First to fourth input buffers stores cells inputted from first to fourth input ports, respectively. Each input buffer is equipped with a main buffer section, a plurality of sub-buffer sections connected to the main buffer section in series and a buffer controller for controlling them. A collision judging section judges whether or not a collision occurs between the cells outputted from each sub-buffer section, and the judged result is sent to a cell converter. The cell converter returns a collision information to the buffer controller in accordance with the judged result, and further sends a cell, which has a victory information since it is judged as a victory over the collision, through a sorter to a self-routing section. The self-routing section outputs the received cell to an output port. This configuration enables a shuffle operation to be carried out in the sub-buffer section and the cell converter to thereby avoid the drop of the throughput.

1. Field of the Invention
The present invention relates to an ATM switch, and more specifically, to an input buffer type ATM switch capable of avoiding a collision between a plurality of cells, which is caused at an output port.
2. Description of the Related Art
An ATM (Asynchronous Transfer Mode) switch determines an output port which is an output destination of an ATM cell (hereafter, merely referred to as a cell) inputted from an input port. That is, the ATM switch stores a cell inputted from the input port in a buffer, and switches the stored cell, and then outputs the switched cell from a predetermined output port. The ATM switch is classified into an input buffer type, a common buffer type, an output buffer type and a cross point buffer type, depending on a buffer configuration method.
FIG. 1 shows an example of a conventional input buffer type ATM switch having four inputs and four outputs. This ATM switch 201 is composed of a first input buffer 2021 having a first input port 2031, a second input buffer 2022 having a second input port port 2033, a fourth input buffer 2024 having a fourth input port 2034, a self-routing section 205 and a collision detector 207.
The first input buffer 2021 to the fourth input buffer 2024 temporarily store therein the cells inputted from the first input port 2031 to the fourth input port 2034, respectively. The cells stored in the first to fourth input buffers 2021 to 2024 are sent to the self-routing section 205.
The self-routing section 205 is provided with a first output port 2061, a second output port 2062, a third output port 2063 and a fourth output port 2064. This self-routing section 205 carries out a routing operation to output the cells sent from the first to fourth input buffers 2021 to 2024 to any of the first to fourth output ports 2061 to 2064.
The collision detector 207 detects whether or not a cell from a certain input buffer collides with a cell from another input buffers at any of the first to fourth output ports 2061 to 2064. In detail, the collision detector 207 receives routing information of the cells from the first to fourth input buffers 2021 to 2024, and then judges whether or not the collision between the cells is caused at least one of the first to fourth output ports 2061 to 2064. Then, the collision detector 207 sends back the judged result to the first to fourth input buffers 2021 to 2024.
When each of the first to fourth input buffers 2021 to 2024 judges that the collision is not caused at any of the first to fourth output ports 2061 to 2064 by referring to this judged result, it sends the stored cell while maintaining its original state to the self-routing section 205. On the other hand, when each of the first to fourth input buffers 2021 to 2024 judges that the collision occurs at any of the first to fourth output ports 2061 to 2064, it determines a victory or a defeat among the collision cells. Then, the victory cell is sent while maintaining its original state to the self-routing section 205 without a delay. The defeat cell is temporally stored in the input buffer. The input buffer in which the defeat cell is stored sends the routing information to the collision detector 207 when the defeat cell is sent out. Then, the input buffer judges whether or not the collision is caused at any of the first to fourth output ports 2061 to 2064 again.
FIG. 2 shows another example of a conventional input buffer type ATM switch having four inputs and four outputs. This ATM switch 210 is composed of a first input buffer 2121 having a first input port 2131, a second input buffer 2122 having a second input port 2132, a third input buffer 2123 having a third input port 2133, a fourth input buffer 2124 having a fourth input port 2134, a self-routing section 215 and a collision detector 217.
The first to fourth input buffers 2121 to 2124 store therein the cells inputted from the first to fourth input ports 2131 to 2134, respectively. The routing information of the cells stored in the respective first to fourth input buffers 2121 to 2124 are sent to the collision detector 217 which is located between the self-routing section 215 and these first to fourth input buffers 2121 to 2124. The self-routing section 215 is provided with a first output port 2161, a second output port 2162, a third output port 2163 and a fourth output port 2164.
The collision detector 217 detects whether or not a cell from a certain input buffer collides with a cell from another input buffers at any of the first to fourth output ports 2161 to 2164 in accordance with routing information of the cells. Then, the cell which is judged not to collide with the other cells at any of the first to fourth output ports 2161 to 2164 is sent through the collision detector 217 to the self-routing section 215.
The self-routing section 215 distributes the cell to any of the first to fourth output ports 2161 to 2164, in accordance with the routing information. On the other hand, if such a judgement is made that the collision occurs at any of the first to fourth output ports 2161 to 2164, the victory and the defeat are determined between the collision cells. Then, the victory cell is sent while maintaining its original state through the collision detector 217 to the self-routing section 215 without a delay. The defeat cell is temporally stored in the input buffer. The input buffer in which the defeat cell is stored sends the routing information to the collision detector 217 when this defeat cell is sent out, and judges whether or not the collision is occurred at any of the first to fourth output ports 2161 to 2164.
In the ATM switch, when any adjustment is not carried out, such a state may be caused that a plurality of cells inputted from a plurality of input ports is sent to one output port at the same time. To avoid the above state, the ATM switch is provided with the input buffers and the collision detector, as shown in FIGS. 1 and 2, and the collision detector investigates whether or not the collision is caused between the cells in advance. If the occurrence of the collision is detected, one of the plurality of collision cells (the victory cell) is outputted to the output port, and the remaining cells (the defeat cells) are temporally waited in the input buffer. After that, the judgment whether or not the collision is caused is repeatedly performed. The cells, which won in the collisions, are outputted from the output port, one by one.
The occurrence of the collision between the cells may bring about such a situation that when a frame is assembled from the cell, the cell is lost or the cell is arraigned in an erroneous order. In order to avoid such a situation, it is important to determine a buffer capacity in each of the buffer configuration methods. However, a diversification of a communication method in recent years makes an estimate of the buffer capacity required by each of the buffer configuration methods difficult. So, the most of the ATM switches, which are presently sold in a market, are equipped with a large capacity of a buffer at a former stage of an input section, in addition to a buffer having a capacity required by each of the buffer configuration method, in order to cope with an unexpectedly burst traffic. According to this configuration, although a cell loss characteristic can be improved, hardware thereof becomes enormous. Thus, this is contrary to the request of the simplicity of the buffer configuration.
So, a technique is developed which uses an FIFO (First Inxe2x80x94First Out) memory and a selection circuit to thereby simplify the buffer configuration simpler and also speed up the entire ATM switches and the input buffer. For example, Japanese Laid Open Patent Application (JP-A-Heisei 5-292116) discloses xe2x80x9cCONTROL CIRCUIT FOR INPUT BUFFER TYPE ATM SWITCHxe2x80x9d. This control circuit is provided with a reading unit to read destinations of a plurality of cells from a top of the FIFO memory and a reservation management table to manage an operation of sending a cell from the FIFO memory. Then, the cell is sent out from the FIFO memory at a reserved cell transfer time.
FIG. 3 is a block diagram showing a schematic configuration of the above-mentioned control circuit. An FIFO memory 221 has taps to read one of a lead cell and a next cell or both of them. An input control circuit 222 and a selector 223 for selecting any one of the two cells are connected to these two taps. A cell outputted from the selector 223 is supplied to a cell transfer memory 224. The cell read out from this cell transfer memory 224 is externally sent out. A cell transfer table 225 and a common controller 226 are connected to the input control circuit 222. In an ATM switch shown in FIG. 3, the two cells can be treated only by a switching operation of the selector 23. Thus, it is possible to substantially halve a transfer time of a cell transfer request signal from the input control circuit 222 to the common controller 226, a transfer time of a response signal from the common controller 226 to the input control circuit 222 and a transfer time of a control signal from the input control circuit 222 to the FIFO memory 221.
Also, Japanese Laid Open Patent Application (JP-A-Heisei 6-105351) discloses xe2x80x9cATM SWITCHxe2x80x9d. This ATM switch is equipped with a first cell buffer which can read out cells at random and a second cell buffer composed of FIFO memories. When an overcrowding state is reported to the second cell buffer, a cell to be sent to another second cell buffer which is not at the overcrowding state is selected from cells stored in the first cell buffer, and sent to the other second cell buffer. According to this technique, it is possible to avoid a decrease of a throughput resulting from an HOL (Head of Line) effect. Here, the HOL effect implies that when an operation of reading out the cells from the FIFO memories is stopped in order to avoid a collision between the cells, the outputs of the cells on and after that cell are all stopped.
However, this conventional ATM switch has a problem that even if it can avoid the decrease of the throughput resulting from the HOL effect, a judgment whether or not the collision between the cells stored in the input buffer occurs, i.e., a shuffle operation must be carried out in order to avoid the collision, each time a cell transfer timing arrives. That is, in the conventional input buffer type ATM switch, only one cell can be read out from the input buffer at a time, even if an order of sending the cells are changed by the shuffle operation. Thus, when a plurality of stored cells exists in the input buffer, there is a cell, which can not be read out from the input buffer, even if an output port is empty due to the cancellation of a competition relation. As a result, such a problem is remaining that the throughput is dropped than another buffer type ATM switch to thereby prolong the overcrowding state.
Moreover, Japanese Laid Open Patent Application (JP-A-Heisei 9-321768) discloses xe2x80x9cATM SWITCHxe2x80x9d. A switch portion in this ATM switch includes an input buffer, a crossbar type switch and an arbiter. The input buffer transiently stores therein an ATM cell inputted from a certain input line. The crossbar type switch switches the ATM cell outputted by the input buffer. The arbiter gives an ON/OFF condition of a crossing switch to a crossbar type switch in accordance with a priority given to an FIFO in the input buffer. Moreover, the ATM switch includes a distributor and a selector. The distributor distributes an input cell to an FIFO corresponding to an output line number obtained from a header information of the inputted ATM cell. The selector selects an FIFO to be read out on the basis of a signal given by the arbiter. This configuration enables the avoidance of the occurrence of blocking, and also enables the improvement of a throughput under a high traffic and a decrease of a discarding rate of a cell.
Therefore, an object of the present invention is to provide an input buffer type ATM switch and switching method of them capable of simplifying a buffer configuration and improving a throughput.
To achieve the above-described object, an ATM switch according to an aspect of the present invention is includes an input port, a main buffer section, a sub-buffer section, a collision judging section, a buffer controller and a routing section.
The input port sequentially receives ATM cells. The main buffer section stores the ATM cells received by the input port and outputs the stored ATM cells in an order of the reception. The sub-buffer section stores the ATM cells from the main buffer section and shuffles the ATM cells stored in the sub-buffer and outputs the shuffled ATM cells.
The collision judging section judges whether or not a collision between the ATM cells outputted from the sub-buffer section occurs and judges whether each of the colliding ATM cells is a victory ATM cell or a defeat ATM cell when the occurrence of the collision is judged. Where, the ATM cells other than the colliding ATM cells are non-collision ATM cells.
The buffer controller which controls the sub-buffer section based on the judging result by the collision judging section such that the victory ATM cell and the non-collision ATM cells are outputted and the defeat ATM cell is stored and held in the sub-buffer section. The routing section which performs a routing operation to each of the victory ATM cell and the non-collision ATM cells from the collision judging section to output from a predetermined output port.
Also, to achieve the above-described object, an ATM switching method according to another aspect of the present invention is composed of the steps of (A) to (G).
In the step (A), the ATM cells sequentially received by an input port is stored into a main buffer section and in the step (B), the ATM cells stored in the main buffer section is outputted in an order of the reception. In the step (C), the ATM cells from the main buffer section is stored into a sub-buffer section, and in the step (D), the ATM cells stored in the sub-buffer is shuffled and the shuffled ATM cells is outputted. In the step (E), it is judged whether or not a collision between the ATM outputted from the sub-buffer section occurs, and also judged whether each of the colliding ATM cells is a victory ATM cell or a defeat ATM cell when the occurrence of the collision is judged. Where, the ATM cells other than the colliding ATM cells are non-collision ATM cells.
In the step (F), the sub-buffer section is controlled based on the judging result at the step (E) such that the victory ATM cell and the non-collision ATM cells are outputted and the defeat ATM cell is stored and held in the sub-buffer section. Also, in the step (G) a routing operation to each of the victory ATM cell and the non-collision ATM cells outputted from the sub-buffer section is performed to send from a predetermined output port.

ATM switch and switching method capable of avoiding collision between cells


Tetraalkyl silicates are produced by the reaction of silicon metal with an alkanol in the presence of an alkali metal salt of an alkoxyalkoxy alcohol or a polyalkylene glycol in either an alkoxyalkoxy alcohol or a polyalkylene glycol or mixtures thereof and recovery of the product. Tetramethyl silicate and tetraethyl silicate are the preferred products. The preferred alkoxyalkoxy alcohol is 2-(2-butoxyethoxy)ethanol. The preferred glycol is diethylene glycol. An indifferent solvent and/or a hydroxide-scavenger may be employed in the reaction mixture.

1. Field of the Invention
This invention relates to the production of tetraalkyl silicates, particularly tetraethyl and tetramethyl silicates.
Alkyl silicates can be made by the first reaction of metallic silicon with the corresponding alkanol. This route requires either high temperature, high pressure, high surface area of the metal, or a combination of these to achieve a practical reaction rate.
Silicon halides can be caused to react with alkanols to make organosilicates. The process produces large amounts of hydrogen chloride which is corrosive and presents a disposal problem.
Electrolytic methods may be employed to produce tetraalkyl silicates. The electrolytic process requires a large capital expenditure, has high operating expenses, and may involve difficult problems of separation.
Another route to tetraalkyl silicates involves transesterification, wherein a high-boiling alcohol reacts with silicon to form an intermediate silicate which then reacts with a lower boiling alkanol to form the desired tetraalkyl silicate.
2. Description of the Prior Art
Anderson et al in U.S. Pat. No. 3,803,197 granted Apr. 9, 1974 disclose a process for preparing alkyl and 2-alkoxyethyl orthosilicates by reacting "simple alcohols" or 2-alkoxyethyl alcohols containing 1-4 carbon atoms in the alkoxy group with silicon in the presence of a catalytic amount of an alkali metal salt of a 2-alkoxyethyl alcohol. This patent teaches preparation of a catalytic alkali metal alkoxide from the metal. Anderson et al apply their invention to both the synthesis of higher boiling orthosilicates and lower boiling silicates.
The preparation of tetraethyl orthosilicates from a source of silicon suspended in tetraethyl silicate and ethanol, catalyzed by a large amount of sodium ethoxide and cocatalyzed by either an ether alcohol or an alkanolamine, is described by Flick et al in British patent application No. 2,018,800A published Oct. 24, 1979 (cf. West German patent application No. 2,816,386 published Oct. 25, 1979).
A process for synthesizing tetraalkyl orthosilicates by contacting a source of silicon with an alcohol and its corresponding alcoholate is the subject of U.S. Pat. No. 4,113,761 granted Sept. 12, 1979. The process of this disclosure requires additionally either a surface active agent, sodium methylate, or the use of pressure (cf. British patent applications No. 1,559,335-6-7).
Bleh et al in U.S. Pat. No. 3,627,807 granted Dec. 14, 1971 disclose a method for preparing tetraalkyl silicates from an alcohol and the corresponding alcoholate in the presence of a large amount of the same tetraalkyl silicate ester. The patent discloses stringent limitations on the ratios of the materials in the reaction mixture and all three compounds (the alcohol, the alcoholate, and the ester) are restricted to the same alkyl group.
U.S. Pat. No. 2,927,937 granted Mar. 8, 1960 to Gaines sets forth a method for preparing alkyl orthosilicates by attrition milling of a silicon source in the presence of an alcohol and an alkaline catalyst, preferably under pressure. One of the five preferred catalysts disclosed by Gaines is sodium ethoxide. Extended ball milling is required for this process.
3. Objects of the Invention
A principal object of this invention is to provide a method for preparing tetraalkyl silicates.
Another object of this invention is to lessen the formation of by-products, especially unsymmetrical mixed esters, in the preparation of tetraalkyl silicates.
Still another object of this invention is to provide a safe and convenient method for preparing potassium alkoxides and potassium glyoxides suitable as catalysts for the reaction of silicon metal and alkanols to make tetraalkyl silicates.
Another object of this invention is to provide a clean surface of silicon at all times during the reaction.
A further object of this invention is to provide a process for the preparation of tetraalkyl silicates which is amenable to continuous operation.
Other objects of this invention will be apparent to the reader from the description and examples below.

Method for the production of tetraalkyl silicates


A knife shaft stripping device is described, in which the stripping fingers (5) are made of plastic and are injection molded in one piece either with a housing top (7) or with a housing bottom (8), and in which supporting stays (6) are associated with the stripping fingers (5), which likewise are made of plastic and injection molded in one piece with the mating housing bottom (8) or housing top (7). Bearing surfaces (12) for the knife shafts (3) are also disposed in the housing top (7) and in the housing bottom (8), and the stripping fingers (5) and supporting stays (6) are provided with abutment surfaces (9, 10) which contact one another when the cutting mechanism (2) is assembled such that the stripping fingers (5) are supported.

This invention relates to a knife shaft stripping device for a document shredder having integrally formed stripping fingers disposed between the knives of the knife shafts in the cutting area of its cutting mechanism.
The stripping fingers of such stripping devices in the cutting mechanisms prevent the shredded material from penetrating between the knives of the knife shafts and clogging them. Shredded material clogging the space between the knives of the knife shafts would lead to difficulties in operation.
German Published Application No. DE-OS 36 16 554 discloses the idea of arranging integrally constructed stripping fingers in the form of stripping grids in a cutting mechanism. The stripping grids are attached to the side members of the cutting mechanism which also contain the bearings for the knife shafts.

Knife shaft stripping device for document shredders


An apparatus for gauging the thickness of coatings on metal products comprises a casing which accommodates a wheel system; a spring actuator with a mechanism for its winding, the actuator being linked to the wheel system so as to enable its rotation; two levers independently balanced in a static state the first of which carries a permanent magnet interacting through its field with a ferromagnetic coating on a product or with the base thereof in case of a nonmagnetic coating, the second of the two levers interacting with the first lever in the event when its force necessary to break away the permanent magnet from the product being gauged is insufficient; two coiled springs, the first of which is connected through one end thereof with the first lever and through the other end with one of the shafts of the wheel system, the second of the two coiled springs being connected through one of its ends with the second lever and through the other end thereof with a spring tensioning control mechanism. Attached to the casing is a magnetic element adapted to attract the permanent magnet after the latter has broken away from the product being gauged. The first lever is returned to its initial position by a reset lever mounted in the casing and connected with the central shaft of the wheel system. Mounted on the central shaft of the wheel system is a pointer for indicating a gauged thickness on a circular scale rigidly secured to the casing. The apparatus is provided with an adjusting shunt mounted in the casing for movement along the permanent magnet and intended for correcting the attractive force of the latter.

1. Field of the Invention
The present invention relates to magnetic gauging systems, and more particularly, to an apparatus for gauging the thickness of coatings on metal products.
The invention can find advantageous application in gauging the thickness of nickel coatings on ferromagnetic and nonmagnetic bases, as well as for gauging the thickness of nonmagnetic coatings on ferromagnetic base.
2. Description of the Prior Art
There is known an apparatus for gauging the thickness of coatings on metal products, wherein the thickness gauged by a permanent magnet is indicated as a function of the force required to attract this magnet to the product being gauged (cf. U.S. Pat. No. 3,716,779; Cl G 01B). This apparatus comprises a wheel system, a spring drive linked to the wheel system so as to enable its rotation; two levers balanced in a static state, one of which mounts a permanent magnet interacting through its field with the ferromagnetic coating of a product or with the base thereof in case of a nonmagnetic coating, the other lever interacting with the first lever in the event when its force necessary to break away the permanent magnet from the product being gauged is insufficient; two coiled springs, the first of each is connected through one end thereof with the first lever and through the other end with one of the shafts of the wheel system, the second of the two coiled springs being linked through one of its ends with the second lever and through the other end thereof with a spring tensioning control means; a magnetic element adapted to attract the permanent magnet after it has broken away from the product being gauged; a reset lever intended for returning the first lever to its initial position and rigidly secured to the central shaft of the wheel system, the former mounting a winding knob and a pointer for indicating a gauged thickness on a round scale.
When the apparatus is wound for gauging by means of the winding knob, the end of the magnet moves below the bearing plane of the apparatus and the wheel system is locked.
When the bearing surface of the apparatus is placed on the surface to be gauged, the end of the magnet lowers flush with the bearing surface and the wheel system is actuated by the spring drive. As this happens, the first coiled spring is wound until the permanent magnet is broken away from the product being gauged. As the permanent magnet breaks away from the surface being gauged, the first lever turns about its axis and the break spring fixed thereon is actuated to stop a break wheel incorporated in the wheel system, as well as the wheel system as a whole.
After the permanent magnet has broken away from the product being gauged, the former is attracted by means of the mangetic element provided to assure more reliable locking.
The additional lever as well as the second coiled spring extend the overall range of thicknesses covered by the apparatus. However, the apparatus is unsuitable for correcting the force of attraction of the permanent magnet, this being the reason for short service life thereof due to premature demagnetization of the permanent magnet caused by interfering fields.
It is an object of the present invention to provide an apparatus for gauging the thickness of coatings on metal products, wherein a means is provided for correcting the attractive force of a permanent magnet to thereby ensure a higher degree of accuracy and longer service life of the apparatus.
The invention provides an apparatus for gauging the thickness of coatings on metal products, comprising a casing accommodating: a wheel system, a spring actuator with a means for its winding linked to the wheel system so as to enable its rotation, two levers independently balanced in a static state, the first of which carries a permanent magnet interacting through its field with a ferromagnetic coating on a product or with the base thereof in case of a nonmagnetic coating, the second of the two levers interacting with the first lever in the event when its force necessary to break away the permanent magnet from the product being gauged is insufficient; two coiled springs, the first of which is connected through one end thereof with the first lever and through the other end with one of the shafts of the wheel system, the second of the two coiled springs being connected through one of its ends with the second lever and through the other end thereof with a spring tensioning control means; a magnetic element attached to the casing and adapted to attract the permanent magnet after the latter has broken away from the product being gauged; a reset lever intended for returning the first lever to its initial position and linked to the central shaft of the wheel system, the former mounting a pointer for indicating readings on a round-shaped scale rigidly secured to the casing, according to the invention, there is provided an adjusting shunt mounted in the casing for movement along the permanent magnet and intended for correcting the attractive force of the latter.
Such apparatus construction makes it possible to improve accuracy and enhance service life of the apparatus due to the possibility of correcting the attractive force of the permanent magnet.
The adjusting shunt is preferably provided with a plate half-embracing the permanent magnet movably mounted on a screw positioned in the casing, and an arrester intended for limiting the movement of said plate.
Such adjusting shunt is simple in construction and is readily adaptable to gauging the thickness of a wide variety of metal coatings.
Where the apparatus is used for gauging the surface of a predetermined thickness, the adjusting shunt is provided in the form of a ring surrounding the permanent magnet and retained thereon by force of friction .

Apparatus with a permanent magnet for gauging the thickness of coatings on metal products with magnetic shunt to adjust for demagnetization of the permanent magnet

prospekt Partizansky, 32, korpus 1, kv. 91


A high flux density grain-oriented electrical steel sheet excellent in high magnetic field core loss property containing, in percentage by weight, not greater than 0.005% of C, 2.0-7.0% of Si, not greater than 0.2% of Mn, one or both of S and Se in a total amount of not greater than 0.005%, the balance being of Fe and unavoidable impurities, optionally containing, in percentage by weight, of not greater than 0.065% of Al, not greater than 0.005% of N and 0.003-0.3% each of one or more of Sb, Sn, Cu, Mo, Ge, B, Te, As, Cr and Bi, the steel sheet having a grain orientation deviating from an ideal {110} less than 001 greater than  orientation by an average of not greater than 5xc2x0, having an average 180xc2x0 magnetic domain width of not greater than 0.30 mm, preferably not greater than 0.26 mm or greater than 0.26 mm and not greater than 0.30 mm, and having an area ratio of magnetic domains of a width greater than 0.4 mm of greater than 3% and not greater than 20%.

1. Field of the Invention
The present invention relates to a grain-oriented electrical steel sheet for use in the cores of transformers and the like and to a method of producing the same.
2. Description of the Related Art
Grain-oriented electrical steel sheet is used primarily as a core material for transformers and generators. The steel sheet has low core loss achieved by utilizing secondary recrystallization during finish annealing in the production process to confer a texture with high-density {110} less than 001 greater than  orientation (Goss orientation). JIS C 2553 classifies the core loss of grain-oriented electrical steel sheet into different grades based on W17/50 (energy loss under excitation conditions of B8 1.7 T, 5.0 Hz).
Transformer cores are of two types, wound and stacked. In order to realize a compact transformer, a designed flux density of higher than 1.7 T, e.g., around 1.9 T, may be used in either type.
Since the stacked core is fabricated by stacking steel sheets like the floors of a building, the flux density may locally become greater than 1.7 T even though the designed flux density is 1.7 T. At higher than 1.7 T, e.g., at W19/50, the transformer core loss is strongly affected.
Increasing awareness of the need for global environmental protection and energy conservation has recently generated demand for grain-oriented electrical steel sheet with still lower core loss, particularly for a steel sheet with low core loss even in a high-intensity magnetic field of, say, 1.9 T. Over many years, there has been seen little or no innovation or improvement aimed at lowering W17/50 core loss to meet this demand.
In light of the foregoing circumstances, the present invention has as its object to provide a high flux density grain-oriented electrical steel sheet low in core loss at excitation flux densities higher than 1.7 T.
The gist of the present invention for overcoming the foregoing issues is as follows.
The present invention provides a high flux density grain-oriented electrical steel sheet excellent in high magnetic field core loss property containing, in percentage by weight, not greater than 0.005% of C, 2.0-7.0% of Si, not greater than 0.2% of Mn, one or both of S and Se in a total amount of not greater than 0.005%, the balance being of Fe and unavoidable impurities, optionally containing, in percentage by weight, not greater than 0.065% of Al, not greater than 0.005% of N and 0.003-0.3% each of one or more of Sb, Sn, Cu, Mo, Ge, B, Te, As, Cr and Bi, the steel sheet having a grain orientation deviating from an ideal {110} less than 001 greater than  orientation by an average of not greater than 5xc2x0, having an average 180xc2x0 magnetic domain width of not greater than 0.30 mm preferably not greater than 0.26 mm or greater than 0.26 mm and not greater than 0.30 mm, and having an area ratio of magnetic domains of a width greater than 0.4 mm of greater than 3% and not greater than 20%.
The method of producing a high flux density grain-oriented electrical steel sheet excellent in high magnetic field core loss property according the present invention comprises a step of making a steel containing, in percentage by weight, 0.015% to not greater than 0.100% of C, 2.0-7.0% of Si, 0.03-0.2% of Mn, one or both of S and Se in a total amount of 0.005-0.050%, optionally containing, in percentage by weight, not greater than 0.065% of Al, not greater than 0.005% of N and 0.003-0.3% each of one or more of Sb, Sn, Cu, Mo, Ge, B, Te, As, Cr and Bi, the balance being Fe and unavoidable impurities, a step of obtaining a starting material by heating and then hot rolling a slab of the steel into a coiled steel sheet or by directly casting a coiled steel sheet from the molten steel, a step of obtaining a steel sheet of final thickness by hot-rolled coil annealing and strong cold rolling, by preliminary cold rolling, precipitation annealing and strong cold rolling, or by hot rolled coil annealing, preliminary cold rolling, precipitation annealing and heavy cold rolling, and a step of subjecting the steel sheet of a final thickness to decarburization annealing, final finish annealing and final coating, which method further comprises a step of rapid heating to a temperature of 800xc2x0 C. or higher at a heating speed of not less than 100xc2x0 C./s immediately prior to the decarburization annealing and a step of effecting magnetic domain control during or at the end of the production process, thereby providing a steel sheet having a grain orientation deviating from an ideal {110} less than 001 greater than  orientation by an average of not greater than 5xc2x0, having an average 180xc2x0 magnetic domain width of not greater than 0.30 mm, preferably not greater than 0.26 mm or greater than 0.26 mm and not greater than 0.30 mm, and having an area ratio of magnetic domains of a width greater than 0.4 mm of greater than 3% and not greater than 20%.

High flux density grain-oriented electrical steel sheet excellent in high magnetic field core loss property and method of producing the same


A hydraulic drive system (1) including a meter-in compensator (37) and a bleed-off compensator (42) comprises a plurality of sensors (64 to 68), a controller (62), and an outlet pressure switching valve (61). The controller (62) determines whether or not the state of a wheel loader (2) which is detected based on the signals output from the sensors (64 to 68) meets a predetermined steering limiting condition. When the controller (62) determines that the state of the wheel loader (2) meets the steering limiting condition, it outputs a command signal to the outlet pressure switching valve (61). The outlet pressure switching valve (61) reduces the flow rate of the hydraulic oil flowing to steering cylinders (18L, 18R), in response to the command signal in such a manner that the flow rate becomes lower than that corresponding to the operation amount of a handle of a steering device (35).

A work vehicle such as a wheel loader includes a work machine such as a bucket. The work vehicle is configured to extend and contract a work machine actuator such as a bucket cylinder and an arm cylinder to thereby move the work machine. The work vehicle is configured to be able to travel. The work vehicle is configured to drive a steering cylinder (steering actuator) to switch (change) a traveling direction. These actuators are hydraulically driven with hydraulic oil. The work vehicle includes a hydraulic drive device to drive these actuators. An exemplary hydraulic drive device is disclosed in Patent Literature 1.
In the hydraulic control device disclosed in Patent Literature 1, a steering actuator and a work machine actuator are connected in parallel to a hydraulic pump. A steering control valve and a work machine control valve are provided for the steering actuator and the work machine actuator, respectively, to control the flow rate of the hydraulic oil flowing to the steering actuator and the flow rate of the hydraulic oil flowing to the work machine actuator, respectively. A meter-in compensator is provided in a meter-in passage connecting the hydraulic pump to the steering control valve. A bleed-off compensator is provided in a bleed-off passage connecting the hydraulic pump to the work machine control valve. The meter-in compensator compensates a differential pressure between an upstream side and a downstream side of the steering control valve to secure the flow rate of the hydraulic oil supplied to the steering control valve. The bleed-off compensator makes use of a pressure on the downstream side of the steering control valve as a pilot pressure. Thus, the hydraulic oil is supplied to the work machine control valve while securing the flow rate of the hydraulic oil which is required for the steering device.


A plate link chain for a continuously variable transmission in a motor vehicle. The chain includes longer and shorter chain links that include longer and shorter link plates that are coupled to each other by pairs of rocker pressure pieces. The plate link chain includes only two types of link plates, namely shorter link plates and longer link plates.

Field of the Invention
The present invention relates to a plate link chain, in particular for a continuously variable transmission in a motor vehicle. The chain has longer and shorter chain links which include longer and shorter link plates that are coupled to each other by pairs of rocker pressure pieces. In addition, the present invention relates to a CVT transmission having such a plate link chain. The letters CVT stand for continuously variable transmission, and mean that the CVT transmission is variable by stepless adjustments.
Description of the Related Art
From the German published application DE 100 36 258 A1 a plate link chain for a continuously variable transmission of a motor vehicle is known. The chain is made up of individual chain links that are connected to one another by articulated devices. Each of the chain links has a plurality of link plates situated essentially parallel to each other, at least part of the chain links having different link plates, with at least one first type of link plate and at least one second type of link plate.
From German published application DE 199 51 949 A1 a plate link chain is known having a plurality of link plates which are connected with one another flexibly by means of pressure pieces, the pressure pieces running transversely to the longitudinal direction of the chain. A deflection of the plate link chain in at least one direction transverse to its running direction to damp pressure vibrations is subject to resistance.
From German published application DE 101 18 102 A1 a plate link chain is known having at least one swivel guard, which ensures that the swivel angle between chain links having different pitches is smaller than 27 degrees.
From German published application DE 197 43 676 A1 it is known additionally to use link plates which have two openings that are separated from each other by means of a central crosspiece.
An object of the present invention is to further improve a plate link chain, in particular with regard to its service life and/or unwanted noise development during operation.


Monitoring packets can be sent periodically across IP network tunnels that traverse internet connections to a customer location, and the monitoring packets used to determine current packet-loss, latency, and jitter metrics in each direction for each available circuit. Circuits may be assigned to circuit sets, each most appropriate to various classes of user traffic, and user traffic assigned to circuit sets based on traffic class. If monitored metrics change beyond set thresholds, a determination is made as to whether the changes are due to circuit saturation or some other cause. If saturation is the problem, logic at either or both tunnel endpoints dynamically adjusts QOS rate limits to optimum values (the highest rate that does not cause threshold violations) in near-real time.

The Internet has become crucial to the every-day operations of billions of individuals, companies, and devices. Access to the Internet is provided by Internet Service Providers (ISPs). A typical business facility might have multiple "circuits" (i.e., bi-directional connections) to the Internet via multiple different ISPs. Sometimes, network connectivity is interrupted or faulty. For example, a circuit associated with one ISP can fail or become inoperable in some way, which causes Internet access through such a circuit to be cut off, become degraded, or otherwise made unavailable. As a result, the reliability and quality of service (QOS) of packets on the network, and network access itself, are diminished.
Conventional techniques attempt to address these deficiencies in different ways. For example, dual wide area network (Dual-WAN) firewalls or routers provide redundancy to Internet connectivity. But this approach employs rudimentary monitoring of circuit status to establish if a circuit is usable or not. If a circuit fails, the failure is often not detected due to the rudimentary monitoring techniques. Even if the failure is detected (often 30 to 120 seconds after the failure), the bad WAN circuit is disabled and the other WAN circuit is put into use, which results in the source Internet Protocol (IP) address of all sessions to be changed for any traffic that was previously on the broken WAN circuit, thereby breaking any sessions that were established. This can cause voice over IP (VoIP) calls to be dropped, web pages to stop loading, and virtual private networks (VPNs) to be disconnected.
Another conventional approach involves domain name server (DNS)-based load balancer devices. In the event of a circuit failure, the device stops handing out the failed circuit's IP address in DNS responses. The destination IP address of the connection changes, so any application tied to specific IP addresses will be interrupted, including VoIP calls, VPNs, secure shell (SSH) connections, remote desktop applications, or the like. Moreover, since the IP address changes, remote users must re-initiate connections. In addition, DNS caching can cause failover from one circuit to another to malfunction. QOS implementations with DNS-based load balancer devices are essentially ineffective since the traffic has already traversed the entire Internet and ISP network before reaching the DNS-based load balancer device.
Yet another conventional approach is to use the border gateway protocol (BGP). BGP is used as the routing protocol of the Internet by sending "keep-alive" packets across interconnects between routers. If packets are not received for a given interval (usually 30 to 120 seconds), the link is declared down and traffic is re-routed. Implementing BGP at an end-customer site is often prohibitively expensive because the hardware is expensive, the setup and implementation is complex, and the ISP circuits that support BGP are also costly. In practice, ISPs don't support fast enough keep-alive timers for failover between circuits to be seamless. Instead, failover takes 30-120 seconds, resulting in end-user application session timeouts. In addition, with BGP, there is a limited amount of control as to how inbound (e.g., download) bandwidth is distributed.
Accordingly, a need remains for improved methods and systems for providing circuit-aware load balancing with dynamic quality of service. Embodiments of the invention address these and other limitations in the prior art.
The foregoing and other features of the invention will become more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

Circuit-aware load balancing with dynamic quality of service


A method provides driving operation data in a network for wirelessly exchanging driving operation data. A first motor vehicle connected to the network by communication technology determines the absolute driving operation data of a second motor vehicle by way of at least one environment sensor disposed in the first motor vehicle. The absolute driving operation data of the second motor vehicle are transmitted by the first motor vehicle to at least one other subscriber to the network.

The invention relates to a method for providing driving operation data in a network for the wireless exchange of driving operation data.
DE 10 2005 017 419 A1 describes a method for the transmission of information relevant to the operation of vehicles. The information is provided by a transmitter unit on a first vehicle in a local region of the first vehicle in a technically analyzable form. The information is received and/or analyzed at least partly by a receiver unit in a second vehicle, when the second vehicle is in the local region of the first vehicle. The vehicles thus provide driving operation data among themselves using wireless communication means.
An indirect provision of driving operation data using infrastructure installations is also known from the prior art. For example, a first motor vehicle can transmit its driving operation data to a stationary infrastructure installation, which transmits the driving operation data of the first motor vehicle to a second motor vehicle after preparing and/or interpreting said data, if appropriate.
However, the reliability and/or availability of devices and methods based on the use of information acquired in such or similar ways relating to driving operation data of other motor vehicles is considerably limited by the fact that only a relatively small portion of all road users is equipped with corresponding communication means.
In known devices and methods, the data of road users that are not equipped with communication devices for transmitting their operational data are not available to other road users and/or infrastructure installations.
DE 10 2004 053 754 A1 discloses a motor vehicle which is able to recognize a reduction in the speed of another preceding road user and to infer a risk of collision between the motor vehicle and the other road user therefrom. However, the reduction in speed or the speed itself is not transmitted to other road users. It is thus not possible to use the invention disclosed for additional purposes in the network.
It is an object of the invention to provide a simple method which enables an improvement in the offering of information made available to a road user.
This object is achieved by a method for providing driving operation data in a network for the wireless exchange of driving operation data. A first motor vehicle connected to the network by communication technology determines the absolute driving operation data of a second motor vehicle by way of at least one environment sensor disposed in the first motor vehicle. The absolute driving operation data of the second motor vehicle are transmitted by the first motor vehicle to at least one other subscriber to the network. Advantageous embodiments and improvements of the invention are described herein.
The invention extends the database that can be used in the network.
In the present invention, absolute driving operation data of a motor vehicle are initially determined by another motor vehicle and then disseminated by this other motor vehicle in a communication network.
The term "absolute driving operation data of a motor vehicle" is understood to mean operational data of this motor vehicle, which relate exclusively to this motor vehicle such as the absolute travel speed of this motor vehicle and/or an absolute position of this motor vehicle. In contrast, speeds relative to the "measuring" motor vehicle are not regarded as absolute driving operation data of a motor vehicle that is "measured" by another motor vehicle. Preferably, the absolute driving operation data are determined in that driving operation data of the "measured" vehicle relative to the "measuring" vehicle (e.g., a relative speed between the "measured" and "measuring" motor vehicle) are evaluated together with known absolute driving operation data of the "measuring" motor vehicle. The absolute driving operation data of the "measuring" motor vehicle can be determined, for example, by way of a tachometer and/or a satellite-based positioning system.
For additionally disseminating the absolute driving operation data of the "measured" motor vehicle, the "measuring" motor vehicle is connected to the network with the aid of communication technology. This connection is preferably carried out by a radio module.
According to the invention, an environment sensor system of the motor vehicle connected to the network with the aid of communication technology is used for the measurement. The environment sensor system preferably includes at least one radar or LIDAR [Light Detection and Ranging] sensor or an image-processing unit.
The "measured" motor vehicle is preferably located in the immediate vicinity of the "measuring" motor vehicle, at least in the range of the environment sensor system of the latter. The "measured" motor vehicle preferably travels directly in front of the "measuring" motor vehicle or directly behind the "measuring" motor vehicle.
The absolute driving operation data are preferably transmitted in the network in such a way that they can be attributed to a defined motor vehicle or at least an individual motor vehicle. This can be implemented, for example, in that the absolute position of the "measured" motor vehicle is determined and transmitted promptly or optionally together with a time specification. With sufficient accuracy of the position specification, it is possible to clearly attribute the absolute driving operation data to the respective "measured" motor vehicle since no other motor vehicle can be located at the exact same location at the same time.
The absolute driving operation data transmitted in the network are preferably evaluated by at least one subscriber to the network, in particular an infrastructure installation, attributing said data to a defined motor vehicle or at least an individual motor vehicle. For example, a model can be built in which the positions and routes of individual motor vehicles are modeled.
According to a preferred embodiment of the present invention, the "measuring" motor vehicle, also referred to hereinafter as the "first motor vehicle," additionally determines absolute driving operation data of the first motor vehicle by way of at least one of its own sensors disposed in the first motor vehicle, and these absolute driving operation data of the first motor vehicle are transmitted by the first motor vehicle to at least one other subscriber to the network. The first motor vehicle thus provides in the network not only the driving operation data of the "measured" motor vehicle, also referred to hereinafter as "second motor vehicle," but also its own driving operation data.
The other subscriber to the network, to which the driving operation data of the second, and optionally also the first, motor vehicle are transmitted, can be formed particularly as a third motor vehicle. The driving operation data of the second motor vehicle can then be evaluated, for example, by a driver assistance system of the third motor vehicle.
Alternately or additionally, the driving operation data of the second, and optionally also the first, motor vehicle can also be transmitted to an infrastructure installation. Such an infrastructure installation in turn transmits the driving operation data of the second motor vehicle and/or traffic information derived from these driving operation data to at least one third motor vehicle. Naturally, several infrastructure installations communicating among each other can also be provided in a network. An information flow can then also be carried out from the first motor vehicle to a third motor vehicle by way of several infrastructure installations.
Preferably, the driving operation data of the second motor vehicle are transmitted by the first motor vehicle only if the second motor vehicle is not connected to the network with the aid of communication technology. It is thus possible to prevent unnecessary communication if the second motor vehicle provides its driving operation data by itself in the network anyway or is at least able to do so.
In order to determine whether the second motor vehicle provides its driving operation data by itself in the network, the first motor vehicle can have means for receiving communication data from subscribers to the network and additionally an evaluation unit for determining whether the second motor vehicle by itself communicates communication data in the network that correspond, in terms of content, to the driving operation data, which are determined by the first motor vehicle and which relate to the second motor vehicle. Consequently, it can be advantageous if the first motor vehicle transmits the driving operation data of the second motor vehicle only if the evaluation unit determines that the second motor vehicle does not communicate any communication data in the network that correspond to these driving operation data in terms of content.
According to an alternately or additionally applicable preferred embodiment of the present invention, the first motor vehicle likewise includes devices for receiving communication data from subscribers to the network and the first motor vehicle includes an evaluation unit to determine whether communication data, which the first motor vehicle receives using these devices from an infrastructure installation, are based on data that correspond, in terms of content, to the driving operation data determined by the first motor vehicle. Advantageously, the driving operation data of the second motor vehicle are transmitted by the first motor vehicle in the network only if the evaluation unit determines that the communication data are not based on data that correspond to the driving operation data in terms of content. A redundant provision of data can thus also be prevented in cases where the driving operation data of the second motor vehicle are indeed not directly received by the first motor vehicle, but are already taken into account in the model of an infrastructure installation.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

Method for providing driving operation data

Bayerische Motoren Werke Aktiengesellschaft


A thermal printer contains a thermal print head with a bead line, a print drum with surface openings, and a two-part sensor assembly with a first member mounted on the thermal print head adjacent the bead line and a second member mounted in one of the surface openings. The first and second members of the sensor assembly are alignable to communicate with one another to detect the presence of the dye donor web. Because the sensors are mounted on the print drum and mounted on or embedded in the print head at the bead line, the dye donor web is detected at the print line.

To print effectively and efficiently using a color thermal printing process, the dye impregnated donor web must be properly positioned relative to the dye receiver. Proper positioning is required to ensure full coverage of the image area by successive color patches. A typical color donor web contains a repeating series of yellow, magenta and cyan color patches, and in some cases, a black patch and/or a clear fusing patch. Each patch must be properly aligned with the receiver to ensure high quality printing. One way to align or index the receiver and donor is by using a detector which will detect whether the color is yellow, magenta, cyan, black or clear, and identify its position.
In some donor sensing arrangements, a donor web is encoded along the edges with marks that are detected by a detecting means. The general alignment is obtained with the sensor elements placed in the donor path past the thermal print head so that the marks are detected after the donor emerges from the print head. Accordingly, it will be appreciated that it would be highly desirable to detect the markings before the donor web exits the printing area.
In other sensing arrangements, the donor web is located in a cassette with an opening therein for engagement with a sensor. The donor passes by the sensor a point that is a relatively long distance from the area where printing occurs. The color sensor senses the color of the donor as the donor is unwound from the donor supply spool before printing occurs. Understandably, much could happen between the location of the sensor and the printing location while the donor ribbon traverses this course. Accordingly, it will be appreciated that it would be highly desirable to have a color sensor to accurately sense the position and color of the donor ribbon close to the printing area for accurate registration of the colors during printing.
U.S. Pat. No. 4,710,781 which issued Dec. 1, 1987 to Stanley W. Stephenson and reissued on Jul. 10, 1990, as U.S. Pat. No. 33,260, discloses an apparatus for identifying different color frames of a donor web. A sensor includes a light emitting diode (LED) to emit red or yellow light and a corresponding photodetector to respond to the red or yellow light. A space saving arrangement positions two LEDs to illuminate the same spot on the donor web adjacent an edge of the web. The yellow and red light pass through dye frames of the moving donor web and illuminate the appropriate photodetectors. The general alignment is obtained with the sensor elements placed in the donor path past the thermal print head so that color frames are detected after the donor emerges from the print head. Where frames are detected after printing, there is an amount of each frame, equal to the length of donor between the print head and detectors, that is wasted. Accordingly, it will be appreciated that it would be highly desirable to have sensors to accurately sense the position and color of the donor web at the print line for accurate registration of the colors during printing and to thereby minimize wasted donor.

Apparatus and method for donor sensing at the print line in a thermal printer


The invention involves a tool head 10, which can be rotated around an axis of rotation 24, with a tool-holding fixture 14, 16 for a tool 20 having a cutting edge 18 and with equipment 38, 40, 44 for adjustment of the radial position of the tool cutting edge 18 with regard to the axis of rotation 24. The invention distinguishes itself by the fact that the tool-holding fixture is divided up into a base element 14, which is supported in a first bearing system 40 in a carrier sleeve 44 so as to be able to rotate around the axis of rotation 24, and a tool-holding element 16, which is supported in a second bearing system 38 in the carrier sleeve 44 so as to be able to rotate around an eccentric axis 42 that is positioned in an eccentric fashion, as well as in parallel to, the axis of rotation 24.

This application claims priority of German Patent Application No. 100 21 723.0 filed May 4, 2000.
The invention involves a tool head that has the ability for radially adjusting the position of the cutting tool.
A tool head of this type is known, for example, from DE 42 18 466 and consists of a tool having a cutting edge and a tool-holding fixture into which the tool is put. Equipment for setting the radial position of the cutting edge with regard to the axis of rotation is supplied in this tool head. This equipment consists of a pressing power converter between the base portion of the tool head and a driven element. Elastic swivel elements in the form of a parallel spring are provided between these parts that have different extension characteristics. The adjustment movement initiated through the pressing power converter is converted into a movement of the tool here, which is rigidly connected to the driven element. The radial position of the cutting edge of the tool is adjusted via these swivel elements.
There is a major need for manufacturing cylinder jacket surfaces, in particular, as dimensionally precise as possible. An excursion of approximately 0.1 mm is required here for the pure tool correction. Furthermore, fairly small plunge cuts and back-offs should also be possible, for which an adjustment distance of 2 to 3 mm is needed, however. This adjustment range is hardly capable of being realized in a reproducible fashion, though, with the known tool heads.
The problem of further developing a tool head of this type in such a way that a simple possibility of adjusting the cutting edge in a radial direction is created that permits both fairly large adjustment amounts, as well as an adjustment lying away from the axis of rotation, is a basis of the invention.
This problem is solved by the invention described herein.
The knowledge that greater adjustment possibilities of the cutting edge, with greater precision and other constructive possibilities, result through the transfer of the adjustment process with regard to bearing systems arranged in an eccentric fashion to each other known from another area to a tool head is a basis for the invention. On top of that, tool heads have a simple structure because of this.
The invention involves a tool head 10, which can be rotated around an axis of rotation 24, with a tool-holding fixture 14, 16 for a tool 20 having a cutting edge 18 and with equipment 38, 40, 44 for adjustment of the radial position of the tool cutting edge 18 with regard to the axis of rotation 24. The invention distinguishes itself by the fact that the tool-holding fixture is divided up into a base element 14, which is supported in a first bearing system 40 in a carrier sleeve 44 so as to be able to rotate around the axis of rotation 24, and a tool-holding element 16, which is supported in a second bearing system 38 in the carrier sleeve 44 so as to be able to rotate around an eccentric axis 42 that is positioned in an eccentric fashion, as well as in parallel to, the axis of rotation 24. The carrier sleeve 44 can be rotated around the axis of rotation 24, the axis of rotation 24 and the eccentric axis 42 lie on a guide line 52, and the tool-holding element 16 and the base element 14 are coupled to each other through a radial guide 48, 50 so as to be secure against twisting and capable of moving along the guide line 52 in such a way that the distance between the tool-holding element 16 and the base element 14, and consequently between the axis of rotation 24 and the eccentric axis 42, change via movement of the carrier sleeve 44 around the axis of rotation 24.
In accordance with the invention, the tool-holding fixture of the tool head is divided up into a base element, which is supported in a first bearing system in a carrier sleeve so as to be capable of rotating around the axis of rotation, and into a tool-holding element, which is supported in a second bearing system in the carrier sleeve so as to be capable of rotating around an eccentric axis lying parallel and in an eccentric fashion to the axis of rotation. The carrier sleeve can be rotated around the axis of rotation here, the axis of rotation and the eccentric axis lie in a guide line, and the tool-holding element and the base element are coupled with each other in a manner that is secure against twisting and that permits motion along the guide line in such a way that the distance between the tool-holding element and the base element, and consequently between the axis of rotation and the eccentric axis, changes by moving the carrier sleeve around the axis of rotation.
Radial adjustment movements can be carried out because of this in a simple way, without axial changes in the position of the cutting edge coming about. The radial adjustment movements can also include fairly large adjustment distance according to this principle. The maximum distance between the eccentric axes corresponds in the process to half a revolution. If, for example, the maximum distance is 0.1 mm, then the adjustment possibility is 0.1 mm/360xc2x0. This results in high resolution with good precision adjustment.
By turning the carrier sleeve around an angle of 90xc2x0, the distance of the axis of rotation to the eccentric axis changes between 0 and the maximum, for example 3 mm.
In accordance with one design form of the invention, the carrier sleeve has been developed as a handle for manual turning around the axis of rotation. This makes quick manual adjustment possible; the carrier sleeve is scaled here, in order to note the rotation movement. Adjustment is only possible when the tool head is at a standstill here.
As an alternative or supplement to this, the carrier sleeve works together with a drive unit, in particular an electrical one. It is then possible because of this to carry out precision adjustments even during the circulation of the tool head.
As an example, the electrical drive unit includes a rotor disk that is located on the outside of the carrier sleeve, and a drive unit coil that is located above and below the rotor disk, that are each connected to the drilling head. The carrier sleeve can now be moved in one direction or another in a simple fashion through the rotor disk by exciting the drive unit coils, and the radial position of the tool-holding element and of the cutting edge can consequently be adjusted.
In accordance with one design form of the invention, a joint spring is provided between a first bearing system and the tool-holding fixture, and the second bearing system and the base element, in particular a parallel spring, that permits relative movement of the tool-holding fixture vis-a-vis the base element. Special forms of tool-holding fixtures and special construction designs for axially securing the tool-holding fixture can be used because of this. The spring serves as a transfer element of the adjustment movement to the tool-holding element in the process. The spring completely encompasses the tool-holding element and the base element in sections.
In accordance with one preferred design form of the invention, the spring has a first recess in the cross-section running in parallel to the axis of rotation, to which a second recess vertically extends. In particular, the second recess is open towards the inside.
An equalization disk is put into the second recess so that the spring can also transfer axial forces. The equalization disk is preferably coated and/or surface-treated for better sliding. It can also have roller guides, though.
In order to transfer forces from the spindle driving the tool head without a float and in order to avoid tolerance-related cutting edge maladjustment from coming about, the tool-holding element and the base element are braced together with each other in the axial direction in an adjustable way.
In accordance with one design form of the invention, the drive unit generates oscillating, angular movement. Non-circular bore holes can be created in a simple way because of this.
The drive unit for the carrier sleeve can also be designed so as to be mechanical; in particular it can include a friction wheel, a toothed rack or a ratchet wheel for the fine adjustment of the carrier sleeve.
The base element is preferably an integral part of the spindle.
Other benefits and features arise from the following description of three design forms of the invention in connection with the drawing.


Processes for preparing oligosaccharides, polysaccharides, glycolipids, glycoproteins, and other saccharide compositions are provided which involve the enzyme facilitated transfer of a preselected saccharide unit from a donor moiety to an acceptor moiety. In accordance with a preferred embodiment, saccharide compositions having a plurality of saccharide units are prepared by appending the saccharide units in iterative fashion to acceptor moieties which are themselves saccharide compositions prepared in accordance with this invention.

This invention relates to saccharide compositions such as, for example, oligosaccharides, polysaccharides, glycolipids, and glycoproteins. More specifically, this invention relates to processes for preparing these and other saccharide compositions by enzymatic techniques.
The term xe2x80x9ccarbohydratexe2x80x9d embraces a wide variety of chemical compounds having the general formula (CH2O)n, such as monosaccharides, disaccharides, oligosaccharides and polysaccharides. Oligosaccharides are chains composed of saccharide units, which are alternatively known as sugars. These saccharide units can be arranged in any order and the linkage between two saccharide units can occur in any of approximately ten different ways. As a result, the number of different possible stereoisomeric oligosaccharide chains is enormous.
Of all the biological polymer families, oligosaccharides and polysaccharides have been the least well studied, due in considerable part to the difficulty of sequencing and synthesizing their often complex sugar chains. Although the syntheses of oligonucleotides and polypeptides are well developed, there is currently no generally applicable synthetic technique for synthesizing oligosaccharides. Organic synthesis of oligosaccharides is further hampered by the lability of many glycosidic bonds, difficulties in achieving regioselective sugar coupling, and generally low synthetic yields.
Much research effort has been devoted to carbohydrates and molecules comprising carbohydrate fragments, such as glycolipids and glycoproteins. Research interest in such moieties has been largely due to the recognition that interactions between proteins and carbohydrates are involved in a wide array of biological recognition events, including fertilization, molecular targeting, intercellular recognition, and viral, bacterial, and fungal pathogenesis. It is now widely appreciated that the oligosaccharide portions of glycoproteins and glycolipids mediate recognition between cells and cells, between cells and ligands, between cells and the extracellular matrix, and between cells and pathogens.
These recognition phenomena can likely be inhibited by oligosaccharides having the same sugar sequence and stereochemistry found on the active portion of a glycoprotein or glycolipid involved in cell recognition. The oligosaccharides are believed to compete with the glycoproteins and glycolipids for binding sites on receptor proteins. For example, the disaccharide galactosyl xcex2 1-4 N-acetylglucosamine is believed to be one component of the glycoproteins which interact with receptors in the plasma membrane of liver cell. Thus, to the extent that they compete with potentially harmful moieties for cellular binding sites, oligosaccharides and other saccharide compositions have the potential to open new horizons in pharmacology, diagnosis, and therapeutics.
There has been relatively little effort to test oligosaccharides as therapeutic agents for human or animal diseases, however, as synthetic methods for oligosaccharides have been unavailable. Limited types of small oligosaccharides can be custom-synthesized by organic chemical methods, but the cost for such compounds is typically very high. In addition, it is very difficult to synthesize oligosaccharides stereospecifically and the addition of some sugars, such as sialic acid and fucose, has not been effectively accomplished because of the extreme lability of their bonds. Improved, generally applicable methods for oligosaccharide synthesis are desired for the production of large amounts of widely varying oligosaccharides for pharmacology and therapeutics.
For certain applications, enzymes have been targeted for use in organic synthesis as one alternative to more traditional techniques. For example, enzymes have been used as catalysts in organic synthesis; the value of synthetic enzymatic reactions in such areas as rate acceleration and stereoselectivity has been demonstrated. Additionally, techniques are now available for low cost production of some enzymes and for alteration of their properties. Environmental concerns and regulatory constraints faced in the chemical and pharmaceutical industries have spurred hope that enzymatic methods may offer clean and mild processes. To date, however, enzymatic techniques have not been found which are useful for the general synthesis of oligosaccharides and other complex carbohydrates in significant amounts.
Accordingly there exists a long-felt need for general synthetic methods for the production of oligosaccharides, glycoproteins, glycolipids, and similar species in an efficient, cost effective, stereospecific, and generally applicable manner.
It is an object of the present invention to provide saccharide compositions, particularly oligosaccharides and chemical moieties which comprise oligosaccharide units.
It is another object of this invention to provide a wide variety of saccharide compositions, including those not found in nature. It is a further object of this invention to provide saccharide compositions useful in mitigating the effects of human or animal diseases.
It is yet another object of this invention to provide improved processes for preparing saccharide compositions.
It is a further object of this invention to provide enzymatic processes for preparing saccharide compositions.
It is still another object of this invention to provide processes for preparing enzymes useful in synthesizing saccharide compositions.
These and other objects are achieved by the present invention, which provides enzymatic processes for preparing oligosaccharides, polysaccharides, glycolipids, glycoproteins, and other saccharide compositions. These processes involve the enzyme-facilitated transfer of a preselected saccharide unit from a donor moiety to an acceptor moiety. Saccharide compositions having a plurality of saccharide units are preferably prepared by appending the saccharide units in stepwise fashion to acceptor moieties which are themselves saccharide compositions prepared in accordance with this invention.
Accordingly, methods for preparing saccharide compositions are provided comprising the steps of providing an acceptor moiety and contacting the acceptor moiety with a glycosyltransferase. The glycosyltransferase is prepared so as to be specific for the acceptor moiety and capable of transferring a saccharide unit to the acceptor moiety. Also provided are reaction conditions and co-reagents as may be necessary and sufficient to effect the covalent bonding of the saccharide unit to the acceptor moiety.
In accordance with preferred embodiments, the acceptor moiety may be a protein, glycoprotein, lipid, glycolipid, or carbohydrate, such as a monosaccharide, disaccharide, oligosaccharide, or polysaccharide. In accordance with other preferred embodiments, the glycosyltransferase is attached to a solid support.
The present methods are capable of stereospecific attachment of the saccharide unit to the acceptor moiety. In general, it is preferred to employ saccharide nucleotides as donor moieties. Uridine, guanosine, and cytidine phosphate materials terminated by the saccharide units to be donated preferably comprise the donor moieties.
It is also preferred to perform the methods of the present invention a plurality of times such that the product of the first iteration becomes the acceptor moiety for a second iteration, and so forth.
The saccharide compositions prepared in accordance with this invention are believed to find wide utility in diagnostics, therapeutics, and pharmacological applications. The present invention also provides means for preparing a glycosyltransferase specific for a particular acceptor moiety and capable of transferring a preselected saccharide unit to the acceptor moiety. Such methods comprise contacting the acceptor moiety with a mixture suspected to contain a plurality of glycosyltransferases under conditions effective to bind the acceptor moiety and the glycosyltransferase specific for the acceptor moiety. The resulting, bound glycosyltransferase is subsequently isolated. It is preferred that the glycosyltransferase be sequenced and that the glycosyltransferase be produced in enhanced quantities for genetic engineering techniques.
As employed herein, the term xe2x80x9csaccharide compositionxe2x80x9d is intended to include any chemical moiety having a saccharide unit within its structure. Sugars, carbohydrates, saccharides, monosaccharides, oligosaccharides, polysaccharides, glycoproteins, and glycolipids provide examples of saccharide compositions. Mixtures and solutions comprising such moieties are also saccharide compositions.
Saccharide compositions are prepared according to this invention by the enzyme facilitated transfer of saccharide units from donor moieties to acceptor moieties. It will be appreciated that such transfer occurs upon contacting the acceptor and donor moieties with a glycosyltransferase, and typically results in covalently bonding of the acceptor moiety and the saccharide unit stereoselectively, that is, in but one stereoisomeric form.
Once the sugar sequence of a desired target saccharide composition has been determined by conventional methods, a retrosynthetic analysis is generally performed to determine an appropriate synthetic scheme for the saccharide composition. Such a synthetic scheme preferably identifies the particular donor moieties, acceptor moieties, and glycosyltransferases necessary to yield the desired saccharide composition.
In accordance with the present invention, an acceptor moiety is provided which is capable of being covalently bound to a preselected saccharide unit. Representative acceptor moieties include proteins, glycoproteins, lipids, glycolipids and carbohydrates. It will be appreciated that acceptor moieties are preferred to the extent that they are present as a structural component of a saccharide composition of interest. For example, in preparing a saccharide composition such as N-acetylneuraminyl xcex1 2-3 galactosyl xcex2 1-4 N-acetylglucosamine, preferred acceptor moieties would be N-acetylglucosamine and galactosyl xcex2 1-4 N-acetylglucosamine. It will likewise be appreciated that where an acceptor moiety is terminated by a saccharide unit, subsequent saccharide units will typically be covalently bound to the nonreducing terminus of the terminal saccharide.
The saccharide unit to be transferred to an acceptor moiety is provided by a donor moiety for the saccharide unit. A donor moiety according to this invention includes the saccharide unit to be transferred and is capable of providing that saccharide unit to the acceptor moiety when contacted by the acceptor moiety and the appropriate glycosyltransferase. Preferred donor moieties are saccharide nucleotides, such as saccharide-terminated uridine phosphates, saccharide-terminated guanosine phosphates, and saccharide-terminated cytidine phosphates. It will be appreciated that donor moieties are preferred to be capable of readily providing their component saccharide unit to an acceptor moiety when placed in contact therewith and with a glycosyltransferase. For example, uridine diphosphate galactose is preferred for transferring galactose to N-acetylglucosamine, while cytidine monophosphate N-acetylneuraminic acid is preferred for transferring N-acetylneuraminic acid, a sialic acid, to galactosyl xcex2 1-4 N-acetylglucosamine.
Upon identification of acceptor moieties and donor moieties necessary for the preparation of a saccharide composition, a glycosyltransferase for each acceptor/donor pair should be prepared. The present invention encompasses a method for preparing a glycosyltransferase specific for an acceptor moiety and capable of transferring a preselected saccharide unit to the acceptor moiety comprising: contacting the acceptor moiety with a mixture suspected to contain a plurality of glycosyltransferases under conditions effective to bind the acceptor moiety and glycosyltransferase specific for the specific for the acceptor moiety, wherein said contacting is in the presence of a donor moiety for the saccharide unit, providing reaction conditions and co-reagents sufficient to effect covalent bonding of the saccharide unit to the acceptor moiety, and isolating the glycosyltransferase. Those skilled in the art will appreciate that a glycosyltransferase may be broadly defined as an enzyme which facilitates the transfer of a saccharide unit from one chemical moiety (here defined as a donor) to another (here defined as an acceptor) and which is named phenomenologically according to the saccharide unit it transfers. Thus, galactosyltransferase transfers galactose, while fucosyltransferase transfers fucose.
Glycosyltransferases according to this invention are those able to effect the transfer of a predetermined saccharide unit to an acceptor moiety. Glycosyltransferases are preferably specific for an acceptor moiety or at least some significant, active, or exposed portion thereof. Specificity is manifested for a glycosyltransferase by its tendency to bind with a particularly sequenced portion of an acceptor moiety when placed in contact or close proximity therewith and to effect the transfer of a particular saccharide unit to that acceptor moiety.
Currently, glycosyltransferases are available only from natural sources and, as a result, are somewhat limited in number. It will be appreciated that known glycosyltransferases are only capable of effecting saccharide unit transfers which are highly specific, both in terms of the chemical identity of the saccharide unit transferred and the stereochemistry of its subsequent attachment to the acceptor moiety. For example, it is known that one N-acetylneuraminyltransferase can effect the transfer of N-acetylneuraminic acid to an acceptor moiety bearing only a galactose unit to produce a saccharide composition having an xcex1 2-3 linkage between the N-acetylneuraminic acid unit and the galactose unit.
Thus, only those sugar linkages found in nature and attributable to naturally-occurring glycosyltransferases may be effected in accordance with the present invention. For example, the linkage of galactose xcex1 1-2 to N-acetylneuraminic acid, which is not found in nature, cannot presently be effected. The methods disclosed herein are, however, applicable to any type of glycosyltransferase which may become available.
While the behavior of a number of glycosyltransferases is known, many glycosyltransferases are currently not fully characterized. The present invention, however, provides methods by which glycosyltransferases amenable to its practice may be identified and prepared. It has now been found that an acceptor moiety can be used as an affinity chromatographic tool to isolate enzymes that can be used to transfer particular saccharide units and, thus, synthesize other glycosides.
In a preferred embodiment, an acceptor moiety is immobilized as, for example, on a solid support. It will be appreciated that the term xe2x80x9csolid supportxe2x80x9d includes semi-solid supports as well. Once immobilized, the acceptor moiety is contacted with a mixture suspected to contain glycosyltransferases, such as one comprising naturally-occurring cell homogenate. Since an immobilized acceptor moiety will bind an enzyme specific for it, this system is then carefully monitored for acceptor-bound enzyme. If no such binding occurs, then it can be concluded that the mixture did not contain an enzyme specific for the particular acceptor. Other mixtures of, for example, animal and/or plant cell homogenates are then contacted with the acceptor moiety until enzyme binding is observed.
When the acceptor moiety is bound by an enzyme, the species are separated and further studied. In a preferred embodiment, the acceptor and the candidate enzyme are again contacted, this time in the presence of a donor moiety which comprises the saccharide unit desired to be transferred to the exceptor moiety. If such contacting results in the transfer of the saccharide unit to the acceptor, the enzyme is a glycosyltransferase useful in the practice of this invention. It will be appreciated that once the glycosyltransferase is identified, it can be sequenced and/or replicated by techniques well-known to those skilled in the art. For example, replication might be accomplished by monoclonal techniques involving the isolation of genetic material coding for the glycosyltransferase and the preparation of an immortal cell line capable of producing the glycosyltransferase. Replication will likely prove desirable for commercial scale production of saccharide compositions in accordance with this invention.
After the glycosyltransferase is identified, it is contacted with the acceptor moiety and donor moiety under conditions sufficient to effect transfer and covalently bonding of the saccharide unit to the acceptor moiety. It will be appreciated that the conditions of, for example, time, temperature, and pH appropriate and optimal for a particular saccharide unit transfer can be determined by one of skill in the art through routine experimentation. Certain co-reagents may also prove useful in effecting such transfer. For example, it is preferred that the acceptor and donor moieties be contacted with the glycosyltransferase in the presence of divalent cations, especially manganese cations such as may be provided by MnCl2.
In a preferred embodiment, the glycosyltransferase is immobilized by attachment to a solid support and the acceptor and donor moieties to be contacted therewith are added thereto. Alternatively, the glycosyltransferase, donor and acceptor are each provided in solution and contacted as solutes. A preferred procedure for immobilization of glycosyltransferasesxe2x80x94and of acceptor moieties, where necessaryxe2x80x94is based on the copolymerization in a neutral buffer of a water soluble prepolymer such as poly(acrylamide-co-N-acryloxysuccinimide (PAN), a cross-linking diamine such as triethylenetetramine, and the glycosyltransferase, as disclosed by Pollack, A., et al., J. Am. Chem. Soc., 1980, 102, 6324-36. The immobilization of the enzymes on PAN is useful because small amounts of enzyme can be used, high yields of enzyme activity are obtained, and the bond between enzyme and polymer is stable. It will be appreciated that attachment of the active sites of the glycosyltransferase to the support should be avoided.
A saccharide composition prepared by contacting an acceptor moiety with a donor moiety and a glycosyltransferase can, in turn, serve as an acceptor moiety to which subsequent saccharide units may be transferred. The addition of saccharide units to saccharide compositions prepared by such contact is preferred for the synthesis of carbohydrates and saccharide chains having greater than about three saccharide units. For example, in preparing the trisaccharide N-acetylneuraminyl xcex1 2-3 galactosyl xcex2 1-4 N-acetylglucosamine, the disaccharide galactosyl xcex2 1-4 N-acetylglucosamine is prepared according to this invention and then employed as an acceptor moiety to which a subsequent unit is added. Those skilled in the art will appreciate that the saccharide units attached to the saccharide compositions of this invention can be the same or different.
The saccharide compositions of this invention find use in an exceedingly wide variety of applications and may be used in the same manner as saccharide compositions available from known sources. It is preferred that the saccharide compositions be employed in therapeutic and preventative treatments for mammals, such as disclosed in U.S. Ser. No. 241,012.
The saccharide compositions of this invention are expected to find use as blocking agents for cell surface receptors in the treatment of numerous diseases of viral, bacterial, or fungal origins, such as asthma, pneumonia, rheumatoid arthritis, and diarrhea. For example, oligosaccharides prepared according to this invention may inhibit the attachment of pathogens such as pneumonia-causing bacteria to mammalian membrane molecules. Such pathogens might be incubated with cellular glycoproteins and glycolipids that have been separated by chromatography or electrophoresis. After detecting specific adherence patterns, the target compound could be analyzed and inhibitory saccharide composition prepared. If either of the complimentary molecules functions through its saccharide component, then specific saccharide compositions should inhibit attachment.
Additional objects, advantages, and novel features of this invention will become apparent to those skilled in the art upon examination of the following examples thereof, which are not intended to be limiting.

Compositions and methods for saccharide synthesis

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