conventional manner through the cam tube end opening 62 and positions the drum brake cam thereon between drum brake shoe ends for brake actuation. FIG. 4 also illustrates a fitting 64 by which grease or another lubricant may be supplied to the interior of the cam tube 10 to lubricate cam shaft bushings provided for the cam tube.
The clamping tube support 14 may be used in several ways to secure the tube 10 in position relative to the component 12 . One such way is now described with reference to FIGS. 1-3 , and 5 . The pair of slot openings 44 in the lower jaw arms 42 and the pair of slot openings 50 in the upper jaw arms 48 are aligned, and the shafts of a pair of bolts 24 are passed through the aligned slot openings 44 and 50 in a direction indicated by an arrow 55 in FIG. 3 . Ends of the bolt shafts are then passed through the slot openings 34 provided in the arms 32 of the base 16 , and the nuts 26 are threaded onto the ends of the bolt shafts and tightened to secure the base 16 and jaws 20 and 22 together. As the nuts are tightened, the head of each bolt 24 and a respective one of the nuts 26 are displaced toward one another. Due to the presence of the inclined jaw arm sections 45 and 47 , as the nuts 26 are tightened, the lower jaw 20 tends to pivot clockwise in the direction indicated by an arrow 66 in FIGS. 1 and 5 , and the upper jaw 22 tends to pivot counterclockwise in the direction indicated by an arrow 68 . As the jaws 20 and 22 move in this way, edges of the circumferential walls surrounding the jaw recesses 52 and 54 frictionally engage or actually dig into the outer barrel surface of the cam tube 10 , thereby securing the tube 10 in position relative to the component 12 . The camming or lever action provided as the nuts 26 are tightened allows the jaws to self-center and tightly clamp onto the cam tube so that vibration, which could damage the cam tube assembly, is reduced. Although the two jaw parts try to separate, the slot openings are designed in such a way that jaw separation is limited, and the jaws bite down on the cam tube barrel as the parts get tighter. The present invention permits relative movement between the jaws and the cam tube along the length of the cam tube before clamping, and is constructed such that adequate contact is maintained with the cam tube by the camming action produced by the support base and jaw configurations after clamping occurs and the relative movement mentioned is prevented.
A comparison of FIGS. 5 and 6 illustrates that the jaws 20 and 22 are securable to either side of the base 16 . The jaws 20 and 22 thus may be oriented so as to face in either cam tube axial direction, making attachment of the cam tube 10 to the component 12 exceptionally easy.
FIG. 7 is an enlarged plan view of the base 16 illustrating the arrangement of the oblong slot openings 34 in the base arms 32 , while FIG. 8 is an enlarged plan view of either the lower jaw 20 or the upper jaw 22 , illustrating the arrangement of the oblong slot openings 44 or 50 in the arms 42 or 48 , respectively. It is evident that, to produce the jaws 20 and 22 most efficiently, they should have essentially the same configuration. By orienting the oblong slot openings 34 in the arms of the base 16 “vertically” and the slot openings 44 and 50 in the arms of the jaws 20 and 22 “horizontally,” appropriate positional adjustment of the jaws 20 and 22 with respect to both the cam tube 10 and the base 16 is facilitated. Orienting the slot openings 44 and 50 horizontally, as illustrated, serves to limit relative movement of the jaws to ensure tight and secure engagement of the of the circumferential walls surrounding the recesses 52 and 54 and the outer surface of the cam tube 10 .
It is conceivable to configure the invention such that it has a single piece jaw instead of two jaws. The U-shaped upper jaw 22 , for example, could alone be used to secure the tube 10 to the base 16 and provide clamping.
Although the use of steel as a jaw material is contemplated, the jaws 20 and 22 could be made of any of a variety of materials. The slot openings 34 , 44 , and 50 , and the recesses 36 , 52 , and 54 , could be formed by way of any of a variety of processes, such as stamping or cutting by water jet or laser, or a combination of such processes. Selection of the bend angle to get the best clamping action may be necessary, depending on the particular environment in which the invention is utilized. The “arch” that actually contacts the barrel could be an elliptical shape that contacts the barrel in the flatter section, or a simple part-circular shape that contacts the barrel mostly at the top when in position. Recesses shaped to accommodate other barrel shapes, such as barrels having square cross sections, are also contemplated.
By way of the present invention, a cam tube support, adjustable to accommodate various tube diameters, is provided. The slot configuration of the three-piece device allows jaw position adjustment both horizontally and vertically, permitting accommodation of variations in tube diameter and providing for various tube support locations. Pieces of the device are structured so that the support can face either axial direction of the tube, providing additional mounting configurations. As the three support pieces are fastened together in a simple manner with two bolts, no welding is necessary, and manufacturing can be simplified. The base 16 can be pre-welded and attached to the vehicle component 12 without the need to precisely locate the base 16 on the component 12 . By having the cam tube support pieces wedge or cam together when the mounting bolts are tightened, secure contact with the cam tube is provided, and vibrations are reduced. The present invention thus provides varied mountings utilizing a simple design, with three main pieces holding the relevant vehicle component and the cam tube in proper relative position. The invention allows for multi-axis variations in location, and consistent contact is maintained when a cam tube is installed.
The cam tube support adjusts to location and tube diameter in such a way that it always provides adequate contact between the support and the cam tube. Clamping is accomplished by having one or two clamping members provide adequate clearance for easy installation. As a final adjustment, the clamping members self-center and tightly clamp onto the cam tube because of the cam or lever action caused by the shapes of the clamping members. The invention can be installed on new equipment or retrofit in the field, is attachable to a welded or bolted support leg, and accommodates significant variation in tube diameter and location.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. | A support arrangement, operable to clamp a cam tube for a drum brake assembly in position relative to an adjacent vehicle component, includes a first jaw having a first pair of arms, each of which has an one opening in an inclined end section, a second jaw having a second pair of arms, each of which has an opening in an inclined end section, and a base associated with the vehicle component and having a third pair of arms. Each of the third pair of arms also has an opening in its end section. Bolts or other such fastener elements are receivable within aligned sets of openings in the first, second, and third pairs of arms, permitting displacement of the first and second jaws relative to the base upon adjustment of the fasteners so that the jaws grip the tube and clamp the tube in its proper position. A clamping process is also described. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a ratchet mechanism for telescope devices on toy vehicles, in particular for telescope supports of crane jibs of toy crane trucks, comprising a manually drivable driving gearwheel rotatably positioned on a telescope base body, a rack-type row of teeth engaging with the driving gearwheel and disposed on a telescope arm which is lodged for longitudinal displacement in the telescope base body, and a pawl being in ratcheting engagement with a tooth gap between two teeth of the driving gearwheel for the telescopic arm to be fixed in different positions of displacement on the telescope base body.
2. Background Art
Ratchet mechanisms of the generic type are very often used in toy vehicles for the most various telescope devices. The use in telescopable crane jibs as such or in laterally extractable supports for the improvement of the stability of a crane truck is to be mentioned in addition to the example mentioned.
In all these possible applications the ratchet mechanism has different purposes, namely, on the one hand, to ensure the drive of the extractable telescopic arm and to fix the telescopic arm in positions of displacement of grid-type sequence on the telescope base body. A mechanism of this type as conventionally used has a manually drivable driving gearwheel which engages with a rack-type row of teeth on the displaceable telescopic arm. A pawl engaging with the driving gear wheel in the way of a ratchet is provided for blocking the telescopic arm; the pawl is suitably actuated, for instance by a spring, in the direction of engagement so as to ensure the mechanism to be reliably blocked in a direction of rotation of the driving gearwheel--as a rule the direction of rotation assigned to the retraction of the telescopic arm.
In order for the telescopic arm to be able to move in the blocked direction, the pawl must be disengaged from the driving gearwheel, which may for instance be done by an externally actuatable release lever. But this causes considerable difficulties in the handling especially by children, since two actuating operations have to be performed simultaneously.
An even more important disadvantage of such constructions resides in the fact that the pawl causes the driving gearwheel and consequently the associated telescopic arm to be blocked inflexibly at least in one direction of movement. If a child tries to push in the telescopic arm inappropriately, directly forcing it in without actuating the driving gearwheel, there is the risk that the pawl breaks and the blocking effect of the ratchet mechanism gets lost, in which case the toy vehicle is as a rule no longer of any use.
SUMMARY OF THE INVENTION
Proceeding from the foregoing, it is the object of the invention to further develop the ratchet mechanism of the generic type such that any damage to the pawl, even when operated inappropriately, can be avoided reliably.
This object is solved by the pawl consisting of elastically flexible plastics so that on the one hand, upon the actuation of the driving gearwheel for the extraction of the telescopic arm, it ratchets over the teeth of the driving gearwheel while being deflected counter to the direction of engagement, and on the other hand, upon the actuation of the telescopic arm in the direction of retraction by a force exceeding a limit, it is elastically deformable in a defined manner such that the pawl again ratchets over the teeth of the driving gearwheel while releasing the telescopic arm in the latter's direction of retraction. The pawl being formed of elastically flexible plastics, this provides for the possibility that upon any excessive actuation of the telescopic arm in the direction of retraction by a force exceeding a certain limit, the pawl is deformed in a defined manner such that it can ratchet over the teeth of the driving gearwheel, releasing the driving gearwheel and thus the telescopic arm in the latter's direction of retraction. As a result of its defined flexibility, the pawl can keep its orderly function. Typically, the solution according to the invention is a solution in terms of plastics technology making use of the specific properties of plastics material such as the enormous elastic deformability.
As a result of the measures according to which the pawl is a plate preferably slightly bent in the direction of engagement about a neutral axis extending parallel to the axis of rotation of the driving gearwheel, which plate is provided with a bearing sleeve on its bearing end, the bearing sleeve resting non-rotatably on an elastically twistable bearing axle on the telescope base body, the design and positioning of the pawl is realized in a constructionally simple way, the restoring forces regularly inherent in any plastics material being used for the pawl always to be reliably biased in its direction of engagement with the driving gearwheel, in particular as a result of the pawl's being lodged against rotation on an elastically twistable bearing axle on the telescope base body.
An advantageous configuration of the ratchet mechanism consists in that a stop is provided on the telescope base body upstream of the side of the pawl oriented in the direction of engagement, the stop defining the depth of engagement of the pawl with the tooth gap of the driving gearwheel such that, upon the application of a force exceeding the limit in the direction of retraction of the telescopic arm, the pawl is disengageable by intrinsic elastic deformation for the release of the driving gearwheel counter to the direction of engagement.
By reason of the teeth of the driving gearwheel being provided with a blind-hole-type recess extending parallel to the flanks and the resulting increase in flexibility of the teeth, the disengaging motion of the pawl upon the application of a force exceeding the limit in the push-in direction of the telescopic arm is supported and consequently the release of the driving gearwheel is facilitated.
In keeping with an embodiment of the ratchet mechanism, a stop is provided on the telescope base body upstream of the lateral edge of the side of the pawl oriented in the direction of engagement, which stop constitutes an abutment for the pawl upon the latter's deformation in the direction of engagement, the pawl being deformable upon the application of a force exceeding the limit in the direction of retraction of the telescopic arm in such a way that the pawl is displaceable past the stop in the direction of engagement beyond its position of engagement with the driving gearwheel. The pawl cooperates in a defined manner with the stop on the telescope base body, the stop supporting only the edge of the pawl. On the one hand, this stop results in that a high blocking effect is produced in the push-in direction of the telescopic arm. On the other hand, the exclusively lateral arrangement of the stop makes it possible for mutual support of the stop and the pawl to be released after a correspondingly strong deformation of the pawl upon the application of a strong force from outside in the push-in direction of the telescopic arm, the pawl being displaceable past the stop in the direction of engagement beyond its position of engagement relative to the driving gearwheel. This helps achieve the release of the driving gearwheel mentioned at the outset and thus of the telescopic arm into the latter's push-in direction.
Preferred embodiments of the invention relate to an unblocking gearwheel advantageously provided for appropriately releasing the pawl's engagement with the driving gearwheel. Being coupled with the driving gearwheel, the unblocking gearwheel is actuated together with the latter by way of a handwheel mounted on the outside of the telescope base body so that the retraction and extraction of the telescopic arm can be managed by a single common operating element. The problems mentioned at the outset regarding the simultaneous actuation of two operating elements for the retraction of the telescopic arm do not occur any longer.
Attention is drawn to the fact that the construction using an unblocking gearwheel can of course be employed in an especially advantageous manner in combination with the deformable pawl according to the invention. But regardless of this, the construction using an unblocking gearwheel is also applicable for improving the convenience of operation in ratchet mechanisms having conventional pawls, the function of protection against rupture of the pawl being however dropped.
Further features, details and advantages of the invention will become apparent from the ensuing description of an example of embodiment of the subject matter of the invention taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partially cut illustration from below of a telescope support,
FIG. 2 is a section of the telescope support along the section line II--II of FIG. 1,
FIG. 3 is a section of the telescope support along the section line III--III of FIG. 1,
FIG. 4 is a perspective exploded view of the pawl comprising the bearing axle of the telescope support according to FIG. 1,
FIG. 5 is a section along the section line V--V according to FIG. 2, and
FIG. 6 is a partial section of the telescope support in analogy to FIG. 2 having a ratchet mechanism differing in design from FIGS. 1 to 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The telescope support 1 illustrated in FIGS. 1, 2 and 5 for a crane jib on toy crane trucks has a telescope base body 2 and a telescopic arm 3 guided therein for longitudinal displacement. The telescope base body 2 is substantially tubular, a bearing sleeve 4 being formed on its end for the articulation of the telescope support 1 for instance on the superstructure of a toy crane truck. Upstream of its end turned away from the bearing sleeve 4, the telescope base body 2 has a convexity 5 on its bottom, the convexity 5 expanding downward in the form of a box and accommodating the ratchet mechanism referenced as 6.
The telescopic arm 3 has a substantially rectangular outer cross-sectional area (FIG. 5) essentially defined by three vertical webs 7, 8, 9 extending longitudinally. The two external webs 7, 9 run in longitudinal guides 10 on the inside of the tubular telescope base body 2. One lateral web 7 is coupled with the central web 8 by way of a horizontal connecting web 11. The connection of the central web 8 with the second external web 9 is made by regularly spaced tooth webs 12 extending vertically in the transverse direction and forming a rack-type row of teeth on the telescopic arm 3. On its outside end the telescopic arm is provided with two axle stubs 13 projecting outward in the transverse direction and producing the articulation for instance on the crane jib of the superstructure of a toy crane truck.
A first embodiment of the ratchet mechanism 6 according to FIGS. 1 to 5 comprises a driving gearwheel 14, an unblocking gearwheel 15 as well as a pawl 16 as essential components. An external handwheel 17 non-rotatably joined to a tubular shaft 18 is provided for the actuation of the ratchet mechanism 6. The shaft 18 lodges rotatably in a sleeve-shaped bearing projection 19 integrally formed on one side wall 20 of the convexity 5. The unblocking gearwheel 15 is integrally formed on the shaft 18 where the latter overlaps the connecting web 11. The shaft 18 ends above the center of the tooth webs 12 of the telescopic arm 3. An annular groove 22 of the driving gearwheel 14 is placed on the edge 21 on the shaft front side, whereby the shaft 18, the driving gearwheel 14 and the unblocking gearwheel 15 are positioned coaxially with each other. In addition, on its side turned away from the shaft 18, the driving gearwheel 14 is rotatably supported by means of an integrally formed axle stub 23 lodging in a cup-shaped bulging 24 on the second side wall 25 of the convexity 5. Further, the driving gearwheel 14 and the unblocking gearwheel 15 are rotatable one in relation to the other by a defined angle of rotation. This is accomplished by means of a recess 26 in the edge 21 on the front side of the shaft 18, a driving web 27 on the annular groove 22 of the driving gearwheel 14 engaging with this recess 26. The recess 26 extending by an angle at circumference exceeding that of the driving web 27, this serves to achieve the mentioned rotatability by a defined angle of rotation of the driving gearwheel 14 relative to the unblocking gearwheel 15. The angle of rotation is about 15° to 20°. As further seen in FIGS. 2 and 3, the driving gearwheel 14 and the unblocking gearwheel 15 are of identical pitch, the shape of the teeth of the driving gearwheel 14 corresponding to that of conventional rack-and-pinion gears. One tooth 28 of the driving gearwheel 14 at a time engages with a tooth gap 29 between two tooth webs 12 of the telescopic arm 3 (FIG. 2.).
The shape of the teeth 30 of the unblocking gearwheel 15 is triangular in a section at right angles to the axis of rotation D, one flank 31 being steep, the other flank 32 being flat. The flat flank 32 may have a slightly convex outward bulging--which is not shown in detail in FIG. 3. The purpose of this arrangement will be specified in detail below.
The pawl 16 of the ratchet mechanism 6 is disposed below the telescopic arm 3 upstream of the driving gearwheel 14 and the unblocking gearwheel 15 seen in the longitudinal direction. The free end 33 of the pawl 16 engages with a gap 34 between two teeth 28 and 30, respectively, of the driving gearwheel 14 and the unblocking gearwheel 15 (direction of engagement E). The pawl 16 has a slightly bent plate body 35 of which the bearing end 36 turned away from the free end 33 is provided with a bearing sleeve 37. The latter's left half referred to FIG. 4, which is assigned to the unblocking gearwheel 15, has a cross-recessed internal cross-sectional area, wheras the right half assigned to the driving gearwheel 14 has the conventional cylindrical internal cross-sectional area. The bearing sleeve 37 lodges on a bearing bolt 38 passing transversely through the convexity 5 and being cross-shaped in cross-section (FIG. 4). As a result, the pawl 16 is fixed against rotation to the bearing bolt 38 which is integrally formed on one side wall 25 of the convexity 5. The bearing sleeve 37 and the bearing bolt 38 are aligned for the pawl 16 in its position of rest to take the position shown in solid lines in FIGS. 2 and 3. The plate body 35 of the pawl 16 has a curvature bent in the direction of engagement E about a neutral axis extending in parallel to the axis of rotation D of the gearwheels 14, 15. On its half facing the unblocking gearwheel 15 (the left half in FIG. 4), the pawl 16 is further provided with a reinforcing fib 39 projecting downward and extending on the lateral edge 44 of the plate body 35 and with a projection 40 on the free end 33 extending in the direction of engagement E.
Proceeding from the side wall 25 a lateral stop 41 is provided on the side of the driving gearwheel 14; it is formed by a rib 42 extending between the bearing sleeve 37 and the driving gearwheel 14. The rib 42 extends about at right angles to the pawl 16. The stop 41 is so narrow that it backs the pawl 16 only very close to the latter's edge 43, as shown in solid lines in FIG. 1.
The functioning of the ratchet mechanism 6 is explained in detail below:
For the normal extraction of the telescopic arm 3, the handwheel 17 is rotated counter-clockwise as referred to FIGS. 2 and 3. The driving gearwheel 14 being correspondingly driven, the telescopic arm is moved outward by way of the gearing with the tooth webs 12. The pawl 16 is actuated counter to its direction of engagement E by the teeth 28 of the driving gearwheel 14, ratcheting over the teeth 28 and 30 of the driving gearwheel 14 and the unblocking gearwheel 15. The bearing sleeve 37 and the bearing bolt 38 being assembled against rotation, these two components get twisted, effecting a restoring force on the pawl 16 in the direction of engagement E.
For the regular retraction of the telescopic arm 3, the handwheel 17 is rotated clockwise. Normally, there would be the blocking effect by the pawl 16 engaging with the tooth gap 29 between two teeth 28 of the driving gearwheel 14. This is when the unblocking gearwheel 15 takes functional action. As a result of the confined rotatability of the unblocking gearwheel 15 relative to the driving gearwheel 14, the fiat flanks 32 of the teeth 28 of the unblocking gearwheel 15 are in clockwise advance of the corresponding flanks 32 of the teeth 28 of the driving gearwheel 14, lifting the pawl 16 counter to the latter's direction of engagement E out of the gaps 29 and 34, respectively. This is shown in dashed lines in FIG. 3. The blocking effect of the pawl 16 is thus cancelled, clockwise rotation of the driving gearwheel 14 and consequently the retraction of the telescopic arm 13 being possible. As a result of the above-mentioned convex design of the fiat flanks 32 of the unblocking gearwheel 15, the disengagement of the pawl 16 is additionally facilitated.
When a high force is inappropriately applied to the telescopic arm 3 in the push-in direction, the pawl 16 supports itself on the corresponding tooth 28 of the driving gearwheel 14. Simultaneously, the pawl 16 is acted upon in the direction of engagement E and comes to rest on the stop 41 of the rib 42. Consequently the push-in movement is blocked. If, however, a very high force is used, exceeding a certain limit, the pawl 16 is deformed so strongly on the side assigned to the driving gearwheel 14 (right half of FIG. 4) that it gets twisted and that in particular the edge 43 located on this side shifts inwardly. This defined deformation is facilitated in that in contrast to the left half of the pawl 16, no reinforcing measures such as the reinforcing rib 39 are provided on the right half. Consequently, this edge 43 can slip past the stop 41 and the pawl 16 can be displaced in the direction of engagement beyond its position of engagement with the driving gearwheel 14 shown in FIG. 2 into the position shown in dashed lines. The blocking effect is thus cancelled and the driving gearwheel 14 and the telescopic arm 3 are released. Upon the retraction of the arm 3, the pawl 16 again ratchets over the teeth 28 of the driving gearwheel 14.
In order to move the pawl 16 again into the position of rest shown in FIG. 2, it is sufficient to rotate the driving gearwheel 14 counterclockwise, whereupon one of the latter's teeth 28 drives the pawl 16 into the position of rest, the latter's deformation being cancelled. The ratchet mechanism 6 is again fully operable.
FIG. 6 shows an alternative configuration of the ratchet mechanism 6 that has proved even more operable in practice than the ratchet mechanism 6 according to FIGS. 1 to 5. Since the essential structure of the ratchet mechanism 6 according to FIG. 6 does not differ substantially from that of the ratchet mechanism according to FIGS. 1 to 5, the following is only an explanation of the differences in design and function:
The teeth 28 of the driving gearwheel 14 are about semicircular in profile, projecting less than the corresponding teeth of the driving gearwheel of the first embodiment. Moreover, blind-hole-type recesses 45 extending parallel to the flanks 32' and increasing the flexibility of the teeth 28 are provided in the embodiment according to FIG. 6.
Further, the rib 42 constituting the stop 41 is designed to be wider in the direction parallel to the axis of rotation D of the gearwheels 14, 15 so that the stop 41 can support not only the edge of the pawl 16, but about one third of its width. This is roughly outlined by the dashed contour of the rib 42 in FIG. 1.
As for the pawl 16 itself, the projection 40 on the free end 33 extends over the entire width of the pawl 16. This is likewise roughly outlined by dashed contours in FIG. 4.
As seen in FIG. 6, the stop 41 is positioned such that the projection 40 of the pawl 16 cannot engage with the tooth gap 29 as far as to the latter's bottom. Thus, the depth of engagement of the pawl 16 is defined such that upon the application of a force exceeding the limit mentioned at the outset in the push-in direction of the telescopic arm 3 and the resulting geared clockwise rotation--as referred to FIG. 6--of the driving gearwheel 14, the pawl 16 is actuated by the corresponding tooth 28 such that it is elastically deformed, as outlined in dashed lines in FIG. 6. As a result of this deformation the pawl 16 moves outward counter to the direction of engagement E until disengaging from the corresponding tooth gap 29 counter to the direction of engagement E. The driving gearwheel 14 can be further rotated by another tooth gap, after which the process just described is repeated. All in all, the telescopic arm 3 can be retracted upon the application of a force exceeding the limit without the pawl 16 being damaged.
The function of the ratchet mechanism shown in FIG. 6 during the regular retraction and extraction of the telescopic arm by actuation of the handwheel 17 does not differ from the function of the ratchet mechanism shown in FIGS. 1 to 5. In this regard there is no need of any further explanation. | A ratchet mechanism for telescope devices on toy vehicles comprises a manually drivable driving gearwheel rotatably positioned on a telescope base body, a rack on the telescopic arm, the rack engaging with the driving gearwheel, and a pawl of ratcheting engagement with a tooth gap of the driving gearwheel for the telescopic arm to be fixed in different positions of displacement on the telescopic base body. The pawl consists of elastically flexible plastics material so that on the one hand it ratchets over the teeth of the driving gearwheel upon actuation of the driving gearwheel for the extraction of the telescopic arm and that on the other hand it is elastically deformable upon actuation of the telescopic arm in the direction of retraction. The pawl then ratchets over the teeth of the driving gearwheel while releasing the telescopic arm in the latter's direction of retraction. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a simple method for locking/unlocking a program on a digital receiver of audiovisual programs, referred to hereinafter as a receiver. The invention also relates to a receiver of audiovisual programs implementing the method.
BACKGROUND
[0002] U.S. Pat. No. 5,969,748 discloses a method of controlling access to television channels. Locking is performed from a list of accessible channels by selecting locking criteria. The criteria selectable from a list are schedule, topic, parental rating and/or channel. The system operates as follows. After having entered his password, the user enters on an interface a criterion from a list of criteria, for example a topic. All the programs of a list of channels encountering this topic are locked. When the user chooses to watch or record a locked program from the list of channels, a screen window appears inviting him to input his password. If the password input is correct, all the programs encountering the selected topic are unlocked. The problem with this method is that it operates only on the basis of a list of accessible channels. It therefore proves to be rather impractical according to this prior art to lock the program of the current channel, that is to say that to which the user is connected at a given moment, since this channel must previously have been tagged in a list of channels. Another problem is that it is impossible to lock a channel which is unknown a priori, that is to say which does not appear in the list of channels. The list of channels may in fact not be complete and the user may find himself faced with a channel discovered by chance and which it is impossible for him to lock. Moreover, when the user chooses to unlock the program, the mode of unlocking is unique.
[0003] The object of the present invention is therefore to alleviate the drawbacks of the prior art by proposing a method of locking a program on a digital decoder not requiring the presence of a list of accessible channels. The method in fact allows the user to lock the program to which the receiver is connected. The method according to the invention additionally makes it possible to unlock a program according to various modes. The invention will for example allow parental control.
SUMMARY OF THE INVENTION
[0004] This aim is achieved by a method of controlling access to audio-visual programmes on a digital receiver of audio-visual programmes, wherein it comprises, regardless of the programme, a phase of locking the programme currently being displayed generated by an manual action during the current programme displaying.
[0005] According to another feature, the phase of locking a current program comprises:
[0006] a step of placing in memory at least one descriptor sent in the packets transmitted by the current program and identifying either the program, or a particular event of the program,
[0007] a step of activating the locking corresponding to the stored descriptor.
[0008] According to another feature, the locking is selected according to one of several modes such as:
[0009] temporary locking,
[0010] permanent locking,
[0011] event-based locking.
[0012] According to another feature, the unlocking is selected according to one of several modes such as:
[0013] temporary unlocking,
[0014] permanent unlocking,
[0015] event-based unlocking.
[0016] According to another feature, the temporary unlocking is eliminated by inhibiting or erasing the descriptor from the memory,
[0017] either following a step of detecting a change of channel,
[0018] or following a detection of a cycle of switching off and switching on the apparatus broadcasting the audiovisual programs.
[0019] According to another feature, the unlocking comprises the steps:
[0020] of displaying a screen window indicating that the chosen service is locked,
[0021] of triggering, by means, access to the process for unlocking the service,
[0022] of displaying a screen window suggesting entry of the user code or exit from the unlocking procedure,
[0023] of comparing the entered code with a stored code,
[0024] of displaying a screen window suggesting various modes of unlocking, if the code entered is correct,
[0025] of selecting a mode of unlocking,
[0026] of unlocking the service according to the mode chosen, or
[0027] of displaying a screen window suggesting that the user code be re-entered or that the procedure for unlocking the service be exited, if the code entered is incorrect.
[0028] According to another feature, failing selection, the unlocking is temporary.
[0029] According to another feature, the re-locking of a service unlocked in a temporary manner is automatic.
[0030] According to another feature, the event-based mode of unlocking relates to the next event or to several consecutive events thereof during which the operator performs the unlocking.
[0031] According to another feature, the locking comprises the steps:
[0032] of accessing the process for locking the program,
[0033] of displaying a screen window prompting the user to enter a user code or to exit the locking procedure,
[0034] of displaying a screen window signaling that the service is locked, if the user code entered is correct, or
[0035] of displaying a screen window suggesting that the user code be re-entered or that the locking procedure be exited, if the user code entered is incorrect.
[0036] According to another feature, the locking can be performed from a list of user-accessible programs.
[0037] According to another feature, the method comprises a step of storing the descriptor of the current event when the mode of unlocking is event-based and a step of detecting, by the microprocessor, the change of descriptor of the event so as to perform the event-based unlocking and allow the decoding of the event.
[0038] Another aim of the invention is to propose a device implementing this method.
[0039] This other aim is achieved by a digital receiver for controlling access to audio-visual programmes comprising a user interface with the receiver, this interface comprising means for triggering locking of the programme currently being displayed activated by an manual action during the current programme displaying, means for selecting via the user interface one of several modes of locking and means of reaction of the receiver ensuring the recording of the information required for implementing the chosen locking.
[0040] According to another feature, the means of triggering of the user interface comprise at least one button making it possible to access the locking or unlocking process.
[0041] According to another feature, the means of reaction comprise means for storing the information associating a program with a mode of locking or of unlocking of the receiver.
[0042] According to another feature, the means of reaction comprise means of detecting an event of the stored program, of triggering the unlocking of the decoder during the event and of causing locking upon detection of the end of the event.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention, together with its characteristics and advantages, will emerge more clearly from reading the description given with reference to the appended drawings in which:
[0044] [0044]FIG. 1 represents the operating diagram of a DVB (Digital Video Broadcast) decoder,
[0045] [0045]FIG. 2 represents in plan view a remote control used for the decoder,
[0046] FIGS. 3 to 7 represent the monitor keyed with various screens at various steps of the method,
[0047] [0047]FIG. 8 represents a flowchart of the locking procedure,
[0048] [0048]FIG. 9 represents a flowchart of the unlocking procedure.
[0049] The invention will be described in conjunction with FIGS. 1 to 9 .
DETAILED DESCRIPTION
[0050] The invention relates to a method of locking/unlocking a program on any type of digital receiver of audiovisual programs, such as a decoder ( 1 ). Digital decoders ( 1 ) are for example of the following types: DVB (Digital Video Broadcast), DSS (Digital Satellite System) or any type of Internet terminal. In all types of digital decoder ( 1 ), there is a means for identifying a program broadcast on a channel in a unique manner. In DVB, it is a triple identifying the program. This triple is composed of three identifiers (“network” ID, “transport stream” ID and “service” ID), one relating to the network, a second, the transport stream, and a third, the service. When it has not been previously stored by the software, the triple identifying the current program can be retrieved, in the case of a DVB decoder, by combining the information found in the PMT table (in which the service ID appears) and “SDT actual” table (in which the original “network ID” and “transport stream ID” data appear. In the case of an Internet terminal, this information will be replaced with the complete name of the current URL which is stored in the search, display and edit utility (otherwise known as the “browser”) and which identifies a program, in the form of a character string.
[0051] A DVB digital decoder used within the framework of our invention is made up as follows.
[0052] The decoder is connected to a television ( 2 ) through a “SCART” socket ( 28 ), to a video recorder ( 3 ) also through a “SCART” socket ( 29 ) and to the switched telephone network ( 6 ) through a modem ( 4 ).
[0053] The decoder ( 1 ) comprises a tuner ( 10 ) linked to a frequency converter of an antenna ( 5 ). The tuner ( 10 ) is connected to an error correction circuit ( 12 ) through a demodulator ( 11 ). The output of the error correction circuit ( 12 ) is linked to a demultiplexer ( 13 ). This demultiplexer ( 13 ) separates the various data packets according to their content and sends them to the relevant items through a buffer memory ( 14 ). The relevant items include among others an access control module comprising a chip card ( 15 ) inserted into a connector ( 16 ), an audio decoder ( 17 ), a video decoder ( 18 ) and a teletext management circuit ( 19 ).
[0054] The access control module also comprises a descrambler ( 20 ), through which any encrypted packet must pass before being stored in the buffer memory ( 14 ). The descrambler ( 20 ) is managed by a verifier circuit ( 21 ), which authorizes or otherwise the descrambling as a function of the user's access rights.
[0055] The decoder also comprises a microprocessor ( 22 ) linked to an infrared interface ( 23 ) capable of receiving signals from a remote control ( 24 ). The microprocessor ( 22 ) is moreover linked to a memory ( 25 ) storing the triples identifying each program. The memory ( 25 ) comprises a program ( 80 ) for locking a program, a program ( 81 ) for unlocking a program as well as a table ( 82 ).
[0056] The microprocessor ( 22 ) reads the demultiplexed data of the program from the buffer memory ( 14 ). These data of the channel correspond to information about each event broadcast by the program. This information may be the name of the event, the parental rating, etc.
[0057] The signals originating from the video decoder ( 18 ), from the audio decoder ( 17 ) and from the microprocessor ( 22 ) are sent to a mixer circuit ( 35 ), connected to the SCART socket ( 28 ) linking the decoder ( 1 ) to the television ( 2 ). This mixer ( 35 ) also receives signals from a video keying circuit ( 27 ), this circuit receiving signals formulated by the microprocessor from a software layer ( 26 ) for managing the infrared signals of the interface ( 23 ).
[0058] All the manipulations will for example be performed from a remote control ( 24 ) illustrated in FIG. 2. The user connects up to the program which he wants to lock, as represented in step ( 801 ) of FIG. 8. He presses a button of the remote control, indicating that he wants to lock the program to which he is connected, as represented in step ( 802 ) of FIG. 8. This button may for example bear the name “lock/unlock” ( 240 ). Actuation of this button ( 240 ) causes the program of a specific signal by the remote control ( 24 ). The specific signal, received by the infrared interface ( 23 ), triggers the processing, by the microprocessor ( 22 ), of a specific subroutine ( 80 ) stored in the memory ( 25 ) associated with the microprocessor ( 22 ) and calling the locking process, as represented in step ( 803 ) of FIG. 8. This specific program ( 80 ) causes the displaying on the television ( 2 ) of a screen window ( 30 ) for entering a code, as represented in step ( 804 ) of FIG. 8. This code may for example be identical to a code already present in the decoder ( 1 ). This code should not be known to persons for whom the program is locked, children for example, since it makes it possible to access the locking or the unlocking of a program. The code is entered by the user from a digital keypad ( 241 ) on the remote control ( 24 ). The entry screen window ( 30 ) is made up of an indication ( 300 ) indicating to the user that he has just accessed the process for locking a program, while inviting him to input his code. This screen window ( 30 ) also displays a zone ( 301 ) provided for the displaying of the entry of the code, for example in the form of asterisks so as to prevent the code from being revealed to an onlooker, and two keys ( 302 , 303 ) corresponding to buttons of the remote control ( 24 ). One button, for example “OK” ( 242 ), is intended for confirming entry of the code, the other button, for example “EXIT” ( 243 ), for exiting the locking process. If the user confirms his code, as represented in step ( 805 ) of FIG. 8, the specific subroutine ( 80 ), executed by the microprocessor ( 22 ), compares the code entered with the code ( 250 ) stored in the memory ( 25 ), as represented in step ( 806 ) of FIG. 8, and if the code entered is correct, the program is then locked as represented in step ( 807 ). The specific subroutine ( 80 ), executed by the microprocessor ( 22 ), allows the sending of the information required for the displaying of a screen window ( 31 ) which then appears, while indicating the locking of the program and while inviting the user by pressing the “lock/unlock” button ( 240 ) of the remote control ( 24 ) to access the process for unlocking the program, as represented in step ( 807 ) of FIG. 8. The user may therefore activate the unlocking program, as represented in step ( 808 ) of FIG. 8. If the user confirms his code and if the code entered is incorrect, the specific subroutine ( 80 ), executed by the microprocessor ( 22 ), compares the code entered with the code ( 250 ) stored in the memory ( 25 ), as represented in step ( 806 ) of FIG. 8, and sends the information so as to display a screen window ( 32 ), indicating that his code is incorrect. The screen window ( 32 ) also invites the user, through a message ( 320 ), to recommence entry of the code by pressing the “OK” button ( 242 ), that is to say to return to step ( 804 ) or to exit the locking process by pressing the “EXIT” button ( 243 ), as represented in step ( 809 ) of FIG. 8. The image of a locked program is not displayed on the screen of the television ( 2 ), the device displays for example only the fact that the program is locked.
[0059] According to a variant embodiment, an event of a current program or a current program is locked following a single press of the “lock/unlock” button ( 240 ) of the remote control ( 24 ). No code entry is required at the moment of the locking of the event or of the channel. On the other hand, unlocking will require the entry of a code stored previously, for example when initially commissioning the decoder, with the aid of a menu (not illustrated). This variant allows instantaneous locking from a single button, this being especially beneficial when the viewer is distracted by a telephone call, a visitor or some other urgent situation.
[0060] The unlocking according to the method occurs as follows.
[0061] When the user seeks to connect up to a locked program, the program for using the decoder examines the table ( 82 ) of locked programs in the memory ( 25 ) and invites the user to unlock by way of the screen window ( 31 ), as represented in step ( 807 ) of FIG. 8. The decoding of the program is executed if the latter is not locked. This screen window ( 31 ) invites the user, via a message ( 310 ), to press the “lock/unlock” button ( 240 ) so as to access the process for unlocking the locked program which he wants to display. After pressing this button ( 240 ), the specific signal, received by the infrared interface ( 23 ), triggers the processing, by the microprocessor ( 22 ), of a specific subroutine ( 81 ) stored in the memory ( 25 ) associated with the microprocessor ( 22 ) and calling the unlocking process, as represented in step ( 901 ) of FIG. 9. A new screen window ( 33 ) then appears. This screen window ( 33 ) is made up of a text zone ( 330 ), indicating that the user has just entered the process for unlocking the program and inviting him to input his code, as represented in step ( 902 ) of FIG. 9. This code is the same as the one used for locking a program. The user enters his code with the aid of the keypad ( 241 ) of the remote control ( 24 ). This entry is manifested by the displaying of asterisks in the zone ( 331 ) of the screen window ( 33 ). The user confirms his code by virtue of the “OK” button ( 242 ) or prefers to exit the unlocking process via the “EXIT” button ( 243 ). In the latter case, the program then remains locked. After confirming the code, as represented in step ( 903 ) of FIG. 9, the specific subroutine ( 81 ) executed by the microprocessor ( 22 ) compares the code entered with the code ( 250 ) stored in the memory ( 25 ), as represented in step ( 904 ) of FIG. 9, and if the code entered is correct, sends the information so as to display a new screen window ( 34 ), as represented in step ( 905 ) of FIG. 9. This screen window ( 34 ) allows the user to select a particular mode of unlocking for the locked program to which he is connected. To do this, the screen window ( 34 ) is made up of a text zone ( 340 ) reminding the user that he is in an unlocking process, of two keys ( 302 , 303 ), corresponding to the “OK” button ( 242 ) and “EXIT” button ( 243 ) of the remote control ( 34 ), respectively for confirming and exiting the process and of a zone ( 341 ) for selection of the mode of unlocking. This selection is made by pressing two shift buttons “<” ( 244 ) and “>” ( 245 ) of the remote control ( 24 ). These shift buttons ( 244 , 245 ), symbolized on the screen window ( 34 ), on either side of the text zone ( 341 ) presenting the mode of unlocking, through two keys “<” ( 342 ) and “>” ( 343 ), allow scrolling of the modes of unlocking the program. The use of the shift buttons ( 244 , 245 ) allows the display of various unlocking menus provided, corresponding to the following three modes: temporary unlocking, permanent unlocking or event-based unlocking. By acting on the shift arrows ( 244 , 245 ) of the remote control ( 24 ), the user selects one of these modes, then confirms his choice by pressing the “OK” button ( 242 ) on his remote control ( 24 ), as represented in step ( 906 ) of FIG. 9. The program is then unlocked according to the mode chosen, as represented in step ( 907 ) of FIG. 9. The user can at any moment choose to leave the unlocking process by pressing the “EXIT” button ( 243 ). If, after comparison in step ( 904 ), the code entered is incorrect, the specific subroutine executed by the microprocessor sends the information so as to display a screen window ( 32 ) indicating that the code entered is incorrect. The window also invites the user in a step ( 910 ) to re-enter his code by pressing the “OK” button ( 242 ), that is to say to return to step ( 902 ) or to exit the unlocking process by pressing the “EXIT” button ( 243 ).
[0062] Failing selection with the aid of the scroll buttons ( 244 , 245 ), the mode of unlocking after a certain time delay ( 909 ) is fixed at “temporary” by the program ( 81 ), as represented in step ( 908 ) of FIG. 9.
[0063] Temporary unlocking of the program signifies that if the user leaves the program which he has just unlocked in order to connect up to, for example, another program and should the user return to the program that he had unlocked, this program will again be locked. The user will therefore have to instigate a new unlocking process if he wishes to have access thereto. This mode allows the user who unlocks a program not to have to worry about locking the program when he leaves it.
[0064] Permanent unlocking of the program signifies that if the user leaves the program for, for example, another program and should he return to the initial program, the latter will still be unlocked. This allows the user to unlock a program for which he estimates that an inaccessibility is no longer necessary.
[0065] Event-based unlocking signifies that the user unlocks the program for the time corresponding to the remaining duration of the event in progress. After the event-based unlocking of the program, when the event has terminated, the program is locked again.
[0066] It is possible to extend event-based unlocking to the event following the event in progress or even to several consecutive events. In this case the program ( 81 ) performs the reading of the code identifying the event and those following it, and interrupts the program when the latter no longer corresponds to the event or to the event sequence chosen.
[0067] In a process for locking a program, the memory ( 25 ) stores the triple identifying the program. Through the use of a so-called MMI software layer ( 26 ), the microprocessor ( 22 ) prohibits connection to the desired program, that is to say does not open the video and audio streams. Thereafter, through the use of this software layer ( 26 ), the microprocessor acts on the video keying circuit ( 27 ) which will manage the display of the screen window ( 31 ) on the television ( 2 ) indicating that the program is locked. At each change of program, the microprocessor ( 22 ) scans the memory ( 25 ) so as to ascertain whether the triple identifying the current program which the user has selected is contained in the table ( 82 ). If the triple is stored in the table ( 82 ) of the memory ( 25 ), the microprocessor ( 22 ), through the software layer ( 26 ), disables the video and audio connection, and then acts on the video keying circuit ( 27 ) which will then take charge of the display of the locking messages. The video keying circuit ( 27 ) also takes charge of showing all the screen windows for entry, unlocking, etc.
[0068] When the unlocking of the program is temporary, the microprocessor ( 22 ) authorizes the mixer ( 35 ) to send the information to the television ( 2 ). The program is automatically re-locked after a change of program.
[0069] When the unlocking of the program is permanent, the triple is removed from the memory ( 25 ) without being reincorporated, except in the case of a new locking of the program.
[0070] When the unlocking relates to a particular event of a program, the memory ( 25 ) will store an information cue relating to the event in progress for which the user wishes that the program be unlocked. This information cue is stored among other information cues about the event in the buffer memory ( 14 ). This information cue is for example the identifier of the event in progress of a given program and has the name “event ID”. This “event ID” identifier is extracted from the information broadcast in the “EIT present/following” table of the current event. During a subsequent selection of the event by a user, a comparison is made between the “event ID” identifier of the event selected and the “event ID” identifier stored. If these values are equal, the program remains unlocked, the unlocked event has not in fact terminated. If these values are different, the program is re-locked automatically since the event for which the program has been unlocked has terminated. In the latter case, the “EIT present/following” table has altered or, stated otherwise, its version number has been incremented.
[0071] When the user performs an event-based unlocking, the microprocessor ( 22 ) receives, from the other items, the signal for detecting a change of event. The microprocessor ( 22 ) then acts on the software layer ( 26 ) so as to re-lock the program. It is also possible to unlock the following event or even several consecutive events.
[0072] It is possible to imagine selection of a mode of locking. The locking could be temporary, permanent or event-based. The locking procedure would then be the same as the unlocking procedure presented above. In the case where event-based locking is desired, the “event ID” identifier of the event in progress of a program is taken out of the “EIT present/following” table and stored in the memory ( 25 ). This event may already form the subject of a locking, for example temporary or permanent, of the program on which it is broadcast. During event-based locking, the “event ID” identifier of the current event is compared with the “event ID” identifier stored. If their values are equal, this signifies that the event for which the program is locked has not terminated, the program then remains locked. On the other hand, if their values are different, this signifies that the event has changed and the program unlocks automatically.
[0073] It should be obvious to persons versed in the art that the present invention allows embodiments in numerous other specific forms without straying from the field of application of the invention as claimed. Consequently, the present embodiments must be regarded by way of illustration, but may be modified within the field defined by the scope of the attached claims, and the invention should not be limited to the details given herein above. | The present invention relates to a method of controlling access to audio-visual programs on a digital receiver of audio-visual programs, wherein it comprises, regardless of the program, a phase of locking the current program generated by an manual action during the current programme displaying. In this way, the user can, with the aid of a particularly simple command, lock or unlock the program currently being displayed.
The present invention also relates to the receiver implementing the method. | 7 |
FIELD OF THE INVENTION
This invention relates generally to a bio-erodible delivery system which enables timed release of medicinals including proteins and small molecules.
BACKGROUND OF THE INVENTION
The rapid progress in recombinant DNA technology has provided researchers and clinicians with a variety of newly discovered proteins in amounts sufficient to enable laboratory and clinical study (Cytokines, A. Meager, Prentis Hall, 1991). Proteins either currently being administered by physicians or under investigation include growth factors, interferons, colony stimulating factors, and interleukins. In nature these molecules may act locally as paracrine agents; i.e., they interact with and activate nearby cells. Further, they can be pleiotropic, i.e., they can activate or stimulate more than one kind of cell.
Delivery of these highly potent molecules for treatment of disease remains a challenge. Serious toxicity, low maximum tolerated doses (MTD), and limited therapeutic windows have been observed. As noted above, since some of these molecules are paracrine agents, localized delivery is another issue (Golumbek, P. T., et al, Cancer Research, 53, 5341 (1993)). As an example, systemic use of certain colony stimulating factors may result in autoimmunity and tissue damage from intense inflammatory reactions. Temporary relief of illness may be followed by permanent damage to the immune system.
Many novel proteins now being investigated for clinical use have very short half-lives. Clearance from the circulation can occur in a few hours or even a few minutes. Hence, prolonged release of effective doses below the MTD would be advantageous.
Recombinant hormones such as BGH are widely used in dairy cattle. BGH is currently administered biweekly by injection. Controlled release of protein components in veterinary vaccines is desirable. Reduction of the frequency of injection and improvement in performance of the bioactive protein would be advantageous.
Bio-erodible polymers have been used for encapsulation of numerous classes of drugs (U.S. Pat. No. 4,349,530; Royer, G. P., et al, J. Parenteral Science & Technol., 37, 34 (1983); Lee, T. K., et al, Science, 213, 233 (1981); WO91/06287 (1991); WO93/25221 (1993), all of which are hereby incorporated by reference). Synthetic polymers and copolymers of lactic acid and glycolic acid have been extensively investigated (U.S. Pat. No. 5,122,367; Langer, Science, 249, 1927 (1990); U.S. Pat. No. 4,983,393 (1991)). Autologous albumin and gelatin are also exemplified in the literature (U.S. Pat. No. 4,349,530; Royer, G. P., et al, J. Parenteral Science & Technol., 37, 34 (1983); Lee, T. K., et al, Science, 213, 233 (1981)). Cross-linking with glutaraldehyde is known to stabilize albumin and gelatin matrices. Glutaraldehyde, however, is non-specific in its reaction with proteins. As a result, the protein drug can be inactivated or covalently bound to the matrix components. The latter reaction lowers the effective amount of deliverable drug or creates an antigenic molecule. A negative consequence of the latter chemical reaction is the development of autoimmunity.
U.S. Pat. No. 4,349,530 discloses implants, microbeads and microcapsules comprising cross-linked but physically-native albumin and a biologically active substance. The implants, microbeads and microcapsules may contain an inactive form of a protease capable of dissolving albumin.
U.S. Pat. No. 4,983,393 discloses a composition for use as an intra-vaginal insert comprising agarose, agar, saline solution glycosaminoglycans, collagen, fibrin and an enzyme.
Failures of conventional delivery systems for proteins are typically attributable to lack of design for controlled release, denaturation of the protein in the matrix, adverse immunological reactions, or chemical modification of the medicinal during formulation.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a bioerodible delivery system which enables timed release of medicinals.
It is an object of the invention to provide a delivery system for proteins which does not alter the biological activity of the proteins.
It is a further object of the invention to provide a delivery system where the release profile is easily altered.
SUMMARY OF THE INVENTION
The subject invention relates to a medicinal delivery system comprising (i) at least one protein selected from the group consisting of gelatin and albumin, (ii) a polymeric stabilizer and/or an external cross-linker, and optionally (iii) an enzyme capable of degrading said protein or said polymeric stabilizer, wherein said system is stabilized by said protein being crosslinked with said polymeric stabilizer and/or said external cross-linker.
The invention also includes a sustained release delivery system comprising
(a) a first gel matrix comprising (i) a protein selected from the group consisting of gelatin and albumin, and (i) a polymeric stabilizer and/or an external cross-linker, and (iii) a medicinal protein wherein said first gel matrix is stabilized by said protein being cross-linked to said polymeric stabilizer and/or said external cross-linker, and
(b) a second gel matrix comprising (i) a protein selected from the group consisting of gelatin and albumin, and (ii) a polymeric stabilizer and/or an external cross-linker, and (iii) an enzyme capable of degrading said protein or said polymeric stabilizer, wherein said second gel matrix is stabilized by said protein being cross-linked to said polymeric stabilizer and/or said external cross-linker.
Also provided by the invention is a medicinal delivery system comprising (i) at least one matrix protein selected from the group consisting of gelatin and albumin, and (ii) a polymeric stabilizer and/or an external cross-linker, wherein said system is stabilized by said protein being crosslinked with said polymeric stabilizer and/or said external cross-linker, and (iii) an enzyme capable of degrading said protein or said polymeric stabilizer embedded on the surface of said system.
Delivery systems of the invention for sustained release comprise at least two gel matrices wherein at least two of said gel matrices have different levels of cross-linking (internal or external), gel density and/or enzyme.
The invention also includes a method for obtaining sustained release of a medicinal comprising administering the delivery systems of the invention to a mammal.
Additionally, the invention includes a method of synthesizing a drug delivery system comprising the steps of mixing matrix protein, protected medicinal protein, hydrolytic enzyme, and polymeric stabilizer and shaping the mixture into a gel matrix, and optionally curing said gel matrix with an external crosslinker.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a gel matrix for the timed release of proteins (gelatin molecules not shown);
FIG. 2 shows periodate oxidation of polysaccharides;
FIGS. 3A and B show companion beads containing hydrolytic enzyme;
FIG. 4 shows an externally catalyzed erosion of protein beads;
FIG. 5 shows an implant or capsule for oral delivery;
FIG. 6 presents schemes for the modification of amino groups in therapeutic proteins and enzymes; and
FIG. 7 is an idealized profile of programmed release: Class I--contains high levels of enzyme and low matrix density and cross-linking; Class II--moderate enzyme concentration, density, and degree of cross-linking; Class III--low enzyme concentration and in a highly cross-linked, dense matrix.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a biopolymer gel matrix 2 designed for the controlled release of medicinals 6 including proteins and small molecules. The hydrophilic, non-immunogenic gel matrix consists of (i) one or more proteins, such as gelatin (collagen) and/or albumin 4, (ii) a polymeric stabilizer 8 such as a polysaccharide or polynucleotide and/or an external cross-linker 10 and optionally (iii) an enzyme 12. The matrix protein concentration (gel density), the composition of the matrix protein 4, the concentration of medicinal 6, the shape and size of the gel matrix 2, the amount of polymeric stabilizer 8, the degree of external cross-linking 10 and the amount of enzyme are adjusted to achieve the desired release profile.
Many proteins denature at hydrocarbon-water interfaces. Indeed, to stabilize sensitive proteins often requires inclusion of an "inert" protein such as albumin. Gelatin (collagen) is commonly used to pre-treat surfaces which inactivate or adsorb proteins. Gelatin and albumin are readily available and have very low antigenic potential. Stable dosage forms can be made at moderate temperatures and near neutral pH.
Various types of collagen may be used as the matrix protein 4 in the subject invention, e.g., types A and B, Bloom Nos. 60-300. Advantageously, human collagen is used for human administration.
In addition to gelatin, other non-immunogenic matrix proteins can be used in the subject invention. Serum albumin can be used especially when a strong gel is desired. Human, bovine and rabbit serum albumin may be used. Advantageously, the albumin is native to the animal into which the gel matrix is to be administered. Available amino groups in the form of lysine are high in number in serum albumin. Lysine constitutes approximately 13% of the amino acid composition of serum albumin.
In one embodiment both gelatin and serum albumin are used together as the matrix protein. The ratio of these two components can vary, for example 50:50 (w/w), 60:40, 70:30, 80:20 or 90:10 with either protein being present as the primary component.
Elastin, hemoglobin, myoglobin and proteins of basement membrane can also be used as the matrix protein 4.
The gel matrix 2 can be formed as beads, granules, implants, microspheres (100-200 microns), threads, cylinders, disks, films or cell-sized microspheres (less than 100 microns) using techniques presented herein and known to those skilled in the art. The gel matrix 2 is typically stabilized internally by cross-linking with the polymeric stabilizer 8, either through ionic bonds, or covalent bonds when the polymeric stabilizer 8 carries amine specific functional groups such as aldehydes and imidates. The gel matrix is optionally stabilized by an external cross-linker 10 such as a multi-functional imidate.
It is useful to stabilize protein gels with covalent cross-links. In solution glutaraldehyde exists in polymeric forms which contain sites for Michael addition reactions with thiols, amines, phenolic hydroxyls, etc. (see Table 1).
TABLE 1__________________________________________________________________________Reactivities of functional groups in proteins.ReagentFunctional Group Acylimidazole Glutaraldehyde Diazonium Salts CHO/NaBH4 Imidates__________________________________________________________________________NH.sub.2 + + + + +SH + + + - - ##STR1## + + + - - ##STR2## - - + - - ##STR3## - - + - -CO.sub.2 H - ? - - -+SS - - - - -__________________________________________________________________________
In the present invention, polyfunctional amine-specific aldehydic and amidination reagents are used to stabilize the matrix in preference to glutaraldehyde which is non-specific (see Table 1).
Gel Matrix Preparation
Advantageously, the gel matrix 2 components include a matrix protein 4, a polymeric stabilizer 8, a hydrolytic enzyme 12, and an external cross-linker 10. The gel matrix 2 is schematically represented in FIG. 1. Gelatin (or other matrix protein) molecules, which are in excess, are not specifically shown. The matrix preparation typically occurs in three steps:
1. The medicinal is mixed with the matrix components (e.g., matrix protein, polymeric stabilizer and enzyme). The medicinal is dissolved or dispersed as an amorphous or crystalline solid. The polymeric stabilizer is optionally included in the formulation prior to gelation. One approach involves formation of a gelatin-polysaccharide bead in a rapidly stirred dispersion in a water-immiscible substance. The anionic polysaccharide can be activated by pre-treatment with sodium m-periodate (FIG. 2). The resulting polyfunctional dialdehyde reacts to form primarily internal cross-links.
2. The gel matrix is formed into the desired shape (beads, cylinders, disks, etc.).
3. The solidified matrix is optionally subjected to an external cross-linker to provide added stability and to prolong release. Multivalent metal cations and/or chemical cross-linkers can be added to cure the outside of the gel matrix. The frequency of chemical cross-links near the outside of the gel is a result of diffusing the bifunctional reagent into a previously formed gel matrix ("curing").
Polymeric Stabilizers
Polysaccharides, such as those listed in the first column of Table 2 are useful as polymeric stabilizers in the gel matrix of the subject invention.
TABLE 2______________________________________Amine specific cross-linking reagents.Polymeric Stabilizers(Internal Cross-linkers) External cross-linkers______________________________________Dialdehyde-dextran ImidatesDialdehyde-dextransulfate ##STR4##Dialdehyde-Chondroitin SulfateDialdehyde-Hyaluronic Acid R = (CH.sub.2).sub.n or (CH.sub.2 CH.sub.2 O).sub.n______________________________________
Chondroitin sulfate and hyaluronic acid are immunologically inert. Strong gels can be formed using polyanions such as polysaccharides in combination with multivalent metal ions and polymeric cations (Joung, J. J., et al, Appl. Biochem. Biotechnol., 14, 259 (1987)). In addition to chondroitin sulfate and hyaluronic acid, dextran (including oxidized dextran, i.e., dextran-CHO) and dextran sulfate have been used successfully. Clinical grade dextran has the advantages of low cost and ease of handling. Polynucleotides are also useful as polymeric stabilizers.
The degree of internal cross-linking can be varied. The rate of release is inversely related to the degree of cross-linking.
External Cross-linkers
Once the gel matrix is formed into the desired shape, treatment with an external cross-linker (i.e., curing the gel matrix) is desirable where added physical stability and prolonged release are needed. For example, beads prepared either in water or in organic medium, can be subjected to curing by soaking the beads in a solution of diimidate. The rate of release is inversely related to the degree of external cross-linking.
Advantageously, amine-specific cross-linkers are used in the subject invention. Diimidates form stable amidine adducts with amino groups of proteins and are especially useful as external cross-linkers. Advantageous compounds useful as external cross-linkers are presented in the second column of Table 2.
For delivery of non-proteinaceous drugs, other less specific cross-linkers are also useful. Examples include: multifunctional alkylating agents, multifunctional acylating agents, and multifunctional carbonates such as ##STR5## in which X is a leaving group such as a halide, a phenol or hydroxy succinimide. If a hydrolytic enzyme is to be included, it must be pre-treated with an analogous mono-functional reagent to avoid covalent immobilization within the matrix. An example of the latter reagent is acetyl imidazole.
In one embodiment of the invention, only an external cross-linker is used, i.e., polymeric stabilizer is omitted.
* * *
Sub-batches of beads (or other shapes) can be prepared by cross-linking (either using internal or external cross-linkers) for varying time periods. For example, beads can be made where 10, 20, 30, 40, 50, 60, 70, 80 or 90 percent of available amino groups are subject to cross-linking. These sub-batches can be used to constitute blends of beads. To illustrate, when these blends of beads contain proportionately more of the heavily cross-linked sub-batch, the release is relatively slow. Blends of beads weighted toward lightly cross-linked sub-batches release drug relatively quickly.
Enzymes
Programmable erosion of the gel matrix (and timed release of the medicinal) is made possible in the present invention by including one or more hydrolytic enzymes in the gel matrix. As an example, when beads are chosen as the gel form, the hydrolytic enzyme can be included directly into the proteinaceous bead containing the drug, in companion beads, or added to the formulation as free enzyme.
Conditions for the preparation and storage of gel matrix must be selected to avoid enzymatic degradation prior to use. It is well known that enzyme activity is strongly dependent on pH, temperature, ionic strength, and the presence of modifiers. Conditions such as low temperature and pH can be selected to suppress enzyme activity. Lyophilization can also be used to suppress enzyme activity.
Enzymes may react with the cross-linker in a manner similar to the medicinal protein, and should therefore be protected. It is well known that amino groups of enzymes can be modified without loss of activity. Therefore, pretreatment of the enzyme according to methods described below with respect to the medicinal proteins (see FIG. 6) may be carried out on enzymes prior to direct incorporation.
In a second embodiment, the hydrolytic enzymes 12 are included in companion gel matrix beads 2 as shown in FIG. 3B. In this case the population of the drug-containing gel matrix beads 2 is homogeneous. The enzyme 12 containing beads 2 are blended to achieve the desired release profile. Companion beads 2 with high enzyme content and low degree of cross-linking would produce fast release. In contrast, companion beads 2 with low enzyme content and high degree of cross-linking would result in slow release.
In a third embodiment, hydrolytic enzymes 12 are added directly to the formulation in soluble or in crystalline form (see FIG. 4). Gel matrix beads 2 and enzyme 12 are mixed just prior to administration or stored together in the dosage form under conditions which do not support enzyme activity such as low ionic strength, low pH, or absence of activators. In a variation of this embodiment enzymes are also present in the gel matrix.
In a fourth embodiment of the invention, an implant or capsule 14 is constructed as shown in FIG. 5. A blend of gel matrix beads 2 with varying amounts of cross-linking is included in the advantageously low density gel capsule or implant 14. Prolonged release is achieved by weighting the blend in favor of highly cross-linked gel matrix beads 2. Also, collagenase (enzyme containing) beads 2 can be included to modulate release rate. The implant or capsule 14 may have a semipermeable membrane (for use as an implant) or enteric coating (for oral use).
An advantageous enzyme is collagenase, which digests the gelatin matrix component. Alternatively, an enzyme specific for the polymeric stabilizer is used. Hyaluronidase, dextranase, or nuclease represent this latter type of enzyme.
Digestion of the gel matrix has two results--reduction of the viscosity of the medium through which the protein medicinal must travel and perforation of the gel matrix surface. The hydrolytic enzymes must have narrow specificities which exclude the medicinal protein.
Purified collagenase selectively cleaves after X in the sequence PRO-X-GLY-PRO where X is any neutral amino acid. PRO can designate either proline or hydroxyproline. GLY represents glycine. Although very frequent in collagen, the sequence, PRO-X-GLY-PRO is generally rare in proteins.
Hyaluronidase cleaves glycoseaminoglyeans but not polypeptides. It catalyzes the hydrolysis of glycosidic bonds of beta-N-acetyl-hexosamine (1,4-linked).
Gels containing relatively high amounts of hydrolytic enzymes will permit faster release of the medicinal. Desired delivery profiles can be produced by blending batches of beads with varying amounts of enzyme. In one embodiment more than one type of enzyme is included in the gel matrix, e.g., dextranase and collagenase.
Medicinal Proteins
As used herein the term medicinals includes proteins as well as small molecule agents. The term "protein" includes naturally occurring proteins, recombinant proteins, protein derivatives and polypeptides. Medicinal proteins useful in the subject invention include colony stimulating factors (CSF) including G-CSF, GM-CSF, and M-CSF; erythropoietin; interleukins, IL-2, IL-4, IL-6, etc; interferons; growth factors (GF) including epidermal-GF, nerve-GF; tumor necrosis factor (TNF); hormones/bioactive peptides; ACTH; angiotensin, atrial natrincetic peptides, bradykynin, dynorphins/endorphins/β-lipotropin fragments, enkephalin; gastrointestinal peptides including gastrin and glucacon; growth hormone and growth hormone releasing factors; luteinizing hormone and releasing hormone; melanocyte stimulating hormone; neurotensin; opiode peptides; oxytocin, vasopressin and vasotocin; somatostatin; substance P; clotting factors such as Factor VIII; thrombolytic factors such as TPA and streptokinase; enzymes used for "replacement therapy," e.g., glucocerebrosidase, hexoseaminidase A; and antigens used in preventative and therapeutic vaccines such as tetanus toxoid and diptheria toxoid.
Protection of the Medicinal Proteins
In order to avoid chemical cross-linking of the medicinal protein within the matrix, prior to exposing the therapeutic protein to the cross-linking reagent, the bioactive protein is modified to deactivate functional groups which would normally react with the cross-linking agent, i.e., the protein is "protected." In the case of certain proteins, there is no need to modify the protein for it to be protected and useful in the subject invention, e.g., a protein where amino groups are not available. Since the cross-linkers of choice attack primary amino groups, these groups are protected in the medicinal protein. For example, the protein is first rendered unreactive to amine-directed reagents by treatment with formaldehyde and a reducing agent, or by other suitable reagents, such as methyl acetimidate. The charge, structure and biological activity of the reductively alkylated protein is not significantly changed but the procedure prevents further reaction with aldehydes or other reactions such as acylation or amidination.
Reductive methylation and amidination are examples of appropriate reactions for amino group protection. These treatments are known to have minimal effect on biological activity probably because of the minor structural change and similar net charge of the reactant and product at neutral pH (Means, G. E., Methods Enzymol., 47, 469 (1977)). Both techniques are convenient and give consistent results. Antigenicity of the reductively methylated proteins is not enhanced over native structures.
Other methods of amino group protection include (i) acylation, (ii) lycosylation and (iii) carbamylation.
Examples of acylation reactions are:
1. acetylation
2. maleylation
3. citraconylation
4. trifluoroacetylation
5. acetoacetylation
6. ethoxyformylation
Examples of glycosyl groups include:
1. glucosyl
2. lactosyl
3. galactosyl
4. mannosyl
5. maltosyl
6. fructosyl
7. arabinosyl
8. fucosyl
9. combinations of the above
Carbamylation reactions are also appropriate for amino group protection: ##STR6## R can be hydrogen, in which case the reactant is cyanate and the product is a substituted urea.
There are numerous other amino group modifications known to those skilled in the art such as guanidination and sulfonylation. Non-specific alkylating reagents are to be avoided. However, where stable derivative favor amine adducts, this class of reagents may be useful.
Examples of protected medicinal proteins are dimethylated and amidinated derivatives of the proteins listed above under "Medicinal Proteins", e.g., dimethylated G-CSF or dimethylated IL-2. It should be noted that the lysines in some proteins are not available for reaction due to location. There is no need for these locations to be protected since the same locations are inaccessible to cross-linking.
Non-Protein Delivery
Although especially well suited for parenteral administration of proteins, the present delivery system is also applicable to formulations with non-protein medicinals, including but not limited to alkaloids, steroids, terpenoids, amino acid derivatives, nucleoside/nucleotide derivatives, polynucleotides, carbohydrates, polysaccharides, lipids, lipopolysaccharides, purines, pyrimidines and derivatives of same.
Advantageous small molecule drugs include: analgesics, anesthetics, antialcohol preparations, anti-infectives, anticoagulants, anticancer drugs, antidepressants, antidiabetic agents, antihypertensive drugs, antiinflammatory agents, antinauseants, anorexics, antiulcer drugs, cardiovascular drugs, contraceptives, decongestants, diuretics, hormones/antihormones, immunosuppressives, narcotic detoxification agents, uncosuric agents, agrichemicals such as pheromones, wood protection chemicals and wound healing promoters.
Particularly advantageous compounds for use in the subject invention are those in crystalline form.
Films for transdermal delivery or for topical application as bandages can also be formed. In this case the film may be used to deliver non-proteinaceous drugs such as anti-infectives and wound healing promoters.
* * *
Typical delivery systems are shown in Table
TABLE 3______________________________________ Hydrolytic ExternalMatrix Protein.sup.1 Polymeric Stabilizer Enzyme.sup.2 Cross-Linker______________________________________G = 100% A = 0 Dextran-CHO Collagenase .sup. DMS.sup.3G = 100% A = 0 Chondroitin sulfate Collagenase DMSG = 100% A = 0 Chondroitin sulfate Hyaluronidase DMSG = 50% A = 50% Dextran-CHO Collagenase DMSG = 50% A = 50% Dextran-CHO Hyaluronidase DMSG = 25% A = 75% Dextran-CHO Dextranase --G = 25% A = 75% Chondroitin sulfate Hyaluronidase DMSG = 50% A = 50% Polynucleolide Nuclease DMSG = 50% A = 50% -- Collagenase DMSG = 50% A = 50% Dextran-CHO Collagenase --______________________________________ .sup.1 G = gelatin (collagen) and A = albumin .sup.2 Delivered either by the same matrix (internal) or by a different matrix (external) .sup.3 Dimethyl Suberimidate
Timed Release of Medicinals and Modes of Administration
An idealized release profile is shown in FIG. 7. Here the concentration of medicinal in the vicinity of the bead reflects the rate of internal degradation of the three different classes of gel matrices. The profile shown depicts the system with identical medicinal concentration in all classes. For example, to have higher levels of medicinal released at a later period, more medicinal would be incorporated in the Class III beads as shown in this example.
Release profiles can be obtained from zero order release to those involving late-stage bursts.
It is also possible to administer more than one medicinal in the same treatment regimen. The drugs could be released simultaneously or sequentially.
Stokes law is applicable, i.e.,
D∝1/rv
The diffusion coefficient (D) is inversely related to the radius of the protein (r) and the viscosity of the medium (v), which is dependent on the density and degree of cross-linking of the gel matrix. Computer modelling of this system with four to seven adjustable parameters can be used to generate a set of hypothetical release profiles for a given therapeutic protein.
Medicinal matrix of the invention is administered to a human or other mammal as beads, disks, threads and implants of various other shapes using techniques known to those skilled in the art. Beads would be normally administered via needle subcutaneously, intramuscularly, intraperitoneally, or intravenously for cell-sized microbeads. Tablets and capsules are used for oral delivery.
Medicinal matrix can be administered concomitant with surgical procedures. An example would be antibiotic matrix following abdominal surgery. Also, implants can be surgically placed under the skin or elsewhere.
* * *
The following Examples are illustrative, but not limiting of the compositions and methods of the present invention. Other suitable modifications and adaptations of a variety of conditions and parameters normally encountered in clinical therapy which are obvious to those skilled in the art are within the spirit and scope of this invention.
EXAMPLES
Example 1
Production of Protected Proteins for Use in the Delivery Systems
Reductive methylation of the protein is carried out with formaldehyde and sodium borohydride at 0°-4° C. in 0.2M borate buffer, pH 9. In cases where lower pH is required, sodium cyanoborohydride is used in place of sodium borohydride at pH values below pH 9. The protein concentration is 1-10 mg/ml. The borohydride is added in advance of the formaldehyde with moderate stirring. For each milliliter of protein solution, 0.5 mg borohydride is added followed by 2.5 microliters of formaldehyde solution (37%) in five increments at five minute intervals. The procedure is repeated if necessary. The modified protein is purified by dialysis or gel filtration.
Example 2
Preparation of Activated Polysaccharide
Generation of dialdehydes from diols by using periodate oxidation is accomplished as follows. The reaction is carried out in the pH range of 4.5-6.5. A polysaccharide, such as chondroitin sulfate, hyaluronic acid, dextran, dextran sulfate, or the like, is dissolved in distilled water (0.1-10 mg/ml). An equal volume of sodium metaperiodate solution (1-50 mM) is added and the mixture is maintained at room temperature in the dark for about an hour. Higher temperature and longer reaction time result in more extensive oxidation. The activated polymer is purified by dialysis, gel filtration or ultrafiltration.
Example 3
Preparation of Molded Gels Containing Bioactive Proteins
Many different shapes are possible because of the reaction dynamics and their control. A cylindrical implant is conveniently made by using a plastic syringe. The syringe is filled with reaction mixture which is then allowed to set. The constricted end is cut off and the plunger is depressed to expel the gel cylinder.
A reaction mixture is as follows: Solution I--Type A gelatin (0.5-5 g) is dissolved in hot Hepes buffer (50 ml, 10 mM pH 7-8.5) and then cooled to 37° C. Solution II--to an activated polysaccharide solution (0.05-1% in 10 mM Hepes, pH 7-8.5) is added the protected protein (and enzyme if included in the formulation). Protected protein concentration is in the range of 10-2000 micrograms/ml and the protected hydrolytic enzyme concentration is in the range of 1-50 micrograms/ml. The reaction mixture is composed of equal volumes of Solution I (gelatin) and Solution II (polymeric stabilizer) described above. The two solutions are mixed with a dispo pipette and loaded into the syringe. The gelation occurs at room temperature in 2-5 hr. The cylinder is forced out in one piece or incrementally forced out and cut into disks of desired thickness. These cylinders or disks are optionally further stabilized by soaking in a solution containing an amine specific cross-linking reagent such as dimethylsuberimidate (10 mM Hepes, 1-100 mM imidate, 1-5 hr). The surface curing reaction is terminated by pouring off the imidate solution and quenching with 0.1M aminoethanol-HCl, pH 8.5 for 1 hour.
Example 3A
Films
The procedure of Example 3 is repeated using other geometric configurations including films containing antibiotics and wound healing promotors. The reaction mixture is poured onto a flat glass plate with borders to provide boundaries of the desired dimensions. The glass plate is cooled to -20° C. and allowed to stand for 4-8 hours.
Example 4
Formation of Microbeads in a Non-miscible Solvent
For formation of microbeads, the Hepes buffer contains 0.1% sodium dodecyl sulfate, and the reaction mixture (as above) is injected into a rapidly stirring hydrocarbon phase (corn oil:petroleum ether-4:1, 100 ml, 0°-4° C.). After an hour, the beads are harvested, washed with petroleum ether, and surface cured as described above. The resulting beads are about 100 microns in diameter.
Example 4A
Beads Containing Dispersed Solid Medicinal
The procedure of Example 4 is repeated but with 10-40% by weight of a crystalline or amorphous solid medicinal suspended in the reaction mixture.
Example 5
Microsphere Formation in Water
The basic gelatin stock solution (5 ml) is mixed with activated polysaccharide with rapid stirring. The concentration of activated polysaccharide is in the range of 0.1-1%. The protected protein is included in the original solution of the activated polysaccharide within the concentration range of 1-5000 micrograms/ml. These microspheres are collected by centrifugation and surface cured as described above.
Example 6
Controlled Release of Azoalbumin from Three Preparations
Controlled release was demonstrated using three preparations made as disks (2×6 mm in diameter) according to Example 3. Class I contained mildly oxidized dextran and was not treated with external cross-linkers; Class II contained intermediate levels of dextran-dialdehyde and was externally cross-linked for thirty minutes with an intermediate concentration of dimethylsuberimidate (DMS). Class III contained the maximum activated polysaccharide and was soaked in 0.1M DMS for five hours. Each preparation contained Type A gelatin/Bloom # 60/1.5% final concentration and 2% protected azoalbumin. All were treated with 200 micrograms of collagenase in one ml of Tris buffer (10 mM, pH 7.4, 1 mM CaCl 2 ). The results are shown in Table
TABLE 4______________________________________ Class I Class II Class III______________________________________Halftime of <5 min 2 wks negligible releasealbumin release over 1 month______________________________________
It will be readily apparent to those skilled in the art that numerous modifications and additions may be made to both the present invention, the disclosed device, and the related system without departing from the invention disclosed. | A bioerodible matrix for the controlled release of medicinals including protein therapeutics is disclosed. A method for controlled drug release is also disclosed. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority to and the benefit of Korean Patent Application Number 2004-21429, filed Mar. 30, 2004, the entire disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a secondary battery and a method of forming the same, and more particularly to a plastic molding type secondary battery in which a gap between a bare cell and a protective circuit board is filled with a plastic molding, and a molding method thereof.
2. Description of the Prior Art
As is generally known in the art, secondary batteries are rechargeable and can be made in a compact form with a large capacity. Thus, secondary batteries have been recently broadly researched and developed. Typical examples of such secondary batteries include nickel metal-hydride (Ni-MH) batteries, lithium (Li) batteries and lithium-ion (Li-ion) batteries.
In such secondary batteries, most bare cells are formed by inserting an electrode assembly including a positive electrode, a negative electrode and a separator into a can formed from a metal such as, for example, aluminum, coupling a cap assembly to the can, injecting an electrolyte into the can, and then sealing the can.
However, a battery is an energy source and the battery has the potential to discharge a large amount of energy. In the case of a secondary battery, a large amount of energy is stored in the battery when it is charged. Also, in order to charge the secondary battery, an external energy source is needed for supplying the energy to be stored in the battery. When an internal short circuit or other disorder of the secondary battery is generated during the above described process or state, the energy stored in the battery may be discharged in a short time, thereby causing safety problems such as fire, explosion, or the like.
Accordingly, in general, a secondary battery is equipped with various kinds of safety devices for preventing fire or explosion caused by disorder of the battery itself in a charged state or during the charging process of the battery. Among these safety devices, a protective circuit board is generally connected to a positive terminal and a negative terminal of a bare cell by a conductive structure, a so-called lead plate. Such a protective circuit board may further include a Positive Temperature Coefficient (PTC) device or a bimetal device. In this case, the protective circuit board can break electric current, for example, when a battery is heated to a high temperature or when battery voltage rapidly increases due to, for example, overcharging/overdischarging, thereby preventing dangers such as explosion and firing of the battery.
A secondary battery including a bare cell coupled with a protective circuit board is enclosed in a separate casing to provide a finished secondary battery. In some cases, the gap between a bare cell and a protective circuit board connected by welding, is filled with a plastic molding to provide a plastic molding type secondary battery. For purposes of downsizing a plastic molding type secondary battery, an external I/O (Input/Output) terminal for making an electric connection between the battery and an external circuit may be formed on one surface of the protective circuit board. This allows the I/O terminal to be exteriorly exposed without the use of, for example, a lead wire.
FIG. 1 is a schematic exploded perspective view showing a conventional pack-type lithium-ion battery before coupling with a plastic molding. FIG. 2 is a sectional view showing a conventional pack-type lithium-ion battery in which a bare cell and a lead plate of a protective circuit board are welded to each other and mounted in a mold.
Referring to FIGS. 1 and 2 , a protective circuit board 30 is disposed parallel with a surface, on which electrode terminals 11 , 12 of a bare cell of a pack-type battery are formed. Additionally, as shown in FIG. 2 , a gap 47 exists between the bare cell 10 and the protective circuit board 30 and may be filled with a plastic molding. When the plastic molding is filled, it may cover the back surface opposite the surface of the protective circuit board facing the bare cell. However, an external I/O terminal 32 formed on the back surface must be exposed to the exterior.
The bare cell 10 includes a positive terminal 11 and a negative terminal 12 on the surface facing to the protective circuit board 30 . The positive terminal 11 may be, for example, a cap plate or a metal plate bonded to a cap plate. The negative terminal 12 is a terminal protruding vertically from a cap plate, and is electrically isolated from the cap plate 13 by a peripheral insulator gasket.
The protective circuit board 30 includes a panel formed of a resin, on which a circuit is disposed, and the external I/O terminal 32 , formed on the outer surface thereof. The protective circuit board 30 has dimensions and a shape which are substantially the same as those of the surface (cap plate surface) of the bare cell facing thereto.
The back surface of the protective circuit board 30 opposite the surface on which multiple external I/O terminals 32 are formed, i.e., the internal surface of the protective circuit board, is equipped with a circuit section 35 and connection terminals 36 , 37 . The circuit section 35 includes, for example, a protective circuit for protecting a battery from overcharging/overdischarging during charging/discharging of the battery. The circuit section 35 and each external I/O terminal 32 are electrically connected to each other by a conductive structure passing through the protective circuit board 30 .
Lead plates 41 , 42 and an insulating plate 43 are disposed between the bare cell 10 and the protective circuit board 30 . The lead plates 41 , 42 , generally formed of nickel, are used to make an electric connection between positive terminal 11 and negative terminal 12 and its respective connection terminal 36 , 37 of the protective circuit board 30 . Also, they may have an “L”-shaped form or a planar structure. By connecting each terminal 36 , 37 of the lead plates 41 , 42 through, for example, welding, it is possible to make electric connections, but such connections may not ensure mechanical integrity of the entire structure. In other words, even if the lead plates 41 , 42 are welded with the connection terminals 36 , 37 , the protective circuit board may not be firmly fixed to the bare cell.
Further, as shown in FIG. 2 , when the bare cell 10 welded to the protective circuit board 30 is mounted into a mold 100 , it is necessary to protect the surface of the external I/O terminal 32 from being covered with a plastic molding in order to allow an electric connection to be made with an external circuit. If the external I/O terminal 32 is formed to protrude from the surface of the protective circuit board, it is possible for the surface of the terminal 32 to be in direct contact with the inner surface of the mold 100 , as shown in FIG. 2 . In addition to this method, it is also possible to form the mold 100 to take a protruded inside shape sufficient to be in contact with the external I/O terminal 32 of the protective circuit board for the purpose of protecting the surface of the terminal 32 .
In order to protect the surface of the external I/O terminal 32 , it is possible for the surface to be in contact with the inner surface of the mold, from the starting point of mounting the protective circuit board 30 in the mold. However, in this process, there is a great potential to generate a gap between the inner surface of the mold and the surface of the external I/O terminal 32 of the protective circuit board. To solve this problem, another method may be used. Specifically, the protective circuit board 30 and the bare cell are mounted in the mold 100 , wherein the inner surface of the mold facing the surface of the terminal 32 is movable, and then that surface is moved toward the surface of the terminal 32 .
More particularly referring to FIG. 3 , it is possible to place the surface of the mold 100 in contact with the external I/O terminal 32 by moving a part of the surface of the mold toward the surface of the terminal so as to form an opening in the mold at a location corresponding to the external I/O terminal, inserting a post-type core 210 into the opening, and advancing the core 210 to protrude into the inner surface of the mold 100 .
When a core 210 is used in the mold, the plastic molding process may be performed as follows. First, a protective circuit board 30 connected to a bare cell 10 is mounted in a mold 100 adapted to receive the protective circuit board 30 in a process of forming a secondary battery. Next, the core 210 is moved toward the protective circuit board 30 through an opening of the mold 100 , so that the front-end 212 of the core 210 is in contact with the surface of the external I/O terminal 32 of the protective circuit board 30 . Finally, a liquid plastic resin is injected into the mold 100 , and then the plastic resin is solidified.
However, in the above-described process, when the core 210 is moved, the protective circuit board 30 is fixed to the bare cell 10 only by a connection between each thin lead plate 41 , 42 and each connection terminal 36 , 37 which tends to push the protective circuit board irregularly toward the bare cell 10 . In this case, as shown in FIG. 3 , the protective circuit board 30 may be oriented away from its correct position, and thus a fine wedge-shaped gap 214 may be generated between the front-end of the core 210 and the surface of the external I/O terminal 32 of the protective circuit board. If the gap 214 is filled with a plastic molding 20 , a problem, so-called a “flash defect,” may be generated. A flash defect may occur when a part of the surface of the external I/O terminal 32 is coated with a plastic film 21 , as shown in FIG. 4 . Additionally, due to the incorrect position of the protective circuit board, other factors responsible for quality below defined standards may be generated.
In order to prevent the protective circuit board from being pushed irregularly toward the bare cell while the core is moved, a method of disposing a support structure made of the same plastic as the molding between the bare cell and the protective circuit board may be used to mount the protective circuit board coupled to the bare cell by lead plates. However, such a support structure may cause another problem in that it may disturb efficient injection of a plastic resin in the step of pouring the plastic into the mold. Accordingly, there is a need for a method and a device to solve the problems as described above.
SUMMARY OF THE INVENTION
AN exemplary embodiment of the present invention is provided whereby a surface of an external I/O terminal of a protective circuit board is prevented from being covered with a plastic molding during a process for protecting the terminal surface. The process may include moving an insertable part of a mold corresponding to the terminal surface to be in contact with the terminal surface during the formation of a plastic molding type secondary battery. The secondary battery may be formed by supportively mounting a protective circuit board and a bare cell, electrically connected to each other through lead plates, in a mold, and pouring a liquid plastic resin into a gap between the protective circuit board and the bare cell.
An embodiment of the present invention provides a plastic molding type secondary battery and a method of forming the same, wherein the battery and the method prevent the problem wherein a gap is generated such that plastic resin between the terminal surface and the front-end of the mold covers the surface of the external I/O terminal with the plastic molding and interferes with the quality of the secondary battery.
In one exemplary embodiment of the present invention, a plastic molding type secondary battery and a method of forming the same are provided, wherein the battery and the method correctly orients a misaligned protective circuit board while also eliminating factors responsible for poor quality of the battery due to the misalignment of the protective circuit board.
More specifically, a method is disclosed including mounting a bare cell and a protective circuit board in a mold; disposing supporting pins in the mold so that a lateral part of the supporting pin is in contact and is correctly aligned with a back surface of the protective circuit board, inserting an insertable core to cause a front-end of the insertable core to move through an axial opening formed on the mold and contact a surface of an external I/O terminal formed on the outer surface of the protective circuit board; and pouring a plastic resin into the mold.
According to one embodiment of the present invention, the bare cell is connected to electric connection leads of the protective circuit board by welding, for example, before mounting them in the mold.
Generally, the mold is adapted to receive the bare cell and the protective circuit board entirely. However, the mold may also be adapted to receive only the upper part of the protective circuit board and the bare cell.
A moveable portion of the mold may be moved under pressure so that it is in close contact with the surface of the external I/O terminal and so that it applies a certain degree of pressure to the protective circuit board. However, such a pressure should not be enough to move the protective circuit board away from its correct position because the supporting pins are disposed on the backside of the protective circuit board.
In order to make the protective part in the above-described manner, the protective part may be formed as an insertable core so that it may be distinguished from the other parts of the mold. More particularly, an opening is formed in the mold at the part corresponding to the surface of the external I/O terminal of the protective circuit board, a post-shaped core is inserted into the opening, and then the core is advanced so that the front-end of the core protrudes into the inner surface of the mold. Eventually, the front-end of the core protruding as described above will be in close contact with the external I/O terminal. Accordingly, even if the mold is filled with a plastic resin, the resin cannot infiltrate the contact surface, thereby preventing the so-called “flash defect”.
According to a further embodiment of the present invention, supporting pins are inserted from the exterior of the mold to the interior of the mold through pinhole(s) formed in a predetermined position of the mold. More specifically, the supporting pins may be inserted through a pinhole formed in a predetermined position of the lateral part of the mold when viewed from the direction of the movement of the protective part, so that the supporting pins are in contact with the back surface of the protective circuit board. However, the supporting pins may be also formed inside the mold when the bare cell connected to the protective circuit board is mounted in the mold.
When the supporting pins are disposed by inserting them into the mold, at least one supporting pin may have a tapered portion at its end inserted in the mold in the direction of the protective circuit board, when viewed from the longitudinal section. In this case, when the protective circuit board moves away from its correct position due to the insertion of the supporting pins into the mold, the tapered portion may be in contact with the outer wall part of the protective circuit board, thereby correcting the position of the protective circuit board.
In a further embodiment, at least one supporting pin may have a step at its end, when viewed from the longitudinal section, wherein the step is thinner than other parts of the pin and is in contact with the back surface of the protective circuit board. The supporting pins extending from the exterior of the mold to the interior of the mold may be relatively thinner at the interior of the mold, and relatively thicker at the exterior of the mold.
Additionally, at least two supporting pins may be formed at both longer lateral sides of the mold because such supporting pins support the protective circuit board uniformly and stably against pressure caused by the movement of the core.
Additionally, a plastic molding type secondary battery is also provided, the battery including a bare cell and a protective circuit board connected to each other through a plastic molding for filling the space between them. The plastic molding type secondary battery may include pinholes formed on a part made of the plastic molding in the direction parallel to the protective circuit board so as to come into contact with one surface of the protective circuit board facing the bare cell over a predetermined zone thereof.
Pinholes may be formed in both sidewalls of the part made of the plastic molding at equal levels on both sides. The pinhole may have a circular shape, a semi-circular shape or any other polygonal shape when viewed from the vertical section to the direction of the pinhole or from the entrance of the pinhole.
At least one pinhole may have a tapered portion at its end, the tapered portion being inclined in the direction toward the protective circuit board, when viewed from the longitudinal section to the direction of the pinhole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic exploded perspective view showing a conventional pack-type lithium-ion battery before coupling with a plastic molding.
FIG. 2 is a sectional view showing a conventional pack-type lithium-ion battery in which a bare cell and a lead plate of a protective circuit board are welded to each other and mounted in a mold.
FIG. 3 is a sectional view showing a problem occurring in the prior art in which a protective circuit board is inclined away from its correct position, and thus a fine wedge-shaped gap is generated between the front-end of a core and the surface of an external I/O terminal of the protective circuit board.
FIG. 4 is a partial perspective view showing a so-called “flash defect” problem occurring in the prior art, in which a part of the surface of an external I/O terminal is insulated with a resin film in a plastic molding type secondary battery.
FIG. 5 is a partial sectional view showing an exemplary embodiment of the present invention in which a protective circuit board connected to a bare cell is mounted in a mold for plastic molding and supporting pins are disposed in the mold so as to be in contact with the back surface of the protective circuit board.
FIG. 6 is a partial sectional view showing the position of supporting pins taken through the narrowest side of the bare cell in FIG. 5 .
FIG. 7 is a partial sectional view showing the mechanism for guiding a protective circuit board moved away from its correct position to the correct position by a supporting pin having a tapered end, according to an embodiment of the present invention as shown in FIG. 6 .
FIG. 8 is a flowchart describing the steps of a method of forming a plastic molding type secondary battery according to the present invention.
FIG. 9 is a front view of a secondary battery showing the position of supporting pins in an exemplary embodiment of the present invention
FIG. 10 is a partial sectional view showing the sectional shapes of supporting pins taken through the narrowest side of the secondary battery of FIG. 9 .
DETAILED DESCRIPTION
A mold for a secondary battery according to an exemplary embodiment of the invention is explained generally as follows. The mold in its complete form includes an upper mold portion and a lower mold portion coupled to each other. The upper mold portion and the lower mold portion may be two pieces of mold disposed on a larger surface of a square type battery parallel to the same. Alternatively, the upper mold portion and the lower mold portion may have a cavity adapted to receive the protective circuit and the connection part of the bare cell, and a cavity adapted to receive the lower part of the bare cell, respectively. For example, when the upper mold portion and the lower mold portion are disposed on the larger surface of a can parallel to the same, the inside part of each of the upper mold portion and the lower mold portion has a cavity having a shape corresponding to the bare cell coupled with the protective circuit board. This ensures that the assembly of the bare cell and the protective circuit board is disposed in a correct position. The mold completed by coupling the upper mold portion and the lower mold portion may include a pinhole-type gate, through which molten plastic resin may be injected into the space between the protective circuit board and the bare cell. Additionally, a runner providing a path for the plastic resin may be connected to the gate. Although the mold and a part of the runner may be integrally formed, remaining resins may be easily solidified in the runner, thereby obstructing the path. Therefore, the rubber is usually formed independently from the mold, and is changed and discarded after use.
Referring to FIGS. 5 and 6 , when the upper mold portion 204 is coupled to the lower mold portion 206 , the parts corresponding to external I/O terminals are removed from the front wall 208 of the upper mold portion, and thus, a hole 216 is formed. A core 210 is inserted into the hole in order to seal the hole 216 tightly to prevent an outward flow of plastic resin injected into the mold 100 . The core 210 is coupled with a core main body 200 on the outside of the mold 100 , and thus it moves back and forth through the hole corresponding to the movement of the core main body 200 .
Once the battery is mounted in the mold 100 , supporting pins 310 , 320 are inserted into the mold 100 through the lateral surface of the mold parallel to the surface having the largest area of the battery. Pinholes may be previously formed at the positions into which the supporting pins 310 , 320 are inserted. The pinholes may be formed in such a manner that the lateral surfaces of the supporting pins 310 , 320 are in contact with the protective circuit board 30 of the battery, and more particularly, the back surface of the circuit section 35 of the protective circuit board, i.e., the surface facing the bare cell 10 , when the battery is mounted in its correct position.
Once the supporting pin is fixed to the mold 100 through the pinhole and the core main body 200 is moved, the core 210 is moved into the mold 100 . The front-end of the core 210 is then in close contact with the terminal surface of the external I/O terminal 32 of the protective circuit board 30 . The front-end of the core 210 may form a continuous surface on the same plane as the peripheral inner surface of the mold 100 . However, the front-end may slightly protrude from the peripheral surface which protects the surface of the external I/O terminal 32 from being covered with a plastic molding. As a result, the surface of the external I/O terminal 32 in the plastic-molded secondary battery has a surface level slightly receded from the peripheral surface, allowing the terminal surface to be used for set connection. If a part of the front-end of the core 210 is worn down during the process of connecting it with the terminal surface, the advancing/retraction of the core 210 may be controlled to compensate for the reduced thickness. The front-end of the core 210 may be formed to correspond to the surface of each external I/O terminal 32 .
Additionally, when the core 210 is moved so that the front-end is in close contact with the surface of the external I/O terminal 32 , the supporting pins 310 , 320 provide resistance to the back surface of the protective circuit section 35 being pushed backwards. When at least three supporting pins are distributed around the lateral surface of the mold 100 , the protective circuit board 30 is protected from forces acting on its edges. Therefore, when at least two supporting pins 310 are disposed at each longer side of the protective circuit board 30 as shown in FIG. 5 and FIG. 6 , the protective circuit board 30 may be retained stably in its correct position even under pressure applied by the core 210 . As a result, the protective circuit board 30 is prevented from becoming dislodged from its correct position, thereby preventing the gap between the external I/O terminal 32 and the front-end of the core 210 from becoming wider and presenting a so-called “flash” problem. Moreover, because the protective circuit board 30 may be prevented from becoming dislodged from its correct position, the procedure for moving the core 210 so that the front-end of the core is in close contact with the surface of the external I/O terminal 32 should be performed easily and freely. In this regard, in one exemplary embodiment, the supporting pin (e.g., 320 ) may have a tapered portion at its longitudinal end, as shown in FIG. 6 .
Referring now to FIG. 7 , in some cases, the protective circuit board 30 mounted in the mold may become dislodged from its correct position by being pushed slightly towards the bare cell. When the tapered portion formed at the end of the supporting pin 320 is directed to the protective circuit board 30 , the sharp end of the supporting pin 320 is inserted into the mold 100 first, allowing the tapered portion to contact the outer wall of the protective circuit board 30 away from its correct position by an angle θ, while the remaining part of the supporting pin 320 is inserted into the mold 100 , thereby guiding and correcting the protective circuit board 30 through the angle θ to its correct position. Assuming that the integral structure of the protective circuit board 30 coupled to the bare cell is slightly inclined, in one exemplary embodiment, at least the supporting pins inserted into any one of the longer sides of the protective circuit board are formed to have a tapered portion. In this case, the resultant secondary battery may have pinholes formed at one side of the mold after the pins are removed, each pinhole having a tapered portion conformed to the shape of the end of the pin.
On the other hand, contrary to the above-described case in which the protective circuit board 30 is inclined toward the bare cell, when the protective circuit board 30 is slightly inclined toward the core of the mold, i.e., toward a hole on the front wall, away from its correct position, the core is inserted and moved before the plastic resin is injected. During this time, the core applies a pressure to the protective circuit board so that the front-end of the core is in close contact with the surface of the external I/O terminal. Therefore, the protective circuit board may be disposed in its correct position, because the protective circuit board is pushed until the back surface thereof is in contact with the supporting pin.
Further, as shown in FIG. 6 , the supporting pin 310 may have a step at its end, when viewed from the longitudinal section, and thus the pin 310 may have thinner portion 300 where it contacts the back surface of the circuit section 35 than at other parts of the pin. For example, assuming that the supporting pin 310 inserted into the mold 100 extends from the exterior of the mold 100 to the interior of the mold 100 , the supporting pin 310 may have a shape such that the part 300 of the supporting pin 310 inside of the mold 100 is relatively thin, while the part outside of the mold 100 is relatively thick. Such a thin supporting pin may have a reduced supporting power, but may also have improved partial elastic deformation characteristics. The number of supporting pins may be increased to compensate for the reduction of supporting power. Moreover, even if the supporting pin is contacts a part of the protective circuit board during the insertion of the supporting pin into the mold, the supporting pin may be easily inserted into the mold due to its improved elastic deformation characteristics.
Further, the section or the entrance of the pinhole has a shape corresponding to the longitudinal section of the supporting pin. For example, the pinhole may have a circular shape, a semi-circular shape or any other polygonal shapes, as necessary.
As can be seen from the foregoing, a plastic molding type secondary battery and a method of forming the same according to an embodiment of the present invention may prevent the problem of a protective circuit board being partially dislodged to generate a gap between the surface of an external I/O terminal and a mold, the surface of the external I/O terminal subsequently becoming partially covered with a plastic molding when a part of the mold corresponding to the surface of the external I/O terminal of the protective circuit board, for example, a core, is moved so as to be in contact with the surface of the external I/O terminal for the purpose of protecting the terminal surface.
In FIGS. 9 and 10 , the position of the supporting pins 410 , 420 in the plastic molding 400 and the section shapes of the supporting pins are shown in an exemplary embodiment of the present invention.
Further, when a protective circuit board of a battery mounted in a mold is slightly pushed toward a bare cell, the position of the protective circuit board may be corrected by using a supporting pin having a tapered portion.
As shown in FIG. 8 , the steps of an exemplary method of forming a plastic molding type secondary battery, described above and also shown in FIGS. 5-7 , are summarized in a flowchart.
Although an exemplary embodiment of the present invention has 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. | A method of forming a plastic molding type secondary battery. A protective circuit board is electrically connected to a bare cell, both mounted in a mold. The mold is capable of receiving the protective circuit board connected to the bare cell and at least of a part of the bare cell, and has an insertable core corresponding to the surface of an external I/O terminal, which is axially movable so as to contact the terminal surface. Supporting pins are trans-axially dispersed in the mold so that a lateral part of the pin is in contact with the back surface of the protective circuit board disposed in a correct position. A resulting plastic molding type secondary battery has pinholes formed on a part made of the plastic molding in the direction parallel to the protective circuit board so as to come into contact with one surface of the protective circuit board. | 8 |
Background of the Invention
In a known method of this kind each rectangle is scanned in a number of vertical lines, the characters to be recognized being divided into groups according to the number of intersections they make with the scanning lines. A further classification within each group takes place according to characteristic properties. In the recognition process the processor subjects the numerical values thus obtained to certain specified treatments. The aforesaid characteristic properties lie in the store of the processor, contained as they are in so-called decision schemes. In the known method it is not easy to change the store contents utilized for testing the characters that have to be recognized. Besides, the recognition process is rather roundabout. Furthermore, the characters have to meet some predetermined criteria.
Automatic recognition systems in which partial images are examined for the purpose of finding their characteristics are also known. In such systems the characteristics dealt with can be considered as a coded representation of all the increments and decrements of the function recorded in a matrix and having the shape of a pattern. To ascertain the presence of a property it is necessary that the coding derived from a pattern to be recognized completely corresponds with a coding recorded in the store of the reading machine. As a great many codings of increments and decrements may occur in practice, owing to the intricate structure of handwriting, such a method requires a large storage capacity. Furthermore the looking-up of the desired coding in the machine store is a complicated and time-absorbing procedure. It may also happen that the relevant coding is not found in the machine store and is thus lost for recognition.
Summary of the Invention
It is an object of the invention to provide a method in which a character is not assigned to a certain class on account of its satisfying the criteria set for that class by the designer, but on account of the probability of its belonging to the relevant group because of the occurrence of a number of properties in the characters. This object is attained in a learning phase in which and in a subsequent working phase partial images and secondary images are formed from the characters, and the properties of the characters are classified according to complexity. The classification within each group of properties is carried out for each of the partial images and secondary images, so that during the learning phase the results of these classifications are recorded as statistic frequencies in a store. After this the learning phase is concluded by recording the logarithmic values of the static frequencies in the store. During the working phase the results of the classification of the properties of freshly introduced characters are utilized in determining, for each class of characters, the product-probability of the properties found by adding up the relevant logarithmic values.
During the learning phase a large number of figures or other characters - as e.g. letters - of the kind to be recognized by a machine for carrying out the method, are tested for certain properties and the probability of occurrence of each of these properties is determined. The number of properties can be increased at will. The method described has been put into practice with a limited number of figures for the learning phase and with a limited number of properties, and the result obtained was considerably better than that of the best method known so far.
The partial images are preferably constituted by the various aspects of complete characters and of parts of characters halved in a vertical or in a horizontal direction.
It is to be recommended to have a first group of properties bear on the discontinuity of lines in aspects in the plane of a figure; a second group of properties on slope configurations of lines in aspects in the plane of a figure; a third group on the occurrence of terminal points in aspects in the plane of a figure, and a fourth on the number of partial areas of which the secondary image consists and on the way each partial area is bordered. The secondary image of a character to be handled is formed by a part of the surface taken by the character, which part remains after the character elements up to and including the first intersection counted from the sides of the enclosing rectangle have been removed and after all the character elements still remaining have been taken away The properties of these partial areas are derived from a top, a bottom, a left-hand and a right-hand aspect of the secondary image. The partial areas are also called "islands" in what follows.
The invention further relates to a device for carrying out the above mentioned method, provided with a device for projecting a character onto a matrix, a camera tube for scanning the matrices, a store for recording the scanning results, a converter of the scanning results, and a processor for handling the converted data.
The device according to the invention is provided with a pattern manipulator comprising a matrix store and means for copying means for rotating by multiples of 90°, means for shifting by multiples of one bit in a horizontal and/or in a vertical direction, means for centring, means for adjusting patterns and for handling pattern strips. All of this is for the purpose of forming partial images in which the character is seen from several different inside and outside viewpoints. This pattern manipulator also is connected to circuits for simultaneously detecting and classifying different properties of the partial images.
Thus the detection of m × x n properties, n being the number of kinds of properties and m the number of partial images, requires only one manipulator and n circuits.
According to the invention a circuit for detecting and classifying discontinuities or jumps of lines in partial images drawn from the store comprises a counter for determining the distance to the first black-to-white transition and a buffer/down counter for determining the distance to the first white-to-black transition of the next row. These two counters together serve to detect a positive jump. Next the circuit also comprises a counter and a buffer/down counter for detecting a negative jump, comprising a device for detecting a first black-to-white transition and a first white-to-black transition serving to block the counters. Lastly, the counter output terminals are connected to a counter and a shift register, which, in combination, serve for classifying the discontinuities.
According to the invention a circuit for detecting and classifying slope configurations in partial images drawn from the store comprises means for detecting a positive and a negative slope and the end of a line, a shift register for determining the succession of positive and negative slopes, and a counter for determining the number of successive slopes.
According to the invention a circuit for detecting and counting terminal points comprises, firstly, a circuit for finding extremes by means of a shift register and a logic circuit for comparing two consecutive rows of a character pattern, and at the same time discriminating according to predetermined conditions. Secondly, a circuit for scanning lines having extremes, a shift register being so arranged that a marking attributed to the line is suppressed when lines do not join, whereas it is maintained as long as the joining point meets the conditions set. And thirdly, a circuit for determining the number of terminal points in an aspect, comprising a first counter for joined black image elements, a register for the largest thickness of line occurring in an extreme, a first comparator for comparing the contents of the counter with those of the register, a second counter for counting the rows of image elements in the case of a joint, a second comparator for comparing the contents of the register with those of the first counter, a logic circuit for discriminating the results of the comparisons according to predetermined conditions, and a third counter for recording the number of terminal points in an aspect.
The device also preferably comprises a working store and a circuit capable of forming a secondary image, consisting of partial areas called "islands," from the inverted information of the quantized pattern. This secondary image forming device contains a device for detecting first white-to-black transitions, the output terminal of which is connected to an AND-gate, owing to which all image elements not forming part of the character proper, from each of the sides of the rectangle enclosing the character, are ignored.
A circuit for detecting and classifying the properties of secondary images may comprise two shift registers for synchronously taking up data, notably for taking up data from the original pattern in one shift register and data from the secondary image in the other, so that the nature of the border between an "island" and the original pattern can be established and recorded with the aid of gates and triggers.
BRIEF DESCRIPTION OF THE VIEWS
The above mentioned and other features, objects and advantages, and a manner of obtaining them are described more specifically below by reference to an embodiment of this invention shown in the accompanying drawing wherein:
FIG. 1 shows a matrix of properties of characters considered and summed by the system of the present invention;
FIG. 2 shows examples of eight aspects of a handwritten FIG. 2 within a demarcated rectangle as considered according to the system of this invention;
FIG. 3 shows indications of the four different types of slopes for lines of characters within a demarcated rectangle;
FIG. 4 shows a co-ordinate system for the positive and negative slopes in a demarcated rectangle as shown in FIG. 3;
FIG. 5 shows examples of classification of some aspects of handwritten Arabic numbers of figures;
FIG. 6 shows the matrices for the discontinuities or "jumps" considered by the system of this invention;
FIGS. 7 through 11 show the different types of slope configurations considered in characters in a demarcated area considered by the system of this invention;
FIG. 12 shows matrices for slope configurations shown in FIGS. 8 and 11 considered by the system of this invention;
FIGS. 13 and 14 show the types of terminal points considered by the system of this invention;
FIG. 15 shows in a demarcated rectangle, a complete pattern for a hand-written FIG. 5 and the four different hatched areas surrounding it considered during four successive 90° turns of the pattern;
FIG. 16 is a secondary image derived from the pattern in FIG. 15 and containing three "islands" or areas not detected by the four successive turns of the matrix of this FIG. 5;
FIG. 17 shows a pattern for a hand-written FIG. 2 from which a secondary image containing two "islands" is obtained as in the manner shown in FIG. 15;
FIG. 18 shows a pattern for a handwritten FIG. 6 from which a secondary image containing a compound "island" is formed when scanned in the manner shown in FIG. 15;
FIG. 19 is a general schematic block wiring diagram of a preferred embodiment of a device or apparatus for carrying out the detection of the aspects of characters or figures according to the steps of the method of this invention;
FIG. 20 is a schematic block wiring diagram of the part of the manipulating circuit 5 shown in FIG. 19 for the coupling of a processor to an external store for copying the matrix in a store;
FIG. 21 shows a pattern of two FIGS. 3 and 5, overlapping a single demarcated area as projected onto a matrix store before their manipulation;
FIG. 22 shows a pattern of one of the FIGS. 5 shown in FIG. 21, after manipulation and its centering on the matrix store;
FIG. 23 is a schematic block wiring diagram of that part of the manipulator circuit 5 shown in FIG. 19 for the coupling of two stores for the different size concentric matrices shown in FIGS. 21 and 22;
FIGS. 24 through 30 show various matrix connection modes for considering a character or figure, herein 4, stored therein from different 90° directions;
FIG. 31 is a schematic block wiring diagram of the part of the manipulator circuit 5 shown in FIG. 19 for rotating the address lines of a matrix store for considering a character from the different directions shown in FIGS. 24 through 30;
FIG. 32 is a schematic block diagram of a part of the manipulator circuit 5 shown in FIG. 19 showing a divider by four and a table of the conditions of its output terminals;
FIG. 33 is a schematic block wiring diagram of another part of the manipulator circuit 5 in FIG. 19 showing a circuit with a decoder controlled by the divider by four shown in FIG. 32;
FIG. 34 is a schematic block wiring diagram of a further part of the circuit shown in FIG. 20 for rotating the pattern stored in the matrix 9;
FIG. 35 is a schematic block wiring diagram of another part of the manipulation circuit 5 in FIG. 19 showing a pattern shifting device;
FIGS. 36 through 41 show square matrices with shaded pattern shiftings for several different presets;
FIG. 42 shows a schematic block wiring diagram that is a part of the manipulator circuit 5 shown in FIG. 19 having a 48-bit shift register for centering a pattern on a matrix;
FIG. 43 is a schematic block wiring diagram of another part of the manipulator circuit 5 shown in FIG. 19 with a shift register for centering a pattern on a matrix;
FIG. 44 shows a FIG. 4 pattern on a matrix with their dotted center lines used for centering the FIG. 4 by the circuits shown in FIGS. 42 and 43;
FIGS. 45 through 48 show matrix squares each with a line for a pattern adjusted to a different slope;
FIG. 49 is a schematic block wiring diagram of the "jump"-detecting device in circuit 6 shown in FIG. 19;
FIG. 50 shows a "jump" pattern on a matrix;
FIG. 51 is a schematic block wiring diagram of the slope detecting device in circuit 6' shown in FIG. 19;
FIG. 52 is a more complete diagram of the circuit shown in FIG. 51;
FIGS. 53 through 57 show matrix patterns of terminal parts of different figure or character lines;
FIGS. 58 through 61 show matrix image elements of parts of different figure or character lines;
FIG. 62 is a schematic block wiring diagram of an extreme detecting device in circuit 6" shown in FIG. 19;
FIGS. 63 through 65 show some states of an output terminal of the shift register 88 shown in FIG. 62;
FIGS. 66 and 67 show other states of the output terminal of the register 88 shown in FIG. 62;
FIG. 68 shows the state of the output terminal of the register 88 shown in FIG. 62 for the condition for an extreme;
FIG. 69 is a schematic block wiring diagram of a device for marking intersections which is another part of the circuit 6" shown in FIG. 19;
FIGS. 70 and 71 show the relative states of the stages of shift registers 88, 104 and 105 in FIGS. 62 and 69;
FIG. 72 is a schematic block wiring diagram of a device for determining the number of terminal points comprising still another part of the circuit 6" shown in FIG. 19;
FIG. 73 is a schematic block wiring diagram of the circuit 7 shown in FIG. 19 illustrating the principle of forming a secondary image; and
FIG. 74 is a schematic block wiring diagram of the circuit 8 shown in FIG. 19 for the detection of the properties of the secondary image from the circuit shown in FIG. 73.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The steps and apparatus of circuits involved in performing the steps of the method, process, or system of this invention are described below in accordance with the following outline, first for the method and then for the apparatus:
I - pattern Manipulation (FIGS. 2, 21 and 22)
A. copying
1. Processor to store
2. Store to processor
3. Processor to 32 × 32 matrix, and vice versa (FIGS. 20 and 23)
B. rotating (FIGS. 24 to 34)
C. shifting (FIGS. 35 to 41)
D. centering (FIGS. 42 to 44)
E. adjusting (FIGS. 45 to 48)
F. other (erasing)
Ii - properties of Images
A. partial Images
1. Jumps (discontinuities of lines) (FIGS. 5, 6, 49 and 50)
2. Slopes (FIGS. 3, 4, 7, 12 and 51-52)
a. beginning
b. end
c. positive
d. negative
3. Terminal Points (FIGS. 13, 14 and 53-72)
a. one-extreme
b. two-intersections
c. more than two
B. secondary Images - ("Islands") (FIGS. 15-18, 73, and 74)
1. number
a. one
b. two
c. three or more
2. borders
a. white
b. black
THE METHOD
In the matrix of FIG. 1 the classes, KO-K9 in the case of figures, are arranged horizontally; the properties, Ea-Ex, being arranged vertically. Wwy is the logarithmic probability value of the property Ey for the figure Kx. The product-probability of all the properties of one class Kx can be determined by adding up the logarithmic values of the relevant column Kx in the matrix.
Properties are determined for the top, bottom, left-hand and right-hand aspect I, II, III, IV, of the complete pattern see arrows before (FIG. 2 a-d, respectively). Each pattern is then divided, horizontally as well as vertically, into two equal parts and properties are also determined for the various aspects see arrows in (FIG. 2 e-h) of the patterns thus divided, in which the halves are viewed from the left, from the right, from the bottom and from the top, respectively. In FIG. 2 the various images are represented as viewed from one observer's position at the left, the figure parts thus seen being drawn in full line. A probability matrix is drawn up for each of these aspects. In addition, a secondary image is formed from each of the characters to be recognized and properties are determined for the top, the bottom, the left-hand and the right-hand aspect. FIG. 15 gives an example of a complete pattern, and FIG. 16 shows a secondary image derived from it.
The properties of the partial images are divided into three groups, one of which relates to discontinuities of lines in an aspect (jumps), a second group relates to slope configurations of lines in an aspect, a third group relating to the presence of terminal points.
The properties of the secondary images relate to the number of partial areas (islands) of which they consist and on the manner in which each partial area is bordered. These properties too are determined for each of the aspects.
Quantized figure patterns consisting of binary image elements constitute the material started from. The figure patterns are available in rectangles of e. g. 32 × 32 image elements.
Use is made of several partial images, each of which is, as it were, the aspect of the figure pattern when viewed from the relevant direction.
The slope of a line in each of the partial images is considered positive or negative according to an agreement illustrated in FIG. 3. Consequently, the information is available as a set of dots, arranged in columns and rows. The co-ordinates are stated in the x and y directions, the positive directions being indicated by the arrows in FIG. 4, in which the aspects are numbered as I, II, III and IV. Each of the four partial images may contain a number of lines ≧ 1. Seen from the relevant viewpoint a line consists of a concatenation of image elements and ends if it is not linked up with the image elements of the adjoining column.
According to the invention the properties are divided into groups. Within each group the properties belonging to it are arranged in classes of increasing complexity. A preferred version of the character recognition procedure utilizes four groups of properties in all. In every case one of the possible classifications is determined for each of the groups of properties of the partial and secondary images, so that no information can be lost for recognition.
In the preferred version the groups of properties relate to discontinuity of lines, slope configurations and terminal points in partial images and to the number of partial areas and their borders in secondary images.
IIA-I DISCONTINUITY OF LINES (JUMPS)
The relative positions of the lines can be classified on the basis of each of the four aspects I, II, III IV. There is a positive difference of relative distances if the beginning of a line is more distant from the side (of the rectangle) from which the pattern is viewed than the end of another line; and a negative difference if the beginning of a line is less distance from the side from which the pattern is viewed than the end of another line.
The following classification is used:
Ps 0 : there is only one line in the aspect, so that no difference of distances can occur;
Ps 1 : + only one positive difference of distances;
Ps 2 : - only one negative difference of distances;
Ps 3 : - + a negative followed by a positive difference of distances;
Ps 4 : + -a positive followed by a negative difference of distances;
Ps 5 : + + two successive positive differences of distances;
Ps 6 : - - two successive negative difference of distances;
Ps 7 : there are more than three lines in the aspect.
FIG. 5 shows examples of this classification for a left-hand aspect, when the hand written figures are scanned from top to bottom, with the positive difference being indicated by arrows pointing to the right and negative differences being indicated by arrows pointing to the left. It is to be observed that a difference of the relative distances of two lines is classified as PS 0 if it is less than or ≦1/10 of the width or the height of the enclosing rectangle for the whole figure or if it is smaller than one image element.
The data obtained are arranged in matrices, the elements of which are formed by the relative frequencies of occurrence of the properties. FIG. 6 shows four matrices, for aspects I, II, III and IV, respectively.
IIA-2 SLOPE CONFIGURATIONS
The definition of positive and negative slopes and of the scanning direction is illustrated by FIGS. 3 and 4. The slope configuration is determined and classified for each of the aspects. A slope always extends across a certain number of columns, when viewed from the relevant direction. The area is marked by a column number indicating the beginning and a column number indicating the end.
The beginning of a slope is defined by at least one of the following possibilities:
the beginning of a line;
a change of direction in at least two successive columns the direction of the line being opposite to that of the preceding part of the line.
The end of a slope is defined as follows:
the end of a line;
a change of direction in at least two successive columns the direction of the line being opposite to that of the preceding part of the line.
FIG. 7 gives some examples in the right-hand aspect. In this figure
a is the beginning of a negative slope;
b the end of a negative slope;
c the beginning of a positive slope and
d the end of a positive slope.
If at the beginning of a line a slope comprises only two adjoining image elements, this slope is not taken into account.
An aspect may exhibit several different configurations as regards the succession of slopes. Generally, this will also depend on the number of lines in the aspect.
If the aspect contains one line, the possibilities most frequently met are those illustrated in FIG. 8, which also gives the codings for the case of a right-hand aspect.
In the code used for expressing slope, configuratons four ternary positions are available. Only a small number of the 3 4 (= 81) possible combinations is actually used. The code is a ternary one, because each element can have three values: +, -, and 0.
The occurrence of some slope classification gives no warrant for conclusions about the shape of the aspect. Thus the classification XS 6 (FIG. 8) might also be found e.g. in an aspect in which occur two lines, as is shown in a right-hand aspect in FIG. 9.
In order to prevent small lines from determining the coding to a considerable extent, the rule has been adopted that in the case of more than one line occurring in an aspect the coding operation is carried out in succession, according to the lengths of the projections of the lines in the relevant aspect.
Thus in the case of the right-hand aspect of the pattern according to FIG. 10 the coding will be XS 5, because part 1 is longer than part 2. Consequently, part 1 is considered first and then part 2 so that the slope configuration found will be - + - 0.
As an aspect may contain more than one line, the classifications according to FIG. 11 have been introduced in addition (example of right-hand aspect), of which XS 11 has been reserved for all the other slope configurations, not covered by the codings XS O to XS 10.
Of the slope configurations too a matrix is drawn up for each of the aspects (FIG. 12), each element being formed by the relative frequency of occurrence of the relevant property in the set of the learning patterns presented.
IIA-3 TERMINAL POINTS
In each of the aspects terminal points are determine and classified as follows:
Pe 0 no terminal point in the relevant aspect;
Pe 1 one terminal point;
Pe 2 two terminal points and
Pe 3 more than two terminal points.
A probability matrix is drawn up again for each of the aspects. The search for terminal points is carried out at those points in the aspect where an extreme value occurs.
An extreme value occurs:
a at the end of a line with a negative slope;
b at the beginning of a line with a positive slope;
c is no slope is found, at the highest black image element or one
of the black elements in the top row;
d at the concurrence of a negative and a positive slope.
Examples of the occurrence of an extreme value according to a,b,c, and d are given in FIG. 13.
For detecting terminal points, the AND-function of the black image elements exhibiting extreme values is determined for a number (r) of rows, each time for two successive rows, counted from an extreme value. The AND-function obtained must always comprise a number (m) of consecutive black image elements.
In the case of a terminal point, the following condition will be satified:
(m.sub.max = 1 and r ≧3) V (m.sub.max ≧ and r ≧2 m.sub.max),
in which m max is the largest number of consecutive black image elements in an AND-function, r being the number of rows involved by the line with the extreme value.
FIG. 14 gives examples of terminal points in the top aspect.
II-B ISLANDS
From the pattern 01 shown in FIG. 15, starting from the top, a first part, hatched (+ 45°) as indicated near the arrow 02, is removed. Then, starting from the right-hand side, a second part hatched (horizontal) as indicated near the arrow 03 is taken away from what remained. Further, starting from the bottom, a third part hatched vertical as indicated near the arrow 04, and, finally, starting from the left-hand side, a fourth part, hatched (- 45°) as indicated near the arrow 05, are taken away. What remains is a "secondary" image consisting of three partial areas or islands, 06, 07 and 08. FIG. 16 shows this secondary image separately.
The pattern according to FIG. 17 has two islands. To be taken into consideration as such, an island has to fulfil the requirement that its projection comprises at least two image elements.
As regards the islands a pattern is viewed from four directions. As characteristic property is considered whether in the original pattern an island, viewed from the relevant direction, is bordered by white or by black image elements. If there is more than one island it is important that the order in which the islands are dealt with is defined.
In the example of FIG. 17 the following situations obtain:
______________________________________ island 09 island 010top aspect black blackbottom aspect white blackleft-hand aspect black blackright-hand aspect black black.______________________________________
For each of the aspects the following classification can be adopted:
Pt 0 no island
Pt 1 1 island, bordered by white
Pt 2 1 island, bordered by black
Pt 3 2 islands -black, black
Pt 4 2 islands - black, white
Pt 5 2 islands - white, black
Pt 6 2 islands - white, white
Pt 7 3 or more islands.
As interruptions of lines also result in the division of islands in parts, the condition applies that islands between which there are no black image elements in the original pattern, shall be at least two image elements apart. If two areas are only one image element apart, they will be regarded as one island.
In the example of FIG. 18 the areas 012 and 013 are considered as one island, because the white strip in between is only one image element wide. The areas 011 and 012 remain separate islands.
If in an aspect at least two adjoining image elements of an island border on white in the original pattern, the relevant island is considered to be bordered by white.
Consequently, in the example of FIG. 18 the codings for the aspects of the two "islands" 011 and combined 012 and 013 are:
______________________________________top PT 5 white, blackbottom PT 3 black, blackleft PT 3 black, blackright PT 3 black, black______________________________________
THE APPARATUS
In the general block diagram of FIG. 19 the document 1 is projected onto a matrix and scanned by the optical scanner 2. The output signal of the scanner is digitized and quantized by the converter 3, after which it can be applied to the processor 4 in order to be recorded in the processor store.
Generally, the information on the processor store consists of a number of figure patterns written on the document 1. Each figure pattern to be recognized is applied to the pattern manipulator 5, by means of which partial images are formed. If the device is provided with a circuit for geometrically separating the patterns, the manipulator 5 can also be used to select the border strips.
The information of the partial images formed by means of the pattern manipulator is applied to circuits 6, 6', and 6" for detecting the properties of the partial images, i.e. jumps 6, slopes 6', and terminal points 6", respectively.
The information of the partial images can also be applied to a switching circuit 9A for forming secondary images, which are recorded in the working store 7. In a preferred embodiment the working store has 32 × 32 bit locations. The secondary images can be aplied to the circuit 8 for detecting the properties. The output terminals of the circuits 6, 6', and 6" and 8 are connected to input terminals of the processor 4, so that the codes of the properties found can be recorded in the processor store. The classification of the pattern is carried out in the processor 4 according to these properties.
The pattern manipulator 5 (FIG. 20) has a semiconductor matrix store 9 having 48 ×48 bit locations. Each separate bit can be written via a write wire 10 from the processor store 4 and read via a read wire 11, the relevant location being indicated by a address pulse on the horizontal and vertical sides, in a manner analogous to the way in which a core store is used.
By means of the pattern manipulator 5, in co-operation with the processor store 4 and possibly a second pattern manipulator, the date can be subjected to the following operations, which can take place in conjunction and simultaneously:
a. copying, direct to or from another manipulator, such as stores 9 and 9' or the processor store 4;
b. rotating, in multiples of 90°;
c. shifting in multiples of 1 bit horizontally, vertically or the two simultaneously;
d. centring;
e. adjusting;
f. other operations, e.g. erasing.
FIG. 21 and 22 give examples of combining some of the above-mentioned operations. FIG. 21 shows the data transferred from the processor store 4 to the manipulator store 9 (FIG. 20). FIG. 22 shows the data recorded in a matrix part 9' comprising 32 × 32 bit locations, in which the pattern has been geometrically separated, such as by shifting (c) and/or erasing (f), adjusted (e) and centered (d).
With regard to the operations mentioned under a-e the following observations can be made:
I-A COPYING The possibilities are:
1. from the processor 4 to the 48 × 48 matrix of store 9;
2. from the store 9 to the processor 4;
3. from the store 9 to e.g. a 32 × 32 matrix of the store 9' or vice versa;
I-A-1 (FIG. 20).
On a program instruction, the processor 4 delivers the first ADDRESS ACCEPTED (AA) signal, which causes the parallel writing of 8 bits at a time from the processor store (4) to the shift register 12 and thence to store 9.
These 8 bits are then shifted out of the register 12 via the write wire 10 to the store 9 by means of eight clock pulses delivered by the 8-pulse generator 13 on reception of the AA-pulse.
In addition, the clock pulses control a horizontal address counter 14. When this counter 14 has received 48 pulses, it passes an output pulse to the vertical address counter 15, causing the latter to do a step.
As soon as the generator 13 has finished, it passes an "8th pulse" signal to the break request (BR) input terminal of the processor 4. Then, when the latter has finished other operations, it delivers another AA-pulse and the process described above is repeated until the store 9 is completely filled, in lines from left to right and from top to bottom, with data from the processor 4.
Addressing the manipulator store 9 is done with the aid of the counters 14 and 15 or, if the data are to be shifted when written to the matrix 9' (see FIG. 23), with the aid of additional counters 21-24, as will be described under c (see FIG. 35). When the counters 14 and 15 reach their final states, a signal then formed blocks the 8-pulse generator 13, thus putting an end to the process.
I-A-2 (FIG. 20)
Contrary to what has been described under I-A-1, a shift register 16 is used in this case. During the readout of the store 9 this shift register 16 is filled with series data, which are then taken over in parallel by the processor 4 via data input terminals 17.
I-A-3 (FIG. 23)
The processor 4 is not required for taking over data from the 48 × 48 matrix of the memory 9 to a smaller matrix 9'. The processor 4 has only to give a start signal under program control and to receive a signal when the copying process has finished.
The addressing of the two matrices 9, 9' (48 ×48 and 32 ×32, respectively) takes place synchronously, but shifted in time.
The counters 18 (HORIZONTAL) and 19 (VERTICAL) are arranged as dividers by 32. The read wire 11 of the store 9 (48 × 48) is connected as a write wire to the store 9' (32 × 32). The addressing lag of the latter store with respect to the former is necessary because the read signal is only available after the relevant store location has been addressed, whereas data, when written, must be available when addressing takes place.
I-B ROTATING (FIGS. 24-31)
The principle on which the rotating process is based is illustrated in FIGS. 24-30. Instead of rotating the data themselves in the memory, the addressing can be changed. A rotation of 90° (FIGS. 24, 25) can thus be achieved by removing the addressing line - at first connected to the top side -to the right-hand side, the connections of the left-hand side being transferred to the top side. In the practical arrangement, however, only the top and the left-hand sides are available. FIGS. 28, 29 and 30 illustrate how the connections have to be arranged in order to give the desired rotations. These figures are the equivalents of FIGS. 25, 26 and 27 for rotations of 90°, 180° and 270°, respectively.
FIG. 31 illustrates how these operations can be implemented. The circuitry shown has to be provided 48 times. FIG. 31 shows the horizontal and vertical addressing line circuits for the location 0 (i.e. a column 0 and row 0) of the store matrix 9. As can be seen from FIGS. 24, 28, 29 and 30, the horizontal addressing line must be connected to address indication lines A0, B47, A47 and B0 for rotations of 0°, 90°, 180° and 270°, respectively. By means of one of the AND to gates P H01 - P H04 the relevant address indication line is connected via the OR-gate P H0 to the addressing line. The vertical addressing line is switched in an analogous manner by means of the AND gates P V01 to P V04 and OR gate P V0 . For practical reasons, however, this switching is not effected at the address terminals of the matrix 9, but at the output terminals of the counters 14 and 15, where the counter state codes -6 bits per counter - are still available. Beyond the rotating circuit these data are decoded and passed, vertically as well as horizontally, to the 48 address terminals.
FIG. 32 illustrates the principle by a four-terminal divider, of which FIG. 33 is a wiring diagram. The two OR-gates OGI, OG2 are connected to a decoder D having a number of output terminals equal to the number of addressing lines to be controlled by it. The addressing data are available in a binary counter which, consequently, has fewer output terminals than there are addressing lines. The number of input terminals of the decoder D is equal to the number of output terminals of the binary counter. The desired connections between the output terminals of the binary counter and the input terminals of the decoder are established by means of the rotating device R (see FIG. 34). FIG. 34 is a block diagram of the rotating device R connected to the store 9.
I-C SHIFTING
For copying data from the processor store 4 to the store 9 of the pattern manipulator 5 (FIG. 20), the addressing of these stores can take place with the aid of the same counters 14 and 15. If the data are to be written to or from the store 9 with some shift, separate address counters - 23, 24 and 21, 22 (FIG. 35), respectively - have to be used for the store 9 and for the processor store 4, respectively. One or both of the address counters 23, 24 of the memory 9 is given an appropriate preset (V.I.), as controlled by the processor program, to obtain the desired shift. Moreover, it is possible to utilize only part of the 48 × 48 bit locations, e.g. 32 × 32, of the store 9' by switching over all the address counters - likewise under program control - from 48 to 32 dividers. The principle is illustrated in FIG. 35, the FIGS. 36 - 41 showing the results obtained with several different presets. The address counters 21 through 24 each constitute a 32 divider consisting of five binary dividers.
I-D CENTRING
Centring is a form of shifting in which the degree of shift is determined in a separate circuit with the aid of the OR-function of the whole figure pattern, horizontally as well as vertically. This OR-function is formed during the recording of the data in the store 9 by means of a 48-bit shift register SR, as shown in FIG. 42.
The preset of the address counters of the store 9, required for centering, is obtained with the aid of a separate counter, the shift counter 20 (FIG. 43). Firstly, the position of the centre line of the figure pattern has to be determined (FIG. 44). The OR-function of the entire pattern is formed when the last line (47) is recorded. The position of the centre line is found by first determining - in line 47 - the number of white image elements up to the beginning of the OR-function and then half the number of image elements of the OR-function itself (FIG. 44). A shift has to be effected, however, which is equal to the distance between the centre line of the matrix itself and the center line of the figure pattern. The centre line of the matrix lies at +24, the state of the shift counter will finally be exactly equal to the difference between the centre line of the figure pattern and the centre line of the matrix, i.e. the desired shift in horizontal direction. The state of the shift counter is now utilized as a preset for the horizontal address counter of the matrix.
After the pattern has been rotated, the vertical shift can be determined by means of a second shift counter and passed as a preset to the vertical address counter of the matrix, after which the entire figure pattern is transferred with the apropriate shift to another matrix or to the processor store 4, the centring operation thus having been carried out.
The position - now known - of the centred figure pattern in the matrix can often be utilized with advantage for carrying out further operations on it. In an analogous manner a figure pattern can e.g. be shifted against the left-hand and top sides of the matrix, if desired.
I-E ADJUSTING (FIGS. 45-48)
II-A-1 PARTIAL IMAGES - "Jumps"
If at the end of each line recorded in the matrix, an additional pulse is applied to the address counter 14, a vertical line (FIG. 45) in the original figure pattern will appear in the matrix as a line having a slope of 45° (FIG. 46). It is also possible to omit a pulse in each line, owing to which the line will be rotated by 45° in the opposite direction (FIG. 47). A smaller angle of rotation can be obtained by adding or omitting a pulse every two lines (FIG. 48). By this principle figure patterns can be adjusted to an upright position.
A description will now be given of a device for detecting and classifying discontinuity of lines in partial images. The data are supposed to be recorded in a 32 × 32 matrix forming part of the store 9' (see FIGS. 21-23 and 36-41). Suppose, for example, that the jumps in the left-hand aspect have to be detected. The data are shifted out row after row, beginning with the row 0. Each row contains the bit numbers 0-31.
In FIG. 49 the data are transferred via input 25, together with clock pulses via input 26, to an AND-gate 27. There is a device 28 for detecting the first black-to-white transition and a device 29 for detecting the first white-to-black transition. The clock pulses are applied via an AND-gate 30 to a counter 31, which counts these pulses until the first black-to-white transition has been detected. At the end of each row of image elements there appears a row-pulse at input 32. By means of AND-gate 33 the state of the counter 31 is tranferred to the buffer/down counter 34. Consequently, this buffer always contains data from the preceding row. The clock pulses are applied via the AND-gate 35 to the buffer/down counter 34, until the first white-to-black transition has been detected. At the beginning of each row the counter 31 has a preset of +2 bits or pulses. Consequently, the state of the buffer/down counter 34 is negative, if there is a jump S of more than 2 image elements (FIG. 50). The negative state of the down counter 34 is marked by the most significant bit of the counter. The counter 31 as well as the buffer/down counter 34 are used for ascertaining positive jumps.
An analogous combination of the counter 36 and the buffer/down counter 37 is used for ascertaining negative jumps. At the beginning of each fresh row, the counter 37 has a preset of bit -2.
Only in the case of black image elements occurring in the preceding row may the jump detection for negative jumps be active. For this purpose a device (trigger 38) for detecting black image elements has been provided. By means of the AND-gate 39 such an element is recorded in a buffer for 40 as buffer black. The AND-gate 42 is blocked, if there are no black image elements in the preceding row, and the AND-gate 41 is blocked, if there is no black image element in the row that is being examined. By this arrangement it is achieved that black elements in the first and the last rows of the pattern are prevented from causing jumps to be recorded.
At the end of each row the gates 41 and 42 are deblocked by a pulse in input 43 preceding the row pulse at input 32. If a positive jump has been detected, the gate 41 delivers a pulse. Likewise the gate 42 delivers a pulse if a negative jump has been detected. The code representing the jump configuration is formed by means of the OR-gate 44, the counter 45 and a shift register 46. The output pulses of the OR-gate 44 are counted by the counter 45 and used as clock pulses in the shift register 46. The binary counter 45 blocks itself after 3 pulses. If the pulse from he gate 41 is a 1, a 1 is recorded in the shift register 46. The states of shift register 46 and counter 45 for the various jump configurations as mentioned in Section II-A1 above and FIG. 5 are indicated below.
______________________________________classification of shift register counter the jumps 46 45PS 0 no jump 00 00PS 1 1 positive jump 10 01PS 2 1 negative jump 00 01PS 3 1 negative and 1 positive jump 10 10PS 4 1 positive and 1 negative jump 01 10PS 5 2 positive jumps 11 10PS 6 2 negative jumps 00 10PS 7 three or more jumps XX 11______________________________________
II-A-2 PARTIAL IMAGES-SLOPES
In what follows a description will be given of equipment for detecting and classifying slope configuration (see block diagram FIG. 51). In this case too the data are supposed to be shifted row by row out of the 32 × 32 matrix 9' (FIGS. 21-23 and 36-41). Slope and jump configurations can be determined synchronously and simultaneously. There is a device 50 for detecting a positive slope and there is a device 51 for detecting a negative slope. If a positive slope is found, trigger 52 is set; while in the case of a negative slope, trigger 53 is set. The change of state of the trigger 52 or 53 causes a pulse to appear at the pulse shapes 54 or 55, respectively. At the beginning of the negative slope the trigger 52 is reset and at the beginning of a positive slope the trigger 53 is reset by means of OR-gates 56 and 57, respectively. At the end of each line of the configuration being analyzed, a signal is available at the output terminal of the gate 44 (FIG. 49) a "jump" pulse is given at the output terminal 48 by means of a trigger 47. At the beginning of the next row of image elements this trigger 47 is reset via an input terminal 49, owing to which, via the gates 56 and 57, the triggers 52 and 53 are reset as well.
The following results have thus been obtained:
a. every time a positive or negative slope begins, a pulse appears at the output terminal of the OR-gate 58;
b. the state of the trigger 59 indicates if this last slope registered is positive or negative.
The output of the OR-gate 58 is applied to the clock pulse terminal 60 of the 4-bit shift register 61. A representation of the sequence of positive and negative slopes is available at the output terminals of the shift register 61, the number of successive slopes being indicated by the output terminal of the counter 87. The output gates for the slope configurations can be connected to these output terminals.
FIG. 52 is a more complete block wiring diagram of the slope detection circuit shown in FIG. 51. Some signals can be obtained from the jump detecting device (FIG. 49). The data are taken from the output terminal 62' of the AND-gate 62 (FIG. 49). This output terminal 62' delivers a number of pulses equal to the number of image elements up to and including the first black element. This number is determined by means of the counter 63, which, at the end of the row of 32 image elements, delivers a row pulse via input 64. During this row pulse the data are transferred in parallel, by means of the AND-gates 65, to the buffer/down counter 66, to one of the input terminals of which the output terminal 62' of the gate 62 is again connected as well. If at the end of a row of image elements the contents of the buffer/down counter 66 is a positive number, this denotes a negative slope. There is a comparator >0 (67) for detecting a positive count and a comparator <0 (68) for detecting a negative count. The states of the two comparators are tested during a pulse via input 69, preceding the row pulse via input 64. The AND-gates 70 and 71 are also connected to the output terminal 40' of the buffer store 40 (FIG. 49). If during the pulse at input 69 the buffer/down counter 66 contains a positive number, the gate 71 delivers a pulse, which is applied to the AND-gate 74. The latter only delivers a pulse if the trigger 75 has been set, which denotes that the last slope detected vas negative too. The trigger 75 can be set by a pulse from the pulse shaper 76, this pulse being formed at the trailing edge of the pulse delivered by the gate 71. When a pulse appears at the output terminal of the pulse shaper 76, the trigger 78 is reset via the OR-gate 77. For the positive slope detection the analogous equipment consists of the gate 70, the pulse shaper 79, the trigger 78 and the AND-gate 81. It has been achieved thus that a change of slope only found in one row does not cause a pulse to appear at the output terminals of AND-gate 74 or 81. Only the changes in the slopes are of importance. For this purpose triggers 52 and 53 indicate the last slope observed. When a pulse appears at the output terminal of the AND-gate 74, the trigger 52 is set via the OR-gate 56. A pulse from AND-gate 81 resets via OR-gate 57 the trigger 53. At the end of a line of bits being tested, the triggers 78, 75, 52 and 53 are reset by means of and AND-gate 83.
If a jump (S) has been detected, trigger 47 (FIG. 49) is set during the pulse at input 43. Then, during a row pulse at input 32 or input 82, a pulse appears at the output terminal of the AND-gate 83. This cannot prevent the AND-gates 74 and 81 from delivering pulses when a jump (S) occurs. When the trigger 52 is set, in order to indicate that the beginning of a positive slope has been detected, a pulse becomes available at the output terminal of the pulse shaper 54. At the beginning of a negative slope a pulse appears at the output terminal of the pulse shaper 55. Only if no jump occurs in the relevant row, the slope can be accepted. During the row pulse at input 82, the polarity of an AND-gate 84 indicates whether no jump S occurs. So a signal denoting a positive slope is only available at the output terminal of the AND-gate 85, and a signal denoting a negative slope only appears at the output terminal of the AND-gate 86. A representation of the sequence of positive and negative slopes is available in the described manner at the output terminals of the shift register 61, the number of successive slopes being determined by an output counter 87.
II-A-3 PARTIAL IMAGE - TERMINALS
Now a description will be given of a device for detecting and recording terminal points.
For detecting terminal points, extremes have to be determined first. The easiest way of doing this is, at the same time when e.g. jumps and slopes in the left-hand aspect (see FIG. 2) are detected, to determine the extremes and, subsequently, the terminal points of the top aspect.
During the jump and slope analysis of the left-hand aspect of the data are shifted out of the 32 × 32 matrix (FIGS. 21-23 and 36-41) line by line. By means of the device to be described below terminal points possibly occurring in the top view are detected simultaneously with this operation. For detecting a terminal point, after an extreme has been found, the relevant line must be followed further. Therefore the various intersections are given serial numbers, on the condition that the line continues without bifurcation. A line that keeps satisfying this condition retains the same marking. In the examples of FIGS. 53-57 the scanning direction is from left to right; the serial number is given after the black-to-white transition. As soon as the condition is no longer met, no marking is given after the black-to-white transition.
Conditions for a correct connection with the preceeding row of image elements are:
a. the intersections in two successive rows must not be shifted by more than two image elements with respect to each other at the leading and the trailing edges. Examples: FIG. 58 correct; FIG. 59 incorrect.
b. in one and the same row a white-to-black transition must be preceded by at least 4 white image elements. Examples: FIG. 60 correct; FIG. 61 incorrect.
FIG. 62 is a functional block diagram of a device by means of which correct connections can be detected. Condition a. The fulfilment of this condition is checked by means of gate circuits connected to a shift register 88 having 36 one-bit sections. The trailing edge of an intersection can be detected at the output terminals 1 and 0 of shift register 88. If terminal 1 signals "black" and terminal 0 signals "white", the output polarity of the AND-gate 89 will change. Data from the preceding row of image elements are available at the output terminal 32 of the shift register 88. At the moment when the gate 89 changes polarity, output terminal 32 can signal "white" or "black". If it signals "black," the AND-gate 91 will change polarity together with gate 89. There are several situations in which the connection is considered correct. For the case of output 32 of register 88 signalling "white," when gate 89 changes polarity, see FIGS. 63, 64 and 65. Now one or more of the output terminals 33, 34 and 35 of register 88 must signal "black" (FIGS. 63-65). In the circuit this can be ascertained by means of an OR-gate 92. If the condition is not satisfied, a pulse appears at the output terminal of the AND-gate 93. The possibilities of correct connections for the case of output 32 of register 88 signalling "black" are illustrated in FIGS. 66 and 67. So in this case a "black" image element has to be signalled by one of the terminals 30 and 31 of register 88. In the circuit this is ascertained by means of an OR-gate 94. If the condition is not satisfied, a pulse appears at the output terminal of the AND-gate 95. Condition b. The leading edge of an intersection can be detected at the output terminals 0 and 1 of the shift register 96, which consists of five 1-bit sections. If terminal 0 signals "black" and terminal 1 signals "white" of the register 96, a change of polarity occurs at the output terminal of the AND-gate 97. The data concerning the preceding image elements is available at the terminals 2, 3 and 4 of the shift register 96. A white-to-black transition in the data supplied is only considered correct, if the terminals 1 to 4 of register 96 signal "white" at the moment its terminal 0 is "black". The "white" condition at the terminals 2, 3 and 4 of register 96 can be ascertained by means of the AND-gate 98. If the condition is not satisfied, the output polarities of AND-gates 99 and 97 change simultaneously. If a too narrow space between intersections is ascertained, the trigger 100 is set. The output of the OR-gate 101 indicates eventually whether a correct connection has been detected at the moment of a black-to-white transition in the data stream. Of course shift register 96 can form part of shift register 88. An extremity in a pattern can be determined with the aid of the AND-gates 103 and 102. The condition for an extremity is the situation according to FIG. 68. The situation of a "black" terminal 1 and a "white" terminal 0 of register 88 is signalled by the polarity of AND-gate 89. Trigger 100 must not be set in this case. The terminals 29 to 35 of register 88 must be "white." These conditions are obtained by means of the gate 103. If an extremity is ascertained, there will be a change of polarity at the output terminal of gate 102.
Intersections can be marked by means of a circuit (FIG. 69) containing shift registers 104 and 105. The circuits for determining the correctness of the connection and for detecting an extreme are connected to the shift register 88 (FIG. 62). The shift registers 104 and 105 can contain the serial number for each of the intersections; the serial number consists of 2 bits, either shift register 104 or 105 containing 1 bit.
In the initial state the shift registers 88, 104 and 105 are empty. As soon as an extreme has been detected, the state of the counter 106 is advanced by one step. At one clock pulse period the AND-gates 107 and 108 are deblocked, the counter state being passed via OR-gates 109 and 110 to the data input terminals of the shift registers 104 and 105. At the next clock pulse the data are taken up in the registers 104 and 105. These data are shifted through the shift registers 104 and 105 in synchronism with the shifting of data through the shift register 88 in FIG. 62. As the trailing edges of the intersections belonging to one line may be shifted with respect to each other, the relevant markings in the shift registers 104 and 105 may exhibit the same variations in place.
If in two successive rows the black-to-white transistions are exactly one above the other, the situations illustrated in FIGS. 70 and 71 can occur at two successive clock pulses n and n+1. The last black-to-white transition indication is available at the output terminals 1 and 0 at shift register 88; and that of the preceding row can be found at its terminals 32 and 33. The coding of the relevant line (in this case 10) has been recorded in the registers 104 and 105. If at clock pulse n the connection is found to be correct, the data occurring at the output terminals 31 of the registers 104 and 105 are fed back to their input terminals via the OR-gates 111 and 112 and the AND-gates 114, 113, and OR-gates 110 and 109, respectively, to the data input terminals. If the connection is correct, the AND-gates 113 and 114 are deblocked. As the intersections may be shifted with respect to each other, the output terminals 29 to 33 of the shift registers 104 and 105 are connected via the OR-gates 111 and 112 to the AND-gates 114 and 113. Thus it has been achieved that a marking disappears in the case of a non-connection and that a line retains the same marking as long as the connection is correct.
The last step in the process is to find out if there are terminal points in an aspect and how many. FIG. 72 illustrates the principle of the relevant circuit by a functional block diagram. The black image elements in the data bitstream are counted by the counter 115. Means have been provided to restore the counter to the zero state as soon as fresh "white" bits appear via input r. The input terminals of an AND-gate 116' are connected to the output terminals 109' and 110' of the gates 109 and 110 of the circuit for marking intersections (FIG. 69). The output terminal of gate 116' changes polarity e.g. at serial number 01. The number of bits at the largest line thickness occurring must be recorded in a register 117. If the serial number 01 of an intersection has been detected, an AND-gate 118 will be in a position to deblock the AND-gates 119, providing the comparator 120 indicates that the register 117 contains a smaller number than the counter 115. At each fresh row of image elements a pulse will appear at the output terminal of the gate 116' providing the connection still exists. The number of these pulses is determined by a counter 121.
Conditions for a terminal point:
a. content of register 117 is 001 and content of counter 121 is 0011;
b. content of counter 121 is ≧2 × the content of register 117.
As soon as one of these two conditions is satisfied, a trigger 123 is set via an AND-gate 122, at least as fas as intersection 01 is concerned. Whether condition a is satisfied is ascertained by AND-gates 124, 125 and 126. A comparator 127 is used for determining whether condition b is fulfilled. The content of register 117 is a binary coded value (3 bits); and the counter 121 is a four-bit counter. The comparison of the three most significant bits of counter 121 with the three data bits of register 117 at the same time implies the introduction of the factor 2. The OR-gate 128 indicates whether one of the two conditions is satisfied. Trigger 123 can be set during an output pulse of gate 116'.
It is assumed that an aspect cannot contain more than 3 extremes. This means that three copies of the described circuit have to be provided, with the exception of counter 115. The counter 129 is used for recording how many terminal points have been found in an aspect. Therefore trigger 123 is connected via a pulse shaper 130 to the OR-gate 131. For the other terminal points, triggers 132 and 133 and pulse shapers 134 and 135 have been provided.
As regards resetting the various triggers, registers, counters etc. the following has to be observed: For each aspect, all registers, counters etc. are restored to the zero state. The circuit always operates as soon as a black-to-white transition is signalled at output terminals 1 and 0 of the shift register 88. After this operation when terminal 1 signals are "white" again, trigger 100 (FIG. 62) is reset, as well as counter 115 (FIG. 72). The reset pulse appears at the output terminal of a pulse shaper 136 (FIG. 62).
II-B SECONDARY IMAGES - "ISLANDS"
Finally a description will be given of a circuit for detecting and recording "islands" in secondary images. The formation of secondary images requires the working store 7 (see FIG. 19) in addition to the store 9.
Either of these stores has a capacity of at least 32 × 32 bits (FIG. 73). Both stores are addressed with the aid of counter 19 for the rows and counter 18 for the columns. The addressing lines of the two stores 7 and 9 are connected to the same output terminals of the counters 19 and 18. The store 9 is also utilized for determining the other properties. So the circuits for detecting jumps, slopes and terminal points are connected to the store 9. A pattern to be recognized is first supplied as a stream of white and black image elements (data) from the processor store 4 to the data input of the store 9 and, through the inverting amplifier 137, in inverted form to the data input of the store 7. When the properties are determined, the pattern contained in the square matrix memory 9 and is examined consecutively from each of its four sides. A secondary image is formed by recording "white" image elements in store 7 for each of the aspects, from the side of the aspect up to the place where the character begins. This means that of the inverted pattern shown in the matrix 7 in FIG. 73, the surface with the wide hatching will be "white." The islands remaining with the dense hatching will be "black".
The switching means 137 to 142 in FIG. 73 constitute the circuit designated by 9A in FIG. 19. The signal DT (FIG. 73) indicates that data are being transferred from the processor store 4 to stores 9 and 7. The data written in store 7 via OR-gate 138 are inverted by means of the inverting amplifier 137 are written to store 7.
Then the data contained in store 9 are read to the circuits for detecting jumps, slopes and terminal points in the aspects I, IV, II and III (FIG. 4). These data are also sent to the circuit 139, which detects the first white-to-black transition. At the aspects I, II and IV an AND-gate 141 is deblocked by means of an OR-gate 140. Via the OR-gate 138 0 data, corresponding to "white" in the pattern, are written to the store 7. The AND-gate 141 is blocked as soon as the first white-to-black transition is detected.
At the last aspect (aspect III) the islands can be completely defined and then properties can be determined. The data concerning the islands appear at the output terminal of the AND-gate 142. When the aspect III is being dealt with the output state of the gate 142 is 0 ("white") at the beginning of each row; as soon as the first white-to-black transition has been detected, the data are passed from store 7 to the output of gate 142.
The principle of determining the properties in circuit 8 (FIG. 19) can be explained by a simple example: If there is only one island in a pattern (FIG. 74), the data from the original pattern are written from store 9 to the shift register 143 (FIG. 74), which can contain 33 bits, i.e. 32 bits from one row plus one bit from the next row. The data appearing at the output 142' of gate 142 of the circuits 7 and 9A in FIG. 73 for forming the islands is transferred to the shift register 144, which also contains 33 bits. A black-to-white transition in the secondary image is signalled by the output of the AND-gate 145. If at the moment when the gate 145 changes polarity, the output 0 of the shift register 143 signals "white". This means that against the original pattern, the island borders on "white." In that case the AND-gate 146 changes polarity and the trigger 147 is set, thus signalling that the island borders on "white" at the right. A transistion from white to black in the secondary image is signalled by the output of the AND-gate 148. When this AND-gate 148 changes polarity at the same time the output 1 of the shift register 143 signals "white," the AND-gate 149 changes polarity and a trigger 150 is set, thus indicating that the island borders on "white" at the left. The situation at the top and bottom borders is determined by means of triggers 151 and 152, respectively. The upper border of the secondary image is signalled by a situation in which the output 0 of the shift register 144 is "black" and the output 32 of the same shift register is "white." If in that situation the output 32 of the shift register 143 is "white" as well, the gate 153 changes polarity and the trigger 152 is set, thus indicating that at the top the island is bordered by "white." In an analogous manner the trigger 151 is set if at the bottom the island is bordered by "white."
While there is described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of this invention. | The invention relates to a method for the automatic recognition of characters, preferably of figures, which may be hand-written on an information carrier provided with an arrangement of demarcated rectangles- one for each character. These handwritten characters are projected on to a matrix, where a camera tube ensures the scanning of the matrix, and the information thus read is recorded in a store and subsequently handled by a processor.
A device for carrying out this method comprises a character pattern manipulator connected to the store in the processor, the output of which manipulator is connected to a number of properties of signals derived from scanning the characters. This manipulator comprises means for copying or transferring the information stored in the processor to other storing matrices, rotating the information stored therein in successive 90° turns, shifting and dividing the stored information, and erasing undesired information parts from the rectangles. The detecting circuitry comprises the detection of discontinuities or "jumps" in lines stored in the matrices, the slopes of the lines, the terminal points of the lines, and the numbers of each in each partial character; and the detection of "islands" or substantially surrounded areas in the matrices of secondary images of the character, including their number and the borders of said "islands". | 6 |
RELATED APPLICATIONS
[0001] This application is related to the applications, Arrouye et al, U.S. patent application Ser. No. ______ (corresponding to attorney docket number P2206-397) for, “A METHOD ADAPTED TO TRANSPARENTLY TRANSFORM OBJECTS FOR AN APPLICATION PROGRAM,” Arrouye et al, U.S. patent application Ser. No. ______ (corresponding to attorney docket number P2211-398) for, “A MULTI-REPOSITORY DISPLAY SYSTEM USING SEPARATE PRESENTATION, ADAPTATION AND ACCESS LAYERS”, and Arrouye, et al, U.S. patent application Ser. No. ______ (corresponding to attorney docket number P2209), for “METHOD AND APPARATUS FOR “JUST-IN-TIME” DYNAMIC LOADING AND UNLOADING OF COMPUTER SOFTWARE LIBRARIES”, which are all incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to interaction with services provided by the operating system in a computer. More particularly, the present invention relates to a method and apparatus for storing information that identifies the state of a particular client's, or user's, interaction with operating system services.
[0004] 2. State of the Art
[0005] A computer's operating system typically provides a variety of different services that are called upon by clients, e.g. application programs and other processes, to perform functions that may relate to hardware components of the computer system, or other software programs. For instance, the file system permits a client to retrieve files from a local hard disk drive to open them within an application program, as well as store them back on the disk drive when they are closed. Another example of an operating system service is a color picker, which enables a client to vary colors which are displayed on a computer monitor and/or printed on a printer.
[0006] Many operating system services require, or at least permit, a client to provide input which determines how the function of the service is to be carried out. For instance, when a file is to be opened in an application program, the client is provided with a choice of available storage locations, and files within that location, from which to select. Similarly, a color picker may provide sliders, or other types of control elements, which enable the user to adjust the colors on a display. These types of services typically have a user interface associated with them, via which the user can provide the necessary input. Other types of operating system services may not require explicit user input, and therefore normally do not have a corresponding user interface. For instance, the operating system may want to keep track of a user name and password for a server, to provide for automatic reconnection.
[0007] One example of a user interface that is provided when an application program issues a call to open or save files comprises a visual display of a directory and its contents. The user selects a file to be operated on by the application program, by clicking on a representation of the file in the visual display of the user interface. Typically, information concerning the directory displayed in the user interface is stored when the access to the operating system service terminates, e.g. the user exits the user interface. The next time the application program calls that service, the operating system causes the user interface to display the most-recently stored directory.
[0008] There are many operating system services which are called by multiple different clients. For instance, the file system service may be called by a text editing portion of a word processor, and then called by the dictionary portion of the same word processor, or by an entirely different application program. When the text portion of the word processor calls the file system again, its user interface will display the contents of the last directory that had been accessed. Thus, if the most recent call to the file system was from the dictionary portion of the word processor, the user interface might display a list of dictionary files. The user must then manipulate the user interface so that it displays the directory containing the desired text files. This can be a time-consuming annoyance to the user.
[0009] Additionally, when a desired directory is displayed to the user, the display typically occurs at a default location in the directory. For example, if files are displayed in alphabetical order, the files which initially appear are those whose names begin with A, B, C, etc. Consequently, a user may have to scroll down the user interface to find a previously selected object. If a directory contains a long list of files this can take some time.
[0010] It is desired to provide an improved method and apparatus for storing state information relating to operating system services across invocations of the services, to ensure correct operation of services, as well as to make the access to such services more convenient for the client.
SUMMARY OF THE PRESENT INVENTION
[0011] The present invention generally relates to a method and system for storing state information relating to shared service programs. A database stores information which preserves the state of a particular operating system service for each client which calls that service. Thus, whenever a client accesses the service, it will be returned to the same state that existed when it last exited that service, even if other clients had accessed the service in the meantime and left it in a different state. The stored information is external to the clients which utilize the services, so that changes to the services can be implemented without affecting the clients.
[0012] In a preferred embodiment of the invention, the state information which is stored for each client-service pair includes as much information as possible which relates to the client's interaction with that service. For example, the state of a file system service might include the directory which was last accessed by the client, together with various parameters that define the user interface for that service, such as the size and location of a dialog window. Additional information along these lines can include position of a scroll button for the window, so that the client is returned to the same position in the directory where it exited the previous time, rather than a default position such as the top of a list.
[0013] The state information is stored under the control of the shared service or the operating system, rather than the application program. The application program need not be modified to provide changes to the state information storing process. The application program, however, can provide context information to affect the storing of the state information indirectly.
[0014] Preferably, the database is accessed by a key. The key includes a caller ID field indicating the application program or other client, a service ID field indicating the shared service program and a caller context ID field which may contain context information provided by the client.
[0015] The caller context ID field in the key allows different states to be stored for different contexts in an application. For example, the same service could be called by the text editing portion of a word processor, and the dictionary portion of the word processor. When the text portion of the word processor calls the service, the user interface will be set up with the state information corresponding to the state of the service which existed the last time the text portion of the word processor called the service. This avoids the annoyance of the user interface showing a directory of dictionary files when one wants to open a text file. The use of the caller context ID field allows two or more different states to be stored; one for each context of the application program.
[0016] In a preferred embodiment of the present invention, the key to the database also has a service context ID field. The service context ID field allows different versions of the shared service program to store different types of state data. A first version of a shared service interface might store the user interface state information in a certain manner. An upgrade to the shared service program can modify the way state information is stored. However, entries to the database may have already been made using the first version of the shared service program. The service context ID allows the upgraded shared service program to determine how the state data is stored in the database; the old way or the new way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention can be further understood from the following description in conjunction with the appended drawings. In the drawings:
[0018] [0018]FIG. 1 is a general block diagram showing the principles of the present invention.
[0019] [0019]FIG. 2 is a diagram illustrating the operation of the method of the present invention using the example of a user interface.
[0020] [0020]FIG. 3 is a diagram illustrating the use of the key to obtain user interface state information from the database.
[0021] [0021]FIG. 4 is a diagram illustrating the position of a user interface on a computer screen.
[0022] [0022]FIGS. 5A and 5B are flow charts illustrating the method of the present invention.
[0023] [0023]FIG. 6 is a diagram that shows a prior art method of displaying a user interface.
[0024] [0024]FIG. 7 is a diagram that shows a method of the present invention displaying a user interface.
[0025] [0025]FIG. 8 is a diagram of a computer system with a computer readable medium suitable for storing the programs of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] [0026]FIG. 1 is a diagram that illustrates the general concepts which underlie the present invention. Block 100 shows an application program A. The application program A calls a shared service program S in block 102 . The shared service program S can be any one of a variety of programs that are called by one or more application programs. These shared service programs can include user interfaces, printer software or procedures in an application programing interface. The application program A can send context information I to the shared service program. The shared service or operating system produces a Key 104 to access and store state information of the shared service program in a database 106 . In a preferred embodiment, the key includes a service ID field to identify the shared service program, a caller ID field to identify the application program and a caller context ID field for any caller context information received from the application program. The Key 104 in a preferred embodiment also includes a service context ID produced by the shared service program.
[0027] Looking again at FIG. 1, when the application program A provides context information J to shared service program S, the resulting Key 108 will be different from Key 104 . This means that the stored state information will be different for different contexts of the application program. Additionally, both a shared service program T and the shared service program S can use the same database without conflict since the Key 110 produced by shared service program T will be different from any key produced by shared service program S.
[0028] The Database 106 stores the state information for the shared service program. For example, a user interface can store positioning and display information and a printer program can store printer setups. This state information is stored under the control of the shared service program or operating system; the application program is not required to store the state information itself.
[0029] By sending the context information, the application program is given some ability to determine what state information is associated with different application contexts.
[0030] Since the application program does not control the storing of the state information, the information to be stored can be modified without requiring modifications to the application program. This process is aided by use of the service context ID field. A new version of the shared service program can change the service context ID, allowing the data structure of the stored state information to be modified without conflicts.
[0031] [0031]FIG. 2 is a diagram illustrating a method of the present invention for use with a file system service. In block 20 , an application program, such as a word processor, calls a “NavGetFile” routine, which is used to open a file within the application. The data sent in this call to the application programming interface for the service includes caller context information. In this example, the caller context information is set to 1. This indicates a first context of the application program. The application program can have as many, or as few, contexts as desired. In a preferred embodiment, context of 0 indicates that the application program is not distinguishing contexts.
[0032] The application programming interface for the service constructs a key. This key has a service ID field, a caller ID field, a caller context ID field, and preferably a service context ID field. The service ID indicates the particular service being called. Each shared service program has a different service ID number. The caller ID number identifies the application program calling the service. The caller context ID field contains the caller context, in this case 1, that is passed from the application program. The service context ID field contains the service context provided by the application programming interface. In this example, the service context ID is set to 0.
[0033] The key is used to determine whether there is any relevant user interface information stored in the database. If there is no state information currently stored in the database, the state of the service is set to a general default setting, or to a default setting for a given application program. Thus, for example, a dialog window for a “GetFile” user interface is displayed at a default size and location, and the contents of a predetermined directory are listed.
[0034] In block 24 , the user modifies the state of the service and exits. Typically, the user will manipulate the interface to find the desired directory, select certain items, and/or change the size or position of the user interface window. In block 26 , the key 22 is used to store the state information in the database. In block 28 , intervening actions occur. Later, in block 30 , the application program calls the same user interface as above. In block 32 , the key 32 , which is the same as the key 22 , is produced. This key is used to access the database in block 34 , and this will pull up the stored state information. In block 36 , the system uses the stored state information to set the state of the called service to the same state that existed when that client exited the service the last time. This can be done even though intervening actions may include calling of the service from a second context of the application program, and modification of the state of the service in that second context.
[0035] [0035]FIG. 3 is a diagram illustrating the use of the key to obtain the database information. In this example, the key is sent to a database which stores the state information. In one embodiment, the key points to an index of another portion of the database. This index is used to obtain the user interface state information. In one embodiment, the database is implemented as a B*tree database. The B*tree database is a database resident on Apple® Macintosh® computers, and is described in chapter 19, volume 4 of Inside Macintosh, Addison-Wesley Publishing Company.
[0036] In the example shown in FIG. 3, the stored state information includes dialog window size, dialog window position, selected item information, directory last used, and an additional state information field. The additional state information field can be used to store any other file access information which is considered useful, such as filtering information and the like.
[0037] As discussed above, the service context ID portion of the key can be used to indicate the arrangement of the state information in the database. Different service INFORMATION DISCLOSURE STATEMENT can indicate different arrangements of the state information fields.
[0038] [0038]FIG. 4 is a diagram that illustrates a user interface 50 , in this case a dialog box, shown on the computer screen 52 . The stored information can include the position of the dialog box 50 on the computer screen 52 ; the size of the dialog box 50 ; a directory, in this case the directory entitled “Folder”; and a selected item, in this case the file entitled “File B”.
[0039] [0039]FIGS. 5A and 5B are flow charts illustrating a method of the present invention. In step 54 , an application program calls an operating system service in a first context. The application program sends an indication of the context to the application programming interface. In step 56 , the application programming interface produces a key, key I. In a preferred embodiment, the key is arranged to include the service ID field, the caller ID field, and the caller context ID field, as discussed above. In step 58 , the key I is used to check the database for setup information. The application programming interface then sets the state for the called service. If no state information is stored in the database for a given key, the application programming interface can use a general default user interface preference, or a default user interface preference for a given application program. Alternately, the system could produce keys to check if any stored information corresponding to the service identification and/or caller ID is in the database, and set up the user interface using this data.
[0040] In step 60 , the user manipulates the service to obtain the desired operation, and exits. In step 62 , the application programming interface uses the key, I, to store state information I about the service in the database. In step 64 , the application program calls the service in a second context. This second context might be different from the first context. The application program sends an indication of the context to the application programming interface. Looking at FIG. 5B, in step 66 , the application programming interface produces a key, key II. Key II is different from key I, because the context ID field is different. In step 68 , the key II is used to check the database. The application programming interface will then set the service to the appropriate state associated with that context. After the user exits the service, the application programming interface stores the state information, state information II, into the database. In step 72 , the application programming interface calls the service in the first context. In step 74 , the application programming interface produces the same key, key I, as discussed above. The key I is used to get state information I, which has been stored in the database. In step 76 , the state information I is used by the application programming interface to set up the state of the service. In this way, the state of the service will be similar to the state that existed after step 60 . Thus, if a user calls the file system to open a file in the text portion of an application program, later calls the file system from a dictionary to get a dictionary file, and then reopens the user interface back in the text portion of the application program, the system will display files in the first directory, rather than the directory of dictionaries.
[0041] One aspect of the present invention concerns the storing of “selected item” information for a user interface. FIG. 6 is a diagram that illustrates a prior art method. In block 120 , a user interface for the file system service displays the directory “Client Addresses”. In block 122 , the user manipulates the user interface to select the file “ONEIL”. In block 124 , the user interface is closed. In block 126 , when the user interface is reopened, the directory “Client Address” is displayed but the previously selected file “ONEIL” is not displayed. The files at the top of the list, “ALVAREZ”-“DIJULIO”, are displayed instead. This can be an inconvenience to the user. For example, consider the case where the user wants to modify the address files to reflect a telephone area code change. After modifying the file “ONEIL”, the next time the user interface is opened, the user must scroll down the user interface to get to the next file to examine, “OWENS”. By the end of the process, a substantial amount of time has been wasted manipulating the user interface.
[0042] [0042]FIG. 7 is a diagram illustrating the method of the present invention. In the present invention, when the interface is closed in step 124 ′, the selected item “ONEIL” is stored in the database as shown in FIG. 2. Alternatively, or in addition, the position of a scroll button 126 in the user interface window can be stored. Looking again at FIG. 7, in block 130 , when the service is recalled, the interface will display the selected item “ONEIL”. If the user wants to open the next file, “OWENS”, it can be easily accomplished.
[0043] In a preferred embodiment, the system can store more than one selected item. It is possible that the files have been modified such that some, or all, of the selected item(s) no longer exist. The display will then show only the previously selected files, if any, that still exist.
[0044] [0044]FIG. 8 is a diagram that shows a computer system 140 including a memory 142 with access to the computer readable medium 144 containing a program to run the methods of the present invention. The computer readable medium can be Read Only Memory, Random Access Memory, Compact Disc, diskette or any other type of medium from which the programs of the present invention can be read.
[0045] It will be appreciated by those of ordinary skill in the art that the invention can be embodied in other specific forms without departing from the spirit or essential character thereof. For example, a “save file” interface may use stored user interface data from an “open file” interface for the same application program and application context.
[0046] The presently disclosed embodiments are therefore considered in all respects to be illustrative, and not restrictive. The scope of the invention is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalence thereof, are intended to be embraced herein. | A database is used to store user interface state information. The database is accessed by a key having a service ID field, a caller ID field, and a caller context ID field. The caller context ID is used to identify the context in the application program from which the user interface is called. In this manner, the system can differentiate between calls from different portions of the application program which can have different user expectations of the desirable user interface state. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a microstrip antenna designed for use on a weapons system. More specifically, the present invention relates to a cylindrical shaped microstrip antenna array which operates at a frequency of 231 MHz±400 KHz and which is adapted for use on a weapons system such as a missile or other projectile.
[0003] 2. Description of the Prior Art
[0004] A microstrip antenna operates by resonating at a frequency. The conventional design uses printed circuit techniques to put a printed copper patch on the top of a layer of dielectric with a ground plane on the bottom of the dielectric. The frequency of operation of the conventional microstrip antenna is for the length of the antenna to be approximately a half-wavelength in the microstrip medium of dielectric below the patch and air above the patch.
[0005] Another type of microstrip antenna is a quarter-wavelength microstrip antenna which is similar to the half wavelength microstrip antenna except the resonant length is a quarter wavelength and one side of the antenna is grounded.
[0006] There is currently a need to provide an antenna which is similar in design and operates in a manner virtually identical to the quarter-wavelength microwave antenna and also provides for a significant increase in bandwidth.
[0007] This microstrip antenna is to be used on a weapons system or projectile such as a missile. There is also a requirement for a frequency of operation for the antenna of 231 MHz±400 KHz.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes some of the disadvantages of the past including those mentioned above in that it comprises a highly effective and efficient microstrip antenna designed to transmit telemetry data from a HARM missile at a frequency of 231 MHz±400 KHz. The microstrip antenna comprising the present invention is configured to wrap around a projectile's body without interfering with the aerodynamic design of the projectile.
[0009] The microstrip antenna of the present invention has three identical conformal antenna elements equally spaced around the circumference of a projectile's body. The antenna has an operating frequency of 231 MHz±400 KHz, and is designed for use with the HARM missile to transmit Telemetry data.
[0010] Each of the three identical antenna elements includes a dielectric printed circuit board, a rectangular shaped radiating element mounted on a top portion of the printed circuit board, and a ground plane mounted on the bottom portion of the printed circuit board.
[0011] A plurality of copper wire electrical shorts, i.e. copper vias are provided along one edge of the radiating element to connect the radiating element to the ground plane. The copper electrical shorts are equally spaced apart and run from the midpoint of radiating element to the one corner of the radiating element. The unique placement and configuration of the vias allows for a substantial increase in the width of the radiating element and an increase in the bandwidth to ±400 KHz about the center frequency of 231 KHz.
[0012] To achieve the proper polarization, each of the three antenna elements are driven with an equal amplitude signal and a progressive 120 degree phase shift. A three way power divider is used to obtain the equal amplitude signals and the progressive 120 degree phase shift is obtained by proper length of the feed lines from the power divider to each of the three antenna elements.
[0013] Each antenna element includes a tuning screw which is used to fine tune the operating frequency of each of the antenna elements of the microstrip antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of the partially shorted microstrip antenna comprising the present invention which includes the three identical antenna elements of the microstrip antenna;
[0015] FIG. 2 is an end view of the microstrip antenna of FIG. 1 ;
[0016] FIG. 3 is a top view of one of three identical microstrip antenna elements including the radiating patch for one of the three identical microstrip antenna elements for the microstrip antenna of FIG. 1 ;
[0017] FIGS. 4A and 4B are side view illustrating the copper wire electrical shorts, i.e. copper vias which are provided along one edge of the radiating element to connect the radiating element to the ground plane of each the antenna elements of the microstrip antenna of FIG. 1 ;
[0018] FIG. 5 is a side view illustrating the stringing technique to fabricate the copper electrical shorts/vias of FIG. 4 ;
[0019] FIG. 6 is a bottom view of one of three identical microstrip antenna elements including the ground plane and tuning screw for one of the three identical microstrip antenna elements for the microstrip antenna of FIG. 1 ;
[0020] FIG. 7 is a view illustrating the electric fields generated by the radiating element for each of the antennas elements of the microstrip antenna of FIG. 1 ; and
[0021] FIGS. 8A and 8B are antenna performance plots for the one of the antennas elements of the microstrip antenna of FIG. 1 ;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] Referring to FIG. 1 , there is shown a perspective view of a microstrip antenna array 20 which includes three identical conformal antenna elements 22 , 24 and 26 which are mounted on the outer surface of a missile 28 , shown in phantom in FIG. 1 . Each of the three antenna elements 22 , 24 and 26 are positioned every 120 degrees around the outer surface of missile 28 in the manner illustrated in FIG. 1 . FIG. 2 is an end view of the microstrip antenna 20 of FIG. 1 illustrating the three identical antenna elements 22 , 24 and 26 of FIG. 1 .
[0023] The present invention which comprises antenna array 20 includes the three antenna elements 22 , 24 , and 26 , shown in FIGS. 1 and 2 is designed for use with the HARM missile. The HARM missile is a supersonic air-to-surface missile designed seek and destroy enemy radar-equipped air defense systems. The Navy and Marine Corps F/A-18 and EA-6B have the capability to employ the AGM-88 HARM (high-speed anti-radiation missile). The Harm missile operates in the P band.
[0024] Referring to FIGS. 1 , 2 , 3 , and 4 A, each of the antenna elements 22 , 24 and 26 includes a dielectric printed circuit board 30 fabricated from a plurality of high frequency laminates 32 and 34 (shown in FIG. 4A ), part number RT/duroid 6002, commercially available from Rogers Corporation of Rogers, Connecticut. The dielectric laminates/layers 32 and 34 selected for each element antenna 20 has overall dimensions of 9.171 inches by 7.312 inches. The thickness of circuit board 30 is about 0.210 inches. RT/duroid 6002 is a microwave material with low loss and a low dielectric constant providing for excellent electrical and mechanical properties at microwave frequencies. It should be understood that the circuit board 30 can be fabricated from three or more layers of a dielectric laminate material such as RT/duroid 6002.
[0025] Each microstrip antenna element 22 , 24 and 26 of antenna 20 also has an outer cover 36 which is an environment protection laminate fabricated from Rogers Corporation Duroid 5870 high frequency laminate. The thickness of the outer cover 36 is about 0.125 inches.
[0026] Each of the microstrip antenna elements 22 , 24 and 26 of antenna 20 includes a generally rectangular shaped copper radiating element or patch 40 which has overall dimension of 8.176 inches in length and a width of 5.304 inches. The copper radiating patch 40 for each microstrip antenna element 22 , 24 and 26 of antenna 20 is mounted on the upper surface of the circuit board 30 for each antenna element 22 , 24 and 26 . Copper plating is used to fabricate the copper radiating patch 40 .
[0027] Each of the microstrip antenna elements 22 , 24 and 26 of antenna 20 also includes a generally rectangular shaped copper ground plane 42 . The copper ground plane 42 for each element 22 , 24 and 26 is mounted on the bottom surface of the circuit board 30 for each antenna element 22 , 24 and 26 .
[0028] A plurality of copper wire electrical shorts 44 shown in FIG. 3 , i.e. copper vias are provided lengthwise along one edge 46 of radiating element 40 to connect the radiating element 40 to the ground plane 42 of each antenna element 22 , 24 and 26 . The copper wire electrical shorts/vias 44 are equally spaced apart and run from the midpoint of radiating element 40 to the one corner of the radiating element 40 .
[0029] As seen in FIG. 3 , the radiating element 40 has sixteen vias 44 , with each via 44 being spaced apart wire center to center by 0.271 inches from an adjacent via. The placement of vias 44 along lower edge 46 of the radiating element 40 is from the midpoint of radiating element 40 to lower right corner of radiating element 40 .
[0030] As shown in FIG. 3 , current flow in the radiating element is from the upper or opposite edge 48 and left side edge 50 of radiating element 40 to through the vias 44 to the ground plane 42 . A plurality of arrows 52 indicating the direction and pattern of current flow on the radiating element 40 . The electrical feed 51 for the radiating patch 40 each antenna element 22 , 24 and 26 is located near the lower edge 46 of radiating patch 40 at the center of the radiating patch 40 .
[0031] Antenna 20 receives three equal amplitude RF electrical signals which are provided to the feeds 50 for the microstrip antenna elements 22 , 24 and 26 . The RF electrical signals are obtained from a commercially available three way power divider(not illustrated). The power divider is electrically connected to each of the three antenna elements 22 , 24 and 26 by electrical transmission lines. The electrical transmission lines, which are electrical cables having different lengths, are configured to provide for a 120 degree progressive phase shift. Thus, when the signal to antenna element 22 is 0 degrees, the signal to antenna element 24 will be 120 degrees and the signal to antenna element be 240 degrees.
[0032] Referring to FIGS. 1 and 6 , there is shown a tuning screw 54 which is used to fine tune the operating frequency of each antenna elements 22 , 24 and 26 of microstrip antenna 20 . The tuning screw 54 for each antenna element 22 , 24 and 26 is located within the ground plane 42 in proximity to the corner 56 of ground plane 42 where edges 48 A and 50 A of ground plane 42 meet. A slot 58 is provided within the tuning screw 54 . The slot 58 within each antenna element 22 , 24 and 26 allows a user to use a screw driver to fine tune the antenna element 22 , 24 and 26 to the desired operating frequency. The use of tuning screw eliminates the tuning tabs within each antenna element 22 , 24 and 26 which have also been used to fine tune antenna elements to a desired operating frequency.
[0033] Referring to FIG. 7 , there is shown a general directional pattern for the electric field generated by each of the antenna elements 22 , 24 and 26 of antenna 20 . This electric field is represented by electric field vectors 59 generated along edge 50 and electric field vectors 60 generated along edge 62 .
[0034] Referring to FIGS. 3 , 4 A and 4 B, there is shown a plurality of copper wire electrical shorts 44 , i.e. copper vias 44 which are provided along one edge of the radiating element and through the dielectric printed circuit board 30 (as shown in FIGS. 4A and 4B ) to connect the radiating element 40 to the ground plane 42 (shown in FIG. 6 ). The copper electrical shorts 44 are equally spaced apart and run from the midpoint of radiating element 40 to the one corner of the radiating element 40 . The unique placement and configuration of the vias 44 allows for a substantial increase in the width of the radiating element 40 and an increase in the bandwidth to ±400 KHz about the center frequency of 231 KHz.
[0035] As shown in FIG. 5 , a single wire copper wire 64 is strung through a plurality of openings 66 in the dielectric printed circuit board 30 is used to fabricate the copper electrical shorts/vias 44 for connecting the radiating element 40 to the ground plane 42 of each of the antenna elements 22 , 24 and 26 . The copper wire 64 is then pulled through the openings 66 until the copper wire 64 is flush and in contact with radiating element 40 and the ground plane 42 (as shown in FIG. 4A ). Solder can then be used to secure the radiating element 40 and copper wire 64 to the ground plane 42 .
[0036] It should be noted that there are openings drilled into the radiating element 40 and the ground plane 42 which align with the openings 66 drilled into the dielectric printed circuit board 30 .
[0037] Utilizing the stringing technique illustrated in FIGS. 4A , 4 B and 5 , saves a considerable amount time and money in fabricating the vias 44 for each of the antenna elements 22 , 24 and 26 of antenna 20 . Using the prior technique of fabricating each separately by placing a separate copper wire in each opening 66 in the dielectric printed circuit board 30 and then soldering the wire to the ground plane and the radiating element required several hours of intensive labor and substantially raised the fabrication cost of the antenna.
[0038] Referring to FIGS. 8A and 8B , there is shown antenna performance plots for one of the antenna elements of the microstrip antenna 20 of FIG. 1 . The antenna performance plots 70 , 72 and 74 of FIG. 8A illustrate horizontal polarization for one antenna element 22 , 24 or 26 of the microstrip antenna 20 of FIG. 1 . The antenna element was mounted on a ten inch diameter tube which simulated a missile, and measurements were made looking perpendicular into the missile. The antenna performance plots 80 , 82 and 84 of FIG. 8A illustrate horizontal polarization for one antenna element 22 , 24 or 26 of the microstrip antenna 20 of FIG. 1 . The plots of FIGS. 8A and 8B show that the microstrip antenna has excellent cross polarization performance.
[0039] From the foregoing, it is readily apparent that the present invention comprises a new, unique, and exceedingly useful microstrip antenna adapted for use on projectiles such as the harm missile, which constitutes a considerable improvement over the known prior art. Many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. | A partially shorted microstrip antenna configured to wrap around a projectile's body without interfering with the aerodynamic design of the projectile. The microstrip antenna has three identical conformal antenna elements equally spaced around the circumference of the projectile's body. The antenna has an operating frequency of 231.0 MHz±400 KHz. Each antenna element includes a plurality of vias which operate as a partial short connecting the radiating element to the ground plane and thereby increase the bandwidth of the antenna element. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 08/444,081 filed May 17, 1995, (now abandoned) which was a continuation of application Ser. No. 08/052,777, filed Apr. 26, 1993 (now abandoned).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved annular seal assembly which has particular application to sealing across annular spaces between facing cylindrical surfaces, such as the annular seal between the exterior of a hanger and the surrounding housing in a well.
2. Description of the Related Art
Prior annular seal assemblies have used annular seals having a U-shaped section with expander rings positioned in the space between the two legs of the ring to, either mechanically or in response to pressure, urge the expander ring inwardly of the legs to wedge the legs outward into sealing engagement with the facing cylindrical surfaces to effectively seal across the annulus between such surfaces.
U.S. Pat. No. 3,288,472 to B. J. Watkins discloses a metal seal which includes a U-shaped ring having legs extending axially away from an annular base and tapering outwardly at an angle preferred to be approximately 2°. This provides an interference fit for the legs of the seal ring with respect to the surfaces against which they are to seal. U.S. Pat. Nos. 3,378,269; 4,766,956; and 5,031,923 all disclose similar metal seals which include annular metal seal rings having a U-shaped section and having an interference fit with the surfaces against which they are to seal.
U.S. Pat. No. 2,075,947 discloses a pipe joint which includes a soft metal seal ring having a pair of upwardly extending spaced legs and a pair of downwardly extending spaced legs with an annular hard metal wedging member positioned between each pair of legs and energized by the nut to be forced between the legs to urge the legs radially into sealing engagement with the outer and inner annular cylindrical surfaces against which they are to seal. Other prior art patents disclosing similar structures include U.S. Pat. Nos. 3,915,462; 2,766,956; 4,900,041 and 5,044,672.
U.S. Pat. No. 3,326,560 to M. D. Trbgovich discloses an adjustable annular seal which has a V-shape and includes a split ring expander positioned between the diverging legs of the seal ring with suitable shoulders containing and urging the seal ring and expander together so that the expander urges the legs of the seal ring radially into sealing engagement with the annular walls against which it is to seal. The expander is described as being substantially coextensive in length with the sealing ring and being resiliently compressible for urging the walls (legs) apart to compensate for wear of the sealing portions. It is stated that the expander should be constrained from moving into engagement with the sealing surfaces and thus should not act as a sealing element itself. It should be noted that this patent specifically suggests the use of a split ring as the expander, it does not suggest any particular advantages. It could be that the advantage was that it was easier to install than a solid ring since it had to be assembled within the seal ring and in the space bounded by the sealing surfaces and the shoulders which urge the expander into the seal ring so that its sealing legs are urged toward the sealing surfaces.
The Lee Company manufactures hydraulic inserts or plugs which are adapted to be inserted into an opening to close and seal the opening. The Lee plug is cylindrical with a tapered reamed hole part way through its center and numerous small grooves in its exterior surface. It is used with a tapered reamed hole part way through its center and numerous small grooves in its exterior surface. It is used with a tapered pin which is driven into the reamed hole until the plug and the pin are flush with each other. The pin wedges the tapered sides of the plug into biting engagement with the surrounding material forming independent seals and retaining rings. This plug does not have any use for sealing across an annulus.
SUMMARY OF THE INVENTION
The seal assemblies and associated methods of the present invention provide for improved sealing qualities by permitting substantially uniform metal-to-metal sealing. The invention also permits mechanical setting of the seal assembly without requiring excessive setting load forces. The seal assembly is then energized using fluid pressure.
An improved seal assembly is described which has an annular metal sealing body having at least one U-shaped channel cross-section and a plurality of segments positioned within the channel. The legs of the channel are connected with an annular base and extend generally perpendicularly to the base. The sealing body is made of a relatively soft steel and the segments are made from a ring of harder steel which is cut into segments by a suitable cutting method which has a minimum kerf. On installation between the surfaces against which it is to seal, the legs are forced toward the segments and the segments transmit this force to the other leg so that they are both in sealing engagement with their respective sealing surfaces. The transmission of this force by the segments is not dependent on overcoming the substantial hoop stresses which would be present in a continuous energizing ring since the ring has been cut into segments. Hoop stress is also known as circumferential stress or tangential stress. The segments are cut from the ring with a minimum kerf at each cut so that they substantially fill the space between the legs completely around the circumference of the sealing body. The segments present radial faces which adjoin the legs of the sealing body. The radial faces include one or more raised ribs which contact the inner surfaces of the legs of the body.
An offset placement of the raised ribs on the segments from those on the outer surfaces of the legs of the sealing body causes radial spring loading to occur within the seal assembly through elastic deformation in the seal body. This spring loading gives the seal assembly greater radial compliance. The increased compliance permits a lower installation load for the seal assembly and causes it to be greatly accommodating to radial movement of the inner and outer annular members which may occur due to high pressure loading or thermal changes.
Methods are described for setting the seal assembly mechanically and then energizing it. Fluid pressure is introduced into the annular space to energize and improve the sealing ability of the seal assembly.
An object of the present invention is to provide an improved sealing assembly for sealing across an annulus which requires a minimum amount of setting load and provides improved sealing.
Another object of the present invention is to provide an improved annular sealing assembly for sealing across the annulus between the interior of a well member and the exterior of another well member in a well.
A further object of the present invention is to provide an improved annular sealing assembly for sealing across the annular space between the exterior of a well hanger and the interior of the well member into which the well hanger is landed.
Still another object is to provide an improved annular sealing assembly for sealing between two spaced apart sealing surfaces in which improved metal-to-metal sealing is provided and initial sealing is sufficient to retain sealing when pressure is supplied to the open end of the sealing ring.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention are hereinafter shown and explained with respect to the drawings wherein:
FIG. 1 is a partial sectional view of an improved seal assembly positioned between two tubular well members and showing its position immediately prior to being moved into its sealing position.
FIG. 2 is a partial sectional view of the apparatus shown in FIG. 1 but illustrating the sealing position of the seal assembly against the sealing surfaces of the two tubular well members. The inner member which has an external taper has been moved downward with respect to the outer member and the seal assembly.
FIG. 3 is a partial sectional view of another form of an improved seal assembly positioned between two tubular members immediately prior to being moved into a set condition. In this form of the invention, the seal assembly is carried by the inner member and is moved downwardly within the outer member which has a tapered inner surface which moves the seal assembly into a set condition.
FIG. 4 is a partial sectional view of the form of the invention shown in FIG. 3 with the seal assembly in a set condition.
FIG. 5 is a partial sectional view of another form of the improved seal assembly positioned between two tubular members and in an unset condition.
FIG. 6 is a partial sectional view of the form of the seal assembly shown in FIG. 5 and in a set condition.
FIG. 7 is a partial sectional view of another form of a seal assembly constructed in accordance with the present invention which provides a seal between opposing faces of joined flanges.
FIG. 8 is a cross-sectional cut-away view of an exemplary bidirectional double sealing ring assembly constructed in accordance with the present invention.
FIG. 9 is a cross-sectional cut-away view of a unidirectional double sealing ring assembly constructed in accordance with the present invention.
FIG. 10 is a cut-away view of the seal assembly of FIG. 8, showing a plurality of segments retained within the seal body.
FIG. 11 is a cross-sectional cut-away view of the seal body of the seal assembly of FIGS. 8 and 10.
FIG. 12 is an enlarged cross-sectional cut-away view of the seal assembly of FIGS. 8 and 10 after having been mechanically set.
FIG. 13A is a cross-sectional cut-away view of a seal assembly carried on an internal member and in an unset condition.
FIGS. 13B-13D depict setting of the seal assembly shown in FIG. 13A.
FIG. 14A is a cross-sectional cut-away of an exemplary seal assembly in an unset condition.
FIG. 14B depicts the seal assembly of FIG. 14A after it has been mechanically set.
FIG. 14C depicts the seal assembly of FIGS. 14A and 14B after having been mechanically set and energized with fluid pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a preferred form of the seal assembly 10 of the present invention is shown carried between lower support ring 12 and upper sleeve 14. Inner cylindrical member 16 is disposed within the interior of an outer cylindrical member 18 with the seal assembly 10 supported thereon as shown. Upper sleeve 14 is releasably secured to inner member 16 by shear pins 20. Lower support ring 12 is supported on snap ring 22 mounted in groove 24 in the exterior of the portion of inner member 16 which is illustrated. The inner member 16 has a lower surface 26 extending above snap ring 22 to downwardly facing shoulder 28. The lower outer corner of shoulder 28 is beveled at 30 to allow ease of assembly of sealing ring assembly 10 thereon and surface 32 above bevel 30 is tapered upwardly and outwardly.
Surface 32 thus provides the wedging surface to cause the setting of sealing assembly 10 as it reaches the outer sealing surface 34 above surface 32. The lower support ring 12 has an external diameter to slide easily within the surface 36 of outer member 18 and a lower tapered outer surface 38 which is adapted to engage upwardly facing tapered seat 40. The interior of the lower portion of lower support ring 12 fits easily around the exterior of inner member 16 and has internal upwardly facing shoulder 42 with rim 44 extending thereabove to engage the lower portion of sealing ring assembly 10 and having a radial thickness to fit around sealing surface 34 of inner member 16.
FIG. 2 depicts the seal assembly 10 in its mechanically set condition so that the seal assembly provides a metal-to-metal seal against the sealing surface 34 on the exterior of inner member 16 and the sealing surface 36 on the interior of outer member 18. The ring assembly 10 has been placed into this set condition by downward movement of the inner member 16 with respect to the outer member 18 from the position depicted in FIG. 1 to the position depicted in FIG. 2. This movement occurs as a result of mechanical application of a setting load to the inner member 16. In wellbore applications, this setting load is typically applied to the inner member by a tool from the surface of the wellbore. As the lower support ring 12 lands on seat 40, further downward movement of inner member 16 results in shearing of the pin 20 so that the inner member 16 moves downward within the interior of rim 44. The tapered surface 32 is disposed downwardly through the seal assembly 10 to cause it to move to its mechanically set condition, the details of which are more clearly set forth with respect to the description of the structure of the seal assembly 10. An example of a preferable setting load is one which approximates or is slightly above the shearing load required to shear a pin or other member, such as shear pin 20 in FIGS. 1 and 2, in order to cause a tapered setting surface to be moved past the seal assembly. It is further pointed out that acceptable setting loads are currently considered to be on the order of 40,000-60,000 lbs.
In a modified form of the present invention shown in FIGS. 3 and 4, the seal assembly 10 is supported on an inner cylindrical member 50 between lower support ring 52 and upper support ring 54. Snap ring 56 is positioned in groove 58 on the lower exterior of inner member 50 to prevent lower support ring 52 from moving downward on inner member and snap ring 60 positioned in groove 62 on the upper exterior of inner member 50 to prevent upper support ring 54 from being forced upwardly on inner member 50. Outer member 64 includes a lower central bore 66; a slightly outwardly and upwardly tapered setting bore 68 thereabove; an outwardly and upwardly tapered bore 70 located above setting bore 68; and an upper straight bore 72 extending thereabove.
The downward movement of seal assembly 10 within outer member 64 is shown in the positions in FIGS. 3 and 4. In FIG. 3, the inner member 50 is moving downward within outer member 64 with the sealing ring assembly 10 approaching tapered setting bore 68. In FIG. 4, the inner member 50 has moved downwardly to the point that seal assembly 10 is in sealing engagement with lower central bore 66 and thus provides a metal-to-metal sealing engagement against the exterior of inner member 50 and against the interior of the outer member 64. This sealing engagement is hereinafter explained in greater detail.
A further arrangement for setting a seal assembly in accordance with the present invention is depicted in FIGS. 5 and 6 where exemplary seal assembly 10 is supported on an inner member 80, such as a hanger, by a lower cylindrical support 82. The support 82 is positioned in an annular channel 84 within the inner member 80. A cylindrical spacer 86 is located above the sealing ring assembly 10. The upper end 88 of the spacer 86 abuts a snap ring 90 which is seated in a groove 92 in the inner member 80. The lower end 94 of the spacer 86 contacts the seal assembly 10.
The outer member 96 features a lower, reduced diameter inner bore 98. Above the lower bore 98 is an upwardly and outwardly tapered intermediate bore 100 which leads to an expanded upper bore 102.
FIG. 5 depicts the seal assembly 10 located in the upper bore 102 in an unset condition. In FIG. 6, the inner member 80 has been moved downwardly with respect to the outer member 96 so that the seal assembly 10 is moved into the reduced diameter lower bore 98, thereby becoming mechanically set by the tapered setting surface presented by the intermediate bore 100.
Another form of the present invention wherein the improved sealing ring assembly may be used is illustrated in FIG. 7 wherein seal assembly 10 is positioned in face groove 110 in flange 112. Flange 112 is secured by cap screws or other suitable fastening means 114 to a structure having a bore therethrough, such as flange 116. Seal assembly 10 is initially positioned within groove 110 and as means 114 are tightened it is brought to its set condition in sealing engagement between the face of flange 116 and the bottom of groove 110.
Turning now to FIGS. 8, 10-12 and 13A-13D, the preferred exemplary seal assembly 10 of the present invention is now described in greater detail. The seal assembly 10 includes an outer seal body 120, best shown in FIG. 11, which is made of a relatively soft steel. The seal body 120 of the preferred embodiment presents an H-shaped cross-section wherein a central web flange 122 has two pairs of relatively parallel inner and outer leg members, 124, 125, respectively, extending generally perpendicularly from the flange 122 so that two cross-sectionally U-shaped channels 126 and 128 are formed on either side of the flange 122. The legs 124, 125 each present a first surface 130 which faces into the respective U-shaped channel 126, 128 which it helps define, and a second surface 132 which faces away from the channel. A pair of raised annular ribs 134, 136 is disposed on each of the second surfaces 132 of each leg 124, 125. The annular rib 134 is located further from the central flange 122 than rib 136. It presents an engagement face 134a and angled side faces 134b and 134c. Preferably, side face 134b is angled at approximately 30° while side face 134c is angled at approximately 45°. Rib 136 also presents an engagement face 136a and angled side faces 136b and 136c. However, both side faces 136b, 136c are preferably angled at approximately 45°.
The raised ribs 134, 136 define unraised annular bands 138, 140 and 142 located adjacent to the ribs 134, 136. The legs 124, 125 have less thickness along an unraised annular band 138, 140 or 142 than they have along a raised rib 134, 136.
A plurality of ring segments 144 are located within the U-shaped channels 126 and 128 of the seal body 120. Although there are at least two segments 144 in each of the channels, it is preferred that there be a greater number such as 12, 24 or 48. FIG. 10 shows 12 such segments 144 which are not connected to each another and are positioned adjacent to one another within a channel. The segments 144 substantially fill the entire circumference of the channels of the seal body 120. Each of the segments 144 is arcuately curved with generally the same curvature as that of the seal body 120. Preferably, the segments 144 are created by machining a solid ring into segments with a minimum kerf. The segments 144 are formed of a harder metal than that which forms the outer seal body 120 such that the segments 144 are substantially non-deformable.
It is preferred that the seal body 120 be formed of a metal or other material which is substantially softer than that which forms the segments 144 as well as that which forms the inner and outer members, such as 80 and 96. Currently, the best results have been obtained using a metal having a hardness of approximately 25-35 on the Rockwell hardness scale to form the segments 144, and a metal having a hardness of around 10 on that scale to form the seal body 120. The greater softness of the seal body 120 results in less scratching of inner and outer members, such as 80 and 96, from the setting of the seal. Such scratching is undesirable as it may result in fluid leakage along the scratches and defeat the effectiveness of a seal assembly.
As best shown in FIGS. 8 and 12, the segments 144 have a rectangular cross-section and present radial side surfaces 146 which are adapted to adjoin the channel-facing surfaces 130 of the legs 124, 125 of the seal body 120. The side surfaces 146 each present leg-contacting projections 148 which contact the channel-facing surfaces 130 on the legs 124, 125. These projections 148 are adjacent non-projected portions 150 of the side surfaces 146. When the segments 144 are assembled within the channels 126, 128, the projections 148 contact the channel-facing surfaces 130 at a point offset, or straddled, from the raised bands 134, 136 of the legs 124, 125. Preferably, the projections 148 contact the channel-facing surfaces 130 at a point corresponding to the location of one of the unraised annular bands 138, 140 and 142 on the second surface 132.
As illustrated in FIG. 10, the segments 144 are preferably aligned with each other within the annular channels 126, 128 so that a slight average gap 152 is present between the segments 144 after the seal has been energized. The presence of such a gap 152 between the segments permits fluid pressure to enter the annular channels 126, 128 within the seal body 120. The gap 152 should not be too great as too great a gap would cause weakness in the structure of the seal assembly 10. A preferred gap size would be approximately 0.5 mm.
In the forms of the present invention, improved sealing is provided without dramatic increases in the installation loads required for setting the sealing assembly. The use of ring segments 144 between the inner and outer legs 124, 125 provides for load transmission between the sealing ring legs during installation without having to overcome substantial hoop stresses which would be present if a solid ring were used in place of segments 144. Hoop stresses in a continuous version of the segments 144 would result in considerable resistance to radial expansion or contraction of the seal assembly during installation. The wedging for setting is provided by the tapered surfaces leading into one of the sealing surfaces which causes one of the legs 124 or 125 to be wedged toward the other leg and cause the segments to transmit the setting load to the other leg so that it is also initially loaded into sealing engagement with the sealing surface against which it is to seal.
As shown in FIG. 12, improved seal assembly 10 is in a set condition positioned between two generally parallel walls of inner and outer cylindrical members 160 and 162. As hereinafter described, seal assembly 10 is to provide an improved metal-to-metal seal between facing surfaces of such members. As may be seen, mechanical setting of the seal assembly 10 creates a spring-type loading within the legs 124, 125 through predominantly elastic deformation of the seal body 120. Such mechanical setting also establishes an indirect load path across the seal assembly 10 which makes the seal assembly 10 less sensitive and more compliant to variations in seal bore diameter, finished dimensions, and expansion and contraction resulting from changes in pressure and thermal changes. Projections 148 on the side surfaces 146 are loaded against the unbanded portions 138, 140, 142 of the legs 124, 125 and cause the unbanded portions 138, 140, 142 to become load-deflected and biased away from the segments 144. This biasing creates moments within portions of the legs 124, 125 through elastic deformation the softer metal of the seal body 120 which urge the banded portions 134, 136 against the adjacent surfaces of inner and outer members 160, 162. This spring loading creates a radially compliant metal-to-metal seal between the seal assembly 10 and each of the inner and outer members 160, 162.
FIGS. 13A-13D depict, in greater detail, a mechanical setting sequence for the exemplary seal assembly 10 in which the seal assembly 10 is being set between an inner cylindrical member 160 and an outer cylindrical member 162. The seal assembly 10 is carried on the inner member 160 between an upper collar 164 and a lower collar 166. The outer cylindrical member 162 features an expanded diameter bore 168, a tapered setting bore 170 and a reduced diameter bore 172. The seal assembly 10 is located within the expanded diameter bore 168 and is in an unset condition. In FIGS. 13B and 13C, the inner member 160 and the seal assembly 10 are moved downwardly with respect to the outer member 162 such that the seal assembly 10 is moved into and through the tapered setting bore 170. During this movement, setting of the ring assembly 10 occurs as the outer legs 125 are biased toward the inner legs 124 by the surface of the tapered setting bore 170. In FIG. 13D, the inner member 160 has been moved downwardly to the extent that the seal assembly 10 has been moved into the reduced diameter bore 172. In FIG. 13D, the seal assembly 10 is in a set condition.
Following mechanical setting, as described above, application of fluid pressure will energize a seal assembly constructed in accordance with the present invention. FIGS. 14A-14C depict mechanical setting and fluid pressure energization of a seal assembly 200 which, in this instance, is shown having a seal body 201 presenting a single U-shaped cross-section formed by the base 202 and inner and outer legs 204, 206, respectively, which are similar to legs 124 and 125 described earlier. Load-transmitting segments 207, having a cross-section similar to the segments 144 described earlier, are located within the channel 209 formed by the base 202 and legs 204, 206. The legs 204, 206 present raised bands 213, 215. It is pointed out that seal assembly 200 is useful for creating a unidirectional seal, or a seal which seals against fluid pressure which is applied from only one direction.
The seal assembly 200 is located within a straight bore 208 formed within a cylindrical outer member 210. It is noted that, for the sake of clarity, upper and lower collars or support members for the ring assembly 200 are not shown in FIGS. 14A-14C although, in practice, these would be present and may be similar to the collars or support members described elsewhere in this specification or which are otherwise known and used in the art. The inner cylindrical member 212 features a reduced diameter section 214, a downwardly and outwardly facing tapered setting surface 216, and an enlarged diameter section 218. In FIG. 14A, the ring assembly 200 is in an unset condition and located within the bore 208 adjacent the reduced diameter section 214 of the inner member 212. In FIG. 14B, the inner member 212 has been moved downwardly with respect to the outer member 210 so that the tapered setting surface is moved past the seal assembly 200 and the enlarged diameter section 218 is located adjacent the seal assembly 200. In this position, the seal assembly 200 is in a mechanically set condition, as described earlier, such that load is transmitted between the outer and inner members 210, 212 across the seal assembly 200 through the legs 204, 206 and the load-transmitting segments 207 and portions of the legs 204, 206 become spring loaded through elastic deformation. This selected elastic deformation of portions of the seal body permits the seal assembly 200 to be mechanically set using setting loads which are not excessively high. Further, sealing of the seal assembly 200 against passage of pressure is relatively efficient because the raised bands 213, 215 on legs 204, 206 provide for multiple sealing barriers (two in this case) against the sealing surfaces of both the outer and inner members 210, 212.
In FIG. 14C, fluid pressure has been increased within the bore 208 above the seal assembly 200 so that the fluid pressure is exerted toward the seal assembly 200 in the direction of arrow 220 in order to energize the seal assembly 200. Due in part to the presence of gaps (such as gaps 152 shown in FIG. 10) between the segments 207, fluid pressure is capable of entering and exerting an expanding influence upon the channel 209 of the assembly 200. As may be seen by comparison of FIGS. 14B and 14C, pressure energization of the seal assembly 200 results in the legs 204, 206 being urged into more secure engagement with the inner and outer members 210, 212.
Construction of the seal assembly 200, as with the other seal assemblies described herein, results in a substantially uniform seal across the sealing surfaces involved. Because gaps, such as gaps 152, are disposed about the entire circumference of the ring assembly 200, the ring assembly 200 will receive the pressurized loading in a relatively uniform fashion about its circumference. Further, the pressurized fluid may be communicated throughout the channel 209 via fluid passages 211 which are formed adjacent the non-projected portions of the segments 207. Fluid pressurization of these passages will also assist in urging the raised ribs of legs 204, 206 into tighter engagement with the outer and inner members 210, 212 each time pressure is applied in the direction of arrow 220.
A feature of the preferred seal assembly 10 described above and shown in FIGS. 1-6, 8, 10 and 13A-13D is that the seal assembly 10 is capable of reliably sealing against fluid pressure from either or both axial directions in the bore. Seal assemblies of this type have been found to seal properly against test pressure loads of approximately 17,500 psi.
In the foregoing described installations of the improved sealing assembly of the present invention, two rings have been used with the open ends of the U-shaped portions of the sealing ring facing in opposite directions. This type of double seal ring was described in detail with respect to FIGS. 8, 10-12 and 13A-13D. However, sealing ring assemblies may be constructed in alternative configurations, such as the stacked, unidirectional seal assembly 250 of FIG. 9, in which two seal bodies 252, 254 are stacked so that the base 256, 258 of each is disposed in the same axial direction. Also, a seal assembly may be formed of a single U-shaped channel cross-section, as was depicted in FIGS. 14A-14C. Further, while the invention has been herein shown and described in what is presently believed to be the most practical and preferred embodiment thereof, it will be apparent to those skilled in the art that many other modifications may be made to the invention described while remaining within the scope of the claims. | Methods and apparatus are described for improved sealing across an annular space between facing sealing surfaces. Methods for mechanically setting and pressure energizing sealing ring assemblies are also described. In one aspect, several sealing ring assemblies are described, each of which include an outer seal body formed of elastically deformable metal and having an annular base with a pair of legs extending from the base to form a channel. A plurality of predominately non-deformable segments are positioned between the legs. The use of segments substantially reduces detrimental hoop stress which would hinder effective setting of a seal between the inner and outer members. In preferred embodiments, the legs and the segments each present raised portions which are offset from each other. The offset arrangement of the raised portions permit the ring assembly to be mechanically set by radial spring loading through elastic deformation of portions of the seal body. The ring assembly is then further energized through increased fluid pressure within the annular space which enters the channel of the seal ring to urge the legs into tighter engagement with the inner and outer members. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to data processing systems and is more particularly concerned with systems which are suitable for operation in a multiprocessor configuration.
A multiprocessor system is one in which there is provided one or more processor modules, a common memory having one or more storage modules and one or more input/output modules, for the handling of data transfers between peripheral equipments and the memory, together with an intercommunication medium for the passage of information between the memory and processing and input/output modules.
In a multiprocessing environment each processing module may require exclusive use of areas of the common memory. Because of the asynchronous nature of the processing modules, two processing modules, may demand access to the same area of the memory simultaneously and it is common place to resolve this clash of store demands by utilising a queue technique which locks the store exclusively to a single processing module for the completion of its Read or Write cycle.
SUMMARY OF THE INVENTION
It is sometimes necessary for a processing module to write to the same area of the memory immediately after reading from that area and this requirement is termed a "Read and Hold" operation and the mechanism is the subject of the present invention. The Read and Hold mechanism causes the store to lock on to the demanding processing module until the subsequent write cycle releases the queue for the demands of the other processing modules. Failure of the Read and Hold mechanism could be catastrophic to system operation, therefore it is necessary to insure that the Hold mechanism is operating and it is further necessary that a failure becomes immediately known to the system.
An object of the present invention is to provide a Read and Hold mechanism which will function in the above mentioned manner.
According to the present invention there is provided a data processing system incorporating a plurality of processing modules and a common memory having a plurality of storage modules each processing module being connected to all storage modules by a separate highway bus for the accessing of each storage module for read, write or read-and-hold operations and the system is arranged such that each storage module returns to an accessing processing module a parity indication indicative of the address of the storage location accessed characterised in that each storage module includes means for inverting the parity indication to be returned to an accessing processing module in response to the next succeeding write operation following a read-and-hold operation.
BRIEF DESCRIPTION OF THE INVENTION
The description which is only one embodiment should be read in conjunction with the following drawings.
Of the drawings:
FIG. 1 shows a multiprocessor configuration.
FIG. 2 shows a block diagram of a processing module.
FIGS. 3a and 3b shows the signals used for read/write cycles.
FIG. 4 shows the read-and-hold mechanism.
FIG. 5 shows an alternative multiprocessor configuration.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 a multiprocessing configuration is shown. Processing modules PM1 and PM2 each have access to a common storage module SM by way of store access unit ACC. The access unit ACC controls entry to the storage module SM. It recognises addresses pertaining to the particular storage module SM and allocates successive store cycles to store demands on a first come first served basis, unless the Read and Hold mechanism is operational when the store is locked onto a particular accessing port. The access unit ACC also generates parity of both the address and data which it receives and returns a parity signal for comparison purposes, to the particular processing module PM1 or PM2 which originated the demand. If the storage module SM is free when a store demand is made by a processing module the demand is allocated immediate access to the storage module. If the storage module is busy subsequent demands are held in a queueing circuit and given access to the storage module in priority order. A typical access unit is more fully disclosed in U.S. Pat. No. 3,787,818.
Referring to FIG. 2 a block diagram of the processing module is shown. The symbols in the drawing represented by an ampersand enclosed within a circle represent AND gates which operate in such a manner that when all the inputs are in the logic "1" state the output is in the logic "1" state. Typically the processing module may be of the type disclosed in U.S. Pat. No. 3,787,813. The processing module PM includes a parallel internal highway MHW by way of which data is circulated between the processor registers PRS and the arithmetic unit AU. The processing module includes data-input gating GI which allows data on the store output leads OL1-OL24 of the Y BUS to be fed onto the internal highway MHW. The processing module also includes data-output gating GO which allows information on the internal highway MHW to be fed by way of store data input register SDIREG onto the X BUS. Each processing module is micro-program controlled by micro-program unit μPROG and some of the bus control signals activate the micro-program control unit whereas some of these control signals are generated by the micro-program unit. The processing module also includes an incoming parity circuit IPC and an outgoing parity circuit OPC.
X BUS
The 24 information leads IL1 to IL24 carry information from the active module i.e. processing module PM1 (FIG. 1) to the passive module i.e. storage module SM (FIG. 1). Both address words and data words share these signal paths during a write cycle whereas only address words use these leads during a read cycle. The control signal leads SIHCS carry control signal information from the active module to the passive module addressed. The control field is made up of the separate control functions, parity, command and bus valid. The single parity control lead PC carries an indication of the type of parity (i.e. odd or even) to be generated in the passive module. The three command wires CW control the operation (Read, Read and Hold, Write or Reset) required. The three wires are redundantly coded to protect against single bit errors in transmission. The relevant command codes are binary coded so that decimal one defines "Read", two defines "Read and Hold", four defines "Write" and seven defines "Reset". The "bus valid" lead BV controls the passive module's acceptance of any message transfer. Only when the active module driving a bus is switched on and operating within predetermined conditions will the "bus valid" signal enable the passive module to accept the other twenty-nine signal paths. Finally the timing lead TX carries a timing signal which indicates to the passive module addressed that the active module has set up a demand for access.
Y BUS
The 24 information leads OL1 to OL24 are used only on read operations to carry the data word read from the passive module to the active module. The response signal leads SOHCS carry response information from the passive module to the active module. The response section is made up of a timing wire together with five linearly coded signals known as "stored parity" SP, "accumulated parity", AP, "valid cycle" VC, "peripheral register busy" PRB and "peripheral status fault" PSF. The stored parity signal SP indicates the value of the parity bit returned from the passive module with the data word from the addressed location when a read operation is performed. The accumulated parity signal AP returns the accumulated parity check bit value, constructed as odd parity over the successive forward data and parity control wires, during one access. The valid cycle signal VC acknowledges to the active module the acceptance of the demand and the control code by the passive module during each cycle. The peripheral register busy signal PRB is used, by a peripheral equipment, to indicate to the active module that a "shared register" is busy. The peripheral status fault signal PSF is used by a peripheral equipment to indicate to the active device that a fault status condition has occurred within the peripheral equipment or its access unit. Finally, the timing lead TY carries a timing signal, generated by the passive module, to indicate to the active module that a demand for access has been accepted, or that a clear-down sequence has been entered.
FIGS. 3a and 3b show the read and write transfer sequences which are initiated by an active module but are synchronised from the passive interface to provide a "full handshake" transfer operation. Referring firstly to FIG. 3a the read sequence will be considered.
The read sequence is used by an active module when one 24 bit data word is required to be selected from the "memory". The "memory" not only includes the individual memory locations in the storage modules but also the administration registers in the access unit. The required address is forwarded on leads IL1 to IL24 of FIG. 2 by the active module to the passive module and the data word addressed is then returned by the passive module to the active module.
FIG. 3a shows the states of the timing, control and information wires in the X direction, and the states of the timing, response and information wires in the Y direction during a read operation. A READ operation begins when an address is placed on the X going information wires together with the READ control signal. The X going timing wire, TX is raised or marked and is maintained in that condition until either a timeout period is exceeded or there is a response from the accepting-end. The accepting-end responds by raising or marking the Y timing wire, TY together with markings on the requisite response wires. If the accepting-end has detected an invalid control signal, the valid cycle response wire, VC will be at the quiescent condition at this point in time. The accumulated parity wire AP will indicate the parity of the forwarded address, which has been received at the passive module. The accepting-end next lowers the Y timing wire, TY and this indicates that the addressed data has been placed on the Y information wires and will remain valid for a defined period. Finally, the X timing wire, TX is lowered.
The write sequence is used by an active module when one 24 bit data word is required to be stored at a defined "location" in the "memory". The address of the required "location" is forwarded by the active module and after it has been accepted by the passive module the data word to be written is forwarded.
FIG. 3b shows the state of the timing control and information wires in the X direction and the states of the timing, response and information wires in the Y direction, during a WRITE operation. A WRITE operation begins when an address is placed on the X going information wires together with the WRITE control signal. The X timing wire, TX is raised and is maintained in that condition until either a timeout period is exceeded or there is a response from the accepting-end. The accepting-end responds by raising the Y response and timing wires. If the accepting-end has detected an invalid control signal, the valid cycle wire, VC will be at the quiescent condition at this point in time. The accumulated parity wire AP will indicate the parity of the forwarded address which has been generated at the passive module. The initiating end next lowers the X timing wire, TX applies the data word to be written to the X information wires and raises the X timing wire, TX. The accepting-end responds by lowering the Y timing wire, TY. If the accepting-end has detected an invalid control signal, or a peripheral-timeout, the valid cycle wire, VC will be at the quiescent condition at this point in time. The accumulated parity wire AP will contain the combined parity over the forwarded address and data word which has been generated by the passive module.
The read and hold sequence is identical to the READ operation except that the "READ and HOLD" signal is placed on the X control wires. The access unit recognises this code and locks the access unit so that any other accesses attempted on other inlet ports are not accepted until the "hold" condition is terminated. A subsequent WRITE or RESET operation on the same bus to the same unit resets this condition. If one of these operations is not performed within ten μsecs the access unit will "time out" and release automatically.
The reset sequence begins when an address is placed on the X going data wires together with the reset control signal. The X going timing wire, TX is raised and is maintained in that condition until either a timeout period is exceeded or there is a response from the accepting-end. The accepting-end responds by raising the Y going timing wire, TY. If the accepting-end has detected an invalid control signal, the valid cycle wire VC will be at the quiescent condition at this point in time. The accumulated parity wire AP will indicate the parity of the forwarded address which has been generated at the access wire. The initiating end next lowers the X going time wire, TX and this causes the accepting-end to lower its Y going timing wire, TY in turn. The Reset control signal causes the passive module's access unit to release any previous hold condition to allow access on other inlet ports.
The invention will be more readily understood with reference to FIG. 4, which shows the Read and Hold mechanism when processing module 1 PM1 initiates a Read and Hold command. The D-type toggle operates in such a manner that information designated D, on the device is transferred to the Q output on the positive edge of the clock pulse designated CP on the device.
Each processing module contains the following, and in particular processing module PM1 contains a parity generator PAR1 typically of the SN74180 type manufactured by Texas Instruments Limited, Invert parity circuit IPAR1 a comparison circuitry, COMP and a fault generating means, FLT. The access unit ACC contains a Read and Hold memory toggle RAH, a parity generator PAR2 typically of the SN74180 type manufactured by Texas Instruments Limited and invert parity circuit IPAR2. The invert parity circuits IPAR1 and IPAR2, only invert on Write operations following a Read and Hold operation and can be Exclusive OR arrangements. The comparator circuit COMP may also be an Exclusive OR arrangement.
Consider processing module PM1 initiating a store demand together with a Read and Hold command. The store demand and the Read and Hold command are transferred by way of the BUS to the Access unit ACC associated with the particular storage module SM. The Read and Hold command sets the Q output of toggle RAH in the access unit ACC to the logic "1" state at the time of the store demand signal, which indicates to the Access Unit ACC that a Read and Hold operation is in progress. The Q output of toggle RAH at this time inhibits the invert parity circuit IPAR2. Processing module PM1, sends by way of the BUS, the address information which depicts the area of storage from which data is to be read, and the parity generator PAR1 constructs a parity digit across the successive 24 address bits to indicate ODD parity. The ODD parity signal is forwarded through the invert parity circuit IPAR1 which only inverts when the associated write cycle is performed.
The output of the invert parity circuit IPAR1, is utilised by processing module PM1, to indicate the expected return parity which the processing module will receive from the access unit ACC over the BUS. Processing module PM1 is programmed to generate a store demand together with a Write command, after the Read and Hold command, which are forwarded to the access unit ACC by way of the BUS.
The Write command resets toggle RAH at the time of the store demand signal, thereby removing the "Read and Hold operation in progress" signal from the Q output of toggle RAH, and enables invert parity circuit, IPAR2 to invert parity. The output of invert parity circuit, IPAR2 is indicative of the parity constructed from the Write operation following a Read and Hold operation. The address of the particular area of the storage module SM in which the new data is to be written will be the same address as the previous Read operation. The parity generator PAR2 constructs a parity digit across the successive address bits/data bits, to indicate ODD parity. This parity digit will be considered hereafter to be a parity indication indicative of the address of the storage location accessed. The Write command enables invert parity circuit IPAR1 and allows the invert parity digit constructed during the Read operation indicative of the expected return parity to the comparator circuit COMP. Invert parity circuit IPAR2 also forwards the inverse parity digit indicative of the Write operation following a Read and Hold operation by way of the BUS to the comparator circuit COMP, which examines both signals. If the Read and Hold mechanism functioned satisfactorily both parity signals will always be identical and the fault circuit FLT will not be activated. The parity signals will be dissimilar if the address information was corrupted during transfer or if the Read and Hold mechanism failed, and the fault circuit FLT would be activated and processing module PM1 would enter its recovery sequence as described in U.S. Pat. specification No. 3,814,919.
If, after the Read operation was complete and during the time storage module was waiting for the following Write operation another processing module attempted to access the store with a Read, Write or Read and Hold command it would be caused to enter its recovery sequence since it would not be expecting inverted parity.
The above description is of one embodiment of the invention only and is not intended to limit the scope of the invention. It will be understood by those skilled in the art that the Read and Hold check mechanism may be extended beyond the processing configuration of FIG. 1 to include an intervening multiplexer MPX, FIG. 5. The Multiplexer Access unit ACC MPX functions in an identical manner to the store access unit ACC one resolving clashes of store demands between processing module 1 PM1 and Processing Module 2 PM2 while the other resolves store demand clashes between the multiplexer MPX and processing module 3 PM3. The multiplexer is transparent to the Read and Hold command and locks onto the commanding processing module and forwards the command to the next stage. It also releases its queue at the following access and returns the inverse parity from the proceeding to the succeeding stage. The Read and Hold mechanism can therefore be applied to many stages of multiplexing ensuring the security of the particular area of store addressed of the storage module, SM during a Read and Hold cycle. | Each processor in the system is provided with a processor bus over which access to all storage and peripheral equipments is gained. Each access is performed as an address read or write operation. However, under certain circumstances it is necessary to perform a "read-and-hold" operation when accessing a data word which is to be modified. Typically, entries in the master capability table fall into such a category where the data word, while being modified, must not be accessed by any other processor. In such a read-and-hold operation it is vital that the store accessed is held throughout the period of the read-and-hold operation. This facility is obtained by incorporating parity inverting arrangements in each access unit and each processor so that the parity for a read-and-hold operation is inverted. A failure of the hold facility would be detected by the interrogating processor since a parity failure would be observed at the end of the operation. The detection of parity failure causes the automatic entry into fault-interrupt arrangements. | 6 |
TECHNICAL FIELD
Disclosed embodiments herein relate generally to solder bumps for providing electrical and mechanical bonds between substrates, and more particularly to an intermediate IC chip solder bump structure, a finished IC chip solder bump structure, and method of manufacturing the same.
BACKGROUND
The packaging of integrated circuit (IC) chips is one of the most important steps in the manufacturing process, contributing significantly to the overall cost, performance and reliability of the packaged chip. As semiconductor devices reach higher levels of integration, packaging technologies, such as chip bonding, have become critical. Packaging of the IC chip accounts for a considerable portion of the cost of producing the device and failure of the package leads to costly yield reduction.
As semiconductor device sizes have decreased, the density of devices on a chip has increased, along with the size of the chip, thereby making chip bonding more challenging. One of the major problems leading to package failure as chip sizes increase is the increasingly difficult problem of thermal coefficient of expansion (TCE) mismatches between materials leading to stress buildup and consequent failure. For example, in flip-chip technology chip bonding is accomplished by means of solder bumps formed on under bump metallization (UBM) layers overlying an IC chip bonding pad where, frequently, improper wetting (bonding) between the solder and UBM layers may lead to a bond not sufficiently strong to withstand such stresses.
In many cases it is necessary to repackage the chip after a package failure, requiring costly detachment of the chip from the package and repeating the chip bonding process in a new package. Some chip bonding technologies use a solder bump attached to a contact pad (the bonding pad) on the chip to make an electrical (and somewhat structural) connection from the chip devices to the package substrate. For example, C4 (Controlled-Collapse Chip Connection) is a means of connecting semiconductor chips to substrates in electronic packages. C4 is a flip-chip technology in which the interconnections are small solder balls (bumps) on the chip bonding pads. Since the solder balls form an area array (a “ball grid array” (BGA)), C4 technology can achieve a very high-density scheme for chip interconnections. The flip-chip method has the advantage of achieving a very high density of interconnection to the device with a very low parasitic inductance.
Solder bumps may be formed by, for example, vapor deposition of solder material over layers of under bump metallization (UBM) layers formed on the bonding pad. In another method, the layers of solder material may deposited by electro-deposition onto a seed layer material deposited over UBM layers formed on the bonding pad. In yet another method, solder bumps may be formed by a solder-paste screen-printing method using a mask (stencil) to guide the placement of the solder-paste. Typically, after deposition of the solder materials, for example, in layers or as a homogeneous mixture, the solder bump (ball) is formed after removing a photoresist mask defining the solder material location by heating the solder material to a melting point (a “reflow” process) such that a solder ball is formed with the aid of surface tension. Alternatively, a solder bump may be formed within a permanent mask made of photoresist or some other organic resinous material defining the solder bump area over the bonding pad. Because of the importance of the solder bumps/balls in such flip-chip techniques, improvements in processes used to form the solder balls on the IC chips are continuously being pursued.
BRIEF SUMMARY
Disclosed herein is a method of manufacturing a solder bump on a semiconductor device. In one embodiment, the method includes creating a bonding pad over a semiconductor substrate, and placing a mask layer over the substrate and the bonding pad. The method also includes forming an opening in the mask layer having a primary solder mold and at least one secondary solder mold joined with the primary mold, where the opening exposes a portion of the bonding pad. In this embodiment, the method further includes filling the primary solder mold and the at least one secondary solder mold with solder material to form corresponding primary and at least one secondary solder columns in electrical contact with the bonding pad. The method also includes removing the mask layer after the filling of the solder molds with the solder material. The method still further includes reflowing the solder material to form a primary solder bump from the solder material of the primary solder column and at least a portion of the solder material from the at least one secondary solder column through cohesion of the solder material from the at least one secondary solder column to the primary solder column when melted.
In another aspect, a solder bump structure is disclosed that is formed on a bonding pad of a first substrate for electrically and mechanically coupling the first substrate to a bonding pad of a second substrate. In one embodiment, the structure includes a primary solder bump comprising a volume of solder material and having a first height and a base perimeter defined by a nadir. In addition, in this embodiment, the solder bump structure further includes at least one secondary solder bump comprising a volume of solder material having a second height less than the first height, the secondary solder bump adjacent the primary solder bump and metallurgically adjoined thereto at the nadir.
In yet another aspect, an intermediate structure is disclosed. In one embodiment, the intermediate structure includes a primary solder column comprising primary solder material and configured to electrically contact a bonding pad on a semiconductor substrate. Also in this embodiment, the intermediate structure includes at least one secondary solder column comprising secondary solder material in electrical contact with the primary solder column, where the at least one secondary column has a height and volume less than a height and volume of the primary solder column. In addition, in this embodiment, the primary solder column is further configured to form a primary solder bump comprising the primary solder material and at least a portion of the secondary solder material through cohesion from the at least one secondary solder column when the intermediate structure undergoes a reflow process.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the principles disclosure herein, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIGS. 1A–1E illustrate an exemplary conventional process for forming a solder bump on a semiconductor chip shown through cross section views of a IC chip bonding pad area; and
FIGS. 2A–2F illustrate one embodiment of an exemplary process for forming solder bump on a semiconductor chip in accordance with the disclosed principles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIGS. 1A–1E , illustrated is an exemplary conventional process for forming a solder bump on a semiconductor chip shown through cross section views of an IC chip bonding pad area. With reference to FIG. 1A , the process of creating the solder bumps begins after the chip bonding pad 10 , for example, Cu or Al formed by vapor deposition, has been formed on the surface of a semiconductor wafer 8 . After the bonding pad 10 is formed, a passivation layer 12 of, for example, silicon dioxide (SiO 2 ) is formed over the semiconductor device surface excluding a portion overlying the bonding pad 10 . Typically, one or more under-bump metallization (UBM) layers, e.g., layer 14 A, of from about 500 Å to about 5000 Å are then deposited over chip bonding pad 10 and a layer of photoresist 16 formed thereover, as shown in FIG. 1B .
The UBM layer 14 A may be, for example, a layer of titanium. The photoresist layer 16 is typically from about 10 to about 25 microns high. As shown in FIG. 1B , the photoresist layer 16 is photolithographically patterned and developed to form an opening 17 above the bonding pad 10 to expose a UBM layer, e.g., 14 A. Additional UBM layers may be formed within the mask opening 17 by, for example, an electroplating process or vapor deposition process forming, for instance, UBM layers 14 B and 14 C in FIG. 1C . Layers 14 B and 14 C may be, for example, layers of copper and nickel, respectively. UBM layers are typically formed over the bonding pad 10 to allow for better bonding and wetting of the solder material to the uppermost UBM layer 14 C adjacent to the solder material, and for protection of the bonding pad 10 by the lowermost UBM layer 14 A. A column of solder material 18 A may either be deposited in layers, for example, a layer of lead followed by a layer of tin, where the solder material layers are later formed into a homogeneous solder during a reflow (e.g., temporary melting) process for solder material. In other embodiments, the solder material may be deposited as a homogeneous solder material by vapor deposition or electroplating onto a “seed layer,” such as UBM layer 14 C.
Looking at FIG. 1D , after removal of the photoresist layer 16 , the UBM layer 14 A is etched through by an etching process, such as a reactive ion etch (RIE) process, to the underlying passivation layer 12 using the solder column 18 A as an etching mask to protect the underlying UBM layers 14 A, 14 B, and 14 C. The solder column 18 is then temporarily heated to a melting point (“reflow”) to form a solder bump 18 B over the UBM layer 14 C, as shown in FIG. 1E . After the reflow process, a homogeneous lead/tin solder bump is formed, for example, with composition ratios indicating weight percent, high lead alloys including 95 Pb/5 Sn (95/5) or 90 Pb/10 Sn (95/10) with melting temperatures in excess of 300° C. or eutectic 63 Pb/37 Sn (63/37) with a melting temperature of 183° C. The resulting solder bump 18 B is composed of a homogeneous material and has a well-defined melting temperature. For example, the high melting Pb/Sn alloys are reliable bump metallurgies that are particularly resistant to material fatigue.
A series of layers may be advantageously used to form the UBM layers. The uppermost UBM layer adjacent the solder bump supplies a wettable layer during reflow for the solder bump subsequently formed over the layers. For example, to form the plurality of UBM layers, some UBM systems may include, reciting the lowermost layer adjacent the bonding pad 10 first, chromium and copper (Cr/Cu), titanium and copper (Ti/Cu), and titanium-tungsten and copper (Ti:W/Cu), and titanium, copper, nickel (Ti/Cu/Ni). Since conventional bumps melt completely in the reflow soldering process of the flip-chip bonding technique to intimately contact the UBM layer, the UBM layer must be able to withstand thermal and mechanical stresses, and resist intermetallic phase formations. Thus, the quality of the UBM layers and wettability during reflow is critical to the reliability of the complete assembly. In addition, the UBM layers help define the size of the solder bump 18 B after reflow, and provide a surface that is wettable by the solder and that reacts with the solder to provide an adhesion bond with mechanical integrity and thereby acceptable reliability under mechanical and heat stresses. Furthermore, the UBM layers act as a barrier between the semiconductor device and the metals in the interconnections.
Turning now to FIGS. 2A–2F , illustrated is one embodiment of an exemplary process for forming a solder bump on a semiconductor chip in accordance with the disclosed principles. Looking first at FIG. 2A , illustrated is a solder bump area 200 early in the process for forming a solder bump to provide an electrical, and mechanical, bond between an IC chip and another component such as a printed circuit board. As shown, a typical solder bump area 200 includes a semiconductor substrate 205 with a bonding pad 210 formed on a portion thereof. Also often included is a passivation layer 215 typically constructed from dielectric material. If a passivation layer 215 is included, a portion of the layer 215 over the bonding pad 210 is removed, perhaps using conventional etching techniques, to expose a part of the bonding pad 210 . One or more UBM layers 220 may then be formed over the passivation layer 215 and in electrical contact with the bonding pad 210 . Although not required, a UBM layer 220 , provides a larger footprint on which to form the solder bump, and often using materials, such as titanium, that provide a stronger bond with the solder bump when formed.
Referring now to FIG. 2B , the same solder bump area 200 discussed above is shown, a little further into the bump formation process. Specifically, a masking layer 225 is placed over the surface of the solder bump area 200 so that certain portions of layers in the area may be removed, while others will remain. In an advantageous embodiment, the mask layer is a photoresist layer 225 that has been deposited over the solder bump area 200 . The photoresist layer 225 is then patterned and developed, typically using conventional photolithography techniques. The portions of the solder bump area 200 no longer masked by the photoresist layer 215 may then be removed, usually through etching. In the illustrated embodiment, a width of the UBM layer 220 is defined using the photoresist layer 225 and etching process.
Turning now to FIG. 2C , a top view of a different pattern is illustrated in the photoresist layer 225 , although in alternative embodiments this may be a different photoresist layer 225 than the layer illustrated in FIG. 2B . As shown, the photoresist layer 225 is patterned and developed so as to create distinct, but interconnected, openings (or “molds”) to be filled with solder material later in the manufacturing process. More specifically, a primary solder mold 230 is formed in the photoresist layer 225 proximate to the center of the solder bump area 200 , typically immediately over the actual bonding pad 210 (and UBM layer 220 , if present). Adjacent to the primary solder mold 230 , two secondary solder molds 235 a , 235 b are also formed in the photoresist layer 225 . These secondary molds 235 a , 235 b may be beneficially formed near the outer edges of the defined UBM layer 220 , and will also be filled with solder material later in the manufacturing process. While the illustrated embodiment shows molds 230 , 235 a , 235 b having an octagonal shape, other various shapes, including circular or teardrop, may also be employed without departing from the broad scope of the disclosed principles.
With reference now to FIG. 2D , illustrated is a top view of the solder bump area 200 after solder material has been deposited. After the patterning and developing of the photoresist layer 225 done with reference to FIG. 2C , solder material is deposited in the primary and secondary solder molds 230 , 235 a , 235 b . Although any appropriate technique may be employed, exemplary embodiments of the disclosed process employs a vapor deposition process or electroplating to deposit the solder material. In addition, any appropriate type of solder material, including alloys of different metals, may be used as the solder material. Examples of solder materials includes, but are not limited to, lead, gold, silver, copper, and tin. In some specific embodiments, the solder material comprises over 90% lead, however this is not required. Embodiments with lead-based alloys may also be eutectic to assist in the reflow process, but again this is not required.
After the solder material is deposited, the photoresist layer 225 is removed from the solder bump area 200 . Once the photoresist layer 225 is removed, a primary solder column 240 remains where the primary solder mold 230 was filled with solder material, while secondary solder columns 245 a , 245 b are present where the secondary solder molds 235 a , 235 b were filled. Moreover, the primary solder column 240 is also substantially larger than the secondary solder columns 245 a , 245 b , for example, where the secondary columns 245 a , 245 b have a volume of solder material anywhere between about 10% to 90% of the volume of the primary column 240 . In addition, solder joining regions 250 are also present now in the solder bump area 200 where solder material filled openings in the photoresist layer 225 that adjoined the primary solder mold 230 and the secondary solder molds 235 a , 235 b . Typically, these joining regions 250 are substantially smaller in overall size and volume than either the primary or secondary solder molds 230 , 235 a , 235 b . In other embodiments, the secondary solder columns 245 a , 245 b simply adjoin directly to the primary solder column 240 . Moreover, the solder columns 240 , 245 a , 245 b shown in FIG. 2D are octagonal shaped, corresponding to the octagonal shape of the solder molds 230 , 235 a , 235 b in the photoresist layer 225 , but any other corresponding shapes are possible.
Looking now at FIG. 2E , illustrated is the solder bump area 200 after a reflow process used to form the final shape of the solder bump. Specifically, the entire assembly, typically having dozens if not hundreds of solder bump areas, is heated to a point where the solder columns 240 , 245 a , 245 b melt. During the reflow process, the primary solder column 240 melts into the primary solder bump 255 , which typically has a spherical shape around its upper half. In addition to the creation of the primary solder bump 255 , secondary solder bumps 260 a , 260 b are also created adjacent to, and adjoined with, the primary solder bump 255 at the nadir defining the base perimeter of the primary solder bump 255 . Furthermore, in accordance with the principles disclosed herein, adjoining of the solder columns 245 a , 245 b along side the primary column 240 results in cohesion between these columns during the reflow process. As a result, solder material originally deposited as part of the secondary solder columns 245 a , 245 b moves towards and into the primary solder column 240 during reflow, as indicated by arrows A 1 and A 2 , thus increasing the volume of the primary solder bump 255 with solder material flowed from the secondary solder columns 245 a , 245 b.
Thus, as all the solder material melts and then is allowed to cool and re-harden during the reflow process to form the finished solder bumps 255 , 260 a , 260 b , the solder material added to the primary bump 255 from the secondary bumps 260 a , 260 b increases the overall volume and size of the primary solder bump 255 such that it is larger than it would have been had only the primary solder column 240 been formed (as is done in the prior art). Therefore, the size of the finished primary solder bump 255 is larger than it would have been if made using only conventional techniques. Additionally, the height of the primary solder bump 255 is substantially taller than the height of each of the secondary solder bumps 260 a , 260 b not only because of the original size of the solder columns, but also because of the movement of material towards the primary solder bump 255 through cohesion. In many embodiments, the height of each of the secondary solder bumps 260 a , 260 b is about 10% to 90% of the height of the primary solder bump 255 , but no specific height ratio is required. Specifically, the volume of the solder material in the primary solder bump 255 and/or its height is sufficient to electrically and mechanically couple the bonding pad 210 of the first substrate 205 to another, corresponding bonding pad of a second substrate, and the volume of solder material of each of the at least one secondary solder bumps 260 a , 260 b is not sufficient and does not reach height enough to contact the second substrate. This is especially beneficial in bonding techniques such as flip-chip techniques. Furthermore, although two secondary solder bumps 260 a , 260 b (and two secondary solder columns 245 a , 245 b ) have been illustrated, the process disclosed herein is not limited to any particular number of secondary columns or bumps, and therefore as few as one may be employed.
Turning finally to FIG. 2F , illustrated is a top view of a finished solder bump area 200 constructed using the principles and processes set forth in this disclosure. This view further demonstrates the spherical shape taken by both the primary and secondary solder bumps 255 , 260 a , 260 b after the reflow process. In addition, the direction of the cohesion that occurs between the primary and secondary solder bumps 255 , 260 a , 260 b is illustrated again using arrows A 1 and A 2 . Moreover, the adjoining of the secondary solder bumps 260 a , 260 b to the primary solder bump 255 at its nadir is also shown.
While various embodiments of forming a unique solder bump for a semiconductor substrate according to the principles disclosed herein have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the invention(s) should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with any claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.
Additionally, the section headings herein are provided for consistency with the suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a “Technical Field,” such claims should not be limited by the language chosen under this heading to describe the so-called technical field. Further, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Brief Summary” to be considered as a characterization of the invention(s) set forth in issued claims. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein. | Disclosed herein are a method of manufacturing a solder bump on a semiconductor device, a solder bump structure formed on a substrate, and an intermediate solder bump structure. In one embodiment, the method includes creating a bonding pad over a semiconductor substrate, and placing a mask layer over the substrate and the bonding pad. The method also includes forming an opening in the mask layer having a primary solder mold and at least one secondary solder mold joined with the primary mold, where the opening exposes a portion of the bonding pad. In this embodiment, the method further includes filling the primary solder mold and the at least one secondary solder mold with solder material to form corresponding primary and at least one secondary solder columns in electrical contact with the bonding pad. The method also includes removing the mask layer after the filling of the solder molds with the solder material. The method still further includes reflowing the solder material to form a primary solder bump from the solder material of the primary solder column and at least a portion of the solder material from the at least one secondary solder column through cohesion of the solder material from the at least one secondary solder column to the primary solder column when melted. | 7 |
BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Disclosure
[0002] This invention relates to machines for pitching lacrosse balls.
[0003] 2. Description of the Related Art
[0004] Baseball pitching devices are well known in the art. These devices generally utilize a rotating drive wheel and a pressure plate spaced apart a distance smaller than a baseball. A baseball fed into the space between the drive wheel and pressure plate is tightly squeezed between the two and propelled forward.
[0005] Another version of this genre of baseball pitching machines has an additional drive wheel replacing the pressure plate. Because the baseball is driven by two wheels, faster ball speeds are obtained.
[0006] One might simply design a similar device for pitching lacrosse balls, but what is needed is a more economical method that permits a pre-existing baseball pitching device to be converted to a lacrosse ball pitching device, thereby obviating the need for retooling.
BRIEF SUMMARY OF THE DISCLOSURE
[0007] Disclosed is a method of converting a baseball pitching machine to a lacrosse ball pitching machine, comprising the steps of obtaining a baseball pitching machine having a drive wheel and a compression plate spaced by a compression space therefrom, reducing the size of the compression space to an extent effective in propelling a lacrosse ball, and elevating the pitching machine so as to raise the compression space to a height of at least 70 inches above ground level.
[0008] Disclosed is a method of converting a baseball pitching machine to a lacrosse ball pitching machine, comprising the steps of obtaining a baseball pitching machine having a drive wheel and a compression plate spaced by a compression space therefrom, and reducing the size of the compression space by about 68%.
[0009] Also disclosed is a conversion kit for converting a baseball pitching machine to a lacrosse ball pitching machine, the kit including a replacement compression plate that, when installed, reduces a compression space between a drive wheel of the pitching machine and a replaced compression plate to an extent effective in propelling a lacrosse ball.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a front-plan view of the converted baseball pitching machine of the invention.
[0011] FIG. 2 is a rear-plan view of the invention.
[0012] FIG. 3 is a side-plan view of the invention, showing the opening to the feed tube.
[0013] FIG. 4 is a side-plan view of the invention showing where the ball is ejected from.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Referring to FIG. 1 in particular and the remaining figures in general, there is shown a lacrosse-modified pitching device 1 , originally designed to pitch baseballs, now modified to pitch lacrosse balls. The basic components include a drive wheel 2 driven about a drive axis 2 b and having a compressible outer rim 2 a . The compressible outer rim 2 a is spaced by a compression space 3 from a compression plate 4 , which itself will also generally have a compression pad 4 a . A feed tube 5 , slightly larger than the diameter of the lacrosse ball 6 to be pitched, is utilized to direct the ball into the compression space 3 .
[0015] The compressible outer rim 2 a and the compression pad 4 a will typically be made of a resilient material such as rubber or polymer plastic. Note, however, that it is not unusual for the compressible outer rim 2 a and compression pad 4 a to be made of different materials and have different resiliencies. Often the compressible out rim 2 a is made of a harder material than the compression pad 4 a.
[0016] As can be seen, the lacrosse ball 6 is fed into the feed tube 5 causing it to enter the compression space 3 . The drive wheel 2 , rotating rapidly counterclockwise in this view, drives the lacrosse ball 6 through and out the compression space 3 , thereby pitching the lacrosse ball 6 .
[0017] Referring more specifically to FIG. 2 , additional components include a tripod receptacle 7 , a swivel joint 8 for aiming the assembly horizontally, a tilt joint 9 for aiming the assembly vertically. Levered tightening screws 10 are provided to locking these joints into place. The tripod receptacle 7 is generally three or more hollow pipe members sized to receive supporting legs. As will be more fully explained below, a set of replacement legs 15 will preferably be provided as part of the modification method.
[0018] A drive motor 11 is provided, preferably controlled by a speed controller 12 that has a manual speed control knob 13 or other type of adjustment control. A separate on/off switch may be provided on the speed controller 12 , but generally it is more economical to have an “off” position on the speed control knob 13 .
[0019] Referring again to FIG. 1 in particular and the remaining figures in general, there is also often provided a carrying handle 14 and a mud flap 17 . The mud flap 17 allows use of the invention 1 in rainy weather by preventing water on the drive wheel 2 from spinning onto the person or device feeding lacrosse balls 6 into the feed tube 5 . A motor shield 18 is also often provided to prevent balls thrown or batted back toward the machine from striking the motor 11 and speed controller 12 .
[0020] The most important modification to the original baseball pitching machine is in the original compression space 3 , which must be reduced to be adapted to the size, friction, and resiliency of a lacrosse ball. The National Collegiate Athletic Association (NCAA) sets standards for equipment used in college sports that are typically followed by their professional counterparts. For a baseball, the diameter is 3 inches and the coefficient of restitution is no more than 0.555. For a lacrosse ball, the diameter is 2.5 inches and the coefficient of restitution is no more than 0.842. Both balls weigh from 5 to 5.25 ounces.
[0021] The coefficient of restitution, c, of a ball is given by:
c = h H
where h is the height to which the ball bounces to when dropped from a height of H. The coefficient of restitution is a measure of the resiliency of the ball.
[0022] The problem for the modifier of a baseball machine for use with a lacrosse ball is that the compressibility of the compressible rim 2 a of the drive wheel 2 and the compressibility of the compression pad 4 a (if any) of the compression plate 4 will vary among manufacturers and models, therefore the compression space 3 required for a lacrosse ball will vary. However, because compression strength is proportional to compression space 3 to good approximation, we can reasonably rely on the standardization of baseballs and lacrosse balls by the NCAA to determine the modified compression space 3 without undue experimentation. We have found that the original compression space 3 will generally be reduced from 60% to 80%, preferably about 68%, of its original size to modify a baseball pitching machine to pitch lacrosse balls.
[0023] More accurately, the equation for the change in compression space distance is approximated by
G B - G L ≅ ( D B - D L ) ′ + F + ϕ K L
where G B is the compression space width for the hardball, G L is the compression space width for the lacrosse ball, D B is the diameter of the hardball, D L is the diameter of the lacrosse ball, F is the compression force exerted upon the balls when in the compression space, and K L is the spring coefficient of the lacrosse ball (wherein F=K L ·ΔD L , where ΔD L is the change in lacrosse ball diameter caused by force F). The equation assumes the hardball to be incompressible. The factor φ is any additional force that may be desired, such as to compensate for the smoother and lower frictional surface of a lacrosse ball in comparison to a hardball.
[0024] Notice from the equation that the difference in compression space distance is independent of the resiliency of the compressible rim 2 a and compression pad 4 a and is simply the difference in ball size plus a constant, F/K L , which will generally be from 0.15 to 0.25 or about 0.21. Hence, for any system, one may generally maintain the same compression force in conversion to lacrosse ball use by reducing the compression space by about 0.5+0.21=0.71 inches.
[0025] For example, the modified baseball pitching machine shown in the drawings is sold by Bata Baseball Machines of San Marcos, Calif. under the product model name of BATA-1. The compression space 3 for an NCAA standard hardball baseball is 2.21 inches. Taking 68% of this, we obtain a compression space 3 of 1.5 inches for an NCAA standard lacrosse ball. Alternatively, we could reduce the value of 2.21 inches by 0.71 and obtain the same result of 1.5 inches.
[0026] Hence, for any particular make or model of machine, we need not know the compression strength of the compression pad 4 a or compressible rim 2 a and engage in complex calculation or experiment. This is because the manufacturer has already set the original compression space 3 size for us for optimal use with a standardized baseball. We need only take 68% of this value to reasonably adapt to a lacrosse ball. Note that the diameter of an NCAA standard lacrosse ball is only 83% of an NCAA standard hardball, but we must reduce the compression space 3 still further because a lacrosse ball is more resilient and has a less frictional surface than a hardball. Of course, there may be other factors involved, depending on machine design, so that one might wish to take 68% as an initial approximation and then fine-tune the compression space 3 with minimal experimentation.
[0027] How the modification in compression space 3 is made is most simply achieved by either drilling new mounting holes 4 b in the compression plate 4 supplied with the baseball pitching machine, or by supplying a replacement compression plate 4 with mounting holes that will provide the desired compression space 3 for lacrosse balls. Such a new plate could be supplied as part of a conversion kit, thereby alleviating the need for a customer to machine any parts.
[0028] The next most important modification to the original baseball pitching machine is in the height. Lacrosse balls are mostly thrown high with lacrosse sticks, so the lacrosse-modified pitching machine 1 needs to be much higher. The compression space 3 , where the ball is ejected, is typically about 40 to 50 inches above ground level on the typical baseball pitching machine. For a lacrosse ball, it is preferred that the compression space 3 be at a height above ground of from about 70 to 90 inches, or about 80 inches. To do this, we preferably choose a model of baseball pitching machine that has removable legs and replace them with longer ones. The BATA-1 model shown in the drawings, for example, comes with 34-inch pipe legs that fit into the tripod receptacle 7 , yielding a compression space 3 height of about 48 inches. By replacing these with 68-inch replacement legs 15 , we obtain a compression space 3 height of about 78 inches. Again, these replacement legs 15 may be supplied as part of a conversion kit for the consumer.
[0029] The third most important modification to the original baseball pitching machine is in the feed tube 5 . Depending upon the make and model of the machine this step may or may not be necessary. As can be seen in FIG. 1 , the original feed tube 16 , shown in dotted outline, on the model BATA-1 is level with an inside diameter large enough to accommodate a 3-inch diameter hardball with room to spare. Further, the tube does not extend very close to the compression space 3 .
[0030] The lacrosse-modified feed tube 5 of the invention has a smaller inside diameter of about three inches to accommodate a 2.5-inch lacrosse ball with half-an-inch to spare. It is preferably tilted downward into the compression space 3 at an angle of from 10° to 20°, preferably about 15°. Note that this angle is in relation to the compression space itself rather than the ground because the device can be tilted. This allows the device to be tilted upward to duplicate the loft normally associated with lacrosse balls when thrown and still permit balls to be fed into the tube without rolling back out. Further, the feed tube 5 is preferably brought in very close to the compression space 3 . Because both the drive wheel 2 and the compression plate 4 obstruct access to the compression space 3 , it is desirable to provide a compression plate clearing cut 5 a and a drive wheel clearing cut 5 b on the feed tube 5 so as to permit the feed tube to be extended right into the opening of the compression space 3 as shown. Again, the feed tube 5 of the invention may be provided to the consumer as a replacement part in a conversion kit, requiring only that the original feed tube 16 be discarded and replaced.
[0031] Of course, while this disclosure has been directed to modifying a hardball pitching machine, the parameters therein may be modified to convert a softball pitching machine with little experimentation. Such a conversion would of course require a greater reduction in the compression space.
[0032] While various values, scalar and otherwise, may be disclosed herein, it is to be understood that these are not exact values, but rather to be interpreted as “about” such values, unless explicitly stated otherwise. Further, the use of a modifier such as “about” or “approximately” in this specification with respect to any value is not to imply that the absence of such a modifier with respect to another value indicated the latter to be exact.
[0033] Changes and modifications can be made by those skilled in the art to the embodiments as disclosed herein and such examples, illustrations, and theories are for explanatory purposes and are not intended to limit the scope of the claims. Further, the abstract of this disclosure is provided for the sole purpose of complying with the rules requiring an abstract so as to allow a searcher or other reader to quickly ascertain the subject matter of the disclosures contained herein and is submitted with the express understanding that it will not be used to interpret or to limit the scope or the meaning of the claims. | Disclosed is a method of converting a baseball pitching machine to a lacrosse ball pitching machine by obtaining a baseball pitching machine having a drive wheel and a compression plate spaced by a compression space 3 therefrom, reducing the size of the compression space 3 to an extent effective in propelling a lacrosse ball, and elevating the pitching machine so as to raise the compression space 3 to a height of at least 70 inches above ground level. | 5 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to a garment protective system and more particularly to a jacket including a protective member and an adjustable member.
It is known to provide motorcycle jackets with protective body armor. Exemplary motorcycle jackets are shown in: U.S. Patent Application No. 2008/0040832 entitled “Ventilated Garment” invented by Bay and published on Feb. 21, 2008; U.S. Pat. No. 7,284,282 entitled “Hybrid Ventilated Garment” which issued to Bay on Oct. 23, 2007; and U.S. Pat. No. 6,263,510 entitled “Ventilating Garment” which issued to Bay et al. on Jul. 24, 2001; all of which are incorporated by reference herein. While these ventilated garments are significant improvements in the industry, additional opportunities to improve user comfort and protection exists.
In accordance with the present invention, a garment protective system includes a protective member and an adjustable member. In another aspect of the present invention, body armor inside a jacket is repositionable due to adjustment of a coupled adjustment strap. A further aspect of the present invention provides a waist belt adjustably coupled to a shoulder area and/or a back area of a jacket. A method of manufacturing a garment is also provided.
The garment of the present invention is advantageous over prior devices in that the present invention garment allows for adjustable repositioning of the body armor and/or protective pads within a jacket. This system advantageously improves wearer comfort and improves protective placement of the armor over the desired, targeted areas of the user. Since the wearers' sizes vary even within a given jacket size, such adjustability of the body armor is advantageous. Furthermore, user positioning on a racing-type motorcycle versus a cruiser-type motorcycle, for example, will often necessitate different body armor positioning within a jacket to maximize comfort and protection. Moreover, user preferences also vary. The adjustable strap system of the present application secures a predetermined armor pad position set by the user while also snugging the protective armor pads to the user's body. This is contrasted to traditional garments which only secure pads to the jacket but not the user, resulting in a loose fitting jacket and, thus, loose fitting armor. It is further advantageous to interchange removable armor within the system. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view showing the preferred embodiment of a garment protective system of the present invention;
FIG. 2 is a front perspective view showing the garment protective system;
FIG. 3 is a front elevational view showing the garment protective system;
FIG. 4 is a rear elevational view showing the garment protective system;
FIG. 5 is a rear elevational view showing the garment protective system in an open position with a jacket removed;
FIG. 6 is a fragmentary perspective view showing a portion of a waist belt employed in the garment protective system;
FIG. 7 is a cross sectional view, taken along line 7 - 7 of FIG. 3 , showing the garment protective system;
FIG. 8 is a fragmentary perspective view, taken within circle 8 of FIG. 7 , showing a portion of the garment protective system;
FIG. 9 is an exploded, front perspective view, showing the garment protective system;
FIG. 10 is a fragmentary and partially exploded, perspective view showing a spine pad and pocket employed in the garment protective system;
FIG. 11 is a cross sectional view, taken along line 11 - 11 of FIG. 10 , showing the garment protective system; and
FIG. 12 is a fragmentary perspective view, taken in the direction of arrows 12 - 12 of FIG. 9 , showing a shoulder pad and pocket employed in the garment protective system, in an open condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 , the preferred embodiment of a garment protective system 15 includes a garment, preferably a jacket 17 , and an adjustable protective system 19 . It should be appreciated that the terms garment and jacket include a stand-alone jacket, such as that shown, in addition to a combined jacket/pant racing suit, or any other article of clothing for covering at least a torso of a wearer. Garment protective system 15 is preferably worn by a person riding a motorsport vehicle, such as a motorcycle or other motorized vehicle such as all-terrain vehicle or snowmobile. Alternately, garment protective system 15 is used for skiing, snowboarding or other sporting endeavors, although various advantages of the present invention may not be fully used.
Jacket 17 includes two major portions, a body 25 and a removable shell or cover 27 . Body 25 has a mesh inner liner 29 , an outer wind resistant layer 31 and an outer mesh material 33 . The outer mesh material 33 is only exposed when shell 27 is optionally removed during warm weather use. Air vents 35 are provided on sleeves 37 and a back torso portion to allow air through the jacket when the vents are unzipped even if a vertical and main zipper closure 39 is in a closed condition. Outer layer 31 may be a textile or leather material.
FIGS. 2-12 illustrates protective system 19 in greater detail. The protective system includes a pair of body armor shoulder pads 51 and their associated shoulder pockets 53 , a body armor spine pad 55 and its associated back pocket 57 , a waist belt 59 , and adjustable straps. A vertically (as viewed in a user standing orientation such as that shown in FIGS. 2-4 ) elongated strap 71 has a lower end sewn to an inside of waist belt 59 and an upper end sewn to an inside surface of shoulder pocket 53 . Similarly, another vertically extending strap 73 is sewn between waist belt 59 and the opposite shoulder pocket 53 . A transversely elongated strap 75 spans between shoulder pocket 53 and back pocket 57 , essentially adjacent to a transverse line 76 , with each end sewn thereto. Similarly, an oppositely extending strap 77 extends from the other side of back pocket 57 to the opposite shoulder pocket 53 . A slide ring 81 and a slide adjuster 83 provide for length adjustment of adjustable straps 71 , 73 , 75 and 77 . The slide adjuster has a generally polygonal B-like shape. A tab 91 is sewn to each shoulder pocket 53 and a slide ring 93 is secured to a looped end of tab 91 . This allows for strap 75 to slide through ring 93 when being adjusted. A similar tab and ring arrangement are employed with the opposite strap 77 and shoulder pocket 53 .
These straps, slide rings and slide adjusters advantageously allow the wearer to predetermine the pad spacing within the jacket, which is thereafter maintained in the desired set position during jacket use and for each subsequent jacket use, until the spacing is manually changed by the user. The adjustment strap construction preferably described and shown herein allows at least the shoulder armor, back armor and belt to be interconnected and work as an interdependent unit, while also somewhat bunching up the jacket liner to correspond to the armor and belt positioning. When the jacket is taken off and put back on by the user, the relative system positioning and adjustments will remain the same each time, until intentionally readjusted by the user.
Each pocket 53 and 57 is defined by one or more inner pocket layers 101 peripherally sewn to inner liner 29 of the jacket. A Velcro® hook and loop type fastener 103 allow for opening and closing of an opening 105 through which the respective shoulder pads 51 and spine pad 55 are inserted and removed. This advantageously allows for easy replacement of the body armor with alternately configured body armor of different characteristics, such as having different sizes or different materials depending on user preference, body sizes and motorcycle uses (for example, racing versus casual long distance riding). By way of example, spine pad 55 of FIG. 11 is preferably a dual density, EVA back pad with the outside portion more rigid than an inside portion. Nevertheless a replacement spine pad or shoulder pad may consist of a single density polyurethane foam pad, a dual density polyethylene foam pad, or the like. As another example, FIG. 9 shows the original three-dimensionally molded, dual density shoulder pads 51 , however, a replacement shoulder pad 51 ′ may include a substantially rigid, injection molded and polymeric outer shell, a non-preformed die cut and fibrous pad, a larger sized foam pad having a greater inside radius, or the like. Such interchangeability further enhances the adjustability and customized nature of the garment protective system. Removal of the pads also allows for easy washing of the pads and/or jacket.
FIGS. 2 and 6 - 8 show waist belt 59 attached to an internal surface of outer jacket material 31 by way of multiple vertically elongated belt loops 141 . Ends of each belt loop are sewn to jacket outer 31 or alternately to the inner liner of the jacket, while waist belt 59 is allowed to freely slide within loops 141 . Waist belt 59 further has a pair of elastic segments 143 and multiple spaced apart sets of snaps 145 to allow for user adjustment of the belt. It is alternately envisioned that hook and loop type fasteners or an adjustable buckle can be substituted in place of snaps 145 .
FIG. 7 illustrates two layers 101 defining pocket 57 which secure spine pad 55 . Layers 101 of the back pocket are peripherally sewn to waist belt 59 adjacent a lower section of spine pad 55 . Alternately, however, an adjustable strap can interconnect the bottom of the back pocket to the waist belt.
The body armor pockets are preferably made from an open nylon mesh material such as the type used for the inner jacket liner. Furthermore, the adjustable straps are preferably made from a non-stretchable polypropylene webbing to prevent body armor movement after the adjustment is set by the user. The slide adjusters and rings are preferably made from a rigid and molded polymeric material.
While various constructions of the garment protective system have been disclosed, it should be appreciated that other modifications may be made which fall within the scope of the present invention. For example, other body armor and/or pad members may be employed with an adjustable positioning arrangement such as that disclosed. Furthermore, the garment protective system can be employed with or without a spine pad and/or a waist belt, although, many of the benefits of the present invention system may not be achieved. Moreover, it is alternately envisioned that other adjustment members and/or adjustable strap geometries can be provided as long as the advantageous functional features of the presently disclosed garment protective system are employed, however, such other configurations and geometries may not fully utilize the benefits and advantages disclosed herein.
Various materials have been disclosed in an exemplary fashion, but other materials may of course be employed, although some of the advantages of the present invention may not be realized. It is intended by the following claims to cover these and any other departures from the disclosed embodiment which fall within the true spirit of the invention. | A garment protective system includes a protective member and an adjustable member. In another aspect of the present invention, body armor inside a jacket is repositionable due to adjustment of a coupled adjustment strap. A further aspect of the present invention provides a waist belt adjustably coupled to a shoulder area and/or a back area of a jacket. | 0 |
BACKGROUND OF THE INVENTION
While a pool cover that extends over the entire pool surface can maintain water temperatures well into the 80's and 90's, they are also bulky, unsightly, and difficult to use and store. Further, they can be dangerous for small children or animals which can be trapped underneath.
SUMMARY OF THE INVENTION
Solar panels provide the same heat retention qualities of a pool cover without the disadvantages. They can be left in the water while the pool is being used and enjoyed by the entire family. Further, solar panels are totally safe and attractive. Solar panels can be stacked easily and neatly at poolside and are impervious to decay and require no special care. A solar panel, while utilizing the sun under conditions hereindescribed, is not dependent or necessarily utilizing the sun in its operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a swimming pool having solar panels of the preferred embodiment of the present invention disposed over the surface of the water.
FIGS. 2 and 3 are perspective sectional views and partially broken away, showing the solar panel including internal construction and the joining of the rim providing novel features of the present invention.
FIGS. 4A and 4B are sectional views showing an alternate preferred embodiment of the present invention to show the novel structural features including spaced films providing an enclosed layer of air.
FIG. 5 is a sectional view showing a cross section of the swimming pool to illustrate the operation of the solar panel of the invention in the sun.
FIGS. 6, 7, 8 and 9 are graphs for illustrating the operation of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a plurality of solar panels 10 are shown as solar panels floating horizontally on the surface 14 of the water in the swimming pool 12. Distributing the solar panels about the surface of the pool as shown in FIG. 1, for example, the solar panel 10 becomes attractive, having the appearance of lily pads about the pool surface 14. More important, the solar panels 10 collect heat energy received over the individual panel covers during the day; and also where the solar panels are located. In addition, the panels provide individual covers for the pool surface 14 during cool night-time temperature since solar panels 10 retain the heat in the pool water. Equally important, and possibly most important, less heat loss is produced by evaporation. By reduction of evaporation, not only is fuel saved, but fuel for heating the pool water is substantially reduced along with a reduction in need for pool chemicals and water. The actual amount of water loss due to evaporation is substantial, without panel 10.
Of course, the highest temperature of a "spa" can be maintained by a minimum of heating fuel by the "spa" water surface when not in use.
As shown in FIG. 3, the solar panel 10 is preferably round to give it maximum self-supporting strength across thereof due to the known physical strength of the circle over other structural configurations. The structural strength solar panel 10 provides sufficient rigidty for handling and use in a swimming pool 12 and other bodies of liquids.
The polyethylene cover 17 is made taut as it is secured to the rim of novel construction in which a semi rigid rectilinear-tubular structure provides the corresponding enclosed area 16 and bead or spline retaining seat or slot 18 is provided. A tapered structural area 18 for securing the cover 17 in the slot 18 and about the periphery. The square tubular structure along with the separating peripheral wall 13 not only provides greater rigidty but decreases the weight of the rim so that the solar panel 10 is lighter than water; i.e. the solar panel 10 will always float with or without the benefit of air trapped between the cover 17 and the water surface 14 or without use of surface tension.
The panel 10, therefore, has two peripheral sections, enclosed rectilinear section 16 providing a trapped air chamber and a cover retaining section 18 for securing the cover 17 about the rim, by spline 15.
The rim is formed from a continuous length of plastic, such as type ABS, which is preferably joined by a peripherally extending member or aluminum slug 20 which projects into the ends of rectilinear end openings of the rim, as shown in FIG. 2 by the area broken away. The ends of the rim are secured by the slug 20 and in the adjacent inner peripheral rectilinear opening 16 and silicone rubber 21, for example, which is inserted into the open ends of the newly formed loop or rim. The silicone rubber 21 has the advantage of vulcanizing at room temperature and absorbs moisture to cure.
Another important feature of the solar panel 10 of the invention is the projection or tab 19 for protection of the polyethylene cover or sheet 17. The projection can be small, e.g. 0.030 to 0.050 inches or 30 to 50 mils. The tab 19 acts to protect the sheet 17 from the surrounding deck of the pool 12, for example, or other surface when the solar panel 10 is laid flat on the surface of the deck or slid across the deck, for example.
As for other important details of the invention, the solar panel 10 is circular or round to decrease cost snd provide a more stable structure for reasons discussed earlier. Further, the circular structure is simpler in construction. It is simpler to make round panels 10 uniform in size and in general, the solar circular is more aesthetic, appearance being important in inducing sales and successful manufacture.
In a sense, the solar circular panels 10 having approximately 5 foot diameter is preferred, i.e. 4 to 6 feet diameter panels for an average size pool 12, approximately 15 feet by 30 feet. Smaller solar panels 10 make retrieval difficult when the desired coverage is provided. Further, the appearance of many, many smaller panels 10, e.g. less than 4 feet diameter, is not aesthetic. On the other hand, larger panels, i.e., larger in diameter than 6 feet, are disproportionally more difficult to handle. The larger panel therefore, requires more material for stiffness of the rim which not only makes handling difficult, but the ease of placement for coverage of the pool 12 is made difficult.
The material of cover 17 and the rim of solar panel 10 is ultra-violet stable having a density less than 1 and capable of being cleansed quickly and easily. The material is not unduly affected by solvents and other chemicals and has excellent material strength to resist puncture, tearing, cracking or other destruction forces.
The solar panels 10 have a acrylonitrile butadiene syrene (ABS) which is a sturdy stable material providing the desired stiffness to weight ratio to withstand engagement with a pool sweeper. The rim in combination with the film cover also has a specific gravity less than 1 and therefore floats. The plug 20 (FIG. 2) is of aluminum material to provide an extremely strong joint, stronger than other sections of the rim while providing for ease of fabrications and relatively inexpensive. Peripheral lateral projections 23 provide interlocking ridges between adjacent floating panels 10 to prevent wind and the like from causing one panel to move on top of another by inhibiting vertical movement of the rims over one another, i.e. interlocking.
In operation on hot days, the pool 12, as shown in 5, will rise 2°, 3°, or 4° per day and cool about 2° at night such that a net gain of more than was lost will cause the temperature to rise above the heater setting of 80° and the heater need not operate to maintain the described temperature, as above. On cooler days and nights there may be a net loss.
If the system turns on at 9 A.M. and off at 4 P.M., as shown by curve 70 in FIG. 9, (FIG. 6 shows this is optimum time for solar heating), the heater will operate for a period 72 in the morning to make up for the net loss from heat gathered the day before and then lost during the subsequent night. This represents the advantages of the solar panels 10, a system of the present invention in which solar energy is used to heat a swimming pool, for example. Natural recirculation of water by pool filtering system removes warm water at the surface and pumps it back into the main body.
As shown graphically on FIGS. 7 and 8, the color of the preferred solar panel is blue-green (aqua) to provide the the preferred advantages over the other colors. A black surface of a solar panel provides greater absorption of light and heat to the surface water of the pool but does not provide the desired attractiveness to the pool 12 as other colors such as blue-green. It should be noted that absorption of the sun's rays by the solar panels is transferred to the surface water of the pool to heat the pool water at the surface.
The reflection of blue-green (aqua) for the aqua appearance is only about 20% of the energy in the sunlight spectrum. Aqua is more attractive and 80% energy absorative compared to black which is 100% absorbative as a reference. Thus, aqua is 80% effecient and the choice of colors is dependent upon individual choice of efficiency over esthetics.
The day to day operation of the exemplary pool with the preferred panels 10 of the present invention is illustrated by the graph of FIG. 9. As illustrated by solid curve of this graph, the pool heater becomes a temperature stabilizer to maintain the temperature, i.e. protect from lower temperature on colder days but avoid unnecessary operation of the heater when the sun is effective for heating and maintaining the desired temperature by panels 10. The resulting operation is that the pool heater operates in the morning, i.e. area 72 in the graph of FIG. 9, according to the temperature of the previous day to conserve energy and fuel. On hot days, the pool water 14 will rise 2°, 3°, or 4° with the heater set at 80° for the day and to allow the pool water to cool about 2° at night which results in a net gain that will cause a temperature rise above the heater setting of 80°. The result of the gain is the heater does not operate on the latter day while on cooler days and nights there may be a net loss.
While the system is in operation at 9:00 A.M. and shuts off at 4:00 P.M. for example, the heater will only remain on long enough in the morning to make up the net loss from heat gathered the day before and then lost on the subsequent night. The operation of the system in this manner offers considerable savings to the pool owner as shown by decreased heating in FIG. 9 by decreasing areas 72.
Operation of a typical pool of the preferred embodiment is illustrated by the graphs in FIGS. 5 through 9; assume a pool with 200,000 lbs water, i.e. 26,000 gals; 630 sq. ft. surface area 14.
Pool water temperature rises 0.83° per hour (open pool) and 1.9° per hour mid-day, with solar panels. This assumes having 63.5% coverage of the pool surface. Assuming the mid-day sun provided 240 BTU per hour per sq. ft., the heat input to the pool equals 96,000 BTU per hour at mid-day. A valid BTU estimate for 9 to 4 P.M. is 96,000 BTU per hour for four hours, which is 384,000 BTU.
Total rise in water temperature = 384,000/200,000 = 1.92°for the day.
Experience shows this is the case: 2° lost at night and 2° gained during the day where the night temperature drops to a low of approximately 60° and the day temperature rises to a high of 75° to 80°.
In an area of warmer temperature, pool 14 produces a net rise of 6° to 8 days with 60% solar panel coverage of the water 10, i.e. 75° to 81°. Without solar panel coverage of 60%, it will produce a loss under the same conditions which is lower by 5°F (1 million BTU -- a loss of about $1.20 in gas).
When the solar panels 10 are placed in an unheated pool, there will be an increase in temperature of up to one or more degrees in the pool 12 each day depending upon weather conditions and coverage by solar panels 10. A one degree variance in the temperature of the water will require heating that will increase fuel cost by approximately 10%.
In operation, heat conduction of the polyethylene film 17 is indicated by the heat differential rise at the film surface wherein the coefficient of heat flow is 2.4 BTU per hour per sq. ft. per ° F. For example, the heat flow of the film that is 6 mils in thickness and 1 sq. ft. is 1° F for 400 BTU (British Thermal Unit) per hour. The above closely approximates the condition that the sun produces at mid-day on a typical day in a warm climate, e.g. Southern Calif. The heat conduction in the hot desert can double the foregoing to provide a 2° F rise above the surface water temperature. It should be apparent that this minimal rise in a bright sun prolongs the life of the polyethylene.
Referring to FIGS. 4A and 4B, the alternate embodiment is a solar panel 10 having parallel, spaced transparent and opaque films 11, 17. As shown by the detail in FIG. 4B, polyethylene films 11, 17 are secured taut by retention by splines 22, 15, respectively, in upper and lower peripheral seats or slots of the hollow rim. The closed rectilinear peripheral enclosure 16 is located between the rim seats, and forming projections of the sides of peripheral enclosure 26. Outer peripheral flanges or projections 14 are also provided on the alternate embodiment for the purpose described supra.
In operation of the alternate embodiment of FIGS. 4A, 4B, any warm air moves to the top of the layer of air space or air chamber formed between films 11, 17 to be cooled by radiation and external air currents. Although this operation may assist at night, i.e. by convection; it produces radiation of heat to the air above, i.e. clear plastic materials radiate in the absence of a coating. Evaporation and radiation are concurrent always in the absence of panels 10.
A disadvantage of the solar panel 10 of FIGS. 4A, 4B is that it is delicate by comparison and unmanageable e.g. if a hole in one of the plastic films allows water to enter between films 11, 17. If thicker film materials are used for "green house" effect the panels become too costly. Also, hot air between films 11, 17 derived from direct rays of the sun keeps the heat of the direct rays from reaching the water in the pool.
Among the most important features of the solar panels of the present invention are the reduction of evaporation and reduction in need for addition of chemicals. This was noted by the significent reduction of water added and chemicals required. For example, if two-thirds of the pool surface is covered by solar panels 10 water, evaporation is reduced by two-thirds and consumption or need for chemicals is reduced by two-thirds; e.g., chlorine (Cl) and hydrochloric acid (HCl).
Expressed in terms of area, the pool water surface area is effectively reduced from 630 sq. ft. to 210 sq. ft. in so far as the loss of water and chemicals in the pool 12 (FIG. 1).
While the solar panels 10 use the heat energy of the direct rays 51, 52 of the sun 50 to heat the pool 12, as shown in FIG. 5, it is not the only or main function of the solar panels 10. The reduction in fuel consumption by the pool heater is primarily the result of reduction in heat loss of the water 14 by reduction of evaporation of the water.
FIG. 5, however, illustrates the operation of the solar panels 10 to utilize the direct rays 51, 52 of the sun 50 to heat the water 14 in the pool 12. As described supra, the solar panels 10 absorb the direct rays 51 of the sun 50 and absorb any rays 53 of the sun which are reflected to the undersurface of the panel 10 on the water 14.
Referring now to FIG. 9, in a typical operation of the solar panels 10 of the present invention is indicated by the solid curve 70 and the dashed curve 71 indicates operation without the solar panels 10. The temperature of the pool water 14 is indicated to be 76° in the early morning from 6 A.M. to 9 P.M. At 9 A.M., the pool heater is started 72 and operates from 2 to 4 hours, i.e. until the water temperature reaches 80° and the heater stops operating, e.g. until 12 A.M.
Between 12 noon and 3 p.m. or 4 p.m., the water is heated by the rays of the sun 50. From 3 or 4 P.M. overnight and until 8 or 9 A.M. of the next day, the water cools 2° to 79° due to decreased evaporation. At this time, the heater starts and operates 1/2 to 1 hour to provide a temperature rise of only 1° to 80°. By 3 P.M. the energy of the sun's rays raises the pool temperature 2° to 82° from 80° between approximately 9:30 A.M. and 3 P.M.
Again, overnight the temperature of the water lowers 2° by cooling to evaporation. This lowers the temperature from 82° to 80° and the heater operation should not be required under the conditions assumed of a minimum temperature of 80° for normal use.
The typical conditions of the foregoing described operation assumes 60% coverage of the area of the water surface, a wind of less than 5 mph, a high ambient temperature 75° to 80°, a low night temperature 55° to 60°, a morning haze, a clear afternoon and a slight fog in the evening and at night. The conditions are far from ideal for maintaining water temperature by a pool heater and a large amount of fuel would normally be consumed to provide a water temperature of 80° as indicated by the dashed curve 71, showing heater operation in time period 73.
Accordingly, the solar panels 10 reduce the operation of the pool heater to a stabilizer, maintaining the desired temperature on colder days and stand by when the energy of the rays of sun 50 are present for heating. Thus, the pool heater is operative the morning after a day in which the energy of the direct rays of the sun is insufficient to provide for any night cooling.
While preferred embodiments of the present invention have been disclosed, it should be clear that the present invention is not limited thereto, as many variations and additional embodiments will be readily apparent to those skilled in the art. For example, the rim can be round in section and secured to the film 17 by other means to provide a suitable taut cover and sturdy rim structure.
As noted in the "Background of the Invention", one of the main disadvantages of conventional swimming pool covers lies in the fact that they are difficult to use and store. These prior covers most often consist of plastic sheets or strips which in some instances are air injected primarily for providing packing material, i.e. bubble cover. One of these plastic covers, i.e. sheet type, is large enough to cover an entire pool and project over the decking for anchoring the cover, i.e. preventing the cover from falling into the pool or protection against wind.
Prior pool covers, including bubble strips extending the length of the pool, are subject to wind curents that manage to flow under the covers, dislocate or actually move the covers from the pool areas to other areas, e.g. neighbor's yard. These wind currents are of such intensity as to pull the large pool covers from under sand bags, and/or steel pipes and "pick up" the bubble type from the pool and move them before wind like a tumble weed. Most are familiar with the problems of prior art pool covers and no further discussion appears necessary. However, the foregoing does not obviate the need and distinct advantages of a pool cover which are discussed supra. | Conservation of energy of a swimming pool is provided by an attractively colored polyethylene panel secured to a circular frame which panel cover and frame are stable, and will not disintegrate due to direct rays of the sun. The panel passes and traps the heat of the sun rays during the day and maintains a pool cover to prevent substantial loss of heat and thereby retain the heat of the pool. The absorption of heat and reduction of evaporation is effective primarily to reduce fuel of the pool heater and also reduces consumption of chemicals and water. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a constitution of a thin film transistor having a high characteristics and reliability.
2. Description of the Related Art
Various devices employing thin film transistors are known. However, since the crystallinity of the silicon film constituting the active layer of a thin film transistor is insufficiently low, a large number of carriers are caused to move by the high electric field which is generated between the drain region and the channel region. This causes a problem of high OFF current. Furthermore, the low crystallinity of the silicon film can effect a low withstand voltage, and this causes serious degradation of the device.
As a means for solving the above problems, JP-B-5-44195 (the term "JP-B-" as used herein signifies "an examined published Japanese patent application") discloses a constitution comprising a plurality of equivalent thin film transistors being connected in a serial arrangement so as to lower the voltage applied to each of the thin film transistors.
However, when a device of the above constitution described in JP-B-5-44195 is manufactured and operated, it has been found that a high voltage is applied locally to the thin film transistor on the drain side. That is, in the constitution above, it has been found that the voltage is not distributed equally to each of the thin film transistors, but that the thin film transistor on the drain side alone is subjected to high voltage.
Moreover, when operated under a high voltage, it has also been found that the breakdown or degradation occurs in sequence from the thin film transistor on the drain side.
SUMMARY OF THE INVENTION
An object of the present invention is, accordingly, to provide a means for solving the aforementioned problems of breakdown and degradation that occur in case a plurality of thin film transistors are serially connected in an equivalent arrangement, which is due to the high voltage that generates locally to a part of the plurality of thin film transistors.
According to a constitution of the present invention, there is provided a semiconductor device comprising a plurality of gate electrodes connected in common and superposed on the active layer, wherein the widest gate electrode is located on the drain side.
In accordance with another constitution of the present invention, there is provided a semiconductor device comprising that it comprises a structure in which three or more gate electrodes connected to a common electrical potential and superposed on the active layer, wherein the widest gate electrodes are located on the source and the drain sides.
Also according to another constitution of the present invention, there is provided a semiconductor device characterized in that it comprises a structure in which a plurality of gate electrodes connected in common are arranged superposed on the active layer, wherein the gate electrodes differs from each other in width.
Furthermore, a constitution having an LDD region or an offset gate region may be combined with the constitution according to the present invention. Additionally, the present invention can be used in either a top-gate type comprising the gate electrode over the active layer (as viewed from the substrate side) or a bottom-gate type comprising the gate electrode under the active layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing a constitution comprising a plurality of equivalently connected thin film transistors;
FIG. 2 is a schematic drawing showing a constitution comprising a plurality of equivalently connected thin film transistors;
FIGS. 3A to 3E are schematic drawings of the devices using the present invention; and
FIG. 4 is a schematic drawing showing a constitution comprising a plurality of equivalently connected thin film transistors.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a constitution according to the present invention comprises a plurality of gate electrodes 106, 107, and 108 each having a width of 109, 110, and 111, respectively, and each superposed on an active layer 100. It can be seen from the widths 109, 110, and 111 that the gate electrodes increase their width with approaching the side on which drain region 104 is located.
Thus, the electric field of the channel region on the side of the drain region 104, where the highest voltage is applied, can be relaxed in this manner. That is, the difference in the intensity of the electric field at the channel region that is formed in the active layer under each of the gate electrodes can be corrected by employing this constitution.
Furthermore, the degradation or the breakdown that proceeds from the portion of the channel region on the drain region side can be suppressed in this manner.
The present invention is described in detail below referring to non-limited examples.
Embodiment 1
FIG. 1 shows a constitution according to the present invention, in which three thin film transistors are connected equivalently in series.
Referring to FIG. 1, a gate electrode 101 is superposed on an active layer 100 by three portions 106, 107, and 108.
Thus, channels are formed in the active layer 100 at portions where the gate electrode patterns 106, 107, and 108 are superposed. The region where a channel is formed is intrinsic (I-type), or substantially intrinsic.
The regions 102, 112, 113, and 104 in the active layer 100 are each doped with P (phosphorus), and exhibit N-type conductivity. The region 102 is the source region, and the region 104 is the drain region. Regions 103 and 105 are each a source contact portion and a drain contact portion, respectively.
The constitution according to the present example is characterized in that the patterns 106, 107, and 108, which function as gate electrodes, differ from each other in pattern width. More specifically, the size of the patterns is different as is shown by widths 109, 110, and 111.
In the present invention, the greatest width is indicated by 111. This constitution is employed based on the observed fact that, in case a plurality of thin film transistors are serially connected in an equivalent manner, a highest voltage is applied to the thin film transistor located on the side of the drain.
By employing the constitution above, the intensity of the electric field in the channel region under each of the gate electrodes can be controlled to yield the same (or approximately the same) value, thereby preventing breakdown or degradation from occurring on a particular portion.
Embodiment 2
A scheme of the present example is shown in FIG. 2. Referring to FIG. 2, the constitution of the present example is characterized in that the width of the gate line 201 corresponding to the crossing with an active layer is partially widened. Thus, the width of the channels corresponding to each of the thin film transistors is differed in this manner.
Referring to FIG. 2, the width of the gate electrode is sequentially increased from that corresponding to the one located on the side of the source region 203 to that of the electrode provided on the side of the drain region, 204 as is shown by 205, 206, and 207. Thus, in this manner, the corresponding channel length is sequentially increased to correct for the difference in electric field inside the channel.
Embodiment 3
The present invention can be applied to a liquid crystal display panel of an active matrix type. In particular, it can be used in peripheral drive circuits in which a high voltage is required. Examples of devices using an active-matrix type liquid crystal panel are given below.
Images can be displayed on liquid crystal panels by either irradiating light from a back light, or by reflecting an external light which is called reflecting type. The constitution according to the present invention can be used in either type.
FIG. 3A shows a photographing device such as a digital still camera, an electronic camera, or a video movie capable of handling a motion picture.
The device electronically stores an image photographed by a CCD camera (or a proper photographing means) provided to a camera body 2002. The thus photographed image is displayed on a liquid crystal display panel 2003 provided to the body 2001. The device is operated by means of operation buttons 2004.
FIG. 3B shows a portable personal computer (information processing device). The device comprises a liquid crystal display panel 2104 with a freely openable cover (lid) 2102, and information is input or a variety of arithmetic operations are made by using a keyboard 2103.
FIG. 3C shows a car navigation system (information processing device) equipped with a flat panel display. The car navigation system comprises an antenna portion 2304 and a main body having a liquid crystal display panel 2302.
Various types of information necessary for the navigation are switched by operation buttons 2303. In general, a remote control device (not shown) is used for the operation.
FIG. 3D shows an example of a projection type image display device. In the figure, the light emitted from a light source 2402 is optically modulated by a liquid crystal display panel to provide an image. The image is projected on a screen 2406 after it is reflected by mirrors 2404 and 2405.
FIG. 3E shows a main body of a video camera (photographing device) equipped with a display device known as a "view finder". A view finder comprises, roughly, a liquid crystal display panel 2502 and an eye piece 2503 on which the image is displayed.
Referring to FIG. 3E, the video camera is operated by operation buttons 2504, and the image is recorded on a magnetic tape stored inside a tape holder 2505. The image photographed by a camera (not shown) is displayed on the liquid crystal display panel 2502. The display panel 2502 also displays the image recorded on a magnetic tape.
Embodiment 4
The present invention refers to a modification of a constitution with reference to Example 2 as is shown in FIG. 2. The constitution shown in FIG. 2 comprises a path from a source to a drain and another different path from a drain to a source. Accordingly, in case the polarity of the supplied signal voltage is inverted, there is a problem that the symmetry of the operation is lost.
Thus, as is shown in FIG. 4, in the present example, the width 205 of the gate electrode on the source region side and that 207 of the gate electrode on the drain region side are provided the same, but wider than that 206 of the gate electrode located at the center.
In this manner, the path (through which the carriers move) from the source region 203 to the drain region 204 can be provided the same as that from the drain region 204 to the source region 203. Thus, the symmetry of the operation can be maintained even in case the polarity of the signal voltage that is supplied between the source and the drain is inverted.
By thus utilizing the present invention on a constitution comprising a plurality of thin film transistors being serially connected in an equivalent arrangement as is described above, the problem of breakdown and degradation can be solved in case a high voltage is applied to a part of the thin film transistors.
While the invention has been described in detail, it should be understood that the present invention is not to be construed as being limited thereto, and that any modifications can be made without departing from the scope of claims. | A semiconductor device comprising a structure in which a plurality of gate electrodes connected in common are arranged superposed on the active layer, wherein the widest gate electrode is located on the drain side. In this manner, local difference in electric field intensity applied to the channel region can be corrected to prevent a local degradation or breakdown from occurring. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional patent application Ser. No. 61/603,393 filed Feb. 27, 2012.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in the field of land development, particularly with water quality treatment and volume reduction of storm water runoff by retention, infiltration, evapo-transporation as is commonly required when constructing new areas or revitalizing/reconstruction of already developed areas. These water quality and volume removal features fall into a class of facilities referred to as best management practices or “BMPs”. Some common representation of BMP facilities include but are not limited to: biorention cells, infiltration trenches, constructed wetland, detention basin, retention basins, et al. BMPs are sometimes also referred to as “green infrastructure”.
The subject of water quality treatment and volume removal of storm water is of interest to those looking to attain construction permits from a county, state or federal entity such as the Environmental Protection Agency or any other organization or entity charged with the protection of environmental resources. Another reason for construction of green infrastructure would be to reduce additional storm water runoff volume from entering a combined sewer. Combined sewers is a term describing collection and conveyance systems within an urban or suburban area may collect runoff from rainfall events as well as sanitary discharges from residences or businesses into a single conveyance, which would then be directed to a waste water treatment plant (WWTP). Combined sewers are still a common practice in older urban areas. In many cases with urbanized areas, the benefit with using BMPs or “green infrastructure” would be as a means of reducing sewer operation fees, which are typically proportional to whatever volume of influent (flow in) would be to a waste water treatment plant (whether or not this influent would be sewage or rainwater). In particular, the application of the device described herein relates to the pretreatment of storm water runoff before entry into green infrastructure areas; a necessary step in order to ensure the longevity and viability of these planted zones, that also serve the function of infiltrating storm water volume in lieu of discharge into combined sewers or steams.
2. The Prior Art
Pretreatment of storm water runoff into green infrastructure or BMPs is known to be an important step in providing for the long term function and operation of urban green infrastructure is to be maintained in a cost effective way. A green infrastructure facility that is not outfitted with a means of pretreatment may undergo scouring or loss of stabilization and plant matter, its planting zone may be overwhelmed with trash and debris, its soil may become clogged with fine sediment rendering its purpose as an infiltration facility useless, excessive oil and heavy metals may kill plant growth especially in urban areas where green infrastructure would more readily encounters such pollutants.
Current practices include the use of fabric or small diameter stone to provide pretreatment by screening pollutants and trash. Some attempts at a manufactured solution have been the use of screens to filter out trash and sediment. However, due to the small cross-sectional flow area presented by these various screening methods, these types of configurations quickly clog and render not only the means of pre-treatment useless, but potentially the whole BMP facility.
prior art teaches nets be used to capture trash from the flow of water from pipes. Prior art also teaches inclined cells be used to efficiently settle sediment from the flow of water. This invention introduces the combination of both technologies in a stacked fashion. This is possible with the reversal of the traditional flow path in the settling cells. Prior art teaches the flow inside the settling cell to be substantially upward, i.e. From the bottom to an overflow weir. This invention teaches a method where the water flows from the top of the settling cells to orifices below the water surface and thus the water is substantially flowing downward. This method has shown to promise remarkable results in test models. The deterministic flow regime of flowing substantially with the direction of gravity proves to enhance the inherent settling direction of the sediment on the cell bottoms and the subtle directional change of the hydraulic flow toward an escape orifice as well as the eddy current in the settling cells all contribute to the separation of sediment from the water flow in this device. Because this device departs from traditional settling regimes claimed in U.S. Pat. Nos. 3,706,384 and 6,676,832 and substantially improves settling efficiency of the Happel et al U.S. Pat. Nos. 6,797,162; 6,428,692; 7,153,417; 724,256 where settling cells operate in series instead of in parallel and do not provide the overlapping features of the settling cells. This invention places a screening or netting surface above a cell settler and among other enhancement this device is new in its form and promises to be compact, cost effective and useful to the implementation of pretreatment of storm water run-off dedicated for evaporation and infiltration in green infrastructure designs, as well as being useful in other circumstances were treatment or cleaning of a liquid is required.
SUMMARY OF THE INVENTION
In view of the foregoing discussion, an object of this invention is to provide an improved storm water pre-treatment device that is currently lacking in the field of drainage and stormwater design.
Another object of this invention is to provide a pre-treatment device that would fit in a narrow (slender) profile, required for effective incorporation into an urban settings where green space area is limited, and where infiltration/plant growth beds cannot be set too deep due to their need for adequate sunlight.
According to a preferred embodiment of the invention, an improved inlet/pre-treatment apparatus comprising: (a) an intake feature; (b) a water quality treatment module comprised of baffle walls, lamina plates, netting, orifice plates arranged in such a way where a co-current flow regime would be established; that is to say, low flow situations would route over, under and through the baffles orifices and between lamina plates for a more effective treatment cycle, higher flows would be split between the more robust treatment mentioned for the low flow situation, as well as through a flow direction that would be treated by netting and some gross pre-treatment; (c) a compartment within the pre-treatment module that would capture oil spills, thus preventing the green infrastructure component (subsequent to the device) from being contaminated; (d) an optional, variable aperture feature that allows for the selection of different possible flow rates and reduction of scour and strain of plant material; (e) aligned clean out openings in the lamina plates to access sediment below the assembly from top of the device enclosure.
As will be appreciated from the ensuing detailed description of a preferred embodiment, the invention affords the advantages of: 1) modularity (more easily repeatable results and ease of installation), the same type (model) of unit can be placed and adjusted for a wide range of situations 2) enhanced water quality and growth viability of planted areas within green infrastructure; by providing (a) complete screening of all trash and floatables influent to infiltrative BMP facilities (aesthetics); (b) less frequent need for remediation of infiltration beds affected by clogged soils (benefit provided by removal of a moderate amount of fines); (c) oil capture before introduction to planting zones, to promote improved growth environment for plants and beneficial bacteria; (d) lastly, protection of soil beds from scour through an adjustable flow rate control feature (optional offline/bypass regime); (e) minimal drop in elevation between inflow and outflow threshold.
The invention and its various advantages will become better understood from the ensuing detailed description of preferred embodiments, reference being made on the accompanying drawings in which like reference characters denote like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic illustration of a storm water treatment system in which the invention is particularly useful; [apparatus embodying the invention; has been arranged collection of isometric views associated with the installation of the invention: FIG. 1B (top-view of implemented device), in this incidence the device is shown being installed to intercept flow before a standard inlet drainage box. Installed in an enclosure, the invention is to be situated upslope of a standard inlet box, hence intercepting flow first to direct towards a green infrastructure BMP. The invention is to be fastened to the inside walls of an appropriate structure of suitable dimensions to accommodate said device. Two knock-outs or orifices are to be made in the box to allow a path of water into and out of the apparatus;]
FIGS. 2A, 2B and 2C are side, front (profile) and top views, respectively, of a preferred embodiment, where storm water would be captured and directed through an interception box (trough). The captured water would then be directed through a debris net, and depending on the magnitude of flow be directed down through the sump of the box containing partial walls, plates and orifices; flow in excess of the capacity of the typical direction of flow would proceed through the net in the top compartment, still exhibiting a reasonable rate of treatment as trash and floatables would be captured by the net and fine sediment would still precipitate through the top of the lamella plates into the sump (lower compartment of the box) These plates are to be engineered to a lab-tested specification to develop various plates (orifice) options to accommodate a widely varying range of flows and sediment loads.
FIG. 1B is a top view is a schematic illustration of a storm water treatment system in which the invention is particularly useful. A representation of a drainage inlet structure, common in the practice of civil engineering drainage design is shown to illustrate the direction of runoff, in the event that flows excessive to the desired capacity of the box is reached.
DRAWING—REFERENCE NUMERALS
1 —Screening mesh and frame
2 —Screening frame attachment point
3 —Flow interception feature
4 —Lamella plates
5 —Orifices in wall 7 that release the flow between plates (lamellae)
6 —Internal wall ‘A’
7 —Internal wall ‘B’
8 —Outlet
9 —Adjustable flow restriction plate (as described in U.S. patent application publication no. 2009/0114577, Duncan)
10 —Sediment storage sump
11 —Oil trap
12 —Enclosure
13 —Effluent recombination chamber
14 —Hinged self-closing effluent control and sediment removal access baffle.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, in FIG. 2A , FIG. 2B & FIG. 2C there is shown a pre-treatment device, having internal walls ( 6 , 7 ) by which lamella plates ( 4 ) are supported. As well as, a housing by which the screening net ( 1 ) and adjustable flow restriction plate ( 9 ) are supported.
All inflow must pass screening mesh and frame ( 1 ) and screening mesh openings ( 2 )
In further detail, still referring to FIG. 2A , FIG. 2B & FIG. 2C , internal wall ‘A’ ( 6 ) also serves the purpose of providing a barrier to low fluid flow, by extending sufficiently higher than the invert of the interception feature ( 3 ) to direct dry weather flow down in front of Internal wall ‘A’ ( 6 ). In addition internal wall ‘A’ ( 6 ) provides volume storage for oil capture ( 11 ) by trapping lighter-than-water fluids between itself and the wall of the enclosure ( 12 ) which houses the apparatus.
In more detail, still referring to FIG. 2A , FIG. 2B & FIG. 2C , internal wall B′ ( 7 ) also serves the purpose of providing a barrier to fluid flow, by extending higher than internal wall ‘A’ ( 6 ), the purpose of this is to direct the water quality treatment flow between the plates ( 4 ). Plates ( 4 ) are inclined and spaced at approximately 1 to 2 inch and approximately inclined at a 55 degree angle to the horizontal. The water quality flow is proportioned by the number of cell compartments formed by plates ( 4 ) and by the size of orifice ( 5 ) as to insure that the flow in each cell compartment preserves a flow stress that is equal in each compartment. This flow stress is expressed in flow per area of each cell bottom plate. The incoming fluid is encouraged to flow parallel to the plate surface in a substantially downward direction. Between the cell plates settlement and migration of sediment onto the lamellae plates ( 4 ) of the treatment system take place under the influence of gravity and density difference of the particulates and the water. Eventually sediment slides from the bottom plate surfaces into the sump ( 10 ) of the enclosure ( 12 ). The orifice openings ( 5 ) in internal wall ‘B’ ( 7 ) are located and sized to facilitate flow as a function of the pressure differential of the water in upstream of plate ( 7 ) and downstream of plate ( 7 ) and related to preserve equality in flow stress in each neighboring settling cell in proportion with the effective horizontal projection of the inclined portion of the plate(s) ( 4 ). Further the orifice is located in such a way that the bottom of the opening is elevated above the bottom plate ( 4 ) of a cells. Orifice ( 5 ) drains to the post-treatment cell ( 13 ).
In further detail, still referring to FIG. 2A , FIG. 2B & FIG. 2C , screening mesh and frame ( 1 ) being supported by and anchored by an attachment point ( 2 ) is attached to the outlet side at the interface of the flow interception feature ( 3 ) and the wall of the enclosure ( 12 ). The screening mesh and frame ( 1 ) will be slid into pre-fabricated slots specifically designed to accommodate the dimensions of the net's hoop ( 2 ). Under this preferred embodiment, this would be the means for securing the screening mesh and frame.
In more detail, still referring to FIG. 2A , FIG. 2B & FIG. 2C , an adjustable flow restriction plate will be installed on the outlet feature ( 8 ), on the interior side of the enclosure's wall ( 12 ).
Referring now to FIG. 1A and FIG. 2B , a profile depth sufficient enough to accommodate fluid flow and treatment will be provided without any substantial vertical drop, such as about 8-18 inches from point of interception to point of discharge which would be considered reasonable.
The construction details of the invention as shown in FIG. 2B are that the enclosure may be made of concrete and the device may be made of metal or of any other sufficiently rigid and strong material such as high-strength plastic, and the like. Further, the various components of the device can be made of different materials.
While the invention has been described with reference to a particularly preferred embodiment, it will be appreciated that various variations and modifications may be made without departing from the spirit of the invention. Such changes are intended to fall within the scope of the appended claims.
CONCLUSION, RAMIFICATIONS, AND SCOPE
Accordingly the reader will see that, according to one embodiment of the invention, we have provided a better, more facilitative method of addressing pre-treatment of influent runoff being to green infrastructure.
While the above description contains many specificities, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. For example (not to be considered as an exhaustive listing), if the device was fitted into another type of structure, such as a manhole or a high density plastic structure, or if only the elevated height of the internal walls ( 6 , 7 ) i.e. “weirs” are used without lamella plates to create an inferior though still somewhat effective version of this device, or vice-versa, if lamellae are used without elevated walls (weirs), or if a different material is used in for any of the parts.
Thus the scope of the invention should be determined by the appended claims (to be provided) and their legal equivalents, and not by the examples given. | An object of this invention is to provide an improved means of water treatment effectiveness. The invention strips floating and sinking particulates from flowing water with netting and inclined settling cells, which are arranged in an overlapping fashion to save treatment space. The effluent invert is virtually level with the influent invert to minimize pressure loss. The device pre-treats water for further treatment by filtering methods and among other application is ideally suited for applications where low depth profile treatment is beneficial or required. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 14/71,871, filed Nov. 5, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 12/447,862, filed Apr. 29, 2009, and is a continuation-in-part of U.S. patent application Ser. No. 12/447,862, filed Apr. 29, 2009, which is a 371 application of International Patent Application No. PCT/US2007/083262, filed Oct. 31, 2007, which claims the benefit of U.S. Provisional Patent Application No. 60/863,764, filed Oct. 31, 2006, the disclosures of which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
The present disclosure relates to inhibitors of butyrylcholinesterase.
BACKGROUND OF THE INVENTION
Neurodegenerative diseases result from deterioration of neurons which over time will lead to neurodegeneration and disabilities.
It is known that reduction in levels of acetylcholine parallels the severity of a neurodegenerative disorder such as Alzheimer's disease (AD). In addition, progression of AD occurs concomitantly with changes in cholinesterase activity, i.e., acetylcholinesterase activity (AcChase) decreases while butyrylcholinesterase (BuChase) activity increases. Since both enzymes hydrolyze acetylcholine, the treatment for AD is based on the assumption that inhibiting the activity of these enzymes, in particular butyrylcholinesterase, will increase the level of acetylcholine. Unfortunately, currently utilized cholinesterase inhibitors are non-specific and show adverse peripheral effects.
Several neurodegenerative disorders are also associated with the formation of beta-amyloid plaques. They seem to be formed in the brain many years before the clinical signs of the disorder, e.g. AD, are detectable. Beta-amyloid plaque formation is associated with BuChase activity. Therefore, BuChase inhibitors can have a significant effect on preventing or retarding the formation of beta-amyloid plaques.
In addition, there is a general need for BuChase specific inhibitors. These compounds may be used in various biochemical, pharmacological, and cell biology applications to study the role of BuChase in normal cell growth and development, e.g., stem cell differentiation. Therefore, there is an unmet need for specific inhibitors of butyrylcholinesterase.
SUMMARY OF THE INVENTION
One aspect of the disclosure relates to inhibitors of butyrylcholinesterase for the treatment of neurodegenerative diseases. These inhibitors have the following general formulas:
wherein
X is O or S;
Y is O or N;
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl, and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
wherein
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl, and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
wherein
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
wherein
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, and unsubstituted or substituted phenyl;
R 3 and R 4 can be the same or different and are independently selected from H or at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
Another aspect of the disclosure relates to pharmaceutical compositions containing a pharmaceutical carrier and a therapeutically effective amount of these inhibitors of butyrylcholinesterase.
Another aspect of the disclosure relates to methods of treating a neurodegenerative disease by administering a therapeutically effective amount of these inhibitors of butyrylcholinesterase.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the effect of di-n-butyl 2-chlorophenyl phosphate (DB2ClPP) on acetylcholinesterase (AcChase) activity. AcChase was pre-incubated with either solvent or di-n-butyl 2-chlorophenyl phosphate, fractionated by native gel electrophoresis, and stained for enzyme activity.
FIGS. 2A and 2B depict phosphorylation of butyrylcholinesterase by di-ethyl 2-chlorophenyl phosphate. Butyrylcholinesterase was incubated with 14 C-labeled diethyl 2-chloro phenyl phosphate, or solvent, then separated using native PAGE. A) Gel stained for enzyme activity. B) Autoradiography of the gel.
FIG. 3 depicts the effect of DB2ClPP on the activity of trypsin.
FIG. 4 depicts the effect of DB2ClPP on the activity of chymotrypsin.
FIG. 5 depicts the effect of di-n-butyl 2-chlorophenyl phosphate on the activity of PKA and S6K2. Protein Kinase A (PKA) and S6K2 were incubated with the indicated concentrations of di-n-butyl 2-chlorophenyl phosphate and assayed as described previously. The reaction mixtures were separated by SDS-PAGE, and then stained for phosphoproteins with Pro-Q® Diamond.
FIG. 6 depicts the effect of DB2ClPP on hexokinase activity.
FIG. 7 depicts the lack of toxicity of di-n-butyl 2-chlorophenyl phosphate on porcine umbilical stem cells. Cells were cultured in Neurobasal Medium with increasing concentrations of di-n-butyl 2-chlorophenyl phosphate for 48 hours. Solvent acted as control. Each concentration had its own corresponding control group. Results are expressed as mortality and are the mean of 3 replicates ±SD.
FIG. 8 is a stick rendering which models the flexible docking of a phosphate with AcChase and BuChase.
FIG. 9 is a stick rendering which models the flexible docking of a phosphonate with AcChase and BuChase.
FIG. 10 is a stick rendering modeling the flexible docking of a phosphinate with AcChase and BuChase.
FIG. 11 is a stick rendering modeling the flexible docking of a phosphoramidate with AcChase and BuChase.
FIG. 12 shows a spectrum resulting from Matrix Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectroscopy. BuChase was incubated with di-n-butyl-2-chlorophenyl phosphate. The excess inhibitor was removed and BuChase was digested with trypsin. The tryptic peptides were then analyzed by MALDI-TOF.
DETAILED DESCRIPTION OF THE INVENTION
One aspect of the disclosure relates to inhibitors of butyrylcholinesterase (BuChase).
The butyrylcholinesterase inhibitors can be represented by a compound of Formula 1 or Formula 2
wherein
X is O or S;
Y is O or N;
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl, and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group; or a pharmaceutically acceptable salt thereof.
Alternatively, when R 1 and/or R 2 is phenyl, the phenyl may be substituted at least once wherein each substituent is independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group.
Alternatively, the C 1 -6 alkyl is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, cyclohexyl and n-pentyl.
Exemplary compounds of Formulas 1 and 2 include but are not limited to:
The butyrylcholinesterase inhibitors can also be represented by a compound of Formulas 3 and 4
wherein
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl, and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
Alternatively, when R 1 and/or R 2 is phenyl, the phenyl may be substituted at least once wherein each substituent is independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group.
Alternatively, the C 1 -6 alkyl is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, cyclohexyl and n-pentyl.
Exemplary compounds of Formulas 3 and 4 include but are not limited to:
The butyrylcholinesterase inhibitors can also be represented by a compound of Formulas 5 and 6
wherein R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, C 1 -6 alkyl, C 1 -6 alkenyl, and unsubstituted or substituted phenyl;
R 3 to R 6 can be the same or different and are independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
Alternatively, when R 1 and/or R 2 is phenyl, the phenyl may be substituted at least once wherein each substituent is independently selected from the group consisting of H, methyl, methoxy, and at least one electron withdrawing group.
Alternatively, the C 1 -6 alkyl is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, cyclohexyl and n-pentyl.
Exemplary compounds of Formulas 5 and 6 include but are not limited to:
The butyrylcholinesterase inhibitors can also be represented by a compound of Formula 7
wherein
R 1 and R 2 can be the same or different and are independently selected from the group consisting of H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, and unsubstituted or substituted phenyl
R 3 and R 4 can be the same or different and are independently selected from H or at least one electron withdrawing group;
or a pharmaceutically acceptable salt thereof.
Alternatively, when R 1 and/or R 2 is phenyl, the phenyl may be substituted at least once wherein each substituent is independently selected from H or at least one electron withdrawing group.
An “electron withdrawing group” draws electrons away from a reaction center. Electron withdrawing groups as defined herein include but are not limited to halogens, nitriles, carboxylic acids and carbonyls. Specific examples of electron withdrawing groups include but are not limited to F, Cl, Br, I, and NO 2 .
A “pharmaceutically acceptable salt” as used herein is any salt that retains at least some of the activity of the parent compound and without imparting any additional deleterious or untoward effects on the subject to which it is administered and in the context in which it is administered compared to the parent compound. A pharmaceutically acceptable salt also refers to any salt which may form in vivo as a result of administration of an acid, another salt, or a prodrug which is converted into an acid or salt.
Pharmaceutically acceptable salts of acidic functional groups may be derived from organic or inorganic bases. The salt may comprise a mono or polyvalent ion. Of particular interest are the inorganic ions, lithium, sodium, potassium, calcium, and magnesium. Organic salts may be made with amines, particularly ammonium salts such as mono-, di- and trialkyl amines or ethanol amines. Salts may also be formed with caffeine, tromethamine and similar molecules. Hydrochloric acid or some other pharmaceutically acceptable acid may form a salt with a compound that includes a basic group, such as an amine or a pyridine ring.
Another aspect of the present disclosure is drawn to therapeutic compositions comprising the presently disclosed compounds and a pharmaceutically acceptable carrier. The carrier may be any solid, semi-solid, or liquid material that acts as an excipient or vehicle for the active compound. The formulations may also include wetting agents, emulsifying agents, preserving agents, sweetening agents, bulking agents, coatings and/or flavoring agents. If used in an ophthalmic or infusion format, the formulation will usually contain one or more salts to adjust the osmotic pressure of the formulation.
The present disclosure provides for inhibitors of butyrylcholinesterase for use in the treatment of a condition or disease which is ameliorated by cholinesterase inhibition. Without wishing to be bound by theory, one of the ways cholinesterase inhibition can be helpful in the treatment of a neurodegenerative disease is by eliminating, reducing, or preventing the formation of beta amyloid plaques.
The diseases or conditions which can be treated by the presently disclosed inhibitors of butyrylcholinesterase include neurodegenerative diseases including, but not limited to, Alzheimer's disease and Lou Gehrig's disease.
Some embodiments include a method of treating Alzheimer's disease, comprising administering a compound described herein, such as DB2ClPP, to a mammal in need thereof.
Some embodiments include a method of reducing the level of a β-amyloid peptide in a brain of a mammal comprising administering an effective amount of a compound described herein, such as DB2ClPP, to the mammal. In some embodiments, the β-amyloid peptide is Aβ40. For example, the level of Aβ40 in the brain of the mammal can be reduced by at least about 10%, at least about 20%, or at least about 30%. In some embodiments, the β-amyloid peptide is Aβ42. For example, the level of Aβ42 in the brain of the mammal can be reduced by at least about 10%, at least about 20%, or at least about 30%.
For any method described herein, such as treating Alzheimer's disease in a mammal, or reducing the level of a β-amyloid peptide in a brain of a mammal, the mammal can be a human being that is at least about 50 years of age, at least about 65 years of age, at least about 70 years of age, at least about 75 years of age, at least about 80 years of age, or at least about 85 years of age.
One of ordinary skill in the art also will recognize that the presently disclosed butyrylcholinesterase inhibitors may be generally useful for performing various chemical, biochemical, pharmacological and cellular studies. For example, it may be useful to knock out the activity of butyrylcholinesterase by using the presently disclosed inhibitors and observing the effects. The presently disclosed compounds may be useful in stem cell research.
The present disclosure also provides for methods of treating neurodegenerative diseases with a therapeutically effective amount of a butyrylcholinesterase inhibitor.
Thus, the compounds of the present disclosure may be formulated for oral, buccal, transdermal (e.g., patch), intranasal, parenteral (e.g., intravenous, intramuscular or subcutaneous), ophthalmic or rectal administration or in a form suitable for administration by inhalation or insufflation.
For oral administration, the compounds may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycollate); or wetting agents (e.g., sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters or ethyl alcohol); and preservatives (e.g., methyl or propyl p-hydroxybenzoates or sorbic acid).
For buccal administration, the compounds may take the form of tablets or lozenges formulated in conventional manner.
The compounds of the present disclosure may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. The compounds may also be formulated for topical ophthalmic administration.
Formulations for injection or topical ophthalmic administration may be presented in unit dosage form, for example in ampules, or in multi-dose containers, optionally with an added preservative. The compounds may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.
The compounds of the present disclosure may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
For intranasal administration or administration by inhalation, the compounds of the present disclosure are conveniently delivered in the form of a solution or suspension from a pump spray container that is squeezed or pumped by the patient. The compounds of the disclosure can also be delivered in the form of an aerosol spray presentation from a pressurized container or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container or nebulizer may contain a solution or suspension of the active compound. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the disclosure and a suitable powder base such as lactose or starch.
As used herein, the term “effective amount” means an amount of a compound of the present disclosure that is capable of inhibiting the symptoms of a pathological condition described herein by modulation of butyrylcholinesterase activity. The specific dose of a compound administered according to the present disclosure will be determined by the particular circumstances such as the compound administered, the route of administration, the state of being of the patient, and the severity of the pathological condition. A proposed dose of a compound of the present disclosure for oral, parenteral, buccal or topical ophthalmic administration to the average adult human for the treatment of the conditions referred to above is about 0.01 to 50 mg/kg of the active ingredient per unit dose which could be administered, for example, 1 to 4 times per day.
In some embodiments, a compound described herein, such as DB2ClPP, is administered orally in an effective amount. For example, in some embodiments, an effective amount in a dosage form can be at least about 0.1 mg, at least about 1 mg, at least about 2 mg, at least about 5 mg, or at least about 10 mg, up to about 100 mg, up to about 200 mg, up to about 300 mg, up to about 400 mg, or up to about 500 mg, of the compound.
The potential as a therapeutic for Alzheimer's disease, or other conditions, may be improved if the compound in question is able to cross the blood brain barrier. In some embodiments, a sufficient amount of a compound described herein, such as DB2ClPP, is administered so that at least about 10 ng, at least about 50 ng, at least about 100 ng, up to about 1 μg, up to about 1 mg, or up to about 100 mg, of the compound crosses the blood brain barrier.
In some embodiments, sufficient amount of a compound described herein, such as DB2ClPP, is administered so that the compound has a concentration of at least about 10 −10 M at least about 10 −9 M, at least about 10 −8 M, up to about 10 −6 M, or up to about 10 −5 M, in the brain.
Aerosol formulations for treatment of the conditions referred to above in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains 20 μg to 1000 μg of the compound of the disclosure. The overall daily dose with an aerosol will be within the range a 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
EXAMPLES
Example 1: Synthesis
Method A
Representative Procedure for Method A.
To a dry 50 mL round bottom flask were added 10 mL of CH 2 Cl 2 and 1.3 mL (2.0 g, 8.2 mmol) of 2-chlorophenyl dichlorophosphate. The solution was cooled to 0° C. using an ice water bath. Then 2.5 equivalents of alcohol and 2.5 equivalents of pyridine in 10 mL of CH 2 Cl 2 were added to the stirring solution via cannulation. The reaction was left to stir overnight at room temperature. The reaction mixture was diluted with 80 mL of diethyl ether and washed three times with 40 mL of 10% HCl. The aqueous layers were combined and washed with 40 mL of CH 2 Cl 2 . The combined organic layer was washed once with 40 mL of saturated sodium bicarbonate, dried over magnesium sulfate, filtered, concentrated in vacuo, and purified by evaporative distillation.
2-Chlorophenyl dimethyl phosphate
Following the representative procedure described above and using methanol, 2-chlorophenyl dimethyl phosphate was obtained as a clear oil: 80% yield; b.p. 183° C./0.2 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 3.92 (d, 6H, 11.4 Hz, CH 3 ), 7.11-7.15 (m, 1H, Ar—H), 7.52 (td, 1H, 8.2, 1.7 Hz, Ar—H), 7.41-7.42 (m, 1H, Ar—H), 7.43-7.44 (m, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 55.22, 55.28, 121.32, 121.34, 125.30, 125.38, 126.03, 128.02, 128.03, 130.65, 146.59, 146.65.
2-Chlorophenyl diethyl phosphate
Following the representative procedure described above and using ethanol, 2-chlorophenyl diethyl phosphate was obtained as a clear oil: 100% yield; b.p. 180° C./0.3 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 1.37 (td, 6H, 7.1, 1.1 Hz, CH 3 ), 4.23-4.32 (m, 4H, CH 2 ), 7.09-7.13 (m, 1H, Ar—H), 7.24 (td, 1H, 8.2, 1.7 Hz, Ar—H), 7.41 (dt, 1H, 7.9, 1.4 Hz, Ar—H), 7.45 (dt, 1H, 8.2, 1.3 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 16.00, 16.03, 16.07, 16.10, 64.97, 65.03, 121.32, 121.35, 125.32, 125.39, 125.76, 127.88, 127.89, 130.57, 146.77, 146.83.
2-Chlorophenyl di-n-propyl phosphate
Following the representative procedure described above and using n-propanol, 2-chlorophenyl di-n-propyl phosphate was obtained as a clear oil: 82% yield; b.p. 245° C./0.3 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.96 (t, 6H, 7.4 Hz, CH 3 ), 1.74 (sextet, 4H, 7.3 Hz, CH 2 CH 2 CH 3 ), 4.11-4.21 (m, 4H, CH 2 CH 2 CH 3 ), 7.08-7.13 (m, 1H, Ar—H), 7.24 (td, 1H, 8.2, 1.7 Hz, Ar—H), 7.41 (dt, 1H, 7.9, 1.3 Hz, Ar—H), 7.46 (dt, 1H, 8.2, 1.3 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 9.94, 23.56, 23.62, 70.37, 70.44, 121.33, 121.35, 125.34, 125.41, 125.71, 125.73, 127.87, 127.88, 130.55, 146.82, 146.89.
2-Chlorophenyl di-i-propyl phosphate
Following the general procedure described above and using i-propanol, 2-chlorophenyl di-i-propyl phosphate was obtained as a clear oil: 70% yield; b.p. 205° C./0.7 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 1.33 (d, 6H, 6.2 Hz, CH 3 ), 1.38 (d, 6H, 6.2 Hz, CH 3 ), 4.81 (sept of doublets, 2H, 6.3, 0.8 Hz, CH(CH 3 ) 2 ), 7.09 (tm, 1H, 8.0 Hz, Ar—H), 7.23 (td, 1H, 8.2, 1.6 Hz, Ar—H), 7.40 (dt, 1H, 7.9, 1.5 Hz, Ar—H), 7.49 (dt, 1H, 8.2, 1.4 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 23.45, 23.47, 23, 50, 23.52, 23.62, 23.64, 23.67, 23.69, 73.94, 74.00, 121.19, 121.21, 125.27, 125.35, 125.43, 127.75, 127.76, 130.48, 147.01, 147.07.
Di-n-butyl 2-chlorophenyl phosphate
Following the general procedure described above and using n-butanol, 2-chlorophenyl di-n-butyl phosphate was obtained as a clear oil: 52% yield; b.p. 205° C./0.6 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.92 (t, 6H, 7.4 Hz, CH 3 ), 1.36-1.45 (m, 4H, 6.2, CH 2 CH 2 CH 2 CH 3 ), 1.65-1.72 (m, 4H, 6.3, CH 2 CH 2 CH 2 CH 3 ), 4.15-4.25 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.09-7.13 (m, 1H, Ar—H), 7.24 (td, 1H, 8.2, 1.6 Hz, Ar—H), 7.41 (dt, 1H, 8.0, 1.4 Hz, Ar—H), 7.45 (dt, 1H, 8.2, 1.3 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.53, 18.59, 32.13, 32.20, 68.62, 68.69, 121.32, 121.34, 125.33, 125.41, 125.68, 127.83, 127.84, 130.54, 146.82, 146.88.
Di-i-butyl 2-Chlorophenyl phosphate
Following the general procedure described above and using i-butanol, di-i-butyl 2-chlorophenyl phosphate was obtained as clear oil: 40% yield; b.p. 179° C./0.7 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.95 (appt dd, 12H, 6.7, 1.1 Hz, CH 3 ), 1.99 (septet, 2H, 6.6 Hz, CH), 3.92-4.01 (m, 4H, CH 2 ), 7.08-7.13 (m, 1H, Ar—H), 7.24 (td, 1H, 8.1, 1.7 Hz, Ar—H), 7.41 (dt, 1H, 8.0, 1.4 Hz, Ar—H), 7.46 (dt, 1H, 8.2, 1.2 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 18.57, 18.59, 18.60, 29.02, 29.09, 74.67, 74.73, 121.37, 121.40, 125.37, 125.44, 125.71, 127.87, 127.88, 130.56, 146.86, 146.91.
Di-n-butyl 4-chlorophenyl phosphate
Following the general procedure described above using dichloro 4-chlorophenylphosphate and n-butanol, di-n-butyl 4-chlorophenyl phosphate was obtained as a clear oil: 84%; b.p. 200° C./0.2 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.92 (t, 6H, 7.3 Hz, CH 3 ), 1.35-1.4 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 1.67 (quintet, 4H, 6.7 Hz, CH 2 CH 2 CH 2 CH 3 ), 4.09-4.20 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.15-7.18 (m, 2H, Ar—H), 7.28-7.31 (m, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.41, 18.51, 32.06, 32.13, 68.31, 68.36, 121.24, 129.57, 130.15, 130.16, 149.23, 149.31.
2-Chlorophenyl di-n-pentyl phosphate
Following the general procedure described above and using n-pentanol, 2-chlorophenyl di-n-pentyl phosphate was obtained as a clear oil: 88%; b.p. 185° C./0.3 mm Hg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.89 (t, 6H, 7.2 Hz, CH 3 ), 1.27-1.39 (m, 8H, CH 2 CH 2 CH 3 ), 1.67-1.74 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 4.14-4.24 (m, 4H, CH 2 CH 2 CH 2 CH 2 CH 3 ), 7.08-7.13 (m, 1H, Ar—H), 7.24 (td, 1H, 8.2, 1.6 Hz, Ar—H), 7.41 (dt, 1H, 7.9, 1.4 Hz, Ar—H), 7.46 (dt, 1H, 8.2, 1.3 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.93, 22.17, 27.48, 29.84, 29.90, 68.93, 69.00, 121.33, 121.35, 125.34, 125.41, 125.68, 125.70, 127.85, 127.87, 130.54, 146.81, 146.87.
2-chlorophenyl dicyclohexyl phosphate
Following the general procedure described above and using cyclohexanol, the crude product was purified by gravity column chromatography (silica gel 1:1, hexane:EtOAc), a second gravity column chromatography (silica gel 7:3, hexane:EtOAc) and evaporative distillation (b.p. 260° C./0.10 mm Hg) to afford 2-chlorophenyl dicyclohexyl phosphate as a colorless oil: 70% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 1.21-1.98 (m, 20H, (OCHC 5 H 12 ), 4.50-4.59 (m, 2H, (OCH) 2 ), 7.06-7.11 (m, 1H, Ar—H), 7.20-7.25 (m, 1H, Ar—H), 7.38-7.41 (m, 1H, Ar—H), 7.47-7.50 (m, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 23.32, 25.01, 32.97, 33.02, 33.15, 33.19, 78.40, 78.47, 121.16, 121.18, 125.22, 125.31, 127.65, 127.66, 130.37, 147.01, 147.07.
Method B
Representative Procedure for Method B.
A solution of dibutyl phosphite (0.73 g, 3.8 mmol) in 3 mL CCl 4 was added dropwise to a stirring solution containing the substituted phenol (3.0 mmol), 5 mL CCl 4 , tetra-n-butylammonium bromide (0.095 g, 0.3 mmol), NaOH (0.18 g, 4.4 mmol) and 5 mL water; it was stirred for an indicated amount of time at room temperature. The reaction mixture was dissolved in 10 mL of CCl 4 , extracted with ice-cold distilled water (3×10 mL), and each of the aqueous layer was washed with 10 mL CCl 4 . The combined organic layer was dried under MgSO 4 , concentrated in vacuo, and purified by evaporative distillation, flash or gravity chromatography.
2-Bromophenyl di-n-butyl phosphate
Following the representative procedure described above using 2-bromophenol (2 hours reaction time), the crude product was purified by evaporative distillation (b.p. 175° C./0.45 mmHg) followed by flash chromatography (silica gel, hexane:EtOAc, 3:2) to give 2-bromophenyl di-n-butyl phosphate as a pale yellow oil: 56% yield; R f =0.49 (hexane:EtOAc, 1:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.92 (t, J=7.4 Hz, 6H, CH 2 CH 2 CH 2 CH 3 ), 1.36-1.46 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 1.65-1.73 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 4.17-4.26 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.02-7.06 (m, 1H, Ar—H), 7.27-7.31, 1H, Ar—H), 7.47 (dt, J=8.2 Hz, 1.3 Hz, 1H, Ar—H), 7.58 (dt, J=8.0 Hz, 1.4 Hz, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.46, 18.54, 32.07, 32.14, 68.61, 68.68, 114.29, 114.38, 120.99, 121.01, 125.93, 128.55, 128.56, 133.54, 147.87, 147.93.
3-Bromophenyl n-butyl phosphate
Following the representative procedure described above using 3-bromophenol, the crude product was purified by gravity chromatography (silica gel, hexane:EtOAc, 4:1) to give 3-bromophenyl di-n-butyl phosphate as a clear oil: 38% yield; R f =0.5 (hexane:EtOAc, 1:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, J=7.4 Hz, 6H, OCH 2 CH 2 CH 2 CH 3 ), 1.36-1.45 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 1.64-1.71 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 4.10-4.20 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 7.16-7.23 (m, 2H, Ar—H), 7.30-7.33 (m, 1H, Ar—H), 7.39-7.40 (m, 1H, Ar—H); 13 C NMR (400 MHz, CDCl 3 ) δ 13.49, 13.50, 18.58, 32.12, 32.19, 68.45, 68.51, 118.75, 118.80, 122.56, 123.47, 123.52, 128.16, 130.70, 151.21, 151.28.
4-Bromophenyl di-n-butyl phosphate
Following the representative procedure described above using 4-bromophenol, the crude product was purified by gravity chromatography (silica gel, 4:1, hexane:EtOAc) to give 4-bromophenyl di-n-butyl phosphate as a clear oil: 32% yield; R f =0.06 (hexane:EtOAc, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, J=7.4 Hz, 6H, OCH 2 CH 2 CH 2 CH 3 ), 1.35-1.44 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 1.63-1.71 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 4.08-4.19 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 7.09-7.13 (m, 2H, Ar—H), 7.43-7.47 (m, 2H, Ar—H); 13 C NMR (400 MHz, CDCl 3 ) δ 13.49, 13.50, 18.57, 32.13, 32.19, 68.40, 68.46, 117.81, 117.83, 121.74, 121.79, 132.65, 149.86, 149.93.
Di-n-butyl 2,4-dichlorophenyl phosphate
Following the representative procedure described above, the crude product was purified by gravity chromatography (silica gel, hexane EtOAc, 9:1) to give di-n-butyl 2,4-dichlorophenyl phosphate as a light yellow oil: 22.26% yield; R f =0.12 (silica gel, hexane: EtOAc, 9:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.930 (t, J=7.4 Hz, 6H, OCH 2 CH 2 H 2 CH 3 ) 2 ), 1.36-1.46 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.65-1.72 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 4.14-4.24 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.26 (dd, 1H, J=8.9, 2.5 Hz, Ph-H), 7.40 (dd, 1H, J=8.8, 1.1 Hz, Ph-H), 7.42 (dd, J=2.6, 1H, 1.1 Hz, Ph-H) 13 C NMR (100 MHz, CDCl 3 ) δ 13.47, 18.54, 32.08, 32.14, 68.73, 68.80, 122.08, 122.10, 126.21, 126.29, 127.92, 130.20, 130.40, 130.42, 145.60, 145.66.
Di-n-butyl 2-fluorophenyl phosphate
Following the representative procedure described above using 2-fluorophenol, the crude product was purified by gravity chromatography (silica gel, hexane:EtOAc, 4:1) to give di-n-butyl 2-fluorophenyl phosphate as a clear oil: 48.25% yield; R f =0.25 (silica gel, hexane:EtOAc, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, J=7.4 Hz, 6H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.36-1.46 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.65-1.72 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 4.13-4.24 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.07-7.17 (m, 3H, Ph-H), 7.35-7.40 (m, 1H, Ph-H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.44, 13.48, 18.52, 32.08, 32.15, 68.47, 68.54, 116.72, 116.91, 122.31, 122.34, 124.40, 124.41, 124.44, 124.45, 125.74, 125.75, 125.80, 125.82, 138.36, 138.42, 138.48, 138.55, 152.24, 152.30, 154.71, 154.77.
Di-n-butyl 3-fluorophenyl phosphate
Following the representative procedure described above using 3-fluorophenol, the crude product was purified by gravity chromatography (silica gel, hexane:EtOAc, 4:1) to give di-n-butyl 3-fluorophenyl phosphate as a clear oil: 31% yield; R f =0.13 (silica gel, hexane:EtOAc, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, J=7.4 Hz, 6H, OCH 2 CH 2 CH 2 CH 3 ), 1.36-1.45 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 1.64-1.71 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 4.10-4.21 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 6.87-6.92 (m, 1H, Ar—H), 6.97 (dtd, 1H, J=9.7, 2.3, 0.8 Hz, Ar—H), 7.02-7.04 (m, 1H, Ar—H), 7.29 (td, 1H, 8.2, 6.6 Hz, Ar—H); 13 C NMR (400 MHz, CDCl 3 ) δ 13.48, 18.57, 32.12, 32.19, 68.41, 68.48, 107.94, 107.99, 108.19, 108.24, 111.86, 112.07, 115.68, 115.71, 115.73, 115.76, 130.36, 130.44, 151.50, 151.57, 151.67, 161.76, 164.21.
Di-n-butyl 3-nitrophenyl phosphate
Following the representative procedure described above, the crude product was purified by gravity chromatography (silica gel, hexane:EtOAc, 4:1) to give di-n-butyl 3-nitrophenyl phosphate as a light yellow oil: 53% yield; R f =0.18 (silica gel, hexane:EtOAc, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 0.94 (t, J=7.3 Hz, 6H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.37-1.46 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.67-1.7 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 4.14-4.24 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.51-7.56 (m, 1H, Ar—H), 7.61 (ddt, 1H, J=8.2, 2.2, 1.1 Hz, Ar—H), 8.05-8.08 (m, 2H, Ph-H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.37, 13.41, 18.49, 32.03, 32.10, 68.67, 68.73, 115.48, 115.53, 119.79, 126.26, 126.31, 130.30, 148.85, 151.10, 151.17.
Di-n-butyl 4-nitrophenyl phosphate
Following the representative procedure described above using 4-nitrophenol (1 hour reaction time), the crude product was purified by gravity chromatography (silica gel, hexane:EtOAc, 3:2) to give di-n-butyl 4-nitrophenyl phosphate as a pale yellow oil: 41% yield; R f =0.31 (hexane:EtOAc, 3:2); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, J=7.4 Hz, 6H, CH 2 CH 2 CH 2 CH 3 ), 1.36-1.45 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 1.66-1.73 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 4.13-4.23 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.36-7.40 (m, 2H, Ar—H), 8.23-8.27 (m, 2H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.46, 18.56, 32.09, 32.16, 68.79, 68.85, 120.47, 120.51, 125.65, 144.60, 155.58, 155.65.
Di-n-butyl 2-methylphenyl phosphate
Following the representative procedure above using 2-methylphenol, the crude product was purified by gravity chromatography (silica gel, 4:1 hexane:EtOAc) to give di-n-butyl 2-methylphenyl phosphate as light yellow oil: 46% yield; R f (silica gel, 80:20 hexane:EtOAc)=0.18; 1 H NMR (400 MHz, DCCl 3 ) δ 0.92 (t, J=7.4 Hz, 6H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.35-1.45 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.64-1.71 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 2.31 (s, 3H, Ar—CH 3 ), 4.09-4.20 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.04-7.08 (m, 1H, Ar—H), 7.14 (dd, J=7.6, 2.0 Hz, 1H, Ar—H), 7.18-7.20 (m, 1H, Ar—H), 7.27-7.29 (m, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.48, 16.30, 16.31, 18.58, 32.16, 32.24, 68.14, 68.205, 119.64, 119.66, 124.80, 124.82, 126.92, 126.94, 129.14, 129.21, 131.22, 149.21, 149.28. MS m/z 300; Calc. 300.
Di-n-butyl 4-methylphenyl phosphate
Following the general procedure above using 4-methylphenol, the crude product was purified by gravity chromatography (silica gel, 4:1 hexane:EtOAc) to give di-n-butyl 4-methylphenyl phosphate as a clear oil:38% yield; R f (silica gel, 80:20 hexane:EtOAc)=0.20; 1 H NMR (400 MHz, DCCl 3 ) □□ 0.92 (t, J=7.4 Hz, 6H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.35-1.44 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.63-1.70 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 2.32 (s, 3H, Ar—CH 3 ), 4.08-4.19 (m, 4H, (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.08-7.13 (m, 4H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) 13.48, 18.57, 20.65, 20.67, 32.14, 32.21, 68.09, 68.15, 119.61, 119.66, 130.04, 134.41, 134.42, 148.54, 148.61. MS m/z 300; Calc. 300.
Di-n-butyl 2-naphthyl phosphate
Following the representative procedure described above using 2-naphthol, the crude product was purified by evaporative distillation (b.p. 235° C./0.23 mm Hg) followed by flash column chromatography (silica gel, hexane:EtOAc, 4:1) to give di-n-butyl 2-naphthyl phosphate as a yellow oil: 54.5% yield; Rf=0.30 (hexane:EtOAc, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 1 H NMR (400 MHz, CDCl3) δ 0.91 (t, J=7.4 Hz, 6H (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 1.36-1.45 (m, 4H (OCH 2 CH 2 CH 2 CH 3 ) 2 , 1.65-1.72 (m, 4H (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 4.12-4.23 (m, 4H (OCH 2 CH 2 CH 2 CH 3 ) 2 ), 7.36 (dd, J=8.9, 2.4 Hz, 1H, Ar—H), 7.41-7.50 (m, 2H, Ar—H), 7.69 (s, 1H, Ar—H), 7.80 (t, J=9.6 Hz, 3H, Ar—H).
Additional Methods
n-Butyl bis(2,4-dichlorophenyl) phosphate
To a round bottom flask charged with pyridine (0.06 mL, 0.00073 mol) in 2 mL dry CH 2 Cl 2 was added n-butyl alcohol (0.067 mL, 0.00073 mol). This solution was added drop-wise via cannulation at 0° C. to a solution of bis(2,4dichlorophenyl) phosphorochloridate (0.15 g, 0.00036 mol) in 3 mL dry CH 2 Cl 2 . The reaction was allowed to react for 24 hrs at room temperature. The reaction was quenched by extracting with 2 mL 10% HCl, 5 mL saturated NaHCO 3 and 10 mL ethyl ether. The aqueous phase was extracted 3×5 mL with diethyl ether. The combined organic layer was dried over MgSO 4 , filtered and concentrated in vacuo. The crude product was purified by gravity column chromatography (silica gel, EtOAc) to give n-butyl bis(2,4-dichlorophenyl) phosphate as an oil: 10% yield; R f =0.36 (EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 0.93 (t, 3H, J=7.6 Hz, CH 3 ), 1.36-1.46 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 1.69-1.76 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 4.37 (q, 2H, J=6.8 Hz, CH 2 CH 2 CH 2 CH 3 ), 7.23 (dd, J=8.8, 2.4 Hz, 1H, Ar—H), 7.40 (dd, 1H, J=8.8, 1.2 Hz, Ar—H), 7.44 (dd, 1H, J=2.8, 1.2 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.44, 18.49, 31.98, 32.05, 70.35, 70.43, 122.23, 122.26, 126.41, 126.48, 128.04, 128.05, 130.42, 131.18, 131.20, 145.14, 145.20.
2-Chlorophenyl diphenyl phosphate
To a round bottom flask charged with NaH (0.1662 g of a 60% dispersion in mineral oil, approximately 0.42 mmol) in 3 mL dry THF was added phenol (0.383 g, 0.40 mmol) in 2 mL dry THF. Then this solution was added drop wise via cannulation to a solution of 2-chlorophenyl dichlorophosphate (0.5 g, 0.20 mmol) in 5 mL dry THF at room temperature. The mixture was allowed to react overnight and quenched by adding 10 mL of saturated NaHCO 3 and 10 mL of diethyl ether. The aqueous layer was extracted with diethyl ether (3×10 mL). The combined organic layer was dried over MgSO 4 , filtered and concentrated in vacuo. The crude product was purified by gravity column chromatography (silica gel, hexane:EtOAc, 7:3) to give 2-chlorophenyl diphenyl phosphate as an orange oil: 10% yield; R f =0.22 (silica, hexane:EtOAc, 7:3); 1 H NMR (400 MHz, CDCl 3 ) δ 7.14 (t, 1H, J=8 Hz, Ar—H), 7.22 (7, 3H, J=7.2 Hz, Ar—H), 7.28 (d, 4H, J=8 Hz, Ar—H), 7.36 (t, 4H, J=8 Hz, Ar—H), 7.41-7.44 (m, 2H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 120.18, 120.23, 121.36, 121.39, 125.50, 125.58, 125.70, 125.71, 126.31, 127.92, 127.93, 129.83, 130.77, 146.53, 146.59, 150.29, 150.37.
Dibutyl 2-chlorophenyl thiophosphate
A mixture containing n-butanol (0.5 mL, 5.4 mmol) and distilled pyridine (0.45 mL, 5.7 mmol) in 5 mL CH 2 Cl 2 was added dropwise to 2-chlorophenyl dichlorothiophosphate (0.56 g, 2.1 mmol) dissolved in 15 mL dry CH 2 Cl 2 . The reaction mixture was allowed to stir for 4 days, followed by dilution with 15 mL CH 2 Cl 2 , and extraction with 10% HCl (1×20 mL) and saturated NaHCO 3 (3×15 mL). The organic layer was dried under MgSO 4 , concentrated in vacuo, and purified by evaporative distillation to yield a pale yellow oil; 73% yield: b.p. 145° C./0.1 mmHg; 1 H NMR (400 MHz, CDCl 3 ) δ 0.94 (t, J=7.4 Hz, 6H, CH 2 CH 2 CH 2 CH 3 ), 1.39-1.48 (m, 4H, OCH 2 CH 2 CH 2 CH 3 ), 1.68-1.75 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 4.22 (dt, J=8.8 Hz, 6.5 Hz, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.10-7.14 (m, 1H, Ar—H), 7.22-7.26 (m, 1H, Ar—H), 7.37 (dt, J=8.2 Hz, 1.5 Hz, 1H, Ar—H), 7.42 (dt, J=8.0 Hz, 1.3 Hz, 1H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.55, 18.70, 31.95, 32.03, 68.93, 69.00, 122.19, 122.22, 125.82, 125.84, 126.11, 126.18, 127.53, 127.54, 130.51, 146.97, 147.04.
Butyl bis(2-chlorophenyl) phosphate
A mixture containing n-butanol (0.17 mL, 1.86 mmol), and distilled pyridine (0.15 mL, 1.86 mmol) in 5 mL CH 2 Cl 2 was added dropwise to bis(2-chlorophenyl) chlorophosphate (0.63 g, 1.56 mmol) dissolved in 15 mL dry CH 2 Cl 2 . The reaction mixture was allowed to stir for 24 hours, followed by dilution with 15 mL CH 2 Cl 2 , extraction with 10% HCl (1×20 mL) and saturated NaHCO 3 (3×15 mL), and was dried under MgSO 4 . Upon concentration in vacuo, a pale yellowish oil was obtained in 77% yield: 1 H NMR (400 MHz, CDCl 3 ) δ 0.92 (t, J=7.4 Hz, 3H, CH 2 CH 2 CH 2 CH 3 ), 1.37-1.46 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 1.70-1.77 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 4.37-4.42 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 7.11-7.16 (m, 2H, Ar—H), 7.23 (dd, J=8.2 Hz, 1.7 Hz, 2H, Ar—H), 7.42 (dt, J=7.9 Hz, 1.4 Hz, 2H, Ar—H), 7.47 (dt, J=8.2 Hz, 1.4 Hz, 2H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.45, 18.49, 32.01, 32.07, 69.97, 70.05, 121.49, 121.51, 125.47, 125.55, 126.14, 126.16, 127.87, 127.88, 130.63, 146.50, 146.56.
Bis(2-chlorophenyl)N-hexyl phosphoramidate
Into a flame-dried 50 mL round bottom flask was added 2.85 mmol of bis(2-chlorophenyl) chlorophosphate dissolved in 4 mL of CH 2 Cl 2 . This mixture was stirred for fifteen minutes at 0° C. Into a separate flame dried 50 mL round bottom flask was placed 1.6 equivalents of n-hexylamine dissolved in 4 mL of CH 2 Cl 2 and 1.9 equivalents of pyridine. This solution was allowed to stir for ten minutes at 0° C. The hexylamine/pyridine solution was then added to bis(2-chlorophenyl) chlorophosphate drop wise over a ten minute period via syringe. The reaction was stirred at 0° C. for ten minutes then stirred at room temperature overnight. Reaction mixture was diluted with 16 mL of CH 2 Cl 2 and washed three times with 20 mL of 10% HCl. The organic layer was washed two times with 18 mL of saturated NaHCO 3 solution, dried over MgSO 4 , and concentrated in vacuo to give bis(2-chlorophenyl)N-hexyl phosphoramidate as a golden oil: 71% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 0.85 (t, 3H, J=7.0 Hz, CH 3 ), 1.19-1.28 (m, 6H, CH 2 CH 2 CH 2 CH 3 ), 1.43-1.50 (m, 2H, NHCH 2 CH 2 ), 3.1-3.2 (dq, 2H, J=10.8, 7.0 Hz, NHCH 2 ), 3.56 (dt, 1H, J=13.4, 6.7 Hz, NH), 7.07-7.11 (m, 2H, Ar—H), 7.21 (td, 2H, J=7.9, J=1.6, Ar—H), 7.40 (dt, 2H, J=8.0, 1.3 Hz, Ar—H), 7.54 (dt, 2H, J=8.2, 1.3 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.95, 22.48, 26.06, 31.33, 31.40, 41.87, 121.74, 121.76, 125.45, 125.52, 125.66, 125.67, 127.74, 127.75, 130.46, 146.81, 146.87.
Bis(2-chlorophenyl) ethylphosphonate
A dried round bottom flask was charged with 0.60 mL (0.81 g, 5.5 mmol) of ethyl phosphonic dichloride and 9 mL of dry THF. To another dried round bottom flask sodium hydride (0.558 g of a 60% dispersion in mineral oil, approximately 14 mmol), 7 mL of dry THF and 2.1 equivalents (1.20 mL, 11.6 mmol) of 2-chlorophenol were added. The sodium 2-chlorophenoxide was added to the stirring phosphonic dichloride solution via cannulation. The mixture was allowed to react overnight at room temperature. The reaction mixture was dissolved in 50 mL of diethyl ether and washed three times with 10 mL of saturated sodium bicarbonate. The organic layer was then washed three times with 10 mL of saturated sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuo to give 2.08 g of a pale yellow oil. The oil was purified by flash column chromatography (silica gel, 3:7, EtOAc:hexane) and evaporatively distilled (220° C./0.2 mm Hg) to afford bis(2-chlorophenyl) ethylphosphonate as a clear colorless oil: 28%; GCMS (m/z) 139 (100%), 295 (M + , 85%); R f =0.41 (2:3, hexane:EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 1.45 (dt, 3H, J=22.0, 7.6 Hz, CH 2 CH 3 ), 2.26 (dq, 2H, J=18.5, 7.7 Hz, CH 2 CH 3 ), 7.09-7.14 (m, 1H, Ar—H), 7.17-7.22 (1H, Ar—H), 7.33 (dt, 1H, J=8.2 Hz, 1.5 Hz, Ar—H), 7.42 (ddd, 1H, J=8.0, 1.6, 0.8 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 19.29, 20.70, 122.26, 122.29, 125.67, 125.73, 125.95, 125.96, 127.81, 127.83, 130.57, 146.22, 146.30.
Bis(2-chlorophenyl) hexylphosphonate
Following the procedure above for bis(2-chlorophenyl) ethylphosphonate and using hexyl phosphonic dichloride, the crude product was purified by evaporative distillation (160-185° C./0.25 mm Hg) to remove 2-chlorophenol to afford bis(2-chlorophenyl) hexylphosphonate as a clear colorless oil: 50% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 0.88-0.91 m, 3H, CH 3 ), 1.30-1.35 (m, 4H, (CH 2 ) 3 (CH 2 ) 2 CH 3 ), 1.44-1.52 (m, 2H, (CH 2 ) 2 CH 2 (CH 2 ) 2 CH 3 ), 1.84-1.95 (m, 2H, CH 2 CH 2 (CH 2 ) 3 CH 3 ), 2.18-2.27 (m, 2H, CH 2 (CH 2 ) 4 CH 3 ), 7.09-7.13 (m, 1H, Ar—H), 7.19 (td, 1H, J=8.0, 1.7 Hz, Ar—H), 7.33 (dt, 1H, J=8.2, 1.5 Hz, Ar—H), 7.40-7.43 (m, 1H, Ar—H).
Butyl 2-chlorophenyl ethylphosphonate
To a dried round bottom flask 0.420 g (1.27 mmol) of bis(2-chlorophenyl) ethylphosphonate in 10 mL of dry THF with stirring was added. To another dried round bottom flask sodium hydride (0.0645 g of a 60% dispersion in mineral oil, approximately 1.6 mmol) and 3 mL of dry THF were added, followed by 1.1 equivalents (0.125 mL, 1.37 mmol) of anhydrous 1-butanol. The sodium butoxide was added to the stirring phosphonate solution via cannulation. After allowing the mixture to react for 36 hours at room temperature, an additional 0.32 equivalents of sodium butoxide was added to the reaction mixture via syringe. The reaction mixture was allowed to react overnight at room temperature. The reaction mixture was diluted in 50 mL of diethyl ether and washed three times with 10 mL of saturated sodium bicarbonate solution. The organic layer was then washed three times with 10 mL of saturated sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuo to give 0.09 g of a yellow oil. The crude product was purified by gravity column chromatography (gravity grade silica gel, 3:2, EtOAc:hexane) to afford butyl 2-chlorophenyl ethylphosphonate as a clear colorless oil: 2% yield, GCMS (m/z) 185 (100%), 276 (M + , 1%); 1 H NMR (400 MHz, CDCl 3 ) δ 0.91 (t, 3H, J=7.2 Hz, OCH 2 CH 2 CH 2 CH 3 ), 1.24-1.43 (m, 5H, OCH 2 CH 2 CH 2 CH 3 and PCH 2 CH 3 ), 1.60-1.69 (m, 2H, OCH 2 CH 2 CH 2 CH 3 ), 1.94-2.04 (m, 2H, PCH 2 CH 3 ), 4.06-4.24 (m, 2H, OCH 2 (CH 2 ) 2 CH 3 ), 7.10 (t, 1H, 5 Hz, Ar—H), 7.21-7.26 (m, 1H, Ar—H), 7.40 (dd, 1H, J=7.9, 1.4 Hz, Ar—H), 7.46 (d, 1H, J=12.8 Hz, Ar—H).
Butyl 2-chlorophenyl hexylphosphonate
Following the procedure above for butyl 2-chlorophenyl ethylphosphonate and using bis(2-chlorophenyl) hexylphosphonate, the crude product was purified by evaporative distillation to remove 2-chlorophenol (140-165° C./0.18 mm Hg) to afford butyl 2-chlorophenyl hexylphosphonate as an oil: 6% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 0.89 (t, 3H, J=6.9 Hz, CH 3 ), 0.91 (t, 3H, J=7.4 Hz, CH 3 ), 1.27-1.45 (m, 8H, OCH 2 CH 2 CH 2 CH 3 , (CH 2 ) 2 (CH 2 ) 3 CH 3 ), 1.60-1.77 (m, 4H, OCH 2 CH 2 CH 2 CH 3 , CH 2 CH 2 (CH 2 ) 3 CH 3 ), 1.92-2.00 (m, 2H, CH 2 (CH 2 ) 4 CH 3 ), 4.05-4.21 (m, 2H, OCH 2 CH 2 CH 2 CH 3 ), 7.07-7.11 (m, 1H, Ar—H), 7.23 (td, 1H, J=8.0, 1.6 Hz, Ar—H), 7.39-7.41 (m, 1H, Ar—H), 7.45 (dt, 1H, J=8.2, 1.4 Hz, Ar—H).
Bis (p-nitrophenyl) ethylphosphonate
To a round bottom flask charged with NaH (0.333 g, 0.0138 mol) in 5 mL dry THF was added 4-nitrophenol (1.1359 g, 0.0081 mol) in 5 mL dry THF. A solution of ethyl phosphonic dichloride (0.6 g, 0.0040 mol) in 5 mL dry THF was then added via cannulation at room temperature. The reaction was allowed to react overnight. The reaction was quenched by adding 15 mL of CH 2 Cl 2 and 15 mL of saturated NaHCO 3 . The aqueous layer was extracted with methylene chloride 3×20 mL. The combined organic layer was dried over MgSO 4 , filtered and concentrated in vacuo. The crude solid product was dissolved in CH 2 Cl 2 and the organic layer extracted several times with saturated NaHCO 3 . The organic layer was dried over MgSO 4 , filtered and concentrated in vacuo to give bis(p-nitrophenyl) ethylphosphonate as a white solid (mp 157-159° C.): 15% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 1.40 (dt, 3H, J=22.4, 7.6 Hz. CH 3 ), 2.22 (dq, CH 2 , J=18.4, 7.6 Hz, CH 2 ), 7.36-7.39 (m, 2H, Ar—H), 8.23-8.26 (m, 2H, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 6.30, 6.38, 19.01, 20.42, 120.97, 121.02, 125.83, 144.98, 154.75, 154.84.
Butyl p-nitrophenyl ethylphosphonate
To a round bottom flask with NaH (0.007 g of a 60% dispersion in mineral oil, approximately 0.18 mmol) in 1 mL dry THF was added dry 1-butanol (0.016 mL, 0.18 mmol). This solution was added drop wise via cannulation to a solution of bis(p-nitrophenyl) ethylphosphonate (0.093 mg, 0.26 mmol) in 3 mL dry THF in an ice/water bath. The mixture was allowed to react at room temperature overnight. The reaction was quenched by adding 5 mL of methylene chloride and 5 mL of NaHCO 3 . The aqueous layer was extracted with methylene chloride (3×5 mL). The organic layer was combined and dried over MgSO 4 , filtered and concentrated in vacuo. The crude product was purified by gravity column chromatography (silica gel, 70:30, EtOAc:hexane) to give butyl p-nitrophenyl ethylphosphonate as an oil: 26% yield; Rf=0.3 (silica gel, 70:30, EtOAc:hexane); 1 H NMR (400 MHz, CDCl 3 ) δ 0.92 (t, J=7.4 Hz, 3H, OCH 2 CH 2 CH 2 CH 3 ), 1.27 (dt, J=21.1, 7.7 Hz, 3H, PCH 2 CH 3 ), 1.34-1.42 (m, 2H, OCH 2 CH 2 CH 2 CH 3 ), 1.61-1.68 (m, 2H, OCH 2 CH 2 CH 2 CH 3 ), 1.96 (dq, J=18.3, 7.6 Hz, 2H, PCH 2 CH 3 ), 4.08 (dq, J=10.1, 6.6 Hz, 1H, OCH(H)CH 2 CH 2 CH 3 ), 4.14-4.22 (m, 1H, OCH(H)CH 2 CH 2 CH 3 ), 7.39 (dd, J=9.3, 1.1 Hz, 2H, Ar—H), 8.24 (d, J=8.9 Hz, 2H, Ar—H).
Bis(2-chlorophenyl) n-butylphosphonate
Into a dried three-neck 100 mL round bottom flask equipped with an addition funnel and a reflux condenser were added magnesium turnings (4.0 g/17 mmol) followed by 1 mL of dry diethyl ether. To this mixture was added drop wise with stirring at room temperature a solution of 1-bromobutane (1.8 mL/17 mmol) in 4 mL of diethyl ether over 30 minutes. After Grignard reagent formation was complete, 2-chlorophenyl dichlorophosphate (1.23 g/5.0 mmol) in 2 mL diethyl ether was added drop wise at rt. After allowing the mixture to stir for 2.5 h, it was worked up by addition of saturated aqueous NH 4 Cl and the organic layer separated. The aqueous layer was extracted with diethyl ether (3×) and the combined organic layer extracted with brine, dried over MgSO 4 , filtered and concentrated in vacuo. The yellowish oil was purified by flash chromatography (silica gel, 3:2, hexane: EtOAc) to give bis(2-chlorophenyl) butylphosphinate as an oil: 21% yield; R f =0.35 (3:2, hexane:EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 0.96 (t, 3H, J=7.4 Hz, CH 2 CH 2 CH 2 CH 3 ), 1.51 (sextet, 2H, J=7.4 Hz, CH 2 CH 2 CH 2 CH 3 ), 1.84-1.95 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 2.19-2.28 (m, 2H, CH 2 CH 2 CH 2 CH 3 ), 7.08-7.13 (m, 1H, Ar—H), 7.19 (td, 1H, J=8.0, 1.7 Hz, Ar—H), 7.33 (dt, 1H, J=8.2, 1.4 Hz, Ar—H), 7.41 (ddd, 1H, J=7.9, 1.6. 0.8 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 16.46, 16.64, 17.16, 17.21, 18.55, 19.94115.25, 115.28, 118.63, 118.69, 118.90, 118.92, 120.79, 120.80, 123.54, 139.24, 139.32.
2-Chlorophenyl di-n-butylphosphinate
The title compound was also isolated during the chromatographic purification of bis(2-chlorophenyl) n-butylphosphonate. Therefore, the 2-chlorophenyl di-n-butylphosphinate was further purified by flash chromatography (silica gel, 4:1 to 3:2, hexane: EtOAc) to give the title compound as an oil: 9% yield; R f =0.23 (3:2, hexane:EtOAc); 0.92 (t, 6H, J=7.2 Hz, CH 2 CH 2 CH 2 CH 3 ), 1.42 (sextet, 4H, J=7.4 Hz, CH 2 CH 2 CH 2 CH 3 ), 1.54-1.75 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 1.84-1.96 (m, 4H, CH 2 CH 2 CH 2 CH 3 ), 7.06-7.10 (m, 1H, Ar—H), 7.22 (td, 1H, J=7.9, 1.7 Hz, Ar—H), 7.39 (dd, 1H, J=8.0, 1.6 Hz, Ar—H), 7.54 (dt, 1H, J=8.2, 1.4 Hz, Ar—H).
Phenyl di-n-pentylphosphinate
Into a dried three-neck 100 mL round bottom flask was added 1.5 equivalents of magnesium turnings and 4 mL of dry THF. This mixture was stirred at room temperature. To a second dried round bottom flask was added 1.5 equivalents of 1-bromopentane diluted in 4 mL of THF. This mixture was stirred for five minutes and transferred to an addition funnel. The 1-bromopentane was added to the magnesium turnings drop wise over a thirty minute period at room temperature. The Grignard reagent begin to form fifteen minutes after the addition was completed. To a third dried round bottom flask was added phenyl dichlorophosphate dissolved in 1 mL of THF and transferred to the addition funnel. The phenyl dichlorophosphate/THF was added to the 1-bromopentane mixture over a fifteen minute period at 0° C. The reaction mixture was stirred at 0° C. for 35 minutes and then removed from the ice bath and allowed to continue stirring for 1.5 hours at room temperature. A golden liquid was obtained and was worked up using saturated NH 4 Cl. The organic layer was isolated and washed with brine and dried over MgSO 4 , filtered, concentrated in vacuo and purified by flash chromatography (silica gel, 3:2, hexane:EtOAc) to give phenyl di-n-pentylphosphinate as a golden oil: 3% yield; R f =0.33 (silica, 3:2, hexane: EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 0.8 (t, J=7.2 Hz, 6H, (CH 2 CH 2 CH 2 CH 2 CH 3 ) 2 ), 1.29-1.39 (m, 8H, CH 2 CH 2 CH 2 CH 2 ), 1.61-1.68 (m, 4H, PCH 2 CH 2 ), 1.79-1.88 (m, 4H, PCH 2 CH 2 ), 7.12-7.34 (m, 5H, Ph-H); 13 C NMR (100 MHz, CDCl 3 ) δ 13.76, 13.78, 21.53, 21.56, 22.11, 32.84, 32.99, 95.33, 96.08, 120.62, 120.67, 124.57, 129.50, 129.64, 129.75.
2-Chlorophenyl di-n-pentylphosphinate
Following the procedure above for the synthesis of phenyl dipentylphosphinate using 2-chlorophenyl dichlorophosphate, the crude product was purified by flash chromatography (silica gel, 3:2, hexane: EtOAc) to give 2-chlorophenyl di-n-pentylphosphinate as a golden oil: 11% yield; R f =0.33 (silica, 3:2, hexane:EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 0.89 (t, J=7.6 Hz, 6H, (CH 2 CH 2 CH 2 CH 2 CH 3 ) 2 ), 1.28-1.41 (m, 8H, CH 2 CH 2 CH 2 CH 2 ), 1.60-1.73 (m, 4H, PCH 2 CH 2 ), 1.86-1.93 (m, 4H, PCH 2 CH 2 ), 7.08 (t, J=7.7 Hz, 1H, Ar—H), 7.19-7.23 (m, 1H, Ar—H), 7.39 (d, J=7.9 Hz, 1H, Ar—H), 7.55 (dd, J=8.1, 1.0 Hz, 1H, Ar—H).
Bis(2-chlorophenyl) ethylphosphonate
A dried round bottom flask was charged with 0.60 mL (0.81 g, 5.5 mmol) of ethyl phosphonic dichloride and 9 mL of dry THF. To another dried round bottom flask sodium hydride (0.558 g of a 60% dispersion in mineral oil, approximately 14 mmol), 7 mL of dry THF and 2.1 equivalents (1.20 mL, 11.6 mmol) of 2-chlorophenol were added. The sodium 2-chlorophenoxide was added to the stirring phosphonic dichloride solution via cannulation. The mixture was allowed to react overnight at room temperature. The reaction mixture was dissolved in 50 mL of diethyl ether and washed three times with 10 mL of saturated sodium bicarbonate. The organic layer was then washed three times with 10 mL of saturated sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuo to give 2.08 g of a pale yellow oil. The oil was purified by flash column chromatography (silica gel, 3:7, EtOAc:hexane) and evaporatively distilled (220° C./0.2 mm Hg) to afford bis(2-chlorophenyl) ethylphosphonate as a clear colorless oil: 28%; GCMS (m/z) 139 (100%), 295 (M + , 85%); R f =0.41 (2:3, hexane:EtOAc); 1 H NMR (400 MHz, CDCl 3 ) δ 1.45 (dt, 3H, J=22.0, 7.6 Hz, CH 2 CH 3 ), 2.26 (dq, 2H, J=18.5, 7.7 Hz, CH 2 CH 3 ), 7.09-7.14 (m, 1H, Ar—H), 7.17-7.22 (1H, Ar—H), 7.33 (dt, 1H, J=8.2 Hz, 1.5 Hz, Ar—H), 7.42 (ddd, 1H, J=8.0, 1.6, 0.8 Hz, Ar—H); 13 C NMR (100 MHz, CDCl 3 ) δ 19.29, 20.70, 122.26, 122.29, 125.67, 125.73, 125.95, 125.96, 127.81, 127.83, 130.57, 146.22, 146.30.
Example 2: Cholinesterase Assays
Acetylcholinesterase (from electric eel), butyrylcholinesterase (from horse serum), DTNB, butyrylthiocholine, acetylthiocholine, and BSA were purchased from Sigma. The dialkyl 2-chlorophenyl (and 4-chlorophenyl) phosphates were solubilized in reagent grade methanol.
Cholinesterase activity measurements were performed essentially according to the method of Ellman (Biochemical Pharmacology 7:88-90, 1961). The composition of the assay mixture was 0.1 M sodium phosphate, pH 7.5, 0.033 M DTNB, 0.001 M MgCl 2 , and 100 μg/mL of BSA containing appropriate amounts of substrate and inhibitor. Each assay was initiated by the addition of substrate and the activity quantified by measuring the formation of the thionitrobenzoate anion at 412 nm at 37° C. Methanol used to solubilize the dialkyl phenyl phosphates [1% (v/v) final concentration] had no inhibitory effect on either enzyme.
Butyrylcholinesterase was pre-incubated at room temperature with inhibitor in the assay cocktail minus substrate for varying periods of time at 25° C. Substrate was then added and the activity measured as described above. The relative rates of enzyme inactivation were determined by plotting enzyme activity versus time of pre-incubation with inhibitor. Results were expressed as the rate constant for the rate of enzyme inactivation. In the case of AcChase, results were expressed as the % of activity remaining relative to the enzyme incubated only with solvents.
Enzyme activity was also measured by native gel electrophoresis. For cholinesterase activity, proteins (10 μg of both acetylcholinesterase and butyrylcholinesterase) were fractionated on Novex precast 10% Tris glycine gels (Invitrogen). Enzyme activity was detected by first incubating the gels in a solution of 5 mM substrate then staining with a solution of copper sulfate/potassium ferricyanide.
The first series of experiments determined the effect of the dialkyl 2-chlorophenyl (and 4-chlorophenyl) phosphates on both AcChase and BuChase. None of the compounds had any inhibitory effect on AcChase (See Table 1). In Table 1, AcChase was incubated with 100 μM of the indicated phenyl phosphate for 60 minutes at 25° C. and then assayed as described above. Results were expressed as the % activity relative to enzyme incubated with solvent ±SD (standard deviation).
TABLE 1
Effect of dialkyl 2-chlorophenyl phosphates
on acetylcholinesterase activity.
Compound
% Activity ± SD
Di-methyl-
101.9 ± 0.019
Di-ethyl-
96.77 ± 0.019
Di-n-propyl-
97.38 ± 0.028
Di-iso-propyl-
97.82 ± 0.045
Di-n-butyl-
97.60 ± 0.029
Di-iso-butyl-
96.18 ± 0.023
Di-n-butyl-(4Cl)
97.61 ± 0.006
Di-n-pentyl-
101.7 ± 0.030
In contrast, several of the compounds showed inhibitory activity on BuChase. While di-methyl- and di-isopropyl 2-chlorophenyl phosphates appeared to have no effect on BuChase activity under standard conditions, they showed inhibitory activity when their concentration was increase as shown in Table 2. The remaining derivatives showed significant inhibitory activity against the enzyme under standard conditions (Table 2). Interestingly, the degree of inhibitory activity, measured as the rate of enzyme inactivation, appears to be a function of the structure of the derivative. In Table 2, BuChase was incubated for increasing periods of time at 25° C. with 100 nM inhibitor then assayed for activity as described above. Rate constants were calculated from a plot of enzyme activity vs. time of inhibitor exposure. Activity measurements at each time point (3 to 4 per compound) were performed in triplicate. Slopes were calculated by linear regression analysis.
TABLE 2
Rates of inactivation of butyrylcholinesterase by
di-alkyl 2-chlorophenyl phosphates.
Compound: (di-alkyl 2-
k (min −1 ) × 10 −2 ±
chlorophenyl phosphate)
S.E.M/Comments
Di-methyl-
Inhibitory at 10 −4 M,
48.9% Inhibition
Di-isopropyl-
Inhibitory at 10 −4 M,
85.3% Inhibition
Di-ethyl-
6.64 ± 2.1
Di-n-prop-
20.21 ± 2.2
Di-n-butyl-
64.76 ± 3.0
Di-isobutyl-
60.83 ± 5.8
Di-n-butyl-(4Cl)
13.01 ± 2.0
Di-n-pentyl-
30.44 ± 3.3
Control
1.64 ± 1.1
Exhaustive dialysis of the inhibited enzyme did not restore enzyme activity, suggesting that the enzyme had been covalently modified, i.e., phosphorylation of the serine within the enzyme's catalytic triad. In some cases of inhibition, cholinesterases are capable of regaining catalytic activity.
Table 3 depicts reactivation of inactive butyrylcholinesterase. BuChase was incubated with excess di-butyl 2-chlorophenyl phosphate for 60 min at 4° C. The excess phosphate was removed using a desalting column. The inactivated BuChase was incubated at 4° C. for various periods of time and then assayed for activity. Results were expressed as percent inhibition and calculated using the following formula; [(activity with solvent only)—(activity with DB-2Cl-PP)]/(activity with solvent only)×100%. There is no significant reactivation over 24 hours as the % remaining activities are statistically the same.
TABLE 3
Reactivation of inactive butyrylcholinesterase
Incubation Period
0 hours
3.5 hours
7 hours
24 hours
% Remaining
0.6
0.6
0.8
1.1
Activity
Using native gel electrophoresis, both AcChase and BuChase activity was detected. Pre-incubation of AcChase with di-ethyl 2-chlorophenyl phosphate had no effect on AcChase activity ( FIG. 1 ). In contrast, the activity of BuChase was nearly completely inhibited by di-ethyl 2-chlorophenyl phosphate ( FIG. 2A ).
The cholinesterases were pre-incubated with 14 C-di-ethyl-2-chlorophenyl phosphate and then fractionated by native gel electrophoresis as described above. The proteins were fixed in the gel with 10% acetic acid/30% methanol. The fixative was removed and replaced with 100 mL of EN 3 HANCE. The gel was incubated for 60 minutes at room temperature with gentle agitation and then placed in 5% PEG and incubated for 30 minutes at room temperature with gentle agitation. The gel was then dried down on a piece of 3 MM filter paper, exposed to X-ray film at −80° C. for 2 weeks, and then developed. Pre-incubation of BuChase with 14 C-labeled di-ethyl 2-chlorophenyl phosphate and gel electrophoresis of the mixture showed that the compound had been covalently modified by the compound ( FIG. 2B ).
Table 4 below shows the relative inhibitory activity of exemplary compounds of the present disclosure. The results were obtained by pre-incubating the enzyme with the compound (final concentration 10 −7 M) for various periods of time and measuring the remaining enzyme activity. The results are shown as the change in absorbance at 412 nm/minute. In order to simplify the results from all the compounds, the enzyme activities were normalized to 2-chlorophenyl-di-n-butyl phosphate which was set as 1.0. Since two different preparations of enzyme were used, the normalization procedure would adjust for any differences in the amount of enzyme. Several of the compounds are potent inhibitors, i.e., the rates of inactivation are so fast that they were not measurable under these conditions. In other cases, the compound's inhibitory activity is not as strong and assay conditions were modified to increase the inhibitor concentration.
Table 4: Rates of inactivation of butyrylcholinesterase by exemplary compounds: Change in Absorbance at 412 nm/Minute. (ND=No Data)
TABLE 4
Change in
Absorbance at
Change in
412 nm/Minute
Absorbance at
(Not Normalized)/
412 nm/Minute
Compounds
Comments
(Normalized)
0.918
1.366
4.18
6.220
0.495
0.737
0.227
0.338
92% inhibition after 1 minute under standard conditions
0.468
0.696
1.75
2.604
Not Inhibitory under standard conditions/ Inhibitory at 10 −4 M. 14.6% inhibition
Not inhibitory under standard conditions. Inhibitory at 10 −4 M: 63.4% inhibition.
ND
ND
ND
ND
Not inhibitory under standard conditions. Inhibitory a 10 −4 M: 29.4% inhibition
Reversible inhibitor: K i = 2.1 μM
ND
ND
100% Inhibition (Immediate under standard conditions)
83% Inhibition (Immediate). 100% Inhibition after 2 minutes
10.04
14.94
0.688
1.024
0.32
0.48
ND
ND
ND
ND
ND
ND
ND
ND
100% inhibition under standard conditions
ND
ND
ND
0.684
1.018
ND
ND
ND
ND
0.688
1.024
Not inhibitory under standard conditions. Inhibitory a 10 −4 M: 73.9% inhibition.
Matrix Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectroscopy was used to show that BuChase was covalently modified ( FIG. 12 ). BuChase was incubated with di-n-butyl-2-chlorophenyl phosphate. Excess inhibitor was removed and the enzyme was digested with trypsin. The tryptic peptides were then analyzed by MALDI-TOF. Unmodified peptide containing the active site serine (MW 2198.86) and modified peptide (MW 2390.9060) can be seen. This is what would be predicted if BuChase had been covalently modified. Irreversible inhibitors usually covalently modify an enzyme, and inhibition cannot therefore be reversed. This results shows that di-n-butyl-2-chlorophenyl phosphate is likely an irreversible inhibitor.
Many of the presently disclosed compounds are irreversible inhibitors. In some respects, it may be desirable to have irreversible inhibitors which act on butyrylcholinesterase as there may be such advantages as reduced dosage and greater efficacy, etc.
Example 3: Specificity of Butyrylcholinesterase Inhibitors
The specificity of di-n-butyl 2-chlorophenyl phosphate (DB-2Cl-PP) was determined by its effects on the serine proteases trypsin and chymotrypsin, protein kinases Protein Kinase A and S6K2, and hexokinase.
For protein kinase activity, histone was used as the substrate for protein kinase A (PKA) and glutathione-S-transferase-S6 (GST-S6) for S6K2. Enzyme was pre-incubated with substrate and varying concentrations of inhibitor on ice for 30 minutes. The control sample contained solvent (methanol). ATP was then added to each sample and the cocktail incubated at 30° C. for 15 minutes. Equal amounts of each mixture were fractionated by SDS-PAGE on a 10% acrylamide gel. The gel was fixed in 50% methanol/10% acetic acid, washed with water, and then stained in Pro-Q Stain in the dark for 60 minutes. The gel was then destained, washed, and scanned on a Typhoon Imager ( FIG. 5 ).
The effect of DB2ClPP (di-n-butyl 2-chlorophenyl phosphate) on the activity of trypsin was assayed. Trypsin was incubated with solvent, 10 μM DB2CPP, or 10 μM DIFP (a known inhibitor of trypsin) for 60 minutes at 25° C. to determine any inhibitory effect of DB2CPP on enzymatic activity. Enzyme activity is given as nmoles of BAEE hydrolyzed per minute at 25° C. Data shown are the mean of three replicates ±SEM. ( FIG. 3 )
The effect of DB2ClPP on the activity of chymotrypsin was assayed. Trypsin was incubated with solvent, 10 μM DB2CPP, or 10 μM PMSF (a known inhibitor of chymotrypsin) for 60 minutes at 25° C. to determine any inhibitory effect of DB2CPP on enzymatic activity. Enzyme activity is given as nmoles of ATEE hydrolyzed per minute at 25° C. Data shown are the mean of three replicates ±SEM. ( FIG. 4 )
The effect of DB2ClPP on hexokinase activity was assayed. Hexokinase was incubated with solvent, 10 mM iodoacetamide (a known hexokinase inhibitor), or 10 μM DB2CPP for 60 min at 25° C. Enzyme activity is given as the nmoles of NADPH generated per min at 25° C. Data shown are the mean of three replicates ±SEM. ( FIG. 6 )
As seen in FIGS. 3 (trypsin), 4 (chymotrypsin), 5 (PKA and S6K2), and 6 (hexokinase), none of the above mentioned enzymes were affected by di-n-butyl 2-chlorophenyl phosphate.
Example 4: Effects of Butyrylcholinesterase Inhibitors on Cells
Porcine umbilical stem cells were cultured in Neurobasal Medium supplemented with B27 (Invitrogen) and antibiotics for various periods of with varying concentrations of di-n-butyl-2-chlorophenyl phosphate. Cells were collected, washed, counted, and analyzed for viability by Trypan Blue staining. Di-n-butyl-2-chlorophenyl phosphate did not have any significant effect on mortality of the porcine umbilical stem cells ( FIG. 7 ).
In addition, uptake of di-n-butyl-2-chlorophenyl phosphate by porcine umbilical stem cells was measured after 24 and 48 hours of culture (Table 5).
TABLE 5
Incubation Period
0 hours
24 hours
48 hours
fg DB2Cl-PP/cell (±SEM)
2.55 ± 0.011
11.57 ± 1.02
13.62 ± 0.003
Also, the uptake of di-n-butyl-2-chlorophenyl phosphate by human umbilical cells was measured after 24 of culture for both undifferentiated cells and differentiating neurons. (Table 6)
TABLE 6
0 hours
24 hours
fg/cell
fg/cell
Undifferentiated
114.72 ± 37.93
795.89 ± 202.41
Neurons
78.85 ± 8.04
820.52 ± 82.32
Example 5: Brain Permeability
An animal study using two groups (n=7/group) of male Long-Evans rats (200-225 g, Charles River, Portage, Mich.) was conducted to determine whether DB2ClPP crosses the blood brain barrier. DB2ClPP was dissolved in dimethyl sulfoxide (DMSO). Rats were injected intraperitoneally with either 0.2 mL DMSO (vehicle control) or 0.2 mL of a 10 mg/mL solution of DB2ClPP with DMSO as solvent. Thirty minutes after DB2ClPP treatment, animals were deeply anesthetized with isoflurane and then decapitated. Brains were removed quickly, rinsed in ice cold phosphate buffer saline (pH 7.4) and block dissected and flash frozen in liquid nitrogen and stored at −80° C. until assayed.
The tissue from two animals injected with DB2ClPP were processed as follows: i) brain tissue (1.5 g) was allowed to thaw on ice in a Dounce homogenizer; ii) 10 mL of methylene chloride was added and the tissue extracted with 20 strokes of the loose fitting pestle. The homogenate was clarified by centrifugation and the supernatant extracted three times with methylene chloride using a separatory funnel. The organic phase was collected, pooled, and dried over magnesium sulfate. The eluate was then concentrated down to a volume of approximately 200 μl under nitrogen and analyzed by GC/MS for the presence of the DB2ClPP. A solution of neat DB2ClPP served as control. The DB2ClPP was present in both samples. Based on a standard curve for DB2ClPP, one sample contained 220 ng and the other 125 ng of DB2ClPP.
Example 6: Inhibition of β-Amyloid Peptides
One of the more significant factors affecting patients with Alzheimer's disease is the elevated level of neurotoxic β-amyloid peptide. The most prominent β-amyloid peptides are referred to as Aβ40 and Aβ42 peptides. For our in vitro studies we used neuroblastoma cells as a biological model for evaluating 3-amyloid peptide production. Cells were cultured in Eagles MEM containing Glutamax, penicillin and streptomycin, and 0.5% fetal calf serum. To monitor the effects of DB2ClPP, cells were grown for 24 hrs in the presence or absence of 10 −8 M DB2ClPP. The supernatant was collected and concentrated using a 2K centrifugal membrane filter. The concentrated solution was then analyzed by ELISA for Aβ40 and Aβ42 peptides. The results, in pg/mL, are shown below. DB2ClPP at 10 −5 M significantly inhibits formation of the two β-amyloid peptides. Results are expressed as the mean of three assays ±Std. Deviation. One point had only one sample due to a technical error.
TABLE 7
Aβ-40
Aβ-42
DB2ClPP
[pg/mg]
[pg/mg]
10 −5 M
203.1 ± 5.2
132.1 ± 2.3
10 −6 M
111.5 ± 0.5
67.4 (one sample)
10 −8 M
87.3 ± 3.4
56.9 ± 3.1
No Inhibitor
122.5 ± 1.7
88.5 ± 0.2
As demonstrated in the results of Table 7, administration of a higher concentration (i.e., 10 −5 M) of DB2ClPP inhibitor resulted in an increased concentration of Aβ-40 and Aβ-42 peptides as compared to when no inhibitor was administered in the control. However, when a lower concentration of DB2ClPP inhibitor was administered (i.e., 10 −5 M), there was a decreased concentration of Aβ-40 and Aβ-42 peptides, including a lower concentration than when no inhibitor was administered. The decreased concentration of Aβ-40 and Aβ-42 peptides when administering a lower concentration of DB2ClPP is an unexpected result.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
The terms “a” and “an” and “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Furthermore, numerous references have been made to patents and printed publications throughout this specification. Each of the above cited references and printed publications are herein individually incorporated by reference in their entirety.
In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described. | Butyrylcholinesterase inhibitors, their formulation, and their use primarily in the treatment of neurodegenerative diseases. These inhibitors generally are phosphates, phosphonates, phosphinates, and phosphoramidates.
These inhibitors can be incorporated in pharmaceutical compositions and administered to a patient in therapeutically effective amounts to treat neurodegenerative diseases. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to technology for video calls and meetings. More specifically, it relates to automatically adjusting eye gaze direction in a set of images to simulate eye-contact.
SUMMARY OF THE INVENTION
[0002] In a typical video meeting or phone conversation, each of two persons has a computer or a portable electronic device, controlled by one or more processors executing software instructions. Each device has a screen and a video camera. Typically, B's camera will be positioned above B's screen. Video of B is transmitted across a communication system from B's camera to A's screen. Because B is looking at A's image on the screen, A will perceive B to be gazing downward, not making eye contact. The present invention analyzes video frames for the orientations of B's head and gaze direction, and uses image editing software to virtually correct the gaze direction of B's eye upward, toward B's camera.
[0003] By “gaze direction” we mean the direction in which a person, or a camera is viewing. The gaze may be directed toward an area or a point.
[0004] Within a given video frame, any aspect of the eye or surrounding tissue and hair might be measured. Parameters may include location, orientation, size, and coloring, in an absolute sense or in relation to other features. The software might determine, for example, such parameters for the visible portion of the sclera (or “white” of the eye); the iris; the eyelid, eyebrows; and eyelashes. In particular, software tools, may be used to determine the exact location of a speaker's pupil. Software tools may be used to adjust the geometry of the eye itself, and possibly also the geometries of neighboring features. For example, the pupil may be moved toward the center of the eye. They eye opening may be enlarged, to offset the apparent reduction in size when a person is looking downward.
[0005] Of course, if the camera is located relative to the screen other than above it, then the necessary corrections must take that into account. The location of the camera may be a static feature of the device. For example, a cell phone or a laptop computer may have a built-in camera. The software may be aware of that fixed location in any number of ways known to software programmers. For example, the location might be “hard-coded” in the software, or obtained from a database. The database might be local or remote. For example, the software might determine what device it is running on from built-in parameters, and refer over a network to a remote database for such data as camera location and screen geometry.
[0006] The video camera may be external to the computer or portable electronic device. This might be because the device does not have a built-in camera, or because an external camera of better quality may be available as an alternative. Determining the camera position might be done as a system calibration exercise. For example, software, provided to the user through a user interface, might instruct the user to look directly at screen(/camera) and then at the camera(/screen). Such calibration allows the amount of correction of gaze direction required for the specific geometry to be calculated.
[0007] Alternatively, the software might simply measure, over some time interval, how the geometry of the user's eyes compares with the geometry they would have if they were directed toward the camera. From such measurement, the position of the camera might be inferred.
[0008] Software suitable for some aspects of functionality of the invention already exist. For example, “red-eye” software can locate the exact location of the pupil. Once the eye has been located, various tools, such as ones available in PHOTOSHOP® and similar image processing software, can be used to redirect the eye toward an image of a face, from looking down to looking forward. For example, various techniques may use the liquify, pucker, bloat, push, lasso, mask, and layer tools of PHOTOSHOP®.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a conceptual diagram illustrating a system implementing eye position correction in a video stream.
[0010] FIG. 2 is a conceptual side view illustrating an angle between a gaze direction of a person engaged in a video call, and the gaze direction of a video camera.
[0011] FIG. 3 is a conceptual downward view illustrating an angle between a gaze direction of a person engaged in a video call, and the gaze direction of a video camera.
[0012] FIG. 4 is a flowchart illustrating a process that corrects gaze direction in a video stream.
[0013] FIG. 5 is a block diagram illustrating an apparatus that corrects gaze direction in a video stream.
[0014] FIG. 6 is a flowchart illustrating a calibration embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0015] This description provides embodiments of the invention intended as exemplary applications. The reader of ordinary skill in the art will realize that the invention has broader scope than the particular examples described here.
[0016] FIG. 1 illustrates a context in which eye position correction might be used. Two people (not shown) are engaged in a video call or video chat, each person using a video capable device 100 for this purpose. A VCD 100 is a device having, as a minimum, some kind of camera 105 , such as a video camera 105 , whereby images of the person using that device may be transmitted to the other person. In this case, one VCD 100 is a laptop computer 102 , and the other is a portable electronic device 101 , such as a cell phone or portable music player. The VCD 100 might also include the capability to receive and transmit audio information.
[0017] There are not necessarily just two VCDs 100 upon which eye focus correction is implemented. There may be many, such as in a video conferencing or distance learning context. There might be only one since all that is required is correction of a single set of images. Indeed, the concept of eye focus correction may be implemented with a sequence of images, without a VCD 100 being directly involved at all. There may be a sequence of video images, captured by a VCD 100 in “near real time” (NRT), a still image, or a collection of still images.
[0018] By NRT, we mean that most of the images transferred by a VCD 100 without significant delay that would be perceptible to a human being. If the video call also includes audio transmission, then the transferred audio and video streams will be reasonably synchronized.
[0019] In the embodiment shown in FIG. 1 , the VCDs 100 communicate with each other over some communication system 110 that is external to the devices. As suggested by the black arrows 111 , the information flow may be in both directions, although unidirectional flow is also possible.
[0020] Throughout this document, by “communication system” we mean any system capable of transmitting or receiving information in electronic digital form. A communication system may be wired or wireless. It may involve a network, such as a wide-area network like the Internet, a local-area network, or a personal-area network. It may employ any technology, such as Wi-Fi, cellular, or BLUETOOTH®. It may be internal to a device, like a computer bus. It may employ any protocol for representing information. A communication system may employ any combination of these or similar technologies.
[0021] By “logic” we mean a sequence of steps implemented in some combination of hardware, and/or software instructions accessed from a tangible storage medium. By a “tangible storage medium” we mean any device capable of temporarily or permanently storing or retaining information, including, for example, computer memory, rotational medium or optical disk, flash memory, or pen drives.
[0022] A VCD 100 may have a user interface 104 , capable of receiving information from a user and providing information to the user. For example, VCD 100 might have a touch screen with various controls, it might have some hardware controls such as a keyboard, or voice controls. The user interface 104 may allow the user to initiate and engage in activities such as a video call or video conference.
[0023] In the embodiment shown, images are transferred in both directions during a video call. From the perspective of the portable electronic device 101 , for example, a set of images 120 is being transmitted from the computer 102 and received by the portable electronic device 101 , in the direction indicated by arrows 131 . A set of output images 135 is being transmitted from the portable electronic device 101 and received by the computer 102 , in the direction indicated by arrows 136 .
[0024] FIG. 2 is a conceptual side view illustrating an eye 200 of a person R (i.e., receiving person) looking at NRT images of another person T (transmitting person), with whom R is engaged in a video call, on a screen 103 of a VCD 100 . Ordinarily, but not necessarily, T will be receiving from R as well as transmitting to R. It is efficient, however, to consider process from a one-sided perspective, then exploit of symmetry. At the particular instant depicted by the figure, the line of sight 210 of T's pupil 201 is directed toward a focal point 150 somewhere below the top of the screen 103 , possibly at the instantaneous location of R's eyes within the images 120 .
[0025] The two video cameras 105 in FIG. 1 were internal to their respective VCDs 100 . The video camera 105 of FIG. 2 , in contrast, is external to the VCD 100 illustrated. It is significant that eye focus correction may be performed for external video cameras 105 , although more information may need to be acquired about the position and properties of the video camera 105 in such configurations. In the figure, the video camera 105 is attached with some kind of clamp 240 . The inventive concepts apply irrespective of whether the video camera 105 is internal, external attached, or external unattached.
[0026] The focus of the illustrated video camera 105 is directed in the vertical toward the level of T's eye 200 . When viewed from the side as in the figure, a pair of rays directed from the pupil 201 , respectively, to the video camera 105 and to the focal point 150 form a vertical angle 230 PHI. T appears to R to be looking downward rather than making eye contact with R directly.
[0027] Of course, over the course of a call, the head and body positions of T and R relative to their respective screens 103 may, and usually frequently will, change. T may look away entirely for any number of reasons, T may leave the room entirely, and so forth. In preferred embodiments, eye shifting software may take all these possibilities into account and respond appropriately.
[0028] T's focal direction may be offset relative to that of the video camera 105 in the horizontal as well as the vertical. This is illustrated conceptually in the downward view of FIG. 3 . Here, a video camera 105 is depicted on top of a screen, at the far left end, and focused on camera focal point 310 . The focal point 150 of T's left eye 301 and right eye 302 is, horizontally, at the center of the screen. From R's perspective, T's view will be skewed to T's right (or equivalently, R's left) by the horizontal angle 320 LAMBDA. Eye focus correction technology should take this horizontal offset into account as well.
[0029] Many modern video cameras 105 implement face- or head-tracking logic, attempting to always focus on the person's face. The above discussion of angles assumes such software. For example, a video camera 105 might be connected to a laptop computer wirelessly or by a USB port. Device driver software, installed on the laptop, may implement face tracking, attempting to keep T's face always in focus. In some implementations, T has the option whether to turn face tracking on or off. Without face tracking, the focal direction of the camera might be straight ahead. Preferably, eye-shifting software will take at both types of configuration into account.
[0030] Alternatively, using familiar principles of trigonometry, the vertical angle 230 PHI and the horizontal angle 320 LAMBDA can be combined into a single angle THETA, which takes both vertical and horizontal skews into account. Eye correction technology may be implemented so as to adjust for the two angles independently, or to compensate for them as a single combined angle.
[0031] FIG. 4 illustrates a process for focal point correction for a video call or meeting. After the 400 , the geometry of the screen and camera of the transmitting VCD 100 are accessed 405 or ascertained 405 . What information is used or needed may depend on where the eye-shifting logic is being performed. For example, such logic might be performed by logic on the VCD 100 transmitting the images 508 ; on the VCD 100 receiving the images 506 ; within the transmitting or the receiving video camera 105 ; or at some other location (e.g., a website or other remote facility) that can access the set of images. In the case of a video camera 105 built into the VCD 100 , obtaining information about properties of a built-in video camera 105 and screen 103 might simply involve reading the information directly from storage in the device. If the make and model of the VCD 100 are known or accessible, then logic might be able to look up parameters of the video camera 105 and/or display 103 . Such look up might involve use of a communication system or network.
[0032] A calibration step might be used to allow the eye-shifting logic to determine enough information about the geometry to do its work. For example, A might be fed a video of herself. By pressing some control on her device, she might be able to allow the logic to correct the images so that she is looking herself in the eye. This approach could be used, for example, even if the video camera 105 were external and somewhat arbitrarily positioned relative to the user, and had unknown properties.
[0033] In step 405 , a digital image is accessed by the logic performing the eye-shifting. Again, how that access occurs depends on what device, system, or facility performs the eye-shifting. The access could be by receipt over some communication system, or retrieval from some storage. The steps 412 , 414 , and 420 check to see whether the subject's face, eyes, and pupils are visible. If not, then the image may be displayed 445 without correction of gaze direction. If only a single eye and pupil are visible, then a gaze adjustment may or may not be applied, depending upon embodiment. Automated red-eye correction in digital images is a technology familiar to persons having ordinary skill in the image processing arts. Pupil location and visibility may be determined by similar logic. Note that an embodiment may employ other criteria to determine whether eye-shifting is appropriate or not. For example, correction may be omitted if an eye is partially obscured. Determination of whether face, eyes, and pupils are visible also involves determination of the locations of those features, which may be stored in tangible storage.
[0034] Parameters specifying bounds for pupil locations may be specified either by the logic or in data accessed by the logic from storage. Out-of-bounds locations or directions may indicate that T is focused on something other than the images (e.g., of R) being received on T's screen 103 . If, according to whichever criteria may be applied in a given embodiment, correction is determined to be warranted, then the logic is applied to adjust 435 T's gaze to be directed toward the video camera 105 .
[0035] As described previously in reference to FIGS. 2 and 3 , correction may be applied for either or both of vertical angle or a horizontal angle. If both, then eye-shifting may be done separately in the horizontal and vertical, or a single shift may be done for the combined angle in three-dimensions.
[0036] Eye position in the displayed images may be measured too. If it is then assumed that T is gazing at the eyes of R in the image, and if the camera gaze direction is ascertainable, then the distance of T's face from the screen may be calculated by triangulation. This calculation may be useful in making gaze direction correction.
[0037] A number of techniques have been published for manually locating an eye in a single image, and shifting the eye focus. These techniques use an image editing tools available in software programs such as PHOTOSHOP®. One technique is to “lasso” and place the eye area into a new layer, then move the image in the new layer to shift the eye focal direction. Other relevant tools may include Distort and Liquify. Of course, other software packages may use different names for similar functionality; also, the above techniques are not intended to be an exhaustive list.
[0038] Actually applying 435 the eye-shifting may be done with varying degrees of with varying degrees of sophistication. Different techniques may exploit different data about facial area including the eye. Eye-shifting might utilize automated image analysis about the geometry, coloring, and lighting of various features of a face. Relevant information on these factors that the logic might infer by analyzing the image for facial features, including, for example, some or all of the pupil, the iris, the sclera or white, the eye shape, the cuticle, the eyelashes, the eyebrows, the cuticles, the eyelids, and surrounding facial tissue and complexion. Logic embodying any technique(s) for shifting the eye focal direction might be used within the inventive concept.
[0039] If eye-shifting is performed, then the corrected image is displayed 440 . After the image, either raw or corrected, is displayed, then if 450 there are more images to display, as in a video stream, then the process continues. Otherwise, it ends 499 .
[0040] FIG. 5 shows structural components of an apparatus or system that executes the process of automated eye-shifting. Some embodiments may not have all of the components that this one has.
[0041] A minimal configuration would have logic 505 that automatically shifts eye focal direction to be directed toward a camera, possibly as in the process embodiment of FIG. 4 , and one or more digital images, possibly in a stream, or time series, of video images. Typically, that processing will involve a processor 503 that executes logic 505 , in the form software instructions and/or hardware. Components of the system may communicate using an internal communication system 509 . The logic may access configuration data and processing preferences 501 , although such data itself is not necessary for a minimal configuration.
[0042] Configuration data might include, for example, the brand/make and model of the transmitting device, and information about the geometry of the video camera 105 and/or screen 103 from which the images are being transmitted. Optical properties of the camera might also be included, as well as information about the device such as processor speed. The logic may take processor speed into account in choosing how sophisticated a method of eye-shifting to employ, or, indeed, whether it can be done at all. The type and speed of the various communications systems involved might also be useful. Configuration data may be collected or determined by logic; it might be provided by a user directly or by a user exercise or experiment; or it might be known in advance, such as when the logic knows the device it is running on, and either knows or can ascertain the properties.
[0043] Data processing preferences might, for example, determine or influence the choice of eye-shifting method to use, or constraints on when or whether eye-shifting is being used at all. Configuration data and data processing preferences may be stored in storage 507 , and accessed by the processor 503 or logic 505 .
[0044] The system may include one or more external communication connections 510 for transmitting images, whether or not they have been corrected by eye-shifting. FIG. 5 actually illustrates a typical (and non-minimal) implementation for, say, a tablet PC, smart phone or laptop computer being used in a call using video meeting software such as SKYPE®, such as either VCD 100 shown in FIG. 1 . In this case, a transmitting VCD 100 will include external communication connections 510 for wired or wireless transmissions over an external communication system to a receiving VCD 100 .
[0045] The system receives a set of images 506 of R from the other VCD 100 over the external communication connections 510 , and displays them on T's display screen 103 . T's video camera 105 captures new images 508 , which are processed by the eye-shifting logic. The resulting images 508 are transmitted over the external communication connections 510 to R. A user interface 104 in the VCD 100 can be used to initiate/terminate the logic, to enter configuration data and preferences, and so forth.
[0046] Calibration of the system might be done according to a scheme such as the one illustrated in FIG. 6 . At the start 600 , video call software, such as SKYPE®, would allow a user to calibrate eye gaze adjustment explicitly, typically through a user interface(UI). For a particular person and portable electronic device 101 , such as a tablet PC, the calibration might be done as part of set-up, and the settings stored. Through the UI, the logic instructs 610 the user to position themself in front of the video camera 105 and screen 103 . Once the logic detects 620 the user's eyes 200 and their features, it so notifies the user, possibly with an audible tone. The logic instructs 630 the user to stare directly at the video camera 105 , and notifies 640 the user upon success. The logic instructs 650 the user to focus on some fixed location on the screen, such as the center. Again, the logic notifies 660 the user when it successfully locates the user's eyes 200 and their features. The logic calculates 670 the angular correction for the eyes. The logic may then determine 680 filter parameters that set bounds on when eye gaze direction correction will be applied at all. For example, the user might be instructed to look at edges of the screen, or just beyond. Gaze sensed during a subsequent video session to be outside the bounds will not be corrected. Again the user may be notified when enough information has been gathered to specify the filter. The logic might give the user the capability to adjust the filter to their personal tastes. Information gathered in the eye correction setup is stored 690 and the process ends 699 . Other orderings of the steps are possible, and some might be omitted in particular implementations.
[0047] Of course, many variations of the above method are possible within the scope of the invention. The present invention is, therefore, not limited to all the above details, as modifications and variations may be made without departing from the intent or scope of the invention. Consequently, the invention should be limited only by the following claims and equivalent constructions. | In a typical video meeting, each of two persons has a computer or a portable electronic device, controlled by one or more processors executing software instructions. Each device has a screen and a video camera. Typically, B's camera will be positioned above B's screen. Video of B is transmitted across a communication system from B's camera to A's screen. Because B is looking at A's image on the screen, A will perceive B to be focused downward, not making eye contact. The present invention analyzes video frames for the orientations of B's head and focus, and uses image editing software tools to virtually correct the gaze direction of B's eye to be directed toward B's camera. A's gaze direction may be similarly adjusted simultaneously. The approach may also be used with 3 or more participants, e.g., in a video conference. | 7 |
This is a division of application Ser. No. 07/976,109, filed Nov. 13, 1992 U.S. Pat. No. 5,305,475.
BACKGROUND OF THE INVENTION
This invention relates to water saving plumbing fixtures. More particularly, it relates to improved means for using a pump to assist in the operation of plumbing fixtures such as toilets and urinals.
DISCUSSION OF THE PRIOR ART
Gravity feed toilets of the type having a reservoir at least partially above the level of a toilet bowl have in the past typically had a water capacity of 3 or more gallons for flushing the toilet. In recent years the efficiency of these toilets have been improved such that in many cases 1.6 gallons of water is sufficient to clean the bowl. However, where especially large amounts of feces are present double flushing may still be needed to completely clean the bowl. Moreover, it was hoped that additional water savings could be effected if these toilets could be made even more efficient during normal flushes and if less water could be employed to flush when only urine and toilet tissue are in the bowl.
One known way to reduce the amount of water needed to effect flushing is to pressurize the flush water. See U.S. Pat. Nos. 2,979,731, 3,431,563 and 5,036,553. However, these prior systems were complex, costly and usually not suitable to completely fit in standard size toilets. They also suffered from other problems.
Thus a need exists for an improved pump operated plumbing fixture which alters the amount of water used based on the type of material to be flushed, more efficiently sequences the flush water with respect to the rim portion and the bowl portion, permits water distribution to multiple fixtures from a single reservoir, permits alternative placement of the reservoir, permits an aesthetically pleasing compact design, resolves potential water overflow problems, meets safety standards relating to electrical shorting, and has good bowl cleaning and waste evacuation characteristics
SUMMARY OF THE INVENTION
In one aspect, the invention provides a plumbing fixture for receiving flushable waste comprising at least one receptacle for receiving the waste, a reservoir tank for storing a volume of flush water, a pump motor and pump (both positioned in the reservoir tank), the inlet of the pump being in communication with the interior of the reservoir tank, a conduit connected between a pump outlet and the receptacle, and control means selectively and operatively connected to the motor to operate the pump for one period of time to deliver a quantity of flush water to the pump outlet.
In another preferred form, the pump means is positioned either inside or outside the reservoir tank and the control means is selectively and operatively connected to the motor to the pump means to operate the pump for at least one other period of time to deliver at least one other quantity of flush water to the receptacle.
In still another preferred form, there are at least two receptacles for receiving waste such as a toilet and an urinal.
In still another aspect, a refill valve is operatively connected to an intake conduit, and a tube is connected between the refill valve and the rim of a toilet bowl.
In still another preferred form, there are control means which include a time delay means to prevent activation of the pump and overflow of the toilet bowl.
In another aspect, there is a fluid passage means disposed through the tank wall and positioned below the motor and electrical connection to the motor.
In yet another aspect, there is a receptacle for storing a fluid such as a cleaning fluid and an additional pump means for pumping such a fluid into the toilet bowl to clean the toilet bowl.
In yet another aspect, there are overflow prevention means for both the reservoir tank and the toilet bowl. Concerning the reservoir tank, an electrically operated fail-safe valve is connected to the supply conduit to shut off the water supply in the instance where there is a leaky supply valve. There is also an overflow sensor connected to a pump motor to pump excess water from the tank. Concerning the toilet bowl, there is a time delay feature to prevent excessive operation of the pump and flooding of the toilet bowl.
In yet another preferred form, there are first and second conduits connected between the pump outlet and the basin and the rim. Control means connected to the motor and pump sequentially delivers a volume of flush water to the rim, a volume of flush water to the bowl either alternatively, or simultaneously, and in selective sequences.
The objects of the invention therefore include:
a. providing a plumbing fixture of the above kind wherein reduced quantities of water can be employed to remove flushable waste from a toilet bowl or a urinal.
b. providing a plumbing fixture of the above kind wherein a pump and motor can be electrically controlled to deliver different quantities of water and in different timing sequences to a toilet bowl and rim.
c. providing a plumbing fixture of the above kind wherein safeguards are provided to substantially reduce the possibility of overflow conditions.
d. providing a plumbing fixture of the above kind wherein the pump can be easily connected or disconnected to a plumbing fixture.
e. providing a plumbing fixture of the above kind wherein one pump can service a multiplicity of plumbing fixtures.
f. providing a plumbing fixture of the above kind wherein a constant, predetermined volume and flow of water is delivered to the jet channel regardless of supply line pressure or flow characteristics.
g. providing a plumbing fixture of the above kind wherein a cleaning fluid can be pumped from a separate tank to the toilet bowl for cleaning purposes.
h. providing a plumbing fixture of the above kind which can be fitted to standard water supply and waste lines.
i. providing a plumbing fixture of the above kind wherein the pump and the reservoir are positioned remote from a toilet bowl or urinal.
j. providing a plumbing fixture of the above kind wherein flush activation is effected by switches.
These and still other objects and advantages of the invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawings. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan, partially fragmentary view of a toilet (with tank lid removed) in which a preferred embodiment of the invention is mounted.
FIG. 2 is a partial sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.
FIG. 4 is partial sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is a partial sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is a partial sectional view taken along line 6--6 of FIG. 3.
FIG. 7 is a rear elevational view of the toilet shown in FIG. 1.
FIG. 8 is a view in side elevation and partially in section illustrating an alternative embodiment.
FIG. 9 is a rear elevational view in partial section of the toilet shown in FIG. 8.
FIG. 10 is a sectional view taken on line 10--10 of FIG. 9.
FIG. 11 is a view similar to FIG. 8 showing still another alternative embodiment.
FIG. 12 is a diagrammatic view of yet another embodiment.
FIG. 13 is a view in vertical section illustrating in more detail a pump and motor for use in the toilets described herein.
FIG. 14 is a diagrammatic view of a control circuit for the motor and pump.
FIGS. 15A-17C are flow charts showing a signal flow block diagram for the control circuit shown in FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a toilet generally 10 having a basin or bowl portion 12 with a hollow rim 14. A "reservoir" 16 is in the form of tank 17. Positioned in the tank 17 is a pump 18 which is of the sump type. It is supported in the reservoir by vibration absorbing feet 19. Pump unit generally 43 includes a pump 18 driven by an electric motor 20 with electric power being supplied by electrical cord 21. The motor 20 drives the pump 18 by means of a sealed and enclosed magnetic drive which is explained below in more detail in conjunction with FIG. 13. It should be noted that one surprising aspect of the invention is positioning an electrical motor in the toilet water tank.
Water enters the pump 18 at inlet 23 and exits the pump 18 by the outlet manifold 25. An outlet conduit 27 delivers water to the lower portion of bowl 12, such as through jet channel 28 (See FIG. 4) attached via connector 68. A smaller conduit 30 delivers water to the rim 14 through the channel 32.
Referring to FIGS. 2 and 3, water enters the tank 17 by the inlet pipe 35 which is connected to a conventional water source. A float valve assembly 37 includes a float 39 which operates a valve (not shown) in pipe 40 by means of rod 42 and lever arm 44. Float 39 is guided by the guide member 45. Water that passes the inlet valve enters the reservoir through the inlet valve hush tube 47. There is also a bypass tube 50 connected to the float valve assembly to deliver a small amount of water to the rim 14 whenever the float valve is in an open condition.
As best seen in FIGS. 4 and 5, there is a return passage 33 between the upper bowl portion 12 and the reservoir 16. This allows for water to pass from the tank to the bowl in case there is an overflow condition in the tank. It also permits flow in the other direction if there is a stoppage in the bowl and a near over flow condition develops.
There is also a dam member 69 which is positioned adjacent the return passage 33 and inside the tank 17. This serves to raise the water level in the tank 17 or the bowl portion 12 before overflowing into the other occurs. A rim vent hole 73 is also provided to facilitate water flow, as best shown in FIGS. 3 and 6.
Referring now to FIG. 7, there are several openings 52 extending through the back wall 11 of the tank 17. The purpose of the openings 52 is that if return passage 33 is blocked to allow overflow water from tank 17 to spill out of the tank. The openings 52 provide a fluid spill passage and are positioned in the tank a distance above the bottom so that overflow water will escape prior to contact with the electrical connection from cord 21 with the motor 20 and are positioned below the point where water could enter the motor. The position of this connection is indicated in FIG. 2. The openings 52 also prevent contaminated water from rising high enough in the tank to contact intake water in pipe 40.
FIGS. 8-11 represent alternative embodiments generally 10A. The same or similar components are designated with the same reference numerals as for the first embodiment except followed by the letter "A". One of the differences between the two embodiments is the placement of the reservoir 16A below the bowl portion 12A and accordingly the water level in the reservoir 16A below that of the bowl portion 12A. A support post 15A for the bowl portion 12A is provided as well as a surrounding housing 22A extending along the sides and back of the bowl portion 12A.
In the FIG. 8 version, positioned on the reservoir 16A is a receptacle 24A which contains a cleaning fluid for cleansing the bowl portion 12A. The cleaning fluid is pumped from the receptacle 24A by means of the conduit 53A connected to the inlet side of the pump 54A driven by the motor 56A. A second conduit 57A extends from the outlet side of the pump 54A to the rim 14A of the bowl portion 12A where it is connected to inlet tube 55A.
FIG. 11 shows an alternative placement of the receptacle 24A outside of the surrounding housing 22A.
FIGS. 9 and 10 particularly illustrate the supply of water to the reservoir 16A, as well as to the rim 14A and bowl portion 12A. The pump 18A and motor 20A are located in the reservoir 16A. Water enters through the float valve assembly 37A and is delivered to the reservoir 16A by the outlet pipe 47A. However, in this instance, inlet water is supplied to the float valve assembly 37A by the supply line 59A. The inlet water is supplied through the back of housing 22A through line 59A and is controlled by a normally closed solenoid which opens, when electrically activated, the valve 60A. Pump 18A supplies water to the bowl portion 12A by means of the conduit 27A which is connected to conduits 27A' and 27A" as well as to manifold 25A. It also supplies water to the rim 14A by the conduit 30A connected to the manifold 25A.
As best seen in FIG. 10, there is a solenoid diaphragm valve 62A connected to conduit 27A'. It is operated by a pilot 63A and is maintained in a closed position until activated to supply water to the bowl portion 12A.
Referring specifically to FIG. 9, there is shown a water level sensor device generally 65A which includes a float 66A mounted on guide rod 64A having an electrical contact cap 67A on the end thereof. Contact by the float 66A with the cap 67A will send an electrical signal to motor 20A to operate pump 18A and thereby determine the maximum level of water 26A in reservoir 16A. Guide rod 64A is supported on bracket 61A which in turn is adjustably connected to support rod 51A. A trapway 49A communicating with the typical outlet drain 58A is also shown.
FIG. 12 illustrates yet another alternative embodiment (generally 70B). The same or similar components are designated with the same reference numerals as for the first embodiment, except followed by the letter "B". In this embodiment 70B, the pump 18B and the motor 20B are located outside of a plumbing fixture such as a wall hung toilet 10B. In this instance, flush water would be contained in reservoir 16B and is pumped from the reservoir 16B by means of the intake conduit 71B and the output conduit 72B. Water is diverted to the toilet 10B and/or the urinal 74B through the diverter valve 75B.
In a preferred manner, the volume of water pumped to the toilet 10B will be 1.6 gallons or less, whereas that normally delivered to the urinal 74B would be 1.0 gallon or less. The volume of water delivered to the toilet 10B and the urinal 74B can be controlled by a timing circuit as is explained later in conjunction with FIGS. 14 and 16A and B.
FIG. 13 shows in more detail a pump 18 which is driven by the motor 20. Both the motor 20 and the pump 18 are enclosed in sealed housings 29 and 31. An electric motor 13 drives rotor 34 having magnets 36 which attract magnets 38 carried by the pump rotor 41. This effects a pumping action causing water to enter at entrance 23 and to exit from manifold 25 (See FIG. 2). It should be noted that placement of the magnets 36 and 38 in their respective plastic housings effects a seal between the rotors 34 and 41, thus reducing the chance of an electrical short into the reservoir water. Foot members 46 provide for suitable spacing of entrance 23 from the bottom of reservoir 16 or 16A (See FIG. 2 or FIG. 3). A support member 48 positions the electric motor 13 at a predetermined distance above the floor of motor housing 29.
FIGS. 14-17C illustrate electrical controls for the previously described embodiments. A microprocessor 80 is programmed to effect the desired and described functions which in the instance of embodiment 10A include a short flush function, a long flush function (which can be activated by the seat cover being closed), as well as a special bowl cleaner flush. These functions can be initiated by the respective switch buttons 81, 82 and 83 which preferably are of the touch type. A switch of this kind would be a membrane switch which would have a long flush and a short flush function in the same switch housing. In the instance of the seat cover closed function, it has in addition to activating switch 84, a monostable multivibrator 85 which is commonly known as a "one-shot".
This particular seat cover closed function is described in more detail in commonly owned U.S. patent application Ser. No. 07/824,808 filed Jan. 22, 1992 which teachings are incorporated herein by reference. See also U.S. Pat. No. 3,590,397. Basically the idea is that the position of a magnet for the bowl lid is sensed by a sensor in the tank and the information leads to control of flushing (e.g. when the lid is first closed, a flush occurs). The level sensor 65A is also inputted to the microprocessor 80. The output side of the microprocessor 80 is connected to the main pump 18A, the pump 54A for the toilet bowl cleanser liquid, and the supply valve solenoid 62A by the lines 86, 87 and 88, respectively. As explained later, in conjunction with embodiment 70B, the short flush button 81 will represent the function of the urinal flush key being pressed as shown at 118 in FIG. 16B.
Referring to FIGS. 15A and B, these represent the flow diagram for embodiment shown in FIGS. 1-7. The first step in the operation of the pump toilet 10 after the start 89 is the decision step 90 as to whether a switch has been activated such as by a key or push button. If a key is not activated, a background timer is updated at 91 and at 92. It is checked to see if it has a designated number of units. If it does, it is reset at 93 and a flush timer is looked at at 94 to determine if it equals 0 seconds. If it does not, it is decremented at 95.
This background timer will operate in conjunction with the flush timer in a manner to be explained in conjunction with the actuation of the later described activation of the long and short keys at 97 and 105 and the timing of the main pump 18. At step 96, the flush timer is checked to see if it is at greater than 30 seconds. If it is not, this allows activation of either the long or short keys at 97 or 105.
If it is the long flush key at 97, such as activated by switch 82, then main pump 18 is turned on at step 99 after a valid input check at 98. This immediately delivers water to the rim portion 14 by way of conduit 30, as well as to the jet in the bowl portion 12 through conduit 27. After a delay of 3.17 seconds as indicated at step 100, the pump 18 is turned off at step 101. This will deliver 1.6 gallons of water and would normally be used to flush fecal matter. At step 102 there is added 60 seconds to the flush timer after which there is a determination made at 103 and 104 as to whether the long or short key has been pressed before another flush cycle is initiated. If instead of the long flush cycle, a shorter one is selected, the short flush key 105 is activated such as by switch 81. After an input check at 106, the pump 18 is activated at 107, and it is operated for 2.07 seconds as indicated at 108. It is turned off at 101 after delivering 1.0 gallon of water. This short flush would normally be used to flush urine and paper. Again 60 seconds would be added to the flush timer as indicated at 102.
The background and flush timers are programmed in conjunction with steps 96 and 102 so that there are two delay features. The first involves a situation where a second flush occurs more than 30 seconds but less than 60 seconds after the first flush. It will be recognized that there is always a 30 second delay between flushes in order to refill the tank 17. In this situation, the toilet may be flushed a second time after the initial 30 second delay, but if this is done, it may then not be flushed a third time until there has been a maximum of 90 seconds from the first flush and add 60 seconds to each flush thereafter. The second alternative involves a situation where the second flush does not occur within 60 seconds of the first flush or 90 seconds after any following flushes. In this case, the background timer automatically resets and the toilet can be flushed again with no limit other than the 30 seconds required to fill the tank. In essence, this means that the toilet may be flushed every 60 seconds without being limited, as in the first case.
Referring to FIGS. 16A and B, these represent the flow diagram for embodiment shown in FIG. 12. It will be seen that steps 89-96 are the same as previously described in conjunction with FIG. 15A. If the toilet flush key 110 is selected, which would be activated such as by switch 82, then the same steps 98-102 would be followed as previously explained in conjunction with FIG. 15B. Similarly, the same determinations of the status of the toilet and urinal flush keys are made at 116 and 117. In the event the seat flush feature is activated such as at 112 and by the lid closed switch 84, the same procedure will be followed as indicated at steps 98-102 for the long flush. In the instance where the urinal flush key is activated at 118, a short flush cycle is initiated which is similar to steps 106-108 and 101 and 102 as described in conjunction with FIG. 15B.
Referring to FIGS. 17A, B and C, these represent the flow diagrams for the embodiment shown in FIGS. 8-10. The steps 89-96 are the same as previously described in conjunction with FIGS. 15A and 16A except for step 122 where supply valve 60A is turned on. If the long flush key 97 is activated, then main pump 18A is turned on at step 99 after a valid input check at 98. This immediately delivers water to the rim portion 14A by way of conduit 30A. Water is prevented from flowing through conduit 27A to the jet in the bowl portion 12A as jet diaphragm valve 62A is closed. After a delay of 0.5 second as indicated at step 123, the solenoid pilot 63A is activated at step 124. This delivers water from pump 18A to flow to the jet in the bowl portion 12A as well as to the rim portion 14A through conduit 30A. After 3.5 seconds as seen at step 100, the valve 62A is closed at step 125. After a delay of 3.0 seconds as indicated at step 126, water continues to flow to the rim portion 14A. After the 3 second delay, the main pump 18A is turned off at step 101. The remaining steps 102-104 are the same as previously described in conjunction with FIG. 15B.
A seat activated function is also shown at step 136 in conjunction with long flush steps 98-101 as previously described.
In the event a shorter flush is desired, such as to flush urine or paper, the short flush button 81 is activated to initiate the short flush as indicated at step 105. The subsequent steps 106-130 are essentially the same as indicated for the respective steps 98-126 except for step 108 where the pump is operated for 2.5 seconds rather than 3.5 seconds.
In addition to the previous flushing functions, there is also an independent cleanser flush indicated at step 131 which delivers a cleaning fluid to the rim portion 14A. After a valid input check at 132, the main pump 18A and the sanitary pump 54A are turned on at step 133A. After a time period of 6.0 seconds at step 133B, the main pump 18A and the sanitary pump 54A are turned off at step 134 after which there is a delay period of 60 seconds as shown at 135.
Referring also to FIGS. 14 and 17B, it is seen that a signal is sent to the microprocessor 80 from the level sensor 65A. This signal is shown as activated at 137 with the main pump 18A being turned on at 138 as well as the jet solenoid to pump water from the reservoir 16A and to the toilet 10A in order to prevent an overflow condition in the reservoir 16A should float valve assembly 37A malfunction. After a delay of 4 seconds, the main pump 18A and jet solenoid are turned off at 140. If the overflow feature has been active 3 times in 60 minutes as shown at 141, the supply valve 60A is turned off at 142 and a waiting period initiated at 143. An additional safety feature in conjunction with the microprocessor 80 is the closing of supply valve 60A in the event of electrical failure to the control circuit and pump 18A and the failure of float valve assembly 37A to close.
Thus our invention provides an improved toilet flushing system which utilizes a minimum of water for each function. The need for double flushing is reduced. While preferred embodiments have been described above, it should be readily apparent to those skilled in the art from this disclosure that a number of modifications and changes may be made without departing from the spirit and scope of the invention. For example, while a delivery of flush water to the rim in a first sequence, to the rim and bowl in a second sequence, and to the rim only in a third sequence has been described in conjunction with the pump toilet, this system can be altered to deliver water only to the rim by eliminating the conduits 27, 27A, 27A' and 27A" to the bowl as well as the valve 62A. Alternatively, flush water delivery only to the bowl can be effected by the herein described system by elimination of the conduits 30 and 30A to the rim and valve 62A. Any combination of the delivery of flush water to the rim and/or bowl can be effected by suitable valving. For example, if it is desired to have water flow only to the bowl in one sequence with a rim-bowl-rim delivery, a valve such as 62A can be placed in conduit 30A. Alternatively, a 3-way valve could be used in conjunction with conduits 27, 27A, 27A', 27A" and 30A.
A long and short flush cycle have been described in conjunction with the previously disclosed embodiments. It should be understood that these two cycles can be employed independently of the bowl cleaner flush or the seat cover activation. In the same manner, a third longer flush cycle could be utilized with the long and short flush cycle as well as an intermediate one with varying quantities of flush water. Similarly, if desired, only a single flush cycle could be employed by eliminating one of the flush cycles and still operate the pump for a period of time to deliver a quantity of water from the reservoir tank to the toilet bowl. While the reservoir 16B and pump 18B have been described in conjunction with one toilet 10B and one urinal 74B, a multiplicity of these plumbing fixtures could be employed by interconnection with output conduits 73B and 74B. All of the flush cycles previously described in conjunction with embodiment 10A can be utilized with toilet 10B.
Further, the seat cover and sanitation functions could be eliminated and still accomplish the water saving feature. Similarly, the overflow features could be eliminated and still accomplish the described water saver functions. Also, the cleanser function could be automated such that the processor would count uses such that after a given number of uses of a toilet (e.g. thirty), the cleaning cycle would automatically occur. A long and short flush cycle have been effected by operating a pump motor for different time intervals. This could also be accomplished by running the pump motor at two different speeds as shown alternatively in dotted line in FIG. 15B. All such and other modifications within the spirit of the invention are meant to be within the scope of the invention. | A toilet has a pump to deliver selected quantities of water from a reservoir to a toilet bowl so as to effect a water savings. In one aspect, both the motor and pump are positioned in the reservoir to deliver water to both the rim and bowl portions. In another aspect, there are conduits connected between the basin, the rim and controls which are provided to deliver water to the rim and bowl either independently, simultaneously or in selective sequences. In alternative embodiments, a refill tube is connected to an intake conduit and the rim of the bowl to effect a water seal, a fail safe valve is connected to the supply conduit, a receptacle with a cleaning fluid and a pump is connected to the bowl and there are at least two receptacles for receiving waste. | 4 |
This application claims the benefit of U.S. Provisional Application No. 60/108,430, filed Nov. 13, 1998.
TECHNICAL FIELD
The invention relates generally to systems that include an automated interrogation device and more particularly to storing information in a database format for use with interactive voice recognition equipment and like.
DESCRIPTION OF THE RELATED ART
There are a number of alternatives for implementing a call-handling facility to transact business. The business transaction may be informational, such as providing product support for items sold by the business which operates the call-handling facility, or may be directed to product marketing. In an automatic call distribution (ACD) implementation, agents are employed to handle incoming and/or outgoing calls. The advantage of an ACD system is that each call is handled by a human. However, in some applications ACD agents must receive significant training in order to ensure competent handling of issues raised by callers. This is particularly true in a product support environment. Another concern is that the operation of an ACD system is expensive.
Automated interrogation devices may be used to at least reduce the number of calls that require handling by a person. The most common automated interrogation device is an interactive voice response (IVR) unit. An IVR may be configured to present menus of options that are traversed in a listen-respond manner. A first listen-respond message may be presented to a caller with a greeting that solicits a response from the caller. The response is detected by the unit and used as a prompt for presenting the next option. Thus, a call processing tree is formed by properly organizing the messages. A first series of messages may be used to verify identification of a caller, such as by requiring input of a personal identification number (PIN) using dual tone multifrequency (DTMF) signals generated by depressing keys at the telephone of the caller. Another sequence may be used to identify the caller's purpose. For example, in a banking environment, the caller may be instructed to depress a designated key if the interest is in obtaining a present account balance, but to depress a different key if the interest is in obtaining information regarding a particular transaction. In a sales environment, the sequence may be related to identifying a product, its price, and the inventory status of the product prior to placing an order.
A call-handling facility having IVR functionality may use a high capacity programmable platform that is flexible, scalable and upgradable. Using this platform, all of the necessary information is maintained at the call-handling facility. Typically, the information is stored in a database format. Depending upon the type of business that is to be transacted, the information distinguishes users of the facility (e.g., by using PINs), provides accounting, distinguishes products, and identifies product availability. Thus, the call-handling facility is self-contained with respect to completion of the business transaction. The concerns are that the high capacity platform is expensive and may be difficult to maintain in some applications.
At a lower end, the IVR functionality may be achieved using a low capacity programmable platform. In many applications, this requires storage of the necessary information at a remote site. Thus, the IVR unit is at the call-handling facility, but a remote host is used as an external database. The host is not solely dedicated to providing support for the single IVR unit. The use of the host reduces hardware costs. However, this requires a real-time data link between the IVR unit and the host in order to complete a transaction.
U.S. Pat. No. 5,345,501 to Shelton describes a telephone central office having a voice response unit and an adjunct computer. Consequently, there are separate data storage capacities for voice messages and vendor information. The vendor information is in a database format of customer identifications and inventory availabilities for a number of vendors. Each vendor maintains a host computer, but the various inventories are uploaded to the adjunct computer at the telephone central office. This reduces the memory storage requirements of the individual host computers. That is, the concern is that the hosts have limited capacity, rather than that the adjunct computer has limited capacity. Business is transacted using the adjunct computer. The information is then transmitted on-line to the appropriate host computers in order to create and activate orders at the hosts. The hosts update their inventory information and download the updated information to the adjunct computer for storage.
While the prior art approaches of storing and accessing the high volume of information needed for a transactional call-handling facility have worked well for their intended purposes, what is needed is a system and method that provide a cost-efficient means for operating a call-handling facility having automated interrogation functionality.
SUMMARY OF THE INVENTION
A system and a method for automated call handling of business interactions include providing local memory having stored records, specific to parties and having pre-programmed messages relating to the business interaction. A remote memory is used to store master records that are accessible by the local memory. In the preferred embodiment, the records stored in the local memory are subsets of the master records. The pre-programmed messages are directed to call parties using an automated interrogation device, which is preferably an interactive voice response (IVR) unit. The local memory provides a reduced capacity storage for the records, typically in a database format. The creation process and the file transfer process from the remote memory are independent from and asynchronous to IVR operation.
The subset records contain sufficient information to allow a calling party to complete an identification procedure and to at least initiate an intended business operation. For example, in a banking environment, the locally stored information may include customer names, account identifications, account balances, dates, and/or other information that is needed to verify identities and that is commonly requested by bank customers. In response to an incoming call, the IVR unit queries the calling party to determine the party's identity. The locally stored record of the party is accessed and may be retrieved to a temporary storage, such as in random access memory (RAM). Thus, the same information is contained in the remotely stored master record, the locally stored subset record, and the temporary storage. The information in the temporary storage is accessible to the automatic interrogation application in the same manner as the pre-programmed static messages. However, the variety and type of messages are increased.
Preferably, the subset records have a format of either one or two database tables. The first table is indexed by the customer identification. The optional second table is indexed according to the business of interest.
The database information in the subset records is readily accessible without an on-line connection to the remote storage of the master records. However, a data exchange is frequently implemented in order to synchronize the two sets of records (i.e., match record information). For example, a synchronization application may detect the times in which there are no ongoing calls within the system. The synchronization process may be implemented with any new callers receiving a message that presents options of calling back in a short time or being placed in a queue. A data connection is formed between the system and the remote storage site. Any updates of information are performed at this time. In an alternative embodiment, the synchronization can occur during ongoing calls, but without consequence on the ongoing calls. For example, there may be two separate instances of storing the subset records, so that the synchronization does not impact any ongoing updates of a subset record of a calling party.
The method of manipulating the data for a call-handling facility includes storing the master records at the site that is remote from the facility and generating subset records from the master records for storage at the facility. Each of the subset records is associated with one user of the call-handling facility and contains a portion of the information contained in the corresponding master record. The automated interrogation device (e.g., an IVR unit) is responsive to connection of a call and directs messages at the calling party. The messages are related to performing a business interaction with the calling party. The calling party is identified and the appropriate subset record is retrieved for temporary storage (e.g., in RAM). In a “retrieve information” application, such as in a banking environment, the IVR may prompt the calling party for an identification and password, then open the local database, retrieve the subset record, verify the identification, read the result, close the subset record, and verbalize results to the caller. In an “enter data” application, such as in a sales environment, the IVR may prompt the caller for an identification and password and data, then open the local database, retrieve the appropriate subset record, verify the identification, alter the subset record according to the obtained data, close the subset record, and signal completion. Periodically, the local storage of subset records is synchronized with the remote storage of master records.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic layout of components of one embodiment of a system for automated call handling in accordance with the invention.
FIG. 2 is a block diagram of one embodiment of a flow of IVR dialog for utilizing the system of FIG. 1 .
FIG. 3 is a process flow of steps for manipulating data for the system of FIG. 1 .
DETAILED DESCRIPTION
With reference to FIG. 1, a system for providing automated call-handling capability includes an automated interrogation device 10 , a switching fabric 12 , and a remotely located host computer 14 . As will be explained in detail below, the preferred embodiment is one in which the automated interrogation device includes an IVR application and a database application for storing records that are subsets of master records within a database application 16 of the host 14 . The system of FIG. 1 allows retrieval and entry of information to and from database records in a manner similar to high-end IVRs, but without incurring the expense and overhead of a real-time link to the host 14 .
The switching fabric 12 is located at the same facility as the automated interrogation device 10 . The type of switching fabric is not critical to the invention. In one embodiment, the switching fabric is a private branch exchange (PBX). The switching fabric is shown as being connected to the public switched telephone network 18 (PSTN). Thus, remotely located telephones may access the automated interrogation device 10 via the PSTN 18 and the switching fabric 12 .
The automated interrogation device 10 is shown as being connected to the host 14 by an input channel 20 and an output channel 22 . The input channel transfers “images” of database records within the external database application 16 to the automated interrogation device. The images are the subset records that are maintained within an internal database 24 for access by the IVR application. In FIG. 1, the IVR application is represented by a controller 26 . While the input and output channels 20 and 22 are represented as being isolated from the switching fabric 12 , this is not critical to the invention. Alternatively, the data that is exchanged with the external database application may be directed through the PSTN 18 .
The subset records in the internal database 24 are maintained in the same manner as the master records of the external database application 16 . The maintenance is also consistent with full-scale databases for IVR systems that are not reliant upon external hosts (i.e., stand-alone IVR systems). However, because the internal database contains only images of the master records, there may be an increased need for a means of verifying and confirming to a calling party that a transaction has been completed. Preferably, the automated interrogation device 10 includes either or both of automatic facsimile capability or automatic e-mail capability. A verification or confirmation is particularly important if the subset records of the internal database 24 do not include inventory information in a sales application of the device. Without the inventory information, availability can be confirmed only after the call has been terminated and the inventory information within the remotely located host 14 has been accessed.
The subset records of the internal database 24 may be generated manually or automatically from the master records of the external database application 16 . The subset records are transferred as files and then loaded onto the hard disk of the automated interrogation device 10 via a file transfer mechanism. This creation and file transfer process is independent and asynchronous of IVR operations. While not critical, the file transfer normally occurs while the IVR is free from calls with persons who require access to the subset records.
In contrast to conventional IVR systems, the automated interrogation device 10 does not directly modify data within the master records. The master records are opened, read or written, and then closed without interacting with a calling party. The automated interrogation device 10 interacts with callers and with the host 14 , but not in a coordinated operation. It is the subset records within the internal database 24 that are utilized during the call. Preferably, the data within the subset records can be modified. The modifications are written to the master records during synchronization operations.
A synchronization application 28 coordinates the transfers of information between the automated interrogation device 10 and the host 14 . The internal database 24 is updated and synchronized to the external database application 16 as needed. Preferably, the synchronization occurs only a limited number of times per day. The process may be triggered manually by an administrator or may be automatically triggered. The internal database 24 is updated while the IVR application of the controller 26 is in-service, but preferably while there are no active users (i.e., callers) of the automated interrogation device 10 . While not critical, the synchronization application may disable the system with respect to receiving incoming calls. The controller 26 does not block incoming calls during the synchronization process. Rather, callers are given the option of being placed in a queue, being connected to an agent, or transferring to an internal extension. In another embodiment, there are two separate instances of the subset records in the internal database 24 , so that incoming calls can continue to be processed without impact on the updating procedure.
In operation, the automated interrogation device 10 processes incoming calls during times that the device is not in communication with the host 14 . A number of messages are directed to a call party. For example, a first message may be a greeting that includes a request for identification. Upon receiving an identification and any required verification (e.g., a password or PIN), the appropriate subset record from the internal database 24 is temporarily stored in memory of the controller 26 . For example, the controller may access the subset record from the internal database 24 and store the record in random access memory 30 (RAM). The combination of the IVR configuration and the subset record determines the sequence of messages to be directed to the call party.
The automated interrogation device 10 includes two converters 32 and 34 . The first converter 32 is used to place the outgoing messages in the proper format. As previously noted, the device is preferably used in an IVR environment, so the converter 32 audibilizes the outgoing messages for transmission via telecommunication lines.
The second converter 34 recognizes responses from call parties and properly formats the responses. For example, the responses may be DTMF tones that are generated by the call party by depressing designated telephone keys. The converter distinguishes the various DTMF signals. Alternatively, the responses from the call party may be voice messages. In this embodiment, the converter 34 is programmed with a sufficiently large vocabulary to identify the call response. The operations converters 32 and 34 are well known in the art.
FIG. 2 is an example of the flow of an IVR dialog between the automated interrogation device 10 of FIG. 1 and a call party. In this example, DTMF signals are used to provide the responses to the system, as indicated by the twelve telephone key designations 36 . The main IVR application 38 may present a standard greeting that provides three options to the call party. Depending upon the key that is depressed by the call party, the process moves to one of the three options. At the first option 40 , the caller is presented with static messages 42 and, optionally, an automatically generated facsimile transmission. The content of the facsimile transmission will vary with the business environment in which the IVR is utilized. At a second option 44 , the call party may transfer to an internal extension, a line group, an operator, or an automatic call distribution (ACD) agent.
The use of the subset records in the internal database 24 of FIG. 1 is triggered by selection of a third option 46 in a call flow of FIG. 2. A typical user prompt presented by the main IVR application 38 is, “Would you like specific information about your account?”. The IVR application 38 then prompts the call party for an identification and a PIN. The response by the call party is stored and the appropriate subset record is retrieved. If the PIN is valid, the call party is prompted with the menu of the local database (LDB). The call party is also offered information from the local database in either spoken or facsimile format. If the PIN is invalid, the caller is again prompted for the number. The calling party is allocated three retries in identifying the appropriate PIN. It should be noted that the entire subset record is retrieved for the call party, with all fields, so that multiple database retrievals are not necessary. In FIG. 1, the subset record is stored in RAM 30 . In FIG. 2, the LDB menu is shown as the customer table 48 of the second menu level.
Typically, only one LDB table 48 is required. However, some applications may require two tables, one that is indexed by the customer ID, and a second one 50 that is indexed by another variable, such as “Product Code,” “Travel Destination” or “Doctor Name.” The internal database 24 is structured to support two database tables. In some applications, it is desirable to enable acceptance of an order from a call party. One possibility is to provide a “Voice Form” 52 . The use of such forms is known in the art.
A process flow of steps for utilizing the system of FIG. 1 is shown in FIG. 3 . In a first step 54 , the master records are stored at the host 14 . This is a conventional step in IVR applications. The data that is included in the master records is dependent upon the business to be conducted or the service to be extended by the system.
In step 56 , identification is made as to the information that is to be included in the subset records. This step may be performed by a system administrator. Typically, the “image” of the external master records is a small percentage of the total data in the remotely located database application 16 . For example, a subset record may include a customer name, an account identification, an account balance, relevant dates, and other information that is repetitively required in the specific IVR application.
Step 58 of configuring the IVR message sequencing is closely tied with the step 56 of identifying the subset information. In one implementation, a system administrator may create an IVR dialog via a number of graphical user interface (GUI) screens. The first GUI screen for designing the call flow of FIG. 2 may be an “Info Center” screen that supports six selections for a menu key. The six selections are “Message,” “FAX,” “Both,” “Menu,” “LDB Data Table 1 ,” and “LDB Data Table 2 .” Each of the final two selections has one parameter, i.e., “Info Center Data Name.”
In a second GUI screen, the fields within the record retrieved from “LDB Data Table 1 ” are configured. The configuration is not critical to the present invention. The configuration includes identifying operations, such as retrieve, enter, verify, ignore and search. Data that is retrieved from the local database is generally spoken to the incoming caller, exactly as static messages are audibilized. An enter data operation enters data into the local database in response to caller inputs, such as DTMF signals or discrete speech that is recognized by the second converter 34 of FIG. 1 . In a verify data operation, more than just the caller's PIN may be required. There may be a second step to verification, such as a question directed to the caller, e.g., “Is your ZIP Code XXXX?”. As another alternative, the verification may be biometric information, such as the incoming caller's speech pattern. A search operation is one in which data is selectively presented to the caller. For instance, if the subset record that is retrieved from the local database 24 includes 100 fields, there may be a limited number of designated fields which are selectively spoken to the call party. However, it should be noted that this designation does not result in more than one retrieval from the local database 24 . An entire subset record including all fields is retrieved and stored in the temporary memory, such as RAM 30 . From the standpoint of the IVR operation, the data that is temporarily stored is essentially the same as the data stored as static messages 42 in FIG. 2 . The variety and type of messages increases, but the treatment of messages remains the same.
The next GUI screen is required only if a second LDB table 50 is included. The process for configuring the information relating to the second table is substantially the same as the process for the first table. Then, a final screen is utilized to configure synchronization of the local database 24 to the remotely located database application 16 . Synchronization will be described more fully below.
in step 60 , the subset records are stored at the internal database 24 of FIG. 1 . The records are stored as one or two tables, but preferably not more. For example, in an inventory environment, the database might have two tables, with one being used to identify the call party and the second being used to list all products and availability dates. From the viewpoint of the IVR application, retrieve operations are executed as single searches into the internal database 24 for a single record. Complex searches are not executed. To the incoming caller, a cause-and-effect relationship appears to exist between the two tables as the process progresses as if there are multiple menu selections, but at the database level no such relationship exists.
The database tables are composed of simple, “flat” records, much like conventional records in a desktop computer database. The number of fields per record is preferably limited to fifty, but this is not critical. The number of subset records is limited by available physical memory, performance goals for retrieving subset records, and performance goals with respect to the synchronization operation.
In step 62 , the IVR is initialized and available for calls. The automated interrogation device 10 of FIG. 1 may be used to process either or both of incoming and outgoing calls. Upon receiving a first call at step 64 , the automated processing is implemented. For instance, the device may prompt the call party for an identification and a PIN at step 66 . Upon receiving a response, a particular subset record is retrieved at step 68 . The entire record is retrieved, with all fields, so that multiple retrieve operations are not necessary.
The call is then processed at step 70 according to the operations performed in steps 56 , 58 and 60 . In some embodiments, the process is used to provide information to the call party. For example, in a banking environment, account information may be conveyed to the call party. In a sales environment, an order may be processed. If there are inventory concerns, the subset record may be modified, but the master record will not be modified until a subsequent synchronization operation is implemented. However, in some embodiments, simultaneous modification of the internal and external databases may be invoked. Nevertheless, typically the call party can enter data into the automated interrogation device 10 , but the transaction will not be guaranteed to be recorded at the remotely located database application 16 within a set time period, or even guaranteed to be accurately entered into the remotely located database application. Without a full awareness of the product availability, guarantees cannot be extended. Thus, the system is best suited for applications in which availability concerns are not dominant, such as providing bank account balances which are not likely to change often in a single day.
In step 72 , a determination is made as to whether it is appropriate to synchronize the subset records of the internal database 24 with master records of the remotely located database application 16 . As previously noted, the synchronization operation typically is executed when there are no ongoing calls with customers. Thus, a positive response to the determination step 72 results in a step 74 of isolating the database from incoming calls. Any incoming calls that are received during the synchronization process may be given the options of transferring to an extension, transferring to a queue, or transferring to a voicemail system. The goal is to avoid mutual exclusion problems, rather than to try to solve such problems.
In step 76 , the synchronization process is executed. The internal database 24 is updated and synchronized with the remotely located database application 16 , using channels 20 and 22 of a communications link. The type of communications link is not critical to the invention. The subset records are received from the remotely located database application 16 as files. The synchronization application 28 checks the files for consistency, integrity and completeness. Optionally, this can be performed at the host 14 .
The verified subset records are loaded to the internal database 24 . The process may be a bulk import of records or there may be an individual replacement of records (i.e., read, modify and write records). The process may occur automatically, or may require manual intervention. If the synchronization fails, the subset records are restored to their original state within the internal database 24 , when possible. For instances in which a portion of the new records have been verified, the verified records can replace the existing records.
When the synchronization process at step 76 is completed, the system is returned to a state for receiving incoming calls, as indicated by the return arrow to step 64 . | A system for automated handling of call interactions includes an automated interrogation device, typically having interactive voice response (IVR) capability, with local memory for storing subset records. Each subset record corresponds to a master record that is remotely stored. The subset record contains sufficient information to allow a calling party to complete an identification process and to at least initiate an intended operation. For example, in a banking environment, the locally stored information may include customer names, account identifications, account balances, dates, and other information that is commonly requested by bank customers. In response to an incoming call, IVR queries are directed to the calling party and the appropriate subset record is accessed. Preferably, the subset record is retrieved to temporary storage, such as random access memory. Thus, there are temporarily three storages of record material specific to the calling party. Information within the subset record is readily accessible without an on-line connection to the remote storage of the corresponding master record. However, data exchanges are frequently implemented in order to match information in the subset records with information in the master records. | 7 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
CROSS REFERENCE TO OTHER PATENT APPLICATIONS
None.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention is directed generally toward a system and method of use for analyzing reflected acoustic fields directed towards a resolution target underwater or in the atmosphere and more specifically toward a system and method of use for fully decomposing a reflected acoustic field into acoustic intensity vector components.
(2) Description of the Prior Art
Sonar systems are well known in the art for tracking and identifying submerged objects or objects in the atmosphere, for mine hunting, for precision underwater mapping and multistatic applications where there is more than one source and/or a receiver.
One sonar system example is a ship that can tow an array of sound-receiving hydrophones arranged in a passive towed array. The passive towed array, in conjunction with sound receiving and signal processing electronics, can detect sound in the water that may indicate the presence of an underwater target. In other arrangements, the ship can tow both the passive towed array and a towed acoustic projector, which together form a bi-static active sonar system. With this arrangement, the towed acoustic projector emits sound pulses.
Each sound pulse travels through the water, striking an object or target in the water, which in turn produces echoes. The echoes are received by the towed array of receiving hydrophones. Therefore, an echo indicates the presence of an underwater object and the direction from which the echo came; subsequently, indicating the direction of the underwater object.
In conventional bi-static active sonar systems, the towed acoustic projector is often deployed and towed separately from the towed array sound receiving hydrophones. A conventional towed acoustic projector typically includes a sound source mounted within a large rigid tow body. The conventional towed acoustic projector is large and heavy.
The towed acoustic projector is typically used to detect objects in deep water and at long ranges. Therefore, the acoustic projector is capable of generating sound having a high pressure level in order to enable the system to receive echoes from and to detect objects in the deep water at long ranges.
The towed array of receiving hydrophones are often deployed and recovered through a hull penetrator below the ship water line. In contrast, in part due to size and weight, the towed acoustic projector is deployed and recovered over the gunwale of the ship with winch and boom equipment.
U.S. Pat. No. 5,438,552 discloses a sonar system for identifying objects including a technique for providing a two-dimensional array of pixels, each one of the pixels representing the intensity of a signal at a predetermined range position and a predetermined cross-range position from a reference position and quantizing the intensity of each one of the pixels into one of a plurality of levels. The technique further includes comparing a distribution of the levels of pixels over a range scan at a cross-range position with the distribution of levels of pixels over a range scan at a different cross-range position to identify the existence of a foreign object such as a mine.
SUMMARY OF THE INVENTION
Accordingly it is a primary object and general purpose of the present invention to provide a sonar system and method capable of more precise target analysis through the use of vector components of sonar waves.
The target analysis method of the present invention comprises the steps of: illuminating a target with acoustic waves; positioning a device at multiple acoustic vector sensing positions about the target in a scattered acoustic field of reflected waves in order to simultaneously measure acoustic pressure and particle velocity at each vector sensing position; converting by using a Hilbert transform the measured acoustic pressures and particle velocities into a complex signal having active real and active imaginary vector components; computing active and reactive acoustic intensities at each vector component; and mapping field structure nulls being zero crossings of the active and reactive intensities to a bitmap representation of decomposed scattered target acoustic intensities of the target.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention and many attendant advantages thereto will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered with the accompanying drawings wherein:
FIG. 1 is a schematic illustrating a sonar target analysis system according to the principles of the present invention;
FIG. 2 is a block diagram of steps used in the sonar target analysis according to the principles of the present invention;
FIG. 3 is a representative bitmap reflection of step 240 of FIG. 2 ;
FIG. 4 is a results chart using a spherical target with an eighteen inch radius; and
FIG. 5 is a results chart using a spherical target with a twelve inch radius.
DESCRIPTION OF THE INVENTION
A sonar tracking system 10 is shown in FIG. 1 to include a sonar transmission or sending system 20 which transmits a signal 34 of infinite-extent sonar waveform planes 22 toward a target 26 (a rigid sphere with a radius 33 ). From the θ=−τγ direction. A radius 32 (in meters) is a distance measured from the center of the target 26 and θ is the conical angle relative to the normal to the direction of plane wave propagation. The signal 34 illuminates the target sphere 26 and is reflected from the sphere to a back-scattered region 28 and a forward-scattered region 30 .
A plurality of acoustic vector sonar sensors or receivers 36 at different vector sensing positions receive a signal 42 from the reflection action. The sensors 36 then simultaneously measure acoustic pressure and particle velocity at each vector sensing position. The measured acoustic pressures and particle velocities are sent via sensing lines 38 to a computer 40 for signal analysis.
The steps of the method are shown in the block diagram of FIG. 2 where the target 26 is illuminated by acoustic wave forms in step 200 . The acoustic vector sonar sensors 36 are positioned and measure the acoustic pressures and particle velocities at each vector sensing position in step 210 . The measured acoustic pressures and particle velocities are converted into a complex signal in step 220 . The active and reactive acoustic intensities are computed at each vector component in step 230 . A bitmap representation of decomposed scattered target acoustic intensities is created to include mapping field structure nulls in step 240 .
A representative bitmap structure of nulls is depicted in FIG. 3 . Null mapping is the process of analyzing null structures in a scattered intensity field by a set of logical operations on sparse matrices constructed from separated real and imaginary components of pressure and particle velocity fields.
The details below describe the structure of a scattered acoustic field by using a separation of the complex intensity field into active and reactive components. Utilizing the dimensionless constant relating an incident (or illuminating) wave to a radius of a sphere 2Πa/λ (or ka); a particular scattered region of interest is in the region of interest is in the resonance range (ka˜3) where the scattered diameter is approximately equal to 1λ and creeping waves are diffracted around the scatterer and combine with pressure scattered by the illuminated surface.
The phase differences caused by the acoustic path lengths of the diffracted waves cause interference patterns that vary with frequency and scattered characteristics which include geometry and material properties. Through a power mapping of the real (active) and imaginary (reactive) complex acoustic intensity; the effects of the illuminated target characteristics on the total acoustic energy fields are characterized.
Of further interest is the understanding of how the scattered vector field characterization extends and transitions into the far-field. In the preferred embodiment, fully-developed scattered intensity fields from simple rigid spheres are examined. Numerical and measured results have been studied and modeling will extend to elastic and fluid-filled boundary conditions.
The following embodiment is a simple scattering case for the rigid target sphere 26 of a radius 32 as shown in FIG. 1 . However, the method is not limited to a rigid spherical shape target. This description includes derivations for fluid-filled thin wall spheres and evacuated spherical shells.
Cylinder mapping is another example. The target only need be on the size order proportional to approximately one wavelength of the illumination frequency such as in the resonance region, where the acoustic wavelength of the illumination field and scatterer size (2*pi/lambda)*(radius of target) is on the order of two or three.
The target sphere 26 illuminated by infinite-extent plan waves 22 from the −π direction. Equation (1) represents the incident pressure
p
i
(
R
,
θ
)
=
P
i
ⅇ
ⅈ
kr
cos
θ
.
(
1
)
Relating the scattering problem to that of a spherical radiator, the Junger reference expressed the incident pressure field of Equation (1) as a series of Legendre functions as Equation (2),
P
i
(
R
,
θ
)
=
P
i
∑
n
=
0
(
2
n
+
1
)
i
n
P
n
(
cos
θ
)
j
n
(
k
R
)
(
2
)
Where P n (cos θ) and j n (kR) are respectively the Legendre polynomial and spherical Bessel function of the first kind. F M, Junger, D. Feit, “Sound, Structures and Their Interactions”, copyright 1993 by Acoustic Society of America, Chapter 10.
The general form of the scattered pressure field from a rigid sphere (∞ denotes the rigid boundary condition of infinite acoustic impedance) is then Equation (3):
p
s
∞
(
R
,
θ
)
=
-
P
i
∑
n
(
2
n
+
1
)
i
n
P
n
(
cos
θ
)
b
n
h
n
(
k
R
)
,
b
n
=
j
n
′
(
k
a
)
h
n
′
(
k
a
)
(
3
)
The symbols h′ n and j′ n are the Hankel and Bessel function of the first kind and their derivatives, respectively.
The vector field describing the complex scattered acoustic intensity is given by Equation (4):
J
=
1
2
p
u
*
=
I
+
i
Q
4
,
p
=
p
i
+
p
s
∞
,
(
4
)
The symbols p and u* are respectively the complex acoustic scalar pressure and conjugated particle velocity. I is the scattered active Intensity. Q is the scattered reactive intensity.
The particle velocity field is related to the gradient of the scalar pressure field by the momentum equation, which in axis-symmetric spherical coordinates becomes Equation (5):
∇
p
(
R
,
θ
)
=
i
ρ
ck
u
(
R
,
θ
)
.
(
5
)
The scattered velocity field u is found in Equation (6) by combining Equations (2), (3), and (5):
u
(
R
,
θ
)
=
P
i
p
c
∑
n
(
2
n
+
1
)
i
n
-
1
{
P
n
(
cos
θ
)
[
j
n
′
(
k
R
)
-
b
n
h
n
′
(
k
R
)
]
r
^
-
P
n
′
(
cos
θ
)
sin
θ
k
R
[
j
n
(
k
R
)
-
b
n
h
n
(
k
R
)
]
}
θ
^
(
6
)
For analysis, it is desirable to maintain the separable spatial vector and complex components of the time: averaged scattered acoustic intensity field as shown in Equation (7) where J (R,θ) is the complex scattered acoustic intensity, I (R,θ) is the real part of J, and Q (R,θ) is the imaginary part of J.
J
(
R
,
θ
)
=
I
(
R
,
θ
)
+
i
Q
(
R
,
θ
)
(
7
)
I
(
R
,
θ
)
=
1
2
R
e
{
p
}
R
e
{
u
*
}
-
1
2
I
m
{
p
}
I
m
{
u
*
}
Q
(
R
,
θ
)
=
1
2
Im
{
p
}
Re
{
u
*
}
+
1
2
Re
{
p
}
Im
{
u
*
}
Empirical data was obtained from Equation (7) with an eighteen inch (0.4572 m) diameter rigid spherical scatterer 200 (radius=0.2294 m), 716.4 Hz incident plane wave 204 from the −π direction, the complex acoustic scalar pressure ρ=1.21 kg/m 3 , c=343 m/s in air, which represents ka=3.0, where c is the sound speed of acoustic propagation in air. The total power in the scattered instantaneous acoustic intensity field (normalized by ρc) can be obtained as well as the spatial and complex decomposition of the scattered intensity field components.
An experiment exemplifies the viability of extracting field structures that can be seen in the spatial and complex separated components of the scattered acoustic intensity field from direct measurements.
In order to create a scattered field where ka=3, spheres milled from oak with diameters of twelve inches (30.48 cm) and eighteen inches (45.72 cm) were illuminated by a source at 3.6 m of 1000 Hz and 716.4 Hz, respectively. Measurements were collected using an acoustic vector sensor probe with radial velocity recorded on the axial velocity sensor, angular velocity component on the “y” velocity sensor, and scalar pressure on the microphone (See FIG. 4 ).
In order to ensure that the spherical coordinate velocity components could be measured using orthogonal sensors, the probes were aligned to the equator of the spheres while maintaining the probe axis normal to the surface of the scatterer. A self-leveling laser guide was used to align the geometry. Angles referenced to the maximum response angle (MRA) were hand-measured using distances to a stationary target offset in the test cell.
The raw sensor data was collected through a signal conditioner with gain set to “high” and corrections turned “off”. At each position, 20,000 samples at a rate of 5120 Hz (approximately four seconds) were acquired (known herein as a data record). Samples were taken primarily along an arc in the forward scattered region. Data was also collected in the forward scattered region for both spheres.
The data samples (time series) from the sensors were processed by first applying phase and sensitivity calibrations, and then filtered to remove 60 Hz noise components. The real signals x(t) were then combined with the Hilbert transform to create the analytic signal
x ~ ( t ) = x ( t ) + i h ^ ( x ( t ) ) = Re { x ( t ) } + i I m { x ~ ( t ) } ( 8 )
where h(x(t)) is the Hilbert transform of x(t). The analytic signals of pressure and velocity were then used to compute the four components of the scattered intensity field in spherical coordinates. For each acquired data record (n) of 20,000 samples, at a position R n θ n the spatial and complex separated components of the time-averaged scattered acoustic intensity field are computed in Equation (9).
I
r
^
(
R
n
,
θ
n
)
=
mean
Re
{
1
2
pu
green
*
(
R
n
,
θ
n
)
}
(
9
)
I
θ
^
(
R
n
,
θ
n
)
=
mean
Re
{
1
2
pu
red
*
(
R
n
,
θ
n
)
}
Q
r
^
(
R
n
,
θ
n
)
=
mean
Im
{
1
2
pu
green
*
(
R
n
,
θ
n
)
}
Q
θ
^
(
R
n
,
θ
n
)
=
mean
Im
{
1
2
pu
red
*
(
R
n
,
θ
n
)
}
FIG. 4 illustrates the agreement of the structure in the forward-scattered region between the model and field measurements for time-average steady-state acoustic intensity for the eighteen inch sphere illuminated by 716 Hz plane waves (ka=3). The structure of most components was observed to agree with the exception of the reactive radial intensity.
FIG. 5 illustrates from testing of the twelve inch sphere. In both FIGS. 4 and 5 , the horizontal axis represents the angle in degrees relative to zero which is the direction of the illumination wave in the forward region. The vertical axis represents pressure and intensity measured in decibels.
In both the twelve inch and eighteen inch sphere analysis, an inspection of the measured reactive radial intensity component indicates that the data matches the model more precisely at a slightly closer range than measured. Given the sensitivity to range for these particular features in the forward scattered region, the range differences noted can be accounted for by small misalignment in both altitude and attitude of the sensor.
The results for testing of the eighteen inch sphere in FIG. 4 include the active radial intensity 430 , the active angular intensity 420 , the reactive radial intensity 400 , the reactive angular intensity 410 , and the pressure 440 .
The results for testing of the twelve inch sphere in FIG. 5 include the active radial intensity 530 , the active angular intensity 520 , the reactive radial intensity 510 , the reactive angular intensity 500 , and the pressure 540 .
The analytical model and experimental data illustrates the ability to extract scattered field features from direct measurement of the time-averaged acoustic intensity field for simple rigid objects.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.
The foregoing description of the invention has been presented for purposes of illustration and description only. It is not intended to be exhaustive nor to limit the invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims. | A target analysis method that includes the steps of: illuminating a target with acoustic waves; positioning a device at multiple acoustic vector sensing positions about the target in a scattered acoustic field of reflected waves to simultaneously measure acoustic pressure and particle velocity at each vector sensing position; converting using a Hilbert transform the measured acoustic pressures and particle velocities into a complex signal having active real and reactive imaginary vector component; computing respective active and reactive acoustic intensities at each vector components; and mapping field structure nulls being zero crossings of the active and reactive intensities to a bitmap representation of decomposed scattered target acoustic intensities of the target. | 6 |
The present application is a continuation of Ser. No. 08/036,229, filed Mar. 24, 1993, now abandoned, which is a continuation of Ser. No. 07/726,792, filed Jun. 28, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to semiconductor integrated circuits, and more specifically to a method of protecting underlying dielectric and metal layers during wet etch by depositing silicon nitride layers.
2. Description of the Prior Art
In semiconductor integrated circuits, formation of interconnect layers is important to the proper operation of these devices. Interconnect signal lines make contact to lower conductive layers of the integrated circuit through vias in an insulating layer. For best operation of the device, the lower conductive layers should not be damaged during formation of the contact via.
Various interlevel dielectric layers are deposited on the integrated circuit during formation of the device. These layers separate the conductive layers from each other. One way to form contact vias through these insulating layers is by a process which utilizes both an isotropic wet etch and an anisotropic plasma etch. A wet etch is performed by exposing the integrated circuit to liquid chemicals, such as hydrogen fluoride. After a via has been opened part way through the insulating layer, an anisotropic etch is performed to expose the underlying conductive layer.
During a wet etch, undesirable voids, defects or stressed regions in a dielectric layer allow the chemicals to travel through the dielectric layers to the underlying conductive layers. This causes some of the conductive material to be etched away, leaving spots where conductive material in a conductive layer is missing. An integrated circuit with missing conductive material is unreliable, and possibly non-functional.
An approach presently used to minimize the possibility of conductive material being etched away is to reduce the period of time allocated for wet etching. This minimizes the likelihood that the underlying conductor will be damaged. However, decreasing the wet etch time also decreases the metal step coverage improvement realized by using a partial wet etch.
The problems caused during a wet etch by chemicals etching material not intended to be removed is not limited to conductive interconnect layers. Mouse bites in die boundaries and holes in bond pads are also attributed to the attack of metal during the formation of vias by wet etching.
It would be desirable to provide a technique to incorporate a layer of material in the interlevel dielectric layers which would act as a wet etch stop during via formation.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for forming a contact via without damaging underlying conductive layers.
It is another object of the present invention to protect underlying conductive layers from damage caused by wet etching of interlevel dielectric layers.
It is a further object of the present invention to provide such a method and structure which is compatible with standard process flows, and which adds minimal additional complexity to the fabrication of a typical integrated circuit.
Therefore, according to the present invention, a method of via formation for multilevel interconnect integrated circuits includes the depositing of a conformal layer of silicon nitride over the device before depositing the topmost layer of an interlevel oxide insulating layer. During the formation of contact vias through the combined oxide and nitride layers, a wet etch is performed. The nitride layer isolates the underlying dielectric and conductive layers from chemicals used in the wet etch, thereby maintaining the integrity of those underlying conductive and dielectric layers even if defects exist in the oxide layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, and further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIGS. 1 and 2 illustrate problems encountered when forming contact vias using prior art techniques; and
FIGS. 3-7 illustrate a preferred method of via formation for use with integrated circuits.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The process steps and structures described below do not form a complete process flow for manufacturing integrated circuits. The present invention can be practiced in conjunction with integrated circuit fabrication techniques currently used in the art, and only so much of the commonly practiced process steps are included as are necessary for an understanding of the present invention. The figures representing cross-sections of portions of an integrated circuit during fabrication are not drawn to scale, but instead are drawn so as to illustrate the important features of the invention.
Referring to FIGS. 1 and 2, a method for forming contact vias according to prior art techniques is shown. In FIG. 1 an integrated circuit device is formed in and on an underlying region 10. Conductive region 10 represents underlying circuitry as known in the art, and the details are not relevant to the present invention. A conformal interlevel dielectric layer 12 is deposited over the surface of the integrated circuit, where a contact via 14 is formed through the dielectric layer 12 using a mask and an etching technique known in the art. A conductive layer is deposited, defined and patterned on the integrated circuit to define interconnect leads 16, 18. The interconnect leads may be metal, such as aluminum, or it may be a silicided polycrystalline silicon layer. A layer of oxide 20 is deposited over the surface of the integrated circuit, followed by a layer of spin on glass.
Once deposited over the surface of the integrated circuit, the glass is then etched back using an anisotropic etch. This results in the formation of filler regions 22 along side steep side walls or inside lower topographical areas on the integrated circuit. Another conformal dielectric layer 24, such as oxide, is then deposited over the surface of the integrated circuit. This dielectric layer 24 may have voids 26, 28, in it, which are cracks or channels in the layer. A void 26 may run through the entire layer itself, or the void 28 may be located somewhere inside the layer. As will be shown, when the integrated circuit undergoes further processing, voids can create defects in the device. Stress regions on dielectric layer 24 will cause a smaller problem.
Referring to FIG. 2, a photoresist layer 30 is deposited and patterned on the integrated circuit. The photoresist layer 30 is used as a mask while the integrated circuit undergoes a wet etch. The wet etching technique is performed by exposing the integrated circuit to liquid chemicals, such as hydrogen fluoride, which selectively remove material from the device. The wet etch is used to create an opening 32 part way through the oxide layer 24. If the oxide layer 24 has voids 26, 28 in it, the chemicals used in the wet etch will etch through materials not intended to be removed and create defects 34, 36 in the integrated circuit.
FIG. 3 illustrates a preferred technique according to the present invention which is used to create integrated circuits, as described above in reference to FIG. 1. This technique produces the underlying conductive region 10, an interlevel dielectric layer 12, a contact via 14, interconnect leads 16, 18, an oxide layer 20, and filler regions of glass 22 as described above.
Referring to FIG. 4, a conformal layer of silicon nitride 38 is deposited over the surface of the integrated circuit. The silicon nitride layer 38 may be 100 to 2,000 angstroms thick. A conformal layer of dielectric 24 is then deposited over the surface of the device. Layer 24 is preferably an undoped CVD oxide layer. As shown in FIG. 4, the dielectric layer 24 contains voids 26, 28.
FIG. 5 illustrates the integrated circuit with a photoresist layer 30 deposited over the surface of the integrated circuit. The photoresist layer 30 is patterned and defined using methods known in the art.
FIG. 6 illustrates the integrated circuit after a wet etch is performed part way through the dielectric layer 24. During the wet etch, chemicals will etch through the voids 26, 28 in the dielectric layer 24 and be stopped by the barrier of silicon nitride layer 38. The underlying layers of dielectric 20, glass 22, and interconnect leads 16, 18 are protected from accidental etching caused by the chemicals traveling through the voids 26, 28.
Referring to FIG. 7 an anisotropic etch is performed using photoresist 30 as a mask. This completes formation of the opening 32 to expose a portion of the interconnect leads 16, 18. FIG. 7 illustrates the integrated circuit with the photoresist layer 30 removed. Conductive material 40 is then deposited and patterned on the device making electrical contact with interconnect leads 16, 18.
As will be appreciated by those skilled in the art, the method described above provides for isolation of the insulating layers and interconnect leads 16, 18 during wet etching. Depositing a layer of silicon nitride 38 adds a minimal amount of complexity to the process flow, and is compatible with standard process flows currently in use. This technique allows for improved via formation in multilevel interconnect integrated circuits. This technique also can be used to make electrical contact to active regions within a substrate.
The period of time allocated for a wet etch can be varied to suit process requirements. For example, a thick silicon nitride layer and a thin overlying oxide layer may be deposited on an integrated circuit. A wet etch can be used to etch completely through the oxide layer, followed by an anisotropic etch to etch through the silicon nitride layer. Alternatively, a wet etch can be used to etch only part way through the oxide layer, with the anisotropic etch performed on the remaining oxide layer, silicon nitride layer, and any underlying layers in order to complete via formation.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. | A method is provided for depositing a silicon nitride layer to protect and isolate underlying layers during wet etching. The silicon nitride layer maintains the integrity of interconnect leads, bond pads, and die boundaries by acting as a wet etch stop. The silicon nitride layer stops the chemicals used in a wet etch from reaching underlying layers in the integrated circuit. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the splitting of logs and, more particularly, to an apparatus for, method of and system for the automation of log splitting.
The invention contemplates utilization in a high speed, quantity production system of splitting logs for purposes such as firewood. Although the principles of the invention are generally applicable to the splitting of logs at any step in the development of an automated system, the primary advantage to this invention, i.e., speed, is best utilized in a large quantity output situation.
2. Prior Art
There exists a large number of patents which have been issued for log splitting devices of varying designs. Surely, there have been multitudes of designs for log splitters which have reached the public domain without benefit of patent protection.
One of the earliest designs of patented log splitters, issuing around 1907, was typified by an axe-head moving against a support, between the two of which a log is positioned. The log is held in place by means of guide rods at either side of the log. The axe-head is also slideably mounted on the guide rods. U.S. Pat. Nos. 846,838 and 846,839 are concerned with a design such as this.
In 1908, U.S. Pat. No. 885,458 issued on a design basically the same as those immediately above, but with the axe-head stationary and the log support moveably mounted on guide rods.
In all of the patents cited above, the dimensions of the log are extremely important. The diameter is strictly limited on the one hand by the distance between the guide rods and on the other hand by the inability to center a log which is too small.
Further, all of the above patents teach the use of an axe-head blade for cutting the log. This axe-head construction results in a massive wedge-like structure which is required either to be pushed through a log or to have a log pushed through it. Clearly, the force required to do this is great. The design of the above mechanisms are such that the log is not really split, but rather only perforated at one end in hope that the pressure of the hydraulic cylinder will cause the log to crack into portions.
Yet another concept is shown by U.S. Pat. No. 3,596,691, which has a specifically stated purpose of making fencing material. This apparatus has a cutting blade which is forced through a log by chain drive system. The apparatus also includes an elaborate mechanism for causing the log to rotate in order to allow splitting of the log along any diameter. Still further, a mechanism is included to hold the split log together, while turning and splitting at another diameter.
Two other patents, U.S. Pat. Nos. 3,077,214 and 3,280,864, concern a stationary blade with an hydraulically operated log pusher. The former patent includes its own hydraulic pump motor while the later patent contemplates operation in conjunction with an independent pump means, such as a tractor. These apparatus are, of course, limited to the size of log which they will accommodate, although not as exacting as the patents above mentioned. Also, the cutting blade in both of the apparatus are substantially bulky requiring large amounts of hydraulic force as noted with respect to previously mentioned concepts. One further comment is that each log must be hand placed between the blade and the pusher. Also, after splitting, the logs, have fallen from the machine must again be handled manually.
A number of issued patents suggest the use of a four-way blade to simultaneously split a log into four portions. Two examples of this approach are shown by U.S. Pat. Nos. 885,458 and 889,328. The former was discussed above with respect to the basic details. The latter involves a blade slideably mounted on guide rods and mechanically forced against a log in the direction of a fixed support. In both cases, the four-way blade is a massive structure requiring much brute force to even begin to split the log. Even the fact that the former patent mentions the four-way blade only in passing indicates the nonimportance and ineffectiveness of the idea as viewed by the inventor.
In U.S. Pat. No. 2,580,735 a four-way blade is shown which is intended to be forced through a log by a combination of hydraulics and mechanics. The log must, however, be manually loaded and unloaded from the apparatus. The blade is intended to split a log into four portions during the first half of a stroke and return the blade to a start position on the second half of the stroke.
An even more recent concept utilized in the prior art is shown by U.S. Pat. No. 3,319,675. In this apparatus, a double sided blade is used to enable logs to be split as the blade moves in both directions. The blade is attached to a slide and activated by a two-way hydraulic cylinder. Abutments at either end of the slide restrain logs during splitting. The logs must be manually loaded into the splitter and manually maneuvered to either again split the sections or remove the sections upon completion of splitting.
The prior art appears to show no concern for automating the log splitting processes to effect an economic, quantity operation.
SUMMARY OF THE INVENTION
The primary object of this invention is to provide an apparatus for, a method of and a system for the splitting of logs which is economic, safe, quick and easy to operate.
Other objects of this invention are to provide a new and improved log splitter which operates by hydraulics, which splits a log into four sections, which splits a log during each stroke of a two-way hydraulic cylinder, i.e., extension and return, and which is adjustable for the size of the log to be split.
Still other objects of this invention are to provide a new and improved log splitter system which is automatically loaded with logs individually, which is automatically orientated to accept and split a log at either end of the stroke of a two-way hydraulic cylinder, and which automatically transports the split logs away from the splitter.
Still another object of this invention is to provide a new and improved log splitter which includes a four-way knife edge blade for splitting logs which operates in four stages to assist in holding the log while splitting and reducing the amount of force necessary to split a log.
Yet another object of this invention is to provide a new and improved log splitter and system of splitting logs which is profitable for both the business of splitting logs for firewood or any other reason and the business of ultimately selling the product of such a system.
A still further object of this invention is to provide a new and improved log splitter which obtains one or more of the objects and advantages set forth above.
These and other objects and advantages of this invention will become apparent from the following description thereof, in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partially broken away, illustrating a system including the log splitter of this invention.
FIG. 2 is a cross-sectional view of the log splitter of FIG. 1.
FIG. 3 is a cross-sectional view of the log splitter taken along the line 3--3 of FIG. 2.
FIG. 4 is a partial cross-sectional view of the log splitter illustrating the adjustable table.
FIG. 5 is a perspective view of one of the knife edge four-way blades of this invention.
FIG. 6 is a schematic illustrating the controls and hydraulics necessary for operation of this invention.
FIG. 7 is a partial, cross-sectional view of the log splitter illustrating the self-loading feature of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention described herein is concerned with an apparatus for splitting logs. The invention is further concerned with a method of splitting logs and an automated system of splitting logs. The single most beneficial feature of the invention is the increase in speed of operation which is possible through the use of this invention. The log splitter of this invention is designed primarily with a view towards a high production system including conveyor input and conveyor output. Since the logs are to be split through the use of hydraulics, a hydraulic pump is, of course, necessary. As in the case of many of the prior art concepts, a tractor having a hydraulic system may be utilized for the pump in this case. On the other hand, an independent pump may be provided for the operation of the splitter.
FIG. 1 illustrates a log splitter, indicated generally at 10, of this invention having an input conveyor 12 and an output conveyor 14 associated therewith. The input conveyor 12 comprises two continuous driven chains 15 alignment supports 17 and stops 18. The continuous chains 15 are driven by means (not shown in the figures) to effect movement of logs from a source into abutting relationship with the stops 18, one after another, between the aligning supports 17.
Logs, from the input conveyor 12, are individually positioned onto an adjustable table, indicated generally at 20, by means of a self-loading mechanism, indicated generally at 22 and more fully described at a subsequent portion of this disclosure. The adjustable table 20 is designed to enable proper positioning of a log within the splitter 10.
The log splitter 10 is supported by a frame 24 in a manner allowing the output conveyor 14 to carry the split logs away from the system. The adjustable table 20 is supported in turn on a base structure 26 which is an integral part of the log splitter 10. Spaced equidistant at either end of the adjustable table 20 is a four-way blade, indicated generally at 28. The four-way blades 28 each include a horizontal 29 and vertical 30 blade. The particularities and design of the four-way blades 28 is more fully explained at a subsequent portion of this disclosure. Each of the four-way blades 28 is partially surrounded by a guide 32 which is intended to restrain the split log from movement in any undesired direction. It is not necessary that the guide 32 completely encircle the four-way blades 28 but only that the guide 32 extend above the horizontal blade 29 a sufficient distance to restrain positions of the log above the horizontal blade 29.
The adjustable table 20 comprises two separate wings 34, one edge of each of which is attached to the base structure 26 by means of hinges (not shown in FIG. 1) or other suitable pivoting means. The other side of each of the wings 34 is supported by hydraulic cylinders 36, an explanation of which will follow subsequently. Between the hinged ends of the wings 34 is a slot 38 in the base structure 26 which extends the longitudinal distance between the four-way blades 28.
Through the slot 38, extends a ram indicated generally at 40. The ram 40 includes a hollow cylindrical pusher 41 with a bar extension 42 permanently attached thereto and extending down through the slot 38. The pusher 41 is of a diameter to be compatible with the diameter of any size of log to be split by the invention. In this respect, the pusher 41 contacts the cross-section of a log to be split at a more or less continuous ring at a given radius, i.e., the radius of the pusher, rather than only at a single point. Thus the pusher 41 assists in centering, holding, and stabilizing the log while in the process of splitting the same.
FIGS. 2 and 3 are of considerable help in explaining the design and working of the log splitter 10 and particularly the ram 40. The bar extension 42 of the ram 40 extends through the slot 38, as noted above, and is permanently attached to the top surface of a slide plate 44, which is positioned between the base structure 26 and a guide plate 46. The base structure 26 and guide plate 46 are both permanently fixed in position by being attached to side plates 48.
The upper surface of guide plate 46, lower surface of base structure 26 and both surfaces of slide plate 44 are smoothly machined and thus the slide plate 44 is capable of easily sliding within and between the base structure and guide plate. The bar extension 42 is attached to the slide plate 44 in such a position that when the slide plate moves to either extreme within the log splitter 10, the ram 40 is moved within the slot 38 between the four-way blades 28.
A bracket 40 is permanently attached to the bottom surface of the slide plate 44. To this bracket 50 is attached the piston of a hydraulic cylinder 52 by means of a pin 53 fastened through the bracket 50 and a connector 54 on the piston of the hydraulic cylinder 52. The opposite end of the hydraulic cylinder 52 is permanently fixed to a portion of the log splitter 10, such as the side plates 48 by means of a pin 56 fastened through a bracket 57 on the cylinder 52 and openings 58 in the side plates 48. In this manner, the hydraulic cylinder 52 is fixed in position, with respect to the log splitter 10, however the piston of the cylinder and thus the ram 40 are able to be moved.
The hydraulic cylinder 52 has two hydraulic lines 60 connected thereto for the purpose of moving hydraulic fluid in and out of the cylinder upon the application of appropriate control signals. The principles of the hydraulic lines 60 and control mechanisms for the hydraulic cylinder 52 are well known in the art and will therefore only be cursorily explained in this disclosure.
The side plates 48 are permanently connected at their respective bottom edges to a second slide plate 62. This second slide plate 62 is journalled or otherwise rendered slidable within a base structure 64. Both surfaces of the second slide plate 62 and the inside surfaces of the base structure 64 are smoothly machined in order to allow relative movement between the two.
The bottom surface of the base structure 64 has an elongated aperture 65 therethrough (FIG. 3) and a bracket 66 which extends upwards through the aperture 65 and is permanently attached to the second slide plate 62. To the bracket 66 is attached the piston of a hydraulic cylinder 68 by means of a pin 69 fastened through the bracket 66 and a connector 70 on the piston of the hydraulic cylinder 68.
The other end of the hydraulic cylinder 68 is permanently attached to a fixed structure such as the frame 24 by means of a pin 71 fastened to a bracket 72 on the cylinder 68 and appropriate openings 73 in the frame 24. The purpose of hydraulic cylinder 68 is to enable movement of the entire log splitter 10 relative to the frame 24 for reasons that will be more fully developed subsequently with respect to the operation of the log splitter.
The hydraulic cylinder 68 has two hydraulic lines 74 connected thereto for the purpose of moving hydraulic fluid in and out of the cylinder upon the application of appropriate control signals. Once again the principles of hydraulic systems in general is known in the art and assumed to be understood herein.
FIG. 4 illustrates the design and function of the adjustable table 20. As noted above, one edge of each wing 34 is attached to the base structure 26, immediately adjacent to the slot 38, by means of hinges 76, or any other suitable means. Also as noted above, the other edge of each wing 34 is supported by means of hydraulic cylinder 36. The piston of each cylinder 36 is attached to each wing 34 by means of a pin 77 fastened through a connector 78 on each piston of the cylinders 34 and a bracket 79 permanently attached to each wing 34.
The other end of each hydraulic cylinder 36 is attached to the respective side plate 48 of the log splitter 10 by means of a pin 80 fastened through a connector 81 integral with the cylinder 36 and a bracket 82 permanently attached to the side plates 48. The hydraulic cylinders 36 have two hydraulic lines 83, each, connecting them to the controls and hydraulic pump for the purpose of causing hydraulic fluid to move in and out at appropriate times in order to raise or lower the wings 34.
FIG. 4 illustrates the positioning of the wings 34 necessary to accommodate logs of differing diameters. The wings 34 and associated portions shown in solid lines indicate the position required for a log having a size such as log A. The wings 34 shown in phantom lines indicate the different position required for a log having a size such as log B. It may easily be seen that the primary purpose of the wings 34 is to position a log so that the center of the log is at the center of the four-way blades 28. Thus the wings 34 are raised or lowered, as required, to position each log at the center of the blades as it enters so that the split portions will be substantially equal.
FIG. 5 illustrates the details of the four-way blades 28 utilized to split the logs into four equal portions. As stated above, there is included the horizontal blade 29 and the vertical blade 30. The vertical blade 30 is designed to contact a log first. The center of the vertical blade 30 includes a leading knife 85 which contacts a log even before the remainder of the vertical blade, i.e., vertical edge 86. The vertical blade 30 is not of a massive width, but rather only thick enough to resist bending upon the pressure of a log. Knife edges are machined at the appropriate places on the blade 30.
The horizontal blade 29 while being arranged to control a log after both the leading knife 85 and vertical edge 86 of blade 30, also has a leading edge 88 which contacts a log before the remainder of the horizontal blade 29, i.e., horizontal edge 89. Both the leading knife 88 and the horizontal edge 89 of blade 29 are constructed so that their respective inner most edges contact a log after the outer most edges. The reason for this design is to assure that the log not move or slip while splitting is taking place. In this respect, the outer most radius of a log is held in position as opposed to the center of the log.
The construction of blade 29 is similar to that of blade 30 with respect to the total thickness of the blade and the machining of the knife edges.
FIG. 7 may be utilized to describe the construction and function of the self-loading mechanism 22 referred to above. The one wing 34 adjacent to the input conveyor 12 includes two fingers 91 (shown in FIG. 1) which are hingedly attached to the wing 34 by any suitable means, such as a pin 92. The fingers 91 include a stop 93 which serves to assure that the fingers 91 only bend as far as to be in line with the wing 34.
The fingers 91 are spring loaded to be in line with the wing 34 and for this reason springs 94 are attached to the fingers 91. One end of each spring 94 is attached to a bracket 95 on each finger 91 and the other end of the spring 94 is attached to a bracket 96 on the wing 34.
FIG. 7 shows a log D positioned on the input conveyor 12 and adjacent to the stop 18. Another log E is shown positioned on the adjustable table 20. Once the log E has begun to be split by the log splitter 10, the adjustable table 20 may be operated to lower the wings 34 in order to be able to accept the next log. As the wings 34 are lowered, the fingers 91 strike the log D and begin to fold upward at the pin 92. As viewed in FIG. 1, the fingers 91 are positioned so that they do not interfere with the chains 15 of the input conveyor 12.
As the wings 34 of the adjustable table 20 continue to move downward, the fingers 91 bend or pivot about pin 92 until they are clear of the log D. Once clear of the log D, the fingers 92 are immediately returned to being in alignment with the wing 34 by reason of the tension on springs 94. At this point, the fingers 91 are ready to pick another log up from the input conveyor 12 and into the log splitter 10. The operation of the log splitter 10 will be fully described below.
FIG. 6 illustrates, in partial schematic, the control of the log splitter 10. A reservoir 97 for hydraulic fluid is provided. The reservoir 97 may be an independent unit attached to the log splitter 10 as necessary, or it may comprise the frame 24 of the log splitter 10 with appropriate connections.
A hydraulic pump 98 is also provided. The hydraulic pump 98 may be an independent unit or, as in the case of many prior art splitters, the pump 98 may be provided by a tractor conveniently positioned relative to the log splitter 10. Appropriate hydraulic connections are present between the reservoir 97 and the pump 98.
Finally, a bank of hydraulic switches, three in this case 101, 102 and 103, are utilized to control the splitter 10. The switches 101, 102 and 103 are connected by appropriate hydraulic lines to the reservoir 97 and pump 98. The switch 101 controls the hydraulic cylinder 52 which operates the ram 40 as described above. For this reason, switch 101 has connected thereto the hydraulic lines 60.
The switch 102 controls the hydraulic cylinder 68 which operates the movement of the splitter 10 relative to the frame 24 as described above. The switch 102 has connected thereto the hydraulic lines 74 for this purpose.
The switch 103 controls the hydraulic cylinders 36 which operate the wings 34 of the adjustable table 20. For this purpose, the switch 103 has hydraulic lines 83 connected thereto which at some point (not shown) have a Y-connection so that both cylinders 36 may be operated.
The operation of the log splitter will be explained in view of all of the above portions which have been discussed. Once the pump 98, input conveyor 12 and output conveyor 14 are operating, logs may be loaded into the conveyor 12. The logs will be moved along the conveyor 12 until they reach the stops 18 at which point they will rest (with the conveyor moving thereunder). The fingers 91 of the adjustable table 20 should be beneath the logs on the conveyor 12. In the event that they are not, the switch 103 is operated to so position the fingers 91.
The first log on the conveyor 12 is loaded into the splitter 10 by operating the switch 103 so that the wings 34 are raised. As soon as the fingers 91 raise the log enough to clear the stops 18, the log moves down the fingers 91 to rest against both wings 34. The adjustable table 20 may then be operated by switch 103 to position the center of the log at the center of the four-way blades 28.
The log at this time is positioned between one of the four-way blades 28 and the ram 40. The ram 40 is then operated, by means of switch 101, to cause the pusher 41 to engage the log and begin forcing the log through one of the four-way blades 28. The operation of the blade 28 is as noted above. As the log is pushed through the blade 28, the guide 32 keeps the portions from falling out of the splitter 10. When the ram 40 has pushed the log completely through the blade 28, the guide 32 assures that the split log falls out either end of the splitter 10 and onto the output conveyor 14. The output conveyor 14 carries the split logs away for further handling, such as stacking.
As soon as the ram 40 has begun pushing the log through the blade 28, the adjustable table is lowered, by operation of switch 103, so that the wings 34 are out of the way and do not interfere with operation. The table 20 is lowered so that the fingers 91 are below the next log on the conveyor 12.
Once the log has been split, the ram 40 is positioned with the vertical leading knife 85 of one blade 28 inside the cylindrical pusher 41. The splitter 10 is now ready for another log. The operation is the same as described above. The switch 103 is operated to load the next log onto the adjustable table 20 and position the log at the center of the blade 28. The switch 101 is operated as before to cause the ram 40 to push the log through the other blade 28.
Thus the two-way hydraulic cylinder 52 causes a log to be pushed through one of the blades 28 at the end of each stroke. The log portions are restrained by the guides 32 in order to be dropped onto the conveyor 14 and carried away.
As may be viewed in FIG. 1, the input conveyor 12 is as wide as the logs are long. The length of each log is preferably the same as the distance between the vertical knife edge 85 of the one blade 28 and the pusher 41 when at the end of its stroke. Since the pusher 41 and ram 40 will be at either one end or the other of its stroke as successive logs are loaded, the logs must be loaded at slightly different positions each stroke. This is the purpose for which the hydraulic cylinder 68, and it associated hardware, are intended.
The entire splitter 10 is moved relative to the frame 24 by operating the switch 102. The splitter 10 need only be moved the thickness of the pusher 41 each time a log is to be loaded.
It may easily be understood that the switches 101, 102 and 103 which operate the splitter 10 may be either manually operated or automatically controlled. Limit switches and other control circuitry (not shown) may be provided to render the operation of the splitter 10 automatic and thus attended operation unnecessary.
As explained above, the primary benefit expected to be achieved through the use of this invention is the speed of splitting logs. Consequently, depending upon the size of logs (diameter), the splitter could be utilized as the missing link in an overall high production system. In this regard, a first log splitter could be arranged to split logs having diameters of from 36 inches to 15 inches. The split logs from the first splitter could then be directed to a second splitter which would handle logs having diameters from 15 inches on down. In the event that the initial logs were under 15 inches in diameter, they would not be sent through the first log splitter.
In any case, a log with a diameter less the one half the height of the blades 28 could be split in two by allowing the adjustable table 22 to lower the whole log below the horizontal blade 29 of the four-way blade 28. In this manner, the log would be split only in two by the vertical blade 30.
Some additional parameters for the log splitter 10 are first that the logs may be 18 to 20 inches in total length. The time required to split a log is anywhere from 4 to 8 seconds depending, of course, upon the particularities of the hydraulics involved. In a unit which was actually built and operated, a 45 gallon hydraulic fluid pump and reservoir were utilized. It was found that a four cylinder diesel engine, as might be used in a tractor, was adequate and proficient for operating the hydraulic cylinders necessary for the log splitter 10.
Modifications, changes and improvements to the preferred forms of the invention herein disclosed, described and illustrated may occur to those skilled in the art who come to understand the principles and precepts thereof. Accordingly, the scope of the patent to be issued hereon should not be limited to the particular embodiments of the invention set forth herein, but rather should be limited by the advance by which the invention has promoted the art. | A log splitter for use in a high production environment utilizes a four-way, stepped knife blade at either end of a longitudinal stroke. A log is automatically placed and positioned between and at the center of the four-way knife blades by a hydraulically operated table. A self centering circular ram connected to a two-way hydraulic cylinder forces the log through either of the four-way knife blades depending upon which end of the stroke the ram was last positioned. The invention contemplates a conveyor input of logs and conveyor output of quartered logs. | 1 |
This invention is an optical switch containing a gas mixture capable of rapidly removing free electrons from a system and was developed pursuant to a contract with the United States Department of Energy.
BACKGROUND
Recently there has been an increasing interest in the possibility of employing inductive energy storage in pulse power applications because of the high intrinsic capacity of such storage when compared with capacitive energy storage and also the fact that this energy can be transferred to the load in nanosecond time scales. The key to utilizing this technology is the availability of a repetitive fast opening switch. A leading contender for such an opening switch is the externally sustained diffuse gas discharge switch.
In a diffuse gas discharge switch, the diffuse discharge is substained by means of gas ionization either by an external electron beam, a laser beam or a combination of both. The fast opening of the switch is usually accomplished by adding an electronegative gas in the gas mixture which attaches the remaining electrons immediately after the external electron source is turned off. The switch opening time depends critically on the electron attachment properties of the electronegative gas. Laser induced enhancement of electron attachment could be used to minimize the switch opening time.
Enhanced electron attachment due to vibrationally excited ground electronic state molecules produced by laser irradiation has been investigated. However, this effect has an inherent disadvantage in the diffuse gas discharge switch in that these molecules can reach vibrational levels due to excitation caused by electron impact and thus lead to undesired electron attachment during the switch conduction phase. In contrast, electronically excited states have higher threshold energies and thus do not effect electron loss in the conduction phase. Therefore, there is a continuing need to provide gas mixtures for diffuse gas discharge switches that are capable of quickly removing free electrons from the switch when the switch is open but yet does not attach to electrons when the switch is closed.
SUMMARY OF THE INVENTION
In view of the above needs, it is an object of this invention to provide a process for fast switching that utilizes the ability of a molecule to capture low energy electrons upon being exposed to a laser light.
It is another object of this invention to provide a gas mixture capable of switching from a conducting state to an insulating state by optically enhanced electron attachment via indirect excitation of molecules to long lived states.
It is a further object of this invention to provide a diffuse discharge switch capable of fast switching. These and other objects will become obvious to persons skilled in the art upon study of the specifications and appended claims. The process of this invention is fast switching of a gas mixture from a conducting state to an insulating state by introducing an electron source to the gas mixture in the absence of light, the gas mixture being a buffered gas and an electron attaching compound. This mixture is in a gas chamber between two electrodes thereby creating a conducting environment within the chamber. To switch to the insulating environment, the external electron source is removed and the laser light is turned on thereby affecting the attachment of low energy electrons. The attachment is caused by the molecules of the compound first being excited to a high lying optically allowed state; second being internally converted to the lowest optically allowed state; and third undergoing intersystem crossing to the triplet state and then remaining in the triplet state for a relatively long time and capturing low energy electrons efficiently while in this triplet state. This compound in the triplet state is an extremely more efficient electron attaching medium than those previously used and can significantly improve the efficiency and speed of a switch. The invention is also a diffuse discharge switch containing a gas mixture of a buffer gas and an electron attaching gas, as well as the gas mixture itself.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic energy level diagram of the buffer and attaching gas system for the optical switch of this invention.
FIG. 2 is a schematic diagram of a typical optical switch application.
FIG. 3 illustrates the observed photoenhanced electron attachment of thiophenol.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Previously various studies have been done on gas mixtures for the purpose of determining characteristics that make the mixtures conductors when the electron switch is closed and good insulators when open. Especially significant are the changes in the electron attaching properties of molecules with changes in their internal energy content since these can be employed to switch the electrical conduction properties to insulating properties. Efficient electron attachment results in a low concentration of free electrons and a high concentration of negative ions. Large changes in the cross section for negative ion formation have been observed when slow electrons collide with molecules excited thermally into vibrational/rotational states of the electronic ground state. Enhanced dissociative attachment via electron capture by vibrationally excited molecules produced by laser irradiation has also been reported. Additionally, enhanced electronic attachment to vibrationally excited HCl and HF molecules produced respectively by laser photo dissociation of C 2 H 3 Cl and C 2 F 3 H have been observed. The only studies known by the applicants on electron attachment to electronically excited molecules are the experiments on the dissociative attachment to O 2 produced in a microwave discharge and the calculation of dissociative attachment cross section for H 2 . Both of these studies indicated larger attachment cross sections for the electronically excited molecules compared to the ground state molecule. These two molecules were excited by direct electron impact of the ground state molecule into the metastable state using microwave discharges for O 2 , and a glow discharge plasma source for H 2 . No laser enhancement of the electron attachment process in these two molecules is possible as no direct or indirect (i.e., intersystem crossing) photo absorption mechanisms exist in these two molecules which will produce long lived metastable states. The novelty of this invention lies in process of electron attachment involving electronically excited molecules and its significance for optical switching.
Certain molecules possess the ability, when exposed to laser light, to be electronically excited to a high lying optically allowed transition state before being internally converted to the lowest optically allowed state and then undergoing intersystem crossing to the triplet state. While in the triplet state, the molecules possess the ability to capture low energy electrons extremely efficiently and this triplet state is maintained for relatively long periods of time. Thus, such molecules are extremely efficient for capturing electrons after a switch is opened thereby interrupting the current. Compounds that undergo such transitions are ones that possess π electrons, two specific types of compounds being ##STR1## where R and R' are radicals and the laser specific wavelengths to provide the excitation of the compounds are determined by each particular compound. Compounds and wavelengths can be determined by examining the optical absorption spectrum of the molecule under consideration, and from a knowledge of the positions of the lowest lying singlet and triplet state, and the quantum efficiency for conversion of the lowest lying singlet state into the metastable triplet state. The absorption spectrum will indicate the optimum laser wavelength to use to obtain the maximum light absorption in the gas, while knowledge of the quantum efficiency will indicate the number of molecules that are produced in the excited triplet state.
The principle of this invention and the required properties of the electron attaching molecules, herein refered to as AX, are shown in FIG. 1, an energy level diagram of a gas mixture of a buffer and attaching gas wherein the attaching gas is C 6 H 5 SH, CH 3 CHO and other similar compounds having a distinctive feature of their lowest electronic states being long lived. The electron attachment properties of AX are brought about by exposing AX at the ground state, S o , to an excimer laser beam to excite the molecules via the single photon absorption to a strongly allowed electronic singlet state, S n , designated AX** which lies below the lowest excited electronic state of the buffer gas. The AX** molecule normally undergoes fast intramolecular relaxation to its first singlet state, S 1 , in about 10 -13 seconds, designated AX*. This AX* species then undergoes rapid intersystem crossing to the lowest triplet state, T 1 , in about 10 -8 to 10 -11 seconds depending on the molecule. AX** remains in the triplet state for a relatively long period of time, greater than a 100 nanoseconds, an ample amount of time to allow collisions with slow electrons.
Classes of molecules that have the characteristics required are certain benzene derivatives and certain carbonyl compounds. In the first group, compounds that are effective are thiophenol (C 6 H 5 SH) and thioanisole (C 6 H 5 SCH 3 ) and in the second group specifically identified are acetyaldehyde (CH 3 CHO) and trifluoroacetaldehyde (CF 3 CHO). Photoexcitation into a highly allowed π→π* singlet state very quickly converges into the lowest excited triplet state with unit efficiency. The life times of the lowest electronically excited states are more than 10 -7 s, quite long enough for low energy electron capture and subsequent attachment.
FIG. 2 illustrates a typical diffuse discharge switch within which this gas mixture would be used. A gas mixture of a buffer gas such as N 2 or Ar is within the chamber 3 with an electron attaching gas with a partial pressure usually between 0.01 to 1.0 torr. When the electron beam 5 is turned on and the laser 7 is off, the electricity is conducted using the electrodes 9 to maintain an uniform field. To turn the switch off, the electron beam 5 is removed and a laser 7 is fired through a laser window 11 into the chamber 3. The electron attaching compound absorbs the light and, by the above described process, captures electrons in the chamber thereby removing the free flow of electrons and converting the gas into an insulator.
FIG. 3 illustrates the observed increase in the electron attachment coefficient of thiophenol versus the density reduced e1ectric field (E/N) using KrF laser beam of 2480 Å. It is shown that at low E/N and hence at low electron energies, the laser has a dramatic effect on the rate of electron attachment in the mixture. | The invention is a gas mixture for a diffuse discharge switch which is capable of changing from a conducting state to an insulating state in the presence of electrons upon the introduction of laser light. The mixture is composed of a buffer gas such as nitrogen or argon and an electron attaching gas such as C 6 H 5 SH, C 6 H 5 SCH 3 , CH 3 CHO and CF 3 CHO wherein the electron attachment is brought on by indirect excitation of molecules to long-lived states by exposure to laser light. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority 35 U.S.C. §119 to European Patent Publication No. EP 14160244.1 (filed on Mar. 17, 2014), which may be hereby incorporated by reference in its entirety.
TECHNICAL FIELD
Embodiments relate to a shut-off valve to fill a tank with a gaseous medium. The shut-off valve includes a valve housing, a piston arranged in the valve housing for displacement in an axial direction and having an axially continuous bore, a first end piece having an outlet opening which is fluidically-connected to the axially continuous bore of the piston; and a second end piece having an inlet opening which is fluidically-connected to the axially continuous bore of the piston. A first end side of the piston and a first end side of the second end piece of the valve housing form a sealing seat upon contact therebetween.
BACKGROUND
During filling of tanks with gaseous media, the filling is to be ended after a defined filling degree has been reached. In filling systems which communicate via infrared interfaces, for example, with a motor vehicle, there is the problem that filling is not possible in the case of fouling, damage or an unsuitable spacing of the infrared interfaces.
A solution is therefore sought which automatically ends a filling operation when the tank is full. One possibility is electromagnetically actuated valves which open and close on the basis of signals. There is the risk here, however, that the explosive gaseous medium may ignite as a result of spark formation. A solution is therefore sought, in which a valve is used which is of purely mechanical configuration and ends the filling operation when the defined filling degree has been reached.
Mechanically actuated valves are configured in such a way that, after a defined pressure has been reached, the valve closes automatically and further filling is thus prevented.
European Patent Publication No. EP 0837280B1 discloses a one-way valve, comprising the valve cone, the valve cone guide, the valve seat and the spring, which is designed to permit the fluid flow in the downstream direction from the inlet opening to the outlet opening and to restrict the fluid flow in the upstream direction from the outlet opening to the inlet opening.
SUMMARY
Embodiments relate to an enhanced shut-off valve which permits filling of a tank, the shut-off valve, actuated purely mechanically, to prevent further feeding of a gaseous medium after a defined pressure has been reached, independently of whether pressure increases, pressure decreases or pressure fluctuations occur on the feed side.
Embodiments relate to an enhanced flow behaviour of a gaseous medium from an inlet opening in the direction of an outlet opening of the shut-off valve in accordance with embodiments, in order to achieve more rapid filling and an optimum filling degree of the tank.
In accordance with embodiments, a shut-off valve for filling a tank with a gaseous medium, the shut-off valve including at least one of: a valve housing having a first end piece with an outlet opening, and a second end piece having an inlet opening; a piston which is axially displaceable in the valve housing, and which has an axially continuous piston bore which is fluidically-connected to the outlet opening and the inlet opening, and a first end side to form, upon contact with the second end piece, a sealing seat; a flow guiding device downstream of the inlet opening and which has at least one bore of the second end piece and a chamber, which bore leads radially to the outside and is fluidically-connected to the inlet opening of the second end piece, the chamber being configured between the piston and the second end piece, with the result that the gaseous medium is to flow from the inlet opening via the at least one radially outwardly arranged bore of the second end piece into the chamber and the gaseous medium in the chamber is directed from the outside to the inside in the direction of the first end side of the second end piece and a deflection of the gaseous medium is brought about in the direction of the axially continuous bore of the piston.
In accordance with embodiments, a shut-off valve may include at least one of: a valve housing having a first end piece with an outlet opening, and a second end piece having an inlet opening and a first end side; a piston axially displaceable in the valve housing and having an axially continuous piston bore which is fluidically-connected to the outlet opening and the inlet opening, and a first end side which, upon contact, forms a seal with the first end side; a flow guiding device downstream of the inlet opening and defining with the second end piece at least one radially-outwardly bore which is fluidically-connected to the inlet opening; and a chamber between the piston and the second end piece, wherein the gaseous medium is to flow from the inlet opening via the at least one bore into the chamber, where it is then directed towards the first end side of the second end piece where the gaseous medium deflected towards piston bore.
In accordance with embodiments, a shut-off valve may include at least one of: a valve housing; a first end piece connected at one end of the valve housing, and having an outlet opening axially extending therethrough; a second end piece connected at another end of the valve housing, and having an inlet opening axially extending therethrough; a piston axially displaceable in the valve housing between the first and second end pieces, and which upon contact, forms a seal with the first end piece, and further which has a piston bore axially extending therethrough which is fluidically-connected to the outlet opening and the inlet opening; a flow guiding device downstream of the inlet opening and defining with the second end piece at least one radially-outwardly bore which is fluidically-connected to the inlet opening; and a chamber between the piston and the second end piece, wherein the gaseous medium is to flow from the inlet opening via the at least one bore into the chamber, and then directed towards the second end piece where the gaseous medium is deflected towards the piston bore.
In accordance with embodiments, the valve housing may comprise a substantially hollow cylinder, in each case one internal thread is attached at both ends in the valve housing. A piston is arranged for axial displacement in the valve housing. The piston has an axially continuous bore which is fluidically-connected on one side to an inlet opening of the second end piece and on the other side to the outlet opening of the first end piece. Upon contact with a first end side of the second end piece, a first end side of the piston forms a sealing seat which seals in accordance with a set or predetermined shut-off pressure, and ignores (and remains closed) a further pressure increase, pressure decrease or any pressure fluctuations on the inlet side of the second end piece, for example, pressure fluctuations caused by the filling system.
Opening of the shut-off valve is not possible without a pressure decrease on the outlet side of the first end piece or upon removal of medium from the tank or the tank system, which removal is caused by usual operation. The end side of the piston and end side of the second end piece are also understood to mean any end-side structural formation which is provided for configuring the sealing seat. For example, as will be described in greater detail later, the first end side of the second end piece may have a contour, in particular a concave contour. The piston is spaced apart from the first end side of the second end piece in the pressureless state.
In accordance with embodiments, a flow guiding device is arranged downstream of the inlet opening. The flow guiding device serves to enhance flow of the gaseous medium from the inlet opening in the direction of the outlet opening by way of targeted deflection of the flow of the gaseous medium. The flow guiding device comprises substantially bores of the second end piece, and a chamber, which bores lead radially to the outside and are fluidically-connected to the inlet opening of the second end piece, and by way of which chamber the gaseous medium is directed from the outside to the inside in the direction of the first end side of the second end piece and a deflection of the gaseous medium is brought about in the direction of the axially continuous bore of the piston. The chamber is arranged substantially between the piston and the second end piece and is delimited by an inner wall of the valve housing.
This solution in accordance with embodiments is advantageous, above all, since the gap between the piston and the second end piece becomes smaller and smaller during filling as the pressure in the tank increases, as a result of which the flow channel is narrowed. Embodiments achieve an enhanced filling degree, since the flow channel makes optimum throughflow of the gaseous medium possible until the valve closes.
The shut-off valve is suitable, in particular, for media such as hydrogen, methane, natural gas or a mixture of hydrogen and natural gas. The use of other types of liquid media, such as, for example, liquid petroleum gas (LPG), is also suitable as a result of a modification of the shut-off valve in accordance with embodiments.
The result is a purely mechanical shut-off valve which closes the passage opening sealingly above a defined pressure on account of a set/predetermined spring force and opens neither in the case of a further pressure increase nor a pressure decrease down to a vacuum in the feed opening and therefore always remains closed. The removal of medium takes place at one or more different locations in the pressure accumulator system.
In accordance with embodiments, a bulge is arranged on the first end side of the second end piece. The bulge is to cause a rapid deflection of the gaseous medium in the direction of the axially continuous bore of the piston.
In accordance with embodiments, the first end piece and/or the second end piece are/is separate components. The first end piece and/or the second end piece are/is fastened to the valve housing. The fastening to the valve housing may take place by way of a suitable known method such as, for example adhesive bonding, brazing, welding, pressing or screwing.
In accordance with embodiments, the first end piece is arranged so as to lie opposite the second end piece. As a result of this arrangement, the valve housing may be of particularly compact and simple configuration.
In accordance with embodiments, the bulge of the second end piece is configured so as to be substantially coaxial with the centre axis of the axially continuous bore of the piston. This ensures that the flow of the gaseous medium takes place in an optimum manner, in particular if the individual components of the shut-off valve are configured as rotational parts. It is also prevented in this way that, in the closed state of the shut-off valve, the bulge of the second end piece may come into contact with the piston, since the bulge protrudes into the axially continuous bore of the piston.
The bulge of the second end piece may be configured as a point having substantially the shape or cross-section of a cylindrical cone or truncated cone. The maximum diameter, or at least the mean diameter of the bulge of the second end piece may be less than the diameter of the axially continuous bore of the piston. This ensures that the gaseous medium may flow with a low or otherwise reduced flow resistance into the axially continuous bore of the piston.
In accordance with embodiments, the first end side of the second end piece has a radially circumferential, approximately concave formation. The radially circumferential, approximately concave formation is to form a running transition with the point. As a result of this geometric refinement, the gaseous medium is directed particularly rapidly and efficiently into the axially continuous bore of the piston.
In accordance with embodiments, the radially outwardly leading bores of the second end piece together have a cross-section which corresponds at least to the cross-section of the inlet opening of the second end piece. This ensures that no throttling or back pressure of the flow of the gaseous medium may occur on account of an excessively small cross-section.
In a further inventive embodiment, the valve housing has a first end side in the cavity, which first end side has a radially circumferential, approximately concave formation, the radially circumferential, concave formation extending between the inner wall of the valve housing and the cavity. As a result, the gaseous medium is deflected more rapidly in the direction of the bulge of the second end piece.
In accordance with embodiments, the radially outwardly leading bores of the second end piece are arranged offset tangentially with respect to the centre axis of the inlet opening of the second end piece. By way of the tangential offset, the outflowing gaseous medium is intended to have a swirl imparted to it, as a result of which the flow stream may be aided further. This is advantageous, above all, since the gap between the piston and the second end piece becomes smaller and smaller and therefore the flow channel is narrowed as the pressure rises.
In accordance with embodiments, an elastic element is arranged between a second end side of the piston and a second end side of the housing valve. The second end side of the piston may be configured as an end side of a collar of the piston. The collar is arranged between the first sliding face of the piston and the second sliding face of the piston. The second end face of the piston, or of the collar of the piston, faces the second sliding face of the piston. The second end side of the valve housing faces away from the first end side of the valve housing and faces the second end side of the piston.
In accordance with embodiments, at least one disc spring may be used as elastic element. Disc springs afford the advantage that relatively high forces may be transmitted in a relatively small installation space. The elastic element is configured in such a way that it prestresses the piston against an end side of the first end piece in the pressureless state. The elastic element may comprise a disc spring assembly which applies a spring force, in order to press the piston against the first end wall of the first end piece. This ensures that the gap or the chamber between the first end side of the piston and the first end side of the second end piece and therefore the flow channel are as large as possible and the gaseous medium may flow into the tank in an unimpeded manner until filling is ended. As a result, vibrations are also avoided in the valve housing.
In accordance with embodiments, at least one first seal element is arranged between a first sliding face of the piston and the valve housing. The at least one first seal element may be arranged in the region between the first end side and the second end side of the valve housing. The at least one first seal element is configured in such a way so as to withstand the high pressure which occurs at the inlet opening of the second end piece during filling. Furthermore, the at least one first seal element is configured in such a way that the piston may slide axially on the at least one seal element. At the same time, the at least one first seal element serves as a mounting of the piston. The at least one first seal element is arranged in a groove in the valve housing. The groove is arranged in a region between the first end side and the second end side of the valve housing.
In accordance with embodiments, at least one second seal element is arranged between a second sliding face of the piston and the first end piece. The at least one second seal element is arranged in the region between the end side of the first end piece and the collar of the piston. The at least one second seal element is likewise configured in such a way that the piston may firstly slide axially and is secondly mounted by the at least one seal element. Since a similarly high pressure occurs at the outlet opening of the first end piece in the case of a fully filled tank as at the inlet opening of the second end piece during filling, the at least one second seal element likewise has to be configured in such a way that it may withstand the high pressure. The at least one second seal element is arranged in a groove in the first end piece.
In accordance with embodiments, at least one third seal element is arranged between the second end piece and the valve housing. The at least one third seal element seals radially against a second end side of the second end piece on a third end side in the region of the internal thread of the valve housing. A radially circumferential groove is configured in the second end side of the second end piece, in which groove the at least one third seal element is arranged.
In accordance with embodiments, the first end piece and the second end piece are fastened to the valve housing by way of screwing. The first end piece and the second end piece are preferably screwed at the ends of the valve housing in each case to the internal threads which are provided for this purpose. The screwing connection affords the advantage that the shut-off valve is connected releasably. For example, the components which are arranged in the shut-off valve may therefore be exchanged, such as springs, seal elements and pistons. In addition, it is possible in a simple way to preset the prestressing force of the spring element, by way of the screwing-in depth of the first end piece into the valve housing, to a desired force which is intended to permit the piston to lift up from the end side of the first end piece only when a defined pressure is reached in the outlet opening during filling. As a result, the tank which is fluidically connected to the shut-off valve, may be filled only as far as a pressure which is defined by the previously set spring force and the shut-off valve may always be held closed reliably even without electric devices, such as, for example, actuators.
In accordance with embodiments, in order that the gaseous medium may be guided into the tank as quickly as possible, the centre axis of the outlet opening of the first end piece is configured so as to be coaxial with the centre axis of the axially continuous bore of the piston.
In accordance with embodiments, the axially continuous bore of the piston has a diameter which is less than the diameter of the outlet opening of the first end piece.
In accordance with embodiments, an annular face is formed on a third end side of the piston, the third end side of the piston facing the first end side of the first end piece. The annular face is defined by the diameter of the axially continuous bore of the piston and the diameter of the outlet opening of the first end piece and is designed depending on the spring force of the elastic element in such a way that, when a predetermined pressure of from 90 to 95% of the shut-off pressure of the tank is reached at the outlet opening of the first end piece, the piston lifts off from the end side of the first end piece, as a result of which the entire surface area of the third end side of the piston becomes active, and the piston is rapidly displaced axially in the direction of the first end side of the second end piece.
The shut-off pressure is defined by the maximum permissible operating pressure of the tank. The shut-off pressure is necessary, in order to prevent damage of the tank or the tank system.
The difference in surface area of the first end side of the piston with respect to the third end side of the piston, the surface area of the third end side of the piston being greater than the surface area of the first end side of the piston, ensures that the shut-off valve remains closed even when the pressure at the inlet opening rises above the shut-off pressure. The shut-off valve remains closed even when the pressure at the inlet opening drops below the shut-off pressure, since the closing force is determined substantially only by the pressure in the tank on the third end face of the piston, minus the force of the disc spring assembly.
In accordance with embodiments, the piston has a first end side, the end side preferably forming a sealing edge. The sealing edge is one which is at least approximately the external diameter of the first end side of the piston. It is particularly advantageous if the sealing edge lies completely on the outer radius of the first end side of the piston, since in this case no additional forces which are induced by the valve inlet pressure may act on the piston in the closed state of the shut-off valve. This ensures that the gaseous medium, on account of the swirl which is imparted by the formation of the flow guiding device, still achieves a sufficient flow even in the case of a very small gap between the sealing edge of the piston and the end side of the second end piece. The sealing edge may be produced from a different material to the piston.
DRAWINGS
Embodiments will be illustrated by way of example in the drawings and explained in the description below.
FIG. 1 illustrates a sectional view of a shut-off valve, in accordance with embodiments.
FIG. 2 illustrates a sectional view along A 1 -A 1 of radially outwardly arranged bores of the shut-off valve, in accordance with embodiments.
FIG. 3 illustrates a sectional view along A 2 -A 2 of the radially outwardly arranged bores of the shut-off valve, in accordance with embodiments.
DESCRIPTION
FIG. 1 illustrates a sectional view through a shut-off valve 1 in accordance with the invention. The shut-off valve 1 comprises substantially a valve housing 11 , an axially displaceable piston 12 , a first end piece 13 and a second end piece 14 . The first end piece 13 and the second end piece 14 are mechanically connected to the valve housing 11 , such as, for example, being screwed into the valve housing 11 . The first end piece 13 has an external thread which may be screwed to the internal thread of the valve housing 11 . Furthermore, the first end piece 13 has an internal thread, by way of which the said first end piece 13 may be connected to a tank (not illustrated). The internal thread is fluidically-connected to the outlet opening 13 . 1 of the first end piece 13 . The first end piece has a groove 13 . 2 , in which at least one first seal element 15 is arranged.
The piston 12 is arranged in the valve housing 11 and is mounted by the at least one first seal element 15 on a first sliding face 12 . 1 which is configured as a sealing face. The second end piece 14 likewise has an external thread, by way of which it may be screwed to the valve housing 11 . An external thread is provided for connection to the filling system or to corresponding pipelines (not illustrated). At least one second seal element 16 is arranged in a second end side 14 . 8 of the second end piece 14 in a first radially circumferential groove 14 . 1 . A second radially circumferential groove 14 . 2 which is likewise configured on a third end side 14 . 9 of the second end piece 14 serves to receive a further seal element (not illustrated). The second end piece 14 has an inlet opening 14 . 3 , through which a gaseous medium may flow from the tank system in the direction of the tank during filling.
The inflowing gas enters into a chamber K through a flow guiding device S having radially outwardly arranged bores 14 . 4 . The radially outwardly arranged bores 14 . 4 of the second end piece 14 , the chamber K, and a bulge 14 . 5 arranged on the first end side 14 . 7 of the second end piece 14 , the bulge 14 . 5 of the second end piece 14 defining the shape of a point. Furthermore, the flow guiding device S comprises a first end side 11 . 4 in the valve housing 11 , the first end side 11 . 4 in the valve housing 11 having a radially circumferential, concave formation 11 . 1 which extends from the inner wall of the valve housing 11 in the direction of the cavity of the valve housing 11 , and a radially circumferential, concave formation 14 . 6 on the first end side 14 . 7 of the second end piece 14 , the radially circumferential, concave formation 14 . 6 forming a running transition with the bulge 14 . 5 of the second end piece 14 .
As a result of the above-described flow guiding device S, the gaseous medium flows particularly advantageously in the direction of the axially continuous bore 12 . 2 of the piston 12 . This is advantageous when the gap, and therefore, the chamber K are reduced in size when the piston 12 is displaced in the direction of the first end side 14 . 7 of the second end piece 14 , since the gaseous medium may flow almost without flow losses into the axially continuous bore 12 . 2 of the piston 12 as a result of the deflections of the radial circumferential, concave formations 11 . 1 , 14 . 6 .
An at least third seal element 17 serves to seal between the valve housing 11 and a second sliding face 12 . 3 of the piston 12 . The at least third seal element 17 is arranged in a groove 11 . 3 , the groove 11 . 3 being arranged in the region between the first end side 11 . 4 and second end side 11 . 5 of the valve housing 11 formed in the cavity. Furthermore, the second at least one seal element 17 serves to mount the piston 12 in the valve housing 11 .
The piston 12 has a collar 12 . 4 , the collar being arranged between the first sliding face 12 . 1 and the second sliding face 12 . 3 of the piston. The collar 12 . 4 has a second end side 12 . 6 of the piston, which second end side 12 . 6 faces the second end side 11 . 5 of the valve housing 11 .
An elastic element 18 is arranged in the cavity of the valve housing 11 , the elastic element 18 , may comprise a disc spring assembly. Ideally, the overlap of the surface areas of the first end side 13 . 4 of the first end piece 13 and the third end face of the piston 12 . 7 in accordance with the diameter of the axially continuous bore 12 . 2 and the diameter of the outlet opening 13 . 1 and the spring force which is set is such that the piston lifts upwardly when the pressure at the outlet opening 13 . 1 of the first end piece 13 has reached from 90 to 95% of the pressure at the inlet opening 14 . 3 of the second end piece 14 .
Since the annular face 13 . 3 is increased to the diameter of the first sliding face 12 . 1 of the piston 12 after the piston 12 has lifted off from the first end side 13 . 4 of the first end piece 13 , the piston 12 is displaced relatively rapidly in the direction of the first end side 14 . 7 of the second end piece 14 until the piston 12 seals against the first end side 14 . 7 of the second end piece 14 and interrupts the flow of the gaseous medium. The sealing takes place via the first end side 12 . 5 of the piston 12 , which first end side 12 . 5 forms a sealing edge. The sealing edge is a substantially outwardly radially circumferential edge of the first end side 12 . 5 of the piston 12 . The radially circumferential edge of the piston 12 may have a bevelled or rounded portion, for example, in the region of the first end side 12 . 5 of the piston 12 .
A ventilation bore 11 . 2 is provided in the valve housing 11 in the region of the elastic element 18 , which ventilation bore 11 . 2 permits pressure equalization of the air in the valve housing 11 between the two at least one first and third seal elements 15 and 17 when the piston 12 is displaced axially.
FIGS. 2 and 3 are a section A 1 -A 1 and A 2 -A 2 , respectively, through the radially outwardly arranged bores 14 . 4 of the second end piece.
In FIG. 2 , the radially outwardly arranged bores 14 . 4 are arranged centrally with respect to the centre axis of the inlet opening 14 . 3 of the second end piece 14 . In FIG. 3 , the radially outwardly arranged bores 14 . 4 of the second end piece 14 are arranged tangentially with respect to the centre axis of the inlet opening 14 . 3 of the second end piece 14 . As a result, the gaseous medium has swirl imparted to it, as a result of which the gaseous medium is directed more rapidly in the direction of the axially continuous bore 12 . 2 of the piston 12 , whereby an enhanced flow behaviour is achieved.
The term “coupled” or “connected” may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms “first,” “second,” etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.
Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments may be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.
LIST OF REFERENCE SIGNS
1 Shut-off valve
11 Valve housing
11 . 1 Radially circumferential, concave formation
11 . 2 Ventilation bore
11 . 3 Groove
11 . 4 First end side
11 . 5 Second end side
11 . 6 Third end side
12 Piston
12 . 1 First sliding face
12 . 2 Axially continuous bore
12 . 3 Second sliding face
12 . 4 Collar
12 . 5 First end side
12 . 6 Second end side
12 . 7 Third end side
13 First end piece
13 . 1 Outlet opening
13 . 2 Groove
13 . 3 Annular face
13 . 4 First end side
14 Second end piece
14 . 1 Groove
14 . 2 Groove
14 . 3 Inlet opening
14 . 4 Radially arranged bores
14 . 5 Bulge
14 . 6 Radially circumferential, concave formation
14 . 7 First end side
14 . 8 Second end side
14 . 9 Third end side
15 First seal element
16 Second seal element
17 Third seal element
18 Elastic element
K Chamber
S Flow guiding device | A shut-off valve to fill a tank with a gaseous medium. The shut-off valve includes a valve housing, a piston arranged in the valve housing for displacement in an axial direction and having an axially continuous bore, a first end piece having an outlet opening which is fluidically-connected to the axially continuous bore of the piston; and a second end piece having an inlet opening which is fluidically-connected to the axially continuous bore of the piston. A first end side of the piston and a first end side of the second end piece of the valve housing form a sealing seat upon contact therebetween. | 5 |
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2010/055880, filed Apr. 30, 2010, which claims the benefit of priority to Ser. No. DE 10 2009 027 316.6, filed Jun. 30, 2009 in Germany, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
The disclosure is based on a holding device for a portable power tool.
Rotary- and chisel-hammer holding devices are known which have a hammer tube and locking bodies which connect the hammer tube to a tool chuck in the fitted state.
SUMMARY
The disclosure is based on a holding device for a portable power tool, in particular a rotary- and/or chisel-hammer holding device, having a hammer tube and at least one locking body which connects the hammer tube to at least one further holding component in a fitted state.
It is proposed that the locking body have at least one locking surface curved about at least one load tilting axis. In this case, the expression “hammer tube” is intended to mean in particular an elongated, hollow component, in particular a hollow shaft, in which a striker of a percussion mechanism, a piston, in particular a skirt-type piston, and/or a percussion pin interacting with a striker is guided in the longitudinal extent of the hammer tube. The expression “load tilting axis” is intended to mean in particular an axis about which the locking body is tilted during a main load, such as, in particular, during a load on the hammer tube and/or on the holding component, to be connected to the hammer tube, in the axial direction of the hammer tube and/or in the circumferential direction of the hammer tube. Large load-bearing areas, small surface pressures, low wear and a long service life can be advantageously achieved by an appropriate configuration.
In this case, the locking surface can have various curvatures which seem appropriate to the person skilled in the art and can also be produced by various methods which seem appropriate to the person skilled in the art, e.g. by means of material removal processes, e.g. milling processes. In an especially advantageous manner, however, the locking surface is formed at least partly by a cambered surface, i.e. a surface produced by a plastic deformation operation, such as, in particular, by a rolling operation, as a result of which the service life can be further increased. The locking surface of the locking body can be designed in principle to be at least partly concave and/or, in an especially advantageous manner, to be at least partly and preferably completely convex.
Various components of the holding device for the portable power tool which seem appropriate to the person skilled in the art can be connected to the hammer tube by means of one or more corresponding locking bodies. However, if the holding device for the portable power tool has a tool holder having at least one holding surface which corresponds with the locking body in at least one operating state, an especially space-saving design, in particular without an additional holding flange, can be achieved. In this connection, the expression “tool holder” is intended to mean in particular a component which has an accommodating region for an application tool, such as in particular for a drill and/or chisel.
In a further configuration of the disclosure, it is proposed that the hammer tube and, in an especially advantageous manner, at least one further holding component have at least one curved holding surface which corresponds with the curved locking surface in at least one operating state, as a result of which surface pressure which occurs and wear which occurs can be further reduced.
The locking body can in principle have various shapes which seem appropriate to the person skilled in the art; for example, said locking body can be designed to be spherical, parallelepiped-shaped, bean-shaped, etc., and preferably correspondingly adapted mating surfaces should then be provided. In an especially advantageous manner, however, the locking body has, in the fitted state, a greater extent at least in the radial direction of the hammer tube than in the axial direction of the hammer tube, as a result of which advantageous overlapping can be achieved.
It is also proposed that the locking body have at least one curved end face and/or a curved lateral surface. In this case, the expression “end face” is intended to mean in particular a surface pointing in the longitudinal direction of the locking body, preferably in the radial direction of the hammer tube, and a “lateral surface” is intended to mean in particular a surface pointing transversely to a longitudinal direction and extending about a longitudinal axis of the locking body. Advantageous force flows and small surface pressures can be advantageously achieved by an appropriate configuration, specifically, in particular, if the locking body has at least two locking surfaces.
BRIEF DESCRIPTION OF DRAWINGS
Further advantages follow from the description of the drawings below. Exemplary embodiments of the disclosure are shown in the drawings. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will also expediently consider the features individually and combine them to form appropriate further combinations.
In the drawing:
FIG. 1 shows a schematic illustration of a rotary and chisel hammer with a partial section through a rotary- and chisel-hammer holding device,
FIG. 2 shows an enlarged illustration of a detail from FIG. 1 , with play and tilt angle shown greatly exaggerated,
FIG. 3 shows an enlarged illustration of a detail of a first alternative, with play and tilt angle shown greatly exaggerated,
FIG. 4 shows an enlarged illustration of a detail of a second alternative, with play and tilt angle shown greatly exaggerated.
DETAILED DESCRIPTION
FIG. 1 shows a schematically illustrated rotary and chisel hammer with a partial section through a rotary- and chisel-hammer holding device of the rotary and chisel hammer. The rotary- and chisel-hammer holding device comprises a hammer tube 10 a in which a striker 36 a of a percussion mechanism (not shown in any more detail) is guided. Furthermore, the rotary- and chisel-hammer holding device has three locking bodies 12 a of the same kind which are uniformly distributed over the circumference of the hammer tube 10 a and which, in a fitted state, connect the hammer tube 10 a to a holding component for conjoint rotation and in an axially fixed manner, said holding component being formed by a tool holder 22 a . The tool holder 22 a has an outside diameter which is smaller than an inside diameter of the hammer tube 10 a and is inserted into the hammer tube 10 a.
The locking body 12 a passes radially through a round aperture in the hammer tube 10 a , said aperture being defined by a holding surface 28 a . The locking body 12 a has two locking surfaces 16 a , 18 a ( FIG. 2 ) which are convexly curved about its load tilting axis 14 a and are formed by cambered surfaces. The locking body 12 a is of cylinder-like design and has, in the fitted state, a greater extent in the radial direction 32 a of the hammer tube 10 a than in the axial direction 34 a of the hammer tube 10 a . The locking surfaces 16 a , 18 a are formed by opposite end faces of the locking body 12 a.
In accordance with the number of locking bodies 12 a , the tool holder 22 a has blind-hole recesses 38 a on its inner circumference, specifically blind holes, the center axes of which extend radially relative to the hammer tube 10 a . The blind-hole recess 38 a is defined in the radial direction by a holding surface 24 a of the tool holder 22 a , said holding surface 24 a corresponding with the locking body 12 a in an operating state and being concavely curved about the load tilting axis 14 a . Furthermore, the rotary- and chisel-hammer holding device has, in the radially outer region of the hammer tube 10 a , a perforated ring 40 a , through which the locking body 12 a passes in the radial direction. In the radially outer region of the perforated ring 40 a , the rotary- and chisel-hammer holding device has a holding component which is formed by a holding ring 42 a and which has a concavely curved holding surface 30 a on its side pointing radially inward, said holding surface 30 a corresponding with the locking surface 16 a of the locking body 12 a in an operating state. The perforated ring 40 a has a stepped outer contour and the holding ring 42 a has a stepped inner contour. The inner contour and the outer contour are matched to one another, and the inner contour and the outer contour engage one inside the other in a positive-locking manner in the axial and radial directions. The perforated ring 40 a and the holding ring 42 a are secured in the axial direction 34 a of the hammer tube 10 a inside a portable power tool housing 46 a by means of a clamping ring 44 a and by means of a step 48 a integrally formed on the portable power tool housing 46 a.
If, for example, a force F 1 loading the tool holder 22 a in an axial direction away from the striker 36 a occurs during operation, the locking body 12 a is tilted about the load tilting axis 14 a running perpendicularly to the axial direction 34 a of the hammer tube 10 a by the force F 1 and a reaction force F 2 opposed to the force F 1 , as shown exaggerated in FIG. 2 for illustration. As a result of the curved locking surfaces 16 a , 18 a and the curved holding surfaces 24 a , 30 a , large contact areas, small surface pressures and low wear are advantageously achieved.
FIGS. 3 and 4 show details of alternative exemplary embodiments. Components, features and functions that remain the same are basically marked with the same reference numerals. To distinguish between the exemplary embodiments, the letters a to c are added to the reference numerals. The description below is basically restricted to the differences from the exemplary embodiment in FIGS. 1 and 2 . With regard to features and functions that remain the same, reference may be made to the description of the exemplary embodiment in FIGS. 1 and 2 .
FIG. 3 shows a detail of an alternative rotary- and chisel-hammer holding device having barrel-shaped locking bodies 12 b which connect together a hammer tube 10 b and a tool holder 22 b of the rotary- and chisel-hammer holding device for conjoint rotation and in an axially fixed manner. The locking body 12 b has a curved locking surface 20 b , specifically a convexly curved lateral surface, and flat end faces 16 b , 18 b . For each locking body 12 b , the hammer tube 10 b has a radial through-aperture which is defined by a holding surface 28 b of the hammer tube 10 b , said holding surface 28 b being concavely curved about a load tilting axis 14 b and corresponding with the locking surface 20 b in an operating state. The holding surface 28 b of the hammer tube 10 b is a lateral surface or encloses the locking body 12 b by 360°. Furthermore, the tool holder 22 b has a radial blind-hole recess which is defined by a holding surface 26 b concavely curved about the load tilting axis 14 b and corresponding with the locking surface 20 b during operation. The holding surface 26 b is formed by a lateral surface or encloses the locking body 12 b by 360°. Compared with the exemplary embodiment in FIGS. 1 and 2 , the hammer tube 10 b is radially defined in the region of the locking body 12 b directly by a portable power tool housing 46 b . The hammer tube 10 b is directly mounted in the portable power tool housing 46 b.
FIG. 4 shows a detail of an alternative rotary- and chisel-hammer holding device having barrel-shaped locking bodies 12 c which connect together a hammer tube 10 c and a tool holder 22 c of the rotary- and chisel-hammer holding device for conjoint rotation and in an axially fixed manner. The locking body 12 c has three curved locking surfaces 16 c , 18 c , 20 c , specifically a convexly curved lateral surface and two convexly curved end faces. For each locking body 12 c , the hammer tube 10 c has a radial through-aperture which is defined by a holding surface 28 c of the hammer tube 10 c , said holding surface 28 c being concavely curved about a load tilting axis 14 c and corresponding with the locking surface 20 c in an operating state. Furthermore, the tool holder 22 c has a radial blind-hole recess which is defined by a holding surface 26 c concavely curved about the load tilting axis 14 c and corresponding with the locking surface 20 c during operation. The holding surface 26 c is formed by a lateral surface or encloses the locking body 12 c by 360°. The hammer tube 10 c is radially defined in the region of the locking body 12 c directly by a portable power tool housing 46 c . The curved end faces of the locking body 12 c correspond with a concave holding surface 30 c of the portable power tool housing 46 c pointing radially inward and with a concave holding surface 24 c of the tool holder 22 c pointing radially outward. | A holding device for hand machine tools, in particular a drill and/or a chipping hammer holding device, includes a hammer tube and at least one blocking body, which, when installed, connects the hammer tube to at least one additional holding component. The blocking body is provided with at least one blocking surface that is curved around at least one load tipping axis. | 1 |
RELATED APPLICATIONS
[0001] This application claims priority to provisional application No. 60/464,762, entitled Wrist Heart Rate Variable Monitor filed Apr. 23, 2003.
FIELD OF THE INVENTION
[0002] This invention relates generally to monitoring heart rate variability using a wrist worn monitor.
BACKGROUND OF THE PRESENT INVENTION
[0003] This invention monitors a user's heart rate variability (HRV). The invention also performs a heart rate variability test. Heart rate variability refers to the interval between heart beats and may be mathematically defined as the one sigma standard deviation of the heart rate about the mean heart rate value. A heart rate variability test is a reflection of a person's current health status. By taking heart rate variability tests over time, an individual is able to gauge improvement or deterioration in their health status. Such improvements or deterioration of health may result from a number of sources including, e.g., changes in lifestyle such as smoking cessation, starting an exercise program, surgery recovery, stressor additions or removals, diet changes. Thus, in this context, the HRV test may be used as a medical motivator. The HRV test may also be used as an early indicator diagnostic tool. For example, the HRV test has been demonstrated to have prognostic associations with future coronary disease.
[0004] Human sleep is described as a succession of recurring stages, including an awake stage, non-REM stages and the REM stage. The awake stage in this context is actually the phase during which a person begins the process of falling asleep. Sleep quality changes with the transition from one sleep stage into another. Significantly for purposes of this invention, the transition from stage to stage is marked with observable, though subtle, changes in bodily function, including heart rate variability.
[0005] Analysis of 24-hour HRV typically shows a nocturnal increase in the standard deviation of heart beat intervals. The heart rate is further known to decrease relatively rapidly as a person transitions from the awake stage to the non-REM stages. As the individual eventually transitions from the non-REM sleep stages to REM sleep, the heart rate becomes more erratic and the variability increases. There are several stages of REM sleep, each marked by changes in heart rate variability. The first REM stage typically lasts about 10 minutes, with each recurring REM stage lengthening, with the final stage lasting about one hour. The inventive monitor is capable of detecting the heart rate variability within each sleep stage as well as the transition from one sleep stage to the next, i.e., the transition from awake to non-REM sleep, the transition from non-REM sleep to REM sleep, and the completion of an REM sleep stage and subsequent transition to the next REM sleep stage.
[0006] Finally, sleep apnea is a condition whereby afflicted individuals literally stop breathing repeatedly during sleep, often for a minute or longer and as many as hundreds of times during a single night's sleep. Very often individuals with sleep apnea experience disrupted sleep and are prevented from reaching the later stages of sleep, such as REM sleep, which the body requires for rest and replenishment of strength. Heart rate variability data can be used to assist the physician in diagnosing and monitoring the efficacy of treatment regimens for sleep apnea. The inventive monitor may be used to determine whether heart rate variability indicates that sleep is continually interrupted and whether a sufficient amount of REM sleep is being obtained.
[0007] A wrist worn heart rate variability monitor for use in the above-mentioned conditions is desirable. The inventive monitor is used in four basic applications. The first application is used to assist the user with a timed nap. The heart rate variability data obtained through the invention is used to determine when the user has achieved sleep or a beneficial level of rest. When the heart rate itself is lowered to a target resting heart rate level, the device starts a timed alarm to wake the user. Both the threshold target heart rate level and the duration of the sleep session may be determined by the user using input buttons to program the device.
[0008] The second application uses the heart rate to determine the duration of a sleep session. Users may use the device at night in this manner to measure the overall duration, and assess the quality, of their sleep. The measured data may be stored in the device's memory and accessed either by the user through the device or by the user's physician. The stored information may be related to the physician residing in a remote location. The results may be assessed for quality of sleep by recognizing when the heart rate is above or below the preset threshold target level as well as variations in the intervals between heart beats. Thus, the data may be used to determine whether or not the user is getting quality sleep, or is waking during sleep which is common in persons suffering from sleep apnea and heavy snoring. This information may be used by the user as a motivator to see a physician and/or a sleep specialist. This information is also valuable to the user's physician in determining if treatment is necessary and what type of treatment would be most effective. Subsequent impact of the treatment may also be evaluated using heart rate variability information.
[0009] The third application utilizes the heart rate to perform a heart rate variability test (HRV). HRV tests are typically performed while the subject is at rest or asleep or may be done over a user's normal 24-hour activities. User's can choose to have an HRV test performed using an input button. An HRV test may be performed in as little as ten seconds, but the longer the test, the more accurate the results. Users can utilize the HRV option while taking a timed nap, during a resting period, or when sleeping at night.
[0010] In the fourth basic application, the device is used in concert with a home's electronics control unit. Many homes are equipped with a controlling computer system. These homes have been referred to as ‘smart houses.’ The home's controlling computer or electronics control unit manages the functions of the home. These functions may include: television; personal computer; shower; home security system; lights; kitchen appliances; garage door and other functional features of a home. This invention is capable of working in concert with the home's controlling computer system and works to synchronize the home's functions with the homeowner's functions. The user wears the device before bed and when the user's heart rate level and variability reach the threshold level, the wrist worn monitor sends out a signal to the home's controlling computer which then prepares the home for the night, i.e., places the home in ‘sleep’ mode. This may comprise functions such as shutting lights and televisions off, ensuring the garage door is down, setting the thermostat at an appropriate temperature for the night, etc. The opposite is done in the morning. When the user's heart rate level and variability rises above the threshold level, the monitor sends a signal to the central home computer to prepare the home for the day, i.e., placing the home in ‘awake’ mode. Thus, functions such as turning on the lights, shower, coffee maker, alarm are accomplished. In addition to using the heart rate variability of the user to control the features
[heading-0011] of the home, the monitor may have a button that manually accomplishes the tasks without use of heart rate variability information.
[0012] The present invention accomplishes these goals.
SUMMARY OF THE INVENTION
[0013] A wrist-worn heart rate variability monitor is provided. Heart rate variability (“HRV”) refers to the interval between heart beats and is a reflection of an individual's current health status. Over time, an individual may use the results of HRV tests to monitor either improvement or deterioration of specific health issues. Thus, one use of the HRV test is as a medical motivator. When an individual has a poor HRV result, it is an indicator that they should consult their physician and make appropriate changes where applicable to improve their health. If an individual's HRV results deviate significantly from their normal HRV, they may be motivated to consult their physician. In addition, the inventive monitor is capable of monitoring the stages of sleep by changes in the heart rate variability and can record the sleep (or rest) sessions with the resulting data accessible by the user or other interested parties. The inventive monitor is thus capable of several novel uses: (1) to assist the user with a nap that allows predetermined time in one or more sleep stages; (2) determination of the duration of a sleep session, including length of time spent in one or more sleep stages; (3) in concert with a home's central electronic and computer control unit, the device uses HRV to determine when the house may be placed in “sleep” mode and when it is appropriate to place the house in “awake mode”; and (4) performance of an HRV test.
[0014] An object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that is capable of timing sleep sessions and recording heart rate variability during the same.
[0015] Another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor capable of performing a heart rate variability test.
[0016] Another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that allows the user to spend a predetermined amount of time in one or more sleep stages while recording the sleep session for future review and analysis.
[0017] Still another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that is capable of differentiating between the user's awake state, non-REM sleep state and REM sleep state.
[0018] Yet another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that allows recording of sleep sessions to determine and improve the quality and duration of the individual's sleep.
[0019] Another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that uses the obtained heart rate variability information to remotely instruct a central home computer to place the home in “sleep” mode when the monitor determines that the user falls asleep.
[0020] Another object and advantage of the present invention is to provide a wrist worn heart rate variability monitor that uses the obtained heart rate variability information to remotely instruct a central home computer to place the home in “awake” mode when the monitor determines that the user has awakened.
[0021] Another object and advantage of the present invention is to provide a wrist worn heart rate variability that is capable of detecting and recording sleep apnea events.
[0022] The foregoing objects and advantages of the invention will become apparent to those skilled in the art when the following detailed description of the invention is read in conjunction with the accompanying drawings and claims. Throughout the drawings, like numerals refer to similar or identical parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a top view of the wrist worn monitor.
[0024] FIG. 2 is a bottom view of the wrist worn monitor with electrodes and wires in phantom.
[0025] FIG. 3 is a side view of one embodiment of the wrist worn monitor closure.
[0026] FIG. 4 is a side view of the wrist worn monitor.
[0027] FIG. 5 is a bottom view of the wrist worn monitor illustrating possible two piece manufacture.
[0028] FIG. 6 is a top view of the membrane attachment.
[0029] FIG. 7 illustrates the membrane attached to the wrist worn monitor.
[0030] FIG. 8A is a bottom view illustrating placement of the alarm elements.
[0031] FIG. 8B is a top view illustrating placement of the alarm elements.
[0032] FIG. 9 is a view of the wrist worn monitor display.
[0033] FIG. 10 is a block diagram of the circuitry.
[0034] FIG. 11 is a block diagram of the communications unit with data transfer options.
[0035] FIG. 12 is a graphical representation of the heart rate.
[0036] FIG. 13 is a flowchart for using the wrist worn monitor to take a timed and recorded nap of specified duration.
[0037] FIG. 14 is a flowchart for using the wrist worn monitor to take a timed and recorded nap with a specified duration in REM sleep stage.
[0038] FIG. 15 is a flowchart for using the wrist worn monitor to take a timed and recorded nap with alarmed exit when REM sleep stage recognized.
[0039] FIG. 16 is a flowchart for using the wrist worn monitor to record Heart Rate Variability and time to analyze sleep duration and quality.
[0040] FIG. 17 is a flowchart for using the wrist worn monitor to monitor for and record Heart Rate Variability for sleep apnea events.
[0041] FIG. 18 is a flowchart for sending the heart rate variability data obtained by the wrist worn monitor to a central home computer to place the home in “sleep” and “awake” modes.
[0042] FIG. 19 is a flowchart for using the wrist worn monitor to perform a Heart Rate Variability (HRV) test.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention is capable of monitoring, recording and analyzing sleep and/or rest sessions. The device monitors an individual's heart rate variability while the user is either at rest or asleep or physically active and records the results for up to 24 hours. The inventive monitor is capable of detecting and measuring the variability of heart rate during the sleep sessions and is further capable of discerning the subtle differences in heart rate variability as the user transitions from one sleep stage to the next. This record is stored in the device's memory and is accessible for review by the user or interested 3 rd parties such as the user's physician or nurse.
[0044] With reference to the accompanying Figures, there is provided a wrist worn heart rate variability monitor 10 . As shown in FIG. 1 , the monitor 10 is comprised of the monitor body 11 , wristband B 12 and wristband A 16 . The attributes of wristband B 12 will preferably be comprised of securing holes 13 , a waking prompt 26 and a wire 15 connecting the waking prompt 26 to the monitor body 11 . The attributes of wristband A 16 will preferably be comprised of securing hooks 18 , at least one wire 20 , electrode A 20 and may include a plastic insert on the back of wristband A. The monitor body 11 will preferably comprise the control unit 51 , electrode B 34 , display 35 , a waking prompt 26 , remote emitter 28 , clock 30 and input buttons 32 . The monitor may have six input buttons 32 which collectively make up the input, though one skilled in the art will recognize that more or fewer input buttons 32 may be used to accomplish the desired goals described herein.
[0045] Turning now to FIG. 2 , the inventive monitor 10 detects electrical signals generated by a body using at least two electrodes 22 , 34 , preferably the electrical signals are electrocardiograph (ECG) signals generated by the heart. Thus, in the preferred embodiment, the monitor 10 detects heart rate. This may be the type of heart rate monitor described in U.S. Pat. No. 5,738,104 or U.S. Pat. No. 5,876,350. The '350 patent discloses that the use of three electrodes is preferable to determine the heart rate to assist in filtering out undesirable noise attributable to the user's physiologic conditions while exercising, etc. Thus, if necessary, three electrodes may be used for the present invention, though the preferred embodiment utilizes two electrodes. Since the invention is designed for use while the user is either sleeping or at rest, the extraneous and undesirable noise associated with general physical activity by the user is not present, two electrodes is preferred. In an alternate embodiment not shown in the Figures, the heart beat signals may be detected using optical sensors.
[0046] The electrodes 22 , 34 are integrated into the monitor. Electrode A 22 is housed in wristband A 16 . Electrode A 22 may partially penetrate the surface of wristband A 16 or may be flush with the surface of wristband A 16 . Electrode A 22 is connected with a wire(s) 200 r fiber optic(s) thread(s) to the applicable unit for measuring the heart rate. These connective wire(s) 20 or thread(s) are housed in wristband A 16 and connect electrode A 22 to the monitor body 11 and in turn, to the applicable heart rate measuring device. Electrode B 34 is disposed on the back surface of the monitor body 12 so that it makes contact with the user's skin when worn. Electrode B 34 may protrude from the back surface of the monitor body 11 or, alternatively, it may be flush with the back surface of the monitor body 11 .
[0047] With reference to FIG. 3 , the monitor 12 is attached to the user's wrist preferably using a system of holes 13 on wristband B 12 and securing hooks 18 on wristband A 16 . The pliability of wristband B 12 allows the user to adjust the position of the securing points allowing electrode A 22 in wristband A 16 to have a proper fit and positioning for an accurate heart rate reading and further provides comfort on the user's wrist. Alternatively, the monitor 10 may be attached to the user's wrist by means of Velcro, buckle attachment, clasp, ball and hole, or other methods not shown in the Figures, but that are well known to those skilled in the art.
[0048] Turning now to FIG. 4 , the monitor 10 may be largely constructed using technology that is conventional for construction of electronic watches. The monitor 10 will most likely be constructed of different types of plastic that range from rigid to pliable. Wristband B 12 may be made of different material than used in wristband A 16 . The material in wristband B 14 may be more pliable than the material in wristband A 16 and vice versa. Such technology is not described herein in detail because it is well known to those skilled in the art.
[0049] As indicated in FIG. 5 , the monitor 10 may be made of two pieces. The monitor may be built using several different methods. It may have a pliable piece of plastic 36 that is inserted on the back side of the device sealing electrode A 22 into wristband A 16 , electrode B 34 into the monitor body 11 and the waking prompt 26 into wristband B 12 . One piece 38 may combine the monitor body 11 and wristband A 16 . Wristband A 16 would house both the waking prompt 26 and electrode A 22 . The second piece 39 would consist of a wristband B 12 and would be connected to the monitor body 11 . The pliable plastic insert 36 may not need to cover electrode B 34 . In both of these cases, the pliable plastic insert 36 would cover electrode A 22 and possibly electrode B 34 respective to the use of the insert 36 . The connectivity method between wristband B 12 and the monitor body 11 is not discussed further as it is well known to those skilled in the art. Additionally, other common forms of manufacture are not described herein as they are well known to those skilled in the art.
[0050] As illustrated in FIG. 6 , a conductive membrane 40 may be attached to the back surface of the monitor 10 to increase the electrical conductivity, thus enhancing the monitor's ability to pick up the electrical signals generated by the heart. The membrane 40 may also be attached to the monitor's wristband covering the electrodes and having contact with the user's skin. The membrane 40 may be porous and may be used in concert with conductive gels. In this embodiment, the user will place a small amount of gel onto the membrane 40 . The membrane will absorb the gel and the conductive properties of the gel will assist the electrodes 22 , 34 in obtaining more accurate heart rate variability information. Preferably, the membrane 40 will retain the gel for multiple uses, thus eliminating the need for repeated applications of the gel to the membrane 40 . The membrane 40 may also be constructed of conductive materials, thus eliminating the need for conductive gel. The membrane 40 will also benefit the fit of the electrode to the user's skin by eliminating or minimizing the space between the electrode and the user's skin.
[0051] FIG. 7 illustrates the preferred embodiment for placement of the conductive membrane 40 . The membrane 40 self-adheres to wristband A 16 . A portion of wristband A 16 surrounding electrode A 22 will be smoothed out, thus ensuring good adhesion of the membrane 40 . The membrane 40 is replaced when necessary by simply removing the used membrane 40 and applying a new membrane 40 .
[0052] FIGS. 8A and 8B provide detail on the waking prompt 26 or alarm. The waking prompt 26 may be audible, silent through use of vibrations or emitted light. The vibrate alarm may be of the type described in either U.S. Pat. No. 4,456,387 or U.S. Pat. No. 5,400,301. The waking prompt 26 may also be partially housed in the pliable plastic insert 36 and housed in wristband B 12 . Alternatively, the waking prompt 26 is housed in the monitor body 11 . FIG. 8A illustrates housing the waking prompt in wristband A 16 . Alternatively, the alarm unit may be housed in wristband A 16 using the pliable plastic insert 36 . An audible or vibrational, or a combination thereof, alarm embodiment may be housed in the monitor body 11 or either wristband 12 , 16 as discussed above.
[0053] Turning now to FIG. 9 , a particular embodiment of the display 35 is illustrated. The monitor 10 will preferably generate an optical gauge or display 35 . The display 35 will preferably assist the user to set the monitor 10 to the desired modes and functions. The attributes of the display 35 may include a running real time clock 39 and allow the user to view their heart rate 44 , alarm settings 46 , heart rate variability test results 48 , recorded rest time results, and the mode of the monitor 50 .
[0054] The exterior of the inventive monitor having been described, the internal circuitry will now be described. FIG. 10 provides a block diagram of the general circuitry blocks 51 and the interconnection thereof. The preferred embodiment thus provides an analog circuit block 52 , a digital controller block 54 , a communications block 56 and a power supply and power management block 58 . Essentially, the electrodes pick up ECG (electrocardiograph) signals from the heart. The ECG signal is then conditioned to remove undesirable attributes, i.e., noise, from the signal. The analog signal is converted to a digital signal and then digitally processed under the software algorithms of the invention. The invention is capable of storing 24 hours of real time data. The details of the electronic circuitry are well known in the art and are not further described herein.
[0055] FIG. 11 is a block diagram of the communications block 56 interconnected with different external communication methods. It is desirable and useful to be able to either store the acquired data internally within the device, externally or to transmit it to external devices. Therefore, it is contemplated that conventional, preferably high speed, communications with external devices is an aspect of the present invention; it is contemplated that at least three types of transceivers accomplish this objective, each transceiver having different attributes and utility. For direct connection to a personal computer for further review, study and analysis of the data, high speed wired links are contemplated in the form of the direct connect USB 2.0 port 60 . For ambulatory data transfer, wireless links are contemplated 62 . For example, connection to a wireless communications devices, e.g., a Bluetooth® wireless device, may be provided. Alternatively, wireless USB 3.0 wireless ports are contemplated for uploading the acquired data. In addition, compatibility with certain medical instruments and notebook personal computers, an infrared transceiver 64 is provided as part of the watch design. The infrared method provides a slow, but proven and direct view optical link. Additional methods of transferring data from the inventive monitor will readily present themselves to those skilled in the art.
[0056] The hardware of the invention having been described, the operation of the invention will now be described.
[0057] FIG. 12 illustrates typical heart rate variability 100 and includes typical heart rate data during a sleep apnea event in phantom 101 . As discussed above, analysis of 24-hour HRV typically shows a nocturnal increase in the standard deviation of heart beat intervals. The heart rate and associated heart rate variability are essentially stable during the awake stage 102 . The heart rate decreases significantly and rapidly 104 as the person begins to fall asleep. The heart rate eventually levels off, and the heart rate variability decreases, as a person eventually transitions 106 from the awake stage 102 to the non-REM stage 108 . The heart rate variability remains relatively stable during the non-REM sleep stage 108 .
[0058] As the individual eventually transitions from the non-REM sleep stage 108 to REM sleep 112 , the heart rate becomes more erratic and the associated variability increases. There are several stages of REM sleep 112 , each marked by changes in heart rate variability. FIG. 12 illustrates the first three REM stages, stage 1 114 , stage 2 116 , and stage 3 118 . Typically, the first REM stage 114 lasts about 10 minutes, with each recurring REM stage 116 , 118 lengthening, with the final stage lasting about one hour. The inventive monitor 10 is capable of detecting the heart rate variability within each sleep stage as well as the transition from one sleep stage to the next, i.e., the transition 106 from awake 102 to non-REM sleep 108 , the transition 1010 from non-REM sleep 108 to REM sleep 112 , and the completion of an REM sleep stage and subsequent transition to the next REM sleep stage.
[0059] Ultimately, the person exits REM sleep 112 and begins to awaken. This transition 122 is marked by an increase in heart rate 120 and is recognized by the monitor 10 when the heart rate increase passes a defined threshold 110 , e.g., three standard deviations above the REM sleep state heart rate mean value. Eventually, the heart rate attains the stable awake stage 102 once more.
[0060] The heart rate data is processed in the digital processor component according to the computer program software code algorithms programmed therein. The essential theory of operation is that the heart rate data is first acquired by the monitor over a defined time interval. Typically at this stage, the user is in the awake state 102 . The software then evaluates the heart rate itself and the variability of the interval between heart beats within a selected time period. Awake parameters are then calculated, comprising the mean awake heart rate value and standard deviation thereof. Alternatively, a heart rate threshold parameter may be entered by the user, corresponding to the user's resting heart rate, below which the user is recognized by the monitor as having fallen asleep. The user's heart rate, and associated variability, is next monitored and evaluated against the awake parameters, or the pre-entered threshold parameter, either periodically or continuously for significant changes. Specifically, the monitor is evaluating the user's heart rate for indication of the user's transition 106 from the awake state 102 to the non-REM sleep state 108 . This transition 106 is marked by a decrease in heart rate 104 and is recognized by the device when the heart rate decrease passes a defined threshold 106 , e.g., three standard deviations below the awake sleep state heart rate mean value. The threshold values of +/−three standard deviations from the local mean heart rate values are for illustrative purposes only. Those skilled in the art will readily comprehend that a number of threshold values may be used, depending on the particular user, etc.
[0061] As discussed above, the heart rate slows, and heart rate variability decreases when the user leaves the awake stage 102 and enters the non-REM sleep stage 108 . Thus, when the awake-to-non-REM sleep threshold is reached 106 , e.g., the user's heart rate drops below three standard deviations below the awake heart rate mean, the software recognizes this event as the user entering the non-REM sleep stage 108 . Next, a new set of non-REM sleep parameters are calculated, including a mean non-REM heart rate and non-REM standard deviation over a defined time interval. The user's heart rate and associated variability is then monitored and evaluated against the non-REM sleep parameters, either periodically or continuously for significant changes.
[0062] The next event in the user's sleep cycle, assuming no interruptions in sleeping pattern, results in the user exiting non-REM sleep 108 and entering the first REM sleep stage or cycle 114 . As described above, the transition from non-REM to REM sleep 110 results in an increase in the heart rate variability. Thus, when, e.g., the user's heart rate variability increases above a threshold level, e.g., the standard deviation about the mean increases by a factor of two as compared with the non-REM sleep standard deviation, the software recognizes this event as the user entering the REM sleep stage. Again, one skilled in the art will recognize that certain individuals may require a standard deviation factor increase that is either larger or smaller than a factor of two greater than the non-REM sleep standard deviation. A new set of REM sleep parameters are calculated, including an REM mean heart rate and an REM standard deviation over a defined time interval. The user's heart rate and associated variability is then monitored and evaluated against the REM sleep parameters, either periodically or continuously for significant changes.
[0063] Next, the user may exit REM sleep 112 , in which case the heart rate increases significantly to cross a pre-defined threshold, e.g., more than three standard deviations over the mean REM sleep heart rate mean. The software is capable of recognizing on this basis that the user is now awake. The monitor is further capable of recognizing outlying data points resulting from transient events, e.g., the sleeping user physically changing positions, where the heart rate is temporarily increased, but rapidly returns to a level within the normal local deviation.
[0064] Alternatively, the user may exit the first REM sleep cycle 114 , but instead of waking up will revert back to non-REM sleep 108 for a small amount of time and then enter the second, longer REM sleep cycle 116 . The software is capable of recognizing the completion of one or more REM sleep cycles by differentially comparing the two sets of heart rate variability parameters. Ultimately, the user awakens and the heart rate increases such that the software recognizes the exit from REM sleep 112 and the awakened state. 122
[0065] Sleep apnea events may occur during either non-REM 108 or REM sleep 112 and are characterized by cessation of breathing and concomitant decrease in heart rate. FIG. 12 illustrates the decrease in heart rate during non-REM sleep in phantom 101 . The monitor is capable of detecting these apnea events when a pre-defined threshold is crossed by the user's heart rate, e.g., the user's heart rate decreases more than two standard deviations from the relevant sleep stage mean heart rate value over a defined time interval 126 . One skilled in the art will readily recognize that the most appropriate time interval is dependent upon a number of factors known in the art. The monitor is further capable of recording the apnea event data for subsequent review by the user and/or a physician. For example, the user may wake to find that six apnea events occurred during the sleep period and use this information as a motivation to see his or her physician. An alternate embodiment provides a waking prompt that activates to bring the user out of the apnea event. The waking prompt 26 may be audio, visual, or vibratory. A further alternate embodiment provides remote transmission of the waking prompt to a 3 rd person or remote device so that the 3 rd person is alerted to the user's apnea event(s).
[0066] With this basic algorithmic theory in place for the software, many inventive applications present themselves.
[0067] With specific reference to FIG. 13 , the monitor is capable of allowing the user to take a nap of specified duration 200 . The user selects timed-sleep mode 202 and enters the desired sleep duration and desired waking prompt 204 . The waking prompt can be, as described above, either an audio, visual or vibrational alarm that is built into the monitor. The monitor acquires a signal of acceptable quality corresponding to the heart beat and begins to monitor for a particular time interval and ultimately calculates awake heart rate mean and standard deviation parameters 206 . The preferred embodiment uses electrodes to acquire the ECG signals, however, an alternate embodiment may include the use of optical sensors to acquire the signal. The monitor then continuously, or periodically, monitors the heart rate for significant change, e.g., a 3 standard deviation decrease in heart rate from its local mean value, i.e., the awake mean in this case 208 . When the monitor recognizes this change 210 , it indicates that the user is now in the early stages of non-REM sleep and the waking prompt timer is started 212 . The monitor then monitors and records the heart rate and associated variability 214 until either the user wakes and manually exits the selected mode or the waking prompt timer expires 216 which activates the waking prompt 218 and the heart rate monitoring is ended.
[0068] The next inventive method 300 is illustrated in FIG. 14 . Here, the monitor also allows the user to exit a nap at a specified point. The difference is that the duration is not specified, rather the user specifies that they wish to be awoken after one or more REM sleep stages or cycles are completed. Thus, the user enters the REM cycle timed sleep mode 302 , awake heart rate parameters are calculated 306 and heart rate monitored for sleep entry 308 as above. When non-REM sleep is recognized 310 , non-REM sleep heart rate parameters calculated 312 and monitored for REM sleep entry 314 as described above. When REM sleep is recognized 316 , REM sleep heart rate parameters are calculated 320 and monitored for completion of the desired numbers of REM sleep stages or cycles 322 . One or more REM sleep cycles may be monitored and completed under this operational mode using a looping algorithm 325 . When the desired numbers of REM sleep cycles are completed 324 the waking prompt is activated 326 to wake the user.
[0069] A further modification of the durationally limited nap is illustrated by FIG. 15 . Here, the user desires to be awaked before falling deeply into the first REM sleep stage or cycle to avoid feeling groggy upon awakening 400 . Thus, the user enters timed sleep mode 402 , the awake heart rate parameters are calculated 408 and monitored for non-REM sleep entry 410 as above. When non-REM sleep is recognized 412 , non-REM sleep parameters are calculated 416 and monitored for non-REM sleep exit 418 as described above. When the monitor recognizes that the user is exiting non-REM sleep 420 the waking prompt is activated 422 to wake the user.
[0070] FIG. 16 provides a method of monitoring both the duration and quality of a user's normal sleeping routine 500 . In this mode, the user enters the sleep timer/heart rate recording mode 504 , the awake heart rate parameters are calculated 506 and monitored for non-REM sleep entry 508 as above. Upon recognition of non-REM sleep entry 510 , the sleep timer and heart rate and variability recorder are activated 512 . Sleep heart rate parameters are calculated 514 and monitored 516 for sleep exit. When sleep exit is recognized 518 , i.e., the user awakens, the sleep timer and recording of heart rate are stopped 520 . In an alternate embodiment, a loop in the algorithm 522 allows for repeating of the previous logic steps in case the user awakens in the middle of the night and then falls asleep once more. This general recording of heart rate and variability thereof allows the user and/or physician to view the time-stamped events of the night for sleep duration and quality, i.e., time spent in non-REM and/or the REM sleep stages or cycles with the ability to view sleep interruption events.
[0071] Turning now to FIG. 17 , the monitor is used to detect sleep apnea events 600 . In this case, the user enters sleep apnea monitoring mode 604 , the awake heart rate parameters are calculated 606 and monitored 608 for sleep entry as above. Once sleep entry is recognized 610 , the sleep timer and heart rate recorder are prompted to begin 612 . Sleep heart rate parameters, including the stages for non-REM and REM sleep stages, are calculated 614 and monitored 616 as above. The monitor is, in this case, monitoring for deviations below the sleep heart rate parameters which are diagnostic of sleep apnea events 101 as indicated in FIG. 12 . The intent of this inventive method is to record the apnea events for later review by the user and/or physician to assist in diagnosing sleep apnea and to assist in monitoring the effectiveness of treatment options. The monitor has the capability, in the preferred embodiment, to stop the sleep timer and heart rate recording 622 when sleep exit is recognized 620 and, as above, restart the timer and recording if the user falls back asleep as illustrated by the looping algorithm 624 . This capability is particularly important if the apnea event causes the user to come out of the sleep state. As discussed above, alternate embodiments include a waking prompt 618 , either audio, visual or vibratory, that will wake the user upon detection of an apnea event. Alternatively, an alarm signal may be transmitted to a 3 rd person alerting them of the user's apnea event(s). Finally, the number of apnea events may be displayed for the user, thus providing motivation to see their physician.
[0072] FIG. 18 illustrates one embodiment of the monitor's ability to assist in controlling a home's functional features based on heart rate variability 700 . In this embodiment, the monitor is used in concert with a home's electronics control unit 702 . Many homes are equipped with a controlling computer system. These homes have been referred to as ‘smart houses.’ The home's controlling computer or electronics control unit manages the functions of the home. These functions may include: television; personal computer; shower; home security system; lights; kitchen appliances; garage door and other functional features of a home. This invention is capable of working in concert with the home's controlling computer system and works to synchronize the home's functions with the homeowner's functions. The user enters remote home control mode 704 and, with the home in ‘wake’ mode 708 , wears the device before bed. The awake parameters are calculated 710 and monitored 712 as above. When sleep is recognized as discussed above 714 , the wrist worn monitor sends out a signal to the home's controlling computer via a home control receiver(s) 716 , which then prepares the home for the night, i.e., places the home in ‘sleep’ mode 718 . This may comprise functions such as shutting lights and televisions off, ensuring the garage door is down, setting the thermostat at an appropriate temperature for the night, etc. The opposite is done in the morning. Thus, the sleeping user's heart rate parameters are calculated as above 720 and monitored 722 for sleep exit 724 . When the user's heart rate level and variability rises above the threshold level, i.e., sleep exit is recognized 724 , the monitor sends a signal to the central home computer via the home control receiver(s) 726 to prepare the home for the day, i.e., placing the home in ‘awake’ mode 728 . Thus, functions such as turning on the lights, shower, coffee maker, alarm are accomplished. In addition to using the heart rate variability of the user to control the features of the home, the monitor may have a button that manually accomplishes the tasks without use of heart rate variability information.
[0073] FIG. 19 provides another application of the invention. A heart rate variability test may be taken by the monitor 800 . Here, the user enters the HRV testing mode 802 and then enters personal physical information 804 which may affect the test results such as age, sex, weight. A target heart rate threshold is entered by the user and desired duration of the test 806 . The target heart rate threshold may be either an upper or lower threshold. The test may be administered either while the user is at rest, while the user sleeps, either in non-REM sleep stage only or in REM sleep stage only or across both sleep stages, or during physical activity. The monitor then monitors the heart rate 812 until the target lower threshold is crossed which either indicates that the user has attained a resting level or, alternatively, has entered the non-REM sleep stage, or, if the monitor is used in connection with physical activity, an upper target heart rate threshold is utilized. In either case, the monitor initiates the heart beat recorder and the HRV test commences 815 for a specified time once the target heart rate threshold is crossed 814 . The longer the HRV test, the more accurate the results will be. When the specified duration is reached, the HRV test concludes 816 and the monitor then processes the data 818 . The data is preferably displayed on a scale of 1-200 to indicate the quality of the user's HRV 820 . Alternatively, a scale from 1-10 may be used or letters, e.g., A, B, C, etc., or even colors like green (good HRV), yellow (marginal HRV), red (poor HRV) may be used.
[0074] The monitor further provides the capability, through use of selective input of operational modes, performance of one or more of the above-described functions in parallel, at the same time, during a single monitoring session.
[0075] The above specification describes certain preferred embodiments of this invention. This specification is in no way intended to limit the scope of the claims. Other modifications, alterations, or substitutions may now suggest themselves to those skilled in the art, all of which are within the spirit and scope of the present invention. It is therefore intended that the present invention be limited only by the scope of the attached claims below: | A wrist-worn heart rate variability monitor is provided. Heart rate variability (“HRV”) refers to the interval between heart beats and is a reflection of an individual's current health status. Over time, an individual may use the results of HRV tests to monitor either improvement or deterioration of specific health issues. Thus, one use of the HRV test is as a medical motivator. When an individual has a poor HRV result, it is an indicator that they should consult their physician and make appropriate changes where applicable to improve their health. The inventive monitor is capable of monitoring the stages of sleep by changes in the heart rate variability and can record the sleep (or rest) sessions with the resulting data accessible by the user or other interested parties. The inventive monitor is thus capable of several novel uses: (1) to assist the user with a nap that allows predetermined time in one or more sleep stages; (2) determination of the duration of a sleep session, including length of time spent in one or more sleep stages; (3) in concert with a home's central electronic and computer control unit, the device uses HRV to determine when the house may be placed in “sleep” mode and when it is appropriate to place the house in “awake mode”; and (4) performance of an HRV test. | 0 |
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER LISTING APPENDIX
Not applicable.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
The present invention relates generally to baby carriers. More particularly, the invention relates to a soft-structured baby carrier that enables the baby to be carried on the caregiver's body.
BACKGROUND OF THE INVENTION
The present invention relates to baby carriers that are used to carry babies in an upright position on the front or back of a caregiver's body. Although this invention could be adapted for use with rigid-frame baby carriers or wrap style baby carriers, preferred embodiments are implemented for use with soft-structured and mei-tai style baby carriers.
Soft-structured and mei-tai style baby carriers usually consist of a flexible baby pouch that secures the baby in an upright position against the front or back of the caregiver's body by means of shoulder straps. There are many variations for how the baby pouch is sized, shaped and constructed. The baby pouch may be constructed as a simple flap of fabric or it may consist of several different components to support the back, front, buttocks or head of the baby. There are also many variations for how and where the shoulder straps connect to the baby pouch. Generally, the baby pouch has two shoulder straps that go over the caregiver's shoulders and either cross in back or loop around the shoulders and attach lower on the baby pouch similar to shoulder straps on a backpack. Soft-structured carriers generally use buckles as a means of attachment. In traditional Asian mei-tais the straps are usually secured by tying knots. Many, but not all, carriers of this type have a waistband that attaches to the bottom of the main body panel so much of the weight of the baby is distributed on the caregiver's hips rather than only on the shoulders for the comfort of the caregiver.
The majority of soft-structured carriers and mei-tais only allow the baby to face into the caregiver's body because allowing the baby to face outwards requires shaping the baby pouch so that the baby's legs can stick out the front by creating a narrow crotch region on the baby pouch. There is debate about whether it is healthy for a baby to be held in this way because, in the facing-out position, the baby's legs hang down and all his weight is concentrated on the narrow crotch region. Some experts believe that it is not healthy for the baby's spine and hip development to be held in this “crotch-dangling” position for long periods of time. Though many of the newer baby carriers that allow babies to face outward attempt to distribute the baby's weight along the baby's buttocks rather than only the baby's crotch, the baby's legs still hang down in a potentially harmful way as the baby's thighs are not supported in carriers with the baby pouch shaped this way and much of the baby's weight is still concentrated on a relatively small area on the baby's body which is potentially unhealthy and not as comfortable for the baby. It is therefore an objective of the present invention to provide a baby carrier that enables the baby to face outward while distributing the weight of the baby over a larger area of the baby's body.
In currently known carriers comprising a baby pouch with no narrow crotch region that only allow the baby to face into the caregiver's body, the baby's legs are usually at a 90-degree or greater angle because the thighs are supported and the baby's legs straddle the caregiver's body. This is considered by many to be a healthier position for the baby's hip and spine development. However, many babies prefer to face out and look at their surroundings and may resist being carried in the facing-in position for a long period of time.
One currently known baby carrier provides a flexible pouch with holes cut out for the baby's legs to stick through at the knees. By forming the pouch so the baby's knees are raised relative to the buttocks, the baby's thighs and buttocks are supported in the front facing-outwards position. However, this design does not easily adjust to accommodate babies of different sizes. The angle of the thigh support is not adjustable, possibly making it uncomfortable for babies that are either too small or too large for the pouch. In addition, if this carrier is not carefully structured with a very deep seat that perfectly fits the baby, the baby's legs may flop out of the pouch and hang down or to the side. Furthermore, in the facing-out position, the baby's torso may not be supported very well because the baby's thighs are by necessity bent up within the pouch in front of the abdomen creating a space between the pouch and the baby's torso.
Another currently known design provides a baby carrier with a thick, rectangular, somewhat-rigid platform that holds up the thighs and buttocks of the baby and allows the baby to be seated while facing out. The seating platform is attached to the baby carrier in a hinge-like manner to create a platform or bench for the baby. However, the seating platform is bulky and does not enable the baby to be turned around to face into the caregiver's body since the platform is enclosed on the two sides with material. Furthermore, the rigid seating platform does not support the baby's torso so that the baby may shift and move around on the seat while being carried.
Other currently known designs provide a rigid-framed baby carrier with a rigid seating platform that supports the baby's thighs in a position in which the baby faces out. However, the rigid-frame is bulky and not convenient for everyday casual use. Also, the rigid seating platform does not support the baby's torso so that the baby may shift and move around on the seat while being carried.
In view of the foregoing, there is a need for improved techniques for providing a baby carrier that enables the baby to be easily carried in multiple positions, including, but not limited to, facing out, while providing the support needed to the various parts of the baby's body.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIGS. 1A through 1D illustrate the anatomy of an exemplary baby carrier with a seat flap, in accordance with an embodiment of the present invention. FIG. 1A is a ¾ view of the baby carrier in a disassembled state. FIG. 1B is a diagrammatic front view of a main body of the baby carrier. FIG. 1C is a diagrammatic top view of the seat flap, and FIG. 1D is a diagrammatic bottom view of the seat flap;
FIGS. 2A through 2C illustrate an exemplary baby carrier with a seat flap in use with a baby in multiple carrying positions, in accordance with an embodiment of the present invention. FIG. 2A is a ¾ view of the baby carrier being worn by a caregiver with the baby in a front carry facing-out position. FIG. 2B is a ¾ view of the baby carrier being worn by the caregiver with the baby in a front carry facing-in position, and FIG. 2C is a ¾ view of the baby carrier being worn by the caregiver with the baby in a back carry position;
FIG. 3 is a ¾ view of an exemplary baby carrier comprising two separate seat flaps, in accordance with an embodiment of the present invention;
FIG. 4 is a ¾ view of an exemplary seat flap that may be used as an add-on accessory for existing baby carriers, in accordance with an embodiment of the present invention;
FIG. 5 is a ¾ view of an exemplary baby carrier comprising a seat flap that does not have a baby pouch, in accordance with an embodiment of the present invention;
FIG. 6 is a ¾ view of an exemplary rigid frame baby carrier comprising a seat flap, in accordance with an embodiment of the present invention; and
FIG. 7 is a ¾ view of an exemplary wrap style baby carrier with a seat flap in a front carry facing-out position, in accordance with an embodiment of the present invention.
FIG. 8 is a ¾ view of an exemplary baby carrier comprising a seat flap attached to the baby pouch at the crotch, in accordance with an embodiment of the present invention;
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is best understood by reference to the detailed figures and description set forth herein.
Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending upon the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive.
The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.
Detailed descriptions of the preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
It is to be understood that any exact measurements/dimensions or particular construction materials indicated herein are solely provided as examples of suitable configurations and are not intended to be limiting in any way. Depending on the needs of the particular application, those skilled in the art will readily recognize, in light of the following teachings, a multiplicity of suitable alternative implementation details.
Preferred embodiments of the present invention provide a baby carrier in the style of a soft-structured carrier or traditional Asian mei-tai in which a baby can be carried on the back or front of the caregiver's body, facing inwards or outwards. The baby carrier itself in preferred embodiments may be constructed in many different ways providing it basically holds the baby in an upright position against the caregiver's body with straps that go over the caregiver's shoulders. Preferred embodiments comprise a seat flap that enables the baby's weight to be distributed evenly along the baby's thighs and buttocks to create a supportive seat for the baby in all carrying positions.
FIGS. 1A through 1D illustrate the anatomy of an exemplary baby carrier with a seat flap 1 , in accordance with an embodiment of the present invention. FIG. 1A is a ¾ view of the baby carrier in a disassembled state. FIG. 1B is a diagrammatic front view of a main body 23 of the baby carrier. FIG. 1C is a diagrammatic top view of seat flap 1 , and FIG. 1D is a diagrammatic bottom view of seat flap 1 . In the present embodiment, the baby carrier comprises a baby pouch 4 , which is a flap of fabric shaped to create a narrow crotch region 17 to allow the baby's legs to stick out the front of the carrier when in a facing-out position. A bottom edge 19 of baby pouch 4 attaches to a padded waistband 5 that is secured in back by connectors such as, but not limited to, adjustable side-release plastic buckles 13 and 14 , which are attached to waistband 5 with extension straps 26 . In alternate embodiments various different types of connectors made of various different materials may be used to secure the waistband such as, but not limited to, snaps, conventional buckles, clasps, slide buckles, etc. In the present embodiment, waistband 5 is adjustable in length to accommodate a wide range of body sizes for the caregiver. Shoulder straps 6 are attached to upper corners 22 of baby pouch 4 . Shoulder straps 6 wrap over the caregiver's shoulders, cross in back and attach by connectors such as, but not limited to, side-release plastic buckles 11 and 12 to the region of baby pouch 4 close to the armpit areas on the opposite sides of the body. Buckles 11 and 12 attach to shoulder straps 6 with extension straps 25 . In alternate embodiments the shoulder straps may attach with different types of connectors such as, but not limited to, snaps, conventional buckles, clasps, slide buckles, etc. and may be configured differently; for example, without limitation, the straps may not cross in back. In the present embodiment, shoulder straps 6 are preferably lightly padded for comfort but not bulky enough to interfere with crossing in the back; however in alternate embodiments the shoulder straps may not be padded. In the present embodiment, the lengths of shoulder straps 6 are adjustable to fit a wide range of body sizes. In some alternate embodiments, the two shoulder straps may be constructed as one piece that crosses in the back like a one piece harness rather than two separate straps.
Referring to FIG. 1A , main body 23 of the baby carrier is shown with seat flap 1 removed to illustrate and how seat flap 1 attaches to main body 23 of the carrier. The attachments that connect seat flap 1 to main body 23 are adjustable to accommodate a range of baby sizes. The present embodiment is preferably sized to fit babies from three months old to three years old. However, alternate embodiments may be implemented to fit a smaller range of babies. A bottom edge 24 of seat flap 1 is attached to main body 23 of the baby carrier with fasteners so that the height of the seat flap can be lengthened or shortened for smaller or bigger babies. In the present embodiment these fasteners are hook and eye closures. There are multiple rows of hooks 8 along the width of bottom edge 24 of seat flap 1 to accommodate different lengths of baby thighs, and where seat flap 1 meets bottom edge 19 of baby pouch 4 there is a row of eyes 7 to which hooks 8 attach. In alternate embodiments the seat flap may be attached to the main body of the baby carrier using various different means such as, but not limited to, snaps, hook and loop material, zippers, etc. In the present embodiment, straps 3 on a top edge 18 of seat flap 1 attach to main body 23 of the baby carrier with adjustable connectors such as, but not limited to, D-rings 10 that are attached near upper corners 22 of baby pouch 4 . Other types of adjustable connectors that may be used to attach the straps of the seat flap to the main body of the carrier in alternate embodiments include, without limitation, snaps, buckles, hook and loop material, etc. In the present embodiment, a crotch strap 2 at the center of top edge 18 of seat flap 1 is preferably adjustable in length as well to accommodate babies of different sizes. Crotch strap 2 loops through a connector such as, but not limited to, a ring 9 that is attached to the front of baby pouch 1 and folds back to fasten seat flap 1 to ring 9 with an adjustable fastener such as, but not limited to, hook and loop fasteners 15 and 16 . In alternate embodiments the crotch strap may fasten the seat flap to the baby pouch using various different means such as, but not limited to, snaps, buckles, clasps, etc. In the present embodiment, crotch strap 2 can be removed or its position can be adjusted to match the length of seat flap 1 . It should be noted that the crotch strap is optional. It makes the seat flap work better and more secure, however, in many practical applications, technically, the seat flap could work without the crotch strap; for example, without limitation, if the baby cooperated and doesn't moves his legs too much.
Referring to FIGS. 1C and 1D , seat flap 1 is preferably shaped with sewn darts to create a bucket seat shape to better fit the shape of a baby's buttocks and thighs. However, the seat flap in alternate embodiments may be a flat piece of material. In the present embodiment, side edges 21 and top edge 18 of seat flap 1 are padded where they come in contact with the baby's thighs for the comfort of the baby. Referring to FIG. 1B , various parts of main body 23 of the carrier including, but not limited to, waistband 5 , shoulder straps 6 and baby pouch 4 may be padded for the comfort of the baby or the caregiver. A top edge 20 of the baby pouch 4 may also be padded where it comes into contact with the baby's upper chest. Some embodiments may be implemented without padding, for example, without limitation, embodiments that are made of especially soft material. In the present embodiment, main body 23 and seat flap 1 are preferably made out of a soft but durable material such as, but not limited to, cotton twill, canvas, corduroy, or denim. Furthermore, all clasps and attachment mechanisms are preferably placed on the carrier so that the carrier is reversible, providing two different fabric options for the caregiver to wear. In order to reverse the carrier, the caregiver removes seat flap 1 and attaches it to the other side of main body 23 . Alternate embodiments of the present invention may be implemented that are not reversible.
In the present embodiment, all straps and connectors are preferably detachable and adjustable to accommodate babies of different sizes. However, alternate embodiments may be implemented where some or all of the straps and connectors are not adjustable. For example, without limitation, the seat flap connectors do not necessarily need to be adjustable. In addition, some straps and connectors may not be detachable, for example, without limitation, the seat flap may be permanently attached to the main body of the baby carrier and still serve its function.
In the present embodiment, extension straps 25 and 26 may be made of various materials such as, but not limited to, webbing, fabric, leather, etc. In some embodiments, extension straps 25 and 26 may be integrated into main body 23 of the baby carrier or seat flap 1 as a continuous piece of fabric. Embodiments utilizing fabric straps may be more aesthetically pleasing; however these embodiments may be more difficult to adjust. In some embodiments, the carrier may comprise a hood or support of some kind for the baby's head that is secured by adjustable straps that change the length of the hood depending on how tall the baby is. In some embodiments comprising a hood or head support, this hood or head support may be detachable.
The present embodiment as illustrated by way of example in FIGS. 1A through 1D includes baby pouch 4 , which is similar to many baby carriers on the market. As explained in the background section, the manner in which the baby pouches in currently known carriers are constructed and connect to the shoulder straps varies widely, with some carriers having more features and complex constructions. However, the present embodiment comprises seat flap 1 , which may be adapted to almost any baby carrier of this type on the market regardless of how complexly or simply the carrier is constructed. For example, without limitation, embodiments of the present invention comprising seat flaps may be implemented for use with baby carriers with rigid frames, soft-structured baby carriers, wrap-style baby carriers, mei tais, onbuhimos, podaegis or other Asian-inspired baby carriers, etc.
FIGS. 2A through 2C illustrate an exemplary baby carrier in use with a baby in multiple carrying positions, in accordance with an embodiment of the present invention. FIG. 2A is a ¾ view of the baby carrier being worn by a caregiver with the baby in a front carry facing-out position. FIG. 2B is a ¾ view of the baby carrier being worn by the caregiver with the baby in a front carry facing-in position, and FIG. 2C is a ¾ view of the baby carrier being worn by the caregiver with the baby in a back carry position. In the present embodiment, the baby carrier comprises a baby pouch 4 with shoulder straps 6 to secure the baby in an upright position to the front or back of the caregiver's body. The baby carrier also comprises a seat flap 1 that attaches to baby pouch 4 at or near the bottom edge of baby pouch 4 , near where baby pouch 4 attaches to a waistband 5 or generally where the baby's buttocks are located if the baby is in the facing-out position. In typical use of the present embodiment, shoulder straps 6 go over the caregiver's shoulders and attach to baby pouch 4 near the armpits of the caregiver. Shoulder straps 6 may or may not cross in the back. Waistband 5 is wrapped around the waist of the caregiver and attached with fastening means on the caregiver's back. The baby may then be placed in baby pouch 4 in any of the positions illustrated by way of example in FIGS. 2A through 2C .
Referring to FIG. 2A , a top edge 18 of seat flap 1 has a strap 3 in each corner so that when the baby is in the facing-out position, pulling up on straps 3 causes seat flap 1 to cup under the baby's buttocks and top edge 18 of seat flap 1 to hook into the area behind the baby's knees. Straps 3 then attach to the main body of the baby carrier on the upper part of the carrier in the region close to the caregiver's armpits creating a seat or sling for the baby's thighs so that the baby's legs do not dangle down from the crotch and the baby's weight is distributed along the baby's thighs and buttocks rather than being concentrated at the crotch. In alternate embodiments, the point of attachment for the seat flap straps could be somewhere around the upper region of the carrier to maximize comfort for the caregiver. The position may have to be adjusted so that it attaches higher up on the carrier like on the shoulder straps or perhaps further back toward the armpits like on the straps where the shoulder straps loop under the caregiver's armpits. It should be appreciated that, in many practical applications, the point of attachment may not necessarily be on the baby pouch as described in the present embodiment. In the front carry facing-out position, the baby can face outwards while his thighs and buttocks are securely cradled and supported by seat flap 1 in a seated position conducive to healthy spine and hip development. Seat flap 1 acts as a sling for the baby's thighs and buttocks that is separate from baby pouch 4 , which holds the baby's torso.
Referring to FIG. 2B , the baby is turned around and facing into the caregiver's body to illustrate how the baby's legs stick out side edges 21 of seat flap 1 and how the baby's buttocks and thighs are equally supported in the front carry facing-in position. In this position, the carrier functions similarly to most of the other carriers on the market of this style that do not allow babies to face out. The baby's legs are held at a 90-degree or greater angle because the thighs are supported and the baby's legs straddle the caregiver's body. Straps 3 on top edge 18 of seat flap 1 can be adjusted in length for better fit and support of the baby when switching between the facing-out and facing-in positions.
Referring to FIG. 2C , the baby is positioned on the back of the caregiver's body facing into the caregiver's body with the baby's legs sticking out side edges 21 of seat flap 1 . The baby's buttocks and thighs are supported. The baby's legs are held at a 90-degree or greater angle because the thighs are supported and the baby's legs straddle the caregiver's body.
FIG. 3 is a ¾ view of an exemplary baby carrier comprising two separate seat flaps 30 , in accordance with an embodiment of the present invention. In the present embodiment, seat flaps 30 are positioned under each thigh of the baby rather than one single seat flap across the width of the baby carrier as describe in the foregoing embodiment. Each separate seat flap 30 comprises a strap 31 on the upper edge corner that attaches to a main body 32 of the carrier near an upper corner 33 of a baby pouch 34 . Each separate flap 30 in this embodiment is attached to baby pouch 34 at a crotch region 35 of baby pouch 34 eliminating the need for a crotch strap as described in the foregoing embodiment.
FIG. 4 is a ¾ view of an exemplary seat flap 40 that may be used as an add-on accessory for existing baby carriers, in accordance with an embodiment of the present invention. In the present embodiment, seat flap 40 comprises a waistband 41 attached at a bottom edge 44 to go around the caregiver's waist independent of the baby carrier being used. Seat flap 40 in this embodiment has straps 42 and 43 at the corners of an upper edge 45 that loop around a convenient point of attachment 46 on the baby carrier in use, creating a supportive seat for the baby's thighs and buttocks as described previously. The straps of seat flap 40 may attach to the existing baby carrier using means other than loops such as, but not limited to, snaps. Those skilled in the art, in light of the present teachings, will readily recognize that existing baby carriers may vary in construction and that embodiments of the present invention may be implemented to adapt to these variations in construction. For example, the baby pouch could be constructed so the pouch detaches at the upper corners from the shoulder strap with fasteners or straps. Or the baby pouch could have a high construction that extends high on the baby's body and includes armholes for the baby's arms to stick out. In these cases, the armholes or the extra fasteners or straps for attaching the baby pouch to the shoulder straps may be convenient attachment points for the seat flap straps 42 and 43 .
FIG. 5 is a ¾ view of an exemplary baby carrier comprising a seat flap 50 that does not have a baby pouch, in accordance with an embodiment of the present invention. In the present embodiment, seat flap 50 provides almost all the support for the baby, attaching at the bottom or back to shoulder straps 54 and a waistband 53 . Additional straps 51 that connect to a crotch strap 52 and shoulder straps 54 take the place of the support usually provided by a baby pouch.
FIG. 6 is a ¾ view of an exemplary rigid frame baby carrier 61 comprising a seat flap 60 , in accordance with an embodiment of the present invention. In the present embodiment, instead of a rigid framed seating platform as is typical with rigid frame baby carriers, baby carrier 61 comprises a flexible seat flap 60 that attaches with seat flap straps 62 to a backrest 63 of rigid frame baby carrier 61 . The bottom edge of seat flap 60 is attached to rigid frame baby carrier 61 at the bottom of backrest 63 . Seat flap 60 also comprises a crotch strap 64 that attaches to a shoulder harness 65 on rigid frame baby carrier 61 . Those skilled in the art, in light of the present teachings, will readily recognize that existing rigid frame baby carriers may vary in construction and that embodiments of the present invention may be implemented to adapt to these variations in construction. For example the rigid frame baby carrier 61 could have a flexible baby pouch that secures the baby to the backrest 63 rather than the shoulder harness 65 illustrated in this embodiment. In this case the seat flap 60 could attach to points on the upper corners of the baby pouch similar to the way described in the preferred embodiment. As another example the backrest 63 could have side extensions that support the baby on the sides that the seat flap straps 62 could attach to.
FIG. 7 is a ¾ view of an exemplary wrap style baby carrier 71 with a seat flap 70 in a front carry facing-out position, in accordance with an embodiment of the present invention. Wrap-style baby carrier 71 is basically a long piece of fabric that wraps the baby securely to the caregiver's body in a variety of positions. In the front carry facing-out position, the baby's thighs are not typically supported well. However, as shown in the present embodiment, seat flap 70 may attach with seat flap straps 72 to the material of wrap style baby carrier 71 with fasteners such as, but not limited to, clips, hook and loop fasteners or snaps near the caregiver's armpits. The bottom edge of seat flap 70 may attach to the material behind the baby's buttocks with fasteners such as, but not limited to, clips, snaps, hook and loop fasteners, etc.
FIG. 8 illustrates another alternate embodiment of the present invention directed to a soft-structured baby carrier with a seat flap comprising a seat flap 80 that fastens to the top edge of the waistband 81 . The narrow crotch region 83 of the baby pouch 82 is attached to the center of the seat flap 80 either permanently or with adjustable connectors. Shoulder straps 86 connect to the top edge of the baby pouch 82 . The seat flap straps 84 attach to the upper region 85 of the baby carrier. The seat flap 80 also comprises a crotch strap 87 that attaches to the center 88 of the baby pouch 82
Having fully described at least one embodiment of the present invention, other equivalent or alternative methods of providing a supportive baby carrier that enables a user to carry a baby in multiple positions according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. For example, the particular implementation of the seat flap may vary depending upon the particular type of baby carrier used. The carriers described in the foregoing were directed to wearable implementations; however, similar techniques are to provide seat flaps for other types of baby carrying devices such as, but not limited to, high chairs, swings, strollers, activity seats, etc. Non-wearable implementations of the present invention are contemplated as within the scope of the present invention. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims.
Claim elements and steps herein have been numbered and/or lettered solely as an aid in readability and understanding. As such, the numbering and lettering in itself is not intended to and should not be taken to indicate the ordering of elements and/or steps in the claims. | An apparatus includes a seat flap for supporting a baby's buttocks and thighs. The seat flap has a top edge, a bottom edge having a shorter length than a length of the top edge and generally curved side edges. A first strap is joined to a first corner of the top edge for adjustably joining to an upper portion of a baby carrier. A second strap is joined to a second corner of the top edge for adjustably joining to the upper portion. Attachments adjustably join the bottom edge about a lower portion of the baby carrier, wherein the baby sits upright, the baby's legs protrude about the generally curved side edges and are supported at least ninety degrees from the lower portion. | 0 |
BACKGROUND OF THE INVENTION
Description of the Prior Art
This invention relates to a yarn draw off tube for an open-end spinning unit.
It is desirable to produce a soft twist yarn having less fluffs by means of a rotor-type open-end spinning unit. However, it is very difficult to produce such a yarn of an evenly distributed less twist as mentioned above by means of an open-end spinning unit for various reasons. First, in an open-end spinning unit, a fiber ribbon deposited on a fiber-collecting surface of a spinning rotor is twisted to form a yarn due to rotation of the spinning rotor while the fiber ribbon is being drawn off from the rotor. The root portion of the yarn which merges into the fiber ribbon on the fiber-collecting surface has less of a twist density than does the other portion of the yarn, and, therefore, yarn breakage often occurs in this portion. This tendency is naturally remarkable in the case of soft twist yarn. To improve the twist density of the yarn root portion, various proposals have been made. For example, in Japanese Unexamined Patent Publication (Kokai) No. 49-132329, a yarn draw off tube provided with a high frictional surface is disposed so as to confront the spinning rotor, thereby imparting a false twist to the yarn. Further, in Japanese Examined Patent Publication (Kokoku) No. 43-24978, an eccentric yarn draw off tube is proposed for improving the twist transmission to the root portion of the yarn. In the case of the former yarn draw off tube, however, the produced yarn becomes fluffy or has snarled fibers in its structure due to excessive rubbing of the frictional surface. In the case of the latter tube, the twist is not satisfactorily transmitted. On the contrary, the yarn tension fluctuates sharply, thereby causing yarn breakage or an uneven thickness.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a yarn draw off tube for an open-end spinning unit which can satisfactorily transmit a twist to the root portion of a yarn during the spinning operation and which can produce a soft twist yarn having few fluffs and a good evenness. To achieve the above-mentioned object, the yarn draw off tube according to the present invention has a yarn inlet eccentric from the center axis of the tube at a specific distance as well as deviating in a specific direction relative to the yarn outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will be apparent from the following description of the embodiments made with reference to the accompanying drawings, in which:
FIG. 1 is a sectional side view of an embodiment according to the present invention;
FIG. 2 is an oblique view of a yarn draw off tube according to the present invention;
FIGS. 3 and 4 are side sectional views diagrammatically illustrating the yarn paths from the spinning rotor to the yarn draw off tube;
FIGS. 5a to 5d are top views of yarn draw off tubes having yarn inlets with different eccentricities;
FIG. 6 is a top view of a yarn draw off tube illustrating an eccentric angle; and
FIG. 7 is a graph showing the relationship between the critical twist coefficient and the eccentric angle of the inlet of the yarn draw off tube.
DETAILED DESCRIPTION OF THE INVENTION
As is shown in FIG. 1, an open-end spinning unit 1 according to the present invention comprises a spinning rotor 3 rotatably supported on a stationary part by a bearing 5 and driven by a belt 7 and a yarn draw off tube 9 fixedly secured to an outer wall of a housing 11 so as to confront the spinning rotor 3. The housing 11 is provided therein with a feed roller 13 for introducing a sliver S into the housing, a presser 15 urged onto the surface of the feed roller 13, a combing roller 17 for opening the sliver S to individual fibers, and a fiber-transporting duct 19 for conveying the individual fibers, along with an airstream, into the spinning rotor 3.
The yarn draw off tube 9, illustrated in FIG. 2, consists of a disc portion 9a and a tube portion 9b extending from the center of the disc portion 9a. The disc portion 9a has a circular yarn inlet 9c eccentric from an axis X of the tube portion 9b. The tube portion 9b has a guide channel 9g extending through its body along the axis X. The guide channel 9g widens toward the bottom of the tube portion 9b and is connected to the yarn inlet 9c through an aperture 9d at the top of the tube portion 9b. On a side wall of the guide channel 9g is provided a yarn outlet 9f. In this connection, the center of the yarn inlet 9c deviates opposite to the yarn outlet 9f relative to the axis X (refer to FIG. 3).
The significance of the eccentricity of the inlet 9c is now explained more specifically with reference to FIGS. 3, 4, 5a to 5d and 6.
FIG. 3 shows the yarn paths as chain lines extending from a fiber-collecting surface 3a of the spinning rotor 3 to the yarn outlet 9f of the yarn draw off tube 9 through the yarn inlet 9c. One twist is imparted to a yarn portion existing between point F or F' on the fiber-collecting surface 3a and point A in the outlet 9f by one revolution of the rotor 3 about the axis X. The twisting occurs at first at point A, farthest from the rotor along the axis X, and the twist is transmitted sequentially upstream along the yarn and finally reaches point F or F'. If the yarn contacts the surface of other objects in the midportion of the yarn path, the twist transmission is more or less disturbed. The degree of easeness of twist transmission will now be explained in regard to various eccentric angles of the yarn inlet 9c of the yarn draw off tube 9, where the eccentric angle θ, shown in FIG. 6, is an angle between the axis M of the yarn outlet 9f (the axis M corresponds to a 0°-180° line) and the diameter N of the yarn inlet 9c passing through the axis X of the tube portion 9b. The eccentric angle is measured in a clockwise direction from the axs M.
The yarn draw off tube shown in FIG. 3 has an eccentric angle of 180°, that is the yarn inlet 9c deviates in a direction opposite to that of the yarn outlet 9f relative to the axis X, as is shown in FIG. 5a.
In the area from 270° to 90° about the axis X in a clockwise direction, the mean yarn path passes through points A, B, E, and F of FIG. 3, where A is a point at the yarn outlet 9f, B and C are points on the bottom edge of the yarn inlet 9c; and D and E are points on the top edge of the yarn outlet 9c. Since the yarn contacts the surface of the yarn draw off tube 9 at AB and BE, and, further, since the tangential angle α at E relatively small, a twist cannot be smoothly transmitted from A to F. Rather, it accumulates mainly in the portion between A and B. On the contrary, in the area from 90° to 270° in a clockwise direction, the mean yarn path passes through the points A, C, D and F' of FIG. 3. Since the surface-contact of the yarn is less than that in the area from 270° to 90° and the tangential angle β at D is relatively large, a twist can be easily transmitted from A to F'. Thus, in the latter area, the accumulated twist in the preceding area and the newly generated twist are simultaneously discharged toward F'. In other words, in the case of the yarn draw off tube of FIG. 5a, the twist is discharged and transmitted smoothly within a half path per one rotation of the spinning rotor.
Contrary to this, in the case of the yarn draw off tube 9 shown in FIG. 4, the yarn inlet 9c deviates in the same direction as the yarn outlet 9f relative to the axis X, as shown in FIG. 5b. In the area from 270° to 90°, the yarn contacts the surface of the guide channel 9g at AB, and, as a result, a twist cannot be transmitted from A to F. On the other hand, in the area from 90° to 270°, the yarn contacts the wall of the yarn inlet 9c at CD, resulting in a poor twist transmission. Accordingly, the twist imparted to the yarn portion at A cannot ascend smoothly toward F or F' in one rotation and instead accumulates in the yarn portion between A and B until the torque of the yarn portion overcomes the frictional resistance of the yarn path. As a result, the twist distribution along the produced yarn becomes uneven, resulting in yarn breakage and yarn of poor quality.
The above analysis can be applied to the yarn draw off tubes shown in FIGS. 5c and 5d, the tube in FIG. 5c having a yarn inlet 9c with an eccentric angle of 90° and the tube in FIG. 5d having an eccentric angle of 270°, respectively. The results of analysis of the ease of twist transmission are as follows, relating the angles not enclosed in brackets relating to the tube shown in FIG. 5c and the angles enclosed in brackets relating to the tube shown in FIG. 5d:
1. In the area from 270° to 90° (from 270° to 90°), the twist transmission is poor.
2. In the area from 90° to 180° (from 180° to 270°), the twist transmission is smooth.
3. In the area from 180° to 270° (from 90° to 180°), the twist transmission is poor.
This means that the twist distribution in the yarns produced by means of the yarn draw off tubes of FIGS. 5b, 5c, and 5d are all more uneven than that produced by means of the yarn draw off tube of FIG. 5a.
The above-mentioned analysis is summarized in Table 1. In Table 1, O and X represent good twist transmission and poor twist transmission, respectively.
TABLE 1______________________________________Ec-centricAngle Area Section of yarn path(θ°) (φ°) --AB --BE --EF --AC --CD --DF FIG.______________________________________180 270˜0 x x x -- -- -- 5a 0˜90 x x x -- -- -- 90˜180 -- -- -- o o o 180˜270 -- -- -- o o o 0 270˜0 x o o -- -- -- 5b 0˜90 x o o -- -- -- 90˜180 -- -- -- o x x 180˜270 -- -- -- o x x 90 270˜0 x x x -- -- -- 5c 0˜90 x o o -- -- -- 90˜180 -- -- -- o o o 180˜270 -- -- -- o x x270 270˜0 x o o -- -- -- 5d 0˜90 x x x -- -- -- 90˜180 -- -- -- o x x 180˜270 -- -- -- o o o______________________________________
As is apparent from Table 1, the yarn draw off tube having a yarn inlet deviating just opposite to the yarn outlet, i.e., a yarn inlet having an eccentric angle of 180°, has the widest area for good twist transmission during each revolution of the spinning rotor.
In order to obtain optimum conditions concerning the deviated position of the yarn inlet 9c, the present inventors performed various types of experiments, the results of which are explained below.
1. Eccentric radius e of the yarn inlet 9c from the axis X
The eccentric radiuse of the yarn inlet 9c also has an effect on twist transmission (refer to FIG. 3). The present inventors performed an experiment in an attempt to discover the optimum range of the eccentric radius e. Five runs were carried out in the experiment, in which a 32' s (cotton counts) yarn was spun from a sliver composed of 30% polyester staple fibers having a fineness of 1.3 denier and a length of 35 mm and 70% of cotton by means of five spinning units, each of which had the yarn draw off tube shown in FIG. 5a. All of the tubes were the same size except for the eccentric radius e. The other test conditions were as follows:
______________________________________Diameter of spinning rotor: 50 mmRotational speed of spinning rotor: 60,000 rpmCombing roller: 90° × 4.5 teeth/in.Rotational speed of combing roller: 7,000 rpmDiameter d of aperture 9d: 3.0 mm______________________________________
The resultant yarns were measured with regard to:
______________________________________Corrected lea breakage strength L (kg)Uster U % U (%)Number of fluffs exceeding 3 mm F No./10 m______________________________________
The results are shown in Table 2.
TABLE 2______________________________________Run No. 1 2 3 4 5______________________________________e (mm) 0 1.0 2.0 3.0 4.0e/d 0 1/3 2/3 1 4/3L (kg) 23.1 25.1 25.8 24.2 22.3U (%) 13.4 12.7 12.2 12.8 13.9F (No./10 m) 79 35 26 25 30______________________________________
As is apparent from Table 2, the yarn draw off tubes utilized for runs 2, 3, and 4 exhibited excellent results. Accordingly, the eccentricity e/d is preferably within a range of from 1/3 to 1.
2. Eccentric angle θ of the yarn inlet 9c
The inventors performed another spinning experiment to confirm the results shown in Table 1 and to determine the preferred range of the eccentric angle. The experimental conditions were as follows:
______________________________________Produced yarn: 100% cotton, 7's (cotton count)Diameter of spinning rotor: 50 mmRotational speed of spinning rotor: 60,000 rpmCombing roller: 65° × 10 teeth/in.Rotational speed of combing roller: 8,000 rpmEccentric radius of yarn inlet: 2 mmDiameter of aperture: 3.0 mm______________________________________
Eight runs, including one blank, were carried out in the experiment, with the eight spinning units having yarn draw off tubes of different eccentric angles. In each run, the yarn was taken up from the spinning rotor through the yarn draw off tube while increasingly varying the winding speed of the yarn, but keeping the rotational speed of the spinning rotor and the draft ratio constant. The draft ratio means the winding speed divided by the feeding speed of the sliver. The winding speed was increased to a critical speed at which the yarn fell down due to a lack of twist per unit yarn length. From the critical winding speed, a critical spinnable twist T c was calculated by using the following equation (1): ##EQU1##
Then the critical twist coefficient α c was calculated by using the following equation (2): ##EQU2## where S represents the yarn count of the produced yarn.
The results are represented by dots in the graph of FIG. 7. In the graph, the dot R represents, for the purpose of comparison, a value of a conventional yarn draw off tube having a non-eccentric yarn inlet.
As the value of the critical twist coefficient α c becomes smaller, the spinning unit can spin a softer twist yarn having a good feel to the touch and has a high productivity. According to the graph, α c is the smallest at an eccentric angle of 180° and increases as it becomes more distant from this point. Thus, it is apparent that the preferable range of the eccentric angle is from 135° to 225°.
According to the present invention, the spinnability of an open-end spinning unit is improved remarkably, and a yarn excellent in strength, as well as in appearance, can be obtained. | A yarn draw off tube for an open-end spinning unit which improves the twist transmission to a fiber ribbon in a spinning rotor. The yarn draw off tube is provided with a yarn inlet on the top wall thereof and a yarn outlet on the lower side wall thereof, and the yarn inlet is eccentric from the center in a direction opposite to the yarn outlet. In the spinning operation, a twist imparted to a yarn drawn off from the spinning rotor can smoothly be transmitted to the root portion thereof. Thereby, yarn breakage is restrained and a yarn of good appearance and strength can be obtained. | 3 |
This is a continuation of application Ser. No. 08/267,358 filed on Jun. 29, 1994 abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a process for the production of a 4-substituted azetidinone derivative which is important as an intermediate in the synthesis of carbapenem compounds.
A carboxylic acid derivative represented by the following general formula I'!: ##STR4##
wherein R 1 represents an alkyl group which may be substituted by an optionally protected hydroxyl group or a halogen atom; and R 2 represents a hydrogen atom or an alkyl group;
is an important intermediate in the synthesis of carbapenem compounds and there have been proposed several methods for the production thereof.
For example, Japanese Patent Laid-Open No. 252786/1987 has disclosed that a 4-substituted azetidinone represented by the following general formula II'!: ##STR5## wherein R 1 and R 2 are as defined above; R represents a hydrogen atom or a protecting group for N which can be easily eliminated; r represents an optionally substituted aromatic group formed together with the two adjacent carbon atoms; X' represents an oxygen atom, a sulfur atom, SO, SO 2 or Nr 4 , wherein r 4 represents a hydrogen atom, an alkyl group or a phenyl group; and Y' represents an oxygen atom, a sulfur atom or Nr 5 , wherein r 5 represents a hydrogen atom, an alkyl group or a phenyl group; is easily hydrolyzed into a carboxylic acid derivative represented by the general formula I'!.
Further, a compound represented by the following general formula II"!: ##STR6## wherein X' is as defined above; and r 6 and r 7 each represent a hydrogen atom or a methyl group; is described in Tetrahedron Lett. Vol. 27, 5687-5690 (1986).
However these 4-substituted azetidinone derivatives represented by the general formulae II'! and II"! are produced with the use of highly expensive materials, i.e., boron triflate or tin triflate, which makes them unsuitable for industrial purposes.
SUMMARY OF THE INVENTION
The present invention relates to a process for the production of a 4-substituted azetidinone derivative which comprises reacting an azetidinone derivative represented by the following general formula: ##STR7## wherein R represents a hydrogen atom or a protecting group for N which can be easily eliminated, R 1 represents an alkyl group which may be substituted by an optionally protected hydroxyl group or a halogen atom; and Z represents a leaving group; with an imide compound represented by the following general formula: ##STR8## wherein R 2 represents a hydrogen atom or an alkyl group; R 3 and R 4 each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a phenyl group, a cycloalkyl group, a naphthyl group or a ring formed by R 3 together with R 4 ; X and Y each represent an oxygen atom, a sulfur atom or N-r 1 , wherein r 1 represents a hydrogen atom or a lower alkyl group;
A, B, D and E each represent a nitrogen atom or C-r 2 , wherein r 2 represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, provided that at least two of A, B, D and E are C-r 2 ; and a five-membered ring involving G, J and K has two carbon/carbon double bonds therein and one of G, J and K represents an oxygen atom, a sulfur atom or N-r 1 while the remaining two represent C-r 2 , wherein r 1 and r 2 are as defined above;
in the presence of a compound represented by the following general formula:
M(Hal).sub.n (R.sup.5).sub.m (V)
wherein M represents a metal atom; Hal represents a halogen atom; R 5 represents a lower alkyl group, a lower alkoxy group, a phenoxy group, a substituted phenoxy group or a cyclopentadienyl group; and n and m are each 0, 1, 2, 3, 4 or 5 provided that n+m stands for the valence of M; and a base to thereby give a 4-substituted azetidinone derivative represented by the following general formulae: ##STR9## wherein R, R 1 , R 2 , R 3 , R 4 , X, Y, A, B, D, E, G, J and K are as defined above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Examples of the protecting group for the hydroxyl group of R 1 include organosilyl groups such as tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triethylsilyl, dimethylcumylsilyl, triisopropylsilyl and dimethylhexylsilyl groups, oxycarbonyl groups such as p-nitrobenzyloxycarbonyl, p-methoxybenzyloxy-carbonyl and allyloxycarbonyl groups, acetyl group, triphenylmethyl group, benzoyl group and tetrahydropyranyl group.
Examples of the protecting group for N include the silyl groups as cited above, benzyl group, p-nitrobenzyl group, p-nitrobenzoylmethyl group, benzhydryl group, p-methoxybenzyl group and 2,4-dimethoxybenzyl group.
Examples of the leaving group of Z include acyloxy groups, for example, linear, branched or cyclic alkanoyloxy groups such as acetoxy, propionyloxy, butyryloxy, isobutyryloxy and cyclohexylcarbonyloxy groups, monocyclic or bicyclic aroyloxy groups optionally having a hetero atom such as benzoyloxy, 1-naphthoyloxy, 2-naphthoyloxy, nicotinoyloxy, isonicotinoyloxy, furoyloxy and thenoyloxy groups, arylalkanoyl groups such as phenylacetoxy group, alkylsulfonyloxy groups such as methanesulfonyloxy, ethanesulfonyloxy, propanesulfonyloxy and trifluoromethanesulfonyloxy groups, arylsulfonyloxy groups such as benzenesulfonyloxy and toluenesulfonyloxy groups, alkoxycarbonyloxy groups such as methoxycarbonyloxy and ethoxycarbonyloxy groups, aralkoxycarbonyloxy groups such as benzyloxycarbonyloxy group, alkoxyalkanoyloxy groups such as methoxyacetoxy and ethoxyacetoxy groups, and carbamoyloxy groups such as N-methylcarbamoyloxy, N-ethylcarbamoyloxy and N-phenylcarbamoyloxy groups; acylthio groups, for example, alkanoylthio groups such as acetylthio and propionylthio group and aroylthio groups such as benzoylthio group;
sulfenyl groups, for example, alkylthio groups such as methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio and tert-butylthio groups and arylthio groups such as phenylthio group; sulfinyl groups, for example, alkylsulfinyl groups such as methanesulfinyl, ethanesulfinyl, propanesulfinyl and butanesulfinyl groups and arylsulfinyl groups such as benzenesulfinyl and toluenesulfinyl groups;
sulfonyl groups, for example, alkylsulfonyl groups such as methanesulfonyl, ethanesulfonyl, propanesulfonyl and butanesulfonyl groups and arylsulfonyl groups such as benzenesulfonyl group; and
halogen atoms such as fluorine, chlorine and bromine atoms.
As the above-mentioned base, secondary and tertiary amines and pyridines can be cited. Examples thereof include secondary amines, for example, alkylamines such as dimethylamine, diethylamine, diisopropylamine and dicyclohexylamine, alkylanilines such as N-methylaniline and heterocyclic amines such as piperidine, pyrrolidine, 2,2,6,6-tetramethylpiperidine, morpholine and piperazine, tertiary amines, for example, alkylamines such as diisopropylethylamine, diisopropylmethylamine and triethylamine, dialkylanilines such as N,N-dimethylaniline, heterocyclic amines such as 1-ethylpiperidine, 1-methyl-morpholine, 1-ethylpyrrolidine, 1,4-diazabicyclo 2,2,2!octane and 1,8-diazabicyclo 5,4,0!undec-7-ene and diamines such as N,N,N',N'-tetramethylethylenediamine and pyridines, for example alkylpyridines such as α-, β- or γ-picoline, 2,3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-lutidine and 2,4,6-collidine, dialkylaminopyridines such as dimethylaminopyridine and condensed heterocyclic pyridines such as quinoline.
Examples of the compound represented by the formula M(Hal) n (R 5 ) m include TiCl 4 , TiCl 3 (OCH 3 ), TiCl 3 (OC 2 H 5 ), TiCl 3 (OC 3 H 7 n ), TiCl 3 (OC 3 H 7 1 ), TiCl 3 (Obu n ), TiCl 3 (Obu 1 ), TiCl 3 (Obu s ), TiCl 3 (Obu t ), TiCl 2 (OCH 3 ) 2 , TiCl 2 (OC 2 H 5 ) 2 , TiCl 2 (OC 3 H 7 n ) 2 , TiCl 2 (OC 3 H 7 1 ) 2 , TiCl 2 (Obu n ) 2 , ZrCl 4 , ZrCl 3 (OCH 3 ), ZrCl 3 (OC 2 H 5 ), ZrCl 3 (OC 3 H 7 n ), ZrCl 3 (OC 3 H 7 1 ) ZrCl 3 (OC 4 H 9 1 ), ZrCl 3 (OC 4 H 9 s ), ZrCl 3 (OC 4 H 9 t ), SnCl 4 , AlCl 3 , Al(OCH 3 ) 3 , Al(OC 2 H 5 ) 3 , Al(OC 3 H 7 1 ) 3 , AlCl 2 C 2 H 5 , AlCl(C 2 H 5 ) 2 , Al(C 2 H 5 ) 3 , AlCl 2 CH 3 , AlCl(CH 3 ) 2 and Al(CH 3 ) 3 .
Examples of the substituent represented by the following general formulae (hereinafter referred to as the auxiliary group) are as follows: ##STR10## wherein r 8 represents a hydrogen atom, a lower alkyl group, a halogen atom or a lower alkoxy group; and k is 0, 1, 2 or 3.
Examples of R 3 and R 4 in the above formulae include alkyl groups having 1 to 15 carbon atoms such as methyl, ethyl, propyl isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, isopentyl, s-pentyl, neo-pentyl, octyl and decyl groups, alkenyl groups having 2 to 10 carbon atoms such as vinyl, allyl, 1-propenyl and 3-butenyl groups, alkynyl groups having 2 to 10 carbon atoms such as ethynyl and 2-propynyl groups, cycloalkyl groups having 3 to 10 carbon atoms such as cyclopropyl, cyclopentyl and cyclohexyl groups, aralkyl groups having 7 to 10 carbon atoms such as benzyl and phenylethyl groups, aralkenyl groups having 8 to 11 carbon atoms such as a styryl group and aromatic hydrocarbon groups such as phenyl, α-naphthyl and β-naphthyl groups.
Examples of the ring formed by R 3 together with R 4 are as follows. ##STR11## wherein · represents a binding site.
Examples of the substituent r 9 include hydrogen atoms, alkyl groups having 1 to 10 carbon atoms, lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, i-butoxy, s-butoxy and t-butoxy groups, phenoxy group, lower alkylthio groups such as methylthio, ethylthio, propylthio and isopropylthio groups, phenylthio group, halogen atoms such as chlorine, bromine and fluorine atoms, oxo group, thioxo group, nitro group, cyano group and substituted amino groups such as dimethylamino, diethylamino and N-methylanilino groups.
The reaction is carried out by forming an enolate from an imide compound represented by the general formula IV!, a compound represented by the general formula V! and an amine, aniline or pyridine in an organic solvent, for example, a chlorinated solvent such as methylene chloride or chloroform, an aromatic solvent such as chlorobenzene or toluene, a polar solvent such as tetrahydrofuran (THF) or acetonitrile or a mixture thereof and then reacting the enolate thus obtained with an azetidinone derivative represented by the general formula III!. The formation of the enolate and the reaction between the enolate and the azetidinone derivative are both performed at a reaction temperature of from -50° to 100° C., preferably from -20° to 50° C.
In this reaction, 1 to 8 mol of the imide compound represented by the general formula IV!, 1 to 8 mol of the compound represented by the compound V! and 1 to 8 mol of the base are each used per mol of the azetidinone derivative represented by the general formula III!.
When R 2 is an alkyl group such as a methyl group, the ratio of the α-compound and β-compound thus formed varies depending on the molar ratio of the imide compound represented by the general formula IV! to the compound represented by the general formula V! or the amine and the type of the auxiliary group. The yield of the β-compound can be elevated by adding a polar solvent such as DMF, THF or acetonitrile to the reaction system. After the completion of the reaction, the target compound can be isolated by a usual work-up.
The compound II! obtained by the method of the present invention can be optionally isolated and then hydrolyzed to thereby give a carboxylic acid derivative represented by the general formula I!: ##STR12## wherein R, R 1 and R 5 are as defined above.
A compound represented by the general formula IV-1! or IV-2! can be produced by, for example, reacting a compound represented by the general formula: ##STR13## wherein R 3 , R 4 , X, Y, A, B, D, E, G, J and K are as defined above;
with a compound represented by the general formula:
R 2 CH 2 COHal
wherein R 2 is as defined above; and Hal represents a halogen atom;
in an appropriate solvent (for example, toluene, ethyl acetate or methylene chloride) in the presence of a base (for example, triethylamine or pyridine) at a temperature of from -80° C. to the boiling point of the solvent, preferably from -20° to 80° C. Next, an example of the process for the production of the compound represented by the general formula IV-1! or IV-2! will be given.
Production Example 1! ##STR14##
To a mixture of 246.8 g of 2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one and 900 ml of toluene, 142.7 g of propionyl chloride was added. Further, 155.9 g of triethylamine was added dropwise into the mixture at 60° C. After the completion of the reaction, the reaction mixture was cooled and successively washed with water, a dilute aqueous solution of caustic soda and water. After distilling off the solvent, 320 g of the product was obtained.
b.p.: 116° C./2 mmHg.
Production Example 2! ##STR15##
To a mixture of 434.5 g of 2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one and 4000 ml of toluene, 249.8 g of propionyl chloride was added. Further, 283.3 g of triethylamine was added dropwise into the mixture at 70° C. After the completion of the reaction, the reaction mixture was cooled and successively washed with water, an aqueous solution of sodium hydrogencarbonate and water. After distilling off the solvent and crystallizing from Isopar G (a paraffin solvent), 520 g of the target compound was obtained.
m.p.: 60°-60.5° C.
EXAMPLES
To further illustrate the present invention in greater detail, the following Examples will be given.
Example 1
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR16## A solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (4.5 g, 19.3 mmol) in methylene chloride (125 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.7 g, 19.3 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (2.5 g, 19.3 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (2.8 g, 9.7 mmol) in methylene chloride (20 ml) were added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, then heated to 20° C. and aged again for 3 hours. The resulting mixture was added to 300 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. The organic layer was separated and analyzed by HPLC. The result showed that it contained 4.1 g of the β-methyl derivative β-methyl derivative:α-methyl derivative=98.6:1.4). The organic layer was washed with 150 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 3.8 g of the β-methyl derivative (β-methyl derivative : α-methyl derivative=98.2:0.2). The pure β-methyl derivative was obtained by silica gel column chromatography again.
m.p. of β-methyl derivative: 138°-140° C.
Example 2
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,2-diethyl-2,3-dihydro-4H-1,3-benzoxazin-4-one): ##STR17##
A solution of 2,2-diethyl-2,3-dihydro-3-propionyl-4H-1,3-benzoxazin-4-one (4.1 g, 15.7 mmol) in methylene chloride (45 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.0 g, 15.7 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (2.0 g, 15.7 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (2.3 g, 7.9 mmol) in methylene chloride (10 ml) were added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, then heated to 20° C. and aged again for 3 hours. The resulting mixture was added to 150 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. The organic layer was separated and analyzed by HPLC. The result showed that it contained 3.2 g of the β-methyl derivative β-methyl derivative:α-methyl derivative=94.6:5.4). The organic layer was washed with 150 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 2.9 g of the β-methyl derivative (β-methyl derivative : α-methyl derivative=95.0:5.0). The pure β-methyl derivative was obtained by purification with silica gel column chromatography again.
m.p. of β-methyl derivative: 184°-185° C.
Example 3
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR18##
A solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (5.5 g, 20.1 mmol) in methylene chloride (55 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.8 g, 20.1 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (2.6 g, 20.1 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (2.9 g, 10.0 mmol) in methylene chloride (10 ml) were added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, then heated to 20° C. and aged again for 3 hours. The resulting mixture was added to 150 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. The organic layer was separated and analyzed by HPLC. The result showed that it contained 4.3 g of the β-methyl derivative (β-methylderivative:α-methyl derivative=99.2:0.8). The organic layer was washed with 150 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 4.0 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=99.6:0.4). The pure β-methyl derivative was obtained by silica gel column chromatography again.
m.p. of β-methyl derivative: 154°-155° C.
Example 4
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR19##
A solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (1.365 g, 5 mmol) in methylene chloride (10 ml) was cooled to -15° C. and a solution of zirconium tetrachloride (1.17 g, 5 mmol) was added thereto. After aging at -15° C. for 30 minutes, a solution of N,N-diisopropylethylamine (646 mg, 5 mmol) in methylene chloride (2 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethyl-silyloxy ethyl!-azetidin-2-one (719 mg, 2.5 mmol) in methylene chloride (5 ml) were added thereto at the same temperature. The mixture thus obtained was aged at -15° C. for 1 hour, then heated to 20° C. and aged again for 5 hours. The resulting mixture was cooled to 0° C. and 30 ml of a 10% aqueous solution of sodium hydrogencarbonate was added thereto under stirring. After eliminating the insoluble matter by filtration, the organic layer was separated from the filtrate and analyzed by HPLC. The result showed that it contained 1000 mg of the β-methyl derivative (β-methyl derivative:α-methyl derivative=99:1).
Example 5
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxy-ethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR20##
A solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (1.365 g, 5 mmol) in methylene chloride (10 ml) was cooled to -15° C. and a solution of aluminum chloride (667 mg, 5 mmol) was added thereto. After aging at -15° C. for 30 minutes, a solution of N,N-diisopropylethylamine (646 mg, 5 mmol) in methylene chloride (2 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl!azetidin-2-one (719 mg, 2.5 mmol) in methylene chloride (5 ml) were added thereto at the same temperature. The mixture thus obtained was aged at -15° C. for 1 hour, then heated to 20° C. and aged again for 5 hours. The resulting mixture was cooled to 0° C. and 30 ml of a 10% aqueous solution of sodium hydrogencarbonate was added thereto under stirring. After eliminating the insoluble matter by filtration, the organic layer was separated from the filtrate and analyzed by HPLC. The result showed that it contained 701 mg of the β-methyl derivative (β-methyl derivative:α-methyl derivative=88:12).
Example 6
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR21##
A solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (1.365 g, 5 mmol) in methylene chloride (10 ml) was cooled to -15° C. and a solution of diethylchloro-aluminum/n-hexane (1M, 5 ml, 5 mmol) was added thereto. After aging at -15° C. for 30 minutes, a solution of N,N-diisopropylethylamine (646 mg, 5 mmol) in methylene chloride (2 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl!azetidin-2-one (719 mg, 2.5 mmol) in methylene chloride (5 ml) were added thereto at the same temperature. The mixture thus obtained was aged at -15° C. for 1 hour, then heated to 20° C. and aged again for 5 hours. The resulting mixture was cooled to 0° C. and 30 ml of a 10% aqueous solution of sodium hydrogencarbonate was added thereto under stirring. After eliminating the insoluble matter by filtration, the organic layer was separated from the filtrate and analyzed by HPLC. The result showed that it contained 190 mg of the β-methyl derivative (β-methyl derivative:α-methyl derivative=52:48).
Example 7
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR22##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (3.26 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.77 g, 14.6 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.74 g, 13.5 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4-isobutyryloxyazetidin-2-one (3.16 g, 10.0 mmol) in methylene chloride (15 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 3.8 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=97.7:2.3).
Example 8
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR23##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (3.26 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.75 g, 14.5 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.75 g, 13.5 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4-propionyloxyazetidin-2-one (3.02 g, 10.0 mmol) in methylene chloride (15 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 4.0 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.4:1.6).
Example 9
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1 ,3-benzoxazin-4-one): ##STR24##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (3.27 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.76 g, 14.5 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.74 g, 13.4 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4- 2-methylbenzoyloxy!azetidin-2-one (3.64 g, 10.0 mmol) in methylene chloride (15 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 4.1 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative 97.8:2.2).
Example 10
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR25##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (3.27 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.79 g, 14.7 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.74 g, 13.5 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4- 4-chlorobenzoyloxylazetidin-2-one (3.84 g, 10.0 mmol) in methylene chloride (15 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 4.2 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.3:1.7).
Example 11
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR26##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (16.33 g, 70.0 mmol) in methylene chloride (100 ml), titanium tetrachloride (13.70 g, 72.2 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (8.72 g, 67.5 mmol) in methylene chloride (50 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4- 2,6-dimethoxybenzoyloxy!-azetidin-2-one (20.49 g, 50.0 mmol) in methylene chloride (50 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 20.0 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=97.1:2.9).
Example 12
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR27##
To a solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (16.33 g, 70.0 mmol) in methylene chloride (100 ml), titanium tetrachloride (13.75 g, 72.5 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (8.73 g, 67.5 mmol) in methylene chloride (50 ml) and a solution of (3R,4R)-4-benzoyloxy-3- (R)-1-tert-butyldimethyl-silyloxyethyl!azetidin-2-one (17.47 g, 50.0 mmol) in methylene chloride (50 ml) were successively added thereto. The mixture thus obtained was heated to 30° C. and stirred for 2 hours. The reaction mixture was cooled to 0° C. and poured into ice/water under stirring. The organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 20.5 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.4:1.6).
Example 13
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR28##
A solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (1.365 g, 5 mmol) in methylene chloride (10 ml) was cooled to -15° C. and zirconium tetrachloride (1.17 g, 5 mmol) was added thereto. After aging at -15° C. for 30 minutes, a solution of N,N-diisopropylethylamine (640 mg, 5 mmol) in methylene chloride (2 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl!azetidin-2-one (719 mg, 2.5 mmol) in methylene chloride (5 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at -15° C. for 1 hour, heated to 20° C. and then aged again for 5 hours. The mixture thus obtained was cooled to 0° C. and 30 ml of a 10% aqueous solution of sodium hydrogencarbonate was added thereto under stirring. After eliminating the insoluble matters by filtration, the organic layer was separated from the filtrate and analyzed by HPLC. The result showed that it contained 920 mg of the β-methyl derivative β-methyl derivative:α-methyl derivative=99:1).
Example 14
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethyl-silyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR29##
A solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (1.365 g, 5 mmol) in methylene chloride (10 ml) was cooled to -15° C. and aluminum chloride (667 mg, 5 mmol) was added thereto. After aging at -15° C. for 30 minutes, a solution of N,N-diisopropylethylamine (640 mg, 5 mmol) in methylene chloride (2 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (719 mg, 2.5 mmol) in methylene chloride (5 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at -15° C. for 1 hour, heated to 20° C. and then aged again for 5 hours. The mixture thus obtained was cooled to 0° C. and 30 ml of a 10% aqueous solution of sodium hydrogencarbonate was added thereto under stirring. After eliminating the insoluble by filtration, the organic layer was separated from the filtrate and analyzed by HPLC. The result showed that it contained 630 mg of the β-methyl derivative β-methyl derivative:α-methyl derivative=85:15).
Example 15
Production of β-methyl derivative (3- (R)-2- (3S,4R) -3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2-isobutyl-2-methyl-4H-1,3-benzoxazin-4-one): ##STR30##
A solution of (±) 2,3-dihydro-2-isobutyl-2-methyl-3-propionyl-4H-1,3-benzoxazin-4-one (9.0 g, 32.7 mmol) in methylene chloride (100 ml) was cooled to 5° C. and a solution of titanium tetrachloride (6.2 g, 32.7 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (4.2 g, 32.7 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl!azetidin-2-one (4.7 g, 16.4 mmol) in methylene chloride (20 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The mixture thus obtained was added to 250 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. The result showed that it contained 7.3 g of the β-methyl derivative. The organic layer was washed with 250 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 6.5 g of the β-methyl derivative (m.ps. of two diastereoisomers: 123°-124° C., 134°-135° C.).
Example 16
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2-ethyl-2-isopropyl-4H-1,3-benzoxazin-4-one): ##STR31##
A solution of (±) 2-ethyl-2,3-dihydro-2-isopropyl-3-propionyl-4H-1,3-benzoxazin-4-one (2.8 g, 10 mmol) in methylene chloride (20 ml) was cooled to 5° C. and a solution of titanium tetrachloride (1.9 g, 10 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (1.3 g, 10 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (1.4 g, 5 mmol) in methylene chloride (10 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The mixture thus obtained was added to 75 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. As a result, it contained 1.5 g of the β-methyl derivative. The organic layer was washed with 75 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 1.4 g of the β-methyl derivative. Based on a chart of 1 H NMR (270Mhz, CDCl 3 ), it was found out that the derivative thus obtained was a mixture of two diastereoisomers.
Example 17
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-hexamethylene-4H-1,3-benzoxazin-4-one): ##STR32##
A solution of 2,3-dihydro-2,2-hexamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (5.8 g, 20.3 mmol) in methylene chloride (50 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.9 g, 20.3 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (2.6 g, 20.3 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (2.9 g, 10.0 mmol) in methylene chloride (10 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The mixture thus obtained was added to 150 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. The result showed that it contained 2.5 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.8:1.2). The organic layer was washed with 150 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 2.5 g of the β-methyl derivative. (β-methyl derivative:α-methyl derivative=97.9:2.1). The pure β-methyl derivative was obtained by silica gel column chromatography again.
m.p. of β-methyl derivative: 154°-155° C.
Example 18
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-tetramethylene-4H-1,3-benzoxazin-4-one): ##STR33##
A solution of 2,3-dihydro-2,2-tetramethylene-3-propionyl-4H-1,3-benzoxazin-4-one (2.6 g, 10 mmol) in methylene chloride (20 ml) was cooled to 5° C. and a solution of titanium tetrachloride (1.9 g, 10 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of N,N-diisopropylethylamine (1.3 g, 10 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (1.4 g, 5 mmol) in methylene chloride (10 ml) were successively added thereto at the same temperature. The mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The mixture thus obtained was added to 75 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. The result showed that it contained 2.1 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=99.2:0.8). The organic layer was washed with 75 ml of water and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to thereby give 2.1 g of the β-methyl derivative. (β-methyl derivative:α-methyl derivative=99.1:0.9). The pure β-methyl derivative was obtained by silica gel column chromatography again.
1 H NMR (270 Mhz, CDCl 3 )δ of β-methyl derivative: 0.01(6H,s), 0.78(9H,s), 1.15(3H,d), 1.20(3H,d), 1.74-2.17(8H,m), 3.14-3.16(1H,m), 3.55-3.57(1H,m), 3.93-3.95(1H,m), 4.11-4.15(1H,m), 6.09(1H,s), 6.86(1H,dd), 7.03(1H,m), 7.44(1H,m), 7.86(1H,dd).
Example 19
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR34##
To a solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (3.82 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.75 g, 14.5 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.75 g, 13.5 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4-propionyloxyazetidin-2-one (3.04 g, 10.1 mmol) in methylene chloride (15 ml) were successively added thereto. Then the mixture thus obtained was heated to 30° C. and stirred for 3 hours. The mixture was cooled to 0° C. and poured into ice/water under stirring. Then the organic layer was separated, washed with water and analyzed by HPLC. As a result, it contained 4.1 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.7:1.3).
Example 20
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR35##
To a solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (3.82 g, 14.0 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.77 g, 14.6 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.74 g, 13.5 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-4- 4-chlorobenzoyloxy!azetidin-2-one (3.84 g, 10.0 mmol) in methylene chloride (15 ml) were successively added thereto. Then the mixture thus obtained was heated to 30° C. and stirred for 2.5 hours. The mixture was cooled to 0° C. and poured into ice/water under stirring. Then the organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 4.4 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.2:1.8).
Example 21
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR36##
To a solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (4.15 g, 15.2 mmol) in methylene chloride (15 ml), titanium tetrachloride (2.99 g, 15.8 mmol) was added at 5° C. After stirring at the same temperature for 5 minutes, a solution of N,N-diisopropylethylamine (1.91 g, 14.8 mmol) in methylene chloride (10 ml) and a solution of (3R,4R)-4-benzoyloxy-3- (R)-1-tert-butyldimethyl-silyloxyethyl!azetidin-2-one (3.81 g, 10.9 mmol) in methylene chloride (15 ml) were successively added thereto. Then the mixture thus obtained was heated to 30° C. and stirred for 2 hours. The mixture was cooled to 0° C. and poured into ice/water under stirring. Then the organic layer was separated, washed with water and analyzed by HPLC. The result showed that it contained 4.7 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.6:1.4).
Example 22
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-pentamethylene-4H-1,3-benzoxazin-4-one): ##STR37##
A solution of 2,3-dihydro-2,2-pentamethylene-3-propionyl-4H-1,3-benzoxazin-4-one (5.5 g, 20.1 mmol) in methylene chloride (55 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.8 g, 20 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of triethylamine (2.0 g, 20.1 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl!azetidin-2-one (2.9 g, 10.0 mmol) in methylene chloride (10 ml) were successively added thereto at the same temperature. Then the mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The obtained mixture was added to 150 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. The result showed that it contained 4.2 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.6:1.4).
Example 23
Production of β-methyl derivative (3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl)propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one): ##STR38##
A solution of 2,3-dihydro-2,2-dimethyl-3-propionyl-4H-1,3-benzoxazin-4-one (4.5 g, 19.3 mmol) in methylene chloride (125 ml) was cooled to 5° C. and a solution of titanium tetrachloride (3.7 g, 19.3 mmol) in methylene chloride (5 ml) was added thereto. After aging at 5° C. for 30 minutes, a solution of triethylamine (2.0 g, 19.3 mmol) in methylene chloride (5 ml) and a solution of (3R,4R)-4-acetoxy-3- (R)-1-tert-butyldimethylsilyloxyethyl! azetidin-2-one (2.8 g, 9.7 mmol) in methylene chloride (20 ml) were successively added thereto at the same temperature. Then the mixture thus obtained was aged at 5° C. for 1 hour, heated to 20° C. and then aged again for 3 hours. The obtained mixture was added to 300 ml of water at 5° C. under stirring and aged at the same temperature for 30 minutes. Then the organic layer was separated and analyzed by HPLC. The result showed that it contained 3.8 g of the β-methyl derivative (β-methyl derivative:α-methyl derivative=98.6:1.4).
Referential Example 1!
Production of (R)-2- (3S,4S)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl!propionic acid: ##STR39##
To a solution of 3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl!propionyl!-2,3-dihydro-2 ,2-pentamethylene-4H-1 ,3-benzoxazin-4-one (2.0 g, 4 mmol) in a solvent mixture of acetone/water (2:1, 15 ml), a 300% aqueous solution of hydrogen peroxide (1.5 g, 13.2 mmol) was added at room temperature. Then a 28% aqueous solution of sodium hydroxide (1.9 g, 13.2 mmol) was added dropwise into the mixture at the same temperature followed by aging for 2 hours. To the mixture thus obtained, 30 ml of water at 5° C. was added. Further, 3 ml of 35% hydrochloric acid was added at room temperature to thereby adjust the pH value of the mixture to 10.0. After washing with 50 ml of methylene chloride, 10 ml of 35% hydrochloric acid was added at the same temperature to thereby adjust the pH value of the mixture to 2.0. The crystals thus precipitated were collected by filtration and dried. Thus 0.9 g of (R)-2- (3S,4S)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl !propionic acid was obtained.
Referential Example 2!
Production of (R)-2- (3S,4S)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl!propionic acid: ##STR40##
To a solution of 3- (R)-2- (3S,4R)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl!propionyl!-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one (7.0 g, 15 mmol) in a solvent mixture of methanol/water (2:1, 45 ml), a 30% aqueous solution of hydrogen peroxide (3.5 g, 30 mmol) was added at room temperature. Then a 28% aqueous solution of sodium hydroxide (2.4 g, 17 mmol) was added dropwise into it and the obtained mixture was stirred until the starting material disappeared in HPLC. After the completion of the reaction, 45 ml of cold water was added to the reaction mixture. After washing with 15 ml of methylene chloride, 35% hydrochloric acid was added to thereby adjust the pH value of the mixture to 3. The crystals thus precipitated were collected by filtration, washed with water and dried. Thus 4.3 g of (R)-2- (3S,4S)-3- (R)-1-tert-butyldimethylsilyloxyethyl!-2-oxoazetidin-4-yl!propionic acid was obtained.
The production process according to the present invention with the use of the compound represented by the general formula V!, which is inexpensive and easy to handle, is an excellent method from an industrial viewpoint.
When R 2 is an alkyl group such as a methyl group, the β-compound, which is important as an intermediate in the synthesis of carbapenem compounds, can be selectively obtained by regulating the molar ratio or selecting an appropriate auxiliary group. | The present invention provides a process for the production of a 4-substituted azetidinone. The process comprises reacting ##STR1## wherein R represents a hydrogen atom or a protecting group for N, R 1 represents an alkyl which may be a substituent having an unprotected or protected hydroxyl group; and Z represents a leaving group; with ##STR2## wherein R 2 represents hydrogen or alkyl, R 3 and R 4 each represent hydrogen, alkyl, alkenyl, alkynyl, phenyl, cycloalkyl, or naphthyl, or R 3 and R 4 , together with the carbon atom to which they are bonded, form a ring system; X and Y each represent oxygen, sulfur or N-r 1 , wherein r 1 represents a hydrogen atom or lower alkyl; A, B, D and E each represent nitrogen or C-r 2 , wherein r 2 represents hydrogen, halogen, lower alkyl or lower alkoxy, provided that at least two of A, B, D and E are C-r 2 ; and a ring involving G, J and K has two carbon/carbon double bonds therein and one of G, J and K represents oxygen, sulfur or N-r 1 while the remaining two represent C-r 2 ; in the presence of
M(Hal).sub.n (R.sup.5).sub.m (V)
wherein M represents a metal atom; Hal represents halogen; R 5 represents lower alkyl, lower alkoxy, phenoxy, substituted phenoxy or cyclopentadienyl; and n and m are each 0, 1, 2, 3, 4 or 5, provided that n+m stands for the valence of M; and a base to thereby give: ##STR3## | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a novel 2-alkynyl-N 9 -propargyladenine and pharmaceutical use thereof. More specifically, the present invention relates to a 2-alkynyl-N 9 -propargyladenine represented by the following formula (I):
[0000]
[0000] wherein R 1 represents halogen, a furyl group or a triazolyl group; R 2 and R 3 each represent hydrogen or an alkyl group having 1 to 8 carbon atoms, or R 2 and R 3 represent a cycloalkyl group in which R 2 and R 3 are linked together; and X represents hydrogen or a hydroxyl group, or a pharmaceutically acceptable salt thereof, which acts as an adenosine A 2a receptor antagonist, and pharmaceutical use thereof.
BACKGROUND ART
[0002] Parkinson's disease (shaking palsy) is a brain disease characterized by tremors (trembling or vibrating) of the body, as well as difficulties in walking, movements, and coordination.
[0003] The development of Parkinson's disease is related to a damage of a part of the brain which controls the muscular movements. Dopaminergic cells, which are concentrated in the relevant part of the substantia nigra, are the most rapidly aging cells in the body, and denaturation of dopamine-producing cells causes a reduction in the production of dopamine and impairs the control of movement, thus developing Parkinson's disease.
[0004] Symptoms very similar to Parkinson's disease as mentioned above are known to be also caused by various other causes, such as Encephalitis lethargica, cerebral arteriosclerosis, intoxication with drugs/carbon monoxide/manganese/cyanide compounds or the like, brain tumor, after a head injury, or syphilis. Including these, a condition in which symptoms such as muscle stiffness, tremor, or akinesia occur in different combinations is called “Parkinson's syndrome”.
[0005] No radical therapeutic methods are known for Parkinson's syndrome, and conventional therapeutic methods have been aimed at controlling the symptoms. Representative therapeutic methods include a method of administering to a patient L-DOPA, which is a precursor of dopamine, singly or in combination with another drug. However, when this therapeutic method is conducted for a long time period, the efficacy of L-DOPA tends to lower over time, and actually patients who received a chronic treatment with L-DOPA had a problem in that the aforementioned symptoms often became severe in addition to occurrence of other adverse reactions due to neurotoxicity intrinsic to L-DOPA.
[0006] On the other hand, adenosine is known to be an endogenous modulator of many physiological functions. It has been revealed that the action of adenosine is mediated by an interaction with different membrane specific receptors which belong to the family of G-protein coupled receptors present on the cell surface, and there are at least 4 subtypes of adenosine receptors, A 1 , A 2a , A 1b , and A 3 .
[0007] In recent years, the role of adenosine as a neurotransmitter, its receptors, and their functional properties have been discovered, and thereby it has been revealed that an antagonist of adenosine A 2a receptor can be used as a therapeutic agent for movement disorder accompanied by Parkinson's syndrome (Patent Literatures 1 to 3).
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: JP 6-211856 A
Patent Literature 2: JP 2007-531729 A
Patent Literature 3: JP 2010-505747 A
Patent Literature 4: JP 11-263789 A
SUMMARY OF INVENTION
Technical Problem
[0012] However, although an adenosine A 2a antagonist described in Patent Literature 1, 8-[(E)-2-(3,4-dimethoxyphenyl)vinyl]-1,3-diethyl-7-methyl-3,7-dihydro-1H-purin-2,6-dione (hereinafter referred to as “KW-6002”) is known, which has conventionally been considered as promising as a therapeutic agent for Parkinson's syndrome, it cannot be said that sufficient comparison is conducted with an adenine derivative which differs in fundamental structure of the skeleton such as the compound of the present invention.
[0013] Patent Literatures 2 to 4 disclose an adenosine A 2a receptor antagonist compound having adenine as a basic skeleton; however, these do not disclose the compound of the present invention as a specific compound, including the synthesis method thereof.
[0014] To describe more specifically, Patent Literatures 2 and 3 disclose an adenosine A 2a receptor antagonist having adenine as a basic skeleton. However, Patent Literature 2 never discloses the compound of the present invention, including the synthesis method thereof. In addition, as shown in the study examples mentioned below, 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine described in Patent Literature 2, and a compound represented by the following formula:
[0000]
[0000] which is listed as a representative compound in Patent Literature 3, compound No. 9 in [Table A], have no potent activity as a potent adenosine A 2a receptor antagonist, and they cannot necessarily be said to be a promising compound.
[0015] Patent Literature 4 also discloses an adenosine A 2a receptor antagonist having adenine as a basic skeleton; however, it does not disclose the compound of the present invention as a specific compound, including the synthesis method thereof. In addition, Patent Literature 4 only discloses the use as a prophylactic or therapeutic agent for diabetes and diabetic complications, which has no relation to the use of the compound of the present invention.
[0016] Accordingly, it has been desired to develop a novel selective adenosine A 2a receptor antagonist the effect of which, as a therapeutic agent for Parkinson's syndrome, is stronger and more continuous.
Solution to Problem
[0017] Conventionally a large number of adenosine A 2a receptor antagonists having adenine as a basic skeleton have been known, and Patent Literatures 2 to 4 also describe many compounds having different substituents or structures. However, for the above compounds, it has not previously fully been pursued to clarify, among numerous structures such as substituents, what factors are entailed in a compound which has a more potent adenosine A 2a receptor antagonist activity or which exhibits a strong effect on improvement of Parkinson's syndrome. Furthermore, as for compounds having substituents and structures like the compound of the present invention, their chemical structures, antagonist activities, and the intensity of improving effect on Parkinson's syndrome have never been known.
[0018] Accordingly, the present inventors have diligently worked on studies to newly find that a 2-alkynyl-N 9 -propargyladenine represented by the following formula (I) unexpectedly has an adenosine A 2a receptor antagonist activity more potent than conventional compounds and improves various symptoms of movement disorder accompanied by Parkinson's syndrome remarkably compared with conventional compounds, and also that administration of the formula (I) compound to a patient with Parkinson's syndrome, singly or in combination with another drug, can be expected to be able to improve the symptoms of Parkinson's syndrome with a smaller dose, for a long time period, and accordingly can solve the problems with conventional therapeutic agents for Parkinson's syndrome as an adenosine A 2a receptor antagonist, thereby completing the present invention.
[0019] That is, the present invention relates to the following (1) to (19):
[0020] (1) A 2-alkynyl-N 9 -propargyladenine represented by the following formula (I):
[0000]
[0000] wherein R 1 represents halogen, a furyl group or a triazolyl group; R 2 and R 3 each represent hydrogen or an alkyl group having 1 to 8 carbon atoms, or R 2 and R 3 represent a cycloalkyl group in which R 2 and R 3 are linked together; and X represents hydrogen or a hydroxyl group, or a pharmaceutically acceptable salt thereof.
[0021] (2) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), wherein R 1 is bromo or chloro.
[0022] (3) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), wherein R 1 is a 2-furyl group or a 2-triazolyl group. (4) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), wherein R 2 is hydrogen and R 3 is an alkyl group having 1 to 8 carbon atoms.
[0023] (5) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), wherein R 2 and R 3 are a cycloalkyl group in which R 2 and R 3 are linked together.
[0024] (6) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), which is 8-bromo-2-alkynyl-N 9 -propargyladenine, or 8-chloro-2-alkynyl-N9-propargyladenine.
[0025] (7) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), which is 8-(2-furyl)-2-alkynyl-N 9 -propargyladenine, or 8-(1,2,3-triazol-2-yl)-2-(1-alkynyl)-N 9 -propargyladenine.
[0026] (8) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), which is 8-bromo-2-(1-hydroxycycloalkyl)ethynyl-N 9 -propargyladenine, or 8-chloro-2-(1-hydroxycycloalkyl)ethynyl-N 9 -propargyladenine.
[0027] (9) The 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to (1), which is 8-(2-furyl)-2-(1-hydroxycycloalkyl)ethynyl-N 9 -propargyladenine, or 8-(1,2,3-triazol-2-yl)-2-(1-hydroxycycloalkyl)ethynyl-N 9 -propargyladenine.
[0028] (10) A pharmaceutical composition comprising the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9), and a pharmaceutically acceptable carrier.
[0029] (11) The pharmaceutical composition according to (10) for use as an adenosine A 2a receptor antagonist.
[0030] (12) The pharmaceutical composition according to (10) or (11) for use in the treatment of Parkinson's syndrome.
[0031] (13) The pharmaceutical composition according to any one of (10) to (12), for use in combination with another adenosine A 2a receptor antagonist or another therapeutic agent for Parkinson's syndrome.
[0032] (14) The pharmaceutical composition according to any one of (10) to (13), for use in combination with one or more therapeutic agents for Parkinson's syndrome selected from the group consisting of L-DOPA, dopamine, dopaminergic agonists, monoamine oxidase B inhibitors (MAO-B), DOPA decarboxylase inhibitors (DCI), or catechol-O-methyltransferase (COMT) inhibitors.
[0033] (15) A kit comprising the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9), and another adenosine A 2a receptor antagonist or another therapeutic agent for Parkinson's syndrome.
[0034] (16) A kit for the treatment of Parkinson's syndrome, comprising the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9), and one or more therapeutic agents for Parkinson's syndrome selected from the group consisting of L-DOPA, dopamine, dopaminergic agonists, monoamine oxidase B inhibitors (MAO-B), DOPA decarboxylase inhibitors (DCI), or catechol-O-methyltransferase (COMT) inhibitors.
[0035] (17) A method for treating Parkinson's syndrome, comprising administering to a subject in need thereof the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9).
[0036] (18) A method for treating Parkinson's syndrome, comprising administering to a subject in need thereof, simultaneously or separately, the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9), and another adenosine A 2a receptor antagonist or another therapeutic agent for Parkinson's syndrome.
[0037] (19) A method for treating Parkinson's syndrome, comprising administering to a subject in need thereof, simultaneously or separately, the 2-alkynyl-N 9 -propargyladenine or a pharmaceutically acceptable salt thereof according to any one of (1) to (9), and one or more therapeutic agents for Parkinson's syndrome selected from the group consisting of L-DOPA, dopamine, dopaminergic agonists, monoamine oxidase B inhibitors (MAO-B), DOPA decarboxylase inhibitors (DCI), or catechol-O-methyltransferase (COMT) inhibitors.
Advantageous Effects of Invention
[0038] The compound of the present invention has high chemical stability, especially high photostability, exerts the effect with a smaller dose, in addition, over a long period of time, as compared with previously reported therapeutic agents for Parkinson's syndrome as an adenosine A 2a receptor antagonist, and is extremely useful as a therapeutic agent for Parkinson's syndrome. Moreover, the combination of the compound of the present invention with L-DOPA, the efficacy of which has conventionally been known to be lowered by long-term administration, can be expected to provide a stronger improving effect on symptoms, and moreover, can control the lowering of the efficacy of L-DOPA by long-term use.
BRIEF DESCRIPTION OF DRAWINGS
[0039] FIG. 1 shows the results of the determination of the adenosine A 2a receptor antagonist activity of the compound of the present invention, determined by using the Magnus method. The vertical line represents the intensity of the inhibition of the relaxing response of the femoral vein when each substance was added in an organ bath, and the horizontal line represents the concentration of each substance added.
[0040] FIG. 2 shows the improving effect on haloperidol-induced catalepsy of the formula (4) compound or the formula (10) compound shown in the synthesis examples, and the positive control KW-6002. The vertical line represents the intensity degree of catalepsy, and the horizontal line represents the dose of each compound.
[0041] FIG. 3 shows the improving effect on haloperidol-induced catalepsy of the formula (4) compound or the formula (5) compound shown in the synthesis examples, and L-DOPA. The vertical line represents the intensity degree of catalepsy, and the horizontal line represents the time after the administration.
[0042] FIG. 4 shows the improving effect on haloperidol-induced catalepsy of the formula (11) compound, the formula (12) compound, the formula (13) compound, or the formula (14) compound shown in the synthesis examples, and the positive control KW-6002. The vertical line represents the intensity degree of catalepsy, and the abscissa represents the dose of each compound.
[0043] FIG. 5 shows the results of the analysis of the action, in 6-OHDA-induced unilaterally substantia nigra lesioned rats, of the formula (4) compound shown in the synthesis examples, or the positive control KW-6002, administered singly or in combination with L-DOPA. The horizontal line represents the time after the administration of the test compound (min), and the vertical line represents the mean rotation count per 15 minutes in the rats.
[0044] FIG. 6 shows the results of the analysis of the action, in 6-OHDA-induced unilaterally substantia nigra lesioned rats, of the formula (4) compound shown in the synthesis examples, or the positive control KW-6002, administered singly or in combination with L-DOPA.
[0045] FIG. 7 shows the results of the analysis of the action, in 6-OHDA-induced unilaterally substantia nigra lesioned rats, of the formula (10) compound shown in the synthesis examples, or the positive control KW-6002, administered singly or in combination with L-DOPA. The horizontal line represents the time after the administration of the test compound (min), and the vertical line represents the mean rotation count per 15 minutes in the rats.
DESCRIPTION OF EMBODIMENTS
(1) Compound of the Present Invention
[0046] The compound of the present invention is a 2-alkynyl-N 9 -propargyladenine represented by the following formula (I):
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein R 1 represents halogen, a furyl group or a triazolyl group; R 2 and R 3 each represent hydrogen or an alkyl group having 1 to 8 carbon atoms, or R 2 and R 3 represent a cycloalkyl group in which R 2 and R 3 are linked together; and X represents hydrogen or a hydroxyl group.
[0047] In the formula, R 1 represents halogen, a furyl group or a triazolyl group. Examples of halogen can include chloro, bromo, or iodo, and examples of furyl groups can include 2-furyl or 3-furyl. Examples of triazolyl groups can include 1-triazolyl or 2-triazolyl.
[0048] R 2 and R 3 each represent hydrogen or an alkyl group having 1 to 8 carbon atoms, or R 2 and R 3 represent a cycloalkyl group in which R 2 and R 3 are linked together. The alkyl group having 1 to 8 carbon atoms is a straight or branched chain alkyl group having 1 to 8 carbon atoms, and specifically, examples of the alkyl group can include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, heptyl, or octyl. The cycloalkyl group in which R 2 and R 3 are linked together is a cyclic alkyl group having 3 to 10 carbon atoms, and specifically, examples of such cycloalkyl group can include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or adamantyl.
[0049] Of the compounds of the present invention, a preferred compound is one which satisfies one or more of the following conditions:
[0050] (a) R 1 is bromo or chloro;
[0051] (b) R 1 is 2-furyl or 2-triazolyl;
[0052] (c) R 2 is hydrogen and R 3 is an alkyl group having 1 to 8 carbon atoms; and
[0053] (d) R 2 and R 3 are a cycloalkyl group in which R 2 and R 3 are linked together.
[0054] Examples of a more preferred compound can include a compound which satisfies the above (a) and (c), a compound which satisfies (a) and (d), a compound which satisfies (b) and (c), or a compound which satisfies (b) and (d).
[0055] Specifically, examples of such preferred compound can include 8-bromo-2-alkynyl-N 9 -propargyladenine, such as 8-bromo-2-(1-octyn-1-yl)-N 9 -propargyladenine, which satisfies the above (a) and (c), and in which X is hydrogen;
[0056] 8-chloro-2-alkynyl-N 9 -propargyladenine, such as 8-chloro-2-(1-octyn-1-yl)-N 9 -propargyladenine, which also satisfies the above (a) and (c), and in which X is hydrogen;
[0057] 8-bromo-2-[2-(1-hydroxycycloalkyl)-1-ethyn-1-yl]-N 9 -propargyladenine, such as 8-bromo-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine, which satisfies the above (a) and (d), and in which X is a hydroxyl group;
[0058] 8-chloro-2-[2-(1-hydroxycycloalkyl)-1-ethyn-1-yl]-N 9 -propargyladenine, such as 8-chloro-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine, which also satisfies the above (a) and (d), and in which X is a hydroxyl group;
[0059] 8-(2-furyl)-2-alkynyl-N 9 -propargyladenine, such as 8-(2-furyl)-2-(1-octyn-1-yl)-N 9 -propargyl-adenine, which satisfies the above (b) and (c), and in which X is hydrogen;
[0060] 8-(2-triazolyl)-2-alkynyl-N 9 -propargyladenine, such as 8-(2-triazolyl)-2-(1-octyn-1-yl)-N 9 -propargyl-adenine, which also satisfies the above (b) and (c), and in which X is hydrogen; or
[0061] 8-(2-furyl)-2-(1-hydroxycycloalkyl)ethynyl-N 9 -propargyladenine, such as 8-(2-furyl)-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine, which satisfies the above (b) and (d), and in which X is a hydroxyl group.
[0062] The compound of the present invention may be in the form of a pharmaceutically acceptable salt, or in the form of a hydrate or a solvate. Examples of such salts include any pharmaceutically acceptable salts such as hydrochloride, sulfate, or phosphate, or organic acid salts such as citric acid.
[0063] Examples of the hydrates or solvates can include one in which 0.1 to 3.0 molecules of water or a solvent are attached to 1 molecule of the compound of the present invention or a salt thereof. In addition, various types of isomers such as tautomers can also be included in the compound of the present invention.
(2) Production Method of the Compound of the Present Invention
[0064] The compound of the present invention can be synthesized, for example, via two steps described below.
[0000]
[0065] In the formula, R 1 to R 3 and X mean the same as those aforementioned.
Step 1:
[0066] Step 1 is a step of deribosylating a 2-alkynyladenosine derivative (formula a compound), which is used as a raw material compound, by a hydrolysis reaction to obtain a 2-alkynyladenine derivative (formula b compound).
[0067] The raw material compound, formula a compound can be prepared based on the method of a publicly-known literature (J. Med. Chem., 1992, 35, 2253) or the like.
[0068] The hydrolysis reaction can be performed by incubation in an aqueous solvent such as water or dioxane, using an acid such as hydrochloric acid or sulfuric acid, under acidic condition, at 50 to 120° C. for approximately 1 to 10 hours.
Step 2:
[0069] Step 2 is a step of treating the above 2-alkynyladenine derivative (formula b compound) with a propargyl halide such as propargyl bromide to synthesize a 2-alkynyl-N 9 -propargyladenine derivative (formula c compound) having a propargyl group at position N 9 , and then performing halogenation at position 8 to obtain the compound of the present invention.
[0070] The reaction of the formula b compound with a propargyl halide can be performed by carrying out the reaction in a single or mixed solvent such as dimethylformamide or dimethylsulfoxide, in the presence of a base such as potassium carbonate or sodium carbonate, using 1 to 3 moles of the propargyl halide with respect to 1 mole of the formula b compound, at 10 to 50° C. for approximately 1 to 10 hours.
[0071] The halogenation reaction at position 8 in the formula c compound can be performed by carrying out the reaction using a halogenating agent such as chlorine, bromine, iodine, or N-halogenosuccinimides such as N-bromosuccinimide, in a single or mixed solvent such as dimethylformamide or dimethylsulfoxide, in the presence of a base such as potassium acetate, using approximately 1 to 3 moles of the halogenating agent with respect to 1 mole of the formula c compound, at 10 to 50° C. for approximately 1 to 10 hours.
[0072] The furylation reaction at position 8 in the formula c compound can be performed by carrying out the reaction using 1 to 3 moles of a furylboronic acid derivative such as 2-furylboronic acid as a furylating agent with respect to 1 mole of the compound which has been subjected to the above halogenation at position 8, in the presence of a palladium catalyst and a base such as potassium carbonate, at 80° C. for approximately 1 to 10 hours.
[0073] The compound of the present invention thus obtained can be isolated and purified by appropriately combining methods routinely used for isolation and purification of nucleobases (for example, various types of chromatography such as adsorption or ion exchange chromatography, recrystallization methods, or the like).
(3) Pharmaceutical use of the Compound of the Present Invention
[0074] As shown in the Examples mentioned below, the compound of the present invention exerts an effect with a smaller dose, in addition, for a long time, as compared with previously reported adenosine A 2a receptor antagonists as a therapeutic agent for Parkinson's syndrome, and is extremely promising as an adenosine A 2a receptor antagonist, especially as a therapeutic agent for Parkinson's syndrome.
[0075] In addition, the combination of the compound of the present invention with L-DOPA, the efficacy of which has conventionally been known to be lowered by long-term administration, can be expected to provide a stronger improving effect on symptoms, and moreover, can be expected to control the lowering of the efficacy of L-DOPA by long-term use.
[0076] The compound of the present invention may be administered singly or in combination with one or more of other drugs used for the treatment of Parkinson's syndrome. The other drug used for the treatment of Parkinson's syndrome may be selected from those usually used. For example, such drugs can include L-DOPA, dopamine, dopaminergic agonists, monoamine oxidase B inhibitors (MAO-B), DOPA decarboxylase inhibitors (DCI), or catechol-O-methyltransferase (COMT) inhibitors.
[0077] The compound of the present invention can be administered as a pharmaceutical product, a supplement, an enteral nutrient, health food and beverages, or the like. In addition, upon administration, the compound of the present invention can be used as an active ingredient, in combination with pharmaceutical aids (such as diluents, binders, disintegrants, lubricants, flavoring agents, solubilizing aids, suspending agents, coatings), and made into various types of compositions such as tablets, capsules, granules, powders, syrups, injections, suppositories, creams, aerosols, or the like according to conventional methods.
[0078] In addition, the compound of the present invention may be made into a kit, together with another adenosine A 2a receptor antagonist, particularly one or more of other drugs used for the treatment of Parkinson's syndrome.
[0079] The administration or intake method is not particularly limited; however, oral administration is preferable. The dose or intake amount may be about 1 to 2000 mg/day, preferably about 10 to 1000 mg/day, although it varies depending on the age, body weight, and severity of symptoms of the subject, administration or intake method, or the like. In addition, in the case of administration in combination with another drug used for the treatment of Parkinson's syndrome such as L-DOPA, the doses of both drugs, the compound of the present invention and L-DOPA, may be about 1 to 2000 mg/day and approximately 10 to 1000 mg/day, respectively.
[0080] Additionally, the compound of the present invention may be mixed with a biodegradable sustained-release carrier and administered in the form of an implant. In addition, for the purpose of sustained-release of the active ingredient, the preparation can be formulated such that the active ingredient is made into a transdermal patch. For the production method of implants and transdermal patches, a well known method may be used.
EXAMPLES
[0081] Hereinafter, the present invention will be described specifically by referring to the Examples; however, the present invention is clearly not limited to these Examples.
Example 1
Synthesis of the Compound of the Present Invention
(A) Synthesis of the Formula (4) Compound and the Formula (5) Compound
[0082] As a compound of the present invention, 8-bromo-2-(1-octyn-1-yl)-N 9 -propargyladenine (formula (I): R 1 ═Br, R 2 ═H, R 3 ═C 6 H 13 , X ═H) (formula ( 4 ) compound)), and 8-(2-furyl)-2-(1-octyn-1-yl)-N 9 -propargyl-adenine (R 1 ═H, R 2 =2-furyl, R 3 ═C 6 H 13 , X═H) (formula (5 compound)) were synthesized according to the synthetic route represented by the following scheme.
[0000]
Step 1:
Synthesis of the formula (2) compound: 2-(1-octyn-1-yl)adenine
[0083] The formula (1) compound: 2-(1-octyn-1-yl)adenosine, which is a raw material compound, was synthesized according to the method of a reference literature (J. Med. Chem., 1992, 35, 2253). Then, 3.0 g (8.0 mmol) of 2-(1-octyn-1-yl)adenosine was added to 30 mL of dioxane, and 30 mL of 0.6 M HCl was further added thereto, and the mixture was stirred at 100° C. for 6 hours. After neutralization with 0.6 M NaOH, the precipitated crystals were collected by filtration and washed with methanol to give 1.79 g (92%) of the formula (2) compound: 2-(1-octyn-1-yl)adenine.
[0084] 1H-NMR(DMSO-d 6 ): δ 12.85(1H, brs), 8.11(1H, s), 7.20(2H, s), 2.39(2H, t, J=7.0 Hz), 1.56-1.27(8H, m), 0.88(3H, t, J=6.8 Hz)
Step 2-1:
Synthesis of the formula (4) compound: 8-bromo-2-(1-octyn-1-yl)-N 9 -propargyladenine
[0085] To a solution of 0.2 g (0.82 mmol) of the formula (2) compound synthesized: 2-(1-octyn-1-yl)adenine and 0.23 g (1.64 mmol) of potassium carbonate in 5 mL of DMF was added 0.12 mL (1.64 mmol)of propargyl bromide, and the mixture was stirred at room temperature for 6.5 hours. To the reaction solution was added water, and the mixture was extracted with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=1/7) to give 177 mg (77%) of the formula (3) compound of interest.
[0086] 1H-NMR(CDCl 3 ): δ 8.04(1H, s) 5.83(2H, brs), 4.98(2H, d, J=2.6 Hz), 2.53(1H, t, J=2.5 Hz), 2.45(2H, t, J=7.4 Hz), 1.69-1.63(2H, m), 1.48-1.35(2H, m), 1.34-1.24(4H, m), 0.89(3H, t, J=6.8 Hz)
[0087] To a solution of 0.5 g (1.78 mmol) of the formula (3) compound obtained: 2-(1-octyn-1-yl)-N 9 -propargyladenine and 39 mg (0.4 mmol) of potassium acetate in 5 mL of DMF was added 0.47 g (2.66 mmol) of N-bromosuccinimide, and the mixture was stirred at room temperature for 1 hour. To the reaction solution was added water, and the mixture was extracted with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=1/1) to give 334 mg (52%) of the formula (4) compound of interest.
[0088] 1H-NMR(DMSO-d 6 ): δ 7.56(2H, brs), 4.93(2H, d, J=2.3 Hz), 3.47(1H, t, J=2.4 Hz), 2.41(2H, t, J=9.4 Hz), 1.57-1.51(2H, m), 1.43-1.33(2H, m), 1.32-1.27(4H, m), 0.88(3H, t, J=6.8 Hz)
Step 2-2:
Synthesis of the formula (5) compound: 8-(2-furyl)-2-(1-octyn-1-yl)-N 9 -propargyl-adenine
[0089] A solution of 50 mg (0.14 mmol) of the above formula (4) compound: 8-bromo-2-(1-octyn-1-yl)-N 9 -propargyladenine, and 31 mg (0.28 mmol) of 2-furylboronic acid, 38 mg (0.27 mmol) of potassium carbonate, and 32 mg (0.028 mmol) of tetrakis triphenylphosphine palladium in 2 mL of water/3 mL of dioxane was stirred under argon atmosphere at 80° C. for 30 minutes, and then another 16 mg (0.014 mmol) of tetrakis triphenylphosphine palladium was added thereto, and the mixture was stirred for additional 1 hour. To the reaction solution was added water, and the mixture was extracted with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=3/2) to give 20 mg (41%) of the formula (5) compound of interest.
[0090] 1H-NMR(DMSO-d 6 ): δ 8.02(1H, s), 7.52(2H, brs), 7.25(1H, d, J=3.4 Hz), 6.79(1H, dd, J=1.1&2.8 Hz), 5.18(2H, d, J=1.8 Hz), 3.40(1H, s), 2.42(2H, t, J=7.0 Hz), 1.58-1.52(2H, m), 1.43-1.39(2H, m), 1.31-1.30(4H, m), 0.88(3H, t, J=6.5 Hz)
(B) Synthesis of the Formula (10) Compound
[0091] Furthermore, starting from the formula (6) compound, via the formula (9) compound, for the formula (10) compound of the present invention, 8-bromo-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine (formula (I): R 1 ═Br, R 2 ═R 3 ═C 6 H 11 , X═OH) (formula (10) compound)) was synthesized according to the synthetic route shown in the following scheme.
[0000]
Step 1:
[0092] The formula (6) compound: 6-chloro-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)purine, which is a raw material compound, was synthesized according to the method of a reference document (J. Med. Chem., 1992, 35, 2253), and to a solution of 1.38 g (2.58 mmol) of this compound in 16 mL of dioxane was added 8 mL of 28% ammonia water, and the mixture was stirred in a sealed tube at 70° C. for 22 hours. The reaction solution was concentrated, and then ethanol was added thereto to perform azeotroping. The residue was crudely purified by silica gel column chromatography (hexane/ethyl acetate=6/1) to give the formula (7) compound: 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]adenosine. To this compound was added 10 mL of dioxane and 10 mL of 0.6 M hydrochloric acid, and the mixture was stirred at 100° C. for 5.5 hours. After cooling, the reaction solution was neutralized with a 0.4 M sodium hydroxide aqueous solution, and after concentration of this solution, the precipitated crystals were collected by filtration, and washed with water and methanol to give 263 mg (39%) of the formula (8) compound: 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]adenine.
[0093] 1H-NMR(DMSO-d 6 ): δ 13.19-12.39(1H, br), 8.13(1H, brs), 7.23(2H, brs), 5.49(1H, s), 1.91-1.24(10H, m)
Step 2:
[0094] Then, to a solution of 261 mg (1.01 mmol) of the formula (8) compound synthesized: 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]adenine and 280 mg (2.02 mmol) of potassium carbonate in 30 mL of DMF was added 0.15 mL (2.02 mmol) of propargyl bromide, and the mixture was stirred for 3 hours. The reaction solution was concentrated, the crystals were filtered off, and the filtrate was concentrated. The residue was purified by silica gel column chromatography (chloroform/methanol=9/1) to give 208 mg (69%) of the formula (9) compound of interest.
[0095] 1H-NMR(DMSO-d 6 ): δ 8.23(1H, s), 7.43(2H, brs), 5.54(1H, s), 5.02(2H, d, J=2.4 Hz), 3.48(1H, t, J=2.1 Hz), 1.85-1.29(10H, m)
[0096] To a solution of 0.16 g (0.54 mmol) of the formula (9) compound obtained: 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine in 5 mL of DMF was added 0.1 g (0.56 mmol) of N-bromosuccinimide, and the mixture was stirred for 1.5 hours. To the solution was added 1 mg (0.01 mmol) of potassium acetate, and the mixture was stirred for 2.5 hours, and then 3 mg (0.03 mmol) of potassium acetate was further added thereto, and the mixture was stirred for 2 hours. Subsequently, to the reaction solution was added 100 mg (0.56 mmol) of N-bromosuccinimide, and the mixture was stirred for 2 hours. To the reaction solution was added water, and the mixture was extracted with ethyl acetate, and the organic layer was washed with a saturated saline solution and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography (ethyl acetate only) to give 60 mg (30%) of the formula (10) compound of interest.
[0097] 1H-NMR(DMSO-d 6 ): δ 7.63(2H, brs), 5.59(1H, s), 4.95(2H, d, J=2.1 Hz), 3.49(1H, t, J=2.3 Hz), 1.85-1.26(10H, m)
(C) Synthesis of the Formula (11) Compound, the Formula (12) Compound, the Formula (13) Compound, and the Formula (14) Compound
[0098] In addition, synthesis of compounds of formulae (11) to (15) was also performed as follows.
[0000]
Synthesis of the formula (11) compound: 8-(2-furyl)-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine
[0099] The formula (10) compound synthesized by the aforementioned method: 8-bromo-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine (1.0 g, 2.7 mmol), and 2-furylboronic acid (598 mg, 5.3 mmol), tetrakis triphenylphosphine palladium (309 mg, 0.27 mmol), and potassium carbonate (738 mg, 5.3 mmol) were dissolved in dioxane (30 mL) and water (20 mL), and the mixture was stirred at 100° C. for 25 minutes. Chloroform and water were added thereto to perform partitioning, and the organic layer was dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (0 to 3% methanol-chloroform). The obtained compound was suspended in chloroform, and the solid was collected by filtration to give the formula (11) compound (155 mg, 0.43 mmol, 16%).
[0100] 1H-NMR(DMSO-d 6 ): δ 8.03(1H, d, J=1.7 Hz), 7.60(2H, brs), 7.27(1H, d, J=3.4 Hz), 6.80(1H, dd, J=1.7 Hz, 3.4 Hz), 5.58(1H, s), 5.21(2H, d, J=2.4 Hz), 3.42(1H, t, J=2.4 Hz), 1.86-1.23(10H, m)
[0101] ESI-MS: 362(M+H)+
Synthesis of the formula (12) compound: 8-chloro-2-(1-octynyl)-N 9 -propargyladenine
[0102] The formula (2) compound: 2-(1-octynyl)-N 9 -propargyladenine (281 mg, 1.00 mmol) was dissolved in dimethylformamide (10 mL), and N-chlorosuccinimide (267 mg, 2.0 mmol) and potassium acetate (29 mg, 0.30 mmol) was added thereto, and the mixture was stirred for 30 hours. A saturated sodium thiosulfate aqueous solution was added thereto to stop the reaction, and then the mixture was extracted with ethyl acetate, and the organic layer was dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was dissolved in chloroform and purified by silica gel column chromatography (hexane:ethyl acetate 3:1). The formula (12) compound was obtained (173 mg, 55%).
[0103] 1H-NMR(CDCl 3 ): 5.58(2H, brs), 4.98(2H, d, J=2.5 Hz), 2.46(2H, t, J=7.3 Hz), 2.36(1H, t, J=2.5 Hz), 1.69-1.25(8H, m), 0.89(3H, t, J=6.5 Hz)
[0104] ESI-MS: 316(M+H)+
Synthesis of the formula (13) compound: 8-chloro-2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine
[0105] The formula (9) compound: 2-[2-(1-hydroxycyclohexyl)-1-ethyn-1-yl]-N 9 -propargyladenine (200 mg, 0.67 mmol) was dissolved in dimethylformamide (7 mL), and N-chlorosuccinimide (180 mg, 1.3 mmol) and potassium acetate (20 mg, 0.20 mmol) was added thereto, and the mixture was stirred for 28.5 hours. A saturated sodium thiosulfate aqueous solution was added thereto to stop the reaction, and then the mixture was extracted with chloroform, and the organic layer was dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, the residue was suspended in chloroform, and the solid was collected by filtration to give the product of interest (49 mg, 0.15 mmol, 22%).
[0106] 1H-NMR(DMSO-d 6 ): 7.60(2H, brs), 5.55(1H, s), 4.98(2H, d, J=2.3 Hz), 3.48(1H, t, J=2.3 Hz), 1.85-1.25(10H, m)
[0107] ESI-MS: 352(M+Na)+
Synthesis of the formula (14) compound: 8-(1,2,3-triazol-2-yl)-2-(1-octynyl)-N 9 -propargyladenine
[0108] The formula (4) compound: 8-bromo-2-octynyl-N 9 -propargyladenine (500 mg, 1.4 mmol), 1,2,3-triazole (96 mg, 1.4 mmol), and potassium carbonate (192 mg, 1.4 mmol) was dissolved in DMF (5 mL), and the mixture was stirred at 100° C. for 1 hour. Chloroform and water was added thereto to perform partitioning, and the organic layer was dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane: ethyl acetate 3:1→1:1). The crude purified product obtained was re-purified by ODS column chromatography (acetonitrile-water 20%→50%) to give the formula (14) compound: 1,2,3-triazol-2-yl body (20 mg, 4%).
[0109] 1H-NMR(CDCl 3 ): 8.03(2H, s), 6.33(2H, brs), 5.47(2H, d, J=2.4 Hz), 2.48(2H, t, J=7.4 Hz), 2.16(1H, t, J=2.5 Hz), 1.69-1.30(8H, m), 0.90(3H, t, J=3.4 Hz)
[0110] ESI-MS: 349(M+H)+
Example 2
Evaluation of the Adenosine A 2a Receptor for Antagonist Activity of the Compound of the Present Invention by the Magnus Method
Evaluation Method:
[0111] In order to clarify the adenosine A 2a receptor antagonist activity of the compound of the present invention, an evaluation by the Magnus method was conducted. The Magnus method is a method of evaluating the action of drugs using muscle contraction/relaxation as an index, and is used generally as a method for determining the antagonist activity.
[0112] In the evaluation, firstly, the femoral vein was excised from male Wistar rats. A Krebs-Henseleit solution aerated with O 2 gas was filled in an organ bath and kept at 37° C., and the excised femoral vein was suspended therein under 0.5 g of resting tension. The contractile and relaxing response was determined via a pickup transducer.
[0113] In order to check the reactivity of the compound, firstly, the test compound was added dropwise in the organ bath. 10 minutes after the dropwise addition, serotonin was added dropwise in the organ bath such that the concentration thereof was 10 −5 M, to make the femoral vein contract. In a state where the contractile response was stable, 10 −7 M of an adenosine A 2a receptor agonist, 2-octynyladenosine was administered to induce the relaxing response, and the inhibitory effect of the compound of the present invention and a positive control on the relaxing response was evaluated. Note that, in the representation of the results, the degree of the contraction at the time of addition of each substance was calculated, on condition that the degree of the relaxation when the compound of the present invention and the positive control were not added dropwise at all was designated as a control for the whole, and the degree of the relaxation for the control for the whole was set to be 100%.
[0114] As a compound of the present invention, the formula (3) compound, the formula (4) compound, the formula (5) compound, the formula (9) compound, and the formula (10) compound, which were described in the synthesis examples, were used. Note that the formula (9) compound is a publicly-known compound which has already been described in Patent Literature 2. In addition, as a positive control, 8-[(E)-2-(3,4-dimethoxyphenyl)vinyl]-1,3-diethyl-7-methyl-3,7-dihydro-1H-purin-2,6-dione (KW-6002) described in Patent Literature 1, which is an adenosine A 2a receptor antagonist which has conventionally been deemed to have an effect on the treatment of Parkinson's syndrome, and the compound of the following formula (hereinafter referred to as “AT-compound”), which is shown in Patent Literature 3, compound No. 9 in [Table A], were used.
[0000]
Evaluation Results:
[0115] As shown in FIG. 1 , compared with KW-6002 or the AT-compound used as a positive control, the compound of the present invention has been shown to inhibit the relaxing action induced by A 2a receptor agonist YT-146 in a concentration-dependent manner, in addition, remarkably strongly, that is, to have an extremely potent activity as an adenosine A 2a receptor antagonist compared with the conventional compounds.
[0116] Of these, the formula (4) compound, the formula (5) compound, and the formula (10) compound exhibit a more potent activity even compared with the formula (3) compound and the formula (9) compound, and therefore it has been suggested that such compounds have bromo or furyl at position 8 and thereby have the adenosine A 2a receptor antagonist activity remarkably potentiated, and thus have a extremely potent antagonist activity.
Example 3
Evaluation of the Binding Affinity of the Compound of the Present Invention to Human Adenosine A 2a Receptor by Binding Assay
Evaluation Method:
[0117] In order to clarify the binding affinity of the compound of the present invention to a human adenosine A 2a receptor, a binding assay for the human receptor and the compound of the present invention was conducted. As a test substance, the formula (4) compound, which is one of the compounds which have been shown to have an adenosine A 2a receptor antagonist activity in the above Example 2, was used, and as a positive control, a publicly-known adenosine A 2a receptor agonist, 2-P-(2-carboxyethyl)phenethylamino-5′-N-ethylcarboxyamide adenosine hydrochloride (hereinafter referred to as “CGS21680 hydrochloride”) was used.
[0118] In addition, as other conditions for the assay, 50 mM Tris-HCl (pH7.4) containing 10 mM magnesium chloride, 1 mM EDTA and 2 unit/mL adenosine deaminase were used for a buffer, CGS21680 hydrochloride was used as a displacer, and CGS21680 hydrochloride [dipropyl-2,3-3H(N)] was used as a tracer. The protocol was according a publicly-known method (The Journal of Pharmacology and Experimental Therapeutics, Vol. 323, No. 2 708-719, or the like), and the reaction time was set at 90 minutes at 25° C. The assay was performed 3 times, and based on the results of the reaction, the Ki value of the compound of the present invention was calculated.
[0000]
TABLE 1
Compound name
Ki value
Standard error
Formula (4) compound
5.81 × 10 −10
4.01 × 10 −11
CGS21680 hydrochloride
2.71 × 10 −8
3.05 × 10 −9
Evaluation Results:
[0119] As shown in the above Table 1, the compound of the present invention has been found to exhibit a strong binding affinity to a human adenosine A 2a receptor.
[0120] In addition, Non-Patent Literature 2 shows the Ki value of the publicly-known compound described in Patent Literature 1, 8-[(E)-2-(3,4-dimethoxyphenyl)vinyl]-1,3-diethyl-7-methyl-3,7-dihydro-1H-purin-2,6-dione (KW-6002), for an adenosine A 2a receptor to be 9.12×10 −9 , and compared with the results of the above Table 1, it has been suggested that the compound of the present invention may have a higher binding affinity than that of KW-6002.
Example 4
Evaluation of the Therapeutic Effect of the Compound of the Present Invention on Haloperidol-Induced Catalepsy
Evaluation Method:
[0121] Haloperidol is known to block dopamine receptors. This method is used generally as a method of evaluating the therapeutic effect of the therapeutic agents for Parkinson's syndrome, by using the effect of inducing catalepsy (when being made to take a certain posture or position of the limbs extrinsically, continuing to keep the posture as it is without willing to change it by oneself) caused by administration of haloperidol.
[0122] The experiment was conducted by using 7 male ddY mice, 5-weeks old, per group. Haloperidol was suspended in 0.5% CMC, and then administered intraperitoneally to the mice at 1 mg/kg. In the study, as a test compound, the compounds each represented by the formula (4), the formula (5), the formula (10), the formula (11), the formula (12), the formula (13), or the formula (14) in the above synthesis examples were used, and as a positive control, KW-6002 (the test compound and KW-6002 were 0.03, 0.1, 0.3, 1, 3, 10 mg/kg) or L-DOPA (100 mg/kg)+benserazide (25 mg/kg) was used. The above 4 compounds were each suspended in 0.5% CMC, and orally administered to the mice 1 hour after the haloperidol administration. In addition, the case where only CMC was administered was designated as a control for the whole. After a lapse of 1, 3, 5, and 7 hours from the administration of the test compound, both forelimbs only, or both hindlimbs only, of a mouse were put in turn on an acrylic stand, height 4.5 cm, width 1.0 cm, and catalepsy was determined, and the state was scored as Table 2 below.
[0000]
TABLE 2
Score 0
For each case where the forelimbs and the hindlimbs are put on the stand, the
holding time of the posture in which the relevant limbs remain put on the
stand is less than 5 seconds.
Score 1
The posture in which the forelimbs remain put on the stand is kept for 5
seconds or more, but less than 10 seconds, and for the hindlimbs the holding
time is less than 5 seconds.
Score 2
The posture in which the forelimbs remain put on the stand is kept for 10
seconds or more, and for the hindlimbs the holding time is less than 5
seconds.
Score 3
(1) Both for the forelimbs and the hindlimbs, the holding time of the posture
in which the relevant limbs remain put on the stand is 5 seconds or more, but
less than 10 seconds, or (2) the holding time of the posture in which the
forelimbs remain put on the stand is less than 5 seconds, and for the hindlimbs
the holding time is 5 seconds or more.
Score 4
(1) The posture in which the forelimbs remain put on the stand is kept for 10
seconds or more, and for the hindlimbs the holding time is 5 seconds or more,
but less than 10 seconds, or (2) the posture in which the forelimbs remain put
on the stand is kept for 5 seconds or more, but less than 10 seconds, and for
the hindlimbs the holding time is 10 seconds or more.
Score 5
Both for the forelimbs and the hindlimbs, the holding time of the posture in
which the relevant limbs remain put on the stand is 10 seconds or more.
Evaluation Results:
[0123] As shown in FIG. 2 , the formula (4) compound and the formula (10) compound in the present invention kept the score of catalepsy low, with a smaller dose than that of KW-6002 used as a positive control, in addition, for a long time, that is, had an effect of improving from lowering the motor function in haloperidol-induced catalepsy. Thus, the compound of the present invention can be considered to be, as a therapeutic agent for Parkinson's syndrome, a compound more promising than KW-6002.
[0124] In addition, as shown in FIG. 3 , when the formula (5) compound was administered, the catalepsy score was also kept low compared with that of L-DOPA or the formula (4) compound, and accordingly it has been suggested that this compound is promising as a therapeutic agent for Parkinson's syndrome as well.
[0125] Furthermore, as shown in FIG. 4 , the formulae (11), (12), (13), and (14) compounds also exhibit an effect for a long time, with a smaller dose than that of the positive control KW-6002, and thus it has been suggested that these compounds are also promising as a therapeutic agent for Parkinson's disease.
Example 5
The Analysis of the Action of the Compound of the Present Invention in 6-OHDA-Induced Unilaterally Substantia Nigra Lesioned Rats
[0126] 6-Hydroxydopamine (6-OHDA) is taken into neurons by dopamine reuptake transporters and acts as a neurotoxin, and is used for the selective denaturation and removal of dopaminergic neurons. This 6-OHDA was locally administered to the corpus striatum to induce the cell death of dopaminergic nerve and reduce dopamine, and thereby induce the symptoms of Parkinson's syndrome. In the study, 6-OHDA was injected into the right ventral tegmental area of male SD rats, 8-weeks old, and after 4 weeks, apomorphine (5 mg/kg, s.c.) was administered, and the animals which had shown a certain count of the counterclockwise rotation were selected. Using the model rats, the evaluation of the test compound as a therapeutic agent for Parkinson's syndrome was commenced.
(1) Preparation Method of A Unilaterally Substantia Nigra Lesioned Rat
[0127] Male SD rats, 8-weeks old, were anesthetized with pentobarbital (50 mg/kg), and the hairs were removed broadly from the occiput through the back of the neck, and then an ear bar was attached thereto, and the rats were fixed in a brain stereotaxic apparatus. The skin of the head was incised 3 to 4 cm with a scalpel, the periosteum was stripped off to expose the skull and the suture was checked. After the coordinate measurement, a hole was made in the skull with an electric drill, and a microinjection cannula was inserted 5.0 mm beneath the brain surface. 6-OHDA was dissolved in a 0.02% ascorbic acid saline solution so as to be 3.5 mg/ml, and the solution was administered at 4 points in the brain at 2 μl/2 minutes. After the administration, the rat was left for 1 minute, and a similar operation was performed for the 4 points. After the completion of the administration, an antibiotic was applied and the incised part was sutured. 4 weeks after the 6-OHDA administration, apomorphine (5 mg/kg, s.c.) was administered, and the count of the counterclockwise rotation for 5 minutes was counted from 5 minutes after the administration. The individuals which made 7 rotations or more for 1 minute were selected as a unilaterally substantia nigra lesioned rat, and used for the evaluation thereafter.
(2) Method of the Behavior Observation
[0128] As a test compound, the formula (4) compound and the formula (10) compound in the synthesis examples were used, and as a positive control, KW-6002 was used. These test compounds were orally administered to the unilaterally substantia nigra lesioned rats, singly or in combination with L-DOPA. Immediately after the administration, the rats were placed in the center of an observation box (70 cm×70 cm×30 cm), and the behavior observation was performed by using a video tracking system (Muromachi Kikai Co., Ltd.), setting 15 minutes as 1 session, for a total of 5 hours (20 sessions), and thus the count of the contralateral rotation was counted. Note that when the test compound has an effect as a therapeutic agent for Parkinson's syndrome, the count of the contralateral rotation will increase.
(3) Results
[0129] As shown in FIGS. 5 to 7 , compared with the case where KW-6002, used a positive control, was administered singly, the formula (4) compound and the formula (10) compound of the present invention have been found to exhibit an effect which is stronger and continuously increase the count of the contralateral rotation, and have a strong effect as a therapeutic agent for Parkinson's syndrome. Moreover, the administration of the compound of the present invention in combination with L-DOPA further increased the count of the contralateral rotation, and accordingly the combination has proved to have a therapeutic effect on Parkinson's syndrome.
[0130] From the results shown in the above, compared with KW-6002 or the AT-compound, which has conventionally been expected as a therapeutic agent for Parkinson's syndrome, the compound of the present invention has been found to exhibit a remarkable effect, with a smaller amount, on the improvement of Parkinson's syndrome, and furthermore be able to maintain the effect for a long time.
Example 6
Photostability Study on the Compound of the Present Invention
[0131] Of the compounds of the present invention, the formula (4) compound, the formula (10) compound, and the formula (11) compound were evaluated for their photostability in solid state.
[0132] The study was conducted in accordance with “Guideline for the Photostability Testing of New Drug Substances and Products.” That is, each compound in solid state was placed under a fluorescent light statically for 3 weeks, and the residual ratio was calculated from the HPLC analysis results before and after the placement. As a result, the residual ratio for the formula (4) compound, the formula (10) compound and the formula (11) compound was 99.0%, 98.8%, and 100.2%, respectively, and accordingly all of the compounds were found to have sufficient photostability.
INDUSTRIAL APPLICABILITY
[0133] The compound of the present invention has high chemical stability, especially high photostability, and compared with previously reported therapeutic agents for Parkinson's syndrome as an adenosine A 2a receptor antagonist, the compound of the present invention exerts an effect with a smaller dose, in addition, for a long time, and is extremely useful as a therapeutic agent for Parkinson's syndrome. Moreover, the combination of the compound of the present invention with L-DOPA, the efficacy of which has conventionally been known to be lowered by long-term administration, can be expected to provide a stronger improving effect on symptoms, and moreover, can be expected to control the lowering of the efficacy of L-DOPA by long-term use. | In the present invention, a novel 2-alkynyl-N9-propargyladenine represented by formula (I)
wherein R 1 represents a halogen atom, a furyl group, or a triazolyl group; R 2 and R 3 each represents a hydrogen atom or a C1-8 alkyl group, or form a cycloalkyl group by bonding to each other; and X represents a hydrogen atom or a hydroxyl group, or a pharmaceutically acceptable salt thereof, has a stronger and longer-lasting effect as a therapeutic agent for Parkinsonian syndromes. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to air vehicles, and more particularly to ornithopters which are those air vehicles that utilize flapping wings to sustain flight. There are basically two main categories of ornithopters; those that have mechanical power sources, and those that wholly sustain flight by human effort alone. The present invention is of the former type employing a small engine, pump, hydraulic circuitry, hydraulic cylinders, and electronics.
2. Description of the Relevant Art
Ornithopter air vehicles have been proposed since the earliest of times. They have been described in Greek fables and histories of air flight. However, unresolved problems have hindered practical development. Those without a power source that depend wholly on human physical effort to sustain flight have not been designed to give the flyer respite to go any distance or achieve any height. Dropping of such a vehicle from another aircraft assures a longer stay in the air, but in that case the aircraft becomes more a glider than an ornithopter. A difficult problem is designing the wing movement in such a manner that the flyer encounters no shock moves, while assuring the flyer complete control of the wing operation.
Previous attempted powered ornithopters have problems with weight and control, as well as with takeoffs and landings. The present invention has solved these problems.
The relevant art is discussed hereinbelow.
U.S. Pat. No. 3,498,574, issued to Ernst in 1970, relates to a fluttering wing aerial propelled apparatus suitable for carrying a man. The Ernst vehicle is operated by the pilot by manipulating a handle which opens and closes parts of a cylinder-piston unit, causing the wing to move in the direction desired by the pilot. The wing exactly follows or copies the movements of the pilot. The wing working force is supplied by fluid under pressure while the pilot works the control. Two cylinder-piston units are employed, one for each wing. The tail is moved physically by the pilot's feet.
The present invention, on the other hand, employs only one cylinder-piston for both wings, and utilizes only the retraction stroke to pull the wings downwardly. The wings are raised by a spring-like device. Also, the tail is operated by a separate double-acting fluid cylinder, which moves the tail up and down, as controlled by the pilot.
U.S. Pat. No. 544,816, issued to Lilienthal in 1895, discloses one of the earliest attempts to design an ornithopter. The vehicle was raised into the air by the flyer running into the wind, and after the vehicle was airborne it was balanced and steered by the flyer by means of a suitable movement of his body so as to displace the center of gravity.
U.S. Pat. No. 2,218,599, issued to Brunner in 1940, discloses a propulsion means for ornithopters.
U.S. Pat. No. 2,407,777, issued to Grawunder in 1946, relates to a glider having two pairs of wings which are actuated by the pilot to control the elevation of the glider as it moves through the air.
U.S. Pat. No. 2,578,845, issued to Schmidt in 1951, discloses an aircraft propelled by beating wings, having two distinct motions comprising the "beat" made by a power-driven reciprocator, and the "swing" motion made by the resistance of the air against the eccentrically-held wing blade. The "swing" motion is at right angles to the "beat" motion. The present invention differs from the Schmidt invention in many aspects. However, one main difference is in the employment of fluid cylinders. The present invention utilizes the retraction stroke of only one cylinder, while the Schmidt invention utilizes a plurality of cylinders.
U.S. Pat. No. 2,783,955, issued to FitzPatrick in 1957, relates to a craft which is suitable for travel in the air, on land, and on and under the water. It is a very complex vehicle designed to perform many functions. In contrast, the present invention is designed only to fly like a bird and is designed as simply as possible to perform this function using only the retraction stroke of only a single piston to achieve the desired movement of the wings.
U.S. Pat. No. 2,859,553, issued to Spencer in 1958, discloses a toy aircraft of the ornithopter or flapping wing type powered by a rubber band which is wound up by crank. When the crank is released, it causes the wing spars to move up and down.
U.S. Pat. No. 3,446,458, issued to Rogallo in 1969, relates to control devices for altering the membrane configuration of a flexible wing aircraft.
U.S. Pat. No. 3,817,478, issued to McDonald in 1974, relates to vehicles for gliding flight, and in particular to an air vehicle adapted for aerial flight to include a pair of hand-operated wings and a foot-operated tail.
The main feature, among others, which sets the present invention apart from any of the above patents or any known ornithopters is the design which actuates both wings simultaneously with only one hydraulic cylinder, and only with the employment of the retraction stroke of that single cylinder.
SUMMARY OF THE INVENTION
The present invention discloses an ornithopter whose purpose is not to replace existing forms of aircraft, but rather to provide an exciting sporting means at relatively low cost, easy transportability, and to be as safe as possible.
The vehicle consists of the main features of all aircraft having a pair of wings, a fuselage, a horizontal tail and an inverted "V" type rudder. It is powered by a small engine, and for purposes of illustration only a motorcycle engine has been employed.
The wings are of special design utilizing features of bird and bat wings which take advantage of aerodynamics principles that provide for more efficient flight. The covering of the vehicle called the sail consists of four parts: the right wing sail, the left wing sail, the center fuselage, and the tail surface sail. The fuselage and wing sails are joined together by zippers for ease of assembly and disassembly. The zippers are located in low stress areas, and do not carry any appreciable load. The sail material, described more fully hereinbelow, is of an excellent aerodynamic quality. The method of attachment and bonding, also described more fully hereinbelow, assures excellent holding qualities and safety.
The engine is connected to a hydraulic pump which drives via hydraulic circuitry a single hydraulic cylinder that utilizes the retraction stroke only to power both wings downwardly. This produces a lift and thrust on the wings similar to that which would be produced by a bird. The wings are brought back to their normal up position by elastic springs which explains one reason why only the retraction stroke is needed to operate the wings. The hydraulic cylinder rod is connected to a forked cable, which through cam-type pulleys retracts both wings downwardly simultaneously. Along with the elastic springs, there are also nylon ropes. These ropes also have some flexibility; however, they function primarily as bump stops to prevent the wings from traveling beyond the intended design limit.
The vehicle has two rear legs or supports which also function as rudders and a shock absorbing front support. The length of these supports is such as to permit the wings to be stroked through their full power stroke. This enables the vehicle to become airborne without any forward rolling motion. Similarly, landing is achieved by gliding into the wind, flaring up to present the maximum sail area to the wind, then reducing altitude until the rear legs contact the ground. The wings are then stroked downwardly to further decelerate the motion of the vehicle, allowing it to settle down on the shock absorbing front support. The rear legs also have attached to them sails which provide the steering surfaces.
The pilot is provided with two sets of controls: the regular motorcycle controls which are located on the motorcycle handlebars and used for controlling the engine speed and hydraulic pump output, and the flight controls which are located on the flight control panel.
The flight control panel, which also serves as the steering or rudder control, houses the electrical components such as the ignition key, switches, and relays as well as the two hand controlled 4-way hydraulic valves required for manually controlling the horizontal tail and manually controlling the position and stroking of the wings.
A primary object of the present invention is to provide a propulsion means having flapping wings which may be operated to closely simulate the operation of the wings of birds.
Another primary object of the present invention is to provide a means of powering both wings simultaneously by the retraction stroke of one hydraulic cylinder.
A still further object of the present invention is to provide a novel type of construction and mechanism to retract the wings.
Yet another object of present invention is to provide pilot control of the operation of the wings and tail as well as automatic control of the wings.
Yet another object of the present invention is to provide a novel type of construction whereby the steering of the vehicle is under the control of the pilot.
Yet another object of the present invention is to provide rear legs and a front support which will permit vertical takeoffs and landings from or onto any type of terrain, and a mechanism to absorb the shock of landing.
Yet another object of the present invention is to provide a novel type of wing construction hereinafter more specifically explained.
Yet another object of the present invention is to provide means of quick disassembly and assembly for easy transportability.
Yet another object of the present invention is to provide rugged and simple construction which will result in low maintenance and repair.
Other objects of this invention will in part be obvious and in part hereinafter pointed out.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the ornithopter constructed in accordance with a first possible embodiment of the invention.
FIG. 2 is a front elevational view of the ornithopter of FIG. 1.
FIG. 3 is a side elevational view taken from the left side of FIG. 2.
FIG. 4 is an enlarged partial plan view of FIG. 1 showing the four parts of the covering of the ornithopter which comprise the sail.
FIG. 5 is a front elevational view of FIG. 4 showing the sail in an aerodynamically-loaded condition.
FIG. 6 is a section showing the method of attachment of the sail to the wing tip tube.
FIG. 7 is a section showing the method of attachment of the sail to the mid portion of the wing.
FIG. 8 is a section showing the method of attachment of the zippers to the sail.
FIG. 9 is a perspective view of the horizontal tail, its construction, and the attachment to the main keel tube.
FIG. 10a is a perspective view of the rear legs along with steering stabilizing surfaces.
FIG. 10b is a perspective view of the flight control panel and the method of attachment to the main keel tube.
FIG. 11 is a partial plan view of the structure of the ornithopter without the sails.
FIG. 12 is a front elevational view of FIG. 11 without the sails.
FIG. 13 is a right side elevational view of FIG. 11, also without the sails.
FIG. 14 is a left side elevational view of a portion of FIG. 11 showing an enlargement of the pilot area.
FIG. 15 is a perspective view of the hydraulic transmission and the wing controls.
FIG. 16 is a front elevational view of the left inboard wing structure.
FIG. 17 is a front elevational view of the left outboard wing structure.
FIG. 18 is a section through the pivot pin of the wing.
FIG. 19 is the electrical schematic for the operation of the ornithopter.
FIG. 20 is the hydraulic schematic for the operation of the ornithopter.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Before explaining the invention in detail, it is to be understood that the present invention is not limited in its application to the details of construction and shape of the embodiments illustrated in the accompanying drawings because the invention is capable of other embodiments and of being practiced and carried out in various ways and with various materials. Furthermore, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and illustration only, and not for the purpose of limitation.
Referring now to the drawings, it is to be understood that like reference numerals designate identical or corresponding parts throughout the several figures.
The ornithopter specifically illustrated in FIGS. 1, 2 and 3 is comprised basically of the fuselage 1, the right wing 3, left wing 4, and the tail 2. FIG. 4 shows the covering of the vehicle called the sail, which is composed also of four parts: the right wing sail 5, the left wing sail 6, the fuselage sail 7, and the tail sail 8. The wing sails 5 and 6 are joined to the center fuselage sail 7 by means of zippers 21. The use of zippers 21 enable the vehicle to be disassembled for shipping and transportation purposes. The zippers 21 are placed in low stress areas and are not under any appreciable load capacity.
FIGS. 5, 6, 7 and 8 show the manner in which the sails are attached to the various structures. FIG. 5 shows the sails in an aerodynamically-loaded condition as they would appear in flight. FIG. 6 shows a section through the wing tip area with the right tip tube 17 holding the latex rubber member 18 which in turn is attached to the "Temperkote" material 19 by means of "LOCTITE" superglue 20. "Temperkote" is a sail material composed of dacron and mylar. The mylar acts as an air barrier, not allowing the air to penetrate, and serves as a good aerodynamic surface. By punching holes in the "Temperkote" material 19, the latex rubber member 18 is bonded to itself as well as to the "Temperkote" material 19 and gives a type of riveting effect that is stronger than merely bonding to the "Temperkote" material. The sail material is flexibly mounted to the wing structure thereby minimizing stress concentrations. The flexibility is provided by the latex rubber member 18, giving and taking, dependent upon the pressures exerted on the sail material.
FIG. 7 shows one possible preferred method of attachment of the sail to the wing keel tube 11 and the wing keel tube 12. The wing keel tubes 11 and 12 run parallel to the center line of the vehicle, that is to the main keel tube 13, and are located midway down the wings 3 and 4. The "Temperkote" sail material 19 is bonded to the latex rubber member 18, which in turn is trapped around the wing keel tube 11. Another latex rubber member 18' is bonded to the "Temperkote" material 19 above the connection for additional strength and to provide the means for riveting discussed hereinabove.
FIG. 8 shows the method of attachment of the sails to the structure through the zipper area. The "Temperkote" material 19 is glued to the latex rubber member 18 as described above. The latex rubber member 18 is wrapped around steel cables 22, which also form the wing leading edge support and which in turn are attached to the wing structure. The zipper 21 is glued to another latex rubber member 18". The zipper utilized is a "Delrin" which is a jacket type chain with double sliders.
FIG. 9 delineates the horizontal tail structure 2. The main structural members are the tail main tube 23 and crossmember 29 which are assembled to the main keel tube 13 by means of the tail plate 229. At both ends of crossmember 29, there are provided fiber glass rods 27 which form a V-tail structure on both sides of the tail. The sail surface is held onto these rods 27 by means of rubber straps 26. The main portion of the sail is held onto the tail main tube 23 by means of the rubber tube 24 which slips over tail main tube 23 and runs substantially its entire length.
At the front of the tail there is provided a flare rod crossmember 31 which is welded into the main keel tube 13. This crossmember 31 provides a means of holding the tail flare rods 28 in place, which in turn, by means of chords 230, supply the tension required to keep the flare in the tail surface. The horizontal tail is actuated by the double-acting hydraulic cylinder 33, pivotally mounted to the saddle 34, whose control is discussed hereinbelow.
FIGS. 10a and 10b illustrate a schematic presentation of the inverted "V" tail rudder, its control, and construction. The flight control panel 43 is supported by the flight control rod 79 axially mounted into bellcrank 46 which is pivotally mounted in support bracket 82 and support bracket 231 with cap 232. Support brackets 82 and 231 are bolted onto the main keel tube 13 support plate 233. The bellcrank 46 is connected to the rear tail bellcranks 30 by means of rudder control cables 42 whereas the rear tail bellcranks are connected to each other through the elastic spring control cable 36.
Steering is accomplished by rotating the flight control panel 43 about its support center line which in turn produces a rotation of the rear tail bellcranks 30 which house rear leg supports 38 and 39 to which the tail surfaces 37 and 47 are mounted by means of crossmembers 48 and 49 respectively, nylon cables 40, and rubber tabs 41. The greater portion of the rudder sail areas are located to the rear of the support leg center lines in order to provide static directional stability in flight.
Rear legs 38 and 39 with bellcranks 30 are pivotally mounted into saddle 34 which is mounted to the main keel tube 13 by means of saddle cap 234.
The flight control panel 43 houses, except for the limit switches, the electrical flight controls shown in FIG. 19 and the two hand actuated 4-way hydraulic valves 168 and 167 controlled by handles 44 and 45 respectively. The horizontal tail is controlled by handle 44 and manual control of the wings is accomplished with handle 45.
FIG. 11 illustrates an unsailed presentation of a partial plan view of the vehicle. The sail has been removed to display more clearly the vehicle structure. At the top of the drawing is shown the front wing crossmember 60 attached to the main keel tube 13. This crossmember 60 supports the leading edge of the wing sails. Further down the drawing there is shown further details of the wing structure. The inboard wing spar 56 attaches to the wing support channels 97 which attaches to the main keel tube 13, and in turn the outboard wing tube 57 freely mounts into the inboard wing spar 56. The wing keel tube 11 and the king post 9 cooperate with guy wires 59 to provide a means of bracing outboard wing tube 57 and adjustment of the angle of attack of the wing tip tube 17. Lastly, the location of the transmission unit 61 is shown.
FIG. 12 again illustrates the vehicle structure from the front elevation with the sails removed. Hereagain is shown the structure of the wing, the inboard wing spar 56, the outboard wing tube 57, the wing tip tube 17, the wing keel tube 11, and the guy wires 59.
FIG. 13 depicts the structure of the vehicle from the right side elevation without the sails. It shows more clearly the positioning of the transmission unit 61. Also shown is the pilot support and power unit 65 which is supported by the tension rod 68 and the drag rod 67. Handlebars 66 are also shown.
FIG. 14 illustrates a left side elevation view. There is depicted the makeup of the front support 14. To the foot 72 there are welded the guide tubes 71 which guide in the main support tubes 84. The shocks caused by landing are absorbed by two springs 73, rather than by the main support tubes 84. The front support tube 74 supports the motorcycle frame 85.
At the upper front portion of the motorcycle frame 85 is the gooseneck 70 which provide means of supporting the handlebar 66 as well as attachment for the tension rod 68 and the drag rod 67. The gooseneck 70 contains an inner spacer 76 which may preferably, but not necessarily, be made of wood. The motorcycle handlebar 66 is held to the gooseneck 70 by means of a special bolt 77 and wing nut 78. It is the wing nut 78 to which the tension rod 68 and the drag rod 67 are attached.
The main support tubes 84 are hinge mounted to the wing support channels 97 by means of brackets 235. To the wing support channels 97 there are attached the sail supports 80 which preferably, but not necessarily, are plywood members, the function of which is to raise the sails over the wing area to provide clearance for the various mechanisms, especially the mechanism to retract the wings which is described hereinbelow.
FIG. 15 illustrates a perspective view of the hydraulic transmission and the wing controls. First, a more detailed explanation of the wing structure is shown and described. The inboard wing spar 56 is made up of the leading edge spar 105 having a hat section and a trailing edge spar 104 having a hat section held together by the U-channels 103 which are bonded to the spars by "LOCKTITE" superglue 20 and reinforced by huckbolts.
The frame tubes 307 provide the necessary support structure for connecting the wing power cylinder 89 to the idler pulley support channels 308 and 309 with pins 310 and pins 88. The idler pulleys 93 are supported to the idler support channels 308 and 309 by means of pivot pins 315 which construction is similar to that shown in FIG. 18. The idler support channels 308 and 309 are attached to the wing support channels 97 by means of brackets 311 and 312. The wing support channels 97 are in turn braced by members 313 and 314. The wing support channels 97 provide a means of retaining the wings and means of attachment to the main keel tube 13 which will be described in FIG. 16.
The wing power cylinder 89 which employs only the retraction stroke to power both wings synchronously, is connected to the wings by means of the main power cable 102 which is yoked to the cylinder rod end 92. Rod end 92 is cammed to actuate the limit switches 201 and 202 (FIG. 19) for the automatic stroking of cylinder 89. The main power cable 102 comprising a forked configuration is guided to each wing around its respective idler pulley 93 and then to and around its respective flexor pulley 94, the attachment to which will be described hereinbelow. The back end of the wing power cylinder 89 terminates into cylinder cap rear 87 which in turn provides a means of attaching to frame tubes 307 with pins 88. The manifold cylinder cap front 90 provides communicating oil passages to the cylinder with and also means of mounting the accumulator 101, the pilot-operated solenoid-controlled 4-way valve 86, and the reservoir with standpipe 91. The standpipe allows the gases to accumulate at the highest point of the system in order to be vented to the atmosphere.
Near the top of FIG. 15 there are shown the wing support channels 97 which hold the wings together in position. Also, above the top of the wing flexor pulleys 94 there are shown the retracting support rods 98. Around the retracting support rods 98 there are mounted a plurality of elastic springs 100 for retracting the wings to their upper position. These elastic springs 100 are preferably, but not necessarily, made of latex tubing. Along with the elastic springs 100 there are two belts of nylon rope 99 closest to the flexor pulley 94. These ropes 99 also give some flexibility, but they also function as bump stops to prevent the wings from overtraveling beyond the design limit.
FIG. 16 illustrates the left inboard wing structure and its attachment to the main body. The wing is pivotally mounted in the wing support channels 97. Channel 97 is attached to the main keel tube 13 by means of the bracket 123 and the cap 122. The bracket 123 in turn is huckbolted to the wing support channels 97. A wing indexing hole 125 is provided through the wing support channels 97 and wing flexor pulley 94, the purpose of which is to enable the positioning of the wings through the proper adjustment of cable terminal 110. Hereagain, there is shown the main power cable 102 in position with regard to the flexor pulley 94. The power cable terminates with cable terminal 110 at its end to provide adjustment by means of the terminal block 112 mounted to the wing flexor pulley 94 and terminal retainer 121.
The method of attachment of the inboard wing spar 56 to the flexor pulley 94 is also shown. Bolts 320 are used to attach the outer flanges with the spar and transmit the aerodynamic couple loads into the flexor pulley 94 while bolts 321 are used to transmit the vertical shear load into the flexor pulley 94 and also for the attachment of rigging tang 111.
FIG. 17 depicts the attachment of the outboard wing tube 57 to the inboard wing spar 56 and the method of bracing thereof to produce a lightweight truss configuration. The wrist bracket 115 provides a means of retaining the outboard wing tube 57, the king post 10, and wing tip tube 17 which fits in socket 116 and slot 323. The inboard wing spar 56 terminates in the bracket 128 which provides a socket hole 117 to accept the outboard wing tube 57 and also provides the means for retaining the wing keel tube 11.
Cable assemblies 59, consisting of a turnbuckle assembly 127 at one end and a rigging tang 111 or 119 at the other end which are attached to the cable using thimbles 322 and nico sleeves 126 swagged into position, cooperate with the king post 10 and keel tube 11 to retain the outboard wing tube 57 in socket 117 and provide means of indexing the wing tip tube 17 by the rotation of tube 57 in its socket hole 117. The rigging tangs 119 are bolted to the king post 10 and keel tube 11 by means of bushing 118. It is by this method that the angle of attack of the wing tip tube 17 can be adjusted to produce the desired propeller force and lift for flight.
FIG. 18 depicts a section through the wing pivot 95, which is also illustrated in FIGS. 15 and 16. In the center of the section there is shown the wing flexor pulley 94 which has been discussed previously hereinabove. At the top of the section there is also illustrated the retracting support rod 98 which has also been discussed previously. The spacer tangs 132 are provided to give the necessary space for attachment which is equal to or the same width as the U-channel 103 to form the box beam. Wear plates 135 are bonded to the main frame members 97 to provide a wear surface for bushings 140. The pivot pin 138 is provided with the special thrust washers 137 which ensure that only the spacer axle tube 139 is loaded by nuts 136. The spacer axle tube 139 provides the seating for the bushings 140. The bushings 140 are mounted into the pulley hub 141 which is, in turn, welded to the wing flexor pulley 94.
FIG. 19 illustrates the electrical schematic that is employed to automatically stroke the wing power cylinder 89. The two limit switches 201 and 202 provide automatic reciprocation when either the right or left pushbutton switch 203 or 204 is depressed. The cam 205 moves with the cylinder motion and actuates the limit switches 201 and 202 at either end of its travel. The limit switches 201 and 202 are double-pole units with one normally-open and one normally-closed contact. Pushing the down pushbutton switch 204 energizes the solenoid 206 and relay 207 to move the cylinder 89 with the cam 92 to the left. At the end of travel, the limit switch 202 is actuated, de-energizing the solenoid 206 and energizing the solenoid 208 and the relay 209. Each relay locks in when it is actuated so that it remains energized thereby preventing actuation of the alternate solenoid. This prevents both solenoids 206 and 208 from being energized at the same time, should a pushbutton switch be accidentally pressed. Pressing the stop switch 210 de-energizes the system.
FIG. 20 illustrates the hydraulic schematic of the vehicle. First, there is shown the pressurized reservoir 91. The oil from the reservoir 91 goes through a filter 162 to a gear pump 83 which is driven by the motorcycle engine 75. The oil then is directed to the unloading valve 166 and the accumulator 101. The unloading valve 166 unloads the pump 83 once the desired pressure in the accumulator 101 is reached, and then allows the pump 83 to work under lower pressures without unnecessarily creating heat. When the system is turned off, it is desirable to have all the components unloaded, such as the accumulator 101. To accomplish this, a hand-actuated valve 160 is provided.
To the right side of the FIG. 20 schematic there is shown a directional control, pilot-operated, solenoid-controlled 4-way valve 86. However, the valve 86 is modified into a 3-way 3-position valve by blocking one port and converting the double-acting hydraulic cylinder 89 into a single-acting device where fluid pressure is used only during the retraction stroke of the cylinder. The cylinder 89 is returned to the extended position by the elastic springs 100 (FIG. 15). Flow control valves 220 and 221 are used to regulate the speed of the cylinder which in turn governs the wing tip velocities.
In the same circuit there is provided a means for manually controlling the positioning and/or stroking of the wings. Valve 167, which is a hand-operated 3-position 4-way valve modified similarly to the automatic valve 86 described hereinabove into a 3-way 3-position valve, is used for this purpose.
The hand-operated 3-position 4-way valve 168 is used to control the double-acting tail cylinder 33 which controls the horizontal tail surface. Again, flow control valves 222 and 223 are provided for adjustment of the speed of operation.
It is clear from the foregoing description that the various objects set forth hereinabove are efficiently attained by the present invention. Because various changes and modifications may be made therein without departing from the spirit and scope of the invention, it is intended that the foregoing description including the accompanying drawings should be interpreted as illustrative and not restrictive. The scope of the invention is indicated by the appended claims, rather than by the foregoing description. | An ornithopter which is propelled upwardly and forwardly by means of flapping wings, similar to the flight of a bird or bat. The power is supplied by a small engine that is mechanically-connected to a hydraulic pump which drives a single hydraulic cylinder and utilizes only the retraction stroke to power both wings simultaneously downwardly. The wings are brought back to the normal position by an elastic device, which in addition will not permit the wings to go beyond optimum positions. A double-acting hydralic cylinder is also provided to move the horizontal tail in an up and down motion. The operation of the wings can be automatic or manually-operated by the pilot. The rear legs and front support are constructed in such a manner that allows the ornithopter to rise and land vertically which permits takeoff and landing from most any type of terrain. The ornithopter can be assembled and disassembled quickly. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/926,815, filed on Jul. 2, 2007. The disclosure of the above application is incorporated herein by reference in its entirety.
FIELD
The present disclosure relates to particulate matter filters, and more particularly, to methods and systems for detection of and protection against thermal conditions.
BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Vehicles may include exhaust after-treatment devices such as particulate matter (PM) filters and catalysts to reduce emissions. In a diesel engine, the PM filter may be referred to as a diesel particulate filter (DPF). Engine control systems may fail to accurately diagnose when there is excessive thermal energy in the exhaust. In some circumstances, excessive thermal energy may damage components of the vehicle.
SUMMARY
A control module comprises a thermal detection module and a protection module. The thermal detection module receives temperature data of a particulate matter filter and determines a temperature based on the temperature data. The protection module selectively reduces output of an engine when the temperature is greater than a temperature threshold.
In other features, the reducing output includes limiting torque of the engine to a predetermined threshold. The reducing output includes limiting power of the engine to a predetermined threshold. The reducing output includes shutting down the engine. The temperature data includes temperature data from an inlet and an outlet of the particulate matter filter. The control module further comprises a protection enable module that generates an enable signal based on at least one of fuel delivery rate, engine speed, ambient temperature, and vehicle speed. The protection module reduces the output when the enable signal is received and the temperature is greater than a temperature threshold.
In further features, the protection enable module generates the enable signal when at least one of the fuel delivery rate, engine speed, ambient temperature, and vehicle speed is outside of a range established by respective lower limits and upper limits. The protection module selectively reduces the output of the engine when the temperature is greater than the temperature threshold and a confirmation condition is present. The confirmation condition is based on at least one of an engine misfire signal, a leaky fuel injector signal, and a pressure signal.
In still other features, the pressure signal is based on a pressure differential between an outlet and an inlet of the particulate matter filter. The thermal detection module evaluates the temperature data and disables the protection module from reducing the output of the engine when the temperature data is determined not to be reliable. The thermal detection module evaluates the temperature data by comparing a rate of change of a component of the temperature data to a predetermined threshold.
A method comprises receiving temperature data of a particulate matter filter and selectively reducing output of an engine when a temperature based on the temperature data is greater than a temperature threshold. In other features, the reducing output includes limiting torque of the engine to a predetermined threshold. The reducing output includes limiting power of the engine to a predetermined threshold. The reducing output includes shutting down the engine.
In other features, the temperature data includes temperature data from an inlet and an outlet of the particulate matter filter. The method further comprises generating an enable signal based on at least one of fuel delivery rate, engine speed, ambient temperature, and vehicle speed. The reducing is performed when the enable signal is received and the temperature is greater than a temperature threshold.
In further features, the method further comprises generating the enable signal when at least one of the fuel delivery rate, engine speed, ambient temperature, and vehicle speed is outside of a range established by respective lower limits and upper limits. The reducing is performed when the temperature is greater than the temperature threshold and a confirmation condition is present. The confirmation condition is based on at least one of an engine misfire signal, a leaky fuel injector signal, and a pressure signal.
In still other features, the pressure signal is based on a pressure differential between an outlet and an inlet of the particulate matter filter. The method further comprises evaluating the temperature data for reliability by comparing a rate of change of a component of the temperature data to a predetermined threshold; and disabling the reducing when the temperature data is determined not to be reliable.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a functional block diagram of an exemplary vehicle according to the principles of the present disclosure;
FIG. 2 is a functional block diagram of an exemplary control module according to the principles of the present disclosure; and
FIG. 3 is a flowchart illustrating the operation of control logic for thermal detection and protection of hardware according to the principles of the present disclosure.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Particulate matter (PM) filters remove particulate matter from engine exhaust. Over time, the particulate matter builds up. This build-up can be removed by burning it in a process called regeneration. Regeneration may be initiated in a variety of ways, such as by heating the PM filter with an electrical heater or combusting a richer air/fuel mixture in the engine.
The heat created in regeneration is intense, and if too much heat is generated, the PM filter may be damaged. In extreme cases, the PM filter may melt and/or break apart, which may cause damage to other components of the exhaust system and the vehicle. In order to prevent over-heating, a control module according to the principles of the present disclosure monitors the PM filter. For example, monitored parameters may include inlet and exhaust temperatures of the PM filter, pressure differentials between inlet and exhaust, airflow rate through the PM filter, etc.
During regeneration, if the PM filter appears to be getting too hot, the regeneration mode may be stopped. For example, this may include leaning out the air/fuel mixture and/or removing power from the heater. If the PM filter remains too hot, or increases in temperature, the control module may request remedial action. Remedial action may include warnings to the driver and automated steps such as torque limiting, power limiting, or fuel limiting the engine. In extreme cases, the control module may power the engine down completely.
When the PM filter is not in regeneration mode, the PM filter should not be operating at the high temperatures expected in regeneration, and the temperature at which remedial action is initiated may be decreased. High PM filter temperatures may be explained by various conditions, including leaky fuel injectors and engine misfires. These conditions may be used to confirm the accuracy of high measured PM temperatures before remedial action is initiated.
In addition to being confirmed by such conditions as leaky fuel injectors and/or engine misfires, temperature data may be checked for rationality. This helps to prevent remedial action from being erroneously initiated based on faulty temperature data. Temperature problems in the PM filter may be determined based on, for example, inlet temperature, outlet temperature, a combination of the two, and historical data of the temperatures. For example, high rates of temperature change may be indicative of a problem. In addition, a large pressure or temperature differential between the inlet and the outlet may indicate a problem.
Referring now to FIG. 1 , an exemplary diesel engine system 10 is schematically illustrated in accordance with the present disclosure. The diesel engine system 10 is merely exemplary in nature. The PM filter system described herein can be implemented in various engine systems implementing a PM filter. Such engine systems may include, but are not limited to, gasoline direct injection engine systems and homogeneous charge compression ignition engine systems. For ease of the discussion, the disclosure will be discussed in the context of a diesel engine system.
The diesel engine system 10 includes an engine 12 that combusts an air/fuel mixture to produce drive torque. Air enters the system by passing through an air filter 14 , and may be drawn into a turbocharger 18 . While a turbo-charged diesel engine 12 is shown, supercharged or naturally aspirated engines may also be used. The turbocharger 18 compresses the fresh air entering the diesel engine system 10 . Generally, the greater the compression of the air, the greater the output of the engine 12 . The compressed air charge then passes through an air cooler 20 before entering into an intake manifold 22 .
Air within the intake manifold 22 is distributed into cylinders 26 . Although four cylinders 26 are illustrated, the systems and methods of the present disclosure can be implemented in engines having a plurality of cylinders including, but not limited to, 2, 3, 4, 5, 6, 8, 10, and 12 cylinders. It should also be appreciated that the systems and methods of the present disclosure can be implemented in a “V”-type cylinder configuration. Fuel may be injected into the cylinders 26 by fuel injectors 28 . Heat from the compressed air charge being further compressed by a piston (not shown) ignites the air/fuel mixture. Combustion of the air/fuel mixture creates power to push the piston back down, which is translated to rotational energy of a crankshaft. Exhaust from combustion exits the cylinders 26 into the exhaust system.
The exhaust system may include an exhaust manifold 30 , a diesel oxidation catalyst (DOC) 32 , and a PM filter 34 , which may include a heater 35 . Optionally, an EGR valve (not shown) may re-circulate a portion of the exhaust back into the intake manifold 22 . The remainder of the exhaust may be directed into the turbocharger 18 to drive a turbine. The turbine provides the power to compress the fresh air received from the air filter 14 . Exhaust flows from the turbocharger 18 through the DOC 32 and into the PM filter 34 . The DOC 32 may oxidize the exhaust based on the post-combustion air/fuel ratio. The amount of oxidation may affect the temperature of the exhaust. The PM filter 34 may receive exhaust from the DOC 32 and filter particulate matter out of the exhaust.
The heater 35 may provide heat to the PM filter 34 to combust particulate matter that builds up over time in a process known as regeneration. While a heater is shown, other methods may be used to promote combustion of particulate matter within the PM filter 34 . For example only, changes to an air-to-fuel ratio and/or spark timing may be made by an engine control module 42 , which controls the engine 12 .
An exhaust system control module 44 may control the PM filter 34 based on various sensed information. More specifically, the exhaust system control module 44 may estimate loading of the PM filter 34 . When the estimated loading reaches a predetermined level and the exhaust flow rate is within a predetermined range, current may be provided to the heater 35 via a power source 46 to initiate the regeneration process. The duration of the regeneration process may be varied based upon the estimated amount of particulate matter within the PM filter 34 .
Current may be applied to the heater 35 during the regeneration process. More specifically, the electric energy may heat the heater 35 at selected portions of the inlet of the PM filter 34 for predetermined periods. Exhaust passing through the front face of the PM filter 34 may be heated. The regeneration process may be achieved using the heat generated by combustion of particulate matter present near the heated face of the PM filter 34 or by the heated exhaust passing through the PM filter 34 .
The PM filter 34 may include a PM filter inlet temperature sensor 56 , a PM filter outlet temperature sensor 57 , and/or a PM filter exterior temperature sensor 58 . The PM filter temperature sensors 56 , 57 , 58 may generate temperature signals that are received by the exhaust system control module 44 .
Referring now to FIG. 2 , an exemplary implementation of the exhaust system control module 44 includes a thermal detection module 80 , a protection enable module 82 , a temperature look-up table 84 , and a protection module 86 . The thermal detection module 80 may receive PM filter temperature values from the PM filter temperature sensors 56 , 57 , 58 .
The thermal detection module 80 may be in communication with the temperature look-up table 84 to determine whether the measured temperatures indicate an over-temperature condition and whether the measured values are rational. The temperature look-up table 84 may store temperatures at which an over-temperature condition may be detected as well as rationality conditions for the measured data.
For example, rationality conditions may include difference between the outlet and inlet temperatures or the rate of change in the measured temperatures over time. For example, temperature data may be determined to be rational if the difference is less than a predetermined threshold and the rate of change of each of the measured temperatures is below another predetermined threshold.
Based on temperature data from the thermal detection module 80 , the protection module 86 determines whether to initiate remedial action with a request to the engine control module 42 . The protection module 86 may evaluate one or more temperatures to see if they are above a threshold. For example, this threshold may vary based upon whether the exhaust system is currently in regeneration mode.
The protection module 86 may also evaluate temperature rationality data from the thermal detection module 80 . This helps to prevent unnecessary remedial action due to high detected temperatures that are a result of sensor error rather than actual high temperatures. The protection module 86 may receive an enable signal from the protection enable module 82 .
The protection enable module 82 may enable remedial action only when allowing remedial action would be safe for the vehicle and the driver. For example, if the ambient air temperature is above a threshold, such as 110° F., or below a second threshold, such as −20° F., the protection enable module 82 may disable remedial action. Alternatively, in these situations, the range of remedial action may be limited. For example, power limiting may be used, but powering down the engine completely may be disabled. Because of the extreme ambient air temperature, it is more important to keep the engine running for user comfort than to protect against a sensed over-temperature condition.
Other protection enable conditions may include vehicle speed, engine speed, and fuel delivery rate. The protection enable module 82 evaluates these and/or other inputs, such as by applying maximum and minimum limits. For example, if a vehicle speed is above a threshold, the protection enable module 82 may disable remedial action. Remedial action may remain disabled until the driver brings the vehicle to a stop.
The protection module 86 may also receive confirmation signals. For example, these may include engine misfire, leaky fuel injector, and pressure delta signals. The protection module 86 may use these signals to confirm that an over-temperature condition is occurring. This may prevent unnecessary remedial action based on misleading temperature data.
For example, a high pressure difference between the inlet of the PM filter 34 and the outlet of the PM filter 34 may occur when an over-temperature condition is occurring. The pressure differential may be measured by a single differential pressure sensor. A pressure differential threshold above which over-temperature conditions may be present may be determined based on a volume flow rate and a temperature. For example, the volume flow rate may be calculated based on mass air flow, while the temperature may be an average of the inlet and outlet temperatures of the PM filter 34 .
If engine misfire is detected or a fuel injector is leaking, extra unburned fuel may arrive at the PM filter 34 , thereby increasing the temperature of the PM filter 34 . In one scenario, the combustion initiated by regeneration may continue even once all the particulate matter is combusted because unburned fuel continues to arrive from the engine. This prolonged combustion may raise temperatures at the PM filter 34 .
In some modes, the protection module 86 may therefore initiate remedial action only when one or more of the confirmation signals is present. Alternatively, when one or more of the confirmation signals is present, the protection module 86 may lower the temperature threshold that defines an over-temperature condition. Which confirmation signals are used by the protection module 86 may be determined while the vehicle is running based on operating conditions and/or may be established by calibration.
Referring now to FIG. 3 , a flowchart depicts exemplary operation of the exhaust system control module 44 . Control begins in step 102 , where temperature is measured. For example, one or more of the inlet, outlet, and exterior temperatures of the PM filter 34 may be measured. A single temperature value may be generated, such as by averaging the inlet and outlet temperatures.
Control continues in step 104 , where control determines whether the temperature measurements are rational. If so, control transfers to step 106 ; otherwise, control returns to step 102 . Rationality of temperature measurements may be determined as described above with respect to the thermal detection module 80 . In step 106 , control determines a temperature threshold. For example, the temperature threshold may be reduced when the exhaust system is not in regeneration mode.
Control continues in step 108 , where control determines whether the measured temperature is greater than the temperature threshold. If so, control continues in step 110 ; otherwise, control returns to step 102 . In step 110 , control displays a warning to the driver. For example, this may include a check engine light, a text-based indicator, or an exhaust system warning light. In addition, a warning sound may be generated.
Control continues in step 112 , where control determines whether enable conditions are met. If so, control transfers to step 114 ; otherwise, control returns to step 102 . As described above, the enable conditions may include, for example, engine speed, vehicle speed, fuel delivery rate, and ambient air temperature. In step 114 , control may determine whether the over-temperature condition is confirmed by other data. If so, control transfers to step 116 ; otherwise, control returns to step 102 . Over-temperature conditions may be confirmed by, for example, engine misfire, leaky fuel injectors, and a pressure differential across the PM filter 34 .
In step 116 , remedial action is performed. For example, the engine control module 42 may be instructed to limit the torque produced by the engine. In various implementations, if the exhaust temperature does not decrease and/or if the derivative of the exhaust temperature does not decrease, more severe remedial action may be taken. For example, the engine's torque may be more severely limited or the engine may be shut down. Control then ends. In various implementations, control may return to step 102 once the exhaust temperature falls below a predetermined threshold. | A control module comprises a thermal detection module and a protection module. The thermal detection module receives temperature data of a particulate matter filter and determines a temperature based on the temperature data. The protection module selectively reduces output of an engine when the temperature is greater than a temperature threshold. A method comprises receiving temperature data of a particulate matter filter and selectively reducing output of an engine when a temperature based on the temperature data is greater than a temperature threshold. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to chemical heat pump system utilizing reversible decomposition-addition reaction. More particularly this invention relates to chemical heat pump system of improved efficiency.
2. Prior Art of the Invention
Recently, heat pump were watched with keen interest since they are useful to save energy because they can recover much energy from lower heat sources using small amounts of energy. In this case both mechanical energy and chemical energy can be used as said small amount of energy.
In a case of so called compression type heat pump using mechanical energy, not only is the so called coefficient of performance (C.O.P.) limited but also temperatures of lower heat source and temperatures of higher heat source (from which energy is recovered) are limited since there are limitations on safety or heat stability of the heating medium and on mechanical strength of the system.
On the other hand, in a chemical heat pump utilizing reversible endothermic and exothermic reactions, the temperature ranges of the lower heat source and the higher heat source in the chemical heat pump system can be broadened, by selecting the raction system.
For example, when a reversible reaction, (e.g. a secondary alcohol decomposing to a ketone and a hydrogen) is utilized, the temperature of the lower heat source is about 55° C.-80° C. and that of the higher heat source is about 160° C.-230° C. (e.g. "Arts for Heat Accumulation and Heat Increase" 117 pages, (1985), Chemical Engineering Symposium Series 8, Edited by Chemical Engineering Association). On the other hand when a reversible reaction between a benzene and a cyclohexane--dehydrogenation and addition of the hydrogen--is utilized, the temperature of the lower heat source can be more than 200° C. and the temperature of the higher heat source may to be from about 300° C. to about 400° C. (ibid., pg. 123).
Generally, a dehydrogenation reaction is an endothermic reaction and a hydrogenation reaction is an exothermic reaction. Therefore, by carring out these reactions in separate reaction vessels, each vessel becomes an exothermic reaction vessel or an endothermic reaction vessel. Namely, by circulating a reactant between the exothermic reaction vessel and endothermic reaction vessel, energy can be recovered through a heat exchanger provided between said exothermic reaction vessel and endothermic reaction vessel. Using this principle alone, however, the efficiency as heat pump system is insufficient. This is because the hydrogenation reaction is negligible when the temperature of the reaction vessel is to high--this fact is consistent with Le Chatelier's principle. Therefore, it is necessary to shift the equiribium by carring out the hydrogenation reaction under compression.
As a new method to solve the above mentioned problem, we have already disclosed a chemical heat pump system utilizing a mixed solution for the reaction system of the hydrogenation--dehydrogenation reversible reaction, in which a hydrogen absorbing alloy was dispersed to make slurry (Japanese Patent Application No. 47350/'85. This system is called "the conventional system" in this specification). However, this system has points to be improved since (1) the hydrogen absorbing alloy is very expensive, (2) a passage of the alloy through the system causes damage because the abrasive slurry is always circulated in the system and shortens the lifetime of the system, (3) the hydrogen absorbing alloy becomes to catalyst to lower the temperature of the higher heat source by lowering the reaction temperature of the exothermic reaction.
We completed this invention as a result of our earlier work concerning a system using no hydrogen absorbing alloy to solve the above mentioned defects. We found that the C.O.P. of the whole system can not be improved if the whole system is only compressed (this system is called vapor compression type in this specification) to carry out the exothermic reaction under a compressed condition. However, the C.O.P. of the whole system can become large if the liquid phase and the gas phase are separated from each other and then each phase is individually compressed.
SUMMARY OF THE INVENTION
Therefore, a first object of the present invention is to provide a simple chemical heat pump system having a large coefficient of performance.
The second object of the present invention is to provide the chemical heat pump system which not only realizes the large coefficient of performance but also realizes excellent durability.
The third object of the present invention is to provide a method to form a chemical heat pump system having a large coefficient of performance and excellent durability by combining known arts.
Above mentioned objects were accomplished by the chemical heat pump system characterized by using a reversible chemical reaction consisting of a decomposition reaction and an addition reaction wherein a gaseous product is formed by said decomposition reaction, and separating the mixture of the gaseous component and the liquid component circulating in the system into a separate gas phase and a separate liquid phase. Then each phase is separately introduced into the addition reaction vessel after separately compressing each phase.
According to the present invention, by separating the mixture into the gas phase and liquid phase, then feeding into the exothermic reaction vessel (addition reaction) after compressing each phase separately, the C.O.P. of the whole chemical heat pump system is remarkably improved.
The chemical heat pump system thus provided by this invention not only shows excellent thermal efficiency but also meets various requirements concerning temperatures of the lower heat source and the higher heat source by choice of the specific chemical reaction system utilized in the chemical heat pump system.
Moreover, in the system provided by the present invention no granular material circulate, therefore the abrasion resistance and durability of the system is excellent.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic drawing of the chemical heat pump of the present invention. In the drawing, symbol (1) is an endothermic reaction vessel, (5) is a separator to separate a mixture into a gas phase and a liquid phase, (7) is a tank to share materials of both the gas phase and liquid phase, (17) is a tank to save liquid material as well as its vapor, (3), (15) and (19) are heat exchangers, (9) and (11) are compressors, (13) is an expansion turbine and (20) is an exothermic reaction vessel.
FIG. 2 is a fundamental diagram explaining the a principle of chemical heat pump.
FIG. 3 is a schematic drawing of a vapor compression type chemical heat pump.
FIG. 4 is a graph showing the relation between temperature caused by an exothermic reaction and the C.O.P. In the drawing, curves shown by CHP-5 are obtained in a vapor compression type system and curves shown by CHPS-5M are obtained in the present invention.
FIG. 5 is a graph showing a relation between a temperature caused by the exothermic reaction and thermal efficiency.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The reversible decomposition reaction utilized in the present invention involves unimolecular decomposition reaction which produces a gaseous product. Such a decomposition reaction is an endothermic reaction if the products are to exist in safety. In the present invention, the endothermic reaction is carried out in the endothermic reaction vessel and it is necessary to use this reaction to pump the heat energy from the lower heat source.
Namely, the products of the decomposition reaction then should be regenerated to the initial reactant under certain reaction conditions. This regenerating reaction in the present invention is preferably an addition reaction in the gas phase. This addition reaction is generally the exothermic reaction. In the present invention, it is preferable if said addition reaction and the before mentioned decomposition reaction are reversible to each other and if no byproducts are produced which get away from the reversible reaction system.
Therefore, although there are many reaction systems in which the decomposition reaction and the addition reaction occur reversibly, the preferable reaction systems in the present invention are reversible hydrogenation--dehydrogenation reactions.
Some of these reaction systems are reactions utilizing aromatic compounds and cycloalkanes or secondary alcohols and ketones.
Concrete examples of the reaction system utilizing aromatic compound are as follows: ##STR1##
The reaction system utilizing secondary alcohols is expressed by the following equation. ##STR2##
Temperatures of the lower heat source and the higher heat source of the chemical heat pump system are determined by the absorbed heat quantity and the temperature of the exothermic reaction. Therefore, in the present invention, it is possible to select the reaction and catalyst, if necessary, corresponding to the temperature of the lower heat source and the desired temperature of the higher heat source.
In the above shown reaction, the gas phase mainly consists of the hydrogen but compounds other than the hydrogen form the liquid phase.
In this case, often the gas phase contains vapors of compounds circulating in the chemical heat pump system.
An outline of the principle of the chemical heat pump used in the present invention is herewith described. The example is the case when the benzene-cyclohexane system is utilized.
FIG. 2 shows the relation between an equilibrium composition, which has a parameter of pressure, and reaction temperature in the case of benzene-cyclohexane system. In FIG. 2, curve ○1 shows that when 10 times the quantity of the hydrogen (a quantity determined by stoichiometry against the benzene) is added, then carring out the gas phase reaction under the reduced pressure of 0.08 MPa (0.81 Kg/cm 2 ), wherein a composition in the reaction system is (benzene/(benzene+cyclohexane))=0.05 at 250° C., the endothermic dehydrogenation reaction of the cyclohexane takes place and the composition ratio becomes to 0.7.
Curve ○2 shows that when carrying out the gas phase reaction under a pressure of 2.0 MPa (20.89 Kg/cm 2 ), wherein said composition of the reaction system is 0.7, the exothermic hydrogenation reaction of benzene proceeds and the composition becomes 0.05.
Repeating the cycles of processes of ○1 and ○2 alternately it is possible to raise the temperature from 250° C. to 367° C. and recover this heat energy, but a compression work (in which the pressure increases from 0.08 MPa to 2.0 MPa) is necessary to realize the above cycle.
According to the drawings, the detail of the present invention will be described below using the benzene-cyclohexane system as an example.
FIG. 1 is a schematic drawing of the chemical heat pump system of the present invention.
In FIG. 1, symbol (1) means the endothermic reaction vessel which absorbs heat of Ql from outside of the system, as the next decomposition reaction proceeds. ##STR3##
On the other hand, symbol (20) is the exothermic reaction vessel in which the next addition reaction takes place. The heat of Qh generated in the exothermic reaction is there taken out of the system. ##STR4##
Namely, as is known, if setting up a fixed bed filled with a catalyst (which supports gas phase dehydrogenation catalyst on a carrier) in the endothermic reaction vessel and passing the cyclohexane through the fixed bed under a pressure of 0.009 MPa (0.09 Kg/cm 2 ) under a temperature of 250° C., the dehydrogenation reaction of the cyclohexane proceeds and, therefore benzene and hydrogen are produced.
It is possible to obtain a yield of 70% in this stage. In this endothermic reaction, the reaction system absorbs heat of Ql from outside of the system.
A mixture formed after the reaction arrives at the separator (5) after passing through the heat exchanger (3) and is there separated into the gas phase and the liquid phase, then saved in the tank (7). The gas phase existing in the tank (7) is compressed by the compressor (9) then introduced into the exothermic reaction vessel (20) after passing through the heat exchanger (19). On the other hand, the liquid phase existing in the tank (7) is compressed by the compressor (11) then is introduced into the tank (17) after passing through the heat exchanger (15). After that, the liquid phase is heated to vaporize it and this vapor flows together with above mentioned gas phase on a line which leads to the heat exchanger (19). The gas phase, containing the vapor, is fed into the exothermic reaction vessel after passing through the heat exchanger (19).
The high pressure gas fed into the exothermic reaction vessel 20 causes the exothermic reaction, namely the hydrogenation reaction of benzene progressing in the fixed catalyst bed, contained therein, for example, filled with a catalyst of Ni system then gives off heat energy of Qh. This reaction, for example, reaches to 90% completion when the reaction temperature is 367° C.
After the reaction, the gas mixture is fed back into the endothermic reaction vessel after the recovery of heat energy through the heat exchanger (19), (15) and (3) and after a reduction of pressure by the expansion turbine (13). In this case it is also possible to use a reducing valve instead of the expantion turbine.
In this cycle, the system not only absorbs heat value of Ql from the lower heat source existing outside of the system but also get both work load WC 1 to operate the compressor (9) and heat value of Qb to generate vapor pressure (which is at the same pressure as that of the compressed gas) by heating the liquid, then giving off the heat value of Qh to the outside of the system. It is possible to absorb Qb from the lower heat source from outside of the system as same as amount Ql. The amount of heat absorbed in this case depends on the amount of circulation, but it is from about 15% to about 20%. The work load of the compressor (11) is negligible in the present invention since the compressor (11) compresses only liquid and the amount of change of volume is quite small. From the expansion turbine, it is possible to recover the the power of WT 1 . This power WT 1 can be utilized for the work load WC 1 performed by the compressor (9).
If the vapor compression type system, which is shown in FIG. 3, is utilized, the mixture of the gas phase and the liquid phase should be compressed, therefore, this system is not preferable because of the following reasons; 1 Some of the vapor may be changed into the liquid by the compression, 2 The electric power consumption to move the compressor may become large, 3 the exothermic reaction may take place in the liquid phase.
Generally, the C.O.P. of the chemical heat pump system is expressed as; ##EQU1## therefore, the efficiency of the heat pump becomes larger when the input work load becomes smaller.
Namely, it can be understood that by separating a the material (which should be compressed) into the gas phase and the liquid phase, it is possible not only to make the reaction conditions favorable and to save electric power which is used for moving the compressor, but also to make the above mentioned C.O.P. larger--this is what takes place in the present invention. Therefore, it is easy to understand also that the system of the present invention can not only utilize the reversible reaction system of the benzene-cyclohexane but it can also utilize other reversible reaction systems which are accompanied with a generation and an extinction of a gaseous phase.
The best compression ratio should be selected in the present invention so that the C.O.P. should not be lowered, considering the conversion in the exothermic reaction, since the power to operate the compressor increases when the pressure in the exothermic reaction vessel increases.
In the present invention, the means to separate the mixture exiting the endothermic reaction vessel) into the gas phase and the liquid phase can be selected from the well known arts, Condensors are known to be preferable to use as the separator from a view point of the efficiency including an economical cost.
If the difference between a molecular weight of the gas components and that of the liquid components is large, a cheap porous glass and other known membrane means for separation of such materials are also useful as the separator means in the present invention.
EXAMPLES
The following examples are set forth for the purpose of illustration so that those skilled in the art may better understand this invention. They are exemplary only, and should not be construed as limiting the invention in any manner.
EXAMPLE 1
The following two systems are compared each other. One system is the chemical heat pump system of the present invention shown in FIG. 1. The other system is the vapor compression type system (shown in FIG. 3) which can be prepared by eliminating the separator (5), the tanks (7) and (17), the compressor (11), the heat exchangers (15) and (19) from the system of FIG. 1.
When the pressure in the exothermic reaction vessel (20) is 2.0 MPa and the temperature Tl of the lower heat source is 503 K., setting a ratio of H 2 /C 6 H 6 =1, the C.O.P. can be calculated using the amount of heat Qh (which is removed from the exothermic reaction vessel)--results are shown in FIG. 4. In the drawing, the curves expressed by CHPS-5 corresponds to the vapor compression system and the curves expressed by CHPS-5M corresponds to the system of the present invention, wherein πc is the assumed efficiency of the compressor.
It is clear from FIG. 4 that the C.O.P. in the case of the vapor compression type is less than 3 in all temperature ranges, but in the case of the present invention, the C.O.P. becomes larger than 3 at the range where the exothermic reaction temperature approaches 330° C. when πc=0.75 and at the range where the exothermic reaction temperature approaches 370° C. when πc=0.95. From these results, it is seen that the system of the present invention is quite excellent.
EXAMPLE 2
When utilizing the reaction system of hydrogenation--dehydrogenation between isopropyl alcohol and acetone, the vapor compression type system can not function within the chemical heat pump system, since the gaseous acetone changes into the liquid phase when the vapor of the system is compressed after the endothermic reaction. In this case, it was very difficult structurally to heat the gaseous acetone before it is compressed to prevent changing the acetone into the liquid phase. On the other hand the chemical heat pump system of the present invention was able to function using the same IPA-acetone reaction system.
Thus, it is illustrated that when the reaction system in which the gas phase is apt to change into the liquid phase upon compression, the method of the present invention is especially useful.
EXAMPLE 3
Using the conventional system utilizing LaNi 5 H 6 .O as the hydrogen absorbing alloy, the system was moved utilizing the same reaction system and realizing same reaction condition as example 1, then compared with the present invention of example 1.
Defining a thermal efficiency as πH=heat power/(the quantity of absorbed heat+the quantity of added work), FIG. 5 was obtained. FIG. 5 proves that the present invention is greatly superior to the conventional system from a view point of the thermal efficiency. | This invention discloses an improved chemical heat pump system utilizing a reversible decomposition reaction-addition reaction system, wherein a gaseous product is generated by said decomposition reaction. The present system can realize a large coefficient of performance (C.O.P) by introducing into the heat pump system, a separation stage (to separate the decomposition reaction mixture circulating in the system into a gas phase and liquid phase) and then compressing each gas phase and liquid phase separately. By choice of the chemical reaction system, the present system is able to meet various requirements concerning temperatures of the lower heat source and the higher heat source. The present system is superior to conventional systems in reducing attrition of the heat pump apparatus. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation in part of U.S. patent application Ser. No. 09/715,514, filed Nov. 17, 2000, and issued Jun. 10, 2003 as U.S. Pat. No. 6,576,226, which application and patent are incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to compositions and methods of treating periodontal disease and related disorders utilizing a sustained, controlled release targeted delivery method to effectively disrupt and inhibit bacterial biofilms at periodontal treatment sites.
BACKGROUND OF THE INVENTION
Periodontal diseases are a major affliction to mankind. Gingivitis, inflammation of gingival (gum) tissue, and periodontitis, inflammation and progressive loss of ligament and alveolar (socket) bone support to teeth, are caused by bacteria which colonize tooth surfaces and occupy the gingival crevice area. These are major periodontal disease afflictions worldwide. Bacterial plaque is the principal causative agent of these periodontal diseases.
Routine daily prevention or removal of plaque by the patient is a cornerstone of periodontal therapy. Toothbrushes, dental floss and various other oral hygiene instruments can be used. These devices require motor skill and dexterity. The daily routines for adequate plaque removal require the patient to be diligent, motivated, educated and skillful. Accordingly, such methods are effective only when used by motivated individuals and then often to a limited extent.
Optimal response of the immune system to defend against bacterial assault is often not realized in patients prone to periodontal disease and the immune response may actually contribute to the disease process.
Conventional periodontal therapy has emphasized mechanical removal of soft and hard accretions of bacteria (i.e., plaque and calculus) from the root surface via use of dental instruments placed into the gingival crevice to mechanically shear the accretions from the tooth structure. See S. Kakehashi and P. F. Parakkal, Proceedings from the State of Art Workshop on Surgical Therapy for Periodontitis , J. Periodontal 53:475 (1982). However, scaling and root planning is often only partially effective in the removal of these accretions. Moreover, the removal is transient and the bacteria re-colonize the root surface.
Adjunctive therapies have been suggested for the treatment of periodontal diseases. Systemic antibiotics have been used in the periodontal therapy. See R. J. Genco, Antibiotics in the Treatment of Human Periodontal Diseases , J. Periodontal 52:545 (1981). However, systemic delivery (e.g., oral or intramuscular) typically does not provide a sufficient concentration of antibiotic over an extended period of time to the gingival crevice area.
Applicant's U.S. Pat. No. 4,685,883 deals with controlled sustained release of chemotherapeutic agents in a bioerodable matrix in the periodontal pocket lesion via placement of the matrix in the periodontal pocket lesion with dental instruments. In one embodiment, the chemotherapeutic agents are incorporated into microspheres. These agents, although in sufficient concentration in the gingival crevice or periodontal pocket lesion, may not be able to adequately penetrate into the mass of the residual bacterial accretions on the tooth surfaces. Moreover, the bacterial accretions can rapidly reform.
Although specific bacteria are essential agents for many periodontal disease, their presence alone on the tooth surface and underneath the gingiva is not sufficient to explain the periodontal disease process. Rather, the host must react to this bacterial challenge if disease is to develop and progress. As with other bacterial infections, the host's immune system acts locally at the invasion site and attempts rapidly to neutralize, remove, or destroy the bacterial agents. In periodontal disease, however, chronic bacterial plaque accumulation causes an excessive and persistent antigenic stimulus. Therefore, the host response, rather than being protective and self-limiting, can be destructive. See R. C. Page, Periodontal Disease, p. 221, Lea and Febiger, Philadelphia, 1989.
Applicant's U.S. Pat. No. 5,939,047 deals with a controlled release topical delivery system to facilitate absorption and deposition of host immune system modulating agents into the gingival and oral mucosal tissues adjacent to the periodontium to dampen deleterious effects of host cell immune response to the periodontal bacteria challenge. If the bacterial challenge remains persistent, however, the host immune response can remain excessive and persistent.
Recent attention has been given to removing unwanted biofilms forming in various industrial processes. Biofilms are notoriously resistant to removal. The tendency of bacteria to adhere, secrete an adhesive extracellular matrix and grow is a strong evolutionary advantage difficult to overcome. So far, little success has been realized. Observation of living bacterial biofilms by modern methods has established that these microbial populations form a very complicated structural architecture. See, e.g., J.W. Costerton, et al., Microbial biofilms , Annu. Rev. Microbial, 49:711 (1995). This suggested the operation of a cell—cell signaling mechanism for bacteria to produce these complex structures. After twenty years of research, it is generally assumed now that all enteric bacteria and gram negative bacteria are capable of cell density regulation using acylated homoserine lactones (AHLs) as autoinducer molecules.
In early stages a biofilm is comprised of a cell layer attached to a surface. The cells grow and divide, forming a dense mat numerous layers thick. When sufficient numbers of bacteria are present (quorum) they signal each other to reorganize forming an array of pillars and irregular surface structures, all connected by convoluted channels that deliver food and remove waste. The biofilm produces a glycocalyx matrix shielding them from the environment. Urinary tract and urinary catheter infections are examples of biofilm infections.
As the biofilm matures, the bacteria become greatly more resistant to antibiotics than when in the planktonic (free cell) state. See H. Anwar, et al, Establishment of aging biofilms: a possible mechanism of bacterial resistance to antimicrobial therapy , Antimicrob Agents Chemother 36:1347 (1992). The host immune system is also significantly less effective against bacteria in the biofilm state. See E. T. Jensen, et al, Human polymorphonuclear leukocyte response to Pseudomonas aeruginosa biofilms , Infect Immun 5:2383 (1990). Certain bacterial strains may be able to confer resistance protecting the biofilm from host defense components that would otherwise bind to the surface of viable bacteria and kill them. See D. Grenier and M. Belanger, Protective effect of Porphyromonas gingivalis outer membrane vesicles against bactericidal activity of human serum , Infect Immun 59:3004 (1991). Yet the bacterial biofilm exudes lipopolysaccharide agitating the host inflammatory response which, in periodontitis, contributes to the tissue destruction.
For Gram-negative bacteria, the signal components in quorum sensing are autoinducers, acylated homoserine lactones (AHLs). These highly membrane-permeable compounds diffuse out of and into the cells and accumulate in localized environments, as the growing population of bacteria increases. At a threshold concentration the autoinducers trigger gene transcription in the localized population of bacteria, activating biochemical pathways and physiological functions appropriate for growth and survival of the bacteria in that environment. Agents which can inhibit AHLs would be beneficial in biofilm disruption or inhibition. See, e.g., S. Srinivasan, et al, Extracellular signal molecule ( s ) involved in the carbon starvation response of marine vibrio sp. strain S 14, J. Bacteriol 180:201 (1998).
Production of another novel signaling molecule is also regulated by changes in environmental conditions associated with a shift from a free-living existence to a colonizing or pathogenic existence in a host organism. This signal molecule is termed autoinducer-2. See, e.g., B. L. Bassler et al., U.S. Patent Application No. 20020107364.
Targeting specific bacteria for inhibition or exclusion from biofilm colonization would be beneficial in creating a more favorable bacterial ecology in the periodontal pocket. For example, gingipains are trypsin-like cysteine proteinases produced by Porphyromonas gingivalis , a major causative bacterium of adult periodontitis. Gingipains play a role in bacterial housekeeping and infection, including amino acid uptake from host proteins and fimbriae maturation.
The present invention solves these and other problems by optimal delivery of biofilm disruption and inhibition agents at localized periodontal treatment sites.
SUMMARY OF THE INVENTION
The present invention relates to the use of time release biodegradable microshapes for sustained, controlled, targeted delivery of agents to disrupt and inhibit the formation of biofilms at localized periodontal treatment sites. The method involves the insertion of biodegradable microshapes containing agents active against bacterial biofilms into the gingival crevice or periodontal pocket region.
In one embodiment of the present invention, biodegradable, time-release microspheres containing agents generally disruptive of bacterial biofilms are delivered by a syringe or other dental instrument. In another embodiment of the present invention, microspheres containing agents generally inhibitive of bacterial biofilms are delivered similarly.
In yet another embodiment of the present invention, biodegradable, time-release microspheres containing agents disruptive to specific bacteria within the biofilm are delivered by a syringe or dental instrument. In another embodiment of the present invention, microspheres containing agents which inhibit colonization of specific bacteria within the biofilms are similarly delivered.
In still another embodiment of the present invention, agents having other methods of action (antibiotics, host modulation agents, etc.) are delivered in microspheres along with agents in microspheres effective against the biofilm by syringe or dental instrument. These agents have synergy in their effectiveness with this embodiment of the present invention.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter in which there is illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, in which like reference numerals and letters indicate corresponding parts throughout the several views:
FIGS. 1A through 1C are diagrammatic views illustrating the human periodontal anatomy, including an illustration of the healthy human periodontium in FIG. 1A, an illustration of the effects of gingivitis in FIG. 1B, and an illustration of the effects of periodontitis in FIG. 1C;
FIG. 2 is a diagrammatic view of dental plaque biofilm on a tooth root surface; and
FIG. 3 is a partial diagrammatic view illustrating the placement into a periodontal pocket lesion, between the tooth and gingiva, of microencapsulated agent effective against the plaque biofilm.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a method for release of agents that disrupt or inhibit bacterial biofilms at localized sites in the mouth. The present method can include local delivery of bacterial biofilm inhibitor or disruptor agents to localized sites in the mouth for treatment of periodontal disease. The present method can employ inserting biodegradable microparticles containing the agents into the periodontal pocket, allowing the microparticles to degrade, and releasing the agents in a controlled, sustained manner. In an embodiment, the method includes inserting using a syringe apparatus or hand delivery device.
In an embodiment, the method employs agents that inhibit or disrupt the glycocalyx matrix of the bacterial biofilm. In an embodiment, the method employs agents that are antagonists of acylated homoserine lactones. In an embodiment, the method employs agents that are furanones or furanone derivatives. In an embodiment, the method employs agents that inhibit specific bacteria from inhabiting the bacterial biofilm. In an embodiment, the method employs agents that bind with or inhibit bacterial lipopolysaccharide. In an embodiment, the method employs agents that are histatin analogues.
In an embodiment, the method employs other chemotherapeutic agents also. These chemotherapeutic agents can be microencapsulated and combined with microencapsulated bacterial biofilm inhibitors or disruptors for insertion into the periodontal pocket. In an embodiment, the method employs chemotherapeutic agents selected from the group consisting of antibiotics, anti-inflammatory agents, and anticollagenolytic agents.
In an embodiment, the method employs biodegradable microparticles configured as microspheres between 10 and 700 microns in diameter.
Bacteria employ a cell—cell signaling mechanism for bacteria to produce biofilms. For example, it is generally believed that all enteric bacteria and gram negative bacteria are capable of cell density regulation using acylated homoserine lactones (AHLs) as autoinducer molecules. Agents which can inhibit AHLs would be beneficial in biofilm disruption or inhibition. In an embodiment, the method employs agents that are antagonists of acylated homoserine lactones. In an embodiment, the present method employs certain furanones as antagonists of AHLs. In an embodiment, the present method employs agents that inhibit autoinducer-2.
When sufficient numbers of bacteria are present (quorum) they signal each other to reorganize forming an array of pillars and irregular surface structures, all connected by convoluted channels that deliver food and remove waste. Such a biofilm includes a glycocalyx matrix shielding the microbes from the environment. In an embodiment, the method employs agents that inhibit or disrupt the glycocalyx matrix of the bacterial biofilm.
Lactoferrin is an iron-binding salivary protein that has been shown to reduce binding of cells in its iron-saturated form. In an embodiment, the method employs iron saturated lactoferrin to disrupt or inhibit biofilm.
Gingipains are bacterial proteinases with a functional role in infection and pathogenesis of periodontitis. Gingipain inhibitors can be agents for periodontal disease therapy. DX-9065a can inhibit gingipain. DX-9065a selectively reduces P. gingivalis growth, suggesting a potential therapeutic effect of gingipain inhibitors on periodontitis. In an embodiment, the present method employs an agent that is a gingipain inhibitor. In an embodiment, the present method employs DX-9065a to disrupt or inhibit biofilm.
Synthetic histatin analogues have shown potential for reduction of viable bacterial counts in the oral biofilm model. dhvar 4 shows action against Gram-negative bacteria. A possible explanation for this finding is that dhvar 4 binds to the negatively charged lipopolysaccharide (LPS) moiety, which is specific for Gram-negative bacteria. Certain Gram-negative bacteria are involved in the development of periodontal disease. The involvement of LPS in the initial binding of amphipathic basis antimicrobial peptides to the bacterial membrane has been reported. Furthermore, comparison of the amino acid sequence of dhvar 4 with bactericidal/permeability-increasing protein (BPI) revealed that the N-terminal 5 amino acids of dhvar 4 show strong homology with the LPS binding domain of BPI. See E. J. Helmerhorst, et al, The effects of histatin - derived basic antimicrobial peptides on oral biofilms , J. Dent Res 78: 1245 (1999).
In an embodiment, the method employs agents that are furanones or furanone derivatives.
Suitable furanones are disclosed in U.S. Pat. Nos. 6,337,347 and 6,455,031, the disclosures of which are incorporated by reference. Such furanones include compounds of Formula 1 or Formula 2:
In Formulas 1 or 2, R 1 -R 21 can independently be H, C 1 -C 4 alkyl group (preferably CH 3 ), OH, NH 2 , SH, or halogen (e.g., F, Cl, Br, or I); R 22 and R 23 can independently be H, S, O, and N (e.g., NR or NH), preferably S or O; R 24 -R 28 can independently be H or halogen; and X, X 1 , and X 2 can independently be O, S, H 2 , or any combination of H plus one halogen or two halogens when one or more R groups is substituted. The furanone can be an optically active isomer.
In an embodiment, the furanone has Formula 1. In an embodiment of Formula 1, at least one of R 1 -R 21 is halogen, or the alkylene chain of the molecule contains a sulfur in the chain.
In an embodiment of Formula 1, R 24 -R 28 are H or halogen, and R 22 -R 23 are H. In an embodiment of Formula 1, one or more carbons forming the backbone of the molecule are substituted with S or S-substituted moieties. In an embodiment of Formula 1, X 1 and/or X 2 is H 2 , H plus halogen, or two halogens. In an embodiment of Formula 1, R 22 is H, S, O or NH and R 23 is S, O, or N. In an embodiment of Formula 1, the alkylene side chain contains one or more double bonds or triple bonds between carbon atoms within the alkylene side chain. In an embodiment of Formula 1, X1-X2 is H2; H plus a halogen; two halogens; H plus OH or NH 2 ; or a double bonded O, NH, or S.
In an embodiment, the furanone has Formula 2. In an embodiment of Formula 2, at least one of R 1 -R 7 is halogen, or the alkylene chain of the molecule contains a sulfur in the chain. In an embodiment of Formula 2, R 22 is H, S, O or NH and R 23 is S, O, or N. In an embodiment of Formula 2, the alkylene side chain contains one or more double bonds or triple bonds between carbon atoms within the alkylene side chain. In an embodiment of Formula 2, X is H2; H plus a halogen; two halogens; H plus OH or NH2; or a double bonded O, NH, or S.
The furanones of Formulas 1 or 2 can also include the above structures with modifications such as: 1) Alteration of the acyl side chain by increasing or decreasing its length. 2) Alteration of the structure of the acyl side chain, such as addition of a double bond or a triple bond between carbon atoms within the acyl side chain. 3) Substitution on carbons in the acyl side chain, e.g., the addition of a methyl group or other group such as an oxo-group, a hydroxyl group, an amino group, a sulfur atom, a halogen or dihalogen or some other atom or R-group to any location along the acyl side chain. 4) Substitution of carbons comprising the backbone of the acyl side chain with S or S substituted moieties or with N or N substituted moieties. 5) Substitution on the homoserine lactone ring portion of the molecule. For example: addition of a sulfur group to produce a thiolactone. 6) Halogenated acyl furanones have been shown to act as blockers to homoserine lactone cognate receptor proteins. 7) Ring size of the acyl side chain varying heterocylic moiety is variable. For example, 4-membered and 6-membered rings containing nitrogen (i.e., beta and delta lactams) are included.
The furanones of Formulas 1 and 2 include compounds such as compounds 1-12:
Suitable furanones are disclosed in U.S. Pat. Nos. 6,060,046 and 6,555,356, the disclosures of which are incorporated by reference. Such furanones include compounds of Formula 3:
In Formula 3, R 1 , R 2 and R 3 can independently be hydrogen, hydroxyl, alkyl containing from 1 to 10 carbon atoms, ether containing from 1 to 10 carbon atoms, ester containing from 1 to 10 carbon atoms, or halogenated alkene containing from 1 to 10 carbon atoms; or R 2 and R 3 together can include an unsubstituted or halogenated alkene containing from 1 to 10 carbon atoms and R 4 can be hydrogen or halogen.
In an embodiment of Formula 3, R 1 is hydrogen, hydroxy or acetoxy; and R 2 and R 3 are independently single unsubstituted or halogenated methylene group. In an embodiment of Formula 3, R 1 is hydrogen, hydroxyl, ester, or ether; and R 2 and R 3 are each together unsubstituted or halogenated methylene group. In an embodiment of Formula 3, R 2 is hydrogen or bromine, R 3 is halogen, and R 4 is hydrogen or bromine. In an embodiment of Formula 3, R 1 is hydrogen, hydroxyl, an ester or an ether group, and R 4 is bromine. In an embodiment of Formula 3, R 1 is hydrogen, hydroxy or acetoxy. In an embodiment of Formula 3, R 3 is chlorine, bromine or iodine. In an embodiment of Formula 3, R 1 is an acetyl group. In an embodiment of Formula 3, R 1 is a hydroxy group and R 2 and R 3 are each bromine.
In an embodiment, the furanone has Formula 4:
In Formula 4, R 1 is hydrogen, hydroxyl, acetoxy, ester or ether; R 2 is Br or H; R 3 and R 4 are independently hydrogen or halogen; and R 5 is C 1 , C 3 , C 5 , or C 11 alkyl.
In an embodiment of Formula 4, R 1 is H, R 2 is Br, R 3 is Br, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is Br, R 3 is H, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R is OAc, R 2 is Br, R 3 is H, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is OH, R 2 is Br, R 3 is H, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is OAc, R 2 is Br, R 3 is H, R 4 is I, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is H, R 3 is Br, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is OAc, R 2 is Br, R 3 is Br, R 4 is Br, and R 5 is C 3 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is Br, R 3 is Br, R 4 is Br, and R 5 is C 1 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is Br, R 3 is H, R 4 is Br, and R 5 is C 1 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is H, R 3 is Br, R 4 is Br, and R 5 is C 1 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is Br, R 3 is H, R 4 is Br, and R 5 is C 5 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is H, R 3 is Br, R 4 is Br, and R 5 is C 5 alkyl. In an embodiment of Formula 4, R 1 is H, R 2 is H, R 3 is Br, R 4 is Br, and R 5 is C 11 alkyl.
In an embodiment, the furanone has Formula 5:
In Formula 5, R 1 , R 2 , R 3 and R 4 are each independently hydrogen, halogen, hydroxyl, methyl, alkyl, ether or ester.
Referring now to FIGS. 1A through 1C, wherein there is diagrammatically illustrated a human periodontal anatomy 10 , progressing from a healthy human periodontium 13 illustrated in FIG. 1A to a periodontium afflicted with periodontitis 17 illustrated in FIG. 1 C.
Specifically, FIG. 1A illustrates a healthy human periodontium 13 . Between the gingival margin 21 and the free gingiva 22 is the healthy gingival sulcus or crevice 19 . The depth 20 of the gingival sulcus or crevice 19 , from the gingival margin 21 to the attachment of the junctional epithelium 23 , is approximately 1-3 millimeters. The junctional epithelium attaches to the tooth 24 at the cementoenamel junction (CEJ) 25 . The gingival tissues 27 , including the epithelium 29 and gingival fibers 31 , are healthy and without inflammation. The alveolar bone crest 33 and periodontal ligament are undamaged.
FIG. 1B illustrates the human periodontium afflicted with gingivitis 15 . The gingival tissues 27 show signs of inflammation and crevicular ulceration 37 , resulting in white cell infiltration into the gingival sulcus or crevice 19 . Furthermore, the ulcerations 37 in the crevicular epithelium 28 result in bleeding upon provocation, such as through brushing and flossing or mastication.
FIG. 1C illustrates the human periodontium afflicted with periodontitis 17 . The gingival tissues 27 are inflamed. The alveolar bone crest 33 and periodontal ligament 35 have broken down due to both bacterial and host defense factors. The breakdown of the attachment of the alveolar bone 39 and periodontal ligament 35 to the tooth root 41 has resulted in the formation of a periodontal pocket lesion 43 . In addition, apical proliferation of the junctional epithelium 23 is noted along the root surface 45 . A chronic white cell infiltrate in the periodontal pocket lesion 43 is persistent. If left untreated, the continual loss of alveolar bone tissue 39 would result in the loss of the tooth 24 .
FIG. 2 illustrates dental plaque biofilm 61 on a tooth surface 41 . Planktonic bacteria 63 can be cleared by antibodies 65 and neutrophils 67 and are susceptible to antibiotics 69 . Neutrophils are attracted to the dental plaque biofilm 61 . Phagocytosis is frustrated yet phagocytic enzymes 71 are released which damage host tissue around the dental plaque biofilm 61 .
Accordingly, the present invention provides methods and compositions for the disruption and inhibition of dental plaque or bacterial biofilms at periodontal treatment sites. Specifically, in a first aspect, the present invention provides a method of treating periodontal disease comprising microencapsulating an agent which can disrupt dental plaque or bacterial biofilm and inserting the microparticles into a periodontal pocket lesion to allow the host immune system to more properly react against the bacterial cells.
In a second aspect, the present invention provides a method of preventing the re-emergence of the bacterial biofilm by insertion of microparticles containing an agent which inhibits biofilm formation into a periodontal pocket lesion. This could be done directly following scaling and root planing (mechanical disruption of the biofilm).
In a third aspect, the present invention provides a method of inhibiting key periodontal pathogens from inhabiting the biofilm by insertion of microparticles containing an inhibitor of one or more specific bacteria into the periodontal pocket lesion. Examples of desired periodontal pathogens to inhibit include Porphyromonas gingivalis, Bacteroides forsythus and Actinobacillus actinomycetemcomitans . This could also be done directly following scaling and root planing.
In an embodiment, the present invention includes a method of local delivery of bacterial biofilm inhibitor or disruptor agents to localized sites in the mouth. This is for treatment of periodontal disease. The method includes the steps of insertion of biodegradable microparticles containing these agents into the periodontal pocket. The method also includes allowing the microparticles to degrade and release the agents in a controlled, sustained manner. In an embodiment, insertion of biodegradable microshapes is accomplished using a syringe apparatus or hand delivery device. In an embodiment, the agents inhibit or disrupt the glycocalyx matrix of the bacterial biofilm. In an embodiment, the agents are antagonists of acylated homoserine lactones. In an embodiment, the agents are furanones or furanone derivatives. In an embodiment, the agents inhibit specific bacteria from inhibiting the bacterial biofilm. In an embodiment, the agents bind with or inhibit bacterial lipopolysaccharide. In an embodiment, the agents are histatin analogues. In an embodiment, other chemotherapeutic agents are microencapsulated and combined with microencapsulated bacterial biofilm inhibitors or disruptors for insertion into the periodontal pocket. In an embodiment, the combining step includes selecting the chemotherapeutic agent from the group consisting of antibiotics, anti-inflammatory agents and anticollagenolytic agents. In an embodiment, the biodegradable microparticles are configured as microspheres between 10 and 700 microns in diameter.
It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
It should also be noted that, as used in this specification and the appended claims, the phrase “adapted and configured” describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a particular configuration to. The phrase “adapted and configured” can be used interchangeably with other similar phrases such as arranged and configured, constructed and arranged, adapted, constructed, manufactured and arranged, and the like.
All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains.
It is to be understood, however, that even though numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | The present invention relates to compositions and methods of treating periodontal disease and related disorders utilizing a sustained, controlled release targeted delivery method to effectively disrupt and inhibit bacterial biofilms at periodontal treatment sites. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of prior application Ser. No. 12/631,803, filed Dec. 4, 2009 and claims the benefit of a foreign priority of Korean Patent Application No. 10-2011-0080392, filed Aug. 12, 2011, which is incorporated herein in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to mitral valve cerclage annuloplasty devices and techniques in which during the final stage of cerclage annuloplasty procedure, a proper tension is applied and maintained safely on the cerclage sutures then firmly secured by using a knot tightening and securing device.
BACKGROUND OF THE INVENTION
[0003] The heart is the center of human circulatory system that pumps blood through our body. It is a muscle that pumps the blood only in one direction. In order for the heart to effectively maintain this unidirectional flow of blood, it must have properly functional valves that prevent back flow through its system, or regurgitation. The heart is divided into four chambers, right and left atria, and right and left ventricles. The four chambers are connected to the aorta, the inferior and superior vena cava, the pulmonary artery, and the pulmonary veins.
[0004] The mitral valve (“MV”) separates the left atrium from the left ventricle while the tricuspid valve (TV) separates the right atrium from the right ventricle. The aortic valve (“AV”) is located between the left ventricle and the aorta while the pulmonary valve (“PV”) is located between the right ventricle and the pulmonary artery.
[0005] Generally, valves should open and close completely with every heart beat or contraction. Incomplete opening and closing of the valves cause improper flow of blood, either back flow and/or reduced. These are valvular diseases. The valvular diseases are divided into two categories, regurgitation and stenosis. Regurgitation is a failure of valve to close completely allowing back flow of blood. Stenosis is a failure of valve to open completely reducing the flow of blood. Both can increase stress on the heart.
[0006] Mitral valve regurgitation (“MVR”) is a valvular disease in which an incomplete closure of the MV results in a back flow of blood. Such back flow of blood increases stress on the heart which can decrease the heart function and eventually lead to an irregular heart beat or a cardiac arrhythmia.
[0007] Traditional treatment of a worsening MVR requires an open heart surgery with a sternotomy or a thoracotomy then opening the heart itself following a cardiopulmonary bypass and a cardiac arrest. Once the chest is opened and access to the heart is gained, the MV is either repaired or replaced with an artificial valve. Although very effective, this open-heart procedure is an invasive high-risk surgery accompanied by a substantial morbidity and mortality. The mortality due to the surgery itself can be as high as 5%. Hence, the procedure is often reserved only to those patients with severe symptomatic MVR.
[0008] This high morbidity rate of the open heart surgery has recently lead to an increase in researches to develop a safer and relatively more simple alternative procedures to repair the MVR using a cardiac catheterization technique. Along this international effort to find a safer alternative procedure, recently, this inventor presented internationally his thesis regarding “the mitral valve cerclage coronary sinus annuloplasty” and demonstrated outstanding result of the MVR treatment involving the application of a circular pressure around the mitral annulus (MA). This thesis has been filed through PCT as an international patent application (application number: PCT/US2007/023836), and is currently published with the international patent office (publication number: WO2008/060553), which are incorporated herein in their entirety.
[0009] The aforementioned thesis and published patent applications disclosed the mitral valve cerclage annuloplasty procedure. Briefly explained, a catheter is placed at the coronary sinus after accessing the right atrium through the jugular vein, and then a cerclage suture is passed through the proximal septal vein. This cerclage suture can easily pass through the right ventricular outflow tract (“RVOT”). The inventor defines this technique as “the simple mitral cerclage annuloplasty.” Then the cerclage suture can be easily pulled into the right atrium thus placing the cerclage suture circumferentially around the MA. Once positioned, tension is applied to the cerclage suture and tightens the mitral valve. This brings together the two leaflets of the MV so that they are approximated to each other thus decreasing the size of its incomplete closure. This procedure can obtain a very similar result when compared to the result of a conventional surgery that directly tightens the mitral annulus, and can immediately reduce the regurgitation effectively treating a MVR.
[0010] However, there were technical problems in the previous thesis and patent applications that needed to be solved. First, there is a need to have a tension locking device that can apply a proper tension and maintain it securely during the procedure. Second, since this tension is maintained with a very fine cerclage suture i.e., 0.014 inch nylon cerclage used in the researches (although thickness may change), it can cause damages on the cardiac tissues where the suture contacts and exerts its pressure.
[0011] To address these technical problems, this inventor has filed Korean patent application (application number 2009-0080708) on Aug. 8, 2008, titled “the Mitral Valve Cerclage Annuloplasty Apparatus” that includes the coronary sinus and the tricuspid valve protection device, and a knot delivery device.
[0012] This patent application has also been filed with the U.S. Patent and Trademark Office and patent offices in other countries.
[0013] In the aforementioned patent application, the cardiac tissue is protected from the damage caused by the direct suture contact using a tissue protective device comprising a coronary sinus tube (“CS tube”) and a tricuspid valve tube (“TV tube”). Further, a knot delivery device is used to place a knot at the end of the tissue protective device to complete the procedure.
[0014] However, even though the knot was placed at the end of the tissue protective device, a slack of suture remained between the end of the tissue protective device and the knot, so that the proper tension needed on the cerclage was difficult to obtain initially, and due to the remaining excess suture, the cerclage became loose.
[0015] In the aforementioned mitral valve cerclage annuloplasty procedure, when the cerclage suture became loose, the tension on the suture decreased thereby reducing its circumferential pressure applied around the MA resulting in a decreased effectiveness of the MVR treatment. This invention is intended to provide a viable solutions to overcome these problems.
SUMMARY OF THE INVENTION
[0016] The objective of this invention is to overcome the shortcomings of the aforementioned mitral valve cerclage annuloplasty apparatus by providing a device that can maintain a constant proper tension without creating a laxity on the cerclage suture thereby applying and maintaining a proper circumferential pressure around the MA and thus, increasing the effectiveness and the success of the mitral valve cerclage annuloplasty.
[0017] This invention achieves the aforementioned objectives by using a simple, easy to use devices described here that can initiate a proper knot placement and maintain its proper tension on the cerclage suture continuously.
[0018] Generally, to achieve its objective and overcome the shortcomings of the aforemetioned mitral valve cerclage annuloplasty apparatus, the current invention comprises a coronary sinus protective device 22 , a tricuspid valve and ventricular wall protective device 24 , a distal coronary sinus tissue protective tube, and a distal tricuspid valve protective tube that connects and becomes fixed, and a tissue protective device 20 with a built-in locking bumps 28 ingrained on the outside of the stem portion 26 .
[0019] This invention further comprises a hollow cap 30 that fits over the tissue protective device 20 with an open proximal end, a closed distal end 31 with two or smaller openings 32 that allows passing of the cerclage sutures, and a built-in locking ridges 35 ingrained on the inside of the hollow cap 30 that interlocks with the stem-portion locking-bumps 28 of the tissue protective device 20 .
[0020] The stem-portion locking-bumps 28 of the tissue protective device 20 and the cap locking ridges 35 interlock in such a manner that only allows the lengthening of the tissue protective device 20 and the hollow cap 30 , and prevents shortening of the tissue protective device 20 and the hollow cap 30 .
[0021] According to the current invention, a ring-hook 34 that allows a suture to be passed through is located at the distal end of the hollow cap 30 .
[0022] In a first embodiment, the stem-portion locking-bumps 28 of the tissue protective device 20 and the cap locking ridges 35 are in a shape of a saw-tooth.
[0023] In a second embodiment, the stem-portion locking-bumps 28 of the tissue protective device 20 is in a shape of a saw-tooth, and the cap locking ridges 35 are formed by equally spaced slits corresponding to the stem-portion locking-bumps 28 .
[0024] In a third embodiment, the hollow cap 30 comprises a cap body 38 and a cap lid 36 such that a neck 36 a of the cap lid inserts into the cap body 38 .
[0025] In a fourth embodiment, the inside of the cap body 38 and the out side of the neck of the cap lid 36 a is in the shape of a screw such that cap can be screwed into the cap body.
[0026] In a fifth embodiment, the stem-portion locking-bumps 28 of the tissue protective device 20 can on the two sides of the stem portion rather than surrounding the entire stem circumferentially.
[0027] As described above, the current invention improves the mitral valve cerclage annuloplasty apparatus by adding the hollow cap 30 to the tissue protective device 20 . The hollow cap 30 holds the cerclage suture knot in place while persistently maintaining a proper tension. When a persistent proper tension on the cerclage suture is maintained without laxity, a proper circumferential pressure around the MA can be sustained continuously thus, increasing the effectiveness and the success of the mitral valve cerclage annuloplasty.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 and FIG. 2 show the mitral valve cerclage annuloplasty apparatus comprising a tissue protective device and a hollow cap. FIG. 1 shows the tissue protective device and the hollow cap before the cap is placed onto the tissue protective device, and FIG. 2 shows the hollow cap fitted onto the tissue protective device.
[0029] FIG. 3 and FIG. 5 show the mitral valve cerclage annuloplasty apparatus in operation with the cerclage suture. FIG. 3 shows the cerclage suture knot placed outside the hollow cap. FIG. 4 shows the hollow cap being pulled outwardly from the stem portion of the tissue protective device while the cerclage suture knot is caught and supported by the closed distal end of the hollow cap. FIG. 5 shows cutting and removing of the excess cerclage suture distal to the knot, and removing the cap pulling suture.
[0030] FIG. 6 shows the process in which the tissue protective device and the hollow cap become engaged in a first embodiment of the mitral valve cerclage annuloplasty apparatus.
[0031] FIG. 7 shows a second embodiment of the mitral valve cerclage annuloplasty apparatus with a different cap configuration.
[0032] FIG. 8 shows a third embodiment of the mitral valve cerclage annuloplasty apparatus with another cap configuration.
[0033] FIG. 9 shows a different configuration of the locking-bumps on the stem portion of the tissue protective device and the locking ridges in the hollow cap of the mitral valve cerclage annuloplasty apparatus.
[0034] FIG. 10 shows another configuration of locking-bumps on the stem portion of the tissue protective device and the locking ridges in the hollow cap of the mitral valve cerclage annuloplasty apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The detailed disclosure of the mitral valve cerclage annuloplasty apparatus (MVA) comprising a tissue protective device and a hollow cap will be discussed.
[0036] According to the current invention, FIGS. 1-2 shows the mitral valve cerclage annuloplasty apparatus (MVA) comprising the tissue protective device 20 and the hollow cap 30 . FIG. 1 shows the tissue protective device 20 and the hollow cap 30 before they are engaged, and FIG. 2 shows the tissue protective device 20 and the hollow cap 30 in an engaged state. The tissue protective device 20 in the current invention differs from the inventor's previous patent application (#2009-0080708) in that the stem portion of the tissue protective device 20 has a built-in locking bumps 28 ingrained on its outer surface.
[0037] Generally, in a conventional MVA techniques cause tissue damage or erosion to the coronary sinus (“CS”), the tricuspid valve (“TV”) and the intraventricular septum (“IVS”) from a direct cerclage suture to tissue contact. These critical structures can be protected from damage by using the tissue protective device 20 comprising hollow tubes that allows passing of the cerclage suture preventing the direct contact of the suture onto the CS, the TV and the IVS tissues. Accordingly, the tissue protective device 20 comprises of a coronary sinus tube 22 (“CS tube”) that protects the CS tissue, a tricuspid valve tube 24 (“TV tube”) that protects the TV tissue and the IVS tissue, and a stem portion 26 with locking bumps 28 ingrained on its outer surface.
[0038] The inside of the cap 30 is hollow to allow insertion of the stem portion 26 of the tissue protective device 20 , and it has an ingrained locking ridges 35 on its inside that interlocks with the locking bumps 28 ingrained on the outer surface of the stem portion 26 .
[0039] The locking bumps 28 on the stem portion 26 and the locking ridges 35 ingrained on the inside of the hollow cap 30 are made so that they interlock in a way that allows only the outward movement of the hollow cap 30 while preventing the inward movement of the hollow cap 30 . Thus, during the procedure, once a knot is made with the cerclage suture, the hollow cap 30 can be advanced outwardly to remove any laxity in the cerclage suture and then continuously maintain a proper tension on the cerclage suture.
[0040] To maintain the proper tension, the preferred shape of the stem-portion locking bumps 28 and the cap locking ridges 35 is that of a saw-tooth.
[0041] The hollow cap 30 comprises a closed distal end 31 with two or more small openings 32 . The purpose of the closed distal end 31 is to support a cerclage-suture knot in place when the cap 30 is moved outwardly, and the purpose of the small openings 32 is to allow passage of the cerclage suture.
[0042] Further, on the outer surface of the closed distal end 31 of the hollow cap 30 comprises a ring hook 34 for attaching a cap-pulling suture used to pull the cap 30 outwardly.
[0043] FIGS. 3-5 show operations of the MVA. FIG. 3 shows the cerclage-suture knot 12 made with a cerclage suture 10 . FIG. 4 shows the cerclage-suture knot 12 supported by the closed distal end 31 as the cap 30 is moved outwardly using the cap-pulling suture 15 . FIG. 5 shows the cerclage-suture knot 12 after the excess cerclage suture has been cut distal to the knot and removed, and removing of the cap-pulling suture 15 .
[0044] In the cerclage annuloplasty procedure, once a proper circumferential pressure is applied onto the mitral valve with the cerclage suture 10 using the MVA of the current invention, a knot delivery device introduced by the inventor in his previous patent application (#2009-008070808) can be used to make the cerclage-suture knot 12 . In this state as shown in FIG. 3 , because the cerclage-suture knot 12 is not tight against the hollow cap 30 , it is difficult to maintain the proper tension on the cerclage suture 10 .
[0045] The cap-pulling suture 15 is first looped around the ring hook 34 of the hollow cap 30 , then it is extended distally to outside the body. The purpose of the cap-pulling suture 15 is to pull the hollow cap 30 outwardly.
[0046] Once the cerclage-suture knot 12 is made as shown in FIG. 4 , when the cap-pulling suture 15 looped around the ring hook 34 is pulled from outside the body, as shown in FIG. 5 , the hollow cap 30 will move outwardly. Since the cerclage-suture knot 12 is caught and supported by the closed distal end 31 of the hollow cap 30 , the cap-pulling suture 15 can pull the hollow cap 30 moving it outwardly until the proper tension on the cerclage suture is obtained. As the hollow cap 30 is pulled outwardly, the locking bumps 28 on the stem-potion of the tissue protective device 20 and the cap locking ridges 35 interlock in a way such that they only allow outward movement of the hollow cap 30 and prevent its inward movement. Hence, even if the cap-pulling suture 15 no longer pulls on the cap outwardly, the hollow cap 30 will not advance inward.
[0047] As shown in FIG. 4 , when the proper tension is obtained on the cerclage suture 10 by moving the hollow cap 30 outwardly, since the cerclage-suture knot 12 is caught and supported by the closed distal end 31 , the circumferential pressure applied around the mitral annulus can be maintained constantly. Hence, the MVR of a patient is eliminated increasing the effectiveness and the success of the mitral valve cerclage annuloplasty.
[0048] As shown in FIG. 5 , after cutting the cerclage suture 10 at a certain distance from the cerclage-suture knot 12 using a cutter (not illustrated here), the remaining excess cerclage suture can be taken out of the body, and the cap-pulling suture 15 can also be pulled out of the body. Hence, the mitral valve cerclage annuloplasty procedure is completed.
[0049] According to the current mitral valve cerclage annuloplasty apparatus, before starting the mitral valve annuloplasty procedure, the tissue protective device 20 must be inserted fully into the hollow cap 30 . Due to the way in which the stem-portion locking bumps 28 of the tissue protective device 20 and the cap locking ridges 35 interlock, it can be difficult to engage the tissue protective device 20 fully into the hollow cap 30 .
[0050] There are various ways to fully engage the hollow cap 30 with the tissue protective device 20 . FIG. 6 shows one of these methods where an expander 50 is used to help engage the hollow cap 30 with the tissue protective device 20 .
[0051] The expander 50 is made in an L-shape with a handle bar 50 a and an expander bar 50 b. The expander bar 50 b is inserted into the hollow cap 30 , and the handle bar 50 a is used to apply force needed to expand the hollow cap 30 . The expander 50 is used to expand the inside space of the hollow cap 30 to allow easier entry of the tissue protective device 20 . The hollow cap 30 can be made of a soft or a silk-like material. If the hollow cap 30 is made of a soft material, the expander 50 can be used to expand the inside space of the hollow cap 30 so that the tissue protective device 20 can be inserted into the hollow cap 30 .
[0052] Three or more expanders 50 are used together to expand the inside space of the hollow cap 30 so that when they are pulled in opposing directions, the inside space of the hollow cap 30 is expanded to allow easier entry of the tissue protective device 20 .
[0053] Once the tissue protective device 20 is fully inserted into the hollow cap 30 , the expanders 50 return to their original position and are removed from the hollow cap 30 thereby achieving their purpose of helping engage the tissue protective device 20 with the hollow cap 30 .
[0054] The expanders 50 can be installed on an expander device (not displayed) which can be operated using a motor or cylinder (not displayed). The expander device is used to operate the expanders 50 so that the expanders can expand or reduce the hollow cap 30 .
[0055] FIG. 7 shows another method of inserting the tissue protective device 20 into the hollow cap 30 where the hollow cap 30 is further divided into a cap body 38 and a cap lid 36 . The cap body 38 and the cap lid 36 can be joined or separated.
[0056] As shown in FIG. 7 , the cap body 38 and the cap lid 36 of hollow cap 30 are configured so that they can be joined or separated. The distal end of the cap lid 36 is formed as a cap-lid neck 36 a so that it can be inserted into the cap body 38 . In other words, when the cap lid 36 is separated from the cap body 38 , the cap-lid neck 36 a can be inserted into the cap body 38 so that the cap lid 36 and the cap body 38 can be become one.
[0057] First, the cap body 38 is separated from the cap lid 36 . Then the two distal tubes of the tissue protective device 20 (the coronary sinus tube 22 and the tricuspid valve tube 24 ) are inserted into the cap body 38 through its upper portion. The tissue protective device 20 is then pulled through the cap body 38 until the stem portion of the tissue protective device is covered by the cap body 38 . Then the cap lid 36 is inserted into the cap body 38 thus uniting the tissue protective device 20 and the hollow cap 30 . An adhesive can be used to firmly secure the cap lid 38 to the cap body 36 .
[0058] FIG. 8 shows another embodiment of the hollow cap 30 with its detachable cap lid 36 and the cap body 38 . The outer surface of the cap lid neck 36 a has screw-like cap-lid thread 36 b, and the inside of the cap body 38 has its corresponding cap-body receiving thread 38 b . Hence, the cap lid 36 can be screwed into the lid body 38 .
[0059] FIG. 9 shows another embodiment of the mitral valve cerclage annuloplasty apparatus with a different distribution of the stem-portion locking bumps 28 of the tissue protective device 20 , and the cap locking ridges 35 .
[0060] FIG. 9 shows the locking bumps 28 ingrained on a part of the stem portion of the tissue protective device 20 rather than over the entire length of the stem portion. Specifically, the locking bumps 28 can be ingrained only on the sides of the stem portion of the tissue protective device 20 . As shown in FIG. 9 , the cap locking ridges 35 can also be ingrained on part of the hollow cap 30 rather than on the entire inside surface. The purpose of ingraining the locking bumps 28 only the sides of the stem portion of the tissue protective device is to facilitate easier flow of the blood.
[0061] FIG. 10 shows another embodiment of the mitral valve cerclage annuloplasty apparatus with a different shape of the cap locking ridges 35 . FIG. 9 shows the cap locking ridges 35 inside the hollow cap 30 made of equally spaced open slits 39 .
[0062] While the invention has been described in terms of specific embodiments, it is apparent that other forms could be adopted by one skilled in the art. Accordingly, it should be understood that the invention is not limited to the specific embodiments illustrated in the Figures. It should also be understood that the phraseology and terminology employed above are for the purpose of disclosing the illustrated embodiments, and do not necessarily serve as limitations to the scope of the invention. | A mitral cerclage annuloplasty apparatus comprises a tissue protective device and a cap device having a cerclage suture disposed within a first protective tube and a second protective tube, the proximal portions of the two tubes being attached side-by-side longitudinally to define a stem portion, the distal portions of the two tubes being separated thereafter, and a cap device that covers the stem portion wherein the stem portion and the cap device interlock, so that once the cerclage suture is knotted on the outer surface of the cap device, cap device can be pulled outwardly to enhance and maintain tension applied to the mitral annulus thus successfully treating the mitral regurgitation. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. Pat. Application Ser. No. 490,245, filed Mar. 8, 1990, issued as U.S. Pat. No. 5,046,577.
BACKGROUND OF THE INVENTION
This invention relates generally to off-road motor vehicles, such as tractors, and more particularly, to a steering mechanism permitting a decreased turning radius for the tractor.
Tractors, whether used in an agricultural setting or in an industrial setting, typically include a fixed axle through which primary driving power is transferred through fixed wheels rotatably mounted on opposing ends of the fixed axle, and a steering axle having pivotally mounted steerable ground engaging wheels rotatably mounted on the opposing ends thereof to support the chassis of the tractor above the ground. Although supplemental driving power is often provided to the steerable ground engaging wheels, a steering mechanism remotely controllable by the operator from the operator's compartment selectively controls the pivotal movement of the steerable wheels relative to the steering axle.
One such steering mechanism incorporates a transversely disposed, horizontally extending hydraulic cylinder supported by the steering axle and connected to the opposing steerable wheels. This hydraulic cylinder affects pivotal movement of the steerable wheels about their respective pivotal connections to the steering axle by manipulating the pressures in the hydraulic cylinder to effect a transverse extension of cylinder rod, causing a turning of the wheels.
Due to physical limitations relating to the range of movement of the steering mechanism and to the eventual interference between the steerable wheels and the steering axle, the amount of pivotal movement of the steerable wheels relative to the steering axle is limited to a given turning angle. This maximum turning angle defines the minimum turning radius of the tractor for a given wheel base length and tread spacing. The selection of the length of the wheel base, i.e., the distance between the fixed axle and the steering axle, is a compromise between the need to minimize the turning radius and, therefore, minimize the wheel base length, and to maximize ride considerations which require longer wheel base lengths. PG,5
These conflicting wheel base requirements can be better resolved by a steering mechanism that will increase turning radius for any given wheel base length, permitting the wheel base length to increase while maintaining established turning radius specifications.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the aforementioned disadvantages of the prior art by providing a steering mechanism for an off-road vehicle that simultaneously combines the turning of the steerable ground wheels with a pivotal movement of the steering axle.
It is another object of this invention to decrease the turning radius for an off-road vehicle for a given wheel base length by simultaneously pivoting the steering axle in the same direction as the steerable ground wheels are turned.
It is a feature of this invention that the steering mechanism affects a simultaneous pivoting of the ground engaging wheels relative to the steering axle and a pivotal movement of the steering axle relative to the chassis.
It is an advantage of this invention that the wheel base length can be increased without increasing the previously established turning radius specifications.
It is another feature of this invention that the steering axle is pivotally supported relative to the chassis by a pivot mechanism that can be coupled to the steering mechanism to affect simultaneous pivotal movement of the steering axle relative to the chassis.
It is another advantage of this invention that the pivot center for the pivotal movement of the steering axle is positioned at a location that will maintain the spacing between the inside ground engaging wheel and the chassis during maximum turning efforts.
It is another feature of this invention that the wheel base of an off-the-road vehicle can be increased to provide more desirable ride characteristics for the vehicle without diminishing the turning radius specification of the vehicle.
It is still another object of this invention to provide a pivot mechanism pivotally supporting the axle relative to the chassis of the vehicle to enable a pivotal movement of the steering axle about a generally vertical axis, as well as a transverse oscillation of the steering axle about a longitudinally extending, horizontal axis relative to the chassis.
It is still another feature of this invention to provide a lost motion mechanism interconnecting the pivot mechanism and the steering axle to accommodate differences in arcuate movements therebetween during steering operations.
It is a further object of this invention to provide a method of steering an off-the-road vehicle by turning the pivotally mounted steerable ground wheels and the steering axle on which the steerable ground wheels are mounted.
It is yet another feature of this invention that the turning of the steerable ground wheels and the pivoting of the steering axle rotatably mounting the steerable ground wheels can be effected simultaneously.
It is still another advantage of this invention that the steering mechanism can be utilized on various mobile equipment, such as combines, forage harvesters, tractors, and industrial equipment, such as loaders and backhoes.
It is still another feature of this invention that the pivot centers for movement of the pivot mechanism and the pivotal movement of the steering axle are longitudinally spaced in alignment with a longitudinally extending, generally horizontal axis about which the steering axle is mounted for transverse oscillation.
It is a further object of this invention to provide a steering mechanism for an off-the-road vehicle operable to effect a pivotal movement of the steerable wheels relative to the steering axle in which they are mounted simultaneously with a pivotal movement of the steering axle relative to the chassis to decrease the turning radius of the vehicle, wherein the steering mechanism is durable in construction, inexpensive manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.
These and other objects, features, and advantages are accomplished according to the instant invention by providing a steering mechanism for improving the turning radius of a tractor wherein the wheels are turned relative to the steering axle simultaneously with a pivotal movement of the steering axle relative to the chassis of the tractor. A connecting link interconnects the pivot mechanism pivotally supporting the steering axle relative to the chassis with the steering mechanism such that a manipulation of the steering mechanism to affect a turning of the wheels affects a pivotal movement of the steering axle in the same direction the wheels are being turned. The pivot mechanism allows for pivotal movement of the steering axle about longitudinally extending horizontal axis in addition to the pivotal movement of the steering axle about a generally vertical axis relative to the chassis. A lost motion linkage interconnecting the pivot mechanism and the steering axle accommodates differences in arcuate movements due to the pivot mechanism and the steering axle pivotally moving about longitudinally spaced pivot centers.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a top plan view of the steering axle located at the front portion of a tractor, this top plan view being taken as a cross section below the tractor main frame as indicated by lines 1--1 of FIG. 2, FIG. 1 exhibiting the prior art steering mechanism of a tractor in which the steering axle is mounted for transverse oscillation relative to the chassis, but is otherwise fixed relative thereto;
FIG. 2 is a cross sectional view taken along lines 2--2 of FIG. 1 to provide a side elevational view of the prior art steering mechanism;
FIG. 3 is a top plan view of the prior art steering mechanism similar to FIG. 1 with the steering mechanism being manipulated to effect a turning of the pivotally mounted steerable ground wheels to cause a right hand turn of the tractor;
FIG. 4 is a top plan view of the steering mechanism incorporating the principles of the instant invention, FIG. 4 being a view similar to that in FIG. 1, but taken along lines 4--4 of FIG. 5;
FIG. 5 is a cross sectional view taken along lines 5--5 of FIG. 4 to depict a side elevational view of the steering mechanism incorporating the principles of the instant invention;
FIG. 6 is a top plan view of the steering axle similar to that of FIG. 4 with the steerable ground wheels being pivoted along with the steering axle into a maximum right turn position;
FIG. 7 is a schematic top plan view of the forward portion of a tractor to demonstrate the increased wheel turn accomplished by the steering mechanism incorporating the principles of the instant invention, the phantom lines depicting the steering axle and associated ground wheels oriented in a straight forward position, the dotted lines indicating the maximum turn of the steerable ground wheels permitted with prior art steering mechanism exemplified in FIGS. 1-3, and the solid lines indicating the maximum turn for the steerable ground engaging wheels as accomplished by the instant invention; and
FIG. 8 is a schematic side elevational view of a tractor depicting a general relationship between the chassis, the rear fixed axle and the forward steering axle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, particularly, to FIGS. 1-3 and 8, a representative view of a prior art tractor steering mechanism can best be seen. The chassis 10 houses an engine 12 serving to provide operational power for the tractor T, and an operator's cab 14 positioned in an elevated location. The operator's cab 14 includes a steering control 15 conventionally operable to manipulate the steering mechanism 20, 30 described in greater detail below. The chassis 10 is supported above the ground G by a rearward fixed axle 16 having a pair of opposing fixed drive wheels 17 rotatably mounted in a customary transversely spaced orientation. The chassis 10 is also supported above the ground g by a steering axle 18 positioned forwardly of the rearward fixed axle 16. The steering axle 18 is provided with a pair of rotatably mounted steerable wheels 19 pivotally connected to the steering axle 18 to permit a rotational movement relative thereto, as will be described in greater detail below.
Referring to FIGS. 1-3, the prior art steering mechanism 20 can best be seen. Some tractors T are provided with an optional drive mechanism 21 providing rotational power to the steerable wheels 19 in addition to the customary operative driving power applied to the fixed wheels 17. The drive mechanism 21 typically includes a gear housing 22 connected to and supported from the steering axle 18. Both the gear housing 22 and the steering axle 18 are pivotally mounted relative to the chassis 10 for transverse oscillation about a longitudinally extending, generally horizontal pivot axis 23, which permits the steering axle 18 to follow varying ground undulations without disrupting the orientation of the chassis 10.
The steerable wheels 19 are pivotably connected to the transversely opposed ends of the steering axle 18 by a pivot axis commonly referred to as a king pin 24. Each steerable wheel 19 is provided with a fixed steering arm 27 extending outwardly therefrom and pivotable therewith. The steering mechanism 20 further includes a hydraulic cylinder 25 mounted to either the gear housing 22 or the steering axle 18, and oriented in a transverse, horizontal position, generally parallel to the steering axle 18. The hydraulic cylinder 25 is provided with a cylinder rod 26 extending transversely from the body of the cylinder 25 in opposing transverse directions. A steering link 28 interconnects each respective end of the cylinder rod 26 with a corresponding steering arm 27, such that an extension of the cylinder rod 26 in either transverse direction will effect a pivoting of the steerable wheels 19 via a connection of the cylinder rod 26 to the steering arms 27 through the steering links 28, as is best shown in FIG. 3.
Referring specifically to FIG. 3, the interference between respective components of the steering axle 18 and the steerable wheels 19, such as for example, an interference between the steering arms 27 and the axle 18, as well as the interference between the chassis 10 and the pivotally turned steerable wheels 19, limits the amount of pivotal movement of the steerable wheels 19 relative to the steering axle 18. The maximum turning angle exemplified in FIG. 3 defines the minimum turning radius for the tractor T for the given wheel base length between the fixed axle 16 and the steering axle 18. Moving the prior art steering axle 18 forwardly away from the fixed axle 16 to improve ride characteristics of the tractor T will result in an increase of the turning radius for the tractor T because of the length of the increased wheel base and the limitations imposed by the maximum steering angle of the steerable wheels 19.
Referring now to FIGS. 4-6, the principles of the instant invention to provide a decreased turning radius for a given wheel base can best be seen. The steering mechanism 30 utilizes as many of the components of the prior art steering mechanism 20 as possible to minimize complication. The steering axle 18 is pivotally mounted relative to the chassis 10 for pivotal movement about a generally vertical axis 38. To permit the steering axle 18 to transversely oscillate to follow changing ground undulations, the longitudinal pivot axis 23 is defined by a longitudinally extending support shaft 32 extending from the chassis 10 and terminating at its forward end 33 in a swivel 34 adapted to receive a first vertical pivot 36.
A support arm 37 is pivotally mounted on the support shaft 32 for pivotal movement about the longitudinal pivot axis 23. The support arm 37 carries a second vertical pivot 38 about which the steering axle 18 is pivotally movable. Accordingly, the entire pivot mechanism 31 pivotally supporting the steering axle 18 relative to the chassis 10 is pivotable about the support shaft 32 defining the longitudinal pivot axis 23, thereby permitting transverse oscillations for the steering axle 18. One skilled in the art will readily realize that other arrangements of pivotable components could be devised to permit the steering axle 18 to be capable of transverse oscillations.
The pivot mechanism 31 also includes a bellcrank 40 affixed to the first vertical pivot 36 to be rotatable about the axis defined by the pivot 36. The bellcrank 40 terminates in a first, forward end 41 carrying a third vertical pivot 42 for connection to a lost motion linkage 45 and a second, rearward end 43 pivotally connected to a connecting link 50 to effect rotation of the bellcrank 40, as will be described in greater detail below. The lost motion linkage 45 is pivotally connected to the bellcrank 40 at the third vertical pivot 42 and includes transversely extending opposing arms 46 pivotally connected to transversely spaced brackets 47 affixed to the steering axle 18. The pivotal connection between the transverse arms 46 and the brackets 47 defines a transverse horizontal axis 49 about which the lost motion linkage 45 is pivotable for reasons that will be described in greater detail below.
A connecting link 50 is pivotally attached to the rearward end 43 of the bellcrank 40 and extends transversely therefrom to a bracket 52 which is affixed to the right steerable wheel 19 to be pivotably movable therewith. One skilled in the art will readily realize that the connecting link 50 could be connected to other components of the steering mechanism 30 so that a pivotal movement of the bellcrank 40 can be effected whenever the steerable wheels 19 are moved relative to the steering axle 18. The purpose of the connecting link 50 being to effect pivotal movement of the bellcrank 40 about the first vertical pivot 36 in response to the pivotal movement of the steerable wheels 19 about the king pins 24.
In operation, the conventional operation of the steering control 15 causes a manipulation of the pressures within the hydraulic cylinder 25 to effect an extension of the cylinder rod 26 to the left as depicted in FIG. 6 causes a pivotal movement of the steerable wheels 19 about the respective king pins 24 in a manner substantially identical to that described above with respect to the prior art steering mechanism 20 depicted in FIGS. 1-3. Since the bracket 52 pivotally moves with the right steerable wheel 19 the pivoted motion of the bracket 52 causes a movement of the bellcrank 40 due to the connection therebetween by the connecting link 50. The rotation of the bellcrank 40 about the first pivot axis 36, as depicted in FIG. 6, causes the forward end 41 of the bellcrank 40 to move to the right of the longitudinal axis 23.
Because of the connection between the bellcrank 40 and the steering axle 18 by the lost motion linkage 45, the steering axle 18 is urged to the right with the forward end 41 of the bellcrank 40. Since the gear housing 22 attached to the steering axle 18 is pivoted about the second, vertical pivot 38, the steering axle 18 pivots about the second vertical pivot 38 in a clockwise direction, as shown in FIG. 6, which is the same direction of rotation of the steerable wheels 19. One skilled in the art will readily realize that operation of the steering mechanism 30 to cause a left turn will result in a movement of the components described above in the opposite direction, in substantially a mirror image to the exemplary depiction of FIG. 6.
Since the bellcrank 40 is pivotal about the first vertical pivot 36 while the steering axle 18 is pivotal about the second vertical pivot 38 which is spaced longitudinally rearwardly of the first vertical pivot 36, the forward end 41 of the bellcrank 40 travels about a different arcuate path than the corresponding portion of the steerable axle 18. The lost motion linkage 45 accommodates this difference in arcuate movement by the pivotal connection with the forward end 41 of the bellcrank 40 at the third vertical pivot 42, permitting relative motion between the bellcrank 40 and the lost motion linkage 45. Likewise, the pivotal connection between the transverse arms 46 and the brackets 47 attached to the steering axle 18 permit the lost motion linkage 45 to be rotated rearwardly about the transverse horizontal axis 49 while the bellcrank 40 and the steering axle 18 are pivoted about their respective pivot connections 36, 38. Accordingly, the lost motion linkage 45 permits the bellcrank 40 which is rotating about an arc having the first vertical pivot 36 as its center to effect pivotal movement of the steering axle 18 about a different arc having the center of rotation defined by the second vertical pivot 38. One skilled in the art will readily realize this arrangement of components will permit only a limited amount of movement for the steering axle 18.
The positioning of the first vertical pivot 36 intermediate the two ends 41,43 of the bellcrank 40, but closer to the forward end 41, while rotating the steering axle 18 about a pivot arm considerably longer than the pivot arm of the bellcrank 40, permits a ratio of movement of the pivoted steerable wheels 19 to be in the range of 5-10 times greater than the angular movement of the steering axle 18 about the second pivot 38. For example, a pivoting of the right steerable wheel 19 in a right turn for the tractor T through an angular movement of approximately 50 degrees may only result in approximately 6-8 degrees of angular movement of the steering axle 18 about the second vertical pivot 38.
By moving the steering axle 18 forwardly from the position shown in FIGS. 1-3, the additional rotative movement of the steering axle 18 positions the inboard end of the left hand tire forwardly of the chassis 10 to eliminate interference therewith during a right hand turn. The placement of the second pivot 38 along the longitudinal axis 23 substantially perpendicular to the inboard end of the right hand tire when turning the tractor T in a right turn, maintains the inboard end of the right hand steerable wheel 19 at substantially the same distance from chassis 10, as this portion of the right steerable wheel 19 moves substantially perpendicularly to the longitudinally axis 23 when the steering axle 18 is pivoted about pivot 38. The. same relationship is true with the opposing wheels 19 during a left hand turn for the tractor T.
Since the steering axle 18 is pivotally mounted on the support shaft 32 by the swivel 34 and the support arm 37, changes in ground undulations will still cause the steering axle 18 to transversely oscillate about the longitudinal axis 23 irrespective of the orientation of the steering axle 18 relative to the chassis 10. Both the first and second vertical pivots 36,38 remain fixed relative to the chassis 10 and in alignment with the longitudinal pivot axis 23 throughout the pivotal movement of the steering axle 18.
Referring now to the schematic view of FIG. 7, the advantages of the instant invention can be seen pictorially. Using the steerable wheels 19 mounted on the steering axle 18 in the straight forward position as shown in phantom lines FIG. 7 as the base reference point, the dotted outline of the steerable wheels 19 reflect the maximum turning ability, i.e. the minimum turning radius, for the tractor T with the prior art steering mechanism described in FIGS. 1-3. Utilizing the principles of the instant invention to simultaneously turn the steering axle 18 about the second pivot 38, as described above, positions the steerable wheels 19 in the position shown in solid lines in FIG. 7.
One skilled in the art will readily realize that a smaller turning radius for a giving wheel base length can be attained through utilization of the instant invention. Placement of the steering axle 18 forwardly relative to the chassis 10 permits the tractor T to have a more comfortable ride characteristic and also positions the inboard end of the outside steerable wheel 19 forwardly of the chassis 10 to prevent interference between. As also demonstrated in FIG. 7, the inboard end of the inside wheel 19 in a respective turn for the tractor T substantially maintain the proximity thereof relative to the chassis 10 due to the location of the second vertical pivot 38. One skilled in the art will readily realize that a maintenance of the turning radius specification will permit the utilization of a longer wheel base, i.e. a movement of the steering axle 18 forwardly from the fixed axle 16 to provide better ride characteristics for tractor T.
One skilled in the art will readily realize that the steering actions of the steerable wheels 19 and the steering axle 18 could be accomplished sequentially rather than simultaneously. Although the preferred embodiment, as described above, utilizes simultaneous steering of the wheels 19 and axle 18 through a mechanical linkage, other hydraulic or electronic embodiments could be utilized to provide a sequential pivoting of the steering axle 18 after a given amount of pivotal movement of the steerable wheels 19. The preferred embodiment described above utilizes most of the existing prior art steering and axle components and requires only the addition of modest mechanical and minimum hydraulic complications to provide the improved steering mechanism.
It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may, be made by skilled in the art upon reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description may be employed by other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown. | A steering mechanism for improving the turning radius of a tractor is disclosed wherein the wheels are turned relative to the steering axle simultaneously with a pivotal movement of the steering axle relative to the chassis of the tractor. A connecting link interconnects the pivot mechanism pivotally supporting the steering axle relative to the chassis with the steering mechanism such that a manipulation of the steering mechanism to affect a turning of the wheels affects a pivotal movement of the steering axle in the same direction the wheels are being turned. The pivot mechanism allows for pivotal movement of the steering axle about longitudinally extending horizontal axis in addition to the pivotal movement of the steering axle about a generally vertical axis relative to the chassis. A lost motion linkage interconnecting the pivot mechanism and the steering axle accommodates differences in arcuate movements due to the pivot mechanism and the steering axle pivotally moving about longitudinally spaced pivot centers. | 1 |
BACKGROUND OF THE INVENTION
In the manufacture of tissue products, it is generally desireable to provide the final product with as much bulk as possible without compromising other product attributes. However, most tissue machines operating today utilize a process known as "wet-pressing", in which a large amount of water is removed from the newly-formed web by mechanically pressing water out of the web in a pressure nip between a pressure roll and the Yankee dryer surface as the web is transferred from a papermaking felt to the Yankee dryer. This wet-pressing step, while an effective dewatering means, compresses the web and causes a marked reduction in the web thickness and hence bulk.
On the other hand, throughdrying processes have been more recently developed in which web compression is avoided as much as possible in order to preserve and enhance the bulk of the web. These processes provide for supporting the web on a coarse mesh fabric while heated air is passed through the web to remove moisture and dry the web. If a Yankee dryer is used at all in the process, it is for creping the web rather than drying, since the web is already dry when it is transferred to the Yankee surface. Transfer to the Yankee, although requiring compression of the web, does not significantly adversely affect web bulk because the papermaking bonds of the web have already been formed and the web is much more resilient in the dry state.
Although throughdried tissue products exhibit good bulk and softness properties, throughdrying tissue machines are expensive to build and operate. Accordingly there is a need for producing higher quality tissue products by modifying existing, conventional wet-pressing tissue machines.
SUMMARY OF THE INVENTION
It has now been discovered that the bulk of a wet web can be significantly increased with little capital investment by abruptly deflecting the wet web, at relatively high consistency, into the open areas or depressions in the contour of a coarse mesh supporting fabric, preferably by pneumatic means such as one or more pulses of high pressure and/or high vacuum. Such abrupt flexing of the web causes the web to "pop" or expand, thereby increasing the caliper and internal bulk of the wet web while causing partial debonding of the weaker bonds already formed during partial drying or dewatering. This operation is sometimes referred to herein as wet-straining. The web can then be dried to preserve the increased bulk. This discovery is particularly beneficial when applied to wet-pressing processes in which a relatively large number of bonds are formed in the wet state, but it can also be applied to throughdrying processes to further improve the quality of the resulting tissue product.
The effects of wet-straining on the web can be quantified by measuring the "Debonded Void Thickness" (hereinafter described), which is the void area or space not occupied by fibers in a cross-section of the web per unit length. It is a measure of internal web bulk (as distinguished from external bulk created by simply molding the web to the contour of the fabric) and the degree of debonding which occurs within the web when subjected to wet-straining. The "Normalized Debonded Void Thickness" is the Debonded Void Thickness divided by the weight of a circular, four inch diameter sample of the web. The determination of these parameters will be hereinafter described in connection with FIGS. 8-13.
Hence, in one aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) dewatering or drying the web to a consistency of 30 percent or greater; (c) transferring the web to a coarse mesh fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (e) drying the web.
In another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) throughdrying the web to a consistency of from about 40 to about 90 percent while supported on the coarse fabric; (g) transferring the throughdried web to a Yankee dryer to final dry the web; and (h) creping the web.
In yet another aspect, the invention resides in a method for making a wet-pressed tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the wet web to a consistency of about 30 percent or greater; (d) transferring the web to a coarse fabric; (e) deflecting the web to substantially conform the web to the contour of the coarse fabric; (f) transferring the web to a transfer fabric; (g) transferring the web to the surface of a Yankee dryer and drying the web to final dryness; and (h) creping the web.
In still another aspect, the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a papermaking felt; (c) pressing the web against the surface of a Yankee dryer and transferring the web thereto; (d) partially drying the web to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) transferring the web to a second Yankee dryer and final drying the web; and (h) creping the web.
In a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdryer fabric and partially drying the web in a first throughdryer to a consistency of from about 28 to about 45 percent; (c) sandwiching the partially-dried web between the throughdryer fabric and a coarse fabric; (d) deflecting the web to substantially conform the web to the contour of the coarse fabric; (e) carrying the web on the throughdryer fabric over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (f) transferring the throughdried web to a Yankee dryer; and (g) creping the web.
In yet a further aspect, the invention resides in a method for making a throughdried tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the wet web to a throughdrying fabric; (c) carrying the web over a first throughdryer and partially drying the web to a consistency of from about 28 to about 45 percent; (d) transferring the partially dried web to a second throughdrying fabric; (e) sandwiching the partially dried web between the second throughdrying fabric and a coarse fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; (g) carrying the web over a second throughdryer to dry the web to a consistency of about 85 percent or greater; (h) transferring the web to a Yankee dryer; and (i) creping the web.
In another aspect the invention resides in a method for making a tissue product comprising: (a) depositing an aqueous suspension of papermaking fibers onto an endless forming fabric to form a wet web; (b) transferring the web to a papermaking felt; (c) compressing the web in a pressure nip to partially dewater the web and transferring the web to a Yankee dryer; (d) partially drying the web on the Yankee dryer to a consistency of from about 40 to about 70 percent; (e) transferring the partially dried web to a coarse mesh fabric; (f) deflecting the web to substantially conform the web to the contour of the coarse fabric; and (g) throughdrying the web.
In all aspects of the invention, the web can be creped, wet or dry, one or more times if desired. Wet creping can be an advantageous means for removing the wet web from the Yankee dryer.
The nature of the coarse fabric is such that the wet web must be supported in some areas and unsupported in others in order to enable the web to flex in response to the differential air pressure or other deflection force applied to the web. Such fabrics suitable for purposes of this invention include, without limitation, those papermaking fabrics which exhibit significant open area or three dimensional surface contour or depressions sufficient to impart substantial z-directional deflection of the web. Such fabrics include single-layer, multi-layer, or composite permeable structures. Preferred fabrics have at least some of the following characteristics: (1) On the side of the molding fabric that is in contact with the wet web (the top side), the number of machine direction (MD) strands per inch (mesh) is from 10 to 200 and the number of cross-machine direction (CD) strands per inch (count) is also from 10 to 200. The strand diameter is typically smaller than 0.050 inch; (2) On the top side, the distance between the highest point of the MD knuckle and the highest point of the CD knuckle is from about 0.001 to about 0.02 or 0.03 inch. In between these two levels, there can be knuckles formed either by MD or CD strands that give the topography a 3-dimensional hill/valley appearance which is imparted to the sheet during the wet molding step; (3) On the top side, the length of the MD knuckles is equal to or longer than the length of the CD knuckles; (4) If the fabric is made in a multi-layer construction, it is preferred that the bottom layer is of a finer mesh than the top layer so as to control the depth of web penetration and to maximize fiber retention; and (5) The fabric may be made to show certain geometric patterns that are pleasing to the eye, which typically repeat between every 2 to 50 warp yarns. Suitable commercially available coarse fabrics include a number of fabrics made by Asten Forming Fabrics, Inc., including without limitation Asten 934, 920, 52B, and Velostar V800.
The consistency of the wet web when the differential pressure is applied must be high enough that the web has some integrity and that a significant number of bonds have been formed within the web, yet not so high as to make the web unresponsive to the differential air pressure. At consistencies approaching complete dryness, for example, it is difficult to draw sufficient vacuum on the web because of its porosity and lack of moisture. Preferably, the consistency of the web will be from about 30 to about 80 percent, more preferably from about 40 to about 70 percent, and still more preferably from about 45 to about 60 percent. A consistency of about 50 percent is most preferred for most furnishes and fabrics.
The means for deflecting the wet web to create the increase in internal bulk can be pneumatic means, such as positive and/or negative air pressure, or mechanical means, such as a male engraved roll having protrusions which match up with the depressions or openings in the coarse fabric. Deflection of the web is preferably achieved by differential air pressure, which can be applied by drawing a vacuum from beneath the supporting coarse fabric to pull the web into the coarse fabric, or by applying positive pressure downwardly onto the web to push the web into the coarse fabric, or by a combination of vacuum and positive pressure. A vacuum suction box is a preferred vacuum source because of its common use in papermaking processes. However, air knives or air presses can also be used to supply positive pressure if vacuum cannot provide enough of a pressure differential to create the desired effect. When using a vacuum suction box, the width of the vacuum slot can be from approximately 1/16" to whatever size is desired, as long as sufficient pump capacity exists to establish sufficient vacuum. In common practice vacuum slot widths from 1/8" to 1/2" are most practical.
The magnitude of the pressure differential and the duration of the exposure of the web to the pressure differential can be optimized depending upon the composition of the furnish, the basis weight of the web, the moisture content of the web, the design of the supporting coarse fabric, and the speed of the machine. Without being held to any theory, it is believed that the sudden deflection of the web, followed by the immediate release of the pressure or vacuum, causes the web to flex down and up and thereby partially debond and hence expand. Suitable vacuum levels can be from about 10 inches of mercury to about 28 inches of mercury, preferably about 15 to about 25 inches of mercury, and most preferably about 20 inches of mercury. Such levels are higher than would ordinarily be used for mere transfer of a web from one fabric to another.
The number of times the wet web can be transferred to a coarse fabric and subjected to a pressure differential can be one, two, three, four or more times. To effect a more uniform bulking of the web, it is preferred that the wet straining vacuum be applied to both sides of the web. This can be conveniently accomplished simply by transferring the web from one fabric to another, in which the web is inherently supported on a different side after each transfer.
The method of this invention can preferably be applied to any tissue web, which includes webs for making facial tissue, bath tissue, paper towels, dinner napkins, and the like. Suitable basis weights for such tissue webs can be from about 5 to about 40 pounds per 2880 square feet. The webs can be layered or unlayered (blended). The fibers making up the web can be any fibers suitable for papermaking. For most papermaking fabrics, however, hardwood fibers are especially suitable for this process, as their relatively short length maximizes debonding rather than molding during the wet-straining operation. The wet-straining process can be used for either layered or homogeneous webs.
In carrying out the method of this invention, the change in Debonded Void Thickness of the web when subjected to the wet-straining step can be about 5 percent or greater, more preferably about 10 percent or greater, and suitably from about 15 to about 75 percent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are cross-sectional photographs of a conventional wet-pressed tissue web and a tissue web processed in accordance with this invention, respectively, illustrating the increase in internal bulk resulting from the method of this invention.
FIGS. 2-7 are schematic flow diagrams of different aspects of the method of this invention referred to above.
FIGS. 8-13 pertain to the method of determining the Debonded Void Thickness of a sample.
FIG. 14 is a schematic illustration of the apparatus used to wet strain handsheets in the Examples.
FIG. 15 is a plot of the Debonded Void Thickness as a function of consistency, illustrating the data as described in Example 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Drawing, the invention will be described in greater detail. Wherever possible, the same reference numerals are used in the various Figures to identify the same apparatus for consistency and simplicity. In all of the embodiments illustrated, conventional papermaking apparatus and operations can be used with respect to the headbox, forming fabrics, dewatering, transferring the web from one fabric to another, drying and creping, all of which will be readily understood by those skilled in the papermaking art. Nevertheless, these conventional aspects of the invention are illustrated for purposes of providing the context in which the various wet-straining embodiments of this invention can be used.
FIGS. 1A and 1B are 150× photomicrographs of handsheets of nominally equal basis weight. The handsheet of FIG. 1A (Sample 1A) was wet-pressed, while the handsheet of Figure 1B (Sample 1B) was wet-pressed and thereafter wet-strained in accordance with this invention. Both handsheets were made from 50/50 blends of spruce and eucalyptus dispersed in a British Pulp Disintegrator for 5 minutes. Both sheets were then pressed between blotters in an Allis-Chalmers Valley Laboratory Equipment press for 10-15 seconds at 90-95 pounds per square inch gauge (psig) pressure. Sheet consistencies were 56±3 percent. Sample 1A was then dried while sample 1B was wet-strained as described herein and then dried. As the photos illustrate, the wet-straining reduced the density of the sheet yielding a significantly higher caliper. Sample 1A is typical of the structure of wet-pressed sheets while Sample 1B has a more debonded structure having greater internal bulk, similar to a throughdried sheet. The Debonded Void Thickness of Sheet 1A was 31.5 microns compared to 38.9 microns for Sheet 1B. Normalizing using basis weight led to Normalized Debonded Void Thickness values of 138.2 microns per gram and 169.9 microns per gram, respectively. The 23 percent increase in Normalized Debonded Void Thickness with only a 14 percent reduction in tensile strength (from 1195 grams per inch of sample width to 1029 grams) illustrates the improvement provided by wet-straining.
FIG. 2 illustrates a combination throughdried/wet-pressed method of making creped tissue in accordance with this invention. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto an endless forming fabric 2 through which some of the water is drained from the fibers. The resulting wet web 3 retained on the surface of the forming fabric has a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4'. The press nip further dewaters the wet web to a consistency of about 30 percent or greater. The dewatered web 6 is then transferred to a coarse mesh throughdrying fabric 7 and wet-strained with vacuum source 8 positioned underneath the throughdrying fabric to abruptly deflect some of the fibers in the web into the open areas or depressions in the throughdrying fabric and thereby partially debond the web and increase its caliper or thickness. Also shown is an optional wet-straining station comprising a coarse mesh fabric 9 and a vacuum source 8', which can be used in addition to the other wet straining operation or as a replacement therefor. Providing two wet-straining stations provides added flexibility in the use of two different coarse mesh fabrics, which can be utilized to wet-strain the web independent of the desired throughdrying fabric. The wet-straining stations can operate on the web simultaneously or in sequence. In addition, in all of the embodiments shown herein, the wet-straining vacuum sources can be assisted by providing a high pressure air source which directs an air stream onto the opposite side of the web, thereby providing a further increase in pressure differential across the coarse fabric and increasing the driving force to deflect fibers into the coarse fabric.
The wet-strained web 10 is then carried over the throughdrying cylinder 11 and preferably dried to a consistency of from about 85 percent to about 95 percent. The dried web 12 is then transferred to an optional transfer fabric 13, which can be either fine or coarse, which is used to press the web against the surface of the Yankee dryer 14 with pressure roll 15 to adhere the web to the Yankee surface. The web is then completely dried, if further drying is necessary, and dislodged from the Yankee with a doctor blade to produce a creped tissue 16.
FIG. 3 illustrates a wet-press method of this invention in which a throughdryer is not used. Shown is a headbox 1 which deposits an aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered in a press nip 5 formed between felt 4 and a second felt 4'. The dewatered web 6 is then transferred to a coarse mesh fabric 31 and wet-strained using vacuum source 8 before transferring to fabric 32. Optionally, a vacuum source 8" can be utilized in addition to vacuum source 8 or in place of vacuum source 8. If used in addition to vacuum source 8, additional wet-straining can be achieved. If the coarseness of fabric 32 is different than that of fabric 31 or if the mesh openings of the two fabrics do not coincide, areas of the web not strained by the first vacuum source can be strained by the second vacuum source. In any event, the second vacuum source acts upon the opposite side of the web to achieve additional straining and debonding of the web. Wet-straining from both sides of the web can be particularly advantageous if layered webs are present, especially if the outer layers are more susceptible to debonding than the inner layer(s). As previously mentioned, a predominance of hardwood fibers in the outer layer lends itself well to wet-straining. The wet-strained web 33 is then transferred to the surface of Yankee dryer 14 using pressure roll 15 and dislodged by doctor blade (creped), resulting in creped tissue 34.
FIG. 4 illustrates a method of this invention utilizing two dryers in series with wet-straining in between. Shown is a headbox 1 which deposits the aqueous suspension of papermaking fibers onto a forming fabric 2 to form a wet web 3 having a consistency of about 10 percent. The wet web is transferred to a papermaking felt 4 and further dewatered and pressed onto the surface of Yankee dryer 14 using pressure roll 15. The consistency of the web after transfer to the surface of the Yankee is preferably about 40 percent. (The Yankee can optionally be replaced by a throughdryer, which would require transfer of the web from the felt 4 to a throughdryer fabric or replacement of the felt with a throughdryer fabric, not shown.) The Yankee (or the throughdryer) serves to partially dry the dewatered web to a consistency of preferably from about 50 to about 70 percent. The partially-dried web is then transferred to a coarse mesh fabric 41 with the assistance of vacuum suction roll 42 and wet-strained using vacuum source 8. Optionally, the web can be sandwiched between fabric 41 and another coarse fabric 41' and further wet-strained using a second vacuum source 8'. The second vacuum source can be applied to the web simultaneously with vacuum source 8 to simultaneously act upon both sides of the web, or the second vacuum source can be applied upstream or downstream of the first vacuum source to sequentially act upon opposite sides of the web. In any event, the application of two or more vacuum straining sources is expected to provide more uniform debonding of the web. After wet-straining, the web is transferred to a Yankee dryer 14' for final drying and creped to yield a creped tissue web.
FIG. 5 illustrates another embodiment of this invention in which two throughdryers are used to dry the web. Shown is the headbox 1 which deposits the aqueous suspension of papermaking fibers onto the surface of forming fabric 2. The wet web 3 is transferred to an optional fine mesh transfer fabric 51 and thereafter transferred to a coarse mesh throughdryer fabric 7. The web is then partially dried in the first throughdryer 11 to a consistency of preferably about 45 percent. The partially dried web is then sandwiched between the throughdryer fabric 7 and coarse mesh fabric 52 and wet-strained using vacuum source 8. (For purposes herein, bringing a web into contact with a coarse mesh fabric, such as sandwiching the web against the coarse mesh fabric 52, is considered "transferring" the web to the coarse mesh fabric, even though the web continues to travel with a different fabric, such as the throughdryer fabric in this case.) Optionally, the web can be simultaneously or subsequently wet-strained from the opposite direction on the throughdryer fabric to further debond the web.
After wet-straining, the web is carried over a second throughdryer 11' and further dried to a consistency of preferably about 85 to about 95 percent, transferred to a fine mesh fabric 53, and pressed onto the surface of a Yankee dryer 14 for final drying, if necessary, and creping to produce creped web 27. In the case of final drying on the second throughdryer, transfer to the Yankee for creping is an option. It is within the scope of this invention that whenever a throughdryer is used to dry the web, the final product can be uncreped.
FIG. 6 illustrates a similar process to that of FIG. 5, but using two throughdrying fabrics. Shown is the headbox 1 depositing the aqueous suspension of papermaking fibers onto the surface of the forming fabric 2. The web 3 is transferred to optional fine mesh fabric 51 and thereafter transferred to throughdrying fabric 7. The web is carried over the first throughdryer 11 and partially dried to a consistency of preferably about 45 percent. The partially dried web is then transferred to a second throughdryer fabric 7' and sandwiched between the second throughdryer fabric and coarse fabric 61. Vacuum source 8 is used to wet-strain and partially debond the web as previously described. Optionally, the web can be wet-strained from the opposite direction using alternative vacuum source 8', either in addition to or in place of vacuum source 8. The web is then further dried in a second throughdryer 11', transferred to a Yankee 14 and creped. Optionally, the web can be wet-strained using optional vacuum sources 8" and 8'". If vacuum source 8" is used, a coarse fabric 62 is used to provide the depressions into which the fibers in the web are deflected.
FIG. 7 illustrates another embodiment of this invention, similar to that illustrated in FIG. 4, but using a throughdryer 11 to final dry the web.
FIGS. 8-14 pertain to the method for determining the Debonded Void Thickness, which is described in detail below. Briefly, FIG. 8 illustrates a plan view of a specimen sandwich 80 consisting of three tissue specimens 81 sandwiched between two transparent tapes 82. Also shown is a razor cut 83 which is parallel to the machine direction of the specimen, and two scissors cuts 84 and 85 which are perpendicular to the machine direction cut.
FIG. 9 illustrates a metal stub which has been prepared for sputter coating. Shown is the metal stub 90, a two-sided tape 91, a short carbon rod 92, five long carbon rods 93, and four specimens 94 standing on edge.
FIG. 10 shows a typical electron cross-sectional photograph of a sputter coated tissue sheet using Polaroid® 54 film.
FIG. 11A shows a cross-sectional photograph of the same tissue sheet as shown in FIG. 10, but using Polaroid 51 film. Note the greater black and white contrast between the spaces and the fibers.
FIG. 11B is the same photograph as that of FIG. 11A, except the extraneous fiber portions not connected or in the plane of the cross-section have been blacked out in preparation for image analysis as described herein.
FIG. 12 shows two Scanning Electron Micrograph (SEM) specimen photographs 100 and 101 (approximately 1/2 scale), illustrating how the photographs are trimmed to assemble a montage in preparation for image analysis. Shown are the photo images 102 and 103, the white border or framing 104 and 105, and the cutting lines 106 and 107.
FIG. 13 shows a montage of six photographs (approximately 1/2 scale) in which the white borders of the photographs are covered by four strips of black construction paper 108.
FIG. 14 is a schematic illustration of the apparatus used to wet strain sample handsheets as described in the Examples. Shown is a sample holder 110 which contains an Asten 934 throughdrying fabric. The sample holder is designed to accept a similarly sized handsheet mold in which the handsheet sample is formed and supported by a suitable forming fabric. Also shown is a vacuum tank 111, a slideable rod 112 connected to a slideable "sled" 113 having a 1/4 inch (0.63 centimeters) wide slot 114 through which vacuum is applied to the sample, a pneumatic cylinder 115 for propelling the sled underneath the sample, and a shock absorber 116 for receiving and stopping the rod. In operation, the vacuum tank is evacuated as indicated by arrow 117 to the desired vacuum level via a suitable vacuum pump. The handsheet, while still in the handsheet mold and having one side is still in contact with the forming fabric of the handsheet mold and at the desired consistency, is placed "upside down" in the sample holder of the illustrated apparatus such that the other side of the handsheet is in contact with the throughdryer fabric of the sample holder. The pneumatic cylinder is then pressurized with nitrogen gas to cause the rod 112 and the connected sled 113 to move at a controlled speed toward the shock absorber at the end of the apparatus. In so doing, the slot in the sled briefly passes under the sample holder as shown and thereby briefly subjects the sample to the vacuum, thereby mimicking a continuous process in which the tissue is moving and the vacuum slot is fixed. The brief exposure to vacuum wet strains the sample as it is transferred to the throughdrying fabric in the sample holder. The handsheet is then dried to final dryness while supported by the throughdrying fabric by any suitable noncompressive means such as throughdrying or air drying. In all of the examples described herein, the speed of the sled was 2000 feet per minute (10.1 meters per second) and the level of vacuum was 25 inches of mercury.
Debonded Void Thickness
The method for determining the Debonded Void Thickness (DVT) is described below in numerical stepwise sequence, referring to FIGS. 8-13 from time to time. In general, the method involves taking several representative cross-sections of a tissue sample, photographing the fiber network of the cross-sections with a scanning electron microscope (SEM), and quantifying the spaces between fibers in the plane of the cross-section by image analysis. The total area of spaces between fibers divided by the frame width is the DVT for the sample.
A. Specimen Sandwiches
1. Samples should be chosen randomly from available material. If the material is multi-ply, only a single ply is tested. Samples should be selected from the same ply position. The same surface is designated as the upper surface and samples are stacked with the same surface upwards. Samples should be kept at 30° C. and 50 percent relative humidity throughout testing.
2. Determine the machine direction of the sample, if it has one. The cross-machine direction of the sample is not tested. The cross-section will be cut such that the cut edge to be analyzed is parallel to the machine direction. For strained handsheets the cut is made perpendicular to the wire knuckle pattern.
3. Place about five inches (127 millimeters) of tape (such as 3M Scotch™ Transparent Tape 600 UPC 021200-06943), 3/4 inch (19.05 millimeters) width, on a working surface such that the adhesive side is uppermost. (The tape type should not shatter in liquid nitrogen).
4. Cut three 5/8 inch (or 15.87 millimeters) wide by about 2" (or 50.8 millimeters) long specimens from the sample such that the long dimension is parallel to the machine direction.
5. Place the specimens on the tape in an aligned stack such that the borders of the specimens are within the tape borders (see FIG. 8). Specimens which adhere to the tape will not be usable.
6. Place another length of tape of about 5 inches (or 127 millimeters) on top of the stack of specimens with the adhesive side towards the specimens and parallel to the first tape.
7. Mark on the upper surface of the tape which is the upper surface of the specimen.
8. Make twelve specimen sandwiches. One photo will be taken for each specimen.
B. Liquid Nitrogen Sample Cutting
Liquid nitrogen is used to freeze the specimens. Liquid nitrogen is dispensed into a container which holds the liquid nitrogen and allows the specimen sandwich to be cut with a razor blade while submerged. A VISE GRIP™ pliers can hold the razor blade while long tongs secure and hold the specimen sandwich. The container is a shallow rigid foam box with a metal plate in the bottom for use as a cutting surface.
1. Place the specimen sandwich in a container which has enough liquid nitrogen to cover the specimen. Also place the razor blade in the container to adjust to temperature before cutting. A new razor blade must be used for each sandwich to be cut.
2. Grip the razor blade with the pliers and align the cutting edge length with the length of the specimen such that the razor blade will make a cut that is parallel with the machine direction. The cut is made in the middle of the specimen. (See FIG. 8).
3. The razor blade must be held perpendicular to the surface of the specimen sandwich. The razor blade should be pushed downward completely through the specimen sandwich so that all layers are cleanly cut.
4. Remove the specimen sandwich from the liquid nitrogen.
C. Metal Stub Preparation
1. The metal stubs' dimensions are dictated by the parameters of the SEM. The dimensions as illustrated in FIG. 9 are about 22.75 millimeters in diameter and about 9.3 millimeters thick.
2. Label back/bottom of stub with the specimen name.
3. Place a length of two-sided tape (3M Scotch™ Double-Coated Tape, Linerless 665, 1/2 inch [or about 12.7 millimeters] wide) across the diameter of the stub. (See FIG. 9).
4. Place about a 1/4" (or about 6.35 millimeters) length of 1/8 inch (or about 3.17 millimeters) diameter carbon rod (manufacturer: Ted Pella, Inc., Redding, Calif., 1/8" [or 3.17 millimeters] diameter by 12-inch [or 304.8 millimeters] length, Cat. #61-12) at one end of the tape within the edges of the stub such that its length is perpendicular to the length of the tape. This marks the top of the stub and the upper surface of the specimen.
5. Place a longer rod below the short rod. The length of the rod should not extend beyond the edge of the stub and should be approximately the length of the specimen.
6. Cut the specimen sandwich perpendicular to the razor cut at the ends of the razor cut (see FIG. 8).
7. Remove the inner specimen and place standing up next to (and touching) the carbon rod such that its length is parallel to the rod's length and its razor cut edge is uppermost. The upper surface of the specimen should face the small carbon rod.
8. Place another carbon rod approximately the length of the specimen next to the specimen such that it is touching the specimen. Again, the rod should not extend beyond the disk edges.
9. Repeat specimen, rod, specimen, rod until the metal stub is filled with four specimens. Three stubs will be used for the procedure.
D. Sputter Coating the Specimen
1. The specimen is sputter coated with gold (Balzar's Union Model SCD 040 was used). The exact method will depend on the sputter coater used.
2. Place the sample mounted on the stub in the center of the sputter coater such that the height of the sample edge is about in the middle of the vacuum chamber, which is about 11/4 inches (or 31.75 millimeters) from the metal disk.
3. The vacuum chamber arm is lowered.
4. Turn the water on.
5. Open the argon cylinder valve.
6. Turn the sputter coater on.
7. Press the SPUTTERING button twice. Set the time using SET and FAST buttons. Three minutes will allow the specimen to be coated without over-coating (which could cause a false thickness) or under coating (which could cause flaring).
8. Press the STOP button once so it is flashing. Press the TENSION button at this time. The reading should be 15-20 volts. Hold the TENSION button down and press CURRENT UP and hold. After about a ten-second delay, the reading will increase. Set to approximately 170-190 volts. The current will not increase unless the STOP button is flashing.
9. Release the TENSION and CURRENT UP buttons as you turn the switch on the arm to the green dot to open the window. The current should read about 30 to 40 milliamps.
10. Press the START button.
11. When completed, close the window on the arm and turn the unit off. Turn off the water and argon. Allow the unit to vent before the specimen is removed.
E. Photographing with the SEM (JEOL, JSM 840 II, distributed by Japanese Electro Optical Laboratories, Inc. located in Boston, Mass.). A clear, sharp image is needed. Several variables known to those skilled in the art of microscopy must be properly adjusted to produce such an image. These variables include voltage, probe current, F-stop, working distance, magnification, focus and BSE Image wave form. The BSE wave form must be adjusted up to and slightly beyond the reference limit lines in order to obtain proper black-&-white contrast in the image.
These variables are adjusted to their optimum to produce the clear, sharp image necessary and individual adjustments are dependent upon the particular SEM being used. The SEM should have a thermatic source (tungsten or Lab 6) which allows large beam current and stable emission. SEMs which use field emission or which do not have a solid state back scatter detector are not suitable.
1. Load the stub such that the specimen's length is perpendicular to the tilt direction and lowered as far as possible into the holder so that the edge is just above the holder. Scan rotation may be necessary depending on the SEM used.
2. Adjust the working distance (39 millimeters was used). The specimen should fill about 1/3 of the photo area, not including the mask area. (For handsheets, a magnification of 150× was used.)
3. Use the tilt angle of the SEM unit to show the very edge of the specimen with as little background fibers as possible. Do not select areas that have long fibers that extend past the frame of the photo.
4. One photomicrograph is taken using normal film (POLAROID 54) for gray levels for comparison. The F-stop may vary. The areas selected should be representative and not include long fibers that extend beyond the vertical edge of the viewing field.
5. Without moving the view, take one photomicrograph using back scatter electrons with high contrast film (51 Polaroid). The F-stop may vary. A sharp, clear image is needed. After the photomicrographs are developed, a black permanent marker is used to black out background fibers that are out of focus and are not on the edge of the specimen. These can be selected by comparing the photomicrograph to the gray level photomicrograph of Step 4 above. (See FIGS. 10 and 11.)
6. A total of twelve photomicrographs are taken to represent different areas of the specimens; one photomicrograph is taken of each specimen.
7. A protective coating is applied to the photo on 51 film.
F. Image Analysis of SEM Photos
1. The 12 photos are arranged into two montages. Six photos are used in each montage. Make two stacks of six photos each, and cut the white framing off the left side of one and the white framing off the right side of the remaining stack without disturbing the photos. (See FIG. 12.)
2. Then, taking one photo from each stack, place cut edges together and tape together with the tape on the back of the photo (3M Highland™ Tape, 3/4 inch [or 19.05 millimeters]). No extraneous white of the background should show at the cut, butted edges.
3. Arrange the photos with a small overlap from top to bottom as in FIG. 13.
4. Turn on the image analyzer (Quantimet 970, Cambridge Instruments, Deerfield, Ill.). Use a 50 mm. El-Nikkor lens with C-mount adaptor (Nikon, Garden City, N.Y.) on the camera and a working distance of about 12 inches (305 millimeters). The working distance will vary to obtain a sharp clear image on the monitor and the photo. Make sure the printer is on line.
5. Load the program (described below).
6. Calibrate the system for the photo magnification (which will generate the calibration values indicated by "x.xxxx" in the program listed below), set shading correction with white photo surface (undeveloped x-ray film), and initialize stage (12 inches by 12 inches open frame motor-driven stage (auto stage by Design Components, Inc., Franklin, Mass.)) with step size of 25 microns per step.
7. Load one of the two photo montages under a glass plate supported on the stage after strips of black construction paper are placed over the white edges of the photos. The strips are 3/4 inch wide (18.9 millimeter) and 11 inches long (279 millimeters) and are placed as in FIG. 13 so that they do not cover the image in the photo. The montage is illuminated with four 150 watt, 120 volt GE reflector flood lamps positioned with two lamps positioned at an angle of about 30° on each side of the montage at a distance of about 21 inches (533 millimeters) from the focus point on the montage.
8. Adjust the white level to 1.0 and the sensitivity to about 3.0 (between 2 and 4) for the scanner using a variable voltage transformer on the flood lamps.
9. Run the program. The program selects twelve fields of view: two per photomicrograph.
10. Repeat at the pause with the second montage after completion of twelve fields of view on the first montage.
11. A printout will give the Debonded Void Thickness.
__________________________________________________________________________G. Computer Program.Enter specimen identityScanner (No. 2 Chainicon LV = 0.00 SENS = 1.64 PAUSE)Load Shading Corrector (pattern - OFOSU3)Calibrate User Specified (Calibration Value = x.xxxx microns per pixel) (PAUSE)CALL STANDARDTOTDEBARE : = 0.For SAMPLE = 1 to 2Stage Scan ( x y scan origin 10000.0 10000.0 field size 16500.0 11000.0 no. of fields 3 4Detect 2D (Lighter than 32 PAUSE)For FIELDScanner (No. 2 ChaLnicon AUTO-SENSITIVITY LV = 0.00)Live Frame is Standard Live FrameDetect 2D (Lighter than 32)Amend (OPEN by 1)Measure field - Parameters into array FIELDRAWAREA: = FIELD AREAAmend (CLOSE by 20)Image Transfer from Binary 8 (FILL HOLES) to Binary OutputMeasure field - Parameters into array FIELDFILLAREA: = FIELD AREADEBNAREA: = FILLAREA - RAWAREATOTDEBARE: = TOTDEBARE + DEBNAREAStage StepNext FIELDPauseNextFIELDNUM: = FIELDNUM * (SAMPLE - 1.)Print " "Print "DEBOND VOID THICKNESS =", (TOTDEBARE / FIELDNUM)/(625.*CAL.CONST)Print " "For LOOPCOUNT = 1 to 7Print " "NextEnd of Program__________________________________________________________________________
EXAMPLES
In order to further illustrate the invention, a number of handsheets were prepared as follows:
The pulp was dispersed for five minutes in a British pulp disintegrator. Circular handsheets of four-inch diameter, conforming precisely to the dimensions of the sample holder used for wet-straining, were produced by standard techniques. The sample holder contained a 94-mesh forming fabric on which the handsheets were formed. After formation the handsheets were at about 5 percent consistency. For those samples not wet-pressed (Example 1), the samples were dried to the consistency selected for wet-straining by means of a hot lamp and then wet-strained. For those experiments involving pressing (Example 2), the handsheet was removed from the sample holder by couching with a dry blotter. The sheet was then pressed in an Allis-Chalmers Valley Laboratory Equipment press. Pressing time and/or pressure were varied to achieve the desired post-pressing consistency. Selected samples were then wet-strained.
Wet-straining of the handsheets was performed using the apparatus previously described in reference to FIG. 14. In all cases, a sample holder containing an Asten 934 throughdrying fabric was placed in the wet-straining apparatus. When the base sheet reached the desired consistency, either by pressing or drying with the lamp, the holder on which the sheet was formed was placed "upside down" in the straining apparatus such that the surface of the sheet not in contact with the forming fabric came in contact with the surface of the throughdrying fabric. A sled was then caused to slide underneath the sample holders exposing the sheet to vacuum, causing the sheet to be wet-strained and transferred to the throughdrying fabric. In all cases, a sled speed of 2000 fpm and a vacuum of 25 inches of mercury were utilized. The sheet, now located on the throughdrying fabric, was then dried to complete dryness in a noncompressive manner.
Example 1
Handsheets were made from a 100 percent eucalyptus furnish and dried with a hot lamp to various consistencies prior to wet-straining as described above. After wet-straining, various physical parameters were measured as shown in TABLE 1 below. (Sample weight is expressed in grams; Consistency is expressed in weight percent; Tensile strength is expressed as grams per inch of sample width; Normalized tensile strength is the tensile strength divided by the sample weight, expressed as reciprocal inches; Debonded Void Thickness is expressed as microns; and Normalized Debonded Void Thickness is the Debonded Void Thickness divided by the sample weight, expressed as microns per gram.)
TABLE 1______________________________________ Consistency Normalized Prior to Debonded DebondedSample Wet Ten- Normalized Void VoidWeight Straining sile Tensile Thickness Thickness______________________________________0.305 13.2 420 1377 86.1 282.30.235 33.6 396 1685 84.1 357.90.227 46.3 255 1123 82.6 363.9______________________________________
For comparison, an air-dried control sample (not wet-strained) weighing 0.238 grams had a tensile strength of 460 grams, a normalized tensile of 1933, a Debonded Void Thickness of 73 microns, and a Normalized Debonded Void Thickness of 306.7 microns per gram.
These results clearly show that wet-straining can be used to increase the void area relative to the weight of the sheet. As the data indicates, conducting the wet-straining at only 13 percent consistency (below the level claimed in this application) did not result in a significant increase in Normalized Debonded Void Thickness. Instead the sheet was primarily molded to the shape of the fabric. However, for the samples wet-strained at higher consistency, a definite increase in the Normalized Debonded Void Thickness was apparent and the tensile strength (a measure of bonding in the sheet) significantly decreased. Hence wet straining becomes effective at approximately 30 percent consistency or greater, with an optimum wet-straining consistency varying with furnish, fabric, etc. However, the optimum consistency is believed to lie in the 40-50 percent range.
Example 2
Handsheets nominally weighing 0.235±0.200 grams were made from a 50/50 blend by weight of eucalyptus and spruce fibers. One set of handsheets was pressed to various consistencies (not wet strained) to serve as a control. Another set was pressed to approximately 50 percent consistency and then wet strained as described above. Consistencies, sample weights and the Debonded Void Areas were measured for each sample. The data is tabulated in TABLE 2 below and further illustrated in FIG. 15. The first six samples listed represent the control samples. The last five samples are the wet-strained samples.
TABLE 2______________________________________ Post Normalized Pressing Normal- Debonded DebondedSample Consis- ized Void VoidWeight tency Tensile Tensile Thickness Thickness______________________________________0.252 30.7 662 2627 73.2 290.50.224 31 760 3393 56.5 252.20.237 34.9 684 2886 72.6 306.30.241 35 761 3158 59.1 245.20.228 58.5 1195 5241 31.5 138.20.229 60.3 1207 5271 29 126.60.224 51.3 774 3455 58.6 261.60.246 51.5 887 3606 64.2 2610.23 52.6 848 3687 63.1 274.30.229 54.3 1029 4493 38.9 169.90.241 58.9 826 3427 55.2 229AVER- 53.72 239.2AGE______________________________________
As shown in FIG. 15, the line in this figure is a regression line for the control data according to the equation: Normalized Debonded Void Thickness=444.5-(5.22×Consistency). As expected, the Normalized Debonded Void Thickness linearly decreased with pressing. While pressing is an effective means for removing water, it causes densification that reduces the Normalized Debonded Void Thickness and makes the resulting sheet less bulky and absorbent.
Also shown in FIG. 15 are the data points for the five wet straining samples and the arithmetic average for the five samples. The average Normalized Debonded Void Thickness of 239.2 at an average consistency of 53.7 percent was 46 percent higher than the predicted value of 163.8 at 53.7 percent consistency from the regression equation. This increase in Normalized Debonded Void Thickness is the desired result of the wet straining operation.
Hence it is clear that wet straining can be used to significantly increase the Debonded Void Thickness of paper. The benefits of this process can be manifested as higher Debonded Void Thickness at a given level of pressing or as the ability to press to a higher consistency while maintaining a given level of Debonded Void Thickness. Which approach is best depends on the amount of bulk and absorbency desired for a given product and the limitations of the particular papermaking process being utilized. In either case, an improved product can be produced via wet straining in accordance with this invention.
It will be appreciated that the foregoing examples, given for purposes of illustration, are not to be construed as limiting the scope of this invention, which is defined by the following claims and all equivalents thereto. | The internal bulk of a tissue web can be improved during manufacturing of the basesheet by subjecting the tissue web to differential pressure while supported on a coarse fabric at a consistency of about 30 percent or greater. The differential pressure, such as by applying vacuum suction to the underside of the coarse fabric, causes the wet web to deflect into the openings or depressions in the fabric and "pop" back, resulting in a substantial gain in thickness or internal bulk. The method is especially adapted to improve the internal bulk of wet-pressed tissue webs. | 3 |
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/377,255, filed Feb. 28, 2003, which is a continuation of U.S. Pat. No. 6,527,775, filed Sep. 22, 2000, the contents of which are hereby incorporated by reference as recited in full herein.
FIELD OF THE INVENTION
[0002] This invention relates to devices and methods for treating distal radius fractures.
BACKGROUND OF THE INVENTION
[0003] Distal radius fractures are among the most common type of bone fracture of the upper extremities. The distal radius fracture is often called a “Colles” fracture (named after a 19 th Century British surgeon who described the fracture). The Colles fracture is associated with a fracture of a distal tip or distal end portion of the radius.
[0004] Distal radius fractures are, unfortunately, most common in the elderly segment of the population. This is because the elderly tend to exhibit some degree of bone density loss or osteoporotic condition making their bones more susceptible to injury. Indeed, just as osteoporosis is known to affect women more often and more severely than men, distal radius fractures are much more common in females than males, typically on the order of about 20:1. Distal radius fractures generally occur as a result of a fall, because the patient tends to brace for the fall by outstretching the hand which then fractures upon impact, at the distal radius at or adjacent the wrist.
[0005] As shown in FIGS. 1 and 2 , the distal radius fracture is such that the major fracture line 15 associated with this type of injury generally occurs just above or proximal to the articular joint surface 11 of the distal radius at the wrist about the metaphysis 12 . As shown in FIGS. 1 and 2 , one common distal radius fracture type separates the shaft 13 of the radius 10 from the distal end portion of the bone. That is, the fracture line 15 defines a first major bone fragment 18 which is located above the fracture line 15 (the distal side) proximate the articular joint surface 11 and extends substantially medially (laterally) across the radius 10 in the metaphysis region. Although not shown, the fracture may also produce smaller bone fragments or splinters along the fracture line. Further, the distal end portion of the radius may be present as multiple (vertically and/or horizontally oriented) fragments disrupting the articular joint surface itself. This latter type of Colles fracture is known as a comminuted intraarticular fracture (not shown).
[0006] FIG. 1 illustrates the fracture line 15 in the radius 10 as a substantially horizontal line which produces an upper or distal fracture fragment 18 as a substantially unitary fragment. Similarly, FIG. 2 illustrates a fracture line 15 in the radius 10 which is offset from a horizontal axis.
[0007] Distal radius fractures can be difficult to treat, particularly in the older osteoporotic patient. Conventionally, this type of fracture has been treated by a closed (non-surgical) reduction and application of a splint (such as a plaster compression dressing) or a cast (typically circular plaster or fiberglass). Unfortunately, primarily because of the patient's osteoporosis, during the healing process, and despite the splint/cast immobilization, the fracture fragments can settle, potentially causing a collapse at the fracture line in the distal radius. FIG. 2 illustrates a loss of radial inclination (in degrees) and a shortened length in the skeletal length line (shown with respect to a neutral length line “L”) which can occur after a fracture in the distal radius. That is, even healed, these types of fractures may cause shortening or collapse of the bone structure relative to the original skeletal length line. This, in turn, can result in deformity and pain.
[0008] Treatment options for a collapsed distal radius fracture are relatively limited. The primary conventional treatments include the use of devices which can be characterized as either external fixation devices or internal fixation devices. External fixation devices are those that stabilize a fracture through the use of percutaneous pins which typically affix one or more bone portions to an external (anchoring or stabilizing) device. Internal fixation devices are those devices which are configured to reside entirely within the subject (internal to the body). Percutaneous pins can be used alone, without anchoring devices, for fixation of Colles type fractures. The use of external devices has conventionally been thought to be particularly indicated in cases of bone toss to preserve skeletal length as noted, for example, in U.S. Pat. No. 5,571,103 to Bailey at col. 1, lines 35-43. However, such devices can be bulky, cumbersome, and or invasive to the user or patient. Further the external fixation devices may not be suitable for use in soft osteoporotic bone.
[0009] In view of the foregoing, there remains a need for improved distal radius fracture treatment devices and techniques.
SUMMARY OF THE INVENTION
[0010] In a preferred embodiment the present invention provides methods and devices for treating fractures in or adjacent the wrist and distal forearm. The present invention is particularly useful for stabilizing and treating distal radius fractures of a patient. The devices and methods of the present invention employs an intramedullary interlocking fixation rod (i.e, it interlocks the distal and proximal fracture fragments together) to stabilize the skeletal structure in a manner which can inhibit the amount of collapse or loss in skeletal length exhibited by a patient with a distal radius fracture. The devices and methods of the present invention may be especially useful for treating distal radius fractures in subjects with osteoporosis.
[0011] One aspect of the invention is a method for treating a distal radius fracture of a patient comprising the use of an internal fixation rod. As noted above, the radius anatomically has an articular joint surfaces a metaphysis region, a shaft portion and a medullary canal associated therewith. The distal radius fracture has a fracture line which divides the radius into a distal fracture fragment portion and a proximal fracture fragment portion. The distal fragment portion includes the distal end of the radius proximate the articular joint surface, and the distal portion of the fracture has a width thereacross. The method comprises the steps of: (a) installing an elongated rod having opposing proximal and distal portions into the medullary canal of the patient such that the proximal portion of the rod resides above the fracture line (closer to the elbow) and the distal portion of the rod resides below the fracture line (closer to the hand); (b) securing a distal fixation member to the elongated rod and into the distal end portion of the radius at a location which is below the fracture line such that the distal fixation member extends internal of the patient substantially laterally across a portion of the width of the distal fracture fragment; and (c) anchoring the elongated rod inside the medullary canal of the radius at a location which is above (distal to) the fracture line.
[0012] Another aspect of the present invention is an internal fixation device for eating or repairing distal radius fractures having a fracture line forming distal and proximal fracture fragments. The radius is anatomically configured with a distal articular joint surface, a metaphysis region, a shaft, and a medullary canal. The anatomic position of the hand is palm forward or front such that the medial orientation is next to the body (fifth finger or ulna side of hand) and the lateral orientation is away from the body (thumb or radial side). Generally stated, the distal portion of the radius has a width which extends across (a major portion of) the arm from the medial side to the lateral side. The device includes an elongated fixation rod having opposing proximal and distal portions. The distal portion includes a head with a laterally extending distal aperture formed therein, and the proximal portion comprises at least one proximal aperture formed therein. The elongated fixation rod proximal portion is sized and configured such that, in position, it resides in the shaft inside a portion of the medullary canal of the radius of a patient. The device also includes a distal fixation member configured to enter the distal aperture and attach to the rod and the distal fracture fragment to hold the distal portion of the rod to the distal fracture fragment. The device further includes at least one proximal fixation member, a respective one for each of the at least one proximal apertures. The proximal fixation member is configured to secure the lower portion of the fixation rod to the radius at a position which is distal to the fracture line. In position, the elongated fixation rod is configured to reside within the radius, and the distal fixation member and the at least one proximal fixation member are configured to reside internal of the body of the patient.
[0013] In a preferred embodiment, the elongated fixation rod has a curvilinear profile. The curvilinear profile includes a distal curve portion at the distal portion of the device. The distal curve portion is adapted to accommodate the radial styloid region of the radius proximate the articular joint surface. The rod can also be provided as a plurality of segments matable or attachable. In one embodiment an intermediate segment can be provided in different lengths to allow for the adjustment of length according to a patient's anatomical considerations. Of course, the rod can be a unitary body provided in a number of standard sizes preferably statistically representative of the treatment population.
[0014] The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an anterior-posterior view of a distal radius fracture illustrating a fracture line proximate the articular joint surface.
[0016] FIG. 2 is an anterior-posterior view of a distal radius fracture similar to that shown in FIG. 1 . This figure illustrates an alternatively configured fracture line proximate the articular joint surface.
[0017] FIG. 3A is an anterior-posterior view of an intramedullary fixation rod attached to the radius for treating a distal radius fracture according to an embodiment of the present invention.
[0018] FIG. 3B is an exploded view of the distal fixation attachment member shown inserted into the fixation rod in FIG. 3A according to one embodiment of the present invention.
[0019] FIG. 4 is a front schematic view of the distal fixation rod of FIG. 3A in position as an internal fixation device held within the body of the patient according to one embodiment of the present invention.
[0020] FIG. 5A is a lateral view of an intramedullary rod configured to interlock or affix the bone fragments of a distal radius fracture according to one embodiment of the present invention.
[0021] FIG. 513 is a cross-sectional view of the rod shown in FIG. 5A taken along line 5 B- 5 B.
[0022] FIG. 6 is a perspective view of an intramedullary fixation device according to one embodiment of the present invention.
[0023] FIG. 7 is a side view (shown oriented anterior to posterior) of an alternate embodiment of an intramedullary system according to the present invention.
[0024] FIG. 8 is a side view (shown oriented anterior to posterior) off another embodiment of an intramedullary system according to the present invention.
[0025] FIG. 9A is a front anterior-posterior view of an alternate embodiment of a distal fixation rod according to the present invention.
[0026] FIG. 9B is an exploded view of the biked or multi-segment according to FIG. 9A .
[0027] FIG. 9C is a front view of a set of intermediate rod segments according to an embodiment of the present invention.
[0028] FIG. 10 is a schematic side view of an intramedullary system with an external detachable positioning guide according to an embodiment of the present invention.
[0029] FIG. 11 is a block diagram of the steps of treating a distal radius fracture according to one embodiment of the present invention.
[0030] FIG. 12 is perspective view of the arm of a patient illustrating a sigmoid or longitudinal incision over the radial styloid area.
[0031] FIG. 13 is an enlarged schematic view of the incision site in the patient shown in FIG. 12 to illustrate preparation of the site for positioning intramedullary fixation rods for distal radius fractures according to an embodiment of the present invention.
[0032] FIG. 14 is an enlarged schematic view of the incision site shown in FIG. 13 illustrating that a small bone window may be made or formed into the radius such that it extends across the fracture site according to the present invention.
[0033] FIG. 15A is an anterior-posterior view of the bone window shown in FIG. 14 ,
[0034] FIG. 15B is a schematic view of the prepared bone site shown in FIG. 15A illustrating the use of a sound or broach instrument which is sized and configured to be inserted into the intramedullary canal of the radius to determine size and/or open or prepare the canal to receive a fixation rod according to an embodiment of the present invention.
[0035] FIG. 16 is a top anterior-posterior view of an intramedullary fixation rod assembled to a rod driver and screw attachment guide according to one embodiment of the present invention.
[0036] FIG. 17 is a side (lateral) view of the device shown in FIG. 16 .
[0037] FIG. 18 is a side of the device shown in FIGS. 16 and 17 showing the device in position in the patient.
[0038] FIG. 19 is a top anterior-posterior view of the device shown in position in FIG. 18 .
[0039] FIG. 20 is a schematic view of the fixation rod in position in the subject according to an embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] The present invention will now be described more fully hereinafter with reference to the accompanying figures, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout. In the figures, certain layers, regions, or components may be exaggerated for clarity.
[0041] As shown in FIG. 3A , in a preferred embodiment, the intramedullary fixation device 25 includes an elongated axially extending rod 26 with a distal portion 27 and a proximal portion 28 . The device 25 also includes a distal fixation member 30 and at least one proximal fixation member 35 (shown as two proximal fixation members 35 a , 35 b ). The rod 26 includes a head 26 h at the distal end portion 27 of the rod 26 . A distal aperture 30 a is formed into the head 26 h of the distal portion such that it extends across the width of the rod 26 .
[0042] As shown, the distal fixation member 30 is configured to enter and extend through and beyond the distal aperture 30 a to engage with the distal fracture fragment 18 and secure the rod 26 and the distal fracture fragment 18 theretogether. Preferably, the distal fixation member 30 is sized to extend across a major portion of the width of the distal fracture fragment 18 . More preferably, the distal fixation member 30 is sized with a length which is sufficient to extend across substantially all of the fracture fragment 18 so as to provide support for the radial, center, and ulna aspects of the distal fracture fragment 18 (the ulna aspect being the part of the fracture fragment adjacent or proximate the ulna 14 while the radial aspect being the portion of the fracture fragment on the opposing side of the view shown in FIG. 3A and the center aspect being the portion in between).
[0043] FIG. 3B illustrates the distal fixation member 30 apart from the rod 26 . The distal fixation member 30 can be configured as any suitable attachment means to secure the distal fracture fragment 18 to the rod 26 , while also providing lateral structural reinforcement. For example, but not limited to, the attachment means can be one or more of a pin, nail, threaded or partially threaded member such as a screw, or a combination of the above. FIG. 3B illustrates the distal fixation member 30 as having, in serial order, from one end to the other, a head portion 30 h , a threaded portion 30 th , and a pin portion 30 p.
[0044] In one embodiment, as shown in FIG. 3A , the head of the distal fixation member 30 h extends beyond the edge of the body of the rod 26 . However, as schematically shown in FIG. 7 , the aperture 25 a can be configured (such as with a countersunk or recessed portion configured with a depth sufficient to receive the head 30 h therein) such that upon assembly, the distal fixation member head 30 h is substantially flush or recessed with the outer contour or profile of the rod 26 . FIG. 3A also illustrates that, in position in the patient, the distal fixation member 30 is preferably configured to directly abut the outer surface of the rod 26 . FIG. 6 is a perspective view of one embodiment of the intramedullary fixation device 25 . This embodiment shows that the rod 26 is configured as a unitary body with a recess to receive the head 30 h of the distal fixation member 30 .
[0045] In a preferred embodiment, the rod 26 is configured with a profile 26 p which is curvilinear when viewed from the anterior-posterior view, as shown, for example, in FIGS. 3A and 4 . As shown, the proximal portion of the rod 28 is substantially linear and is configured to anally extend within the medullary canal of the patient in the radial shaft. As the rod 26 approaches the metaphysis region ( 12 , FIG. 1 ) it gradually curves from the substantially linear axial extending portion so as to position the distal end 27 e of the rod 26 proximate the radial styloid region of the distal radius. Preferably, the rod 26 is configured to follow the contour line of the radius as it transitions from the proximal portion 28 having a substantially linear contour in the shaft region to the distal portion 27 which has a curvilinear or slight arcuately contoured shape proximate the metaphysis region.
[0046] FIGS. 3A and 4 also illustrate that the head 26 h of the rod 26 is preferably configured with a body which has an increased perimeter or area size with respect to the proximal 28 portion of the rod 26 . It is also preferred that the distal end of the head 26 h be beveled or inclined 27 i . As shown, the tip or end of the head 26 b lopes downwardly from the side surface adjacent the radial portion toward the ulna aspect of the fracture fragment 18 .
[0047] It is additionally referred that the distal aperture 30 a be formed in the rod 26 such that it allows the distal fixation member 30 to extend therethrough and reside at a position which is angularly offset tore the axial is. As show in FIG. 3A , the axial axis is coincident with the centerline of the proximal portion of the rod (indicated by the letter “a” in FIG. 3A ). Preferably, the distal fixation member 30 extends at a position which is less than about ninety degrees, and preferably between about 10 degrees to less than about 90 degrees, away from the axial axis, such that it is approximately in-line with the articular surface.
[0048] In this embodiment, the head 26 h of the rod 26 can buttress the distal radius region and increase the structural effectiveness of the rod. Thus, together with the proper positioning of the distal portion 27 of the rod 26 in the distal radius and/or the medial extension of the distal fixation member 30 , the head 26 h , can reinforce or positively affect the structural integrity of the device to help support the radial styloid region of the distal fracture fragment.
[0049] Referring again to FIG. 3A and FIG. 4 , at least one, and preferably two or more, proximal fixation members 35 are used to secure the rod 26 to the shaft region 13 of the radius 10 at the lower or proximal portion of the rod 26 . FIG. 3A illustrates the use of two similarly sized proximal fixation members 35 a , 35 b , respectively, while FIG. 4 illustrates the use of one 35 . Preferably, as shown in FIG. 5A , the proximal fixation members 35 a , 35 b are respective self-tapping screws positioned on the rod 26 such that they are proximate to each other. However, pins, nails, or other attachment means (as well as numbers and positioning of same) can also be used as will be appreciated by one of skill in the art. It will be appreciated, by those of skill in the art, that the proximal fixation members 35 and corresponding apertures 25 a are primarily used to inhibit shortening of the skeletal structure. As shown in FIG. 5A , the proximal fixation member 35 transversely extends in serial order, through a portion of the radius shaft, through a corresponding proximal receiving aperture 25 a formed in the rod 26 , and then into an opposing portion of the radius shaft to thereby secure or locate and hold the proximal portion of the rod 25 relative to the radius, the proximal fixation member having a length and opposing ends sized and configured accordingly 36 , 38 .
[0050] FIG. 4 schematically illustrates the preferred post-operative position of the intramedullary fixation device 25 in the patient. That is, post-operatively in position in the patient, the rod 26 and distal and proximal fixation members 30 , 35 are held within the body of the subject such that the device 25 is an internal fixation device and is devoid of externally located coupling or fixation members.
[0051] As shown in FIG. 4 , the rod 26 is installed into the medullary canal of the patient such that the distal portion 27 of the rod 26 resides distal to the fracture line 15 (but substantially within the distal radius, preferably so as to reside proximal to the articular joint surface 11 ) and the bottom or proximal portion 28 of the rod 26 extends through and resides proximal to the fracture line 15 . The distal fixation member 30 is secured to the rod 26 and to the distal end portion of the radius at a location which is distal to the fracture line 15 in the metaphysis region of the distal radius. As is also shown, the distal fixation member 30 extends (to reside internal of the body of the patient) substantially transversely across a portion of the width of the distal fracture fragment 18 . The device 25 may not be preferred for use with commuted distal radius fractures.
[0052] In position, the rod 26 is configured such that it also extends through a portion of the medullary canal to terminate therein in the shaft region 13 of the radius 10 ( FIG. 1 ) (at a location which is proximally spaced away from the fracture line 15 ). The proximal portion 28 of the rod 26 is anchored to the radius so as to reside inside the medullary canal of the radius. The proximal portion 28 of the rod 26 is fixed in position relative to the shaft of the radius by the use of at least one pin, screw, or the like, as discussed above. As is also noted above, it is more preferred that two (and potentially three or more) to provide increased structural stability so as to inhibit the propensity of the rod 26 to toggle or move distally with the distal fragment.
[0053] FIG. 4 also illustrates that the proximal end of the rod 28 e may be configured with a reduced cross-sectional size or tapered perimeter relative to the portion of the rod 26 thereabove to allow for ease of insertion into the patient. Preferably, as shown, the proximal end of the device 28 e is substantially pointed.
[0054] FIG. 5A illustrates the rod 26 with a length “L”, a width “W” and a thickness “T”. It is envisioned that the rod 26 be provided or be made available for use in a plurality of lengths and widths so that the clinician can select the appropriate dimensions according to the particular anatomical needs of the patient. Preferably, for the distal radius fracture, the length of the rod 26 is between about 2-5 inches long, and more preferably between about 2.5 inches-4.0 inches long. It is also preferred that the width of the rod 26 be provided in an arrangement of incremental sizes. It is thought that suitable widths may be between about 2-8 mm in width and more preferably between about (2.5-4 mm) in width.
[0055] As shown in FIG. 5B , the rod 26 is held in the medullary canal of the radius of the patient. The lower or proximal portion 28 of the rod 26 is preferably held substantially centrally in the shaft portion 13 of the radius 10 . In one embodiment, the cross sectional shape of the rod 26 is rectangular. The rod 26 can be configured with other cross-sectional shapes, such as, but not limited to, circular, oval, square, triangular, and hexagon. It is also preferred that in designs with sharp edges, that the edges be radiused (“break edges”) to reduce the likelihood of stress fractures in the rod 26 (or in the bone adjacent the rod). Further, the distal portion 27 of the rod 26 may have a different cross-sectional shape and configuration from the proximal portion 28 of the rod 26 . For example, the proximal portion 28 of the rod 26 may have a circular shape with the addition of a ribbed portion on one side to inhibit rotation once in the intramedullary canal in the radius of the patient, while the distal portion 27 of the rod 26 can have an oval or rectangular shape (not shown).
[0056] FIG. 7 illustrates another embodiment of an intramedullary fixation device 25 ′ according to the present invention. In this embodiment, the rod 26 is configured as first and second attachable segments or links 127 , 128 . As shown, the distal segment 127 of the rod 26 is configured with the head of the rod 26 h while the proximal portion 128 is again configured to reside in the medullary canal of the radius shaft. The two segments 127 , 128 are configured to align ad mate together to define the rod 26 . As shown in FIG. 7 , a linking screw 120 is inserted into a threaded aperture 120 a that it spans the first and second segments 127 , 128 when aligned. Of course, other attachment means or segment link configurations can also be used, such as, but not limited to, bayonet type fittings, friction fit or threaded matable female/male components, and the like.
[0057] FIG. 8 illustrates another embodiment of an intramedullary fixation device 25 ″ for the radius according to the present invention. In this embodiment the rod 26 includes a proximal extension 28 ext . As shown, the proximal extension 28 ext is tapered adjacent the proximal end portion 28 of the rod 26 . The extension 28 ext is configured to reside in a more proximal portion of the radius shaft (away from the hand and closer to the elbow). This embodiment may also be used in the absence of a distal radius fracture to treat proximal radius fractures. FIG. 8 also illustrates that the distal fixation member 30 is oriented at about 45 degrees with respect to the axial axis. In any event, this configuration can allow for additional support in the shaft region of the radius (i.e., more proximal “purchase”)
[0058] FIG. 9A illustrates a rod 26 having a body with multiple segments or links 127 ′, 129 , 128 ′. As shown, in this embodiment, the rod 26 is defined by three segments, the distal segment 127 ′, an intermediate segment 129 , and a proximal segment 128 ′. FIG. 9B illustrates that, in this embodiment, the distal segment 127 ′ includes a protrusion 127 p ′ while the upper portion of the intermediate segment 129 includes a recess 129 r configured and sized to matably and/or securely receive the protrusion 127 p ′ therein. Similarly, the proximal segment 128 ′ includes a recess 128 r ′ formed therein configured to receive the intermediate segment protrusion 129 p therein. Preferably, the segments 127 ′, 129 , 128 ′ are sized and configured to be held together by a frictional fit of the interlocking or mating components, however, a biocompatible adhesive can also be used, as desired. Other attaching means can also be used to secure the segments together as will be appreciated by those of skill in the art. For example, the protrusion 127 p ′ can be threaded and configured to threadably engage with a threaded recess 129 r formed in the upper portion of the intermediate segment 129 . Similarly, the proximal recess 128 r ′ can be threaded and configured to threadably engage with the intermediate segment 129 p protrusion (which can be configured as a correspondingly configured male threaded component).
[0059] As shown in FIG. 9C , the intermediate segment 129 can be provided in an assortment of lengths to allow the rod 26 to be adjusted to a desired length according to the anatomical considerations of the patient. Alternatively, the intermediate segment 129 can be a plurality of similarly sized or different, incrementally sized segments. In this way, the distal and proximal segments 127 ′, 128 ′ can be provided as standardized-length components with the intermediate segment 129 providing an adjustable length. Thus, the clinician can custom fit the rod 26 at the use site. That is, the clinician can assess the patient and then determine the appropriate number or size of intermediate segments 129 to be used dependant on the length desired. This custom fit does not require the use of a preformed rod or a special order rod. Rather, the fit can be carried out at the clinic, use, or instillation site (proximate in time or contemporaneous with the treatment) to fit the number and size components together according to the needs of the patient. Alternatively, the distal and/or proximal segments 127 ′, 128 ′ can also (or alternatively) be configured as or provided in different lengths.
[0060] FIG. 10 illustrates the use of an insertion or positioning guide 150 affixed to the distal end portion 27 of the rod 26 to allow for ease of insertion and placement into the patient. As shown, the guide 150 includes an axially (or longitudinally) extending arm 151 which is configured to reside external of the body of the patient when the rod 26 is inserted into the intramedullary canal. As is also shown, the guide arm 151 includes a visual locating, means or visual indicia 153 , 155 which correspond to the proximal fixation apertures 25 a 1 , 25 a 2 to mark or identify the location of the internal apertures when the rod 26 is in a desired position in the patient. This allows the physician to be able to insert the proximal fixation members 35 a , 35 b in the proper location, aligned with the proximal apertures on the rod 26 held inside the patient.
[0061] As shown, the visual indicia 153 , 155 is preferably provided as laterally extending drill guides 153 , 155 which act to support a drill as it enters the patient and allows the drill to be inserted therein and guided to the desired location to provide bores into the bone on opposing sides of the rod 26 that are aligned with the rod proximal fixation apertures 25 a 1 , 25 a 2 .
[0062] Referring to FIG. 12 , generally described, to position the intramedullary fixation rod 26 into the patient, an incision is made, such as a sigmoid or longitudinal incision over the radial styloid region of the patient's arm (adjacent to the base of the thumb). As shown in FIG. 13 , dissection is carried down to the interval between the first and second dorsal compartments. Care should be taken so as not to injure the branches of the dorsal radial nerve. A small area of exposed bone is present between the first and second compartments (typically covered only by periosteum). As shown in FIGS. 14 and 15 A, a small bone window 16 is preferably formed or made into the radius in his area. It may be appropriate to elevate the sheaths of the first and second dorsal compartments to facilitate adequate exposure for the bone window 16 . Although shown as a substantially rectangular bone window, other shapes may also be used to provide access to the fracture region.
[0063] As shown in FIG. 15 w , a finder, sound, or broach-like device 175 can be used prior to inserting the fixation rod 26 into the patient. The device 175 is preferably semi-flexible to follow the contour of the canal in the radius. The device 175 can be inserted through the bone window 16 and about the fracture region and used to determine the size and length of the intramedullary canal and/or to open the canal to a size suitable for receiving the fixation rod 26 . The sounds are available in length-and width calibrated sizes to help determine a size and length suitable for the fixation rod 26 according to the particular patient's intramedullary canal structure. As such, the device 175 can bore out or ream and/or define a desired entry and insertion passageway for the device 25 , 25 ′, 25 ″ in advance of an actual installation into the patient. A fluoroscopic evaluation technique can be used to visualize the insertion of the device 175 and can help determine if the canal needs to be enlarged with a reamer or if a insertion path needs to be formed or shaped.
[0064] After the appropriate size and length fixation rod 26 is selected, the rod can be attached to an insertion guide device 150 , 150 ′. FIG. 10 illustrates one embodiment of a guide 150 . As shown, an applicator/handle or driver 150 is attached to the rod 26 into the distal aperture 30 a ). The handle or driver 150 then allows the physician to insert and guide the rod 26 into the desired location in the medullary canal in the radius. Once the head 26 h of the rod 26 is positioned below the articular joint surface, in its desired location in the distal radius, the proximal fixation members 35 ( 35 a , 35 b ) are ready for insertion. Preferably, a small incision (or two) is made at the proximal site of the radius. A drill or driver is inserted into the locator or drill guide holder 152 to align the entry of the proximal fixation member about the proximal aperture 25 and then force the threaded proximal fixation member(s) 35 ( 35 a , 35 b ) through the bone on the first (dorsal) side of the shaft of the radius, through the rod aperture 25 a 1 , ( 25 a 2 ) and into the bone on the opposing (volar) side of the radial shaft. Preferably, the proximal fixation member 35 ( 35 a , 35 b ) extends through both sides of the bone. Next, the guide 150 shown in FIG. 10 is removed and the distal fixation member 30 is then inserted into the rod 26 through the distal aperture 30 a and attached to the distal radius ( FIG. 4 ). Preferably, the distal fixation member 30 is inserted into the radius at the fracture site or at an exposed site (created by removing a portion of the bone) to allow the head 30 h ( FIG. 3A ) of the distal fixation member 30 to be inserted into the rod 26 such that it rests directly against the body of the rod 26 (either protruding, flush recessed therewith) and extends into the distal fracture fragment 18 .
[0065] FIGS. 16 and 17 illustrate an additional embodiment of an insertion guide 150 ′. In this embodiment, the device 150 ′ includes a rod driver 250 and an interlocking screw attachment guide 151 ′. Once the proper rod size is identified, the rod 26 is attached to the rod driver 250 . The rod driver 250 is attached to the fixation rod 26 via the distal aperture in the head of the rod 26 and an associated attachment member (shown as a screw 30 a ) and the interlocking screw attachment guide 151 ′ is attached to the rod driver 250 . As for the other guide embodiment described above, the interlocking screw attachment guide 151 ′ provides a screw guide alignment means such as screw or pin portals 153 , 155 to facilitate proper orientation and location of the proximal screws or pins into the patient and into the shaft 25 of the fixation rod 26 . Thus, in this embodiment, the span of the screw attachment guide 151 ′ is configured to provide the proper alignment position relative to the rod driver 250 .
[0066] As shown in FIGS. 18 and 19 , the rod driver 250 of the insertion guide 150 ′ is used to direct the rod 26 into the intramedullary canal of the patient. The rod driver 250 allows a physician to direct the fixation rod 26 into the radius through the bone window 16 . The position of the rod and the reduction of the fracture can be verified by a fluoroscopy unit. Once the rod 26 is in position, a small incision can be made so that the proximal attachment guides 153 , 155 can be inserted therein. Traction may be appropriate to reduce the fracture at this time. The proximal attachment members 35 a , 35 b can then be inserted into the radius after the region has been drilled and/or tapped. Again, the proper positioning of the proximal attachment members 35 a , 35 b , can be verified by the fluoroscopy unit. The interlocking screw attachment guide 151 ′ an then be removed from the patient and the rod driver 250 . The rod driver 250 can be detached from the fixation rod 26 and the distal fixation member 30 can be inserted into the distal fragment and the fixation rod 26 as shown in FIG. 20 .
[0067] Routine closure is performed on the incision sites and then, preferably, a long arm cast is applied to the patient. The typical healing process is about six weeks, during which time it is preferred that the treatment area be protected from undue stress and activity.
[0068] A rod according to the present invention can be formed from a number of suitable biocompatible materials including titanium, stainless steel, and cobalt chrome. Because the radius is not a weight bearing extremity strength is not as important in this type of fixation rod as it might be in other fixation rod applications.
[0069] Surface coatings may also be used as appropriate. For example, as the device 25 , 25 ′, 25 ″ chronically resides in the body, surface or other treatments may also be applied to, or integrated into, the rod 26 and/or the fixation members 30 , 35 to achieve one or more of increased lubricity, low coefficient of friction (each for easier insertion) as well as increased tissue biocompatibility such as resistance to microbial growth and/or configured to reduce the incidence of inflammation or infection during healing. In one embodiment, the rod 26 comprises a material, at least on its exposed surfaces, which can inhibit the growth of undesirable microbial organisms. Preferably, the rod is coated with a biocompatible antimicrobial solution or coating which can inhibit the growth of bacteria, yeast, mold, and fungus. One suitable material may be the antimicrobial silver zeolite based product available from HealthShield Technologies LLC of Wakefield, Mass. Another alternative is a Photolink® Infection Resistance antimicrobial coating or a hemocompatible coating from SurModics, Inc. of Eden Prairie, MN. The coating may also include other bioactive ingredients (with or without the antimicrobial coating), such as antibiotics, and the like. One product is identified as LubiLAST™ lubricious coatings from AST of Billerica, Mass.
[0070] In addition to, or alternatively, a rod according to the present invention can be configured with a biocompatible lubricant or low-friction material to help reduce any discomfort associated with the insertion of the device into the body. Coatings which may be appropriate include coatings which promote lubricity, and wettability. For example, a hydrophilic coating which is applied as a thin (on the order of about 0.5-50 microns thick) layer which is chemically bonded with UV light over the external surface of the rod 26 . One such product is a hydrophilic polymer identified as Hydrolene® available from SurModics, Inc., of Eden Prairie, MN. Other similar products are also available from the same source. Still further, the rod 26 can be configured not only to provide the lubricious coating but to also included bioactive ingredients configured to provide sustained release of antibiotics, anti microbial, and anti-restenosis agents, identified as LubrilLast™ from AST as noted above.
[0071] FIG. 11 illustrates the steps of a method for treating a fracture in the radius of a patient according to one embodiment of the present invention. An elongated axially extending rod is inserted into the intramedullary canal of the patient (Block, 210 ). Proximal fixation members are then secured to the rod to hold the rod in the intramedullary canal attached to the proximately located bone in the radius shaft (Block 220 ). A distal fixation member is inserted into a distal portion of the rod such that it extends substantially medially or transversely across a distal portion of the radius (Block 230 ). A bone window may be formed into the radius to define an entry point for the rod (typically the window is formed into a small area of exposed bone which is present between the first and second compartments and covered only by periosteum) in the styloid region adjacent the two bone fragments.
[0072] The internal intramedullary radius fixation devices and associated treatment methods of the instant invention can provide improved or alternative treatment options over those conventionally available. The devices and methods of the instant invention may inhibit the collapse in the skeletal structure along the fracture fragment region and may be useful for the osteoporotic patient. The devices of the instant invention can also provide increased structural integrity and/or strength when in position in the distal radius fracture fragment.
[0073] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. In the claims, means-plus-function clauses, if used, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein. | Medical kits for treating fractures in or adjacent the wrist and distal forearm employ an intramedullary interlocking fixation rod (i.e, it interlocks the distal and proximal fracture fragments together) to stabilize the skeletal structure in a manner which can inhibit the amount of collapse or loss in skeletal length exhibited by a patient with a distal radius fracture. | 0 |
CROSS REFERENCE TO RELATED APPLICATION(S)
The present invention claims the benefit of U.S. Provisional Application Ser. No. 61/727,381 filed Nov. 16, 2012, which is hereby incorporated by reference as if it were set forth in its entirety.
BACKGROUND
The present invention relates to self-adhesive panels and an associated method.
Traditionally, drywall can be installed using a drywall panel, studs, and screws or nails. Studs are placed with the centers of the studs 16 or 24 inches apart (“on center”) on each wall requiring drywall installation. Drywall panels are installed with minimal joints and with the edges of each panel aligned with stud centers. Drywall panels are mounted onto corresponding studs and secured to the studs using nails or screws.
SUMMARY
A panel includes a core and a layer of adhesive on top of a core of the panel. A release liner covers the layer of adhesive. The release liner includes segments configured so that any of the segments can be selectively individually removed, exposing corresponding sections of the layer of adhesive.
An assembly includes studs spaced apart and a panel adhered to the studs. The panel includes a core and a layer of adhesive on top of the core. A release liner covers the layer of adhesive and includes segments configured, sized, and spaced so that any of the segments can be selectively individually removed, exposing corresponding sections of the layer of adhesive for adhering the panel horizontally or vertically onto the studs.
A method includes removing segments of a release liner of a panel to expose segments of adhesive on the panel. The method further includes aligning the panel studs such that the segments of adhesive are facing the studs and adhering the panel to the studs.
A method of manufacturing includes applying an adhesive to a panel, applying a release liner on top of the adhesive, and perforating the release liner to define removable segments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an embodiment of a drywall panel according to the present invention.
FIG. 2 is a front view of a first embodiment of a release liner of a drywall panel.
FIG. 3 is a front view of a second embodiment of a release liner of a drywall panel.
FIG. 4 is a front view of a drywall panel installed vertically on studs.
FIG. 5 is a front view of a drywall panel installed horizontally on studs.
FIG. 6 is an exploded side view of installation of a drywall panel using a two part adhesive.
DETAILED DESCRIPTION
In general, a panel of the present invention is typically made from a core, base, or body of gypsum or another material but can be made of other materials based on applications such as fireproofing and bathroom installation where moisture is a greater concern. For instance, the panel can be drywall, plasterboard, wallboard, sheetrock, gypsum board, plywood, DensGlass® fiberglass mat gypsum panels (available from Georgia-Pacific Gypsum LLC, Atlanta, Ga.), or other type of rigid panel. The drywall panel can be ½ inch thick or ⅝ inch thick, based on commercial or residential application. One or more sides of the drywall panel can be covered with paper (or other materials) like standard drywall panels. One side of the drywall panel includes a layer of adhesive on top of the paper (if any), the adhesive covered by a release liner, eliminating the need for coating the drywall panel with adhesive prior to installation. In a preferred embodiment, the release liner is segmented or perforated such that it can be removed in sections, exposing corresponding sections of adhesive underneath.
Adhesive layered on the drywall panel of the present invention can be contact cement, construction adhesive such as PL 200 (manufactured by Henkel of Westlake, Ohio), liquid glue, or any other suitable adhesive, glue, cement or building material. Adhesive used with the drywall panel of the present invention can be one part, where the only adhesive used is the layer on the drywall panel itself. In an alternative embodiment, a two part adhesive (or cement) can be used, with adhesive both on the drywall panel and on the installation location (e.g. on the studs) of the wall on which the drywall panel is installed.
FIG. 1 is a side view of one embodiment of drywall panel 10 . Drywall panel 10 is primarily made of gypsum board 12 . Gypsum board 12 is typically covered by a paper layer on both sides with gypsum in between the two paper layers. For simplicity, the paper layers are not specifically delineated. Gypsum board 12 is covered by a layer of adhesive 14 . Adhesive 14 is covered by release liner 16 . Release liner 16 of drywall panel 10 extends past adhesive 14 and gypsum board 12 for ease of installation. In one embodiment, release liner 16 extends past adhesive 14 and gypsum board 12 by a desired amount, such as ¼ of an inch, which provides a gripping surface 16 G that allows a person installing drywall panel 10 to pull on the extended portion of release liner 16 to remove release liner 16 and expose at least a portion of adhesive 14 .
FIG. 2 is a front view of a first embodiment of release liner 16 of drywall panel 10 . Release liner 16 includes tabs 18 , 20 , 22 , 24 , and 26 . Tabs 18 , 20 , 22 , 24 , and 26 are sized, spaced, and coded such that drywall panel 10 can be installed horizontally or vertically by selectively removing individual tabs to expose desired portions of adhesive 14 . Tabs 18 , 20 , and 22 can each be 4 inches wide. In between tabs 18 and 20 , tabs 24 and 26 can each be 5 inches wide. In between tabs 20 and 22 , tabs 24 can each be 4 inches wide. Tabs 18 are generally removed for installation whether drywall panel 10 is installed horizontally or vertically, and regardless of stud spacing. Tabs 20 and tabs 18 are removed when drywall panel 10 is installed vertically onto a wall with studs that are 16 inches on center. Tab 22 and tabs 18 are removed when drywall panel 10 is installed vertically onto a wall with studs that are 24 inches on center. Remaining tabs can be left in place for installation. Tabs 24 and tabs 18 are removed when drywall panel 10 is installed horizontally onto a wall with studs that are either 16 inches or 24 inches on center. In an alternative embodiment, when drywall panel 10 is installed horizontally and vertically, if needed, tabs 18 , 20 , 22 , 24 , and 26 can all be removed, exposing all of adhesive 14 .
Drywall panel 10 can be manufactured starting with a typical drywall panel, such as gypsum board 12 of FIG. 1 . Gypsum board 12 is typically covered by a paper or polymer film layer on both sides with gypsum in between the two paper or polymer film layers. Adhesive 14 can then be pre-applied to gypsum board 12 on top of one of the paper or polymer film layers. Release liner 16 is then applied on top of adhesive 14 . Release liner 16 can be pre-perforated or pre-segmented prior and subsequently applied on top of adhesive 14 . In an alternative embodiment, release liner 16 can be perforated or segmented after release liner 16 is applied on top of adhesive 14 . The perforations in release liner 16 define tabs, such as tabs 18 , 20 , 22 , 24 , and 26 as shown in FIG. 2 . Each tab can be color-coded, signifying when it is appropriate to remove the tab during horizontal or vertical installation of drywall panel 10 .
FIG. 3 is a front view of a second embodiment of release liner 16 ′ of drywall panel 10 . Release liner 16 ′ includes tabs 28 , 30 , 32 , 34 , and 36 . Tabs 28 , 30 , 32 , 34 , and 36 are sized, spaced, and marked with symbols such that drywall panel 10 can be installed horizontally or vertically by selectively removing individual tabs to expose desired portions of adhesive 14 . Tabs 28 , 30 , and 32 can each be 4 inches wide. In between tabs 28 and 30 , tabs 34 and 36 can each be 5 inches wide. In between tabs 30 and 32 , tabs 34 can each be 4 inches wide. The symbols marked on tabs 28 , 30 , 32 , 34 , and 36 are for illustration purposes only. Tabs 28 , 30 , 32 , 34 , and 36 can be marked with symbols, Arabic numerals corresponding to stud spacing dimensions (such as the Arabic numerals shown on tabs 30 and 32 ), and/or any suitable visual indicia or tactile indicia (such as Braille).
Tabs 28 are marked with triangles and are removed whether drywall panel 10 is installed horizontally or vertically. Tabs 30 are marked with circles and are removed in addition to tabs 28 when drywall panel 10 is installed vertically onto a wall with studs that are 16 inches on center. Tab 32 is marked with a star and is removed in addition to tabs 28 when drywall panel 10 is installed vertically onto a wall with studs that are 24 inches on center. Tabs 34 are marked with a rectangle and are removed when drywall panel 10 is installed horizontally onto a wall with studs that are either 16 inches or 24 inches on center. In an alternative embodiment, when drywall panel 10 is installed horizontally, tabs 28 , 30 , 32 , 34 , and 36 can all be removed, exposing all of adhesive 14 .
Drywall should be installed with as few joints as possible, therefore depending on the shape and size of the wall, vertical or horizontal installation can be more appropriate. For vertical installation, the layout of the wall should be checked to determine the distance between the centers of studs, for example whether studs are 16 inches or 24 inches on center. For walls taller than 10 feet, horizontal bridging between studs should be installed to keep studs on center. Prior to installing drywall panel 10 , drywall panel 10 is measured to see if drywall panel 10 will line up with the center of a stud. If drywall panel 10 does not line up, drywall panel 10 is cut to line up with a center of the nearest stud. Once drywall panel 10 is aligned with the center of a stud, that stud is the layout stud.
After drywall panel 10 is properly measured, tabs 18 are removed regardless of stud spacing. If drywall panel 10 is cut such that one of tabs 18 is no longer on drywall panel 10 , remaining tab 18 and whichever tab ( 20 , 22 , 24 , or 26 ) is nearest the cut edge are removed. If a wall contains studs 38 that are 16 inches on center, tabs 20 and tabs 18 are removed, as shown in FIG. 4 . If a wall contains studs 38 that are 24 inches on center, tab 22 and tab 18 are removed. Drywall panel 10 now contains exposed sections of adhesive 14 that line up in parallel with studs onto which drywall panel 10 is mounted. The exposed sections of adhesive 14 can be discontinuous, that is, separated by tabs that remain in contact with adhesive 14 .
Drywall panel 10 can be carried over to the wall and stood up at a distance (e.g. 1 to 2 inches or 3 to 4 inches) away from the wall. If drywall panel 10 is installed on a wall from left to right, the left edge of drywall panel 10 is the leading edge. If drywall panel 10 is installed from right to left, the right edge of drywall panel 10 is the leading edge. The leading edge of drywall panel 10 should be aligned on and in contact with the wall such that drywall panel 10 is snug to any adjacent wall, stud, or sheetrock. The rest of drywall panel 10 is then pressed against the wall with, in one embodiment, at least 45 pounds of pressure while ensuring that the outside edge of drywall panel 10 is in the center of the layout stud. Once one drywall panel 10 is installed, additional drywall panels 10 are installed along the length of the wall in the same manner until the wall is adequately covered. Fasteners, such as nails or screws, can optionally be attached to further secure drywall panel 10 ; however, such fasteners are made unnecessary by adhesive 14 .
FIG. 4 is a front view of an embodiment of drywall panel 10 having release liner 16 , with drywall panel 10 shown broken away to reveal studs 38 . Drywall panel 10 is installed vertically on studs 38 . Studs 38 are spaced 16 inches on center. Tabs 18 and 20 have been removed from drywall panel 10 to reveal adhesive 14 . Drywall panel 10 is aligned with the center of layout stud 38 L such that adhesive 14 binds drywall panel 10 to studs 38 , with adhesive 14 aligned in parallel with studs 38 . Adhesive 14 may be in continuous contact with studs 38 along substantially an entire length of drywall panel 10 .
For horizontal installation from the ground up, the highest point of the floor in front of the wall is found using a laser level taking measurements every ten feet. The stud closest to the highest point of the floor should be marked at 48.5 inches. That stud is then used as a reference point to measure off a level laser line and mark the rest of the studs. This ensures that when drywall panel 10 is installed, drywall panel 10 stays on center of the studs. Once the rest of the studs are marked, a level line is drawn across all of the studs, such as using a chalk line. A guide bar can be installed along the top of the line to more easily align drywall panel 10 on studs. After the wall is properly marked, drywall panel 10 is measured to see if drywall panel 10 will line up with the center of a stud. If drywall panel 10 does not line up, drywall panel 10 is cut to line up with the center of a stud. Once drywall panel 10 is aligned with the center of a stud, that stud is the layout stud.
After drywall panel 10 is properly measured, tabs 18 are removed. If drywall panel 10 is cut such that one of tabs 18 is no longer on drywall panel 10 , remaining tab 18 and whichever tab ( 20 , 22 , 24 , or 26 ) is nearest the cut edge are removed. Tabs 24 are also removed. The exposed sections of adhesive 14 can be discontinuous, that is, separated by tabs that remain in contact with adhesive 14 . In an alternative embodiment (not shown), all tabs ( 18 , 20 , 22 , 24 , and 26 ) are removed, exposing all of adhesive 14 .
Once the tabs are removed and the desired sections of adhesive 14 are exposed, drywall panel 10 can be carried over to the wall and stood up at a distance (e.g. 1 to 2 inches or 3 to 4 inches) away from the wall. A person should stand on each end of drywall panel 10 and lift drywall panel 10 such that the top edge of drywall panel 10 leans toward the wall. Drywall panel 10 is then aligned with the chalk line or guide bar and should be snug to any adjacent wall, stud, or sheetrock. When drywall panel 10 is properly aligned, the top edge of drywall panel 10 is pressed into the studs. The rest of drywall panel 10 is subsequently pressed into the wall, applying, for example, greater than or equal to 45 pounds of pressure from the top edge down, ensuring that the vertical edge of drywall panel 10 is aligned on the center of the layout stud. Once one drywall panel 10 is installed, additional drywall panels 10 are installed along the length of the wall adjacent to the first drywall panel 10 .
After the bottom row of drywall panels 10 is installed, a second row of drywall panels 10 is installed above the bottom row. In order to stagger vertical joints, the first drywall panel 10 installed in the second row should be cut such that the first drywall panel 10 aligns with the center of the stud that is closest to the center of the first drywall panel 10 installed in the bottom row; this is the layout stud. The desired tabs on the first drywall panel 10 in the second row are unzipped (i.e., removed) and drywall panel 10 is installed aligning the bottom edge with the top edge of the panel underneath drywall panel 10 and ensuring that drywall panel 10 is snug to any adjacent wall, stud, or sheetrock. Drywall panel 10 in the second row is then installed from the bottom up, pressing the bottom edge into the wall and working up drywall panel 10 , applying, for example, greater than or equal to 45 pounds of pressure and ensuring that the vertical edge is aligned on the center of the layout stud. Additional drywall panels 10 are installed along the length of the wall adjacent to the first drywall panel 10 in the second row. If necessary, subsequent rows of drywall panels 10 are installed above the second row until the wall is covered in drywall panels 10 as desired.
Drywall panel 10 can also be horizontally installed on exterior framing. 48 inch increments are measured from the roof edge down at both ends of the building. A reference line is made using a chalk line, and a guide bar should be installed on the bottom side of the chalk line. Drywall panel 10 is measured to see if drywall panel 10 will line up with the center of a stud. If drywall panel 10 does not line up, drywall panel 10 is cut to line up with the center of the nearest stud. Once drywall panel 10 is aligned with the center of a stud, that stud is the layout stud. After drywall panel 10 is properly measured, tabs 18 are removed. If drywall panel 10 is cut such that one of tabs 18 is no longer on drywall panel 10 , remaining tab 18 and whichever tab nearest the cut edge are removed. Tabs 24 are also removed. In an alternative embodiment, all tabs are removed, exposing all of adhesive 14 .
After the tabs are removed and the desired sections of adhesive 14 are exposed, two people can each lift one end of drywall panel 10 while leaning the top edge of drywall panel 10 away from the wall slightly. The bottom edge of drywall panel 10 should be aligned on the guide bar while ensuring that drywall panel 10 is snug to any adjacent wall, stud, or sheetrock. The bottom edge of drywall panel 10 is then pressed on to the wall, and the rest of drywall panel 10 is subsequently pressed into the wall from the bottom up and with, for example, greater than or equal to 45 pounds of pressure. To ensure maximum holding strength, fasteners, such as nails or screws can be installed around the perimeter of drywall panel 10 . Additional drywall panels 10 are installed along the length of the wall adjacent to the first drywall panel 10 . Subsequent rows of drywall panels 10 are installed until the wall is covered in drywall panels 10 as desired.
FIG. 5 is a front view of drywall panel 10 having release liner 16 , with drywall panel 10 shown broken away to reveal studs 38 . Drywall panel 10 is installed horizontally on studs 38 . Tabs 18 and 24 have been removed from drywall panel 10 to reveal adhesive 14 . Drywall panel 10 is aligned with the center of layout stud 38 L. Adhesive 14 binds drywall panel 10 to studs 38 . Adhesive 14 is substantially perpendicular to studs 38 .
FIG. 6 is an exploded side view of installation of drywall panel 10 using a two part adhesive such as contact cement, one part of which is on drywall panel 10 and the other part of which is on stud 38 . Drywall panel 10 includes gypsum board 12 and adhesive 14 from which the appropriate portion of release liner 16 has been removed. The paper of gypsum board 12 is not shown for simplicity. Stud 38 includes two-by-four 40 and adhesive 42 , which is applied to stud 38 prior to installation of drywall panel 10 . Drywall panel 10 is mounted onto stud 38 such that adhesive 14 and adhesive 42 are in contact. Subsequently, at least 45 pounds of pressure is applied to drywall panel 10 such that adhesive 14 and adhesive 42 are sufficiently bonded, securing drywall panel 10 to stud 38 .
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, features or steps described with respect to one embodiment can be readily utilized in conjunction with another embodiment, as desired for particular applications. | A panel includes a core and a layer of adhesive on top of a core of the panel. A release liner covers the layer of adhesive. The release liner includes segments configured so that any of the segments can be selectively individually removed, exposing corresponding sections of the layer of adhesive. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to the stabilization of fatty organic compounds, and particularly fatty alcohols and derivatives thereof.
The present invention also relates to the synthesis, particularly on an industrial scale, of fatty alcohol derivatives wherein the reactants and their derivatives may be subject to undesired side reaction such as oxidation. Unwanted oxidation, whether with atmospheric oxygen or with other oxidizing reactants, is a particularly well-known side reaction which those who work in this field would like to avoid because it leads to undesired side effects such as unpleasant odors and loss of the desired color in the product.
It has long been known that fatty organic compounds, particularly those derived from natural sources, can be subject to undesired oxidation, particularly when the compound in question is in the liquid state; and particularly in the presence of acids such as sulfuric or sulfuric acids. This phenomenon is well known as to fatty alcohols, such as stearyl alcohol. For this reason, such products are frequently stored and shipped in the solid state, generally as particles or flakes. However, providing such materials in the solid state frequently involves additional steps of subdividing the product into a manageable form such as flakes, pellets, or otherwise, so as to facilitate operations such as handling, pouring, measuring, and packaging. The steps necessitated in putting such products into particle form necessarily introduce additional equipment and handling requirements which one would desire to eliminate if possible. Indeed, the additional steps necessary to appropriately subdivide the solid materials can cause undesired losses of material and changes in purity, and also require periodic cleaning and maintenance of the equipment used.
Thus, it would be desirable to be able to provide products such as fatty alcohols in liquid form, if only a means were available whereby oxidation of such products could be inhibited or eliminated. The savings in energy and equipment usage as well as in packaging materials required for handling of the particulate solids, would be significant. However, to date there remains an unfilled need for a means for stabilizing fatty compounds such as fatty alcohols against undesired oxidation and the resultant side effects such as color degradation, in a manner which is economical and readily practiced and yet which does not interfere with subsequent reactions or other uses of the fatty material in question.
BRIEF SUMMARY OF THE INVENTION
The present invention solves these needs and provides additional advantages as described herein.
One aspect of the present invention thus comprises a liquid product comprising a fatty alcohol containing 12 to 24 carbon atoms and an effective amount, such as up to about 1.0 wt. %, of hypophosphorous acid to inhibit undesired oxidation of the fatty alcohol in situ or in subsequent reaction thereof.
Another aspect of the present invention is a method of inhibiting oxidation of fatty alcohol containing 12 to 24 carbon atoms, comprising adding thereto hypophosphorous acid in an amount effective to inhibit oxidation of said fatty alcohol.
Other aspects of the present invention relate to the use of hypophosphorous acid to inhibit undesired oxidation in the course of a reaction of fatty alcohol, which reaction is carried out under conditions which might ordinarily give rise to oxidation of the fatty alcohol or the reaction product thereof. Thus, for instance, the present invention also comprises a process for esterifying a fatty alcohol in the liquid state, wherein the alcohol and the product of its esterification undergo little or no oxidation. The process comprises esterifying said fatty alcohol in the liquid state in mixture with hypophosphorous acid, wherein the hypophosphorous acid is present in said mixture in a small amount effective to inhibit oxidation of the alcohol and its ester.
DETAILED DESCRIPTION OF THE INVENTION
It has been discovered that fatty alcohols containing admixed therewith a small amount of hypophosphorous acid exhibit, surprisingly, a diminished tendency to undergo oxidation and exhibit a diminished tendency to exhibit oxidation-related side effects upon the reaction of such fatty compounds, particularly including esterification reactions. By "fatty alcohols" are meant herein monohydric and polyhydric fatty alcohols, particularly those containing 12 to 24 carbon atoms exhibiting straight-chain or branched-chain structure, which are saturated or which contain one or more carbon-carbon double bonds.
The preferred fatty alcohol which is a subject of this invention is stearyl alcohol.
The "oxidation-related" side effects to which stearyl alcohol and other such substances can be subject, include undesired color changes such as a loss of transparency, or a change in color from for instance a white or near-white color to an off-white color which is typically light tan or darker.
The freedom from such oxidation-related side effects is particularly pronounced when a fatty alcohol containing mixed therewith hypophosphorous acid as described herein is subjected to reaction, and particularly to esterification reactions.
In particular, reactions to which fatty alcohols are subjected in the industrial arena, and which are vulnerable to oxidation-related deterioration in the absence of the stabilization provided by the present invention, include esterification with carboxylic acids (containing one or more carboxylic group) including lower alkanoic acids containing e.g. 1 to 6 carbon atoms, as well as esterification with medium length or long-chain fatty acids containing from 6 to 24 or more carbon atoms and one or more carboxylic acid functionality. Other reactions to which this invention is applicable include esterification with sulfur-containing reactants such as thiocarboxylic or thiodicarboxylic acids such as thiodipropionic acid.
Esters are made by the customary procedure, e.g. reacting the fatty alchohol (in admixture with hypophosphorous acid) with the desired acid reactant, under acidic conditions. The esters made by the foregoing esterification reactions in the presence of hypophosphorous acid are useful as lubricants, emollients, mold release agents, and in other applications familiar to the industrial chemist.
Other preferred fatty alcohols to which the present invention is applicable include fatty alcohols such as oleic, linolenic, linolenic, lauric, caproic, myristic and palmitic alcohols, as well as mixtures of any of the foregoing fatty alcohols.
The amount of hypophosphorous acid which should be present in mixture with the fatty alcohol should be an amount sufficient to inhibit oxidation of the fatty alcohol when the fatty alcohol is in the liquid state and exposed to the ambient atmosphere. Those of ordinary skill in this art will readily recognize that the appropriate amount of hypophosphorous acid which provides the desired inhibition of oxidation can readily be ascertained, by a simple comparison of properties (such as, particularly, onset of color or discoloration) as between a sample containing a given amount of hypophosphorous acid and the equivalent sample, subject to the same treatment, but not containing any hypophosphorous acid.
In general, however, effective amounts of hypophosphorous acid will generally be up to about 1.0 wt. % or even up to about 0.1 to 0.5 wt. % based on the amount of the fatty alcohol or alcohols present. Higher amounts will generally be effective, but it can be expected that at sufficiently higher amounts of hypophosphorous acid no additional amount of oxidation inhibition would be realized. Preferably, the amount of hypophosphorous acid which is effective to inhibit oxidation and its related side effects is generally about 0.02% to about 0.075%, and more preferably about 0.05%, expressed as percent by weight of the fatty alcohol or alcohols present.
The hypophosphorous acid is preferably added to the fatty alcohol as soon as it is produced or recovered, or as soon as practicable thereafter. If the fatty alcohol is being stored under conditions limiting its contact with oxygen, the hypophosphorous acid is preferably added before, or as soon as practicable after, exposure to oxygen (even ambient atmospheric oxygen).
It has been found that carrying out reactions, e.g. esterifications, with fatty alcohol to which hypophosphorous acid has previously been added, produces products which are significantly and unexpectedly freer of oxidative degradation than is found when hypophosphorous acid is first added to the fatty alcohol at the time of reaction. This behavior, which is demonstrated in Example 3, is particularly unexpected since one would expect the same given amount of hypophosphorous acid, subjected to the same reaction conditions, to have the same effect whether the hypophosphorous acid is added when the reaction is carried out or is already present. Instead the applicants have found that when the hypophosphorous acid is already present, its beneficial effects are substantially more pronounced.
The hypophosphorous acid should have been present in the fatty alcohol long enough to be equilibrated with the fatty alcohol, i.e. present preferably for at least 1 hour, and more preferably for at least 24 hours.
The invention will be illustrated in the following examples, which are provided for purposes of illustration and which should not be interpreted as exhibiting an intention to limit the scope of the invention described herein.
EXAMPLE 1
Samples (50 grams each) of commercial stearyl alcohol derived from natural sources were placed in each of two 4-ounce jars, and 0.05 g of a 50 wt. % aqueous solution of hypophosphorous acid ("HPA") was added to one of the jars. Both jars were then placed, uncapped, in a 250° F. oven. The heating simulates the conditions to which the stearyl alcohol would be subjected in use as a reactant, and also accelerates the onset of any oxidation. The color (as the "APHA color") was determined after 36, 85 and 146 days in the oven, using "method 120" on a HACH 2000 spectrophotometer. Initially the color was determined in a 10% solution in toluene (approximately 2.6 grams of sample per dilution). When the color exceeded the 500 APHA range of the color determination method, samples were further diluted, as necessary, and the results mathematically converted to correspond to those of a 10 wt. % solution. The results of the color determinations are set forth in Table 1:
TABLE 1______________________________________ APHA Color of 10% Toluene SolutionTime (days) No HPA added 0.05% HPA added______________________________________ 0 0 036 5 385 28 37146 8200 1040______________________________________
Higher APHA color numbers are associated with the observance of more color and a greater loss of transparency in the sample, which in turn is associated with the sample having undergone a higher degree of oxidation. Thus, the data in Table 1 show that addition of HPA to the sample significantly inhibited the oxidation undergone by the tested sample. The pronounced difference at 146 days indicates a considerable improvement in long-term shelf-life of the fatty alcohol.
EXAMPLE 2
The procedure of Example 1 was repeated except that 0.5 grams of para-toluenesulfonic acid was added to each sample to hasten any color development. The samples were analyzed for color, using the procedure described in Example 1, every 6 hours after they were placed in the oven. The results are set forth in Table 2:
TABLE 2______________________________________ APHA Color of 10% Toluene SolutionTime (hrs.) No HPA Added 0.05% HPA Added______________________________________ 0 0 0 6 8 612 67 6318 123 11424 220 16530 287 20436 356 24042 465 34848 564 40454 1112 76060 1620 96466 2550 120072 3640 2000______________________________________
These results, like the results shown in Table 1, indicate that addition of HPA in accordance with the present invention significantly inhibited oxidation of the fatty alcohol.
EXAMPLE 3
To each of two 16-ounce jars was added a 200 gram sample of a commercial stearyl alcohol derived from natural sources. To one of the jars was added 0.2 g of a 50 wt. % aqueous solution of HPA (providing a content of 0.05 wt. % HPA). The contents of the jars were each mixed and then the jars were placed, loosely capped, in a 200° F. oven. After specific lengths of time in the oven, samples from each jar were removed and subjected to a test in which the stearyl alcohol was reacted with recrystallized thiodipropionic acid ("TDPA") to form distearyl thiodipropionate ("DSTDP"), and the DSTDP was tested for coloration by the technique described in Example 1 except that solutions tested were 50% in toluene. To each sample that had been taken from a jar to which HPA had not previously been added, 0.05 wt. % HPA was added at the time of reaction with the thiodipropionic acid. Table 3 sets forth the color test results:
TABLE 3______________________________________ APHA Color of 50% Toluene Solution 0.05% HPA Added Before Placement 0.05% HPA AddedTime (days) No HPA In Oven Only at Rxn. w/TDPA______________________________________30 40 0 290 4800 14 2530______________________________________
These results, like the results in Tables 1 and 2, demonstrate that addition of HPA to the fatty alcohol significantly inhibits oxidation and discoloration of the alcohol and of its reaction product. In addition, these results surprisingly show that carrying out the reaction with fatty alcohol to which the hypophosphorous acid has previously been added provides product that is substantially less prone to oxidative degradation. | Fatty alcohol containing admixed therewith a small amount on the order of up to 1.0 wt. % of hypophosphorous acid, exhibits markedly reduced oxidation and oxidation-related deterioration such as discoloration and other side effects. This discovery is particularly useful when the fatty alcohol is subjected to reactions such as esterification under conditions which could cause or accelerate undesired oxidation. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/707,353, which was filed Aug. 11, 2005, and which is incorporated herein by reference.
BACKGROUND
[0002] U.S. Pat. No. 6,354,760, which is entitled System for Transferring Loads Between Cast-in-Place Slabs and issued Mar. 12, 2002, to Russell Boxall and Nigel Parkes, discloses a load plate for transferring loads between a first cast-in-place slab and a second cast-in-place slab separated by a joint. The load plate has at least one substantially tapered end adapted to protrude into and engage the first slab. The load plate is adapted to transfer between the first and second slabs a load directed substantially perpendicular to the intended upper surface of the first slab.
[0003] PCT application WO 03/023146 A1, which was published Mar. 20, 2003, is entitled Load Transfer Plate for in Situ Concrete Slabs, and for which Russell Boxall and Nigel Parkes are applicants and inventors, discloses a tapered load plate that transfers loads across a joint between adjacent concrete floor slabs. The tapered load plate accommodates differential shrinkage of cast-in-place concrete slabs. When adjacent slabs move away from each other, the narrow end of the tapered load plates moves out of the void that it created in the slab thus allowing the slabs to move relative to one another in a direction parallel to the joint. Tapered load plates may be assembled into a load-plate basket with the direction of the taper alternating from one tapered load plate to the next to account for off-center saw cuts.
BRIEF SUMMARY
[0004] This Brief Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Brief Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[0005] Embodiments of the invention relate to an on-grade joint-stability system for on-grade concrete slabs. Such a system may include: a first on-grade concrete-slab portion; a second on-grade concrete-slab portion that is separated from the first on-grade concrete-slab portion by a joint; a first on-grade plate having a first portion and a second portion, the first portion of the first on-grade plate being positioned underneath, and connected to, the first concrete-slab portion, and the second portion of the first on-grade plate being positioned underneath the second concrete-slab portion; and a second on-grade plate having a first portion and a second portion, the first portion of the second on-grade plate being positioned underneath the first concrete-slab portion, and the second portion of the second on-grade plate being positioned underneath, and connected to, the second concrete-slab portion, such that height differentials across the joint are substantially prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description in consideration of the accompanying drawings, in which like reference numbers indicate like features, and wherein:
[0007] FIG. 1 is a side view of an on-grade joint-stability system for on-grade concrete slabs in accordance with embodiments of the invention.
[0008] FIG. 2 is a top view of the system of FIG. 1 .
[0009] FIGS. 3-7 are flow charts showing steps for stabilizing a joint between on-grade concrete-slab portions in accordance with embodiments of the invention.
DETAILED DESCRIPTION
[0010] In the following description of the various embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which are shown, by way of illustration, various embodiments of the invention. Other embodiments may be utilized and structural and functional modifications may be made without departing from the scope and spirit of the present invention.
[0011] Load plates of the type disclosed in the issued U.S. Patent and the published international patent application discussed above are well suited to transferring loads between load-bearing concrete slabs that are at least approximately 6 inches deep. The phrase “load-bearing slabs” refers to floors designed to accommodate fork lifts and other relatively heavy loads.
[0012] For situations in which load transfer is not required, such as, sidewalks, malls, and in stores in which forklifts do not ride along the floor, shallow floor slabs, for instance, floor slabs that are less than approximately five inches deep, are typically used.
[0013] Although load transfer may not be needed, joints between shallow floor slabs should be stabilized to prevent adjacent slabs from developing height differentials relative to one another. Height differentials of this type are tripping hazards, which may undesirably cause people to trip, fall, get injured, and initiate related personal-injury litigation.
[0014] Slabs can curl due to differential shrinkage throughout the slabs depth. Different lengths curl more or less. In saw-cut joints, this curling of slabs occurs. Joint stability (i.e., preventing differential vertical movement between adjacent slabs) is desirable so that the slabs curl together.
[0015] If concrete floor slabs are shallow, for instance less than approximately five inches deep, concrete may not consolidate (i.e., fill in void spaces) as desired if conventional plate arrangements, such as those disclosed in the issued U.S. patent and the published international patent application discussed above, are used. Aggregate used in concrete is measured according to the smallest dimension of the particle. For example, a three-quarter inch aggregate may, in fact, be three-quarter inch in width, but substantially larger in length, e.g., 1.25 inches. Particles of such size below a conventional load plate located at the mid-depth of the slab may cause voids to occur below the plates when the slab thickness is less than approximately five inches. Conventional plate arrangements may be used, however, when the slab thickness is at least six inches, such as floors that are designed to handle use of forklifts.
[0016] Moreover, slabs having a specified height of four inches may actually be only 3.25″ deep in particular places due to tolerances in the level of the subgrade. Based on the considerations discussed above, using plates located halfway up the height of the slabs is associated with various shortcomings.
[0017] Embodiments of the invention are directed to on-grade plates for use with on-grade concrete slabs less than approximately five inches deep for the purpose of insuring joint stability rather than for traditional load-transfer functionality. “On-grade concrete slabs,” as used herein, refers to concrete slabs placed on a subgrade and/or a subbase. The subgrade is the natural in-place soil. The subbase is generally a compactible fill material that brings the surface to a desired grade.
[0018] In accordance with embodiments of the invention, trapezoidal plates may be situated on the subgrade or subbase. Plates having other shapes, including, but not limited to, a circle or a rectangle, may also be used. Plates may be triangular shaped. A pointed end may, however, present a safety hazard and may produce undesirable stress concentrations. Therefore, the pointed end may be omitted such that the plate takes on a generally trapezoidal shape.
[0019] The plates permit substantially full consolidation of the concrete slab for slab thicknesses down to approximately four inches deep. If such a plate is at grade with a 4″ slab, it produces a situation above the plates that is similar to an 8″ slab with plates embedded at a height of 4″. In this way, plates in accordance with embodiments of the invention avoid under-consolidation of concrete beneath the plate and spalling of concrete above the plate as may happen if the concrete cover above the plate is too thin.
[0020] The wide end of the trapezoidal plate may have either a stirrup or stud protruding into a concrete-slab portion to create a positive connection between the plate and the concrete-slab portion. The plates may be situated in an alternating fashion such that each successive plate is rotated 180 degrees relative to its neighboring plates. For instance, referring to FIG. 2 , plate 106 - 1 has its wide end oriented to the left, plate 106 - 2 has its wide end oriented to the right, and plate 106 - 3 has its wide end oriented to the left. As is discussed in more detail below, alternating the orientation of the plates in such a way operates to prevent height differentials across joints between slab portions thereby preventing a trip hazard despite movement of the slabs due to slabs settling, shrinking, crowning, and the like.
[0021] On-grade plates oriented alternately work together to prevent height differentials between adjacent concrete slabs as follows. Referring to FIGS. 1 and 2 , slab portions 100 - 1 and 100 - 2 are cast in place and divided via saw cut 102 and crack 104 . Plates 106 - 1 and 106 - 3 are positioned such that they will be positively connected, via their respective stirrups 108 - 1 and 108 - 3 , to slab portion 100 - 1 . Similarly, plate 106 - 2 is positioned such that it will be positively connected, via its stirrup 108 - 2 , to slab portion 100 - 2 . Although not shown in FIG. 2 , additional on-ground plates 106 may be oriented in alternating directions (as is the case with plates 106 - 1 , 106 - 2 , and 106 - 3 ) at a joint between slab portions.
[0022] If slab-portion 100 - 1 moves upward, then the plates 106 - 1 , 106 - 3 , and any additional plates oriented the same way, underneath slab portion 100 - 1 will be lifted via the positive connection established by stirrups 108 - 1 and 108 - 3 between plates 106 - 1 and 106 - 3 and slab-portion 100 - 1 . Lifting of the plates in this way will result in the respective portions of the plates 106 - 1 , 106 - 3 , and any additional plates oriented the same way, that are positioned underneath slab portion 100 - 2 to lift slab portion 100 - 2 thereby preventing a height differential across the saw cut 102 .
[0023] If slab-portion 100 - 1 moves downward, then the portion of plate 106 - 2 , and any additional plates oriented the same way, underneath slab portion 100 - 1 will be pushed down. This will cause slab portion 100 - 2 to be pulled down through the stirrup on plate 106 - 2 (and through the stirrups on other plates oriented in generally the same direction) thereby preventing a height differential across the saw cut 102 .
[0024] The principles discussed above with respect to preventing height differentials across saw cut 102 apply to upward and downward movement of slab-portion 100 - 2 . Namely, if slab-portion 100 - 2 moves upward, then the portion of plate 106 - 2 , and any additional plates oriented in generally the same direction, underneath slab portion 100 - 1 will lift slab portion 100 - 1 thereby preventing a height differential across the saw cut 102 .
[0025] If slab-portion 100 - 2 moves downward, then the portion of plates 106 - 1 , 106 - 3 , and any additional plates oriented the same way, underneath slab portion 100 - 2 will be pushed down. This will cause slab portion 100 - 1 to be pulled down through the respective stirrups 108 - 1 and 108 - 3 on plates 106 - 1 and 106 - 3 (and through the stirrups of other plates oriented across saw cut 102 in generally the same direction as plates 106 - 1 and 106 - 3 ) thereby preventing a height differential across the saw cut 102 .
[0026] Instead of (or in addition to) a stirrup 108 , other means for positively connecting a plate 106 to a slab portion 100 may be used. For example, a headed stud that protrudes from the plate at a location relatively close to the saw cut may be used.
[0027] In accordance with embodiments of the invention, a blockout sheath with foam or fins inside of the blockout sheath may be used to create voids to the sides of the plates. Techniques of this type are well known in the art, are discussed in the issued U.S. patent mentioned above, and, therefore, do not need to be discussed herein in detail.
[0028] The plates may be made of steel or any other suitable material. To prevent corrosion, an epoxy coating may be applied to the plates and/or a vapor barrier may be used under the slabs.
[0029] FIGS. 3-7 are flow charts showing steps for stabilizing a joint between concrete on-grade slabs in accordance with embodiments of the invention. Referring to FIG. 3 , a positive connection between a first portion of a first on-grade plate and a first portion of an on-grade concrete slab is established, wherein a second portion of the first on-grade plate is positioned underneath a second portion of the on-grade concrete slab that is separated by a joint from the first portion of the on-grade concrete slab, as shown at 300 . A positive connection between a second portion of a second on-grade plate and the second portion of the on-grade concrete slab is established, wherein the first portion of the second on-grade plate is positioned underneath the first portion of the on-grade concrete slab such that the first and second on-grade plates substantially prevent height differentials across the joint from occurring, as shown at 302 .
[0030] Referring to FIG. 4 , if the first portion of the on-grade concrete slab is trying to move downward relative to the second portion of the on-grade concrete slab, the yes arrow will be followed, as shown at 402 . Then, the first portion of the on-grade concrete slab pushes the first end of the second on-grade plate downward thereby causing the second on-grade plate to pull the second portion of the on-grade concrete slab downward via the positive connection between the second portion of the second on-grade plate and the second portion of the on-grade concrete slab, as shown at 404 .
[0031] Referring to FIG. 5 , if the first portion of the on-grade concrete slab is trying to move upward relative to the second portion of the on-grade concrete slab, the yes arrow will be followed, as shown at 502 . Then, the first portion of the on-grade concrete slab pulls the first end of the first on-grade plate upward, via the positive connection between the first portion of the first on-grade plate and the first portion the on-grade concrete slab thereby causing the second end of the first on-grade plate to push the second portion of the on-grade concrete slab upward, as shown at 504 .
[0032] Referring to FIG. 6 , if the second portion of the on-grade concrete slab is trying to move downward relative to the first portion of the on-grade concrete slab, the yes arrow will be followed, as shown at 602 . Then, the second portion of the on-grade concrete slab pushes the second end of the first on-grade plate downward thereby causing the first on-grade plate to pull the first portion of the on-grade concrete slab downward via the positive connection between the first portion of the first on-grade plate and the first portion of the on-grade concrete slab, as shown at 604 .
[0033] Referring to FIG. 7 , if the second portion of the on-grade concrete slab is trying to move upward relative to the first portion of the on-grade concrete slab, the yes arrow will be followed, as shown at 702 . Then, the second portion of the on-grade concrete slab pulls the second end of the second on-grade plate upward, via the positive connection between the second portion of the second on-grade plate and the second portion the on-grade concrete slab thereby causing the first end of the second on-grade plate to push the first portion of the on-grade concrete slab upward, as shown at 704 .
[0034] Although the subject matter has been described in language specific to structural features and/or methodological acts, the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. | Embodiments of the invention relate to an on-grade joint-stability system for on-grade concrete slabs. Embodiments of the system may include: a first on-grade concrete-slab portion; a second on-grade concrete-slab portion that is separated from the first on-grade concrete-slab portion by a joint; a first on-grade plate having a first portion and a second portion, the first portion of the first on-grade plate being positioned underneath, and connected to, the first concrete-slab portion, and the second portion of the first on-grade plate being positioned underneath the second concrete-slab portion; and a second on-grade plate having a first portion and a second portion, the first portion of the second on-grade plate being positioned underneath the first concrete-slab portion, and the second portion of the second on-grade plate being positioned underneath, and connected to, the second concrete-slab portion, such that height differentials across the joint are substantially prevented. | 4 |
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