An etching solution for a multiple layer of copper and molybdenum includes: about 5% to about 30% by weight of a hydrogen peroxide; about 0.5% to about 5% by weight of an organic acid; about 0.2% to about 5% by weight of a phosphate; about 0.2% to about 5% by weight of a first additive having nitrogen; about 0.2% to about 5% by weight of a second additive having nitrogen; about 0.01% to about 1.0% by weight of a fluoric compound; and de-ionized water making a total amount of the etching solution 100% by weight.

1. Field of the Invention
The present invention relates to an etching solution for a metal layer, and more particularly, to an etching solution for a copper-molybdenum layer and an etching method using the same.
2. Discussion of the Related Art
In general, in order to form a metal line on a substrate for a semiconductor device, several steps are required such as forming a metal layer on a substrate using sputtering, forming a photoresist (PR) pattern on the metal layer by coating, exposure and development and etching the metal layer with a cleaning step before and/or after each of the steps. The metal layer is patterned using the PR pattern as an etching mask during the etching step. A dry etching method using plasma or wet etching method using an etching solution may be used for the etching step.
Recently, the resistance of a metal layer has been an issue for semiconductor devices. Resistance of a metal layer is a crucial factor for a RC (resistance-capacitance) signal delay component in semiconductor devices. Likewise, resistance of metal layers should be considered to increase the panel size and resolution of thin film transistor liquid crystal display (TFT-LCD) devices. For a large-size TFT-LCD device, the RC signal delay should be reduced and a material having low resistivity should be developed. In general, metals such as chromium (Cr) (resistivity of about 12.7×10−8 Ωm), molybdenum (Mo) (resistivity of about 5×10−8 Ωm), aluminum (Al) (resistivity of about 2.65×10−8 Ωm) and alloys thereof have been used for the metal layers of TFT-LCD devices. However, those metals are not suitable for gate and data lines of a large-size TFT-LCD device due to their high resistance. As a result, copper (Cu) has been suggested as a material for a metal line. Copper (Cu) has a lower resistivity than aluminum (Al) and chromium (Cr), and has other advantages for the environment. However, copper has disadvantages with respect to the photolithographic process, which includes PR coating and patterning steps. Moreover, copper has a poor adhesion to an insulating layer including silicon (Si).
To overcome the disadvantages of a copper (Cu) single layer, a multiple layer including copper (Cu) has been suggested. For example, a multiple layer of copper (Cu) and titanium (Ti) has been evaluated as a metal line for a large-size TFT-LCD device. An etching solution for the multiple layer of copper (Cu) and titanium (Ti) has already exist and several other etching solutions have been suggested. However, since the etching solution for the multiple layer of copper (Cu) and titanium (Ti) includes fluoric ion due to a chemical property of titanium (Ti), layers having silicon in TFT-LCD devices (e.g., a glass substrate, an active layer of silicon, an insulating layer of silicon nitride (SiNx) or silicon oxide (SiO2)) are also etched. This undesired etching of the layers including silicon complicates the fabricating process of the TFT-LCD devices.
Accordingly, a multiple layer of copper (Cu) and molybdenum (Mo) is suggested. The multiple layer of copper (Cu) and molybdenum (Mo) may have properties equal to or better than the multiple layer of copper (Cu) and titanium (Ti) by controlling a thickness ratio. Moreover, since fluoric ions do not have a direct influence on the etching of the multiple layer of copper (Cu) and molybdenum (Mo), only a small amount of fluoric ions may be added to an etching solution for the multiple layer of copper (Cu) and molybdenum (Mo) such that a layer including silicon is not etched.
An etching solution including phosphoric acid, nitric acid and acetic acid for the multiple layer including copper (Cu) is disclosed in a published patent No. KP 1999-0017836, and an etching solution including iron chloride (III) hexa-hydride and hydrofluoric acid for a multiple layer including copper (Cu) is disclosed in a published patent No. KP 2000-0032999. However, when these etching solutions are used to etch a multiple layer of copper (Cu) and molybdenum (Mo), several drawbacks exist. First, etching speed is too high to control the etching step so that process margin is insufficient. Second, since a taper angle of the cross-sectional profile of the etched multiple layer is equal to or greater than about 90°, device defects or inferiority may occur during a subsequent process. Third, straightness of the etched multiple layer is not good. Fourth, when the etching solution including iron chloride (III) hexa-hydride and hydrofluoric acid is used, a layer including silicon is undesirably etched as in the case of the etching solution for a multiple layer of copper (Cu) and titanium (Ti).
FIG. 1A is a perspective scanning electron microscope (SEM) image showing a pattern of copper (Cu) and molybdenum (Mo) formed by etching with an etching solution including phosphoric acid, nitric acid and acetic acid, and FIG. 1B is a perspective scanning electron microscope (SEM) image showing a pattern of copper (Cu) and molybdenum (Mo) formed by etching with an etching solution including iron chloride (III) hexa-hydride and hydrofluoric acid. As shown in FIGS. 1A and 1B, the pattern of copper (Cu) and molybdenum (Mo) has a poor profile and a poor straightness. Especially, in FIG. 1B, the glass substrate has a rough top surface because hydrofluoric acid of the etching solution etches the glass substrate which includes silicon.
Another etching solution which includes hydrogen peroxide is suggested for etching a multiple layer of copper (Cu) and molybdenum (Mo). However, the etching solution has a first optimum pH value of about 2 to about 4 for copper (Cu) and a second optimum pH value of about 4 to about 7 for molybdenum (Mo). As a result, the molybdenum (Mo) layer may remain as a residue when the etching solution is controlled to have the first optimum pH value for copper (Cu), and etching speed of the copper (Cu) layer is severely reduced when the etching solution is controlled to have the second optimum pH value for molybdenum (Mo).
FIG. 2A is a cross-sectional scanning electron microscope (SEM) image showing a pattern of copper (Cu) and molybdenum (Mo) formed by etching with an etching solution including hydrogen peroxide, FIG. 2B is a perspective scanning electron microscope (SEM) image showing a pattern of copper (Cu) and molybdenum (Mo) formed by etching with an etching solution including hydrogen peroxide, and FIG. 2C is a perspective scanning electron microscope (SEM) image showing a substrate after etching with an etching solution including hydrogen peroxide. As shown in FIGS. 2A and 2B, the pattern of copper (Cu) and molybdenum (Mo) has a relatively good profile and a good straightness. As shown in FIG. 2C, however, a large number of molybdenum (Mo) residues are observed on the substrate because the etching solution having a pH value suitable for copper (Cu) does not etch molybdenum (Mo) completely.

Etching solution for multiple layer of copper and molybdenum and etching method using the same


In an apparatus at a spinning preparation machine for changing sliver cans, sliver is delivered by a delivery device and deposited in a sliver can. The apparatus comprises means for moving a full sliver can away from the region of the delivery device and means for subsequently bringing in an empty sliver can, from a reserve position to the region of the delivery device. An intermediate storage device is arranged to be brought in to the delivery device during changing of the sliver cans is provided. In order to avoid disadvantageous piling up of the sliver on the intermediate storage device and/or in the sliver can and to allow can changing at maximum sliver production speeds, the immediate storage device is arranged to be driven such that it is movable whilst collecting the sliver.

The invention relates to an apparatus at a spinning preparation machine, for example a card, card drawing mechanism, draw frame, combing machine or the like, for changing sliver cans. In one known arrangement, sliver is delivered by a rotary plate and deposited in a sliver can, the arrangement comprising means for moving a full sliver can away from the region of the rotary plate, means for subsequently bringing in an empty sliver can from a position of readiness to the region of the rotary plate, and an intermediate storage means, for example a holding plate, arranged to be brought in to the rotary plate during changing of the sliver cans.
A known apparatus (DE 36 18 857 A) has an intermediate storage means in the form of a plate, which can be pivoted about an axis from a pivoted-out position to a position under the rotary plate. The plate is provided with a drive for the pivoting, preferably a pneumatic press. After separation of the sliver, which continues to be supplied, the intermediate storage means in the form of a plate is pivoted into a position under the rotary plate so that the separated sliver is caught by the plate. When the empty sliver can is placed under the rotary plate, the plate is moved out again. When the plate is moved out, which is preferably carried out with a jerking movement, the sliver deposited on the plate in the form of sliver cycloids is thrown off and transferred to the empty sliver can. In order to facilitate that throwing-off, the plate has a slight inclination such that the edge which is at the front while moving away from the region of the rotary plate is closer to the rotary plate. It is disadvantageous that the sliver continuing to run onto the plate becomes heaped into a column of sliver in undesirable manner, which results in its piling up in the empty can and consequently in a lack of uniformity. In addition, problems of space in the height direction also arise as a result. Finally, it is disadvantageous that can changing is not possible at maximum speed or in the region of the maximum speed without disadvantageous piling up of the sliver.
It is an aim of the invention to provide an apparatus of the kind described at the beginning that avoids or mitigates the mentioned disadvantages and that especially avoids disadvantageous piling up of the sliver on the intermediate storage means and/or in the sliver can and allows can changing at maximum sliver production speeds.
The invention provides a can-changing apparatus for a spinning preparation machine, comprising:                a filling station at which a sliver can can be filled with fibre sliver from a sliver delivery device;        a device for removing a full can from the filling station;        a device for delivering an empty can to the filling station; and        an intermediate storage device which can be positioned to collect sliver delivered during changing of the cans, in which the intermediate storage device is arranged to be driven such that it is movable beneath the delivery device whilst collecting the sliver.
As a result of the fact that the intermediate storage means is moved during deposition, disadvantageous piling up of the sliver is avoided both on the intermediate storage means and in the empty can. It is especially advantageous that can changing is possible at especially high sliver production speeds, ideally without—or without substantially—reducing the delivery speed of the sliver-producing machine. As a result of use of the intermediate storage means, operation at a higher delivery speed is possible during can changing. Because there exists a direct relationship between variations in delivery speed and the quality obtained during such variations, this increases both the efficiency of the machine and the quality of the sliver produced during can changing. In particular, disadvantageous drafting effects in the sliver are reduced or avoided.
In one preferred embodiment, the sliver can is an oblong can. Advantageously, the movement of the oblong can during deposition is a rectilinear, reciprocating movement. In that case, the movement of the intermediate storage means during changing of the oblong can is preferably a rectilinear, reciprocating movement. Advantageously, the intermediate storage means is arranged to be brought in in a direction perpendicular to the longitudinal axis of the oblong can.
In another preferred embodiment, the sliver can is a round can, and the movement of the round can during deposition is a rotary movement. In that case, the movement of the intermediate storage means during changing of the round can is preferably a rotary movement.
Advantageously, the intermediate storage means is arranged to be brought in in the direction towards the delivery device and away therefrom. Advantageously, the intermediate storage means is arranged to be brought into a position underneath the delivery device. Where the cans are oblong cans, the intermediate storage means, for example holding plate or the like, is advantageously substantially oblong. Where the cans are round cans, the intermediate storage means, for example holding plate or the like, is advantageously substantially round.
Advantageously, a clearing element or the like is provided, which can be used for clearing the sliver off from the intermediate storage means. Advantageously, the clearing element and the intermediate storage means are arranged to be moved relative to one another. Preferably, the clearing element is stationary. Advantageously, the clearing element is arranged between the sliver delivery device and the intermediate storage means. Advantageously, the clearing element is capable of clearing the sliver off from the upper surface of the intermediate element. In use, it is preferred that the cleared sliver drops into the empty can, for example, onto a lifting bottom of the empty can. Advantageously, a sliver separating device is provided. Advantageously, the sliver separating device is capable of separating the sliver deposited in the full can from the subsequently supplied sliver. For example, before deposition, there may be produced, in the sliver, a thin location from which the sliver tears off when the full can is moved away. Advantageously, the height of the intermediate storage means is adjustable relative to the sliver delivery device and/or the sliver can.
Where oblong cans are used, during change-over, the sliver delivery device is advantageously located at that end face of the full can which is next to the empty can. The full can may be moved away from and/or the empty can subsequently brought in perpendicular to the longitudinal direction of the can (via the long wall surface). Instead, the full can may be moved out and/or the empty can subsequently brought in in the longitudinal direction of the can (via the short wall surface).
It is preferred that, during changing of the sliver cans, sliver that continues to be supplied from the delivery device is deposited on the intermediate storage means.
The invention also provides an apparatus at a spinning preparation machine, for example a card, card drawing mechanism, draw frame, combing machine or the like, for changing sliver cans, wherein sliver is delivered by a rotary plate and deposited in a sliver can, comprising means for moving a full sliver can away from the region of a rotary plate, comprising means for subsequently bringing in an empty sliver can from a position of readiness to the region of the rotary plate and comprising an intermediate storage device, for example a holding plate, arranged to be brought in to the rotary plate during changing of the sliver cans, wherein there is associated with the intermediate storage device a drive element, which is capable of imparting to the intermediate storage device during changing of the sliver cans a movement which substantially corresponds to the movement of the sliver can during deposition of the sliver.

Apparatus at a spinning preparation machine for changing sliver cans


A lower and upper end plugs of an annular fuel rod, into and out of which cooling water flows, comprises: a lower end plug including a filter for debris which has a plurality of pins intersecting each other at the proper position of an inner channel main inlet, through-holes into which the pins of the debris filter are fitted, and at least one inner channel auxiliary inlet through which the cooling water flows into a lower inner channel thereof when the inner channel main inlet is blocked by debris, and which has a through-hole shape; and an upper end plug including at least one upper handling groove and hole, into which a fuel rod handling tool is coupled, at a proper position of an inner circumference of the inner channel main outlet in a circumferential direction.

1. Field of the Invention
The present invention relates to an annular fuel rod, and more particularly to a lower and upper end plug of an annular fuel rod, in which a filter for debris is installed in front of the inner channel main inlet of a lower end plug, thereby intercepting an inflow of debris in which at least one inner channel auxiliary inlet with a through-hole shape is formed in a cylindrical wall of said lower end plug, thereby supplying cooling water when the debris is caught up in the debris filter to thus prevent the inner surface temperature of a fuel rod from increasing excessively and in which the upper end plug is provided with a groove in which a tool for pulling the fuel rod is located, thereby making it easy to handle the fuel rod when a nuclear fuel assembly is being assembled or disassembled.
2. Description of the Prior Art
In general, a commercial nuclear power plant is equipped with nuclear fuel assemblies. As illustrated in FIGS. 1 and 2, the nuclear fuel assembly 100 comprises fuel rods 101, guide tubes 103, grid spacers 105, a lower end fitting 106, and an upper end fitting 107.
Each fuel rod 101 is provided with lower and upper end plugs 108 and 109 at lower and upper ends thereof.
Here, each fuel rod 101 has cylindrical uranium pellets inserted into a cladding tube of zirconium alloy. These uranium pellets undergo nuclear fission to generate a high-temperature heat.
Meanwhile, the support grids 105 support the fuel rods 101 and function to maintain a distance between the fuel rods 101. Each guide tube 103 is used as a passage for a control rod that moves up and down in order to control a heat flux of the fuel rods 101.
The upper end fitting 107 and the lower end fitting 106 function to hold and support the nuclear fuel assembly 100 to the upper and lower structure of a reactor core. If necessary, the lower end fitting 106 includes a filter (not shown) for filtering debris floating in the reactor core.
Meanwhile, the lower and upper end plugs 108 and 109 installed at the lower and upper ends of each fuel rod have a conical shape, are welded to the cladding tube (not shown), and prevent the internal gas charged into the cladding tube from leaking out.
Generally, 150 or more nuclear fuel assemblies 100 are loaded into the reactor core.
Meanwhile, the nuclear fuel assembly 100 has cylindrical fuel rods, and is designed so that the cooling water flows through subchannels, each of which are surrounded by four rods or a combination of three rods 101 and one guide tube 103, in an axial direction, or gaps between the rods 101.
At this time, each subchannel 111, surrounded by the rods 101, refers to a channel, the circumference of which is typically partly open to allow fluid to freely move to an adjacent subchannel when used.
As illustrated in FIGS. 3, 4 and 5, there has been disclosed an annular fuel rod 201 that is different from the cylindrical fuel rod has been reported (U.S. Pat. No. 3,928,132 (1975), title: Annular Fuel Element for High-Temperature Reactors, and inventor: Roko Bujas).
Here, each annular fuel rod 201 comprises at least one annular pellet 203, an inner cladding tube 205 provided at an inner circumference of the pellet 203, and an outer cladding tube 207 provided at an outer circumference of a pellet 203.
For this configuration, cooling water flows through the external subchannels 213 and inner channels 211 of the fuel rods 201 at the same time, and absorbs the heat generated from the fuel rods 201. However, an annular fuel rod 201 increases its heat area per bundle to decrease its heat flux, so that it can maintain a low inner surface temperature therein, when compared to a cylindrical fuel rod.
In this manner, in the case in which a low inner surface temperature of each fuel rod 201 is maintained, the possibility of damaging a fuel surface due to an increase in the inner surface temperature is reduced, and thus the safety allowance limit of the fuel rods 201 can be increased.
In the above-described cylindrical fuel rods and annular fuel rods, each cylindrical fuel rod is characterized in that, because the cooling water flows through the subchannels, the cooling water moves freely between the adjacent subchannels. This movement of the cooling water between the adjacent subchannels is based on various factors. The main factor is the loss of pressure generated in the subchannel region, and thus a movement of the cooling water occurs in order to maintain an equilibrium pressure.
Meanwhile, in the case of the annular fuel rod, an external subchannel exchanges cooling water freely with the adjacent external auxiliary channels, because the inner channel makes it impossible for the cooling water to move between the channels because it is enclosed by the inner cladding tube.
Therefore, the debris floating in the cooling water is caught in the inner channel, thereby blocking the inner channel. Further, in a case where the debris blocks the inner channel, it obstructs the flow of the cooling water to reduce the flow rate in the inner channel. For this reason, the heat generated from the wall of the inner channel cannot be sufficiently removed, and thus the temperature of the channel wall surface increases. Furthermore, when the temperature continues to increase, the wall surface of the inner channel is damaged which can cause accidents such as damage to the nuclear reactor. Accordingly, the advantages of the annular fuel rod are decreased.
As described above, in order to prevent the temperature from excessively increasing at the surface wall of the channel, a smooth supply of cooling water to the channel is important when operating a nuclear reactor. To this end, it is important to secure a fluid channel to supply the cooling water, capable not only of minimizing the amount of debris flowing into the inner channel but also cooling the surface of the inner channel even if debris caught in the debris filter blocks the main inlet of the inner channel.
To this end, a nuclear fuel assembly, to which a filter for removing the debris floating in the inner channel is applied, was proposed by Korean Patent No. 10-0074788 (1994), 10-0077453 (1994), 10-0074788 (1994), 10-0010878 (1999), 10-0453268 (2004), and so on. However, the existing debris filter is applied to an existing nuclear fuel assembly with cylindrical fuel rods, and is adapted to be integrally formed with a lower end fitting. For this reason, there is a possibility of debris flowing through a gap between the lower end fitting and the adjacent lower end fitting and through a gap between the lower end fitting and the wall of a reactor core, to thus enter into the subchannels.
Further, the debris filter of the lower end fitting of the nuclear fuel assembly cannot completely filter the debris, and thus the debris flowing from the lower end fitting flows into the subchannel.

Lower and upper end plugs of an annular fuel rod


A turborefrigerator in which a coolant discharged from a turbocompressor is condensed in a condenser by dissipating heat to a cooling medium and is then reduced by a throttling mechanism, and thereafter, the coolant evaporates by absorbing heat from a cooled medium in an evaporator and is circulated to the turbocompressor. The present invention simplifies the configuration of such a turborefrigerator, so that the size, weight and cost thereof are reduced. Moreover, the present invention enhances the coefficient of performance thereof and prevents lubricating oil and a cooling medium from blending with each other to cause inconveniences. Thus, the turborefrigerator of the present invention is further provided with an inverter motor whose output shaft directly connected to an impeller of the turbocompressor is supported by a bearing lubricated by a liquid refrigerant, and with a control unit adapted to control both of a suction vane, which is provided in the turbocompressor, and the inverter motor by associating said suction vane and the inverter motor with each other.

When a turbocompressor 1 is operated, a high-pressure gaseous refrigerant discharged from this turbocompressor 1 is fed to a condenser 2 wherein the gaseous refrigerant is condensed and liquefied by dissipating heat to a cooling medium, such as cooling water, flowing and passing through a heat transfer tube 3, as illustrated in FIG. 12(A).
Then, this liquid refrigerant flows into an intercooler 4 in which the pressure of the liquid refrigerant is throttled or reduced to an intermediate pressure in a high-pressure-side throttling (or pressure reducing) mechanism 24. Thus, a part of the liquid refrigerant evaporates. Further, liquid drops are separated by an eliminator 26. Thereafter, the vapor is sucked into a high-stage-side impeller 8 of the turbocompressor 1.
The remaining liquid refrigerant is cooled owing to latent heat of the vaporization. Thereafter, the remaining liquid refrigerant is reduced by a low-pressure-side pressure reducing mechanism 25. Thus, the flow rate of the liquid refrigerant is regulated. Simultaneously, adiabatic expansion thereof occurs, so that a low-pressure gas-liquid two-phase flow thereof is obtained.
Then, this refrigerant enters an evaporator 5 wherein this medium evaporates and vaporizes by absorbing heat from cooled media such as brine and cooling water flowing and passing through a heat transfer tube 6 and is changed into a low-pressure gaseous refrigerant. This low-pressure gaseous refrigerant is sucked again into the turbocompressor 1.
Centrifugal impellers 7 and 8 of the turbocompressor 1 are fixedly mounted on an end portion of the rotary shaft 9 in such a manner as to be spaced in the direction of the shaft, and are enclosed in a hermetic housing 10.
Further, a pinion 11 is fixedly mounted on the other end portion of this rotary shaft 9. In a gear chamber 19, the pinion 11 engages with a gear (or wheel) 12 which is fixedly mounted on an output shaft 14 of an induction motor 13.
Rotary shaft 9 of the turbocompressor 1 is supported by bearings 15 and 16 in the gear chamber 19, while the output shaft 14 of the induction motor 13 is supported by bearings 17 and 18.
Oil reservoir 20 is formed in the bottom portion of the gear chamber 19. Lubricating oil stored in the oil reservoir 20 is extracted by an oil pump 21 to an oil cooler 22 wherein the lubricating oil is cooled by allowing the lubricating oil and the cooling medium, which has flowed through the heat transfer tube 23, to perform heat exchange therebetween. Further, after foreign materials are removed from the lubricating oil by a filter 27, the cooled lubricating oil is supplied to and lubricates the pinion 11, the gear 12 and the bearings 15, 16, 17 and 18. Thereafter, the lubricating oil returns to the oil reservoir 20.
Referring now to FIG. 12(B), there is shown Mollier chart (or diagram) of this cooling cycle.
Gaseous refrigerant sucked into the turbocompressor 1 when being in a state A is then brought into a state B by being compressed by means of a low-stage-side impeller 7. Subsequently, the gaseous refrigerant is sucked into the high-stage-side impeller 8 when being in a state C, and is then put into a state D by being compressed.
This gaseous refrigerant is brought into a state E by being cooled by the use of a condenser 2. Subsequently, this refrigerant gas becomes a saturated liquid refrigerant, which is in a state F, by being condensed. This saturated liquid refrigerant is then put into a state G by being reduced by means of the high-pressure-side pressure reducing mechanism 24 of the intercooler 4. Further, a part of this saturated cooling medium evaporates and is brought in a state C and is then sucked into the high-stage-side impeller 8.
The rest of this liquid refrigerant is put into a state H and is further brought into a state I by being reduced by means of the low-pressure-side pressure reducing mechanism 25. This cooling medium becomes put into the state A by evaporating in the evaporator 5, and is then sucked into the turbocompressor 1.
Incidentally, in Mollier chart, reference character J designates a saturated liquid line; and K a saturated vapor line.
However, in the case of the aforementioned conventional turborefrigerator, the rotary shaft 9 of the turbocompressor 1 is supported by bearings 15 and 16. Further, the output shaft 14 of the induction motor 13 is supported by bearing 17 and 18. Furthermore, power of the induction motor 13 is transmitted to the turbocompressor 1 through the gear 12 and the pinion 11. Consequently, the aforesaid conventional turborefrigerator has encountered problems in that the configurations of the turbocompressor 1, a speed-increasing mechanism and the induction motor 13 becomes complex, that not only the dimensions, weight and cost thereof are increased but the mechanical loss thereof is high, and that the coefficient of performance (COP) is low.
Further, the bearings 15, 16, 17 and 18 and the gears 11 and 12 are lubricated by the lubricating oil. Therefore, it is necessary to change the lubricating oil periodically. Moreover, the lubricating oil and the cooling medium cannot be prevented from blending with each other through the rotary shaft 9.
When the temperature and pressure rise, the cooling medium having blended with the lubricating oil evaporates. Thus, there are a fear that the inconveniences, such as the cavitation of the oil pump 21 and the lubrication failure and seizure of the bearings 15, 16, 17 and 18, are caused.
Moreover, when lubricating oil blends with the cooling medium, the heat-transfer-performance of the condenser 2 and the evaporator 5 is degraded. Thus, there is a fear that reduction in the cooling ability, increase in power consumption; abnormal stop of the refrigerator are caused.


A demodulator recovers a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal. Such a demodulator may include: a QAM-decoding block operable to map a received signal vector onto a constellation so as to yield a first symbol, and identify a next-most probable second symbol based upon the signal vector; and a selection unit operable to select, among the first and second symbols, the one having the lower error content as corresponding to the transmitted symbol. A corresponding method may include similar steps.

Transmission of data (input data) through a channel typically involves coding and modulation. Coding generally changes the representation of the input data to a format whose characteristics are better suited to withstand the noise characteristics of the channel. Modulation takes the coded digital data and converts it to an analog radio wave.
Multiple carrier modulation techniques, e.g., orthogonal frequency division multiplexing (OFDM), are generally known. An example of a modulation technique generally known per se, and generally known-to-be used-with OFDM, is quadrature amplitude modulation (QAM).
For example, 16 QAM can transfer up to 16 (=24) different types of symbols on a given sub-channel of, e.g., an OFDM-coded signal. FIG. 1 depicts a constellation 100 of symbols 102 corresponding to 16QAM, according to the Background Art. Each symbol 102 is centered in a cell 110. Symbols are identified by Cartesian coordinates that assume a unit value of R (to be discussed further below). A received signal vector is represented by a vector in polar notation (amplitude, phase). Assuming an ideal and noiseless channel, two example received signal vectors 106 and 108 having coordinates (√{square root over (2)}R, θ1) and (3√{square root over (2)}R, θ2), respectively, are depicted. Because an ideal, noiseless channel is assumed, received signal vectors 106 and 108 are mapped exactly to symbols (R,R) and (−3R,3R), respectively.
A real channel is not ideal. So before sending input data through a real channel, a training or initializing process is performed on the channel to determine an amount that the channel should be expected to change the amplitude
  (      Δ                                A      CH      expected        )and phase
  (      Δ                                Θ      CH      expected        )of a transmitted signal vector (TV), i.e., to determine the transfer function
  (      H    CH    noiseless    )of the real but (assumed) noiseless channel.
                              H          CH          noiseless                =                  f                                (                                          Δ                                                                                A                  CH                  expected                                            ,                              Δ                                                                                Θ                  CH                  expected                                                      )                                              (        1        )            A Background Art receiver then compensates the received vector (RV) by the expected amounts of change to produce a corresponding expected (compensated) vector (EV), i.e., to decode RV. Assuming a noiseless channel, FIG. 2 depicts such a non-ideal channel compensation scheme according to the Background Art. In FIG. 2, received vector RV would have been mapped into cell 110A, but compensated vector EV is mapped to polar coordinates (√{square root over (2)}R, θ1) in cell 110B, which identifies symbol (R,R) as corresponding to RV.
A real channel also is not noiseless. Hence, received vector is more accurately described as follows.
                    RV        =                                            H              CH              noiseless                        ·            TV                    +          NV                                    (        2        )            What otherwise would have been a compensated vector EV for a noiseless channel is now described as an equivalent vector (EQV), as follows.EQV=EVnoiseless+NV  (3)Equivalent vector EQV will typically not map directly to a symbol because of noise in the channel. According to the Background Art, the cell into which compensated vector EQV maps is considered to determine the symbol which compensated vector EQV represents. In other words, received vector RV is decoded by assuming that equivalent vector EQV represents the symbol of the cell in which EQV is mapped. Up to an amplitude R of noise can be decoded with high confidence. Such a decoding scheme is depicted in Background Art FIG. 3 for cell 110i.


Compression molding suitable anisotropic magnet powder had not been established facing the difficulty of contradiction of high density and magnet powder alignment. By applying both magnetic field and pressure at the moment when the resin is melted into liquid state by heating, both high density and a high degree of magnet powder alignment are attained. Furthermore, application of degassing and ultrasonic vibration were found to be effective. An anisotropic bonded magnet with the maximum energy of more than 20 MGOe, in other words, more than 80% of the theoretical value of maximum energy product, is obtained.

1. Field of the Invention
The present invention relates to an anisotropic bonded magnet which is made by compression molding to obtain a high density and a high magnetic powder alignment and also relates to its production method.
2. Description of the Related Art
Bonded magnets are made of magnet powders embedded in organic resin or metallic resin. They have lower levels of magnetic energy compared to their fully densified counterparts such as sintered magnets.
Bonded magnets, which have excellent formability, can be formed in complex shapes with close mechanical tolerances as well as are free from cracking. Because of the above mentioned advantages, their application area is rapidly spreading.
They may be formed by extrusion, compression, and injection molding.
Injection molding has advantages in forming complex shapes and integrated components with high precision. Injection molding can form the most complicated shapes among three mentioned molding methods. However the magnet has low magnetic energy because the volume fraction of magnet powder is limited to under 60 to 65 percent to provide good flowability in the process.
Extrusion molding has merit during continuous production to provides a low cost magnet. Also extrusion molding gives better magnetic energy than injection molding due to the volume fraction of magnet powder of 70 to 75 percent.
Compression molding gives the highest magnetic energy because of maximum volume fraction of 80 to 90 percent. It can also produce magnets of complex shape.
As mentioned previously, the major shortcoming of the bonded magnet is its low maximum energy product. Recently anisotropic magnet powders with high maximum energy product have been developed to overcome the mentioned shortcomings. However compression molding which is suitable for anisotropic magnet powder has not been established facing the difficulty of contradiction of high density and magnet powder alignment.
Here, anisotropic magnet powder is an aggregation of fine magnet particles which consist of uniaxial crystals and have unidirectional magnetization. Magnet powder alignment means to align the magnetization of each particle to an applied magnetic field.
To solve the difficulty described above, the following technology concerning compression molding has been proposed.
In Japanese patent application Laid- Open (Kokai) No. 1-205403, warm molding is proposed in order to utilize a resin softening phenomenon before curing reaction is set forth. The compound consists of melt spun magnet powder and thermosetting resin.
The patent application discloses that high density is attained by use of a heating temperature of 30 to 100.degree. C. at which the softening phenomenon occurs before curing reaction. Above 100.degree. C. curing has begun before the magnet was sufficiently densified. Further, adhesion of resin to the mold is observed.
Using a compound which consists of Nd.sub.14 Fe.sub.76 Co.sub.5 B.sub.5 melt spun powder and epoxy resin, a bonded magnet with (BH)max of 10.3-11.2 MGOe and density of 6.7 to 7.1 g/cm.sup.3 was attained by compression molding at 45 to 77.degree. C.
However the magnet shows a relatively low maximum energy product of 11.2 MGOe in spite of high density of 7.1 g/cm.sup.3, because the melt spun rare earth magnet powder is isotropic.
Furthermore, the applied resin shows poor thermal durability due to its low melting point.
In Japanese patent application Laid- Open (Kokai) No. 2-116104, compression molding below curing temperature followed by curing is proposed. The molding temperature is set between softening point and about 50.degree. C. higher in order to increase flowability of the resin. In this embodiment a bonded magnet with maximum energy product of 9.0 MGOe and density of 6.1 g/cm.sup.3 was obtained.
A compound consists of ortho-cresol novolak type epoxy resin with a melting point of 40.degree. C. and rare earth magnet powder was compression-molded at 100.degree. C. followed by curing at 120.degree. C. The patent application discloses that the magnet which has superior thermal durability and relatively high magnetic property with high density are obtained by forming at an elevated temperature to keep the softening state of the resin. However the magnet shows considerably low maximum energy product of 9.0 MGOe because of low density of 6.1 g/cm.sup.3. Furthermore the invention requires a curing process after compression molding.
Japanese patent application Laid- Open (Kokai) No. 4-11702 proposes fine resin powder which enables high magnetic property by means of reducing the amount of resin to that of magnet powder. In the invention compression molding with a magnetic field is disclosed.
The particle size of the magnet powder is from 0.1 to 500 .mu.m, which is ordinary for this kind of use, and the particle size of the resin powder is chosen to be one tenth of the magnet powder. When they are mixed into a compound, fine resin powder covers the surface of magnet powder evenly by electro-static force. In the invention, a bonded magnet is manufactured in a single process, namely, curing is performed at the same time as compression molding. In at least one of the embodiments, a magnetic field of 15,000 Oe is applied in the compression molding.
In embodiment 1, a compound of barium ferrite magnet powder and fine polymethylmethacrylate powder with the particle size of 0.05 to 0.06 .mu.m was compression-molded with the applied magnetic field of 15000 Oe. Curing reaction proceeds simultaneously with the molding. The obtained bonded magnet had the density of 3.40 g/m.sup.3 and (BH)max of 1.35 MGOe.
In embodiment 3, a compound of NdFeB magnet powder (MQ powder A) and fine polymethylmethacrylate powder with the particle size of 0.05 to 0.06 .mu.m was compression-molded with the applied magnetic field of 5000 Oe. Curing reaction proceeds simultaneously with the molding. The magnet had the density of 5.49 g/cm.sup.3 and (BH)max of 7.3 MGOe.
In the embodiments, anisotropic powder such as hexagonal plate shaped barium ferrite or elongated NdFeB powder is used. Applied magnetic field aligns the direction of magnetization of the anisotropic powder and thus increases the maximum energy product of the bonded magnet.
In spite of the statements that the invention provides good magnetic property and high density because of reduced amount of resin, the obtained bonded magnets have low maximum energy product and low density. Therefore this invention is considered rather to combine molding and curing processes into one production step.
Japanese patent application Laid- Open (Kokai) No. 4-349603 proposes micro-capsules made of thermal polymerized resin which contains lubricant. The capsule coats the surface of magnet powder and reduces frictional resistance of the compound at the mold surface to obtain a high densified magnet. Furthermore the capsule avoids galling of mold by the compound.
In embodiment 1, a compound of (Pr, Sm)Co magnet powder are compression-molded with an applied magnetic field of 24 kOe and cured at 180.degree. C. A bonded magnet with maximum energy product of 15.0-15.7 MGOe and density of 6.82-6.95 g/cm.sup.3 was obtained.
However the invented process had not attained sufficient maximum energy product in spite of its high density. It may be due to low degree of magnet powder alignment although compression molding is carried out in a magnetic field of as high as 24 kOe. Another problem in this invention is that the manufacturing process of the compound becomes quite complicated. Furthermore, high density brings less amount of resin as binder and causes brittleness of the bonded magnet as well as low flowability in molding.
The major shortcoming of the bonded magnet is low maximum energy product. Therefore development of suitable compression molding has been anticipated to improve maximum energy product. The problem in compression molding of a bonded magnet was contradiction of high density and magnet powder alignment. The problem has not been solved in spite of various inventions as described previously.

Method of producing an anisotropic bonded magnet


The invention involves a system and method for preserving and dispensing liquids from a corked bottle. The system includes a manifold connected to a supply of pressurized gas. Fluidly connected to the manifold is a tube assembly, which extends through the cork of a bottle for the introduction of pressurized gas to the inner portion of the bottle. A second tube within the tube assembly is provided for the transfer of liquid out of the bottle to the manifold for dispensing through the dispensing valve. A floating tip assembly is provided on the distal end of the outer tube member for covering the gas and liquid openings during insertion of the tube assembly into the bottle. The floating tip assembly moves either automatically or manually after insertion of the tube assembly to allow gas and fluid to flow through the assembly.

Numerous approaches have been applied to tapping into wine bottles while maintaining atmosphere within the bottle. For example, Lane U.S. Pat. No. 3,883,043 discloses a Dispenser for Vintage Wines. The dispenser includes a cap member having an offset gas container with a manually operated valve. A tube extends from the gas container into the bottle. A second tube is provided to allow the liquid out of the bottle.
Hayden, U.S. Pat. No. 4,011,971, discloses a tubular member to penetrate a cork-type closure to place the tubular member in fluid communication with the interior of the sealed container. The tubular member has two passages with one adapted to allow the free flow of liquid from the container, and the other adapted to allow the inflow of an innoxious gas to replace the removed liquid. The passage adapted to allow the inflow of an innoxious gas is connected to a compartment in a housing mounted on the tubular member having an innoxious gas retained under pressure. A valve is provided in the housing to allow the innoxious gas to flow into the container when the pressure in the container is below a preselected level.
U.S. Pat. Nos. 7,712,637 and 8,141,746 to Lambrecht disclose a wine extraction and preservation device and method. The device includes a source of pressurized gas connected to a non-coring needle. Pressurized gas is allowed to travel into the bottle. After a predetermined pressure is achieved, the bottle is laid on its side and a valve turned to allow pressurized fluid to come out of the bottle through the needle. The valve is operated to alternate between pressure and dispensing from the bottle.
U.S. Patent Application No. 2010/0155419 to Nishino discloses a Beverage Server System. The system includes a pair of needles, or one needle positioned inside of the other for extension through the cork member. Pressurized gas is provided to one needle and the wine is allowed to flow out of the container through the second needle.
U.S. Patent Application No. 2011/0204093 to Lee discloses a Wine Dispensing Device. The device includes a tubular helically threaded member. A second fluid tube extends through the threaded member and attaches to the distal end of the threaded member, which is displaceable toward the distal end of the bottle. Air is injected through the threaded member and liquid is ejected through the second tube.
These devices suffer from numerous drawbacks including that they are difficult to insert into bottles and easily breakable during use. Other drawbacks include valves that are difficult to construct or operate. The prior art devices also suffer from an inability to purge air out of the assembly prior to insertion into the bottle. Finally, the prior art fails to address portability and the need to expand to commercial volume with a like constructed piece of equipment.
Finally, there are ergonomic needs that a preservation and serving system must satisfy in order to achieve acceptance by the end user. The system must be easily and quickly assembled using minimal hardware and requiring a minimal number of tools. Further, the system should not require excessive strength to assemble or include heavy component parts. Moreover, the system must assemble together in such a way so as not to detract from the aesthetic appearance of the assembled system. Finally, the system should be expandable to provide for individual users as well as commercial enterprises.
Thus, the present invention provides a preservation and dispensing system for liquids in corked bottles, which overcomes the disadvantages of prior art preservation and dispensing systems. The preservation and dispensing system for liquids in corked bottles of the present invention not only provides for relative ease in the assembly and use, it also permits dispensing without the need to stop and re-pressurize the container. Further, the present system permits the tube and manifold assembly to be purged with inert gas to prevent the introduction of air into the bottle.

Preservation and dispensing system for corked bottles


A fireplace has a firebox with a controllable outside air vent to provide a source of cooler air for mixing with and modulating the temperature of the air heated by the fireplace. The air vent is vertically formed between a combustion chamber and a surrounding shell so that a convective current causes the air to flow therethrough and pass over the top surface of the combustion chamber to keep it cooler than otherwise possible with heated room air. Convective currents in another air duct formed between the shell and the combustion chamber circulates room air around the combustion chamber to transfer heat to the room air. The warmed outside air and room air mixes in a plenum above the fireplace prior to entering the room, thereby modulating the temperature of the heated air and permitting it to burn without excessively heating the room. A damper regulates the flow of outside air into the air vent, as desired.

This invention relates generally to gas heaters comprising fireplaces having fireboxes, and more specifically to fireboxes for direct vent and vent-free gas fireplaces. The invention may also be used without gas burners and instead with conventional wood burning fireplaces such as fireplace inserts which are typically added after a home is built.
The many advantages of fireplaces have been known for centuries. Today, fireplaces are desired and used chiefly for decorative purposes or as supplemental heating sources for homes. Not only can they provide a reliable, cost effective source of heat, but they are always considered to add a soothing, entertaining, and attractive atmosphere to a home.
It is no surprise then that fireplaces are becoming increasingly popular. Recent developments in gas fired fireplaces have resulted in versatile fireplace units that in some cases are freestanding and that in other cases may be installed relatively easily and inexpensively as compared to their woodburning counterparts that quite often require extensive construction and design considerations to install, especially after the home is first built. Modern fireplaces, however, are not without application difficulties that may interfere with their use and enjoyment. For instance, in many cases fires may only be tolerated for shortened time periods because of the intense heat that they can produce. This problem is especially evident when entertaining groups of people in a room with a fireplace. The temperature in the room quickly becomes unacceptably warm, leaving the host of the gathering with the choice of turning off the fireplace or opening windows. Neither of these options is desirable. Opening windows will create chilly drafts and noticeably warm and cool spots in the room, while shutting down the fireplace will detract from the ambiance of the room. Too often, the aesthetics of the fireplace are sacrificed because the room becomes too hot, too soon. Indeed, many gas-fired fireplaces are equipped with sensors that will shut the fire down when either the temperature of the fireplace or of the room reaches a predetermined set point, all to the dismay of the fireplace owner when the fireplace shuts down in a matter of minutes once a gathering begins.
Although as expected the firebox itself becomes very hot as a fire burns within it, the top area of the combustion chamber becomes especially hot as the heat naturally rises and concentrates at the horizontal beam spanning the top front of the firebox opening. This concentrated heat, if not properly insulated, literally bakes the surrounding building materials, such as wood studs and the finish materials as well. This not only shortens the life and sacrifices the appearance of the finish, but also is an ineffective use of the heat. Furthermore, as these surrounding building materials heat up, they themselves become a source of radiant heat which further intensifies the heat emanating into the room from the fireplace.
Finally, the warmth from a fireplace and the use of room air for combustion increases the negative pressure of a home in relation to the outside atmosphere. Thus, when an outside door is opened, it can cause a rush of cold heavy air into the home. The blast of cold air is always unwelcome and a warm fire only intensifies this experience. To alleviate these undesirable effects, quite often a homeowner will crack open a window while a fire is burning in a fireplace. Unfortunately, this often creates a chilly draft which is also undesirable.
One solution offered by several prior art devices is to provide outside air to the fireplace, not just for combustion purposes, but to more efficiently harness the heat of the fireplace by circulating cold outside air around the firebox to simultaneously heat the outside air and cool the firebox, thereby more efficiently using the heat generated by a fire while concurrently introducing cooler air into the room and alleviating the intense heat emanating from the fireplace. One such example is found in U.S. Pat. No. 4,928,667 which incorporates a blower to force outside air through a heat exchanger having a serpentine path and then into the room. While this arrangement does serve to capture heat which might otherwise escape through the flue, it requires a blower to force the outside air through the heat exchanger and yet does not reduce the heat concentrated at top of the firebox opening. Furthermore, the addition of a blower increases the initial cost and complexity of the fire place, and also the energy cost and maintenance over its useful life.
Fireplaces having fireboxes of prior art design are therefore disadvantaged in that they either suffer from intense heat generation which can force them to be shut down or otherwise inefficiently mix in outside air at increased cost and without eliminating the concentration of heat at its most intense point of build up, they can inefficiently transfer heat to building materials surrounding this point of concentrated intense heat, and they can increase the negative pressure in the home relative to the outside atmosphere.

Gas heater having firebox with controllable outside air mixing vent


A trailer is designed to receive, transport and unload large cylindrical bales of agricultural products such as hay, including bales which may be out-of-round due to a flat side caused by settlement during storage or transport. The trailer has a wheel-mounted frame extending the full length of the trailer and a plurality of cradles mounted on the frame to receive and support the bales. Each cradle has a latch by which the cradle may be released from its normally horizontal position to rotate under the force of gravity to an unload position. During rotation of the cradles to the unload position, pusher or kicker members contact and propel the bales outwardly from the cradles to insure that the bales land and/or come to rest on the ground in the desired position with their round sides in contact with the ground. In a first embodiment, a kicker mechanism moves relative to the rotating cradle, while in a second embodiment the kicker is a stationary member rigidly attached to the frame. The cradles may be oriented on the trailer either with the bales' longitudinal axes transverse to the trailer frame to provide for an end-over-end unload of the bales, or with the bales' longitudinal axes parallel to the trailer frame to provide for a rolling unload of the bales.

1. Field of the Invention
This invention relates to a trailer for receiving, transporting and unloading large cylindrical bales of agricultural products, and, in particular, to a cylindrical bale trailer which uses the force of gravity to unload the bales so that the round side of the bale is always in contact with the ground, and which is capable of automatically unloading bales which are out-of-round, i.e., flattened on one side, and resistant to rolling motion.
2. Description of Related Art
Present farming methods involve the processing of hay and other agricultural products in the field into large cylindrical bales having a round side surface and two flat end surfaces, which are approximately 4-5 feet in length, 5 feet in diameter, and weigh as much as 2000 pounds. Such bales of agricultural products are used as feed for livestock. Typically, cylindrical bales are prepared and stored in the field for many months before being used as feed. In order to protect the bales from rain during storage, the bales are made with a tightly wound round surface which tends to shed water better than the flat end surfaces. Therefore, it is desirable to store large cylindrical bales with their round surface touching the ground, i.e., the watershed orientation. Moreover, when the bales are distributed for use as livestock feed, it is also desirable to place the bales with the round surface on the ground because the bale ends are the desirable places on the bale for livestock to feed.
The size of these cylindrical bales makes manual handling by laborers impractical, if not impossible, and the loading, transporting and unloading of such bales has become a problem which is not effectively or efficiently solved by utilizing conventional farm equipment. A need for specialized equipment for loading, transporting and unloading such large cylindrical bales has been recognized, and a number of specialized trailers have been previously proposed for this purpose. However, the specialized bale carriers known to applicant have disadvantages. Some of the prior devices such as disclosed in U.S. Pat. Nos. 5,123,800 and 5,137,412 are impossible to load using conventional farm equipment, e.g., a conventional 3-point hitch spear on a tractor rear or a spear mounted on a front end loader, because of the above-ground height and/or the orientation of the bale carrying cradle on the trailer. Some of the prior devices such as disclosed in U.S. Pat. No. 4,261,676 require a special hydraulic lift apparatus to load the bales and hydraulic ram apparatus to unload the bales. Some of the prior devices such as disclosed in U.S. Pat. No. 4,411,572 employ complex mechanical linkage to enable the bale cradle to rotate between transverse and longitudinal orientations to the trailer frame.
However, one problem which the prior devices do not discuss or attempt to solve is the settlement of the bales during storage and/or transport due to their great weight. This settling causes the part of the bale in contact with the ground or the carrying surface of a cradle to flatten, or go out-of-round. A flattened or misshapen bale poses a special handling problem because, when combined with the great weight of the bale, it causes the bale to resist rolling off of a bale cradle which is designed for gravity unload such as disclosed in U.S. Pat. Nos. 4,138,159, 4,411,572, 5,123,800, and 5,137,800. Because such flattened and out-of-round bales resist rolling and, thereby, will not self-unload under the force of gravity, these prior devices require additional handling and/or special equipment to unload.


An effective amount of carnitine is administered to broiler type poultry to prevent or alleviate ascites. In the preferred embodiment, a carnitine supplemented diet is fed to broiler type chickens in a feed composition during the phase of rapid tissue accretion where a high oxygen requirement stresses the birds"" cardiovascular support system. The feed composition preferably contains between 5 and 1000 ppm of carnitine.

1. Field of Invention
The present invention relates generally to disease prevention in livestock, and, more specifically, to the prevention or alleviation of ascites in broiler type poultry.
2. Background
Ascites, also known as pulmonary hypertension syndrome, is a condition characterized by the accumulation of serous fluid in the spaces between tissues and organs in the abdominal cavity and is most prevalent as an affliction of poultry. The fluid is clear or amber in color, originates from the liver and has the general composition of plasma. Also referred to as waterbelly, high altitude disease and avian edema, ascites is attributable to the inability of the cardiovascular system to meet tissue oxygen demands.
The economic consequences associated with ascites are severe and occur due to a combination of increased bird mortality and condemnations along with reduced growth rate and feed efficiency. In the United States alone, annual poultry industry losses due to ascites are estimated to exceed 65 million dollars. Though estimates for dollar losses in other countries are not as readily available, the annual global impact of this disease likely exceeds a billion dollars.
In most cases ascites is brought about by a divergent bird oxygen requirement and its cardiovascular ability to supply oxygen as a nutrient. The inability of the cardiovascular system to meet tissue oxygen demands may result from may different circumstances, one example of which is a reduced atmospheric oxygen concentration. It was under these conditions in the 1970""s that ascites was first recognized as a disease in broiler flocks grown at high altitude in South Africa and South America. Birds initially compensate for reduced tissue oxygen supply by increasing cardiac output. However, problems arise when the return blood volume exceeds the capacity of the heart to pump the blood. As a result, the heart enlarges, becomes round in outline and develops a dilated right ventricle. The right heart failure causes increased vena cava pressure and liver congestion. Classic ascites ensues due to the increased hepatic hydrostatic pressure resulting in transudation of fluid through the liver capsule into the abdominal cavity. The chronically elevated intrahepatic pressure leads to loss of hepatic parenchyma, intrahepatic fibrosis (cirrhosis) and hepatic dysfunction.
Other factors contributing or predisposing poultry to ascites have been identified. Pulmonary tissue damage, such as caused by exposure of birds to dust and ammonia, as well as diseases affecting the lungs (e.g., infectious bronchitis, Newcastle disease, infectious coryza, colibacillosis, aspergillosis), is known to be associated with an increased incidence of ascites, as is reduced cardiac function. Excess furazolidone, toxic fat and excess salt in the diet are also predisposing factors, along with cold distress brought about by nonevaporative heat loss.
Despite a better understanding of the disease, there has been a dramatic rise in ascites incidence in recent years. Primarily responsible is the increased growth rate of today""s genetically engineered birds. The desire to achieve rapidly growing lean strains of meat chickens and the demands from processors to increase yields by reducing the overall size of visceral organs has meant a selection of strains susceptible to ascites. To put it in perspective, the age to slaughter and the amount of feed required to produce a given quantity of chicken meat has been more than halved since the early 1950""s. See Havenstein, G. B., P. R. Ferket, S. E. Scheldeler and B. T. Larson, Growth, Livability and Feed Conversion of 1957 vs. 1991 Broilers When Fed xe2x80x9cTypicalxe2x80x9d 1957 and 1991 Broiler Diets, Poultry Science, Vol. 73, pp. 1785-1794 (1994). In the early 1950""s the average length of time required to grow a broiler chicken to a 4 pound harvest weight exceeded 15 weeks. Through genetic selection, this time period has been reduced to a current average of about 6 weeks. Consequently, bird metabolic events that are needed to produce a unit of poultry meat have been squeezed into a shorter time period, creating a high metabolic demand in today""s bird. Such metabolic demand is further elevated by environmental factors, such as low and high ambient temperature, and disease. As a bird having a high metabolic demand possesses a higher oxygen requirement, severe stress is placed on the bird""s cardiovascular support system. The stress is exacerbated when gain composition consists primarily of protein gain, as is the case with broiler type birds. Studies by the inventors show that trial broilers consumed 3.1 liters of oxygen per gram of protein gain versus just 0.82 liters of oxygen per gram of fat over a 35 day production period. Thus, a bird""s ability to consume and transport oxygen not only has the potential to impact bird health via ascites, but also carcass composition by limiting protein synthesis ability.
The incidence of ascites in fast growing birds may be reduced by lowering gain accretion rate, such as by feeding low caloric density rations and restricting feed intake; however, lowering growth rate is not appealing to the poultry industry as it fails to maximize bird productivity.
There is thus a need for an aid to prevent or alleviate ascites in stressed, rapidly growing livestock, particularly poultry. The present inventors have discovered such an aid in a carnitine supplemented diet for poultry. The diet is unexpectedly effective at reducing the incidence of ascites (as evidenced in a reduced hematocrit, right ventricle weight and ascites heart ratio) in broiler type poultry and potentially enhances growth rate, feed efficiency, survivability and carcass quality.
In the patent art, U.S. Pat. No. 5,213,815 discloses a method of treating ascites comprising the administration of Eyebright herb and Brewer""s yeast to poultry in need thereof. In U.S. Pat. No. 4,970,080, ascites is purportedly treated by feeding small amounts of zeolite to the affected animal.
Heretofore, carnitine in poultry diet has been reported to have no beneficial effect on feed intake, body and abdominal fat weight or on carcass or liver lipid levels in growing broilers (Cartwright, Poultry Science, Vol. 65, Suppl. 1, p. 21, 1986). Dietary carnitine has been shown to retard ethanol metabolism in broilers (Smith et al., Poultry Science, Vol. 71, Suppl. 1, p. 64, 1992), and, in U.S. Pat. No. 5,362,753, to increase the hatchability of eggs.
Unrelated to poultry, carnitine has been used as a supplement in pig diets (U.S. Pat. Nos. 5,124,357 and 5,192,804 and PCT Publication WO 98/24328), a smolting feed for salmon (U.S. Pat. No. 5,722,346) and in a catfish diet (U.S. Pat. No. 5,030,657). The use of carnitine in the treatment of heart failure or myocardial ischemia is discussed in U.S. Pat. No. 4,075,352 and PCT Publication WO 98/43617.
Notwithstanding the known uses of carnitine, the prior art wholly fails to teach or suggest as disclosed and claimed herein a carnitine supplemented diet fed to broiler type poultry to prevent or alleviate ascites.

Carnitine supplemented diet to prevent or alleviate ascites in broiler type poultry

The Board of Regents for Oklahoma State University


A foamed electrical wire, containing: a conductor; and a foamed insulating layer; in which the foamed insulating layer comprises a thermoplastic resin that is a crystalline thermoplastic resin having a melting point of 150° C. or more or a non-crystalline thermoplastic resin having a glass transition temperature of 150° C. or more, and the average bubble diameter of the foamed insulating layer is 5 μm or less.

Inverters have been employed in many types of electrical equipments, as an efficient variable-speed control unit. Inverters are switched at a frequency of several kHz to tens of kHz, to cause a surge voltage at every pulse thereof. Inverter surge is a phenomenon in which reflection occurs at a breakpoint of impedance, for example, at a starting end, a termination end, or the like of a connected wire in the propagation system, followed by applying a voltage twice as high as the inverter output voltage at the maximum. In particular, an output pulse occurred due to a high-speed switching device, such as an IGBT, is high in steep voltage rise. Accordingly, even if a connection cable is short, the surge voltage is high, and voltage decay due to the connection cable is also low. As a result, a voltage almost twice as high as the inverter output voltage occurs.
As coils for electrical equipments, such as inverter-related equipments, for example, high-speed switching devices, inverter motors, and transformers, insulated wires made of enameled wires are mainly used as magnet wires in the coils. Further, as described above, since a voltage almost twice as high as the inverter output voltage is applied in inverter-related equipments, it is required in insulated wires to have minimized partial discharge deterioration, which is attributable to inverter surge.
In general, partial discharge deterioration is a phenomenon in which an electrical insulating material undergoes, in a complicated manner, for example, molecular chain breakage deterioration caused by collision with charged particles that have been generated by partial discharge of the electrical insulating material, sputtering deterioration, thermal fusion or thermal decomposition deterioration caused by local temperature rise, and chemical deterioration caused by ozone generated due to discharge. For this reason, reduction in thickness, for example, is observed in the actual electrical-insulation materials, which have been deteriorated as a result of partial discharge.
In order to obtain an insulated wire in which no partial discharge is caused, i.e., an insulated wire having a high partial discharge inception voltage so as to prevent an insulated wire from the deterioration caused by such a partial discharge, such measures are studied as increasing the thickness of an insulating layer of the insulated wire, or using a resin having a low dielectric constant in the insulating layer.
However, when the thickness of the insulating layer is increased, the resultant insulated wire becomes thicker, and as a result, size enlargement of electrical equipments is brought about. This is retrograde to the demand in recent miniaturization of electrical equipments represented by motors and transformers. For example, specifically, it is no exaggeration to say that the performance of a rotator, such as a motor, is determined by how many electrical wires are held in a cross section of a stator slot. As a result, the ratio (space factor) of the sectional area of conductors to the sectional area of the stator slot, has been highly increased in recent years. Thus, if the thickness of the insulating layer is increased, the space factor is lowered, which is not preferable.
On the other hand, with respect to the dielectric constant of an insulating layer, most of resins that are generally used as a material for the insulating layer have a dielectric constant from 3 to 4, and thus there is no resin having a specifically low dielectric constant. Furthermore, in practice, a resin having a low dielectric constant cannot always be selected when other properties that are required for the insulating layer (heat resistance, solvent resistance, flexibility and the like) are taken into consideration.
As a means for decreasing the substantial dielectric constant of the insulating layer, such a measure is studied as foaming the insulating layer, and foamed electrical wires containing a conductor and a foamed insulating layer have been widely used as communication lines. Conventionally, foamed electrical wires such as those obtained by foaming an olefin-based resin such as polyethylene or a fluorine resin have been well-known. As examples of such foamed wires, foamed polyethylene insulating electrical wires are described in Patent Literatures 1 and 2, foamed fluorine resin insulating electrical wires are described in Patent Literatures 3 and 4, the both insulating electrical wires are described in Patent Literature 5, and a foamed polyolefin insulating electrical wire is described in Patent Literature 6. However, in such conventional foamed electrical wires, the dielectric breakdown voltage is decreased as the foaming magnification is increased.

Foamed electrical wire and a method of producing the same


The method of the invention is based on the comparison of local vapor concentrations at the inlet and outlet refrigeration ports and taking action based on that comparison. Control apparatus incorporating the invention is installed inside a refrigeration enclosure, adjacent to a port, preferably at the lowermost port. If the enclosure contains multiple ports at similar height, then each port has a form of the control apparatus attached to it. The control apparatus adjusts a flow of vapor leaving the interior of the enclosure. The control apparatus includes a duct assembly and a blower system. The bottom portion of the duct assembly is a tunnel enclosure through which a conveyor belt passes. Connected to an inside edge of the tunnel enclosure is a duct that extends upward from the conveyor belt. A blower for this duct either sucks vapor away from the conveyor belt or blows vapor from the enclosure interior toward the belt. Regardless of the flow direction, a vapor curtain forms inside the tunnel enclosure and represents a transitional region from all vapor to all air. Control of the blower for the duct assembly is based on vapor concentrations in the tunnel enclosures adjacent to each port. A microprocessor compares measured concentration levels and alters the blower motor frequency in such a manner as to minimize the difference in concentration levels at each port.

In operating cryogenic refrigeration equipment, effort must continually be expended to minimize the amount of air that enters the equipment during operation. In such equipment, the refrigerant is a cryogenic fluid that is vaporized during the refrigeration process. Characteristically, air manages to enter the refrigeration enclosure through ports which allow product to pass into and out of the enclosure. Typically, the air is much warmer and contains a considerable amount of moisture relative to the environment inside the enclosure. Moreover, the moist air can be thought of as a contaminant in the sense that it reduces the purity level of the vapor inside the enclosure.
There are a number of reasons to minimize air infiltration: refrigeration efficiency, economics and capacity to recycle the vaporized refrigerant. Refrigeration efficiency is defined as the quantity of heat removed from a product being cooled, compared to the amount of refrigeration being expended by the cryogen. When moist air enters a refrigeration enclosure, it will necessarily be cooled to the current temperature therewithin. Cooling of air instead of product decreases the cooling potential of the refrigerant, and hence decreases refrigeration efficiency. Additionally, freezing of the water vapor can potentially lead to a damaging build-up of ice inside the enclosure. Ice build-up can become severe enough to require a stop in the production line of the product being cooled, to allow for a thawing period. Clearly, the cooling potential of the refrigerant is reduced or lost during this thaw cycle. The net result is a higher cost in operation.
To recycle the refrigerant, the best approach is to start with the purest stream possible from the source, which in this case is a refrigeration enclosure. The economics associated with recycling a refrigerant are greatly impacted by relatively small changes in the purity of the vapor inside the enclosure. Hence, the greatest economic advantage is achieved when air infiltration is minimized.
Minimization of air infiltration is important in both tunnel and spiral refrigerators. Typically, a tunnel refrigeration enclosure has an entrance port to allow product to enter the enclosure, an exit port to allow product to leave the enclosure, and a flat conveyor in-between. A spiral refrigeration enclosure has similar porting, except that the ports are at different heights relative to the base of the refrigeration enclosure. Inside the enclosure, the conveyor follows a spiral or helical pattern between the ports.
U.S. Pat. No. 3,728,869 to Schmidt describes the recycling of cryogenic vapors from an enclosure (primarily a spiral refrigerator). The pressure within the refrigeration enclosure is kept above atmospheric pressure to minimize air and other contaminant infiltration, and pressure and gravitational effects cause a flow thereof from each refrigeration port. The exiting vapor is collected in adjacent vestibules or spillover boxes in such a manner as to form a vapor barrier above the vestibule. Air infiltration is prevented by a vapor dam. Vapor is removed from the bottom of a vestibule by a piping network driven by a blower system. Control of vapor removal is through motorized on/off dampers in the ducting leading away from the vestibules.
U.S. Pat. No. 4,356,707 to Tyree et al., describes several refrigeration enclosure designs which utilize both mechanical and cryogenic refrigeration. A spiral refrigeration enclosure using a cryogenic refrigerant is described wherein diluting chambers are positioned adjacent the refrigeration ports. The concern at a lower port is to minimize outflow of the denser-than-air cryogen vapor from the refrigeration enclosure. A chamber adjacent to the lower port includes several baffles and a blower system operated at a constant frequency. Vapor is retarded from leaving the refrigeration enclosure by sucking a portion of the vapor from a dilution chamber and redirecting it back into the enclosure. The remaining portion of the vapor exits through the refrigeration enclosure opening and dilutes any air trying to enter the enclosure. Side vanes, manually positioned, are used to balance flow across a conveyor belt.
Variable fan speed control has been employed in the prior art as a means to prevent premature spillover of cryogenic vapor from a refrigeration enclosure or to prevent air from entering. In U.S. Pat. Nos. 4,528,819 (Klee) and 4,800,728 (Klee), the concern is how to prevent loss of cryogen vapor from a refrigeration enclosure or air infiltrating into the enclosure. A temperature sensor is used to indicate whether cryogenic vapor is leaving the enclosure or air is entering the enclosure. Coupled to the temperature sensor is a blower system. In U.S. Pat. No. 4,528,819, the blower is on the exhaust line of the refrigeration enclosure. In U.S. Pat. No. 4,800,728, the blower mechanism is internal to the refrigeration enclosure and is part of the circulation system.
Other methods have been employed to minimize the vapor leaving a refrigerator or the surrounding air from contaminating the interior of a refrigeration enclosure. U.S. Pat. No. 4,947,654 (Sink et al.) describes atmosphere control within spiral refrigerators and tunnel refrigerators. For spiral refrigerators, an improvement to the dilution system discussed in U.S. Pat. No. 4,356,707 is disclosed. The blower or blowers of the dilution system are no longer operated at a fixed frequency, but control of the blower system is now coupled to the cryogen injection rate. The primary sensing device can be either a temperature sensor inside the enclosure or a pressure sensor in the liquid supply line that feeds the cryogen injectors. The exit port can have a similar system to prevent air infiltration by letting a small amount of vapor exit through the port. For a tunnel refrigerator, similar means are discussed for minimizing air infiltration and reducing the premature loss of vapor from the refrigerator.
U.S. Pat. No. 4,955,206 (Lang et al.) discusses a variable speed control method for maintaining the environment within a refrigerator. For a tunnel refrigerator, maintenance of the internal environment is enhanced by the addition of a photocell transmitter and receiver sensor system located outside the entrance port and a baffle-linkage scheme surrounding one of the internal axial fans. The sensor system provides control information based upon how much vapor is leaving the refrigerator. If an excessively high level of vapor is escaping, the baffle-linkage system directs flow away from the port. If the opposite is true, the baffle-linkage responds by directing vapor toward the port. In a spiral refrigerator, the dilution blower system is coupled to the photocell sensing system and is not dependent on the injection rate. In both refrigerator configurations, the blower systems have either variable or single speed drives.
Another method for maintaining cryogenic purity inside a refrigeration enclosure is by employing a controlled evacuation system on the enclosure. U.S. Pat. No. 5,186,008 (Appolonia et al.) discusses a method for controlling an amount of vapor extracted from an enclosure as part of a recycle effort. For a spiral refrigeration enclosure, the locations of suction are at an upper vestibule and at the bottom of the refrigeration enclosure. For the bottom suction location, the amount of vapor leaving the enclosure is a constant ratio relative to the injection rate. The remaining portion of vapor resulting from injected cryogen exits through the entrance and exit ports. Sufficient suction needs to be applied at the upper vestibule to minimize gravitational effects on the vapor flow leaving through the lower port and to prevent air infiltration in the upper port. Hence, the pressure in the upper vestibule region is required to be the lowest pressure relative to the refrigeration enclosure and the surrounding atmosphere.
It is an object of this invention to provide an improved apparatus and method for minimizing escape of refrigerant vapor from a refrigeration enclosure and inlet of air into the enclosure.

Method and apparatus for retention of a refrigerant fluid in a refrigeration enclosure


In order to increase a capacity, or a number of mobile stations (MSs), or users, that may engaged in concurrent communication sessions, a communication system is provided that schedules a different MS, or user, in each beam of multiple predetermined, fixed beams associated with a coverage area, in particular a sector. By simultaneously scheduling a user in each beam of the multiple beams, a performance and throughput of communication system is significantly increased over the prior art. In one embodiment of the present invention, a portion of a shared communication channel that is allocated to each MS is concurrently transmitted to each MS via a beam associated with the MS. In other embodiments of the present invention, voice channels, data channels, and control channels associated with each MS scheduled in a beam may be concurrently transmitted to each MS via the beam associated with the MS.

An important goal in designing a wireless communication system is to maximize system capacity, that is, to maximize a number of users that may simultaneously be served by the communication system. One way of increasing system capacity is to use a smart antenna system. Smart antenna systems use an array of antenna elements to wirelessly transmit information to a target mobile station (MS). The use of an array of antenna elements allows a transmitted signal to be beamformed so that a narrower, more focused beam is transmitted to the MS. That is, by adjusting the amplitudes and phases of the signals conveyed to each antenna element, a desired beam may be formed. By beamforming the transmitted signal, multipath fading of the transmitted signal and interference with non-targeted users is reduced since the beam is more narrowly focused.
There are two primary types of smart antenna systems, switched beam antenna systems and adaptive antenna systems. In a cellular communication system, a switched beam antenna system comprises a use of multiple predetermined, fixed beams in a sector of a cell. The outputs of the multiple antenna elements of the switched beam antenna system are combined in such a way as to form narrow, directional beams that are spatially selective. As a target MS moves through the sector, the switched beam system switches the information intended for the MS from one beam to another. That is, when the MS is in a first beam of the multiple beams, all of the transmit power available in the sector is allocated to the first beam. When the MS is in a second beam of the multiple beams, all of the transmit power available to the sector is allocated to the second beam.
By confining the signal transmitted to a particular MS to a beam containing the MS, system performance is improved since confinement of the transmitted signal to the correct beam reduces interference observed by other mobile stations not in this beam. In addition, confinement of the signal transmitted to a particular MS to a beam containing the MS permits a reduction in transmit power, and concomitantly in interference observed by the other mobile stations. As a result, system capacity is improved since the reduction in interference permits increased frequency reuse, in a Time Division Multiple Access (TDMA) communication system, or orthogonal code reuse, in a Code Division Multiple Access (CDMA) communication system.
However, utilization of a switched beam antenna system to focus a beamed signal upon a target MS moving through a sector only begins to address the issue of increasing system capacity, which is a continuing constraint upon operation of wireless communication systems. Therefore, a need exists for a method and apparatus for obtaining additional capacity improvements through utilization of a switched beam antenna system in a wireless communication system.

Method and apparatus for using switched multibeam antennas in a multiple access communication system


New and useful products are based on sheeted cellulose impregnated with a polyfunctional isocyanate and a fire retardant material. The fire retardants are chosen from organophosphorous esters compatible with the isocyanate in the proportions used. Preferred impregnating compositions use about one part of isocyanate and two parts of a halogenated diphosphate ester. Other compatible phosphorous based materials may be included for viscosity control.

Various paper and similar products have been impregnated with polyisocyanates for uses which include decorative paneling and structural skins of products such as foam or honeycomb filled sandwich panels. Many other applications, such as air filters and floor and roof underlayments, have also become important. Hunter, in U.S. Pat. No. 5,008,359, describes one method of making such products. A sheeted cellulosic paper, such as kraf linerboard, is at least partially impregnated with an essentially uncatalyzed polyfunctional isocyanate. Normally several sheets so impregnated would be superposed and subsequently cured in a press under heat and considerable pressure to form thin panels. Use of any customary catalysts was avoided since they appeared to cause poor adhesion between various plies of the laminates. Preferred pressing temperatures are in excess of 150.degree. C. with pressures of 3000 kPa or greater. A poly(diphenylmethane diisocyanate) (PMDI) appeared to be preferred as the impregnant.
Hunter et al., in U.S. Pat. No. 5,140,086 describe an apparent improvement on the above process. In order to achieve better and more uniform impregnation of the cellulosic substrate the isocyanate is applied in admixture with a miscible organic solvent. Propylene carbonate is the preferred solvent. This was chosen because of its low toxicity, viscosity and vapor pressure at room temperature, its high boiling point of 242.degree. C., and because it is substantially odorless and colorless. A high boiling point material was desirable to prevent blistering during the heat curing operation. In addition to improving impregnation uniformity, propylene carbonate used in a range of 5-20%, gave improved physical properties. It was speculated that the propylene carbonate also may serve as a copolymerizable reactant to some extent. Curing of the product was done under conditions of heat and pressure similar to those described above. It was permissible to include up to 0.5% of a catalyst with the isocyanate-solvent mixture to accelerate the curing reaction.
A later patent to the same inventors, U.S. Pat. No. 5,280,097, is directed to making laminated panel materials in which the earlier products and methods are used as substrates for decorative overlays. The overlay, such as a melamine resin treated printed paper, could be applied to the isocyanate treated substrate or to a laminate formed from a number of substrate plies. These were then preferably cured simultaneously in a single pressing step.
Dimakis, in U.S. Pat. Nos. 5,220,760 and 5,345,738, describes foam filled structural panels made using skins of kraft paper impregnated as taught in one of the above patents.
All of the above noted methods and products require the use of extremely expensive presses for curing the product. However, it has been known that polyisocyanates impregnated into cellulosic substrates will cure to insoluble polymers over prolonged periods of time at ambient conditions. This is believed to be due to slow reaction with the natural moisture present in the substrate, with atmospheric moisture, and possibly by reaction with hydroxyl groups of the cellulosic substrate. PMDI is generally the isocyanate of choice. Wallick, in U.S. Pat. Nos. 5,292,391 and 5,332,458 teaches application of a material such as PMDI to corrugated medium for strength enhancement of corrugated container board without adversely affecting repulpability of the product. The preferred procedure is to apply the isocyanate by spraying after corrugation but prior to application of adhesive at the single facer of the corrugator. Heat curing is thereafter minimized to enhance repulpability. Curing of the isocyanate impregnant continued well after application of the second liner to the product.
PMDI products are composed of a wide range of oligomriers and varying amounts, typically 40-60% of monomeric 4,4'-diphenylmethane diisocyanate (MDI). NCO-- functionality of the products sold as PMDI can vary widely, e.g., from about 1.4 to 3.2, with viscosities ranging from about 50 to 1800 cps. As the curing reaction with water occurs under ambient conditions an intermediate reaction product is 4,4'-diaminodiphenylmethane (MDA). This, in turn, again reacts with available --NCO groups to ultimately form insoluble polyureas. MDA is a relatively toxic chemical and it is desirable that its content, as well as the content of residual unreacted MDI, should be as low as possible. Thus it is highly desirable that cure rates should be relatively rapid and that the curing reaction of the PMDI should approach completion with a minimum of unreacted products. If suitably rapid cure rates could be achieved under ambient conditions numerous applications of the polymer impregnated product would present themselves. In the case of flat panels, elimination of the hot pressing step would considerably reduce the cost. Park et al. in U.S. Pat. No. 5,580,922 describe a cellulose product impregnated with a polyisocyanate along with a smaller amount of triacetin or triethyl citrate. The additives speed curing of the isocyanate to polyureas under room temperature conditions and reduce the presence of undesirable reaction intermediate products.
While PMDI is used to a large extent for preparation of urethane foams and other products by reaction with various polyols or polyethers, it is also used by itself as an adhesive for medium density composite wood products and oriented strand boards. However, in all of these uses the product is hot pressed to effect the reaction to polyureas in a minimum time.
Certain applications of products such as those described above in the Hunter et al. or Park et al. patents would find broader application if they had enhanced resistance to burning. Urethane foams have long employed organophosphorous based or heavily halogenated chemicals for inducing fire resistance. For best results, these are frequently used in combination with an inorganic additive, typically antimony oxide. However, the chemistry of urethanes is quite different from that of the present system and it is unclear whether those fire retardants conventionally used with urethianes would be acceptable at all. Extensive experimental work has indeed shown this to be the case. Problems of coreactivity and lack of compatibility with PMDI have greatly complicated the problem. The present inventors have no knowledge of fire retardant materials being successfully used with neat polyisocyanates where they are not to be further reacted with other materials such as polyols.
The present invention presents a solution to the problem of making fire retardant PMDI impregnated cellulose products in its finding that a very limited group of additives are highly effective in conveying fire resistance.

Fire retardant composite products of cellulose impregnated with isocyanate compositions


A musical instrument stand has a pair of first leg devices, a pair of second leg devices, a pair of adjustment mounts, a main connector, a collar, a clamping device, and an adjustment tube. A first rivet fastens one of the first leg devices, one of the second leg devices, and one of the adjustment mounts together. A bolt fastens the main connector and one of the adjustment mounts together. The collar receives a lower sleeve of the clamping device. The clamping device receives an upper portion of the main connector. The adjustment tube is inserted through the clamping device and the main connector.

The present invention relates to a musical instrument stand. More particularly, the present invention relates to a musical instrument stand which can be folded easily.
U.S. Pat. No. 5,713,547 has disclosed a guitar stand which has a main hollow rod, a first hollow leg, a second hollow leg, a first brace, a second brace, a first bracket, and a second bracket. A pivot means fastens the first hollow leg and the second hollow leg on the main hollow rod pivotally. A hollow upper block is disposed on top of the main hollow rod. The pivot means has a lobe, a transverse plate and a longitudinal plate which is disposed on top of the transverse plate. A main hollow rod has a lobe disposed on an upper portion of the main hollow rod. A circular hole and a curved hole are formed on the main hollow rod. A hollow upper block has a lower protrusion inserted in an upper end of the main hollow rod. A first and a second round cushions are disposed adjacent to a first and a second sides of the hollow upper block, respectively. The first round cushion has a first center hole. The second round cushion has a second center hole. A first bolt passes through the first center hole to fasten the first round cushion on the hollow upper block. A second bolt passes through the second center hole to fasten the second round cushion on the hollow upper block. A longitudinal plate is disposed on a top of the transverse plate. The longitudinal plate has an upper hole to match the corresponding circular hole and a lower hole to match the corresponding curved hole. A first fastening member passes through the circular hole and the upper hole and a second fastening member passes through the lower hole and the curved hole to fasten the lobe and the longitudinal plate together. A first and a second joints are disposed on the first and the second hollow legs, respectively. Each of the first and the second joints has a threaded lower portion inserted in a top interior of the corresponding hollow leg, an annular flange abutting the threaded lower portion, and a top recess to receive the transverse plate. A bevel is disposed beneath the top recess. A notch is formed on a top rim of the first hollow leg. A third and a fourth fastening members fasten the first and the second joints on the transverse plate. The first brace is fastened on a lower portion of the first hollow leg. The second brace is fastened on a lower portion of the second hollow leg. A first hook extends from a top end of the first bracket to be inserted in the first brace. A second hook extends from a top end of the second bracket to be inserted in the second brace. However, the hollow leg will be detached from the respective joint if the user extends the hollow leg to the utmost.
An object of the present invention is to provide a musical instrument stand which can be folded easily.
Yet another object of the present invention is to provide a musical instrument stand which can stand stably.
Accordingly, a musical instrument stand comprises a pair of first leg devices, a pair of second leg devices, a pair of adjustment mounts, a main connector, a collar, a clamping device, and an adjustment tube. A first rivet fastens one of the first leg devices, one of the second leg devices, and one of the adjustment mounts together. A bolt fastens the main connector and one of the adjustment mounts together. The clamping device has a lower sleeve. The collar receives the lower sleeve of the clamping device. The clamping device receives an upper portion of the main connector. The adjustment tube is inserted through the clamping device and the main connector.