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TECHNICAL FIELD
[0001] The verification system and method described below relate to object identification systems, and more particularly, to ink jet printers that identify solid ink sticks.
BACKGROUND
[0002] Solid ink or phase change ink imaging devices, hereafter called solid ink printers, encompass various imaging devices, such as printers and multi-function devices. These printers offer many advantages over other types of image generating devices, such as laser and aqueous inkjet imaging devices. Solid ink or phase change ink printers conventionally receive ink in a solid form, either as pellets or as ink sticks. A color printer typically uses four colors of ink (yellow, cyan, magenta, and black). The solid ink pellets or ink sticks, hereafter referred to as ink, sticks, or ink sticks, are delivered to a melting device, which is typically coupled to an ink loader, for conversion of the solid ink to a liquid. A typical ink loader includes multiple feed channels, one for each color of ink used in the imaging device. Each feed channel directs the solid ink within the channel towards a melting device located at the end of the channel. Each melting device receives solid ink from the feed channel to which the melting device is connected and heats the solid ink impinging on it to convert the solid ink into liquid ink that is delivered to a print head for jetting onto a recording medium or intermediate transfer surface.
[0003] Each feed channel may have a corresponding insertion opening to receive solid ink sticks. Alternatively, a solid ink jet printer may have a common insertion port in which solid ink sticks are loaded and then delivered to the channel that corresponds to the loaded ink stick. In both types of loading systems, the ink stick may be identified by detecting encoded indicia on the stick and comparing the detected data to data stored in the printer. The stored data identifies the ink sticks that are configured for use in the printer and the color of the ink sticks. Only if the detected data corresponds to the stored data is an ink stick accepted by the printer or released from the insertion opening or port to a feed channel in the printer.
[0004] In printers having an insertion opening for each feed channel, keyed openings may be placed over the insertion ports to help ensure a printer user properly places and orients ink sticks of the correct color or series in a feed channel. To accomplish this goal, each keyed opening has a unique shape. The ink sticks of the color corresponding to a particular feed channel have a shape corresponding to the shape of the keyed opening. The keyed openings and corresponding ink stick shapes exclude from each ink feed channel ink sticks of all colors except the ink sticks of the proper color for the feed channel. Unique keying shapes for other factors are also employed in keyed openings to exclude from a feed channel ink sticks that are formulated or intended for other printer models.
[0005] As the number of pages printed per minute increases for solid ink printers so does the demand for ink in the printer. To supply larger amounts of ink to printers, the cross-sectional area of the feed channels may be increased. Consequently, the insertion openings for the channels and the keyed plates covering the openings are likewise enlarged. These larger openings enable smaller solid ink sticks to pass through without engaging the keyed plates over the openings. Thus, solid ink sticks that do not conform to the appropriate color for a feed channel can be loaded into the feed channel and delivered to the melting device at the end of the feed channel. Even if the smaller stick is the correct color for the feed channel, its size may impair the ability of the stick to cooperate with guiding structure within the feed channel. Likewise, as common insertion ports increase in size, ink stick not configured for use in the printer may be inserted in the port. As long as these sticks have an identification code that corresponds to a code stored in the memory of an identification code detector, these sticks may be used in the printer. Thus, ensuring insertion ports in a solid ink printer are loaded only with ink sticks configured for transport within the feed channel is a desirable goal.
SUMMARY
[0006] A solid ink stick loader verifies position and orientation of an ink stick prior to an ink stick identification operation. The solid ink stick loader includes an identification code detector located proximate an ink stick insertion area, the identification code detector being oriented to obtain an identification code positioned on the ink stick in a predetermined location, a first displaceable member located proximate the ink stick insertion area, the first displaceable member being movable between a first position and a second position, a second displaceable member located proximate the ink stick insertion area, the second displaceable member being movable between a third position and a fourth position, and a sensor coupled to at least one of the first displaceable member and the second displaceable member to generate a verification signal in response to the ink stick being in a position and orientation in the ink stick insertion area that enables the identification code detector to obtain the identification code from the ink stick, the sensor being coupled to the identification code detector to provide the verification signal to the identification code detector and enable the identification code detector to obtain the identification code from the ink stick.
[0007] A method verifies the position and orientation of an object located in a loading area within a printer prior to reading identification data from the object. The method includes detecting an object to be identified in an area, detecting a feature of the detected object at a predetermined position, and generating a signal indicating position and orientation of the object in the area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Features for verifying position and orientation of a solid ink stick in particular, and of an object to be identified in general are discussed with reference to the drawings.
[0009] FIG. 1 is a side view of a solid ink stick interacting with a pair of displaceable members to enable movement of the solid ink stick from an insertion port in a solid ink printer.
[0010] FIG. 2 is a side view of a solid ink stick interacting with a pair of displaceable members to disable movement of the solid ink stick from an insertion port in a solid ink printer.
[0011] FIG. 3 is a side view of another solid ink stick interacting with a pair of displaceable members to disable movement of the solid ink stick from an insertion port in a solid ink printer.
[0012] FIG. 4 is a side view of an embodiment of a displaceable member that interacts with an object to be identified.
[0013] FIG. 5A is a simplified side view of an embodiment of a displaceable member that interacts with an object to block movement of a slide.
[0014] FIG. 5B is a simplified side view of the displaceable member in FIG. 5A in a position to allow movement of the slide.
[0015] FIG. 6 is a side view of a pair of displaceable members joined by a mechanical linkage in a position that enables a single sensor to generate a signal to enable movement of an object to be identified.
[0016] FIG. 7 is a side view of a pair of displaceable members joined by a mechanical linkage in a position that enables a single sensor to generate a signal to disable movement of an object to be identified.
[0017] FIG. 8 is a side view of a pair of displaceable members joined by a mechanical linkage that enables a single sensor to generate a signal to disable movement of an object to be identified.
[0018] FIG. 9 shows a number of embodiments of ink sticks with verification interlock features that interact with the displaceable members of a verification interlock.
DETAILED DESCRIPTION
[0019] The term “printer” refers, for example, to reproduction devices in general, such as printers, facsimile machines, copiers, and related multi-function products. An exemplary solid ink printer having an insertion port 10 for the loading of solid ink sticks is shown in FIG. 1 . The solid ink printer may have an insertion port for each feed channel or it may have only one common insertion port from which a solid ink stick, once identified, is moved to the corresponding feed channel. An identification code detector (not shown) obtains an identification code from the solid ink stick in the insertion port. This code is compared to data stored in the printer to determine whether the solid ink stick is configured for used in the printer and the feed channel in which the solid ink stick should be used. The identification code detector may be a single device or an array of code activators, such as optical sources, and an array of code detectors, such as optical receivers, that operate to read an identification code on a solid ink stick.
[0020] In the port 10 , the solid ink stick 14 is inserted from the left, although other port configurations may be used that permit loading of the solid ink stick from any direction other than the wall 24 in which the displaceable members 18 and 20 are located. The solid ink stick 14 includes a side 28 and a feature 30 . “Feature” refers to a recess or protuberance in a surface of an object having a predetermined position that enables the orientation of the object to be verified by the displaceable members. In FIG. 1 , the feature 30 is a recess into which displaceable member 20 can extend, although features may be used to provide an indication of an object's orientation in the insertion port.
[0021] In order to enable the solid ink stick to be moved from the insertion port 10 , the displaceable members 18 and 20 must be in a predetermined configuration that corresponds to a predetermined position of one side of the solid ink stick and its feature. As shown in FIG. 1 , the displaceable member 20 must extend into the feature 30 and the displaceable member 18 must be depressed by the side 28 in order for movement of the solid ink stick to be enabled. Thus, insertion of the solid ink stick 14 within the port 10 enables the displaceable member 20 to be fully extended and the displaceable member 18 to be retracted within the wall 24 . The interaction of the solid ink stick with two displaceable members enables the position and orientation of a solid ink stick to be verified as being correct for identification and movement of the solid ink stick. As described below, the two displaceable members may be independent of one other with each one having a sensor for detecting movement of the member. Alternatively, the two members may be coupled to one another, either through a mechanical link or through common structure in an integrated part.
[0022] Identification of an ink stick as being appropriate or inappropriate for use within a printer enables movement of the identified ink stick from the insertion area. This enablement does not necessarily include movement. Identification may be performed using electronic sensors, positioning and displacement of mechanical arms, links, or other actuators, or decoding of data placed on the ink stick. The results of the identification process may be conveyed to a user with an accept/reject signal that may be displayed or used to generate a visible or audible signal at the printer, such as at a control panel, or remotely, at, for example, a pager or remote terminal. Once the identification results are communicated to a user or operator, the printer may wait for a confirmation signal from the user or operator before opening a gate or operating a conveyor to move the ink stick. Thus, communication of the identification results is required for movement of the ink stick, but does not necessarily cause the ink stick to move immediately. Consequently, the term “enabling movement” or the like is intended to encompass such motionless activities or the like.
[0023] In FIG. 2 and FIG. 3 , two situations are shown that result in the solid ink stick remaining in the insertion port. In FIG. 2 , the solid ink stick 14 , which can be used in the printer, has been loaded into the port; however, it has not been fully inserted into the port. Consequently, displaceable member 18 has not been sufficiently depressed by the side 28 to enable movement of the solid ink stick. Thus, even if an identification code detector determines the identification code on the solid ink stick corresponds to a code indicating the stick can be used in the printer, the stick will be not moved. This type of operation helps prevent the solid ink stick from becoming jammed if the stick is moved before it is in proper position for movement. For example, if an otherwise proper ink stick is not in the correct position to engage a solid ink transport system coupled to the insertion port, then the displaceable arms prevent attempts to engage the solid ink transport system with the ink stick. In FIG. 3 , a solid ink stick 40 is one that is not configured for use in the feed channel or printer coupled to the port 10 . This anomaly is detected because the ink stick 40 does not have the feature 30 . Consequently, the displaceable member 20 is depressed rather than extended and movement of the stick is not enabled.
[0024] FIG. 4 illustrates one embodiment of a displaceable member. The displaceable member 50 includes a series of teeth 54 that engages a gear 58 that is biased by a spring 60 or the like to a position that extends the displaceable member from an insertion port wall. A surface that urges the displaceable member 50 against the biasing force causes the displaceable member 50 to move to the right and the teeth 54 rotate the gear 58 in a counterclockwise direction. A sensor 64 generates a signal in response to the movement of the gear. The number of gear teeth moving past the sensor 64 may be counted to evaluate whether the displaceable member 50 has been sufficiently moved to enable movement of the object acting on the displaceable member. After the ink stick or other object is removed, the biasing on the gear 58 returns the displaceable member to its original position.
[0025] FIG. 5A and 5B illustrates another embodiment of a displaceable member. This configuration includes a displaceable member 70 , a pivoting link 74 , a blocking member 76 , and a lockable slide 78 . The displaceable member 70 is coupled to the pivoting link 74 at one end of the link by pin 82 . A pivot pin 80 is mounted to a rigid structure at the other end of the link 74 so the pivoting link 74 pivots about its pivot pin 80 . In response to the displaceable member 70 being moved to the right, the pivoting link 74 pivots about pivot pin 80 to urge the end of the blocking member 76 into engagement with slide 78 to prevent its movement. Upon removal of the ink stick that moved member 70 towards the slide 78 , the member 70 moves under the influence of a biasing member (not shown) or gravity, if arranged vertically, to the left. This movement pivots link 74 in the clockwise direction link and disengages blocking member 76 from slide 78 . When slide 78 is free to move, its movement may be used to release a movable gate, actuate an ink stick transport, or activate a sensor, for example. Slots 88 and 90 in link 74 enable the movement of the member 74 and blocking member 76 to be coordinated.
[0026] In the embodiments shown in FIG. 4 and FIG. 5 , each displaceable member may be configured with a sensor that generates a position signal. For example, the sensor 64 may be an optical sensor having an optical source and optical detector that are positioned to enable the gear teeth to pass between them. The gaps between the gear teeth enable the light to pass from the source to the detector, while the gear teeth block the light from the source. The changes in the signal generated by the sensor may be counted to determine the amount of movement of the displaceable member to evaluate whether the ink stick is in the correct position and orientation for identification. In a similar manner, a sensor may be positioned with respect to each sensor associated with a displaceable member of the embodiment shown in FIG. 5 to enable the sensor to generate a signal indicative of the blocking member's movement. The signal from each sensor for each displaceable member may be provided to a signal position generator, which generates a position indicative of the ink stick's position and orientation from the two signals generated by the sensors associated with the two displaceable members. For example, flip-flops, or other logic gates may be used to generate a position signal indicating the ink stick is in position for identification in response to the signals from the sensors indicating the displaceable member interacting with the object feature is in the correct position and the displaceable member interacting with the object side is also in the correct position.
[0027] Another embodiment may enable one displaceable member to interact with a sensor to generate a position signal for use within the printer and the other displaceable member may be coupled to a movable gate to enable movement of a solid ink stick from an insertion port selectively. In all of the embodiments discussed herein, the displaceable members may directly block or enable an identification code detector, a movable gate, or transport device. Alternatively or additionally, the displaceable members may generate signals that are used by a controller to operate a gate, an identification code detector, or transport device in a selective manner.
[0028] Another embodiment of the displaceable members that enables a single sensor to be used with two displaceable members is shown in FIG. 6 , FIG. 7 , and FIG. 8 . In FIG. 6 , the displaceable members 100 and 104 are coupled to one another by a mechanical linkage 110 . The linkage pivots about a pivot pin 114 . The linkage 110 includes a position flag 118 . The position flag moves into and out of a position in which the flag 118 blocks the path between an optical source and an optical detector in an optical sensor 120 . In FIG. 6 , no object is in an insertion port and the displaceable members 100 and 104 extend to the same length and the flag 118 blocks the light from being received by the optical detector in the sensor 120 . In FIG. 7 , an ink stick that is configured for use in the insertion port is inserted into the port. When the ink stick has been fully inserted into the port, the displaceable member 100 is moved to the right by the side of the ink stick and the linkage 110 pivots in the counterclockwise direction. This movement extends the displaceable member 104 . If the ink stick has the corresponding recess in the corresponding position, the displaceable member 104 extends into the feature and the flag 118 moves into a position in which the flag no longer blocks the light between the optical source and detector in the sensor 120 . The sensor then generates a position signal that indicates the ink stick is in position for identification. In FIG. 8 , the recess is not in the correct position to receive the displaceable member 104 . Consequently, the displaceable members 100 and 104 block further ingress of the ink stick into the insertion port and the sensor 120 generates a position signal that indicates the ink stick is not in position for identification. Although the displaceable members are shown in these figures as being coupled to one another through a mechanical link, the displaceable members may be integrally formed in a single component, such as a plastic injection molded part.
[0029] The position signal generated by any of the embodiments may be used in a number of ways to help prevent ink sticks that are either improperly placed in the port or are not configured for use in the port. For example, the position signal may be used to enable the identification code detector. The position signal may be coupled to the identification code detector and, if the signal indicates the ink stick is in the proper position and orientation for identification, the detector is enabled to obtain the identification code from the ink stick. In another embodiment, the insertion port may include a movable gate that blocks egress of the ink stick from the insertion port to the ink stick transport system. This movable gate is operated by a gate actuator, such as an electrical motor coupled to the gate. The position signal may be coupled to the gate actuator to prevent the actuator from operating the gate to enable movement of the ink stick from the insertion port in response to the signal indicating the ink stick is either not configured for use in the port or not in the correct position or orientation for identification. This embodiment enables the printer to respond to the identification code detector only when the ink stick is in the correct position and orientation for identification.
[0030] For the two displaceable members to verify position and orientation of an ink stick correctly, the ink stick includes at least two surface features that interact with the displaceable members. While the ink stick may be formed with features specifically incorporated in the ink stick for verification of the position and orientation of the ink stick, the displaceable members may be configured to interact with surface features that exist in current ink stick designs. For example, ink sticks are configured with protrusions and indentations for interactions with feed channel structures. The displaceable members may be arranged in an insertion area to take advantage of accessing the feed channel features for position and orientation verification. Such an arrangement may be most advantageously used in an insertion area for a single channel as an arrangement of displaceable members in a common insertion area for multiple feed channels that accurately interacts with a multitude of different ink configurations may be difficult. In an insertion area that supplies ink stick to multiple feed channels, the ink sticks may be formed with specific verification interlock features.
[0031] A number of ink stick embodiments depicting various verification interlock features are shown in FIG. 9 . These ink sticks take advantage of the push-pull operation of the verification interlock to provide the interlock features on the ink stick surface. Specifically, only one protuberance or one indentation is required in the formation of the ink stick to provide a verification interlock feature. For example, ink sticks 900 A, 900 B, 900 C, and 900 D provide a verification interlock feature 904 A, 904 B, 904 C, 904 D, respectively, with a single indentation 908 A, 908 B, 908 C, or 908 D. These indentations interact with the displaceable member being pulled or extended to verify position and orientation. The planar faces 912 A, 912 B, 912 C, and 912 D provide the interaction with the displaceable member being pushed. The indentations 904 B and 904 C indent two planar surfaces of the ink stick, while the insets 904 A and 904 D indent only one planar ink stick surface. In a similar manner, ink sticks 900 E and 900 F provide a verification interlock feature 904 E and 904 F, respectively, with a single protuberance 908 E or 908 F. These protuberances interact with the displaceable member being pushed to verify position and orientation. Planar surfaces 912 E and 912 F interact with the displaceable member being extended. Provided that an ink stick verification interlock features do not adversely impact the integrity of other ink stick features, such as feed channel features, then the verification interlocks may be incorporated in a plurality of ink stick configurations to enable a single insertion port to have the displaceable members installed for interaction with the interlock.
[0032] Those skilled in the art will recognize that numerous modifications can be made to the specific implementations described above. Therefore, the following claims are not to be limited to the specific embodiments illustrated and described above. The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
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A solid ink stick loader verifies position and orientation of an ink stick prior to an ink stick identification operation. The solid ink stick loader includes an identification code detector located proximate an ink stick insertion area, the identification code detector being oriented to obtain an identification code positioned on the ink stick in a predetermined location, a first displaceable member located proximate the ink stick insertion area, the first displaceable member being movable between a first position and a second position, a second displaceable member located proximate the ink stick insertion area, the second displaceable member being movable between a third position and a fourth position, and a sensor coupled to at least one of the first displaceable member and the second displaceable member to generate a verification signal in response to the ink stick being in a position and orientation in the ink stick insertion area that enables the identification code detector to obtain the identification code from the ink stick, the sensor being coupled to the identification code detector to provide the verification signal to the identification code detector and enable the identification code detector to obtain the identification code from the ink stick.
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RELATED APPLICATION
This application is a continuation-in-part of co-pending Application Ser. No. 004,393, filed Jan. 18, 1979 and new abandoned.
BACKGROUND OF THE INVENTION
Numerous types of thermally responsive actuator devices have been employed in combination with an automotive fan clutch. However, difficulties have arisen in obtaining consistent accurate rapid operation of an automotive fan clutch at desired temperatures.
It is therefore an object of this invention to provide a thermally responsive actuator device particularly for use with an automotive fan clutch which device operates the clutch consistently accurately and rapidly at desired temperatures.
Another object of this invention is to provide a thermally responsive actuator device which has high operational capacity in consideration of its physical size.
Another object of this invention is to provide a thermally responsive actuator device which is capable of accurately sensing temperature changes in air mass flow.
Another object of this invention is to provide a thermally responsive actuator device which during rotation thereof creates air flow adjacent the actuator device, so that the actuator device accurately senses ambient air conditions.
Other objects and advantages of the thermally responsive actuator device of this invention reside in the construction of parts, the combination thereof, the method of manufacture, and the mode of operation, as will become more apparent from the following description.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of a thermally responsive actuator device of this invention.
FIG. 2 is an exploded perspective view, with parts broken away and drawn on a slightly smaller scale than FIG. 1, of a thermally responsive actuator device of this invention in combination with an automotive fan clutch unit.
FIG. 3 is a sectional view, drawn on a slightly larger scale than FIG. 2, showing the combination of FIG. 2. This figure also illustrates a radiator or heat exchanger of the automotive apparatus with which the structure shown and disclosed is associated. This figure illustrates the clutch mechanism in a de-actuated condition.
FIG. 4 is a fragmentary sectional view of the apparatus of FIG. 3, illustrating the clutch mechanism in an actuated condition.
FIG. 5 is a sectional view, drawn on a larger scale than the other figures, showing the portion of a thermally responsive actuator device of this invention which includes a movable actuator stem.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 5 show a thermally responsive actuator device 10 of this invention which includes a casing 12. The casing 12 has a cavity 14 which has therewithin a portion of an actuator rod or stem 16. The actuator rod or stem 16 extends from the casing 12 and is axially movable with respect thereto. Joined to the casing 12 and in communication with the cavity 14 thereof is an elongate coiled tube 20. As best illustrated in FIG. 1, the coiled tube 20 has at least one convolution and may comprise several convolutions.
Within the cavity 14 and within the coiled tube 20 is a thermally responsive expansible-contractible material which comprises any suitable element or combination of elements giving the material the physical property characteristic of a high coefficient of expansion over a given temperature range. The thermally responsive material may, for example, be a wax, or polyolefinic material, or a material of the plastics class, or the like.
The casing 12 is enclosed within a housing 24 and is movable with respect thereto. A spring 28 urges the casing 12 against an internal wall of the housing 24. A bracket 30 is attached to the housing 24 and extends therefrom in the form of a plurality of wings 30a which engage and support the coiled tube 20.
The exterior of the housing 24 is shown as being threaded and is threadedly mounted within a clutch housing 36, having a cavity 38 therein. The actuator rod 16 extends into the cavity 38.
Within the cavity 38 is an engagement plate 42 which is supported upon pin members 44, which permit axial movement of the engagement plate 42. A plurality of spring members 46 are recessed in an internal wall of the cavity 38 and engage the engagement plate 42 and urge axial movement thereof toward the actuator rod 16. Also within the cavity 38 of the clutch housing 36 and adjacent the engagement plate 42 is a clutch plate 50 which has opposed clutch surfaces 50a and 50b. The clutch plate 50 is supported by a splined portion 54a of a drive shaft 54 and is urged by a spring 56 toward the engagement plate 42. The clutch plate 50 is axially movable upon the splined portion 54a of the drive shaft 54 and is rotatable with rotation of the drive shaft 54. Normally the drive shaft 54 is rotated with operation of an automotive engine with which the apparatus discussed and shown herein is associated.
The drive shaft 54 has attached thereto a bearing member 58, upon which the clutch housing 36 is supported for rotation with respect to the drive shaft 54. The clutch housing 36 has attached thereto for rotation therewith a plurality of fan blades 60.
The thermally responsive actuator device 10 of this invention is positioned adjacent a radiator or heat exchanger 64, through which air flows to cool liquid therewithin, as illustrated by arrows 66 in FIG. 3. The radiator or heat exchanger 64 is part of the cooling system of the automotive engine with which the apparatus shown and discussed herein is associated.
During initial operation of an automotive engine, not shown, with which the apparatus shown and discussed herein is associated, and during "cooler" temperature conditions, the clutch mechanism is in the condition illustrated in FIG. 3. Ordinarily in clutch apparatus of the type illustrated, there is slight "clutch drag" which causes the clutch housing 36 to have slight rotation with rotation of the drive shaft 54, even when the clutch mechanism is not actuated. Thus, there is always, at least, a small volume or mass of air drawn through the radiator 64 when the drive shaft 54 is rotating. Rotation of the clutch housing 36 causes rotation of the thermally responsive actuator device 10 and the bracket 30. The wings 30a of the bracket 30 are of such a physical size and shape that the wings 30a cause movement of air adjacent the coiled tube 20 during rotation of the bracket 30. Thus, the air in contact with the coiled tube 20 is never stagnant, and the coiled tube 20 is constantly exposed to a stream of air which flows from the radiator 64. Thus the coiled tube 20 and the casing 12 and the thermally responsive material therewithin are accurately sensitive to the temperature of the air flowing from the radiator 64. Therefore, when the temperature of the air flowing from the radiator 64 rises to a predetermined magnitude, the coiled tube 20 and the casing 12 and the thermally responsive expansible-contractible material therewithin rapidly respond to the change in temperature. The thermally responsive material within the casing 12 and within the coiled tube 20 rapidly assumes a volume such that the actuator rod 16 is forced to move outwardly from the casing 12, toward the engagement plate 42 and moves the engagement plate 42 toward the clutch plate 50. The engagement plate 42 engages the clutch plate 50 and moves the clutch plate 50 into engagement with the internal surface of the clutch housing 36, as illustrated in FIG. 4. Such movement of the engagement plate 42 is against the forces of the spring members 46. When this movement of the engagement plate 42 and the clutch plate 50 occurs, the clutch housing 36 is rotated with the drive shaft 54 at the rate of rotation thereof, and the fan blades 60 are moved in an annular path with rotation of the clutch housing 36. Thus, an increased volume of air moves through the radiator 64 for cooling the coolant fluid which flows within the radiator 64.
When the temperature of air which travels through the radiator 64 and which engages the thermally responsive actuator device 10 is reduced in temperature to a predetermined magnitude, the volume of the thermally responsive material within the casing 12 and the coiled tube 20 rapidly reduces to a predetermined magnitude. Then the spring members 46 force the engagement plate 42 toward the casing 12; the clutch plate 50 moves from engagement with the clutch housing 36, and the actuator rod 16 is moved further into the casing 12, to the positions thereof illustrated in FIG. 3. The spring member 56 moves the clutch plate 50 away from the internal wall of the clutch housing 36. Thus, the clutch housing 36 is not rotated at the rate of rotation of the drive shaft 54, and the volume of air flowing through the radiator 64 is reduced.
Therefore, it is understood that a thermally responsive actuator device 10 of this invention is capable of accurately and rapidly sensing and responding to changes in ambient temperature conditions.
A thermally responsive actuator 10 of this invention may be in combination with a clutch mechanism for operation thereof as shown and described herein, or a thermally responsive actuator device 10 of this invention may be used with or in combination with any other suitable apparatus for thermally responsive actuation thereof.
Although the preferred embodiment of the thermally responsive actuator of this invention has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportions and arrangement of parts, the combination thereof, and the mode of operation, which generally stated consist in a thermally responsive actuator within the scope of the appended claims.
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A thermally responsive actuator device which includes an extending tubular coil temperature sensing portion. The tubular coil contains a thermally responsive expansible-contractible material which operates upon an actuator member. Thus, the thermally responsive material accurately and rapidly senses ambient or air mass flow temperature conditions for operation of the actuator member.
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CROSS REFERENCE TO RELATED APPLICATION
This is a divisional application of U.S. application Ser. No. 09/708,759, filed Nov. 8, 2000, of the same title, now issued as U.S. Pat. No. 6,584,672, to which priority under §120 is claimed, the contents of which being herein incorporated by reference hereto, priority also being claimed under §119 to French Patent No. 99 14173, filed on Nov. 10, 1999.
BACKGROUND OF THE INVENTION
The present invention relates to a method for the manufacture of bundles of metal sheets of annular shape for stators of electric machines from stamped sheets.
It is known, for constructing stators of small and medium electric machines and, in particular, of alternators of motor vehicles, to form bundles of rings cut out by stamping in magnetic sheets or the like and to assemble them by riveting or welding.
The cut-out rings have, toward the inside, open slots formed by arms which are directed radially inward and which in the bundle will form the pole pieces of the stator. Cutting out an entire ring by stamping has some disadvantages: there is a large amount of waste, since that part of the sheet which corresponds to the inside diameter of the ring can be used only for forming a ring of smaller diameter, and indeed only insofar as the thickness of the sheet and the diameter correspond to the technical characteristics required. On the other hand, there is also a large amount of sheet waste corresponding to that part of the sheet which is outside the diameter of the ring.
The construction of the rings does not make it possible to maintain the required shape tolerances and the exact dimensions both of the rings and of the ring bundles on account of the internal stresses which are generated during stamping and which cannot easily be eliminated because of the closed shape of the ring. The internal stresses have an influence on the size tolerances of the inside and outside diameters of the rings and on the parallelism of two faces of a sheet bundle. It is often necessary to carry out additional machining of the stator before the required tolerances can be adhered to.
The Applicant's U.S. Pat. No. 4,597,172, the content of which is incorporated by reference, proposed a method and an apparatus for the manufacture of bundles of metal sheets from ring segments, in particular ring segments at 120°, without this being a limiting value.
This method and apparatus are satisfactory and make it possible, on the one hand, to make savings with regard to the sheet waste, since only ring segments are cut out and, on the other hand, to adhere more closely to the geometry of the bundle in that the internal stresses generated during the stamping of a closed ring are eliminated.
U.S. Pat. No. 4,102,040, the content of which is incorporated by reference, proposes a manufacturing method which, according to one variant, involves bending the sheet bundle formed by causing it to mate with the lateral surface of a drum in a continuous operation. When the two ends of the bundle meet, they are held by means of a connecting device and welding is then carried out.
U.S. Pat. No. 4,198,743, the content of which is incorporated by reference, describes a method which, according to one variant, makes it possible to form a C-shaped magnetic core by the middle of a sheet bundle being immobilized and by two simultaneously gripping tools being employed to exert, from the center, continuous forces making it possible to obtain the C-shape.
SUMMARY OF THE INVENTION
The object of the present invention is to propose a new method for the manufacture of bundles of metal sheets for the stators of electric machines, making it possible, in particular, to reduce considerably the waste attributable to this manufacture and to simplify the implementing apparatus.
The method according to the present invention is defined by a combination of the following steps:
The bundle is held gripped between a flat surface bearing on the bundle surface having the grooves, over approximately half the length of the segment, leaving approximately one quarter of the total length free at each end, and means bearing on the face having the pole pieces, the two ends are prebent by means of a multiple-slide press over approximately half their free parts, so as to form, on each of them, an arc of approximately 40°, by pressure being applied to their corresponding grooved surfaces, against punches of corresponding shape, the two free ends are bent by means of a multiple-slide press over the entirety of their free parts in a 90° arc of a circle, by pressure being applied to the grooved surface of the two ends, against punches of corresponding shape, the bundle is released and is held solely along two edges, one on the inner face and the other on the outer face of the bundle, corresponding to the midpoints of the segments, pressure is applied to the arcuate parts of the bundle until the cylinder is closed, the joined ends are laser-welded or plasma-welded, thus forming a cylindrical component.
The advantages of the method according to the invention are that the formation of the ring is carried out sequentially, thus allowing better cylindricity due to the fact that the fibers of the metal expand between two steps. On the other hand, the machine used is a multiple-slide machine which has existed for a long time. It is necessary to adapt the machine to implement the method with the result being that there is virtually no need for correction of cylindricity after the welding of the ends of the folded bundle.
According to a preferred variant of the invention, two segments are cut out from a sheet metal band, which are back to back and are offset at a distance equal to half the distance between two pole pieces, thus making it possible to limit sheet waste to a minimum, virtually to those parts of the sheet which correspond to the spaces between the poles.
On the other hand, there is no stress during stamping, since the pieces are cut out in straight segments, thus avoiding the problems which they may present with regard to the geometry of the stator.
In order to adhere to the geometry of the stator, the sheet bundles, after being finally assembled, may be subjected to calibration by means of a hydraulic press in the case of strict tolerances.
An apparatus for implementing the method according to the invention is also proposed.
The implementing apparatus is defined in that it comprises a sheet metal stamping station for the formation of rectilinear segments, a station for stacking and deforming the bundles with a predetermined height, a station for assembling by the affixation of at least two welding beads, and a station for folding the bundles on a multiple-slide press to form cylindrical components, said folding station likewise being provided with a station for welding the joined ends of each bundle, the folding station comprising a first plate provided with a bearing surface perpendicular to said plate, for receiving each of the bundles, and with three slides, one which of is located on the side having the teeth and is provided with a stop piece for holding the bundle against said bearing surface and two punches and two slides are located on the opposite side, each provided with a die for bearing on the ends of the bundle and for prebending them over approximately 40° against the punches of the first slide, with a second plate parallel to the first and having three slides arranged in the same way as those of the first plate, the two slides acting on the outer surface of the bundle having dies with a surface concave over approximately a quarter of a cylinder, in order to push the prebent ends of the bundle against corresponding punches of the opposite slide into an arc of a circle of 90°, with a third plate provided with a bearing surface for receiving the still planar part of the previously bent bundle, with a slide provided with a stop surface for holding this bundle against said flat surface and two slides facing one another on either side of the 90°-bent parts of the bundle and provided with dies having a concave cylindrical surface intended for pushing the arcuate ends of the bundle up to complete closure and the formation of a cylinder, and with a fourth plate provided with a bearing surface, on which the bundle rests with its generatrix opposite the generatrix along which the two ends of the bundle are joined, with a first slide provided with a member making it possible to hold the bundle against said bearing surface and with four slides uniformly distributed along a circumference and provided with four dies with concave surfaces having the dimensions and the radius of approximately a quarter of a cylinder, making it possible to keep the ring thus formed closed, and with a laser-welding or plasma-welding device for welding the joined ends of the bundle along a generatrix.
BRIEF DESCRIPTION OF THE DRAWINGS
The method according to the invention will be described with the aid of the accompanying drawing.
FIG. 1 shows a plan view of a bundle of metal sheets before folding.
FIG. 2 is a diagrammatic view of the complete apparatus for implementing the method.
FIGS. 3 to 6 are front views of the parts of the station for folding in four steps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Rectilinear sheet segments 1 are cut out by known means by stamping from sheet metal bands and have a form of a band provided with teeth 2 , the shape of which is that of the pole pieces of the stator of an electric machine. The back of the rectilinear segment has notches 3 arranged in the extension of the teeth 2 .
These sheet segments may be cut out either from a band representing a width equal to approximately the width of the band or from a band which has double this width, the cut-out bands being back to back and having an offset corresponding to half the space between two teeth, thus limiting the waste.
After a bundle being obtained by stacking, the height of which corresponds to the length of the stator, the segments are welded by means of at least two welding beads which are preferably located in notches 3 , the bundle is arranged on a multiple-slide machine in order to carry out the formation of the annular stator. For this purpose, the bundle together with the segments 1 is placed with a central part, on the side where the notches 3 are located and which is intended for forming the outer surface of the stator, onto a bearing surface 4 (FIG. 3 ), while the bundle is held on the inside, for example, by means of a stay 5 . Action is taken on the two free ends of the bundle, which each represent approximately one eighth of the length of the bundle, and the ends of the bundle are bent into the position A′, B′ against punches of corresponding shape, thus forming two arcs of approximately 40°. Subsequently (FIG. 4 ), the ends are bent over the free length (that is to say, one quarter of the length of the bundle) in order to form an arc A, B of approximately 90° against other punches. Thereafter, the bundle is held with two opposite edges (FIGS. 5 and 6 ), and action is taken on the ends of the bundle in order to obtain the complete closure of the ring. When the closure of the ring is obtained, a laser-welding or plasma-welding bead is applied to the ends, thus ensuring the closing of the ring, and the stator is thereby formed.
Finally, the stator is placed into a hydraulic calibrating press in order to make it possible to ensure the geometry of the final stator.
The notches 3 located on the outer surface of the segments make it possible to obtain the formation of the ring more easily than if the outer surface were continuous.
Referring to FIG. 2 , the main stations of an apparatus for implementing the method have been shown diagrammatically. A first stamping station 10 makes it possible, from a metal sheet, to cut out segments having a shape such as that shown in FIG. 1 . This is then followed by a stacking station 11 for forming the bundles with a predetermined height. This is then followed by a welding station 12 making it possible to affix at least two welding beads in order to hold the elements of each bundle relative to one another, and finally this is followed by a station 13 which forms the stator. This station 13 will be described explicitly with reference to FIGS. 3 to 6 . Upon the exit of the stator formed at the station 13 , the bundles enter a calibrating press 14 , in order to ensure the exact inner and outer geometry of the bundle, and the bundles finally arrive at a packaging station 15 .
These various stations have been designated briefly, but, of course, each comprises devices making it possible also to carry out some other operations, for example the stacking station 11 may be combined with a weighing station which makes it possible to check, by weight, whether the stator comprises the specified weight of metal and, if appropriate, to add segments in order to complete it. There may also be provision, after welding, for cooling the bundles before passing on to the next step. However, this type of apparatus is not the subject of the present invention which is concerned, above all, with the implementation by means of multiple slides of the method which relates more specifically to the folding of the bundles in order to form a stator, as will be described with reference to FIGS. 3 to 6 .
For folding, a bundle of assembled sheets is placed on its face opposite that of the pole pieces, and the bundle is passed in successive steps through a multiple-slide press. In principle, this folding and the final closing of the stator take place in four successive steps, the bundle being displaced each time parallel to one direction and more specifically perpendicularly to plates (in principle, arranged vertically) which support slides. The machine comprises four plates 16 , 17 , 18 and 19 ( FIGS. 3 , 4 , 5 , 6 ) which are arranged one behind the other and are each provided with a rectangular central hole 16 ′, 17 ′, 18 ′, 19 ′ which makes it possible to pass the bundles from one plate to the other.
The first plate 16 comprises a bearing surface 4 , on which the bundle will rest, and three slides 21 , 22 , 23 , the slide 21 located on the opposite side with respect to the bearing surface is provided with a stop surface 5 , by means of which the bundle is held on the bearing surface 4 , at the same time leaving approximately at least a quarter of the length of each bundle on either side. The two slides 22 and 23 are located on the opposite side and are each provided with a die 25 , 26 having a surface which has approximately an S-shaped cross section and which will slide and come to bear on the free ends of the bundle, in order to exert pressure and form an arc of approximately 40° at each of the two ends by pressing said ends against punches 5 A, 5 B.
The bundle will subsequently pass through this plate 16 via the hole 16 ′ in order to arrive at the plate 17 illustrated in FIG. 4 , which is likewise provided with a bearing surface 27 and three slides 28 , 29 and 30 arranged virtually in the same way as the slides of the plate 16 . The slide 28 is likewise provided with a stop surface 31 , by means of which the partially bent bundle is held against the bearing surface 27 .
If the length of the bands closing the bundles is relatively large, two slides may be employed in order to hold the bundles against the bearing surfaces involved in the previous two steps.
The two slides 29 and 30 likewise comprise, at their ends, two concave dies 32 and 33 which are articulated at one end on the slide and by means of which said slides come to bear on the prebent ends of the bundle and deform them until approximately an arc of 90° is formed, as illustrated in FIG. 4 , by pressing on corresponding punches 31 A, 31 B.
Subsequently, passing through the hole 17 ′, the bundle will approach the plate 18 which is likewise provided with a bearing surface 34 and three slides 35 , 36 and 37 . The slide 35 is provided this time with a bearing surface which is a finger 35 D coming to bear between two polar teeth in order grip the bundle against the bearing surface 34 . The two lateral slides 36 and 37 are likewise each provided with a concave die 36 A, 37 A for pushing the bent ends of the bundle until the bundle forms a cylinder.
After the bundle has been formed in this way, it passes toward the plate 19 through the hole 19 ′ and comes to bear on a bearing surface 38 . A slide 39 similar to the slide 35 holds the cylinder against the bearing surface 38 by means of a finger 39 D, while four slides 40 , 41 , 42 and 43 , uniformly distributed on the surface of the plate 19 and each provided with a concave die 40 A, 41 A, 42 A, 43 A, the shape of which corresponds approximately to a quarter of a cylinder, grip the bundle in order to keep it closed in its final position, while a laser-welding or plasma-welding machine, not illustrated, applies a welding bead to the joined ends of the bundle. From this moment, the bundle leaves through the hole 18 ′ in order to enter a calibrating press for ensuring its geometry, before undergoing cooling in order to eliminate the stresses attributable to the welding bead.
The use of slides for deforming a sheet bundle and for forming a stator has the advantage that the machine can easily be adapted to the different dimensions of the desired production. In the first two plates 16 and 17 , the slide supports are each held in two linear and parallel guides, while, on the plates 18 and 19 , the guides are two concentric circles which make it possible to modify the position of the slide supports as a function of the requirements and the dimensions of the stator to be formed.
It is clear that the plates 16 and 17 may be separate boards or the two faces of the same board, since, on one board 16 , the slides 21 , 22 , 23 can very easily be arranged on one side and the slides 28 , 29 and 30 on the other, and, likewise, on the plates 18 and 19 there may be either separate boards or the two faces of the same board. In the same way, the bearing surfaces 4 , 27 , 34 , 38 may be in one piece which passes through these plates, of which the transverse cross section over the entire length of advance decreases, since, during the first two steps, the bundle rests on wide surfaces, while, at the end, it is to rest virtually on a generatrix.
Multiple variations and modifications are possible in the embodiments of the invention described here. Although certain illustrative embodiments of the invention have been shown and described here, a wide range of modifications, changes, and substitutions is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the foregoing description be construed broadly and understood as being given by way of illustration and example only, the spirit and scope of the invention being limited only by the appended claims.
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The method makes it possible to form a stator of an electric motor by means of a multiple-slide press ( 21, 22, 23 ). The starting point is a bundle consisting of rectilinear segments of sheets obtained by stamping and welded. The stator is formed by means of four successive operations carried out by four groups of slides of a multiple-slide press and corresponding dies. The cylinder formed is subsequently welded along its joining generatrix and is calibrated in a hydraulic press.
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BACKGROUND OF THE INVENTION
[0001] In modern contemporary fencing installations it is not unusual to include a swinging gate or door to provide access to the area being enclosed. Usually the swinging gate is provided with a “bolt” which engages and locks into a thumb latch which is mounted on the stationary adjoining wall or post. These closure installations work acceptably well until some misalignment occurs between the bolt and the latch. The misalignment can be severe in instances where the length of the gate exceeds a few feet. Misalignment frequently occurs in areas subject to frost heaving of the gate and/or the fence or post on which the thumb latch (keeper) is mounted. The frost heaving can be embarrassing because it may cause the gate to “stick” in the closed position due to the force transmitted to the latch by the misaligned bolt. The same situation occurs in hurried installations where the gate post upon which the gate is hinged settles due to improper packing of the earth about the post during construction.
[0002] Upon forcing a gate to open once misalignment has occurred, it is difficult if not impossible to close the gate and engage the bolt with the thumb latch due to the lack of registration of the bolt and latch.
[0003] It is usually necessary to remove and re-mount the latch assembly (or the bolt) to permit the gate to be closed and latched in the secure position after the misalignment of the latch and bolt has occurred. This invention will compensate for the misalignment which occurs due to faulty installation or during heaving resulting from frost penetration.
SUMMARY OF THE INVENTION
[0004] This invention allows for substantial vertical misalignment of the bolt and latch assembly of a garden gate type lock and will permit latching and unlatching of the bolt despite reasonable relative vertical misalignment of the gate and latching post.
[0005] This latch assembly comprises a standard thumb latch keeper which is permanently mounted on a stationary post or wall and wherein a latch bolt is arranged to pivot about the end of the bolt remote from the keeper so as to engage the latch keeper.
[0006] The latch assembly thus comprises a bolt which will be found to be somewhat longer than a standard latch bolt, but the end of the bolt remote from the latch is pivoted to allow the bolt to pivot in a vertical plane, and the bolt will be maintained within a guide having a slot which confines the pivoting motion of the bolt to that in a vertical plane.
[0007] The bolt will pivot in a vertical plane within the guide which will compensate for a substantial amount of misalignment between the gate and the stationary post or wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a perspective view of a pivoting bolt gate latch of this invention mounted on a gate and post.
[0009] [0009]FIG. 2 is a perspective view of the latch of this invention.
[0010] [0010]FIG. 3 is a development of the base of the latch of this invention.
[0011] [0011]FIG. 4 is a close-up perspective view of the gate latch of this invention.
[0012] [0012]FIG. 5 shows a perspective view of an alternative embodiment of this invention.
[0013] [0013]FIG. 6 shows yet another embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] [0014]FIG. 1 shows gate 10 and a stationary post member 12 on which the latch bar assembly 14 and the keeper 16 are mounted. Latch bar assembly 14 shows a pivoting latch bar 18 mounted on pivot 20 . The latch bar 18 is held in keeper 16 by a thumb release member 22 . In this Figure, the post 12 is shown in a somewhat sunken position.
[0015] [0015]FIG. 2 shows the latch bar member 14 in greater detail. Member 14 comprises a one piece base 24 having mounting holes 26 . Base 14 also comprises an integral upstanding guide portion 28 having a slot 30 formed therein to receive pivoting latch bar 18 therein. A base return lip 32 is formed by bending the upstanding guide portion 28 at 34 to form a large flat surface to provide an enhanced bearing surface for pivoting latch 18 . The large flat exposed surface 32 is provided also for the safety of persons using the gate latch device.
[0016] Base 14 is provided with a raised dimple 36 on which pivot 20 is mounted.
[0017] [0017]FIG. 1 shows a gate installation in which for reason unknown, the post 12 has sunk somewhat. The pivoting latch 18 is able to engage keeper 16 by its ability to drop in slot 30 to accommodate the sunken position of keeper 16 on post 12 . This position is represented by the position of latch bar 18 shown in solid lines in FIG. 2.
[0018] [0018]FIG. 3 shows the latch assembly having the keeper 16 engaging the pivoting latch bar 18 . Keeper 16 comprises a base 40 having an upstanding flange 42 upon which thumb latch 44 is pivoted about pivot 46 .
[0019] Flange 42 is provided with a “V” shaped notch to guide pivoting latch bar 18 into engagement with thumb latch 44 . Screws 48 secure the latch and keeper to their respective support members 10 and 12 .
[0020] [0020]FIG. 4 shows an alternative quick mounted for the latch member on a tubular gate member having a square cross section. Here gate post member 50 is engaged by a two piece base plate combination assembly 54 and 56 . In this installation the base 54 is engaged by clasp 56 . Base 54 is provided with slot 58 through which tongue 60 of clasp 56 is captured. Clasp 56 is shaped to surround post 50 and lip 58 is provided for attachment of bolts 60 of base 54 through clasp 56 to secure the member 52 to post 50 . This method of attachment is quick, easy and robust.
[0021] Pivoting latch bar 18 is guided by slot 30 of base 54 . Return lip 62 provides additional bearing surface for latch bolt 18 and a safety reinforcement as well. The presence of the lip 62 presents a flat surface parallel to the base 54 which avoids the narrow projecting lip present in most prior art devices. Besides strengthening the base of the latch assembly, this lip is designed to eliminate injuries to persons using the latch of this invention.
[0022] [0022]FIG. 5 shows a modification of the gate latch 72 of this invention to accommodate mounting on a round post 70 . Base 74 of latch 72 is shaped in a similar manner of the latch 52 of FIG. 4. Base 74 is provided with a slight concavity at 76 to give more surface contact with gate post 70 . Clasp 78 is made to have tongue 80 pass through slot 82 of base 74 of latch 72 . Bolts 84 serve to close clasp 78 on post 70 to complete the mounting of latch 72 on post 70 .
[0023] A pivot 86 provides the center of rotation for latch 88 . Latch 88 is guided in slot 90 of base 74 . Lip 92 functions to eliminate any sharp projections protruding from latch 72 and increase the strength of the base member 74 .
[0024] In summary, the latch of this invention provides a base which is produced to have three integral cooperating flat surfaces to produce a strong base having a smoothly operating movement which is capable of compensating for settling of gate or latching posts. The latch is so produced so it can compensate for large misalignments of latch and keeper due to frost and settlement of gate and post members.
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This application reveals a gate latch assembly in which a pivoting bolt permits substantial misalignment to occur between the bolt and latch members and yet permit successful latching of the assembly.
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TECHNICAL FIELD
This disclosure relates generally to control systems for electric motors, and, in particular, to operating multiple electric motors in a system at different speeds.
BACKGROUND
Some commercial heating, ventilation, and air-conditioning (HVAC) systems include multiple fans and electric motors in multiple units that work together to provide heating and cooling to a building. For example, the air conditioning or refrigeration systems in many large buildings include multiple condenser units that are located on the roof of the building. Each condenser unit includes an electric motor that drives a fan to direct air over a radiator to cool and condense a refrigerant from a vapor phase to a liquid phase.
In many HVAC systems, multiple motorized units, such as condensers, operate in tandem to provide sufficient cooling capacity for a building or other facility. A central control unit is connected to the fan motors in each of the condenser units and is configured to activate the fan motors, deactivate the fan motors, and adjust the operating speed of the fan motors based on the cooling requirements of the building.
One challenge confronting HVAC systems that include multiple condenser units or other units that include electric motors is the operation of the individual units in an energy efficient manner. For example, in one existing HVAC system, a central controller can operate the fans in multiple condenser units at different speeds, but all of the fans must operate at the same speed. In some operating conditions, the HVAC system could operate more efficiently if only some of the motors operated simultaneously. In another embodiment, a single controller operates the fan in a single condenser unit, then the control signal from the controller is propagated to a second fan motor in a second condenser unit at a lower level, to a third motor in a third fan unit at still a lower level, etc. to enable a single control unit to operate the fans in multiple condenser units at different speeds. One drawback of the aforementioned system is that the controller is unable to operate the fans in all of the condenser units at a maximum speed in situations where the HVAC system is required to operate at high capacity.
One approach that controls multiple fan motors at different speeds includes a controller that communicates with each motor individually, either through individual control lines or through a digital control system that communicates using, for example, wired or wireless digital networking. While such systems are known to the art, the added complexity required in the controller and the added infrastructure required to run individual control wires or add digital control systems to the motors in existing HVAC units adds to the cost and maintenance burden for building and operating the HVAC system. Consequently, improvements to HVAC control systems that enable operating different motors in the HVAC system over a full range of different operating speeds during operation without requiring generation of individual control command signals for each motor would be beneficial.
SUMMARY
In one embodiment, a motor control system for controlling multiple electric motors has been developed. The system includes a first electric motor including a first electric motor control unit, a second electric motor including a second electric motor control unit, the second electric motor control unit, and a controller operatively connected to the first electric motor control unit and the second electric motor control unit. The first electric motor control unit is configured to operate the first electric motor at a first rate in response to receiving a control signal at a first level and at a second rate in response to receiving the control signal at a second level, and operate the first electric motor at a plurality of intermediate operating rates between the first rate and the second rate in accordance to a first predetermined control curve in response to receiving the control signal at an intermediate level between the first level and the second level. The second electric motor control unit is configured to operate the second electric motor at the first rate in response to receiving the control signal at the first level and at a third rate in response to receiving the control signal at the second level, the third rate being different than the second rate, and operate the second electric motor at another plurality of intermediate operating rates between the first rate and the third rate in accordance to a second predetermined control curve in response to receiving the control signal at the intermediate level between the first level and the second level. The controller is configured to generate a single control signal to operate both the first electric motor and the second electric motor. The control signal is at one of the first level, the second level, and one of a plurality of intermediate levels between the first level and the second level.
In another embodiment, a method for controlling multiple electric motors has been developed. The method includes generating a single control signal at one of a first level, a second level, and a plurality of intermediate levels between the first level and the second level, operating a first electric motor at a first rate in response to receiving the single control signal at the first level, operating the first electric motor at a second rate in response to receiving the single control signal at the second level, operating the first electric motor at a plurality of intermediate rates between the first rate and the second rate in accordance to a first predetermined control curve in response to receiving the control signal at one of the plurality of intermediate levels, operating a second electric motor at the first rate in response to receiving the single control signal at the first level, operating the second electric motor at a third rate in response to receiving the single control signal at the second level, the third rate being different than the second rate, and operating the second electric motor at another plurality of intermediate operating rates between the first rate and the third rate in accordance to a second predetermined control curve in response to receiving the control signal at one of the plurality of intermediate levels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic diagram of a control system that generates a single control signal to operate multiple motors in an HVAC system at different rates.
FIG. 1B is a schematic diagram of the control system of FIG. 1A where the single control signal operates all of the motors at either a maximum or minimum operating speed.
FIG. 2 is a block diagram of a process for configuring and operating the motors in the HVAC system depicted in FIG. 1A and FIG. 1B .
FIG. 3 is a graph of predetermined control curves that are used to operated different motors in an HVAC system at different rates.
FIG. 4 is another graph of predetermined control curves that are used to operated different motors in an HVAC system at different rates.
DETAILED DESCRIPTION
For a general understanding of the environment for the system and method disclosed herein as well as the details for the system and method, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate like elements. As used herein, the term “control curve” refers to data that a motor control device references to identify an operating rate for the motor that corresponds to the level of a control signal. The controller deactivates the motor or operates the motor over a range of operating speeds between a minimum operating rate and a maximum operating rate with reference to the control curve and the control signal.
FIG. 1A and FIG. 1B are block diagrams that depict a motor control system that is used, for example, in an HVAC system. FIG. 1A and FIG. 1B include a controller 104 that is operatively connected to motor control units 118 A, 118 B, 118 C and 118 D. The motor control units 118 A- 118 D are each configured to adjust the rate of rotation of motors 116 A, 116 B, 116 C, and 116 D, respectively. In the system 100 , the controller 104 includes a control signal module 108 that generates a single control signal for all of the motor control units 118 A- 118 D that is distributed through, for example, a single electrical connection 112 . In one embodiment the motor control units 118 A- 118 D are also digital control units or are hybrid analog/digital control units in an alternative embodiment. In many HVAC systems, the motors 116 A- 116 B are electric motors that operate, for example, using alternating current (AC) or direct current (DC) electrical power. While FIG. 1A and FIG. 1B depict the system 100 with four motors 116 A- 116 D and four motor control units 118 A- 118 D, respectively, alternative configurations include two or more motors that each receive a single control signal from a controller such as the controller 104 .
In one embodiment, the controller 104 is a digital controller that is, for example, operatively connected to one or more thermostats (not shown) and generates a control signal to operate the motors 116 A- 116 D at different speeds to maintain a predetermined temperature within a building. In one embodiment, the control signal module 108 generates one electrical signal at a selected voltage level for each of the motor control units 118 A- 118 D. During operation, the controller 104 changes the voltage level within a predetermined range, such as 0 V to 10 V, to increase and decrease the operating rates of the motors 116 A- 116 D. As described below, the motor control units 118 A- 118 D are each configured to respond to a single control signal differently to enable the motors 116 A- 116 D to operate at different rates for some control signals, as depicted in FIG. 1A , while still enabling all of the motors to operate at a single rate for at least one predetermined control signal, as depicted in FIG. 1B .
In the system 100 , each of the motor control units 118 A- 118 D is configured to respond to a single control signal voltage using a predetermined control curve that is stored within a memory of each of the control units 118 A- 118 D. In one embodiment, the memory in each of the control units 118 A- 118 D stores multiple control curves and an operator reconfigures one or more mechanical switches, such as the switches 120 A- 120 D, in each of the motor control units 118 A- 118 D, respectively, to select one control curve. In the embodiment of FIG. 1A and FIG. 1B , each one of the motor control units 118 A- 118 D stores four different control curves in memory, and the switches 120 A- 120 D are dual-inline package (DIP) switches with two individual switch elements that enable selection between the four different control curves. In another embodiment, each one of the motor control units 118 A- 118 D is programmed with a single control curve that is selected for use with the corresponding control unit through, for example, a software or firmware programming process.
FIG. 3 is a graph depicting control curves in one embodiment of the system 100 . In FIG. 3 , a chart 300 depicts control curves 304 , 308 , 312 , and 316 . The chart 300 depicts analog voltage control signal levels in a range from 0 to 10 volts on the horizontal axis and the operational rate of each motor corresponding to the control signal that are expressed as percentages of the maximum operating rate of the motor is depicted on the vertical axis. In the chart 300 , the control curves 304 - 316 converge at 100% operational speed when the analog voltage control signal reaches 10 volts. The control curves 303 diverge from each other as the analog input voltage decreases, with, for example, each control curve having a linear segment with a different slope in the chart 300 . In the example of the chart 300 , each control curve has a minimum operational rate, which is a 30% operational rate depicted on the cutoff threshold line 328 . At any control voltage level below the cutoff point for each one of the control curves, the corresponding motor controller deactivates the motor (e.g. runs the motor at a rate of 0%). In FIG. 3 , the cutoff threshold line 328 intersects the control curve 304 at approximately 0.5 volts, the control curve 308 at approximately 1.0 volt, the control curve 312 at approximately 1.5 volts, and the control curve 316 at approximately 2.0 volts.
Referring to FIG. 1A and FIG. 3 , the motor control unit 118 A is configured to use the control curve 304 , the motor control unit 118 B is configured to use the control curve 308 , the motor control unit 118 C is configured to use the control curve 312 , and the motor control unit 118 D is configured to use the control curve 316 . In FIG. 1A , the control signal module 108 in the controller 104 generates a single voltage control signal of approximately 2.0 volts. Each of the motor control units 118 A- 118 D receives the single control voltage signal through, for example, control wires 112 . As depicted in FIG. 3 , the 2.0 volt control voltage is depicted as vertical line 320 that extends through each of the control curves 304 , 308 , and 312 . The operating speed for each of the motors 116 A- 116 C corresponds to the intersection between the vertical line 320 and the corresponding control curves 304 - 312 along the vertical axis. For example, the line 320 intersects the control curve 304 at a motor rate of approximately 41%, and in FIG. 1A the motor 116 A operates at approximately 41%. Similarly, the line 320 intersects control curve 308 at approximately 38%, and the motor 116 B operates at a rate of 38%, and the line 320 intersects the control curve 312 at approximately 34%, and the motor 116 C operates at a rate of 34%. For exemplary purposes, the control voltage line 320 is set to be slightly below the cutoff line for the control curve 316 . Thus, the line 320 does not intersect the control curve 320 and the motor control unit 318 D deactivates the motor 316 D.
In FIG. 1A , the controller 104 generates the control signal to operate the motors 116 A- 116 C at reduced rates and to completely deactivate the motor 116 . In some operating conditions, the three motors 116 A- 116 C provide sufficient airflow to operate, for example, condensers in an air conditioning or refrigeration system while the motor 116 D is deactivated. When deactivated, the motor 116 D consumes minimal electrical energy and the control system 100 can operate in an efficient manner.
Referring to FIG. 1B and FIG. 3 , the individual motor controllers 118 A- 118 D are configured to enable each of the motors 116 A- 116 D to operate at a rate of 100% in response to a single control signal from the controller 104 . In the system 100 , the control signal module 108 generates a control voltage of 10 volts, which is depicted as the vertical line 324 in the chart 300 . The vertical line 324 intersects each of the control curves 304 - 316 at the 100% operating rate level on the vertical axis of the chart 300 . Consequently, in FIG. 1B each of the motor controllers 318 A- 318 D operates one of the motors 316 A- 316 D, respectively, at a 100% operating rate. Thus, in the system 100 , the control curves 304 - 316 enable the controller 104 to generate a single control signal to operate all of the motors at 100% when the HVAC system runs at maximum capacity. During operation, the controller 104 also generates a plurality of control voltages in addition to the exemplary control voltages 320 and 324 that are shown in FIG. 3 . The motor control units 318 A- 318 D operate the respective motors 316 A- 316 D at different rates that are determined by the intersection of the control voltage and the corresponding control curve.
FIG. 4 depicts a chart 400 with an alternative set of control curves 404 , 408 , 412 , and 416 . In the chart 400 , the control curves 404 - 416 intersect at a control voltage of approximately 0.5 volts, which corresponds to a minimum cutoff operating rate for the motors of, for example, 30% as depicted by the cutoff line 428 . In the configuration of FIG. 4 , multiple motor control units that are configured to use the different control curves 404 - 416 each operate motors at the minimum 30% operating rate in response to receiving a single control voltage of approximately 0.5 volts as depicted on the vertical line 420 . If the control voltage drops below the 0.5 volt threshold, then each of the motor controllers deactivates the corresponding motor. As the control voltage level increases, the individual motor controllers operate the motors at different rates. In the chart 400 , a maximum control voltage of 10 volts depicted along the line 424 intersects the control curve 404 at an operating rate of 100%, the control curve 408 at an operating rate of 90%, the control curve 412 at an operating rate of 80%, and the control curve 41 at an operating rate of 70%. Thus, in the configuration of FIG. 4 , only motors that are configured to operate according to the control curve 404 reach a 100% operating rate when the control voltage is at a maximum level.
While FIG. 3 and FIG. 4 depict illustrative embodiments of control curves, alternative configurations of the system 100 include different control curve configurations. For example, alternative configurations include a different number of control curves, such as two or more control curves. While FIG. 1A and FIG. 1B depict four motors that are each configured to use a different control curve as an example, many HVAC systems include a different number of motors and two or more motors can be configured to operate using a single control curve. While the control curves depicted in FIG. 3 and FIG. 4 are linear, other control curve shapes including exponential or quadratic control curves are used in alternative embodiments. The control curves as illustrated in FIG. 3 and FIG. 4 have a positive slope, which is to say that the operating rate of the motors on the control curves increases as the voltage of the control signal increases. In an inverted control signal embodiment, the control curves have negative slopes where the operating rate of the motors on the control curves decreases as the voltage of the control signal increases. In still another embodiment, the control curves include a combination of positive and negative slopes over for different ranges of the control signal between the minimum and maximum control signal voltage.
The embodiments of the control curves that are depicted in FIG. 3 and FIG. 4 are shown as graphics for illustrative purposes. In one embodiment of the software in the motor control units 118 A- 118 D, each control unit stores data corresponding to, for example, the slope of the control curve, the minimum cutoff threshold, and at least one point on the control curve, such as the 100% utilization point at the maximum control signal voltage depicted in FIG. 3 . The control software then identifies the rate for operating the motor given the analog voltage of the control signal using, for example, algebraic techniques that are well-known in the art for finding a value of a dependent variable (the motor rate) on a curve given the value of the independent variable (the analog control signal voltage level).
In the embodiment of system 100 , the controller 104 and control signal generation module 108 generate analog voltage control signals in a predetermined voltage range of, for example, 0 volts to 10 volts. In one alternative configuration, the control signal generation module 108 generates voltages at a plurality of predetermined levels, such as for example at 0.5 volt increments between 0 volts and 10 volts. In another embodiment, the analog control signal is based on the amplitude of an electrical current instead of voltage. In still another embodiment, the analog control signal is a modulated signal. While analog control signals are common in many HVAC control systems, in an alternative embodiment of the system 100 the controller sends a single command signal that is encoded in a digital data format to all of the motor controller units 118 A- 118 D. For example, in one embodiment the control system 100 sends a digital data frame including a numeric value in a range of 0 to 100 to all of the controller units 118 A- 118 D to select an operating rate for the motors in the system 100 . Regardless of the form of the control signal, the controller 104 sends a single control signal to all of the motor controller units 118 A- 118 D and the motor controller units 118 A- 118 D each operate the corresponding motor based on the predetermined control curve and the command signal.
FIG. 2 is a block diagram of a process 200 for configuring and operating a plurality of motors in a motor control system with the motors operating at different rates using a single control signal for all of the motors. In the discussion below, a reference to the process 200 performing an action or a function refers to a controller, such as the system controller 104 or the motor controller units 118 A- 118 D, executing stored instructions to perform the action or function with one or more components in the system. Process 200 is described in conjunction with the motor control system 100 of FIG. 1A and FIG. 1B for illustrative purposes.
Process 200 begins with selection of control curves for individual motor controllers (block 204 ). In the motor control system 100 , a technician or other operator configures the switches 120 A- 120 D in each of the motor control units 118 A- 118 D to select one of the control curves for use with each motor. In the examples of FIG. 1A and FIG. 1B , the switches 120 A- 120 D in the motor control units 118 A- 118 D are configured in one of four different configurations to select one of four different control curves. In alternative configurations, the motor control units are programmed with data corresponding to predetermined control curves via software or firmware updates.
Process 200 continues as a central controller, such as the controller 104 in the system 100 , generates a single control signal for all of the motor control units (block 208 ). As depicted in FIG. 1A and FIG. 1B , the control signal generation module 108 in the controller 104 generates a voltage signal at a selected level and each of the motor control units 118 A- 118 D receives the same control voltage signal. If the motor control units are configured with the control curves 304 - 316 that are depicted in FIG. 3 , then voltage control signal may intersect one or more of the control curves 304 - 316 , or be below the minimum cutoff threshold 328 . Using the example control voltage of 2.0 volts described above in conjunction with the line 320 in FIG. 3 , the control signal is below the cutoff level for the control curve 316 and the motor control unit 318 D in FIG. 1A (block 212 ) and the motor control unit 318 D deactivates the motor 316 D (block 216 ).
For the remaining control curves 304 - 312 , the control voltage signal is above the cutoff threshold (block 212 ), and each of the motor controllers 318 A- 318 C identifies an operating rate for one of motors 316 A- 316 C, respectively, with reference to the intersection between the control signal 320 and the corresponding control curves 304 - 312 (block 220 ). For example, in the configuration of FIG. 1A the controller 118 A operates the motor 116 A at a rate of 41% compared to the maximum operating rate of the motor in accordance with the control curve 304 , the controller 118 B operates the motor 116 B at a rate of 38% in accordance with the control curve 308 , and the controller 118 C operates the motor 116 C at a rate of 34% in accordance with the control curve 312 . The motor controllers 118 A- 118 D continue to operate the motors 116 A- 116 D at the identified rates as long as the control signal remains at the selected voltage level (block 224 ).
Process 200 continues as the controller 104 generates control signals at various levels for the motor controllers in the motor control system 100 (block 208 ). During operation, the controller 104 can change the level of the single analog voltage signal to increase or decrease the total operational rate of the motors in the system 100 . As depicted above in FIG. 3 , if the controller 104 increases the control signal to 10 volts, then each of the motor controllers 118 A- 118 D operates the corresponding motor 116 A- 116 D at a 100% rate in accordance with the control curves 304 - 316 . The controller 104 can also generate control signals at intermediate levels to operate the motors 116 A- 116 D at various intermediate rates, to deactivate some of the motors while operating others at intermediate rates, or to deactivate all of the motors.
It will be appreciated that variations of the above-disclosed apparatus and other features, and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.
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In a motor control system, a controller generates a single control signal for a motor control unit in a first electric motor and another motor control unit in a second electric motor. The motor control units in the first and second electric motors operate the first and second electric motors at a first rate in response to the control signal being at a first level. The motor control unit in the first electric motor operates the first electric motor at a second rate and the motor control unit in the second electric motor operates the second electric motor at a third rate in response to the control signal being at a second level, the third rate being different than the second rate.
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TECHNICAL FIELD
[0001] The invention relates to a thermally bonded nonwoven fabric having improved thermal and chemical stability. The invention further relates to uses of this nonwoven fabric.
PRIOR ART
[0002] Melt-bondable fibers and nonwoven fabrics produced therefrom are known from EP 0 340 982 B1. Melt-bondable fibers are dual-component fibers composed of a first, at least partially crystalline, polymer component and a second component, adhering to the surface of the first component, containing a compatible blend of polymers comprising at least one amorphous polymer and at least one polymer which is at least partially crystalline. The melting temperature of the second component is at least 30° C. below that of the first component, but is at least equal to or greater than 130° C. In addition, the weight ratio of the amorphous polymer of the second component to the at least partially crystalline polymer of the second component is in the range of 15:85 and 90:10, and has a value such that binding of dual-component fibers to a similar dual-component fiber is prevented, and the first component forms the core and the second component forms the sheath for a dual-component fiber spun in the form of a sheath-core configuration. This dual-component fiber is mixed with conventional polyester fibers and thermally bonded to produce a nonwoven fabric, which is processed into an abrasive fleece by application of abrasive particles.
[0003] Heat-bondable conjugate fibers are known from JP 07-034326 which have a sheath-core configuration, and have a core made of a polyester containing polyethylene terephthalate (PET) as the main component, and have a sheath that is produced from a copolymerized polyester or a side-by-side conjugate fiber composed of polyethylene terephthalate and a copolymerized polyester. The copolymerized polyester represents the lower-melting component, and contains butylene terephthalate units and butylene isophthalate units as repeating structural units. A nonwoven fabric produced from these dual-component fibers is designed to have excellent thermal resistance and fatigue resistance against pressure stress, so that it may be used as an alternative material for polyurethane seat coverings, primarily in the automotive sector.
[0004] Thermally bonded nonwoven fabrics may also be produced from a mixture of drawn and undrawn PET fibers. However, these nonwoven fabrics require bonding under heat and pressure in a calender. The bonding capability of the undrawn amorphous PET fibers is based not on a melting process, but, rather, on the crystallization process for PET, which begins above 90° C. provided that crystallizable fractions are still present. Such nonwoven fabrics have high chemical and thermal stability. However, the production process permits little flexibility. Thus, for undrawn PET fibers, for example, it is not possible to activate the bonding capability multiple times, since this requires a process that is irreversible below the melting temperature. In addition, bonding of nonwoven fabrics having weights per unit area >150 g/m 2 with undrawn PET fibers is difficult, since in the calendering process the external heat cannot penetrate sufficiently into the nonwoven web. A more or less pronounced gradient always occurs.
DESCRIPTION OF THE INVENTION
[0005] The object of the invention is to provide a thermally bonded nonwoven fabric having improved thermal stability properties, in particular the shrinkage tendency of the nonwoven fabrics obtained. In addition, the chemical stability is increased compared to fibers containing copolymers of monomer mixtures such as isophthalic acid/terephthalic acid.
[0006] The object is achieved according to the invention by use of a thermoplastically bonded nonwoven fabric containing a low-shrinkage dual-component core-sheath fiber. The low-shrinkage dual-component core-sheath fiber is composed of a crystalline polyester core and a crystalline polyester sheath which has a melting point at least 10° C. lower than the core, and has a hot-air shrinkage of less than 10%, preferably less than 5%, at 170° C. At temperature stresses of 150° C. (1 h), a corresponding nonwoven fabric exhibits a thermal dimensional change (shrinkage and curl) of less than 2%. In the context of the invention, the term “crystalline” means a polyester polymer having a heat of fusion (DSC) of >40 joule/g and a width of the melting peak (DSC) preferably occurring at <40° C. at 10° C./min.
[0007] The sheath of the low-shrinkage dual-component fiber is preferably composed of a homogeneous polyester polymer, produced from a monomer pair, of which greater than 95% is formed from a single polymer pair. In the case of the polyester described in the claims, this means that >95% of the polymer is composed of a single dicarboxylic acid and a single dialcohol.
[0008] The mass ratio of the core-sheath component is typically 50:50, but for specialty applications may vary between 90:10 and 10:90.
[0009] A nonwoven fabric is particularly preferred in which the sheath of the dual-component core-sheath fiber is composed of polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), or polyethylene terephthalate (PET).
[0010] Further preferred is a nonwoven fabric in which the core of the low-shrinkage dual-component core-sheath fiber is composed of polyethylene terephthalate or polyethylene naphthalate (PEN).
[0011] The nonwoven fabric according to the invention may contain additional fibers besides the low-shrinkage dual-component core-sheath fiber, depending on the particular use. It is preferred to use 0 to 90% by weight of monofil standard polyester fibers, for example, together with the low-shrinkage dual-component fiber.
[0012] The nonwoven fabric according to the invention is preferably composed of low-shrinkage dual-component core-sheath fibers having a titer in the range between 0.1 and 15 dtex. The nonwoven fabric according to the invention has a weight per unit area between 20 and 500 g/m 2 . For a weight per unit area of 150-190 g/m 2 , for example, the nonwoven fabric according to the invention achieves a bending stiffness of greater than 1 Nmm transverse to the machine direction, as determined in accordance with ISO 2493.
[0013] The method for producing the thermally bonded nonwoven fabric is characterized in that the fibers are laid out to produce a nonwoven fabric, thermally bonded, and immediately compressed if necessary. In the method, the fibers of the nonwoven fabric according to the invention are placed in a thermal fusion oven which allows uniform temperature equilibration of the binding fibers. The low-shrinkage dual-component core-sheath fibers are preferably laid out wet in a paper layout process and dried, or laid out dry using a carding or airlaid process and then bonded at temperatures of 200 to 270° C., and optionally compressed using a calender or press tool at rolling temperatures below the melting point of the sheath polymer, preferably <170° C. This compression is preferably carried out immediately after the bonding process in the dryer, when the fibers are still hot. However, the structure of the fibers also allows subsequent heat treatment, since the bonding process may be activated multiple times.
[0014] The thermally bonded nonwoven fabrics obtained have shrinkage and curl values in the range of <2%, preferably <1%.
[0015] The nonwoven fabrics according to the invention are suitable as a liquid filter medium, membrane support fleece, gas filter medium, battery separator, or nonwoven fabric for the surface of composite materials on account of their high thermal stability, low shrinkage tendency, and stability with regard to chemical aging. This is particularly true for use as an oil filter medium in motor vehicle engines.
[0016] The invention is explained in greater detail below with reference to the figures, which show the following:
[0017] FIG. 1 shows a diagram illustrating the maximum tensile forces for nonwoven fabrics A and B in the form of an index, after storage in air and in oil, relative to the respective new state (DIN 53508 and DIN 53521);
[0018] FIG. 2 shows a diagram illustrating the maximum tensile force elongation for nonwoven fabrics A and B after storage at 150° C. in air and in oil, relative to the respective new state (DIN 53508 and DIN 53521);
[0019] FIG. 3 shows a diagram illustrating the maximum tensile forces for nonwoven fabrics A and B at various temperatures in the form of an index, relative to the respective new state (DIN EN 29073-03);
[0020] FIG. 4 shows an electromicrograph of a membrane support fleece bonded with undrawn polyester fibers (nonwoven fabric E; comparative example);
[0021] FIG. 5 shows an electromicrograph of a membrane support fleece which according to the invention is composed of 100% low-shrinkage PET/PBT dual-component fiber (nonwoven fabric F);
[0022] FIG. 6 shows a DSC curve for a dual-component fiber A containing crystalline sheath polymer (in this case PET/PBT; according to the invention); and
[0023] FIG. 7 shows a DSC curve for a dual-component fiber B containing amorphous sheath polymer (in this case PET/coPET; prior art).
TEST METHODS
Bending Stiffness
[0024] The bending stiffness was determined in Nmm in accordance with ISO 2493.
Thermal Dimensional Change (Shrinkage)
[0025] The sample (DIN A4-size sample) was provided with marks 200 mm apart in the longitudinal and transverse directions. The samples were stored for 1 hour at 150° C. in a circulating air oven and then cooled for 20 minutes at room temperature, after which the dimensional change was determined. This value was expressed as a percentage of the starting value for the longitudinal and transverse directions. The algebraic signs preceding the percentage value indicate whether the dimensional change is positive (+) or negative (−). The mean value was determined from at least six individual values (measurements).
Thermal Dimensional Change (Curl)
[0026] The sample (DIN A4-size sample) was provided with marks at which the thickness was determined in accordance with ISO 9073/2. The samples were stored for 1 hour at 150° C. in a circulating air oven and then cooled for 20 minutes at room temperature, after which the thickness was redetermined at the marks (ISO 9073/2). The curl (B), expressed as a percentage, was calculated as follows:
[0000] B (%)=(Thickness after storage×100/Thickness before storage)−100
[0027] The mean value was determined from at least six individual values (measurements).
Testing of Hot-Air Shrinkage
[0028] Twenty individual fibers were tested. The fiber was provided with a pretensioning weight as described below. The free end of the fiber was placed in the clamp of a clamping plate. The length of the clamped fiber was determined (L 1 ). The fiber, freely suspended without weight, was then temperature-equilibrated for 10 minutes at 17° C. in a circulating air drying oven. After cooling for at least 20 minutes at room temperature the same weight from the determination of L 1 was suspended from the fiber again, and the new length (L 2 ) after the shrinkage process was determined.
[0029] The percentage of hot-air shrinkage was calculated from the following expression:
[0000] HS (%)=(Σ L 1 −ΣL 2 )*100/Σ L 1
[0000]
TABLE 1
Size of pretensioning weight
Pretensioning weight
Titer (dtex)
(mg)
≦1.20
100
>1.20
100
≦1.60
>1.60
150
≦2.40
>2.40
200
≦3.60
>3.60
250
≦5.40
>5.40
350
≦8.00
>8.00
500
≦12.00
>12.00
700
≦16.00
>16.00
1000
≦24.00
>24.00
1500
≦36.00
[0030] In the freely suspended state the fiber should have an uncurled appearance. If the curl was too great, the next heavier weight was selected.
Heat of Fusion (DSC)
[0031] The sample was weighed in a DSC apparatus from Mettler Toledo and heated from 0° C. to 300° C. using a temperature program of 10° C./min. The area beneath the endothermic melting peak obtained, in conjunction with the original fiber weight and the associated masses of the sheath or core component, represents the heat of fusion of the respective component in J/g.
EXAMPLE 1
[0032] Nonwoven fabric A represents a dry-laid, carded, and thermally bonded nonwoven fabric having a weight per unit area of 190 g/m 2 . This nonwoven fabric was composed of 75% low-shrinkage PET/PBT dual-component fiber having a sheath melting point of 225° C. and a core-to-sheath ratio of 50:50, and up to 25% conventional PET fibers. The thickness was 0.9 mm, and the air permeability was 850 L/m 2 s at 200 Pa. 140 g/m 2 of the fibers were carded by combing using a cross-layer, and the remaining 50 g/m 2 were carded in a longitudinal layout. The nonwoven fabric was bonded in a thermal fusion oven at approximately 240° C., and was calibrated to the target thickness using an outlet press tool.
COMPARATIVE EXAMPLE
[0033] Nonwoven fabric B was produced analogously as for nonwoven fabric A. The differences consisted in use of conventional PET/CoPET dual-component fibers having a sheath melting point of approximately 200° C., and reduction of the oven temperature to 230° C. The resulting weight per unit area, thickness, and air permeability were comparable.
[0034] The advantages of nonwoven fabric A according to the invention compared to nonwoven fabric B are as follows:
The width of the nonwoven fabric after the dryer decreased by only about 9% for nonwoven fabric A, whereas a loss in width of approximately 21% occurred for nonwoven fabric B. The transverse bending stiffness for nonwoven fabric was 15% greater. The increase in thickness after storage at 150° C. (thermal dimensional change) for nonwoven fabric A was 1.5%, and for nonwoven fabric B, 4.7%. The thermal and chemical stability for storage at 150° C. in air and in oil was much better for nonwoven fabric A ( FIGS. 1 and 2 ). The diagrams clearly show greater destruction of nonwoven fabric B when stored in motor oil. In particular, the brittleness in FIG. 3 indicates a problem with the chemical stability of nonwoven fabric B in oil. The maximum tensile forces at various temperatures show a much more favorable progression for nonwoven fabric A ( FIG. 3 ).
EXAMPLE 2
[0040] Nonwoven fabrics C and D represent wet-laid, dried, and thermally bonded nonwoven fabrics having a weight per unit area of 198 g/m 2 and 182 g/m 2 , respectively. These nonwoven fabrics were composed of 72% low-shrinkage PET/PBT dual-component fiber having a sheath melting point of 225° C. and a core-to-sheath ratio of 50:50, and up to 28% conventional PET fibers. The fibers were present as dispersible short-cut fibers. The fibers were deposited on a screen belt in the paper-laying process, dried, and thermally bonded in a second dryer. The exceptional properties of these nonwoven fabrics consisted in the very good mechanical test values and excellent shrinkage characteristics (Table 2). In this case a comparison could not be made to nonwoven fabrics composed of conventional dual-component fibers having a CoPET sheath, since on account of the high shrinkage values it has not been possible heretofore to use such fibers on this nonwoven fabric apparatus; i.e., the fibers exhibited reductions in width of at least 20%. The wet nonwoven fabrics according to the invention exhibited reductions in width of approximately 3%.
[0000]
TABLE 2
Test values for nonwoven fabrics C and D
Nonwoven
Nonwoven
fabric C
fabric D
Weight per unit area
198
g/m 2
182
g/m 2
Thickness
1.10
mm
0.99
mm
Air permeability
714
L/m 2 s
796
L/m 2 s
Maximum longitudinal tensile force
536
N/5 cm
446
N/5 cm
Maximum transverse tensile force
358
N/5 cm
329
N/5 cm
Longitudinal bending stiffness
2.5
Nmm
1.9
Nmm
Transverse bending stiffness
2.1
Nmm
1.6
Nmm
Longitudinal shrinkage at
0.0%
0.3%
150° C., 1 h
Transverse shrinkage at
0.0%
0.0%
150° C., 1 h
Curl at 150° C., 1 h
0.7%
1.5%
[0041] The low-shrinkage dual-component fibers according to the invention offer advantages, in particular for use in the wet-laying process employing separate dryers for water removal and for thermal fusion, since in contrast to undrawn binding fibers these fibers may be activated multiple times, i.e., are not completely reacted upon the first drying process.
[0042] Nonwoven fabrics A, C, D according to the invention are particularly suited for use as motor oil filter media in motor vehicles.
EXAMPLE 3
[0043] For use as membrane support fleeces, calendered PET nonwoven fabrics (comparative example; nonwoven fabric E) composed of a mixture of drawn and undrawn monofil PET fibers represent prior art. As a result of the calendering process, there is a risk of surface sealing in particular for heavy nonwoven fabrics having weights per unit area >150 g/m 2 , since for good bonding of the nonwoven fabric high rolling temperatures or slow production speeds are required in order to conduct the necessary heat to the interior of the nonwoven fabric. Sealed surfaces entail the risk of film formation, which in turn results in poor membrane adhesion and lower flow rates (comparative nonwoven fabric E). FIGS. 4 and 5 demonstrate the difference in surfaces for a conventional nonwoven fabric (comparative example; nonwoven fabric E; FIG. 4 ) and for a nonwoven fabric according to the invention (nonwoven fabric F; FIG. 5 ).
[0044] The complete absence of surface sealing for nonwoven fabric F ( FIG. 5 ) is also shown in a comparison of test values for the two nonwoven fabrics. The air permeability of nonwoven fabric F increased by an order of magnitude, whereas the other test values were comparable (Table 3).
[0000]
TABLE 3
Test values for nonwoven fabrics E and F
Nonwoven
Nonwoven
fabric C
fabric D
Weight per unit area
190
g/m 2
190
g/m 2
Thickness
0.26
mm
0.25
mm
Air permeability (200 Pa)
5
L/m 2 s
41
L/m 2 s
Maximum longitudinal tensile force
520
N/5 cm
514
N/5 cm
Maximum transverse tensile force
470
N/5 cm
560
N/5 cm
[0045] Use of conventional dual-component fibers containing copolymers in the sheath has not become established in this application area due to the high shrinkage values and the associated weight fluctuations, in addition to the frequent denial of food safety authorization for sheath polymers. The nonwoven fabrics according to the invention, composed of the corresponding dual-component fibers, overcome both drawbacks, since they are low-shrinkage and pose no difficulties in food safety authorization because they are composed of homopolymers.
EXAMPLE 4
[0046] To further demonstrate the differences in the nonwoven fabrics according to the invention compared to conventional nonwoven fabrics containing dual-component fibers having sheaths based on copolymers, FIGS. 6 and 7 show a comparison of differential scanning calorimetry (DSC) curves for fibers containing crystalline sheath polymer (fiber A; in this case PBT) to DSC curves for conventional dual-component fibers (fiber B; in this case CoPET). The analysis of the heats of fusion of the lower-melting component showed that the sheath for fiber B has a much lower heat of fusion, in J/g, than fiber A.
[0047] The heat of fusion is a direct measure of the crystalline fractions in the polymer. The core-to-sheath ratios in both fibers were 1:1, resulting in the following heats of fusion for the fiber sheaths:
[0000]
Fiber A
63 J/g
Fiber B
29 J/g
[0048] Here as well, the core of both fibers, which in each case is composed of PET, may be used as a measurement reference. The values obtained for the heat of fusion are comparable (59 J/g versus 54 J/g).
[0049] Independent of the measured values, in a comparison of the DSC curves the low peak height and the wider peak base are characteristic of fiber sheaths based on copolymers (in this case CoPET). The melting point as well as the crystallinity, i.e., the tendency of the polymers to crystallize, are reduced by incorporation of comonomers such as isophthalic acid into polyethylene terephthalate.
[0050] The nonwoven fabrics according to the invention are therefore based on fibers of the fiber A type.
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The invention relates to a thermally bound non-woven material containing a low-shrinkage dual-component core-sheath fibre consisting of a crystalline polyester core and a crystalline polyester sheath which has a melting point at least 10° C. lower than the core, the heat-shrinkage characteristic of said fibre being less than 10% at 170° C.
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FIELD OF THE INVENTION
The invention relates to a device for encapsulating electronic components with a thermosetting synthetic resin, which device mainly comprises: a mold consisting of an upper mold part and a lower mold part and containing mold cavities, plunger pots and injection gates, heating means for heating the mold, a frame which is reciprocally movable relative to the mold, a number of plungers coupled to the frame and movable in the plunger pots, which plungers can each cooperate with a spring, and a drive mechanism for moving the frame and the plungers relative to the mold.
BACKGROUND OF THE INVENTION
A transfer press of the multiplunger type is generally used for encapsulating electronic components, in particular semiconductors and integrated circuits (IC), in a synthetic material, usually a thermosetting plastic. For this purpose, a strip comprising the relevant IC crystals and consisting of several lead frames is positioned in the mold cavities, upon which the mold is closed. The crystals are connected to the lead frames by gold wires, which are usually provided via a bonding process, e.g., ultrasonic weld. A pressed pellet of the synthetic material to be connected to the frames is introduced into each plunger pot of the mold, which has been heated in the interim. The pellets are heated by the hot mold walls and start melting. During the further heating-up and fusion of the pellets and within a certain time, called transfer time, the plungers introduced into the plunger pots now press the molten synthetic material into the mold cavities, where the material is cured. Then the mold is opened and the strip of cohering encapsulated components is removed from the mold, after which the individual encapsulated components are finally cut from the strip.
The pellets, which are usually cylindrical in shape, may have varying dimensions, depending on the dimensions of the components to be encapsulated, the number of bolt cavities to be filled by a single pellet, the dimensions of the gates, etc. In practice, pellets are frequently used having a diameter of 6 to 18 mm and having a diameter/length ratio of between 1 and 1.7; subject to the dimensions of the products to be encapsulated. The pellets may exhibit length deviations of approximately ±1 mm.
European Patent Application 0 070 320 discloses a device as described in the opening paragraph in which the pellets are pressed and the mold cavities are filled by means of plungers which are loaded by springs.
This known device has the disadvantage that the force to be transmitted by a single plunger is limited and equal to the total force applied divided by the number of plungers. If a pellet having excess length is present in one of the plunger pots, the spring of the relevant plunger is compressed. This increases the pressure on the pellet, which results in a better contact of the synthetic material with the walls of the plunger pot, the mold, and the gates. Owing to this improved contact, the pellet or the not yet molten core of the pellet will be quickly heated up, by which the viscosity of the synthetic material will quickly fall and the compressed spring will relax with a jolt. This sudden relaxation of the spring results in a too high uncontrolled displacement of the relevant plunger, which in its turn results in too high injection speeds of the synthetic material, which may increase to such an extent that the components are damaged. Thus the gold wires may become deformed (wire sweep) or fractured, or the weld bond connections may be broken.
SUMMARY OF THE INVENTION
The invention has for its object to eliminate these disadvantages and to provide a device which permits encapsulation of electronic components without causing damage to these components and which permits processing larger quantities of synthetic material than were customary hitherto in shorter cycle times.
According to the invention, this object is mainly achieved in that the device comprises a locking mechanism which is movable between an operational position and an idle position, the plungers being fixed relative to the frame in the operational position of the locking mechanism and being loaded by the springs in the idle position of the locking mechanism.
The molding cycle preferably can be carried out in two phases. In a first phase, the transfer phase or filling phase, when the locking mechanism is in an operational position, all plungers are rigidly coupled to the frame. The maximum speed of the plungers is limited and equal to the frame speed. The plungers are displaced in a controlled manner with such an optimum speed that in this phase damage to the components as a result of an excessive flow speed of the synthetic material is avoided. In addition, the transfer time is reduced in that the springs are made inoperative, so that a higher pressure can be transmitted via each plunger. In this first phase of the molding cycle, the maximum pressure bearing on the plungers is limited to a certain maximum value through limitation of the current intake of the electric motor which serves to drive the frame. After completion of the transfer phase, in a second phase of the molding cycle, the curing phase, the locking mechanism is set to its idle position, so that the plungers are acted upon by the springs. The same maximum pressure of, for example, approximately 70×10 5 Pa, is now applied to all plungers, which have now come to a standstill. The switch-over from the first to the second phase takes place when the mold cavities are full.
Tests have shown that with the device according to the invention damage to the components can be avoided, the cycle time can be shortened, and the components in addition have a regular and smooth exterior. The hitherto customary transfer time of 13-20 seconds can be reduced by several seconds in a total machine cycle of approximately 60 seconds.
A preferred embodiment of the device according to the invention is characterized in that the locking mechanism comprises a locking bar which is slidable relative to the frame between an idle position and a locking position and which cooperates with a lever mechanism for driving the plungers. A very simple construction can suffice for simultaneous locking of all plungers due to this measure.
Another preferred embodiment of the device according to the invention is characterized in that a lever mechanism of the device comprises a number of levers equal to the number of plungers, each lever being rotatably fixed with one end on a joint pivot shaft which is mounted to the frame, while the other free end is loaded by an associated spring and cooperates by means of its central portion with an associated plunger, the locking bar cooperating with the free ends of the levers. A very compact assembly is obtained in this way comprising a frame, lever mechanism and locking mechanism. Due to the lever mechanism, comparatively weak springs can suffice owing to the obtained leverage action.
Since in a further preferred embodiment of the device according to the invention a sliding lock is positioned between each lever and the locking bar, the locking may be transferred from the locking bar to the plungers in a simple manner.
In yet another preferred embodiment of the device according to the invention, the levers are firmly pressed against a stop block by means of the sliding locks in the locking position of the locking bar, and pressed resiliently against the stop block under the load of the associated spring in the idle position of the locking bar. The levers may be coupled to the frame rigidly or resiliently by means of the stop block.
In a yet further preferred embodiment of the device according to the invention, each sliding lock is loaded by a spring and pressed against the associated lever. It is achieved through this measure that the sliding locks always bear on the levers, also in the idle position of the locking bar, so that shifting of the locking bar between the idle position and the locking position is facilitated.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be explained in more detail with reference to the drawing, in which
FIG. 1 diagrammatically shows an embodiment of a device according to the invention in perspective view,
FIG. 2 diagrammatically shows the drive mechanism with the frame used in the embodiment of FIG. 1,
FIG. 3 diagrammatically shows the frame with the locking bar in the locking position,
FIG. 4 shows the frame with the locking bar in the idle position,
FIG. 5 shows a practical embodiment of the device according to the invention partly in side elevation and partly in longitudinal section taken on the line V--V in FIG. 6,
FIG. 6 shows an embodiment of the device partly in front elevation, partly in cross-section taken on the line VI--VI in FIG. 5,
FIG. 7 shows the drive mechanism of FIG. 2 on an enlarged scale together with the frame,
FIG. 8 shows the frame in side elevation on an enlarged scale,
FIG. 9 shows the frame in cross-section taken on the line IX--IX in FIG. 8,
FIG. 10 contains three diagrams representing the locking of the plungers, the pressure on the plungers, and the plunger speed, respectively, seen over a full machine cycle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device 1 diagrammatically depicted in FIG. 1 comprises a mold 3 comprising of an upper mold part 5 and a lower mold part 7 with mold cavities 9 which, when the mold is closed, are in connection with plunger pots 13, which are provided in the upper mold part 5, via injection gates 11. The lower mold part 7 rests on a mold block 15 in which conventional components of the drive for displacing the lower mold part 7 relative to the upper mold part for closing and opening the mold 3, are accommodated (not shown). Plungers 17, which can slide in the plunger pots 13, are coupled by means of coupling elements 19 to a frame 21 which is movable relative to the mold 3 and which comprises a lever mechanism 23 consisting mainly of a number of levers 25 (only one of which is shown) which with one end are rotatably mounted to a common pivot shaft 27 which is fastened to the frame 21. The other free end of each of the levers 25 is loaded by a corresponding spring 29 which presses the lever at the end against a stop block 31 of the frame 21. The levers 25 cooperate with the plungers 17 by means of a pressure element 33 on a corresponding lever central portion. The plastic pellets to be processed are indicated with the reference design at C. Heating of the mold 3 and fusion of the pellets C while the mold is closed take place in a conventional manner by heating means to be explained below.
FIG. 2 diagrammatically shows the drive mechanism 35 for displacing the frame 21 and the plungers 17. This drive mainly comprises a housing 36 with a threaded-spindle mechanism 37 consisting of a threaded spindle 39 which is driven by an electric motor 41 via a pinion in a gear 45. The threaded-spindle mechanism 37 can be readily controlled, force and speed being susceptible to a very accurate control by means of a servo system.
FIGS. 3 and 4 diagrammatically show the operation of the locking mechanism according to the invention. The locking mechanism 47 shown comprises mainly a locking bar 49 and sliding locks 51 which are provided with sliding capability on the frame 21 between the locking bar 49 and the levers 25. The locking bar 49 is provided with recesses 53 and elevations 55 and is transversely slidable from left to right in the drawing figure between a locking position as shown in FIG. 3 and an idle position, FIG. 4. FIG. 3 shows the locking bar 49 in the locking position, whereby the locking bar 49 with its elevations 55 bears on the sliding locks 51 and thereby presses the levers 25 against the stop block 31, thus locking them. The springs 29, which act directly upon the levers 25, are inoperational, so that the plungers 17 during the transfer stroke are rigidly coupled to the frame 21, while the levers 25 cooperate with collars 18 on the plungers 17 via the pressure elements 33 (FIG. 1). As was explained in more detail above, operations take place with the plungers 17 in this locked position during this first phase of the molding cycle, the transfer phase, during which all plungers are displaced with the same relatively high, controlled speed.
FIG. 4 shows the locking bar 49 in the idle position, whereby the sliding locks 51 come into a free position at the level of the recesses 53, so that the plungers 17 are no longer rigidly coupled to the frame 21 and come under the influence of the springs 29, which lie behind the sliding locks 51 as seen in the drawing and act directly on the levers 25, as will be explained further below. As was described above, in this second phase of the molding cycle, the curing phase, pressure is exerted with the unlocked plungers under spring load, the same force being exerted on all plungers. For the purpose of switching over from the first phase to the second phase through shifting of the locking bar 49 from the locking position into the idle position, the pressure is momentarily removed from the plungers, so that the locking bar 49 can be easily shifted.
As is shown in FIG. 1, the bifurcated coupling elements 19 enclose a neck portion 20 on the plungers 17 below the collar 18. The length of the difurcation groove of elements 19 is greater than the thickness of the coupling elements 19, so that a relative displacement of the coupling elements 19 and the plungers 17 is possible. Differences between the plastic volumes in the plunger pots and between the pressures on the plungers during the curing phase can be compensated through relative displacements of the plungers 17 to the coupling elements 19, during which phase the plungers 17 are loaded by the springs 29.
FIGS. 5 and 6 show the device 1 of the multiplunger type with the upper mold part 5, the lower mold part 7, a lower mold part block 57 and with an upper mold part block 59 with plunger pots 13 positioned next to one another in line in longitudinal direction of the mold block. The two mold blocks 57 and 59 comprise heaters 61 for heating the mold 3, to a temperature between 170° C. and 200° C. usual in practice. The reference numeral 63 denotes a support block which forms part of a drive mechanism (not shown) for displacement of the lower mold part 7 relative to the upper mold part 5 for closing and opening the mold 3. The plunger pots 13 extend to inside a plunger block 65 provided with guides 67 for the plungers 17 and with a duct 69 running in the longitudinal direction of the plunger block through which duct the plastic pellets to be processed can be introduced into the plunger pots 13; any suitable feed device may be used for this. Further components are of a conventional nature and will not be explained any further.
FIG. 7 shows the drive mechanism 35 with the threaded-spindle mechanism 37 consisting of threaded spindle 39, electric motor 41, pinion 43, and gear 45. The numeral 71 denotes a straight guide for two crossbeams 73 which are coupled to the frame 21 via rods 75. The frame 21 will be explained further with reference to FIGS. 8 and 9. These FIGS. show the frame 21 with the lever mechanism 23 comprising the pivot shaft 27 with the levers 25, the springs 29, the stop block 31, and the pressure elements 33. The locking mechanism 47 comprises the locking bar 49 with the recesses 53 and the elevations 55 which in the embodiment shown can be shifted by a pneumatic mechanism 77. Guiding elements 49 serve to guide the locking bar 49 during the shifting movements. Numeral 51 denotes the sliding locks which are pressed against the levers 25 by means of springs 81. The springs 81 are fixed with their ends on pins 83 on the sliding locks 51 and on pins 85 on the frame 21. Guiding bars 87 for guiding the sliding locks 51 are mounted on the frame 21. The reference numeral 89 indicates set screws which serve to set the pre-compression of the springs 29.
In FIG. 10, diagram a indicates the locking of a plunger, diagram b the pressure on the plunger, and diagram c the plunger speed, seen over a full machine cycle.
Legend
T0 machine cycle start; start of transfer phase; start of plunger movement;
T1 plunger enters plunger pot;
T2 plunger hits pellet;
T3 end of transfer phase; start of curing phase;
T4 end of curing phase;
T R lifting of pressure from plunger;
T5 mold opens;
T6 plunger returns to initial position;
T0 end of machine cycle; start of new transfer phase.
It is clear from diagram a that the locking mechanism is in the operational position I from the beginning T0 up to the end T3 of the transfer phase, and that it is in the idle position 0 during the remainder of the machine cycle.
Diagram b mainly shows the constant pressure P MAX on the plunger during the curing phase, from the end of the transfer phase T3 to shortly before T R , the lifting of the pressure from the plunger. During molding of the pellets from T2 to T3, pressure fluctuations occur caused by unequal fusion of the pellets, differences in pellet volumes, inhomogeneous viscosity of the fused plastic material, etc.
Finally, diagram c shows the constant speed V T of the plunger during the transfer phase from T0 to T3, whereas during the curing phase, T3 to T R , the speed of the then stationary plunger has fallen to zero.
The operation of the device was explained above. The device according to the invention is mainly meant for encapsulating semiconductors and integrated circuits. It will be obvious that the device may also be used for encapsulating other products.
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A device for simultaneously encapsulating a number of electronic components is provided with a locking mechanism in which a molding cycle has two phases, i.e. in a first transfer phase, during which plungers for injecting molten resin into encapsulation cavities are locked and driven at a high, controlled speed, followed by a second curing phase, during which the plungers are spring-loaded, unlocked, and stationary, and are subject to the same maximum pressure of the transfer phase. In this way damage to the products is prevented, while the cycle time is reduced and the products obtained have an even and smooth appearance.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light emitting diode module, more particularly to a light emitting diode module having a latching component for conveniently installing the light emitting diode thereon or unloading the light emitting diode therefrom.
2. Description of Related Art
A light emitting diode (LED) is a device for transforming electricity into light. When a current flows through a junction comprising two different semiconductors, electrons and holes combine to generate light. LEDs are small, inexpensive, with low power requirements and an extremely long working lifetime under specific conditions; more and more LED modules with different capabilities are being developed. However, the LEDs are sensitive to temperature and may be permanently damaged by excessive temperatures. High temperature performance of LEDs is an adverse aspect of LED technology that has not been satisfactorily resolved. As the LEDs are used for a long time and more power is added to the LEDs, heat generated by the LEDs must be quickly removed therefrom to prevent them from becoming unstable or being damaged. Accordingly, LED modules with heat dissipation devices are needed.
Generally, the LED modules have thermal management components with good heat dissipation qualities. Usually, the LED usually has a smaller volume and it is different to secure the LED to the thermal management component.
What is needed, therefore, is an LED module having a latching component for conveniently installing the LED thereto or unloading the LED therefrom.
SUMMARY OF THE INVENTION
An LED module includes a latching component, a frame holding an LED thereon, a heat spreader located in the latching component and a heat transfer member having a heat-dissipating unit remote from the LED and a heat pipe thermally connecting the heat spreader, the LED and the heat-dissipating unit together. The latching component cooperates with the heat spreader to tightly press the frame to be attached on the heat spreader. The heat transfer member thermally connects with the heat spreader and transfers heat from the LED to an ambient environment. The latching component has two spring pieces fixed therein. The two spring pieces are electrically connected with a power source. Furthermore, the two spring pieces push the frame toward the heat pipe and the heat spreader and electrically connect with the frame and the LED.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is an exploded, schematic view of an LED module in accordance with a preferred embodiment of the present invention;
FIG. 2 is an enlarged rear end view of a latching component of the LED module of FIG. 1 ;
FIG. 3 is an assembled view of FIG. 1 ; and
FIG. 4 is an enlarged, partial view of FIG. 3 with a part thereof being cut away.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-4 , an LED module in accordance with a preferred embodiment of the present invention comprises a latching component 10 , a frame 20 mounting an LED 800 thereon and located in the latching component 10 , a heat spreader 30 attached to the frame 20 and a heat-transfer member having a heat pipe 40 and a heat-dissipating unit 50 . The heat pipe 40 thermally connects the frame 20 with the heat-dissipating unit 50 .
The latching component 10 is made of elastic plastic and has a cylindrical configuration. The latching component 10 comprises a cylindrical body 110 . The body 110 has a top surface 120 on a front end portion thereof and a rear end portion (not labeled) opposite the front end portion. A round opening 122 is defined in a center of the top surface 120 for offering the LED 800 an exit so that the LED 800 is exposed over the top surface 120 of the body 110 . Three elastic legs 130 are extended from an edge of the rear end portion of the body 110 and are evenly spaced from each other along a circumference of the body 110 . Each leg 130 comprises a position portion 132 extending from an edge of the rear end portion of the body 110 and a hooked portion 134 extending inwardly from the position portion 132 and having an acute angle to the position portion 132 . A pair of spring pieces 140 are formed on an inner surface of the top surface 120 of the body 110 . Each spring piece 140 comprises a strip-shaped body 142 and a pair of fixed claws 144 extending from two opposite end portions of the strip-shaped body 142 . The fixed claws 144 are upwardly and outwardly curved to be parallel to the body 142 and each defines a hole 146 therein. A pair of projections 148 are formed on the inner surface of the top surface 120 of the body 110 and engaged in the holes 146 of the fixed claws 144 of each spring piece 140 to position the spring piece 140 on the inner surface of the body 110 of the latching component 10 .
The frame 20 has a round plate 200 , such as a printed circuit board and the LED 800 is electrically connected to the frame 20 to emit light. The frame 20 comprises a top surface on which the LED 800 is mounted and a bottom surface on an opposite side to the top surface. Three pins 210 (only one shown) are formed on the bottom surface of the frame 20 .
Since the LED 800 inherently has a too small surface available to sufficiently transfer heat therefrom, the heat transfer member is used to transfer the heat to a place where it can be dissipated. The heat pipe 40 and the heat-dissipating unit 50 can satisfy this demand. Firstly, the heat spreader 30 is used to spread the heat from the LED 800 . The heat spreader 30 can be made of aluminum or copper. The heat spreader 30 has a cylindrical body 300 with a hollow cylindrical portion in a center thereof. A circular passage 310 is defined through the center of the heat spreader 30 . Three slots 320 are defined in an outer surface and along an axial direction of the body 300 of the heat spreader 30 , corresponding to the legs 130 of the latching component 10 . The three slots 320 divide the circumference of the body 300 of the heat spreader 30 into three equal parts. Three positioning holes 322 are defined in a front-end portion of the body 300 of the heat spreader 30 and corresponding to the pins 210 of the frame 20 .
The heat pipe 40 has an evaporating section 42 engaged in the passage 310 of the heat spreader 30 , and a condensing section 44 perpendicular to the evaporating section 42 and inserted through the heat-dissipating unit 50 . The heat-dissipating unit 50 comprises a plurality of metallic fins 52 . The fins 52 are parallel to and separate from each other. A through hole (not shown) is defined in a center of the heat-dissipating unit 50 , transversely extending though all of the fins 52 . The evaporating section 42 and the condensing section 44 of the heat pipe 40 are fixed in the passage 310 of the heat spreader 30 and the through hole of the heat-dissipating unit 50 respectively by soldering; accordingly, the condensing section 44 of the heat pipe 40 is thermally engaged with the metallic fins 52 , and the evaporating section 42 of the heat pipe 40 is thermally engaged with the heat spreader 30 . The heat pipe 40 is preferably included to quickly transfer the heat from the LED 800 to the heat-dissipating unit 50 which can be arranged at a location remote from the LED 800 and can have a large heat-dissipating surface available to facilitate heat dissipation.
In assembly, the evaporating section 42 of the heat pipe 40 extends in the passage 310 of the heat spreader 30 by soldering and a front end of the evaporating section 42 projects out from the passage 310 so as to absorb the heat from the LED 800 quickly. The pins 210 of the frame 20 are inserted and positioned in the positioning holes 322 of the front end portion of the body 300 of the heat spreader 30 . The bottom surface of the frame 20 is attached on the top surface of the evaporating section 42 of the heat pipe 40 . The latching component 10 covers the heat spreader 30 and the legs 130 of the latching component 10 slide along the slots 320 of the heat spreader 30 until the hooked portions 134 of the legs 130 exert spring forces to clasp and engage a rear end portion of the heat spreader 30 . Accordingly, the latching component 10 is secured to the spreader 30 by the hooked portions 134 engaging the rear end portion of the heat spreader 30 . As the legs 130 of the latching component 10 engage the heat spreader 30 to exert the latching forces thereon, the bodies 142 of the spring pieces 140 of the latching component 10 also exert spring forces to press the frame 20 to be tightly attached to the heat spreader 30 , and the frame 20 is thus tightly sandwiched between the latching component 10 and the heat spreader 30 . The bodies 142 resiliently engage with positive and negative electrodes 220 on the round plate 200 , whereby the spring pieces 140 are electrically connected with the round plate 200 and the LED 800 . Wires (not show) which are connected to a power source can be extended through two holes 150 (only one shown) defined in a periphery of the latching component 10 to electrically connect with the spring pieces 140 . Thus, the round plate 200 and the LED 800 are electrically connected with the power source via the spring pieces 140 .
In operation, the evaporating section 42 of the heat pipe 40 absorbs the heat from the LED 800 . A minor part of the heat is conducted to the heat spreader 30 by the evaporating section 42 of the heat pipe 40 and a major part of the heat is directly transferred to the fins 52 of the heat-dissipating unit 50 ; the heat from the LED 800 is thus quickly removed to avoid a high temperature performance of the LED 800 and ensure that the LED 800 operates at a normal working temperature. Furthermore, the heat pipe 40 transfers the heat generated by the LED 800 to the heat-dissipating unit 50 which is located at a location remote from the LED 800 and thus has a large heat-dissipating surface available to facilitate heat dissipation.
In the preferred embodiment of the present invention, the frame 20 is sandwiched between the latching component 10 and the heat spreader 30 . The frame 20 is secured on the heat spreader 30 by the legs 130 of the latching component 10 clasping on the heat spreader 30 and it is convenient for installing/unloading the LED 800 to/from the heat spreader 30 . Moreover, the heat spreader 30 is located in the latching component 10 to be coupled as a unit, which is very advantageous in view of the compact size and portable requirement of heat dissipation devices with the LEDs.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples here described merely being preferred or exemplary embodiments of the invention.
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An LED module includes a latching component, a frame holding an LED thereon, a heat spreader located in the latching component and a heat transfer member having a heat-dissipating unit remote from the LED and a heat pipe thermally connecting with the heat spreader, the LED and the heat-dissipating unit. The latching component cooperates with the heat spreader to tightly press the frame being attached on the heat spreader. The heat transfer member thermally connects with the heat spreader and transfers heat from the LED to an ambient environment. The latching component has two spring pieces pushing the frame toward the heat spreader and the heat pipe. The spring pieces electrically engage with the frame to thereby electrically connect with the LED.
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CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation of U.S. application Ser. No. 11/149,389 filed on Jun. 10, 2005, which is a continuation of U.S. application Ser. No. 10/856,863 filed Jun. 1, 2004, now issued as U.S. Pat. No. 6,913,344, which is a continuation of U.S. application Ser. No. 10/102,697 filed on Mar. 22, 2002, now issued as U.S. Pat. No. 6,742,871, all of which are herein incorporated by reference.
CO-PENDING APPLICATIONS
Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending granted patents/applications filed by the applicant or assignee of the present invention:
6428133
6526658
6795215
7154638
The disclosures of these co-pending granted patents/applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The following invention relates to a printhead assembly having a flexible printed circuit board to provide power and data to individual printhead modules in a printer.
More particularly, though not exclusively, the invention relates to a printhead assembly having a flexible printed circuit board for providing data and power connections to individual printhead modules in an A4 pagewidth drop on demand printhead capable of printing up to 1600 dpi photographic quality at up to 160 pages per minute. The flexible printed circuit board also has associated therewith a pair of busbars for carrying the power thereto.
The overall design of a printer in which the assembly can be utilized revolves around the use of replaceable printhead modules in an array approximately 8½ inches (21 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a “Memjet” chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, might be other MEMS print chips.
In a typical embodiment, eleven “Memjet” tiles can butt together in a metal channel to form a complete 8½ inch printhead assembly.
The printhead, being the environment within which the assembly of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative. An air pump would supply filtered air through a seventh chamber to the printhead, which could be used to keep foreign particles away from its ink nozzles.
Each printhead module receives ink via an elastomeric extrusion that transfers the ink. Typically, the printhead assembly is suitable for printing A4 paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a printer assembly having a flexible printed circuit board and busbars for delivering power and data to printhead modules of the assembly.
It is a further object of the present invention to provide an improved printhead assembly.
SUMMARY OF THE INVENTION
The present invention provides a printhead assembly for a pagewidth drop on demand ink jet printer, comprising:
an array of printhead modules extending substantially across said pagewidth,
a flexible printed circuit board carrying data and power to said modules, the flexible printed circuit board also extending substantially across said pagewidth,
a pair of busbars electrically connected to the flexible printed circuit board and carrying power thereto, the busbars also extending substantially across said pagewidth.
Preferably said busbars are soldered to said flexible printed circuit board.
Preferably said flexible printed circuit board contacts individual fine pitch flex PCBs on each printhead module.
Preferably said flexible printed circuit board has a series of gold plated, domed contacts which interface with contact pads on said fine pitch flex PCBs.
Preferably the flexible printed circuit board extends from one end of the assembly for data connection.
Preferably said printhead modules are fixed to an elongate channel and an elastomeric ink delivery extrusion is situated between the modules and the channel and the flexible printed circuit board is sandwiched between the elastomeric ink delivery extrusion and the channel and extends around one edge of the extrusion to carry power and data to the printhead modules.
Preferably the busbars are situated between the flexible printed circuit board and the elastomeric ink delivery extrusion.
Preferably said gold plated, domed contacts and said contact pads are located alongside said printhead modules and are biased into mutual contact by a resilient force exerted thereon by said channel.
Preferably said flexible printed circuit board is bonded to the channel.
As used herein, the term “ink” is intended to mean any fluid which flows through the printhead to be delivered to print media. The fluid may be one of many different colored inks, infra-red ink, a fixative or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:
FIG. 1 is a schematic overall view of a printhead;
FIG. 2 is a schematic exploded view of the printhead of FIG. 1 ;
FIG. 3 is a schematic exploded view of an ink jet module;
FIG. 3 a is a schematic exploded inverted illustration of the ink jet module of FIG. 3 ;
FIG. 4 is a schematic illustration of an assembled ink jet module;
FIG. 5 is a schematic inverted illustration of the module of FIG. 4 ;
FIG. 6 is a schematic close-up illustration of the module of FIG. 4 ;
FIG. 7 is a schematic illustration of a chip sub-assembly;
FIG. 8 a is a schematic side elevational view of the printhead of FIG. 1 ;
FIG. 8 b is a schematic plan view of the printhead of FIG. 8 a;
FIG. 8 c is a schematic side view (other side) of the printhead of FIG. 8 a;
FIG. 8 d is a schematic inverted plan view of the printhead of FIG. 8 b;
FIG. 9 is a schematic cross-sectional end elevational view of the printhead of FIG. 1 ;
FIG. 10 is a schematic illustration of the printhead of FIG. 1 in an uncapped configuration;
FIG. 11 is a schematic illustration of the printhead of FIG. 10 in a capped configuration;
FIG. 12 a is a schematic illustration of a capping device;
FIG. 12 b is a schematic illustration of the capping device of FIG. 12 a , viewed from a different angle;
FIG. 13 is a schematic illustration showing the loading of an ink jet module into a printhead;
FIG. 14 is a schematic end elevational view of the printhead illustrating the printhead module loading method;
FIG. 15 is a schematic cut-away illustration of the printhead assembly of FIG. 1 ;
FIG. 16 is a schematic close-up illustration of a portion of the printhead of FIG. 15 showing greater detail in the area of the “Memjet” chip;
FIG. 17 is a schematic illustration of the end portion of a metal channel and a printhead location molding;
FIG. 18 a is a schematic illustration of an end portion of an elastomeric ink delivery extrusion and a molded end cap; and
FIG. 18 b is a schematic illustration of the end cap of FIG. 18 a in an out-folded configuration.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 of the accompanying drawings there is schematically depicted an overall view of a printhead assembly. FIG. 2 shows the core components of the assembly in an exploded configuration. The printhead assembly 10 of the preferred embodiment comprises eleven printhead modules 11 situated along a metal “Invar” channel 16 . At the heart of each printhead module 11 is a “Memjet” chip 23 ( FIG. 3 ). The particular chip chosen in the preferred embodiment being a six-color configuration.
The “Memjet” printhead modules 11 are comprised of the “Memjet” chip 23 , a fine pitch flex PCB 26 and two micromoldings 28 and 34 sandwiching a mid-package film 35 . Each module 11 forms a sealed unit with independent ink chambers 63 ( FIG. 9 ) which feed the chip 23 . The modules 11 plug directly onto a flexible elastomeric extrusion 15 which carries air, ink and fixitive. The upper surface of the extrusion 15 has repeated patterns of holes 21 which align with ink inlets 32 ( FIG. 3 a ) on the underside of each module 11 . The extrusion 15 is bonded onto a flex PCB (flexible printed circuit board).
The fine pitch flex PCB 26 wraps down the side of each printhead module 11 and makes contact with the flex PCB 17 ( FIG. 9 ). The flex PCB 17 carries two busbars 19 (positive) and 20 (negative) for powering each module 11 , as well as all data connections. The flex PCB 17 is bonded onto the continuous metal “Invar” channel 16 . The metal channel 16 serves to hold the modules 11 in place and is designed to have a similar coefficient of thermal expansion to that of silicon used in the modules.
A capping device 12 is used to cover the “Memjet” chips 23 when not in use. The capping device is typically made of spring steel with an onsert molded elastomeric pad 47 ( FIG. 12 a ). The pad 47 serves to duct air into the “Memjet” chip 23 when uncapped and cut off air and cover a nozzle guard 24 ( FIG. 9 ) when capped. The capping device 12 is actuated by a camshaft 13 that typically rotates throughout 180°.
The overall thickness of the “Memjet” chip is typically 0.6 mm which includes a 150 micron inlet backing layer 27 and a nozzle guard 24 of 150 micron thickness. These elements are assembled at the wafer scale.
The nozzle guard 24 allows filtered air into an 80 micron cavity 64 ( FIG. 16 ) above the “Memjet” ink nozzles 62 . The pressurized air flows through microdroplet holes 45 in the nozzle guard 24 (with the ink during a printing operation) and serves to protect the delicate “Memjet” nozzles 62 by repelling foreign particles.
A silicon chip backing layer 27 ducts ink from the printhead module packaging directly into the rows of “Memjet” nozzles 62 . The “Memjet” chip 23 is wire bonded 25 from bond pads on the chip at 116 positions to the fine pitch flex PCB 26 . The wire bonds are on a 120 micron pitch and are cut as they are bonded onto the fine pitch flex PCB pads ( FIG. 3 ). The fine pitch flex PCB 26 carries data and power from the flex PCB 17 via a series of gold contact pads 69 along the edge of the flex PCB.
The wire bonding operation between chip and fine pitch flex PCB 26 may be done remotely, before transporting, placing and adhering the chip assembly into the printhead module assembly. Alternatively, the “Memjet” chips 23 can be adhered into the upper micromolding 28 first and then the fine pitch flex PCB 26 can be adhered into place. The wire bonding operation could then take place in situ, with no danger of distorting the moldings 28 and 34 . The upper micromolding 28 can be made of a Liquid Crystal Polymer (LCP) blend. Since the crystal structure of the upper micromolding 28 is minute, the heat distortion temperature (180° C.-260° C.), the continuous usage temperature (200° C.-240° C.) and soldering heat durability (260° C. for 10 seconds to 310° C. for 10 seconds) are high, regardless of the relatively low melting point.
Each printhead module 11 includes an upper micromolding 28 and a lower micromolding 34 separated by a mid-package film layer 35 shown in FIG. 3 .
The mid-package film layer 35 can be an inert polymer such as polyimide, which has good chemical resistance and dimensional stability. The mid-package film layer 35 can have laser ablated holes 65 and can comprise a double-sided adhesive (ie. an adhesive layer on both faces) providing adhesion between the upper micromolding, the mid-package film layer and the lower micromolding.
The upper micromolding 28 has a pair of alignment pins 29 passing through corresponding apertures in the mid-package film layer 35 to be received within corresponding recesses 66 in the lower micromolding 34 . This serves to align the components when they are bonded together. Once bonded together, the upper and lower micromoldings form a tortuous ink and air path in the complete “Memjet” printhead module 11 .
There are annular ink inlets 32 in the underside of the lower micromolding 34 . In a preferred embodiment, there are six such inlets 32 for various inks (black, yellow, magenta, cyan, fixitive and infrared). There is also provided an air inlet slot 67 . The air inlet slot 67 extends across the lower micromolding 34 to a secondary inlet which expels air through an exhaust hole 33 , through an aligned hole 68 in fine pitch flex PCB 26 . This serves to repel the print media from the printhead during printing. The ink inlets 32 continue in the undersurface of the upper micromolding 28 as does a path from the air inlet slot 67 . The ink inlets lead to 200 micron exit holes also indicated at 32 in FIG. 3 . These holes correspond to the inlets on the silicon backing layer 27 of the “Memjet” chip 23 .
There is a pair of elastomeric pads 36 on an edge of the lower micromolding 34 . These serve to take up tolerance and positively located the printhead modules 11 into the metal channel 16 when the modules are micro-placed during assembly.
A preferred material for the “Memjet” micromoldings is a LCP. This has suitable flow characteristics for the fine detail in the moldings and has a relatively low coefficient of thermal expansion.
Robot picker details are included in the upper micromolding 28 to enable accurate placement of the printhead modules 11 during assembly.
The upper surface of the upper micromolding 28 as shown in FIG. 3 has a series of alternating air inlets and outlets 31 . These act in conjunction with the capping device 12 and are either sealed off or grouped into air inlet/outlet chambers, depending upon the position of the capping device 12 . They connect air diverted from the inlet slot 67 to the chip 23 depending upon whether the unit is capped or uncapped.
A capper cam detail 40 including a ramp for the capping device is shown at two locations in the upper surface of the upper micromolding 28 . This facilitates a desirable movement of the capping device 12 to cap or uncap the chip and the air chambers. That is, as the capping device is caused to move laterally across the print chip during a capping or uncapping operation, the ramp of the capper cam detail 40 serves to elastically distort and capping device as it is moved by operation of the camshaft 13 so as to prevent scraping of the device against the nozzle guard 24 .
The “Memjet” chip assembly 23 is picked and bonded into the upper micromolding 28 on the printhead module 11 . The fine pitch flex PCB 26 is bonded and wrapped around the side of the assembled printhead module 11 as shown in FIG. 4 . After this initial bonding operation, the chip 23 has more sealant or adhesive 46 applied to its long edges. This serves to “pot” the bond wires 25 ( FIG. 6 ), seal the “Memjet” chip 23 to the molding 28 and form a sealed gallery into which filtered air can flow and exhaust through the nozzle guard 24 .
The flex PCB 17 carries all data and power connections from the main PCB (not shown) to each “Memjet” printhead module 11 . The flex PCB 17 has a series of gold plated, domed contacts 69 ( FIG. 2 ) which interface with contact pads 41 , 42 and 43 on the fine pitch flex PCB 26 of each “Memjet” printhead module 11 .
Two copper busbar strips 19 and 20 , typically of 200 micron thickness, are jigged and soldered into place on the flex PCB 17 . The busbars 19 and 20 connect to a flex termination which also carries data.
The flex PCB 17 is approximately 340 mm in length and is formed from a 14 mm wide strip. It is bonded into the metal channel 16 during assembly and exits from one end of the printhead assembly only.
The metal U-channel 16 into which the main components are place is of a special alloy called “Invar 36 ”. It is a 36% nickel iron alloy possessing a coefficient of thermal expansion of 1/10 th that of carbon steel at temperatures up to 400° F. The Invar is annealed for optimal dimensional stability.
Additionally, the Invar is nickel plated to a 0.056% thickness of the wall section. This helps to further match it to the coefficient of thermal expansion of silicon which is 2×10 −6 per ° C.
The Invar channel 16 functions to capture the “Memjet” printhead modules 11 in a precise alignment relative to each other and to impart enough force on the modules 11 so as to form a seal between the ink inlets 32 on each printhead module and the outlet holes 21 that are laser ablated into the elastomeric ink delivery extrusion 15 .
The similar coefficient of thermal expansion of the Invar channel to the silicon chips allows similar relative movement during temperature changes. The elastomeric pads 36 on one side of each printhead module 11 serve to “lubricate” them within the channel 16 to take up any further lateral coefficient of thermal expansion tolerances without losing alignment. The Invar channel is a cold rolled, annealed and nickel plated strip. Apart from two bends that are required in its formation, the channel has two square cutouts 80 at each end. These mate with snap fittings 81 on the printhead location moldings 14 ( FIG. 17 ).
The elastomeric ink delivery extrusion 15 is a non-hydrophobic, precision component. Its function is to transport ink and air to the “Memjet” printhead modules 11 . The extrusion is bonded onto the top of the flex PCB 17 during assembly and it has two types of molded end caps. One of these end caps is shown at 70 in FIG. 18 a.
A series of patterned holes 21 are present on the upper surface of the extrusion 15 . These are laser ablated into the upper surface. To this end, a mask is made and placed on the surface of the extrusion, which then has focused laser light applied to it. The holes 21 are evaporated from the upper surface, but the laser does not cut into the lower surface of extrusion 15 due to the focal length of the laser light.
Eleven repeated patterns of the laser ablated holes 21 form the ink and air outlets 21 of the extrusion 15 . These interface with the annular ring inlets 32 on the underside of the “Memjet” printhead module lower micromolding 34 . A different pattern of larger holes (not shown but concealed beneath the upper plate 71 of end cap 70 in FIG. 18 a ) is ablated into one end of the extrusion 15 . These mate with apertures 75 having annular ribs formed in the same way as those on the underside of each lower micromolding 34 described earlier. Ink and air delivery hoses 78 are connected to respective connectors 76 that extend from the upper plate 71 . Due to the inherent flexibility of the extrusion 15 , it can contort into many ink connection mounting configurations without restricting ink and air flow. The molded end cap 70 has a spine 73 from which the upper and lower plates are integrally hinged. The spine 73 includes a row of plugs 74 that are received within the ends of the respective flow passages of the extrusion 15 .
The other end of the extrusion 15 is capped with simple plugs which block the channels in a similar way as the plugs 74 on spine 17 .
The end cap 70 clamps onto the ink extrusion 15 by way of snap engagement tabs 77 . Once assembled with the delivery hoses 78 , ink and air can be received from ink reservoirs and an air pump, possibly with filtration means. The end cap 70 can be connected to either end of the extrusion, ie. at either end of the printhead.
The plugs 74 are pushed into the channels of the extrusion 15 and the plates 71 and 72 are folded over. The snap engagement tabs 77 clamp the molding and prevent it from slipping off the extrusion. As the plates are snapped together, they form a sealed collar arrangement around the end of the extrusion. Instead of providing individual hoses 78 pushed onto the connectors 76 , the molding 70 might interface directly with an ink cartridge. A sealing pin arrangement can also be applied to this molding 70 . For example, a perforated, hollow metal pin with an elastomeric collar can be fitted to the top of the inlet connectors 76 . This would allow the inlets to automatically seal with an ink cartridge when the cartridge is inserted. The air inlet and hose might be smaller than the other inlets in order to avoid accidental charging of the airways with ink.
The capping device 12 for the “Memjet” printhead would typically be formed of stainless spring steel. An elastomeric seal or onsert molding 47 is attached to the capping device as shown in FIGS. 12 a and 12 b . The metal part from which the capping device is made is punched as a blank and then inserted into an injection molding tool ready for the elastomeric onsert to be shot onto its underside. Small holes 79 ( FIG. 13 b ) are present on the upper surface of the metal capping device 12 and can be formed as burst holes. They serve to key the onsert molding 47 to the metal. After the molding 47 is applied, the blank is inserted into a press tool, where additional bending operations and forming of integral springs 48 takes place.
The elastomeric onsert molding 47 has a series of rectangular recesses or air chambers 56 . These create chambers when uncapped. The chambers 56 are positioned over the air inlet and exhaust holes 30 of the upper micromolding 28 in the “Memjet” printhead module 11 . These allow the air to flow from one inlet to the next outlet. When the capping device 12 is moved forward to the “home” capped position as depicted in FIG. 11 , these airways 32 are sealed off with a blank section of the onsert molding 47 cutting off airflow to the “Memjet” chip 23 . This prevents the filtered air from drying out and therefore blocking the delicate “Memjet” nozzles.
Another function of the onsert molding 47 is to cover and clamp against the nozzle guard 24 on the “Memjet” chip 23 . This protects against drying out, but primarily keeps foreign particles such as paper dust from entering the chip and damaging the nozzles. The chip is only exposed during a printing operation, when filtered air is also exiting along with the ink drops through the nozzle guard 24 . This positive air pressure repels foreign particles during the printing process and the capping device protects the chip in times of inactivity.
The integral springs 48 bias the capping device 12 away from the side of the metal channel 16 . The capping device 12 applies a compressive force to the top of the printhead module 11 and the underside of the metal channel 16 . The lateral capping motion of the capping device 12 is governed by an eccentric camshaft 13 mounted against the side of the capping device. It pushes the device 12 against the metal channel 16 . During this movement, the bosses 57 beneath the upper surface of the capping device 12 ride over the respective ramps 40 formed in the upper micromolding 28 . This action flexes the capping device and raises its top surface to raise the onsert molding 47 as it is moved laterally into position onto the top of the nozzle guard 24 .
The camshaft 13 , which is reversible, is held in position by two printhead location moldings 14 . The camshaft 11 can have a flat surface built in one end or be otherwise provided with a spline or keyway to accept gear 22 or another type of motion controller. The “Memjet” chip and printhead module are assembled as follows:
1. The “Memjet” chip 23 is dry tested in flight by a pick and place robot, which also dices the wafer and transports individual chips to a fine pitch flex PCB bonding area. 2. When accepted, the “Memjet” chip 23 is placed 530 microns apart from the fine pitch flex PCB 26 and has wire bonds 25 applied between the bond pads on the chip and the conductive pads on the fine pitch flex PCB. This constitutes the “Memjet” chip assembly. 3. An alternative to step 2 is to apply adhesive to the internal walls of the chip cavity in the upper micromolding 28 of the printhead module and bond the chip into place first. The fine pitch flex PCB 26 can then be applied to the upper surface of the micromolding and wrapped over the side. Wire bonds 25 are then applied between the bond pads on the chip and the fine pitch flex PCB. 4. The “Memjet” chip assembly is vacuum transported to a bonding area where the printhead modules are stored. 5. Adhesive is applied to the lower internal walls of the chip cavity and to the area where the fine pitch flex PCB is going to be located in the upper micromolding of the printhead module. 6. The chip assembly (and fine pitch flex PCB) are bonded into place. The fine pitch flex PCB is carefully wrapped around the side of the upper micromolding so as not to strain the wire bonds. This may be considered as a two step gluing operation if it is deemed that the fine pitch flex PCB might stress the wire bonds. A line of adhesive running parallel to the chip can be applied at the same time as the internal chip cavity walls are coated. This allows the chip assembly and fine pitch flex PCB to be seated into the chip cavity and the fine pitch flex PCB allowed to bond to the micromolding without additional stress. After curing, a secondary gluing operation could apply adhesive to the short side wall of the upper micromolding in the fine pitch flex PCB area. This allows the fine pitch flex PCB to be wrapped around the micromolding and secured, while still being firmly bonded in place along on the top edge under the wire bonds. 7. In the final bonding operation, the upper part of the nozzle guard is adhered to the upper micromolding, forming a sealed air chamber. Adhesive is also applied to the opposite long edge of the “Memjet” chip, where the bond wires become ‘potted’ during the process. 8. The modules are ‘wet’ tested with pure water to ensure reliable performance and then dried out. 9. The modules are transported to a clean storage area, prior to inclusion into a printhead assembly, or packaged as individual units. The completes the assembly of the “Memjet” printhead module assembly. 10. The metal Invar channel 16 is picked and placed in a jig. 11. The flex PCB 17 is picked and primed with adhesive on the busbar side, positioned and bonded into place on the floor and one side of the metal channel. 12. The flexible ink extrusion 15 is picked and has adhesive applied to the underside. It is then positioned and bonded into place on top of the flex PCB 17 . One of the printhead location end caps is also fitted to the extrusion exit end. This constitutes the channel assembly.
The laser ablation process is as follows:
13. The channel assembly is transported to an eximir laser ablation area. 14. The assembly is put into a jig, the extrusion positioned, masked and laser ablated. This forms the ink holes in the upper surface. 15. The ink extrusion 15 has the ink and air connector molding 70 applied. Pressurized air or pure water is flushed through the extrusion to clear any debris. 16. The end cap molding 70 is applied to the extrusion 15 . It is then dried with hot air. 17. The channel assembly is transported to the printhead module area for immediate module assembly. Alternatively, a thin film can be applied over the ablated holes and the channel assembly can be stored until required.
The printhead module to channel is assembled as follows:
18. The channel assembly is picked, placed and clamped into place in a transverse stage in the printhead assembly area. 19. As shown in FIG. 14 , a robot tool 58 grips the sides of the metal channel and pivots at pivot point against the underside face to effectively flex the channel apart by 200 to 300 microns. The forces applied are shown generally as force vectors F in FIG. 14 . This allows the first “Memjet” printhead module to be robot picked and placed (relative to the first contact pads on the flex PCB 17 and ink extrusion holes) into the channel assembly. 20. The tool 58 is relaxed, the printhead module captured by the resilience of the Invar channel and the transverse stage moves the assembly forward by 19.81 mm. 21. The tool 58 grips the sides of the channel again and flexes it apart ready for the next printhead module. 22. A second printhead module 11 is picked and placed into the channel 50 microns from the previous module. 23. An adjustment actuator arm locates the end of the second printhead module. The arm is guided by the optical alignment of fiducials on each strip. As the adjustment arm pushes the printhead module over, the gap between the fiducials is closed until they reach an exact pitch of 19.812 mm. 24. The tool 58 is relaxed and the adjustment arm is removed, securing the second printhead module in place. 25. This process is repeated until the channel assembly has been fully loaded with printhead modules. The unit is removed from the transverse stage and transported to the capping assembly area. Alternatively, a thin film can be applied over the nozzle guards of the printhead modules to act as a cap and the unit can be stored as required.
The capping device is assembled as follows:
26. The printhead assembly is transported to a capping area. The capping device 12 is picked, flexed apart slightly and pushed over the first module 11 and the metal channel 16 in the printhead assembly. It automatically seats itself into the assembly by virtue of the bosses 57 in the steel locating in the recesses 83 in the upper micromolding in which a respective ramp 40 is located. 27. Subsequent capping devices are applied to all the printhead modules. 28. When completed, the camshaft 13 is seated into the printhead location molding 14 of the assembly. It has the second printhead location molding seated onto the free end and this molding is snapped over the end of the metal channel, holding the camshaft and capping devices captive. 29. A molded gear 22 or other motion control device can be added to either end of the camshaft 13 at this point. 30. The capping assembly is mechanically tested.
Print charging is as follows:
31. The printhead assembly 10 is moved to the testing area. Inks are applied through the “Memjet” modular printhead under pressure. Air is expelled through the “Memjet” nozzles during priming. When charged, the printhead can be electrically connected and tested. 32. Electrical connections are made and tested as follows: 33. Power and data connections are made to the PCB. Final testing can commence, and when passed, the “Memjet” modular printhead is capped and has a plastic sealing film applied over the underside that protects the printhead until product installation.
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A modular printhead assembly has a plurality of printhead modules, a fluid delivery structure, and a flexible printed circuit board. Each printhead module has a printhead integrated circuit and a fluid distribution assembly. The modules are received by the fluid delivery structure which also supplies each module with fluid. The printed circuit board is sandwiched between the modules and the supply structure and carries power and data to the modules.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a national phase entry under 35 U.S.C. §371 of International Application No. PCT/SE2009/050152 filed Feb. 12, 2009, published in English, which claims priority from Swedish Application No. 0800475-6 filed Feb. 28, 2008, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a method of bleaching a pulp. More specifically, the present invention relates to a method of bleaching an oxygen delignified pulp, such as an oxygen delignified hardwood pulp, to a brightness of 88 to 92% ISO.
BACKGROUND OF THE INVENTION
In bleaching processes for both softwood and hardwood pulps, the pulps are normally delignified in one or more oxygen steps and thereafter bleached by means of various sequences comprising chlorine dioxide steps, extraction steps, peroxide steps, etc.
Hardwood pulps differ from softwood pulps in that they contain high amounts of Hexenuronic Acid (HexA). The amount of HexA depends on the raw material used and the cooking conditions. Modern methods of cooking, which utilize relatively low cooking temperatures, normally render high contents of HexA. HexA is oxidized by potassium permanganate (KMNO 4 ) and thereby contributes to the kappa number. In a hardwood pulp with a kappa value of 10, 50 to 70% of the kappa value could be a result of HexA and only 30 to 50% is attributed to lignin and other compounds.
During bleaching, HexA can be reduced by oxidation with bleaching chemicals such as chlorine dioxide and ozone. A more economical way to do so is to degrade HexA by means of acid hydrolysis at high temperature, which lowers the amount of double bonds in the remaining pulp. Therefore, a hot chlorine dioxide step (D HT ) is often accommodated in modern bleach plants. In this stage both oxidation and acid hydrolysis are performed. The high temperature in D HT can provide a reduction of the kappa number from for example 10.5 to 2.5. Hence, most of the reduction of the kappa number, typically 85 to 90%, is achieved in such a D HT -step and only a minor part, typically 10 to 15%, in a following extraction step (E). Moreover, it is believed that lignin is also degraded into smaller, more water soluble pieces during the D HT -step.
Swedish Patent No. 466,062 discloses a method of bleaching a chemical pulp in a sequence comprising at least four bleaching steps, with final bleaching in a first and a second chlorine dioxide step. Between the chlorine dioxide steps an alkaline extraction is carried out and washing takes place between the first chlorine dioxide step and extraction. Immediately after said washing step, NaOH is charged in an amount of 4 to 10 kg/ton pulp. Thereafter, an oxidizing agent is admixed in an amount of up to 2 kg/ton pulp. An acid is added for lowering the pH-value, but without effecting a complete neutralization of residual alkaline.
Swedish Patent No. 526,162 discloses a bleaching process for hardwood pulp wherein an oxygen-delignified and washed pulp is subjected to a chlorine dioxide bleaching step at high temperature, such as at least 90° C., and treated with a chelating agent without any intermediate wash. The pulp is thereafter washed and subjected to a pressurized peroxide bleaching step in which alkali is also added. The bleached pulp is finally washed in order to obtain a pulp with a brightness of 88 to 90% ISO.
International Application No. WO 02/075046 discloses a method for end bleaching of pulp comprising two chlorine dioxide steps. The pulp is washed and dewatered after the first chlorine dioxide step to a concentration of 12 to 50% in order to remove dissolved metal ions. Thereafter, alkali is added for extraction and rapid increase of the pH. Before the pulp is introduced into the second chlorine dioxide step, acid and chlorine are added to the pulp.
The previously known methods generally perform well, even though they may be fairly expensive or complex. Nonetheless, there remains a desire to further improve the bleaching, especially for hardwood pulps, and reduce the overall costs for the bleaching.
Hence, one object of the present invention is to provide a method for bleaching a hardwood pulp to a brightness of from about 88 to 92% ISO in a cost effective manner.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other objects have been realized by the invention of a method for bleaching an oxygen delignified and washed pulp having a consistency of between 8 and 20% comprising (i) subjecting the pulp to a first chlorine dioxide bleaching step to obtain a bleached pulp; (ii) washing the bleached pulp to obtain a washed pulp; (iii) subjecting the washed pulp at a consistency of between 8 and 20% to an alkaline extraction step to obtain an alkali-containing pulp; (iv) adding chlorine dioxide to the alkali-containing pulp and adjusting the pH in a second chlorine dioxide bleaching step to obtain a bleached alkali-containing pulp, wherein step (iv) is performed directly after step (iii) without any intermediate washing step; and (v) subjecting the bleached alkali-containing pulp to a peroxide treatment step directly after the second chlorine dioxide bleaching step.
In another embodiment, however, step (v) comprises subjecting the bleached alkali-containing pulp to an intermediate washing step prior to the peroxide bleach treatment step. Preferably, the method includes the first chlorine dioxide bleaching step being carried out at a temperature of between about 80 and 90° C. More preferably, the first chlorine dioxide bleaching step is carried out at a temperature of between about 85 and 95° C.
In accordance with one embodiment of the method of the present invention, the first chlorine dioxide bleaching step is carried out at a pH of between about 2 and 4.
In accordance with another embodiment of the method of the present invention, the washed pulp is subjected to an alkaline extraction step at a pH of between about 8 and 14. Preferably, the washed pulp is subjected to the alkaline extraction step at a pH of between about 9 and 12.
In accordance with another embodiment of the present invention, the pH is adjusted to an adjusted pH of between about 2 and 4.
In accordance with another embodiment of the apparatus of the present invention, the first chlorine dioxide bleaching step is carried out at a pH of between about 2.5 and 3.5.
In accordance with another embodiment of the method of the present invention, the washed pulp is subjected to the alkaline extraction step at a temperature of between about 75 and 85° C.
In accordance with another embodiment of the method of the present invention, the second chlorine dioxide bleaching step is carried out at a temperature of between about 75 and 90° C.
In accordance with another embodiment of the present invention, the pulp is a hardwood pulp or a eucalyptus based pulp.
The method of bleaching a pulp in accordance with the present invention comprises subjecting an oxygen delignified pulp to a hot chloride dioxide bleaching step at a temperature of 80 to 95° C. and a pH of 2 to 4 followed by washing. During the bleaching step, a substantial reduction of the kappa number will be accomplished. The pulp is thereafter subjected to an alkaline extraction step and a chlorine dioxide bleaching step integrated with said alkaline extraction step. In the present disclosure, integrated should be interpreted as following directly after the preceding step without any intermediate wash.
It has been determined that it is possible to obtain a brightness of more than 88% ISO when bleaching a hardwood pulp by means of the method according to the present invention. Furthermore, excellent reverted brightness can be achieved. The COD generation is also reduced compared to bleaching methods according to previous known methods used to obtain the same brightness. Moreover, the overall cost for bleaching a hardwood pulp is reduced as a consequence of lower chemical costs and/or lower investment costs for the bleaching plant, mainly as a result of fewer required washing steps.
Even though the method according to the present invention is intended for bleaching hardwood pulp, it is also believed to be suitable for bleaching softwood pulp.
DETAILED DESCRIPTION
In accordance with the present invention, an oxygen-delignified and washed pulp is subjected to a hot chlorine dioxide step (D HT ) in a reactor in order to reduce the kappa value to typically 3 or less. The hot chlorine dioxide step is performed at a temperature of 80 to 95° C., preferably 85-95° C., on a pulp having a consistency of 8 to 20%, preferably 8 to 15%, at a pH of 2 to 4, preferably pH 2.5 to 3.5, for a period of time sufficient to reduce the kappa number to the desired value. It should be noted that the time required for achieving the desired result depends on selected values of the parameters given above. However, the skilled person can easily determine the suitable period of time for the selected parameters by routine tests.
After the hot chlorine dioxide step the pulp is washed in accordance with conventional techniques, for example by using a wash-press or a dewatering-press, in order to remove the dissolved matter.
Alkali, for example in the form of a liquid containing NaOH, is thereafter added to the pulp in order to subject the pulp to an alkaline extraction step at a pH of 8 to 14, preferably pH 9 to 12, for a period of time sufficient to dissolve oxidized lignin. The consistency of the pulp should in this step be 8 to 20%, preferably 8 to 15%. The alkaline extraction step may suitably be performed at a temperature of 75 to 85° C. for 2-30 minutes, preferably 5 to 15 minutes.
Chlorine dioxide is added to the pulp directly after the alkaline extraction step, i.e. without any intermediate wash, and the pH of the pulp is adjusted to 2 to 4, preferably pH 2.5 to 4. This chlorine dioxide addition will subject the pulp to a second chlorine dioxide bleaching step. The temperature of the pulp should preferably be the same, or substantially the same, in this second bleaching step as in the alkaline extraction step. Since there is no washing step between the alkaline extraction step and the second chlorine dioxide bleaching step, these are considered to be integrated steps.
After the second bleaching step, the pulp may be subjected to a peroxide treatment. This may be performed directly after the second bleaching step, i.e. integrated with the alkaline extraction and chlorine dioxide bleaching step, or after an intermediate washing step. The peroxide treatment is performed at a temperature of from 75 to 90° C. for a period of time sufficient to accomplish the desired final brightness, such as 88 to 92% ISO, after subsequent wash of the pulp. It should be noted that the time required for achieving the desired result depends on the amount peroxide used and the temperature of the pulp given above, but can easily be determined by the skilled person by routine tests.
According to an alternative embodiment of the bleaching method of the present invention, the alkaline extraction step and the second chlorine dioxide bleaching step are repeated after an intermediate wash.
The amount of chemicals required in each step of the process according to the present invention to obtain the desired result can be easily determined by the skilled person by using common general knowledge within the field of bleaching or by mere routine tests.
It has been noted that by using a sequence comprising a hot chloride dioxide bleaching step followed by an integrated alkaline extraction and chlorine dioxide bleaching step in accordance with the present invention, it is possible to obtain a brightness of 89% ISO when bleaching a hardwood pulp. By repeating the integrated alkaline extraction and chlorine dioxide bleaching step in such a sequence, it is possible to obtain a brightness of about 92% ISO. Moreover, 92% ISO can also be obtained by using a sequence comprising a hot chloride dioxide bleaching step followed by an integrated alkaline extraction and chlorine dioxide bleaching step and a subsequent peroxide step in accordance with a preferred embodiment of the present invention.
The bleaching method according to the present invention has proven to be especially suitable for bleaching Eucalyptus-based pulps.
EXAMPLE 1
A sulphate pulp produced from Eucalyptus grandis wood was used for laboratory tests. The unbleached pulp had a kappa number of 18. After oxygen delignification, the pulp had a kappa number of 10.5, a viscosity of 1090 ml/g and a brightness of 65% ISO.
The pulp was bleached with two different sequences according to the invention, S inv1 and S inv2 , and two reference sequences, S Ref1 and S Ref2 . The sequences (S inv1 , S inv2 , S Ref1 , S Ref2 ) are listed below and the results are shown in Table 1.
S Ref1
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 2.6 for 150 minutes followed by washing Alkaline extraction step of the pulp at 12% consistency at 85° C. and pH 10.0 for 60 minutes followed by washing A second chlorine dioxide bleaching at a pulp consistency of 12%, a temperature of 75° C. and a pH of 3.5 to 3.9 for 120 minutes followed by washing A peroxide step at a pulp consistency of 12%, a temperature of 85° C. and a pH of 10.0 for 90 minutes followed by a final washing
S ref2
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 2.7 for 150 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 85° C. and pH 11.3 in the presence of 0.2 MPaO 2 and peroxide for 60 minutes followed by washing A second chlorine dioxide bleaching at a pulp consistency of 12%, a temperature of 75° C., and a pH of 3.7 to 3.9 for 120 minutes followed by washing
S inv1
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 2.5 for 150 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 80° C. and pH 10.5 for 10 minutes followed by addition of chlorine dioxide in order to achieve a chlorine dioxide bleaching at 80° C. for 30 minutes, and pH 3.1 to 3.5 Addition of peroxide to the pulp in order to achieve a peroxide step at 85° C. and pH 9.5-10 for 90 minutes
S inv2
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 2.7 for 180 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 80° C. and pH 10.5 for 10 minutes followed by addition of chlorine dioxide in order to achieve a chlorine dioxide bleaching at 80° C. and a pH of 3.1 to 3.5 for 30 minutes followed by washing Addition of peroxide to the pulp with 12% consistency in order to achieve a peroxide step at 85° C. and pH 10.0 for 90 minutes
The results show that it is possible to obtain a brightness of 90% ISO with the sequence S inv1 of the present invention at approximately the same chemical cost as the reference sequence S ref2 . However, the sequence S inv1 gives a much lower investment cost for a bleach plant, as it requires fewer washing steps. Furthermore, S inv1 also provides 0.5% ISO higher reverted brightness and 20% lower COD generation than S ref2 .
The alternative sequence S inv2 according to the present invention renders a lower chemical cost. Furthermore, it also provides 0.5% ISO higher reverted brightness and 15% lower COD generation than S ref2 .
S Ref1 has the lowest estimated chemical cost and a slightly higher reverted brightness than the sequence S ref2 . The COD generation is also lower than S ref2 but the investment cost for this four step sequences is substantially higher than for the sequences according to the present invention, S inv1 and S inv2 , due to the number of washers required.
TABLE 1
S Ref1
S Ref2
S inv1
S inv2
Brightness [% ISO]
90
90
90
90
Bleaching stages
4
3
2
3
Total time [min]
420
330
280
280
Washers
4
3
2
3
Bleached pulp
Rev. brightness [% ISO]
88.0
87.7
88.2
88.2
Viscosity [ml/g]
890
900
840
895
COD total [kg/odt]
24.8
26.1
20.5
22.0
Chemicals
ClO 2 [kg active Cl]
19
19.5
20.5
21.5
H 2 O 2 [kg/odt]
3
3
3
3
NaOH [kg/odt]
8.5
11
11.5
8.5
H 2 SO 4 [kg/odt]
3.0
4.0
6.0
5.5
MgSO 4 [kg/odt]
1.0
1
1.0
1.0
Oxygen [kg/odt]
—
4.0
—
—
Estimated chemical cost
14.5
16.5
16.8
15.7
[US$/odt]
EXAMPLE 2
A sulphate pulp produced by a wood mixture of 70% Eucalyptus nitens and 30% Eucalyptus globulus was used for laboratory tests. The pulp had, after oxygen delignification (in a processing plant) a kappa number of 8.6, a viscosity of 935 ml/g and a brightness of 64% ISO. The pulp was bleached according to two sequences according to the present invention, S inv3 and S inv4 , and one reference sequence S Ref3 .
The sequences (S inv3 , S inv4 and S Ref3 ) are listed below. The results for a brightness of 91% ISO are shown in Table 2 and the results for a reverted brightness of 89% ISO are shown in Table 3.
S Ref3
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 3.2 for 90 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 85° C. and pH 11.3 in the presence of 0.2 MPa O 2 and peroxide during 60 minutes followed by washing A second chlorine dioxide bleaching at a pulp consistency of 12%, a temperature of 60 to 75° C. and a pH of 2.9 to 3.7 for 120 minutes followed by washing
S inv3
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 3.3 for 90 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 80° C. and pH 11.4 for 10 minutes followed by addition of chlorine dioxide in order to achieve a chlorine dioxide bleaching at 80° C. and a pH of 3.0 to 3.9 for 30 minutes followed by washing Addition of peroxide to the pulp with 12% consistency in order to achieve a peroxide step at 80° C. and a pH of 11.2 to 11.5 for 60 minutes
S inv4
Chlorine dioxide bleaching of a pulp with 10% consistency at 90° C. and pH 3.3 for 90 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 80° C. and pH 11.4 for 10 minutes followed by addition of chlorine dioxide in order to achieve a chlorine dioxide bleaching at 80° C. and a pH of 3.0 to 3.9 for 30 minutes followed by washing An alkaline extraction step of the pulp at 12% consistency at 80° C. for 10 minutes followed by addition of chlorine dioxide in order to achieve a chlorine dioxide bleaching at 80° C. and a pH of 4.9 to 5 for 60 minutes followed by washing
TABLE 2
S inv3
S inv4
S Ref3
Brightness [% ISO]
91
91
91
Bleaching stages
3
3
3
Total time [min]
190
200
270
Washers
3
3
3
Bleached pulp
Rev brightness [% ISO]
89.0
88.3
88.1
Viscosity [ml/g]
830
820
850
COD total [kg/odt]
17
16
24
Chemicals
ClO 2 [kg active Cl]
22
28
23
H 2 O 2 [kg/odt]
5
—
3
NaOH [kg/odt]
11
10
11
H 2 SO 4 [kg/odt]
5
5
5
MgSO 4 [kg/odt]
1
0
1
Oxygen [kg/odt]
0
0
4
Estimated chemical cost
20.3
17.6
19.4
[US$/odt]
The results show that by utilizing the sequence S inv4 it is possible to obtain a brightness of 91% ISO at a 10% lower chemical cost and a 30% lower COD generation than with the reference S Ref3 . The sequences S inv4 and S Ref3 result in substantially the same reverted brightness and will result in approximately the same investment cost of a bleach plant.
The sequence S inv3 has a higher chemical cost but the investment cost of a bleach plant will be approximately the same as in the case of the reference S Ref3 . However, S inv3 results in a 0.9% higher reverted brightness and a 30% lower COD generation than the reference S Ref3 .
At a reverted brightness of 89% ISO, the sequences S inv3 and S inv4 showed 5% and 12% lower chemical cost, respectively, when compared to the reference S Ref3 .
TABLE 3
S inv3
S inv4
S Ref3
Rev. Brightness [% ISO]
89
89
89
Bleaching stages
3
3
3
Total time [min]
190
200
270
Washers
3
3
3
Bleached pulp
Brightness [% ISO]
91.0
91.5
91.6
Viscosity [ml/g]
835
820
845
Chemicals
ClO 2 [kg active Cl]
26
35
32
H 2 O 2 [kg/odt]
5
—
3
NaOH [kg/odt]
11
10
11
H 2 SO 4 [kg/odt]
5
5
5
MgSO 4 [kg/odt]
1
0
1
Oxygen [kg/odt]
0
0
4
Estimated chemical cost
20.3
18.7
21.3
[US$/odt]
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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Methods for bleaching oxygen delignified and washed pumps having a consistency of between 8 and 20% are disclosed including a first chlorine dioxide bleaching step, washing the bleached pulp, subjecting the washed pulp to an alkaline extraction step to obtain an alkali-containing pulp, adding chlorine dioxide and adjusting the pH in a second chlorine dioxide bleaching step performed directly after the alkaline extraction step without an intermediate washing step, and subjecting the bleached alkali-containing pulp to a peroxide treatment step directly after the second chlorine dioxide bleaching step or with an intermediate washing step prior to the peroxide treatment step.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to expansion valves of the type employed for controlling flow of refrigerant in refrigeration and air conditioning systems. Typically, in an air conditioning system, such as those employed for automotive passenger compartment cooling, an expansion valve throttles the flow of pressurized liquid refrigerant flowing from the condenser at relatively high pressures to provide relatively low pressure flow to an evaporator for heat absorption and return therefrom to the compressor inlet. In particular, expansion valves employed for controlling flow of liquid refrigerant to an evaporator in an automotive air conditioning system are of the type known as a "block" valve, wherein the valve body or block has a separate return flow passage provided therethrough in which vaporized refrigerant discharged from the evaporator flows to permit heat transfer therewith for control purposes.
Examples of such block type thermal expansion valves for automotive air conditioning use are those shown and described in U.S. Pat. No. 4,542,852, U.S. Pat. No. 5,269,459 and U.S. Pat. No. 5,547,126.
Heretofore, known thermal expansion valves have employed an actuator rod mechanism for moving a valve member and to expose the rod mechanism to the refrigerant flowing in the return passage to the compressor for heat transfer therebetween. It is also known to employ heat transfer through the rod to provide a temperature signal which in turn operates a pressure responsive means connected to the actuator rod mechanism for controlling the function of the expansion valve in response to changes in the temperature of the refrigerant discharging from the evaporator.
It is also known to provide a fluid filled chamber having pressurized fluid therein which acts upon a diaphragm as the pressure responsive means to move the valve actuator rod mechanism. It is also known to have a portion of the rod filled with the pressurized fluid to thereby be in heat transfer relationship with the refrigerant flowing through the return passage to the compressor inlet.
Such known thermal expansion block valves employed for automotive air conditioning applications have required precision machining of surfaces in the block for providing the build up or assembly of the valve on the block and provide accurate controlling of the valving action. Typically, the passages, ports and particularly the valve seat in the block have necessitated costly set up and machining operations from opposite ends of the block and have resulted in relatively high manufacturing costs for valves employed in high volume automotive applications. Furthermore, it has been required to completely assembly the valve components on the block in order to perform calibration and testing of the valve. This has resulted in costly assembly and testing operations and has prevented the detection of defective parts or assembly until the entire valve has been fully assembled.
Furthermore, the construction of known thermal expansion block valves has required expensive machine set ups for controlling the tolerances and location of the surfaces in the block for assembly of the valve components. Known block type thermal expansion valves for automotive air conditioning applications utilize an aluminum block which required that the machining operations be performed prior to application of anodic coating and thus precludes continuous manufacturing operations from the machining of the block to a final assembly and testing of the valve.
It has, therefore, long been desired to provide a way or means of providing a thermally responsive expansive valve for control of refrigerant in a refrigeration or air conditioning system such that the operating components of the valve may be assembled and calibrated prior to final assembly. It has also been desired to provide a thermally responsive expansion valve of the block type in a manner which minimizes the need for tight tolerance control of the location and machining of the valving surfaces in the block and which may be machined in a single set up and assembled in a continuous process.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a thermally responsive refrigerant expansion valve of the block type which is particularly suitable for automotive air conditioning systems. The thermally responsive expansion valve of the present invention utilizes a preassembled and precalibrated cartridge including a fluid charged capsule valve operating rod mechanism and valve obturator and valve seat the cartridge subassembly can be fabricated and calibrated as a separate unit which is then assembled into a blind bore formed in one ported end of the valve block. The thermally responsive expansion valve of the present invention eliminates the need for machining the block and assembly of the components from opposite ends of the block. The thermally responsive expansive valve of the present invention provides a valve which may be calibrated and tested for leakage prior to final assembly and which may be assembled from one side or end of the block.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section of the assembled thermally responsive expansive valve of the present invention;
FIG. 2 is a section view taken along section indicating lines 2--2 of FIG. 1; and
FIG. 3 is a section view of the cartridge including the fluid filled capsule operating rod mechanism and valve obturator for assembly into the block of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 through 3, the valve assembly of the present invention is indicated generally at 10 and includes a cartridge subassembly indicated generally at 12 which includes a fluid filled capsule indicated generally at 14 which has an upper shell 16 and a lower shell 18 which are joined together at their periphery with a thin diaphragm 20 disposed therebetween generally in sandwiched arrangement. The shell 16, 18 and diaphragm 20 are secured peripherally and sealed by any suitable expedient as for example weldment as denoted by reference numeral 22 in FIG. 3.
The upper shell 16 forms a chamber 24 above the diaphragm 20 which is charged with a suitable fluid, as for example, refrigerant and is sealed at charging by plug 26. The lower shell 18 has a hub portion 28 which is threaded externally and internally with an annular cap or adjustment member 30 threadedly engaging the internal threads in hub 28, it being understood that the cap 30 is rotatable for axial adjustment in the hub 28. As shown in FIGS. 1 through 3, cap 30 threadedly engages the interior of the hub 28 with threads 29.
Diaphragm 20 has a hollow tubular member 32 attached at its upper end preferably centrally thereto with the interior hollow of the member 32 communicating with the fluid charged chamber 24 and the opposite or lower end closed. A stiffening or backing plate 34 is provided about the central region of the undersurface of diaphragm 20; and, the upper end of a spring 36 is registered against the undersurface of plate 34 with the lower end of spring 36 registered on the bottom of a counterbore 31 formed in the cap 30. Rotation of cap 30 in threads 29 serves to adjust the preload of spring 36 on diaphragm 20 as desired.
A tubular extension member 38 has an end thereof attached to the cap 30 with the closed end of tubular member 32 extending downwardly within the extension 38. As shown in FIGS. 1 through 3, member 30 has its upper end threadedly engaging at 31 the bottom of cap 30.
Extension 38 has an annular valve seat 40 formed at the bottom of a bore 42 formed in the lower end of the extension 38 with a valve obturator in the form of a spherical member 44 disposed on the valve seat 40. The extension 38 has a pair of deformable tabs 46, 48 formed in the wall of counterbore 42 with a compression spring 52 captured by the tabs which are deformed to the position shown in FIG. 3 to detain the lower end of the spring 52 with the upper end thereof registered against and biasing the valve member 44 upwardly against the valve seat 40.
An operating rod 50 is received in the tubular extension member 38 with the upper end thereof contacting the closed end of the tubular extension 32 and the lower end of rod 50 contacting the spherical valve member 44.
The extension 38 is cross ported at ports 54, 56 in the upper region thereof, to permit refrigerant fluid, in a manner as will hereinafter be described to enter the interior of the extension and to be in heat transfer relationship with the tubular member 32 which is filled with the fluid in chamber 24.
The member 38 is also cross ported in the lower region thereof as denoted by reference numerals 58, 60 to permit refrigerant flowing over the valve seat 40, upon opening thereof, to flow to the interior of extension 38 and outwardly through the ports 58, 60.
It will be understood that the upper portion of the operating rod 50 has a dimensionally precision or controlled diameter so as to closely interfit the inner diameter of extension member 38 to permit only a very small leakage of fluid around the operating rod and into the region of the cross ports 54, 56.
In order to calibrate the cartridge subassembly 12, the capsule 14 is placed in a suitable fixture (not shown) and the capsule exposed to fluid at a preselected temperature for calibration. Fluid pressure is supplied in an isolated manner in a fixture (not shown) to the lower end of the extension 38. The cap 30 is then rotated with respect to lower shell 28 to adjust the preload in spring 36 and the tubular extension 32 rotated to adjust contact against operating rod 50 to open valve 44 to produce a desired flow through outlet ports 58, 60. Once calibrated, the cap 30 then may be secured rotationally with respect to lower shell 28 by a suitable expedient, as for example, an anaerobic adhesive or staking.
Once the cartridge subassembly 12 has been calibrated, it is removed from the unshown calibration fixture and is inserted into blind bore 62 formed in an end or side of the valve block 64.
The external threads of hub 28 of the capsule 14 engage threads 66 provided in a counterbore or enlarged diameter portion 68 formed in the upper end of the bore 62 in block 64. An annular seal ring 70 is provided in an annular groove in the upper end of the block 64 for effecting a seal between the lower shell 18 and the end of the block 64.
An annular seal 72 is provided in an annular groove on the extension member 38 with the groove disposed between cross ports 54, 56 and cross ports 58, 60 for sealing between the extension 38 and the bore 62 formed in the block. An additional annular seal ring 74 is provided in an annular groove formed in the extension 38 and is disposed between the cross ports 58, 60 and the lower end of the extension 38 and seals between the extension 38 and the bore 62 of the block 64. Thus, the ports 58, 60 are isolated between the seal rings 72, 74 and communicate exclusively with an outlet passage or port 76 formed in the block. A high pressure inlet passage or port 78 is formed in the block 64 and is located below the seal ring 74 such that port 78 communicates exclusively with the movable valve member side of the valve seat 40.
Block 64 also has a through passage 80 formed therein spaced from the passages 76, 78 and disposed to communicate exclusively with cross ports 54, 56. Through passage 80 is isolated from outlet port 58 by annular seal ring 72.
Thus, in operation as the flow through passage 80 and ports 54, 56 effects heat transfer through the wall of tubular member 32 and to the fluid in the interior of tubular extension 32 and chamber 24. The expansion and contraction of the fluid in the chamber 24 causes movement of diaphragm 20, rod 50 and the valve member 44 which controls flow between the high pressure inlet of the valve and the outlet passage 76.
It will be understood that the valve assembly 10 is typically connected in a refrigeration or air conditioning system with the refrigerant flow from the condenser entering ports 78 and the reduced pressure expanded flow in outlet passage 76 connected to the inlet of an evaporator (not shown) with the evaporator discharge passed through passage 80 for return to the inlet of the compressor (not shown).
The present invention thus provides a unique construction and method of assembly for a refrigerant expansion valve having a cartridge subassembly including the thermally response fluid filled capsule and operating rod and high pressure valve member preassembled as a unit and which may be precalibrated prior to installation in a valve receptacle or body.
The cartridge subassembly has a threaded extension on the thermally responsive capsule, adjustment of which provides for setting the preload and opening point of the valve at a predetermined calibration temperature; and, the cartridge requires no further calibration upon assembly into the valve body. The cartridge subassembly eliminates the need for precision machining and location of a valve seat and tight tolerance control in machining the valve body. The blind bore in the block for receiving the cartridge is machined and threaded from one end of the block requiring only a single machine set-up; and, the need for machining of the opposite block end is eliminated. The present invention thus provides an easy to manufacture and assemble reliable and reduced cost expansion valve for use in refrigeration or air conditioning systems and is particularly suitable for high volume mass production of automotive air conditioning systems.
Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims.
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An improved thermally responsive expansion valve for use in controlling flow of refrigerant in a circulating system has a cartridge sub-assembly with a fluid charged diaphragm capsule, an operating rod mechanism, a valve seat and captured valve obturator. A tubular extension with the valve seat is adjustably threaded onto the capsule. The cartridge subassembly may be thermally pre-calibrated before installation in a blind bore in a valve body. During calibration, the tubular extension is rotated to adjust the diaphragm and operating rod mechanism to provide the desired obturator movement from the valve seat at the calibration temperature.
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FIELD OF THE INVENTION
The present invention relates generally to the field of pumping apparatuses and, more particularly, to reciprocating pumping apparatuses designed for supplying food-related products at a substantially constant pressure to food packaging, processing, or other similar equipment.
BACKGROUND OF THE INVENTION
Numerous types of pumps having a plurality of features directed to improving performance of the pump for one or more specific applications are currently available on the market today. One application where pumps have evolved significantly to address the needs of the industry are those which are designed to transport food-related products such as ground meat, emulsifications, stews, etc. When pumps of this type supply such products to packaging or other processing equipment positioned downstream from the pump, it is often important that the pump supply a substantially continuous flow of product at a predetermined, constant pressure. This ensures, for instance, that constant weights of packaged product are provided since packaging machines often operate on a timed basis.
A popular type of pump particularly suitable for use with food-related products is the reciprocating pump. One type of reciprocating pump utilizes a single piston and cylinder configuration. Typically, this pump will interact with a source of product such that a charge of product will be drawn into the cylinder on the piston's intake stroke and then discharged from the cylinder on the piston's discharge stroke. As is readily apparent, when using only a single piston it is impossible to maintain a constant flow of product under a uniform pressure since discharge only occurs during one-half of the piston's cycle.
In order to compensate for the lack of discharge over one-half of a typical single piston reciprocating pump's cycle, dual or multi-piston configurations have been devised. U.S. Pat. No. 3,108,318 to Miller et al. ("Miller I"), issued Oct. 29, 1963, is representative of this particular type of reciprocating pump. Miller I generally discloses a horizontal dual piston configuration in which one piston and its associated cylinder alternately reciprocate with a second piston and its associated cylinder to pump food products through a common discharge manifold. The disclosure indicates that both the first piston and its cylinder retract so that product may enter into a discharge chamber. After fully retracting, the first cylinder advances through the discharge chamber to trap a charge of product while the first piston stalls momentarily in its retracted position. After the first cylinder has properly seated against the end of the discharge chamber, the first piston advances through the cylinder to discharge the product therefrom. The second piston and its cylinder proceed under the same cycle, but the timing associated with the movement of the second piston and its cylinder is such that the second piston and cylinder are 180° out-of-phase in relation to movement of the first piston and its cylinder. Consequently, when the first piston is discharging product, the second piston and cylinder are retracting to receive a charge of product in the discharge chamber. This dual piston configuration and the timing of their reciprocation thus produces a more uniform flow and pressure at discharge.
Alternately reciprocating dual piston pumps improve both the uniformity of the flow rate and the product pressure at discharge. However, pressure drops and decreases in flow rate discharge still occur since there is often a slight delay between the end of the discharge stroke of the first piston and the start of the discharge stroke of the second piston. In order to achieve consistent weights in packaged foods, it is important that such variations be reduced to acceptable levels. Consequently, numerous refinements of dual piston configurations have been proposed.
U.S. Pat. No. 3,456,285 to Miller et al. ("Miller II"), issued Jul. 22, 1969, discloses one type of alteration of a dual piston alternately reciprocating pump. Miller II generally discloses a horizontal dual piston pump in which both the pistons and their respective cylinders reciprocate as disclosed in Miller I discussed above. However, Miller II incorporates a number of additional features. For instance, the pistons and cylinders are positioned below a hopper which includes paddles to assist in forcing product down into the discharge area through which the cylinders pass to trap a charge of product. Furthermore, the cycles of the pistons overlap, which is achieved by driving the pistons with low and high pressure hydraulics. High pressure hydraulic fluid is used to drive the first piston through its cylinder to discharge product while the second piston and cylinder are being retracted. When fully retracted, the second cylinder is advanced through the discharge area to obtain a charge of product. After sealing of the charge by the second cylinder is completed, the second piston is advanced within the cylinder by low pressure hydraulic fluid. However, no product is discharged from the second cylinder since a valve positioned in the manifold connecting the outlets from the two cylinders only accepts flow from one cylinder at a time, that being the cylinder under the highest pressure. After the first piston completes its discharge stroke, high pressure hydraulic fluid is applied to the second piston to initiate its discharge stroke while the first piston and cylinder are retracted to complete the cycle which is thereafter repeated.
U.S. Pat. No. 4,191,309 to Alley et al., issued Mar. 4, 1980, discloses a product portioning or metering assembly used in combination with a pumping apparatus similar to that disclosed by Miller II. The disclosure of Alley et al. Illustrates, however, a number of variations in pump operations. For instance, the initial advancement of the first piston from its retracted position under the low pressure hydraulic fluid as the second piston is performing its discharge stroke under the high pressure hydraulic fluid is said to provide "precompression" which permits accurate metering of the product to be dispersed by removing air pockets therefrom prior to discharge. Presumably, this movement of the piston is termed as "precompression" since only low pressure hydraulic fluid is being applied to the first piston, and thus no product is discharged from its associated cylinder since discharge occurs only from the cylinder under the highest pressure. The precompression stroke continues until the low pressure hydraulic fluid is unable to overcome the increasing pressure within the cylinder as a result of compression of the product, at which point the first piston stalls. After the second piston completes its discharge stroke, high pressure hydraulic fluid is applied to the first piston, which remained in the stalled position by continually receiving the low pressure hydraulic fluid, to initiate its discharge stroke as the second piston and cylinder retract to repeat the above cycle.
U.S. Pat. No. 4,691,411, to Higashimoto, issued Sep. 8, 1987, discloses a dual piston alternately reciprocating pump which also incorporates a precompression stroke. This particular pump is a vertical pump which includes a hopper positioned above two feed cylinders, each of such cylinders having a reciprocating piston contained therein. A shutter plate is positioned between each cylinder and the hopper to essentially function as an inlet valve to the cylinders and the pistons move alternately within the cylinders through essentially intake and discharge strokes so as to provide a substantially uniform discharge of product. However, the pump also includes a precompression stroke to further refine the pressure variation at discharge. After a piston has reached bottom dead center ("BDC") and the shutter plate for the respective cylinder is closed, the piston advances through the cylinder on a precompression stroke which continued for a pre-determined time established by a time, regardless of the pressure attained in the cylinder during such precompression. After the lapse of the pre-determined time, further movement of the piston is terminated by the drive assembly, thereby completing the precompression stroke. Just prior to the time in which the other piston completes its discharge stroke, signal is sent to the drive assembly for the stalled piston to initiate its discharge stroke. After the lapse of a predetermined time, the other piston retracts on its intake stroke to complete the cycle. Although precompression is used by Higashimoto, its benefits are limited by the precompression stroke being defined by a pre-set time. Since different charges may possibly be obtained on each stroke when certain products are being pumped or with variations in pump speed, a time-dependent precompression stroke might not produce a consistent precompression pressure. This precompression pressure variation would adversely affect the pressure variation ar discharge.
U.S. Pat. No. 4,700,899 to Powers et al., issued Oct. 20, 1987, discloses another refinement of a dual piston alternately reciprocating pump. The general structure and operation or the pump disclosed by Powers et al. is similar to that disclosed by Miller I and II and Alley et al., utilizing two reciprocating pistons and cylinders. The heads of the pistons, however, are modified in that they incorporate a plurality of apertures through which a vacuum is drawn as the pistons are retracted on their respective intake strokes. This vacuum is maintained as the cylinder sleeves are propelled through the discharge chamber to allegedly assure full deaeration of the product.
Providing a pulsation free flow (i.e. free of deviation in discharge pressure), has of course not been limited to pumps used in the food industry. Reciprocating pumps have been designed to provide a pulsation free delivery of a liquid by a variety of methods. For instance, U.S. Pat. No. 4,359,312 to Funke et al., issued Nov. 16, 1982, allegedly provides a pulsation free delivery of a liquid from a dual piston alternately reciprocating pump by incorporating a feedback system which utilizes sensors positioned on the common discharge to ultimately adjust the speeds of the pistons, including adjustments which compensate when liquid is discharged simultaneously from both cylinders. U.S. Pat. No. 3,847,507, to Sakiyama et al., issued Nov. 12, 1974, discloses a feedback circuit for a single reciprocable piston (although reference is made to utilizing two pistons if a higher flow output is required) which uses a pressure sensor within the cylinder to activate a motor to move the piston within the cylinder to maintain a constant pressure on the discharged liquid. U.S. Pat. No. 1,723,874 to Lunge, issued Aug. 6, 1929; U.S. Pat. No. 2,010,377 to Sassen, issued Aug. 6, 1935; and U.S. Pat. No. 3,816,029 to Bowen et al., issued Jun. 11, 1974, each generally pertain to attempting to provide pulsation free delivery of a liquid by using specially designed cams to drive the pistons in a timed relation. The complexity of these types of apparatuses, as well as the results achieved, however, makes them somewhat undesirable for use in food-related applications.
SUMMARY OF THE INVENTION
The present invention generally relates to an improved dual piston alternately reciprocating pumping apparatus for providing a substantially uniform product pressure at discharge. Consequently, the present invention is particularly advantageous for use in combination with packaging or processing equipment for food-related products in which it is desirable to receive precise amounts of product under a substantially uniform pressure and density.
One embodiment of the present invention generally includes three primary components, namely a hopper for supplying product to the actual pumping apparatus, a cylinder housing containing at least two feed cylinders, each cylinder having a single feed piston reciprocally positioned therein, and a drive assembly for generally alternately reciprocating the feed pistons. The hopper is preferably positioned above the cylinder housing such that product may gravitate from the hopper into the respective feed cylinders at the appropriate time. In this regard, a reciprocating shutter plate is positioned between each feed cylinder and the hopper to regulate flow into the feed cylinders in a timed fashion which properly coincides with the reciprocation or the feed pistons as discussed below. These shutter planes thereby function essentially as an intake valve for the feed cylinders, whereas a discharge outlet positioned in the upper portion of each feed cylinder functions as the exhaust valve to allow product to be discharged therefrom into a common manifold connecting the outlets. The discharge outlet for each feed cylinder is preferably slot-shaped so as to extend around a portion of the circumference of the feed piston and also tapers inwardly from the cylinder wall to the location where it connects to the common manifold. Although the discharge outlets are not directly closed at any time during operation, a valve positioned in the manifold changes positions upon receipt of an appropriate signal to alternately accept flow from the cylinders in a timed fashion (i.e., flow is only accepted from one cylinder at a time).
The feed piston positioned within each feed cylinder reciprocates through an intake stroke, where it assists in obtaining a full charge in the cylinder by drawing product therein (the valve in the manifold housing having closed off communication with this cylinder), and a discharge stroke where the piston advances through the cylinder to discharge product through the discharge outlet and into the common manifold (the valve in the manifold having opened to accept flow therefrom). Preferably, the feed pistons are wedged-shaped such that they taper downwardly toward the discharge outlet within the respective cylinder when the feed piston is at or near top dead center ("TDC"). Consequently, product tends to gravitate down this inclined surface of the feed piston toward the discharge outlet, thereby reducing the potential for product becoming trapped in the feed cylinders.
The timing for reciprocation of the feed pistons in their respective cylinders is important to providing a substantially uniform discharge pressure. In this regard, the discharge strokes of the pistons overlap to a degree. More particularly, the present invention utilizes a precompression stroke wherein one feed piston moves away from bottom dead center ("BDC") to compress the product within the respective feed cylinder as the second feed piston undergoes its discharge stroke. Precompression occurs since the valve positioned in the common manifold only accepts flow from one discharge outlet and feed cylinder at a time. Consequently, air pockets and the like in the product are removed (i.e., forced out of the cylinder through various sealing points) until a predetermined pressure related to the pressure within the feed cylinder is detected by a pressure sensor or transducer, which signals the end of the precompression stroke. After reaching this pressure, the drive assembly for the first feed piston is turned or switched off until it receives a signal that the second feed piston has nearly completed its discharge stroke, such that the discharge stroke of the first feed piston may then be initiated. However, no product is actually discharged from the cylinder having the first feed piston until the second feed piston reaches TDC, at which time the valve in the manifold is repositioned to accept flow from the cylinder having the first feed piston. By basing a precompression stroke of an adjustable, predetermined pressure versus, for instance, a timed delay, a more uniform product pressure prior to discharge may be obtained, which coincides with a more uniform product discharge pressure.
Preferably, the present invention also includes a number of additional features to further assist in attaining a more uniform product discharge pressure. For instance, a vacuum housing device is positioned between the hopper and the feed cylinders to remove air from the product as it flows into the selected feed cylinder, which desirably affects the uniformity of the charge initially supplied to the feed cylinders by creating a more uniform product density. Moreover, an auger positioned within the hopper is driven by a suitable drive assembly to mix the product near the inlet to the feed cylinders to reduce the likelihood of product becoming jammed in this area, the result of such jamming being that the amount of product supplied to the selected feed cylinder could be adversely affected.
In operation of the present invention, a given product such as sausage material is placed within the hopper. Upon initiation of the drive assembly, the shutter plate for the first feed cylinder, for instance, opens to allow product to begin flowing therein. At this point, the first feed piston has completed its discharge stroke and has slightly retracted to reduce the pressure within the first feed cylinder to allow the shutter plate to be more easily opened. At this time, the second feed piston is on its discharge stroke and product is being discharged from the second feed cylinder. As the first feed piston retracts within the cylinder after the shutter plate is opened, product flows by gravity into the cylinder and is also drawn into the cylinder by the suction-type action of the retracting first feed piston since the valve in the common manifold has closed communication with the first feed cylinder. The vacuum device also removes air from the product as it enters the cylinder to supply a product of more uniform density thereto. After the first feed piston reaches the end of its intake stroke at BDC, the shutter plate for the first feed cylinder is closed to isolate the cylinder from the hopper. The first feed piston thereafter begins its precompression stroke, during which a pressure sensor monitors a pressure related to that within the first feed cylinder generated by the compression of the product therein. Precompressing continues until a certain predetermined pressure is achieved, after which a signal is sent to the drive assembly to stop further advancement of the first feed piston. The first feed piston thereafter initiates its discharge stroke when a signal is received by the drive assembly that the second feed piston has neared completion of its discharge stroke. However, no product is discharged from the first feed cylinder at this point since the valve in the manifold does not allow communication therewith until the second feed piston actually completes its discharge stroke. After the second feed piston reaches TDC, the valve is repositioned to accept product from the first feed cylinder as the first feed piston continues its discharge stroke.
Advantages of the present invention generally relate to achieving a more uniform product discharge pressure that results in providing a product having a substantially uniform density. Consequently, when used with a packaging machine, a constant packaged weight may be obtained.
The present invention includes various features to achieve the desired results. For instance, the vacuum device is positioned between the hopper and the feed cylinders to move air from the product as it enters the selected feed cylinder to provide a more air-free initial charge of product prior to any precompression. Moreover, a precomposition stroke, the length of which depends upon a pressure related to that within the feed cylinder, is used to provide a more consistent charge prior to initiation of the discharge stroke by further reducing the amount of air contained within the product. Furthermore, a unique feed piston configuration reduces the likelihood of product becoming trapped in the cylinder by tapering the face of the piston such that product flows down the face of the piston to the respective discharge outlet. Relatedly, the discharge outlets are slot-shaped so as to extend around a portion of the perimeter of the associated feed piston so as to obtain a larger flow of product therein, and such discharge outlets also taper inwardly toward the manifold to further enhance pressure uniformity at discharge.
Additional advantages of the present invention will become apparent from the following discussion, particularly when taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the present invention with portions of the cylinder housing broken away to illustrate the feed pistons and cylinders and the hydraulic pistons and cylinders;
FIG. 2 is a top view of the hopper;
FIG. 3 is a cross-sectional view of the hopper of FIG. 2 taken along line 3--3;
FIG. 4 is a cross-sectional view of the hopper of FIG. 2 taken along line 4--4;
FIG. 5 is a top view of the shutter plate assembly;
FIG. 6 is a perspective view of the upper portion of the cylinder housing;
FIG. 7 is a cutaway view of a portion of the feed cylinder taken along line 7--7 of the cylinder housing of FIG. 6, illustrating the positioning of the wedged-shaped piston therein;
FIG. 8 is a cross-sectional view of the cylinder housing of FIG. 6 taken along line 8--8;
FIG. 9 is a partial cross-sectional view of the cylinder housing of FIG. 6 taken along line 9--9;
FIG. 10 is a perspective view of a feed cylinder and the interrelationship between the preferred wedged-shaped feed piston and funnel-shaped discharge outlet;
FIG. 11 is a perspective view of a preferred feed piston configuration;
FIG. 12 is a cross-sectional view of the piston of FIG. 11 taken along line 12--12;
FIG. 13 is a perspective view of one known feed piston configuration;
FIG. 14 is a perspective view of a second known feed piston configuration;
FIG. 15 is a schematic of the preferred hydraulic drive system for the present invention; and
FIG. 16 illustrated exemplary timing curves of the reciprocation of the feed pistons, specifically indicating the possible varying lengths of the precompression strokes to obtain the desired precompression pressure.
DETAILED DESCRIPTION
The present invention will be described with reference to the accompanying drawings which illustrate the various features of the present invention contributing to the provision of a product having a substantially uniform pressure at discharge. Referring to FIG. 1, the pumping apparatus 20 of the present invention generally includes three primary components, namely a hopper 24, cylinder housing 28, and drive assembly 32. Any number of types of food-related products such as ground beef, etc., may be positioned in the hopper 24 and pumped by the generally alternately reciprocating movement of the first and second feed pistons 120, 124 to an appropriate downstream processing or packaging machine.
As illustrated in FIGS. 2-4, the hopper 24 includes two side walls 36 and two end walls 40, all of which are integrally connected to define a substantially continuous inner surface which reduces the potential for product becoming trapped therein. Preferably, both side walls 36 and/or both end walls 40 taper inwardly from the upper portion of the hopper 24 to its lower portion, as best illustrated in FIGS. 3 and 4, such that product will easily slide down through the hopper 24 and into the hopper outlets 56 for passage into the cylinder housing 28.
The lower portion of the hopper 24 contains a divider 44 which separates the individual hopper outlets 56. The divider 44 is a triangular structure having a first divider surface 48 and a second divider surface 52, both of which taper from the top of divider 44 down toward the associated hopper outlet 56 to direct flow of product thereto. The hopper outlets 56 are aligned with the first and second feed cylinders 104, 108 positioned within the cylinder housing 28 and taper inwardly from their respective upper ports 60 to their lower ports 64 such that the lower ports 64 are preferably the same size as the first and second feed cylinders 104, 108. An auger 280 is preferably positioned above the hopper outlets 56, as best illustrated in FIG. 3, and is rotatably driven by an appropriate drive mechanism (not shown) to mix and break up the product so that product continues to flow into the hopper outlers 56 during operation. As illustrated in FIG. 3, the auger 280 preferaby includes two substantially circular hoops 284, one being positioned over each hopper outlet 56, which are attached to the auger shaft 288 by hoop connectors 292.
As will be discussed in more detail below, the incorporation of a precompression stroke in a preferred embodiment results in the reduction of air pockets within the product to attain a more uniform product pressure and density prior to discharge, which thus improves the uniformity of the discharge pressure as well. In order to enhance the uniformity of product density initially supplied to the first and second feed cylinders 104, 108, a vacuum ring 72, illustrated in FIGS. 3 and 4, is positioned between each hopper outlet 56 and the associated first and second feed cylinder 104, 108. The function of each vacuum ring 72 is to remove air from the product prior to entering the first and second feed cylinders 104, 108. In this regard, a vacuum pump (not shown) attaches to the vacuum connector 74 on the hopper 24 (FIG. 1), which interacts with the vacuum rings 72 to apply the necessary suction to the vacuum rings 72. The vacuum rings 72 are preferably positioned in vacuum ring slots 68 in proximity to each lower port 64 of the hopper outlets 56. The vacuum rings 72, however, could be positioned in a number of alternate locations to perform the same desired function.
The hopper 24 has a hopper mounting plate 76 positioned on the lower portion thereof which is used to attach the hopper 24 to the shutter plate holder 88 of the cylinder housing 28. Although any number of suitable methods may be used to establish this connection, preferably a pivotal connection (not shown) is used such that the hopper 24 may be pivoted away from the shutter plate holder 88 and the cylinder housing 28 to provide access to the first and second feed cylinders 104, 108 to allow for the cleaning thereof. The only real limitation for establishing the connection between the hopper 24 and the shutter plate holder 88 of the cylinder housing 28 is that the alignment of the hopper outlets 56 and the first and second feed cylinders 104, 108 must be substantially maintained during operation of the pumping apparatus 20.
The shutter plate holder 88 is appropriately positioned between the hopper 24 and the cylinder housing 28 as best illustrated in FIG. 1, the lower portion of which has a pair of shutter plate holder outlets 90 in alignment with the respective hopper outlets 56 and the first and second feed cylinders 104, 108 as best illustrated in FIG. 5. Preferably, the shutter plate holder outlets 90 are the same size as the lower ports 64 of the hopper outlets 52 and as the first and second feed cylinders 104, 108. Although any number of methods of attachment may be used, preferably the shutter plate holder 88 is pivotally connected (not shown) to the cylinder housing 28 such that access may be obtained to the first and second feed cylinders 104, 108.
A pair of shutter plates 92 are positioned within parallel receiving areas of the shutter plate holder 88 which reciprocate in a timed relationship with reciprocation of the first and second feed pistons 120, 124 to essentially function as intake valves for the first and second feed cylinders 104, 108. In order to produce the desired timed reciprocation, a system such as that disclosed in U.S. Pat. No. 4,691,411 to Higashimoto, issued Sep. 8, 1987, is preferred since it interacts with that portion of Higashimoto corresponding to the drive assembly 32 of the present invention for reciprocating the first and second feed pistons 120, 124.
In order to allow flow of product into the first and second feed cylinders lug, 108, each shutter plate 92 has a shutter plate outlet 96 which is preferably the same size as the lower ports 64 of the hopper outlets 56, the shutter plate holder outlets 90, and the first and second feed cylinders 104, 108. The primary advantage of this uniform passageway from the hopper 24 to the first and second feed cylinders 104, 108 is the reduction of potential for product becoming trapped therein. Consequently, the reciprocation of the shutter plates 92 moves the shutter plate outlets 96 into and out of alignment with, ultimately, the hopper outlets 56 and the first and second feed cylinders 104, 108 to allow flow of product into and out of the first and second feed cylinders 104, 108 at the appropriate time.
Since the shutter plates 92 move through product flowing down through the hopper outlets 56 during operation, it is desirable to construct the shutter plates 92 from materials which nave a low surface friction and a high strength, such as a high density polyethylene. A preferred material for forming the shutter plates 92, however, is a virgin, ultra-high molecular weight polyethylene.
The cylinder housing 28 contains those portions of the pumping apparatus 20 used to actually discharge the product. As illustrated in FIGS. 1, 6, and 8, the cylinder housing 28 contains the first and second feed cylinders 104, 108 which are positioned in substantial alignment with the associated hopper outlets 56 and shutter plate holder outlets 90 as described above. The first feed cylinder 104 has a reciprocable first feed piston 120 contained therewithin and second feed cylinder 108 similarly has a second feed piston 124. The first and second feed pistons 120, 124 reciprocate in a timed relationship (discussed below) to alternately allow product to enter the respective first or second feed cylinders 104, 108 by proper alignment of the shutter plate outlet 96 of the shutter plate 92 associated therewith, and to alternately discharge product from the first and second feed cylinders 104, 108, after closing of the associated shutter plate 92 such that the shutter plate outlet 96 is not aligned with the shutter plate holder outlet 90, through a feed outlet 112 positioned on each of the first and second feed cylinders 104, 108.
As best illustrated in FIGS. 8-10, each feed outlet 112 is preferably slot-shaped so as to follow a portion of the perimeter of the respective first or second feed piston 120, 124 which allows more product to be supplied thereto. Moreover, the feed outlets 112 also preferably taper inwardly toward the position where the feed outlets 112 connect to the manifold 168. This tapering of the feed outlets 112 further assists in providing a more uniform product discharge pressure. Although the feed outlets 112 remain open throughout operation of the pumping apparatus 20, a valve 172 positioned within the manifold 168 only allows flow of product from first and second feed cylinders 104, 108 in essentially a timed, alternate fashion. Consequently, the feed outlets 112 are in essence closed during a portion of the cycle of the reciprocation of the first and second feed pistons 120, 124, particularly during their intake and precompression strokes as is discussed in more detail below.
The first and second feed cylinders 104, 108 contain reciprocable first and second feed pistons 120, 124, respectively. The structural configuration of the first and second feed pistons 120 and 124 are similar and therefore only discussion of one will follow. Referring particularly to FIGS. 10-12, the first feed piston 120 is preferably wedged-shaped such that it tapers downwardly over at least a portion of the piston face 128. As best illustrated in FIG. 10, this downward tapering of the piston face 128 directs product toward the feed outlet 112 of the first feed cylinder 104 as the first feed piston 120 nears TDC. Since the downward taper of the piston face 128 initiates from the point in the first feed cylinder 104 farthest from the associated feed outlet 112, the wedge-shaped design reduces the potential for product becoming trapped in the first feed cylinder 104, stagnating for a time, and possibly later being discharged. Moreover, in order to reduce the potential for product passing between the first feed piston 120 and the first feed cylinder 104, first feed piston 120 also incorporates two O-ring slots 132 which contain O-rings 136 to establish a sufficient seal between first feed piston 120 and first feed cylinder 104.
Although numerous materials are suitable for the manufacture of the first and second feed pistons 120, 124, those which have low surface friction and high strength characteristics are must desirable so that in the preferred configuration, product will easily flow down the piston face 128. The preferred material, however, is a high density polyethylene or, if available in the quantities required for the first and second feed pistons 120, 124, a virgin ultra-high molecular weight polyethylene.
Various configurations of feed pistons have been previously used in pumping apparatuses of the type generally disclosed herein, namely food pumps. A cutout feed piston 176 having a crown 180 and a cutout 184, as well as O-ring slots 192 for retaining an o-ring for establishing a seal with a cylinder wall, is illustrated in FIG. 13. The cutout 184, which is substantially horizontal, is in part defined by a substantially vertical cutout fall 188 which essentially bisects the cutout feed piston 176. In this type of configuration, it would appear that there would exist a high potential for product becoming trapped on both the cutout 184 and the upper portion of the crown 180 during the reciprocating motion, particularly at TDC.
A second configuration of a known feed piston is illustrated in FIG. 14. Crown feed piston 196 has an upper crown 200 entirelY surrounded by a stepped surface 04. In addition, an O-ring slot 208 is provided for retaining an O-ring to sealingly engage the piston and its cylinder. This configuration, however, would also appear to produce a strong potential for product becoming trapped on the top of crown 200 and/or the stepped surface 204 during the reciprocating motion of the crown feed piston 196, particularly that portion of the stepped surface 204 positioned on the back side of crown 200 in relation to an outlet port of the type suggested herein.
The first and second feed pistons 120, 124 are reciprocatingly driven by an appropriate drive assembly 32 in a particular timed relationship. Although the drive assembly 32 is illustrated in FIG. 1 as being separate from the cylinder housing 28, the two may of course be combined into a single unit. Preferably, the drive assembly 32 is a hydraulic system including a first hydraulic cylinder 150 and piston 152 associated with first feed cylinder 104 and piston 120, and a second hydraulic cylinder 154 and piston 156 associated with the second feed cylinder 108 and piston 124. As will become apparent in the discussion which follows, a similarly structured pneumatic system may also be appropriate.
Due to the structural and operational similarities, further discussion of the drive assembly 32 will primarily reference that portion associated with a single feed piston, namely first feed piston 120. The first hydraulic cylinder 150 is positioned substantially directly below the first feed cylinder 104 and is separated therefrom by a cylinder divider 144. The piston shaft 140, connected to the first feed piston 120, extends through the cylinder divider 144 and attaches to the first hydraulic piston 152 which is reciprocally positioned within the first hydraulic cylinder 150 as best illustrated in FIGS. 1 and 15. Although numerous methods of attaching the piston shaft 140 to the first feed piston 120 may be utilized, it may be necessary to modify the piston face 128 in the manner indicated by the dashed lines in FIG. 12 (i.e., positioning a small block on the central region of the piston face 128) so that a fastener 300 may seat against a substantially flat surface 304 to engage the piston shaft 140, which in this configuration would extend up into the body of the first feed piston 120. The first hydraulic piston 152, also appropriately connected to the piston shaft 140, has an upper piston face 160 and a lower piston face 164. Consequently, reciprocation of the first feed piston 120 is generally achieved by providing a flow of hydraulic fluid to the upper or lower piston face 160, 164 of the first hydraulic piston 152 by a system and in a manner to be described in more detail below.
The preferred drive assembly 32 for the pumping apparatus 20 is substantially similar to that disclosed in U.S. Pat. No. 4.691,411 to Hiqashimoto, issued Sep. 8, 1987, which is hereby incorporated by reference herein, except primarily for the addition of the pressure sensors 248 (discussed below) which determine the length of the precompression stroke for the first and second feed pistons 120, 124, as opposed to the timer utilized by Higashimoto. Each of the pressure sensors 248 is a commercially available unit that is able to compare two inputs. Depending upon the magnitudes of the two inputs, one of two states or outputs are generated by the pressure sensors 248. The first input relates to an actual pressure being sensed (within the feed or hydraulic cylinders as discussed below) that can vary during normal pumping operations. This input relates to the pressure in the particular cylinder at any instance in time. A second input is a predetermined or preset input that relates to a desired or suitable pressure. The second input is entered or controlled by the user or operator of the pumping apparatus 20. The two inputs are continuously compared by each pressure sensor 248. When the first input or actual pressure sensed becomes equal to or greater than the preset pressure, the output of the pressure sensor 248 charges and an electrical signal is outputted indicative of the condition that the desired pressure has been reached or exceeded. This electrical signal indicating such a state can be used to control or stop the application or further hydraulic fluid to the appropriate hydraulic piston and cylinder. As can be readily understood, because the operator of the pumping apparatus 20 is able to control the magnitude of the second input, adjustment can be made to achieve a desired, uniform pressure in the reed cylinders. Consequently, the possibility of non-uniform or inconsistent product deliveries is reduced because of the presence of a desired pressure that results in product, having the desired density, being discharged.
Generally regarding the configuration of the hydraulic system utilized, a hydraulic pump 216 receives hydraulic fluid from a hydraulic source 212. The hydraulic pump 216 directs hydraulic fluid to the first and second solenoids 232, 236 which directly control the reciprocation of the first and second feed pistons 120, 124, respectively, by primarily applying hydraulic fluid to the appropriate surface of the first and second hydraulic pistons 152, 156, respectively. Flow regulators 240 may be positioned between the first solenoid 232 and the first hydraulic piston 152 and between the second solenoid 236 and the second hydraulic piston 156. Moreover, various devices such as a pressure indicator 224, pressure relief valve 220, and check valve 228, which enhance the operational safety of the drive assembly 32, may be positioned between the hydraulic pump 216 and the first and second solenoids 232, 236.
Although the drive assembly 32 has only been generally described, the description of the reciprocation of the first and second reed pistons 120, 124 in a manner illustrated by the timing curves of FIG. 16 better emphasizes its operational significance. With reference to FIG. 16, at time T 0 the first feed piston 120 undertakes its discharge stroke as a result of the first solenoid 232 directing flow of hydraulic fluid to the lower piston face 164 or the first hydraulic piston 152. At time T 1 , an upper limit detector 272 positioned on or near the first feed cylinder 104 senses that the first feed piston 120 is nearing the end of its discharge stroke. This upper limit detector 272 sends a signal to the second solenoid 236, resulting in the application of hydraulic fluid to the lower piston face 160 of the second hydraulic piston 156 to initiate the discharge stroke of the second feed piston 124. However, no product is actually discharged from the second feed cylinder 108 since the valve 172 within the manifold 168 is still positioned to only accept flow from the first feed cylinder 104.
After a predetermined time delay at time T 2 , a signal is sent to the first solenoid 232 to initiate the downward stroke of the first feed piston 120 by directing the flow of hydraulic fluid to the upper piston face 160 of the first hydraulic piston 152. Moreover, the valve 172 within the manifold 168 is now repositioned upon receipt of an appropriate signal to accept flow from the second feed cylinder 108 and the second feed piston 124 continues its discharge stroke. After another predetermined time delay at T 3 , the first solenoid 232 discontinues the flow of hydraulic fluid to the first hydraulic piston 152. This initial retraction of the first feed piston 120 removes pressure from the shutter plate 92 associated with the first feed cylinder 104 such that it may be more easily opened. After the lapse of another predetermined rime delay at T 4 to allow the associated shutter plane 92 to fully open, the first solenoid 232 reinitiated the flow of hydraulic fluid to the upper piston face 160 of the first hydraulic piston 152 so that the first feed piston 120 retracts, resulting in product flowing from the hopper 24 into the first feed cylinder 104 as described above. Vacuum ring 72 also removes air from the product at this time.
At time T 5 , the first feed piston 120 reaches BDC as sensed by a lower limit detector 276 positioned on the lower portion of the first feed cylinder 104, at which time the lower limit detector 276 sends a signal to the first solenoid 232 to discontinue the flow of hydraulic fluid to the upper piston face 160 of the first hydraulic piston 152. A second lOWer limit detector 276, being positioned on the lower portion of the second feed cylinder 108, performs the same function for the second feed piston 124 by interacting with the second solenoid 236. After the lapse of a predetermined time delay at time T 6 , during which time a signal is sent to the shutter plate 92 for the first feed cylinder 104 to close the shutter plate 92 to move the shutter plate outlet 96 out of alignment with the hopper. outlet 56 associated therewith, the first solenoid 232 directs hydraulic fluid to the lower piston face 164 of the first hydraulic piston 152 to initiate the precompression stroke for the first feed piston 120.
The precompression stroke of the first feed piston 120 continues until a predetermined pressure is achieved or exceeded in the hydraulic line directed to the lower piston face 164 of the first hydraulic piston 152, as sensed by a first pressure sensor 248 positioned thereon. This pressure is, of course, directly related to the pressure within the first feed cylinder 104. Consequently, the first pressure sensor 248 could alternately be positioned directly to sense the pressure within the first feed cylinder 104 as indicated by the dashed lines in FIG. 15. Upon sensing the predetermined pressure, a signal from the first pressure sensor 248 is converted to an electrical signal by known methods and is directed to the first solenoid 232 to discontinue the application of additional hydraulic fluid to the lower piston face 164 of the first hydraulic piston 152 which occurs at time T 7 . At rime T 8 , at which time the upper limit detector 272 for the second feed piston 124 senses that it is nearing the end of its discharge stroke, a signal is directed to the first solenoid 232 to reinitiate the application of hydraulic fluid to the lower piston face 164 of the first hydraulic piston to initiate the discharge stroke of first feed piston 120. However, no discharge from the first feed cylinder 104 is achieved until the valve 172 is the manifold 168 receives the signal that the second feed piston 124 has reached TDC, at which time the valve 172 will move to accept flow from the first feed cylinder 104. Thereafter, the cycle repeats itself during the remainder of operation of pumping apparatus 20.
As can be appreciated based upon the foregoing description, the time between time T 6 and T 7 , i.e., the time of the precompression stroke, may vary depending upon, in part, the initial uniformity of product pressure within the first and second feed cylinders 104, 108 prior to the precompression stroke, as may the time between time T 7 and T 8 , i.e., the time between the end of the precompression stroke and the beginning of the discharge stroke. This feature is advantageous in that the length of the precompression stroke is not limited to a predetermined time, but instead depends upon the achievement of a predetermined pressure, which enhances the uniformity of product pressure at discharge.
In order for proper precompression to be achieved and maintained, a number of factors must be taken into account. For instance, when a referenced sensor or detector, such as an upper limit detector 272 or a pressure sensor 248, senses the proper condition, there will be a certain inherent time delay before the appropriate reaction is initiated. As an example, between the time one pressure sensor 248 detects the desired precompression pressure within, essentially, the first feed cylinder 104, and the time the first solenoid 232 stops the flow of additional hydraulic fluid to the first hydraulic piston 152, the first hydraulic piston 152, and thus the first feed piston 120, will have traveled a certain distance to further increase the precompression pressure. Consequently, the desired precompression pressure may have to be adjusted during initial operation of the pumping apparatus 20. By incorporating a discharge pressure sensor 296 positioned downstream of the manifold 168 to monitor the discharge pressure, however, the degree of adjustment required to maintain a substantially constant discharge pressure may be easily detected.
Another important factor in achieving and maintaining the desired precompression pressure is the timing of reciprocation between the first and second feed pistons 120, 124. More particularly, the timing must be such that the first feed piston 120 is able to complete its precompression stroke prior to the second feed piston 124 completing its discharge stroke. Although it may be possible to establish a perfect timing such that there will be no delay between the end of the precompression stroke and the beginning of the discharge stroke of the first and second feed pistons 120, 124, it is unlikely that this could be maintained throughout continued operation. Therefore, the reciprocation speeds and timing are such that there will typically be a sufficient delay between the end of the precompression stroke and the beginning of the discharge stroke. For example, for one type of product, the time for the first feed piston 120 to travel from BDC to TDC is approximately 34 seconds, whereas the precompression stroke of the second feed piston 124 only lasts approximately 5 seconds. Consequently, there is sufficient overlap to ensure that a proper precompression will typically be achieved.
The foregoing description of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, in the skill or knowledge of the art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by their particular applications or uses of the invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.
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A dual piston alternately reciprocating pumping apparatus utilizing, in part, a pressure based precompression stroke to provide product at a substantially uniform discharge pressure. In operation, a first feed piston is advanced through a first feed cylinder to discharge product therefrom, during which time a second feed piston is retracting within a second feed cylinder to obtain a product charge therein. The second feed piston reaches bottom dead center and thereafter advances through the second feed cylinder on a precompression stroke, during which no product is discharged from the second feed cylinder. After a predetermined pressure related to that within the second feed cylinder is detected, further advancement of the second feed piston is terminated and is not reactivated until the first feed piston nears top dead center. Therefore, a product having a substantially uniform discharge pressure is provided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. provisional patent application Ser. No. 60/955,283, filed on Aug. 10, 2007, which is fully incorporated herein by reference.
FIELD
This present disclosure relates generally to acoustic filters and more particularly, to multi-chambered acoustic filters configured with connecting tubes that are less costly to manufacture.
BACKGROUND
Acoustic filters are used to dampen pulsation vibrations in fluid flow systems. It has been the practice (see, e.g., U.S. Pat. No. 2,993,559 to Everett) to provide an internal flow element within a vessel arranged to divide and recombine flowing fluids to offset and cancel pulsations. This has been accomplished by defining separate flow paths by means of bulkheads and connecting tubes.
As is well known in the art, whenever fluids are pumped under high pressure, pulsating vibrations will undoubtedly occur. High intensity noise may also occur in systems that produce high frequency pulsations. In addition to noise and vibration, there exists a possibility that the vibrations will damage system piping or components. The potential damage necessitates incurring substantial maintenance and equipment replacement costs. Thus, there is a need for an fluid pulsation dampener that operates quietly and efficiently, and prevents component deterioration as described above.
SUMMARY
The various embodiments and examples provided herein are generally directed to acoustic dampener systems. The disclosed embodiments generally describe a fluid pulsation dampener that substantially attenuates pulsations in a given frequency range. The disclosed embodiments permit acoustic dampeners to have smaller overall dimensions and may be economically produced and implemented. This is largely accomplished by the three-chamber structure described below, wherein there are few inner bulkheads and shorter connecting tubes.
Moreover, the disclosed embodiments may be used as a fluid pulsation dampener for fuel injection systems. Typically, fuel injection systems generate modest amount of noise and vibration. By incorporating the disclosed pulsation dampener into the fuel rail of a fuel injection system, it may attenuate the fluid pulsations and vibrations generated by the fuel injectors of the internal combustion engine.
These, as well as other objects, features and benefits will now become clear from a review of the following detailed description of illustrative embodiments and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings wherein:
FIG. 1 is a longitudinal cross-sectional view of the acoustic dampener, integrated in the Fuel Rail of a Fuel Injection System;
FIG. 2 is a cross-sectional view of the connecting area of Chamber 1 , Chamber 2 , and Chamber 3 through the helical grooves machined in Plug 2 and Tube 2 ; and
FIG. 3 is a cross-sectional view of connecting area of Chamber 1 and Chamber 2 through the helical groove machined in Plug 1 .
DETAILED DESCRIPTION
The detailed description set forth below in connection with the appended figures is intended as a description of various embodiments of the invention disclosed herein and is not intended to represent the only embodiments in which the invention may be practiced. The detailed description includes specific details for providing a thorough understanding of the invention. It will be apparent to those skilled in the art, however, that the invention may be practiced without these specific details.
FIG. 1 is a longitudinal cross-sectional view of an acoustic dampener. For purposes of this disclosure, acoustic dampener and pulsation dampener may be used interchangeably without straying from the spirit of the exemplary embodiment herein since both acoustic and pulsation dampeners have the ability to carry sound. In one exemplary embodiment, the acoustic dampener 100 is integrated into the fuel rail of a fuel injection system. The pulsation dampener 100 consists of Tube 1 , which is the fuel rail with attached injector sockets 102 . Tube 2 is lodged inside Tube 1 in a coaxial arrangement, defining an annular Chamber 1 , which is the pulsation inlet for the un-dampened pulsations generated by the injectors (not shown) in the injector sockets 102 . In the exemplary embodiment, the fluid inlet 104 designates the area where the fluid enters the dampener 100 , while pulsations inlet, i.e. Chamber 1 , designates the area where the pulsations enter the dampener 100 . The fluid inlet 104 and the pulsation inlet may or may not be identical in structure, depending on the pulsation's source location.
FIG. 2 is a cross-sectional view of the connecting area of Chamber 1 , Chamber 2 , and Chamber 3 through the helical grooves 200 machined in Plug 2 and Tube 2 . Tube 3 , which is partially inserted in Tube 1 , provides the second support for Tube 2 inside Tube 1 . Plug 3 , inserted into the opposite end of Tube 3 , is the fluid inlet port 104 of the pulsation dampener 100 . Plug 3 also seals Chamber 3 inside Tube 3 . (See FIG. 1 ). The three expansion chambers (Chamber 1 , Chamber 2 and Chamber 3 ) work in cooperative fashion so as to substantially cancel or eliminate unwanted noise that may arise from the acoustic or pulsation properties of fluid flow.
In the disclosed embodiment, the un-dampened pulsations may enter either Chamber 1 or Chamber 2 , wherein one is placed inside the other. Chamber 3 , which can also be a partition of Chamber 1 or Chamber 2 , is the outlet for the dampened pulsations. The series of connecting tubes in the disclosed arrangement may allow fluid flow in and out of the chambers (Chamber 1 , Chamber 2 , and Chamber 3 ) or, alternatively, split and recombine the flow in a predefined sequence.
FIG. 3 is a cross-sectional view of connecting area of Chamber 1 and Chamber 2 through the helical groove 200 machined in Plug 1 . Plug 1 seals the end of Tube 1 and Tube 2 and provides support for Tube 2 inside Tube 1 . The opposite end of Tube 2 , having a helical groove 200 on its outer surface, is inserted into Tube 3 and plugged by the Plug 2 . (See FIG. 2 ).
The connecting tubes (Tube 1 , Tube 2 , and Tube 3 ) of the exemplary embodiment are the helical grooves 200 machined on the outer surfaces of Plug 1 and Plug 2 and on the outer surface of the fluid inlet end of Tube 2 (See FIGS. 2 and 3 ). Plug 1 connects Chamber 1 and Chamber 2 while Plug 2 connects Chamber 2 and Chamber 3 . Chamber 1 and Chamber 3 are connected by the helical groove 200 at the end of Tube 2 . In an exemplary embodiment, the connections between the tubes may be largely accomplished by friction fit between the helical groove 200 structure and the immediately surrounding tube. As one of ordinary skill in the art may appreciate, one may substitute an equivalent structure so as to bond the connecting tubes together without deviating from the scope of the disclosed embodiments.
While the specification describes particular embodiments of the present invention, those of ordinary skill can devise variations of the present invention without departing from the inventive concept. Also, the previous description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
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A reactive acoustic dampener includes a nested three chambered configuration and connecting tubes that may be fully integrated into the fuel rail of a fuel injection system.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. 100 53 139.3 filed Oct. 26, 2000, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to a device in a fiber processing machine, such as a carding machine or a cleaner for setting the distance between cooperating clothings, such as the clothing of the main carding cylinder of a carding machine and the clothing of a flat bar of a traveling flats assembly.
The distance between the clothing of the main carding cylinder and the clothing of a member cooperating therewith is of substantial significance as far as machine technology and fiber technology are concerned. The carding result, that is, the cleaning, nep-formation and fiber shortening is to a large measure dependent from the carding clearance, that is, the distance between the clothing of the main carding cylinder and the clothing of the traveling or stationary flat bars. The guidance of air about the main carding cylinder and the heat removal are also dependent from the distance between the clothing of the main carding cylinder and the facing clothed or even non-clothed surfaces, such as a waste separating mote knife or cover elements of the machine. The extent of the distances depend from different, partially opposed effects. The wear of cooperating clothings leads to an enlargement of the carding clearance which results in an increase of the nep number and a decrease of the fiber shortening. An increase in the carding cylinder rpm, for example to increase the cleaning effect, causes, because of centrifugal forces, an enlargement of the carding cylinder, including its clothing and thus a decrease in the carding clearance results. The carding cylinder also expands and thus the carding clearance decreases because of the temperature increase in case a large quantity of fiber is processed or particular fiber types, for example, chemical fibers are handled.
In practice, during assembly of a carding machine, first the flat bars are installed and then the distance between the clothing points of the carding cylinder clothing and the clothing points of the flat bar clothings is determined by gauges. Such a distance is measured, for example, at every other flat bar, and an average value is formed from the measured values. The flat bars of a flat bar set regularly have different heights so that the distances are accordingly different. For changing the distance between the points of the flat bar clothings and the points of the main carding cylinder clothing, that is, to set a predetermined carding clearance, the position of the flexible bend (carrying the sliding guide for the flat bars) is radially adjusted at several locations by means of set screws. Thus, by changing the position of the sliding guide, the radial position of the flat bars is altered and, as a result, the distance between the clothings of the flat bars and the main carding cylinder is set.
An adjustment of the flexible bends as outlined above is complicated, time-consuming and requires skill and experience. Further, the geometry of the flexible bend depends from the number of the circumferentially distributed set screws. It is a further drawback that the entire flexible bend cannot be adjusted in one step. It is a particular disadvantage that the differences in the height positions of the flat bars are included in the measurements. Because of these height differences and the use of a plurality of circumferentially distributed set screws, the carding clearance cannot be set in a desired manner.
In a known arrangement, as described, for example, in European Patent No. 801 158 a sensor is provided with which the working distance of the carding clothings (also termed as “carding clearance”) can be measured, that is, the effective distance of the points of a clothing from a machine component facing the clothing can be determined. Such a machine component may also have a clothing but may also be, for example, a cover element provided with a guiding surface. The sensor is configured particularly for measuring the working distance between the carding cylinder and the flat bars of a traveling flats assembly. Such a working distance changes as the wear increases. By means of an optical instrument the carding clearance between the carding cylinder clothing and the flat bar clothings is to be sensed from the side of the working region. It is a disadvantage of this arrangement that the change of the carding clearance gives no indication to what extent the change is to be traced back to the different flat bars.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, sets the carding clearance in a simple and time-saving manner.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber processing machine includes a roll having a circumferential surface provided with a first clothing having clothing points; a counter member having a surface provided with a second clothing cooperating with the first clothing and having clothing points; and a device for setting a clearance between the clothing points of the first and second clothings. The device includes an arrangement for approaching the roll and the counter member to one another until the clothing points of the first and second clothings contact and for moving away the roll and the counter member from one another until the clothing points of the first and second clothings assume a desired clearance. The device further has an arrangement for emitting a signal when the clothing points of the first and second clothings contact one another.
The measures according to the invention provide for a very accurate setting of the carding clearance in a simple and time-saving manner. It is a particular advantage of the invention that the setting is carried out without changing the shape of the flexible bend and the sliding guide; as a result, the previously uniformly and precisely set flexible bend and sliding guide retain their shape. It is a further advantage that the setting of a particularly narrow carding clearance is possible. This is of significance since the smaller the carding clearance, the better the carding effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a fragmentary side elevational view of a traveling flats assembly.
FIGS. 3 a , 3 b and 3 c are fragmentary side elevational views of a traveling flats assembly illustrating the displacement of the flat bars before, during and after contact between the clothing of a flat bar and the clothing of the main carding cylinder.
FIG. 4 a is a schematic side elevational view of a traveling flats assembly, also illustrating the flexible bend and a shiftable slide guide.
FIG. 4 b is a view similar to FIG. 4 a showing the slide guide shifted in the direction A for radially repositioning the flat bars.
FIG. 5 is a schematic side elevational view of a device for shifting the slide guide.
FIGS. 6 and 6 a are schematic views of an embodiment of a device for determining a contact between clothing points.
FIG. 7 a is a schematic side elevational view of a flexible bend having a series of set screws.
FIG. 7 b is a sectional view taken along line 7 b — 7 b of FIG. 7 a.
FIG. 8 is a block diagram of an electronic control and regulating device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a carding machine CM which may be for example, an EXACTACARD DK 803 model, manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM has a feed roller 1 , a feed table 2 cooperating therewith, licker-ins 3 a , 3 b , 3 c , a main carding cylinder 4 having a rotary axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 , 8 , a web guiding element 9 , a sliver trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 , having flats 14 , a coiler can 15 and a sliver coiler 16 .
Turning to FIGS. 2, 5 and 7 a , a flexible bend 17 is mounted by screws 32 on either side of the carding machine, laterally of the machine frame. The flexible bend 17 is provided with a plurality of set screws 31 . The flexible bend 17 has a convex upper face 17 a and an underside 17 b . The upper face 17 a of the flexible bend 17 supports a slide guide 20 , made, for example, of a low-friction synthetic material. The slide guide 20 has a convex upper surface 20 a and a concave lower surface 20 b . The concave lower surface 20 b lies on the convex upper surface 17 a and may slide thereon as indicated by the arrows A, B. The flat bars 14 have at opposite ends (spaced from one another parallel to the cylinder axis M) a flat bar head 14 a from which extend two steel pins 14 b adapted to glide on the convex upper surface 20 a of the slide guide 20 in the direction of the arrow C. The underface of each flat bar 14 carries a flat bar clothing 18 . The circle circumscribed on the flat bar clothings 18 is designated at 21 . The carding cylinder 4 has along its circumference a cylinder clothing 4 a such as a sawtooth clothing. The circle circumscribed about the cylinder clothing 4 a is designated at 22 . The clearance between the circles 21 and 22 is designated at d and amounts to, for example, 0.20 mm. The clearance between the convex upper surface 20 a of the slide guide 20 and the circle 22 is designated at e. The convex upper surface 20 a has a radius r 1 , and the circle 22 has a radius r 2 . The radii r 1 and r 2 intersect in the rotary axis M of the carding cylinder 4 .
FIGS. 3 a , 3 b and 3 c show, to an exaggerated extent for better understanding, the change of the distances between the clothings 18 of the flat bars 14 and the clothing 4 a of the carding cylinder 4 .
FIG. 3 a shows the initial position of the flat bars 14 ′, 14 ″, 14 ′″ after their positioning on the upper face 20 a of the slide guide 20 . For manufacturing reasons the respective distances a 1 , b 1 , and c 1 are different between the respective clothings 18 a , 18 b and 18 c , on the one hand and the cylinder clothing 4 a , on the other hand. For example, the distance a 1 , between the clothing 18 a of the flat bar 14 ′ and the cylinder clothing 4 a is smaller than the distance b 1 (for example, {fraction (1/100)} inch) between the clothing 18 b of the flat bar 14 ″ and the cylinder clothing 4 a , whereas the distance c 1 between the clothing 18 c of the flat bar 14 ′″ and the cylinder clothing 4 a is greater than the distance b 1 .
According to FIG. 3 b , the flat bars 14 ′, 14 ″and 14 ′″ are slowly shifted radially to the carding cylinder 4 in the direction D until the points of the clothing 18 a (having the smallest clearance a 1 , according to FIG. 3 a ) and the cylinder clothing 4 a are just in contact with one another, that is, the clearance a 2 is zero, while the clearance between the clothing 18 b , 4 a and between the clothing 18 c , 4 a is b 2 and c 2 , respectively. Such a minimal contact is harmless even if the carding cylinder 4 rotates. The contact between a flat bar clothing 18 and the cylinder clothing 4 a is sensed by a device 23 as will be described in conjunction with FIGS. 6, 6 a.
Subsequently, as shown in FIG. 3 c , the flat bars 14 ′, 14 ″ and 14 ′″ are shifted radially in the direction E in such a manner that the points of the clothing 18 a of the flat bar 14 ′ and the cylinder clothing 4 a are just separated from one another, that is, a clearance a 3 is obtained. The clearance a 3 should be as small as safely possible, for example, between {fraction (1/1000)} and {fraction (2/1000)} inch. As a result of the above-described manipulation the clearances b 3 and c 3 are as small as possible. A small distance a 3 , b 3 and c 3 , that is, a possibly small carding clearance is desirable for achieving superior carding results.
In FIGS. 4 a and 4 b , shifting of the slide guide 20 on the flexible bend 17 in the direction of the arrow A is shown. Due to the wedge shape of the slide guide 20 , its circumferential displacement, for example, in the direction of the arrow A, will increase the clearance b 1 , b 2 and b 3 between the respective flat clothings 18 a , 18 b and 18 c on the one hand and the cylinder clothing 4 a , on the other hand; that is, the clearance between the circles 21 and 22 (FIG. 2) is increased. Thus, by shifting the slide guide 20 in the direction A, the flat bars 14 are lifted from their position shown in FIG. 4 a in the direction E into the position illustrated in FIG. 4 b . The flat bars 14 are slowly moved between the end roller 13 a and the end roller 13 b of the traveling flats assembly 13 by a belt 40 in the direction C (FIG. 2 and 4 a ) and are reversed as they travel on the end roller 13 b to be moved on the idling side of the traveling flats assembly in the rearward direction F.
As shown in FIG. 5, a carrier element 26 affixed to the slide guide 20 is coupled with a toothed rack 27 a engaging a gear 27 b which is rotatable in the directions O, P and which is rotated by a drive, such as a reversible motor 28 . The device can circumferentially shift the slide guide 20 in the direction of the arrow A or B. The drive 28 is coupled with an inputting device 29 with which the desired, smallest carding gap a 3 , for example, {fraction (3/1000)} inch may be set as a desired magnitude. Such a setting may also be performed by an electronic control and regulating device 33 (FIG. 8) which has a desired value memory and/or an inputting device.
As shown in FIG. 6, a device 23 is coupled to the flat bar clothings 18 and the cylinder clothing 4 a in an electric circuit for emitting a signal when the clothing 18 of a flat bar 14 contacts the clothing 4 a of the carding cylinder. Thus, the clothing points of the clothings 4 a and 18 act as electric contacts. The device 23 may be structured such that the clothing 4 a of the cylinder 4 whose bearings are electrically insulated from the frame, is connected with one pole of an electric current source 24 , whereas the other pole is coupled to the machine frame in a non-illustrated manner, so that the flat bars 14 are coupled with that pole of the current source. The electric circuit contains an indicating device 25 which shows whether or not a contact is present between the clothing points. Such a contacting may also be detected by measuring the electric resistance in the circuit, or by an arrangement based on sound detection. Or, as other alternatives of contact-sensing, the acceleration of the traveling flats is sensed or, in case of a stationary carding cylinder 4 , a motion of the carding cylinder as entrained by the contacting traveling flat bar is observed.
Turning to FIG. 7 a , a circumferential groove 30 is provided in the flexible bend 17 . The slide guide 20 which is composed of an elastic, low-friction synthetic material is, as shown in FIG. 7 b , accommodated in the groove 30 such that one part of the slide guide 20 is situated within the groove 30 whereas another part projects beyond the convex upper surface 17 a of the flexible bend 17 . The slide guide 20 is shiftable within the groove in the direction of the arrows A, B so that the concave lower face 20 b slides on the bottom surface 30 a of the groove. The side faces 30 b and 30 c of the groove constitute lateral guides for the slide guide 20 . By means of the set screws 31 first the flexible bend 17 is set, while maintaining its correct shape, to a carding clearance of, for example, {fraction (6/1000)} inch. It is only with the device shown in FIGS. 4 a , 4 b and 5 that the carding clearance may be reduced to such an extent that the flat bar clothing 18 which originally has the smallest distance from the cylinder clothing 4 a , contacts the latter. Subsequently, the carding clearance may be set very accurately to a desired magnitude with the device shown in FIGS. 4 a , 4 b and 5 .
FIG. 8 illustrates an electronic control and regulating device 33 , such as a microcomputer to which there are connected an inputting device 34 for the desired carding clearance, the drive 28 for rotating the gear 27 b , the device 23 to detect a contact between the flat bar clothing 18 and the cylinder clothing 4 a , the indicating device 25 , the inputting device 29 and a switching element 35 for actuating the drive 28 .
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A fiber processing machine includes a roll having a circumferential surface provided with a first clothing having clothing points; a counter member having a surface provided with a second clothing cooperating with the first clothing and having clothing points; and a device for setting a clearance between the clothing points of the first and second clothings. The device includes an arrangement for approaching the roll and the counter member to one another until the clothing points of the first and second clothings contact and for moving away the roll and the counter member from one another until the clothing points of the first and second clothings assume a desired clearance. The device further has an arrangement for emitting a signal when the clothing points of the first and second clothings contact one another.
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This application is a continuation, of application Ser. No. 783,728 filed Oct. 3, 1985, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the reaction products of the alpha-halogenated half esters or amides of succinic acid and thiadiazole dimercaptides as new compositions of matter and their use as lubricant additives possessing multifunctional properties such as extreme pressure, antiwear, antioxidant and anticorrosion.
Compounds of the present invention have several useful properties as lubricant additives. Most of the literature on oil additives discloses novel compositions which possess one useful property for each invention. For example, U.S. Pat. No. 2,836,564 discloses the condensation products of alpha-halogenated aliphatic monocarboxylic acids and 2,5-dimercapto-1,3,4-thiadiazole as new compositions of matter which possess only one useful property, namely corrosion and/or rust inhibition. In addition, there is nothing in the literature that discloses or suggests the use of the above new compositions as multifunctional lubricant additives.
One of the useful properties according to the present invention is the inhibition of corrosion or rusting of metallic surfaces of equipment employing lubricants, especially in equipment where steam or water is present. As little as a 0.03% concentration in a lubricating media inhibits rusting of metal surface which is in contact with sea water at 60° C. for more than two days. Another useful property imparted to lubricants according to the present invention is reducing wear and friction to metal surfaces of machinery operating under heavy loads, where metal slides against metal, resulting in deterioration of conventional lubricants and excessive wear. The novel additives of the present invention also impart extreme pressure (EP) and antioxidant properties to lubricants.
Typical performance data for the products of the invention, including EP, antiwear, and rust inhibition properties are recorded in Table I.
The invention also relates to a number of novel intermediate compounds useful in preparing the thiadiazole lubricant additive compounds of the invention.
SUMMARY OF THE INVENTION
The compounds of this invention are defined as compounds of the structure
Z.sub.1 --S--Q--S--Z.sub.2,
wherein:
Q is a bivalent thiadiazole ring moiety selected from the group consisting essentially of 1,3,4-thiadiazole; 1,2,4-thiadiazole; 1,2,3-thiadiazole; and 1,2,5-thiadiazole; ##STR1## and ##STR2## wherein: R and R"' are each independently selected from the group consisting essentially of hydroxyl, alkoxy, branched or straight chain alkylenoxy of from 2 through 22 carbon atoms, arylalkoxy, OR', NHR', and NR'R';
R' and R" are each independently selected from the group consisting essentially of hydrogen, alkyl, branched or straight chain alkylene of 1 through 22 carbon atoms, arylalkyl, and heterocyclicalkylene, with the further proviso that at least one of R, R', R", or R"' forms a carboxyl group with the adjacent carbon atom to which it is linked.
To provide adequate rust inhibition, the compounds of the present invention include at least one carboxyl group. (See, e.g., Example 16).
Preferred compounds are as above, wherein: (1) Q is the 1,3,4-thiadiazole moiety, R' and R" are hydrogen, and R and R"' are hydroxyl; (2) R and R"' are--OC 13 H 27 , R' is C 13 H 27 , R" is hydrogen, and Q is the 1,3,4-thiadiazole moiety; and (3) R and R"' are--OC 13 H 27 , R' is C 13 H 27 , R" is hydrogen, and Q is the 1,3,4-thiadiazole moiety and the triethylamine, triethanolamine, and tripentylamine salts thereof; (4) R and R"' are--OC 13 H 27 , R' and R" are hydrogen, and Q is the 1,2,4-thidiazole moiety; (5) R and R"' are--OC 18 H 35 , R' and R" are hydrogen, and Q is the 1,2,4-thiadiazole moiety; (6) R and R"' are--OC 18 H 37 , R' and R" are hydrogen, and Q is the 1,2,4-thiadiazole moiety; (7) R' and R" are hydrogen; R and R"' are NHR"" or NR"" 2 wherein R"" (can be the same or different) is selected from the group consisting of hydrogen, alkyl, branched or straight chain alkylene of 1 through 22 carbon atoms, arylalkyl, and heterocyclicalkylene; and (8) the compound of (7) wherein R"" is--C 12 H 25 .
Among the preferred novel intermediate compounds of the invention are: 4-tridecyl monoester of 2-bromo-succinic acid; ditridecyl 2-bromo-succinate; 4-oleyl monoester of 2-bromo-succinic acid; 4-octadecyl monoester of 2-bromo-succinic acid; and 2-bromo-4-dodecylamino-4-oxobutanoic acid.
Included among the novel oil additive compounds of the invention are those as above defined having a carboxyl group and those compounds wherein the carboxyl group is in the form of an alkali metal or amine salt to enhance the useful properties.
The lubricant of the invention is defined as a major amount of a grease or oil of lubricating viscosity and a minor amount of a compound of the invention as above defined as a lubricant additive to provide enhanced properties to said grease or oil.
DETAILED DESCRIPTION OF THE INVENTION
The new compositions of matter of the present invention are the reaction products of the monoester or monoamide of 2-halosuccinic acid with the alkali metal salts of thiadiazole dimercaptides according to the following equation: ##STR3##
M=Na, K, Li, NH 4 R=OR', NHR', NR' 2
The thiadiazole dimercaptide can also react with 1 mole of the above monoester or monoamide and 1 mole of the diester or diamide to yield a monocarboxy reaction product having the following structure: ##STR4##
The above reaction products can also be obtained by the addition of thiadiazole dimercaptan (commercially available) ##STR5## to the ester or amide derivative of maleic acid.
The intermediate ester or amide derivative of succinic acid can be prepared by the reaction of a primary or secondary alcohol or amine with halosuccinic anhydride in a suitable solvent. Among the solvents that can be used are the following: Hexane, toluene, THF, and ether. The temperature ranges between 25° to 150° C., preferably 25°-80° C.
Bromosuccinic anhydride can be prepared by refluxing bromosuccinic acid with acetyl chloride followed by distillation of the reaction product. The diester of bromosuccinic acid is prepared by refluxing the acid with 2 moles of the desired alkanol for 7 hours in the presence of a catalytic amount of para toluene sulfonic acid.
Reaction of thiadiazole dimercaptide with the bromosuccinic acid derivative is carried out in ethanol at reflux for 6-12 hours, preferably 8-10 hours. Other solvents can be used such as acetone, acetonitrile, tetrahydrofuran, p-dioxane, etc. The range of the reaction temperature is 25°-150° C. and preferably 70°-100° C.
The following examples are specific embodiments thereof and are not intended to limit the scope of this invention. Structure is confirmed by infrared spectra and in most cases, also by elemental analysis.
EXAMPLE 1
Preparation of [(1,3,4-thiadiazol-2,5-diyl)dithio]-bis(2,2'-succinic acid):
About 68 g. of a solution of 39.6 g. (0.6 mole) of KOH (85%) in 200 ml. of abs. ethanol is added to a stirred slurry of 15.0 g. (0.1 mole) of 2,5-dimercapto-1,3,4-thiadiazole in 80 ml. of abs. ethanol, at 10°-15° C. The resultant mixture is stirred at 10°-15° C. for a half hour, and thereafter, a clear solution of 39.4 g. (0.2 mole) of bromosuccinic acid in 70 ml. of abs. ethanol is added dropwise over a period of 15 minutes at 10°-15° C. followed by the gradual addition of the remainder of the KOH solution at the same temperature range over a period of 15 minutes. After adding 100 ml. of abs. ethanol, the reaction mixture is stirred in the cooling bath for more than one hour, then overnight in water bath at ambient temperature.
The white emulsion-like reaction mixture is refluxed for 6 hours. The hard insoluble solid at bottom of reaction flask is removed by the decantation, dissolved in 500 ml. of distilled water and filtered. pH of filtrate is approximately 8. The filtrate is cooled to 15° C. then acidified with 20% HCl to pH 1.
The acidified aqueous solution is stripped to remove water and volatiles at 60° C. and 5 mm. pressure and the resultant 87.9 g. of an off-white solid residue (slightly wet) is extracted with 3×80 ml. portions of hot acetone. The unextracted solid is dried at about 50° C. and a reduced pressure of 30-50 mm. Hg to obtain 45.3 g. of a white solid which is mostly inorganic salt.
The acetone extract is treated with charcoal then heated on a steam bath to remove solvent. The reddish brown, very viscous residue is again extracted with ether then with tetrahydrofuran and the extract is filtered by gravity to remove 0.5 g. of white solid (discarded).
The clear filtrate is heated on a steam bath and the reddish residue is dried at 100° C. for 8 hours under reduced pressure to obtain 77% yield of a light yellow solid product of this example; m. p. 135°-145° C. (opaque). It is soluble in H 2 O and acetone.
Anal. Calc'd: C, 31.4; H, 2.64; N, 7.33; S, 25.1;
Found: C, 31.8; H, 2.76; N, 6.51; S, 23.5.
EXAMPLE 2
Preparation of 4-tridecyl ester 2-bromosuccinic acid
A mixture of 18.4 g. (0.103 mole) of bromosuccinic anhydride, 21.6 g. (0.108 mole) of tridecanol and 100 ml. of tetrahydrofuran is stirred at ambient temperature for 1.5 hours then refluxed for 3 hours. The clear reaction mixture is stripped at 60° C. under reduced pressure to obtain 99.6% yield of a pale yellowish brown liquid product of this example.
Anal. Calc'd: C, 53.8; H, 8.24; Br, 21.1;
Found: C, 54.4; H, 8.35; Br, 20.7.
EXAMPLE 3
Preparation of ditridecyl 2-bromosuccinate
A mixture of 19.7 g. (0.1 mole) of bromosuccinic acid, 40.1 g. (0.2 mole) of tridecanol, 0.25 g. of p-toluenesulfonic acid and 200 ml. of toluene is refluxed for 7 hours, using a Dean-Stark trap. There is collected 3.6 ml. of H 2 O in the trap which is exactly the calculated amount for this reaction when completed.
The reaction mixture is filtered by gravity and the clear filtrate is stripped at 65° C., 5 mm. pressure to obtain a liquid residue. Drying at about 60° C. under reduced pressure afforded 54.1 (96% yield) of a slightly cloudy liquid product of this example.
An attempt to purify the product by dissolving in hexane, washing with 5% NaHCO 3 solution followed by washing 2X with water, removing the solvent on steam bath and drying the residue at 60° C. under reduced pressure fails to give a clear colorless liquid product. Heating the sample at 100° C. for 4 hours also fails to have any effect. No attempt is made to distill the crude product. However, the infrared spectrum is in agreement with the required structure.
EXAMPLE 4
Preparation of tris(tridecyl ester) [1,3,4-thiadiazol-2,5-diyl)dithio]-bis(2,2'-succinic acid)
A monopotassium mercaptide of 2,5-dimercapto-1,3,4-thiadiazole is prepared by the slow addition of a solution of KOH in methanol to a slurry of 2,5-dimercapto-1,3,4-thiadiazole in methanol followed by refluxing for 15 minutes and using 1:1 molor ratio. Filtration of the dark reddish reaction mixture and stripping the solvent off at about 50° C. and 20-30 mm. vacuum affords the greenish yellowish solid of monopotassium salt in 95% yield.
A solution of 14.05 g. (0.025 mole) of ditridecyl 2-bromosuccinate in 100 ml. abs. ethanol is added all at once to a stirred slurry of 4.7 g. (0.025 mole) of the above monopotassium mercaptide in 50 ml. of abs. ethanol. The mixture is then refluxed for 8 hours and filtered. The white precipitate is washed twice with small portions of cold abs. ethanol, adding washing to filtrate. Weight of the dried precipitate is 2.6 g. Calculated amount of KBr by-product is 3.0 g.
The filtrate is cooled in ice to 5°-8° C. before the addition of a solution of 1.65 g. (0.025 mole) of KOH in 40 ml. of abs. ethanol. The temperature of stirred mixture rose to 12° C. The ice bath is removed and stirring continued at ambient temperature for 0.5 hour. A solution of 9.5 g. (0.025 mole) of 4-tridecyl 2-bromosuccinic acid in 10 ml. of abs. ethanol is added dropwise to the stirred reaction mixture followed by refluxing for 12 hours. The white precipitate is filtered off, washed several times with hexane and then dried to weigh 2.7 g. (calc'd KBr 3.0 g.).
The clear filtrate is stripped at 60° C. and 10 mm. pressure to remove the solvent. There is obtained 25.4 g. of a light yellowish brown viscous liquid residue which is dissolved in 150 ml. of hexane. The resulting solution is washed three times with tap water and saturated solution of sodium chloride to break the emulsion. After drying with anhydrous sodium sulfate, the washed hexane solution is stripped as above and the residue is dried at 50° C. under reduced pressure to obtain 22.0 g. (91.8% yield) of a light yellowish brown slightly viscous liquid product of this example. The result of antioxidant properties in a paraffin oil is recorded in Table II.
Anal. Calc'd: C, 63.3; H, 9.54; N, 3.01;
Found: C, 63.1; H, 9.43; N, 2.83.
EXAMPLE 5
Preparation of bis(4,4'-tridecyl ester) [(1,3,4-thiadiazol-2,5-diyl)dithio]-bis(2,2'-succinic acid)
A dipotassium dimercaptide of 2,5-dimercapto-1,3,4-thiadiazole is prepared by reacting 3.8 g. (0.025 mole) of 2,5-dimercapto-1,3,4-thiadiazole with 3.3 g. (0.05 mole) of potassium hydroxide in 100 ml. of abs. ethanol, following the procedure of Example 4.
A solution of 19.0 g. (0.05 mole) of 4-tridecyl 2-bromosuccinic acid (Example 2) in 50 ml. of abs. ethanol is added dropwise to the above stirred dipotassium mercaptide solution over a period of 15 minutes. After stirring for a few minutes, an additional 50 ml. of abs. ethanol is added and the resulting mixture is refluxed for 6 hours. The white precipitate is filtered off and washed several times with cold abs. ethanol, then dried at 60° C. under reduced pressure to obtain 5.35 g. of white solid (calc'd KBr=5.95 g.). The filtrate, combined with ethanol washing, is stripped to remove solvent at 65° C. and 1 mm. pressure. There is obtained 19.7 g. of viscous liquid residue which is redissolved in 200 ml. of hexane resulting in a cloudy solution. Filtration by gravity does not clarify the solution completely. The filtrate is washed with water, dried and stripped as in Example 4 to obtain 16.9 g. (93 % yield) of a viscous liquid which solidified on standing to an off-white solft solid product of this example.
Anal. Calc'd: C, 57.9; H, 8.37; N, 3.75;
Found: C, 58.2; H, 8.68; N, 3.54.
EXAMPLE 6
Preparation of the triethylamine salt of bis(4,4'-tridecyl ester) [(1,3,4-thiadiazol-2,5-diyl)dithio]-bis(2,2'-succinic acid)
A solution of 0.51 g. (0.005 mole) of triethylamine in 25 ml. of hexane is added gradually to a stirred solution of 1.8 g. (0.0025 mole) of the product in Example 5, in 100 ml. of hexane. At once, the mixture becomes cloudy and is stirred at ambient temperature overnight. Thereafter, it is refluxed for 2 hours. A small viscous bottom layer is separated, washed with hexane and dried to obtain 1.7 g. of a viscous light yellowish brown material which is soluble in water and in acetone. Infrared spectrum indicates an amine salt for this product (B). The hexane layer is heated on a steam bath to obtain a soft colorless residue; the weight after drying at 60° C. under reduced pressure is 0.5 g. (A). By-product (A) is soluble in hexane and in oil but insoluble in water. It is believed to be an amide derivative but its structure is not determined.
EXAMPLE 7
Preparation of the triethanolamine salt derivative
Experiment of Example 6 is repeated except substituting triethanolamine for triethylamine and tetrahydrofuran for hexane. There is obtained a light yellowish brown semi-solid material, soluble in water and in acetone but insoluble in hexane or oil. Infrared spectrum is in agreement with the structure of a salt reaction product.
EXAMPLE 8
Preparation of tripentylamine salt derivative
Experiment of Example 6 is again repeated except substituting tripentylamine for triethylamine. There is obtained 100% yield of a dark, slightly viscous, yellowish brown material. The product is insoluble in water, soluble in acetone and partially soluble in paraffinic mineral oil.
EXAMPLE 9
Preparation of bis(4,4'-tridecyl ester) [(1,2,4-thiadiazol-3,5-diyl)dithio]-bis(2,2'-succinic acid)
Example 5 is repeated using the same quantities, procedure and reactants except the dipotassium dimercaptide of 1,2,4-thiadiazole (prepared according to procedure of W. A. Thaler and J. R. McDivitt; J. Org. Chem. 36, 14-18 (1971) is substituted for the 1,3,4-thiadiazole dimercaptide and the reflux time is 8-9 hours. There is obtained 17.3 g. (95% yield) of a light yellowish brown viscous liquid product of this example. It is soluble in acetone and hexane but partially in H 2 O.
Anal. Calc'd: C, 57.9; H, 8.37; N, 3.75;
Found: C, 58.2; H, 8.49; N, 3.28.
EXAMPLE 10
Preparation of 4-oleyl ester 2-bromosuccinic acid
Experiment of Example 2 is repeated using oleyl alcohol and the following quantities: 17.9 g. (0.1 mole) of 2-bromosuccinic anhydride, 28.2 g. (0.105 mole) of oleyl alcohol and 100 ml. of tetrahydrofuran. There is obtained 45.2 g. of a medium dark yellowish brown liquid product of this example that is contaminated with small amount of unreacted oleyl alcohol.
Anal. Calc'd: C, 59.1; H, 8.79; Br, 17.9;
Found: C, 59.7; H, 9.06; Br, 16.6.
EXAMPLE 11
Preparation of 4-octadecyl ester 2-bromosuccinic acid
Similar to Example 10, the octadecyl derivative is prepared using only 1% molar excess of octadecanol. There is obtained 44.7 g. (99.5% yield) of a light tan waxy solid product of this example.
Anal. Calc'd: C, 58.8; H, 9.19; Br, 17.8;
Found: C, 58.6; H, 8.8; Br, 17.5.
EXAMPLE 12
Preparation of bis(4,4'-oleyl ester) [(1,2,4-thiadiazol-3,5-diyl)dithio]-bis(2,2'-succinic acid)
Experiment of Example 9 is repeated except that the oleyl ester of bromosuccinic acid (Example 10) is substituted for the tridecyl ester of bromosuccinic acid. There is obtained a light yellowish brown viscous liquid product of this example in 90% yield. It is soluble in acetone and in a paraffinic mineral oil. The result on antioxidant properties in a paraffin oil is listed in Table II.
Anal. Calc'd: C, 62.5; H, 8.90; N, 3.17;
Found: C, 62.2; H, 8.85; N, 3.12.
EXAMPLE 13
Preparation of bis(4,4'-octadecyl ester) [(1,2,4-thiadiazol-3,5-diyl)dithio]-bis(2,2'-succinic acid)
By repeating experiment of Example 12 and substituting the octadecyl ester derivative of Example 11 for the oleyl ester derivative of Example 10, there is obtained a waxy pale yellowish brown solid product of this example in 84% yield. Melting point, 41°-43° C. It is soluble in hexane and slightly soluble in acetone.
Anal. Calc'd: C, 62.3; H, 9.31; N, 3.16;
Found: C, 62.4; H, 9.48; N, 2.82.
EXAMPLE 14
Preparation of 2-bromo-4-dodecylamino-4-oxobutanoic acid
A solution of 9.3 g. (0.05 mole) of dodecylamine in 30 ml. of hexane is added dropwise to a stirred mixture of 9.0 g. (0.05 mole) of 2-bromosuccinic anhydride in 70 ml. of hexane at 5°-10° C. over a period of 15 minutes. Reaction is exothermic and the mixture is stirred for an additional 15 minutes while still in cooling bath. As a result, the temperature rises to 15° C. and the reaction takes the appearance of a white emulsion. Hexane (100 ml.) is added and stirring is continued at ambient temperature for 24 hours. The white insoluble solid is filtered off, washed several times with hexane then dried at about 50° C. and reduced pressure to obtain 16.1 g. (89% yield) of a white slightly waxy solid product of this example; m. p. 62°-70° C. (opaque).
Anal. Calc'd: C, 52.8; H, 8.30; Br, 21.9; N, 3.84;
Found: C, 53.2; H, 8.78; Br, 23.1; N, 3.96.
EXAMPLE 15
Preparation of [(1,2,4-thiadiazol-3,5-diyl)dithio]-bis[2,2'-(4-dodecylamino-4-oxo)-butanoic acid]
A hot solution of 13.1 g. (0.036 mole) of the monoamide product of Example 14 in 50 ml. of absolute ethanol is added gradually to a stirred mixture of 4.1 g. (0.018 mole) of dipotassium dimercaptide of 1,2,4-thiadiazole, prepared according to procedure of W. A. Thaler and J. R. McDivitt, J. Org. Chem. 36, 14-18 (1971). The resultant mixture gets significantly cloudy and is refluxed for 9 hours. The white insoluble solid is filtered off, washed twice with 2.5 ml. of ice cold abs. ethanol, adding the washing to the filtrate. After drying at 60° C. and reduced pressure, there is obtained 3.7 g. of a white solid which is water soluble and represents 86% of the calculated amount of KBr.
The filtrate is stripped at 60° C. and about 5 mm. pressure to obtain 13.4 g. of a yellowish brown residue which in turn is dissolved in 200 ml. of hot ether giving cloudy solution. A small amount of white solid (discarded) is collected on filtration and the filtrate is washed with 2×100 ml. of water, dried with anhydrous sodium sulfate then heated on a steam bath to remove solvent and volatile material. The residue is finally dried as above to afford 10.1 g. (78% yield) of a yellowish brown slightly soft solid product of this example which is insoluble in water but soluble in acetone.
Anal. Calc'd: C, 57.0; H, 8.43; N, 7.81;
Found: C, 57.1; H, 9.33; N, 7.45.
EXAMPLE 16
Bis(ditridecyl ester) [(1,2,4-thiadiazol-3,5-diyl)dithio]-bis(2,2'-succinic acid)
Example 9 is repeated using the same molar ratios, procedure and reactants except ditridecyl 2-bromosuccinate of Example 3 is substituted for 4-tridecyl 2-bromosuccinic acid of Example 2. There is obtained 92% yield of a pale yellow viscous liquid crude product of this example. It is soluble in acetone and hexane but insoluble in water.
Anal. Calc'd: C, 66.98; H, 10.34; N, 2.52;
Found: C, 65.7; H, 9.77; N, 1.98.
TABLE I__________________________________________________________________________Performance Data of Additives in a Paraffinic Mineral Oil Shell Four-Ball Shell Four-Ball Weld Pt., kg Wear Scar, mm Rust Inhibition ASTM D 2596 ASTM D 2266 ASTM D 665 A & B__________________________________________________________________________Base Oil* 80 0.80 Severe rust after 24 hrs in distilled and sea waterExample 41% in base oil 160 0.66 No rust after 48 hrs in sea water.0.05% in base oil -- -- No rust after 48 hrs in distilled water.Example 51.0% in base oil 160 -- --0.05% in base oil -- -- No rust after 48 hrs in sea water.Example 60.05% in base oil -- -- No rust after 48 hrs in sea water.0.03% in base oil -- -- Very slight rust after 48 hrs in sea water.Example 80.05% in base oil -- -- No rust after 48 hrs in sea water.Example 91% in base oil 160 0.67 --0.05% in base oil -- -- No rust after 48 hrs in sea water.0.03% in base oil -- -- Slight rust after 48 hrs in sea water.Example 121% in base oil 160 0.67 --0.05% in base oil -- -- No rust after 48 hrs in sea water.0.03% in base oil -- -- Severe rust after 24 hrs in sea water.Example 131% in base oil 160 0.66 --0.05% in base oil -- -- Moderate rust after 24 hrs in sea water.Example 150.05% in base oil -- -- No rust after 48 hrs in sea water.0.03% in base oil -- -- No rust after 48 hrs in sea waterExample 160.05% in base oil Severe rust in sea water in less than 20 hours.__________________________________________________________________________ *Base oil: 160 SUS solvent refined paraffinic mineral oil.
TABLE II______________________________________Evaluation of Antioxidant Properties of Compositionsin a Paraffin Oil by Means of High Pressure DSCat 185° C. and 500 PSI O.sub.2 Induction TimeComposition min.______________________________________Paraffin Mineral Oil (PMO) 1.91% Tridecyl ester (Example No. 4) 133.4in PMO1% Dioleyl ester (Example No. 12) 107.0in PMO1% Zinc diamyldithiophosphate 109.0in PMO (Commercial Product)______________________________________
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The reaction products of the alpha-halogenated half esters or amides of succinic acid and thiadiazole dimercaptides as new compositions of matter and their use as lubricant additives possessing multifunctional properties such as extreme pressure, antiwear, antioxidant and anticorrosion.
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FILED OF THE INVENTION
The invention pertains to an embroidery machine in which a large number of individual embroidery stations are arranged horizontally.
BACKGROUND OF THE INVENTION
Two basic arrangements have thus far been introduced for realizing the drive of embroidery tools of industrial embroidery machines.
According to one arrangement, a main motor with a main drive shaft is arranged along and across the embroidery machine. Cam plates for the individual drives of the embroidery tools are fastened on this main drive shaft. The movement is, via roller levers and additional transfer elements, transferred onto several oscillating shafts which extend along the entire machine and, in turn, actuate the linear movement of the corresponding embroidery tools at the numerous embroidery stations. A similar arrangement is described and schematically illustrated in FIG. 1 of DE 3,502,894.
According to a different arrangement, the main drive shaft is arranged along the machine. The corresponding cam plates are fastened on the front and the rear of this rotating main drive shaft. The movements are transferred from these cam plates onto different oscillating shafts which extend along the embroidery machine and, in turn, actuate the different embroidery tools at the numerous embroidery stations. Such an arrangement is illustrated in FIG. 1 of EP 0,193,625.
This particular patent also suggests a new solution in which the cam plates are replaced by highly dynamic electric motors, so that the different oscillating shafts which extend along the embroidery machine are driven by "electronic cam gears" in order to actuate the embroidery tools.
All three solutions have one severe disadvantage: when an industrial embroidery machine has a length of 10-20 m, it becomes very difficult to control the long oscillating shafts in a dynamic fashion at higher rotational speeds. The torsion and the torsional oscillations of these long shafts lead to a distortion of the movement to be performed by the embroidery tools as well as to a chronological phase displacement between the front and rear portion of the machine. This aspect represents one of the factors which limit the rotational speed of industrial embroidery machines if the machines operate with rotational speeds above 200 rpm.
SUMMARY OF THE INVENTION
The invention is based on the objective to remove the technical limitation of the rotational speed and simultaneously attain a less expensive solution.
According to the invention, this objective is attained by the fact that the drives for the needles as well as the other embroidery tools are arranged approximately in the center of the embroidery machine.
Due to the arrangement of the drives for the different oscillating shafts actuating the different embroidery tools in the center of the machine, the oscillating length of the drive shafts is generally cut in half, so that the limiting values of the tolerable dynamic fluctuations only occur at higher rotational speeds. The aforementioned measure also eliminates the main drive shaft which is arranged along or perpendicularly to the machine.
This concentrated central arrangement facilitates a combination of all these drives into one compact actuation group.
It is possible to distribute several such actuation groups along the machine in order to divide the oscillating drive shafts for the different embroidery tools into even shorter sections. These actuation groups are preferably incorporated into modular, premounted structural components which, if assembled in a row during the final mounting process, result in embroidery machines with the corresponding length. These actuation groups may be connected with each other via one collective shaft and driven by one collective motor. However, modern actuation technology makes it possible to equip each actuation group with its own drive motor, and to synchronize the motors with each other very accurately.
The requirements of embroidery technology, the dynamic problems of such large machines, and the relatively high rotational speeds result in quite complex moving sequences of the individual embroidery tools which must be synchronized with each other in the most accurate fashion possible. Cam gears with double cams have been successfully used for such drives. These cam gears may be easily adjusted relative to each other chronologically in order to take into consideration the special requirements of the embroidery process. However, the shape of the cams is constant, which means that the moving sequence of the corresponding embroidery tools is also constant. The use of highly dynamic motors and modern control technology makes it possible to realize such complex movement sequences by means of controlling/regulating the motor. This technology also makes it possible to store different preprogrammed moving sequences, and to retrieve the moving sequences from the machine program on request. However, it was established that even the most modern motor and control technology reaches its limits at extreme accelerations/decelerations. Depending on the technological possibilities and requirements of the embroidery process, an optimal solution may be attained by the fact that some of the embroidery tools are driven via cam gears, while other embroidery tools are driven via highly dynamic regulated motors.
The moving sequences of all the embroidery tools must be accurately synchronized. If the main actuation group is arranged in the center of the machine, the problem of connecting/synchronizing the embroidery tools at the front side and the rear side of the material to be embroidered arises. A mechanical connection for the conventional design of industrial embroidery machines with a center trough for the tenter frame is comparatively demanding and difficult. One drive motor on the actuation group for the embroidery tools in front of the tenter frame and a second drive motor on the actuation group behind the tenter frame are electrically synchronized in a very accurate fashion, whereby the possibility of exactly defined, small chronological displacements between the movements of the embroidery tools in front of the tenter frame and behind the tenter frame is provided in the control mechanism.
A different new design makes it possible to eliminate the center trough for the tenter frame.
This design facilitates a direct mechanical connection between the actuation groups in front of the tenter frame and behind the tenter frame. There are two basic variations to attain this objective, namely a direct mechanical connection via corresponding drive shafts and similar elements, or an electronic coupling may be provided according to a different variation.
This solution makes it possible to use only one main drive motor in the center of the machine, and the exact chronological synchronization of the moving sequences is ensured without additional effort.
BRIEF DESCRIPTION OF THE FIGURES
The invention is described below, in detail, with the aid of the figures. The figures and their description disclose additional characteristics and advantages of the invention, as follows:
FIG. 1 is a perspective view of a central assembly module for an embroidery machine with a center drive.
FIG. 2 is a cross-sectional view through a central assembly module taken on line II--II of FIG. 1.
FIG. 3 is a cross-sectional view through a separate embroidery tool drive with a separate motor for actuating the drill.
FIG. 4 is a front view, partly in cross-section, through a frame according to FIG. 1 including illustration of an additional mechanical connection for the drives on the front side and rear side of the frame.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
According to the invention, a frame of an embroidery machine is of U-shaped construction and includes lower, transversely extending supports 27 arranged between lateral posts 26 which define a channel 28 that is open on a front side therebetween. An approximately U-shaped frame is formed which is reinforced by supports 29 extending in a longitudinal direction.
Additional longitudinal supports 30 are arranged below supports 29. The embroidery tools are arranged on the supports 29. This particular design provides the advantage that additional U-shaped frames may be connected to the front side of the frame.
A main motor 1 is arranged centrally on the front side of the frame, and the motor drives an actuation group 2 which is also situated on the front side of the frame.
An additional actuation group 4 which is driven by the main motor 3 is arranged on the rear side of the frame.
The two actuation groups 2, 4 act upon assigned longitudinal shafts 5, 6, 7, whereby the corresponding embroidery tools are actuated via connecting rods 10, 11, 12.
Connecting rod 10 drives longitudinal shaft 5 for actuation of the embroidery needle, while connecting rod 11 drives longitudinal shaft 7 for actuation of the thread guide.
Actuation group 4 arranged on the rear side drives the oscillating longitudinal rod 9 for the actuation of the shuttle via the connecting rod 12.
FIG. 1 shows drives 1, 3 arranged in the center of the frame, and thus the aforementioned elements are also actuated centrally. The connecting rods 10, 11, 12 act upon corresponding levers which are connected with the previously described longitudinal shafts such that they rotate together. This is illustrated in FIG. 2.
FIG. 2 additionally shows that connecting rod 11 acts upon lever 8 which is illustrated in two different positions. Depending on the position of lever 8, the thread guide 13 accordingly assumes two different positions 13, 13'.
Longitudinal shaft 6 is connected with drill 20 via an additional lever, while longitudinal shaft 5 is coupled with needles 19.
These two tools interact with an opposing shuttle 21. The actuation of the shuttle is performed via connecting rod 12 acting upon oscillating longitudinal rod 9 which in turn actuates shuttle 21 such that it performs a vertical oscillating movement.
The oscillating movements of the different connecting rods 10, 11, 12 are produced by correspondingly rotating cams in the actuation groups 2, 4.
Gear output shaft 31 is, for example, connected with a cam plate 22 such that they rotate together, whereby an assigned roller lever braces itself on the cam plate, and a double roller lever 23 is provided for the actuation of the thread guide.
Actuation group 4 on the rear side of the frame has an identical gear output shaft 32 which is coupled with an assigned cam plate 24 for actuation of the shuttle such that they rotate together. Also, double roller lever 25 is coupled with connecting rod 12.
Material shafts 39 are arranged vertically on top of each other in the area of channel 28, whereby the material shafts 39 move in the vertical as well as horizontal direction.
FIG. 1 also shows that not only the actuation for the embroidery tools is provided with one or more centrally arranged motors, but that the drill also has its own assigned motor 15 which is also arranged approximately in the center of the frame. This measure also attains the characteristics which are essential for the invention, namely a center drive for shafts which extend over the frame in the longitudinal direction and which are no longer exposed to excessive torsional oscillations.
FIG. 3 shows that the actuation of the drill 20 is flanged onto the motor 15.
The movement of the extended drive shaft 17 of the motor 15 is transferred, via a lever mechanism 18 that is coupled with a connecting rod 16 engaging on a lever 33 which is in turn connected with the oscillating longitudinal shaft 6, such that they rotate together. Additional levers which actuate a longitudinal tube 34 around the rotational axis of the longitudinal shaft 6 in an oscillating manner are connected with the longitudinal shaft 6 such that they rotate together. A catch 35 engages with longitudinal tube 34, and drill 20 is either advanced in a direction toward the embroidery base 40 and penetrates the same or is retracted depending on the position of the catch. The needles 19, with their own separate drives, are arranged above the drill 20, whereby a catch 37 is connected with an identical longitudinal tube 38.
One important aspect in the variations according to FIGS. 1 and 2 is the fact that the main motor 1 on the front side and the main motor 3 on the rear side are electronically coupled with each other. This provides the important advantage that the aforementioned cam plates may be adjusted relative to each other, electronically, without requiring mechanical adjusting elements.
This particular example pertains to an electronic gear, which means that the rotational speed and the phase position of the two main motors 1, 3 is controlled electronically, with mutual feedback and a synchronization that may be changed selectively.
FIG. 4 shows a mechanical coupling by means of a mechanical connecting shaft 41 as an alternative to the previously described electronic coupling between the motors 1, 3 whereby only the main motor 1 is provided on the front side of the frame which drives the actuation group 2 on the front side via a corresponding drive shaft that is not shown in detail. The mechanical connecting shaft 42 which drives the actuation group 4 on the rear side via a spur gear and an assigned output shaft is driven via an output shaft 41 and a corresponding additional spur gear.
This particular variation makes it possible to couple individual embroidery tool drives and/or several embroidery tool drives which are combined into a group with an electric drive motor via switchable couplings such that the embroidery tool drives may be selectively switched on or off.
The design of the frame also indicates that vertical supports 43 are arranged within the area of the supports 29 which extend in the longitudinal direction, whereby the supports are also designated as creel towers on which the tenter frame with the material shaft is arranged and guided such that they may be moved in the longitudinal direction.
It is important that all the shafts are, as described above, extendable on the front side so that an additional assembly module may be connected to the front side of the assembly module according to FIG. 1. The additional assembly module is driven via the actuation unit 2, 4 of the assembly module illustrated in FIG. 1.
This measure facilitates higher rotational speeds and a substantially higher output may be obtained in comparison to an arrangement in which the entire actuation is solely arranged on the front side.
One additional essential characteristic is that the abovementioned drive motors are controlled electronically, so that the necessity for providing different mechanical adjusting elements is eliminated as the control of these motors 1, 3 is performed electronically. Thus, the mechanical function of the machine is substantially simplified and is designed in a much more inexpensive manner.
The drive also becomes quieter and oscillates less due to the direct extent of the forces.
The actuation unit may be designed in an easily exchangeable manner due to the compact construction and the modular actuation boxes. This means that embroidery machines with different output may be combined simply in a modular manner.
While the invention has been described above with respect to certain embodiments thereof, it will be appreciated by one skilled in the art that variations and modifications may be made without departing from the spirit or scope of the invention.
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The invention pertains to an embroidery machine with a plurality of embroidery stations provided with corresponding embroidery tools which are attached to shafts that oscillate during the operation of the machine and extend along the embroidery machine. The shafts are actuated via corresponding drives. To reduce the torsion as well as the torsional oscillation of long shafts which leads to a distortion of the movement of the embroidery tools and to a chronological phase displacement between the front and the rear portion of the machine, the drives for the needles and for the other embroidery tools are arranged approximately in the center of the embroidery machine.
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This application is a continuation of application Ser. No. 427,715, filed Sept. 29, 1982, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to a tube cut-off apparatus utilizing a horizontal moveable cutting blade to scarf an opening in the top of a tube, and then actuating a vertically movable cutting blade to sever the tube.
2. Description of the Prior Art
The prior art is exemplified in patents to: Czarnick U.S. Pat No. 2,741,309; Tuttle U.S. Pat. No. 2,879,844; Borzym U.S. Pat. No. Re. 22,114; Aver U.S. Pat. No. 3,129,624; Borzym U.S. Pat. Nos. Re. 30,025, 4,108,029 and Hill U.S. Pat. No. 4,015,496. These all disclose the principle of scarfing the opening in the top of a tube and thereafter severing the tube with a vertical blade. By this method of operation the tube ends thus severed are free of dimpling which would otherwise occur with the utilization of a single severing blade. The present invention utilizes the old principles disclosed in the prior art and discloses an improved apparatus which is ideally suited for use in tube mill operations wherein the die is moved rapidly with the tube as it is formed in the mill and is immediately severed by the die, after which the operation is repeated. This type of cutt-off die apparatus is frequently referred to in the art as a "flying" cut-off.
SUMMARY OF THE INVENTION
The present invention is in a novel tube cutting apparatus which utilizes the principles of the prior art, namely the severing of a tube without dimpling the wall of the tube in that a scarfing blade is initially drawn across the upper wall of the tube creating an opening, or severed portion, which then receives the cutting end of a blade and slices through the tube. The invention pertains to the precise arrangement of the functional elements of the die which are supported on a bottom plate, or die shoe of the apparatus. An upper platen or upper die shoe supports a vertical cut-off blade which projects downwardly. A pair of vertical cams are supported on the upper platen and extend downwardly, one of the cams having a roller cam pivotally supported therein. The roller cam is in engagement with the upper end of a diagonal track which during downward movement of the cams causes movement of a slide in a horizontal direction. The slide has supported thereon a scarfing blade which is drawn across the upper chord of the tube for creating the initial opening. As the cams move down through the lower platen, the scarfing tool moves to an out of the way position, to the right of the tube, and the upper cutting blade then slices through the tube. During the downward movement of the cams and upper blade, the cams engage rollers supported on die blades which move longitudinally a slight distance to close the jaws of cut-off die blocks which instantly tightly grip the tubing in their relatively closed position. The lower platen on which the die blocks, jaws, etc. are mounted include a raised T-shaped rail on the top surface of the lower plate. The die blocks and clamping slides are undercut on their bottom surfaces to provide recesses to conform to the T-rail and thus are firmly fixed against lateral movement, but may have limited movement on the T-rail in a longitudinal direction. The invention further includes the provision of a retaining frame which surrounds the T-Rail and moves with the longitudinal movement of the elements which are supported on the T-rail in a limited fashion. One of the advantages of the invention lies in the positioning of the drive elements namely the clamping cam and slide propelling means on the same side, to the right of the vertical cut-off plate, this arrangement permitting use of the die in relatively smaller space limited presses. Further the invention includes the feature that the cams control the positioning of the die blocks, as well as moving them and scarfing blade between the desired positions. A primary feature of the present tube cut-off machine is the arrangement wherein the cam element, the horizontal slide, the blade holders, and the scarfing blade are in-line i.e. substantially horizontally aligned which provides a more accurate cutting arrangement and a more efficient operation with added tool life to the units of the apparatus. Side forces are eliminated, twisting action is reduced and efficiency is increased.
Further features of the invention include the fine adjustment of the depth of the scarfing cut which may be made in the tube by adjusting the carrier supporting the scarfing knife relative to the slide member.
Features of the invention include:
The clamping cams serve the dual function of clamping the tube and driving the horizontal slide which supports the scarfing blade.
Both the clamping action and horizontal blade movement are drawn from the same side, i.e. to the right of the vertical cutting blade.
All of the bearing housings and clamping slides ride on the T-shaped rail or guide member, with the housings apertured on their bottom sides to receive the T-rail configuration and thus accurately position the elements.
The clamping slides and bearing housings are held together on the T-rail by means of the retainer which includes the side rails connected to transverse extending end straps.
Another feature is that the bearing for driving the horizontal slide is located on one of the clamping cams.
A further feature includes a fine adjustment mechanism whereby the height of the horizontal scarfing blade can be adjusted relative to the tube edge.
Another feature is that the track for driving the horizontal slide is located in the slide itself and the bearing caps are used as side supports for the horizontal slide.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the improved tube cut-off apparatus with a portion of a side strap of a retaining frame broken away to better illustrate the invention;
FIG. 2 is a plan sectional view through the cut-off apparatus taken substantially along the line 2--2 of FIG. 1;
FIG. 3 is an end elevational view taken along the line 3--3 of FIG. 1;
FIG. 4 is a cross sectional view through the cut-off die taken along the line 4--4 of FIG. 1;
FIG. 5 is a cross sectional view of the blade holder and blade taken along the line 5--5 of FIG. 1;
FIG. 6 is a perspective view disclosing a notch cut in the upper edge of a tube by a horizontal tube scarfing plate;
FIG. 7 is a cross sectional view of a scarfing blade height adjustment taken substantially along the line 7--7 of FIG. 1;
FIG. 8 is a side elevational view similar to FIG. 1, disclosing the apparatus in a closed position;
FIG. 9 is a cross sectional view taken along the line 9--9 of FIG. 1.
FIG. 10 is a schematic view disclosing a sliding retaining frame and associated die structure in schematic form.
FIG. 11 is an end elevational view of the schematic disclosure of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the exemplary embodiment of the invention as disclosed in the drawings a tube cutting apparatus is referred to at 10. The apparatus 10 includes upper and lower die plates 11 and 12 also referred to as die shoes or structures. The upper and lower plates are held in alignment vertically by means of telescoping die parts 13 & 14 in conventional fashion in the art.
A vertical cut-off blade 15 is supported in a blade holder 16 from the plate 13. A cam holder 17 is suspended from the plate 11 as best shown in FIG. 4, and supports downwardly projecting vertical locking cams 18 spaced transversely relative to the apparatus. One of the locking cams 18 also has supported therein a rotatable bearing or roller 19, the same being rotatably fixed to a shaft 19' threaded into one of the cams 18.
The lower plate 12 is provided with a guide or T-shaped rail 20 extending substantially the length of the lower plate 12. The rail 20 has overhanging projections 21. A retaining carriage 22 of rectangular configuration includes side rails 23, connected at the rear to an end rail or transverse block 24 by means of fasteners 25.
As best shown in FIGS. 3 & 4, transversely extending retaining members or connecting ears 26 are suitably secured to a first slide block 28 by securing means such as bolts (not shown). The connecting ears 26, as best shown in FIG. 3 project inwardly underneath the overhanging projections 21 of the T-rail 20 so as to permit sliding of the block 28 with the frame 22 but the block 28 is restrained against vertical movement, since the T-rail is firmly secured to the lower plate 12. As best shown in FIGS. 2 and 3 vertical brackets 27 are connected to the ends of the rails 23. A first die slide block 28 is supported on the T-rail 20, having its lower surfaces suitably apertured to conform to the raised guide rail and thereby slide thereon. The block 28 includes a cut out portion 29 which supports a pair of jaws 30 positioned in laterally spaced relation. Brackets 31 and fasteners 32 retain the jaws 30 in the cut out portions 29 of the block 28.
A second die slide block 33 also suitably apertured on its lower surface to slide on the T-guide rail 20 is adjacent to the first block 28 and slightly spaced therefrom longitudinally. The relationship of the slide blocks 33 and 28 is well disclosed in the schematic view FIG. 10. The slide block 28 is secured for movement with the frame 23 by means of bolts 28' which extend through the side rails 23 and are threaded into the ends of slide block 28, as indicated at 28". The second slide block 33 is also apertured as indicated at 34 to provide a seat for adjacent jaws 35 held in position by brackets 36 and fasteners 37. Top brackets 38 and 39 engage recesses 40 to assist in retaining the jaws 30 and 35 in position. The jaws 30 and 35 as best shown in FIG. 1 are longitudinally spaced in their open position and are laterally spaced, as shown in FIG. 2 to provide openings 41 through which the blades 15 and 64 function. The first and second slide blocks 28 and 33 are undercut as previously described to conform to the T-rail and this is best disclosed in FIG. 3 as an example.
The rearmost portions of the second or rear slide block 33 support in laterally spaced relation horizontal side caps or blocks 42 as best shown in FIG. 4 which include horizontal inwardly projecting guide ledges 43. A horizontal slide 44 includes longitudinal recesses 45 which mate in sliding relation with the guide ledges 43 and support the slide 44 for longitudinal movement on the structure. The slide 44 is provided with a recess track or cam surface 46 which is engaged by the roller bearing cam 19 on the ascending or movement of the cams 18 and 19. Thus this cam movement causes the slide to reciprocate and achieve its function.
A bearing housing 47 is best shown in FIG. 1 and extends transversely across the T-rail 20 again being suitably apertured on its bottom surface so as to be fixed against lateral movement. Side caps or blocks 48 are securely connected to the bearing housing 47. The caps 42 and 48 include recesses 49 which accommodate support therein upper portions of rollers 50 adapted to be engaged by the cam surfaces 51 and 52 as best shown in FIG. 1. The front rollers or roller cams 50 are supported on shafts 72 carried within recesses 73 of the rear slide blocks 33, as best shown in FIG. 1. The rear rollers and bearing housing 47 are reaction members or means for the vertical cams 18. The rear rollers 50 are also supported on shafts 72 within recesses 75 of the bearing housing 47. The bearing housing 47, as best shown in FIG. 4 also has connected thereto by suitable bolts (not shown) connecting ears 26 which secure the bearing housing 47 for sliding movement on the T-rail 21.
The transverse connector block 24 of the carriage 22 has supported thereon a spring tension mechanism or resilient means 53 which comprises a threaded rod or connector means 54 which is supported on the bearing housing 47 in a bore 47' and projects through a threaded holder 56 supported in a bore 55 in block 24. A threaded tubular holder 56 is threaded into the bore 55 and is longitudinally adjustable therein. The rear end of the rod 54 includes a captive spring 59 held captive by means of a head 57 on the holder 56 and a washer and nut 58 on the end of the rod 54. The rod 54 is threaded into the second or rear slide block 33 as indicated in FIG. 1. This mechanism brings about tension movement tending to pull the slide block 33 back to the position shown in FIG. 1, from a position when the jaws are almost closed in the clamping position.
The spring tension mechanism 53 is adjustable by rotating the nut 58 which increases or decreases the force on the clamping of the clamping blocks 28 and 33. In other words the rotation of this nut controls, or increases and decreases the unclamping force.
The clamping pressure on the die clamping blocks is tightened or loosened by rotating the nut 57. As best shown in FIGS. 1 and 4 the threaded rod 54 is contained within a bore 33' in the block 33.
As best shown in FIG. 1 a scarfing blade holder block 60 is removably connected to the slide 44 by securing screws 61, the holder block 60 extending longitudinally and diagonally. The block 60 includes a nose portion 62 having a scarfing blade retainer slot 63 supporting a scarfing blade 64. The scarfing blade 64 includes at opposite ends thereof scarfing blade portions 65 which during operation open up the top chord slot 65' as shown in the tube in FIG. 6 at 68. Thus each blade may be used twice by simply reversing the blade position by removal and replacement of the screws 67 which contain the blade in the retainer slot 63 of the nose portion 62. FIG. 8 discloses the Tube 68 clamped in the jaws 69.
FIGS. 7 and 9 disclose the vertical adjustment of the scarfing blade 64 which may be moved vertically for adjustment relative to the tube. Initially the screws 61 are loosened permitting loosening of the clamping lug 61; see FIG. 9. The holder block 81 may now be raised or lowered by turning the screw head 82 which turns the threaded member 80 which is in the threaded bore 81. Thus the scarfing blade can be vertically adjusted as desired.
FIG. 7 discloses an adjusting mechanism for the holder block 60 containing the scarfing blade 64. The holder 60 is supported for vertical movement relative to the horizontal slide 44 by means of a support member 78 connected to the slide 44 by means of a screw 79. A vertical adjusting screw 80 is threaded into a threaded bore 81 and upon rotation of the head 82 the screw 80 rotates moving the block 60 vertically and thereby adjusting the scarfing blade relative to the tube to be scarfed.
THE OPERATION
The cut-off apparatus disclosed as the invention may be utilized in any suitable mechanical press which will move the die shoes or plates together and return them to their original position. Because of the compactness of the present unit it is also ideally suited for smaller four post presses, open gap presses and flying cut-off presses of the type associated with tube producing mills. It also can be ideally used with open gap presses where a relatively short distance is provided between the ram centerline to the rear open face of the press.
The apparatus disclosed thus is versatile and since the clamping cams and horizontal blade are all actuated from the same side allowing a very limited distance from the tube centerline to one die edge, the unit will fit into very small presses, such as the C-Frame type of press.
In operation the tube 66 is inserted through the opening 69 in the jaws as indicated in FIG. 1. The upper plate 11 now moves in the direction of the lower plate 12.
The cams 18 are moved downwardly and as the cam surfaces 51 move downwardly the roller cams 50 rotate unto the cam surface 52 which causes movement of the second slide block 33 to the left and movement of the frame and retaining carriage 23 slightly to the right. This movement closes the jaws tightly clamping the tube. The roller cam 19 simultaneously enters into recessed cam track 45' which causes movement of the slide 44 to the right in FIG. 1, and the blade holder block 60 is simultaneously moved whereupon the scarfing blade 64 cuts the upper surface of the tube leaving the recess 65. The scarfing blade, holder 60 and slide 44 move to the right and the cut-off blade 15 now servers the tube by entering the recess 65 and cutting through the tube leaving no dimple. The spring tension mechanism 58 now functions to open up the die blocks and jaws again to the position shown in FIG. 1 with the cams 18 returning to the position indicated and the apparatus is now ready for the next cut.
The vertical cams and cam rollers serve the dual function of moving the blocks 28 and 33 and also actuating the slide which provides a positive and coordinated operation. Major operating parts such as the slide blocks and rear block all ride on the T-rail which provides a failure proof operating assembly 22. Further the horizontal blade holder 60 may be adjusted vertically by the utilization of a suitable gauge inserted between the lower surface of the scarfing blade holder 60 and the upper surface of the tube gripping jaws 35 to the various depth positions desired by the operator for a particular tube wall thickness. It is also a feature of the invention that the pull type of horizontal blade and holder reduces the stroke size requirement over other cut-off apparatus. A further advantage by the present combination is that size and weight are greatly reduced which is highly desired where the apparatus is used in flying cut-off presses.
The important advantages of the present design lie in the present arrangement of a platen with a T-shaped supporting rail on which the die blocks with jaws are mounted for horizontal movement. Fore and aft movement of the assembly is restrained by the floating frame to which the slide block 28 is connected. The rectangular containing frame provides for the movement in concert of the movable members in their clamping function, held freely in the sliding position by the vertical cam member. The cam member, the slide, the scarfing blade are in substantial in line, i.e. in longitudinal alignment so that side thrust forces are eliminated and effective operation is maintained.
The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.
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A tube cut-off apparatus includes a horizontally moving scarfing blade which opens up the top of a tube permitting a vertical moving cut-off blade to move through the opening and finish cutting the tube. An upper die plate supports the vertical cut-off blade and a locking cam arrangement includes spaced vertically extending cams which provide for longitudinal movement of clamping slides in turn opening and closing jaws of die blocks which support the tube to be cut. A horizontally movable slide member carries a scarfing blade which cuts horizontally the upper tube portion and moves out of the way to permit the vertical blade to shear through the tube. The scarfing and clamping arrangement is actuated entirely by the mechanism on one side of the apparatus with the cams performing the clamping function as well as the actuation of the slide member. The sliding blocks and associated clamping members are all supported on a T-shaped rail and the moving elements on the rail are confined and maintained in position by a retaining frame which surrounds the elements, the said frame having limited horizontal movement.
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FIELD OF THE INVENTION
This invention relates to a roof bolt drill pot drive and has been devised particularly though not solely for use in mining operations.
BACKGROUND OF THE INVENTION
In many mining operations, the face is mined by a continuous mining machine having some form of cutting head on the front of the machine which mines the face and removes the minerals for transport to the surface. As the mining machine advances it is necessary to support the roof above the face, and this is commonly achieved by drilling long vertical holes upwardly into the roof and securing roof bolts in place using a quick setting epoxy cement. The holes for the roof bolts are sometimes drilled by a separate drill rig, and the bolts are then secured in place by an alternative power operated bolting socket.
In order to simplify the roof drilling and bolting operation it has become common place to mount the drill rig on the mining machine and to combine the drill rig and the power bolting socket in a single unit. This enables the roof bolts to be drilled and bolted from the mining machine as the machine advances into the face. Existing roof bolt drills of this type are however bulky and cumbersome to operate, frequently requiring the interchange of parts and/or the incorporation of a separate roof bolt drive socket after the drilling operation has been completed. The changeover between drilling mode and roof bolting mode takes time which of course slows the advance of the mining machine and restricts the rate of mining of the mineral face.
The bulky nature of the drilling and bolting mechanisms also limits the number of such drills that can be located side by side across the width of a mining machine and therefore restricts the pitch of the roof bolts which may be inserted using these conventional drills. Mining would be much safer if the bulk of the drilling and bolting machines could be reduced, allowing the machines to be located closer to the mining face, and furthermore allowing a greater number of machines to be placed side by side across the width of the continuous miner.
One of the reasons for the bulk of the machines is that the drilling operation requires a high speed drive with a relatively low torque requirement, whereas the bolting operation is not critical on speed but requires a high torque to securely fasten the nut on the roof bolt. To meet both of these requirements it has been necessary to provide a high speed, high torque drive motor which is large and bulky and which adds to the size of the roof bolt drilling machine.
SUMMARY OF THE INVENTION
The present invention therefore provides a roof bolt drill pot drive comprising a drive motor having a drive shaft, a drill chuck coupled to and driven by the drive shaft, and a bolt socket driven by the drive shaft via a reduction gear box, the drill chuck being coaxially mounted with the bolt socket and both the drill chuck and bolt socket being permanently coupled to and simultaneously driven by the drive motor.
Preferably the drive motor comprises an hydraulic or pneumatic motor, of the vane or gear type.
Preferably the drill chuck is mounted on and coaxial with the drive shaft.
Preferably the reduction gear box comprises a planetary gear box having sun and ring gears coaxial with the drill chuck and bolt socket.
BRIEF DESCRIPTION OF THE DRAWINGS
Notwithstanding any other forms that may fall within its scope, one preferred form of the invention will now be described by way of example only with reference to the accompanying drawing which is a vertical cross section through a roof bolt drill pot according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred form of the invention a roof bolt drill pot is provided driven by an hydraulic motor having vanes (1) contained within a housing (2) and supplied with working fluid, which is typically oil, under pressure through inlet pipe (3) from hose connections (4). Oil passing through the motor returns via outlet (5) to return hoses.
The hydraulic motor drives a hollow drive shaft (6) which extends upwardly through the housing and is directly coupled to a drill chuck (7). The drill chuck, which is typically a square section socket, is arranged to engage the lower end of the drill used for drilling roof bolt holes. The chuck (7) is mounted on and directly coupled to the drive shaft (6) so that it rotates at the same speed as the hydraulic motor (1).
The drill pot is also provided with a bolt socket (8) which is located coaxially with the drive chuck (7) about the centreline (9) and which is adapted to engage with and tighten the bolt head or nut of the roof bolt. The bolt socket has an outwardly extending flange (10) which extends downwardly in a skirt (11) which engages with and is driven by a planetary gear train (12). The planetary gear train comprises a sun gear (13) directly coupled to and driven by the drive shaft (6), a reaction ring gear (14) coupled to and held stationary by the housing (2) and a series of planetary gears (15) each located on shaft (16) and engaged between the ring gear and the sun gear. The shafts (16) are journaled in bearings supported by and engaged with a spider (16A), in turn fastened to and rotatable with skirt (11) so that rotation of the sun gear (13) by the drive shaft (6), operates the planetary gear train and causes the bolting socket (8) to rotate at a much reduced speed driven by the output from the spider (16A).
In this manner operation of the hydraulic motor (1) causes the drill chuck (7) to rotate at high speed and the bolt socket (8) to rotate at a much lower speed with considerable torque multiplication due to the reduction gearing of the planetary gear train (12).
In use a drill bit is firstly engaged in the drill chuck (7), and the drill pot axially advanced upwardly to drill a hole for the roof bolt of the mine. The drill is then withdrawn and removed from the drill pot. The roof bolt is then placed in the hole and the nut of the bolt engaged with the socket (8) whereupon the hydraulic motor (1) is actuated again to tighten the nut on the bolt. Both the drill chuck (7) and the bolting socket (8) are driven simultaneously by the hydraulic motor (1), but the operation of one does not interfere with that of the other as the drill simply passes through the opening of the socket during drilling operations, and the socket (8) is above the drill chuck (7) for use in the bolting operation.
Because the torque from the hydraulic motor (1) is considerably amplified by the planetary gear box (12), it is possible to provide a high speed, low torque hydraulic drive motor which is extremely compact and therefore enables the size of the drill pot to be reduced. Similarly the coaxial arrangement of the hydraulic drive motor, the planetary reduction gears, the drill chuck, and the bolt socket enables an extremely small drill pot to be achieved. Drill pots of this nature can be placed closely side by side on a mining machine and furthermore are very convenient and fast to operate.
As a further optional feature, the lower end (17) of the hollow drive shaft may be closed off by a rotatable spigot (18) driven by radial vanes (19) about an axis (20). Water is supplied to the drill during the drilling operation through a gallery (21) and thence by a passageway (22) into the lower end (17) of the hollow drive shaft. During the drilling operation the spigot (18) is rotated into the closed position as shown in the accompanying drawings.
Rotation of the spigot to the open position wherein the aperture (23) is aligned with the drive shaft (17) is achieved by the application of hydraulic pressure from the supply channel (3), bled off through aperture (24) and controlled by spool valve (25). The spool valve (25) is actuated by the water pressure supplied to the gallery (21) so as to cause the valve (25) to open or close as water pressure is supplied or removed from the gallery (21). In this manner, the supply of water under pressure through the gallery (21) actuates the spool valve (25) to rotate the spigot (18) to the closed position during the drilling operation, but the removal of water pressure causes the spool valve (25) to open in the opposite direction causing the oil from supply channel (3) to rotate the spigot to the open position allowing water to drain from the bore hole after the drillinq operation has ceased. Because the aperture (23) in the spigot (18) is substantially the same size as the hollow drive shaft (17), opening of the spigot (18) also allows the plastic sheer pins from the bolting operation to drop out through the lower part of the drill pot when the valve (18) is opened.
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A mining roof bolt drill pot drive wherein the drill chuck and the bolt tightening socket are coaxially mounted and permanently coupled to and simultaneously driven by a drive motor. The drill chuck is directly driven by the drive motor and the bolt socket is driven via a reduction planetary gear box giving speed reduction and torque multiplication. An automatic valve for supplying cooling water to the drill during drilling and allowing excess water together with expended sheer pins to be discharged from the base of the drill pot is also described and claimed.
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This is a Division of application Ser. No. 09/562,099 filed May 1, 2000. The entire disclosure of the prior application is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention is directed to a circuit that can be both non-permanently programmed and permanently programmed.
2. Description of Related Art
Fuses and fusible links are circuit elements that open by burning out or breaking when a relatively high current is applied. By selectively breaking or leaving intact specific fusible links, a circuit can be customized or programmed using these fusible elements. An antifuse is the opposite of a regular fuse. That is, an antifuse is normally an open circuit until a programming current is forced through it. Fuses and antifuses may be used to address many problems, including calibration requirements of analog circuits such as digital/analog converters, or current or voltage sources, logic synthesis circuits such as digital delays lines, or chip specific performance data to be used by the end system in which the chip will be used. These fusible and antifusible circuits are generally “programmed” after chip fabrication has been completed and during the wafer testing phase of chip production. The programming may be used to add additional resistors into a circuit to compensate for variations introduced during the manufacturing process or to compensate for oscillator frequency variations induced by manufacturing stress.
In many of these cases, it is desirable to simulate a programmed state before actually programming the device. For example, analog circuit calibration may require additional steps of simulation and refinement based on the previewed or simulated results obtained. These results are incorporated into further simulations to correctly calibrate the circuit during the testing phase. After testing, the circuit may then be permanently programmed.
Conventional programmed circuits employing, for example, fuses and anti-fuses, generally do not permit preview or simulation of the programmed circuit. Conventional programmed circuits require specialized packaging to ensure no overlay of the fusible or antifusible link occurs. That is, a conventional circuit can only be permanently programmed and not previewed. Once the conventional circuit is programmed, no further changes or refinements to the circuit are possible.
U.S. Pat. No. 6,037,871 to Watrobski et al. describes such a fusible link circuit including a preview feature that uses fusible links in combination with transistors to permanently set the value of an output. However, this fusible link circuit also requires special manufacturing and packaging techniques, as discussed above. For previewable devices such as those described in Watrobski, the device imposes specialized packaging, manufacturing, handling and cost limitations. Conventional fuse programming methods require that the selected device packaging technique be suitable for the programming structures. For example, the device packaging techniques need to facilitate air access to the fuse for burning and to avoid overlays that may act as heat sinks. A heat sink would increase the fuse blow temperature, which could possibly exceed the circuit temperature tolerance. Thus, manufacturers of products requiring these features must select packaging and fabrication techniques that are tailored to these fusible circuits and which are typically more expensive than non-programmable circuit fabrication and packaging techniques.
Erasable programmable read only memory (EPROM) and electrically erasable programmable read only memory, (EEPROM), devices may be programmed and reprogrammed. However, EPROM devices rely on specialized fabrication techniques and typically include a quartz window through which ultraviolet light of a specific wavelength may be introduced for several minutes to erase the chip in preparation for re-programming. In use, the quartz window is covered to prevent accidental erasure of the device. The EPROM devices require physical removal of the chip and or physical manipulation of the cover over the quartz window as well as considerable time to effect erasure in preparation for re-programming. Thus, EPROM devices require both specialized fabrication techniques and specialized handling during programming.
EEPROM circuits typically use floating gates surrounded by a much thinner insulating layer which can be erased by applying a voltage of the opposite polarity to the charging voltage to the non-floating gate. EPROM circuits overcome some of the EPROM device limitations with respect to the use of ultraviolet light to effect erasure. However, EEPROM devices also require special fabrication techniques in their manufacture. Furthermore, EEPROM devices require that special opposite polarity voltage levels be adopted for reading and writing to the EEPROM device.
SUMMARY OF THE INVENTION
Conventional programmable circuits are either write-once circuits that can be programmed but not re-programmed or read and write devices that can be programmed and re-programmed. The write-once circuits do not provide for simulating or previewing the state of a circuit before programming the circuit permanently. The read and write devices can be re-programmed after simulating or previewing the circuit but require special handling and manufacturing techniques.
Thus, a programmable circuit is needed that can be fabricated using conventional reliable and inexpensive fabrication techniques and that provides a preview function which uses normal circuit voltage levels for permanent programming and higher voltage levels for permanent programming.
This invention provides systems and methods for programming a circuit using a pull-down transistor as an antifuse in the circuit.
This invention separately provides a circuit having a preview function useable to simulate circuit characteristics using normal voltage.
This invention further provides a circuit that uses a higher voltage to permanently program the circuit.
The circuit can be fabricated using conventional, inexpensive and reliable fabrication techniques. The circuit includes a spike enable input structure which is used to determine when the chip is to be programmed. The circuit also includes a test and spike input structure which has at least two functions controlled by the setting of the spike enable input structure.
When the spike enable input structure is in the default or open state, a programmable transistor is in an open state. As a result the voltage at the output structure is at a first predetermined value. External tester electronics can be attached to the test and spike input structure to drive the output structure to the first predetermined voltage by leaving the test and spike input undriven or by driving the test and spike input structure to the first predetermined voltage. Conversely, the external electronics can drive the output structure to a second predetermined value by driving the test and spike input structure to the second predetermined value. Thus, the output of the circuit can be simulated or previewed before permanent programming of the circuit occurs.
A programmed state of the simulated programmable previewable circuit can be created by asserting an enable signal on the spike enable input. A test and spike input is then pulsed with a programming voltage that is higher than either the first or second predetermined voltages. The programming voltage is of sufficient amplitude, pulse width and frequency to cause the programmable transistor to enter the failure mode, known as snap back. During the snap back mode, the programmable transistor carries a large current density. The large current density in turn causes silicon to dissolve into the metallic layer connected to a source drain of the programmable transistor, so that a void is created below the interface which is then infilled by metal flow in a process called spiking. The metal tends to form sharp spikes which penetrate the junction and forms a short circuit which creates a permanent closed path. Thus, a permanent closed state is created by spiking the programmable transistor as a result of the programming operation. The circuit may still be changed and previewed during the non-permanent default, or simulation phase.
Various exemplary embodiments of the methods according to this invention comprises applying a signal having the second predetermined voltage to the test and spike input structure while a signal is applied to the spike enable input structure to hold the programmable transistor in an open state. The output signal generated in response to the applied input signal is compared to the desired output signal. A determination is made whether the generated output signal corresponds to the desired output signal. If the comparison indicates that the examined output signal corresponds to the desired output signal, a programming signal is then applied to the test and spike input while the spike enable input is driven to the closed state to permanently program the pull-down transistor to a spiked condition, thus, the second predetermined voltage becomes permanently applied to the output structure.
It should be noted that the programmable previewable circuit of this invention does not rely on fuses. Instead, the programmable previewable circuit uses spiking of the transistor to permanently set the circuit to a closed state. Therefore, the programmable previewable circuit can be used in circuits without the special packaging normally required to minimize heat sink problems. Since the circuit can use conventional, inexpensive and reliable manufacturing techniques, it will reduce or eliminate the manufacturing changes required to use conventional programmable circuits.
This is a major advantage in situations where the integrated circuit must be covered by some passivation or encapsulation since any material covering a fuse will act as a heat sink requiring higher currents and voltages in order to cause the fuse to blow. These higher currents and voltages could damage the surrounding circuits.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of various exemplary embodiments of the systems and methods according to this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein:
FIG. 1 shows a conventional fusible link circuit;
FIG. 2 shows an exemplary embodiment of the programmable previewable circuit according to this invention;
FIG. 3 shows an exemplary embodiment of the programmable previewable circuit of this invention after the programmable previewable circuit is permanently programmed;
FIG. 4 shows an exemplary cross sectional view of the development of a spike in exemplary embodiment of this invention;
FIG. 5 shows an exemplary embodiment of a programming pulse signal according to this invention; and
FIG. 6 shows a temperature controlled oscillator that that incorporates one exemplary embodiment of this invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 shows one example of a conventional fusible link circuit 100 . The fusible link circuit 100 comprises a program input structure 134 , an output buffer element 138 , an output structure 140 , a fusible link 136 and a pull-up resistor 147 . The program input structure 134 , the fusible element 136 , the pull-up resistor 147 and the output buffer element 138 are all connected to a common node 155 . The pull-up resistor 147 is connectable to a predetermined voltage source 120 . The fusible link 136 is normally closed to connect the node 155 to ground. The output buffer element 138 is connected to the output structure 140 . In the fusible link circuit 100 , when an input signal of sufficient amount of power is input to the program input structure 134 , the fusible element 136 is blown or forced to an open condition. In response, the logic output at the output 140 is established at the voltage of the predetermined voltage source 120 . If, however, the fusible element 136 is left intact, then the buffer logic output 140 is held at a ground voltage due to the node 155 being connected to ground, through the fusible element 136 .
In this type of conventional fusible link circuit 100 , the output signal present on the buffer logic output 140 is entirely dependent on the state of the fusible link 136 without regard to the input signal on the input 134 . For instance, if a signal applied to the program input structure 134 is insufficient to force the fusible element 136 to an open condition, then the output on the buffer logic output 140 would have a value of approximately zero. If, however, the buffered logic output 140 is to be driven to a high level, dependent upon the supply voltage, then the fusible element 136 will need to be forced to an open condition by the input signal on the program input structure 134 . Consequently, the conventional fusible link circuit 100 suffers from the fact that the output of the circuit is totally dependent upon the state of the fusible element 136 . In such configurations, simulating a blown fusible element is not possible since the output level at the output 140 is totally dependent on the physical state of the fusible elements 136 .
Consequently, if, after destroying the fusible element 136 , it is found that the fusible element 136 should not have been forced to an open condition, it is impossible to repair the fusible element 136 , particularly in an integrated circuit, to achieve the previous state. One technique for dealing with this problem is presented in U.S. Pat. No. 6,037,871 to Watrobski et al. The 871 patent employs fusible links in and transistors in combination to accommodate testing and permanently setting the device. However, Watrobski suffers from the problem of requiring special packaging requirements. For example, Watrobski's technique cannot be used when the circuit must be covered, since the covering material will act as a heat sink that effectively prevents the fusible link from being blown without hurting the circuit.
FIG. 2 illustrates one exemplary embodiment of the programmable previewable circuit 200 according to this invention. The programmable previewable circuit 200 includes a spike enable input structure 257 , a test and spike input structure 254 , an output structure 258 , a pull-down transistor 248 , an isolating input buffer 246 an isolating output buffer 256 and a resistor 247 . The output structure 258 , the test and spike input structure 254 , the pull-up resistor 247 and a first junction 248 a of the pull-down transistor 248 are connected at a node 255 . The other end of the resistor 247 is connected to a voltage source 220 that applies a first predetermined voltage to the node 255 through the resistor 247 . In contrast, the second junction 248 b of the pull-down transistor 248 is connected to a “ground” voltage 230 that supplies a second predetermined value. When the transistor 248 is closed to connect the node 255 to the ground voltage 230 , the node 255 is driven to the second predetermined voltage.
In the circuit 200 , the spike enable input structure 257 is normally at a voltage level that places the pull-down transistor 248 into a default open, state. This both disconnects the node 255 from the ground and prevents the pull-down transistor 248 from being permanently set. External electronics can be applied to the test and spike input structure 254 to drive the output buffer 256 to a desired predetermined voltage value. In particular, the external test electronics can either not place a voltage on the test and spike input structure 254 or can place the first predetermined voltage on the test and spike input structure 254 . As a result, the pull-up resistor 247 pulls the node 255 to the first predetermined voltage supplied by the voltage supply 220 . In contrast, the external test electronics can place the second predetermined voltage corresponding to the ground voltage 230 , on the test and spike input structure 254 . As a result, the node 255 is pulled to the second predetermined voltage by the external test electronics. The value of the output buffer 256 can then be read at the output structure 258 .
In order to permanently program the circuit 200 , a large current is forced through the transistor 248 by applying a signal to the spike enable input structure 257 that closes the transistor 248 . A higher voltage programming pulse train of sufficient amplitude, duration and frequency is applied to the test and spike input structure 254 . The large potential across the transistor 248 between the voltage applied through the test and spike input structure 254 to the first junction 248 a and the second predetermined function applied by the ground voltage 230 to the second junction 248 b causes the transistor 248 to go into snap back. This creates a very large current density through the functions 248 a and 248 b . This large current density causes the contacts on the junctions 248 a and 248 b to spike down through the junctions 248 creating a short circuit to the ground voltage 230 , permanently removing the resistor 247 and the voltage source 220 from the circuit 200 .
The output structure 258 of the exemplary embodiment of the circuit 200 can be coupled to a temperature controlled oscillator circuit 600 as shown in FIG. 6, such that a grounded state or spiked state of the transistor 248 can be simulated by applying an input signal of the described levels to the test and spike input structure 254 while the spike enable input structure 257 holds the transistor 248 in an open state. Consequently, the programmable previewable circuit according to this invention is capable of non-destructively simulating logical states of one or more programmable previewable elements of an electronic circuit.
Such programmable previewable circuits, however, are not limited to the application of temperature controlled oscillator 600 but are also applicable to any of known or later developed circuit, including integrated circuits, that require programming, circuits that enable functions such as logic network synthesis in ASICs, encoding or inscription of serial numbers, passwords, or electronic “combination lock” data, and storage of performance data in a product measured prior to reaching an end user require programming. In such circuits, whether or not a given programmable previewable circuit element is to be forced to a spiked condition or left at its default state is typically determined independently of the element itself.
For example, in programmable logic devices, a synthesized logic network is realized by permanently setting or forcing to a known state the required programmable previewable circuit elements based on algorithms generated by a compiler. A serial number is a known digital quantity which is encoded into a device. A device's measured output power can be represented by a digital quantity encoded in a plurality of programmable previewable circuit elements. In these cases, the typical configuration of a fusible link circuit is described by a fuse element located between a ground node and a “blow” node as shown in the conventional circuit of FIG. 1 . In these configurations, simulating a blown fuse is not possible since “normal” logic voltage applied to the input would destroy the fuse element.
The programmable previewable circuit according to this invention, however, allows measurement or changes in a circuit's behavior to be observed by applying the first or second predetermined voltages to the circuit so long as the first and second predetermined voltages remain within the normal voltage levels for each circuit. The measured values of the circuit's behavior over the combinations of the simulated states can then be compared to a predetermined reference value. The combination of programmed and default states for the various programmable previewable antifuses associated most closely with the desired reference output signal can be permanently written or programmed into a circuit by applying a close signal to particular ones of the spike enable input structures 257 to close the corresponding transistor 248 and by applying higher programming voltages sufficient to cause spiking of the metallic contacts through the junction and into the substrate, but low enough to avoid any damage to the other circuit elements.
Once it has been determined that the desired output state to be generated at the output structure 258 requires the transistor 248 to be spiked, the spike enable input structure 257 is enabled and a programming voltage pulse train of sufficient amplitude and with peaks of sufficient duration and frequency is applied to the test and spike input structure 254 to cause the transistor 258 to spike. This input signal should include an amplitude which is low enough so as not to damage other elements in the circuit while being high enough to cause the transistor 248 to spike. The spiking causes a short circuit to ground at the junctions 248 a and 248 b.
FIG. 3 shows the physical changes that take place in the programmable previewable circuit 200 as a result of enabling the spike enable input structure 257 while placing the programming signal input pulse train of FIG. 5 , on the test and spike input structure 254 . The resistive path 260 to the ground voltage 230 created by spiking the first junction 248 a of the transistor 248 is shown in FIG. 3 .
FIG. 4 illustrates a cross sectional view of one exemplary embodiment of the pull-down transistor 248 . In particular, FIG. 4 shows just the first junction 248 a of the transistor 248 after spiking. As shown in FIG. 4, the transistor 248 includes a substrate 310 , a junction 248 a , which, in this exemplary embodiment of the transistor 248 is a n + region 320 , an insulation layer 330 of silicon dioxide (SiO 2 ) and a metallization layer 340 . The metallization layer 340 connects the junction 248 a to the node 255 . In particular, the metallization layer 340 extends through a window formed on the insulation layer 330 and contacts the n + region 320 . In various exemplary embodiments of the metallization layer 340 , usable in the programmable previewable circuit according to this invention, the metallization layer 340 comprises aluminum doped with 1% silicon.
Before spiking, the n + region 320 separates the metallization layer 340 from the substrate 310 . However, after spiking, a spike 350 of the material forming the metallization layer 340 extends through the n + region 320 and into the substrate 310 . As a result, the metallization layer 340 is permanently resistively connected to the substrate 310 .
FIG. 5 shows one exemplary embodiment of a programming pulse train 500 that can be applied to the test and spike input structure of 254 to initiate snap back in the transistor 248 and thus spike the transistor 248 . As shown in FIG. 5, the pulse train 500 includes first-sixth pulses 510 - 560 , separated by inter-pulse periods 515 - 555 . In general, during the pulses 510 - 560 a voltage of approximately 15V-20V is applied to the transistor 248 from the test and spike input structure 254 . In contrast, during the inter-pulse periods 515 = 14 555 , a voltage of approximately OV is applied to transistor 248 . However, depending on the design of the transistor 248 , the voltage to be applied during the pulses can be higher or lower, so long as the applied voltage is sufficient to spike the transistor 248 .
The exemplary pulse train 500 includes six pulses 510 - 560 . However, it should be appreciated that the number, amplitude, duration and frequency of the pulses may be varied freely so long as the transistor 248 spikes without damaging other circuit elements of the chip.
The first pulse 510 of the exemplary embodiment is followed by an interpulse period 515 . The second pulse 520 is in turn followed by an interpulse period 525 . The first pulse 510 is 0.5 microseconds long while the first interpulse period 515 is 2 milliseconds long and the second pulse 520 is 0.4 microseconds long. The remaining pulses are 0.4 microseconds long while the other interpulse periods 525 - 555 are 2 milliseconds long. However, it should be appreciated that junctions composed of different compounds and different structures than those used in this exemplary embodiment may be used, and that junctions composed of different compounds may employ different voltage levels, pulse widths and interpulse widths. For example, CMOS junctions may be used in place of the NMOS junctions used in the exemplary embodiment of the transistor 248 described above.
In general, programming a programmable previewable circuit can be accomplished using any type of signal that will induce spiking into the particular type of transistor used in the programmable previewable circuit according to this invention. Any type of transistor which can be spiked can be used in the programmable previewable circuit according to this invention. Different types of transistor fabrication techniques may be used. Furthermore, metallization layers differing from the exemplary metallization layer 340 containing 1 percent silicon, or aluminum copper combinations, may also be used. It should be appreciated that various pulse widths, frequencies and durations will be appropriate for different metallization layers, different circuit feature sizes and or different transistor fabrication techniques, and should be selected to ensure spiking while avoiding damaging other circuit circuits in the chip.
FIG. 6 shows a tunable temperature controlled oscillator circuit 600 that incorporates an exemplary embodiment of the programmable previewable circuit according to this invention. The temperature controlled oscillator circuit 600 is connected to first, second, third, fourth and fifth programmable previewable circuits 692 , 694 , 696 , 698 , and 699 .
An accessible test and spike input structure 602 , 604 , 606 , 608 , and 610 , is coupled, respectively, to each of the programmable previewable circuits 692 , 694 , 696 , 698 , and 699 . Each of the test and spike input structures 602 , 604 , 606 , 608 , and 610 is coupled to one of the input structures of the programmable previewable circuits 692 - 699 . A common spike enable structure 611 is coupled to the spike enable input structures 257 of the programmable previewable circuits 692 - 699 , for example, spike enable input structure 257 of FIG. 2 .
The programmable previewable circuits 692 - 699 includes the output structures 258 , which are coupled to the gates of the associated MOS transistors 612 , 614 , 616 , 618 , and 620 , respectively. Each of the MOS transistors 612 - 620 is coupled to an associated capacitor 612 - 620 . These five capacitors 612 - 620 are also coupled to an input 634 of a Schmitt trigger 632 . An output signal on a trigger output 636 is determined, at least in part, by the operable presence or absence of each of the capacitors 622 , 624 , 626 , 628 , and 630 on the tuneable temperature controlled oscillator circuit 600 . The operable states of the capacitor, 622 - 630 are determined by the simulated or actual states of the respectively associated programmable previewable circuits 692 - 699 .
The outputs of the programmable previewable circuits 692 - 699 can be temporarily programmed by applying input signals to the corresponding programmable previewable circuit input structures 254 to simulate the desired output. The programmable previewable circuits 692 - 699 can be permanently programmed by applying an enable signal to the corresponding spike enable input structure 257 .
The circuit 600 is designed to generate an output 640 signal having a predetermined frequency that is indicative of the sensed temperature. However, due to the variations of integrated circuit fabrication, the signal provided at the output 640 must be determined and tuned with respect to a predetermined reference signal. Consequently, the signal provided at the output 640 may be adjusted by applying five input signals simultaneously to the inputs of the programmable previewable circuits 692 - 699 and then varying these signals to generate a range of outputs that are then compared to the desired signal to be obtained at the output 640 .
While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For instance, this invention is not limited to the embodiments shown, but is applicable to any programmable previewable circuit useful for programming or establishing the output of an electronic circuit. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
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A programmable circuit and method of programming that provide an easily fabricated circuit that does not require specialize manufacturing or packaging techniques. The circuit provides for temporarily setting the circuit outputs which can then be used for testing. The circuit also provides for permanently setting the output by applying sufficient voltage and current to the transistor that permanent spiking of the metallized contact layer through the junction occurs.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit and priority of Korean Patent Application No. 10-2012-0087431 filed Aug. 9, 2012. The entire disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an energetic reactive plasticizer for a plastic bonded explosive, and specifically to an energetic reactive plasticizer for a plastic bonded explosive which has high performance and insensitiveness without a migration problem of a plasticizer by being bonded with a polymer binder for a plastic bonded explosive.
BACKGROUND ART
Currently, efforts to make energetic materials insensitive have been a significant issue in development of explosives and a propellant. As a part of such efforts, plastic bonded explosives (PBXs) having low sensitivity and improved mechanical properties while maintaining high energy properties have been developed. Such PBX now becomes an elementary component of high-energy explosives, polymeric binders and other additives used in a small amount such as a plasticizer or a stabilizer.
Currently, a polyurethane polymeric binder on the basis of a hydroxyl-terminated polybutadiene (HTPB) has been used as a widely applicable polymeric binder system, together with various additives so as to improve processability, mechanical properties and chemical stability. Although such polymeric binder shows excellent properties in making high-energy materials insensitive, it has been proposed that it generally disadvantageously reduces the energy density of PBX on the whole owing to its low energy potential. In this regard, many studies have been being made to increase the whole energy density through development of energetic binders and plasticizers containing energetic functional groups such as, for example, nitro (C—NO 2 ), nitrate (O—NO 2 ), nitramine (N—NO 2 ), azido (—N 3 ) and difluoroamino (—NF 2 ) and application thereof.
The term “energetic functional groups” as used herein has common and general meaning as used in the field of molecular explosives, i.e, referring to functional groups, when being applied to a molecular explosive or a plasticizer, known to contribute to the increase in the whole energy level of PBX to which the explosive or plasticizer were applied. Nitro (C—NO 2 ), nitrate (O—NO 2 ), nitramine (N—NO 2 ), azido (—N 3 ), difluoroamino (—NF 2 ) or the like as described above may be mentioned. The term “energetic” as used herein means that the whole energy level of a molecular explosive is more increased by any known methods comprising the introduction of such “energetic” functional groups.
However, those polymeric binders and plasticizers which comprise such energetic functional groups have problems such as low heat stability, non-compatibility with explosives and low processability. Therefore, it has been an important rising issue to ultimately achieve both high performance and insensitiveness in explosives. Further, when an energetic plasticizer is applied, an additional problem such as a migration of the energetic plasticizer from PBX occurs over a long period of time. Such migration of an energetic plasticizer involves further additional problems in PBX such as increase in sensitivity to impact and decrease in storage stability and long-term stability owing to deterioration in mechanical properties. Therefore, the realization of an explosive having both high performance and insensitiveness still has been an important matter to be achieved in this field of art.
When a highly energetic polymer which can satisfy both high performance and insensitiveness at the same time is prepared, it is anticipated to obtain a novel energy material which is combined with a molecular explosive and a binder and has an excellent performance and safety.
SUMMARY OF THE INVENTION
The present invention is to provide an energetic reactive plasticizer which can satisfy the high performance and insensitiveness required in the next-generation explosives without a plasticizer migration and thereby preventing various problems accompanied with such migration.
DETAILED DESCRIPTION OF THE INVENTION
PBX is majorly composed of a molecular explosive and a prepolymer and a curing agent for the formation of a binder, and additionally comprises other additives such as a plasticizer on necessary. All the components are introduced, mixed together and then loaded into a container for an explosive, this procedure of which is called a casting process. The prepolymer and the curing agent react in the container to form a binder while solidifying the components in the container.
The ‘reactive plasticizer’ is a high energy alkyne compound having low viscosity, which can be served as a plasticizer during mixing of PBX and attached to a polymer in a casting or curing process as above. The reactive plasticizer acts as a plasticizer in the preparation of PBX, and a part of or the whole plasticizer is bound into a binder by click reaction by itself in a curing process of the final preparation process.
The present inventors have found that by using a reactive plasticizer in a way of introducing high energy prepolymers in PBX preparation process, it acts as a plasticizer during the casting process, thereby solving the conventional viscosity problem and further it binds to a binder during a curing process, thereby reducing bleeding or migration of a plasticizer, and thus completed the present invention.
In other words, the present invention provides a novel reactive plasticizer having high energy potential by comprising a high energy functional group as well as a functional group which can react with a corresponding energetic prepolymer/a curing agent during a curing process in the preparation of a binder for PBX, thereby being bound to the high energy polymer binder as a side chain thereof.
The energetic reactive plasticizer according to the present invention binds with a side chain of a binder via a click reaction between azide and acetylene groups during the curing process. For such reaction, the energetic reactive plasticizer of the present invention comprises acetylene functional groups and the bond between the energetic functional group and the reactive functional group is an ester bond.
The ester-based energetic reactive plasticizer is an ester-based compound obtained according to the following reaction scheme 1:
(wherein, n=a natural number selected from 0-10).
As seen from the above reaction scheme 1, the reactive energetic plasticizer containing ester groups in the backbone chain is formed by esterification reaction between 2,2-dinitropropyl alcohol (DNP-OH) and an acetylene-containing carboxylic acid (AA). The esterification reaction may be carried out under the conventional reaction conditions known in this field of art and thus an energetic reactive plasticizer comprising ester groups in the backbone chain is synthesized as shown in the above reaction scheme 1.
The acetylene-containing carboxylic acid used in the above reaction includes for example, propiolic acid (n=0), 4-pentynoic acid (n=2) and 5-hexynoic acid (n=3), resulting in 2,2-dinitropropyl propiolate (DNPPE), 2,2-dinitropropyl-4-pentynoate (DNPPA) or 2,2-dinitropropyl-5-hexynoate (DNPHA), respectively.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is the results of viscosity test data for determining the availability of DNPPA as a plasticizer, showing viscosity changes of poly(GAP-co-THF) polyol prepolymer, prepared DNPPA and a mixture thereof (1:1 by weight), respectively.
FIG. 2 is the results of viscosity test data for determining the availability of DNPHA as a plasticizer, showing viscosity changes of poly(GAP-co-THF) polyol prepolymer, prepared DNPHA and a mixture thereof (1:1 by weight), respectively.
FIG. 3 is a plot showing the FT-IR spectroscopy result of DNPPE.
FIG. 4 is a plot showing the FT-IR spectroscopy result of DNPPA.
FIG. 5 is a plot showing the FT-IR spectroscopy result of DNPHA.
FIG. 6 is a plot showing the DSC result of DNPPE.
EXAMPLES
Preparation Example 1
Synthesis and analysis of 2,2-dinitropropyl propiolate ester (DNPPE)
An energetic reactive plasticizer, DNPPE was synthesized as shown in the following reaction scheme 2 via esterification reaction of DNP-OH and propiolinic acid.
10 mL dichloroethylene, DNP-OH (5 g, 33.8 mmol), propiolinic acid (2.3 g, 37.2 mmol) and polymerized phosphoric acid (10.2 g) were placed into a 2-neck flask, and then the mixture was refluxed at 80° C. for 24 hours. The reactants were washed with dichloromethylene and NaHCO 3 (10%) solvent and then washed at least 5 times with distilled water. The solvent was removed under reduced pressure and the resultant was distilled at 80° C. under high vacuum condition, resulting in DNPPE.
The conformation of thus synthesized DNPPE was identified by the following methods. Firstly, 1 H-NMR spectrum was used to identify the molecular structure of DNPPE, resulting in: 1 H NMR (CDCl 3 , d, ppm): 3.08 (1H, ═C—H), 2.25 (3H, —CH 3 ), 5.02 (2H, —CH 2 —COO—).
Further, from the FT-IR spectroscopy results as represented in FIG. 3 showing peaks indicating the presence of a nitro group (1500 cm −1 ), a carbonyl group (C═O, 1650 cm −1 ) and an acetylene group (2250 cm −1 ), the synthesis of DNPPE was confirmed.
Thus synthesized DNPPE was purified by distillation, and the purity was determined as 84% by GC analysis. From the DSC analysis results as shown in FIG. 6 , it was found that its degradation began at 200° C. and hit the maximal degradation at 220° C.
Preparation Example 2
Synthesis and analysis of 2,2-dinitropropyl-4-pentynoate (DNPPA)
An energetic reactive plasticizer, DNPPA was synthesized as shown in the following reaction scheme 3 via esterification reaction of DNP-OH and 4-pentynoic acid.
4-pentynoic acid (3 g, 30.6 mmol), DNP-OH (4.59 g, 30.6 mmol), 4-dimethylaminopyridine (DMAP) (1.03 g, 9.18 mmol) and 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC.HCl) (6.45 g, 33.66 mmol) were placed into a 2-neck flask; then 26 ml dichloromethylene (MC) was further added thereto; and the mixture was stirred at room temperature for 4 hours. Solvent was removed from the reactants under reduced pressure, and the resultants were washed once with an aqueous solution of NaCl (10 wt %)/ethyl acetate and then washed 5 times with distilled water. Ethyl acetate was removed under reduced pressure and the resultant was distilled at 110° C. under high vacuum condition, resulting in DNPPA.
The conformation of thus synthesized DNPPA was identified by the following methods. Firstly, 1 H-NMR spectrum was used to identify the molecular structure of DNPPA, resulting in: 1 H NMR (CDCl 3 , d, ppm): 2.01 (1H, 2.21 (3H, —CH 3 ), 2.51 (2H, —OOCCH 2- CH 2 —), 2.62 (2H, —OOCCH 2- CH 2 —) 4.96 (2H, —CH 2 —COO—).
Further, from the FT-IR spectroscopy results as represented in FIG. 4 showing peaks indicating the presence of a nitro group (—NO 2 , 1566 cm −1 ), a carbonyl group (C═O, 1755 cm −1 ) and an acetylene group (C—H, 3300 cm −1 ), the synthesis of DNPPA was confirmed.
Preparation Example 3
Synthesis and analysis of 2,2-dinitropropyl-4-hexynoate (DNPHA)
An energetic reactive plasticizer, DNPHA was synthesized as shown in the following reaction scheme 4 via esterification reaction of DNP-OH and 5-hexynoic acid.
5-hexynoic acid (3.43 g, 30.6 mmol), DNP-OH (4.59 g, 30.6 mmol), 4-dimethylaminopyridine(DMAP) (1.03 g, 9.18 mmol) and 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC.HCl) (6.45 g, 33.66 mmol) were placed into a 2-neck flask; then 27 ml dichloromethylene was further added thereto; and the mixture was stirred at room temperature for 4 hours. Solvent was removed from the reactants under reduced pressure, and the resultants were washed once with an aqueous solution of NaCl (10 wt %)/ethyl acetate and then washed 5 times with distilled water. Ethyl acetate was removed under reduced pressure and the resultant was distilled at 110° C. under high vacuum condition, resulting in DNPHA.
The conformation of thus synthesized DNPHA was identified by the following methods. Firstly, 1 H-NMR spectrum was used to identify the molecular structure of DNPHA, resulting in: 1 H NMR (CDCl 3 , d, ppm): 2.00 (1H, C—H), 2.2 (3H, —CH 3 ), 2.55 (2H, —OOCCH 2- CH 2 CH 2- ), 1.85 (2H, —OOCCH 2- CH 2 CH 2- ), 2.27 (2H, —OOCCH 2- CH 2 CH 2- ) 4.92 (2H, —CH 2 —COO—).
Further, from the FT-IR spectroscopy results as represented in FIG. 5 showing peaks indicating the presence of a nitro group (—NO 2 , 1563 cm −1 ), a carbonyl group (C═O, 1753 cm −1 ) and an acetylene group (≡C═H, 3301 cm −1 ), the synthesis of DNPHA was confirmed.
Example 1
Decrease in Viscosity of a Prepolymer Due to the Plasticizer
For measuring viscosity, a viscometer, MCR 301 from Anton Paar Physica Co. was used by using a parallel plate having a 1 mm gap (CP25-1-SN9356, diameter=25 mm) at the temperature range of 30-60° C. at a constant shear rate of 1.0 s −1 with a temperature elevation rate of 1° C./minutes. After measuring viscosity of a poly(GAP-co-THF) polyol prepolymer and the prepared plasticizer per se, viscosity of a mixture of the plasticizer and the poly(GAP-co-THF) polyol prepolymer (1:1 w/w) was measured, so as to determine the plasticization properties represented by the decrease in viscosity. The test results obtained from the cases wherein the above obtained plasticizer, DNPPA and DNPHA was applied respectively, were represented in FIGS. 1 and 2 . As shown in FIGS. 1 and 2 , as compared to viscosity of the poly(GAP-co-THF) polyol prepolymer, viscosity of a mixture of the plasticizer prepared according to the present invention and the poly(GAP-co-THF) polyol prepolymer was significantly lowered, over the whole temperature range measured, thereby showing the significant plasticizing effect of the synthesized plasticizer according to the present invention.
INDUSTRIAL APPLICABILITY
The energetic reactive plasticizer according to the present invention is designed to be present in a form bound to the polymeric binder through covalent bond with the branch of the polymeric backbone of polymeric binder during a curing process, so as to prevent a conventional migration or exudation problem of an energetic plasticizer from the molded plastic PBX, while ensuring the essential physical properties required in an energetic plasticizer used in plastic PBX preparation, such as increased energy density and enhanced processability by lowered viscosity in a blending process.
When the energetic reactive plasticizer according to the present invention is applied to the plastic PBX preparation, the conventional plasticizer migration problem from plastic PBX can be prevented, leading to further advantageous effects such as an improvement in long term storage property of PBX and energy density increase in the whole composition.
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Disclosed is an energetic reactive plasticizer for a plastic bonded explosive (PBX), and specifically an energetic reactive plasticizer for PBX which has high performance and insensitiveness without a plasticizer leak by being bonded with a polymer binder for a plastic bonded explosive.
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STATEMENT OF GOVERNMENT LICENSE RIGHTS
[0001] This invention was made with government support by the Small Business Innovation Research program of the U.S. Department of Energy, Contract SC0002291. The government has certain rights in the invention.
FIELD OF THE INVENTION
[0002] Our invention provides a rotary bypass shear comminution process to produce precision wood feedstock particles from veneer.
BACKGROUND OF THE INVENTION
[0003] Wood particles, flakes, and chips have long been optimized as feedstocks for various industrial uses (see, e.g., U.S. Pat. Nos. 2,776,686, 4,610,928, 6,267,164, and 6,543,497), as have machines for producing such feedstocks.
[0004] Optimum feedstock physical properties vary depending on the product being produced and/or the manufacturing process being fed. In the case of cellulosic ethanol production, the feedstock should be comminuted to a cross section dimension of less than 6 mm for steam or hot water pretreatment, and to less than 3 mm for enzymatic pretreatment. Uniformity of particle size is known to increase the product yield and reduce the time of pretreatment. Uniformity of particle size also affects the performance of subsequent fermentation steps.
[0005] Piece length is also important for conveying, auguring, and blending. Over-length pieces may tangle or jam the machinery, or bridge together and interrupt gravity flow. Fine dust-like particles tend to fully dissolve in pretreatment processes, and the dissolved material is lost during the washing step at the end of preprocessing.
[0006] Particle shape can be optimized to enhance surface area, minimize diffusion distance, and promote the rate of chemical or enzyme catalyst penetration through the biomass material. Such general goals have been difficult to achieve using traditional comminution machinery like shredders, hammer mills, and grinders.
[0007] Gasification processes that convert biomass to syngas present a different set of constraints and tradeoffs with respect to optimization of particle shape, size, and uniformity. For such thermochemical conversions, spherical shapes are generally favored for homogeneous materials, and enhancement of surface area is less important. Cellulosic plant derived feedstocks are not homogeneous, and thus optimal properties involve complex tradeoffs.
[0008] A common concern in producing all bioenergy feedstocks is to minimize fossil fuel consumption during comminution of plant biomass to produce the feedstock.
SUMMARY OF THE INVENTION
[0009] Herein we describe a comminution process to produce a new class of wood feedstock particles characterized by consistent piece size and shape uniformity, high skeletal surface area to volume ratio, and good flow properties. Such precision feedstock particles are conveniently manufactured from wood veneer materials at relatively low cost using the disclosed low-energy comminution processes.
[0010] The invention provides a process of comminution of wood veneer having a grain direction and a substantially uniform thickness (Tv) to produce wood particles characterized by a disrupted grain structure, a substantially uniform length dimension (L) aligned substantially parallel to the grain direction, a width dimension (W) normal to L and aligned substantially cross grain, and a height dimension (H) normal to W and L and substantially equal to the Tv. The wood veneer is fed in a direction of travel substantially normal to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel wherein the cutting discs have a uniform thickness (Td) that is substantially equal to the desired particle length (L). This comminution process produces uniform wood particles of roughly parallelepiped shape, characterized by L×H dimensions that define a pair of substantially parallel side surfaces with substantially intact longitudinally arrayed fibers, L×W dimensions that define a pair of substantially parallel top and bottom surfaces, and W×H dimensions that define a pair of substantially parallel end surfaces with crosscut fibers and a disrupted grain structure characterized by end checking between fibers.
[0011] The veneer is preferably aligned within 30° parallel to the grain direction, and most preferably the direction of veneer travel is within 10° parallel to the grain direction.
[0012] To further enhance grain disruption, the veneer and cutting discs may be selected such that Td÷Tv=4 or less, and preferably 2 or less, in which case the comminution process tends to promote pronounced surface checking between longitudinally arrayed fibers on the top and bottom surfaces of the particles.
[0013] For production of feedstocks for bioenergy processes, a Td is typically selected in the range between 1/32 inch and ¾ inch. For use in many conversion processes the veneer Tv and the cutting disc Td are paired such that at least 80% of the produced wood particles pass through a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. For particular end uses, the veneer Tv and cutting disc Td may be co-selected to produce precision feedstocks such that at least 90% of the particles pass through either: an ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a ⅛-inch screen having a 3.18 mm nominal sieve opening; a No. 4 screen having a 4.75 mm nominal sieve opening screen but are retained by a No. 8 screen having a 3.18 mm nominal sieve opening; a ⅛-inch screen having a 3.18 mm nominal sieve opening but are retained by a No. 16 screen having a 1.18 mm nominal sieve opening; a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening; a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 20 screen having a 0.85 mm nominal sieve opening; or, a No. 20 screen having a 0.85 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening.
[0014] The wood veneer may be comminuted in a green, seasoned, or rehydrated condition, but to minimize feedstock recalcitrance in downstream fractionation processes the veneer should be comminuted at a field moisture content greater than about 30% wwb.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a photograph of similarly sized (A) prior art wood cubes typical of coarse sawdust or chips, and (B) wood feedstock particles produced from veneer by the disclosed comminution process; and
[0016] FIG. 2 is a perspective view of a prototype rotary bypass shear machine suitable for comminuting wood veneer into precision particles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] We have applied engineering design principles to develop a low-energy comminution process that produces a new class of wood particles from veneer. The comminution process produces prominent end checks and some surface checks that disrupt the grain structure and greatly enhance the particles' skeletal surface area as compare to envelope surface area. Representative wood feedstock particles of the invention are shown in FIG. 1B , which indicates how the nominal parallelepiped shape or extent volume of the particles is cracked open by pronounced checking that greatly increases surface area.
[0018] The term “veneer” as used herein refers generally to wood peeled, sawn, or sliced into sheets of a given constant thickness (Tv).
[0019] The term “grain” as used herein refers generally to the arrangement and longitudinally arrayed direction of plant fibers within a wood veneer material. “Grain direction” is the orientation of the long axis of the dominant fibers in a sheet of wood veneer.
[0020] The terms “checks” or “checking” as used herein refer to lengthwise separation and opening between fibers in a wood particle. “Surface checking” may occur on the lengthwise surfaces a particle (that is, on the L×W surfaces); and “end checking” occurs on the cross-grain ends (W×H) of a particle.
[0021] The term “skeletal surface area” as used herein refers to the total surface area of a wood particle, including the surface area within open pores formed by checking between plant fibers. In contrast, “envelope surface area” refers to the surface area of a virtual envelope encompassing the outer dimensions the particle, which for discussion purposes can be roughly approximated to encompass the particle's extent volume dimensions.
[0022] The term “field moisture content” refers to veneer that retains a harvested moisture content above the approximately 30% fiber saturation point below which the physical and mechanical properties of wood begin to change as a function of moisture content. Such a veneer has not been dried below its fiber saturation point and then rehydrated, e.g., by soaking in water.
[0023] The adjectives “green” and “seasoned” indicate veneers having moisture contents of more than or less than 19%, respectively.
[0024] The term “disc” refers to a circular object having a uniform thickness (Td) between two opposing flat sides of equal diameter. Td is conveniently measured with an outside caliper.
[0025] The feedstock particles produced by our rotary bypass shear comminution process can be readily optimized for various bioenergy conversion processes that produce ethanol, other biofuels, and bioproducts. The particles advantageously exhibit: a substantially uniform length (L) along the grain direction that is determined by the uniform thickness (Td) of the cutter discs; a width (W) tangential to the growth rings (in wood) and normal to the grain direction; and a height (H), oriented radial to the growth rings and normal to the W and L dimensions, that is substantially equal to the thickness (Tv) of the veneer raw material.
[0026] We have found it very convenient to use wood veneer from a centerless rotary lathe process as a raw material. Peeled veneer from a rotary lathe naturally has a thickness that is oriented with the growth rings and can be controlled by lathe adjustments. Moreover, within the typical range of veneer thicknesses, the veneer contains very few growth rings, all of which are parallel to or at very shallow angle to the top and bottom surfaces of the sheet. In our process, we specify the veneer thickness (Tv) to match the desired wood particle height (H) to the specifications for a particular conversion process.
[0027] The veneer may be processed into particles directly from a veneer lathe, or from stacks of veneer sheets produced by a veneer lathe. Our preferred manufacturing method is to feed veneer sheet or sliced materials into a rotary bypass shear with the grain direction oriented across and preferably at a right angle to the feed direction through the machine's processing head, that is, parallel to the shearing faces.
[0028] The rotary bypass shear that we designed for manufacture of precision wood feedstock particles is a shown in FIG. 2 . This prototype machine 10 is much like a paper shredder and includes parallel shafts 12 , 14 , each of which contains a plurality of cutting disks 16 , 18 . The disks 16 , 18 on each shaft 12 , 14 are separated by smaller diameter spacers (not shown) that are the same width or greater by 0.1 mm thick than the Td of the cutting disks 16 , 18 . The cutting disks 16 , 18 may be smooth 18 , knurled (not shown), and/or toothed 16 to improve the feeding of veneer sheets 20 through the processing head 22 . Each upper cutting disk 16 contains five equally spaced teeth 24 that extend 6 mm above the cutting surface 26 . The spacing of the two parallel shafts 12 , 14 is slightly less than the diameter of the cutting disks 16 , 18 to create an intermeshing shearing interface. In our machine 10 , the cutting disks 16 , 18 are approximately 105 mm diameter and the shearing overlap is approximately 3 mm.
[0029] This rotary bypass shear machine 10 used for demonstration of the manufacturing process operates at an infeed speed of one meter per second (200 feet per minute). The feed rate has been demonstrated to produce similar particles at infeed speeds up to 2.5 meters per second (500 feet per minute).
[0030] The width, or thickness (Td), of the cutting disks 16 , 18 establishes the length (L) of the particles produced since the veneer 20 is sheared at each edge 28 of the cutters 16 , 18 and the veneer 20 is oriented with the fiber grain direction parallel to the cutter shafts 12 , 14 and shearing faces of the cutter disks 16 , 18 . Thus, wood particles from our process are of much more uniform length than are particles from shredders, hammer mills and grinders which have a broad range of random lengths. The desired and predetermined length of particles is set into the rotary bypass shear machine 10 by either installing cutters 16 , 18 having uniform widths (Td) equal to the desired output particle grainwise length (L) or by stacking assorted thinner cutting disks 16 , 18 to the appropriate cumulative cutter width (Td).
[0031] It should be understood that, alternatively, an admixture of for example nominal 2×2 mm and 2×4 mm particles can be produced directly from 2 mm veneer by stacking the shafts 12 , 14 of machine 10 with a desired ratio of alternating pairs of 2 mm- and 4 mm-wide cutting discs 16 , 18 .
[0032] Fixed clearing plates 30 ride on the rotating spacer disks to ensure that any particles that are trapped between the cutting disks 16 , 18 are dislodged and ejected from the processing head 20 .
[0033] We have found that the wood particles leaving the rotary bypass shear machine 10 are broken (or “crumbled”) into short widths (W) due to induced internal tensile stress failures. Thus the resulting particles are of generally uniform length (L) along the wood grain, as determined by the selected width (Td) of the cutters 16 , 18 , and of a uniform thickness (H, as determined by the veneer thickness, Tv), but vary somewhat in width (W) principally associated with the microstructure and natural growth properties of the raw material species. Most importantly, frictional and Poisson forces that develop as the veneer material 20 is sheared across the grain at the cutter edges 28 tend to create end checking that greatly increases the skeletal surface areas of the particles. Substantial surface checking between longitudinally arrayed fibers further elaborates the L×W surfaces when the length to height ratio (L/H) is 4:1 and particularly 2:1 or less.
[0034] The output of the rotary bypass shear 10 may be used as is for some conversion processes such as densified briquette and pellet manufacture, gasification, or thermochemical conversion. However, many end-uses will benefit if the particles are screened into more narrow size fractions that are optimal for particular end-use conversion processes. In that case, an appropriate stack of vibratory screens or a tubular trommel screen with progressive openings can be used to remove particles larger or smaller than desired. In the event that the feedstock particles are to be stored for an extended period or are to be fed into a conversion process that requires very dry feedstock, the particles may be dried prior to storage, packing or delivery to an end user.
[0035] We have used this prototype machine 10 to make feedstock particles in various lengths from a variety of plant biomass materials, including: peeled softwood and hardwood veneers; sawed softwood and hardwood veneers; softwood and hardwood branches and limbs crushed to a predetermined uniform height or maximum diameter; cross-grain oriented wood chips and hog fuel; corn stover; switchgrass; and bamboo. The L×W surfaces of peeled veneer particles generally retain the tight-side and loose-side characteristics of the raw material. Crushed wood and fibrous biomass mats are also suitable starting materials, provided that all such biomass materials are aligned across the cutters 16 , 18 , that is, with the shearing faces substantially parallel to the grain direction, and preferably within 10° and at least within 30° parallel to the grain direction.
[0036] We currently consider the following size ranges as particularly useful biomass feedstocks: H should not exceed a maximum from 1 to 16 mm, in which case W is between 1 mm and 1.5×the maximum H, and L is between 0.5 and 20×the maximum H; or, preferably, L is between 4 and 70 mm, and each of W and L is equal to or less than L.
[0037] For flowability and high surface area to volume ratios, the cutter disc thickness Td and veneer thickness T dimensions are co-selected so that at least 80% of the particles pass through a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. For uniformity as reaction substrates, at least 90% of the particles should preferably pass through: a ¼″ screen having a 6.3 mm nominal sieve opening but are retained by a No. 4 screen having a 4.75 mm nominal sieve opening; or a No. 4 screen having a 4.75 mm nominal sieve opening but are retained by a No. 8 screen having a 2.36 mm nominal sieve opening; or a No. 8 screen having a 2.36 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. Most preferably, the subject biomass feedstock particles are characterized by size such that at least 90% of the particles pass through: a ¼ inch screen having a 6.3 mm nominal sieve opening but are retained by a ⅛-inch screen having a 3.18 mm nominal sieve opening; or a No. 4 screen having a 4.75 mm nominal sieve opening screen but are retained by a No. 8 screen having a 2.36 mm nominal sieve opening; or a ⅛-inch screen having a 3.18 mm nominal sieve opening but are retained by a No. 16 screen having a 1.18 mm nominal sieve opening; or a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening; or a No. 10 screen having a 2.0 mm nominal sieve opening but are retained by a No. 20 screen having a 0.85 mm nominal sieve opening; or a No. 20 screen having a 0.85 mm nominal sieve opening but are retained by a No. 35 screen having a 0.5 mm nominal sieve opening.
[0038] Suitable testing screens and screening assemblies for empirically characterizing the produced wood particles in such size ranges are available from the well-known Gilson Company, Inc., Lewis Center. Ohio, US (www.globalgilson.com). In a representative protocol, approximately 400 g of the subject particles (specifically, the output of machine 10 with 3/6″-wide cutters and ⅙″ conifer veneer) were poured into stacked ½″, ⅜″, ¼″, No. 4, No. 8, No. 10, and Pan screens; and the stacked screen assembly was roto-tapped for 5 minutes on a Gilson® Sieve Screen Model No. SS-12R. The particles retained on each screen were then weighed. Table 1 summarizes the resulting data.
[0000] TABLE 1 Screen size ½″ ⅜″ 3¼″ No. 4 No. 8 No. 10 Pan % retained 0 0.3 1.9 46.2 40.7 3.5 7.4
These data show a much narrower size distribution profile than is typically produced by traditional high-energy comminution machinery.
[0039] Thus, the invention provides precision wood particles characterized by consistent piece size as well as shape uniformity, obtainable by cross-grain shearing a veneer material of selected thickness by a selected distance in the grain direction. Our rotary bypass shear process greatly increases the skeletal surface areas of the particles as well, by inducing frictional and Poisson forces that tend to create end checking as the biomass material is sheared across the grain. The resulting cross-grain sheared plant biomass particles are useful as feedstocks for various bioenergy conversion processes, particularly when produced in the size classifications described above.
EXAMPLES
[0040] Wood particles of the present invention were manufactured as described in above described machine 10 using 3/16″ wide cutters from a knot-free sheet of Douglas fir ⅙″ thick veneer (10-15% moisture content). The resulting feedstock was size screened, and from the Pass ¼″, No Pass No. 4 fraction for the precision desired in this particular experiment a 10 g experimental sample was collected of particles that in all dimensions passed through a ¼″ screen (nominal sieve opening 6.3 mm) but were retained by a No. 4 screen (nominal sieve opening 4.75 mm). Representative particles from this experimental sample (FS-1) are shown in FIG. 1B .
[0041] Similarly sized cubes indicative of the prior art were cut from the same veneer sheet, using a Vaughn® Mini Bear Saw™ Model BS 150D handsaw. The sheet was cut cross-grain into approximately 3/16″ strips. Then each strip was gently flexed by finger pressure to break off roughly cube-shaped particles of random widths. The resulting feedstock was size screened, and a 10 g control sample was collected of particles that in all dimensions passed through the ¼″ screen but were retained by the No. 4 screen. Representative cubes from this control sample (Cubes- 1 ) are shown in FIG. 1A .
[0042] The outer (or extent) length, width, and height dimensions of each particle in each sample were individually measured with a digital outside caliper and documented in table form. Table 2 summarizes the resulting data.
[0000]
TABLE 2
Samples
Number of
Length
Width
Height
(10 g)
pieces
(L)
(W)
(H)
Control cubes
n = 189
Mean 5.5
Mean 5.0
Mean 3.9
(Cubes-1)
SD 0.48
SD 1.17
SD 0.55
Experimental particles
n = 292
Mean 5.3
Mean 5.8
Mean 3.3
(FS-1)
SD 0.74
SD 1.23
SD 0.82
[0043] The Table 2 data indicates that the extent volumes (extent L×extent W×extent H) of these rather precisely size-screened samples were not substantially different. Accordingly, the cubes and particles had roughly similar envelope surface areas. Yet the 10 gram experimental sample contained 54% (292/189) more pieces than the 10 gram control sample, which equates to a mean density of 0.34 g/particle (10/292) as compared to 0.053 g/cube. FIG. 1 indicates that the roughly parallelepiped extent volumes of typical particles ( 1 B) contain noticeably more checks and air spaces than typical cubes ( 1 A). These differences demonstrate that the feedstock particles produced from veneer by rotary bypass shear comminution had significantly greater skeletal surface areas than the control cubes indicative of prior art coarse sawdust and chips.
[0044] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
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Comminution process of wood chips to produce wood particles, by feeding wood chips in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) aligned normal to W and L, wherein the W×H dimensions define a pair of substantially parallel end surfaces with crosscut fibers.
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Japanese Patent Application No. 11-306507, filed Oct. 28, 1999 hereby incorporated by reference in its entirety. International Application No. PCT/JP00/07505, filed Oct. 26, 2000 is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
This invention relates to a composite NC lathe which has enabled a processing operation like that of a machining center by providing a tool spindle having an ATC (automatic tool changing device), and provides a two opposed main shaft lathe provided with a tool changeable tool spindle and tool turrets.
BACKGROUND
The directions (control axes of a NC machine) of work and cutting tool operations on a NC lathe are represented by X, Y, Z and A, B, C. A Z-axis represents the direction of main shafts, an X-axis the direction in which a tool cuts into a work and is fed, a Y-axis the direction in which the Y-axis is orthogonal to both the Z-axis and X-axis, a C-axis an angle around the Z-axis, an A-axis an angle around the X-axis, and B-axis an angle around the Y-axis.
Conventionally, a two-opposed-main-shaft and two-opposed-tool-turret lathe provided with a left main shaft and a right main shaft facing each other on the same axis and two tool turrets which are the left and right tool turrets corresponding to the respective main shafts are known (Japanese Patent Application Laid-Open Nos. 3-222012 and 8-126901). In this type of lathe, at least one of the main shafts is provided movable in the direction of the Z-axis, and a work is transferred between the left and right main shafts in accordance with a movement of a main shaft in the direction of the Z-axis. Because a work is transferred between the left and right main shafts, the processing of the work as a whole including the portion thereof which is gripped by a chuck can be carried out on the same machine.
Moreover, in this kind of lathe made capable of fixing rotary tools, such as milling cutters and drills and the like to tool turrets, the flattening, drilling and thread cutting of a circumferential surface of a work can be done by controlling the left and right of the Z-axis, the X-axis and the C-axis. This enables works of a variety of shapes to be processed throughout from a state of a raw material to that of a finished product on the same machine.
However, it is inevitable that the movable main shafts are less rigid compared with fixedly provided main shafts. Therefore, a heavy load cutting operation by a lathe having movable main shafts is restricted. Although the tool turrets are capable of changing tools in use in a short period of time, the bearing rigidity of the tools and the dimensions of usable tools are restricted because limitations are placed on support structures for the turrets and the weight and dimensions of the same.
In such a conventional lathe having two opposed main shafts and two opposed turrets, the two tool turrets are provided on the rear side of the main shafts when viewed from the side of an operator so as to maintain a work attaching to and detaching from the main shafts and to allow an operator approach the machine. Furthermore, the lathe also includes a third turret disposed on the front side of the main shafts in addition to two tool turrets disposed on the rear side of the main shafts.
A composite NC lathe provided with a single main shaft, and a single ATC-carrying tool spindle capable of controlling a B-axis and provided on a tool rest is known (Japanese Patent Application Laid-Open No. 4-283003). This kind of lathe is provided with a rotary tool such as a milling cutter and the like on the tool spindle, and capable of carrying out a processing operation of a machining center such as a process for making a large hole or flattening a diagonal surface. In this lathe, a turning process may be carried out by a turning tool which is fixed to the tool spindle in a rotation-stopped state. In this kind of composite NC lathe, only one tool spindle is fixed to the tool rest, and it is therefore possible to increase the bearing rigidity of the tools and the rotational torque imparted to the tools. This enables a heavy load cutting operation to be carried out, and large-size tools to be fixed to the tool spindle. Since many tools can be held in a tool magazine of ATC, a work can be processed by many kinds of tools. However, the ATC takes much time to change tools, and reduces a processing efficiency since a processing operation cannot be carried out when the tools are changed. When a work of an elongated shape is cut to a large depth with a tool, the work is bent due to a cutting reaction force, and a heavy load cutting operation can not be carried out.
A single-main shaft single-spindle single-turret type composite NC lathe which is a single-main shaft single-spindle type composite NC lathe added with a tool turret as mentioned above has further been provided (Japanese Patent Application Laid-Open No. 5-31601). In the lathe of this structure, a tool spindle is provided on the rear side of the main shaft when viewed from the side of an operator, and a tool turret on the front side of the main shaft.
However, when one of two tool rests is formed of an ATC-carrying tool rest with the other formed of a turret tool rest, the imbalance of processing load and processing efficiency between the turret side and the ATC side becomes large, and much time is lost due to the transfer of the tool rest and a tool changing operation of the ATC. Therefore, the processing efficiency cannot be sufficiently improved.
SUMMARY
Due to the recent progress in technology and the diversification of demands, an increase in the kind of works and a decrease in the quantity thereof have become inevitable even at machine manufacturing sites. Moreover, the labor saving and the improvement of the productivity have been on demand. In order to meet such requirements, it is necessary to process works of various shapes in a state of raw material into finished products efficiently on the same machine. In the present invention, it is unnecessary to make an arrangement for changing the kind of the machine in use when the operation for transferring works between many kinds of machines and the kind of works are changed. Moreover, a loss of time during the processing operation is avoided, and the heavy load cutting of a work becomes possible. This enables many kinds of works to be processed continuously in an unmanned condition with a high efficiency.
The composite NC lathe according to the present invention is provided with a left main shaft 1 L and a right main shaft 1 R facing each other on the same axis, a left turret tool rest 8 L and a right turret tool rest 8 R positioned on the lower front side of the main shafts 1 L, 1 R, when viewed from the side of an operator, a third tool rest 6 positioned on the upper rear side of the main shafts 1 L, 1 R when viewed from the side of the operator, a tool magazine 19 holding tools to be fixed to the third tool rest, and an automatic tool changing device 20 for these tools. The left turret tool rest 8 L and right turret tool rest 8 R are provided with tool turrets 9 L, 9 R respectively on which many tools can be fixed. The third tool rest 6 is provided with a tool spindle 14 directed toward a work. The left main shaft 1 L and right main shaft 1 R are connected to main shaft motors 4 L, 4 R that can control C-axis and can be driven independently or synchronously. The movement of the third tool rest 6 can be set in the directions of the Z-axis, X-axis and Y-axis. The tool spindle 14 is provided on the tool rest 6 . Furthermore, the tool spindle 14 is capable of controlling the position in the direction the B-axis and fixing the position.
When the composite NC lathe according to the present invention is used, the processing of a work can be continued by simultaneous operations of the left turret tool rest and right turret tool rest even while the tools are changed on the third tool rest (which will hereinafter be referred to as “composite tool rest”) 6 provided with the ATC-carrying tool spindle 14 . Only a special processing operation and a heavy-load processing operation which cannot be carried out on the turret tool rests may be carried out on the composite tool rest. Therefore, it is possible to minimize the influence which a tool changing operation of the composite tool rest and the transfer time of the tool rest exert on decreasing the processing efficiency, and a processing cycle time can be improved.
In the processing of a bar material in which both end portions of an elongated work are gripped by the left main shaft and right main shaft, a balanced cutting operation can be carried out by a composite tool rest of a large cutting reaction force and two turret tool rests of a small cutting reaction force. Namely, a heavy load cutting operation not accompanied by the flexure of the work can be carried out, and a further improvement of the processing efficiency can be attained.
When the left main shaft 1 L is provided fixedly in the structure according to this invention, it is possible to improve the bearing rigidity of a work in the processing work in a first step, and to simplify a method of supplying a bar material through a central hole of the left main shaft. When the right main shaft 1 R is provided so that this shaft can be moved in the direction of the Z-axis, the transfer of a work between the left main shaft and right main shaft can be carried out. When a locking device for mechanically stopping the movement of the right main shaft in the direction of the Z-axis is provided, the rigidity of the right main shaft during a heavy load cutting operation can be heightened.
When both the left and right tool turrets 9 L, 9 R are provided so that they can be moved in the direction of the Z-axis and the direction of the X-axis, it is possible to carry out a simultaneous processing operation using an arbitrary combination of the composite tool rest and two turret tool rests. In this case, when the left and right tool turrets 9 L, 9 R are rendered movable from a position in which the left main shaft is opposite to a work to a position in which the right main shaft is opposite to the work, it is possible to freely combine the left and right main shafts and tool turrets, and the kind of the tools usable for the processing operation on each side can be increased.
When the tool turrets 9 L, 9 R are formed so that rotary tools can be fixed thereto, it is possible to process a work stopped by the rotary tools on the turrets simultaneously with a milling process applied to the work on the composite tool rest.
When the tool turrets 9 L, 9 R are fixed to the portions of the respective tool rests 8 L, 8 R which are close to the opposite tool rests, the tools on the two tool turrets can be brought close to each other. Therefore, the processing of the work gripped by one main shaft can be done easily by using the two tool turrets.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general perspective view of one embodiment of the composite NC lathe according to the present invention;
FIG. 2 is a schematic diagram showing the relationship between a composite tool rest and a tool magazine; and
FIG. 3 shows an example work process of a flattening process operation;
FIG. 4 shows an example work process that includes simultaneous operation by two tool turrets and a total of three turning tools;
FIG. 5 shows an example work process including a tool changing operation;
FIG. 6 shows an example work process in which the work is retained by pressing members;
FIG. 7 shows a work profess carried out by a rotary tool on a tool spindle;
FIG. 8 shows an example work process carried out by a tool fixed to a right turret.
Referring to the drawings, reference numerals 29 L, 29 R denote left and right head stocks, a reference numeral 6 a composite tool rest, reference numerals 8 L, 8 R left and right turret tool rests, and 9 L, 9 R left and right tool turrets, a reference numeral 14 a tool spindle, 19 a tool magazine of ATC, and 20 an automatic tool changing device.
DETAILED DESCRIPTION
The composite NC lathe shown in the drawings is provided with a left head stock 29 L and a right head stock 29 R facing each other on the same axis. A left chuck 2 L and a right chuck 2 R are provided on the opposite end portions of the main shafts supported on the two head stocks 29 L, 29 R. The left and right main shafts are rotated separately and synchronously as necessary by main shaft motors 4 L, 4 R which can control C-axis and contains encoders in portions 3 L, 3 R thereof. The left head stock 29 L is fixed to a bed 5 , while the right head stock 29 R is movable in the direction of the Z-axis. When a heavy load cutting process is carried out, the right head stock 29 R can be fixed to the bed 5 by a clamp device (not shown) adapted to hold the right head stock 29 R with hydraulic power. The bed 5 is a slanted type inclined at an angle of 30 to 45 degrees in the direction in which a front portion of the bed is lower when viewed from the side of an operator. A rear portion of the bed 5 is formed of a horizontal guide surface adapted to guide a movable carriage 7 for a composite tool rest 6 in the direction of the Z-axis. Turret tool rests 8 L, 8 R movable in the directions of the X-axis and Z-axis respectively are provided on the lower front side of the main head stocks 29 L, 29 R. The turret tool rests are provided on the sides thereof which are close to the other turret tool rests. In other words, tool turrets 9 L, 9 R are provided at a right end portion of the left turret rest and at a left end portion of the right turret rest. A guide for the movements of the right head stock 29 R and two turret tool rests 8 L, 8 R in the direction of the Z-axis is provided on an inclined surface on the front side of the bed 5 . The turret tool rests 8 L, 8 R are moved in the direction of the Z-axis by a feed screw provided in parallel with this guide. When two feed screws engaged with the turret tool rests 8 L, 8 R are provided apart by a distance close to a width of the bed, it is possible to process a work held by the right main shaft by means of a tool on the left tool turret as well as a work held by the left main shaft by means of a tool on the right tool turret.
Although the details are not shown in the drawings, the two turrets 9 L, 9 R are capable of fixing rotary tools such as a milling cutter and the like thereto, and a light load milling process and a hole making process can be carried out on the side of the turrets 9 L, 9 R.
Concerning the structures of the head stocks 29 L, 29 R and turret tool rests 8 L, 8 R, the left head stock 29 L is most preferably provided fixedly. When such a structure is employed, the structure of, for example, a bar feeder used to supply a work to a processing region through the center of the left main shaft by using the bar feeder can be simplified. The right head stock can be provided so that it does not move thereof in the direction of the Z-axis. In this case, the delivery of a work from the left side to the right side is carried out by utilizing a hand of a loader/unloader which is adapted to load and unload a work onto and from the lathe. The left turret tool rest 8 L is naturally made movable only in the directions of the Z-axis and X-axis. The right turret tool rest 8 R can also be made movable in the direction of the X-axis when the right head stock 29 R is set movable in the direction of the Z-axis. However, more preferably, it is recommended that the right turret tool rest be provided movable in the directions of the Z-axis and X-axis so as to constantly utilize the right turret tool rest 8 R when a processing operation is carried out with the right head stock 29 R fixed so as to bear a heavy load.
The movable carriage 7 for the composite tool rest 6 is provided movable in the direction of the Z-axis and along the Z-axis direction guide 10 provided on a horizontal surface on the rear side of the bed 5 . This movable carriage is provided thereon with a longitudinal guide 16 extending horizontally so as to cross the Z-axis at right angles thereto. Furthermore, an inclined base 17 is adapted to be movable along this guide by an inclined base-moving motor (not shown). This inclined base is provided with an upper surface extending at an angle equal to that of a slanting surface at the front side of the bed, and an X-axis direction guide 11 is provided on the same upper surface. The inclined base 17 is mounted with a feed base 12 for the composite tool rest 6 so that the feed base can be moved along the X-axis direction guide 11 by a feed motor 13 . This feed base 12 has a rotary tool base 15 provided with a tool spindle 14 and fixed thereto so that the tool base can be turned to left and right at 90 degrees respectively around a B-axis with a position in which the tool spindle is set so as to face in the direction of the X-axis as an origin.
The tool spindle 14 is formed so that the rotation thereof can be stopped sharply by a locking device (not shown) contained in the rotary tool rest 15 . Therefore, rotary tools, such as a milling cutter, a drill and the like can naturally be attached to the tool spindle 14 . It is also possible to fix turning tools (bit and the like) to the tool spindle 14 in a locked state.
A tool 18 fixed to the tool spindle 14 on the composite tool rest 6 formed as described above can make operations which will be described below. First, as basic operations of the tool rest of a lathe, the movement thereof in the directions of the Z-axis and X-axis can be set owing to a movement of the movable carriage 7 in the direction of the Z-axis and a movement of the feed base 12 in the direction of the X-axis. Moreover, the direction in which the tool extends can be inclined freely toward the first head stock or the second head stock owing to a B-axis control operation of the rotary tool rest 15 . Furthermore, the movement of the feed base 12 , i.e. the tool spindle 14 in the direction of the Y-axis can be set by controlling a longitudinal movement of the inclined base 17 and an X-axis movement of the feed base 12 synchronously in the relation corresponding to an angle of inclination of an upper surface of the inclined base 17 . Namely, when the tool spindle 14 to which, for example, a face milling cutter is fixed is moved in the direction of the Y-axis with a C-axis movement of the main shafts stopped, a large flat surface parallel to the main shafts can be formed on a circumferential surface of the work. It is also possible to form an inclined flat surface and a curved flat surface by controlling an angle of the tool spindle 14 around the B-axis.
An ATC 20 having a tool magazine 19 for tools to be fixed to the composite tool rest 6 and adapted to attach and detach a tool in this tool magazine to and from the tool spindle 14 on the composite tool rest is provided adjacent to a rear left end of the bed 5 . The illustrated tool magazine 19 has a structure in which a circulating chain 22 to which plural tool holders 21 are connected in the outward direction with respect to the lathe is provided, and in which the selection of tools is carried out by setting one of the tools fixed to the tool holder in a transfer position with respect to the ATC 20 by a circulating movement of the circulating chain.
The ATC 20 has a structure provided with a swing arm 23 provided with tool gripping claws at both ends thereof, and this swing arm is fixed to a traverser 25 which moves forward and backward along the guide rail 24 extending in the direction of the Z-axis.
Between a space in which the tool magazine 19 and the ATC 20 are provided and a space in which the composite tool rest 6 is moved, a partition 27 having a shutter 26 is provided as shown in FIG. 2 . While the composite tool rest 6 processes a work, the tool magazine 19 transfers a tool to be used in a subsequent stage to a transfer position, and the swing arm 23 of the ATC grips a selected tool by one tool gripping claw 28 thereof, transfers the tool toward the tool rest along the guide rail 24 and stands by.
When the composite tool rest 6 returns to the origin (home position) in the direction of the X-axis at a stage in which a processing operation by the fixed tool is finished. The rotary tool rest 15 is moved to a position spaced at 90 degrees around the B-axis to direct the movable carriage 7 toward the ATC. The shutter 26 is opened with the tool spindle left in this condition, and the movable carriage 7 is moved toward the ATC, the tool gripped by the tool spindle 14 being delivered to the swing arm 23 . The swing arm is then turned 180 degrees, and a new tool is fixed to the tool spindle 14 .
The composite tool rest 6 and ATC 20 move in the directions in which they leave each other, and the shutter 26 is closed. The ATC then returns the tool received to the tool magazine 19 , which starts an operation for selecting a tool to be used in a still subsequent stage. On the other hand, the composite tool rest 6 starts carrying out a processing operation by a newly fixed tool with predetermined timing.
According to the composite NC lathe in this embodiment described above, the following work processing operation can be carried out.
A. As shown in FIG. 3, a flattening process for a left work is carried out by a milling cutter fixed to a tool spindle 14 with a left main shaft 1 L fixed as a turning operation for a right work is carried out by a right turret 9 R with a right main shaft 1 R rotated. During this time, a heavy load cutting operation of the composite tool rest can be made possible by carrying out a drilling process for the left work by a left turret 9 L simultaneously with the flattening process, and preventing the flexure of the work by pressing a receiving member fixed to the left turret 9 L against the work. A processing operation with the condition of the left side and that of the right side reversed can also be carried out.
B. As shown in FIG. 4, it is possible to turn works gripped by the left main shaft 1 L and right main shaft 1 R separately, or a work gripped at both end portions thereof, fix a turning tool to a tool spindle 14 , and thereby process the works simultaneously by two tool turrets 9 L, 9 R and a total of three turning tools. During this time, a tool load on the tool spindle 14 and that on the two turrets are exerted in the directions contrary to each other, so that it is possible to carry out a balanced cutting operation not accompanied by the flexure of the work.
C. As shown in FIG. 5, while a tool spindle 14 carries out a tool changing operation, or, while the tool spindle 14 is moved between left side and right side, the processing of works can be continued on the left side and right side by respective spindles and tool turrets.
D. As shown in FIG. 6, when a processing operation in which an extremely large cutting reaction force is exerted on a work by a tool fixed to a tool spindle 14 , the work is retained by pressing receiving members fixed to left and right turrets 9 L, 9 R against the work. This enables the present invention go carry out a heavy load cutting operation, which was impossible in a conventional lathe of this kind. In this case, processing the work by rotating the work at a low speed with both end portions of the work gripped by main shafts on both sides is also possible, in which it is possible to exert on the work a large torque resistant to the processing reaction force by operating the two main shafts synchronously.
E. As shown in FIG. 7, it is possible that, while a processing operation is carried out by a rotary tool on a tool spindle 14 with one main shaft 1 R fixed, a cutting process is carried out simultaneously for a work on the other main shaft 1 L by two tools on both the left and right tool turrets.
F. As shown in FIG. 8, a left work can be processed by a tool which is fixed only to a right turret, by drawing back the left turret 9 L, and using a left main shaft 1 L and a right turret 9 R. It is also possible to carry out a reverse operation. When a work on the opposite side is processed at this time by a tool fixed to a tool turret 14 , it is possible to prevent a decrease in a processing efficiency ascribed to the non-use of the other tool turret.
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A two-opposed-main-shaft type composite NC lathe provided with a tool changeable tool spindle and tool turrets, comprising: a left turret rest and a right turret rest provided on a lower front side of a left main shaft and a right main shaft facing each other on a Z-axis; a third tool rest positioned on an upper rear side of the left and right main shafts and provided with a tool spindle; a tool magazine holding tools therein which are to be fixed to the third tool rest; and an automatic tool changing device. The left and right main shafts are provided with main shaft motors capable of controlling a C-axis and being driven independently and synchronously with each other. The tool spindle on the third tool rest is capable of controlling the directions of the Z-axis, an X-axis, a Y-axis and a B-axis and fixing the rotations thereof.
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FIELD OF THE INVENTION
The present invention relates to a method for making improved abrasion resistant overlays for use in making decorative laminates and the like. More specifically, the present invention provides improved an improved method for making abrasion resistant overlays for use in making decorative laminates and the like using grit particles, generally aluminum oxide, that have been micro-encapsulated in a resin, generally melamine-formaldehyde resin.
BACKGROUND OF THE INVENTION
Decorative laminates are conventionally manufactured by assembling several layers of a sheet material such as paper or fabric impregnated with resins of various kinds. Typically, the resins may be selected from phenolics, aminoplasts, polyesters, polyurethanes, epoxy resins, melamine resins and the like.
The selection of the paper or fabric to be used, and the resin for impregnation is governed by the intended end-use of the finished laminate. For some end uses, surface decoration is not required, but in many instances colors and/or patterns are desired to add eye appeal to the finished laminate. While color and/or pattern decoration may be desired for an outer surface of the laminate, the core or base functions primarily as a strengthening support, and may comprise wood, such as plywood, multiple layers of unbleached or dark colored paper or cloth, and may utilize dark colored, less expensive impregnating resins, such as phenolic resins.
However, when a decorated or printed surface is desired in the laminate, an outer surface layer known as a decor sheet is used to cover the core layer or layers. The decor sheet can be colored decorative paper which may be pigmented with titanium dioxide and/or other opacifying pigments or printed decorative paper, where decorative paper is further printed with patterns to mask the dark-colored core stock. The decor layer may be impregnated with a wide variety of resins such as melamine resins, polyester resin, etc.
Needless to say, given that the decorative laminates discussed herein are often exposed to foot traffic (when used in flooring) or general wear and tear (when used in countertops and the like) it is generally desired to protect the decor layer in some manner that would prevent damage to the decorative image. To impart the desired wear and/or abrasion resistance to these decorated laminates, it has long been the practice to place a resin-impregnated surfacing paper known as an overlay sheet over the decor sheet. Upon consolidating the laminate, the overlay sheet becomes transparent, permitting the printed pattern on the decor sheet to be seen through the overlay sheet. Recently, it has been found that small inorganic particles, known in the industry as “grit,” can be added to the overlay sheet to impart added abrasion resistance to the laminates incorporating them. This grit, which very frequently is comprised of aluminum oxide particles, can also be added directly to the printed decor papers that have been coated with resins. While there have been many methods disclosed for the addition of the grit to these papers, as will be discussed in detail below, there are several methods that are preferred.
However, regardless of the method that is used to incorporate the grit into the paper, be it overlay or decor sheet, the use of the grit in the papermaking process has added heretofore non-existent problems. More specifically, while the addition of grit to these papers has been used effectively to produce laminates having desirable wear-resistant properties, the use of the highly-abrasive grit can cause problems in the papermaking process. For example, the mixing and transportation of the abrasive slurries carrying the grit to the point where the grit is added to the paper itself results in a large amount of wear on the pumps, pipes, and other process equipment used in the process. Additionally, once the grit has been added to the paper, the presence of the grit on the paper significantly adds to the wear and tear on the drying machines and other downstream equipment. Most importantly, though, the presence of the grit in the paper during the lamination process can result in damage and wear to the highly polished caul plates. Thus, for all of these reasons, it is considered highly desirable to lessen or eliminate the wear and tear on the equipment used to make wear resistant overlay paper as well as the caul plates used to laminate that paper while maintaining the wear-resistant properties of the paper itself.
In attempting to address these problems, it has been found that by using grit, such as aluminum oxide particles, which have been micro-encapsulated in a melamine-formaldehyde or a similar type of resin prior to adding the grit to the papermaking process, that wear and tear on the paper and laminating process machinery is reduced while the wear-resistant properties of the end product laminate made using the paper are not significantly diminished. In this regard, U.S. Pat. No. 5,962,134 to Shah et al. discloses one technique for encapsulating grit particles in melamine-formaldehyde resin. However the Shah et al. reference is silent as to preferred methods for incorporating the micro-encapsulated grit into finished paper products. Additionally, AU 9806636 owned by Depco Pty Ltd entitled Wear Resistant Surfaces and Laminates discloses that similar micro-encapsulated abrasive particles can be added to overlay paper during the papermaking process. As with the Shah et al. patent, though, the Depco reference is relatively silent on the incorporation of the micro-encapsulated grit particles into the papermaking process saying only that the micro-encapsulated grit should be incorporated “with and or supplementary to the other raw materials.” Similarly, WO 97/26410 owned by Arjo Wiggins S. A. discloses the utility of the use of micro-encapsulated grit in wear resistant overlay and decor papers for decorative laminates without providing much guidance as to the incorporation of the grit into the papers themselves.
Thus, while these references disclose the general utility of adding micro-encapsulated grit to overlay-type laminate papers, they fail to disclose the preferred methods for incorporating these materials into the papers efficiently and effectively. Accordingly, it would be desirable to have a method for incorporating micro-encapsulated grit particles in overlay or decor laminating papers that is inexpensive, efficient, causes minimal damage to papermaking equipment, and provides finished papers having the desired wear-resistant properties.
SUMMARY OF THE INVENTION
The present invention relates to preferred methods for applying micro-encapsulated grit to a fibrous cellulosic overlay or decor sheet, generally paper, in a manner which is inexpensive, efficient, causes minimal damage to papermaking equipment, and provides finished papers having the desired wear-resistant properties. More specifically, the present invention provides methods for producing such paper for use in wear-resistant laminates wherein particles of micro-encapsulated grit are evenly distributed across the surface of the paper and are preferably incorporated in the paper in the z-direction. Additionally, the present invention provides methods for producing such paper for use in wear-resistant laminates that are efficient in the distribution of micro-encapsulated grit on and in the paper fibers, that are efficient in their use of water in the papermaking process, that result in relatively little waste of the micro-encapsulated grit materials, and that can be used in laminates to create the desired wear-resistant and decorative properties. Finally, the present invention provides methods for producing such paper for use in wear-resistant laminates wherein the papermaking equipment and laminating equipment are protected, where possible, from unnecessary wear and tear.
Specifically, the present invention provides methods for producing paper for use in wear-resistant laminates wherein micro-encapsulated grit is deposited on and through the paper by means of the primary headbox or a secondary headbox at the “wet end” of the papermaking machine. In another preferred embodiment, the micro-encapsulated grit is applied using a slot orifice coater positioned at the wet end of paper machine. In this preferred embodiment, the use of a slot orifice coater (as contrasted with a secondary headbox) increases the efficiency and uniformity of the micro-encapsulated grit application and reduces waste. In an alternate preferred embodiment, the micro-encapsulated grit is applied at the “dry end” of the papermaking machinery thereby preventing unnecessary wear on the paper drying machinery and felts. In this preferred embodiment, the micro-encapsulated grit is preferably only partially cured thereby enhancing the ability of the particles to adhere to the paper.
In the preferred embodiment where the micro-encapsulated grit is applied through the primary headbox, the preferably fully cured micro-encapsulated grit is mixed directly into the paper slurry prior to the deposition of the slurry on the paper wire. This method is preferable to other methods in that the micro-encapsulated grit is incorporated in the paper throughout the z-direction thereby enhancing the long-term abrasion resistant qualities of the resultant paper. The drawbacks of this method include some damage to the recycling pumps and slurry tank as well as potential loss of micro-encapsulated grit to the floor, etc. due to the relatively inefficient nature of the headbox application method.
In the preferred embodiment where the micro-encapsulated grit is applied using a secondary headbox, the secondary headbox can be located anywhere downstream of the primary headbox prior to the dryers, i.e. anywhere on the “wet end.” This method is preferable to other methods, such as dry-end addition, in that the micro-encapsulated grit is incorporated in the paper throughout the z-direction, and the extent to which the micro-encapsulated grit penetrates the paper fibers is adjustable depending on how far down the wire the secondary headbox is located. As mentioned above, the incorporation of the micro-encapsulated grit particles in the z-direction enhances the long-term abrasion resistant qualities of the paper made by the process. The drawbacks of this method, as in the use of the primary headbox, include some damage to the recycling pumps and slurry tanks as well as potential loss of micro-encapsulated grit to the floor, etc. due to the relatively inefficient nature of the headbox application method.
In the preferred embodiment where the micro-encapsulated grit is applied using a slot orifice coater, the slot orifice coating head applicator is may be positioned anywhere after the primary headbox and before the dryers, but it is preferably located near and, more preferably, immediately after the dry line, i.e., the point at which the deposited fibers begin to exhibit consolidation and there is no layer of surface water. Preferably, the slot orifice coater includes a bead-type or curtain-type applicator, and is most preferably a curtain-type applicator. Also it is preferred that the slot orifice coater is used in conjunction with a positive displacement pump which enables a predetermined amount of the micro-encapsulated grit composition to be evenly distributed across the surface of the cellulosic paper sheet. A static mixer may be incorporated in the slot orifice coater supply line to prevent or reduce the amount of micro-encapsulated grit settling out of the slurry.
In the preferred embodiment wherein the micro-encapsulated grit is deposited on the paper web at the dry end of the papermaking machine, i.e. after the dryers, the grit is applied to the web using a powder coater or similar-type process equipment to evenly distribute the micro-encapsulated grit on the web. In this preferred embodiment, the micro-encapsulated grit is preferably only partially cured thereby facilitating the adhesion of the grit to the paper web. Preferably, if the dryer cans have imparted too much heat to the web creating a “tacky” surface after the micro-encapsulated grit has been deposited, an extra set of chilled rollers is supplied to cure the “tacky” web prior to winding.
Other objects and advantages will be apparent from the following description, the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a papermaking process for use in accordance with an embodiment of the method of the present invention wherein the micro-encapsulated grit is deposited on the web through the primary headbox;
FIG. 2 is a schematic diagram of a papermaking process for use in accordance with an embodiment of the method of the present invention wherein the micro-encapsulated grit is deposited on the web through a secondary headbox;
FIG. 3 is a schematic diagram of a papermaking process for use in accordance with an embodiment of the method of the present invention wherein the micro-encapsulated grit is deposited on the web through a slot orifice coater; and
FIG. 4 is a schematic diagram of a papermaking process for use in accordance with an embodiment of he method of the present invention wherein the micro-encapsulated grit is deposited on the web at the “dry end” of the papermaking process.
DETAILED DESCRIPTION OF THE INVENTION
Initially, with respect to all of the embodiments of the invention disclosed herein, the grit employed in the present invention prior to micro-encapsulation can be a mineral particle such as silica, alumina, alundun, corundum, emery, spinel, as well as other materials such as tungsten carbide, zirconium boride, titanium nitride, tantalum carbide, beryllium carbide, silicon carbide, aluminum boride, boron carbide, diamond dust, and mixtures thereof. The suitability of the particular grit will depend on several factors such as availability, cost, particle size distribution and even the color of the particles. Considering cost availability, hardness, particle size availability and lack of color, aluminum oxide is generally the preferred grit for most applications. End use performance dictates the basis weight, ash loading, size and type of grit particles. The grit preferably has an average particle size of about 10 to 100 microns and a particle size distribution of about 10 to 150 microns.
Further, if micro-encapsulated grit is to be used in accordance with the present invention as disclosed above, the micro-encapsulation coating may be any suitable polymeric coating but is preferably an aminoplast or phenoplast resin. Furthermore, the micro-encapsulation of the particles may be accomplished by many of the micro-encapsulation methods known in the art including the following: injection treatment coating wherein particles in a shear zone are spray-coated; fluid bed coating, including Wurster & related coating processes, wherein the grit is spray coated in a fluid bed of particles; conventional spray drying wherein the coating and particles are mixed and atomized under heat; dry-on-dry coating wherein an impact mill is used to mix a ratio of 10× size core with 1× size coating particles; MAIC coating process wherein a magnetic field is used to assist the impaction coating process using vibrating screens that impact and screen particles during dry-on-dry coating thereby separating out coated from uncoated particles in a tower; vapor deposition coating wherein the particles to be coated are tumbled in a free radical pyrolysis zone; spinning-disc coating wherein the particles are released from the edges of a spinning film coater with polymer solution into a drying tower; spray chilling coating wherein a PEO/Wax melt coating is applied to particles at 100% solids; extrusion encapsulation wherein the coating is pumped through concentric tubes (outer) and particle (inner) through a concentric nozzle into a curing bath; spray congealing coating wherein the particles and coating are sprayed into in a hardening bath; interfacial condensation wherein the particles are activated with a coupling agent and are slurried in a reactive polymer or monomer; and coacervation coating wherein the polymer and particles are mixed in a slurry, after which the liquid is evaporated wherein the process is improved by coacervate precipitation with polymer of opposite charge or other insolubilization method. Additionally, as mentioned above, the micro-encapsulation method described fully in U.S. Pat. No. 5,962,134 to Shah et al. would be operative in the present invention. Of course other micro-encapsulation methods known in the art and not specifically discussed herein would also be operable and are considered within the scope of the present invention.
The grit may be encapsulated in any of a number of different resins as discussed above, but preferably is encapsulated in an aminoplast or phenoplast resin. Most preferably, the resin is melamine-formaldehyde resin. The micro-encapsulated grit may be cured using any of the known curing methods. Examples of curing methods that would be operable in accordance with the present invention include spray drying, spray drying with a flame treatment, ionizing radiation treatment, and oxidative congealing. Oxidative congealing is considered preferable for some applications because it is a virtually instantaneous aqueous quenching process resulting in a cured melamine resin coating on the grit along for a high throughput. Furthermore, oxidative congealing produces a cured grit coating that has rough protrusions which interlock with the paper fiber, potentially reducing fall off and migration during lamination. Spray drying with a flame treatment is also considered preferred for some applications. As mentioned previously, in the case of the “wet end” additions, it is preferable that the micro-encapsulated grit be fully cured. However, in the preferred embodiment that calls for a “dry end” addition, it is preferable that the micro-encapsulated grit only be partially cured for the reasons discussed herein.
For the slot orifice coater addition embodiment disclosed herein, the grit slurry employed in accordance with the present invention will typically include a binder material. The binder material may be any of the commonly used binders such as melamine resins, polyvinyl alcohol, acrylic latex, starch, casein, styrene-butadiene latex, carboxymethyl cellulose (CMC), microcrystalline cellulose, sodium alginate, etc., or mixtures thereof which are used in coating compositions where the coating material is to be bonded to a substrate such as a decor sheet or overlay sheet. Melamine resins such as melamine-formaldehyde are advantageously used as the binder material in the present invention since the melamine-formaldehyde resin is also commonly used to saturate the decor sheet. The binder is usually employed in an amount of about 1 to 10% by weight of coating solids. It is noted that when the micro-encapsulated grit coating is from a headbox, either primary or secondary, binders may or may not be used.
For the “wet end” addition of the micro-encapsulated grit through the primary or secondary headbox, solid composition (by weight) of the slurry is preferably between 0.5 and 5%, and more specifically, generally between 1 and 2% For the “wet end” addition using a slot orifice coater, the micro-encapsulated grit slurry medium can contain about 5 to 95% and, preferably, about 10 to 80% micro-encapsulated grit by weight. As such, the slurry preferably has a viscosity of about 50 to 150 cps when coating from a bead-type slot orifice coater and about 50 to 500 cps when coating form a curtain-type slot orifice coater. For curtain coating, the slurry preferably also includes a small amount of a surfactant (0.05 to 0.5%).
For all embodiments of the invention disclosed herein wherein the finished product is an overlay sheet, the overlay sheet is preferably formed from fibers conventionally used for such purpose and, preferably, is a bleached kraft pulp. The pulp may consist of hardwoods or softwoods or a mixture of hardwoods and softwoods which is normally preferred. Higher alpha cellulose such as cotton may be added to enhance certain characteristics such as post-formability. The basis weight of the uncoated overlay sheet may range from about 10 to 40 pounds per 3000 square feet, and preferably about 15 to 40 pounds per 3000 square feet.
It is generally desired that the finished laminate made using an overlay or decor sheet made by the methods of the present invention have abrasion values of between 1,500 to 20,000 cycles (NEMA: LD3.13). These desired abrasion values can be achieved by selecting the grit, the micro-encapsulation resin, the base stock, and the micro-encapsulated grit coating methods and conditions, and the saturation resin as is known in the art.
As best shown in FIG. 1, one preferred method for producing paper 10 A for use in wear-resistant laminates in accordance with the present invention involves depositing the micro-encapsulated grit on and through the paper at the “wet end” of the paper machine by means of the primary headbox 12 A. In this embodiment, the micro-encapsulated grit is first mixed with the paper fibers and water to form a paper slurry 14 A. If the paper that is being made is a decor sheet, rather than just a standard non-decorative wear-resistant overlay, decorative materials such as paper chips or pigments can be added during this step. Once the slurry 14 A is sufficiently homogenized, it is fed to the primary headbox 12 A and then coated over the wire 16 A to form a paper web 18 A. The paper web 18 A is then pulled through the dryers 20 A, preferably including felt and can dryers, in order to remove the remaining moisture in the web 18 A as known in the art. The web 18 A then passes over an inspection and final drying area 22 A prior to winding at the winder 24 A. Once wound, the resultant product is ready for shipping to the consumer for incorporation in a decorative laminate as is known in the art.
As best shown in FIG. 2, in another embodiment of the present invention the micro-encapsulated grit is applied using a secondary headbox 19 B at the “wet end” of the paper machine by means of the primary headbox 12 A. In this embodiment, the micro-encapsulated grit is kept separate from the paper fibers until after the paper fibers have been coated on the wire 16 B. First the paper fibers are mixed with water to form a paper slurry 14 B. As with the prior embodiment, if the paper that is being made is a decor sheet, rather than just a standard non-decorative wear-resistant overlay, decorative materials such as paper chips or pigments can be added during this step. Once the slurry 14 B is sufficiently homogenized, it is fed to the primary headbox 12 B and then coated over the wire 16 B to form a paper web 18 B. At some point along the wire 16 B, but prior to the dryers 20 B, the secondary headbox 19 B is positioned. A slurry of micro-encapsulated grit and water 21 B, having been mixed and homogenized prior to addition to the secondary headbox 19 B, is then added to the web 18 B. The paper web 18 B is then pulled through the dryers 20 B, preferably including felt and can dryers, in order to remove the remaining moisture in the web 18 B as known in the art. The web 18 B then passes over an inspection and final drying area 22 B prior to winding at the winder 24 B. Once wound, the resultant product is ready for shipping to the consumer for incorporation in a decorative laminate as is known in the art.
As best shown in FIG. 3, in another embodiment of the present invention, the micro-encapsulated grit is applied using a slot orifice coater 19 C on the wet end of paper machine. The term “slot orifice coater” as used herein is used in the same manner it is used in the art, namely, to designate a coater having a central cavity which opens on and feeds a slot through which the coating is forced under pressure. Examples of slot orifice coaters useful in the present invention include curtain coaters in which the overlay is coated as it passes through a falling curtain of the coating composition and coaters in which the overlay is coated as it contacts a bead of the coating composition as it is extruded from a slot orifice. The latter type coaters can be oriented to coat the substrate as it passes directly above the coater, directly below the coater or to the side of the coater. The slot width of the slot orifice coaters used in the process typically range from 0.4 to 0.8 mm. The gap height (i.e., the distance between the edge of the slot orifice and the substrate surface) is about 0.5 to 1.55 mm when coating form a bead and about 2.5 to 25 mm when coating form a curtain. The coating head pressure is about 5 to 25 psig when coating form a bead and about 5 to 150 psig when coating from a curtain. A slot orifice coater useful in the present invention is sold by Liberty Tool Corp. under the tradename Technikote. Other manufacturers also make slot orifice coaters useful herein.
In this preferred embodiment, the use of a slot orifice coater 19 C (as contrasted with the primary headbox 12 A or secondary headbox 19 B) increases the efficiency and uniformity of the micro-encapsulated grit application and reduces waste. In this embodiment, as with the use of a secondary headbox 19 B, the micro-encapsulated grit is kept separate from the paper fibers until after the paper fibers have been coated on the wire 16 C. First the paper fibers are mixed with water to form a paper slurry 14 C. As with the prior embodiments, if the paper that is being made is a decor sheet, rather than just a standard non-decorative wear-resistant overlay, decorative materials such as paper chips or pigments can be added during this step. Once the slurry 14 C is sufficiently homogenized, it is fed to the primary headbox 12 C and then coated over the wire 16 C to form a paper web 18 C. At some point along the wire 16 C, but prior to the dryers 20 C, the slot coater 19 C is positioned. A slurry of micro-encapsulated grit and water 21 C, having been mixed and homogenized prior to addition to the slot coater 19 C, is then added to the web 18 C. The paper web 18 C is then pulled through the dryers 20 C, preferably including felt and can dryers, in order to remove the remaining moisture in the web 18 C as known in the art. The web 18 C then passes over an inspection and final drying area 22 C prior to winding at the winder 24 C. Once wound, the resultant product is ready for shipping to the consumer for incorporation in a decorative laminate as is known in the art.
As best shown in FIG. 4, in another embodiment of the present invention, the micro-encapsulated grit is applied at the “dry end” of the papermaking machinery thereby preventing unnecessary wear on the paper drying machinery and felts. In a preferred version of this embodiment, the micro-encapsulated grit is preferably only partially cured thereby enhancing the ability of the micro-encapsulated grit particles to adhere to the paper. In this preferred embodiment, as with the use of a secondary headbox 19 B and slot orifice coater 19 C, the micro-encapsulated grit is kept separate from the paper fibers until after the paper fibers have been coated on the wire 16 D and dried by the dryers 20 D. First the paper fibers are mixed with water to form a paper slurry 14 D. As with the prior embodiments, if the paper that is being made is a decor sheet, rather than just a standard non-decorative wear-resistant overlay, decorative materials such as paper chips or pigments can be added during this step. Once the slurry 14 D is sufficiently homogenized, it is fed to the primary headbox 12 D and then coated over the wire 16 D to form a paper web 18 D. The paper web 18 D is then pulled through the dryers 20 D, preferably including felt and can dryers, in order to remove the remaining moisture in the web 18 D as known in the art. At some point after the dryers 20 D, the micro-encapsulated grit 21 D, in powder form, is spread across the web 18 D using a powder applicator or like machinery. Preferably, the micro-encapsulated grit 21 D is only partially cured to aid the particles in adhering to the web 18 D. In a preferred embodiment, the web 18 D is then passed through chilled rollers 23 D to finish the curing of the micro-encapsulated grit as well as to help set the micro-encapsulated grit 21 D on the web 18 D. The web 18 D is then fed to the winder 24 D. Once wound, the resultant product is ready for shipping to the consumer for incorporation in a decorative laminate as is known in the art.
Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims:
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A method for forming an abrasion resistant sheet which comprises forming a web of cellulosic fibers on a papermaking machine and applying a slurry including an encapsulated abrasion-resistant grit to the upper surface of the web on the papermaking machine.
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BACKGROUND OF THE INVENTION
1. Field of the Invention This invention relates to the calibrating of an array of recording elements such as light-emitting diodes (LEDs).
2. Brief Description of the Prior Art
Electronic image-recording apparatus of a type comprising a line exposure array stationed in a light-exposing relationship to a photosensitive material and comprising a plurality of linearly spaced apart light-emitting diodes are known in the art. Means are generally provided for effecting a relative displacement between the light exposure array and the photosensitive material in a direction transverse to the longitudinal axis of the exposure array so as to effect an exposure of the entire surface of the photosensitive material.
One can distinguish two types of imaging using LED bars, namely bi-level imaging and grayscale imaging. In the former, each pixel of the photosensitive media experiences either maximum or zero exposure by an element of the LED bar, and the image comprises dots of maximum optical density on a background of minimum optical density. On the other hand, grayscale imaging requires that each pixel receives an exposure that is continuously variable, or variable over a number of discrete levels. The latter type of imaging is needed in areas such as high quality black and white and color reproductions and requires control of the exposure parameters with a high degree of precision.
The requirements for grayscale printing call for extremely uniform light output levels for all the LED elements on the printhead (2% for example). This result is difficult to achieve due to variations in the light output of individual LEDs within an array and variations between arrays, variability in the amount of current supplied by the individual channels of the driver integrated circuit and in particular, nonuniformity introduced by the lens system. A suggested solution to this problem to date has been to supply the printhead with correction data for each LED in the form of on-time correction or current level correction. See, for example, U.S. Pat. No. 5,300,960. This need to supply data for correction increases the complexity of the printhead interface and the cost of the printhead.
In addition, where data for uniformity correction is used typically there has been available only one or two bits for uniformity correction as part of the corrected image data. This implies that after burn-in testing of all the LEDs, all LEDs must be within a specified uniformity range of say ±15% or less from the average light output level for that printhead. If any LED on the printhead falls outside of that range, the printhead is not suited for this application and may be discarded. Another proposed method of avoiding these difficulties is described in DE 3421914 A1 and uses a photographic filter which is exposed to the non-uniform light output of the LEDs and its density is adjusted such that light output from the LED filter combination becomes uniform across the printhead. A problem with this approach is the difficulty of accurately adjusting density across the printhead so that the average LED intensity is within a suitable narrow range.
A Selfoc (trademark of Nippon Sheet Glass Limited) lens array (SLA) or gradient index fiber lens array is typically used in known printheads but presents difficulties in obtaining uniformity. This problem arises due to the fact that an SLA lens is a composite of many lens elements with some variation in element spacing, transmission efficiency is very independent on lens positioning relative to each LED. In addition, the SLA lens typically introduces non-uniformity on the order of 10%.
SUMMARY OF THE INVENTION
In accordance with the invention, an extremely uniform printhead can be achieved even if no correction data is input by taking advantage of the aging characteristics of the LEDs. LEDs typically age exponentially during the first few hours of operation and then enter a linear aging process (see FIG. 1). By first aging all the LEDs in the printhead past the exponential decay region and into the linear region, then measuring the light output for each individual LED in the lensed printhead, and differentially again aging the LEDs, one can obtain an extremely uniform printhead. The differential aging is accomplished by aging all the LEDs for different lengths of time (although aging at differing current levels or temperatures are also possibilities), the lowest intensity LED aged the least, the highest intensity LED aged the longest. Thus, for example, if the lowest intensity LED in the printhead scan is 0.3 μW/dot and another LED is at 0.35 μW/dot, if the aging rate is 0.01 μW/dot/hour, that LED would be aged for 5 hours to reduce its intensity to 0.3 μW/dot, achieving perfect uniformity between the LEDs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating a typical intensity vs. time profile during burn-in of LEDs. In this graph light output measured is normalized to time equal zero.
FIG. 2 is a schematic of an LED printhead and apparatus used for calibrating same.
FIGS. 3A and 3B is a flowchart describing operation of the calibration method of the invention.
FIGS. 4A, B, C, D and E are graphs illustrating various examples in the calibration method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Because printheads of the type described herein are well known, the present description will be directed in particular to subject matter forming part of, or cooperating more directly with, the present invention.
An apparatus for use in the calibration method of the invention is typified by the diagram of FIG. 2; an LED printhead including a linear array 10 of several thousand triggerable radiation sources 20; e.g., LEDs is illustrated. The LEDs are formed on chip arrays which are in turn mounted with electronic driver chips on an appropriate support as is well known, see for example U.S. Pat. No. 5,079,567, the contents of which are incorporated herein by this reference. The LED chip arrays are positioned end to end so that a continuous row of LEDs is formed. Optical means 30 for focusing the LEDs for exposure onto a recording medium is also provided. In this regard, gradient index optical fiber devices such as Selfoc (trademark of Nippon Sheet Glass Co., Ltd.) arrays are highly suited. The LEDs of the array 10 are triggered into operation by means of image processing electronics 14 that are responsive to image signal information from a data source 17 such as a computer or scanner 17. The image processing electronics activates respective current drivers 16 and the drivers provide current to the LEDs when an image dot or pixel is to be recorded. Depending on the duration for which any given LED is turned on, the exposure effected by such LED is more or less made. Data for selecting the particular LEDs to be turned on for a particular recording line of pixels is provided in digital form, i.e., digital bits of 1's and 0's that are stored for each line in registers 18 which incorporate a data bus and latch registers for storing the data bits to allow the next line of data to be fed to the shift registers as the present line of data is being printed, see for example, U.S. Pat. No. 4,746,941, the contents of which are incorporated herein by this reference. Briefly, as noted in this patent, data lines D 0 -D 5 are independent lines each carrying a signal representing a digital bit (0 or 1) so that together their respective signals define a digital six bit number from decimal 0 to decimal 63. This image data signal is passed along lines D 0 -D 5 which comprises an image data signal bus. As noted above, associated with each LED is a data register means 18 for latching data from this bus during each cycle of operation for printing a single line of dots. A token bit may be used to enable a data register means associated with a particular LED to accept the data while other data register means associated with other LEDs await their respective data.
The data register means for each LED comprises a pair of latches or bi-stable multi-vibrators for each of the existing data lines. The pair of latches are connected in master-slave relationship wherein in response to a token bit signal at the enable input terminal of the master latch, an image data signal at the data input terminal of the master latch will cause the output of the master latch to either change or remain the same depending upon the image data signal. The six master latches in the data register means of each LED are commonly connected to simultaneously receive the token bit signal from the token bit shift register. In response to clock pulses from the image processing electronics 14, the token bit is passed from stage to stage of the token bit shift register and accordingly outputted sequentially for enablement of the master latches of a respective data register. With movement of the token bit from stage to stage of the token bit shift register, the data bits occurring on lines D 0 -D 5 are accepted by the data registers and in turn all the data registers on one side of the printhead have acquired their respective six bits of data. A latch enable signal is then applied to cause respective slave latches to latch the data at their respective outputs. The respective outputs of the slave latches are now communicated to the data input terminals of respective comparators for determining the duration of exposure for each LED in accordance with the techniques described in U.S. Pat. No. 4,746,941. The master latches are now free to receive the image data signals for the next line of dots to be recorded.
The token bit register and data registers are incorporated in an integrated circuit driver chip which also includes the comparators, latches, and current drivers to comprise a driving circuit for a group of say 64 LEDs. An identical driver chip may be located on an opposite side of an LED array so that one of the driver chips drives the odd-numbered LEDs of an array including 128 LEDs and the other driver chip drives the even-numbered diodes of the array. An up-down counter also may be made part of each chip. As is well known, driving circuitry for each of an odd and even group of LEDs may be mounted on modules that can be independently tested before being assembled on a printhead. With assembly of the modules on the printhead, electrical interconnections are made to allow passage of the token bit and other signals between adjacent chips.
Typically, printheads of the type described herein are suited for exposure of photosensitive media. Where the recording medium is say photographic film, the latent image formed line by line by selective exposure of said LEDs may be subsequently developed by conventional means to form a visible image. Where the medium is an electrophotographic receptor, the LEDs may be used to form an electrostatic image on a uniformly electrostatically charged photoconductor and this image developed using opaque toner particles and perhaps transferred to a copy sheet, see U.S. Pat. No. 3,850,517.
As may be noted in FIG. 2, a photosensor device 27 such as a silicon photodetector, or a charge-coupled device, is positioned at the image focal plane of the gradient index lens array 30 to sense the light output from a single LED 20. This LED is enabled by a suitable signal from a microprocessor 31 to the image-processing electronics 14.
As may be noted from the graph of FIG. 1 during burn-in of an LED module array or entire printhead array of LEDs, the LEDs typically exhibit an initial exponential decay in intensity where the LEDs are cycled on and off for predetermined cycle periods using a predetermined current level. It is known that brighter LEDs tend to exhibit a more rapid initial decay than weaker LEDs within a group or groups of arrays of LEDs formed by similar process conditions.
By understanding the mechanisms associated with the aging process it becomes possible to tune the aging curve to minimize the amount of burn-in time required to achieve uniformity, while at the same time meeting the design parameters of light intensity drop over product life and magnitude of differential aging associated with LEDs being on for different lengths of time throughout life. A tradeoff forms between light reduction during product life and the amount of time in burn-in required to achieve uniformity.
With reference now to the flowchart of FIGS. 3A and 3B in step 100 a newly assembled or virgin printhead with SLA is assembled in the test fixture. In step 110, the LED printhead is subject to conventional burn-in testing for 24 hours @50% duty cycle, and 8 mA current to each LED. This test should place the decay of intensity, or aging characteristic, of all LEDs on the printhead within the linear range. At this point, conventional burn-in testing would end and the LEDs would be calibrated by measuring light outputs and determining correction data associated with the LEDs. However, in accordance with the calibration process of the invention the light intensity after lensing of each LED (assume 4864 LEDs on the printhead) is measured and stored in step 120. This step is made by sending data only to a register associated with one LED and enabling it and measuring the intensity after lensing of the light emitted by the LED. The sensor 27 is then stepped to the next location by motor 42 which is responsive to signals from the microprocessor controller 31. The light output from the LED may first be sensed to determine accurate positioning of the photosensor device 27. Outputs from the photosensor device 27 are input to an A/D converter and then to the microprocessor controller 31. In lieu of stepping a single photosensor device, a row of photosensors accurately calibrated may be positioned at the focal plane of the LEDs. In step 130, the LED or LEDs having the minimum LED light level measured are noted and the value of this minimum measured light level (MIN.) is stored. In step 140, the value MIN. is compared with a product of a specification for minimum average light level required for this printhead multiplied by one minus the desired uniformity specification which say is 15% for a printhead that will be corrected using uniformity correction bits or as low as 2% for a printhead that will not be corrected using uniformity correction bits so that if lines D 0 -D 5 are to be available for carrying image data, 63 levels of gray may be realized. If MIN. is less than this product, then the printhead is unacceptable for this specification (case 1) and calibration ends, step 150. The reason for this as shown in the graph of FIG. 4A is that the process of aging the printhead would cause the average LED intensity for this printhead to be below the specified minimum average light level. Note in calibrating this printhead it is desirable that all printheads for a particular application have at least a specified minimum average light level with all LEDs on a printhead being within a specified range from the LED with minimum light output.
In the event that MIN. is not less than the minimum average light level specified multiplied by one minus the uniformity specification then the process proceeds to step 160 wherein a determination is made as to whether or not MIN. is greater than the maximum average light level (see FIG. 4B). Assuming the answer is yes, it is an instance of case 2 and the process proceeds to step 170 wherein a target for burn-in is defined as the maximum average light level specified. In step 180 for each of the 4864 LEDs, there is computed a differential age time according to the relationship LED light level minus target light level, divided by the decay rate or drop, which is constant in accordance with the LED aging characteristic being in the linear range (see FIG. 1). Alternatively if the decay rate is expressed as a percent drop per time unit (%/hour) then the differential age time is computed according to the relationship LED light level minus target light level, divided by the product of target light level times decay rate. In step 190, if any LEDs have a differential age time less than zero, then the additional burn-in time is set to zero. In step 200, the LEDs are differentially aged according to the respective calculations made in step 180 using a 50% duty cycle at a current to each of 8 mA. The calibration process now loops back to step 120 wherein the light intensities of each of the LEDs is measured again. After this second measurement, assume the case 3 situation arises either from the initial measurement or the remeasurement from case 2. In case 3, and with reference to FIG. 4D, assume further that the MIN. is determined to be less than or equal to the maximum average light level specified but greater than or equal to the minimum average light level. For case 3, the target is set to the minimum of the maximum average light level or the product of the MIN. multiplied by one plus the uniformity specification (step 210).
Step 220 notes that the maximum LED light level that was measured in step 120 was stored in memory and flagged as "MAX." Step 230 notes that from the measurement of LED light level or intensity measured in step 120 that an average was taken of these measurements and identified as "AVG." In step 240, a determination is made as to whether or not MIN. divided by AVG. is less than one minus the uniformity specification. If the answer is yes, obviously some LEDs including that at light level MIN. are outside of the desired range for all LEDs on that printhead and further burn-in is needed using the target determined in 210. If the answer is no, then the process proceeds to step 250 wherein a determination is made as to whether or not MAX. divided by AVG. is greater than one plus the uniformity specification. If the answer is yes, obviously some LEDs including MAX. are outside of the desired range for all LEDs on that printhead and further burn-in testing is needed using the target determined in step 210.
If the answer in step 250 is no, it implies that MIN. is within the range defined by one minus the uniformity specification and MAX. is within the range defined by one plus the uniformity specification, thus all LEDs on the printhead are within a desired plus-minus uniformity range of the average for this printhead. Futhermore, the calibration process thereby ensures that the average of the light intensities of the LEDs for this printhead will be between the minimum average light level specified and the maximum average light level specified.
As may be seen in FIG. 4C, D, and E, case 3 is illustrated with three examples. In the example shown in FIG. 4C where MIN. is below the specified minimum average light level, the target value for burning-in is set to MIN. multiplied by one plus the uniformity specification. This serves to bring the average down just far enough to get the MIN. LED into the uniformity requirement. In the example of FIG. 4D wherein MIN. falls between the specified minimum average light level and the specified maximum average light level, the target value is also set to MIN. multiplied by one plus the uniformity specification. This will also bring the average down just far enough to get the MIN. LED into the uniformity requirement. In the example of FIG. 4E, where MIN. is just below the maximum average light level so that the uniformity range allowed from the average for this printhead will allow some LEDs to be above the maximum average light level, the target value is set to maximum average light level. This will bring the average down to the maximum average light level meeting both of the requirements that the average intensity for this printhead be no greater than the maximum average light level and all the LEDs on the printhead are within a specified range from their average intensity.
This approach to the uniformity problem offers the advantages of reduced complexity and cost in the printhead interface. There are no extra components needed in the printhead or manufacturing process therefor to achieve this as there is with the photographic coating approach. Aging is already a part of the standard manufacturing process (to burn-in past the exponential decay zone), its duration is merely increased. After aging to uniformity the LEDs age at close to the same rate since they are all in the linear portion of the aging curve, providing good stability in uniformity over the operating life of the printhead.
If desired, calibration in the LED may be maintained during printing use by keeping track of those LEDs that are being under-utilized. During periods of non-printing activity such as during warm-up or shutdown, the under-utilized LEDs may be turned on to cause them to age uniformly with those LEDs having greater use; see for example U.S. Pat. No. 4,799,071.
While the invention will find particular utility with reference to gray level printheads the calibration method of the invention is also useful for binary printheads. The invention is not limited to LEDs but is also applicable to other recording elements that may be calibrated with the method claimed.
With the method described herein the use of one or two bits to correct for nonuniformities, in LEDs on a printhead may become unnecessary. The data line for these two extra bits may be either eliminated from the printhead or used for defining additional gray levels. Thus a 4 bit gray level printhead having 2 extra bits of correction may handle 6 bits of gray level data. Using differential burning-in testing to obtain a specified ±2% uniformity is not possible without use of other correction schemes since an SLA typically has non-uniformity on the order of -3% to +6%.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A method for producing a calibrated printhead having a plurality of light-emitting recording elements such as LEDs includes the steps of (a) burning-in the recording elements until a further aging characteristic of the recording elements is in a generally linear range; (b) measuring a light intensity emitted by each recording element after the burning-in in step (a); (c) establishing a target value for additional burning-in of at least those recording elements having measured light intensities above a minimum measured light intensity for a recording element; and (d) respectively providing additional burning-in to those recording elements towards the target value. An apparatus including the calibrated printhead has no data provided to the printhead which is corrected for relative non-uniformity of the recording elements to each other.
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FIELD OF THE INVENTION
This invention relates generally to axial flow fans primarily, but not exclusively, for use in agricultural environments such as barns, greenhouses and the like.
BACKGROUND OF THE INVENTION
Agricultural environments often are quite "hostile" to mechanical devices such as fans. A fan intended for use in such an environment therefore should be of relatively robust construction and able to resist occasional accidental impacts. Corrosion is a particular problem due to the presence of moisture, animal waste, chemicals and the like. Wide temperature variations often must also be accommodated.
Conventional fans for agricultural use typically are of the so-called box-fan type, comprising a housing which has a square outside shape and a generally cylindrical opening or "tunnel" at the center through which air is blown by a motor-driven fan blade assembly. The housing may be constructed of galvanized sheet steel or wood chip-board. The construction techniques used tend to mean that the housing does not have a smooth external configuration; rather, the structure of the housing often presents large open corners or other crevices in which debris and dust collects quickly in use. As a result of these factors, the housing of a conventional box fan tends to be susceptible to rotting and/or corrosion, which leads to high maintenance costs.
In addition, energy efficiency is a concern. Thus, while a ventilating fan in a barn might be perceived as a relatively unsophisticated device that is not a major factor in terms of energy consumption, a single barn may require a large number of individual fans, each of which may operate continuously. As such, the fans collectively represent a significant energy drain.
Little attention usually is paid to energy efficiency in the design of such fans. For example, the fan blade assembly typically is driven directly by an electric motor which has to be supported in the air flow opening through the housing. Usually, this is accomplished by means of a pair of motor mounting bars that extend vertically across the opening in spaced parallel positions, one on either side of the motor. These bars present a relatively large surface area to the air flowing through the opening. As such, the bars not only block part of the opening, but also create turbulence in the air flowing through the opening--further impeding efficiency of air flow.
Further, since the motor mounting bars extend generally vertically across the opening, the motor mount cannot accommodate distortions in the shape of the air flow opening caused by expansion and contraction of the housing due to temperature changes. As a result, the fan blades may come into contact with the housing in some situations.
Newer, more expensive designs for wall exhaust applications are metal, moulded plastic or fibreglass and improve somewhat on maintenance and performance, but tend to be relatively large and obtrusive. In a barn, for example, the fans represent an impediment to traffic along the outside of the barn walls. Provision is sometimes made for so-called "add on" performance enhancing exhaust cones which are designed to modify and smooth the air flow of the exhaust, but which add to cost and obtrusiveness.
An object of the present invention is to provide a number of improvements in fans which are designed at least partly to address the problems of the prior art.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a fan which has a housing defining an air flow opening extending about an axis, a fan blade assembly supported in the housing for rotation about said axis, and a motor carried by the housing and coupled to the fan blade assembly for rotating the assembly about said axis. The air flow opening has a generally cylindrical shape defined by an inlet section, an outlet section, and a throat between the sections. The inlet section has a conically tapered shape which converges smoothly in a direction towards the throat and the outlet section has a conically tapered shape which diverges smoothly in a direction away from the throat. The inlet and outlet sections merge smoothly with the throat so that turbulence in the air flow through the opening is minimized.
Accordingly, in contrast to prior art designs in which little attention is paid to management of the air flow through the fan housing, the invention provides specially profiled air flow opening, which is designed to promote smooth and turbulence-free air passage through the fan housing, without the need for add-on performance enhancing cones.
The throat may be defined by a short cylindrical section between the inlet and outlet sections, or simply by the intersection of the inlet section and the outlet section.
The invention also provides an improved motor support means designed to minimize both obstruction of the air flow through the housing and turbulence in that air.
Accordingly, a further aspect of the invention provides a fan which includes a housing defining an air flow opening extending about an axis, a fan blade assembly, a motor directly coupled to the fan blade assembly coaxially therewith for rotating said assembly and means for supporting the motor in the housing so that the blade assembly rotates about the said axis in use. The motor supporting means comprises at least three support arms which are of substantially equal length and spaced substantially equi-angularly about the said axis, extending generally radially between the motor and the housing. Each arm has a substantially uniform, relatively thin and flat cross-sectional shape so that the arm has a major dimension and a minor dimension. Each arm is disposed with its major dimension in line with the axis of the air flow opening and its minor dimension facing the air flow. Each arm is coupled to each of the housing and the motor respectively at points spaced along the major dimension of the arm so as to resist misalignment of the motor with respect to the axis of the air flow opening.
It will be understood that this form of motor mount presents a number of advantages as compared with the prior art. As noted previously, by positioning the motor mount arms "edge on" to the air flow, both obstruction of the air flow and turbulence are minimized. In fact, the arms may act as flow "straighteners" actually enhancing turbulence-free flow.
Further, by providing at least three radial support arms which are spaced substantially equi-angularly about the axis of the air flow opening, the motor mount is essentially self-centering. In other words, the motor remains centered in the air flow opening despite any distortions of the housing that might arise, for example, due to temperature changes. This minimizes the risk of impact between the fan blades and the housing when distortions do occur. Also as indicated previously, twisting of the motor in the air flow opening is resisted by the way in which the arms are attached to the housing and motor.
A still further aspect of the invention provides a fan which includes a housing defining an air flow opening extending about an axis, a fan blade assembly, means supporting the fan blade assembly in the housing for rotation about the said axis, and a motor carried by the housing and coupled to the fan blade assembly for rotating the assembly about said axis. The housing is a moulded unit having an inner surface defining the said air flow opening, an outer perimeter surface, and front and rear surfaces extending between the inner surface and the outer surface. Preferably, the housing is moulded in one piece, for example by a conventional rotational moulding technique. Examples of suitable materials are plastics such as polyethylene, and fibre-reinforced resins, e.g. fibreglass. In any event, the housing is designed to present a relatively smooth and "crevice-free" exterior surface so that the housing tends to remain relatively clean and free of debris in use and does not provide pockets in which chemicals or other contaminants can accumulate. Selection of the particular material is of course important in providing corrosion resistance to the housing.
BRIEF DESCRIPTION OF DRAWINGS
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a particular preferred embodiment of the invention by way of example, and in which:
FIG. 1 is a rear perspective view of a fan in accordance with a preferred embodiment of the invention;
FIGS. 2 and 3 are front and rear elevational views respectively of the housing of the far shown in FIG. 1;
FIGS. 4 and 5 are sectional views taken respectively on lines 4--4 and 5--5 of FIG. 3;
FIG. 6 is an enlarged detail view of the top part of FIG. 4;
FIG. 7 is a rear elevational view of the complete fan;
FIG. 8 is a sectional view on line 8--8 of FIG. 7; and,
FIG. 9 comprises views denoted (a) to (k) illustrating examples of different types of fan installations that may be achieved by using a fan in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, a fan is shown to include a housing 20 which defines an air flow opening 22 extending about an axis 24. A fan blade assembly 26 is supported in the housing for rotation about axis 24 and is driven by a motor 28. Motor 28 is supported in the housing by motor support means generally indicated at 30. In this embodiment, the motor is directly coupled to the fan blade assembly 26, and is supported on axis 24. This will be the usual arrangement although it is to be understood that the invention is not limited thereto. In an alternative embodiment, the motor could be mounted elsewhere on the housing and coupled to the fan assembly by a belt and pulley arrangement or other drive means.
FIGS. 2 to 5 show the fan housing 20 in some detail. In this embodiment, the housing is a one-piece plastic moulding made by a conventional rotational moulding technique. The moulded unit has an inner surface 32 (FIGS. 4 and 5) which defines the opening 22 through the housing, an outer perimeter surface 34 and front and rear surfaces 36 and 38 respectively extending between the inner surface 22 and the outer surface 34. In the embodiment shown, the outer surface 34 has a square shape in profile defined by flat rectangular top and bottom surface portions 34a and 34b and end surface portions 34c and 34d.
The inner surface 32 is specially profiled to appropriately manage the air flow through opening 22 as will be described in more detail later, primarily with reference to FIG. 6.
Each of the front and rear surfaces 36 and 38 is shaped to define a marginal rib 36a, 38a around the perimeter of the surface, which has some strengthening effect. The rib also provides a traditional visual appearance at the front and rear surfaces of the fan housing and may be used for securing the fan in a wall opening. A so-called "stop flange" may be moulded around the inside edge of the outer perimeter surface of the housing as indicated in ghost outline at 39 in FIG. 8.
Moulded into the plastic material during the moulding process are a number of "captive" nuts which can be used to attach external components to the housing. At the front and rear surfaces of the housing, these nuts are moulded into the two peripheral ribs 36a and 38a. Their locations are indicated by reference numeral 40 in each of FIGS. 2 and 3, from which it will be seen that nuts are provided in each of the corners of each of the front and rear faces, and at locations intermediate the corners. Further nuts are moulded into the inner surface 32 defining the air flow passageway 22, as also indicated by reference numeral 40. The nuts themselves are not shown but similar nuts are indicated at 40a in FIG. 6. These nuts provide attachment points for motor mount arms of the motor support means 30, to be described in more detail later.
FIG. 6, shows in some detail the profile of the inner surface 32 of the moulding, which defines the air flow opening 22. FIG. 6 also shows the hollow, double wall structure that is achieved using the rotational moulding technique. It should be noted that the housing could be solid or foam-filled instead of hollow. The locations of two of the mounting nuts are indicated at 40 in FIG. 6; the nuts themselves are not of course visible since they are embedded within the plastic material, but they are indicated at 40a.
It will be seen from FIG. 6, in conjunction with the preceding views, that the air flow opening 22 has a generally cylindrical shape defined by an inlet section 42, an outlet section 44 and a short cylindrical throat 46 between the two sections.
As noted previously, it is not necessary that the throat have any significant axial length. The direction of air flow through the opening is indicated by arrow 48 in FIG. 6. Inlet section 42 has a conically tapered shape which converges smoothly in a direction towards the throat 46 (in the direction of air flow) and the outlet section 44 has a conically tapered shaped which diverges smoothly in a direction away from the throat 46 (also in the direction of air flow). The inlet and outlet sections merge smoothly with the throat so that turbulence in the air flow through the opening is minimized.
By way of example (i.e. without limiting the scope of the invention), the inlet section 42 and the outlet section 44 may each define a cone angle of approximately 8°.
Upstream of inlet section 42, surface 32 is smoothly rounded at 32a adjacent the rear peripheral rib 38a, avoiding any sharp corners that might induce turbulence in the air flow. The corresponding surface at the outer end of the outlet section 44 is stepped adjacent rib 40a to provide a surface 32b which is conically tapered so that an optional outlet end extension cone (shown in ghost outline at 49) can be fitted to the housing should this be desired by the user of the fan and secured by screws (not shown). The thickness of the cone will be selected to correspond with the thickness of the inner surface 32 and the depth of the step so that a smooth and effectively uninterrupted surface will be presented to the air flow when a cone is used.
FIG. 7 is essentially an elevational view from the left in FIG. 1 (the rear of the fan) and shows in detail the support means 30 for the fan motor 28. FIG. 8 is a vertical sectional view on line 8--8 of FIG. 7.
In accordance with one aspect of the invention, the fan motor support means comprises at least three support arms which are of equal length and spaced equi-angularly about the rotational axis 24 of the fan blade assembly 26. In this particular embodiment, four support arms are provided, and are individually denoted 50. The arms extend radially outwardly with respect to axis 24 and are spaced mutually at right angles with respect to one another. Each arm extends between the motor 28 and the inlet section 42 of housing 20, as perhaps best shown in FIG. 8.
Each arm comprises a flat plate having a relatively thin and flat cross-sectional shape which is substantially uniform throughout the length of the arm so that the arm has a major dimension and a minor dimension. The minor dimension of the arm is denoted 52 in FIG. 7 and the major dimension of the arm is denoted 54 in FIG. 8. The arms are disposed so that the major dimension (54) of each arm is in line with the rotational axis 24 while the minor dimension (52) faces the air flow through the air flow opening 22. In this way, obstruction of the air flow by the arms 50 is minimized, as is turbulence caused by the motor support means. As noted previously, it is thought that the configuration and arrangement of the arms 50 may in fact have a "flow straightening" effect that would actually reduce turbulence.
By way of comparison, it has been calculated that, for a 36" diameter fan, the motor mounting arms of the invention represent less than 0.3% of the total surface area of the air flow opening at its inlet end. This compares with about 6.8% for a fan having a prior art motor mount. It is generally acknowledged that any air blockage is effectively doubled due to turbulence.
Each arm is coupled to the housing and the motor respectively at points spaced along the major dimension 54 of the arm so as to resist misalignment (tipping) of the motor with respect to the axis 24 of the air flow opening. In other words, by making a relatively "wide" arm and attaching the arm to the housing and the motor at points spaced along this wide dimension, the motor is rigidly held and any tendency to tip is resisted by the arm.
In the illustrated embodiment, each arm 50 has a lateral flange 56 at its outer end which is bolted to the inner surface of the housing 20 using the captive nuts incorporated into the moulding as discussed previously. Two of the mounting points represented by these nuts are indicated at 40 in FIG. 6. Similar pairs of moulded-in nuts are provided for the outer ends of the other three arms. At their inner ends, each of the arms 50 is bolted to an angle bracket 58 (see FIG. 7) that is welded to the motor casing so as to extend parallel to axis 24. Each of the brackets has a longitudinal extent corresponding to the major dimension 54 of arm 50 and the arm is bolted to the bracket at two spaced positions close to opposite edges of the arm.
It will be appreciated from FIG. 7 that, in addition to minimizing air flow obstruction and turbulence, and supporting motor 28 against twisting, the arms also provide what has been called a "self-centering" support for the motor. In other words, the motor will always be held points equidistantly spaced from the outer ends of the four arms 50, irrespective of any distortion of the housing 20 that might take place, for example, due to temperature changes or damage. Thus, any risk of the fan blades contacting the inner surface 32 of the housing is minimized. This compares with a conventional motor mount arrangement in which mounting bars extend generally diametrally of the air flow opening 22. In such a situation, housing can easily distort laterally along a diameter at right angles to the "diameter" occupied by the mounting arms. This can cause interference between the blade tips and the interior of the housing which is a common problem for the prior art. Re-alignment of the blade in the prior art is by trial and error and can be tedious and time consuming. In contrast, with the illustrated motor supporting arrangement, the motor is always supported equidistant from four equi-angularly spaced points on the inner surface of the housing.
The fan blade assembly 26 is essentially conventional and comprises a central hub 60 and a series (in this case three) of fan blades 62 that extend radially outwardly from the hub. As diagrammatically shown in FIG. 8, the hub 60 is mounted co-axially on an output shaft 28a of motor 28, providing the direct drive for the fan assembly discussed previously.
FIG. 9 illustrates various configurations that may be achieved using the basic box fan shown in the previous views. The views denoted (a) to (d) are all front views that show respectively different styles of fan. A protective screen will normally be bolted to the front face of the housing 20, using the attachment points 40 represented by the captive nuts. In FIG. 9, the fans are shown with the front screen removed. Where additional external components have been added to the basic housing, it is to be understood that they will have been attached using the captive nuts referred to previously, providing the attachment points denoted 40.
FIG. 9(a) shows a basic stationary circulating fan. In FIG. 9(b), chain clips or hinged hanging bars have been added as indicated at 62 to provide a hanging circulating fan. FIG. 9(c) shows a spray misting accessory kit 64 as having been added to the basic fan to provide for moisture in the air flow. In FIG. 9(d) wheels 66 and feet 68 have been added to the housing to make a portable circulating fan.
Different installation configurations are shown in FIGS. 9(e) to (k). All of these views are longitudinal cross-sectional views through the fan.
FIG. 9(e) shows the basic fan of FIGS. 1 to 8 installed in an opening in a wall 70. The next two views show the same fan but with louvre accessories bolted to the fan housing; in FIG. 9(f) an exhaust louvre accessory is shown at 72, and in FIG. 9(g) both an exhaust louvre accessory 72 and an inlet louvre accessory 74 are shown.
FIG. 9(h) is essentially the same as FIG. 9(e) but with a weather hood accessory 76 bolted to the outlet side of the fan housing.
FIG. 9(i) again shows the basic fan but this time with an optional performance enhancing cone 78 frictionally fitted to the outlet side of the fan housing. FIG. 9(j) shows the same installation as FIG. 9(i) but with an inlet louvre accessory 80 added at the opposite side of the housing. Finally, FIG. 9(k) shows a modified inlet louvre 82 which incorporates a slant fitting so that the fan exhaust is directed downwardly.
It is to be understood that the various configurations shown in FIG. 9 are possible arrangements only and are not be regarded as exhaustive. For example, two louvre accessories can be used to effectively insulate the fan during winter time. This avoids shutting down the fan, which is usually what happens when a cover is used, as in the prior art.
It should also be noted that the preceding description relates to particular preferred embodiments of the invention and that many modifications are possible, some of which have already been mentioned, while others will readily occur to a person skilled in the art. For example, though reference has been made to a plastic housing made in one piece by rotational moulding, a similar result could be obtained using separate components bonded together. Also, as noted previously, a belt drive fan could be used instead of the direct drive illustrated. While four motor mounting arms have been shown, as few as three, or more than four arms could be used. The size of the fan overall may of course vary. In particular, throat sizes and related fan components may vary to fit any existing axial fan blade size. The outside profile shape of the fan may be square as shown in the drawings, or rectangular, round or other appropriate shape.
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An axial flow fan primarily for use in harsh and/or corrosive environments such as agricultural barns has a one-piece plastic moulded housing which defines an air flow passageway, and a direct drive fan assembly supported in the air flow passageway by a novel motor mount. The mount includes at least three radially disposed support arms of equal length which maintain the fan assembly in the center of the air flow opening despite distortions in the housing that might occur for example due to temperature changes. Each support arm is a thin and flat plate disposed edge on to the air flow so as to minimize resistance. The air flow opening is smoothly contoured to define a convergent conical inlet section and a divergent conical outlet section for improved efficiency of air flow.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a cylinder block for an internal combustion engine, and more particularly to a cylinder block made of light alloy and produced by die-casting.
2. Description of the Prior Art
It is well known to die cast a cylinder block using a light alloy such as aluminum alloy as a material thereof. Such a die-cast cylinder block is not provided with an upper deck section, so that the top section of each engine cylinder is not integrally connected to an outer wall structural of the cylinder block. In this connection, the upper deck section in a cylinder block produced by conventional casting using molding sand is provided with such a upper deck section which serves to integrally connect each engine cylinder top section and the outer wall section of the cylinder block. The reason why the deck section is not provided in the die-cast cylinder block is that a metallic die for forming the water jacket is pulled up during die-casting thereof. As a result, the upper section of each engine cylinder is not integral with the outer wall section of the cylinder block and is accordingly, free from secure restraint. This leads to a reduction in flexural and which results in vibrations and, thus, of the cylinder block, thereby readily vibrating to generate noise.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a cylinder block for an automotive in-line multiple-cylinder internal combustion engine comprises outer wall means including oppositely located first and second end wall sections, and oppositely located first and second side wall sections, the top surface of the wall sections being continuous and lying on a common plane. The cylinder block further comprises an elongate cylinder row structure spacedly located within the outer wall means and including a plurality of cylinder sections whose neighbouring cylinder sections are integrally connected with each other. The cylinder sections contain first and second extreme cylinder sections located at the opposite extremities of the cylinder row structure and positioned in the vicinity of the first and second end wall sections of the outer wall means, each cylinder section being formed with a cylinder bore therein. The top surface of the cylinder row structure lies on the above-mentioned common plane. The first extreme cylinder section is integrally connected with the first end wall section of the outer wall means. The second extreme cylinder section is integrally connected with the second end wall section of said outer wall means. Accordingly, first and second coolant passages are formed separately and independently from each other. Each coolant passage is defined between the side wall section and the cylinder row structure.
The thus arranged cylinder block has greatly improved flexural and tortional rigidity though produced by die-casting, thereby suppressing noise due to cylinder block vibration. Also, the coolant flow to two coolant passages located at the opposite sides relative to the cylinder row structure is controllable to improve cooling characteristics of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the cylinder block according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate like parts and elements, in which:
FIG. 1 is a plan view of a cylinder block of a conventional in-line four-cylinder internal combustion engine;
FIG. 2 is a vertical cross-sectional view of the cylinder block of FIG. 1;
FIG. 3 is a plan view of an embodiment of a cylinder block in accordance with the present invention;
FIG. 4 is a vertical cross-sectional view of the cylinder block of FIG. 3;
FIG. 5 is a side view of the cylinder block, with the coolant pump removed, as viewed from the direction of an arrow A of FIG. 3;
FIG. 6 is a plan view of another embodiment of the cylinder block in accordance with the present invention;
FIG. 7 is a vertical sectional view of the cylinder block of FIG. 6;
FIG. 8 is a side view of the cylinder block, with the coolant pump removed, as viewed from the direction of an arrow B of FIG. 6; and
FIG. 9 is a cross-sectional view taken in the direction of the arrows substantially along the line 9--9 of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
To facilitate understanding the present invention, a brief reference will be made to a conventional cylinder block 1 made of light alloy, depicted in FIGS. 1 and 2. The cylinder block 1 of this kind is formed without an upper deck section to which a cylinder head (not shown) is secured, i.e., an engine coolant passage fully opens to the top surface of the cylinder head. This is because the metallic die used to form the coolant passage core, during casting by using molding sand, is removed upwardly to leave a cylinder row structure 3 during die-casting. In the cylinder row structure 3, neighbouring cylinder sections 4 are connected integrally with each other to increase the rigidity of the cylinder row structure and to shorten the whole length of the cylinder block 1. Otherwise, each cylinder section 4 may be independent and separate from each other.
With such a conventional cylinder block, the upper deck section is not provided and the opposite extremities of the cylinder row structure 3 do not connect respectively with the front and rear wall sections 5, 6 and accordingly the major part of the cylinder sections 4 are not restrained relative to the body of the cylinder block 1. This causes a low rigidity against flexure in the vertical and lateral directions, distortion and the like of the cylinder block itself, with the result that the cylinder block 1 readily vibrates due to engine piston movements and combustion in engine cylinders. Particularly, the front wall section 5 of the cylinder block 1 to which a timing cover (not shown) is attached, tends to readily vibrate, thereby generating a high level noise. Additionally, with of the conventional cylinder block 1, the rigidity of the connection of a transmission (not shown) to the cylinder block rear wall section 6 is low and therefore, the natural vibration frequency of the combined cylinder block and transmission becomes lower, thereby resulting in an increase in passenger compartment noise of a low frequency range.
In view of the above description of the conventional cylinder block construction, reference is now made to FIGS. 3 to 5, wherein an embodiment of a cylinder block according to the present invention is illustrated by the reference numeral 10. The cylinder block 10 is made of a light alloy such as aluminum alloy and produced by die-casting, which cylinder block is used for an automotive in-line multiple-cylinder internal combustion engine. The cylinder block 10 comprises an outer vertical wall structure 12 including oppositely located front and rear wall sections 14, 16, and oppositely located right-side and left-side side wall sections 18, 20. The wall sections 14, 16, 18, 20 are continuous and integral with each other, and their top surfaces lie on a common plane 12a. It will be understood that a cylinder head (not shown) is secured on this common plane 12a of the cylinder block 10.
A cylinder row structure 22 includes, in this instance, four cylinder sections 24 which are connected integrally with each other and aligned in a row. Each cylinder section 24 is formed therein with a cylinder bore 24a within which a piston (not shown) is locatable. The surface of the cylinder bore 24a may be covered with a cylinder liner. The cylinder row structure 22 is spacedly located within the outer wall structure 12, in which the wall sections 14, 16, 18, 20 are generally parallel with the axis of each cylinder section 24 of the cylinder row structure 22. Additionally, the cylinder row structure 22 is connected integrally at its opposite extreme end sections with the front and rear end wall sections 14, 16, by means of front and rear connecting wall sections 26, 28, respectively. In other words, the cylinder sections 24 located at the opposite extremities of the cylinder row structure 22 are connected integrally with the front and rear end wall sections 14, 16 by the front and rear connecting wall sections 26, 28, respectively. It will be understood that the front and rear connecting wall sections 26, 28 may not be prominent so that the cylinder section 24 is merely connected integrally with the front or rear wall section 14, 16 of the outer wall structure 12. The top surface of the cylinder row structure or the cylinder sections 24 and the connecting wall sections 26, 28 lie on the common plane 12a. Accordingly, separate right-side and left-side engine coolant passages 30, 32 or water jackets are defined by the connecting wall sections 26, 28 and between the inner wall surface of the outer wall structure 12 and the outer wall surface of the cylinder row structure 22. In other words, the right-side and left-side coolant passages 30, 32 are formed oppositely relative to the cylinder row structure 22, and separate and independent from each other. As shown, the coolant passages 30, 32 fully open at the common plane 12a. It will be understood that each coolant passage 30, 32 is formed by extracting or drawing up a metallic die corresponding to the coolant passage during its production by die-casting.
As best seen in FIG. 5, the front wall section 14 of the outer wall structure 12 is formed with coolant inlet openings 34, 36 which are in communication with the right-side and left-side coolant passages 30, 32, respectively. It will be understood that engine coolant is introduced through these openings 34, 36 into the coolant passages 30, 32, respectively. These coolant inlet openings 34, 36 are formed during die-casting or by machining after die-casting. The right-side and left-side coolant passages 30, 32 may be in communication with each other through a small hole which is formed, for example by drilling, through a wall section between the neighbouring cylinder sections 24, in order to obtain a small amount of coolant flow between the right-side and left-side coolant passages 30, 32. More specifically, the cross-sectional area of the coolant inlet opening 36 is larger than that of the other coolant inlet opening 34, so that the coolant flow amount to the left-side coolant passage 32 is controlled larger than that to the right-side coolant passage 30. These coolant inlet openings 34, 36 communicate through a coolant distributor member 38 with a coolant pump 40 secured to the front wall section 14 of the cylinder block 10. The reference numeral 41 denotes a coolant suction pipe connected to a coolant radiator (not shown). The coolant suction pipe 41 is in communication with a coolant suction opening 42 formed through the front wall section 14. Accordingly, the engine coolant is sucked through the suction pipe 41 and the suction opening 42 into the coolant pump 40 and then distributed into the right-side and left-side coolant passages 30, 32 through the coolant inlet openings 34, 36 under the action of the distributor member 38.
In the thus arranged cylinder block, the neighbouring cylinder sections 24 are integrally connected with each other to form the cylinder row structure 22, and the opposite extremities of the cylinder row structure 22 are integrally connected respectively to the front and rear wall sections 14, 16 of the cylinder block 10. As a result, the cylinder block 10 has a strength which is generally equal to that of a conventional cylinder block which is provided with its upper deck section on which a cylinder head is securely mounted. Additionally, the bore pitch or distance between the neighbouring cylinder sections 24 can be reduced to shorten the whole length of the cylinder block 10. Therefore, the cylinder block 10 has improved rigidity against flexure in the vertical and lateral directions and distortion thereof. This suppresses generation of noises due to low cylinder block rigidity. Furthermore, from the point of view that a transmission (not shown) is secured to the rear end section or the rear wall section 16 of the cylinder block 10, the above-mentioned configuration of the cylinder block 10 greatly contributes to an improvement in the connection rigidity or strength between the cylinder block and the transmission since the front and rear wall sections 14, 16 are connected through the cylinder row structure 22. This greatly decreases low frequency noise within a passenger compartment, and extends the critical rotational speed of a propeller shaft (not shown).
Also, by differentiating the sectional area of the coolant inlet openings 34, 36 formed at the front wall section 14 of the cylinder block 10, the amounts of engine coolant supplied to the right-side and left-side coolant passages 30, 32 are controllable. Thus, the exhaust side of the engine can be predominantly cooled in an engine of the cross-flow induction-exhaust type in which intake and exhaust systems are respectively located at the opposite sides of the engine body. More specifically, in this instance, the coolant inlet opening 36 for the left-side coolant passage 32 located near the exhaust system is larger than the inlet opening 34 for the right-side coolant passage 30 located near the intake system. With this arrangement, a larger amount of engine coolant is supplied to the exhaust system side coolant passage 32 of the cylinder block 10, thereby maintaining the temperatures at the various sections of the engine uniform. This prevents the generation of excessive thermal stress and strain due to temperature difference.
FIGS. 6, 7, 8 and 9 illustrate another embodiment of the cylinder block according to the present invention. In this embodiment, a right-side coolant inlet passage 44 communicating with the right-side coolant passage 30 is formed outside of a boss portion 48 for supporting a cylinder head bolt (not shown), and opens through the coolant inlet opening 34 at the front wall section 14 of the cylinder block 10. Similarly, a left-side coolant inlet passage 14 communicating with the left-side coolant passage 32 is formed outside of a boss portion 50 for supporting a cylinder head bolt (not shown), and opens through the coolant inlet opening 36 at the cylinder block front wall section 14. As shown, the coolant inlet openings 34, 36 are formed at projecting sections 52, 54 which project respectively from the right- and left-sides of the cylinder block front wall section 14. It will be understood that the coolant inlet openings 34, 36 are formed considerably spaced apart from the axis of cylinder block 10 as compared with in the above-mentioned embodiment of FIGS. 3 to 5. The coolant pump 40 secured on the cylinder block front wall section 14 is communicates through the distributor member 38 with the coolant inlet openings 34, 36, so that engine coolant supplied from the coolant pump 40 is distributed into the two coolant inlet openings 34, 36 to be introduced into the right-side and left-side coolant passages 30, 32.
In the thus arranged cylinder block 10, by virtue of the fact that the coolant inlet passages 44 and 46 are formed outside of the cylinder head bolt boss portions 48, 50, there are no holes for engine coolant flow at the cylinder block front wall section 14 to which a timing cover (not shown) is securely attached. As a result, the rigidity or strength of the front wall section 14 can be further improved, which decreases the vibration transmitted to the timing cover, thereby suppressing noise generation at the timing cover. Besides, as compared with the cylinder block provided with the openings for coolant flow through the cylinder block front wall section 14, the wall thicknesses, indicated by t and t', of the cylinder block front and rear end sections are allowed to decrease, which enables a further shortening of the whole length of the cylinder block 10.
As appreciated from the above, according to the present invention, the cylinder block is improved in rigidity or strength against flexure and distortion, thereby decreasing engine noise. Furthermore, it is possible to improve the connection rigidity of the transmission to the cylinder block. Moreover, cooling characteristics of the engine can be improved by differentiating the sectional areas of the cooling inlet openings of the separate coolant passages formed oppositely of the cylinder row structure.
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A cylinder block for an automotive in-line multiple-cylinder internal combustion engine, comprising an outer wall structure, an elongate cylinder row structure spacedly located within the outer wall structure including a plurality of cylinder sections whose neighboring cylinder sections are integrally connected with each other, and first and second connecting wall portions which integrally connect the cylinder sections at the extremities of the cylinder row structure with the outer wall structure so as to define independent coolant passages at the opposite sides of the cylinder row structure, thereby improving flexural and tortional rigidities though produced by die-casting.
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TECHNICAL FIELD
The present invention relates to a communication system, to a communication apparatus and communication method, and to a computer program that apply space-division multiple access (SDMA) in which wireless resources on a spatial axis are shared by a plurality of users. More particularly, the present invention relates to a communication system, to a communication apparatus and communication method, and to a computer program that realize space-division multiple access while avoiding inter-network interference.
BACKGROUND ART
Wireless communication eliminates the burden of wiring work for wired communication of the past, and is additionally catered for usage as a technology that realizes mobile communication. For example, IEEE (The Institute of Electrical and Electronics Engineers) 802.11 may be cited as an established standard regarding wireless LANs (Local Area Networks). IEEE 802.11a/g is already widely prevalent.
With many wireless LAN systems such as IEEE 802.11, an access control protocol based on carrier sense such as CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) is implemented, with each station being configured to avoid carrier collisions during random channel access. Also, virtual carrier sensing may be cited as a methodology for resolving the hidden terminal problem in wireless communication. The RTS/CTS handshake is a representative example of a signal transmission sequence utilizing virtual carrier sensing.
FIG. 10 illustrates a major frame format used for an RTS/CTS handshake in an IEEE 802.11 system. As illustrated, IEEE 802.11a/b/g frames are all composed of a PLCP (Physical Layer Convergence Protocol) preamble and PLCP header which correspond to a physical header, and a PSDU (PHY Service Data Unit) field which corresponds to a MAC (Media Access Control) frame. Also, FIGS. 11A to 11C illustrate respective PSDU formats for the RTS, CTS/ACK, and DATA frames defined in IEEE 802.11.
At the beginning of a PSDU, a Frame Control field and a Duration field are jointly defined. The Frame Control format is further segmentalized with various information stated therein, such as the frame type or protocol version, a resend indicator, and data path information, for example. In the Duration, a counter value called the NAV (Network Allocation Vector) is set. The counter value is taken to indicate the transmission completion time for a subsequent ACK frame, for example. A frame-receiving station to which the frame is not addressed set a NAV counter value on the basis of information in the Duration, and refrains from transmission operations during a communication sequence unit.
As illustrated in FIG. 11A , in an RTS frame, a Receiver Address (RA) indicating the recipient and a Transmitter Address (TA) indicating the sender are stated after the Duration. Also, as illustrated in FIG. 11B , in a CTS frame and an ACK frame, respective sender addresses (TAs) of an RTS and a DATA frame are copied in the Receiver Address (RA) following the Duration. Also, as illustrated in FIG. 11C , in a DATA frame, a plurality of Address fields Addr 1 to 4 are included following the Duration, and are used in order to specify the sender and recipient stations, etc. Also, net information provided to upper layers is stored in the Frame Body following the Address fields. A FCS (Frame Check Sequence) consisting of a 32-bit CRC (Cyclic Redundancy Check) is appended at the end of all frames. For example, at a recipient station that receives a frame, the FCS is recalculated and checked to determine whether or not it matches the FCS that was sent. In the case where they do not match, that frame is discarded as corrupted. In so doing, only correct MAC frames are recognized and processed.
An exemplary RTS/CTS communication sequence will be explained with reference to FIG. 12 . In the figure, there exist four stations STA 2 , STA 0 , STA 1 , and STA 3 , wherein only adjacent stations are positioned within radio wave range. STA 3 is a hidden terminal to STA 0 , and STA 2 is a hidden terminal to STA 1 . Given such a communication environment, consider circumstances where STA 0 wants to transmit information to STA 1 using an RTS/CTS handshake.
Upon producing a transmit request at time T 0 , STA 0 monitors the medium state for just a given frame interval DIFS (Distributed Inter Frame Space), and if no transmission signal exists in this space, conducts a random backoff. In the case where no transmission signal exists in this space as well, STA 0 obtains an exclusive channel usage transmission opportunity (TXOP), and transmits an RTS frame to STA 1 at the time T 1 . Herein, information indicating that the frame is an RTS is stated in the Frame Control field of the RTS frame, information indicating the amount of time until the transmission transaction related to the frame ends (i.e., the amount of time until the time T 8 ) is stated in the Duration field, the address of the recipient STA 1 is stated in the RA field, and the address of the STA 0 itself is stated in the TA field.
This RTS frame is also received by STA 2 , the station adjacent to STA 0 . STA 2 conducts virtual carrier sensing upon recognizing from the Frame Control field that the frame is an RTS frame and also recognizing from the RA field that the frame is not addressed to STA 2 itself. In other words, STA 2 recognizes that the medium is occupied until the time T 8 when the transmission transaction ends, and STA 2 enters a transmission-denied state without conducting physical carrier sensing. The work of entering this transmission-denied state is realized by set a NAV counter value on the basis of information stated in the Duration field and refraining from transmission operations until the counter expires, and is also called “setting a NAV”.
Meanwhile, STA 1 , upon receiving an RTS frame in which its own address is stated in the RA, recognizes that the adjacent station STA 0 whose address is stated in the TA wants to transmit information to STA 1 itself. Then, STA 1 replies with a CTS frame at a time T 3 after a given frame interval SIFS (Short IFS) has elapsed since the time T 2 when reception of the RTS frame ended. Information indicating that the frame is a CTS frame is stated in the PSDU Frame Control field inside this CTS field. Information indicating the amount of time until the transmission transaction related to the frame (i.e., the amount of time until the time T 8 ) is stated in the Duration field. The address of the sender (STA 0 ) that was stated in the TA field of the RTS frame is copied to the RA field.
This CTS frame is also received by STA 3 , the station adjacent to STA 1 . STA 3 conducts virtual carrier sensing upon recognizing from the Frame Control field that the frame is a CTS frame and also recognizing from the RA field that the frame is not addressed to STA 3 itself. In other words, STA 3 recognizes that the medium is occupied until the time T 8 when the transmission transaction ends, and STA 3 enters a transmission-denied state without conducting physical carrier sensing.
Meanwhile, STA 0 , upon receiving a CTS frame in which its own address is stated in the RA, recognizes that STA 1 has acknowledged the initiate transmission request from STA 0 itself. Then, STA 0 initiates transmission of a DATA frame at a time T 5 after a given frame interval SIFS has elapsed since the time T 4 when reception of this CTS frame ended.
DATA frame transmission ends at a time T 6 , and in the case where STA 1 is able to decode the frame without error, replies with an ACK frame at a time T 7 after a given frame interval SIFS. Then, the transmission transaction for a single packet ends at a time T 8 when STA 0 finishes receiving this ACK frame.
When the time T 8 is reached, the respective hidden terminals STA 2 and STA 3 drop their NAVs and return to an ordinary transmission state.
According to the RTS/CTS handshake, nearby stations STA 2 and STA 3 that were able receive at least one of an RTS and a CTS transition to a transmission-denied state. As a result, STA 0 and STA 1 are able to transmit information from STA 0 to STA 1 and reply with an ACK from STA 1 without being impeded by sudden transmission signals from a nearby station. In other words, by using the RTS/CTS handshake in conjunction with the CSMA/CA control protocol, it may be possible to reduce collision overhead in an overloaded state.
In a conventional wireless LAN system, the CSMA/CA control protocol is not only effective for intra-network interference, but also for inter-network interference. For example, as illustrated in FIG. 13 , consider the case there exist two adjacent networks, with one network being composed of STA 0 acting as an access point with STA 1 and STA 2 connected thereto, and the other network being composed of STA 4 acting as an access point with STA 3 and STA 5 connected thereto. With IEEE 802.11, control is conducted so as to not produce unnecessary collisions between nearby stations according to a virtual carrier sensing mechanism like that discussed above. Consequently, even if STA 2 and STA 3 exist within each other's signal ranges, by setting a NAV STA 2 is able to avoid conditions in which STA 2 receives interference due to a signal from STA 3 while receiving a signal from STA 0 .
Meanwhile, with the IEEE 802.11a/g standard, orthogonal frequency-division multiplexing (OFDM) is used in the 2.4 GHZ band or the 5 GHz band to support a modulation method that achieves a maximum communication rate (physical layer data rate) of 54 Mbps. Also, with the standard's amendment IEEE 802.11n, MIMO (Multi-Input Multi-Output) communication methods are adopted to realize high throughput (HT) exceeding 100 Mbps. Herein, MIMO is a communication method that realizes spatially multiplexed streams by providing a plurality of antenna elements at both the transmitter end and the receiver end (as is commonly known).
For example, by increasing the number of antennas on a MIMO communication device to increase the number of spatially multiplexed streams, throughput for 1-to-1 communication can be improved while maintaining backwards compatibility. Improvements in per-user throughput for communication as well as in throughput for multiple users overall is being demanded for the future.
The IEEE 802.11ac Working Group is attempting to formulate a wireless LAN standard whose data transfer rate exceeds 1 Gbps by using the frequency band below 6 GHz. For its realization, space-division multiple access methods whereby wireless resources on a spatial axis are shared by a plurality of users, such as multi-user MIMO (MU-MIMO) or SDMA (Space-Division Multiple Access), are effective.
With a space-division multiple access system, it is possible to spatially separate multiple user signals received contemporaneously by conducting signal processing that multiplies the outgoing/incoming signals of the plurality of antenna elements by wait values. It also becomes possible to contemporaneously distribute a plurality of signals to multiple users by multiplying signals by similar wait values and then transmitting.
When starting operation of space-division multiple access with a new wireless LAN standard, it is necessary to give due consideration to backwards compatibility with the old standard, since it will be necessary to operate in a communication environment where communication devices of the new standard and communication devices of the old standard. In the legacy IEEE 802.11 standard, carrier sensing mechanisms such as CSMA/CA and RTS/CTS were adopted. Consequently, in a new standard such as IEEE 802.11ac, it is necessary to optimally combine carrier sensing and space-division multiple access.
For example, there has been proposed a communication system that combines the two technologies of carrier sensing in the legacy IEEE 802.11 standard and space-division multiple access with an adaptive array antenna by using RTS, CTS, and ACK frames in a frame format that maintains backwards compatibility with the legacy 802.11 standard (see PTL 1, for example).
FIG. 14 illustrates an exemplary transmission sequence using an RTS/CTS handshake in a space-division multiple access system. In the example illustrated, there exist three stations STA 0 , STA 1 , and STA 2 , and it is assumed that STA 0 transmits data contemporaneously to STA 1 and STA 2 .
STA 0 conducts physical carrier sensing in advance and confirms that the medium is clear, and after additionally conducting a backoff, sends an RTS frame which indicates that STA 0 will transmit information to STA 1 and STA 2 by space-division multiple access. However, the format of the RTS frame used at this point is not necessarily limited to that illustrated in FIG. 11A . Also, a term different from RTS may be determined by the standard.
In response to receiving an RTS frame, STA 1 and STA 2 contemporaneously transmit respective CTS frames (CTS- 1 , CTS 2 ) in order to indicate that they are in a state able to receive information. However, the CTS frames used at this point are not necessarily that illustrated in FIG. 11B , and are assumed to be in a format enabling STA 0 to separate the two signals. Also, a term different from CTS may be determined by the standard.
STA 0 , on the basis of the incoming signals of the received CTS- 1 and CTS- 2 , multiplies these signals by a wait value for each antenna element required for spatial separation (i.e., conducts antenna coefficient learning), thereby separating and receiving the two signals. Additionally, STA 0 uses this wait value to contemporaneously transmit DATA frames (DATA- 1 , DATA- 2 ) to STA 1 and STA 2 . DATA- 1 and DATA- 2 are frames transmitted by signals that are sent while taking into account the wait coefficients of the antennas such that interference does not occur at their destinations. STA 1 is able to receive DATA- 1 , while STA 2 is able to receive DATA- 2 .
Once STA 1 and STA 1 finish receiving their respective DATA frames, they contemporaneously reply with ACK frames (ACK- 1 , ACK- 2 ). STA 0 then receives these ACK frames, thereby ending a sequence for transmitting data to multiple stations using space-division multiple access.
Although an exemplary sequence for transmitting information by utilizing the RTS/CTS handshake is illustrated in FIG. 14 , contemporaneous data delivery by space-division multiple access may also be applied to frame exchange sequences besides the above. However, since the principal matter of the present invention is not directly related to which communication sequence is used, further explanation thereof will not be given in this specification.
With a wireless LAN system of the past, inter-network interference can be avoided by a CSMA/CA control protocol as discussed above. With 1-to-1 communication, time management for securing a station's band may be comparatively loose. In contrast, with a system to which space-division multiple access has been applied, it is necessary to secure a band for all stations to be multiplexed, which demands more strictness in time management.
Hereinafter, the problem of inter-network interference in a space-division multiple access system will be examined in detail.
Assuming the transmission sequence illustrated in FIG. 14 , it becomes necessary for STA 0 to contemporaneously transmit data to the plurality of peers STA 1 and STA 2 . In other words, it is necessary for STA 0 to secure a state such that transmission can occur with both destinations STA 1 and STA 2 at the timing when transmission of a plurality of DATA frames (DATA- 1 , DATA- 2 ) is initiated.
For example, in the case of assuming a station placement wherein a plurality of networks overlap as illustrated in FIG. 13 , conditions are expected wherein STA 0 's transmission sequence and STA 4 's transmission sequence overlap in time and interference occurs between STA 2 and STA 3 . At this point, in the case where STA 2 has set a NAV due to receiving a CTS frame from STA 3 , STA 2 will be unable to reply to an RTS frame addressed to STA 2 itself from STA 0 . As a result, information is not transmitted from STA 0 to STA 2 , and waste occurs. In contrast, assuming the case where a NAV is not set even though STA 2 has received a CTS frame from STA 3 , an outgoing signal from STA 2 will interfere with data reception at STA 3 , and waste will similarly occur.
Consequently, in the case where it is desired to efficiently operate a space-division multiple access system in which parts of wireless networks are placed within radio wave range of each other such that their stations interfere with each other as illustrated in FIG. 13 , it is preferable to arrange transmission sequence units for each network so as to not overlap in time, as illustrated in FIG. 16 , for example.
Also, FIG. 17 illustrates another exemplary station arrangement in which a plurality of networks overlap. In the example illustrated, there is a network having an access point STA 0 with STA 1 and STA 2 being connected thereto as terminals (client devices), and a network having an access point STA 4 with STA 3 and STA 5 connected thereto. STA 1 is within radio wave range of STA 4 . In this way, problems similar to the above occur even in the case where an access point STA 4 is within interference range of a terminal STA 1 connected to another network, and wireless network usage efficiency worsens significantly.
In this way, in the case where it is desired to conduct space-division multiple access in circumstances where exclusive placement of frequency channels used by networks is difficult, such as with wireless LAN devices, it is preferable to perform control such that transmission sequences do not overlap in time among wireless networks or among devices.
For example, proposals have been made for a system that detects the presence of a nearby network by receiving a pilot signal (see PTL 2, for example). However, in typical wireless LAN systems pilot signals do not exist and only ordinary frames are transmitted, making utilization of this technology difficult. Also, a wireless network does not actively report to nearby equipment when its own signals will be transmitted. For this reason, it cannot be arranged in advance such that signals do not overlap among networks.
Also, proposals have been made for a wireless communication system that takes a resolving action once the problem of inter-network interference becomes significant (see PTL 3, for example). However, it is desirable to control networks such that the problem does not occur in the first place.
Also, neither system disclosed in PTL 2 and 3 assumes space-division multiple access. In a space-division multiple access system, the problem of inter-network interference is significantly exhibited compared to the case of carrying out a CSMA/CA system protocol with an ordinary wireless LAN system. For this reason, the inventors reason that there is a need for a methodology that discovers and coordinates inter-network interference problems earlier.
CITATION LIST
Patent Literature
PTL 1: Japanese Unexamined Patent Application Publication No. 2004-328570
PTL 2: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2007-510384
PTL 3: Japanese Unexamined Patent Application Publication No. 2005-287008
SUMMARY OF INVENTION
Technical Problem
An object of the present invention is to provide a superior communication system, a communication apparatus and communication method, and a computer program able to communicate optimally by applying space-division multiple access in which wireless resources on a spatial axis are shared by a plurality of users.
Another object of the present invention is to provide a superior communication system, a communication apparatus and communication method, and a computer program able to optimally realize space-division multiple access while avoiding inter-network interference.
Solution to Problem
This application has been devised with reference to the above problems, and the invention described in Claim 1 is a communication system consisting of a plurality of stations, including stations that conduct space-division multiple access using an array antenna, wherein
when conducting a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted among a base station and one or more terminals, the base station transmits a first frame that reports, to the one or more terminals, time information related to a transmission sequence unit scheduled on its own network, and the one or more terminals transmit a second frame for reporting, to nearby stations, time information related to the transmission sequence unit in response to receiving the first frame.
However, the “system” discussed herein refers to the logical assembly of a plurality of apparatus (or function modules realizing specific functions), and it is not particularly specified whether or not respective apparatus or function modules exist within a single housing. (This applies similarly hereinafter.)
According to the invention described in Claim 2 of this application, in a communication system in accordance with Claim 1 , it is configured such that the terminal sends a third frame that reports, to the base station, time information related to a second transmission sequence unit being scheduled on a network of a nearby station in response to receiving the second frame from that nearby station.
According to the invention described in Claim 3 of this application, in a communication system in accordance with Claim 2 , it is configured such that the base station, on the basis of time information related to the second transmission sequence unit obtained by decoding the received third frame, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
According to the invention described in Claim 4 of this application, in a communication system in accordance with Claim 2 , the first frame, the second frame, and the third frame are transmitted as management frames.
According to the invention described in Claim 5 of this application, in a communication system in accordance with Claim 2 , the first frame, the second frame, and the third frame are addressed and transmitted to a broadcast address.
According to the invention described in Claim 6 of this application, in a communication system in accordance with Claim 1 , the second frame is transmitted as a frame addressed to the base station from the terminal.
Also, the invention described in Claim 7 of this application is a communication apparatus, comprising:
a communication unit able to conduct space-division multiple access using an array antenna; and
a controller that controls communication operation by the communication unit;
wherein
when the controller operates as a base station and conducts a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more terminals, the controller causes a first frame to be transmitted which reports, to the one or more terminals, time information related to a transmission sequence unit scheduled on its own network, and in response to receiving a third frame from at least one of the one or more terminals that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
Also, the invention described in Claim 8 of this application is a communication method for conducting space-division multiple access using an array antenna, such that when operating as a base station and conducting a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more terminals, the method includes:
a step of transmitting a first frame that reports, to the one or more terminals, time information related to a transmission sequence unit scheduled on its own network;
a step of receiving a third frame from at least one of the one or more terminals that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station; and
a step of adjusting the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit, on the basis of time information related to the second transmission sequence unit obtained by decoding the received third frame.
Also, the invention described in Claim 9 of this application is a computer program stated in a computer-readable format such that processing for a communication apparatus to transmit frames is executed on a computer, the computer program causing the computer to function as
a communication unit able to conduct space-division multiple access using an array antenna, and
a controller that controls communication operation by the communication unit,
wherein
when the controller operates as a base station and conducts a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more terminals, the controller causes a first frame to be transmitted which reports, to the one or more terminals, time information related to a transmission sequence unit scheduled on its own network, and in response to receiving a third frame from at least one of the one or more terminals that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
A computer program in accordance with Claim 9 of this application is defined to be a computer program stated in a computer-readable format such that given processing is executed on a computer. In other words, by installing a computer program in accordance with Claim 9 of this application onto a computer, cooperative action is exhibited on the computer, which operates as a base station on a network, thereby enabling operational advantages similar to those of a communication system in accordance with Claim 1 of this application to be obtained.
Also, the invention described in Claim 10 of this application is a communication system consisting of a plurality of stations, including stations that conduct space-division multiple access using an array antenna, wherein
when conducting a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted among a plurality of stations, the information source station transmits a first frame that reports, to one or more stations given to be information recipients, time information related to a transmission sequence unit scheduled on its own network, and the one or more stations given to be information recipients respectively transmit a second frame for reporting, to nearby stations, time information related to the transmission sequence unit in response to receiving the first frame.
Also, according to the invention described in Claim 11 of this application, in a communication system in accordance with Claim 10 , it is configured such that the one or more stations given to be information recipients send a third frame that reports, to the information source station, time information related to a second transmission sequence unit being scheduled on a network of a nearby station in response to receiving the second frame from that nearby station.
Also, according to the invention described in Claim 12 of this application, in a communication system in accordance with Claim 11 , it is configured such that the information source station, on the basis of time information related to the second transmission sequence unit obtained by decoding the received third frame, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
Also, according to the invention described in Claim 13 of this application, in a communication system in accordance with Claim 11 , the first frame, the second frame, and the third frame are transmitted as management frames.
Also, according to the invention described in Claim 14 of this application, in a communication system according to Claim 11 , the first frame, the second frame, and the third frame are transmitted as beacon frames or probe response frames.
Also, according to the invention described in Claim 15 of this application, in a communication system in accordance with Claim 11 , the first frame, the second frame, and the third frame are addressed and transmitted to a broadcast address.
Also, according to the invention described in Claim 16 of this application, in a communication system in accordance with Claim 10 , the second frame is transmitted as a frame addressed to the information source station from the station given to be an information recipient.
Also, the invention described in Claim 17 of this application is a communication apparatus, comprising:
a communication unit able to conduct space-division multiple access using an array antenna; and
a controller that controls communication operation by the communication unit;
wherein
when the controller operates as an information source and conducts a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more stations given to be information recipients, the controller causes a first frame to be transmitted which reports, to the one or more stations given to be information recipients, time information related to a transmission sequence unit scheduled on its own network, and in response to receiving a third frame from at least one of the one or more stations given to be information recipients that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
Also, the invention described in Claim 18 of this application is a communication method for conducting space-division multiple access using an array antenna, such that when operating as an information source and conducting a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more stations given to be information recipients, the method includes:
a step of transmitting a first frame that reports, to the one or more stations given to be information recipients, time information related to a transmission sequence unit scheduled on its own network;
a step of receiving a third frame from at least one of the one or more stations given to be information recipients that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station; and
a step of adjusting the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit, on the basis of time information related to the second transmission sequence unit obtained by decoding the received third frame.
Also, the invention described in Claim 19 of this application is a computer program stated in a computer-readable format such that processing for a communication apparatus to transmit frames is executed on a computer, the computer program causing the computer to function as
a communication unit able to conduct space-division multiple access using an array antenna, and
a controller that controls communication operation by the communication unit,
wherein
when the controller operates as an information source and conducts a transmission sequence unit whereby the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted with one or more stations given to be information recipients, the controller causes a first frame to be transmitted which reports, to the one or more stations given to be information recipients, time information related to a transmission sequence unit scheduled on its own network, and in response to receiving a third frame from at least one of the one or more stations given to be information recipients that reports time information related to a second transmission sequence unit being scheduled on a network of a nearby station, adjusts the start time of the transmission sequence unit scheduled on its own network so as to not overlap in time with the second transmission sequence unit.
A computer program in accordance with Claim 19 of this application is defined to be a computer program stated in a computer-readable format such that given processing is executed on a computer. In other words, by installing a computer program in accordance with Claim 19 of this application onto a computer, cooperative action is exhibited on the computer, which operates as an information source station on a network, thereby enabling operational advantages similar to those of a communication system in accordance with Claim 10 of this application to be obtained.
Advantageous Effects of Invention
According to the present invention, it is possible to provide a superior communication system, a communication apparatus and communication method, and a computer program able to optimally communicate by applying space-division multiple access in which wireless resources on a spatial axis are shared by a plurality of users.
Also, according to the present invention, it is possible to provide a superior communication system, a communication apparatus and communication method, and a computer program able to optimally realize space-division multiple access while avoiding inter-network interference.
According to the inventions described in Claims 1 , 2 , 7 to 11 , and 17 to 19 of this application, it is possible to exchange time usage information for transmission sequence units among different networks or among non-adjacent equipment.
According to the inventions described in Claims 3 and 12 of this application, a base station that initiates its own transmission sequence unit disposes the start time for its own transmission sequence unit in a time slot which is not being used by an adjacent network or adjacent equipment. As a result, multiple wireless networks or wireless communication devices are able to utilize a channel by time division even in cases where exclusive placement of frequency channels is difficult, and efficient space-division multiple access can be realized.
Further objects, features, and advantages of the present invention will become apparent from the following detailed description based on embodiments of the present invention and the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating an exemplary configuration of a communication apparatus that realizes space-division multiple access.
FIG. 2 is a diagram illustrating an exemplary communication sequence such that transmission sequence units for respective networks do not collide given the network topology illustrated in FIG. 13 .
FIG. 3 is a diagram illustrating an exemplary communication sequence for the case where information related to a transmission sequence unit, such as “time information”, is transmitted using a beacon frame by an access point, and transmitted using an action frame by a terminal.
FIG. 4 is a diagram illustrating an exemplary communication sequence for the case where information related to a transmission sequence unit, such as “time information”, is transmitted by being included inside a typical frame.
FIG. 5 is a diagram illustrating an exemplary configuration of a time information element (TIME IE) stating “time information” related to a transmission sequence unit.
FIG. 6A is a diagram illustrating a PSDU format for an RTS frame in which a time information element is stated.
FIG. 6B is a diagram illustrating a PSDU format for a CTS/ACK frame in which a time information element is stated.
FIG. 6C is a diagram illustrating a PSDU format for a DATA frame in which a time information element is stated.
FIG. 6D is a diagram illustrating a PSDU format for an action frame in which a time information element is stated.
FIG. 6E is a diagram illustrating a PSDU format for a beacon or probe response frame in which a time information element is stated.
FIG. 7 is a diagram illustrating an exemplary configuration in which a time information element is stated in part of an Aggregated frame that stores a plurality of MPDUs in a single PSDU.
FIG. 8 is a diagram illustrating an exemplary communication sequence controlled such that the transmission sequences of respective stations do not collide with each other in an ad hoc communication environment.
FIG. 9 is a diagram illustrating how time information for transmission sequence units is reported via beacon frames transmitted every given beacon transmission timing, and how each station successively schedules a time for its own transmission sequence unit in FIG. 9 .
FIG. 10 is a diagram illustrating a major frame format used for an RTS/CTS handshake in an IEEE 802.11 system.
FIG. 11A is a diagram illustrating a PSDU format for an RTS frame defined in IEEE 802.11.
FIG. 11B is a diagram illustrating a PSDU format for CTS/ACK frames defined in IEEE 802.11.
FIG. 11C is a diagram illustrating a PDSU format for a DATA frame defined in IEEE 802.11.
FIG. 12 is a diagram for explaining an exemplary RTS/CTS communication sequence.
FIG. 13 is a diagram illustrating how a network composed of STA 0 as an access point with STA 1 and STA 2 connected thereto and a network composed of STA 4 as an access point with STA 3 and STA 5 connected thereto exist adjacent to each other.
FIG. 14 is a diagram illustrating an exemplary transmission sequence using an RTS/CTS handshake in a space-division multiple access system.
FIG. 15 is a diagram illustrating conditions where a STA 0 transmission sequence and a STA 4 transmission sequence overlap in time, and interference is produced between STA 1 and STA 3 .
FIG. 16 is a diagram illustrating how transmission sequence units for each network are arranged so as to not overlap in time.
FIG. 17 is a diagram illustrating another exemplary station arrangement in which a plurality of networks overlap.
DESCRIPTION OF EMBODIMENTS
Hereinafter, embodiments of the present invention will be explained in detail and with reference to the drawings.
With a space-division multiple access system, it is possible to spatially separate multiple user signals received contemporaneously by conducting signal processing that multiplies the outgoing/incoming signals of a plurality of antennas by wait values. It is also possible to contemporaneously distribute a plurality of signals to multiple users by multiplying signals by similar wait values and then transmitting.
FIG. 1 illustrates an exemplary configuration of a communication apparatus that realizes space-division multiple access. The illustrated communication apparatus is equipped with a plurality of transmission antennas 11 - 0 , 11 - 1 , etc. In a physical layer processor 12 , input/output signals for the respective antennas 11 - 0 , 11 - 1 , etc. are respectively multiplied by wait values W 0 to W 3 . In so doing, a signal processor 12 is able to handle single independent streams. Then, by providing transmission subsystems consisting of such a physical layer processor 13 in parallel, space-division multiple access becomes possible, and the communication apparatus can handle multiple streams.
These physical layer processors 13 provided in parallel are connected to a MAC layer processor 14 , whereby signal processing necessary for a wireless LAN system is conducted.
Furthermore, in a space-division multiple access system, a plurality of MAC instances may operate in parallel in some cases.
The communication apparatus illustrated in FIG. 1 is taken to be able to operate as either an access point or a terminal in infrastructure mode, or alternatively, is able to autonomously communicate in ad hoc mode.
At this point, operation of a station will be explained, taking by way of example a station arrangement in which a plurality of wireless networks overlap, as illustrated in FIG. 13 . Each station STA 0 to STA 5 may be configured as the communication apparatus illustrated in FIG. 1 .
In FIG. 13 , a network composed of STA 0 as an access point with STA 1 and STA 2 connected thereto and a network composed of STA 4 as an access point with STA 3 and STA 5 connected thereto exist adjacent to each other. Also, while STA 2 and STA 3 are within each other's radio wave ranges, STA 0 and STA 4 are disposed in locations unable to receive each other's radio waves.
In the network consisting of STA 0 , STA 1 , and STA 2 , communication is conducted using sequences like that illustrated in FIG. 14 . Also, in the network consisting of STA 4 , STA 3 , and STA 5 , communication is likewise conducted using sequences like that illustrated in FIG. 14 .
FIG. 2 illustrates an exemplary communication sequence such that transmission sequence units for respective networks do not collide given the network topology illustrated in FIG. 13 . In the illustrated communication sequence, time usage information for transmission sequences is exchanged among different networks or among non-adjacent equipment, and on the basis of this information, a station that initiates a transmission sequence disposes its own transmission sequence time in a time slot which is not being used by an adjacent network or adjacent equipment.
First, STA 0 transmits a message (MSG- 00 ) containing “time information” which includes information such as the transmission sequence start time and transmission sequence duration that STA 0 is scheduling, the transmission sequence recurrence interval, etc. In MSG- 00 , it is stated that the illustrated transmission sequence unit- 0 is scheduled from a time to.
Furthermore, although omitted in FIG. 2 , in every transmission sequence unit, information is transmitted from an access point to a plurality of terminals by using an RTS/CTS handshake like that illustrated in FIG. 14 , for example. In this specification, the series of sequences in which the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted between an information source and an information recipient is defined to be a “transmission sequence unit”.
Upon receiving the message MSG- 00 , STA 1 and STA 2 are able to obtain information on the future timing that STA 0 , the message source, is scheduling for the transmission sequence unit- 0 .
STA 1 and STA 2 , upon determining that frame transmission is not necessary until the start time t 0 of the next transmission sequence unit- 0 , may conduct power-saving operation until time t 0 .
The message MSG- 00 sent from STA 0 that includes “time information on a transmission sequence being scheduled by me” may be addressed and sent to just the stations in a communicating relationship with STA 0 in some cases, but since it is information that should also be received by stations on the other overlapping network, it is desirable that the message be addressed to a broadcast address and sent such that it will also be received by stations belonging to other logical networks.
STA 1 and STA 2 send time information containing the same content as the time information issued by STA 0 with MSG- 00 , in order to further propagate the time information for the transmission sequence unit- 0 being scheduled by STA 0 to nearby stations. In FIG. 2 , this corresponds to the message MSG- 02 sent by STA 2 . Meanwhile, since STA 1 is unable to confirm the existence of another nearby station, it determines that forwarding MSG- 00 to nearby stations is unnecessary, and in the illustrated example does not send a message equivalent to MSG- 02 . However, it may also be configured such that STA 1 does send a message equivalent to MSG- 02 , regardless of nearby station conditions.
Herein, The message MSG- 02 sent from STA 2 that includes “time information on a transmission sequence being scheduled by a peer” may be addressed and sent to just the stations in a communicating relationship with STA 2 in some cases, but since it is information that should also be received by stations on the other overlapping network, it is desirable that the message be addressed to a broadcast address and sent such that it will also be received by stations belonging to other logical networks.
STA 3 , upon receiving the message MSG- 02 sent by the nearby station STA 2 , is able to recognize the future timing at which STA 2 will conduct the transmission sequence unit- 0 . At this point, STA 3 may in some cases determine whether or not the timing of the transmission sequence unit- 0 to be used by STA 2 overlaps the timing of a transmission sequence unit to be used by STA 3 itself. In the case where it is determined that the two overlap, STA 3 sends the message MSG- 03 in FIG. 2 to STA 4 , its peer access point, in order to report the time information in MSG- 02 announced by STA 1 . It may also be configured such that STA 3 sends the message MSG- 03 to STA 4 without determining whether or not the transmission sequence unit timings overlap as above.
By decoding the contents of the message MSG- 03 received from STA 3 , STA 4 is able to ascertain the times at which there is a possibility that STA 3 will receive interference. Then, on the basis of this information, STA 4 schedules the schedule time for its own transmission sequence unit- 4 so as to not overlap with the transmission sequence unit- 0 . In the example illustrated in FIG. 2 , STA 4 arranges the transmission sequence unit- 4 , which includes frames addressed to STA 3 , starting from a time t 4 .
However, the principal matter of the present invention is not limited to a specific method for determining whether or not the transmission sequence units of respective logical networks overlap. For example, a methodology like that indicated in PTL 3 may be used in order to determine overlaps in transmission sequence units.
Additionally, STA 4 sends a message MSG- 44 containing schedule information for this transmission sequence unit- 4 as “time information” similar to the above. In MSG- 44 , it is stated that the transmission sequence unit- 4 is scheduled from time t 4 . Upon receiving the message MSG- 44 and decoding its contents, STA 3 and STA 5 obtain information on the future timing that STA 4 is scheduling for the transmission sequence unit- 4 .
The message MSG- 44 sent from STA 4 that includes “time information on a transmission sequence being scheduled by me” may be addressed and sent to just the stations in a communicating relationship with STA 4 in some cases. However, since it is information that should also be received by stations on the other overlapping network, it is desirable that the message MSG- 44 be addressed to a broadcast address and sent such that it will also be received by stations belonging to other logical networks.
The exemplary communication sequence for network collision avoidance illustrated in FIG. 2 assumes the case where terminals (STA 2 , STA 3 ) and not access points interfere with each other, as illustrated in FIG. 13 . In contrast, conditions may also exist wherein a terminal STA 1 directly interferes with an access point STA 4 other than the access point STA 0 to which STA 1 is connected (or housed inside), as illustrated in FIG. 17 .
In the case of the example illustrated in FIG. 17 , an outgoing message MSG- 01 from a terminal STA 1 is directly propagated to another access point STA 4 . Then, by decoding the contents of the message MSG- 01 , STA 4 is able to recognize the time slot to be used by the overlapping wireless network, and thus schedules the schedule time for its own transmission sequence unit- 4 so as to not overlap with the transmission sequence unit- 0 , as discussed earlier.
The messages used in the communication sequence illustrated in FIG. 2 (MSG- 00 , etc.) may be sent as action frames in which the “time information” is stated independently. An action frame is a type of management frame requesting that an action take place between stations, and is also defined in IEEE 802.11. Alternatively, “time information” or other information related to a transmission sequence unit may be sent contained in a frame such as a beacon frame or a probe response frame. A beacon frame is a frame for announcing information required for network operation, while a probe response frame is a response frame from an access point responding to a probe request frame sent from a terminal in order to detect a network. Both beacons and probe responses are also defined in IEEE 802.11 as frames in which typical control information is stated. Also, they may be contained in part of another typical frame.
FIG. 3 illustrates an exemplary communication sequence for the case where information related to a transmission sequence unit, such as “time information”, is transmitted using a beacon frame by an access point and transmitted using an action frame by a terminal given the network topology illustrated in FIG. 13 .
First, upon scheduling a transmission sequence unit- 0 , STA 0 sends a beacon frame stating information such as the “time information” (equivalent to MSG- 00 ) at a given beacon transmission timing.
Upon receiving the beacon frame from STA 0 , STA 1 and STA 2 are able to obtain information on the future timing that STA 0 is scheduling for the transmission sequence unit- 0 .
STA 2 sends an action frame stating the “time information”, etc. (equivalent to MSG- 02 ) in order to further propagate the time information for the transmission sequence unit- 0 being scheduled by STA 0 to nearby stations. Meanwhile, since STA 1 is unable to confirm the existence of another nearby station, it determines that forwarding information to nearby stations is unnecessary, and in the illustrated example does not send an action frame.
STA 3 , upon receiving the action frame MSG- 02 from the nearby station STA 2 , is able to recognize the future timing at which STA 2 will conduct the transmission sequence unit- 0 . At this point, STA 3 may determine whether or not the timing of the transmission sequence unit- 0 to be used by STA 2 overlaps the timing of a transmission sequence unit to be used by STA 3 itself. In the case where it is determined that the two overlap, STA 3 sends an action frame (equivalent to MSG- 03 ) to STA 4 , its peer access point, in order to report the “time information”, etc. Alternatively, it may be configured such that STA 3 sends an action frame to STA 4 without determining whether or not the transmission sequence unit timings overlap as above.
By decoding the contents of the action frame received from STA 3 , STA 4 is able to ascertain the times at which there is a possibility that STA 3 will receive interference. Then, on the basis of this information, STA 4 schedules the schedule time for its own transmission sequence unit- 4 so as to not overlap with the transmission sequence unit- 0 . After that, STA 4 sends a beacon frame stating information such as the “time information” (equivalent to MSG- 44 ) at a given beacon transmission timing.
Upon receiving the beacon frame MSG- 44 from STA 4 , STA 3 is able to obtain information on the future timing that STA 3 is scheduling for the transmission sequence unit- 4 . Then, STA 3 sends an action frame stating “time information” etc. (MSG- 43 ) in order to further propagate the time information for the transmission sequence unit- 4 to nearby stations.
After that, the access points STA 0 and STA 4 repeatedly send beacon frames containing information equivalent to MSG- 00 or MSG- 44 every time their respective beacon transmission timings are reached.
Also, FIG. 4 illustrates an exemplary communication sequence for the case of transmitting information related to a transmission sequence unit, such as “time information”, contained in typical frames when given the network topology illustrated in FIG. 13 . The method for including information in a frame discussed herein is also taken to include multiplexing. Also, in the illustrated example, “time information” is transmitted via an RTS/CTS handshake, and control frames such as RTS, CTS, and ACK are used as the typical frames. Furthermore, although these frames are referred to as RTS frames and CTS frames herein for the sake of convenience, these frames may be referred to by different names in some cases.
STA 0 conducts physical carrier sensing in advance and confirms that the medium is clear, and after additionally conducting a backoff, sends an RTS frame which indicates that STA 0 will transmit information to STA 1 and STA 2 by space-division multiple access. At this point, STA 0 includes information such as “time information” for the scheduled transmission sequence unit- 0 in the RTS frame by multiplexing.
In response to receiving an RTS frame, STA 1 and STA 2 contemporaneously transmit respective CTS frames (CTS- 1 , CTS 2 ) in order to indicate that they are in a state able to receive information. At this point, STA 1 and STA 2 include “time information”, etc. in the individual CTS frames in order to further propagate the time information for the transmission sequence unit- 0 being scheduled by STA 0 to nearby stations (hidden terminals to STA 0 ). Also, STA 1 and STA 2 also include “time information” for transmission sequence units on adjacent networks that was acquired from nearby stations in their CTS frames.
STA 0 , on the basis of the incoming signals of the received CTS- 1 and CTS- 2 , multiplies these signals by a wait value for each antenna element required for spatial separation, thereby separating and receiving the two signals. Additionally, STA 0 uses this wait value to contemporaneously transmit DATA frames (DATA- 1 , DATA- 2 ) to STA 1 and STA 2 . At this point, STA 0 includes information such as the “time information” for the scheduled transmission sequence unit- 0 in each DATA frame (DATA- 1 , DATA- 2 ).
DATA- 1 and DATA- 2 are frames transmitted by signals that are sent while taking into account the wait coefficients of the antennas such that interference does not occur at their destinations. STA 1 is able to receive DATA- 1 , while STA 2 is able to receive DATA- 2 .
Once STA 1 and STA 2 finish receiving their respective DATA frames, they contemporaneously reply with ACK frames (ACK- 1 , ACK- 2 ). At this point, STA 1 and STA 2 include “time information”, etc. in their individual ACK frames in order to further propagate the time information for the transmission sequence unit- 0 being scheduled by STA 0 to nearby stations (hidden terminals to STA 0 ). Also, STA 1 and STA 2 include “time information” for transmission sequence units on adjacent networks that was acquired from nearby stations in their ACK frames.
STA 0 then receives these ACK frames, thereby ending a sequence for transmitting data to multiple stations using space-division multiple access.
In the exemplary communication sequence illustrated in FIG. 4 , it is possible to reduce the overhead of transmitting independent frames such as action frames by including and transmitting such information in frames used to transmit data as discussed above. However, time information is not necessarily required to be included in all frames every time.
FIG. 5 illustrates an exemplary configuration of a time information element Time IE which states “time information” related to a transmission sequence unit. In the illustrated example, an information element is composed of the following fields.
(1) Element ID: an identifier indicating that the current element states time information.
(2) Length: indicates the length of the current element. (A time information element is variable-length in some cases.)
(3) Time: a value indicating the transmission time of the current frame.
(4) TXID: an identifier that identifies a transmission sequence unit. (The identifier is composed of a numerical value assigned by the station that determines the transmission sequence unit, and a flag that identifies sending/receiving. By referencing this flag, it can be determined by reference whether the current time information is information related to sending or information related to receiving.)
(5) SEQ Time: the scheduled start time for the transmission sequence unit (expressed on the basis of the time indicated in the above Time field).
(6) SEQ Duration: the scheduled duration of the transmission sequence unit.
(7) SEQ Interval: the interval (period) of the transmission sequence unit.
Herein, the above fields (4) to (7) are a single set that state “time information” for a one transmission sequence unit per set. By stating multiple sets of (4) to (7) in an information element Time IE, “time information” for a plurality of transmission sequence units can be expressed contemporaneously. Time information is transmitted in a form like the above.
With the communication sequences illustrated in FIGS. 2 to 4 , respective frames that perform the role of propagating “time information” may be used.
FIGS. 11A to 11C illustrated PSDU formats for respective RTS, CTS/ACK, and DATA frames defined in IEEE 802.11. In contrast, FIGS. 6A to 6E illustrate PSDU formats of respective RTS, CTS/ACK, DATA, action, and beacon/probe response frames in which time information elements are stated and which are used in the respective exemplary communication sequences illustrated in FIGS. 2 to 4 . The exemplary configuration of the Time IE field included in each frame is as illustrated in FIG. 5 , while other fields are as already explained. In the exemplary communication sequence illustrated in FIG. 4 , a time information element is added to the ordinary frame fields and sent in typical frames such as RTS, CTS/ACK, and DATA, as illustrated in FIGS. 6A to 6C . A time information element is stored in the payload and sent in management frames such as an action frame, as illustrated in FIG. 6D . Also, a time information element is added to other fields and information elements stated in an ordinary beacon or probe response and sent, as illustrated in FIG. 6E .
Also, with IEEE 802.11n which is related to high-speed communication, an Aggregated frame format is defined, which reduces overhead by constructing a single physical layer data unit from a plurality of frames (MPDUs (MAC Protocol Data Units) or MMPDUs (MAC Management Protocol Data Units). FIG. 7 illustrates an exemplary configuration in which a time information element is stated in part of an Aggregated frame that stores a plurality of MPDUs in a single PSDU. In the illustrated example, five MPDUs are aggregated. Of these, the first MPDU (MPDU- 1 ) is storing content equivalent to an action frame storing a time information element. The subsequent MPDUs (MPDU- 2 , MPDU- 3 , etc.) respectively store content equivalent to the data frame illustrated in FIG. 11A .
In the foregoing description, an infrastructure network composed of an access point and client devices connected thereto was taken by way of example. However, other forms of wireless network exist such as ad hoc networks or mesh networks, wherein respective stations autonomously control their behavior and establish links where each station has equal standing. Hereinafter, a method of operating a space-division multiple access system in accordance with the present invention will be explained, taking by way of example an ad hoc mesh network configured without a specific control station.
In the case where a specific control station does not exist on the network, each station determines transmission sequence timings for its own outgoing frames by itself. For example, in the case where there exist three autonomously operating stations STA 0 , STA 1 , and STA 2 communicating with each other, STA 0 determines timings for transmissions addressed to STA 1 and STA 2 . Similarly, STA 1 determines timings for transmissions addressed to STA 0 and STA 2 , while STA 2 determines timings for transmissions addressed to STA 0 and STA 1 .
In the following explanation, it is presumed that each of the stations STA 0 to STA 2 periodically send a beacon signal with the intention of announcing autonomous control information to individual nearby stations. Also, the respective stations STA 0 to STA 2 are taken to be provided with the ability to send a probe response frame as necessary upon receiving a probe request frame.
Stations STA 0 to STA 5 are arranged as illustrated in FIG. 13 and constitute a mesh network, or a plurality of overlapping wireless networks. In the same drawing, each station is a station that conducts autonomous operation, but each is only within radio wave range of its neighboring stations. Each station is using space-division multiple access to contemporaneously deliver data addressed to a plurality of stations. Also, STA 4 is using a space-division multiple access communication sequence like that illustrated in FIG. 14 to communicate with STA 3 and STA 5 . In the case where STA 1 wants to contemporaneously send data to STA 0 and STA 3 , STA 1 similarly transmits by space-division multiple access.
FIG. 8 illustrates an exemplary communication sequence controlled such that the transmission sequences of respective stations do not collide with each other in such an ad hoc communication environment.
STA 0 sends a beacon frame stating information such as “time information” for a scheduled transmission sequence unit (equivalent to MSG- 0 ) at a given beacon transmission timing.
Upon receiving the beacon frame from STA 0 , STA 1 and STA 2 are able to acquire information on the future timing that STA 0 is scheduling for a transmission sequence unit. Then, STA 1 and STA 2 schedule the schedule times of their own transmission sequence units on the basis of this information so as to not collide with STA 0 's transmission sequence unit.
Herein, STA 1 and STA 2 , upon determining that frame transmission is not necessary until the start time of the next transmission sequence unit, may conduct power-saving operation until that start time.
The message MSG- 0 containing time information may be addressed and sent to just the stations in a communicating relationship with the sending station in some cases, but since it is information that should also be received by stations on the other overlapping network, it is desirable that the message be addressed to a broadcast address and sent such that it will also be received by stations belonging to other logical networks.
Thus, STA 1 and STA 2 generate new time information by adding the time information for a transmission sequence unit to be received that was obtained from MSG- 0 from STA 0 to time information for their own transmission sequence units, and respectively send frames for propagating this time information to nearby stations. This is equivalent to the message that STA 1 sends as MSG- 1 and the message that STA 2 sends as MSG- 2 in FIG. 8 . Similarly to MSG- 0 , since MSG- 1 and MSG- 2 are information that should also be received by stations on the other overlapping network, it is desirable that the messages be addressed to a broadcast address and sent such that they will also be received by stations belonging to other logical networks. In FIG. 8 , STA 1 states and propagates the message MSG- 1 in an action frame, while STA 2 states and propagates the message MSG- 2 in a beacon frame and an action frame.
Also, STA 4 sends a beacon frame stating information such as “time information” for a scheduled transmission sequence unit (equivalent to MSG- 4 ) at a given beacon transmission timing.
STA 3 decodes the contents of the beacon frames individually received from STA 1 and STA 4 , and ascertains the times at which there is a possibility that it will receive interference. Thus STA 3 is able to schedule the schedule time for a transmission sequence unit to be used by STA 3 itself so as to not overlap with the transmission sequence units to be used by the respective nearby stations.
STA 2 also propagates a message MSG- 2 containing time information to nearby stations with an action frame.
Upon receiving the action frame from STA 2 , STA 0 and STA 3 obtain information on the future timing that STA 2 is scheduling for a transmission sequence unit. On the basis of this information, STA 0 and STA 3 schedule the schedule times of their own transmission sequence units so as to not overlap with STA 0 's transmission sequence unit.
Further explanation is omitted or reduced, but according to the exemplary communication sequence illustrated in FIG. 8 , each station generates “time information” collecting together its own transmission sequence unit time information with transmission sequence unit time information received from nearby stations, and propagates it to nearby stations.
The respective stations cross-reference their own transmission sequence unit time information with transmission sequence unit time information received from nearby stations, and schedule the times for their own transmission sequence units so as to not overlap with each other. As a result, the system as a whole is scheduled such that the transmission sequence units up to two hops ahead, for example, do not overlap. FIG. 9 illustrates how time information for transmission sequence units is reported via beacon frames transmitted every given beacon transmission timing, and how each station successively schedules a time for its own transmission sequence unit. Herein, detailed explanation of the method for determining whether or not transmission sequence units overlap in the present invention is omitted, but the principal matter of the present invention may use a methodology like that indicated in PTL 3, for example.
In the exemplary communication sequence illustrated in FIG. 8 , there is a case where each station sends transmission sequence unit “time information” as independently stated action frames, and a case where each station includes and sends “time information” in a frame that states typical control information, such as a beacon frame or a probe response frame. Also, although not drawn in FIG. 8 , “time information” may be included and sent in other typical frames such as RTS, CTS, DATA, and ACK by multiplexing, etc.
However, with an ad hoc mesh network, since each station sends beacon frames, propagating “time information” via beacon frames and action frames as illustrated in FIG. 8 is considered to be efficient.
Furthermore, with an ad hoc mesh network, a format similar to that illustrated in FIGS. 5 to 7 may be used as the frame format stating “time information”.
INDUSTRIAL APPLICABILITY
The foregoing thus describes the present invention in detail and with reference to specific embodiments. However, it is obvious that persons skilled in the art may make adjustments or substitutions to such embodiments within a scope that does not depart from the principal matter of the present invention.
In this specification, an embodiment applied to a new wireless LAN standard such as IEEE 802.11ac attempting to realize very high throughput of 1 Gbps was primarily described, but the principal matter of the present invention is not limited thereto. For example, the present invention may be similarly applied to other wireless LAN systems wherein wireless resources on a spatial axis are shared among a plurality of users, or to various wireless systems other than LAN.
In this specification, the series of sequences in which the learning of antenna coefficients and the transmission of information by space-division multiple access using learned antenna coefficients is conducted between an information source and an information recipient is defined to be a “transmission sequence unit”. A typical transmission sequence is a single RTS/CTS handshake as illustrated in FIG. 14 , but the principal matter of the present invention is not necessarily limited thereto. Also, in the case of ample TXOPs, etc., reverse direction information transmission from the information recipient (RTS receiving station) to the information source (RTS sending station), or in other words RDG (Reverse Direction Grant), may also be applied. For example, IEEE 802.11n defines an RD protocol in order to further increase the efficiency of data transmission in a TXOP.
In short, the present invention has been disclosed in the form of examples, and the stated content of this specification is not to be interpreted in a limiting manner. The principal matter of the present invention should be determined in conjunction with the claims.
REFERENCE SIGNS LIST
11 antenna
12 signal processor
13 physical layer processor
14 MAC layer processor
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Space-division multiple access is optimally realized while avoiding inter-network interference.
Time usage information for transmission sequence units is exchanged among different networks or non-adjacent equipment, and on the basis of this information, a station that initiates a transmission sequence unit disposes the start time of its own transmission sequence unit in a time slot which is not being used by an adjacent network or adjacent equipment. As a result, multiple wireless networks or wireless communication devices are able to utilize a channel by time division even in cases where exclusive placement of frequency channels is difficult, and efficient space-division multiple access can be realized.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 2003-37589, filed Jun. 11, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a linear compressor and a control method thereof.
[0004] 2. Description of the Related Art
[0005] A linear compressor is widely used to compress coolant in a freezing cycle such as a refrigerator, etc. The linear compressor measures the magnitude of a stroke of a piston, and controls an operation of the piston by applying a current to a driving motor of the linear compressor based on an analysis of the measured magnitude of the stroke of the piston.
[0006] FIG. 1 is a cross-sectional view of a position detection sensor of a piston of a conventional linear compressor. As illustrated in FIG. 1 , the position detection sensor comprises a sensor body 100 , a sensor coil 101 , a core support 102 , and a core 103 .
[0007] The sensor body 100 includes the sensor coil 101 inside. The sensor coil 101 has a first sensor coil 101 a connected in series to a second sensor coil 101 b having the same inductance value, size, and number of turns with those of the first sensor coil 101 a . The core support 102 made of non-magnetic material supports the core 103 and is combined to the piston (not shown).
[0008] As the core 103 combined to the piston of the compressor moves back and forth along an inner hole of the sensor body 100 , a predetermined reactance is generated in the sensor coil 101 according to the reciprocal movement of the piston.
[0009] FIG. 2 is a diagram of a position detection circuit of the piston of the conventional linear compressor. As illustrated in FIG. 2 , two serial sensor coils 101 are connected in parallel with two serial dividing resistors Ra and Rb, and a triangle pulse is inputted as a power source 105 . A difference of divided voltages divided by the dividing resistors Ra and Rb is amplified by an amplifier 104 to detect a maximum output voltage according to the piston in which the core 103 moves back and forth starting from a center point between the first sensor coil 101 a and the second sensor coil 101 b . An analog signal processor 106 receives an output pulse from the amplifier 104 and detects the position of the piston through a predetermined signal process.
[0010] FIG. 3 illustrates an output pulse from the amplifier 104 in FIG. 2 according to the reciprocal movement of the piston of the linear compressor. As illustrated in FIG. 3 , the output voltage from the amplifier (line “a”) has a linear output property for the reciprocal movement of the piston. The position of the piston can be detected with the output voltage because the output voltage is proportional to the position of the piston.
[0011] However, the sensor circuit of the conventional linear compressor may have the linear property varying an angle of a slope of the graph according to external environment such as a temperature and a pressure. If the sensor circuit of the conventional linear compressor takes the linear property represented by a small angle of the slope like a line “b” due to the external environment, the piston controlled according to a normal operation in a high cooling capacity may have a problem of colliding with a valve of a cylinder. Further variation of cooling capacity may excessively enlarge between a high cooling state and a low cooling state.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is an aspect of the present invention to provide a linear compressor that detects a position of a piston accurately regardless of external environmental conditions.
[0013] Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
[0014] The foregoing and/or other aspects of the present invention are achieved by providing a linear compressor having a core combined to one end of a piston to detect a position of the piston reciprocally moving up and down, and a first sensor coil and a second sensor coil detecting the position of the core, wherein the core comprises an upper core having a length shorter than one half of the length of the first sensor coil and the second sensor coil in series.
[0015] According to an aspect of the invention, the core includes an upper core; and a lower core spaced apart from the upper core by a predetermined distance.
[0016] According to an aspect of the invention, a middle point between the upper core and the lower core passes a middle point between the first sensor coil and the second sensor coil when the piston passes a center point of a reciprocal moving path of the piston.
[0017] According to an aspect of the invention, the linear compressor includes a first branch comprising the first sensor coil and a predetermined first dividing resistor connected in series; a second branch comprising the second sensor coil and a predetermined second dividing resistor connected in series; a source power applied to the first branch and the second branch; and a voltage comparator receives voltages applied to the first dividing resistor and the second dividing resistor as inputs.
[0018] According to an aspect of the invention, the voltage comparator receives voltages taken from the opposite terminals of each of the first sensor coil and the second sensor coil as the inputs.
[0019] According to an aspect of the invention, the linear compressor further includes a controller controlling the position of the piston based on a top dead center detected by measuring a difference of time taken for a center point of the upper coil to pass a coil origin, or a middle point between the first sensor coil and the second sensor coil, according to reciprocal movement of the piston.
[0020] According to an aspect of the invention, the linear compressor further includes a controller controlling the position of the piston based on a top dead center detected by measuring a difference of time taken for the center point of the upper coil to pass the coil origin, or the middle point between the first sensor coil and the second sensor coil, according to the reciprocal movement of the piston.
[0021] According to an aspect of the invention, the linear compressor includes a controller controlling the position of the piston by detecting a top dead center on a basis of a difference of time taken for an output of the voltage comparator to become 0 twice as the piston is positioned near the top dead center.
[0022] According to an aspect of the invention, the linear compressor includes a controller controlling the position of the piston by detecting a top dead center on a basis of a difference of time taken for the output of the voltage comparator to become 0 as the piston is positioned near the top dead center.
[0023] According to an aspect of the invention, the linear compressor includes a controller detecting an offset value indicating the degree of how far a center point of reciprocation movement of the piston is off from a predetermined center point by measuring a difference of time taken for a center point of the upper core to pass a coil origin positioned at a middle point between the first sensor coil and the second sensor coil, and by measuring a difference of time taken for a center point of the lower core to pass the coil origin according to the reciprocal movement of the piston.
[0024] According to another aspect of the present invention, the above and other aspect may be also achieved by providing a control method of a linear compressor having a core combined to one end of a piston moving up and down, and a first sensor coil and a second sensor coil detecting a position of the core, including forming the core comprising an upper core and a lower core being spaced from each other; detecting a top dead center of the piston by measuring a time taken for a center point of the upper core to pass a middle point between the upper coil and the lower coil according to reciprocal movement of the piston; and controlling a position of the piston on a basis of the top dead center.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompany drawings of which:
[0026] FIG. 1 is a cross-sectional view of a position detection sensor for a piston of a conventional linear compressor;
[0027] FIG. 2 is a diagram of a position detection circuit for the piston of the conventional linear compressor;
[0028] FIG. 3 is a waveform of an amplifier according to reciprocal movement of the piston of the conventional linear compressor in FIG. 2 ;
[0029] FIG. 4 is a cross-sectional view of a position detection sensor for a piston of a linear compressor according to an embodiment of the present invention;
[0030] FIG. 5 is a block diagram of a position detection circuit for the piston of the linear compressor according to the embodiment of the present invention;
[0031] FIGS. 6A-6C and 7 A- 7 C are waveforms of a voltage comparator according to reciprocal movement of the piston of the linear compressor;
[0032] FIG. 8 is an output waveform of the voltage comparator according to the position of the piston of the linear compressor according to the embodiment of the present invention;
[0033] FIGS. 9A and 9B illustrate the position of the piston according to the embodiment of the present invention corresponding to passage of time.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
[0035] FIG. 4 is a cross-sectional view of a position detection sensor for a piston of a linear compressor according to an embodiment of the present invention. As illustrated in FIG. 4 , a position detection sensor 40 comprises a sensor body 1 , a sensor coil 2 , a core support 3 , and a core 4 .
[0036] The sensor body 1 includes a sensor coil 2 inside. The sensor coil 2 comprises a first sensor coil 2 a connected in series with a second sensor coil 2 b . The first sensor coil 2 a and second sensor coil 2 b have the same inductance value, size, and number of turns. The core support 3 is made of non-magnetic material that supports the core 4 and is combined to the piston (not shown).
[0037] The core 4 comprises an upper core 4 a and a lower core 4 b respectively having a short predetermined length. The upper core 4 a and lower core 4 b are spaced apart from each other by a predetermined distance. The length of each of the upper core 4 a and the lower core 4 b should be preferably less than one half of the length of the sensor coil 2 comprising the first sensor coil 2 a and the second sensor coil 2 b . The upper core 4 a is connected to the lower core 4 b by the core support 3 .
[0038] As the core 4 combined to the piston of the compressor moves back and forth along an inner hole of the sensor body 1 , a predetermined reactance is generated in the sensor coil 2 according to the movement of the core 4 within the inside of the sensor coil 2 .
[0039] FIG. 5 is a block diagram of a position detection circuit for the piston of the linear compressor according to the embodiment of the present invention. As illustrated in FIG. 5 , the position detection circuit comprises the first sensor coil 2 a , the second sensor coil 2 b , a first dividing resistor R 1 , a second dividing resistor R 2 , a power source 10 , a voltage comparator 11 , a digital signal processor 12 , and a controller 13 .
[0040] The power source 10 applies power to a first branch having the first sensor coil 2 a and the first dividing resistor R 1 connected in series, and to a second branch having the second sensor coil 2 b and the second dividing resistor R 2 connected in series.
[0041] The voltage comparator 11 receives voltages taken from a corresponding terminal of each of the first dividing resistor R 1 and the second dividing resistor R 2 as a comparison signal V+ and a comparison signal V−, respectively. Also, the voltage comparator 11 may receive voltage taken from a terminal of each of the first sensor coil 2 a and the second sensor coil 2 b.
[0042] The digital signal processor 12 transmits a rectangular pulse to the controller 13 according to an output of the voltage comparator 11 , and then the controller 13 controls a driving motor (not shown) of the linear compressor based on the rectangular pulse.
[0043] FIGS. 6A through 6C and 7 A through 7 C are input waveforms of the voltage comparator 11 according to reciprocal movement of the piston of the linear compressor.
[0044] FIG. 6A represents a triangle pulse from the power source 10 , and FIG. 6B represents waveforms inputted to a positive terminal and a negative terminal of the voltage comparator 11 .
[0045] FIG. 6B represents the input waveform of the voltage comparator 11 when a center point (will be referred to as an upper core origin) of the upper core 4 a passes a middle point (will be referred to as a coil origin) between the first sensor coil 2 a and the second sensor coil 2 b , or compression when the piston reaches near a top dead center during a compression stroke. If the triangle pulse is applied from the power source 10 , an inductance L 2 of the second sensor coil 2 b becomes greater than an inductance L 1 of the first sensor coil 2 a during the negative portion of the triangle pulse input. Accordingly, the input waveform V− input into the negative terminal of the voltage comparator 11 has a longer time delay than the time delay of the input waveform V+ input into the positive terminal of the voltage comparator 11 .
[0046] As illustrated in FIG. 6C , the digital signal processor 12 generates a rectangular waveform Vd having a high level when the input waveform V+ of the positive terminal of the voltage comparator 11 is greater than the input waveform V− of the negative terminal.
[0047] FIG. 7A through 7C are waveforms when the upper core origin is inclined toward the first sensor coil 2 a from the coil origin. In this case, the inductance L 1 of the first sensor coil 2 a becomes greater than the inductance L 2 of the second sensor coil 2 b during the negative cycle of the triangle input. Accordingly, the input waveform V+input into the positive terminal of the voltage comparator 11 has a longer time delay in comparison with the input waveform V− as shown in FIG. 7B . FIG. 7C illustrates a rectangular waveform Vd output from the digital signal processor 12 corresponding to the waveforms in FIG. 7B .
[0048] FIG. 8 is a waveform that is output from the voltage comparator 11 according to a position of the piston of the linear compressor according to an embodiment of the present invention. As illustrated in FIG. 8 , a waveform “c” has three zero points and corresponds to the input waveforms illustrated in FIGS. 6B and 7B .
[0049] The output waveform of the voltage comparator 11 passes through a first zero point as a middle point (will be referred to as a core origin), between the upper core 4 a and the lower core 4 b , passes the coil origin.
[0050] An output V 0 of the voltage comparator 11 has a second zero point in a top area if the upper core origin of the upper core 4 a passes the coil origin, and the output V 0 of the voltage comparator 11 has a third zero point in a bottom area if the center point of the lower core 4 b passes the coil origin.
[0051] When the output V 0 of the voltage comparator 11 is at the second zero point during the compression stroke of the piston, the piston is at a top origin position. The top origin position is also passed during an extension stroke. The top origin is a fixed position, and an exact position of the top dead center can be estimated by measuring the amount of time that the piston takes to pass the top origin twice, once during the compression stroke and once during the extension stroke.
[0052] Also, the position of the top dead center can be estimated based on the duration of time that passes before the output V 0 of the voltage comparator 11 passes the second zero point having a zero output in the top area twice.
[0053] A waveform “d” in FIG. 8 is the output waveform V 0 of the voltage comparator 11 when the external environmental conditions of the sensor such as a temperature, and pressure have changed. The waveform “d” illustrates that the zero points do not vary regardless of changes to the external environment. Accordingly, the top dead center can be found accurately on the basis of the top origin that is not affected by the external environment, and the position of the piston can be controlled based on the aforementioned.
[0054] FIGS. 9A and 9B illustrate magnitude of a stroke of the piston of the linear compressor according to an embodiment of the present invention corresponding to passage of time. As illustrated in FIG. 9A , the stroke of the piston appears as a sine waveform “E” according to the passage of the time. The magnitude of the stroke of the piston appears as a sine waveform “F”, in a case where the core origin does not match to the coil origin and gets inclined to the top dead center, that is, an offset occurs, when the piston is in a middle point of a reciprocal moving path.
[0055] Even for such cases, the stroke of the piston can be controlled because the top dead center can be measured based on a measured time that the piston takes to pass the top origin twice.
[0056] If the position of the lower core 4 b is inclined near to the coil origin, the bottom origin is adjusted upward to the coil origin in FIG. 9A . With such a configuration, an offset value indicating the degree that the center point of the reciprocal moving path of the piston is off from a predetermined center point can be detected by measuring an elapsed time that the piston takes to pass the altered bottom origin twice and by measuring the time that the piston takes to pass the top origin twice.
[0057] FIG. 9B illustrates the output waveform Vd of the digital signal processor 12 corresponding to curved lines E and F in FIG. 9A .
[0058] Also, even if the core 4 includes only the upper core 4 a , the output waveform V 0 of the voltage comparator 11 has the second zero point in the top area, and the top dead center can be estimated in the same manner on a basis of duration for passing the top origin.
[0059] The position of the piston of the linear compressor can be measured and controlled according to this embodiment of the present invention.
[0060] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A linear compressor having a core combined to one end of a piston to detect a position of the piston reciprocally moving up and down. A first sensor coil and a second sensor coil detect the position of the core. The core has an upper core having a length shorter than one half of the length of the first sensor coil and a lower core having a length shorter than one half of the length of the second sensor coil in series. A method of controlling the operation of the linear compressor includes timing the upper core and the lower core driven by the piston through a stroke cycle, receiving the time and calculating a top dead center position based on the time or an offset value respectively, and controlling a piston stroke by varying the power driving the linear compressor according to the calculated top dead center or offset value.
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This application is a continuation of application Ser. No. 08/772,815, filed Dec. 24, 1996, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a device for punching apertures in a sheet of material. More particularly, the present invention is a hand operated punching device for making apertures in a sheet of material suitable for holding a smaller sheet of material, such as a business card.
Business cards are used by many people to identify themselves and their company/organization that they are associated with. The business cards are small in form and can be easily carried and organized. It is quite common for a person to attach a business card to correspondence, reports, brochures or other documents. Typically, the business card is either stapled or clipped to the item. Stapled business cards are not easy to remove and the stapling process damages the business cards. "Paper-clipping" the business card to the document is also not a satisfactory solution since paper-clipping also damages the business card and the business card can be easily separated from the document.
In addition to stapling or paper-clipping business cards to documents, some devices have been advanced for forming spaced-apart parallel slits in the document. The slits are suitably sized to receive opposite corners of a business card. U.S. Pat. Nos. 4,893,435 and 4,879,932 disclose two such devices. In both of these devices, a pair of slitting blades extend downwardly from an upper platen and are sized, positioned and arranged to form the spaced-apart parallel slits. In U.S. Pat. No. 4,893,535, the upper platen moves generally normal to the sheet of paper wherein the operator exerts downward pressure upon an upper surface of the platen. In U.S. Pat. No. 4,879,932, the upper platen pivots on a pin forming a hinge with a lower base. The slitting blades pivot with respect to the pin when downward force is applied to the platen.
One disadvantage of the above-described devices is that neither device makes apertures in the document, but rather, only small slits. Insertion of the business cards into the slits is not particularly easy. The cutting devices are also only blades, which can dull easily with use. Therefore, there exists a need to provide a hand operated punching device that forms apertures in a sheet of paper suitable for holding a business card, the device being constructed to withstand repeated and continuous use.
SUMMARY OF THE INVENTION
A punching device for punching an aperture in a sheet includes a housing and a handle pivotally joined to the housing with a first pivot connection. A drive plate is slidably displaceable in the housing. The drive plate includes a protrusion extending from a surface. The drive plate is preferably pivotally joined to the handle with a second pivot connection remote from the first pivot connection. A punch is disposed in the housing and operably engages the protrusion of the drive plate such that displacement of the drive plate in the housing causes operation of the punch.
In a preferred embodiment, a plurality of punches are provided in the housing. Each punch operably engages a protrusion formed on the drive plate. Preferably, the protrusions comprise ramp structures such that displacement of the drive plate in a horizontal direction causes the punches to be displaced in a vertical direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a punching device of the present invention.
FIG. 2 is a sectional view of a punching device taken lines 2--2 of FIG. 1.
FIG. 3 is an exploded perspective view of the punching device.
FIG. 4 is a top plan view of a housing of the punching device.
FIG. 5 is a bottom plan view of the housing.
FIG. 6 is a perspective view of a drive plate an upper surface thereof.
FIG. 7 is a perspective view of the drive primarily a lower surface thereof.
FIG. 8 is a perspective view of a punch having a roller assembly.
FIG. 9 is a perspective view of a cover primarily illustrating an upper surface thereof.
FIG. 10 is a perspective view of the cover primarily illustrating a lower surface thereof.
FIG. 11 is a portion of a sheet of material illustrating location of apertures made by the punching device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A punching device 10 of the present invention is illustrated in FIGS. 1, 2 and 3. In the embodiment illustrated, the punching device 10 includes a housing 12 having a base portion 14 and an upper portion 16. A handle generally indicated at 18 is pivotally attached to the housing 12 with a pivot pin 20. A drive plate 22 is preferably joined to the handle 18 with a pivot pin 24 that is spaced-apart from the pivot pin 20. A lower surface 26 of the drive plate 22 includes protrusions 28 that engage punches 30 disposed within the upper portion 16.
A sheet of material 44 (FIG. 11) to be punched is positioned within a slot 32 formed between an upper surface 34 of the base portion 14 and a lower surface 36 of the upper portion 16. When the handle 18 is pushed downwardly in a direction indicated by arrow 38 toward the upper portion 16, the handle 18 urges the drive plate 22 in a direction indicated by arrow 40, which in turn, urges the punches 30 toward the base portion 14 to punch one or more apertures 42 in the sheet of material 44 as illustrated in FIG. 11. Unlike prior art devices previously advanced, the punching device 10 of the present invention provides apertures 42 rather than slits, which allow easy insertion of a smaller card, such as a business card, not shown, into the apertures 42.
Referring now to individual components of the punching device 10, the housing 12 is preferably formed from a single unitary piece wherein the base portion 14 is integrally attached to the upper portion 16. In the embodiment illustrated, a connecting portion 50 proximate the pivot pin 20, joins the base portion 14 to the upper portion 16. If desired, the base portion 14 can be manufactured separate from the upper portion 16 and attached thereto with suitable fasteners and/or welds, adhesives or the like. The slot 32 for accepting the material 44 to be punched is relatively narrow between the surfaces 34 and 36 to limit the thickness of the material which will be punched. The slot 32 opens to a wider portion indicated at 52. The wider portion 52 allows the sheet of material 44 to be easily grasped and pulled in order to align the sheet of material 44 with the punches 30 at the desired location.
In a preferred embodiment, the upper surface 34 includes a step assembly 54 comprising steps 55 of increasing height from the punches 30 and toward the connecting portion 50. The step assembly 54 provides forward facing surfaces 56 that an operator can use to control the location of apertures 42 to be punched in the sheet of material 44 from an edge of the material 44 contacting the forward facing surfaces 56. In FIG. 2, the heights of the individual steps 55 of the step assembly 54 have been exaggerated in order to enhance understanding. The height of each of the individual forward facing surfaces 56, for example, can be 0.010 of an inch.
In an alternative embodiment illustrated in FIG. 3, lines 57, such as by engraving, can be provided on the upper surface 34. The lines 57 function as reference markers to be used by the operator for locating the apertures 42 as desired in the sheet of material.
The upper portion 16 includes a support portion 58 extending from the connecting portion 50 and a wider container portion 60. Preferably, the support portion 58 is narrower than the container portion 60 to provide an open area 62 behind the container portion 60 such that the sheet of material 44 can be easily grasped after insertion in the slot 32. In the embodiment illustrated, the container portion 60 includes an upwardly facing opening 64 of a void 66 formed in the container 60. The void 66 includes an enlarged recess 68 and individual bores 70 for the punches 30. Each bore 70 opens to the slot 32 with an opening 72 smaller than the corresponding bore 70.
Referring also to FIG. 8, each punch 30 includes a cutting head 76 that preferably extends into the opening 72 in a retracted position so as to maintain the alignment of the punch 30 with the opening 72. A shaft portion 78 couples the cutting head 76 to an enlarged cap member 80. The cap member 80 forms an annular flange 82. As illustrated in FIGS. 2 and 3, a spring 84 is disposed in each of the bores 70 to engage a lower surface thereof and also engage the annular flange 82 of each corresponding punch 30. Springs 84 individually retract the punches 30 after displacement downwardly towards the base portion 14. Preferably, the cutting heads 76 are received by apertures 87 in dies 88 disposed in the base portion 16. The dies 88 are located in suitable recesses 89 and held therein by suitable fasteners such as snap rings 90. Referring also back to FIG. 1, a cover 91 removably attaches to the base portion 14 to form a recess 93 to collect punched material. A cover plate 95 attaches to the base portion 14 and covers an aperture 105 (FIG. 5) convenient for manufacture by casting.
As described above, the punches 30 are displaced toward the base portion 14 by the drive plate 22. Referring to FIG. 2, 6 and 7, an upper portion 92 of each of the punches 30 engages one of the protrusions 28 formed on the lower surface 26 of the drive plate 22. In a preferred embodiment, the upper portions 92 comprise rollers 94 that engage the protrusions 28. The rollers 94 reduce friction between the punches 30 and the protrusions 28. If desired, the upper portions 92 can be a rigid solid element that engages the protrusions 28.
In the embodiment illustrated, the protrusions 28 comprise ramp structures. The ramp structures 28 are particularly useful because as the springs 84 expand to return the punches 30 to the retracted position, the drive plate 22 is urged in a direction opposition to arrow 40 to return the handle 18 to its upright position. In a further embodiment, some of the ramp structures 28, for example, two out of four, include flat portions 100. The flat portions 100 reduce the force trying to return the handle 18 to its upright position. Specifically, as the drive plate 22 is displaced in the direction of arrow 40, some of the rollers 94 would reach and engage the flat portion 100 while the remaining rollers 94 would still engage the inclined portion of the ramp structures 28. Since only those rollers 94 that are engaging the inclined portions of the ramp structures 28 contribute to the net force tending to return the handle 18 to its upright position, the amount of force at the end of stroke of displacement of the drive plate 22 to hold the punches 30 down is reduced.
The drive plate 22 is coupled to the handle 18 through a drive shaft 102. The drive shaft 102 extends from the handle 18 through a bore 103 formed in the rigid support portion 58 that opens to the recess 68. The drive plate 22 is attached to an end of the drive shaft 102 with a fastener 106 located in a recess 107 of the drive plate 22.
A cover plate 110 illustrated in FIGS. 2, 3, 9 and 10 closes the opening 64. The cover plate 110 slides onto the container portion 60 wherein perimeter portions of an upper surface 111 of the cover plate 110 engages a perimeter flange 112. Suitable fasteners 118 retain the cover plate 110 in position. The drive plate 22 slides upon a lower surface 113 of the cover plate 110. Preferably, spaced-apart, machined surfaces 115 are provided on the drive plate 22 (FIGS. 6 and 7) to engage the cover plate 110 in order to provide smooth operation.
Removal of the cover plate 110 and the drive plate 22 from the drive shaft 102 allows access to the punches 30. By merely removing selected punches 30 from the bores 70, the operator can configure the punching device 10 to punch a selected number of apertures 42 having a selected arrangement.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A punching device for punching an aperture in a sheet includes a housing and a handle pivotally joined to the housing with a first pivot connection. A drive plate is slidably displaceable in the housing. The drive plate includes a protrusion extending from a surface. The drive plate is preferably pivotally joined to the handle with a second pivot connection remote from the first pivot connection. A punch is disposed in the housing and operably engages the protrusion of the drive plate such that displacement of the drive plate in the housing causes operation of the punch.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part application, which claims priority to the U.S. patent application having Ser. No. 11/157,730, filed Jun. 21, 2005 now U.S. Pat. No 7,882,638, the entirely of which is incorporated herein by reference.
FIELD
The present embodiments relate, generally, to bearings and wear resistant services and processes for producing bearings and wear resistant surfaces for use in downhole tools and products, including but not limited to radial and linear bearings for downhole turbines, jaws, motors, and other similar apparatuses, the manufacturing processes usable both within a bearing housing and external to a bearing housing.
BACKGROUND
When drilling a well, a downhole motor is used to provide a rotational force to a drill bit via a rotating drive shaft, also called a mandrel. The mandrel is rotated within a bearing housing. The rotation of the mandrel relative to the bearing housing can create significant amounts of friction, which can quickly wear down components, and can cause deformation, overheating, and other types of damage.
Bearing assemblies have been developed to compensate for these difficulties, conventional bearing assemblies being usable to resist and withstand the friction created when a central shaft rotates within a housing. Prior techniques and assemblies include use of a coating process about the mandrel and inner diameter of the housing, use of carbide inserts, and use of standard roller and ball bearings. Prior coating techniques include various means for applying a facing surface to a bearing, such as welding, spraying, plating, or various manual techniques.
Prior coating processes generally include adhesion and fusion processes. Fusion is typically more reliable than adhesion due to the fact that when fusion is used, a coating material is melted partially into the carrier metal to form a superior bond. Use of fusion normally requires a significant amount of heat, in excess of 800 or 900 degrees Fahrenheit, to melt the surface of materials, which can often disadvantageously affect the metallurgical properties of the bearing housing, mandrel, and other components subjected to the high temperatures. In addition, extreme heat can dilute the fused material into the substrate, causing undesired intermingling and creating an unsuitable coating.
Further, fusion processes require large apparatuses for application of material and for heating, causing the performance of fusion operations to be impossible within restricted spaces, such as surfaces within an assembled bearing housing.
As a result, conventional bearings often have a first hard facing surface disposed over a mandrel, formed using a fusion process, while a second opposing hard facing surface disposed along the inner surface of the bearing housing is formed using a differing material and/or a differing process. Often, the exterior hard facing surface along a housing member is worn out more quickly than the interior hard facing surface along a drive shaft, limiting the useful life of a conventional radial bearing to about 300 operating hours, requiring frequent costly and time consuming replacement.
Attempts to overcome this difficulty have typically focused on the types of materials used to form bearing surfaces, however attempted improvements to bearings and wear resistant surfaces have resulted in only negligible increases in the operational life of these surfaces due to the difficulties inherent in forming a fused hard facing surface along the interior of a housing.
Other prior attempts to overcome these difficulties have included use of a “dummy” tubular sleeve, over which interior facing materials and an external layer can be applied and fused together, using the same process and materials. The tubular sleeve can then be machined and/or ground away, so that only the interior facing layer and the external layer remain. The resulting product can then be installed over a mandrel within a bearing housing, however use and destruction of an additional tubular sleeve is a time-consuming and costly process.
A need exists for a method for producing a radial bearing or similar wear resistant surface, the method being usable within a bearing housing, thereby eliminating the need for a “dummy” tubular sleeve and related manufacturing steps, such as shrink-fitting components to engage the tubular sleeve, thereby significantly reducing the time and cost required for manufacture of the radial bearing or wear resistant surface. Additionally, the production of a wear resistant surface within a bearing housing, eliminating the need for bulky inserts, would conserve space within the housing, enabling a mandrel having a greater diameter to be installed for accommodating high torque and/or side loading applications.
A further need exists for a method for producing a radial bearing or similar wear resistant surface using fusion to associate an interior facing layer with an external layer, providing a radial bearing capable of high side load applications and a useful life of 1200 to 1500 operating hours, or more, as compared to a useful life of 300 operating hours for a conventional radial bearing or wear resistant surface.
A need also exists for a method for producing a radial bearing or similar wear resistant surface having opposing hard facing layers using comparatively low energy, which maintains the temperature of the bearing housing and other components as low as 400 degrees Fahrenheit, or less, to avoid changing the metallurgical properties of the components.
The present embodiments meet these needs.
SUMMARY
In an embodiment, the present method can include providing a housing having a matching member installed therein. A first hard facing layer can be mounted over the outer surface of the matching member, and a second hard facing layer can be concentrically disposed over the first hard facing layer, mounted within the inner surface of the housing.
In a further embodiment, the present method includes providing a bearing housing having a mandrel installed therein. A laser configured for insertion into the bearing housing is provided, such that the laser beam or a portion of the laser is inserted into the bearing housing.
In another embodiment, the present method can include providing a bearing sleeve having a mandrel installed therein. A laser configured for insertion into the bearing sleeve can be provided, such that the laser beam or a portion of the laser is inserted into the bearing housing.
In an embodiment, the laser can include an inner diameter laser, such as a high power direct diode laser, which advantageously requires less energy to operate than larger lasers, thereby applying less heat to the bearing housing and/or the mandrel. As a result, the bearing housing, the mandrel, and other associated components can be retained at a temperature of 400 degrees Fahrenheit, or less, preventing negative changes to the metallurgical properties of the components that can be caused by excessive heat. Further, during operation, an inner diameter laser produces a very small affected zone, heating only a very small area of the mandrel and/or the bearing housing when used, further avoiding any disadvantageous metallurgical affects.
In an alternate embodiment, a plasma transferred arc device can be provided in lieu of a laser.
A fusible material, which can include any material able to be connected to another material through a fusion process, is applied to the inner surface of the housing and to the outer surface of the mandrel, or to other base surfaces used in lieu of a mandrel and/or bearing housing, while using the laser to heat and melt the base material of the base surface locally, creating a puddle, such that the fusible material is positioned into the puddle, heated, and melted, thereby connecting the fusible material with the base material. In an embodiment, the fusible material can include a powder containing tungsten carbide, cobalt, nickel, silicon carbide, ceramic, other hard facing materials, or combinations thereof. A first hard facing layer is thereby formed over the outer surface of the mandrel, while a second hard facing layer is formed over the inner surface of the bearing housing. In an embodiment, the fusible material can be projected toward the point of contact between the laser and the bearing surfaceunder an inert gas, such as nitrogen, helium, krypton, argon, or other similar inert gases.
The hard facing layers can then be machined, using any conventional machining technique, to form opposing hard facing surfaces.
Throughout the process, the temperature of the bearing housing, the mandrel, and all associated components can be retained at or below 400 degrees Fahrenheit.
In an embodiment, a male bearing insert can be disposed over the mandrel, and/or a female bearing insert can be disposed over the male bearing insert and inserted into a bearing housing, and the respective inner and outer surfaces of the inserts can have the hard facing layers formed thereon. The male and female bearing inserts, the bearing housing, and/or the mandrel can include any material sufficiently durable to withstand the temperature and pressure of downhole operations, and sufficiently ductile to absorb the shock and load of the drilling process, such as carbon steel, stainless steel, inconel, aluminum, other similar metals, or combinations thereof.
In a further embodiment, the present method can include manufacturing a hard facing layer by engaging a first bearing layer, disposed within a bearing housing, with a fusible material, while using a laser to heat the fusible material to form a first hard facing layer. A second hard facing layer can be separately provided to form a radial bearing. In an embodiment, a second bearing layer can be simultaneously or alternatively engaged with the fusible material while heating using the laser to form a second hard facing layer over the second bearing layer. The hard facing layers can then be machined to form suitable hard facing surfaces.
The present embodiments also relate to an alternate method for manufacturing a radial bearing. A bearing housing and a mandrel are provided, as described previously. A first bearing layer is mounted over the outer surface of the mandrel, and a second bearing layer is provided over the first bearing layer, mounted within the inner surface of the bearing housing.
A laser, as described previously, is inserted into the bearing housing, and a fusible powder is applied to the first and second bearing layers while using the laser to connect the fusible powder to the bearing layers, thereby forming hard facing layers on the bearing layers. The hard facing layers are then machined to form opposing hard facing surfaces.
Through use of a laser cladding fusion process, a very strong metallurgical bond is provided between the resulting bearing/wear resisting layers and base material surfaces, forming a high-performance bearing capable of high torque and side load applications, having an extended operational life expectancy. Additionally, laser fusing enables the bearing/wear resisting layers to be fused to the base material surfaces using a minimum of energy, while affecting only a small zone of the base surfaces on which the hard facing layers are formed, thereby minimizing the dilution of the fusible material into the base surfaces, regardless of the speed at which the fusion process is performed. The small area of the bearing layer that is affected by the heating serves to strengthen the bond between the hard facing surface and the bearing layer. Further, use of a controlled laser can provide lower porosity surfaces having a uniform thickness and finish, reducing or eliminating the need for any post-machining steps and resulting in an optimal coating with well-controlled thickness.
The present methods are thereby usable to manufacture a radial bearing efficiently and cost-effectively, within a bearing housing, the radial bearing having a useful life expectancy of 1200 to 1500 operating hours, or longer.
Additionally, due to the ability of the present methods to form a coating of a controllable thickness directly to a base surface on a mandrel and/or a bearing housing, conventional bulky inserts are not required, thereby conserving a considerable quantity of usable space within the bearing housing. This feature of the present invention allows a mandrel having a larger diameter to be utilized within the bearing housing, enabling mud motors that incorporate bearings produced using the present methods to perform higher torque and side loading applications.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the embodiments presented below, reference is made to the accompanying drawings, in which:
FIG. 1 depicts a cross-sectional view of a mandrel disposed in a bearing housing containing bearings manufactured through use of the present embodiments.
FIG. 2 depicts a cross-sectional view of a mandrel within a lower housing of a mud motor, containing bearings produced through use of the present embodiments.
The present embodiments are detailed below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that the embodiments can be practiced or carried out in various ways.
Referring now to FIG. 1 , a cross-sectional view of a mandrel ( 42 ) disposed within a bearing housing ( 12 ) is depicted. The mandrel ( 42 ) is configured for engagement with a drill bit and is designed to rotate within the bearing housing ( 12 ) while the bearing housing ( 12 ) remains stationary, thereby imparting rotational force to the drill bit to enable drilling of a well.
To prevent damage to the mandrel ( 42 ), the bearing housing ( 12 ), and/or any other attached components or equipment, a radial bearing ( 14 ) is depicted installed concentrically about the mandrel ( 42 ), within the bearing housing ( 12 ). While FIG. 1 depicts a radial bearing installed within a bearing housing, it should be noted that the present embodiments can be used to form similar wear resistant surfaces for a variety of downhole tools and other applications, in addition to radial bearings for protecting a downhole mud motor.
The mandrel ( 42 ) is shown having an outer surface ( 23 ) with a first bearing layer ( 16 ) disposed thereon. The first bearing layer ( 16 ) can be integral with the mandrel ( 42 ), welded to the mandrel ( 42 ), or secured using other means, such that the first bearing layer ( 16 ) rotates concurrent with the rotation of the mandrel ( 42 ) during drilling operations. For purposes of this application, the term mandrel includes all components engaged with the mandrel that experience rotatable and/or slidable motion concurrent with the mandrel.
The first bearing layer ( 16 ) has a first hard facing surface ( 18 ) formed thereon. The first hard facing surface can be formed by fusing a powdered fusible material, such as tungsten carbide, silicon carbide, cobalt, nickel, ceramic, and/or other similar materials, then machining the resulting layer to form the first hard facing surface ( 18 ).
A second bearing layer ( 20 ) is shown concentrically disposed over the first bearing layer ( 16 ), mounted within the bearing housing ( 12 ). The second bearing layer ( 20 ) can be secured integral with the inner surface of the bearing housing ( 12 ), or secured to the bearing housing ( 12 ) using welding or similar means, such that the second bearing layer ( 20 ) remains stationary with respect to the mandrel ( 42 ) and the first bearing layer ( 16 ) during.
The second bearing layer ( 20 ) has a second hard facing surface ( 22 ) formed thereon, which can be produced using materials and processes similar to those of the first hard facing surface ( 18 ).
The hard facing surfaces ( 18 , 22 ) can be formed along their respective bearing layers ( 16 , 20 ) within the bearing housing ( 12 ) through use of a laser ( 44 ) adapted for insertion into the bearing housing ( 12 ), such as an inner diameter laser. Alternatively, a plasma transfer arc technique could also be used to fuse a powdered fusible material to the bearing layers ( 16 , 20 ). The mechanical and physical properties of the second bearing layer ( 20 ) and second hard facing surface ( 22 ) can be similar to those of the first bearing layer ( 16 ) and first hard facing surface ( 18 ), or the differing bearing layers ( 16 , 20 ) and hard facing surfaces ( 18 , 22 ) can have differing properties. For example, in an embodiment, the second hard facing surface ( 22 ) within the bearing housing ( 12 ) can be formed using an inner diameter laser, while the first hard facing surface ( 18 ) on the mandrel ( 42 ) is formed using other means, resulting in hard facing surfaces having differing properties.
However, it is an advantage of the present invention that opposing hard facing surfaces ( 18 , 22 ) associated with both the mandrel ( 42 ) and the bearing housing ( 12 ) can be formed using similar materials and processes, ensuring an approximately equal operational life and even wear on both hard facing surfaces ( 18 , 22 ). Typically, the interior hard facing surface of a conventional radial bearing housing will wear down and fail before the exterior hard facing surface along the mandrel requires replacement.
Through use of the described processes, the bearing layers ( 16 , 20 ) and hard facing surfaces ( 18 , 22 ) can be substantially thinner than conventional bearing materials, conserving space within the bearing housing ( 12 ), thereby enabling the mandrel ( 42 ) to have a diameter greater than those used in conventional bearing assemblies. The improved thickness of the mandrel ( 42 ) enables the mandrel ( 42 ) to be utilized for applications requiring greater stress and/or higher torque.
The formation of the hard facing surfaces can be performed by maneuvering the laser and fusible material from a first end of a radial bearing to a second end. However, when providing a wear resistant surface to a component having a smaller diameter-to-length ratio, which can be more significantly affected by the heat of the laser, it can be desirable to move a laser from the center of the component toward a first end to form a first portion of the wear resistant surface, then from the center of the component toward the second end to form the remainder of the wear resistant surface. The temperature of the component is thereby controlled to prevent negative modifications to the material properties of the component caused by excessive heat.
Typically, the laser can be maneuvered in a linear direction within a housing or sleeve, such as by using a mechanical and/or robotic apparatus, while the housing or sleeve is rotated, to form the hard facing layer throughout the desired portion of the interior of the housing or sleeve. Other methods are also usable, such as moving the housing or sleeve in both a linear direction and a rotational direction while the laser remains stationary.
Referring now to FIG. 2 , a cross-sectional view of an embodiment of a mandrel ( 42 ) within the bearing housing ( 12 ) of a mud motor is shown. The bearing housing ( 12 ) is shown having a first housing segment ( 11 ) threaded to a second housing segment ( 13 ). The mandrel ( 42 ) includes a mandrel extension ( 43 ) threaded thereto. The mandrel ( 42 ) is the rotational component of a mud motor, and has a first end ( 10 ) configured for attachment to a drill bit for drilling a well by imparting rotational force to the drill bit.
The mandrel ( 42 ) has an outer surface ( 23 ) with which a first lower radial bearing layer ( 16 ) and a first upper radial bearing layer ( 17 ) are integrated. The bearing housing ( 12 ) has a second lower radial bearing layer ( 20 ) integrated therewith, concentrically disposed about the first lower radial bearing layer ( 16 ). The bearing housing ( 12 ) further has a second upper radial bearing layer ( 21 ) associated therewith, concentrically disposed about the first upper radial bearing layer ( 17 ).
Each of the bearing layers ( 16 , 17 , 20 , 21 ) has a hard facing surface (depicted in FIG. 1 ) formed thereon, such that the opposing surfaces of the lower radial bearing layers ( 16 , 20 ) and those of the upper radial bearing layers ( 17 , 21 ) abut during drilling operations for resisting wear as the mandrel ( 42 ) and first bearing layers ( 16 , 17 ) rotate, while the bearing housing ( 12 ) and the second bearing layers ( 20 , 21 ) remain stationary with respect to the mandrel ( 42 ) and first bearing layers ( 16 , 17 ).
With the mandrel ( 42 ) inserted in the bearing housing ( 12 ), a cavity is defined between the upper and lower sets of radial bearing layers ( 16 , 17 , 20 , 21 ), within which a plurality of thrust bearings ( 24 ) are disposed. The thrust bearings ( 24 ) transmit the axial load from a drill string ( 26 ) engaged with the bearing housing ( 12 ) via the mandrel ( 42 ) to a drill bit engaged with the mandrel ( 42 ).
In operation, the hydraulic horsepower of the drilling fluid causes the mandrel ( 42 ) to rotate, which imparts a rotational force to an attached drill bit, for boring a bore hole. The abutting hard facing surfaces of the bearing layers ( 16 , 17 , 20 , 21 ) allow rotation of the mandrel ( 42 ) relative to the bearing housing ( 12 ) while minimizing abrasive wear there between. The radial bearings clutch radial forces and allow stabilization of the mandrel ( 42 ) relative to the housing ( 12 ) during drilling operations. These abrasive forces can be significant, as a typical mud motor can rotate at 100 to 300 revolutions per minute, or more, thus the improved durability of the radial bearings produced using the present methods is extremely desirable.
While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.
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Methods for manufacturing bearings and wear resistant surfaces usable in various downhole tools are described herein. A housing is provided. A laser configured for insertion into the housing, such as an inner diameter laser, is used to connect a fusible material to the inner surface of the housing or an insert disposed therein to form a hard facing layer on the inner surface. Simultaneously or independently, the laser can be used to connect the fusible material to the outer surface of a mandrel within the housing to form a second hard facing layer. The present methods thereby produce durable radial bearings having extended operational life, which can be produced within a bearing housing, or externally for transport and installation in existing bearing housings.
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CROSS REFERENCE TO RELATED APPLICATIONS
This present application is a continuation application of application Ser. No. 14/182,900, filed Feb. 18, 2014, which application is a continuation of application Ser. No. 13/839,732, filed Mar. 15, 2013, now U.S. Pat. No. 8,794,849, which is a continuation of application Ser. No. 13/447,613, filed Apr. 16, 2012, now U.S. Pat. No. 8,708,573, which is a continuation of application Ser. No. 12/876,943, filed Sep. 7, 2010; a continuation-in-part of application Ser. No. 12/061,064, filed Apr. 2, 2008, now U.S. Pat. No. 7,789,572; a continuation-in-part of application Ser. No. 11/930,751, filed Oct. 31, 2007, now U.S. Pat. No. 7,651,277; a continuation-in-part of application Ser. No. 11/254,356, filed Oct. 20, 2005, now U.S. Pat. No. 7,325,976; a continuation-in-part of application Ser. No. 10/982,374, filed Nov. 5, 2004, now U.S. Pat. No. 7,207,724; a continuation-in-part of application Ser. No. 11/025,090, filed Dec. 29, 2004, now U.S. Pat. No. 7,182,523; a continuation-in-part of application Ser. No. 11/108,489, filed Apr. 18, 2005, now U.S. Pat. No. 7,118,286; a continuation-in-part of application Ser. No. 09/908,140, filed Jul. 17, 2001, now U.S. Pat. No. 6,960,025, which is a non-provisional application of Provisional Application No. 60/218,705, filed Jul. 17, 2000. The application hereby claims priority to all of the aforementioned applications, which are also all hereby incorporated by reference in their entirety.
FIELD OF INVENTION
The present invention relates generally to connectors for use in telecommunication networks such as voice, data or video networks. More specifically, to a connector system in which only certain plugs can mate with certain receptacles to provide discriminating access to particular information networks.
BACKGROUND
A need has developed to limit user access in data networks for security or other purposes. In recent years, buildings/offices are being equipped with different information networks, each having access to different data. It is important to restrict access to these networks to only authorized users. While some restrictions may be achieved using software approaches, such as passwords, the applicants have identified the need to restrict access further using some type of “physical barrier” to the networks. The present invention fulfills this need among others.
SUMMARY OF INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
The present invention provides a connector system which uses physical barriers to prevent unauthorized users from connecting to data networks. More specifically, the applicants recognize that the best protection against unauthorized users “hacking” into data networks containing confidential information is to prevent them from even connecting to the network. This can be accomplished using physical barriers which prevent plugs from mating with receptacles. To this end, the present invention facilitates discriminating mating among similar, but different, plugs and receptacles by using a system of geometrically matched connector components which allows certain combinations of plugs and receptacles—i.e., mating pairs—to mate, while preventing other combinations from mating. Thus, the connector system of the present invention imparts physical security to a particular data network by ensuring that only authorized users who possess a particular connector component can physically connect to the particular data network.
In a preferred embodiment, the network comprises: (a) a set of optical plugs, each plug having a housing and a ferrule, the housing having a front and back orientation and having a front face defining an opening, the ferrule being disposed within the opening, the housing defining a first keying element on the front face around the opening, the keying element for each optical plug of the set of optical plugs being different; and (b) a set of optical receptacles, each receptacle having an opening to receive the plug and a ferrule-receiving portion to receive the ferrule, the ferrule-receiving portion defining a second keying element to cooperate with the first keying element, the second keying element for each receptacle of the set of the optical receptacles being different and being adapted to cooperate with one and only one of the first keying elements, wherein plugs and receptacles having keying elements that cooperate are mating pairs.
Having the keying element located on the face of the plug provides for a number of benefits. First, these features can be molded with a relatively small change to the mold dies. Specifically, the opening around the ferrule is typically defined in the molding process by a core pin which is inserted into the outer mold. Changing core pin configurations is a relatively inexpensive and easy step compared to altering the configuration of the outer molds. Therefore, as mentioned above, the connector system of the present invention provides for a variety of different plug configurations with only slight modifications to the molding process.
Having the security features on the front face of the plug also provides for an early indication of non-mateability. Specifically, since the features are located on essentially the leading edge of the plug, they are positioned optimally to “stub” as soon as possible when a plug is inserted into a non-mating receptacle. The applicants recognize that interference between connector components which are non-mating should be made as soon as possible to minimize the possibility of coupling light between connectors. That is, if close enough, optical connectors are able to couple, albeit with high loss, even if the connectors are not mechanically engaged. This condition can be meliorated by preventing the light carrying elements from getting too close—hence the desire to stub early. Stubbing early also provides an early signal to the user that the plug is non-mating and avoids the tendency of trying to force a plug into a non-mating receptacle.
Additionally, by locating the keying feature on the leading surface of the plug, the corresponding keying feature on the receptacle may be located internally and still provide an early indication of non-mateability. This is beneficial since it is desirable to locate the keying feature of the receptacle internally to minimize the ability of the keying feature to be tampered with or otherwise overridden. As discussed below, this is of particular importance in the configuration of the MT-RJ and LC connectors in which the plug defines the slot and the receptacle defines the key. If the key is removed, the security feature is breached. Having the key located within the receptacle reduces this risk.
Yet another benefit of having the keying features located on the front face of the plug is the visual indication the plug provides with respect to its keying features. That is, one can readily determine the keying configuration of the plug by visual inspection of its front face. There is no need to look into an opening to inspect the internal geometry of the plug to determine its keying configuration.
Another aspect of the present invention is an economical process for producing the plugs by altering their geometry at their front end though a simple mold modification. In a preferred embodiment, the process comprises: (a) molding a first housing for a first plug of a set of plugs using a core pin to define an opening having a first keying element in a first position; and (b) molding a second housing for a second plug of the set of plugs by adjusting only the core pin to define the opening having a first keying element in a second position different than the first position.
Yet another embodiment of the present invention is a multi-connector assembly in which two or more of the connectors have different secure features. In one embodiment, the connector system comprising a multi-plug connector, each plug having a housing and a ferrule, the housing having a front and back orientation and having a front face defining an opening, the ferrule being disposed within the opening, the housing defining a first keying element on the front face around the opening, at least two housings of the multi-plug connector having different the first keying elements.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a mating pair of the present invention in which a plug is being inserted into a receptacle.
FIG. 2 shows a non-mating pair in which a plug has a slot which is not in the proper position to accept a key of a receptacle.
FIG. 3 shows an end view of a first plug showing a first keying element (a slot) in a first position to accept a second keying element (a key) of a first mating receptacle as shown in FIG. 4 . FIG. 3A shows an end view of second plug with a first keying element (a slot) in a second position which accepts a second keying element (a key) of a second mating receptacle as shown in FIG. 4 a.
FIG. 4 shows an end view of the first receptacle having a second keying element (a key) in a first position to accept a first keying element of the first plug shown in FIG. 3 to form a first mating pair. FIG. 4 a shows an end view of the second receptacle having a second keying element (a key) in a second position to accept a first keying element of the second plug in FIG. 3 a to form a second mating pair.
FIG. 5 shows a plug having a slot configuration capable of mating with jacks having keys in different positions.
FIGS. 6( a )-6( c ) show top perspective, front and rear views, respectively, of an MT-RJ connector plug having security features of the present invention.
FIGS. 7( a ) and 7( b ) show top perspective and front views, respectively, of an MT-RJ connector receptacle.
FIG. 8 shows a front and side perspective view of an LC connector plug having security features of the present invention.
FIG. 9 shows a front perspective view of an LC connector receptacle having security features of the present invention.
FIG. 10 shows schematically the discrete positions available for the first keying element.
FIG. 11 shows a series of LC connector plugs in which the first geometries are different.
FIG. 12 shows a hybrid adapter.
FIGS. 13( a ) and ( b ) show duplex and quad connectors having receptacles with the same security features.
FIGS. 14( a ) and ( b ) show duplex and quad connectors having receptacles with different security features.
FIG. 15 is an exploded perspective view of a prior art MT-RJ connector and illustrating alignment pins/receiving holes.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention relates to a connector system comprising a series of connector components which interconnect with each other in a discretionary way. Referring to FIG. 1 , a preferred embodiment of a mating plug 101 and receptacle 100 of the connector system is illustrated. As shown, the plug 101 is partially inserted into the receptacle 100 , which, in this embodiment, is a jack having a tub portion 102 . Although a jack is discussed herein in detail, it should be understood that the receptacle of the present invention is not restricted to a jack and may be any structure configured to receive a plug, including, for example, an adapter for connecting two plugs together or an integral connector on an active device (e.g., transceiver) or passive device (e.g., splitter).
The plug typically contains a conductive element, such a fiber or wire, which mates with a similar element in the receptacle. In fiber optic applications, it is common for the conductive element to be contained in a ferrule 150 , which in turn is housed by the plug 101 as shown in FIG. 1 . In a preferred embodiment, the ferrule is an MT-type ferrule, which, as known, is rectangular having side surfaces 151 , 152 , a bottom surface 153 and a top surface (not shown).
The outer surface of the plug 101 and the inner surface of the tub 102 have first and second geometries, respectively, which cooperate to allow only certain pairs of plugs and receptacles to mate (herein “mating pairs,” “mating plug and jack,” or “keyed pair”), and which physically interfere for all other combinations of plugs and jacks (herein “non-mating pairs,” “non-mating plugs and jacks” or “non-keyed pairs”), thereby preventing non-mating plugs and jacks from effecting an optical or electrical coupling.
The first and second geometries may embody any known keying mechanism which discriminates between connector components. Such keying mechanisms include, for example, a key and slot relationship between the plug and jack, a receptacle dimensioned to receive only certain sized or shaped plugs, and even a magnetic signature for either attracting (for mating pairs) and repulsing (non-mating pairs). Preferably, the keying mechanism involves just a slight modification to the plug and jack such that essentially the same molds can be used to manufacture connectors of different keyed pairs. Although molding is preferred, it is should be understood that other techniques for producing the first and second geometries can be used including, for example, over molding and machining.
In a preferred embodiment, the invention uses a key and slot mechanism. For simplicity, the term “keying elements” refers collectively to the key and the slot. Specifically, the slot can be embodied in the first or second geometry and the key can be embodied in the other geometry. In the particularly preferred embodiment shown in FIGS. 1-4 , the key is part of the second geometry, while the skit is part of the first geometry; that is, the plug 101 has a slot 103 and the tub portion 102 of the jack has a key 104 .
This configuration is preferred since the key may cooperate with other “ribs” on the connector for pre-alignment purposes. More specifically, with particular reference to FIG. 3 , an end view of housing 301 of the plug 101 is shown. The housing comprises four walls each wall having a slot 103 , 302 a , 302 b , and 302 c , respectively. FIG. 4 depicts an end view of housing 401 of the tub 400 in which the key 104 having a bottom surface portion 470 and ribs 402 a , 402 b , and 402 c having left, right and top surface portions 471 , 472 , 473 , respectively, are disposed on the walls of the housing. The key 104 and the ribs 402 a , 402 b , and 402 c cooperate with the slots 103 , 302 , 302 a , 302 b , and 302 c , respectively, to effect pre-alignment of the ferrule located within the plug with the jack before final mating of the connector plug with the connector jack. The final mating may be between the conductive elements of the connector system, such as, for example, between a couple of MT-type ferrules, which employ precise alignment pins/receiving holes 28 ( FIG. 15 ) on the ferrule face. Such ferrules are well known in the art. By pre-aligning the MT ferrules through the synergistic use of the key and slot, the inter-engagement of the closely-toleranced alignment pins/receiving holes is facilitated. The above-described synergistic keying and aligning feature of the present invention is realized with the MT-RJ connector (Tyco Electronics, Harrisburg, Pa.).
In a preferred embodiment, the mating end of the key 104 contains a flat portion shown as 105 and the mating end of the plug 101 has a chamfers 106 on the corners of the edges of the slot 103 , while the remainder of the mating end of the plug comprises a flat portion 107 . The radius corners on the key 106 and the chamfers on the plug 101 work as a guiding device and provide for the necessary alignment between the key and the slot when the plug is inserted into the tub of the jack. On the other hand, as shown in FIG. 2 , when a user attempts to mate two non-mating plug and jack components, the flat portion of the key 105 contacts the flat portion of the plug 101 and provides for definite physical interference between the plug and jack when the slot and key do not correspond. Accordingly, the use of this geometry prevents a user from forcing two non-mating plugs and jacks together. Therefore, the physical interference provided between the flat portion 105 of the tub and the flat portion 107 of the key assures that only desired combinations of plugs and jacks will mate.
The position of the key 104 on the tub 102 and the slot 103 on the plug 101 can be varied in such a manner so that a plurality of mutually-exclusive slot and key positions are formed. In one embodiment, the series of key and slot locations are mutually exclusive so that there is a one-to-one correspondence between jacks and plugs. In another embodiment, certain plugs may be configured to mate with a variety of different jacks. For example, it may be worthwhile to give network administers or people with high security clearance certain “master” plugs which are capable of mating with a number of jacks having different slot positions. Referring to the figures, FIG. 5 shows an embodiment of a master plug 501 which has a slot 502 that is configured (which, in this embodiment, means it is wide enough) to mate with jacks 503 and 504 which have different key positions 505 and 506 , respectively. Although a wide slot is used in this embodiment to effect mating with two or more jacks having different key configurations, it should be understood that other embodiments are possible, such as, for example a plug with two or more slots.
The number of possible mutually exclusive mating pairs for a given plug and receptacle is a function of the physical parameters of the plug and the receptacle. More specifically, with reference to FIGS. 1-4 , mutual exclusivity is ensured by adhering to the following relationships:
X 1− C/ 2+( D−A )+Δ<= F/ 2 (1)
X 2+ B/ 2< A/ 2 −W (2)
X 1 a +Clear1+ Z=X 1 b (3)
wherein:
A=the width of the plug 101 ; B=the width of the slot 103 on the plug 101 ; C=the width of the key 104 ; D=the distance across the opening of the tub; F=the width of the ferrule residing within the plug; Δ=CLF−CLA, wherein
CLA=centerline of the width of the plug; and CLF=centerline of the ferrule residing within the plug.
X1=the distance from the center of the opening in the tub 102 to the center of the key 104 for each mutually exclusive position. X2=the distance from the center of the plug 101 to the center of the slot 103 for each mutually exclusive position; X1a=the X1 distance for a sequentially first key in a series of connectors; X1b=the X1 distance for a sequentially second key in a series of connectors; W=the wall thickness of the plug housing Z=the minimum distance required to ensure that the flat portion of the key does not contact the flat portion of the plug 107 when a user attempts to mate a mating pair; Clear1=the clearance distance between the center side of the key and the center side of the slot.
These relationships must be satisfied for the mating pairs to mate and for the non-mating pairs to definitely not mate. Specifically, for a mating pair, Relationship (1) requires that half the ferrule width must be no less than X 1 less one half of C added to the difference between the width of the tub opening D less the width of the plug added to the difference between the centerline of the ferrule within the plug and the centerline of the plug. This ensures that the key is not positioned outside of the area on which at least a portion of the ferrule will reside. By adhering to this parameter, the key will have some overlap with the ferrule, and thus will provide for pre-alignment of the ferrule in the same manner as do the ribs on the three sides of the ferrule without the key.
Relationship (2) requires that X 2 added to one-half of dimension B is less than one-half of dimension A less W. This assures that the slot resides on the plug within the confines of the plug walls.
Finally, according to Relationship (3), for each mutually exclusive position, the distance X 1 for the first connector in the system (X 1a ) added to Clear 1 added to a predefined interference interval Z would correspond to the distance X 1 for the next slot/key position (X 1b ). Z is the minimum distance required to ensure that the flat portion of the key does not contact the flat portion of the plug 107 when a user attempts to mate the two portions of a connector which is intended to mate.
By way of example, four mutually exclusive locations for locating the slot on the plug housing and the key on the tub are defined below for an MT-RJ connector. The MT-RJ connector has the following dimensions:
A=7.15±0.05 mm
B=1.25 mm
C=0.95±0.04 mm
D=7.24±0.04 mm
F=4.5±0.04 mm
Clear1=0.15 mm
W=0.8 mm
Based on these MT-RJ dimensions, it has been found that the following X 1 key positions satisfy the relationships above:
Mating pair
Key Position
X 1
1
1
0.8 mm
2
2
1.6 mm
3
3
−0.8 mm
4
4
−1.6 mm
For example, FIG. 3 shows an end view of a first plug housing 301 showing a first keying element 103 (a slot) in a first X 1 position to accept a second keying element 104 (a key) of a first receptacle housing 401 as shown in FIG. 4 . FIG. 4 shows an end view of the first receptacle housing 401 having a ferrule-receiving portion having a second keying element 104 (a key) in a first X 1 position to accept a first keying element 103 of the first plug housing 103 shown in FIG. 3 to form a first mating pair. FIG. 3A shows an end view of second plug housing 301 a with a first keying element 103 a (a slot) in a second X 1 position which accepts a second keying element 104 a (a key) of a second receptacle housing 401 a as shown in FIG. 4A . FIG. 4A shows an end view of the second receptacle housing 401 having ferrule-receiving portion 450 having a second keying element 104 a (a key) in a second X 1 position to accept a first keying element 103 a of the second plug housing 301 a shown in FIG. 3A to form a second mating pair.
Although the data above indicates four mutually exclusive positions, it should be understood that additional positions are possible within the parameters of the MT-RJ connector. Additionally, it should be understood that the combinations of various key positions can be used to increase the number of permutations of mating pairs. For example, in addition to the four mating pairs listed above, additional mating pair configurations may obtained from the following combinations of key positions:
Mating pair
Key Positions
5
1, 2
6
1, 2, 3
7
1, 2, 3, 4
8
2, 3
9
2, 4
10
2, 3, 4
11
3, 4
12
1, 3
13
1, 4
14
1, 3, 4
15
1, 2, 4
In a preferred embodiment, the key and slot components are combined with the industry standard MT-RJ connector. FIG. 6 and FIG. 7 show the key-slot combination added to the MT-RJ connector as produced by Tyco Electronics of Harrisburg, Pa.
FIGS. 6 ( a )-( c ) show the plug 602 of the MT-RJ connector combined with the slot 601 of the present invention. FIGS. 7( a ) and 7( b ) show the center tub portion 703 of an MT-RJ connector jack. The key is shown as 701 located in one of the plurality of possible positions. The three pre-alignment ribs are shown as 702 a , 702 b , and 702 c . The key 701 functions as the discriminating member for allowing or preventing mating with a plurality of plugs, while at the same time functioning as the pre-alignment member for the remaining side of the ferrule not aligned with ribs 702 a , 702 b , and 702 c.
To provide a simple and readily apparent indication to the user of which plugs mate with which receptacles, it is preferable to mark mating pairs with indicia or color to indicate their compatibility. In a preferred embodiment, the components of a mating pair are a similar color different from all others used in the connector system.
Referring to FIGS. 8 and 9 , another embodiment of the connector system of the present invention is shown. FIG. 8 shows a plug 800 , which is one of a set of different plugs in the system. Each plug has a housing 801 which defines a first geometry. The first geometry comprises a front face 804 with an opening 802 (demarcated with dotted line), and a ferrule (not shown) within said housing and disposed in said opening. Around said opening 802 is a first keying element 803 . The keying element for each different optical plug of said set of optical plugs is different.
FIG. 9 shows a receptacle 900 for receiving a particular plug (not shown) and is one of a set of different receptacles. The receptacle 900 has a second geometry configured to receive the first geometry of a plug. The second geometry comprises a cavity 901 to receive a plug and a ferrule-receiving portion 904 having a borehole 902 to receive the ferrule of the plug. The ferrule-receiving portion 904 defines a second keying element 903 to cooperate with a first keying element of a particular plug. The second keying element for each receptacle of said set of said optical receptacles is different and is adapted to cooperate with one and only one first keying element. Plugs and receptacles having keying elements that cooperate are referred to herein as “mating pairs.”
Although the LC connector system described above is a single-fiber ferrule rather than a multifiber ferrule, the general keying features are essentially the same as those described above with respect to the MT-RJ connector. Further, the keying features of the plug 800 and receptacle 900 of the present invention may be implemented in any well known optical connector including, for example, other single-fiber ferrule connectors such as MU, SC, ST, or FC connectors. For illustrative purposes, the security features are described with respect to the LC connector system, which includes the LC plug (plug 800 ) and LC adapter (receptacle 900 ). Aside from the security features described herein, these connector components are the same as those specified in the LC Standard available on-line or from OFS (Japan), and the common features between them will not be addressed herein.
Like the MT-RJ embodiment described above, the keying features of the LC connector are contained on the front face of the plug. This is important for a number of reasons. First, these features can be molded with a relatively small change to the mold dies. Specifically, the opening around the ferrule is typically defined in the molding process by a core pin which is inserted into the outer mold. Changing core pin configurations is a relatively inexpensive and easy step compared to altering the configuration of the outer molds. Therefore, as mentioned above, the connector system of the present invention provides for a variety of different plug configurations with only slight modifications to the molding process.
Having the security features on the front face of the plug also provides for an early indication of non-matability. Specifically, since the features are located on essentially the leading edge of the plug, they are positioned optimally to “stub” as soon as possible when a plug is inserted into a non-mating receptacle. The applicants recognize that interference between connector components which are non-mating should be made as soon as possible to minimize the possibility of coupling light between connectors. That is, if close enough, optical connectors are able to couple, albeit with high loss, even if the connectors are not mechanically engaged. This condition can be meliorated by preventing the light carrying elements from getting too close—hence the desire to stub early. Stubbing early also provides an early signal to the user that the plug is non-mating and avoids the tendency of trying to force a plug into a non-mating receptacle.
Additionally, by locating the keying feature on the leading surface of the plug, the corresponding keying feature on the receptacle may be located internally and still provide an early indication of non-matability. This is beneficial since it is desirable to locate the keying feature of the receptacle internally to minimize the ability of the keying feature to be tampered with or otherwise overridden. As discussed below, this is of particular importance in the configuration of the MT-RJ and LC connectors in which the plug defines the slot and the receptacle defines the key. If the key is removed, the security feature is breached. Having the key located within the receptacle reduces this risk.
Yet another benefit of having the keying features located on the front face of the plug is the visual indication the plug provides with respect to its keying features. That is, one can readily determine the keying configuration of the plug by visual inspection of its front face. There is no need to look into an opening to inspect the internal geometry of the plug to determine its keying configuration.
The keying elements that may be used in the LC connector are the same as those described above with respect to the MT-RJ embodiment. In a preferred embodiment, the keying elements comprise a slot and a key. The slot can be embodied in the first or second geometry and the key can be embodied in the other geometry. In a first configuration, the slot is embodied in the first geometry and the key is embodied in the second geometry, while in a second configuration, the key is embodied in the first geometry and the slot is embodied in the second geometry.
The LC connector shown in FIGS. 8-9 has a first configuration. This configuration is advantageous for a number of reasons. First, the first keying features do not prevent a plug from mating with an ordinary receptacle. This is particularly beneficial since a plug with keying elements can be nevertheless “mated” with standard equipment used for the polishing, testing and inspection of the ferrule. Specifically, the polishing, testing and inspection equipment for single fiber ferrules typically comprises a ferrule receiving interface, similar to that of a receptacle, which receives just the ferrule disposed in the opening of the housing. The housing is not engaged. If a key protrudes into the space between the opening and the ferrule, it would preclude coupling with this existing equipment. Conversely, by having slots extend radially outward from the opening, and thereby maintain the space between the opening and the ferrule, a standard ferrule receiving interface, which does not have keying features, can be used. For example, a plug having a first keying element can be coupled to a standard LC ferrule receiving interface connected to a polishing device for polishing the ferrule, or to a microscope for inspecting the endface geometry of the ferrule, or to a photodetector for testing optical attenuation of the ferrule assembly.
Furthermore, since the physical “barrier”—i.e., the key—is located on the receptacle in the first configuration, it will serve to facilitate discriminatory mating among, not only plugs employing security features, but also existing plugs which have no security features of the present invention. Specifically, if a slot in the plug is necessary to accommodate the key of the receptacle, then plugs without slots will not mate with receptacles having the key. Therefore, ordinary, non-secure type plugs which do not have the slot in the proper position will not mate with the receptacle. In contrast, a non-secure receptacle will mate with a secure plug of the first configuration. Specifically, since the physical barrier is absent from the receptacle, any ordinary or secure plug can mate with it. As discussed below, the situation with the second configuration is opposite from that of the first, meaning that a secure plug cannot mate with a non-secure receptacle but a secure receptacle can mate with a non-secure plug. To provide for discrimination between secure and non-secure connectors components, a secondary key is added to the system as discussed below.
A connector system having the second configuration offers certain benefits, but also presents certain challenges. One benefit is that the space consuming security feature—i.e., the slot—resides in the receptacle which is typically larger than the plug and better suited for accommodating this feature. That is, since a slot is defined by the material around it, a slot requires more room than a key. The receptacle does not have the same space constraints as a plug (which is designed to be inserted in the receptacle) and may be more capable of accommodating the slot than the plug. Additionally, it may be preferable to have one “master” plug which plugs into all receptacles having security features. This is easily accomplished with a connector system of the second configuration. Specifically, the master plug would simply be one having no key to interfere with the first geometry of the receptacle. The simplicity in offering a master plug in the connector system of the second configuration also gives rise to a challenge facing the system—the ability of non-secure plugs to mate with secure receptacles (discussed below).
Referring to FIG. 10 , a preferred embodiment of the first keying element 803 is shown schematically. The figure shows the opening 802 in which the ferrule is disposed and which is configured to receive the ferrule-receiving portion 904 . Positioned around the opening 802 are spatially discrete positions 101 ( a )-( h ) for the first keying element. Similar discrete positions exist around the ferrule-receiving portion 904 (see FIG. 9 ) to define the location of the second keying element. In a preferred embodiment, the first keying element comprises one or more slots in a combination of positions 101 ( a )-( h ) and the second keying element comprises keys in corresponding positions. It should be understood that to facilitate cooperation between the first and second keying elements, the combination of slot positions in the plug must be the same as the combination of key positions in the ferrule receiving portion 904 . In other words, each slot must correspond to a key in the same relative position to facilitate a mating pair. For example, a plug having a first keying element which comprises slots in positions 1001 a , 1001 d , 1001 e , and 1001 d , will mate with a receptacle having a second keying element comprising keys 905 , 906 , 907 , and 908 is the same relative positions (see FIG. 9 ).
The number of slots in the combination of first keying elements depends upon the number of possible positions of the slots. Specifically, the number of possible permeations of different mating pairs is given by the following equation:
nCr
=
n
!
r
!
·
(
n
-
r
)
!
wherein:
n equals the number of spatially discrete positions for the keying elements, and
r is the number of positions occupied.
n C r therefore provides for the number of mutually exclusive combinations or permeations of mating pairs.
Below is a table providing data on the theoretical number of mating pairs, n C r , for different n and r values.
Number of Mutually
Number of Spatially
Number of
Exclusive Combinations
Discrete Positions n
Positions Occupied r
n C r
4
1
4
2
6
3
4
4
1
5
1
5
2
10
3
10
4
5
5
1
6
1
6
2
15
3
20
4
15
5
6
6
1
From this data, it is clear that the maximum number of permutations (i.e., n C r ) is reached when the number of positions occupied equals n divided by 2. Therefore, in the preferred embodiment, either n/2 slots (if n is an even integer) or (n±1)/2 slots (if n is an odd integer) of spatially discrete positions are occupied by either a slot with respect to the plug or a key with respect to the receptacle. (For purposes of simplicity, hereinafter, n will be presumed to be an even number.) Therefore, using the equation above, the embodiment shown in FIGS. 8, 9 and 10 , in which n equals 8 and r equals 4, the maximum number of permutations of mating pairs is 70.
Referring to FIG. 11 , different of plugs 1101 - 1110 of a set are shown in which the first keying elements comprise slots in different combinations of positions as defined in FIG. 10 and accompanying text. In these drawings, the opening 802 which is constant in all the plugs and the slot positions are shown with a phantom line. Specifically, plug 1101 shows slots in a combination of positions 1001 c , 1001 d , 1001 e , and 1001 f ; plug 1102 shows slots in a combination of positions 1001 e , 1001 f , 1001 g , and 1001 h ; plug 1103 shows slots in a combination of positions 1001 a , 1001 b , 1001 g , and 1001 h ; plug 1104 shows slots in a combination of positions 1001 a , 1001 b , 1001 c , and 1001 d ; plug 1105 shows slots in a combination of positions 1001 b , 1001 d , 1001 e , and 1001 g ; plug 1106 shows slots in a combination of positions 1001 b , 1001 c , 1001 e , and 1001 h ; plug 1107 shows slots in a combination of positions 1001 a , 1001 c , 1001 f , and 1001 h ; plug 1108 shows slots in a combination of positions 1001 a , 1001 d , 1001 f , and 1001 g ; plug 1109 shows slots in a combination of positions 1001 a , 1001 d , 1001 e , and 1001 h ; and plug 1110 shows slots in a combination of positions 1001 b , 1001 c , 1001 f , and 1001 g . It should be understood that each of the plugs described above will mate with a receptacle having a key in the same position. For example, plug 1109 will mate with receptacle 900 which has keys 904 , 905 , 906 and 907 in the same positions as the slots (i.e., 1001 a , 1001 d , 1001 e , and 1001 h ).
In a preferred embodiment, the connector system of the present invention may contain one or more master plugs of varying levels. That is, there may be lower-level master plugs, which can mate with receptacles of two different networks, or higher-level master plugs, which can mate with receptacles of three or more networks. The difference in the level of the mater plug is a function of the r number of slots occupying n possible positions—the more slots there are, the higher the plug's level. Specifically, the master plug comprises a first keying element having a third combination of greater than n/2 slots, in which the slots occupy the positions of at least two different first combinations as described above. Higher level master plugs have slots which occupy the positions of three or more different first combinations.
Aside from showing the different combinations of keying elements, FIG. 11 illustrates the ease with which the various plugs can be made. Specifically, in a preferred embodiment, the process of manufacturing an optical connector comprises molding different plugs by adjusting the core pin which defines the opening 802 while leaving the outer molds essentially the same. In other words, rather than using different molds to modify the outside of the housing—which can be expensive, the present invention involves simply adjusting the core pin—which is relatively inexpensive. Referring to FIG. 11 , the process is described in greater detail. The process comprises first molding a first housing 1101 a for a first plug 1101 of a set of plugs 1101 - 1110 using a core pin (not shown) to define an opening 802 and a first keying element in a first combination of positions 1001 c , 1001 d , 1001 e , and 1001 f . Next, a second housing 1102 a for a second plug 1102 is molded by adjusting only said core pin to define first keying element in a second combination of positions 1001 e , 1101 f , 1001 g , and 1101 h , which is different from first combination of positions.
To effect the different combinations of positions, the core pin is preferably adjusted by rotating it in θ increments, in which θ is equal to 360°/m, wherein m is an integer. Preferably m is an integer from 2-18, more preferably from 2-5, and even more preferably from 3-4. In the embodiment shown in FIG. 10 , m is 4, thus the core pin is adjusted by rotating it in 90° increments. It should be clear that rotating this core pin in 90° increments in subsequent molding operations will produce plugs 1103 and 1104 , respectively. Plugs 1105 - 1108 were prepared using a different core pin which was also rotated in 90° increments. Plugs 1109 and 1110 were prepared using yet a different core pin which was rotated in a 90° increment. It is worthwhile to mention that since the combination of positions 1001 b , 1001 c , 1001 f , and 1001 g is symmetrical with respect to two axes, the core pin can only be rotated by one 90° increment before repeating the same combination of positions.
Once the housings are prepared, a ferrule is disposed in the opening of each housing to form a subassembly. A fiber may be terminated in the ferrule either before or after the preparation of the subassembly. For field-terminatable connectors, it may be preferable to dispose just a fiber stub in the ferrule. This configuration facilitates field installation of a fiber as discussed, for example, in WO2005004285. Regardless of whether a stub or a fiber is terminated in the ferrule, the preferred keying arrangement of the present invention in which slots radiate outwardly from the opening 802 allows the subassembly of the LC connector to be polished, inspected, and tested using standard polishing equipment as mentioned above.
An advantage of the connector system of the present invention is that different receptacles may be combined to form “hybrid” adapters. More specifically, aside from the second keying element extending outward from the ferrule receiving portion, the receptacles are the same as those used for standard connectors. This allows different receptacles to be combined back to back to form hybrid adapters. In a particularly preferred embodiment, a secure receptacle is combined with a nonsecure receptacle by ultrasonically welding, or other known technique. Such a configuration is particularly useful in situations in which the nonsecure end of the adapter is located in an inherently secure area, for example, behind a wall or panel, where access is already limited. In other words, since connectors within cabinets and walls cannot be accessed readily after construction, the advantages derived from a secure connector at those ends would be minimal. Thus, it is preferable to use a nonsecure connector in these situations so the installer need not concern himself with the “proper” secure connector configuration during the installation of the infrastructure wiring.
To discriminate between secure and non-secure connector systems, the present invention provides for a secondary key & slot configuration, which is either non-existent or in a different position for all plugs and receptacles which are outside of the given connector system 800 . For example, referring to FIG. 8 , the first geometry comprises a secondary plug 810 , which is shown in the same relative position for all plugs of a given set, but which may be in different positions as discussed below. Referring to FIG. 9 , the second geometry of the geometry of the receptacle comprises a secondary slot 910 are preferably, but not necessarily, in the same position for all the receptacles of a given set of receptacles. The secondary slots 910 are adapted to receive secondary keys 810 . This way, only plugs and receptacles of a given set of having accommodating secondary keys/slots will mate. In a preferred embodiment, at least a portion of the secondary key 810 is disposed in the plug and is an extension of the side loading structure which is an LC connector standard. Therefore, in the preferred embodiment, the secondary key not only provides for discriminating mating between secure and non-secure connectors, but also enhances side load strength.
It is worthwhile to note that the use of the secondary key/slot adds another security feature to the connector system—essentially another keying mechanism. This additional keying feature increases the number of permutations within a given connector system. That is, rather than maintaining the same secondary key and slot location for all connectors within a system, it can be moved to form different classes within the same family
Preferably, the keying elements (primary and secondary) are positioned such that not mating pairs “stub” at about the same axial position relative to one another regardless of whether the connectors are interfering because they are different types of secure connectors or whether they are interfering because they are secure/non-secure connectors. This way, the user becomes accustomed to the point at which non-mating connector components interfere, thereby reducing the risk of the user forcing non-mating components together.
To provide a simple and readily apparent indication to the user of which plugs mate with which receptacles, it is preferable to mark mating pairs with indicia or color to indicate their compatibility. In a preferred embodiment, the components of a mating pair are a similar color different from all others used in the connector system.
The system described allows for a series of mutually-exclusive connectors to be used in a manner which provides physical security to a network system. In light of the often highly sensitive data stored on many of the networks in use today, this is a highly desirable feature. The present invention is an effective way to segregate separate networks and assure that the proper users are connecting to the desired network. Additionally, the present invention may be employed in the manufacture of devices in which fibers or wires need to be connected in particular arrangements. More specifically, the discriminating connectors of the present invention can be engineered into a system such that, during manufacturing, the correct connection of the fibers/wires is ensured by the mating pairs and their ability to prevent all other “incorrect” connections. Applications requiring particular routing of fibers or wires include, for example, routers, backplane assemblies, and even component devices such as multiplexers/demultiplexers.
Considering, for example, routers/backplane assemblies, the connector system of the present invention can be used to organize switch racks and, more specifically, to manage patch cables to reduce clutter and improve the ease, reliability, and security of the patch cable installation by providing customer specific patch cables/backplane connections.
By way of background, although network architectures may vary, common to most networks, and of particular interest herein, are switch rack systems. Such systems involve multiple-port switches mounted in a rack. Each activated port of a switch is connected to an aggregation box in the panel with a patch cable. The aggregation box, in turn, is connected to a deaggregation or breakout box with a trunk cable. The breakout box breaks out the trunk into individual channels again. The interconnections between the ports and the aggregation box and between the aggregation and breakout boxes may be accomplished using optical fiber or electrical conductor.
One of the objectives in designing switch racks is to minimize floor space. To this end, efforts are generally concentrated on increasing port density. This means increasing the number of ports on a particular switch and increasing the number of switches that fit into a particular rack or panel. A challenge in designing and installing such high port density switch racks is organizing the patch cables interconnecting the ports to the aggregator. Each activated port requires a discrete connection to the aggregator. This can lead to a great quantity of patch cables and general clutter, which creates a strong likelihood that a patch cable will be connected to the wrong port in error. Even trained technicians find it difficult to work around such clutter effectively and without making errors. If a patch cable is in fact connected to the wrong port, it may take hours to troubleshoot and resolve the problem in the mass of interconnections. Therefore, a need exists for a switch rack system that reduces the likelihood of improper interconnections.
The connector system of the present system fulfills this need among others. Specifically, the patch cables may be configured with one or more particular secure connectors to ensure that the correct plug is plugged into the correct receptacle. In one embodiment, the interconnections are not only secure, but customized for a particular user. Specifically, Applicants recognize that many of the interconnections involve multi-connector assemblies such as duplex and quad connectors. Applicants also realized that the multi-connector assemblies provide an opportunity to increase the number of permutations of the secure connectors to the extent that particular duplex and quad connector assemblies can be provided on a per customer basis.
By way of background, referring to FIGS. 13( a ) and 13( b ) , one embodiment of the invention is shown as a duplex and quad connectors having the same secure configuration for each connector. Specifically, the duplex connector 1301 has to two identical receptacles 1302 , 1303 , each having the same D-type configuration. (It should be apparent that this receptacle configuration corresponds to the plug 1101 shown in FIG. 11 .) Likewise, the quad connector 1304 shown in FIG. 13( b ) , comprises four identical receptacles 1305 . (Again each receptacle corresponds to the plug 1101 shown in FIG. 11 .)
Although the connector embodiments of FIGS. 13( a ) & ( b ) work well to ensure a secure connection, they are limited in the number of unique configurations they can make. Specifically, referring to FIG. 13( a ) , the duplex connector 1301 with identical receptacles 1302 and 1303 only has four unique combinations using the primary tooling. Likewise, the quad receptacle 1304 shown in FIG. 13( b ) is also limited to just four unique combinations using primary tooling. As used herein, the primary tooling refers to the tooling required to make embodiments 1101 - 1104 as shown in FIG. 11( b ) . As mentioned above, one of the advantages of the connector system shown in FIG. 11 , is the ability to provide different receptacle and plug configurations simply by rotating the core pin. In other words, different configurations can be manufactured using the same tooling. This is desirable from a production cost standpoint.
Although the number of permutations of the quad shown in FIG. 13( b ) could be increased to forty (40) by using the ten (10) alternative configurations keying configuration illustrated in plugs 1101 - 1110 in FIG. 11 , this requires additional tooling because plugs 1105 - 1110 cannot be produced by rotating the core pin used in the manufacture of plugs 1101 - 1104 .
In addition to a desire to avoid additional tooling requirements, Applicants have identified a need to further increase the number of unique connector combinations so that certain multi-connector configurations can be customized for a particular user. To this end, Applicants disclose herein multi-connector assembly in which two or more of the geometries of the connectors of a given assembly are different. For example, one embodiment of the duplex connector 1401 of the present invention is shown in FIG. 14( a ) . In this embodiment, the duplex connector 1401 comprises one receptacle 1402 having a geometry similar to the receptacles shown in FIG. 13A , but its second receptacle 1403 has a different geometry, corresponding to the plug 1103 shown in FIG. 11 . By configuring the duplex connector 1401 such that at least two of the receptacles have different first geometries, the number of unique combinations increases from four to sixteen.
Even more permutations can be derived from the quad connector 1404 as shown in FIG. 14( b ) . Specifically, quad connector 1404 can be arranged such that at least two of the receptacles have different geometries. As shown in FIG. 14B , quad 1404 has four receptacles 1405 , 1406 , 1407 , 1408 , all of which have a different geometry. Specifically, 1405 corresponds to plug 1101 , receptacle 1406 corresponds to plug 1102 , receptacle 1407 corresponds to plug 1104 and receptacle corresponds to plug 1103 . It should be understood that while each of these is different, the number of different plug/receptacle geometries can carry from two to four in this assembly. By altering the geometries within the quad connector, the number of unique permutations increases dramatically. For example, just using the primary tooling described above, 256 combinations are possible. When all ten keying combinations are used as shown in FIG. 11, 1600 unique combinations are possible.
In addition to increasing the number of unique connector assemblies, varying the geometry among the connectors of a given assembly also improves the resilience of the connector to a “forced” connection. Specifically, when the geometries are aligned as they are in the connectors of FIGS. 13( a ) & ( b ), a user can force the connection by biasing the mating connector to one side or the other. For example, if a user wanted to force a connection to the duplex connector 1301 of FIG. 13( a ) , the user could urge the plug assembly to the left of the duplex connector 1301 during mating. However, by varying the geometries as in the embodiment of FIGS. 14( a ) and ( b ) such that there is no polarization or alignment of the geometries, a user can no longer urge the mating connector to one side or the other to force the connection. Thus, the embodiments of FIGS. 14( a ) and ( b ) are also less prone to forced connections.
It should be understood that specific plug assemblies such as a duplex and quad are not illustrated particularly herein, but that such connectors assemblies are produced by clipping together simplex connectors, such as those shown in FIG. 11 , with a known clip (see, for example, U.S. Pat. No. 7,500,790, incorporated herein by reference.)
Because the present invention provides for so many unique combinations, it is possible to designate certain unique configurations for certain customers. In this regard, the color of the connector itself may be used to render it unique for a certain customer. For example, the quad connector embodiment shown in FIG. 14( b ) may be provided in green for one customer and be provided in blue for a different customer. Thus, the physical connectors themselves may be the same but the colors are different based on the user.
In one embodiment, the housings are color coded as described above. In another embodiment, the connectors comprise strain relief boots extending rearwardly (not shown) that are color coded to increase the number of color permutations possible. Such strain relief boots are well known and are disclosed, for example, in U.S. Pat. No. 7,695,197, incorporated herein by reference.
It should be understood that while the multiple connector configurations were discussed in terms of a patch cords, the application is by no means limited to patch cord applications. Indeed, the unique multi-connector arrangements can be applied in any situation requiring multi-connector connections. In this regard, it should be understood that the foregoing is illustrative and not limiting and that obvious modifications may be made by those skilled in the art without departing from the spirit of the invention. Accordingly, the specification is intended to cover such alternatives, modifications, and equivalence as may be included within the spirit and scope of the invention as defined in the following claims.
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A multifiber connector comprising a rectangular-shaped ferrule having a plurality of fibers, alignment structure positioned on a front face of the ferrule, the alignment structure being at least one of alignment pins and pin-receiving holes, a housing defining a ferrule opening, the ferrule opening sized and shaped to accommodate disposition of the ferrule therein, wherein when disposed within the ferrule opening the ferrule extends forward from a front face of the housing; the housing having an outer periphery, wherein the outer periphery is defined by at least a top wall, a bottom wall, and first and second side walls, each of the side walls defining a recess having a curved surface, each recess positioned at an intermediate point along the height of the first and second side walls, and a key on the outer periphery of the housing on at least one of the top wall and the bottom wall, the key being offset to one side of a centerline bisecting the connector into first and second side portions, wherein the key prevents the multifiber connector from mating with a standard adapter which would otherwise mate with the multifiber connector but for the location of the key.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates generally to boxes used for shipping and storage and, more particularly, to triangular shipping boxes.
[0006] 2. Related Art
[0007] Triangular shipping containers are made from cardboard and have a generally triangular cross-section. Examples of such boxes are that used by FedEx. A FedEx triangular shipping container is shown in FIGS. 1 and 2. In FIGS. 1 and 2, overlapping longitudinal sides of the container are adhesively attached to form a triangular body. The ends are closed by the use of a tab that is bent perpendicularly and inserted into a receiving slot to assume a position normal to the receiving slot.
[0008] Other triangular shipping containers use a series of straps, like tie wraps, to encircle the triangular cross-section. Several straps are used along the longitudinal length of the container/box to prevent the box from unraveling. The ends of such boxes use end caps that are stapled to the sides of the box.
[0009] All of the triangular shipping containers of the prior art commonly share the characteristic of becoming somewhat destroyed upon a fill opening of the box/container. For example, opening the FedEx box along the longitudinal length requires that the adhesive forces holding cardboard sides be overcome. In practice, the box is essentially destroyed as the adhesive forces are stronger, by necessity, than the cardboard material, resulting in ripping or tearing of the cardboard upon opening. In addition, a great deal of force must be exerted to “rip” the sides of the box apart.
[0010] Similarly, whenever staples are used for the end caps of triangular shipping containers, removal of the staples can destroy and disfigure the end of the box. In addition, the straps that encircle the triangular circumference of the box/shipping container must be cut and permanently destroyed. In short, it is a lot of bother and effort to open one of the boxes/shipping containers open, and often results in a box that cannot be resued.
[0011] There is a need in the art to provide a triangular shipping container that is reusable, and that can be easily opened.
SUMMARY OF THE INVENTION
[0012] It is in view of the above problems that the present invention was developed. The invention is a triangular shipping container that is easily closed, easily opened, and that is reusable. The container is formed from a cardboard sheet that is provided with a number of mating male and female tabs. The matching arcuate shapes of the male tabs and female cutouts are unique. In addition, the female cutout is further provided with paired scoring that provides easy closing and opening of the shipping container. It is noted that the angle of entry of the male tab relative to the plane of the female cutout is acute.
[0013] Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings:
[0015] [0015]FIG. 1 is an elevated view of half of a shipping container/box of the prior art;
[0016] [0016]FIG. 2 illustrates a section view, taken along line 2 - 2 of FIG. 1;
[0017] [0017]FIG. 3 illustrates a plan view the cardboard sheet of the present invention;
[0018] [0018]FIG. 4 illustrates an elevated, partial section view of a portion of the assembled container of the present invention that shows the mating of the male tab into the female cutout on the right side, and an unmated male-female pair on the left side; and
[0019] [0019]FIG. 5 illustrates a section view, taken along line 5 - 5 of FIG. 4, showing the relative angle between the male tab, and the side wall that accommodates the female cutout
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to the accompanying drawings in which like reference numbers indicate like elements, FIG. 3 illustrates a plan view the cardboard sheet, shown generally at 10 of the present invention. Specifically, sheet 10 is provided with four longitudinal sides 12 separated by scored lines 14 . Triangular end piece 16 is on one end, with a middle triangular end piece 18 provided with male tab 20 adapted for insertion into female cutout 22 located proximate interior triangular end piece 24 . Preferably, male tab 20 has an arcuate area to accommodate the surface area presented by multiple fingers. Clipped end 30 of overlapping longitudinal section 32 helps to form an overlap of longitudinal sides 12 associated with triangular end piece 16 , and is better shown in FIG. 4.
[0021] Turning to FIG. 4, the left male tab 20 from overlapping longitudinal section 32 may be pushed into female cutout 22 . Preferably, male tab 20 is wide to accommodate more than 1 finger (and preferably 3 or 4 fingers simultaneously) so that the force of repetitive closing will can be distributed across several fingers and not make any one finger uncomfortable.
[0022] Once inserted into female cutout 22 , male tab 20 assumes an acute angle with respect to the plane of female cutout 22 . This is best shown in FIG. 5. It has been found to be remarkably easy to push male tab 20 into female cutout 22 . As also may be apparent from the drawings, the closure force exerted by male tab 20 originates from the base area, shown generally at 32 , of male tab 20 . This (acute angle, and base-originating closure force) provides a tremendous mechanical advantage over tabs used for closures in the prior art.
[0023] In order to extract male tab 20 from female cutout 22 , there is, in the preferred embodiment, a pair of sored slits 34 is provided. The slits 34 permit a virtual tab 34 to be formed therebetween. Virtual tab 34 has one end that forms an edge portion of female cutout 22 . This virtual tab 34 may be pulled away from longitudinal side 12 to form a space larger than that presented by female cutout 22 , such space permitting the insertion of one or more fingers. Quite remarkable in the lack of effort required, the fingers may then easily pull male tab 20 out of female cutout 22 . An identical operation is contemplated for the male tab 20 (associated with middle triangular end piece 18 ) in conjunction with female cutout 22 (associated with interior triangular end piece 24 ).
[0024] For extremely thick cardboard, it is preferred that the distance between male tabs be more than twelve inches and, preferably, thirteen and one-sixteenth inches.
[0025] In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained.
[0026] The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
[0027] As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. For example, Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
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The invention is a triangular shipping container that is easily closed, easily opened, and that is reusable. The container is formed from a cardboard sheet that is provided with a number of mating male and female tabs.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention related to an Internet-based system for electronically matching loads of motor vehicles between those who wish to ship them and those who might transport them. Based on a ‘reverse auction’ concept, the loads will be bid on by carriers and the lowest or best bid will be accepted by shippers.
[0003] 2. Description of the Related Art
[0004] Description of the Related Art: In the field of motor vehicle transporting, a typical transaction between a shipper, e.g., one who wishes to ship vehicle(s), and a carrier, e.g., one who may be hired to transport the motor vehicle(s), usually requires the shipper to have direct communication with many different carrier sales representatives or dispatchers by phone, facsimile, electronic mail and/or in person to determine the carrier's rate and schedule, e.g., date of pick up. This is because carriers have varying rates and irregular routes with no set schedules, and shipper information on available carriers is not widely available to bring the parties together. Similarly, shippers generally have no marketplace for publicizing their motor vehicle transport needs to motor vehicle carriers on the open market. This situation exists for both business and individual private shippers to carrier.
[0005] A shipper typically spends endless hours matching a carrier to the motor vehicle(s) to be shipped. Once the shipper has matched their motor vehicle(s) to a carrier, transfer of data details from shipper to carrier quite often are transposed, presenting costly and timely errors for both the shipper and the carrier. With no marketplace for the carrier to view, quite often the carrier must relocate its equipment, incurring high costs and loss of time. This poor equipment utilization also contributes to environmental pollution as well. Additionally, when a shipper hires a carrier, the shipper has no easy way of finding information regarding the carrier's ability to perform the transaction in a safe and timely manner. After the carrier has been given authorization from the shipper to handle the transaction, the shipper does not have the ability to simply track the whereabouts of their motor vehicle(s). For individual private shippers to acquire the use of a motor vehicle transport carrier, they usually unknowingly end up contacting a broker listed under the ‘Auto Transport’ section in the Yellow Pages of the phonebook as opposed to an actual carrier, which results in the private shipper incurring a large broker fee—anywhere from 10 to 50 Percent of the cost of the transport. And once the broker has placed the motor vehicle(s) with a carrier, the private shipper—in most cases—is not able to track their motor vehicle(s) through the broker and does not know how to contact the carrier directly.
[0006] If similar information were to become available to the vehicle shipping industry on a large-scale, significant savings in time and expense to both shippers and carriers could be realized. In addition, shippers would have carrier statistics available to them prior to assigning motor vehicle(s) to a carrier and would have the ability to track their motor vehicle(s) available to them.
BRIEF SUMMARY OF THE INVENTION
[0007] Briefly, in accordance with one aspect of the invention, carriers register in the system and must meet certain criteria to be accepted in the system for opportunities to bid on a load of automobiles to be transported. Carriers can manage certain aspects of their accounts online through a web-based interface.
[0008] In accordance with another aspect of the invention, shippers register in the system and must meet certain criteria to be accepted as an organization that has automobiles to ship from one location to another. Shippers receive bids from automobile carriers to ship those loads. Shippers can manage certain aspects of their accounts online through a web-based interface.
[0009] In accordance with another aspect of the invention, shippers post loads of one or more automobiles in the system using an online web-based interface. Loads have a start and end bid date and time. Once a load is posted, the database searches the carrier records for carriers that match the criteria of the load including start and end destinations and date and time ranges of pickup and delivery. Frequent searches will be conducted daily between the start date and time, and the end date and time for bids. When matching carriers are found in the database, each matching carrier will be notified by electronic mail that there are loads requesting a bid.
[0010] In accordance with another aspect of the invention, carriers who are notified about loads to be bid on can enter the system and place one bid for each load requesting a bid using a web-based interface. When a bid is submitted, the shipper of the load will be notified by electronic mail that a bid has been submitted for the load. That shipper can then return to the system to check the status of the bidding for any of the shipper's posted loads. Shippers can let the bid auction continue until it is finished or may elect to end the bidding opportunities early.
[0011] In accordance with another aspect of the invention, once the auction period is expired or otherwise ended by the shipper, any carrier that had been notified about the bidding opportunity will be notified by the system in an electronic mail that the time period has expired. Those carriers who posted bids will be informed that their bid has been received and is being reviewed by the shipper. The shipper will analyze each bid using a web-based interface and select the winning bid based on price and pickup and delivery timeframes. The selected carrier will be notified by electronic mail that its bid is the selected bid.
[0012] In accordance with another aspect of the invention, the selected carrier must return to the system and, using a web-based interface, either accept or decline the agreement to transport the shipper's load. This is done because there may be an extended timeframe between submission of the bid against the load and the award, and this can give the carrier an opportunity to ‘overbook’ its transport. If the agreement is accepted, the shipper is again notified with an electronic mail that the carrier has agreed to transport the load. An agreement is put in place and all shipping documents are generated so the carrier can print them out and use them in its process. If the agreement is declined, the shipper is notified that the selected carrier is overbooked and has declined the load; the bid is then removed from the list of bids; and the shipper must return to the system to select another bid from the remaining bids that were submitted. This process continues until either the load is accepted by a carrier or there are no longer any valid bids in the list. If this should occur, the shipper uses the web-based interface to re-post the load for possibly a different length of time to gather more bids to select from.
[0013] Briefly in accordance with another aspect of the invention, carriers can return to the system and indicate a running status of the shipper's load once it has been awarded to them. The status will allow the shipper to track the load as it travels from the pickup point to the delivery point.
[0014] Briefly in accordance with another aspect of the application, shippers and carriers (users) are provided a feedback tool that will result in a grade or rating for each user. The system will combine grade reports against each user that will result in a current grade for that user based on feedback from other users who have also done business with the graded user.
[0015] In accordance with another aspect of the invention, both shippers and carriers (customers) receive monthly invoices for the service, depending on their account types and the billing cycles associated with those account types. Billing is handled on a base rate plus a per-automobile basis with the base rate covering a pre-determined number of automobiles in each load posted per month. The database job engine determines which accounts are due an invoice, how the customer wants to be invoiced (paper, electronic mail, facsimile, etc.), and then generates the appropriate invoices. In the event of paper invoices, a batch will be set up and the proper administrative personnel will be notified by electronic mail that a batch of invoices is awaiting printing. Invoices can be collected either by the customer sending a check or card information in the mail or by the customer paying online with a credit/debit card or electronic check, transaction using a web-based interface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] The foregoing features and advantages of the disclosed embodiments of the invention will be more readily appreciated as the same become better understood from the following detailed description when taken in conjunction with the accompanying drawings, wherein:
[0017] FIG. 1 illustrates the general operation and architecture of the Internet, across which the disclosed embodiments of the invention are implemented.
[0018] FIG. 2 illustrates a block diagram of the system operating using the Internet to deliver the application to users in accordance with the entire invention.
[0019] FIG. 3 illustrates the major entities included and addressed in accordance with the entire invention.
[0020] FIG. 4 illustrates the account management system in accordance with one aspect of the invention FIG. 5 illustrates the Auction/Bid/Agreement/Award system in accordance with one aspect of the invention.
[0021] FIG. 6 illustrates an extension of the Auction/Bid/Agreement/Award system in accordance with one aspect of the invention.
[0022] FIG. 7 illustrates the invoicing process in accordance with one aspect of the invention.
[0023] FIG. 8 illustrates the load tracking process in accordance with one aspect of the invention.
[0024] FIG. 9 illustrates the user grading system in accordance with one aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 is a diagram depicting in general an overview of one system 10 formed in accordance with the present system. As shown therein, the system 10 includes a plurality of hosting servers 11 coupled to the Internet 12 through an internal routed network 13 and thence to the requesting client's computer system 14 . It is to be understood that while this embodiment of the invention is described for use with the Internet 12 , the system can be implemented on a private IP routed network.
[0026] FIG. 2 illustrates key aspects of a bid engine 22 of the system 10 , which includes a web application server 16 that provides all of the communication from the server, on which the application resides, 11 to the requesting client 14 and back to the server. The system delivers the assembled application to the client 14 , compiles and executes server-side application code, and handles communication from between the client 14 and to the server 10 via (HyperText Transfer Protocol) HTTP version 1.1. The database server 18 provides the database management engine and stores all of the application data, including user records, system logs, and bid data, that the system uses. The scheduler 20 is an integral part of the database server 18 and will handle all of the scheduled tasks required by the system 11 . The bid engine 22 handles all bidding against posted loads and is a combination of code compiled and executed by the web application server 16 and tasks run by the scheduler 20 .
[0027] FIG. 3 illustrates, in industry standard entity relationship notation, what major entities participate in the system. A visitor 24 is any visitor to the system's web-based application—or website. Visitors 24 are people operating web browsers via a client computer. An entity 30 is a human or a non-human entity that plays a role, other than just the casual visitor 24 , in the system. All entities 30 are registered within the system through the system's registration process. A person 26 is a human entity 30 and a place 28 is a non-human entity 30 such as a company. Each person 26 has a role 32 in the system. An account 34 is a combination of one non-human entity 30 and one or more human entities 30 . The account 34 is the core of the system and that upon which everything is based upon. An account 34 can be invoiced 48 and can post a load 36 —made up of one or more load items 38 , and can bid 40 on posted loads 36 . When an account 34 selects a bid 40 for the load 36 the account 34 has posted, the account 34 posting the load 36 and the account 34 bidding on the posted load 36 will enter into an agreement 42 for the bidding account 34 to handle the load 36 and the account 34 that has posted the load 36 will award 44 the load 36 to the winning account 34 . After the account 34 handling the load 36 picks it up, that account 34 will ensure that it maintains load status 46 in the system so that the account 34 owning the load 36 can determine by using the system where the load 36 is currently located at any given time. Finally, if the account 34 is a paying account, an invoice 48 is generated on the desired schedule and provided to the account 34 by the desired method (physical mail, electronic mail, or facsimile). The account 34 responsible for satisfying the invoice 48 can make payment 50 by check (physical paper or electronic) or with a debit/credit card using one or more transactions 51 .
[0028] FIG. 4 illustrates, in industry standard flow charting notation, how a visitor 24 registers for an account 34 using the system. Depending on the type of visitor 24 , they will provide different types of identifying information to the system. Upon submission of the visitor's information into the system, the database will be queried to see if this visitor 24 might already have an account 34 in the system. If it is found that the visitor 24 is already a registered account 34 holder, he or she will be offered the opportunity to log on to the system. If the visitor's company is already registered but the visitor 24 is not a registered user under that company's account 34 , the visitor 24 will be offered an opportunity to become a member of that company's account 34 . Should the visitor 24 agree to become a member of the existing company's account 34 , the visitor 24 will complete the registration information form and submit it to the system. The system will make that visitor 24 an inactive member of the company's account 34 and an email will be sent to the company account 34 administrator asking him or her to validate this new visitor 24 . Once validated, the visitor 24 will be sent an email welcoming him or her to the company's account 34 as a user.
[0029] Visitor's 24 will find the system's website through various means such as online search engines, word of mouth, or corporate direction 54 . If the visitor 24 is a shipper of motor vehicles the visitor 24 will provide the company name and DUNS number to the system through the registration process 56 . If the visitor 24 is a carrier of motor vehicles the visitor 24 will provide a US DOT Number, and MC Number, and a company name to the system through the registration process 56 . Once the visitor 24 submits the information to the system, the system's database will search 58 for a company with a matching set of criteria (DUNS number or MC Number depending on whether the visitor 24 is from a shipper or from a carrier) and company name. Should the database find that the visitor 24 is from a company that does not exist in the system 60 ; a new account 34 will be established with the visitor 24 as the account 34 administrator 80 . Both the account 34 and the visitor 24 will be suspended 82 , 83 until the account 34 background can be investigated and determined, through a manually performed process 100 , to be from a valid source. If the account 34 type is a paid account type 84 , payment will be collected either online 86 , 88 or through an invoice 168 depending on the visitor's 24 selected payment and billing preference. If, through the manually performed process 100 the visitor 24 and the company are validated, the account 34 will be activated, removing the suspension from the account and the visitor. FIG. 7 indicates, in industry standard flow charting notation as a continuation of FIG. 4 , the invoice and payment process that services the entire scope of the system. After the account has been validated, a payment process will be executed following the steps outlined in FIG. 7 .
[0030] FIG. 7 illustrates, in industry standard flow charting notation, the process followed for all invoicing and invoice payments in the system. The account type is checked 164 to determine if there is a charge for it. If there is a charge for the account type 166 and invoice is generated based on the account 34 holder's invoicing preference. Depending on invoice type preference, the invoices are distributed 170 .
[0031] When the payment is received against the invoice the system checks to see if the payment terms have been met 172 . If the terms have not been met the account 34 is suspended 186 and email is sent to the system management 188 and the account 34 holder 190 indicating what needs to happen to ensure the account 34 is paid in full and the suspension lifted. If the terms have been met and an online payment is used 174 the selected online payment process component will be employed to complete the transaction 176 and the system's database is updated 178 to reflect the current payment. In the event a manual payment is received 180 , it will be deposited in the bank manually 182 and the database will be updated 178 to reflect the current payment.
[0032] Once the database is updated 178 the account 34 will be looked at by the database to determine if it is paid on full or not 184 . If the account has not been paid in full 184 , the account 34 is suspended 186 and email is sent to the system management 188 and the account 34 holder 190 indicating what needs to happen to ensure the account 34 is paid in full and the suspension lifted. If the account 34 has been paid in full and the account has been suspended 192 , the database will activate the account 194 and email is sent to the system management 196 and the account 34 holder 198 indicating that the account has been activated, and email is sent to the system management 200 and the account 34 holder 202 indicating that the account has been paid in full.
[0033] FIG. 5 illustrates, in industry standard flow charting notation, the process for placing loads 36 of motor vehicles on the system and bidding 40 to carry said loads 36 of motor vehicles from a start point to a destination. A shipper will visit the system through the web-based interface, log on with his or her credentials, and assemble 104 one or more loads 36 , each containing one or more motor vehicles or load items 38 . Using the system's user interface, the visitor 24 will enter the location the load 36 will be picked up and the location the load 36 is destined for, and a range of times and dates that the load 36 can be picked up and delivered. The visitor 24 will then enter one or more vehicles, up to ten, into each load 36 by selecting make, model, year, number of doors, trim package, and entering the Vehicle Identification Number (VIN) of each vehicle in the load along with a unique reference number of the shipper's choice e.g., rental car number, auction number, dealership stock number, etc. 36 . Once the load is assembled 104 , the visitor will set how long the bidding 40 will remain active 106 on this load 36 . Finally, the visitor 24 will submit the load to the system's database for advertisement and bidding on by carriers of motor vehicles who are also registered users of the system. Preferably, several times over the course of each hour of each day the database scheduler 20 will start a search of the records for qualified carriers 108 who have the right capabilities and qualifications to carry the submitted load 36 of motor vehicles. Matching criteria include whether the carrier services both the start point and the destination, if the carrier has the proper type of carrier requested by the shipper, and if the carrier has a valid insurance certificate. Each matching motor vehicle carrier that is found during the search 110 will be notified 112 by email that they are invited to bid 40 on the load 36 .
[0034] FIG. 6 , in industry standard flow charting notation, continues this notification process and shows the notified carrier clicking a link provided in the notification email 148 that will carry him or her back to the system via the Internet as a visitor 24 . After logging on with his or her credentials, the load that the visitor 24 is being asked to bid on will be displayed. If a bid 40 already exists from the visitors company 150 at the time of the visit the visitor 24 will be unable to place a bid 40 but can view the bid currently against the load 36 and the visitor 24 will be notified on the screen that only one bid 40 is allowed per carrying company. If a bid 40 has not yet been placed by the visitor's 24 company 150 , the visitor will have the opportunity to place a monetary bid 40 against the load 36 . If the visitor 24 elects to submit a bid 40 , the bid is submitted 154 through a form on the system and then it is stored in the system's database 156 . Upon receipt of a bid 40 from a carrier, the system's database will again analyze the bid 40 and the bidding carrier's profile (ensuring nothing has changed) since the bid was offered 114 . If the bid still meets the original criteria then the bid is stored in the database 116 and the shipper is notified by email that a bid has been received for his or her load 117 .
[0035] On a schedule of preferably at least once an hour of each day, and ideally 3 to 6 times an hour, the database scheduler 20 will analyze all of the active bids in the database and determine if the bidding 40 timeframe has expired 118 . If the bidding timeframe has not yet expired, the search process in item 108 will be repeated for all loads 36 where the bidding 40 timeframe has not expired. If the bidding 40 timeframe has expired, the database will close 120 the bidding 40 on all loads 36 where the bidding 40 timeframe has expired. Shippers with loads 36 where bidding 40 is being closed will be notified by email that the bidding period has expired 122 . If bids 40 are not available for a load 36 after the bidding 40 has stopped 124 , FIG. 6 shows that the shipper who submitted the load 36 will be notified by email 158 that no carriers have provided a bid 40 on the load 36 . The database-will then mark the status of the load 36 as a no-bid load 36 . The shipper can then elect to repost the load 36 by re-setting the bid timeframe 106 .
[0036] If bids 40 are available for the load 36 after the bidding 40 timeframe has expired 124 , the shipper will be notified by email 126 that one or more bids have been received by the system for the shipper's load 36 . The shipper will follow a link in the notification email back to the system as a visitor 24 and will then be able to examine all bids and then select 128 one of the submitted bids 40 using the bid selection tool in the system. Once a bid 40 is selected by the visitor 24 , the carrier submitting the bid is notified by email 130 that their bid 40 has been selected by the shipper. The notified carrier will follow a link in the notification email back to the system as a visitor 24 , and the carrier must either accept or decline 132 the load 36 . If the visitor declines the load 36 , the visitor's bid 40 is removed 144 from the list of bids 40 placed against the load 36 and the shipper of the load 36 is notified by email 146 that the selected carrier has declined the load 36 . If there are other bids 40 available against the load 36 , the email will also instruct the shipper to return to the system, following a link as a visitor 24 , and select another bid 128 from the remaining bids. If the carrier who has followed the link in the notification email back to the system as a visitor accepts 132 the load 36 , then the visitor is asked to agree to the load 36 by executing an agreement 134 with the shipper. Upon execution of the agreement 134 , the system will email 136 all of the other carriers who have submitted bids 40 for the load 36 that the load 36 has been awarded 44 , 140 , and all of the shipping documents will be created for printing 138 by the visitor 24 . Finally, the system's database will seal 142 the load 36 from any further change by marking it as awarded 44 .
[0037] FIG. 8 illustrates, in industry standard flow charting notation, the process of the load- 36 carrier keeping a record of where the load 36 is currently at and what the status of the load 36 is. After accepting the award 44 a carrier prepares 206 using his or her own internal procedures to pick up and transport the load 36 . Once the load 36 has been physically picked up at it's start point the carrier will return to the system as a visitor 24 and set the status 208 fore the load 36 as ‘picked up’. Frequently, throughout the transport the carrier will return to the system as a visitor and update the status 210 , 208 of the load 36 . When the load is delivered to its destination, the carrier will return to the system as a visitor 24 and set the status 212 for the load 36 as ‘delivered’. Once this status is entered into the system's tracking system the database will seal the tracking record from any further changes 214 . Sealing this status record will start the process by which both the shipper and the carrier rate each other on their performance.
[0038] FIG. 9 illustrates, in industry standard flow chart notation, how the grading process works. The system will provide a grading system that will show how easy each carrier and shipper is to work with, how prompt payment is, how courteous personnel are, and what the overall quality of the experience was. When the load status 46 for a load 36 has been marked as delivered, this will initiate email notifications to both the shipper and carrier accounts 216 inviting each to return to the system as visitors 24 and grade each other. Following a link in the notification email back to the system 218 as a visitor 24 , the visitor will complete a yet-to-be-determined and always changing set of feedback items that will provide a numerical score for the account 34 being rated 220 . When the visitor 24 submits the grade to the system, the database will calculate a numerical score for the rated account 34 based on previously submitted grades as well as this one and upgrades 222 the account's 34 grade. Once the account has received it's new grade, the account being graded will be notified by email 224 that it has been graded by the visitor's 24 account 34 .
[0039] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0040] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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A method and system for electronically matching shipper user requests for motor vehicle transport companies (carriers) who meet the criteria needed for transporting such motor vehicles via a web-based application utilizing web structures (visitor and referral tracking, membership and account management, billing and invoicing, electronic commerce, and back-office management tools) and a unique post-bid mechanism that functions similar to a reverse electronic auction. Shippers create an account and enter load details into the system for carriers to bid on. Each load can be set with an expiration date and deadline for bid submission. Carriers create an account and pre-determined profile describing their services, at which point the system will match carriers with the shipper's load details (based on their profile) and notify each carrier that it can place a bid to transport that load of motor vehicle(s). Any qualified carrier can then place one bid on each load of automobiles it is qualified to carry. The shipper of the automobiles will, either at the expiration date and time or upon terminating the bidding early, select the most qualified bid from the list of resulting bids and enter into an agreement with the carrier submitting the bid. Should that carrier accept the agreement, the load of automobiles is then awarded to that carrier for transport.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 11/636,337, filed Dec. 8, 2006 now U.S. Pat. No. 7,598,710 and entitled BATTERY CHARGER WITH TEMPERATURE CONTROL, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to the field of electronic circuits. More particularly, the present invention relates to battery charger integrated circuit.
BACKGROUND
It is a common experience that when charging a battery, the battery charger integrated circuit (IC) that generates the charging current tends to overheat. The rise in temperature is caused by the IC power consumption in form of heat dissipation of the charging current. Naturally, when the charging current is reduced, the heat is also reduced. Over the years, there have been many attempts to achieve an optimal charging current value that effectively charges the battery and does not overheat battery charger IC at the same time. Some of these attempts seem to be either too complicated or too expensive. Because most of the rechargeable batteries are used in consumer electronic products, the cost and the size of the battery charger IC are important factors for the electronics manufacturers.
The present invention provides an effective, small-sized, and inexpensive circuit and a method to achieve both effective charging and overheating prevention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 illustrates a block diagram of a battery charger with temperature control that has a temperature sensing circuit and a charging current generator circuit in accordance with an embodiment of the present invention.
FIG. 2 illustrates a detailed schematic diagram of the battery charger with temperature control in accordance with an embodiment of the present invention.
FIG. 3 illustrates a flow chart illustrating a method of temperature control in a batter charger circuit in accordance with an embodiment of the present invention
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to different embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these different embodiments, it will be understood that they are not intend to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of the ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
Now referring to FIG. 1 , a block diagram of a battery charger integrated circuit (IC) with temperature control 100 in accordance with an embodiment of the present invention is illustrated. Battery charger integrated circuit with temperature control 100 includes a temperature sensing circuit 100 electrically coupled to a charging current generator circuit 120 . Temperature sensing circuit 110 receives a first reference voltage (VREF 1 ) 101 and reading temperature voltage (VDT) obtained from a direct temperature measurement of battery charger integrated circuit 100 . In one embodiment, a die temperature indicator (DTI) 102 is used to measure the temperature of battery charger integrated circuit 100 . The current generated by the die temperature indicator (DTI) 102 is proportional to the temperature of battery charger integrated circuit 100 . This current is converted into temperature reading voltage (VDT) by a sensing resistor (RT) 103 . Temperature sensing circuit 110 compares the temperature reading voltage (VDT) with the first reference voltage (VREF 1 ) and generates a second reference voltage (VREF). The second reference voltage (VREF) is, in turn, fed to charging current generator circuit 120 . Charging current generator circuit 120 uses the second reference voltage (VREF) to generate a reference current (I 1 ) and a charging current (IOUT) for a battery 160 that is plugged into battery charger integrated circuit 100 . In one embodiment, charging current (IOUT) mirrors the reference current (I 1 ) and is linearly proportional to second reference voltage (VREF), e.g., IOUT is proportional to VREF.
In operation, temperature sensing circuit 110 compares the temperature reading voltage (VDT) with first reference voltage (VREF 1 ). Whenever temperature reading voltage (VDT) surpasses first reference voltage (VREF 1 ), temperature sensing circuit 110 adjusts second reference voltage (VREF). As such, charging current generator circuit 120 senses the adjustment in second reference voltage (VREF) and changes the reference current (I 1 ) that, in turn, changes the charging current (IOUT). In one embodiment, temperature sensing circuit 110 is constructed so that second reference voltage (VREF) is linearly proportional to first reference voltage (VREF 1 ) and temperature reading voltage (VDT). In one embodiment, temperature sensing circuit 110 is constructed in such a manner that second reference voltage is a function of the first reference voltage (VREF 1 ) and the temperature reading voltage (VDT). It is noted that any relationship between first reference voltage (VREF 1 ) and second reference voltage (VREF) so that the change in the temperature reading voltage (VDT) causes a change in second reference voltage (VREF) that causes a change in the charging current (IOUT) is within the scope of the present invention
Now referring to FIG. 2 , the detailed schematic diagram of a battery charger integrated circuit with temperature control 200 in accordance with an embodiment of the present invention is illustrated. More particularly, temperature sensing circuit 110 includes a first error amplifier 201 that is electrically coupled to a first n-channel Metal Oxide Semiconductor (nMOS) 202 and a resistive divider circuit configured by a first resistor (R 1 ) 203 and a second resistor (R 2 ) 204 . More particularly, first reference voltage (VREF 1 ) is electrically connected to an inverting terminal of first error amplifier 201 . Die temperature indicator (DTI) 102 is connected between the inverting terminal and non-inverting terminal of first error amplifier 201 . Sensing resistor (RT) is connected to the non-inverting terminal of first error amplifier 201 and an electrical ground 111 . The output terminal of first error amplifier 201 is electrically coupled to the gate of first nMOS transistor 202 . First resistor (R 1 ) 203 is electrically connected to the inverting terminal of first error amplifier 201 and the drain of first nMOS transistor 202 . Second resistor (R 2 ) 204 is electrically coupled between the drain and the source of first nMOS transistor 202 .
Continuing with FIG. 2 , charging current generator circuit 120 includes a second error amplifier 211 connected in series to a second nMOS transistor 212 , and current mirror circuit configured by a first pnp bipolar junction transistor 214 and a second pnp bipolar junction transistor 215 . More particularly, first pnp bipolar junction transistor 215 and second pnp bipolar junction transistor 215 form a current mirror with first pnp bipolar junction transistor 214 . First pnp bipolar junction transistor 214 is connected as a diode and its collector connected to the drain of second nMOS transistor 212 . The collector of second pnp bipolar junction transistor 215 is connected to battery 162 . The bases of first pnp bipolar junction transistor 214 and second bipolar junction transistor are connected together and to an input voltage (VIN) 150 . The non-inverting terminal of second error amplifier 211 is connected to the source of second nMOS transistor 212 and to a resistor (RC) 213 . The other terminal of resistor (RC) 213 is connected to electrical ground 111 .
Referring again to FIG. 2 , in operation, when reading temperature voltage (VDT) is less than first reference voltage (VREF 1 ), the output of first error amplifier 201 is LOW, causing first nMOS transistor 202 to be in cutoff mode. As a result, second reference voltage (VREF) equals to first reference voltage (VREF 1 ) divided by the sum of first resistor (R 1 ) 203 and second resistor (R 2 ) 204 and multiplied by second resistor (R 2 ) 204 . However, as the temperature of battery charger integrated circuit 200 increases, temperature reading voltage (VDT) also increases. If temperature reading voltage (VDT) exceeds first reference voltage (VREF 1 ), the ratio between first reference voltage (VREF 1 ) and second voltage reference (VREF) will start to change. Second reference voltage (VREF) is fed to charging current generator circuit 120 . There, second reference voltage (VREF) is compared with voltage (VX) at the non-inverting terminal of second error amplifier 211 . Second error amplifier 211 is configured such that it sets voltage (VX) equals to second reference voltage (VREF). Thus, the reference current (I 1 ) equals second reference voltage (VREF) divided by resistor (RC) 213 . In one embodiment, first npn bipolar transistor (Q 1 ) and second npn bipolar transistor (Q 2 ) 215 have different sizes so that the charging current (IOUT) is proportional to the reference current (I 1 ) by a factor of K. When the temperature reading voltage (VDT) exceeds first reference voltage (VREF 1 ), reflecting the limit in the temperature of the die temperature indicator (DTI) 102 is reached, first error amplifier 201 adjusts its output voltage that turns on first nMOS transistor 202 . The turning on of first nMOS transistor 202 changes the value of resistive divider ratio by bypassing currents to electrical ground 111 from second reference voltage (VREF) node, thus changing second reference voltage (VREF). This change in second reference voltage (VREF) is introduced to charging current generator circuit 120 at the non-inverting terminal of second error amplifier 211 . The lowering of second reference voltage (VREF) reduces the gate voltage of second nMOS transistor 212 . Thus, the reference current (I 1 ) is also reduced. As a consequence, the charging current (IOUT) will also be reduced.
Now referring to FIG. 3 , a flow chart 300 representing a method of providing temperature control for a battery charger circuit is illustrated. Method 300 includes the steps of providing a temperature reading voltage, providing reference voltages that are related to the temperature reading voltage, comparing the first reference voltage (VREF 1 ) with the temperature reading voltage (VDT), and adjusting the second reference voltage (VREF) in order to reduce the temperature whenever the temperature reading voltage (VDT) surpasses the first reference voltage (VREF 1 ).
Now referring to step 301 , a temperature reading voltage (VDT) is provided that is proportional to the die temperature indicator of the batter charger circuit. In reality, step 301 is implemented by connecting a die temperature indicator (DTI) to a sensing resistor (RT) across the two input terminals of an error amplifier such as first error amplifier 201 as shown in FIG. 2 of the present invention.
Referring now to step 302 , a first reference voltage (VREF 1 ) is provided. Also in step 302 , a second reference voltage (VREF) is derived from first reference voltage (VREF 1 ). Then, a reference current (I 1 ) and charging current (IOUT) are generated using the second reference voltage (VREF). Step 302 is implemented by connecting first reference voltage (VREF 1 ) source to the inverting terminal of first error amplifier 201 as shown in FIG. 1 and FIG. 2 .
Referring to step 302 , temperature reading voltage (VDT) is compared with first reference voltage (VREF 1 ). Step 302 is implemented by first error amplifier 201 connected to die temperature indicator (DTI) 102 and sensing resistor (RT) 103 as shown in FIG. 2 of the present invention.
Referring now to step 304 , whenever the temperature reading voltage (VDT) surpasses the first reference voltage (VREF 1 ), adjusting the second reference voltage (VREF) so that the charging current (IOUT) is adjusted. Step 304 is implemented by temperature sensing circuit 110 connected to charging current generator circuit 120 as shown in FIG. 2 . If the temperature reading voltage (VDT) is less than the first reference voltage, continue step 303 and the normal operation of battery charger circuit 200 .
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. It should be understood, of course, the foregoing disclosure relates only to a preferred embodiment (or embodiments) of the invention and that numerous modifications may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims. Various modifications are contemplated and they obviously will be resorted to by those skilled in the art without departing from the spirit and the scope of the invention as hereinafter defined by the appended claims as only a preferred embodiment(s) thereof has been disclosed.
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A battery charger integrated circuit with temperature control is disclosed that includes a temperature sensor circuit and a charging current generator circuit. Upon receiving a temperature reading voltage (VDT), the temperature sensing circuit is operable to generate a second reference voltage (VREF) that is a function of the first reference voltage (VREF 1 ). The charging current generator circuit generates and continuously adjusts a reference current (I 1 ) and a charging current (IOUT) according to the second reference voltage (VREF). Whenever the temperature reading voltage (VDT) exceeds the first reference voltage, the temperature sensor circuit is operable to adjust the second reference voltage (VREF).
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PRIORITY APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 15/212,902, filed Jul. 18, 2016, which is a continuation of U.S. application Ser. No. 13/961,377, filed Aug. 7, 2013, now issued as U.S. Pat. No. 9,477,616, all of which are incorporated herein by reference in their entirety.
BACKGROUND
[0002] Apparatus such as computers and other electronic products (e.g., digital televisions, digital cameras, cellular phones, tablets, gaming devices, e-readers, and the like) often have memory devices with memory cells to store information. Oftentimes, such apparatuses have multiple memory devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a block diagram of an embodiment of a system that contains selectable devices.
[0004] FIG. 2 is a flowchart illustrating an embodiment of an example method to select a device to perform an operation.
[0005] FIG. 3 is a flowchart illustrating an embodiment of an example method to set a device identification.
[0006] FIG. 4 is a flowchart illustrating an embodiment of an example method to select a device to perform an operation.
DETAILED DESCRIPTION
[0007] In a system with multiple devices, such as a memory system with multiple dies, a Chip Select (CS#) reduction method enables a system to save board space by sharing CS#, Command/Address bus (CA bus), and/or a data bus across more than one device.
[0008] Several terms are to be defined first. ID_a is an assigned identifier (id) value held by the device as set by an AssignID command. An ID_a is selected once upon initialization and is not changed until the device is initialized again. An ID_s (or select identifier) is used to select which device is to be used to perform a command.
[0009] In accordance with a CS# reduction method, in order for a system to indicate which device(s) it wishes to target for operation among those on the shared signaling, it must first configure an ID_a value for each device in the system following a power cycle. Then to enable a device(s) response to subsequent command(s), it will issue a SelectID command such that ID_s is equal to the ID_a of the targeted device(s). The ID_a assignment sequence is dependent on the presence of a SIN/SOUT (Select Input and Select Output) daisy chain between all devices in the system as shown in FIG. 1 .
[0010] FIG. 1 shows system 100 comprising devices 10 , 120 , 130 , and 140 . Device 110 has an SIN 112 and an SOUT 114 . Device 120 has an SIN 122 and an SOUT 124 . Device 130 has an SIN 132 and an SOUT 134 . Device 140 has an SIN 142 and an SOUT 144 . Devices 110 , 120 , 130 , and 140 are daisy chained to each other in that SOUT 114 is coupled to SIN 122 . SOUT 124 is coupled to SIN 132 , and SOUT 134 is coupled to SIN 142 . It should be understood that each of devices 110 , 120 , 130 , and 140 may have other inputs not illustrated in FIG. 1 . For example, the devices may have a chip select input and a command/address input in addition to SIN and SOUT.
[0011] Upon the initialization of system 100 , SIN 112 is internally pulled high while SOUT 114 , SOUT 124 , SOUT 134 , and SOUT 144 are all internally driven to a low level. Once device 110 has its ID_a set as part of the initialization process, it will drive SOUT 114 high to enable the next device in the chain (device 120 ) to accept an AssignID command to set its ID_a. This continues for each of devices 120 , 130 , and 140 . It should be understood that while four devices 110 , 120 , 130 , and 140 are shown in FIG. 1 , this process can be expanded to include more devices. Upon initialization, the first device in the chain (e.g., device 110 of FIG. 1 ) will have its SIN internally pulled high and all devices will have SOUT internally driven low. A device will only accept the AssignID command when its SIN is high. Once a device has its id set, it will drive its SOUT high to enable the next device in the chain (e.g., device 120 of FIG. 1 ) to accept the AssignID command. SOUT may also be left to FLOAT after the id is set. In this manner, the pull-up on the SIN pulls the line to a high logic level. It should be understood that the polarity and actual implementation of this daisy-chain logic is relative to this example. The polarity levels can be reversed such that a low logic level enables the device, in other implementations.
[0012] With continued reference to FIG. 1 , Chip Select (CS#) 150 and Command/Address bus (CA) 160 are also present. CS# 150 is coupled to device 110 via CS line 152 , which is in turn coupled to each of devices 120 , 130 , and 140 via CS line 152 . Command/Address bus 160 is coupled to each of devices 110 , 120 , 130 , and 140 via CA line 162 .
[0013] After setting the ID_a for each device, to enable a device(s) response to subsequent command(s), a system will issue the SelectID command such that ID_s is equal to the ID_a of the targeted device(s). Thereafter, the system selects which device is to perform a command through use of the ID_s. When commands need to be issued for another device, another SelectID command will be issued. A flowchart illustrating such a process is provided as FIG. 2 .
[0014] An incoming command is analyzed ( 202 ). If the incoming command is a SelectID command ( 204 ), then the ID_s variable is updated to the value specified in the command being analyzed ( 206 ). Thereafter, control continues with the next command ( 202 ).
[0015] If the incoming command is not a SelectID command, then the devices maintain the ID_s as set by the last SelectID command. If the ID_s is equal to the ID_a, then the command is executed ( 210 ), e.g., the operation is performed. Otherwise the command is ignored, because it is intended for another device in the system ( 212 ). Thereafter, the flow continues with the next command to be analyzed ( 202 ).
[0016] Each device in the system performs the method outlined in FIG. 2 . Therefore, each command will eventually be executed by a device with an ID_a equal to the ID_s of the command.
[0017] Across the shared signaling, more than one device may share the same ID_a value if a system desires parallelism. In other words, by setting the ID_a of each of devices 110 , 120 , 130 , and 140 to the same value, a command will be processed by each of devices 110 , 120 , 130 , and 140 . In one alternative, each device may have a unique ID_a if a system desires access to each individual device. In another alternative, partial parallelism may be obtained by setting the same ID_a of each device in the group of devices intended to perform the command, while setting the ID_a of other devices to a different value.
[0018] Once the ID_a is set via the AssignID command, subsequent AssignID commands are ignored and it cannot be changed without a power cycle and/or id scheme reassignment sequence.
[0019] A problem may arise in the case where the daisy chain of SIN/SOUT connections within a system or across devices in a system is broken due to a defect or performance marginality. A failure which prevents or delays a device from having its intended ID_a set may prevent every other device behind it in the daisy chain from receiving its intended ID_a. With reference to FIG. 1 , if device 120 fails, then devices 130 and 140 will not be able to receive the AssignID command. Redundancy schemes of parity/XOR and spare devices cannot address this issue. The unsuccessful assignment of each ID_a throughout the system will cause the incorrect number of devices to respond to system operation and can result in unacceptable data loss or even total system failure in some circumstances.
[0020] A method is presented by which the risk of unacceptable data loss and/or total system failure due to any break in the SIN/SOUT daisy chain may be contained within the system manufacturing environment.
[0021] In this scheme, the value of ID_a for each device is stored to a persistent area within the device and within the system manufacturing environment. Persistent areas may include, but are not limited to: poly-fuses, metal fuses, memory array cells, non-volatile memory, and the like. In one embodiment, a persistent area is a fuse or set of fuses that store the ID_a.
[0022] Upon subsequent device initializations, logic will check if the value for its ID_a should be loaded from a persistent area stored within the device or not. If values stored within the persistent area are available, as would be the case upon exit from the system manufacturing environment, the ID_a value is set according to the persistent identifier stored in the persistent area. Thus, ID_a assignment is now independent of the SIN/SOUT daisy chain.
[0023] With reference to FIG. 3 , a flowchart illustrating the logic used to set ID_a is shown. Upon initialization, ID_s and ID_a are set to 0x00 ( 302 ). It should be understood that this value is just for purposes of this example only. Other values of ID_s and ID_a may also be used. In this example, 0x00 serves as a known default value. Thereafter, a flag named id_assigned_flag is set to FALSE ( 304 ). Then the device is checked to determine if a flag persistent_id_flag is TRUE. Persistent_id_flag is a flag that indicates whether or not the device in question has a value that has already been stored in the persistent area. If the persistent id has already been set, then ID_a is set to the value contained in the persistent area ( 350 ). The next command is accepted ( 352 ). Thereafter. ID_s is checked to determined if it is equal to ID_a ( 354 ). If not, no action is taken ( 356 ) and the next command is worked on ( 352 ). If ID_s is equal to ID_a, then the command is intended for the device and the operation is performed ( 358 ).
[0024] If the persistent id_flag has not been set, then the first command has to be analyzed to determine if the command is intended to set the ID_a of the device ( 308 ). If so, id_assigned_flag is then checked to determine if it is FALSE in combination with SIN=Asserted. If both conditions are met, then ID_a is set for the device ( 316 ), the id_assigned_flag is set to TRUE ( 318 ), and SOUT is set high ( 320 ). If either condition is not met, the command is ignored.
[0025] If the first command was not intended to set the ID_a of the device, the operation is performed ( 319 ) and SOUT is set high ( 320 ) such that all subsequent commands are performed without deference to the state of ID_s relative to ID_a (i.e., CS# reduction method is not used).
[0026] After the SOUT is asserted, the next command is accepted ( 322 ). If id_assigned_flag is TRUE, then ID_s is checked to see if it is equal to ID_a (i.e., is the command intended for this particular device) ( 326 ). If not, then no operation is taken ( 334 ) and the next command is accepted ( 322 ). Otherwise, the command is intended for the device. The command is checked to see if it is intended to write ID_a to the persistent area ( 328 ). It should be understood that the diagram depicts a single command for ease of illustration. The decision to write the ID_a to persistent area may be a single command or a series of commands. If not, then the operation is performed ( 332 ) and then the next command is accepted ( 322 ).
[0027] If the command is intended to write ID_a to the persistent area, then ID_a is written to the persistent area and the persistent id_flag is set to TRUE ( 330 ). Thereafter, the next command is accepted ( 322 ). Otherwise, the operation is performed ( 332 ) and then the next command is accepted ( 322 ).
[0028] Pursuant to the limitations of the persistent areas that are used to store the persistent values (e.g., loaded from values as programmed to poly-fuses, metal fuses, memory array cells, etc.), these can be configured and reconfigured at any time during the lifetime of the device.
[0029] Even in the case of a failure or marginality of the SIN/SOUT connection, system failure is avoided because each die has a valid ID_a.
[0030] Another problem may also exist. As described above, upon initialization, the first device in the chain (e.g., device 110 from FIG. 1 ) will have its SIN internally pulled high and all devices will have SOUT internally driven low. A device will only accept the AssignID command when its SIN is high. Once a device has its id set, it will drive its SOUT high to enable the next die in chain (e.g., device 120 ) to accept the AssignID command.
[0031] Once all devices have their ids set, devices react to subsequent system commands only if the ID_s of the command is =ID_a. Once the id is set via the AssignID command, subsequent AssignID commands are ignored and it cannot be changed without a power cycle.
[0032] A problem arises in the case where the system is required to toggle between two or more ID_a schemes, but without incurring a power cycle in between or requiring additional SelectID commands. Expected instances where avoidance of a power cycle and/or additional SelectID commands would be required include, but are not limited to:
[0033] 1) When a system has configured its ID_a scheme for parallel operation, but wishes to “mask” or isolate one or more devices on the shared signaling from any level of use. This may occur, for example, in cases where a system incorporates a spare/redundant device. In such an instance, the system may wish to mask the spare/redundant device from unnecessary operation(s) (e.g., for energy savings, etc.). With reference to FIG. 1 , a system may have each of device 110 , 120 , and 130 operating, but, for certain commands, device 140 would not be operating.
[0034] 2) When a system has configured its ID_a scheme such that there is both individual die access and parallel die access. In other words, there is more than one ID_a on the shared signaling (e.g., for individual die access), but then desires the performance of a parallel response for common and/or time-critical command sequences (e.g., power down entry, mode register write, etc.). This allows a system to avoid managing the overhead of iterating through the sequence of issuing a SelectID+command for each ID_a on the shared signaling.
[0035] One method by which this is possible is to create a second device identifier that all devices respond to, regardless of their current ID_a value. This identifier may be referred to as “ID_m” and is defined as follows:
[0036] ID_m=“master” id value held by the device, overrides ID_a
[0037] The ID_m value can be passed to the device by incorporating it into the existing SelectID command format, by creating a new command, or via any defined sequence of signal(s). The logic by which to enable or disable a device's response to receiving the ID_m value and the ID_m value itself can be either non-volatile values maintained by the device permanently or volatile values which can be managed by a system if desired (e.g., overwrite to entirely mask a device from operation until next power-cycle, etc.).
[0038] The example below describes one possible implementation and demonstrates how it can be used to resolve the problems previously outlined. In this example, there are four devices sharing a CS# and CA bus (e.g., devices 110 , 120 , 130 , and 140 from FIG. 1 ).
[0039] Assume the value for ID_m is defined and incorporated into the existing SelectID command such that all devices will respond to subsequent command(s) when the ID_s is set to 0x3Fh.
[0040] Now, if a system configured for parallelism needs to “mask” or isolate one or more devices on the shared signaling from any level of use, it may configure its id scheme as follows. With continued reference to FIG. 1 , assume that the system desires that device 130 be selectively masked from the rest of the devices. In such a situation, the ID_m of devices 110 , 120 , 130 , and 140 are each set to the same value (for illustrative purposes, ID_m=0x3Fh). But only the ID_a of devices 110 , 120 , and 140 are set to the same value (for illustrative purposes, ID_a=0x00h). The ID_a of device 130 is set to a separate, unique value, not equal to the ID_a of devices 110 , 120 , and 130 (for illustrative purposes, ID_a of device 120 =0x05h).
[0041] By setting the ID_a of device 130 to a unique value, the system can selectively mask device 130 from responding to commands by setting the ID_s of a command to 0x00h to exclude the device 130 . When a command is set to 0x00h, only device 110 , 120 , and 140 would execute the command—device 130 will ignore it because device 130 does not respond to commands intended for 0x00h. By setting the ID_s of a command to a value of 0x3Fh (the value of ID_m), each of devices 110 , 120 , 130 , and 140 will execute the command. Thus, the system can avoid the power cycles required to toggle between id configurations and avoid any overhead of issuing additional SelectID commands. The system can access all four of devices 110 , 120 , 130 , and 140 , or it can select devices 110 , 120 , and 140 in a parallel configuration to execute a command. The system can also access device 130 alone.
[0042] For systems configured with more than one ID_a, but that need selective parallel responses, it may configure its id scheme such that ID_m of each of devices 110 , 120 , 130 , and 140 is the same value (for illustrative purposes: 0x3Fh) while the ID_a of each device is different (for illustrative purposes the ID_a of device 110 is 0x00h, the ID_a of device 120 is 0x01h, the ID_a of device 130 is 0x02h, and the ID_a of device 140 is 0x03h). In this configuration, a system may set ID_s with values of 0x00/01/02/03 for individual access to devices 110 , 120 , 130 , or 140 , respectively. The system can set the ID_s to a value of 0x3Fh when desiring a parallel response to command(s) such that each of devices 110 , 120 , 130 , and 140 perform the command. By doing so, this system can avoid the power cycles normally required to toggle between id configurations and avoid any overhead of issuing additional SelectID commands.
[0043] FIG. 4 presents a flowchart illustrating the operation of a device in a system that is using ID_m. A command is received ( 402 ). As an initial matter, the command is analyzed to see if the command is a SelectID command ( 404 ). These commands are intended to set the ID_s of the next series of commands until another SelectID command is received. If the command is intended to set the ID_s, the ID_s is updated ( 406 ), and the system prepares for the next command ( 402 ). Until another SelectID command is issued, the ID_s associated with any command remains ID_s.
[0044] If the command is not a SelectID command, the ID_s of the command is checked to see if it is equal to the ID_m of the device ( 440 ). If so, the device performs the operation. If not, the ID_s is checked to see if it is equal to the ID_a of the device ( 408 ). If so, the device performs the operation ( 410 ). If not, the command is not intended for the device and is ignored ( 412 ). Thereafter, the device processes the next command ( 402 ).
[0045] These illustrations of apparatus are intended to provide a general understanding of the structure of various embodiments and are not intended to provide a complete description of all the elements and features of apparatuses that might make use of the structures described herein.
[0046] Any of the components described above can be implemented in a number of ways, including simulation via software. Thus, the apparatus described above may all be characterized as “modules” (or “module”) herein. Such modules may include or be included in hardware circuitry, single and/or multi-processor circuits, memory circuits, software program modules and objects and/or firmware, and combinations thereof, as desired by the architect of the apparatus and as appropriate for particular implementations of various embodiments. For example, such modules may be included in a system operation simulation package, such as a software electrical signal simulation package, a power usage and distribution simulation package, a capacitance-inductance simulation package, a power/heat dissipation simulation package, a signal transmission-reception simulation package, and/or a combination of software and hardware used to operate or simulate the operation of various potential embodiments.
[0047] The apparatus of various embodiments may include or be included in electronic circuitry used in high-speed computers, communication and signal processing circuitry, single or multi-processor modules, single or multiple embedded processors, multi-core processors, data switches, and application-specific modules including multilayer, multi-chip modules. Such apparatus may further be included as sub-components within a variety of electronic systems, such as televisions, cellular telephones, personal computers (e.g., laptop computers, desktop computers, handheld computers, tablet computers, etc.), workstations, radios, video players, audio players (e.g., MP3 (Motion Picture Experts Group, Audio Layer 3) players), vehicles, medical devices (e.g., heart monitor, blood pressure monitor, etc.), set top boxes, and others.
[0048] Embodiments of methods and apparatus similar to or identical to the embodiments described above with reference to FIG. 1 through FIG. 4 include the following:
[0049] In one embodiment, a method for selecting devices within a system that contains a first device, a second device, and a third device is presented. The method comprises: assigning an identical master identifier to each device within the system; assigning a first assigned identifier to the first device; assigning a second assigned identifier to the second device; assigning a third assigned identifier to the third device; and selecting each of the first device, second device, and third device by setting a select identifier to a value equal to the master identifier.
[0050] In another embodiment, the method may further comprise: selecting only the first device by setting a select identifier to a value equal to the first assigned identifier, selecting only the second device by setting a select identifier to a value equal to the second assigned identifier; and selecting only the third device by setting a select identifier to a value equal to the third assigned identifier; wherein the first assigned identifier is not equal to the second assigned identifier, the first assigned identifier is not equal to the third assigned identifier; and the second assigned identifier is not equal to the third assigned identifier.
[0051] In another embodiment, the method may further comprise: selecting only the first device by setting a select identifier to a value equal to the first assigned identifier, and selecting both the second device and the third device by setting a select identifier to a value equal to the second assigned identifier; wherein the first assigned identifier is not equal to the second assigned identifier, the first assigned identifier is not equal to the third assigned identifier; and the second assigned identifier is equal to the third assigned identifier.
[0052] In another embodiment, each of the first, second, and third devices in the system are memory devices.
[0053] In one embodiment, a method for selecting devices within a system that contains a first device, a second device, and a third device is presented. The method comprises: assigning a first assigned identifier to the first device; assigning a second assigned identifier to the second device; assigning a third assigned identifier to the third device; wherein assigning the first assigned identifier to the first device comprises setting the first assigned identifier equal to a persistent identifier associated with the first device.
[0054] In another embodiment, the persistent identifier is stored in a persistent area of the device.
[0055] In another embodiment, assigning the second assigned identifier to the second device comprises setting the second assigned identifier equal to a second persistent identifier associated with the second device. The persistent identifier is stored in a persistent area of the second device.
[0056] In another embodiment, assigning the third assigned identifier to the third device comprises setting the third assigned identifier equal to a third persistent identifier associated with the third device; wherein the third persistent identifier is stored in a persistent area of the third device.
[0057] In one embodiment, a method of executing a command on a device within a multiple device system is presented. The method may comprise: receiving a command; updating a select identifier when the command is a SelectID command; determining if there is a persistent identifier associated with the device; setting the assigned identifier of the device from a persistent area within the device when there is a persistent ID associated with the device; determining if the command is intended for the device by comparing the select identifier (ID_s) to the assigned identifier (ID_a) of the device; ignoring the command when the command is not intended for the device; and performing the command when the command is intended for the device.
[0058] In another embodiment, the method may further comprise: determining if the command is intended to write a persistent identifier to the device: writing the persistent identifier to a persistent area of the device.
[0059] In another embodiment, the method may further comprise: determining if the command is intended to write a value to the assigned identifier of the device; determining if the assigned identifier has previously been set: determining if a select input (SIN) to the device is asserted; and writing the value to the assigned identifier to the device when each of the determining steps above are true.
[0060] In another embodiment, the method may further comprise: asserting a select output (SOUT) output of the device; wherein the SOUT of the device is coupled to an SIN of a second device.
[0061] In one embodiment, a system may comprise: a first device having a first master identifier and a first assigned identifier, the first device being capable of being accessed using either the first master identifier or the first assigned identifier; a second device having a second master identifier and a second assigned identifier, the second device being capable of being accessed using either the second master identifier or the second assigned identifier; and third device having a third master identifier and a third assigned identifier, the third device being capable of being accessed using either the third master identifier or the third assigned identifier. The system accesses one of the first, second, or third devices by setting a select identifier to one of the first master identifier, second master identifier, third master identifier, first assigned identifier, second assigned identifier, or third assigned identifier.
[0062] In another embodiment, the first master identifier, the second master identifier, and the third master identifier are each set to a first value; the first assigned identifier and the second assigned identifier are each set to a second value that is different from the first value; and the third assigned value is set to a third value that is different from the first and second values.
[0063] In another embodiment, the system is arranged to access each of the first, second, and third devices by setting the select identifier to the first value; the system is arranged to access the first and second devices by setting the select identifier to the second value; and the system is arranged to access the third device by setting the select identifier to the third value.
[0064] In another embodiment, the first master identifier, the second master identifier, and the third master identifier are each set to a first value; the first assigned identifier is set to a second value that is different from the first value; the second assigned identifier is set to a third value that is different from the first value and the second value; and the third assigned value is set to a fourth value that is different from the first value, second value, and third value.
[0065] In another embodiment, the system is arranged to access each of the first, second, and third devices by setting the select identifier to the first value; the system is arranged to access the first device by setting the select identifier to the second value; and the system is arranged to access the second device by setting the select identifier to the third value; and the system is arranged to access the third device by setting the select identifier to the fourth value.
[0066] In another embodiment, each of the first, second, and third devices are memory devices.
[0067] In one embodiment, a device may comprise: a chip select input; a command/address input; a select in (SIN) input; a select out (SOUT) output; and a persistent area. The persistent area is configured to contain a value for an assigned identifier.
[0068] In another embodiment, the device is arranged to set the assigned identifier from the persistent area.
[0069] In another embodiment, the device may further comprise a flag. The flag indicates if the device sets the assigned identifier from the persistent area or if an external entity sets the assigned identifier.
[0070] In another embodiment, the device is arranged to set an assigned identifier if the SIN is set to a high level.
[0071] In another embodiment, the device is arranged to receive an assigned identifier value via the command/address input.
[0072] In another embodiment, the SOUT is arranged to be coupled to the SIN of another device.
[0073] In another embodiment, the device is arranged to write a value to the persistent area.
[0074] In another embodiment, the persistent area is selected from one of the following: poly-fuses, metal fuses, memory array cells, and non-volatile memory.
[0075] The above description and the drawings illustrate some embodiments of the invention to enable those skilled in the art to practice the embodiments of the invention. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Examples typify possible variations. Portions and features of some embodiments may be included in, or substituted for, those of others. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description.
[0076] The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
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Several systems and methods of chip select are described. In one such method, a device maintains two identifiers, (ID_a and ID_m). When the device receives a command, it examines the values of ID_a and ID_m relative to a third reference identifier (ID_s). If either ID_a or ID_m is equivalent to ID_s, the device executes the command, otherwise, the device ignores the command. By using two different identification methods, a system has options in choosing to activate devices, being able to selectively switch between selecting multiple devices and single devices in a quick manner. In another such method, a device may have a persistent area that stores identification information such as an ID_a. Thus, system functionality may remain independent from any defect/marginality associated with the physical or logical components required for initial ID_a assignment of all devices in the system.
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BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates to hybrid electric vehicles and a method for estimating vehicle wheel torque.
2. Background Art
Unlike pure electric vehicles that use a battery as a power source for a motor in a power flow path to traction wheels, a hybrid electric vehicle has an engine (typically an internal combustion engine) and a high voltage motor for powering the vehicle. A known powertrain configuration for a hybrid electric vehicle consists of two power sources that are connected to the vehicle traction wheels through a planetary gearset. A first power source in this powertrain configuration is a combination of an engine, a generator and a planetary gearset. A second power source comprises an electric drive system including a motor, a generator and a battery subsystem. The battery subsystem acts as an energy storing device for the generator and the motor.
In the case of the first power source, the engine speed can be decoupled from the vehicle speed since the generator acts as a torque reaction element for a reaction gear of the planetary gearset. This results in both a mechanical torque flow path and an electromechanical torque flow path, which function in tandem to deliver driving torque to the vehicle traction wheels. The generator reaction torque effects engine speed control as it provides a reaction torque in the torque flow path from the engine. This operating mode commonly is referred to as a non-parallel operating mode. If the generator is braked, the reaction element of the gearset also becomes braked, which establishes a fully mechanical power flow path from the engine to the traction wheels through the gearset. This is referred to as a parallel operating mode. An example of a powertrain configuration of this type can be seen by referring to co-pending U.S. patent application Ser. No. 10/248,886, filed Feb. 27, 2003, now U.S. Pat. No. 6,991,053, dated Jan. 31, 2006. This co-pending patent application is assigned to the assignee of the present invention.
In the powertrain configuration disclosed in the co-pending patent application, torque is delivered through the powertrain for forward motion only in the case of the first power source. In the case of the second power source, the electric motor draws electric power from the battery and provides driving torque independently of the engine in both forward and reverse drive. In this operating mode, the generator, using battery power, can drive against a one-way clutch on the engine output shaft to propel the vehicle forward.
A control system is used to effect integration of the two power sources so that they work together seamlessly to meet the driver's demand for power at the traction wheels without exceeding the limits of the battery subsystem. This is accomplished in the powertrain of the co-pending patent application by coordinating the control of the two power sources. Under normal powertrain operating conditions, a vehicle system controller interprets a driver demand for power, which may be an acceleration or deceleration demand, and then determines a wheel torque demand based on driver demand and powertrain limits. The vehicle system controller also will determine when and how much torque each power source must provide to meet the driver's demand and to achieve specified vehicle performance, such as fuel economy, emissions, driveability, etc. The vehicle system controller can control the engine operating speed for each torque demand so that an efficient operating point on the speed-torque engine characteristic curve will be established.
A control system of the type discussed in the preceding paragraphs requires a so-called drive-by-wire control system as the two power sources cooperate seamlessly to achieve optimal performance and efficiency. Such a drive-by-wire system requires a torque monitor strategy to ensure that the control system wheel torque demand and the actual powertrain torque output are within a predefined range so that unintended vehicle acceleration will be avoided.
U.S. Pat. No. 5,452,207, which is owned by the assignee of the present invention, discloses a torque estimation method based on a vehicle dynamics model, a torque converter model and an engine torque model. Estimates of torque are obtained from at least two of the models. The torque estimates are weighted according to a predefined strategy and then transferred to a controller for developing torque estimates based on the weighted individual torque estimates.
A wheel torque estimation strategy is disclosed also in U.S. Pat. No. 5,751,579, which also is owned by the assignee of the present invention. It provides an estimate of wheel torque based upon engine combustion torque. The estimated torque is proportional to engine acceleration and engine powertrain mass.
SUMMARY OF INVENTION
The control method of an embodiment of the invention will provide an estimate of the total output torque at the traction wheels for any given driving condition. The torque estimate is used to perform wheel torque monitoring. The method estimates total wheel torque for any given torque of the motor, the generator and the engine in various operating modes. These modes include a non-parallel mode and a parallel mode.
When the powertrain configuration is operating in a non-parallel mode, both the engine and the motor cooperate with the gearset to establish both a mechanical torque flow path and an electromechanical torque flow path. In a so-called parallel operating mode, the generator rotor is braked.
The method of the invention performs a torque monitoring function to ensure that the vehicle does not accelerate when acceleration is not intended. It eliminates the need for using a torque sensor for measuring total wheel torque.
The method uses multiple powertrain inputs, including motor speed, generator speed, engine speed, motor torque, generator torque, engine torque and generator brake status. After calculating engine and motor angular accelerations, the strategy will determine the operating mode. Separate subroutines are used for the non-parallel mode (both positive and negative power flow) and the parallel mode to calculate output torque of the gearset.
After the output torque of the gearset is computed in either of the separate subroutines, the strategy computes a total wheel torque estimate.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic representation of a hybrid electric vehicle powertrain for an automotive vehicle capable of embodying the present invention;
FIG. 2 is a flowchart illustrating the control software strategy for calculating an estimate of total wheel torque; and
FIG. 3 is a sub-routine used in carrying out the routine of FIG. 2 wherein the operating mode for the powertrain is determined.
DETAILED DESCRIPTION
The powertrain of FIG. 1 includes an internal combustion engine as shown at 10 . A planetary gear unit 12 includes a ring gear 14 , which is connected driveably to a torque input countershaft gear element 16 . The engine torque output shaft is connected driveably to carrier 18 for the planetary gear unit 12 . Sun gear 20 of the planetary gear unit 12 is connected driveably to generator 22 . The generator is electrically coupled, as shown at 24 , to a high voltage electric motor 26 , which may be an induction motor. The output rotor of the motor is connected to gear element 28 of torque output countershaft gearing 30 . A countershaft gear 32 engages gear 16 . A countershaft gear of larger pitch diameter, shown at 34 , driveably engages motor output drive gear element 28 . A smaller pitch diameter countershaft gear element 36 driveably engages torque output gear 38 , which distributes torque to a differential-and-axle assembly 40 to deliver driving torque to vehicle traction wheels 42 .
A generator brake 44 , when applied, anchors the rotor of generator 22 , which also anchors sun gear 20 . When the generator brake is applied, a mechanical torque flow path from the engine to the differential-and-axle assembly 40 is established. This is referred to as a parallel driving mode. When the brake 44 is released, reaction torque of the generator establishes torque reaction for the sun gear 20 because of the direct mechanical coupling between the sun gear and the generator rotor. Engine speed thus can be controlled by controlling generator.
The generator torque is under the control of transmission control module 46 , which communicates with vehicle system controller 48 . Input variables for the vehicle system controller 48 include a driver-controlled drive range selection at 50 and a signal from an accelerator pedal position sensor 52 . Another driver input for the vehicle system controller is a brake pedal position sensor signal 56 .
Battery 58 is connected to the generator 22 and the motor 26 through a high voltage bus 60 . The battery is under the control of the vehicle system controller by means of a contactor control signal at 62 .
The transmission control module receives from the vehicle system controller a desired wheel torque signal, a desired engine speed signal and a generator brake command as shown at 64 . The transmission control module 46 distributes a generator control signal through signal flow path 68 that extends from the module 46 to the brake 44 .
For the purpose of describing the output torque estimation method, reference will be made to the strategy flow charts of FIGS. 2 and 3 . The various method steps involved in the strategy of FIGS. 2 and 3 make use of moment of inertia terms, torque ratio terms, torque terms and angular acceleration terms for elements of the powertrain. Some of these terms are as follows:
J eng is the combined inertia values for engine and carrier;
J gen — couple is the combined moment inertia of the generator/sun gear;
J mot — eff the sum of the combined motor/gear inertia and the generator inertia reflected at the motor;
T gen2mot is the torque ratio from generator shaft to motor shaft;
T eng2mot is the torque ratio from engine shaft to motor shaft; and
T mot2wheel is the torque ratio from motor shaft to wheel.
In FIG. 2 , the strategy routine begins at 70 , where the various inputs for the controller 48 are read and then stored in computer memory (RAM). The inputs are motor speed, ω mot , generator speed, ω gen , engine speed, ω eng , motor torque, τ mot , generator torque, τ gen , engine torque, τ eng , and generator brake status (the brake 44 is either “on” or “off”). The default operating mode is a non-parallel mode indicated by the statement “Parallel Mode=FALSE.”
The first entry in the initialization step sets the parallel mode (internal variable) to FALSE. This occurs in the first entry only. As the strategy routine proceeds, the operating mode will be determined for each control loop of the processor, as will be explained subsequently.
The routine then proceeds to action block 72 , where motor angular acceleration is calculated. This is done using the functional relationship: dotω mot =dω mot /dt, which is a derivative of the angular velocity of the motor rotor. The result of the calculation at action block 72 is stored in memory, and the routine then proceeds to action block 74 where the engine angular acceleration is calculated. This is done in accordance with the following relationship: dotω eng =dω eng /dt, which is the derivative of the angular engine velocity.
After the information obtained at action block 74 is stored in memory, the routine proceeds to action block 76 , where the operating mode is determined. The routine at action block 76 is a subroutine indicated in FIG. 3 . That subroutine will determine whether the powertrain is in the parallel mode or in the non-parallel mode. As explained previously, the generator brake is applied when the powertrain is in the parallel mode and is released to establish plural power flow paths in the non-parallel mode. As previously explained also, the default operating mode is a non-parallel mode.
The routine then will proceed to decision block 78 , where the controller will determine whether the generator brake is on. If the inquiry at 78 is negative, the operating mode set during initialization is confirmed. If the inquiry at 78 is positive, the routine will proceed to decision block 80 , where it is determined whether the generator speed is less than a predetermined threshold generator speed C gen — spd .
If the result of the inquiry at 80 is negative, the non-parallel mode determination is confirmed. If the result of the inquiry at 80 is positive, the routine then will proceed to decision block 82 , where it is determined whether the generator torque is less than a predetermined threshold C gen — tq .
If the result of the inquiry at 82 is negative, the non-parallel mode is confirmed. If the result of the inquiry at 82 is positive, the parallel mode is set to “TRUE”, which is a change in mode from non-parallel operation to parallel operation. This occurs at action block 84 .
If the powertrain is in a parallel operating mode, as determined at decision block 86 ′, the control routine will proceed to decision block 88 , where it is determined whether the generator speed is less than a predetermined threshold generator speed C gen — spd . If the result of the inquiry at 88 is positive, the operating mode is changed at action block 90 from the parallel mode to the non-parallel mode (the setting is “FALSE”).
If the result of the inquiry at 88 is negative, the routine proceeds to action block 92 , where it is determined whether the generator torque is less than a predetermined threshold C gen — tq . If the result of the inquiry at 92 is positive, again the operating mode is changed at action block 90 from the parallel mode to the non-parallel mode. If the result of the inquiry at 92 is negative, the parallel mode at decision block 88 is confirmed. Likewise, a negative result of the inquiry at decision block 88 is a confirmation of the parallel mode indicated at 86 ′.
Based upon the operating mode that is determined in the subroutine of FIG. 3 , the method uses one of two different ways to calculate planetary output torque at the motor shaft. If the powertrain is in a non-parallel operating mode as confirmed at 86 in FIG. 2 , the routine of FIG. 2 will proceed to action block 94 , where static planetary output torque is calculated. This is done using the relationship:
τ p@mot =T gen2mot *τ gen
where:
τ p@mot =torque at motor shaft;
T gen2mot =torque ratio from generator to motor shaft; and
τ gen =generator torque.
On the other hand, if it is determined that the powertrain is in the parallel operating mode at 86 , the routine will proceed to action block 96 , where static planetary output torque is computed using the relationship:
τ p@mot =−T gen2mot *(τ eng −J eng *dotω eng )
where:
τ p@mot =torque at motor shaft;
T gen2mot =torque ratio from engine to motor shaft;
τ eng =engine torque;
J eng =lumped moment of inertia of engine and the element of the gearing to which it is connection; and
dotω eng =engine angular acceleration.
Following either of the calculations at action blocks 94 and 96 , the routine will proceed to action block 98 where the total wheel torque is estimated. This is done using the following relationship:
τ total — wheel =T mot2wheel *(τ mot −τ p@mot +J gen — couple *dotω eng −J mot — eff *dotω eng )
where:
τ total — wheel =total wheel torque estimate;
T mot2wheel =torque ratio from motor to wheels;
τ mot =torque @ motor shaft;
J gen — couple =coupled moment of inertia of generator and the element to which it is connected;
dotω eng =engine angular acceleration; and
J mot eff =sum of the lumped motor and gearing inertia and the lumped generator inertia reflect at the motor.
Although an embodiment of the invention has been described, it will be apparent to a person skilled in the art that modifications may be made to the invention without departing from the scope of the invention. All such modifications and equivalents thereof are intended to be covered by the following claims.
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A method for estimating traction wheel torque in a hybrid electric vehicle powertrain that does not require a torque sensor. The method relies upon variables including speed, torque, moments of inertia and angular acceleration of powertrain components. Separate strategy routines are used for a parallel operating mode and for a non-parallel operating mode.
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RELATED REFERENCES
[0001] This application is a divisional of application Ser. No. 09/669,344, filed Sep. 26, 2000.
BACKGROUND OF THE INVENTION
[0002] The present invention relates in general to the field of proton exchange membrane (“PEM”) fuel cell systems, and more particularly, to an improved PEM fuel cell system having improved discrete fuel cell modules with improved mass transport for ternary reaction optimization and a method for manufacturing same.
[0003] A fuel cell is an electrochemical device that converts fuel and oxidant into electricity and a reaction by-product through an electrolytic reaction that strips hydrogen molecules of their electrons and protons. Ultimately, the stripped electrons are collected into some form of usable electric current, by resistance or by some other suitable means. The protons react with oxygen to form water as a reaction by-product.
[0004] Natural gas is the primary fuel used as the source of hydrogen for a fuel cell. If natural gas is used, however, it must be reformed prior to entering the fuel cell. Pure hydrogen may also be used if stored correctly. The products of the electrochemical exchange in the fuel cell are DC electricity, liquid water, and heat. The overall PEM fuel cell reaction produces electrical energy equal to the sum of the separate half-cell reactions occurring in the fuel cell, less its internal and parasitic losses. Parasitic losses are those losses of energy that are attributable to any energy required to facilitate the ternary reactions in the fuel cell.
[0005] Although fuel cells have been used in a few applications, engineering solutions to successfully adapt fuel cell technology for use in electric utility systems have been elusive. The challenge is for the generation of power in the range of 1 to 100 kW that is affordable, reliable, and requires little maintenance. Fuel cells would be desirable in this application because they convert fuel directly to electricity at much higher efficiencies than internal combustion engines, thereby extracting more power from the same amount of fuel. This need has not been satisfied, however, because of the prohibitive expense associated with such fuel cell systems. For example, the initial selling price of the 200 kW PEM fuel cell was about $3500/kW to about $4500/kW. For a fuel cell to be useful in utility applications, the life of the fuel cell stack must be a minimum of five years and operations must be reliable and maintenance-free. Heretofore known fuel cell assemblies have not shown sufficient reliability and have disadvantageous maintenance issues. Despite the expense, reliability, and maintenance problems associated with heretofore known fuel cell systems, because of their environmental friendliness and operating efficiency, there remains a clear and present need for economical and efficient fuel cell technology for use in residential and light-commercial applications.
[0006] Fuel cells are usually classified according to the type of electrolyte used in the cell. There are four primary classes of fuel cells: (1) proton exchange membrane (“PEM”) fuel cells, (2) phosphoric acid fuel cells, and (3) molten carbonate fuel cells. Another more recently developed type of fuel cell is a solid oxide fuel cell. PEM fuel cells, such as those in the present invention, are low-temperature low-pressure systems, and are, therefore, well-suited for residential and light-commercial applications. PEM fuel cells are also advantageous in these applications because there is no corrosive liquid in the fuel cell and, consequently, there are minimal corrosion problems.
[0007] Characteristically, a single PEM fuel cell consists of three major components—an anode gas dispersion field (“anode”); a membrane electrode assembly (“MEA”); and a cathode gas and liquid dispersion field (“cathode”). As shown in FIG. 1, the anode typically comprises an anode gas dispersion layer 502 and an anode gas flow field 504 ; the cathode typically comprises a cathode gas and liquid dispersion layer 506 and a cathode gas and liquid flow field 508 . In a single cell, the anode and the cathode are electrically coupled to provide a path for conducting electrons between the electrodes through an external load. MEA 500 facilitates the flow of electrons and protons produced in the anode, and substantially isolates the fuel stream on the anode side of the membrane from the oxidant stream on the cathode side of the membrane. The ultimate purpose of these base components, namely the anode, the cathode, and MEA 500 , is to maintain proper ternary phase distribution in the fuel cell. Ternary phase distribution as used herein refers to the three simultaneous reactants in the fuel cell, namely hydrogen gas, water vapor and air. Heretofore known PEM fuel cells, however, for various reasons have not been able to efficiently maintain proper ternary phase distribution. Catalytic active layers 501 and 503 are located between the anode, the cathode and the electrolyte. The catalytic active layers 501 and 503 induce the desired electrochemical reactions in the fuel cell. Specifically, the catalytic active layer 501 , the anode catalytic active layer, rejects the electrons produced in the anode in the form of electric current. The oxidant from the air that moves through the cathode is reduced at the catalytic active layer 503 , referred to as the cathode catalytic active layer, so that it can oxidate the protons flowing from anode catalytic active layer 501 to form water as the reaction by-product. The protons produced by the anode are transported by the anode catalytic active layer 501 to the cathode through the electrolyte polymeric membrane.
[0008] In the typical PEM fuel cell assembly, a PEM fuel cell is housed within a frame that supplies the necessary fuel and oxidant to the anode and cathode flow fields of the fuel cell. These conventional frames typically comprise manifolds and channels that facilitate the flow of the reactants. However, usually the channels are not an integral part of the manifolds, which results in a pressure differential along the successive channels. FIG. 2 is an illustration of a conventional frame for the communication of the reactants to a fuel cell. This pressure differential causes the reactants, especially the fuel, to be fed into the flow fields unevenly, which results in distortions in the flow fields causing hot spots and other problems leading to inefficiency. This also results in nonuniform disbursement of the reactants onto the catalytic active layers. Ultimately, this conventional method of supplying the necessary fuel and oxidant to a fuel cell results in a very inefficient process.
SUMMARY OF THE INVENTION
[0009] Accordingly, there is a need for an economical and efficient fuel cell assembly and fuel cell stack assembly that have an optimized supply and mass transport system. Herein provided is a an improved fuel/oxidant supply and distribution means. As a result of the present invention, significant improvement in, inter alia, power density, efficiency, and life of the fuel cell are provided at the cell and stack level.
[0010] In one embodiment, the distribution frame of the present invention comprises: a substantially planar frame, the substantially planar frame having an anode side, a cathode side, and a central cavity suitable for housing the fuel cell assembly; at least 2 fuel inlet apertures, the fuel inlet apertures extending completely through the distribution frame and each fuel inlet aperture being located 180° from the other, and each fuel inlet aperture having an interior side; an air inlet aperture, the air inlet aperture extending completely through the distribution frame and the air inlet aperture being located 90° from each fuel inlet aperture and 180° from an air and water outlet aperture, the air and water outlet aperture extending completely through the distribution frame, the air inlet aperture and the air and water outlet aperture each further having an interior side; a plurality of fuel supply channels, the fuel supply channels located on the anode side of the distribution frame and extending from the interior side of each fuel inlet aperture to the central cavity and being integral to each fuel inlet aperture; a plurality of air supply channels, the air supply channels located on the cathode side of the distribution frame and the air supply channels extending from the interior side of the air inlet aperture to the central cavity and being integral to the air inlet aperture; and a plurality of air and water outlet channels, the air and water outlet channels located on the cathode side of the distribution frame, the air and water outlet channels extending from the interior side of the air and water outlet aperture to the central cavity, and being integral to the air and water outlet aperture.
[0011] Other aspects and advantages of the present invention will be apparent to those ordinarily skilled in the art in view of the following specification claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like numbers indicate like features, and wherein:
[0013] [0013]FIG. 1 is a schematic of a typical PEM fuel cell assembly.
[0014] [0014]FIG. 2 is an illustration of a conventional frame for housing and supplying reactants to a fuel cell assembly.
[0015] [0015]FIG. 3 is a depiction of one embodiment of the distribution frame of the present invention housing a fuel cell assembly.
[0016] [0016]FIG. 4 is an illustration of one embodiment of the fuel side of one embodiment of the distribution frame of the present invention.
[0017] [0017]FIG. 5 is an illustration of one embodiment of the air side of one embodiment of the distribution frame of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] [0018]FIG. 3 depicts one embodiment of an individual fuel cell assembly of the present invention. As shown in FIG. 3, fuel cell 11 is housed within distribution frame 10 . Distribution frame 10 not only houses fuel cell 1 , but also facilitates transportation of the fuel and the oxidant to the fuel cell necessary for the electrochemical exchange in the fuel cell. This individual fuel cell assembly can be combined with other fuel cell assemblies to form a fuel cell node, and ultimately a stack assembly, to provide higher voltages and current for power generation. Of note in FIG. 3 are fuel inlet 22 , fuel inlet 24 , air inlet 12 and air and water outlet 14 . The fuel inlets 22 and 24 , air inlet 12 , and air and water outlet 14 are apertures in the distribution frame extending completely through the distribution frame, and run substantially perpendicular to, or at 90° angles from, one another in the distribution frame to facilitate the efficient flow of the fuel and oxidant to and through the anode gas and liquid flow field and cathode gas flow field, respectively.
[0019] Shown in FIG. 4 is one embodiment of the anode side of distribution frame 10 . In this embodiment, fuel inlet 12 and fuel inlet 14 provide the fuel to the fuel cell housed within the cavity of distribution frame 10 necessary for the electrochemical reaction. Specifically, the fuel is fed to the anode gas flow field through fuel supply channels 18 and 16 that stretch from the interior sides or surfaces of fuel inlet 12 and fuel inlet 14 , respectively. Fuel supply channels 18 and 16 are shaped such that the supply of the fuel to the anode is preferably maintained at a constant velocity, i.e., the channels are of sufficient length, width and depth to provide fuel to the anode at a constant desired velocity. The velocity of the fuel entering the anode gas flow field via fuel supply channels 18 and 16 may be less than the velocity of oxidant entering the cathode gas flow field via air supply channels 25 . The number of fuel supply channels in the distribution frame stoichiometrically balances the number of air supply channels so as to achieve a 2.0 to 1.0 to 2.8 to 1.0, preferably 2.0 to 1.0 to 2.4 to 1.0, air to fuel ratio. Fuel supply channels 18 and 16 also provide an edge-on connection between the fuel supply inlets and the anode gas flow field of the fuel cell housed within the cavity of the distribution frame to allow for enhanced dispersion of the fuel through the anode gas flow field.
[0020] Suitable primary materials of construction for distribution frame 10 include, but are not limited to, nylon-6, 6, derivatives of nylon-6, 6, polyetheretherketone (“PEEK”), styrene, mylar, textar, kevlar or any other nonconductive thermoplastic resins such as polypropylene. Other materials may be suitable as recognized by those skilled in the art with the benefit of this disclosure. Materials that have good compression properties are most suitable; therefore, enhancements to improve their compression properties may be suitable. Distribution frame 10 is preferably substantially circular.
[0021] Shown in FIG. 5 is the cathode side of distribution frame 10 . Air is a necessary reactant for the electrochemical exchange and may be fed to fuel cell 11 via air inlet 24 in combination with air supply channels 26 . Air supply channels 26 stretch from the interior surface or side of air inlet 24 to fuel cell 11 , and are of such sufficient size and shape that they enable air to be fed to the cathode gas flow field at a constant velocity, i.e., they are of sufficient height, width and depth. The number of fuel supply channels 18 and 16 will most often exceed the number of air supply channels 26 to maintain a stoichiometric balance of the reactants. Free water is formed continuously in the cathode gas and liquid flow field as a by-product of the electrochemical reaction. Air and water outlet 22 and air and water outlet channels 25 facilitate the flow of this free water from fuel cell 11 to allow for optimal water management in the fuel cell and to avoid flooding and the resultant loss in power. In a stack assembly, this free water may be transported for use in other parts of the fuel cell unit, unit here meaning the balance of plant assembly. Air and water outlet 22 and air and water outlet channels 25 also facilitate dissipation of the heat generated by the electrochemical reactions.
[0022] Although the present disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and the scope of the invention as defined-by the appended claims.
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The present invention comprises an improved flow field and reactant supply system, which provides improved and more efficient mass transport of the reactants to a fuel cell and thus the fuel cell stack assembly. The improved reactant supply system comprises an improved distribution frame adapted to house a fuel cell.
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[0001] This application claims priority from French patent application number 0204499, filed Apr. 11, 2002, and the benefit of U.S. Provisional Application No. 60/381,333, filed May 20, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a novel process for the preparation of combretastatins and of their derivatives.
[0004] 2. Description of the Art
[0005] The term “combretastatins” or “stilbene derivatives” is understood to mean the derivatives of following general formula (I):
[0006] in which A represents a hydroxyl group or an amino group, and their pharmaceutically acceptable salts.
[0007] Mention may be made, among the salts, of the hydrochloride, acetate, phosphate or methanesulphonate. When A in the compound is an amino group, it can also be coupled to amino acids to result in amides, and their pharmaceutically acceptable salts.
[0008] The synthesis of stilbene derivatives or combretastatins, which can be in the form of a pharmaceutically acceptable salt, and the pharmaceutical compositions which comprise them are disclosed in Patents U.S. Pat. No. 4,996,237, U.S. Pat. No. 5,525,632, U.S. Pat. No. 5,731,353 and U.S. Pat. No. 5,674,906. These patents disclose combretastatins and their metabolites and disclose their in vitro oncologic activity.
[0009] According to these patents, combretastatins are prepared from (3,4,5-trimethoxybenzyl)triphenylphosphonium salts, which are condensed with a 3-nitro- or 3-hydroxy-4-methoxybenzaldehyde (the hydroxyl group of which is protected) in the presence of sodium hydride or of lithium derivatives, and then the derivative obtained, when it is nitrated, is reduced in the presence of zinc.
[0010] The isomer with the cis configuration is subsequently prepared by the action of light or by chromatographic separation of the mixture.
SUMMARY OF THE INVENTION
[0011] The present invention provides novel processes for the preparation of combretastatins or stilbene compounds of formulae (I) and (III)
[0012] wherein A is
[0013] and
[0014] PG is a protecting group selected from the group consisting of tert-butoxycarbonyl, benzyloxycarbonyl and 9-fluorenylmethyloxycarbonyl, or the pharmaceutically acceptable salts thereof. In addition, the novel intermediate compound of formula III is disclosed and claimed.
DETAILED DESCRIPTION OF THE INVENTION
[0015] A first process route V0 1 for the preparation of derivatives of formula (I) for which A represents an amino group has first been discovered, which process is an improvement to the process disclosed in the abovementioned patents, which consists, after the Wittig condensation of (3,4,5-trimethoxybenzyl)triphenylphosphonium bromide or chloride and 3-nitro-4-methoxybenzaldehyde, in carrying out reduction of the nitro group with of iron, instead of the zinc as is used in the prior publications, which makes it possible to achieve an overall reaction yield, with respect to the aldehyde charged, of 60% (the yield with respect to the aldehyde charged in Patent U.S. Pat. No. 5,525,632 is between 21% and 33%).
[0016] The first process route V0 2 consists in condensing 3,4,5-trimethoxybenzaldehyde with (4-methoxy-3-nitrobenzyl)triphenylphosphonium bromide or chloride. For both these first two processes routes V0 1 and V0 2, the reaction is carried out in the presence of a base chosen in particular from potassium tert-butoxide, sodium tert-pentoxide, sodium hydride, butyllithium, LDA (lithium dilsopropylamide), sodium methoxide, potassium carbonate or alkaline derivatives of hexamethyldisilazane.
[0017] This reaction is carried out in various solvents, such as ethers (THF), polar aprotic solvents (acetonitrile, NMP, DMF, DMSO, and the like), alcohols, aromatic solvents or water, at a temperature which will be adjusted by a person skilled in the art to the base used and to the solvent used.
[0018] This reaction, as regards the first process route V 0 2 , is described in particular in the publication by K. G. Piney which appeared in Bioorg. Med. Chem., 8(2000), 2417-2425.
[0019] 2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]nitrobenzene is reduced according to the improved process of the invention by the action of iron. It is advantageous to use an amount of iron in excess if complete conversion of the starting material is desired. This excess is advantageously greater than 2 equivalents per one mol of starting nitro derivative.
[0020] It has been shown that the same stage, carried out in the presence of zinc in acetic acid, a conventional solvent for reductions with zinc, does not make it possible to obtain complete reaction (in Patent U.S. Pat. No. 5,525,632, the yield of the reduction carried out on the pure Z isomer varies between 46% and 66%) and, moreover, that the amounts of zinc used are large and consequently result in considerable industrial waste. Furthermore, the process generates a large amount of “azo” compound resulting from coupling between the amino formed and the nitroso intermediate in the reduction.
[0021] Reduction with nascent hydrogen, generated by ammonium formate in the presence of a conventional catalyst, such as palladium or platinum, leads to high isomerization of the double bond to the undesirable E isomer and to partial saturation of the double bond.
[0022] The abovementioned Piney publication describes the reduction by sodium hydrosulphite of a pure nitro Z isomer, obtained after chromatography and recrystallization, leading to an amino Z isomer with a yield of only 37%.
[0023] Hydrogenations with molecular hydrogen, catalysed by platinum or palladium, are rarely complete and result in particular in the saturation of the ethylenic double bond.
[0024] A second process has also been found which avoids the intermediate reduction stage necessary when starting from a nitro derivative. This is because it is much more economical to condense, according to a first method of carrying out this second process, a (3,4,5-trimethoxybenzyl)triphenylphosphonium bromide or chloride with 3-amino-4-methoxybenzaldehyde or, according to a second method of carrying out this second process, condensing 3,4,5-trimethoxybenzaldehyde with a (3-amino-4-methoxybenzyl)triphenyl-phosphonium salt.
[0025] This second process according to its two alternative forms requires a stage in which less in the way of CMR (Cancerogenic, Mutagenic or Reproductive) toxic products are given off in comparison with the first processes routes V0 1 and V0 2, which is a considerable advantage at the industrial level from the viewpoint of safety and production cost.
[0026] According to the second process route V0 3 for implementing the invention, the (3,4,5-trimethoxybenzyl)triphenylphosphonium salt and 3-amino-4-methoxybenzaldehyde are brought together and the reaction is carried out, preferably, in the presence of a base chosen in particular from potassium tert-butoxide, sodium tert-pentoxide, sodium hydride, butyllithium, LDA, sodium methoxide, potassium carbonate or alkaline derivatives of hexamethyldisilazane. Use is preferably made of sodium methoxide.
[0027] This reaction is carried out in various solvents, such as ethers (THF), polar aprotic solvents (acetonitrile, NMP, DMF, DMSO, and the like), alcohols, aromatic solvents or water, at a temperature which will be adjusted by a person skilled in the art to the base used and to the solvent used.
[0028] The reaction temperature will be adjusted by a person skilled in the art as to the base used. When methoxide is used, the reaction temperature is preferably between 0° C. and 10° C. After reaction, the base used is neutralized with an acid in aqueous solution, the organic phase is washed and concentrated, and the expected product is obtained after chromatographing the crude concentrate.
[0029] According to the second process route V0 4 for implementing the invention, in which the (3-amino-4-methoxybenzyl)triphenylphosphonium salt and 3,4,5-trimethoxybenzaldehyde are brought together, the reaction is preferably carried out in the presence of a base chosen in particular from potassium tert-butoxide, sodium tert-pentoxide, sodium hydride, butyllithium, LDA, sodium methoxide, potassium carbonate or alkaline derivatives of hexamethyldisilazane. Use is preferably made of sodium methoxide.
[0030] This reaction is carried out in various solvents, such as ethers (THF), polar aprotic solvents (acetonitrile, NMP, DMF, DMSO, and the like), alcohols, aromatic solvents or water, at a temperature which will be adjusted by a person skilled in the art to the base used and to the solvent used.
[0031] The reaction temperature will be adjusted by a person skilled in the art to the base used. When methoxide is used, the reaction temperature is preferably between 0° C. and 10° C. After reaction, the base used is neutralized with an acid in aqueous solution, the organic phase is washed and concentrated, and the expected product is obtained after chromatographing the crude concentrate.
[0032] The derivative obtained according to the second process route V0 3 or V0 4 or during the second stage of the first process route V0 1 or V0 2 has the formula (IIa):
[0033] It is advantageous, when it is desired to couple serine with the compound of formula (IIa), to use L-serine doubly protected on the nitrogen of the serine and on the hydroxyl functional group of general formula (IIb)
[0034] where PG represents a protective group for the amine functional group well known to a person skilled in the art, to give a novel intermediate of following general formula (III):
[0035] which is subsequently cleaved, preferably simultaneously with the opening of the ring, by acid hydrolysis according to a deprotection reaction well known to a person skilled in the art. Preferably, the PG group of the formulae (IIb) or (III) represents a protective group selected from the following groups: tert-butoxycarbonyl, benzyloxycarbonyl (CBZ) or 9-fluorenylmethyloxycarbonyl (FMOC).
[0036] The compound of formula (III) above is novel and is claimed as such.
[0037] The condensation is advantageously carried out in the presence of EDCI (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) or in the presence of DCC (dicyclohexylcarbodiimide) and of HOBT (hydroxybenzotriazole) or in the presence of DCC (dicyclohexylcarbodiimide) and of HOSU (N-hydroxysuccinimide) or, finally, in the presence of TOTU (O-[(ethoxycarbonyl)cyanomethyleneamino]-N,N,N′,N′-tetramethyluronium tetrafluoroborate) or of HBTU (O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate) or of N,N-carbonyldiimidazole. The reaction is preferably carried out in a solvent which is inert with respect to the reaction, which solvent is chosen in particular from polar aprotic solvents, such as acetonitrile, dimethylformamide, tetrahydrofuran or chlorinated aliphatic solvents, such as dichloromethane, or, finally, esters.
[0038] The coupling to the derivative of formula (IIa) can also be carried out by the action of a mixed anhydride, synthesized in situ between a chloroformate or a carboxylic acid chloride, for example pivaloyl chloride, and doubly protected L-serine of formula (IIb), in the presence of a tertiary base of the NMM (N-methylmorpholine) type in various solvents which are inert with respect to the reaction such as, for exampe, esters, ethers, chlorinated solvents, acetonitrile, and the like. The mixed anhydride is preferably prepared at a temperature of between 0° C. and 10° C. and then the reaction is carried out at ambient temperature. After reaction, the reaction mixture is hydrolysed with an aqueous solution, then the phases are separated and the organic phase is washed with aqueous base.
[0039] The double deprotection of the compound of formula (III) is carried out by the action of an organic or inorganic acid. Use is preferably made of concentrated aqueous hydrochloric acid in an alcoholic medium. The reaction temperature is, according to a better means of implementation of the invention, preferably between 50° C. and 70° C.
[0040] The invention will be more fully described with the help of the following examples, which must not be regarded as limiting the invention.
[0041] The composition of the mixtures, the monitoring and the progression of the reactions, and the yield of the unisolated products/intermediates and their assays are determined by HPLC (High Performance Liquid Chromatography) analysis. HPLC conditions: column—octadecyl silicagel; detection—UV 242 nm; mobile phase—water, trifluoroacetic acid, acetonitrile. Thin layer chromatographic analysis (TLC) was performed using silica gel plates with cyclohexane/ethyl acetate.
[0042] Experimental
EXAMPLE 1
[0043] First Process Route V0 2 According to the Invention
[0044] (Z)-N-[2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenyl]-L-serinamide hydrochloride
[0045] General Scheme of the Synthesis
[0046] The novel “inverse Wittig” process, starting from (4-methoxy-3-nitrobenzyl)triphenylphosphonium bromide and 3,4,5-trimethoxybenzaldehyde, makes it possible to obtain the mixture of Z and E isomers of 2-methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]nitrobenzene with a Z/E ratio of 75/25.
[0047] This ratio is sufficiently high in the Z nitro isomer to be able to use the Z/E mixture directly in the reduction and to obtain, by crystallization of the hydrochloride, the Z amino isomer with an IS HPLC assay of 97% (IS, internal standardization).
[0048] (4-Methoxy-3-nitrobenzyl)triphenylphosphonium bromide (4) is prepared according to the following example:
[0049] 3-Nitro-4-methoxybenzaldehyde (1, 90.5 g) is charged, followed by 450 ml of THF and 90 ml of ethanol, into a 2-litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solid and a reflux condenser surmounted by a bubble counter. The resultant pale-yellow solution is cooled to 10° C. and then 10 g of sodium borohydride are charged over 40 minutes at 10-15° C. (the reaction is very exothermic and the temperature has to be maintained with an ice/acetone bath); at the end of the addition, the brown solution turns navy blue. The solution is stirred for 30 minutes at 10° C., the end of the reaction is monitored by TLC (thin layer chromatography), the solution is stirred for an additional 1 hour at 10° C. and then the temperature is allowed to return to ambient temperature. The addition funnel is replaced by a 500 ml pressure-equalizing dropping funnel, via which 300 ml of distilled water is added dropwise over 30 minutes while maintaining the mixture at 20° C. Gas evolution is observed when the addition of water is started. The mixture is concentrated to ⅔ volume on a rotary evaporator (50° C./20 mmHg) and a white product crystallizes in the aqueous concentrate in the form of lumps. The cooled aqueous phase is extracted with 250 ml and then 150 ml of dichloromethane, and the combined organic phases are washed with 250 ml of distilled water and then dried over magnesium sulphate. After filtration, the dichloromethane solution is used as is in the following bromination reaction. The yield at this stage is regarded as being 100%. The alcohol (2) is commercially available but very difficult to obtain.
[0050] 3-Nitro-4-methoxybenzyl bromide (3)
[0051] The dichloromethane solution of 3-nitro-4-methoxybenzyl alcohol (2) is charged into a 1 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a dropping funnel and a reflux condenser surmounted by a bubble counter, and 100 ml of dichloromethane are added. The stirred solution is cooled to 5° C. and then 135.4 g of phosphorus tribromide are added dropwise while maintaining the temperature at 5° C. The solution is stirred at 5° C. for 1.5 hours, the end of the reaction is monitored by TLC and then 250 ml of saturated sodium hydrogen carbonate solution are added dropwise while maintaining the temperature at 15° C. Very strong evolution of gas takes place with a slight delay as the phosphorus tribromide is added. The organic phase is separated, and is washed successively with 250 ml of distilled water and 200 ml of saturated sodium hydrogen carbonate solution. The organic phase is dried over magnesium sulphate, filtered and concentrated on a rotary evaporator (50° C./20 mmHg). A solid (119 g) in the form of green-yellow felt-like needles is obtained with a chemical yield over two stages of 97%. Product (3) can also be prepared according to the following scheme, described in the publication: K. G. Piney et al., Bioorg. Med. Chem., 8 (2000), 2417-2425.
[0052] (3-Nitro-4-methoxybenzyl)triphenylphosphonium bromide (4)
[0053] 3-Nitro-4-methoxybenzyl bromide (3, 119 g) is charged into 1000 ml of stirred toluene in a 2 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solids and a reflux condenser surmounted by a bubble counter, and the stirred mixture, warmed to 25° C., forms a solution. Triphenylphosphine (126.5 g) is then added and the resultant solution is gradually heated to 60° C.; a precipitate begins to form at about 30° C. The mixture is maintained at 60-65° C. for 4 hours, is then cooled to 30° C. and is filtered through a sintered glass filter. The filter cake is washed on the filter twice with 300 ml portions of toluene, sucked dry and dried in an oven (35° C./20 mmHg/ hours). (4-Methoxy-3-nitrobenzyl)triphenylphosphonium bromide (217 g) is obtained with a chemical yield of 88%. The synthesis is also described in the publication: (solvent used: dichloromethane) K. G. Piney et al., Bioorg. Med. Chem., 8(2000), 2417-2425.
[0054] [0054] 1 H N.M.R. spectrum: (300 MHz, (CD 3 ) 2 SO, δ in ppm): 3.90 (s, 3H), 5.26 (d, J=15 Hz, 2H), 7.33 (mt, 2H), 7.41 (mt, 1H), from 7.65 to 8.05 (mt, 15H).
Mass spectrum: m = 428 EI m/z = 262 [PPh 3 ] + base peak DCI m/z = 445 MNH 3 + m/z = 428 M + m/z = 263 [PPh 3 H] + base peak
[0055] IR spectrum: (KBr)
[0056] 2869, 2843, 2776, 1619, 1527, 1438, 1362, 1287, 1270, 1111, 752, 692 and 502 cm −1
[0057] Z and E Mixture of 2-methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]nitrobenzene (6) and (7)
[0058] 3,4,5-Trimethoxybenzaldehyde (5, 54.7 g), (4-methoxy-3-nitrobenzyl)triphenylphosphonium bromide (4, 148.6 g) and 1300 ml of toluene are charged, at 20° C. and under nitrogen, into a 2 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a dropping funnel and a reflux condenser surmounted by a bubble counter. The stirred suspension is cooled to 5° C. using an ice bath and then 63.2 g of a 25% w/w solution of sodium methoxide in methanol are added at 5° C. over 40 minutes. As the addition progresses, the suspension color changes from off-white to yellow and then to brown. The mixture is stirred for 1 hour at 5° C. and the end of the reaction is monitored by HPLC (complete consumption of the aldehyde). Acetic acid (3 g, 0.05 mol) is then added. The suspension is heated to 40° C. and is maintained at 40° C. for 30 minutes. At this temperature, only the salts remain insoluble. The mixture is filtered at 40° C. through a sintered glass filter (No. 3) and the salts are washed on the filter 3 times with 100 ml portions of toluene. The filtrate is returned to a round-bottomed flask with 250 ml of distilled water, and the two-phase mixture is stirred for 20 minutes at 40° C. and then the phases are separated. The toluene phase is washed twice with 250 ml portions of distilled water and then concentrated to dryness on a rotary evaporator. The residue is taken up in 600 ml of isopropanol and 12 ml of toluene at 40° C. The expected product begins to crystallize and the temperature is allowed to return to ambient temperature overnight with slow stirring. The stirred suspension is cooled to and maintained for 1 hour at 5° C., then filtered through a sintered glass filter, and the filter cake is washed twice with 125 ml portions of isopropanol, sucked dry and dried in an oven under vacuum (35° C./30 mmHg/18 hours). A mixture of Z and E isomers (6) and (7) (91.7 g) is obtained with a Z/E ratio of 75/25 (IS IPLC) and a yield of 95%.
[0059] The synthesis is also described in the publication: (solvent used: dichloromethane: base used: NaH) K. G. Piney et al., Bioorg. Med. Chem., 8(2000), 2417-2425.
[0060] Numerous operating conditions were experimented with, such as:
[0061] Solvents: TUF, acetonitrile, methanol and other alcohols, dichloromethane, NMP, DMF, DMSO, and the like.
[0062] Bases: potassium t-butoxide, sodium t-pentoxide, sodium hydroxide, NaH, BuLi/LDA, potassium carbonate and the like.
[0063] Temperatures: from −10° C. to the reflux temperatures of some solvents.
[0064] Z-2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenylamine hydrochloride (8):
[0065] A 75/25 Z and E mixture of 2-methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]-nitrobenzene (6) and (7) (80 g), 640 ml of absolute ethanol and 160 ml of distilled water are charged, at 20° C. and under nitrogen, into a 2 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solid, a reflux condenser surmounted by a bubble counter, and a heating bath. The mixture is rapidly stirred and heated in an oil bath, 7.8 ml of 6N hydrochloric acid are added to the suspension at 50° C. and then the temperature of the mixture is raised to 77±2° C. to afford an almost complete solution. Iron powder (52 g) is added portionwise over 5 minutes. With the first addition, the mixture passes into solution and then a blackish deposit is formed on the walls of the round-bottom flask. The mixture is maintained at 77±2° C. for 2 hours and the disappearance of the starting nitro compounds (6) and (7) is monitored by HPLC. The mixture is allowed to cool to 40° C. and is filtered through a sintered glass filter covered with clarcel (CELITE) and the filter cake is rinsed twice with 160 ml portions of 80/20 ethanol/water mixture. The combined filtrate, aqueous mother liquors and aqueous wash liquors are concentrated on a rotary evaporator. As soon as the azeotrope has been driven off, an oil begins to separate from the residual aqueous phase. The aqueous phase is extracted in a separating funnel twice with 300 ml portions of dichloromethane, and then the combined organic phase is washed twice with 300 ml portions of half-saturated aqueous sodium chloride solution and with 300 ml of distilled water. The organic phase is concentrated to dryness on a rotary evaporator to afford 76 g of an oil which exhibits a Z/E ratio of 80/20 by HPLC. This oil is dissolved in 591 ml of methanol and transferred into a stirred 1 litre round-bottom flask, 100 ml of 2.32N methanolic hydrochloric acid are then added, precipitation is initiated and the mixture is allowed to precipitate overnight with stirring. The amount of methanol and methanolic hydrochloric acid is such that the final concentration of Z isomer (determined by HPLC) is equal to 8.8% w/v. In the morning, the mixture is filtered through a sintered glass filter. The dried filter cake weighs 8.2 g and is composed only of the E isomer (HPLC). The filtrate (693 g), ratio Z/E=86/14 (IS HPLC), is concentrated to half weight on a rotary evaporator, 400 ml of acetonitrile are added to the 347 g of concentrate and the mixture is reconcentrated until a concentrate of 347 g is again obtained. Acetonitrile (1000 ml) is then added and the mixture is concentrated until crystallization begins. The concentrate is then transferred into a stirred 4 litre round-bottom flask containing 1500 ml of acetonitrile at 60° C. The mixture copiously precipitates. The mixture is kept stirred at 60° C. for 2.5 hours and is allowed to cool to 30° C. over approximately 1 hour. The slurry is filtered through a sintered glass filter (the E isomer (9) is soluble in the filtrate). The filter cake is washed twice with 200 ml portions of acetonitrile and dried in an oven (35° C./30 mmHg/18 hours). Z-2-methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]-phenylamine hydrochloride(45.7 g, 8) is obtained with an IS HPLC assay of 97% and a yield as such of 56%, i.e., a yield of Z isomer obtained with respect to Z isomer charged of 72%.
EXAMPLE 2
[0066] Synthesis According to the Second Process Route V0 3 According to the Invention.
[0067] The advantage of the second process route V0 3 with respect to the first “inverse Wittig” process route V0 2 is that of carrying out the Wittig reaction between a product which has already been reduced, the aminoaldehyde (1a), and the phosphonium (2a) and thus of eliminating a chemical stage which gives off CMR products.
[0068] (Z)-N-[2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenyl]-L-serinamide hydrochloride
[0069] General Scheme of the Synthesis
[0070] 3-Nitro-4-methoxybenzaldehyde (1, 20 g) and 350 ml of absolute ethanol are charged into a 2 litre three-necked flask under argon and equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solids, a reflux condenser surmounted by a bubble counter, and a heating bath. The mixture is stirred and heated to 60° C. to afford a solution. The dropwise addition of 115 ml of distilled water is carried out at 60° C., and followed by addition of 14 ml of 2N hydrochloric acid. Iron powder (24.7 g) is then introduced portionwise. The temperature of the mixture is allowed to return to ambient temperature over 2 hours. The reaction is complete (TLC). The mixture is filtered through CELITE (Celite Corporation, 137 West Central Avenue, Lompoc, Calif. 93436) and concentrated under vacuum. The residue is dissolved in dichloromethane, the organic solution is washed twice with distilled water and then dried over magnesium sulphate, filtered and concentrated to dryness under vacuum. Crude (1a) (16 g) is obtained and is chromatographed on a silica column eluting with dichloromethane. Two fractions comprising the clean expected product are obtained, which fractions, after concentrating, give 11.5 g of pure (1a), i.e. a yield of 69%.
[0071] [0071] 1 H N.M.R. spectrum: (300 MHz, (CD 3 ) 2 SO, δ in ppm): 3.88 (s, 3H), 5.11 (unresolved peak, 2H), 7.01 (d, J=8 Hz, 1H), 7.14 (d, J=2 Hz, 1H), 7.18 (d, J=8 Hz, 1H), 9.53 (s, 1H).
Mass spectrum: m = 151 EI m/z = 151 M + base peak m/z = 136 [M-CH 3 ] + m/z = 108 [136-CO] + m/z = 80 [108-CO] +
[0072] IR spectrum: KBr
[0073] 3464, 3437, 3367, 3349, 1675, 1655, 1582, 1513, 1293, 1241, 1139, 1023, 803 and 640 cm −1
[0074] Z- and E-2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenylamine (8′) and (9′)
[0075] The phosphonium salt (2a) is a starting material already disclosed in the original patent Ajinomoto Co. Ltd, U.S. Pat. No. 5,525,632 and WO 01/12579 A2.
[0076] Phosphonium salt (2a, 8.0 g), followed by 2.20 g of aminobenzaldehyde (1a) and 100 ml of toluene, are charged into a 250 ml three-necked flask under nitrogen and equipped with a magnetic stirrer, a thermometer, a T piece, a dropping funnel, a reflux condenser surmounted by a bubble counter, and a cooling bath. The stirred suspension is cooled to 5° C. and 3.51 ml of a 25% w/w methanolic sodium methoxide solution are added over 15 minutes. After 2.5 hours at 5° C., the reaction remains incomplete (conversion rate: 45%) but does not change further (HPLC) and the Z/E ratio is 61/39. Acetic acid (0.2 ml) diluted in 50 ml of water is then added, the temperature rises to 13° C., the mixture is stirred for 30 minutes and then the phases are separated. The organic phase is concentrated under vacuum on a rotary evaporator and 8 g of a yellow oil are obtained. By HPLC, this oil comprises starting aldehyde, phosphine oxide and the expected product mixture with a Z/E ratio of 61/39. The oil is chromatographed on a silica column (40 parts w/w) eluting with a cyclohexane/ethyl acetate/triethylamine (50/50/2) mixture. Two series of combined fractions are concentrated to dryness: the first dry extract of 360 mg consists of 93% of the Z isomer plus unidentified impurities; the second, of 2.09 g, consists of starting aldehyde and a Z/E mixture representing 39% and 37.5% by IS HPLC. The balance by weight of Z isomer (8′), determined by IS HPLC, is 1.15 g with respect to 2.20 g of aldehyde charge, i.e. a yield of 24%.
EXAMPLE 3
[0077] Synthesis According to the Second Process Route V0 3 According to the Invention
[0078] The advantage of route V0 3 with respect to the first “inverse Wittig” process route V0 2 is that of carrying out the Wittig reaction between a product which has already been reduced, (3-amino-4-methoxybenzyl)triphenylphosphonium bromide (1b), and 3,4,5-trimethoxybenzaldehyde (5) and thus of eliminating a chemical stage which gives off CMR products.
[0079] (Z)-N-[2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenyl]-L-serinamide hydrochloride
[0080] General Scheme of the Synthesis
[0081] Compound (4, 30 g), 240 ml of ethanol and 60 ml of distilled water are charged into a 1 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solid, a reflux condenser surmounted by a bubble counter, and a heating bath. 6N hydrochloric acid (1.76 ml) is added to the stirred suspension, which is heated to 70° C. Iron powder (9.9 g) is then added portionwise over 15 minutes; the mixture remains insoluble. The mixture is maintained at 75° C. for 2 hours; the organic materials slowly pass into solution while a brownish deposit of iron and of iron oxide is formed. After monitoring by HPLC, 5% of starting material still remains; 2 g of iron are again added and heating is continued for 1 hour; the conversion is complete. The mixture is cooled to 40° C. and filtered through clarcel, the filter residue is rinsed with 100 ml of ethanol containing 20% water, and the filtrate is concentrated to dryness under vacuum on a rotary evaporator. The residue is taken up in 300 ml of isopropanol and crystallizes from the mixture, which on stirring and heating to 50° C. passes back into solution. A 5N solution of hydrochloric acid in isopropanol (14 ml) are then added, a precipitate forms, the mixture is held at 50° C. for 1 hour and then it is allowed to return to ambient temperature. The slurry is filtered through a sintered glass filter and the filter cake is washed with 50 ml of isopropanol, sucked dry thoroughly and dried in an oven under vacuum. Compound (1b, 27.3 g) is obtained with a yield as such of 89.9%.
[0082] [0082] 1 H N.M.R. spectrum: (300 MHz, (CD 3 ) 2 SO, δ in ppm): 3.78 (s, 3H), 5.03 (broad d, J=15 Hz, 2H), 6.43 (unresolved peak, 1H), 6.62 (broad s, 1H), 6.82 (broad d, J=8 Hz, 1H), from 7.60 to 8.00 (mt, 15H).
Mass spectrum: m = 397 EI m/z = 397 M + m/z = 382 [M-CH 3 ] + m/z = 262 [PPh 3 ] + base peak DCI m/z = 398 MNH 4 + m/z = 263 [PPh 3 H] + base peak
[0083] IR spectrum: KBr
[0084] 3254, 2474, 1920, 1628, 1520, 1439, 1433, 1279, 1110, 736, 690, 527 and 511 cm −1
[0085] Z- and E-2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenylamine (8′) and (9′)
[0086] Compound (1b, 11.02 g), 4 g of (5) and 70 ml of toluene are charged into a 250 ml three-necked flask under nitrogen and equipped with a magnetic stirrer, a thermometer, a T piece, a dropping funnel, a reflux condenser surmounted by a bubble counter, and a cooling bath. The stirred suspension is cooled to 5° C. and 4.92 ml of a 25% w/w solution of sodium methoxide in methanol are added over 15 minutes. The suspension is stirred at 5° C. for 2.5 hours, then 0.2 ml of acetic acid diluted in 50 ml of water is added, the temperature rises to 14° C. and the mixture becomes very thick. It is diluted with 10 ml of toluene and 10 ml of water. A brown insoluble material remains. The mixture is filtered through clarcel, the filter cake is washed 3 times with 50 ml portions of toluene (the wash liquors comprise virtually only the starting aldehyde and are not added to the two-phase filtrate), the phases of the clear filtrate (pH 12) are separated, and the organic phase is concentrated to dryness under vacuum at 40° C. The Z/E ratio, determined by IS HPLC, is 43/57. The resultant brown oil (4 g) is chromatographed on a silica column (100 parts w/w) eluting with a cyclohexane/ethyl acetate/triethylamine (50/50/2) mixture. Two series of combined fractions are concentrated to dryness: the first dry extract of 1.1 g consists of 14% of E isomer and 59% of Z isomer; the second weighs 1.08 g and consists of 86% of E isomer and 7% of Z isomer. The balance by weight of Z isomer (8′), determined by IS HPLC, is 0.725 g with respect to 4 g of aldehyde charged, i.e., a yield as such of 11.3%.
[0087] Z-4-{2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenylcarbamoyl}-2,2-dimethyloxazolidine-3-carboxylic acid tert-butyl ester (11)
[0088] Release of the Case (8′) from the Hydrochloride (8)
[0089] Compound (8) (44 g), 16 g of sodium hydrogen carbonate and then 200 ml of distilled water and 375 ml of dichloromethane are charged into a 1 litre Erlenmeyer flask. The mixture is stirred for 20 minutes at ambient temperature and two clear phases are obtained. The organic phase is separated, dried over sodium sulphate and then filtered. Approximately 400 ml of a dichloromethane solution comprising (8′) are obtained.
[0090] Preparation of 2,2-dimethyloxazolidine-3,4-dicarboxylic acid 3-tert-butyl ester (10)
[0091] Although commercially available, this product is very difficult to obtain. The compound was therefore prepared by saponification with lithium hydroxide of its methyl ester according to: J. Org. Chem., 63(12), p. 3983 (1998).
[0092] [0092] 1 H N.M.R. spectrum:(300 MHz, (CD 3 ) 2 SO, δ in ppm): 1.38 (s, 3H), 1.45 (s, 9H), 1.55 (s, 3H), 3.95 (mt, 1H), 4.16 (mt, 1H), 4.31 (mt, 1H), from 12.50 to 13.10 (broad unresolved peak, 1H).
Mass spectrum: m = 245 DCI m/z = 263 MNH 4 + m/z = 246 MH + m/z = 207 [MNH 4 -t-Bu] + base peak m/z = 146 [MH-BOC] +
[0093] IR spectrum: KBr
[0094] 1744, 1704, 1638, 1407, 1368, 1164, 1104, 856, 836 and 623 cm −1
[0095] Coupling
[0096] The solution of (8′) is charged into a 2 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a funnel for the addition of solid, a reflux condenser surmounted by a bubble counter, and an ice bath, 600 ml of dichloromethane are added and the mixture is cooled with stirring. 2,2-Dimethyloxazolidine-3,4-dicarboxylic acid 3-tert-butyl ester (10, 42.9 g) is added at 5° C., a solution forms, and then 48 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) are added portionwise between 5° C. and 10° C. The mixture is slowly allowed to return to ambient temperature by allowing the ice in the bath to melt overnight. In the morning, 330 ml of distilled water are added and the mixture is vigorously stirred. The mixture turns cloudy over 30 minutes (hydrolysis of the EDCI). Stirring is maintained for a further 30 minutes. The mixture is separated by settling in a separating funnel and the organic phase is washed successively twice with 280 ml portions of 0.55N sodium hydroxide solution and then with 300 ml of distilled water. The organic phase is concentrated to dryness on a rotary evaporator (50° C./50 mmHg). A sticky oil (79.4 g, 11) is obtained, which oil hardens at 20° C., with a yield by weight with respect to (8) charged of 117%.
[0097] [0097] 1 H N.M.R. spectrum: (400 MHz, (CD 3 ) 2 SO, at a temperature of 373 K, δ in ppm): 1.41 (s, 9H), 1.53 (s, 3H), 1.64 (s, 3H), 3.64 (s, 6H), 3.71 (s, 3H), 3.86 (s, 3H), 3.99 (dd, J=9 and 3 Hz, 1H), 4.19 (dd, J=9 and 7 Hz, 1H), 4.52 (dd, J=7 and 3 Hz, 1H), 6.48 (d, J=12.5 Hz, 1H), 6.55 (d, J=12.5 Hz, 1H), 6.58 (s, 2H), 7.02 (mt, 2H), 8.13 (broad s, 1H), 8.82 (broad s, 1H).
Mass spectrum: m = 542 DCI m/z = 560 MNH 4 + base peak m/z = 543 MH + m/z = 504 [MNH 4 -t-Bu] + m/z = 443 [MH-BOC] +
[0098] IR spectrum: CCl 4
[0099] 3409, 2982, 2938, 2837, 1712, 1698, 1534, 1363, 1249, 1133, 1092 and 851 cm −1
[0100] Other coupling conditions were employed, such as:
[0101] Mixed anhydride (pivaloyl chloride/(10)).
[0102] DCC/HOBT, DCC/HOSU, TOTU, N,N-carbonyldiimidazole, and the like.
[0103] In acetonitrile, DMF, THF, dichloromethane, ester, and the like.
[0104] EDCI HCl in dichloromethane gave the best result.
[0105] (Z)-N-[2-Methoxy-5-[2-(3,4,5-trimethoxyphenyl)vinyl]phenyl]-L-serinamide hydrochloride
[0106] Compound (11) (61.8 g), dissolved in 54 ml of methanol, is charged at 20° C. into a 1 litre three-necked flask equipped with a mechanical stirrer, a thermometer, a T piece, a reflux condenser surmounted by a bubble counter, and a heating bath, and 150 ml of isopropyl acetate, 99 ml of a 2.3N solution of hydrochloric acid in methanol and 8.2 ml of distilled water are added. The mixture is stirred and heated at 60° C. for 3 hours. The solution, cooled to 40° C., is clarified by filtration through a sintered glass filter (No. 4) rinsed with 40 ml of methanol. The filtrate is returned to the stirred three-necked flask, 194 ml of isopropyl acetate are added, the mixture is reheated to 40° C., the solution is seeded with 0.2 g of (12) and then 194 ml of isopropyl acetate are added dropwise over 1 hour. The mixture slowly crystallizes as the isopropyl acetate is being added. The mixture is allowed to return to ambient temperature and is then cooled to and maintained overnight at 5° C. In the morning, the slurry is filtered through a sintered glass filter and the filter cake is sucked dry, washed four times with 50 ml portions of isopropyl acetate, sucked thoroughly dry and then dried in an oven to constant weight (35° C./10 mmHg). Compound (12) (28 g) is obtained with a yield over 2 stages (coupling and then deprotection operations) of: 56%, and an IS HPLC assay >98%, i.e. an overall yield as such, for the synthesis carried out according to the first process route V0 2, of 30% [(12) obtained with respect to (5) charged].
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The present invention provides novel processes for the preparation of combretastatins or stilbene compounds of formulae (I) and (III)
wherein A is NH 2 or
and PG is a protecting group.
The disclosed and claimed processes include (1) Wittig condensation between a nitromethoxybenzaldehyde and a trimethoxybenzylphosphonium salt or between a trimethoxybenzaldehyde and a nitromethoxybenzylphosphonium salt to provide an intermediate compound of formula (I) wherein A is NO 2 , and subsequent iron powder reduction to provide a compound of formula (I) wherein A is NH 2 ; (2) Wittig condensation of the same precursor aldehydes and phosphonium salts wherein NO 2 is replaced by NH 2 to provide a compound of formula (I) wherein A is NH 2 ; and (3) a process for condensation of a compound of formula (I) wherein A is NH 2 with a doubly protected serinamide to provide an intermediate of formula (III), and subsequent hydrolysis to provide a compound of formula (I) wherein A is —NH—C(═O)CH(NH 2 )CH 2 OH, or the pharmaceutically acceptable salts thereof. Also claimed is a compound of formula (III).
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BACKGROUND OF INVENTION
This invention relates to improvements in the process of partial oxidation of petroleum feedstocks to produce synthesis gas and related products therefrom. In particular, the improvements relate to the recovery of unreacted carbon and temperature moderation of the reactor used to produce the synthesis gas.
The oxygen-blown partial oxidation of petroleum feedstocks requires the addition of a tempering medium such as steam to keep the reactor temperature within certain permissible limits. These limits are set by the economy of operation and the temperature restrictions of the reactor refractory material. Past practice has been to inject high pressure superheated steam into the petroleum feedstock charged to the partial oxidation generator. This practice is effective but usually requires either a waste heat recovery apparatus or a supply of clean, non-polluting fuel to operate a special boiler used to produce the tempering steam. These requirements add to the cost of the equipment utilized in the process, attendant maintenance costs and energy requirements.
A problem connected with the process is handling the unconverted or unreacted carbon. Normally the carbon is scrubbed from the reactor gaseous effluent with water resulting in a water and/or oil slurry which is thereafter contacted with petroleum naphtha. The naphtha preferentially wets the carbon and separates the carbon from the water stream. The carbon may then be transferred to a heavy oil stream by mixing heavy oil with the naphtha. The heavy fraction from the distillation process contains substantially all of the unreacted carbon which can be used as the feedstock for the partial oxidation reactor thus completely utilizing the carbon contained in the oil charge to produce a useful product. The process briefly described above requires a substantial amount of equipment and energy to separate and recycle the carbon.
SUMMARY OF THE INVENTION
The invention herein relates to concentrating the water-carbon slurry from the reactor gaseous effluent scrubbing step, mentioned above, to about 5 to 7 percent carbon, mixing the concentrated slurry with a fuel oil and returning same without vaporization to the partial oxidation generator as a substitute for the commonly used superheated high-pressure steam.
Various means may be used to accomplish the required concentration of the slurry stream including gaseous-flotation and electro-flotation. The gaseous flotation process separates the carbon as a carbon-water slurry, providing a more useful form, in the concentrations required. One such method described herein is the utilization of a flotation tank and a screw conveyor which removes carbon-water concentrate from the surface of the liquid within the flotation drum for transmittal to a second drum where the carbon-water concentrate may be slurried with oil in such a way that the resulting properties of the mixture allow conventional processing equipment to be used.
The carbon-water concentrate is transmitted from the flotation drum to the oil slurry drum by means of the screw conveyor system which would be operating under the control of a variable speed motor for providing proper removal of carbon in the concentration required.
The screw conveyor discharges the concentrated carbon-water slurry onto a baffle plate therein which is continuously washed with oil. The oil runs off the baffle plate into a surge area of the oil slurry drum which may contain mixers for providing a more uniform mixture of the oil slurry and carbon-water concentrations. The concentrated slurry and oil mixture is conducted into the reactor through a fuel preheater in a conventional manner. A portion of the oil slurry mixture is recirculated through the oil slurry tank to enhance the mixing properties.
It is therefore an object of the present invention to provide a more efficient process for the production of synthesis gas by partial oxidation.
It is another object of the present invention to temper the operating temperature of a partial oxidation reactor utilizing water as the tempering medium.
It is yet another object of the present invention to handle the unreacted carbon produced during the partial oxidation of petroleum feedstocks.
It is still another object of the present invention to provide a technique for concentrating water-carbon slurry resulting from the washing of reactor effluent gas.
It is another object of the present invention to mix and recirculate concentrated carbon-water slurry with petroleum feedstock in an efficient manner.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the process of the present invention in block form for the concentration and utilization of unreacted carbon produced during the partial oxidation process.
FIG. 2 is a detail of a flotation drum for concentrating the carbon water slurry produced at one stage during the process described in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated in block form, a diagram of the partial oxidation and carbon removal process of the present invention. A partial oxidation reactor 10 combines a petroleum feedstock with oxygen in a known manner to produce fuel gas consisting of carbon monoxide and hydrogen plus unreacted carbon (CO + H 2 + C). The outlet 11 of the reactor 10 feeds a cleaning tower 12, which receives water therein for washing the gaseous effluent and delivering clean fuel gas from outlet 13. Water washing of the effluent removes the entrained carbon from the gas and results in a carbon-water slurry which is conveyed from the cleaning tower 12 through outlet 14. The carbon-water slurry is typically about 0.5 percent by weight carbon. The slurry is delivered to a carbon removal and concentration apparatus 15. In accordance with techniques to be described further herein, a concentrated slurry of carbon and water of about five to seven percent carbon by weight is delivered to the output 16.
The concentration of the carbon at 15 results in a relatively clean water in outlet line 17 which may be recirculated to the cleaning tower 12 having an additional make up water inlet 18.
The concentrated slurry at 16 is mixed with a petroleum feedstock (oil), at 19, which is thereafter conducted to a preheater 20 and through line 21 to the partial oxidation reactor 10. The heater outlet 21 supplies the fuel oil and unreacted carbon for the partial oxidation reactor 10 as well as water which serves as a moderator for the reaction in 10.
The system described above therefore handles all of the unreacted carbon in a manner which supplements the fuel for production of the fuel gas and eliminates the necessity for providing a stream of superheated steam to the reactor 10. Provision for tempering steam would require a heater and supplementary fuel supply. It should be noted that the fuel supply necessary for producing the superheated steam would preferably be a clean fuel so as to reduce the amount of equipment necessary for cleaning the stack gases therefrom. The associated equipment and fuel requirements for such a process would add considerable to the cost of building and maintaining the partial oxidation plant.
An apparatus for the removal and concentration of carbon which is shown generally at 15 and FIG. 1 is detailed in FIG. 2 and described below.
A carbon-water slurry drum 30 receives the output of the tower 12 at inlet 14. The drum 30 has a screw conveyor 31 which removes carbon and water in a concentrated form for delivery to an oil slurry drum 32. The carbon-water slurry from the tower 12 is concentrated by means of flotation utilizing a gas injector 33. It should be understood that an electrode may be substituted for the gas injector 33 for producing bubbles within the tank 30 to float the carbon to the top of the tank 30 in a more concentrated form. Water outlet 17 shown above in FIG. 1 conducts relatively clean water back to the tower 12 as described.
The oil slurry drum 32 has a baffle plate 34 disposed therein to receive a supply of oil through an inlet supply line 35. The concentrated carbon and water slurry delivered at the outlet 36 of the screw conveyor 31 falls on the baffle 34, and is partially mixed with the oil washing the baffle 34. A surge area 37 in the tank 32 may be equipped with a propeller-type mixer 38 or other apparatus suitably adapted for agitating the slurry oil mixture. An outlet line 39 of the slurry drum 32 delivers the oil slurry mixture to a circulating pump 40, which delivers the oil slurry mixture to the heater 20 as shown in FIG. 1. A portion of the oil slurry mixture is recirculated from an outlet of the circulating pump 41 to the inlet 35 of the oil slurry drum 32.
Fuel oil to the system is supplied through an inlet 42 to the slurry drum 32 as indicated in drawing. This may be supplied in controlled amounts to regulate the concentration of oil and slurry mixture in the surge portion 37 of the drum 32. Likewise the variable speed motor 43 driving the screw conveyor 31 through shaft 44 may be controlled at various speeds in order to regulate the amount of carbon slurry injected into the slurry drum 32.
The present invention therefore has the benefits of simplifying a process for partial oxidation while at the same time utilizing by-product unreacted carbon in a mixture with water to regulate the temperature of the oxidation reactor as well as supplement the fuel supply for reacting the byproduct material. Furthermore, a means has been devised for regulating the concentration of carbon-water input to the system to a fairly concentrated weight range of 5 to about 7 percent carbon in water which previously was thought too highly concentrated to be useful.
While the foregoing description has been limited to what is considered to be the preferred environment of the present invention and it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and the scope of the invention.
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Unreacted carbon produced during the partial oxidation of fossil fuel is removed from the reactor gaseous effluent with water, resulting in a carbon-water slurry. The carbon-water slurry is concentrated to about five to seven percent by weight of carbon mixed with fuel and injected into the reactor for the dual purposes of utilizing the carbon contained in the slurry as the feedstock for the partial oxidation process and the water as a temperature moderator for the reactor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the registration of sheets within a plane so that the sheet may be exactly located in its proper orientation within the plane.
2. Description of the Prior Art
In the prior art there are numerous means proposed for precisely orienting a sheet within a plane. For example, it is known to orient a sheet upon a horizontal surface by registering a corner, or edge of the sheet upon a corner or edge formed on the surface. If the sheet edges are not straight or square with each other, other means must be provided to register the sheet within the plane. Even if the sheet edges are square, it is often desirable to write upon the sheet, or move something upon the sheet Thus, forces are imparted to the sheet and have a tendency to move the sheet from its registered position. To secure the sheet against such movement, it is well known to support the sheet using one or more locating pins wherein the pins project from a surface comprising the plane of registration. The pins extend through one or more apertures formed in the sheet and thereby help to secure against lateral movement of the sheet within the plane.
In U.S. Pat. No. 3,710,457 a stack of answer sheets for use with an automatic grading device is disclosed. The answer sheets are held by a pin which extends through an aperture formed on each of the sheets. The aperture is positioned in a prescribed relationship with an edge of the sheet. Guide bars located against the edge of the sheet cooperate with the pin to prevent rotational movement of the sheet. In the embodiment illustrated in FIG. 8 of this patent, a triangular aperture is formed in the sheet and the aperture is made smaller than the pin which extends through it. A flap is formed in the sheet adjacent to the aperture and the flap deflects as the larger pin enters the smaller aperture. The flap thereby prevents tearing of the sheet as the sheet is mounted on the pin. In this construction for registering the sheet, it will be noted that four edge elements of the sheet are being used to register the sheet. As used herein the term register implies producing a condition of correct alignment or proper relative position within a plane. The four edge elements comprise two edge elements contacted by guide bars engaging an edge of the sheet and two converging edge elements which border the aperture and are engaged by the pin. The use of four distinct edge elements to define position and orientation of a sheet comprises an over-constraint. In a design imposing a condition of over-constraint, there exists the problems of having:
(1) undesired clearance between the sheet being registered and the locating means, i.e., pins and edge guide bars, with attendant uncertainty as to position or orientation of the sheet; or
(2) potentially damaging interference between the sheet and the registration aids.
It is therefore an object of the invention to provide a sheet registration means wherein the registration condition of over-constraint and its attendant problems are avoided and wherein a condition of exact constraint exists.
SUMMARY OF THE INVENTION
The invention pertains to an improved sheet registration means including locating means associated with a plane in combination with registration edge elements on a sheet for registering the sheet in the plane, the sheet having one or more flaps formed in the sheet; and the improvement which comprises wherein the one or more flaps cooperate with means external to the sheet for resiliently biasing a total of only three registration edge elements of the sheet against the locating means and wherein the registration edge elements are so oriented relative to each other as to form well separated centers of rotation.
The invention also pertains to sheets that are specially constructed for mounting on pin means so that when mounted a condition of exact constraint exists in defining the registration of the sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
FIG. 1 is a plan view of a portion of a sheet registered by two pins in a condition of exact constraint;
FIG. 2 is a perspective view of a portion of the sheet shown in FIG. 1;
FIG. 3 is a plan view of a second embodiment of the invention illustrating a sheet registered by three pins in a condition of exact constraint;
FIGS. 4 and 5 are plan views of third and fourth embodiments of the invention each showing a sheet registered in a condition of exact constraint.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 a sheet 10 includes identical "A" shaped apertures 12, 12', which are punched or otherwise suitably formed within the sheet. Hex pins 11, 11' extend through the respective apertures. The hex pins may be fixed to a horizontally disposed planar surface 14 upon which the sheet rests. Resilient flaps 15, 15' are integrally formed on the sheet and border or are adjacent the apertures so that when the pins are inserted, the flaps rest upon flats of the hex pins and resiliently urge registration edges 16, 17 and 16' which border the apertures into engagement with other opposed flats formed on the hex pins. As may be noted in FIG. 1, the center to center distance between hex pins 11, 11' is slightly greater than the distance between corresponding points defining the apertures to establish a clearance 13 in one of the apertures so that only one flat of the hex pin 11' engages a registration edge 16' of the aperture 12'. The hex pin 11, it will be noted, engages two converging registration edges 16, 17 of the aperture 12. The hex pins 11 and 11' thereby function as a locating means.
Not counting engagement by the flaps, since they are resilient, the sheet is constrained in total by engagement of only three registration edges 16, 17 and 16'.
To establish a condition of exact constraint it is important that instantaneous centers of rotation arising from the registration condition be reasonably well separated; that is, separated approximately on the general order of the sheet dimensions. An instantaneous center of rotation represents a point about which the sheet, when engaged at only two registration edges, can be considered to be turning with pure rotation to cause engagement of a third registration edge with an opposed flat on one of the pins. For example, were registration edge 16' to be slightly out of engagement with its otherwise opposite land on hex pin 11' the sheet, under the spring force of flap 15', would tend to rotate about a point comprising the center of hex pin 11 to return registration edge 16' into engagement with its opposed land on hex pin 11' This point comprises an instantaneous center of rotation for the two registration edge elements 16 and 17 and is determined by the intersection of their respective perpendiculars as shown by dashed-dotted lines 18-19. Any two registration edge elements are associated with a respective instantaneous center of rotation about which pure rotation can be considered to occur were the third registration edge element to be slightly displaced from its opposing flat on the hex pin. Parallel dash-dotted lines 19, 19' define an instantaneous center of rotation at infinity. Dash-dotted lines 18 and 19' intersect at a point (not shown) outside the sheet, but which point nevertheless is well displaced from another instantaneous center of rotation at the center of hex pin 11. The separation of these centers of rotation provides a stability to the registration of the sheet in that there is a tendency for the sheet to return to its original registered position when subjected to a temporary unbalanced force causing one of the registration edges to leave contact with its corresponding flat on the hex pin.
With reference now to the alternate embodiment disclosed in FIG. 3 rectangular pins 21, 31 and 41 serve to register sheet 20 which includes three "C" shaped apertures 22, 32, and 42 through which a respective rectangular pin extends. Registration edges 26, 36 and 46 border their respective apertures and each engage an opposing flat formed on the respective pin. Clearances 23, 33 and 43 are provided between other bordering edges of each aperture and the respective pins. Resilient flaps 25, 35 and 45 formed in the sheet engage respective pins to bias the three registration edges into engagement with the pins. The condition for exact constraint is met in providing for only three edge elements of the sheet being in engagement with the locating pins. In addition the instantaneous centers of rotation as defined by the intersections of dash-dotted lines 28, 38 and 48 are well separated.
In the embodiment shown in FIG. 4, a sheet 50 is registered in a condition of exact constraint by three locating means or pins 51, 52 and 53 fixed to the planar surface in which the sheet is to be registered. Registration edge elements 57, 58 and 59 of the sheet comprise two of the external edges of the sheet. The registration edge elements 57, 58 and 59 are resiliently biased against pins 51, 52 and 53 respectively by cooperation of resilient flap 55, formed in the sheet 50 adjacent to aperture 54, and member 56 which is fixed relative to the aforesaid planar surface. Member 56 may comprise a rectangular or other shaped pin that extends from the surface and through aperture 54 and provides a land against which the resilient flap may resiliently rest to push the three registration edge elements of the sheet into engagement with the registration pins. It will be noted that the instantaneous centers of rotation for this registration means, defined by the intersections of dash dotted lines 60, 61, and 62 are well separated.
In the embodiment shown in FIG. 5 a sheet 70 is registered in a condition of exact constraint by three registration aids or pins 71, 72 and 73 fixed to the planar surface in which the sheet is to be registered. Registration edge elements 77, 78 and 79 of the sheet comprise edges which border an aperture 74 formed in the sheet. The registration edge elements 77, 78 and 79 are resiliently biased against pins 71, 72 and 73 respectively by cooperation of resilient flap 75, formed adjacent aperture 74, and member 76 which is fixed relative to the aforesaid planar surface. Member 76 may comprise a pin that extends from the surface and through aperture 74 and provides a land against which the resilient flap may resiliently rest to pull the three registration edge elements of the sheet into engagement with the registration pins. The instantaneous centers of rotation for this registration means, as defined by the intersections of dash dotted lines 80, 81 and 82 are also well separated.
Other modifications may include a sheet having only one "A" perforation as shown in FIG. 1 and one other registration edge comprising a natural edge of the sheet, assuming means, such as gravity, is provided to bias the edge against a corresponding locating aid and that the centers of rotation are well separated and only three edge elements are being engaged.
The sheet may comprise paper such as plain paper or coated papers such as photographic papers or the sheet may be comprised of other materials consistent with the spirit of the invention.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be affected within the spirit and scope of the invention.
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To register a sheet within a plane, a sheet registration means is provided comprising a flap formed on the sheet for resiliently biasing registration edge elements of the sheet against fixed locating pins. A total of no more and no less than three registration edge elements of the sheet are engaged by the locating pins to provide exact location of the sheet in its proper orientation within the plane.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of the applicant's co-pending application Ser. No. 363,325, filed May 24, 1973 now U.S. Pat. No. 3,873,955. Application Ser. No. 363,325, now U.S. Pat. No. 3,873,955, is a continuation of co-pending application Ser. No. 109,487, filed Jan. 25, 1971, now abandoned, and application Ser. No. 109,487 is a division of co-pending application Ser. No. 866,528, filed Oct. 15, 1969, now U.S. Pat. No. 3,624,407.
BRIEF SUMMARY OF THE INVENTION
This invention relates to primary control means for furnaces and the like and, more particularly, to an improved primary control incorporating an improved control circuit and an improved bimetallic type safety switch and effective to control a burner of a furnace.
In the past, primary controls have been utilized to control the burners in furnaces and such prior primary controls have incorporated relatively bulky, heavy and complicated main motor relays and safety circuit relays which function to control the furnace burner. Prior primary controls for furnaces have become increasingly complicated and expensive in the attempts to control reliably the furnace burners and such prior primary controls have many complicated, interrelating parts which are heavy, bulky and expensive and incorporate numerous moving parts with the result that prior primary controls have a relatively short life and are often plagued with service problems.
An object of the present invention is to overcome the aforementioned as well as other disadvantages of prior primary controls for furnaces and to provide an improved primary control which eliminates the necessity of providing main motor and safety circuit relays, which provides improved furnace burner control, and which is extremely reliable in operation.
Another object of the invention is to provide an improved primary control for furnaces which is relatively compact and light in weight, which operates with relatively little heat generation, and which is readily adaptable to meet the control requirements of various types of furnaces.
Another object of the invention is to provide an improved primary control for furnaces which incorporates improved and greatly simplified means for controlling furnace burner operation.
Another object of the invention is to provide an improved primary control for furnaces which is economical and commercially feasible to manufacture, assemble and test with mass production labor and methods and which is durable and efficient in operation.
Another object of the invention is to provide an improved primary control for furnaces incorporating improved means assuring fail-safe operation of the unit and associated furnace burner.
The above as well as other objects and advantages of the present invention will become apparent from the following description, the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic circuit diagram of a primary control embodying the present invention;
FIG. 2 is a perspective view of a primary control structure embodying the present invention;
FIG. 3 is a top view of the base of the primary control illustrated in FIG. 2;
FIG. 4 is a top view of the circuit board of the primary control illustrated in FIG. 2, showing the components of the circuit illustrated in FIG. 1 assembled thereon;
FIG. 4A is a bottom view of the structure illustrated in FIG. 4 and indicating the circuitry embodied thereon;
FIG. 5 is a partial cut away section of the primary control illustrated in FIG. 2 and illustrating the bimetallic type safety switch embodied therein with the contacts thereof in the open position;
FIG. 6 is a partial cut away section of the structure illustrated in FIG. 5, showing the same during the resetting operation thereof; and
FIG. 7 is a partial cut away section of a portion of the structure illustrated in FIG. 5, showing the safety switch contacts in the closed condition.
DETAILED DESCRIPTION
Referring to the drawings, and more particularly to FIG. 1 thereof, the circuitry for a primary control, generally designated 10, embodying the present invention is schematically illustrated therein. As shown in FIG. 1, the primary control 10 is comprised of a step down transformer 12 having a primary winding 14 and secondary windings 16 and 18, the primary winding 14 being adapted to be connected to a conventional source of 120 volt alternating current while, in the embodiment of the invention illustrated, each of the secondary windings 16 and 18 of the isolated step-down transformer has a potential of approximately 8 volts AC. The primary control 10 also includes a bimetallic type safety switch generally designated 20, including normally closed contacts 21 and 22 and a heater coil 23; a conventional thermostat generally designated 24; a reed switch, generally designated 25, having contacts 26 and 28 and independent concentrically wound coils RC1 and RC2, the contacts 26 and 28 being enclosed within a hermetically sealed glass envelope 30 while the coils RC1 and RC2 are concentrically wound therearound; a triac Q1 and a silicon controlled rectifier SCR1. The primary control 10 also includes a cadmium sulfide flame detector 32, resistors R1, R2, R3, R4, R5, R6, R8, and R9; capacitors, C2 and C3; a potentiometer R7 and diodes D1 and D2. As shown in FIG. 1, the primary control 10 is connected to and adapted to control a conventional burner 34 of a furnace (not shown). The terminal 35 of the burner 34 is connected to the source of power by the lead L1 while the terminal 36 of the burner is connected to the terminal 37 of the triac Q1 by the lead L2, the terminal 38 of the triac Q1 being connected to the source of power by the lead L3 through a fuse F1. The contact 28 of the reed switch 25 is connected by the lead L4 to the lead L2 through the resistor R8 while the contact 26 is connected to the gate 39 of the triac Q1 by the lead L5, the resistor R9 and the capacitor C3 being connected across the leads L2 and L3 by the leads L4 and L6 to protect the triac Q1.
The terminal 40 of the secondary winding 16 is connected to the contact 21 of the safety switch 20 by the lead L7 while contact 22 of the safety switch is connected to the terminal 42 of the thermostat 24 by the lead L8, the terminal 44 of the thermostat being connected by the lead L9 through the resistors R5 and R6 and the coil RC1, to the terminal 46 of the diode D1. The terminal 48 of the diode D1 is connected to the center tap 50 of the secondary windings of the transformer 12 by the lead L10. The capacitor C2 is connected across the resistor R6 and the coil RC1 of the reed switch 25 by the lead L11 while the resistor R3 is connected between the leads L9 and L10 by the lead L12 as illustrated in FIG. 1. The terminal 44 of the thermostat 24 is also connected to the terminal 52 of the diode D2 by the lead L13 through the resistor R4, the terminal 54 of the diode D2 being connected to the center tap 50 of the transformer 12 by the lead L10. As shown in FIG. 1, the contact 22 of the safety switch 20 is connected to the terminal 56 of the silicon controlled rectifier SCR1 through the heater coil 23 and the coil RC2 of the read switch 25, the potentiometer R7 being connected across the coil RC2. The terminal 58 of the silicon controlled rectifier SCR1 is connected to the center tap 50 of the transformer 12 by the leads L14 and L10 while the gate 60 of the rectifier SCR1 is connected to the terminal 52 of the diode D2 by the lead L15 and to the terminal 62 of the secondary winding 18 of the transformer by the lead L16 through the resistor R1, the cadmium sulfide flame detector 32 and the resistor R2.
The above described components are preferably mounted on one side of the circuit board 65 as illustrated in FIG. 4 and the entire circuit structure is integrated as by soldering as illustrated in FIG. 4A. In use, the circuit board 65 is mounted on a base 66 within a housing 67.
Referring in greater detail to the components of the primary control 10, the safety switch 20 illustrated schematically in FIG. 1 and illustrated structurally in FIGS. 4, 5, 6 and 7 is comprised of a mounting base 68 adapted to be secured to the circuit board 65 of the primary control, the circuit board 65 being formed of plastic or other suitable non-conducting material having sufficient strength to withstand the forces exerted thereon in carrying the components of the primary control as illustrated in FIG. 4 and the various electrical leads as illustrated in FIG. 4A. The mounting base 68 is generally U-shaped in side view, as illustrated in FIGS. 4, 5, 6 and 7, and includes a substantially flat, horizontally extending web portion 72 having upwardly projecting flange portions 74 and 76 at the opposite ends thereof. A support bracket 78 is provided which is riveted or otherwise fixed to the upper end of the flange portion 74 as viewed in FIG. 5 and the support bracket 78 carries a bimetallic blade 80 one end of which is fixed to the free end of the bracket 78 while the opposite end of the bimetallic blade 80 carries a substantially flat bimetallic blade 82 the free end of which is provided with an integral flange 84 that projects angularly downwardly from the flat body portion of the blade 82. A pair of contact blade springs 86 and 88 are provided having struck out portions 90 and 92, respectively, which function as the normally closed contacts 21 and 22 in the safety switch 20. The blade 86 includes a generally upwardly projecting portion 94 which carries the struck out portion 90 and an integral generally horizontally extending portion 96 which is secured to the web portion 72 of the mounting base 68 by a rivet 100, the portion 96 being electrically insulated from the mounting base 68 by an electrical insulator (not shown) disposed between the portion 96 and the web portion 72 of the mounting base 68. The blade 88 includes a generally upwardly projecting portion 102 which carries the struck out contact portion 92 and an integral generally horizontally extending portion 104 which is also secured to the web portion 72 of the mounting base 68 as by a rivet 106.
As shown in FIG. 7, in the normally closed condition, the upper end portion 102 of the blade 88 is adapted to engage the free edge of the downwardly projecting portion 84 of the bimetallic blade 82 whereby the contact portion 92 is maintained in engagement with the contact portion 90 of the blade 86, an adjusting screw 108 being provided which threadably engages a projecting portion 109 on the flange 74 to permit initial adjustment of the blade 82.
The bimetallic blade 80 is adapted to bend upwardly upon an increase in temperature whereas the bimetallic blade 82 is adapted to bend downwardly upon an increase in temperature, the bimetallic blade 82 thus acting as a compensator for variations in ambient temperature. The heater element 23 surrounds the bimetallic blade element 80, the heater element 23 functioning to heat the bimetallic element 80 as will be described hereinafter in greater detail whereby the bimetallic elements 80 and 82 move upwardly so that the upper end portion of the blade spring 88 disengages from the free end of the flange portion 84 of the bimetallic blade 82 and moves to the right, as viewed in FIGS. 5, 6 and 7 so as to open the contacts 21 and 22 of FIG. 1.
Means are provided for resetting the safety switch and returning the contacts 21 and 22 to their normally closed position. Such means is comprised of an elongate plunger 110 which is preferably formed of plastic or other suitable non-conducting material and which is supported for sliding movement by the upwardly projecting flange portion 76 of the mounting base 68 and by the end wall 112 of the housing 67 of the primary control 10, the flange portion 76 and the wall 112 of the housing 67 having openings 116 and 118, respectively, which function as bearing supports for the plunger 110. The plunger 110 is of stepped construction and includes a button portion 120 and an enlarged annular flange portion 122 which is joined to the button portion 120 by a radially extending flange 124 adapted to seat in a recess 125 provided in the end wall 112 of the housing. A reduced diameter portion 126 is also provided on the plunger 110 as well as a further reduced diameter portion 128, the portion 126 being adapted to pass through the opening 116 defined by the flange 76 while the portion 128 is adapted to pass through an opening 130 defined by the blade 88 and to engage the upper end portion 94 of the blade 86. A spring 132 is provided one end portion of which engages the flange 76 of the mounting base 68 while the opposite end of the spring 132 engages the flange 124 of the plunger 110 so as to bias the plunger toward the wall 112 of the housing 67. With such a construction, when the contact portions 90 and 92 are in the open condition, as illustrated in FIG. 5, the contact portions 90 and 92 may be moved to the normally closed position by manually pushing the button portion 120 of the plunger 110 to the left as viewed in FIG. 5. The shoulder 127 intermediate the portions 126 and 128 of the plunger 110 then engages the blade element 88 while the portion 128 of the plunger 110 passes through the opening 130 in the blade 88 and engages the blade 86 so that the blades 86 and 88 move to the left and assume the position illustrated in FIG. 6, the upper end of the blade 88 engaging the outer surface of the portion 84 of the bimetallic blade 82 so as to move the bimetallic blade 82 upwardly during such operation due to the cam action of the portion 84 of the blade 82 whereby the components assume the position illustrated in FIG. 6. Closing the contact portions 90 and 92 is effected upon release of manual pressure on the end of the button portion 120 of the plunger 110, the spring 132 functioning to return the plunger 110 to the inoperative position illustrated in FIG. 7 with the flange 124 of the plunger abutting the wall 112 of the housing 67. The spring blades 86 and 88 then move back to the right as viewed in FIG. 7, and since the upper end portion 102 of the blade 88 is stopped by the free end of the downwardly inclined portion 84 of the blade element 82, the contact portions 90 and 92 close and remain closed until the switch is again opened by upward movement of the blade 82.
The rectifier SCR1 is a conventional silicon controlled rectifier and may, for example, carry a rating of approximately four amperes. The thermostat 24 may be of any desired or conventional construction while the reed switch 25 is preferably of the type disclosed in the applicant's co-pending application entitled "Switch Construction." As previously mentioned, such a switch is comprised of a pair of contacts 26 and 28 carried by reeds hermetically sealed within a glass envelope 30. Such a reed switch also includes the electrically insulated, independently wound concentric coils RC1 and RC2, the magnetic fluxes of such coils being additive when in phase. The reed switch 25 preferably has a very large differential between pull-in and drop-out ampere turns or coil power. By way of example, the reeds preferably will pull in at about 60 ampere turns, but will not drop out until below 20 ampere turns, a ratio of at least 3 to 1. In the embodiment of the invention illustrated in FIG. 1 the maximum power to the coil RC1 is well below that required to pull-in the reed switch and close the contacts 26 and 28. The power is, however, enough to hold the reed switch contacts 26 and 28 closed once pull-in has been established, due to the very large differential. The reed switch coil RC2, on the other hand, has sufficient power when combined with RC1 to pull in the reed switch. Since reed switches are very fast they are capable of following an alternating current voltage to open or close 60 or 120 times per second. To avoid this opening and closing and the associated wear, the diode D1 and capacitor C2 are provided. The diode D1 is preferably a 200 milliampere diode which supplies half wave rectified current to the capacitor C2 to establish a DC supply for the reed switch coil RC1. The capacitor C2 is preferably a 47 microfarad 15 volt DC capacitor. The diode D1 and capacitor C2 function to form a DC supply for the holding coil RC1 so that flux is always present on the coil RC1 when the thermostat call for heat. This flux is very small however. With such a construction and since relatively small current passes through the contacts 26 and 28, such contacts are very reliable over a relatively long life.
The triac Q1 is a bidirectional thyrister which may be gate triggered from a blocking to a conducting state for either polarity of applied voltage, and is preferably mounted in a recess 135 defined by an integral flange 136 projecting outwardly from one side of the base 66 and functioning to isolate the other components of the control 10 from the heat generated by the triac Q1. The resistors R1 and R2 are preferably carbon resistors having ratings of 150 ohms and 560 ohms, respectively, 1/2 watt, the purpose of the resistor R1 being to prevent the accidental destruction of the diode D1, transformer 12 or silicon controlled rectifier SCR1 by a serviceman in the field. In this connection the resistors R1, R2, R5 and R9, the diode D2 and the capacitor C3 are all provided in the primary control 10 solely for the purpose of protecting other components and to protect against erroneous wiring in the field. The resistors R1, R2, R5 and R9, the diode D2 and the capacitor C3 are thus not essential to the basic circuit performance.
Typical values for the components in the control system described above are as follows:
SCR1 4 AMP Silicon controlled rectifierD1 200 Ma diodeD2 200 Ma diodeR1 Carbon resistor 150 ohms, ± 20%, 1/2 wattR2 Carbon resistor 560 ohms, ± 20%, 1/2 wattR3 Wirewound resistor 20 ohms, ± 20%, 5 wattR4 Carbon resistor 3300 ohms, ± 20%, 1/2 wattR5 Carbon resistor 47 ohms, ± 20%, 1/2 wattR6 Wirewound resistor 680 ohms, ± 20%, 1 wattR7 Wirewound potentiometer 1 ohm, ± 20%, 2 wattR8 Carbon resistor 82 ohms, ± 20%, 1/2 wattR9 Carbon resistor 82 ohms, ± 20%, 1/2 wattC2 Capacitor 47 mfd 15 VDCC3 Capacitor 22 mfd 200 V Mylar foil
It will be understood, however, that these values may be varied depending upon the particular application of the principles of the present invention.
Assuming a basic knowledge of the triac Q1, the silicon controlled rectifier SCR1, and the cadmium sulfide flame detector 32, a typical thermostat cycle operates in the following manner. It should be noted initially that whenever the reed contacts 26 and 28 are closed, current will flow from the source of electric power through the lead L1, the burner 34, the lead L2, the resistor R8 and the contacts 26 and 28, to the gate of the triac Q1 and the lead L3. When the gate of the triac Q1 is energized the full motor current will then pass through the triac Q1. This starts the burner and has the same effect as closing a set of relay contacts between the lead L2 and the lead L3.
Whenever the thermostat contacts close, a continuous holding flux is established in the coil RC1 by the DC supply network comprised of the diode D1 and the capacitor C2. Current also flows through the resistor R4 to the gate 60 of the silicon controlled rectifier SCR1. If the cadmium sulfide flame detector 32 registers darkness, no current can be shunted away from the gate 60 of the silicon controlled rectifier SCR1 and SCR1 will conduct. When SCR1 conducts, current also passes through the pull-in coil RC2 of the reed switch 25 and the heater 23 of the safety switch 20. With a flux established in the coil RC2 and the coil RC1, the reed switch contacts 26 and 28 will pull in and the triac Q1 will start the burner. If the cadmium sulfide flame detector 32 does not register flame, the silicon controlled rectifier SCR1 will continue to conduct and the safety switch 20 will open the contacts 21 and 22 due to the heating action of the heater 23 raising the bimetallic blade 82 through the raising of the bimetallic blade 80. It is preferred that the contacts 21 and 22 open and lock out after approximately 15 seconds. If the cadmium sulfide flame detector registers flame, then the flame detector 32 decreases in resistance and shunts current away from the gate 60 of the rectifier SCR1. SCR1 will no longer conduct, the heating coil 23 of the safety switch will be deenergized but the coil RC1 will continue to hold in the reed relay contacts 26 and 28. If the cadmium cell 32 registers flame and for some reason the flame should go out during the thermostat cycle, the rectifier SCR1 will again conduct and the heating coil 23 will be energized so as to open the contacts 21 and 22 into a lock-out condition. When the thermostatic conditions are satisfied and the contacts thereof open, the coil RC1 is deenergized thereby opening the contacts 26 and 28 and also deenergizing the triac Q1. No current is then available through the resistor R4 to energize SCR1 even though the cadmium cell 32 registers no flame. It should also be understood that the same cycle would occur if the thermostat were connected to line voltage and placed in one leg of the transformer primary control.
An important aspect of the present invention resides in the fact that if there is a failure in the primary control 10, the primary control 10 will fail in a safe condition. For example, if the silicon controlled rectifier SCR1 is shorted from anode to cathode it will conduct electric current supplied by the secondary winding 16 of the transformer. The cadmium sulfide flame detector 32 will have no effect on the control circuit. Since current through the rectifier SCR1 must also pass through the safety switch heater 23, the safety switch contacts 21 and 22 will open after approximately 8 seconds into a lock-out condition. The only way to start the burner again is by depressing the manual reset plunger 110. An open circuit in the rectifier SCR1 will render the control circuit inoperative since no starting current is provided in the coil RC2. The burner will thus never start. A short circuit from the gate to the cathode of the rectifier SCR1 has the same effect as an open circuit between the anode and cathode of SCR1. An open circuit from gate to cathode of the rectifier SCR1 also has this effect.
Failure of the diode D1 in the short circuit causes AC voltage to appear across the capacitor C2 and since AC voltage is destructive to the capacitor C2 it will generally cause it to fail short circuited. Hence, there is no coil power to the reed switch coil RC1 and the reed switch is incapable of holding. The burner would then become inoperative. If the diode D1 fails open circuited, there is likewise no power to the coil RC1 and the burner becomes inoperative.
A short circuit failure of the diode D2 reacts the same as a gate to cathode short of the rectifier SCR1 as previously described. An open circuit failure of the diode D2 will generally be destructive to the rectifier SCR1 and any failure of the SCR1 will render the control circuit inoperative as previously described.
An open or short circuit failure of the capacitor C2 will prevent the reed switch 25 from pulling in and the burner from operating. The burner will also be prevented from operating if either of the coils RC1 or RC2 of the reed switch 25 become open or short circuited since such failure will prevent the reed switch from pulling in and closing the contacts 26 and 28.
The resistor R1 prevents the accidental destruction of the diode D2 by a serviceman in the field. This could happen if a serviceman accidentally shorted one of the thermostat terminals with the proper terminal of the cadmium sulfide flame detector 32. Open circuit failure would react in the same manner as an open circuit in the flame detector 32. Short circuit of either of the resistors R1 or R2 would simply eliminate the protection measure from the equipment.
The resistor R3 is a wirewound type so that short circuit failure can be beglected. Open circuit failure of the resistor R3 would result in elimination of thermostat bias current used for conventional thermostat "pre-heaters." The resistor R3 plays no other role in the circuit other than for this home comfort feature.
Continuing the description of the fail-safe operation of the primary control 10, the resistor R4 is utilized for the purpose of calibrating the cadmium sulfide flame detector 32. If the resistor R4 is open circuited then SCR1 never receives current from gate to cathode and will never turn on. Since the rectifier SCR1 must conduct to pull in the reed switch through the coil RC2, the burner will never turn on. If the burner is in the middle of a cycle when the resistor R4 fails open, then the burner will fail to start on the next cycle. If the resistor R4 fails in a short circuit condition, then neither of the coils RC1 or RC2 will be energized and the reed switch contacts will not close so that the burner will be inoperative.
The resistor R5 protects the diode D1 from current surges to the capacitor C2 during normal operation. If the resistor R5 were to short circuit then the diode D1 may fail shorted and the burner would become permanently inoperative in the manner previously described in connection with the failure of the D1. If the resistor R5 fails open circuited, then no power will be furnished to the coil RC1 and the reed switch contacts will not close. The burner would then be inoperative.
The resistor R6 functions to limit the power to the coil RC1. The resistor R6 is calibrated and calibrates the coil RC1 to within a specified drop-out range for the reed switch. As is well known, wire wound resistors do not fail short. If open circuit failure results, then no power is supplied to the coil RC1 and the reed switch will not pull in. The burner will thus be inoperative if the resistor R6 fails open circuited.
The wire wound potentiometer R7 is used to calibrate the pull-in voltage of the reed switch. This is accomplished by shunting current away from the reed switch coil RC2. An open circuit in the potentiometer R7 allows the reed switch to pull in at lower line voltage than the set-point voltage, as for example 90 volts. Short circuit of the potentiometer R7 prevents power from flowing to the reed switch coil RC2 and the reed switch will not close the contacts 26 and 28. The burner will then be inoperative.
The heating coil of the safety switch 20 cannot fail shorted. An open circuit failure functions in the same manner as an open circuit failure of the anode to cathode on the rectifier SCR1 previously described. With respect to the cadmium sulfide flame detector 32, this flame detector maintains approximately 1,500 ohms at 1 foot candle illumination. Short circuit results in the failure to start the burner when the thermostat closes. An open circuit causes the safety switch 20 to lock out.
While a preferred embodiment of the invention has been illustrated and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.
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Primary control means for furnaces and the like including burner control means, means including solid state means effective to control said burner control means in response to a flame detector signal, bimetallic safety switch means, and means for interfacing between an isolated low voltage control circuit and said burner control means.
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FIELD OF THE INVENTION
[0001] The illustrative embodiment of the present invention relates generally to maintaining a timed event list in an electronic device, and more specifically to maintaining a timed event list in an electronic device in a manner in which event insertion time into the list and event retrieval time from the list are not proportional to the size of the list.
BACKGROUND OF THE INVENTION
[0002] Electronic devices function by executing operations such as processes, tasks, events, and threads (a lightweight process). The term “event” shall be used generally herein to include tasks, processes, events, threads and similar terms. When events are required to be performed by a certain time, they are referred to as scheduled or timed events. The timed events are stored in memory accessible to the electronic device in a list known as an event list. In order for the system to function properly, the events must be scheduled in the correct order. Existing events must be identified and executed on schedule. New events must be inserted into the event list in the proper location so that they maybe executed at the correct time. While the scheduling of events is important in every system, it takes on increased importance in electronic devices where the timely execution of events is of paramount importance, such as in real-time computer systems and in computer simulations.
[0003] The conventional method of maintaining a timed event list is to store individual events in a data structure known as a linked list. A linked list is a collection (i.e.: a list) of smaller data structures known as nodes. A node in a linked list includes a section for data and a section holding at least one pointer to a next node in the list. In doubly-linked lists, a section for a pointer to the previous node in the linked list is also included. A pointer is a value that identifies a memory location in the electronic device. The nodes in a linked list are often not stored in adjacent memory locations in the system and the pointers allow the list to appear as an uninterrupted structure. The initial node in the list is referred to as the “head node” and is pointed to by a separate pointer known as the “header pointer”. The last node in the list is referred to as the “tail node” and contains a pointer to a null reference, known as a “null pointer”. In some implementations the last node on the list also may be pointed to by a separate pointer known as a “tail pointer”. Linked lists are a widely used type of data structure because the memory requirements of the linked list does not need to be statically specified (the memory for a linked list is dynamically assigned as new nodes are added to the list ). A linked list with zero nodes in it is referred to as an empty linked list. In such a case the header pointer is a null pointer.
[0004] The conventional method of maintaining a timed event list requires the linked list to be sorted. Linked lists may be sorted through the use of “sort keys”. A sort key is a piece of data which is used to compare data contained in each of the individual nodes in the linked list. For example, timed event lists are sorted by the time of execution for the events which are recorded in the nodes of the linked list, so the sort key for the linked list would be the execution time of an event. The mechanisms used to sort a linked list are well known in the art. In order to rearrange a nodes position in the linked list, the pointer in the node and its surrounding node/nodes must be adjusted. Often this is accomplished through the use of a temporary node which serves as a holding spot for a pointer while the adjacent pointers are being re-oriented. A new node may be inserted into a linked list which has been sorted by event execution time by incrementally traversing the linked list and checking the execution time of the event in each node against the execution time of the event in the node being inserted. Once the proper insertion position has been located, the pointers of the nodes are readjusted and the new node is inserted between the appropriate existing nodes.
[0005] When it is applied to a timed event list, the conventional method of storing events in a linked list format has one major drawback. The method requires the serial traversal and inspection of the existing nodes in the linked list in order to insert a node with a new event. The linked list holding the timed events is sorted by time. Unfortunately, as the number of events in a timed event list grows larger, a larger portion of system time is spent traversing and inspecting the nodes in the linked list in a search for the proper insertion point. In electronic devices requiring the timely execution of events such as real-time computer systems and computer simulations this causes an unacceptable performance degradation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a block diagram of an environment suitable for practicing an illustrative embodiment of the present invention;
[0007] [0007]FIG. 2 is a block diagram of a linked list;
[0008] [0008]FIG. 3A is an illustrative embodiment of the present invention utilizing an array and linked list combination to maintain a timed event list;
[0009] [0009]FIG. 3B is a block diagram of the illustrative embodiment of FIG. 3A at a later time;
[0010] [0010]FIG. 3C is a block diagram of the illustrative embodiment of FIG. 3B at a later time; and
[0011] [0011]FIG. 3D is a block diagram of the illustrative embodiment of FIG. 3C at a later time.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The illustrative embodiments of the present invention provide a method for maintaining a timed event list for suitable systems requiring time critical processing of scheduled events, such as the SN4000 switch from Sycamore Networks of Chelmsford, Mass. A rapid insertion method for new events creates more available time for processing scheduled events. By using a multitude of linked lists which are stored in an array and sorted by time through the use of a hashing algorithm, the illustrative embodiments of the present invention provide an insertion time that is independent of the number of events that have been scheduled. With less time spent searching for the proper event insertion point, the system is able to process more events in a timely manner.
[0013] [0013]FIG. 1 depicts an environment suitable for practicing an illustrative embodiment of the present invention. The system 1 includes a non-volatile storage area 2 , such as a hard drive. Also included in the system 1 is a processor 4 and a memory area 6 . The memory 6 includes a protected area of memory 7 , into which the operating system 8 for the system 1 is loaded. The protected area of memory 7 is used only by the operating system 8 and is unavailable to a system user or another application. The operating system 8 maintains a list of tasks or events for execution. Events must be scheduled onto the event list, retrieved from the event list, and performed in a timely manner.
[0014] [0014]FIG. 2 depicts a linked list used in the illustrative embodiments of the present invention. The linked list 11 includes a head node 14 , individual nodes 18 and 20 , and a tail node 22 . Each node contains a data section 15 and a pointer section 16 . The data section 15 contains the data held by the node, such as a scheduled event with a start time. The pointer section 16 holds a pointer which points to the next node in the linked list. Each node is linked through a pointer to the next node in the linked list 11 . Thus, the node 14 has a pointer that points to the next node 18 . The node 18 includes a pointer that points to the next node 20 . The pointer section of the the node 20 includes a pointer that points to the node 22 . The final node 22 in the linked list 11 includes a pointer pointing to a null reference which indicates that the linked list is at an end. Each node is stored in a memory location in the memory 6 of the system 1 . The linked list 11 is accessed through the header pointer 12 which points to the head node 14 in the linked list. In order to access nodes in the middle of a linked list, it is necessary to traverse the linked list from the end of the linked list to the node in question. Those skilled in the art will realize that in a double-linked list it is possible to traverse the linked list in both directions through the use of pointers pointing to the preceding and following nodes in the linked list.
[0015] Conventional methods of maintaining timed events in a linked list suffer from slow insertion times. Specifically, the time required to traverse the linked list to find the proper insertion point negatively impacts system performance. Likewise, the re-sorting of the linked list after every insertion point is found also slows system performance. The illustrative embodiment of the present invention avoids the slow insertion problem by using a plurality of linked lists in combination with an array. By using multiple linked lists in a large array, the linked lists are greatly shortened. Since the linked lists have a short length, the insertion may be done at the end of the linked list without having to sort each linked list. A pointer to the tail of the list allows immediate insertion. This provides great time savings to the system during the event insertion process. Since the events in the linked list must be accessed in a timely manner, the linked lists are inserted in an array and the array is sorted by time.
[0016] An array is a series of logically adjacent memory locations located in the memory 6 of the system 1 . The memory locations all hold items of a same data type, such as integer values, pointers, or defined data structures. In one embodiment of the present invention, the array memory locations hold a data structure which includes a header pointer and a tail pointer to a linked list. The linked list may be traversed from the header node to examine data and new nodes may be inserted at the tail pointer. If the linked list is empty, the header pointer and tail pointers are null pointers. In another embodiment of the present invention, the array holds a tail pointer to a doubly linked list. The linked list may be traversed backwards from the tail to examine data and new nodes may be inserted at the tail of the linked list. Those skilled in the art will recognize that there are many different data structures which may be employed without departing from the scope of the present invention. The array is chosen to be a size much larger than the expected number of events occurring at any given time. The array is accessed through the array name which the operating system 8 cross-references to a given memory location, and an index which will be referred to herein as the “now pointer”. The index represents an offset from the array starting point. For example, if the now pointer has a value of 40, the memory location indicated by the now pointer is the starting point of the array offset by 40 memory locations. The now pointer is synchronized with the system clock and iterates to the next position in the array at predetermined time intervals, such as 10 milliseconds. As a result, each memory location pointed to by the now pointer represents the current time. The other memory locations in the array, modulo by the size of the array, such as 8192, represent future times. For example, if the now pointer was being advanced through the array every 10 milliseconds, and was currently at location 20 , location 21 would represent the current time plus 10 milliseconds.
[0017] The illustrative embodiment of the present invention schedules an event by first inserting the event information, including the scheduled time for execution, into the data section of a node structure. The scheduled event time included in the data section of the node is compared against the current time indicated by the position of the now pointer in the array. The scheduled event time is subtracted from the current time (if the scheduled time equals the current time, the event is immediately executed). The difference from the subtraction operation represents how far in the future the event is scheduled to occur. The time differential is divided by the time parameter controlling the now pointer advancement, and the result has a modulo operation performed on it with the size of the array. Those skilled in the art will recognize the sequence of mathmatical operations performed to determine an insertion point for a new node as a “hashing algorithm.” For example, if the time differential were 300 milliseconds, the 300 milliseconds would be divided by the time parameter controlling the now pointer advancement, such as 10 milliseconds, to arrive at result of 30. The current array position indicated by the now pointer would have 30 added to it and the result would undergo a modulo operation using the size of the array, such as 8192, to determine the proper placement for the timed event. If there were more than 30 memory locations remaining between the positon of the now pointer and the end of the array, the node holding the timed event would be inserted in a the linked list referenced by the array location 30 memory locations from the current position. If, however, the now pointer was closer to the end of the array than 30 memory locations, the now pointer would advance as many locations as possible to the end of the array and then wrap around and continue counting from the beginning of the array to determine the insertion point.
[0018] As noted above, the array in the illustrative embodiment of the present invention is chosen to have many more memory locations than there are events occurring at any one time. The size of the array results in most of the memory locations referencing linked lists with one or zero nodes. The timed event node is inserted onto the end of the linked list referenced at the specified location. If the linked list referenced by the memory location is empty, the pointers in the array memory location are re-oriented to point directly to the new node. A null pointer is inserted into the pointer section for the new timed event node. If the linked list referenced by the array memory location already contains at least one node, the new timed event node will be inserted at the end of the current linked list by redirecting the null pointer in the final node of the linked list to the new timed event node. Again, the new timed event node will have a null pointer inserted into its pointer section. The linked list does not have to be sorted. Using this method, the illustrative embodiments of the present invention provide an expedited means of inserting new timed events into a timed event list.
[0019] FIGS. 3 A- 3 D illustrate the process of maintaining a timed event list in an illustrative embodiment of the present invention. FIG. 3A depicts the components used to process the timed event list of the illustrative embodiments. A system 1 includes an array 30 of adjacent memory locations numbered from 0 to 8,191, an array of 8,192 memory locations. Those skilled in the art will recognize that the size of each memory location, such as 1 byte, 2 bytes, or 4 bytes, will vary according to the system 1 being utilized. An array index, referred to as a now pointer 31 which is indicating memory location [0005], keeps track of the current location in the array and is synchronized with the system clock. The now pointer iterates through the array at predetermined intervals, such as advancing every 10 milliseconds. Included in some, but not all, of the memory locations in the array 30 are references to a plurality of linked lists 32 , 34 , 36 , 38 , and 40 . The linked lists are composed of one or more nodes 35 , which include a data section and a pointer section to the next node, if any, in the linked list. The data section contains the record of a timed event to be executed by the system 1 .
[0020] [0020]FIG. 3B depicts the array 30 previously shown in FIG. 3A at a later time interval. The now pointer 31 has advanced to memory location [0006] of the array 30 . During the time period the now pointer is pointing to the memory location, the method of the present invention will check for a linked list located at that location. The linked list 34 , containing a node 35 , is pointed to by a reference in memory location [0006], the current location in the array. The record of the timed event contained in the data section is examined to see if it indicates an event that is ready for execution. If the event included in the linked list referenced by the current array memory location is ready for execution, the system 1 executes the event. If the event is not ready for execution, the scheduled time is compared to the current time as detailed above, and the node is deleted from the linked list 34 . The deleted node is reinserted into the array 30 at the memory location corresponding to its scheduled time for execution as explained above. Each node of the linked list is examined and either executed or removed and executed. Since there are more memory locations than events, the majority of memory locations will include references to linked lists that are either empty or have one node to examine.
[0021] [0021]FIG. 3C depicts the array 30 previously shown in FIG. 3A and FIG. 3B following the processing of the memory locations [0006],[0007] and [0008]. The now pointer 31 is now pointing to memory location [0009]. The node 35 , which formerly was in linked list 34 when it was located at memory location [0006], has been rescheduled to memory location [0010] where it is attached to linked list 42 , a previously empty linked list. The now pointer 31 examines linked list 36 , as above, and either executes the timed event contained in each node or reschedules the node to the appropriate time, as outlined above.
[0022] [0022]FIG. 3D depicts the array 30 of FIGS. 3 A- 3 C with the now pointer pointing to memory location [0010]. Node 35 , which was previously examined and not executed, is now executed, as the scheduled time and the time referenced by the memory location are the same. New timed events or rescheduled events have been inserted into the linked list 44 at memory location 14 . In real-time computer systems and computer simulations there are usually more events scheduled in the near future than later in time so that the linked lists referenced by the memory locations nearer the now pointer 31 are more likely to contain non-empty linked lists than those farther away (in space and time ).
[0023] The illustrative embodiment thus allows a rapid examination, execution, and rescheduling of timed events. The overhead required to process the timed event list is less than that used in conventional methods which allows the system to process scheduled events in a time critical manner.
[0024] It will thus be seen that the invention attains the objects made apparent from the preceding description. Since certain changes may be made without departing from the scope of the present invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a literal sense. Practitioners of the art will realize that the system configurations depicted and described herein are examples of multiple possible system configurations that fall within the scope of the current invention. Likewise, the types of data structures noted in the drawings and description are examples and not the exclusive types of data structures which may be employed within the scope of the present invention.
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A method for maintaining a timed event list is disclosed. The illustrative embodiment of the present invention provides a method of rapidly inserting, examining, rescheduling and executing events in a timed event list in a time critical manner. By limiting the time required to insert events into a timed event list, and further limiting the time required to retrieve events from a timed event list, the method of the present invention increases the time available to a system to process timed events.
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This application is a continuation of U.S. patent application Ser. No. 10/999,786, filed Nov. 29, 2004 now U.S. Pat. No. 7,434,073 entitled “A FREQUENCY AND VOLTAGE SCALING ARCHITECTURE,” the content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
Embodiments of the invention relate to the field of microprocessor architecture. More particularly, embodiments of the invention relate to a technique to scale frequency and operating voltage of various functional units within a microprocessor.
BACKGROUND
In order to help reduce power in microprocessors while minimizing the impact to performance, prior art techniques for reducing processor clock frequency have been developed. Among these prior art techniques are architectures that divide the processor into various clock domains. For example, one prior art technique has a separate clock domain for the integer pipeline, a separate clock domain for the floating point pipeline, and a separate clock domain for memory access logic.
Using separate clock domains for each pipeline and/or memory access cluster can pose challenges to maintaining the performance of the processor due to the amount of overhead circuitry needed to control each clock domain.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments and the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
FIG. 1 illustrates a clock and voltage scaling architecture according to one embodiment of the invention.
FIG. 2 illustrates a front-side bus computer system in which one embodiment of the invention may be used.
FIG. 3 illustrates a point-to-point computer system in which one embodiment of the invention may be used.
DETAILED DESCRIPTION
Embodiments of the invention relate to a frequency and voltage control architecture for a microprocessor. More particularly, embodiments of the invention relate to techniques to distribute and control a clock and operating voltage among a number of clocking domains within the microprocessor, such that the frequency and operating voltage of each domain can be controlled independently.
FIG. 1 illustrates a clock and voltage domain architecture according to one embodiment of the invention. In particular, FIG. 1 illustrates a processor architecture 100 that has been divided into three fundamental clocking domains: A front end domain 101 , having a trace cache 102 , branch predictor 103 , renaming unit 104 , decoding unit 105 , sequencer 106 , free list 107 , renaming table 108 , and a re-order buffer (ROB) 109 ; several back end domains 110 , having a memory ordering buffer (MOB) 111 , a first-level cache 112 , physical register files 113 , issue queues 114 , bus interface 116 and execution units 115 ; and a memory domain including a second level cache memory 119 . In one embodiment, the bus interface is a front-side bus interface, while in other embodiments it is a point-to-point bus interface.
The front-end domain, back-end domains, and the memory domain each have at least one first-in-first-out (FIFO) queue 117 used to help synchronize the exchange of information between the various clock domains. In one embodiment of the invention, at least some of the synchronization queues are queues that provide other functionality within the processor, whereas in other embodiments, the synchronization queues are dedicated to the clock domain control architecture. In addition to clock domains, one embodiment of the invention divides the processor into voltage domains, which can be regulated independently of each other. In at least one embodiment, the clock domains and the voltage domains are the same and include the same functional units, however, in other embodiments the clock domains and voltage domains are not the same and may include different functional units.
In one embodiment of the invention, each clock within the various clock domains may be synchronized to a reference clock. However, in other embodiments, each domain clock may not be synchronous in relation to other domain clocks. Furthermore, in at least one embodiment, the back-end domains may communicate between each other via signals known as “crossbars”.
In order to control each of the clock and voltage domains, one embodiment of the invention attempts to minimize a product of the energy and the square of the (“delay 2 ”) of each domain by determining the energy and performance of each domain at certain time intervals. Energy and performance may be determined at two time intervals, in at least one embodiment, by calculating the energy and delay of a domain during a first time interval and estimating the energy and delay of the domain in a subsequent time interval. A frequency and voltage pair for the subsequent time interval may then be chosen by minimizing the ratio between the energy-delay 2 product of the first time interval and that of the subsequent time interval.
For example, in one embodiment of the invention, the processor energy, “E”, for interval n+1 is estimated according to the following equation:
E
n
+
1
E
n
=
1
+
E
FE
,
n
E
n
×
(
V
n
+
1
2
V
n
2
-
1
)
In the above equation, “E FE,n ” is the energy of the front-end domain at time interval “n”, where as “E n+1 ” is the energy of the front-end at time interval n+1 and “V n+1 ” is the operating voltage of the front-end domain at time interval n+1, and “V n ” is the operating voltage of the front-end domain at time interval n.
Performance of the processor as a function of the frequency of the front-end domain can be estimated by using the clock frequency of the front-end domain for a given time interval, the rate at which instructions are fetched by the front-end, and the rate at which micro-operations (decoded instructions) are delivered to subsequent pipeline stages. In one embodiment, the performance estimation, “T n+1 ”, of an interval, n+1, is estimated according to the equation:
T
n
+
1
T
n
=
1
+
(
f
n
f
n
+
1
-
1
)
×
1
-
p
n
1
+
b
In the above equation, “p n ” is the average number of entries in the front-end queue for the n-th interval, and “b” is the branch misprediction rate. The value, “1+b”, is an indicator of the rate at which the fetch queue may be loaded and “1−pn” is an indicator of average number of entries in the queue. “T n ” is the performance of front-end at interval “n”, “fn” is the frequency of the front-end domain at interval n, and “f n+1 ” is the frequency of the front-end domain at the following time interval.
Once the energy and performance of the processor has been calculated according to the above equations, in one embodiment, the front-end domain frequency and voltage can be adjusted for the next time interval, n+1, at the end of each time interval, n. In one embodiment, the selection of frequency and voltage is made according to the ratio:
R
(
〈
f
,
V
〉
)
=
E
n
+
1
E
n
×
T
n
+
1
T
n
×
T
n
+
1
T
n
The frequency and voltage selected for the interval n+1 are those that minimize the above ratio. If two or more pairs are found that result in the same value, R, then the pair with the minimum frequency is chosen, in one embodiment. The frequency and operating voltage of the front-end domain may then be set to the appropriate values for the interval n+1 and the process repeated for the next interval.
Each back-end frequency and operating voltage may be estimated in a similar manner to the front-end, by estimating the energy and performance of the processor as a function of the operating voltage and frequency of each back-end domain and choosing a frequency and operating voltage that minimizes the ratio between the energy performance product between interval n+1 and interval n. In one embodiment, the processor energy, “E n ”, as a function of the back-end domain energy, “E BE,n ” is estimated according to the equation:
E
n
+
1
E
n
=
1
+
E
BE
,
n
E
n
×
(
V
n
+
1
2
V
n
2
-
1
)
Performance of the processor as a function of the frequency of each back-end domain can be calculated at each interval, n+1, according to the equation:
T
n
+
1
T
n
=
1
+
S
×
(
1
-
2
m
n
)
2
×
p
,
where
p
=
-
L
q
,
n
+
L
q
,
n
2
+
4
L
q
,
n
2
and
S
=
(
f
n
f
n
+
1
-
1
)
×
f
n
+
1
-
f
n
f
max
-
f
min
In the above equation, m n is the number of second level cache misses divided by the number of committed micro-operations for the interval, n, and L q,n is the average utilization of all micro-operation issue queues for all back-end domains containing execution units. Once the energy and performance of the processor has been calculated according to the above equations, in one embodiment, the back-end domain frequency and voltage can be adjusted for the next time interval, n+1, at the and of each time interval, n. In one embodiment, the selection of frequency and voltage is made according to the ratio:
R
(
f
n
+
1
,
V
n
+
1
)
=
E
n
+
1
E
n
×
T
n
+
1
T
n
×
T
n
+
1
T
n
The frequency and voltage selected for the interval n+1 are those that minimize the above ratio. If two or more pairs are found that result in the same value, R, then the pair with the minimum frequency is chosen, in one embodiment. The frequency and operating voltage of the back-end domain may then be set to the appropriate values for the interval n+1 and the process repeated for the next interval.
FIG. 2 illustrates a front-side-bus (FSB) computer system in which one embodiment of the invention may be used. A processor 205 accesses data from a level one (L1) cache memory 210 and main memory 215 . In other embodiments of the invention, the cache memory may be a level two (L2) cache or other memory within a computer system memory hierarchy. Furthermore, in some embodiments, the computer system of FIG. 2 may contain both a L1 cache and an L2 cache, which comprise an inclusive cache hierarchy in which coherency data is shared between the L1 and L2 caches.
Illustrated within the processor of FIG. 2 is one embodiment of the invention 206 . Other embodiments of the invention, however, may be implemented within other devices within the system, such as a separate bus agent, or distributed throughout the system in hardware, software, or some combination thereof.
The main memory may be implemented in various memory sources, such as dynamic random-access memory (DRAM), a hard disk drive (HDD) 220 , or a memory source located remotely from the computer system via network interface 230 containing various storage devices and technologies. The cache memory may be located either within the processor or in close proximity to the processor, such as on the processor's local bus 207 . Furthermore, the cache memory may contain relatively fast memory cells, such as a six-transistor (6T) cell, or other memory cell of approximately equal or faster access speed.
The computer system of FIG. 2 may be a point-to-point (PtP) network of bus agents, such as microprocessors, that communicate via bus signals dedicated to each agent on the PtP network. Within, or at least associated with, each bus agent is at least one embodiment of invention 206 , such that store operations can be facilitated in an expeditious manner between the bus agents.
FIG. 3 illustrates a computer system that is arranged in a point-to-point (PtP) configuration. In particular, FIG. 3 shows a system where processors, memory, and input/output devices are interconnected by a number of point-to-point interfaces.
The system of FIG. 3 may also include several processors, of which only two, processors 370 , 380 are shown for clarity. Processors 370 , 380 may each include a local memory controller hub (MCH) 372 , 382 to connect with memory 22 , 24 . Processors 370 , 380 may exchange data via a point-to-point (PtP) interface 350 using PtP interface circuits 378 , 388 . Processors 370 , 380 may each exchange data with a chipset 390 via individual PtP interfaces 352 , 354 using point to point interface circuits 376 , 394 , 386 , 398 . Chipset 390 may also exchange data with a high-performance graphics circuit 338 via a high-performance graphics interface 339 .
At least one embodiment of the invention may be located within the PtP interface circuits within each of the PtP bus agents of FIG. 3 . Other embodiments of the invention, however, may exist in other circuits, logic units, or devices within the system of FIG. 3 . Furthermore, other embodiments of the invention may be distributed throughout several circuits, logic units, or devices illustrated in FIG. 3 .
While the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments, which are apparent to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention.
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A method and apparatus for scaling frequency and operating voltage of at least one clock domain of a microprocessor. More particularly, embodiments of the invention relate to techniques to divide a microprocessor into clock domains and control the frequency and operating voltage of each clock domain independently of the others.
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BACKGROUND OF THE INVENTION
Rudolf Diesel himself used vegetable oils for operating the first diesel engines. Like many people after him, he assumed that petroleum would soon run out. The ready availability of petroleum and its fractions in the last century led, in automotive construction, to engines which are optimized with respect to the use of middle distillates of petroleum. In order to achieve a lower level of environmental pollution, considerable improvements were made both in engine technology and in the fuel composition.
Very different considerations, the reduction of the CO 2 emission into the atmosphere and the industrial use of renewable raw materials, once again focused attention on the use of vegetable oils. Their high viscosity makes them unsuitable for use in pure form as fuel in modern automotive diesel engines. The esters of rapeseed oil proved suitable for use in diesel engines. For this purpose, the rapeseed oil is cleaved and the resulting generally unsaturated carboxylic acids are esterified with methanol and the glycerol liberated is isolated. This chemical processing increases the cost of the rapeseed oil methyl ester as diesel fuel to a not inconsiderable extent (DE-A42 09 779, U.S. Pat. No. 5,354,878). Use in winter is limited because the setting point of these esters is between -10 and -20° C.
The use of rapeseed oil methyl esters does not result in a further accumulation of CO 2 in the atmosphere, because this gas was withdrawn from the atmosphere during growth. A great advantage is the biodegradability and the fact that there is virtually no sulfur content. Rapeseed oil methyl ester is therefore suitable as a fuel particularly in forestry and agriculture, in nature conservation and water catchment areas, nature reserves and lakes and rivers. Rape can be cultivated on set-aside areas, reducing the subsidies for agriculture, but the rapeseed oil methyl ester can be used economically as diesel fuel only if the State waives the imposition of a tax to a high degree or entirely. The erection of special plants for the production of rapeseed oil methyl ester will remain limited because the annual production of rape fluctuates greatly. On the one hand, these fluctuations are weather-related or a smaller or greater quantity is cultivated because other crops are preferably produced, depending on the world market price. This irregular production of the vegetable oils occurs more or less with all agriculturally produced oils. Moreover, only the excess quantities not used for food and other industrial purposes are employed for fuels.
It was therefore the object to avoid the above disadvantages of rapeseed oil methyl ester when used as a diesel fuel and to find a way of using vegetable oils in a more suitable form.
SUMMARY OF THE INVENTION
Surprisingly, it was found that the direct use of liquid vegetable or animal oils without prior esterification as diesel fuel is possible with the simultaneous use of acetals.
The invention thus relates to diesel fuels based on natural, liquid triglycerides of vegetable or animal origin and acetals.
Mixtures of acetals and rapeseed oil or other natural triglycerides of vegetable or animal origin, such as, for example, palm oil, palm kernel oil, soybean oil, peanut oil, sunflower oil, canola oil, coconut oil, tall oil or linseed oil, are used. Rapeseed oil and soybean oil are particularly suitable.
From 5 to 95% by weight of triglycerides and from 5 to 95% by weight of acetals may be used. The diesel fuel may also contain up to 75% by weight of esters, preferably rapeseed oil methyl ester, diesel oil or other organic compounds which conform to the diesel specification.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Acetals which have a flashpoint, according to the diesel specification, of more than 55° C. and advantageously a low viscosity are used. This makes it possible to establish the viscosity required for the fuel.
It is known that acetals increase the cetane number. Some mixtures of acetals and triglycerides have cetane numbers which are considerably above those currently encountered in practice, which leads to better combustion of the fuel with less emission. The acetals suitable for the invention are biodegradable, and the setting points and CFPP (cold filter plugging point) values achieved with the acetal/triglyceride mixtures are lower than those achieved with rapeseed oil methyl ester. Acetals are petrochemical products which can be produced in a large volume in existing chemical plants or chemical plants which are easily modified. Coupling the use of triglycerides as fuels with the large-scale petrochemical industry would better compensate fluctuations in the availability of, for example, rapeseed oils and other trigylcerides than special plants for the production of esters thereof, because these large plants can also be used for the production of other chemicals. These mixtures contain virtually no sulfur, nitrogen or aromatics.
The acetals of the diesel fuels according to the invention are reaction products of aldehydes or dialdehydes with alcohols and can be described by the following formulae: ##STR2## R 1 to R 7 are alkyl or alkenyl radicals of 1 to 20 carbon atoms. These radicals may be linear, branched, saturated or mono- or polyunsaturated. The sum of all carbon atoms in R 1 to R 7 may be up to 30. R 8 may be O or (CH 2 ) n , where n is a number from 0 to 5.
Acetals in which R 1 is an alkyl radical having 1 to 6 carbon atoms, R 2 to R 7 are alkyl radicals having 1 to 12 carbon atoms and R 8 is an alkylene radical having 1 to 5 carbon atoms are also suitable.
Acetals in which R 1 is an alkyl radical having 2 to 4 carbon atoms, R 2 and R 3 are alkyl radicals having 4 to 8 carbon atoms, R 4 to R 7 are alkyl radicals having 1 to 5 carbon atoms and n is the number 0 are likewise very suitable.
For the required cetane number, these diesel fuels contain no nitrogen-containing ignition improvers which increase the emission of nitrous gases. The oxygen content may be adjusted in a wide concentration range, depending on requirements.
TABLE 1______________________________________ Setting point (at Viscosity rotating Density 20° C. thermo- 20° C. according toSample designation meter) °C. (Aerometer) UbbelohdeComposition DIN/ISO g/cm.sup.3 mPas Cetane(in % by weight) 3016 DIN 51757 DIN 51562 number______________________________________Dibutyl formal (DBF) -50.00 0.83 1.20 61.5075% DBF -32.00 0.85 2.60 59.5025% Rapeseed oil50% DBF -26.00 0.88 5.90 57.0050% Rapeseed oil25% DBF -15.00 0.89 17.20 51.4075% Rapeseed oil10% DBF -10.00 0.91 37.50 46.9090% Rapeseed oil75% DBF -15.00 0.85 2.20 59.0525% Soybean oil50% DBF -12.00 0.88 5.50 57.0050% Soybean oil25% DBF -7.00 0.89 15.90 56.8075% Soybean oil10% DBF -2.00 0.91 32.50 47.5090% Soybean oil35% DBF -23.00 0.85 4.60 53.8035% Rapeseed oil30% Diesel25% DBF -17.00 0.84 4.10 51.5025% Rapeseed oil50% Diesel15% DBF -14.00 0.84 3.60 49.3015% Rapeseed oil70% Diesel17.5% DBF -11.00 0.88 9.80 50.5052.5% Rapeseed oil30% Diesel12.5% DBF -15.00 0.86 7.00 49.4037.5% Rapeseed oil50% Diesel7.5% DBF -18.00 0.84 4.90 48.2022.5% Rapeseed oil70% DieselDiesel -15.00 0.82 3.30 45.00Soybean oil -1.00 0.92 54.0 <45Rapeseed oil -15.00 0.92 70.60 <45______________________________________
TABLE 2______________________________________Effect of acetals on the cetane number of dieselConcentration of the additives (mg/kg) No. 1 No. 2 No. 3______________________________________pure diesel oil 49.1 49.1 49.1 200 49.1 49.1 49.2 1000 49.2 49.3 49.520000 50.3 50.8 51.460000 51.0 52.8 53.5______________________________________ No. 1: Isobutyraldehyde di2-ethylhexyl acetal No. 2: Butyraldehyde dibutyl acetal No. 3: Glyoxal tetraethyl acetal
TABLE 3______________________________________Biodegradation of acetals according to OECD guidelines 301 BAcetal Degradation in % after 28 days______________________________________Isobutyraldehyde 2-diethylhexyl acetal10 mg/l 7120 mg/l 63Acetaldehyde dioctyl acetal10 mg/l 7520 mg/l 66Butyraldehyde dibutyl acetal10 mg/l 95______________________________________ mg/l relates to the pure acetal solution.
Table 1 shows that mixtures of formaldehyde dibutyl acetal (also referred to as dibutyl formal) and rapeseed oil and soybean oil give diesel fuels which have considerably high cetane numbers in some cases. Considerable amounts of diesel oil may be added to the mixtures according to the invention. As a result, the cetane numbers required in practice are also reached. Mixtures of trigylceride and acetal in a ratio of, for example, 1:1 give the very good cetane number of 57, a setting point of less than -25° C. and viscosities of about 6 mpas. Such a winter-resistant, biodegradable diesel fuel having a high cetane number, virtually without sulfur, nitrogen and aromatics, which minimizes the emitted pollutants, would be an optimum fuel for environmentally sensitive areas, such as nature reserves, water catchment areas, forests, rivers, lakes and inner cities.
Table 2 also shows the effect of acetals as cetane number improvers in a hydrocarbon fraction suitable as diesel fuel. It is evident that cetane number improvement is proportional to the concentration of acetals of the formulae (I) and (II).
The effect is small in pure hydrocarbons, and consequently acetals have not been widely used as cetane number improvers in practice to date. There are much more effective products for this purpose, such as, for example, peroxides and nitrates, which are used in amounts of up to 500 ppm.
The optimum products based on nitrates introduce nitrogen into the diesel fuel, which increases the proportion of oxides of nitrogen in the exhaust gases (DE-A-41 29 911; U.S. Pat. No. 4,541,837; DE-A-31 36 030; U.S. Pat. No. 5,433,756; DE-A-32 33 834).
Table 3 shows the good biodegradability of acetals. It increases with decreasing molecular weight, favoring the low molecular weight acetals as preferably used for the mixtures according to the invention.
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The present invention relates to environmentally friendly diesel fuel, containing natural, liquid triglycerides of natural or animal origin, such as rapeseed or soybean oil, and acetals of the formula (I) or (II) ##STR1## in which the substitutents have the meaning defined in the description. This diesel fuel is biodegradable and free of sulfur, nitrogen and aromatics.
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CROSS REFERENCE TO PRIOR APPLICATIONS
This patent application is a continuation application of U.S. patent application Ser. No. 12/304,015, filed on Jan. 13, 2009, which is a U.S. national phase application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2007/061777, filed Jun. 12, 2007, and claims the benefit of Japanese Patent Application No. 2006-162972, filed Jun. 13, 2006. The International Application was published in Japanese on Dec. 21, 2007 as WO 2007/145191. The disclosures of all prior applications are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
The present invention relates to a coated tablet which is coated with a polyvinyl alcohol copolymer for film coating.
BACKGROUND
For example, it is reported that, when a commercial metformin hydrochloride-containing tablet and a commercial olmesartan medoxomil-containing tablet are packed together in a one-dose pack, then the metformin hydrochloride-containing tablet turns reddish. This phenomenon is assumed to be caused by the event that the (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (hereinafter referred to as “DOMDO”) group released from olmesartan medoxomil in the olmesartan medoxomil-containing tablet is hydrolyzed and converted into diacetyl and acetoin, and then these react with the guanidino group of metformin hydrochloride in the metformin hydrochloride-containing tablet. This reaction is known as Voges-Proskauel (VP) reaction. As a matter of course, however, the discoloration of drugs is unfavorable and it is considered necessary to prevent the discoloration by means of some devices in drug preparation methods.
In general, for the purpose of preventing or masking discoloration or coloration of medical and pharmaceutical tablets, uncoated tablets are coated. Depending on the properties of the compounds in uncoated tablets, the coating methods and coating agents are selected.
Recently, a polyvinyl alcohol copolymer for film-coating comprising polyvinyl alcohol (referred to hereinafter as “PVA”), acrylic acid and methyl methacrylate has been developed. This was first developed as a agent of capsules shell for solution-filling (see, for example, International Publication WO 02/17848); but owing to its excellent film formability, physical strength, adhesiveness, oxygen shieldability and the like, it has come to be applied as a film coating agent (POVACOAT (trade name)) (see, for example, PHARM TECH JAPAN (2005) vol. 21, no. 2, pp. 257-261; Proceedings of the 22th Symposium for Drug Formulation and Particle Design, pp. 77-80 (2005 in Hamamatsu).
DISCLOSURE OF INVENTION
A main object of the present invention is to provide a novel coated tablet comprising a guanidino group-having drug, which does not exhibit obvious discoloration when packed together with a DMDO group-having drug in a one-dose pack.
The present inventors have intensively studied and found that the above object is achieved by a coated tablet in which an uncoated tablet containing guanidino group-having drug is coated with a PVA copolymer for film-coating (hereinafter simply referred to as “PVA copolymer”) comprising PVA, acrylic acid and methyl methacrylate.
The present invention includes, for example:
(1) A coated tablet characterized in that an uncoated tablet containing a guanidino group-having drug is coated with a PVA copolymer comprising PVA, acrylic acid and methyl methacrylate.
(2) The coated tablet of the above (1), wherein the PVA, one constituent of the PVA copolymer has a degree of polymerization ranging from 400 to 600 and a degree of saponification ranging from 85 to 90 mol %.
(3) The coated tablet of the above (1) or (2), wherein the polymerization ratio of the constituents of the PVA copolymer is such that PVA is within a range of from 70 to 85% by weight; acrylic acid is within a range of from 2.0 to 8.0% by weight; and methyl methacrylate is within a range of from 17 to 21% by weight.
(4) The coated tablet of any one of the above (1) to (3), which is coated with the PVA copolymer within a range of from 0.5 to 20.0% by weight relative to the weight of the uncoated tablet.
5) The coated tablet of any one of the above (1) to (4), wherein the guanidino group-having drug is metformin hydrochloride, camostat mesilate, zanamivir hydrate, cetrorelix acetate, tegaserodmaleate, desmopressin acetate, eptifibatide, bivalirudin, ganirelix acetate, buserelin acetate, famotidine, triptorelin pamoate, pinacidil, histrelin, thymopentin, adrenochrome guanylhydrazone mesilate, cimetidine, benexate hydrochloride betadex, gusperimus hydrochloride, nafamostat mesilate, guanabenz acetate, or argatroban.
(6) A one-dose pack comprising at least the coated tablet of any one of the above (1) to (5) and a tablet that contains a drug having a (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (DMDO) group.
(7) The pack of the above (6), wherein the DMDO group-having drug is olmesartan medoxomil, prulifloxacin, or lenampicillin hydrochloride.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 Color change profile of tablets is shown. The vertical axis indicates color difference (ΔE), and the horizontal axis indicates time (week). In the drawing, -□- indicates the result of coated tablets of the present invention of Example 1; -Δ- indicates the result of hydroxypropylmethyl cellulose 2910-coated tablets of Comparative Example 1; and -●-indicates the result of Glycoran tablets (uncoated tablets).
FIG. 2 Color change profile of tablets is shown. The vertical axis indicates color difference (ΔE), and the horizontal axis indicates time (week). In the drawing, -□- indicates the result of coated tablets of the invention of Example 1; -⋄- indicates the result of PULLULAN (★)-coated tablets of Comparative Example 2; and -●- indicates the result of Glycoran tablets (uncoated tablets).
DETAILED DESCRIPTION OF THE INVENTION
The “PVA copolymer” used in the present invention is composed of PVA, acrylic acid and methyl methacrylic acid. The polymerization ratio of each constituent of the PVA copolymer is not particularly limited insofar as it can form a film as the PVA copolymer, and, for example, PVA is preferably within a range of from 70 to 85% by weight, acrylic acid is preferably within a range of from 2.0 to 8.0% by weight; and methyl methacrylate is preferably within a range of from 17 to 21% by weight. More preferably, PVA is within a range of from 75 to 80% by weight; acrylic acid is within a range of from 2.5 to 7.5% by weight; and methyl methacrylate is within a range of from 17.5 to 20% by weight.
The suitable “PVA” as one of the constituents of the PVA copolymer is such that the polymerization ratio is, for example, within the range of from 400 to 600, preferably within the range of from 450 to 550, and the degree of saponification is, for example, within the range of from 85 to 90 mol %, preferably within the range of from 86 to 89 mol %.
The PVA copolymer may be a commercial POVACOAT (registered mark, Nisshin-Kasei) in which PVA, acrylic acid and methyl methacrylate are copolymerised at a ratio of 80.0% by weight, 2.5% by weight and 17.5% by weight, respectively, and polymerization degree of the said PVA is 500 and saponification degree of the said PVA is within a range of from 86.5 to 89.0 mol % by weight.
The “guanidino group-having drug” contained in the coated tablet of the present invention refers to a drug having a guanidino group or a substituted guanidino group in the chemical structure of the drug. Herein, the substituted guanidino group refers to the guanidino group having the same or different 1 to 4 substituents at a substitutable position.
Examples of the substituents may include, for example, straight or branched alkyl, cyano, nitro, and pyridyl (e.g., 2-pyridyl, 3-pyridyl, 4-pyridyl).
Specific examples of the “guanidino group-having drug” may include metformin hydrocloride, camostat mesilate, zanamivir hydrate, cetrorelix acetate, tegaserod maleate, desmopressin acetate, eptifibatide, bivalirudin, ganirelix acetate, buserelin acetate, famotidine, triptorelin pamoate, pinacidil, histrelin, thymopentin, adrenochrome guanylhydrazone mesilate, cimetidine, benexate hydrochloride betadex, gusperimus hydrochloride, nafamostat mesilate, guanabenz acetate or argatroban.
The “DMDO group-having drug” refers to a drug having a DOMDO group in the chemical structure of the drug. Specific examples of the “DMDO group-having drug” may include olmesartan medoxomil, prulifloxacin or lenampicillin hydrochloride.
In the present invention, an uncoated tablet before being coated may be obtained by granulating an active ingredient such as guanidino group-having drug with an excipient, a disintegrant, a binder and so on and milling, followed by mixing the milled powder with a lubricant, and then compacting into a tablet. As for the excipient, the disintegrant, the binder and the lubricant, those materials which are commonly used for preparing tablets may be utilized.
The coated tablet of the present invention may be obtained by coating an uncoated tablet comprising a guanidino group-having drug with a coating solution containing a PVA copolymer by an ordinary method.
The content of the PVA copolymer in the coated tablet of the present invention is usually within a range of from 0.5 to 20% by weight relative to uncoated tablet weight, preferably within a range of from 1.0 to 10% by weight and more preferably within a range of from 1.5 to 5.0% by weight.
In addition, the content of the PVA copolymer in the coating layer may be usually within a range of from 40 to 80% by weight, preferably within a range of from 45 to 75% by weight and more preferably within a range of from 50 to 70% by weight.
An additive commonly used in the coating layer can be contained if necessary. The additive is not particularly limited insofar as it is a pharmaceutically acceptable additive, and, for example, coating agent (e. g., titanium dioxides, precipitated calcium carbonate), lubricant (e. g., talc), adsorbent (e. g., light anhydrous silicic acid, a hydrous silicon dioxide, magnesium silicate), colorant (e. g., red iron oxide, yellow iron oxide, titanium dioxide, tar dye) can be included. Among them, titanium dioxide is more preferable. For example, these additives can be included in an amount of less than 5% by weight in a coating solution together with a PVA copolymer, and can be involved in a coating layer through coating an uncoated tablet with the coating solution.
Hereinafter, the present invention is described in more detail by reference to the Examples, Comparative Examples and Test Examples. As a matter of course, the present invention is not limited to the following examples.
Example 1
Commercial Glycoran tablets (250 mg, uncoated tablets, by Nippon-Shinyaku) of a guanidino group-having drug were obtained; 10,800 g of the Glycoran tablets were put into an aeration drying-type coating machine (DRC-650 type, by Powrex); using a coating solution prepared by dissolving or suspending 400 g of a PVA copolymer (POVACOAT (registered trademark), by Nisshin Kasei), 264 g of titanium dioxide (TIPAQUE A-100, by Ishihara Sangyo) and 136 g of talc (Talc PKP-81, by Fuji Talc Industrial Co.) in 7,200 g of purified water, coated tablets of the present invention coated with the PVA copolymer in a ratio of 3.7% (w/w) relative to the weight of the uncoated tablet were obtained.
Comparative Example 1
Commercial Glycoran tablets (250 mg, uncoated tablets, by Nippon-Shinyaku) were obtained; 10,800 g of the Glycoran tablets were put into an aeration drying-type coating machine (DRC-650 type, by Powrex); using a coating solution prepared by dissolving or suspending 435.2 g of hydroxy propylmethyl cellulose 2910, 89.6 g of propylene glycol and 115.2 g of titanium dioxide (TIPAQUE A-100, by Ishihara Sangyo) in 5,760 g of purified water, comparative coated tablets coated with the hydroxy propylmethyl cellulose 2910 in a ratio of 4.0% (w/w) relative to the weight of the uncoated tablet, were obtained.
Comparative Example 2
Using a coating agent characterized by oxygen permeation shieldability like POVACOAT, pullulan (by Hayashibara), comparative coated tablets were produced.
Text Example 1
Commercial Glycoran tablets (250 mg, uncoated tablets; by Nippon-Shinyaku) were obtained; 10,800 g of the Glycoran tablets were put into an aeration drying-type coating machine (DRC-650 type, by Powrex); using a coating solution prepared by dissolving 400 g of pullulan (by Hayashibara) in 4,600 g of pure water, comparative coated tablets coated with the pullulan in a ratio of 3.7% (w/w) relative to the weight of the uncoated tablet were obtained.
Commercial Glycoran tablets (uncoated tablets), coated tablets produced in Example 1 and Comparative Example 1, three tablets, each were respectively put into a recloseable polyethylene bag (Unipack A-4, by Seisannippon) together with three tablets of a DMDO group-having drug Olmetec (20 mg, by Daiichi-Sankyo), and stored under the conditions of 40.degree. C. and 75% RH. After 1, 2, 3 and 4 weeks, the tablets were checked for discoloration with a color difference meter (spectral color difference meter SE2000, by Nippon Denshoku Kogyo).
The results are shown in FIG. 1 . When the color difference (ΔE) is 3 or above, the reddish discoloration of the tablet is recognized with the naked eye; but significant color change could not be discernible with the naked eye when the value is not more than 2.5. The color difference (ΔE) means the numerical value converted from the data of color difference between the aged tablets and the original tablets before the test.
As is obvious from FIG. 1 , the coated tablets of the present invention produced in Example 1 were remarkably prevented from being discolored, as compared with the Glycoran tablets and the hydroxypropylmethyl cellulose 2910-coated tablets produced in Comparative Example 1.
Text Example 2
Commercial Glycoran tablets (uncoated tablets), coated tablets produced in Example 1 and Comparative Example 2, three tablets, each were respectively packed with cellophanpoly (by Nihonshokai) together with three tablets of a DMDO group-having drug Olmetec (20 mg, by Daiichi-Sankyo), and stored under the conditions of 40.degree. C. and 75% RH. After 1 and 2 weeks, the tablets were checked for discoloration with a color difference meter (spectral color difference meter, SE2000, by Nippon Denshoku Kogyo).
The results are shown in FIG. 2 . When the color difference (ΔE) is 3 or above, the reddish discoloration of the tablet is recognized with the naked eye; but any clear color change could not be discernible with the naked eye when the value is not more than 2.5.
As is obvious from FIG. 2 , the coated tablets of the present invention produced in Example 1 were remarkably prevented from being discolored, as compared with the Glycoran tablets produced in Comparative Example 2.
INDUSTRIAL APPLICABILITY
As described above, the coated tablet of the present invention can markedly prevent reddish discoloration reaction that could occur when the tablet was kept in contact with or in close contact with a DMDO group-having drug. Accordingly, the coated tablet of the present invention is useful since the color change of the tablet can be prevented even when packed in a one-dose pack together with a DMDO group-having drug.
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A main object of the present invention is to provide a novel coated tablet which contains a drug having a guanidino group and does not suffer an obvious color change even when packed in a one-dose pack together with a drug having a (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (DMDO) group. The present invention provides a coated tablet characterized in that an uncoated tablet containing a drug having a guanidino group has been coated with a polyvinyl alcohol for film coating which comprises polyvinyl alcohol, acrylic acid, and methyl methacrylate.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application related to copending U.S. patent application entitled "System and Method for Probing Dense Pad Arrays" (Attorney Docket No. 10981416-1) filed on even date herewith and accorded U.S. Ser. No. 09/088,370, and to copending U.S. patent application entitled "Split Resistor Probe and Method" (Attorney Docket No. 10980939-1) filed on even date herewith and accorded U.S. Ser. No. 09/288,347, both of which are incorporated herein by reference.
TECHNICAL FIELD
The present invention is generally related to process for manufacturing test equipment and, more particularly, is related to a process for assembling an interposer.
BACKGROUND OF THE INVENTION
Integrated circuits such as processors and other similar devices are operating at much greater speeds to perform an ever increasing number of operations each second. Many of these integrated circuits are placed on printed circuit boards or other similar structures and are in electrical communication with many different electrical components and other integrated circuits resident on the same printed circuit board. In order to facilitate communication between the integrated circuits and the several other electronic components, the integrated circuit contacts electrical conductors on a printed circuit board through pads that are often arranged in a dense grid or array on the printed circuit board.
Oftentimes, it is necessary to test the operation of such new integrated circuits after they are fabricated either to test prototypes or to diagnose problems experienced with the integrated circuits. In particular, generally one or more of the pads in the array into which the integrated circuit is inserted are probed to access the signal thereon so that the signal can be transmitted to a logic analyzer or oscilloscope. The fact that the pins of the integrated circuits and corresponding pads on the printed circuit board are arranged in a dense array make such testing difficult to accomplish in light of the high frequency operation of such integrated circuits.
To explain further, a typical printed circuit board includes several groups of signal conductors that run between various components on the board. When a probe conductor is joined to one of the pads, a very small capacitance between the probe conductor and the signal conductors on the order of picofarads presents an undesirable load impedance on the pads. In particular, at low frequencies, this impedance is acceptably high. However, at very high signal frequencies on the order of hundreds of megahertz, the impedance presented by such a capacitance will drop, resulting in extraneous loading on the conductors between the integrated circuits.
In addition, a similar small capacitance may exist between the probe conductor and the remaining pads, or aggressor pads in the pad array. At high frequencies, these capacitances present a low impedance which results in cross-talk between the aggressor pads and the probe conductor.
This extraneous loading and cross-talk results in distortion of the signal on the pins of the integrated circuit that causes error to the data represented by the transmitted signals. Consequently, the ability to test the integrated circuit is hampered by the use of the probe itself.
SUMMARY OF THE INVENTION
In light of the foregoing, the present invention provides for a process to manufacture an interposer which includes an interposer socket assembly to use in probing dense pad arrays that minimizes the associated extraneous pin loading and cross-talk discussed above. The process of the present invention comprises the steps of: mounting a number of resistors onto a number of predetermined positions in a pad array on an interposer board; inserting a number of interposer pins of a pin socket into the pads of the pad array on the interposer board, wherein the ends of the interposer pins protrude through the interposer board; placing a solder preform around the ends of the interposer pins; and, heating the solder preforms in a solder re-flow oven to solder the interposer pins to the respective pads of the pad array.
The present invention may also be viewed as a process for assembling a ball grid array assembly on a printed circuit board, comprising the steps of: mounting a number of resistors onto a number of predetermined positions in a pad array on the printed circuit board; placing a ball grid array assembly onto the pad array; and, heating a number of solder balls on the ball grid array assembly in a solder re-flow oven to solder the ball grid array assembly to the pad array.
The present invention provides distinct advantages in that, for example, a number of resistors may be easily positioned among interposer pins which protrude from a dense pad array by putting the resistors in place before the interposer pins are put into place. Thus, the resistors can be employed to address the problems of extraneous pin loading and cross-talk without interfering with or otherwise damaging the interposer pins themselves. Also, the present process prevents solder from being deposited on contact regions of the interposer pins as well. Other advantages of the invention include the fact that the processes are simple in design, user friendly, efficient, and easily implemented for mass commercial production.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a perspective view of a printed circuit board having a socket to receive a processor;
FIG. 2 is an exploded perspective view of the printed circuit board of FIG. 1 with an interposer socket assembly and an integrated circuit;
FIG. 3 is an exploded side view of the printed circuit board, socket, and interposer socket assembly of FIGS. 1 and 2 and a processor to be plugged in to the interposer socket assembly;
FIG. 4 is a drawing providing an illustration of a pad array employed in the interposer socket assembly of FIG. 2;
FIG. 5A is an exploded side view of the assembly of a pin socket used in the interposer socket assembly of FIG. 3;
FIG. 5B is an exploded side view of the mounting of resistors to a pad array on an interposer board of the interposer socket assembly of FIG. 3;
FIG. 5C is an exploded side view of the insertion of the interposer pins of the pin socket through the interposer board of the interposer socket assembly of FIG. 3;
FIG. 5D is an exploded side view of the placement of the solder preforms onto the protruding interposer pins of FIG. 3;
FIG. 5E is an exploded side view of the attachment of the resistor shield over the resistors in the interposer socket assembly of FIG. 3;
FIG. 5F is a side view of the assembled interposer socket assembly of FIG. 3;
FIG. 6 is a side view of a ball grid array assembly mounted to a printed circuit board with resistors mounted therein;
FIG. 7A is an exploded side view of the mounting of the resistors to a pad array on the ball grid array assembly of FIG. 6; and
FIG. 7B is an exploded side view of the mounting of the ball grid array assembly to the printed circuit board.
DETAILED DESCRIPTION OF THE INVENTION
Turning to FIG. 1, shown is a printed circuit board 101 as used in many personal computers on which is mounted a few representative capacitors 103 and a memory bank 106. Also, the printed circuit board 101 includes a socket 109 into which a processor may be inserted. The socket 109 includes a grid of holes which are arranged to receive a processor (not shown). The holes are placed relatively close together. When a processor fitted into the socket 109, it is quite difficult to access the innermost pins of the processor for diagnostic purposes. One such means to provide the needed access to the processor pins is to use an interposer which is placed between the processor and the socket 109.
With reference to FIG. 2, shown is an exploded perspective view of an interposer 123 that is plugged into the socket 109 on the printed circuit board 101 when in use. A processor 125 in turn is plugged into the interposer 123 as shown. The interposer 123 includes an interposer socket assembly 126 which is adapted to mate with the socket 109. In particular, the socket assembly 126 includes a number of interposer pins that protrude from the bottom in a pin grid array (not shown) which mimics the pins of a processor that normally is plugged into the socket 109. Each of the interposer pins is coupled to a probe tip which includes probe tip resistors (not shown). The interposer 123 also includes electrical connectors 129 which allow diagnostic equipment to be electrically coupled to the individual pins in the interposer socket assembly 126. The individual probe tips extend from their respective interposer pins to a contact point in one of the electrical connectors 129. The diagnostic equipment may include, for example, and oscilloscope or logic analyzer.
Referring next to FIG. 3, shown is an exploded side view of the printed circuit board 101, the socket 109, the interposer socket assembly 126, and a processor 153. The interposer socket assembly 126 includes a pin socket 156 which includes a number of interposer pins 159. Note that not all of the interposer pins 159 are shown in order to keep the drawing from looking too complex and difficult to read. The interposer pins 159 are pressed into holes 163 in the pin socket 156. On one end, the interposer pins 159 include a female electrical contact 166 in which the processor pins 169 are inserted.
The interposer socket assembly 126 also includes an interposer board 173 which includes a pad array 176 with a number of resistors 179. The pad array 176 is similar to the pad arrays described in copending U.S. Patent Application entitled "System and Method for Probing Dense Pad Arrays" (Attorney Docket No. 10981416-1) filed on even date herewith and accorded U.S. Ser. No. 09/088,370, and which is incorporated herein by reference in its entirety. The pad array 176 may also be similar to the pad arrays described in copending U.S. Patent Application entitled "Split Resistor Probe and Method" (Attorney Docket No. 10980939-1) filed on even date herewith and accorded U.S. Ser. No. 09/288,347, and which is incorporated herein by reference in its entirety. The interposer pins 159 are soldered to the pads of the pad array 176 using a number of solder preforms 183. Finally, a resistor shield 186 is attached to the interposer board 173 to protect the resistors 179 as will be discussed.
Turning to FIG. 4, shown is a top view of a pad array probing system 200 which provides a further illustration of the pad array 176. The pad array probing system 200 includes a dense pad array 176 which comprises a grid of pads 203 which are conductive holes that extend through a printed circuit board 204 or other similar flat surface member. The pads 203 are generally suited to receive the pins of a socket, an integrated circuit or other electronic device. In addition, the dense pad array 176 may also be a ball grid array, a pin grid array, an array of vias on a printed circuit board, a number of closely aligned conductors on a printed circuit board, or multi-chip module. The dense pad array 176 further includes a number of first probe tip resistors 179a which have a first end 209 and a second end 213. The first end 209 of each probe tip resistor 179a is electrically coupled to a respective pad 203, forming a predetermined coupling length 216 between the first ends 209 of the first probe tip resistors 179a and the pads 203, respectively. The predetermined coupling length 216 is as short as possible such that the first probe tip resistors 179a are directly adjacent to the pads 203, which is generally as short as manufacturing processes will allow. Note that the uppermost pads 203 are coupled to an external probe tip resistor 179b as shown.
The dense pad array 176 further includes a number of transmission lines 223a, 223b, 223c, and 223d. The transmission lines 223a-d are routed from the second ends 213 of the first probe tip resistors 179a out of the dense pad array 176 to a number of second probe tip resistors 179c. The second probe tip resistors 179c include a first end 229 and a second end 233. The transmission lines 223a-d are coupled to the first end 229 of the second probe tip resistor 179c. The second ends 233 of the second probe tip resistors 179c are electrically coupled to a connector 129 which in turn is electrically coupled to a logic analyzer 239 or oscilloscope (not shown) via a cable 243. Although the transmission lines 223a-d are generally shown exiting the dense pad array 176 in a uniform manner, it is possible that the transmission lines 223a-d follow any particular pathway in any convenient direction out of the dense pad array 176 based on various considerations. For example, it may be preferable to minimize the length of the transmission lines 223a-d to limit interference at high frequencies, or manufacturing limitations may dictate the actual routes employed out of the dense pad array 176. Also, the placement of the pads 203 may limit the possible exit routes for a particular pad 203 out of the dense pad array 176. Additionally, although the transmission lines 223a-d are shown only on the top side of the printed circuit board 204, it is possible that the transmission lines 223a-d be placed on either side of the printed circuit board 204 or a combination thereof using vias which route the transmission lines 223a-d through the printed circuit board 204.
The functionality of the dense pad array 176 is as follows. An integrated circuit such as a processor may have several pins which are generally lodged into each pad 203 in the pad array 176. The pads 203 are also electrically coupled to other integrated circuits and various components on the printed circuit board 101. Signals propagate between the integrated circuit attached to the pad arrays 176 and other components on the printed circuit board 204 during the operation of the overall circuit on the printed circuit board 101.
The first probe tip resistors 179a, transmission lines 223a-d, and second probe tip resistors 179c are employed to access the signals propagated on the pads 203 of the dense pad arrays 176 in order to test the operation of the integrated circuit attached to the dense pad arrays 176. Note that the first and second probe tip resistors 179a and 179c are called "probe tip" resistors because they are located at the tip of what is considered a probe applied to each of the pads 203. In particular, a signal propagated on the pads 203 is also transmitted through the first probe tip resistors 179a, along the transmission lines 223a-d, and through the second probe tip resistors 179c to the logic analyzing device 139 or other similar diagnostic equipment. The placement of the first probe tip resistors 179a with their first ends 209 as close as possible to the pads 203 reduces the loading of the pads 203 which would otherwise occur if there were no probe tip resistor 179a coupling the transmission lines 223a-d to the respective pads 203 within the dense pad array 176. The same is true regarding the external probe tip resistors 179b in which the electrical coupling to the connector 139 may cause the loading of the respective pads 203 to which the external probe tip resistors 179b are coupled. In addition, the second probe tip resistors 179c are coupled to the transmission lines 223a-d at a point outside of the dense pad array 176 to reduce the effects of cross-talk between the pads 203 and the transmission lines 223a-d due to a capacitance between any one of the pads 203 and a transmission line 223a-d which is routed near the respective pad 203.
Turning to FIGS. 5A-5F, shown are a number of side views which illustrate the process by which the interposer socket assembly 126 is assembled. First, as shown in FIG. 5A, the interposer pins 159 are inserted into the holes 163 in the pin socket 156. This may be performed by manually inserting and pressing the interposer pins 159 into the holes 163 or by using, for example, a vibratory feeder. The holes 163 have a diameter that is slightly smaller than the diameter of the interposer pins 159 which allows the interposer pins 159 to be pressed into and retained by the pin socket 156 with the thin ends of the interposer pins 159 protruding from the pin socket 156.
Next, as shown in FIG. 5B, a number of resistors 179 are soldered to the pad array 176 on the interposer board 173 as discussed previously. The resistors 179 may mounted to the interposer board 173 by simply soldering the resistors 179 into place. This may be accomplished, for example, using double tipped soldering equipment (not shown) in a manual or automated process. For example, the resistors 179 may be placed using any industry standard pick-and-place surface mount assembly equipment. The resistors 179 may also be mounted to the interposer board 173 using some sort of adhesive such as an epoxy which would prevent the occurrence of "tomb stoning" by the resistors 179, which is described in later text. For example, the epoxy may be dispensed automatically using any industry standard dispensing machine.
The next step in the process is shown in FIG. 5C in which the interposer pins 159, now an integral part of the pin socket 156 are inserted into the grid of pads of the pad array 176. This may be performed manually or using automated positioning equipment. The interposer pins 159 thus extend through and protrude from the interposer board 173 and the corresponding pad array 176. Then, as shown in FIG. 5D, the solder preforms 183 are placed over the narrow ends of the protruding interposer pins 159 and fall flat against the interposer board 173. This step may be accomplished by manually placing the solder preforms 183 over the interposer pins 159 or by placing the solder preforms 183 over the interposer pins 159 using a fixture that places multiple preforms over multiple pins at the same time. Thereafter, the assembled interposer board 173 and pin socket 156 are placed in a solder re-flow oven and heated until the solder preforms 183 flow. Note that in some cases, if the size of the resistors 179 is very small, then the additional flow of solder from the solder preforms 183 may cause the resistors 179 to stand up on end due to the attraction to the greater amount of liquid solder. This is known as the "tomb stoning" effect which refers to the fact that the resistors 179 stand up on end like a tombstone.
When the assembled interposer board 173 and pin socket 156 are taken from the solder re-flow oven, the solder between the interposer pins 159 and the pads of the pad array 176 hardens, thereby fixing the interposer pins 159 to the pad array 176. Once the interposer pins 159 are soldered to the pads of the pad array 176, the resulting assembly may be employed to probe dense pad arrays as part of the interposer 123.
With reference to FIG. 5E, an optional step in the process to assemble the interposer socket assembly 126 is shown. In particular, the interposer pins 159 protruding from a pad array 176 are inserted into the grid of holes in the resistor shield 186 which is then attached to the interposer board 173 using suitable adhesive. The placement of the interposer pins 159 into the holes of the resistor shield 186 may be accomplished manually or using automated positioning equipment.
The resistor shield 186 guards against electrostatic discharge and protects that resistors 179 from being disturbed. Also, the resistor shield 186 insulates the resistors from random conductors on the socket 109 into which the interposer 123 is inserted and prevents the interposer pins 159 from being crammed too far into the socket 109. In addition, the resistor shield 186 helps maintain the parallel nature of the interposer pins 159. FIG. 5F shows the assembled interposer socket assembly 126 with the resistor shield 186.
The present process of assembling the interposer socket assembly 126 is advantageous due to the fact that it allows the resistors 179 to be mounted within the pad array 176 without disturbing, deforming, or depositing solder on the interposer pins 159.
With reference to FIG. 6, shown is a ball grid array assembly 303 that is attached to a printed circuit board 306 via a number of solder balls 309. Encased within the ball grid array assembly 303 is a processor 313. The solder balls 309 are affixed to pads in a pad array 316 that includes several resistors 319.
Turning to FIGS. 7A and 7B, shown are steps in a process to construct the ball grid array assembly 303 with the pad array 316 and accompanying resistors 319. The process begins with FIG. 7A in which the resistors 319 are soldered to predetermined points in the pad array 316. Thereafter, as shown in FIG. 7B, the ball grid array assembly 303 is placed against the printed circuit board 306 in such a manner that the solder balls 309 come into contact with the pads in the pad array 316. The resulting assembly is then heated in a solder re-flow furnace and the solder balls 309 flow so as to electrically coupled to the pads of the pad array 316. Thus, the steps of the process illustrated in FIGS. 7A and 7B allow the resistors 319 to be placed within the pad array 316 without disruption or interference with the solder balls 309 during the re-flow process. Note that in an additional step, the resistors 319 may be affixed to the printed circuit board 306 with an adhesive such as epoxy to prevent an occurrence of the tomb stoning effect during the solder re-flow.
Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention.
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Disclosed is a process to manufacture an interposer which includes an interposer socket assembly to use in probing dense pad arrays that minimizes the associated extraneous pin loading and cross-talk caused by a probe tip. The process comprises the steps of: mounting a number of resistors onto a number of predetermined positions in a pad array on an interposer board; inserting a number of interposer pins of a pin socket into the pads of the pad array on the interposer board, wherein the ends of the interposer pins protrude through the interposer board; placing a solder preform around the ends of the interposer pins; and, heating the solder preforms in a solder re-flow oven to solder the interposer pins to the respective pads of the pad array.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of applicant's co-pending application, Ser. No. 727,750 Filed Apr. 26, 1985, now abandoned.
TECHNICAL FIELD
The present invention is related broadly to the field of building construction. More narrowly, however, it relates to methods for supporting brick veneers applied to the front of structures. Specifically, the invention deals with apparatus for strengthening concrete footings for supporting brick veneers applied to the outside vertical walls of buildings, and methods employing such implements.
BACKGROUND OF THE INVENTION
Depending upon the climate in which a building is constructed, the particular materials employed in constructing the building vary. While in some climatic conditions wood would be appropriate, other conditions might dictate that stucco or brick be used.
The appearance of brick is particularly desirable in the construction of residential buildings. Construction of brick homes is on the upswing in view of the ever-increasing fashionability of such dwellings. Such is the case regardless of the climatic conditions of any particular area, although brick homes would tend to have a greater functionality in areas where winters tend to be cold.
In building a brick home, a foundation, typically utilizing large concrete blocks, is first laid. The walls of the building are, in turn, framed and erected on the foundational blocks. The framing is, typically, flush with the outwardly facing surfaces of the foundational blocks.
A brick veneer is, in turn, erected over the framing on what is to be the outside of the building. Because of the weight of the veneer, a support footing is provided, and the veneer is built up on top of the footing. Typically, such a footing is made of poured concrete.
Present methodology for supporting such brick veneers envisions one of a number of processes. A first method (and one which is generally impracticable) consists of digging all the way down to the footing of the foundation and pouring concrete to that depth. Such a method tends to be impracticable for a number of reasons, but it is particularly inapplicable when the building being constructed is a rambler home. With such structures, digging to a depth of eight feet or more would be required. Not only would digging to such a depth involve significant time and effort, but it would also require the pouring of large volumes of concrete.
A second method known in the prior art includes providing a plurality of cantilevered iron rods which are made to extend perpendicularly from the foundation wall (that is, generally horizontally) at depths slightly below the surface of the ground. Concrete is, in turn, poured to encase the rod extensions. Such a method is somewhat improved over the previously discussed method, and the improvement would provide some strength to the brick veneer footing.
For a number of reasons, however, problems remain when this method is practiced. For example, the method presents difficulties as far as anchoring the cantilevered rods. Additionally, because of the length of the rods, fitting of the rods relative to the foundational blocks can pose problems.
Even when such a method is practiced, the support provided by the rods is, in some respects, limited. The strength rendered to the footing by the rods is a function of how adequately the rods are anchored. Even when the rods are securely anchored, however, there is give in the rods as a result of their having some measure of resiliency. When significant loads are placed on the footing, the rods can bend and the adequacy of the footing be diminished.
An additional problem encountered when pouring such concrete footings is the deterioration of structural components because of frost in the ground. If the frost conditions are severe, major structural impairment can occur.
It is to these problems in the prior art that the invention of the present document is directed. It not only provides a footing strengthening method and apparatus which are more effective to support the significant weights of brick veneers, but it also functions to deflect frost rising within the ground outwardly and upwardly away from the foundation of the building.
SUMMARY OF THE INVENTION
The present invention includes an apparatus for reinforcing a concrete footing for a brick veneer as discussed above, such veneers to be applied to the outside vertical walls of a structure being built. The apparatus is a support bracket which includes a hook portion for attachment to the foundation blocks at a location proximate the lower edge of the framing. The hook portion includes a leg which can be inserted through an aperture broken through an outwardly facing surface of the foundation blocks. A shoulder, intersecting the leg of the hook portion, is, when the leg is inserted through the aperture, seated on a lowermost portion of the periphery of the aperture broken through the concrete foundation block. With the shoulder so seated, the leg of the hook portion would tend to orient itself generally vertically. The bracket further includes a support portion, integrally formed with the hook portion, functioning, when the hook portion cooperates with the aperture in the foundation block, to engage the outwardly facing surface of the foundational wall to brace the bracket. The footing formed by pouring concrete around a plurality of the brackets in a relatively shallow trench dug adjacent the foundation to receive the footing is, thereby, strengthened.
The present invention further comprises a method of strengthening footings which support brick veneers as discussed previously. The method can include the digging of a trench at the surface of the ground and adjacent the foundation blocks comprising the foundation of the building. The trench would extend a sufficient vertical distance to allow mounting of a plurality of brackets, as previously discussed, at a short distance below the frame footing. The trench would extend upwardly and outwardly in a sloping fashion around the foundation of the structure. A plurality of support brackets would be provided at appropriate, predetermined intervals to adequately support a brick veneer footing formed when concrete is subsequently poured in the trench. The brackets could be mounted to the foundation by punching holes in the foundation blocks at the appropriate intervals and inserting the hook portion of a bracket in each of the apertures.
A bracket could also be mounted as the foundation blocks are being laid. The bracket hook portion would then be mounted extending over the top of a block and into a hollow space of the foundation block, and the support portion, when the invention is practiced in this manner, would be held in place between the foundation block into which the bracket is hooked and that immediately below.
In either manner of practicing the invention, with the brackets securely attached to the foundation, concrete would be poured into the trench to encase the brackets. A polystyrene form placed around in-place brackets could be used to define the space into which concrete is to be poured.
In practicing a preferred embodiment of the method invention, a horizontally disposed reinforcement rod or rebar could be positioned within perimeters defined by the brackets to provide additional strength against shearing forces along an axis parallel to the foundational wall. This reinforcing rod could be wire-tied to the brackets and, if a plurality of rebars are employed, at predetermined distances apart on the inside of the angled portion of the brackets. As can be seen then, the present invention is an improved apparatus and method for strengthening concrete brick veneer footings. Additional features and advantages obtained in view of those features will become apparent with reference to the DETAILED DESCRIPTION OF THE INVENTION, appended claims, and accompanying drawing
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a segment of a building foundation with the framing of the building seated thereon, wherein a brick veneer footing constructed in accordance with the present invention is illustrated;
FIG. 2 is a side sectional view of the footing illustrated in FIG. 1;
FIG. 3 is a side elevational view of a support bracket in with the invention; and
FIG. 4 is a side sectional view of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawing wherein like reference numerals denote like elements throughout the several views, FIG. 1 illustrates a portion of the structure of a building being constructed to have a brick veneer 8 facing outwardly. FIG. 2 illustrates a foundation footing 10 which is laid at an appropriate depth below ground level 12. A foundational wall 14 is constructed on top of the foundation footing 10 and is built up, as illustrated in the figures, to slightly above the ground level 12. The foundational wall 14 is formed from a multiplicity of concrete blocks 16 which are laid in an appropriate masonry pattern. Concrete blocks 16 typically used in the construction of foundations are hollow, being formed with hollow spaces defined therewithin, and it is contemplated that the present invention would be used in conjunction with such blocks 16.
An upper surface 18 of the foundational wall 14, in turn supports a wooden frame 20 constructed of appropriately sized boards. A typical frame 20 includes a footing 22, extending generally horizontally on top of the foundational wall 14, and a multiplicity of generally vertically disposed studs 24 spaced at lateral distances from one another. What is an outer side of the frame 20 can be overlain with sheeting 26 which can incorporate insulative properties to function to retain heat either inside or outside the structure, depending upon the season. Typically, such sheeting 26 would have an outwardly facing surface 28 flush with the outwardly facing surface of the foundational wall 14.
The manner of constructing a building as defined to this point is well known in the art. The present invention, however, relates to methods and apparatus for supporting a brick veneer 8 to be applied to the outer side of the building's frame 20.
Because of the weight of such veneers 8, a special footing 30 needs to be laid in order to support the veneer 8. In order to minimize the difficulty and expense in laying such a footing 30, a trench 32 is dug to a relatively shallow depth along the foundational wall 14, and the trench 32 is provided with a side 34 which slopes upwardly and outwardly from the deepest part 36 of the trench 32. In cross section, therefore, the trench is basically triangular.
The footing is ultimately formed by pouring concrete into the trench 32 and filling the trench to where the concrete is substantially at the ground level 12. It will be understood, however, that, should it be desirable to minimize the amount of concrete to be used in forming the footing 30, the concrete can be poured to a point at which it does not completely fill the trench 32.
Because of the relative shallowness of the trench 32, and the commensurate relatively small size of the footing 30, such a footing 30 might not adequately provide the strength necessary to support the veneer 8 to be placed thereon. The present invention, therefore, envisions strengthening the footing by having placed a plurality of support brackets 38 in the trench 32 prior to filling it with concrete and anchoring those support brackets 38 to the foundational wall 14.
FIG. 3 illustrates a support bracket 38 in accordance with the preferred embodiment of the invention. The bracket 38 includes a hook portion 40 and a support portion 42. The hook portion 40 includes a leg 44 which, when the bracket 38 is anchored to the foundational wall 14 in a manner to be discussed hereinafter, is disposed generally vertically. The hook portion 40 also includes a shoulder 46 which, although not essential to the invention, is shown as intersecting the leg 44 of the hook portion 40 generally perpendicularly. It will be seen, therefore, that, when the bracket 38 is anchored to the foundational wall 14 for its intended purpose, the shoulder 46 will be generally horizontal.
The support portion 42 can be formed integrally with the hook portion 40, and it is envisioned that the support bracket 38 would be formed from a metal strap angled in a fashion to form the bracket 38 in a desired configuration. The support portion 42 includes a first length 48 shown as forming an acute angle to the leg 44 of the hook portion 42. A first end 50 of the support portion first length 48 is connected to the shoulder 46 of the hook portion 40 by appropriate members. A short interconnecting member 52 is shown as being generally parallel to the leg 44 of the hook portion 40 to define a channel 54 substantially the length of the shoulder 46. This channel 54 can be made so that it has a width, as illustrated at 56, similar to the thickness of a wall of a concrete block 16 to which the bracket 38 will eventually be mounted. A longer interconnecting member 58 is shown as extending generally perpendicular to the leg 44 of the hook portion 40, and the longer member 58 intersects the shorter member 52 and the first end 50 of the support portion first length 48.
FIG. 3 illustrates a second, wall engaging length 60 extending from the end of the first length 48 opposite that by which it is attached to the shoulder 46. The second, wall engaging length 60 of the support portion 42 is shown as being generally perpendicular to the leg 44 of the hook portion 40, although such a construction is not exclusive. A distal end 62 of the second length 60, in any case, is spaced at a sufficient distance from the hook portion leg 44 so that the thickness of a concrete foundation block wall can be received therebetween.
Referring now to FIGS. 1 and 2, in constructing the footing 30 for the brick veneer 8, the mason would dig a trench 32 to a depth of approximately three foundation blocks 16. It is believed that a concrete footing poured to that depth is adequate, in view of the support brackets 38, to provide sufficient strength to the veneer 8. The side 34 of the trench 32 angles upwardly and away from the foundational wall 14 to define an acute angle. Although not essential to the invention, this side 34 can be dug at an angle approximating the angle at which the first length 48 of a support portion 42 of a bracket 38 would be disposed once the bracket 38 is anchored to the foundational wall 14. By digging the trench 32 with a side 34 so angling, frost and moisture rising in the ground toward the ground level 12 would be deflected away from the foundation wall 14.
With a depth of three foundation blocks thus exposed, apertures 64 can be punched out, in the uppermost row of blocks 16 if desired, in the outwardly facing surfaces of those blocks 16. The apertures 64 can be made at intervals small enough so that sufficient strength will be imparted to the footing 30 by the support brackets 38. Since building codes of many cities require that, when cantilevered rods as known in the prior art are used as supports, they be spaced at distances of no greater than 32 inches, such spacing could appropriately be adopted for the spacing of the present support brackets 38. It is believed, however, because of the strength of the present brackets 38 over that of cantilevered rods, spacing could be made at greater intervals.
With apertures 64 so punched out of the outwardly facing surfaces of the foundation blocks 16, a support bracket 38 can be anchored in each of the apertures 64. The leg 44 of the hook portion 40 can be inserted through the aperture 64 and the bracket 38 rotated so that the shoulder 46 of the hook portion 40 is seated on the lowermost portion of the periphery of the aperture 64. Because the distance between the short interconnecting member 52 and the leg 44 of the hook portion 40 approximates the thickness of the block outwardly facing wall, movement of the bracket 38 toward and away from the foundation will be limited. The sizing of the channel 54 will, additionally, function to dispose the leg 44 of the hook portion 40 generally vertically.
The support portion 42, if necessary, can be pulled back as the leg 44 of the hook portion 40 is inserted into the aperture 64. When the bracket 38 is in position, the support portion 42 can be released. Release of the support portion 42 will allow the distal end 62 of the support portion length 60 to engage the outwardly facing surface of the foundation blocks 16. The support portion 42 of the bracket 38 will, thereby, function to re-vector the forces exerted upon the veneer footing 30 by the bricks supported thereby in a direction toward the foundational wall 14 rather than parallel thereto.
Once the series of support brackets 38 are in place with their shoulders 46 seated on the lowermost portions of their respective apertures 64, concrete can be poured into the trench 32 and allowed to harden. As the concrete is poured into the trench 32, it can be allowed to flow into apertures 64. As it hardens, therefore, it not only forms the footing 30, but it also serves to anchor the footing 30 and the brackets 38 to the foundational wall 14. The footing 30 thereby formed will provide improved strength over footings constructed in manners known in the art.
A second embodiment of the invention envisions placing the support bracket 38 into position as the concrete blocks 16 are being laid. In this embodiment, the leg 44 of the support bracket 38 is inserted into a hollow space formed within the concrete block during its manufacture, with the wall engaging length 60 being placed between the concrete block 16 into which leg 44 is hooked and that immediately below. Concrete can then be poured into the hollow concrete block 16 and into the trench 32 to anchor the bracket 38 and form the footing 30.
A polystyrene form can be utilized to define the trench side wall 34 and contain the concrete poured therein.
If it is desired to impart to the footing 30 additional strength against shearing forces exerted along an axis parallel to the base of the foundation, a length or lengths of rebar 66 can be secured to the brackets 38 about their peripheries. Although two rebars 66 are shown in FIGS. 1, 2, and 4 as being secured at locations within the peripheries of the brackets 38 and at opposite ends of the support portion first length 48, it will be understood that other manners of positioning these rebars 66 are contemplated as being within the scope of the invention. For example, a rebar 66 might be placed on top of the bracket 38 at the intersection of the short and long interconnecting members 52, 58.
Numerous characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention. The invention's scope is, of course, defined in the language in which the appended claims are expressed.
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A method employing a support bracket (38) to strengthen the footing (30) which undergirds a brick veneer (8) to be applied to a building. A trench (32) is excavated adjacent the foundational wall (14) of the building being constructed, and brackets (38) are anchored to the wall (14). With the brackets (38) in place, concrete is poured into the trench (32) to form the footing (30).
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CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 08/932,733, filed on Sep. 17, 1997, now U.S. Pat. No. 6,308,206, which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
Computer system management as currently implemented relies heavily on such known management platforms as Hewlett-Packard Co.'s (“HP”) OpenView, IBM's NetView, Sun Microsystem's SunNet Manager, and others. These platforms are typically used with third party tools that perform the specific tasks required to manage particular devices, including Intel-based PC desktop computers and server systems, network devices such as hubs, bridges, and routers, and other similar equipment. Examples of these third party tools include HP's NetServer Assistant for managing the NetServer line of computers and Interconnect Manager used for managing network devices such as routers. As a general rule, these tools are complex, expensive, and difficult to use without extensive training.
SUMMARY OF THE INVENTION
The Internet makes it possible to create applications that perform many of the functions now performed by management platforms and third party add-on tools in a much simpler manner. These applications will be easier to use by novices than known tools and will lower the overall cost of system management.
The embodiments of the present invention described herein require certain generic computer systems and components to function. There must be a set of computer systems or network devices that must be managed. A set of client systems are used to manage the sets of computer systems and/or network devices. In some cases, the managed system and the client system are the same system. At the manufacturer's site, a system is located and used for warehousing and analyzing data from the managed systems. The manufacturer's system is only needed for implementing such management features as analysis and verification of system information, transmission of advisory information back to users and system registration.
Any of the known web browsers such as Netscape Corp.'s Netscape Navigator or Microsoft Corp.'s Internet Explorer must be installed on all client systems used as management systems and at least one of the managed or client systems must have an Internet HTTP Server (Web Server) running on it. Finally, an implementation of one of the known technologies that make it possible to retrieve and/or alter configuration information is needed on the managed and client systems, including an implementation of any one of Simple Network Management Protocols (“SNMP”), DMTF/DMI, ISO/CMIP or other proprietary protocols.
With these required components, all of which are known, the system's configuration can be viewed or changed over the Internet using an HTML document to list and display the managed systems, together with icons that represent the state of the managed systems. By using “active controls” or Java scripts, the state of the managed systems can be dynamically updated by changing the color of associated icons or the displayed text. Using embedded commands or identifiers within template documents, a program can be created to automatically acquire needed system information.
In another embodiment, an HTML CGI document containing desired system information and a reference link back to the system at the manufacturer's selected site is created, allowing the manufacturer's system to retrieve this system information automatically. The system information is then analyzed against a list of currently valid system configurations to detect potential problems. In turn, if potential problems are detected, the information is sent back to the managed system automatically.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the system components and architecture of the present invention;
FIG. 2 is a flow chart for a first embodiment of the present invention;
FIG. 3 is a flow chart for a second embodiment of the present invention;
FIG. 4 is a flow chart for another embodiment of the present invention;
FIG. 5 is a flow chart for yet another embodiment of the present invention; and
FIGS. 6, 7 , 8 , and 9 are flow charts for different implementations of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The various embodiments of the present invention can operate within any particular realization of the generalized system architecture shown in FIG. 1 . This generalized architecture comprises a set of computer systems 10 , a set of network devices 15 , or any combination of computer systems 10 and network devices 15 , all of which must be managed. A set of client systems 20 are used to manage the computer systems 10 and the network devices 15 . In at least one embodiment, it is possible that the managed computer system 10 and the client system 20 doing the management comprise the same system.
In several embodiments of the present invention, a manufacturer's system 50 is used for warehousing and analyzing data from and for the managed systems. Manufacturer's system 50 is only necessary for implementing such features as analysis and verification of managed systems' information, system registration, and transmission of advisory information back to the customers.
A web browser such as Netscape Corp.'s Navigator or Microsoft Corp.'s Internet Explorer must be installed on all client systems 20 used to manage other systems. At least one of the managed systems 10 or the client systems 20 needs an Internet HTTP server, also known as a Web Server, running on it. Finally, the managed systems 10 and the client systems 20 need an implementation of at least one of several known or proprietary technologies that permit the retrieval and altering of desired configuration information. These implementations can include any one of SNMP, DMTF/DMI, or ISO/CMIP.
Configuration Management
In a first embodiment of the present invention, configuration management is accomplished by using various Web-based elements. As shown in FIG. 2, an HTML document 101 that lists the managed systems and devices is created (FIG. 2, step 201 ). Document 101 contains a list of system names linked to Uniform Resource Locators (“URL”s) that point uniquely to a Common Gateway Interface (“CGI”) or a Microsoft Internet Server Application Programming Interface (“MS ISAPI”) script program 151 . When invoked or executed by user actions (FIG. 2, steps 201 and 203 ), which actions include clicking on the system name, script program 151 generates HTML document 103 that contains the system information, which can then be displayed (FIG. 2, step 209 ). Document 101 can be automatically generated by a program using an auto-discovery algorithm such as HP's OpenView or it may be manually created using an HTML editor, in which case the users will need to know the URLs for the systems being managed.
In this implementation, script program 151 can be located either on the system/device being managed or on another system that has an HTTP (Web Server) server, or on both systems. This allows one system to be a proxy for another system or to be a backup system. This is helpful when the particular system of interest is down or if the system cannot run an HTTP server. Using proxies creates redundancy and also permits using the management facilities described herein with devices that are not able or do not want to run an HTTP server.
An HTML configuration template document 102 is created using any preferred HTML editor (FIG. 2, step 211 ). Document 102 will contain such standard HTML elements as labels, icons, text, references to Java scripts, active objects and other documents as necessary. In places where the actual parameter values are displayed, a placeholder is embedded. The placeholder includes an identifying start meta character at the beginning and an end meta character at the end of the placeholder to make the placeholder identifiable to script program 151 . The body of the placeholder contains identification information such as SNMP object ID, that uniquely identifies the attribute whose value is to be retrieved and displayed.
The CGI or ISAPI script program 151 is invoked by the HTTP server as a result of an end user request for information, which the user initiates by “clicking” on the icon or symbol labeled with the device name in the system/device list of document 101 (FIG. 2, step 203 ). When invoked, script program 151 retrieves parameters passed to it using standard CGI/ISAPI interfaces (FIG. 2, step 209 ). In this embodiment of the present invention, the parameters are: a) information type (existing/new); b) IP address of the system of interest; c) SNMP community name; d) system configuration file name; and e) template file name. The information type parameter indicates whether the program is to return an existing configuration file or whether it must create a new one. The IP address parameter identifies the system for which information is to be retrieved (the managed system). The SNMP community name (an SNMP artifact used for security) identifies the community to which the SNMP agent used for retrieving the requested information belongs. The system configuration file name is the name of the file to which newly retrieved information is written to. The template file name is the name of the template file the program will use to determine what information is to be retrieved.
After script program 151 retrieves this information, it parses the template document, sequentially retrieves the embedded object identifiers, performs an SNMP or other request to retrieve the value of the requested attribute (object), converting the retrieved value to a meaningful form if necessary, and replaces the embedded placeholder with this value (FIG. 2, step 209 ). Once all required values have been obtained, script program 151 writes the generated file, document 103 , out to disk using the system configuration file name retrieved from the passed parameters (FIG. 2, step 213 ). It then passes a reference back to the HTTP server indicating that the server should return this file to the user initiating the request (FIG. 2, arrow from step 207 to step 201 ).
Real Time System Configuration Verification
In this embodiment, system configuration information can be verified in real time with minimal customer effort. This function is difficult to implement under existing non-Web based technologies and is typically not provided by vendors.
The process to verify system configurations starts with the user loading HTML document 101 and clicking on the appropriate icon or label representing the system of interest. This causes CGI script program 151 to be executed on one of the managed systems 10 . Script program 151 then fills the fields in a template form 102 , creating document 103 (described below). The process by which script program 151 fills template form 102 to create document 103 is similar to that described in the preceding embodiment. Once document 102 is filled out by program 151 , document 102 is returned to the user's Web browser as document 103 (FIG. 3, step 251 ).
Document 103 is a CGI form in which all the fields are labeled. For example, in addition to including a label “System Name”, there is a field value parameter which is assigned the value of System Name, e.g. “Mango”.
CGI form document 103 contains a “submit” button. When a user clicks on this button (FIG. 3, step 253 ), the contents (name-value pairs) of document 103 are transmitted to the system referenced in the form URL. In this case, the referenced system is system 50 at the manufacturer's location (FIG. 3, step 255 ). On receiving document 103 , the HTTP server on system 50 executes a script program 153 defined in the URL. Program 153 parses document 103 and saves the parameter values retrieved from it in a database 200 .
Script program 153 then executes program 155 on system 50 with a pointer to the data that was just entered database 200 (FIG. 3, step 257 ). Program 155 retrieves this data and compares specific system configuration information such as version numbers of the software components and supported hardware/software against those in a standard/supported system configuration database 202 , which is independently created (FIG. 3, step 259 ). The results of this comparison reveal differences between the configurations of the managed systems 10 and currently valid configurations. Examples of these differences could be differences in the versions of software/firmware/hardware components or the presence of hardware/software components that are known to have potential problems. Once these differences are determined, program 155 prepares a difference report formatted as an HTML document, document 107 , and passes it back to script program 153 (FIG. 3, step 259 to step 255 ). Program 153 then returns document 107 to the client browser 20 from which the request originated using a standard HTTP protocol (FIG. 3, step 255 to step 251 ).
Mail/HTTP-Based System Configuration Verification and Customer Advisories
The previously described methods for Configuration Management and Real Time System Configuration Validation assume a user invokes a Web browser and requests system information. In the following embodiment, configuration information is created and transmitted without user intervention, the advisory corresponding to potential problems or out of date components, and the advisory being transmitted back to the user asynchronously via the Internet or other e-Mail mechanisms.
This method requires a program 157 running on one or more of the managed systems 10 (FIG. 4, step 301 ). A modified version of program 153 , called here program 159 , plus a modified version of program 155 , called here program 161 , run on system 50 at the vendor's location. In addition to these programs, an e-Mail system must be running on system 50 . The e-Mail system must be able to send and receive electronic mail messages to and from other systems that are connected to the Internet.
Program 157 executes at predetermined periodic intervals on systems 10 . It can be configured to run on each of the managed systems 10 , on one of the managed systems 10 , or on some number of systems between these extremes. In those cases where program 157 is not running on all the systems, it behaves as a proxy agent and is able to retrieve information from the other systems for which it is configured to be a proxy.
When program 157 executes, it retrieves data from one or more of the managed systems 10 using one of the standard or proprietary protocols such as SNMP or DMI. It then creates a set of files 109 , one for each system it is configured for, which contains detailed system information. The specifics of the information are determined by template document 102 . In addition to the system information, program 157 also creates appropriate e-Mail headers that include mailing lists so that document 109 has a format and fields compatible with the e-Mail system so that document 109 can be sent to the configured destinations.
Program 157 submits files 109 to the e-Mail program by placing them in the outgoing bin or, alternatively, communicating directly with the e-Mail server using standard APIs such as MAPI.
The e-Mail system takes the files generated by program 157 and delivers them to the recipient, which in this implementation is program 159 running on system 50 . Program 159 extracts the system information and downloads it into database 200 (FIG. 4, step 303 ).
Program 161 executes at configured intervals on system 50 . It extracts information from database 200 sequentially, compares this information with standard information of valid configurations in database 202 and generates a set of files, called document 111 , one for each system for which configuration analysis is performed or on which configuration obsolescence is detected (FIG. 4, step 305 ). Program 161 adds appropriate e-Mail system headers that include destination addresses of configured recipients and writes these to the outgoing bin of the e-Mail system or uses the e-Mail system's APIs to submit them to the e-Mail system (FIG. 4, step 307 ). The e-Mail system in turn delivers them to the recipient.
System Registration
In general, most customers do not fill out system registration forms. Perhaps the customer sees no benefit to spending time filling out the forms. This embodiment of the present invention eliminates some of the effort needed to fill out these forms. It also makes possible the collection of substantially more system information, making it possible to send advisory information back to customers automatically when components become obsolete or when problems are discovered, using the previously described embodiments.
After the customer has received the newly purchased system, installation is accomplished by executing an installation program. The last part of the installation program is modified so that it executes program 163 (FIG. 5, step 351 ). Program 163 brings up an electronic form document 113 for the customer to fill out (FIG. 5, step 353 ). The customer fills out basic information such as the customer's name and e-Mail address. After this information is entered, program 163 uses template document 102 to gather system configuration information in a manner similar to program 151 and creates document 117 by appending the basic customer information to configuration information using the CGI form “Name-Value” format (FIG. 5, step 355 ).
Document 117 is an HTML form consisting of name-value pairs for customer information, entered by the customer, and the system configuration information entered by program 163 . The form URL points to program 153 on system 50 .
After creating document 117 , program 163 takes one or both of the following actions: (1) transmits document 117 as a CGI script form to system 50 at the manufacturer's site using the HTTP protocol (FIG. 5, step 357 ), and (2) adds e-Mail headers to document 117 and places it in the outgoing bin of the electronic mail system located somewhere in the customer's network. The mail system delivers document 117 to systems on a predetermined mail distribution list. The specific action taken depends on: (1) whether the customer wants a real time check of his system configuration and (2) whether the customer wants systems at multiple locations to save this configuration information. After transmitting these documents, program 163 waits for a response on the same TCP/IP port as a web browser, typically port 80 .
To the web server on system 50 , document 117 transmitted over FITTP looks identical to a CGI form request that would have been generated had document 117 been displayed in the context of a web browser and had a user clicked on the “Validate Configuration” button. This results in the same actions described under the “Real Time System Configuration Verification” section (FIG. 5, step 369 ). Program 153 retrieves information in document 117 , enters it into database 200 , and executes program 155 with a pointer to the data just entered in database 200 (FIG. 5, step 359 ). Program 155 retrieves the data just entered and compares it with standard/supported system database 202 (FIG. 5, step 371 ). The differences between the configuration of the system being currently registered and the standard configuration are then formatted as an HTML document 107 and passed back to the script program 153 . Program 153 then returns document 107 to the system being registered. Document 107 is then received by program 163 (FIG. 5, step 357 ), which was waiting for a response on port 80 . Program 163 then writes document 107 to a file (FIG. 5, step 367 ) and executes the web browser with a command line parameter pointing to it (FIG. 5, step 369 ). This causes document 107 to be displayed by the web browser on the system being registered and provides immediate feedback on any potential configuration problems.
System Alert Monitoring and Exception Handling
A system alert condition is generated when some system parameter exceeds predetermined boundary conditions. For example, if the system temperature goes too high, an alert is triggered. Traditional methods for handling alerts use industry standard or proprietary protocols such as SNMP or DMTF/DMI and send alert information packets to receiving system management consoles like HP's OpenView. At these consoles icons representing the systems from which the alerts originate change colors (from, for example, green to red). This notifies the administrator that something is wrong.
In this embodiment, program 165 executes on managed systems 10 waiting for alerts from the local SNMP or DMI agents (FIG. 6, steps 401 and 403 ). On reception of an alert, program 165 decodes the alerts using the alert ID to index into an alert translation data file document 119 . Based on the alert ID the alert data file returns an alert record consisting of the following fields: (1) alert type, (2) alert description, (3) system name, (4) the name of an icon bit map file used to display this alert in the web browser, and (5) a URL reference to the help files, document 120 , that provides additional information about the alert. This record is entered into a local trap Management Information Base (“MIB”) table, if SNMP is used, or another document 121 (FIG. 6, step 405 ).
Like program 165 , program 167 also receives SNMP or DMI alerts on the management system 20 . When an alert is received, program 167 determines the system from which the alert came, based on the addressing information in the alert packet (FIG. 6, step 407 ). It then launches the local web browser with command line parameters that point to the CGI script program 151 and the system name from which the alert was received. Script program 151 reconstructs document 103 using appropriate icons specified in document 121 or the SNMP local trap MIB (FIG. 6, step 409 ), links the icons to help files associated with the icons and returns document 103 to the browser as described under the earlier Configuration Management embodiment (FIG. 6, step 413 ). The browser in turn displays document 103 . When a user clicks on the icon representing system/sub-system status, the browser displays the help document that was linked to the icon.
In an alternative implementation of this embodiment (see FIG. 7 ), document 102 is modified by changing the header information to produce document 123 . When program 151 receives a request from the HTTP server it uses the modified document 123 to create document 125 which is identical to document 103 except for the header information (FIG. 7, step 451 ). The header information indicates to the web browser that document 125 must be updated periodically. Each time the browser requests an update (FIG. 7, step 453 ), program 151 is executed by the HTTP server (FIG. 7, step 455 ) and it re-creates document 125 with the latest system status and configuration information and returns it to the web browser. This ensures that all alerts generated since the last update are reflected in the system status section of the newly created document 125 .
In a third alternative implementation of this embodiment (see FIG. 8 ), program 151 , a modified version of program 165 , here called program 169 , and the HTTP web server all execute on managed systems 10 . Program 169 is similar to program 165 , except that it executes program 151 upon receiving an alert in addition to its normal functions. In this implementation, document 102 is replaced by document 127 . Document 127 is identical to document 102 except the header information is modified to indicate that it is a “multi-part-with-replace” document, a known type of document. When web browsers receive such documents, they connect to the web browser asynchronously. When a user initiates a request in this implementation, program 151 uses document 127 to create document 129 (FIG. 8, step 501 ), which is document 103 with a modified header. As the header information from the template is directly copied to the output document, document 129 is also a “multi-part-with-replace” document. When an alert is received by program 169 (FIG. 8, steps 503 and 505 ), it launches program 151 with an appropriate command line indicating it should re-create document 129 and re-transmit it to the web browser (FIG. 8, step 507 ). The technique used here to asynchronously send documents on alert conditions to the web browser is commonly referred to as “Server Push”, i.e., documents are pushed from the HTTP server without being explicitly requested by the web browser.
In a fourth implementation of this particular embodiment (see FIG. 9 ), document 102 is modified to include references to “active objects” such as a Java applet or an ActiveX program to create document 131 . In this implementation, program 151 uses document 131 as input and produces document 133 , which is similar to document 103 but includes the references to the active objects in document 131 . A property of such active objects is that displaying them causes the browser to execute the “bytecode” corresponding to the active objects. The executing embedded programs (the active objects) in turn read the system status file document 121 at programmed intervals and change the displayed icons to correspond to the current system state in the same manner as described for the other implementations of this embodiment.
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Methods for using the Internet to create applications that perform many of the functions now performed by management platforms and third party add-on tools in a much simpler manner are described herein. The applications are easier to use by novices than known tools and lower the overall cost of system management. Using known system components, the system's configuration can be viewed or changed over the Internet using an HTML document to list and display the managed systems, together with icons that represent the state of the managed systems. By using “active controls” or Java scripts, the state of the managed systems can be dynamically updated by changing the color of associated icons or the displayed text. Using embedded commands or identifiers within template documents, a program can be created to automatically acquire needed system information. In another embodiment, an HTML CGI document containing desired system information and a reference link back to the system at the manufacturer's selected site is created, allowing the manufacturer's system to retrieve this system information automatically. The system information is then analyzed against a list of currently valid system configurations to detect potential problems. In turn, if potential problems are detected, the information is sent back to the managed system automatically.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Application No. 60/504,337 filed Sep. 19, 2003 entitled MODEL CONVERSION KIT AND METHOD which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
This invention relates generally to model vehicles, and more specifically to converting a model vehicle to a powered vehicle.
Powered model vehicles, in particular radio-controlled vehicles, typically have little connection with non-powered model vehicles, such as plastic models, particularly with respect to the level of detail usually associated with non-powered model vehicles. In addition, the variety in types of vehicles commercially offered as non-powered model vehicles far exceeds the variety in types of vehicles commercially offered as powered or radio-controlled vehicles. Current products that provide a bridge between powered or radio-controlled vehicles and model vehicles are toy-like in appearance and function. A product is needed in which a non-powered model vehicle may be converted to a powered model vehicle.
Therefore, the object of the present invention is to provide a conversion kit for converting a non-powered model vehicle to a powered model vehicle.
Another object of the present invention is to provide a conversion kit for converting a non-powered model vehicle to a radio-controlled vehicle.
Yet another object of the present invention is to provide a conversion kit, to convert a non-powered model vehicle to a powered or radio-controlled model vehicle, that provides for a finished product that is simple in design, easy to assemble, and has a low cost to manufacture.
A further object of the present invention is to provide a conversion kit that can be adapted to a wide range of currently-available non-powered model vehicles.
A still further object of the present invention is to provide a conversion kit that can result in a powered vehicle that can provide better performance than similarly-sized radio-controlled vehicles.
A yet still further object of the present invention is to provide a conversion kit that can produce a powered vehicle that can be driven in protected or unprotected conditions, at slow speeds or speeds exceeding twenty miles/hour.
A yet still further object of the present invention is to provide an adjustable motor mount that allows adjustments of gear ratios.
A yet still further object of the present invention is to provide an effective full suspension with a simple design.
A yet still further object of the present invention is to provide superior driving control through full ball joint steering with 0°-30° of front pick-up.
A yet still further object of the present invention is to provide a conversion kit that can accommodate many non-powered model vehicle body styles.
A yet still further object of the present invention is to provide a conversion kit that can accommodate various chassis length and width.
A yet still further object of the present invention is to provide a conversion kit that can accommodate for a range of desired non-powered model vehicle uses from classis look to racing speed.
SUMMARY OF THE INVENTION
The objects set forth above as well as further and other objects are achieved by the present invention. The solutions and advantages of the present invention are achieved by the illustrative embodiment described herein below.
The present invention includes a conversion kit for converting a non-powered vehicle model to a powered vehicle, in particular, a radio-controlled vehicle. The conversion kit can include, but is not limited to, a chassis plate, a steering assembly having mountable connection to the chassis plate, a rear assembly having mountable connection to the chassis plate, a means for powering the non-powered vehicle model, and a means for attaching the chassis plate to a model shell of the non-powered vehicle model. Optionally, the present invention can include a means for controlling movement of the powered vehicle.
The present invention also includes a method for converting a non-powered vehicle model that has a vehicle shell to a powered vehicle. The method includes the steps of detaching the vehicle shell from the non-powered vehicle model, attaching a rear assembly onto a chassis plate, attaching a steering assembly onto the chassis plate, attaching a means for powering the non-powered vehicle model onto the chassis plate, and attaching the chassis plate onto the underside of the vehicle shell. Optionally, the method can include the step of attaching a means for controlling the movement of the powered vehicle.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description. The scope of the present invention is pointed out in the appended claims.
DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a pictorial, schematic view of the major parts of a conversion kit and powered vehicle model of the illustrative embodiment of the present invention;
FIG. 2 is a pictorial view of rear assembly parts of the conversion kit and a method of rear assembly construction of the illustrative embodiment of the present invention;
FIG. 3 is a pictorial view of front assembly parts of the conversion kit and the method of steering assembly construction of the illustrative embodiment of the present invention;
FIG. 4 is a pictorial view of the parts of a non-powered vehicle model that are used along with the conversion kit to create the powered vehicle of the illustrative embodiment of the present invention;
FIG. 5 is a schematic diagram of a chassis assembly of the illustrative embodiment of the present invention;
FIG. 6 is a schematic diagram of a chassis plate of the illustrative embodiment of the present invention;
FIG. 7 is a schematic diagram of a front bulkhead of the illustrative embodiment of the present invention;
FIG. 8 is a schematic diagram of first and second steering arms of the illustrative embodiment of the present invention;
FIG. 9 is a schematic diagram of a right rear bulkhead of the illustrative embodiment of the present invention;
FIG. 10 is a schematic diagram of a left rear bulkhead of the illustrative embodiment of the present invention;
FIG. 11 is a schematic diagram of a rear wheel of the illustrative embodiment of the present invention; and
FIG. 12 is a schematic diagram of a rear upper plate of the illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is now described more fully hereinafter with reference to the accompanying drawings, in which the illustrative embodiment of the present invention is shown. The following configuration description is presented for illustrative purposes only. Any non-powered vehicle model may be suitable for use of the conversion kit and method of the present invention, and for producing the powered vehicle of the present invention. In particular, the invention is not limited to automobile models or even to wheeled models, but can be adapted to any model by changing the dimensions of the components of the conversion kit as desired. The dimensions and details that follow are provided for illustrative purposes only and are not to limit the invention to these dimensions and details.
Referring now to FIG. 1 , conversion kit 10 A and powered vehicle 10 of the illustrative embodiment of the present invention can include, but are not limited to, conventional vehicle shell 11 , chassis plate assembly 11 A that provides the housing for the means for powering 60 conventional vehicle shell 11 , non-powered vehicle model size-dependent chassis plate 35 , steering assembly 30 A, rear assembly 20 , means for powering 60 the non-powered vehicle model 110 B such as, for example, conventional motor, made by, for example, GWS®, and means for attaching chassis plate 35 to conventional vehicle shell 11 such as first adhering surface 103 and second adhering surface 103 B, for example VELCRO® strips. Model vehicle kits, such as those supplied by REVELL®, AMT®, and ERTL®, contain conventional vehicle shell 11 and conventional rims/hubcaps 13 . Conversion kit 10 A may optionally include a means for controlling 61 the powered vehicle 10 such as, for example a CIRRUS® CS-10BB, having electrical connection 62 with means for powering 60 . Note that throughout the following discussion, various types of conventional screws that are described are available from suppliers such as, for example, DU-BRO®, RR ROBINSON RACING®, and TEAM LOSI®. Screw sizes can vary depending on the size of the model. For a 1/24 or 1/25 scale model, screws, ball joints, nuts, and threaded rods are generally 2-56 in various lengths, while set screws and some threaded rods are 4-40 in various lengths. The invention is not limited to these specifications, types and sizes of screws, or manufacturers.
Continuing to primarily refer to FIG. 1 , powered vehicle 10 of the present invention is prepared according to the steps of the method of the present invention which include, but are not limited to, detaching conventional vehicle shell 11 from non-powered vehicle model 10 B, attaching rear assembly 20 ( FIG. 2 ) to rear wheel assembly mount 35 A ( FIG. 5 ), attaching steering assembly 30 A ( FIG. 1 ) to steering assembly mount 35 B ( FIG. 5 ), attaching means for powering 60 non-powered vehicle model 10 B such as, for example, conventional motor, to chassis plate 35 ( FIG. 5 ), and attaching chassis plate 35 onto underside 11 B of conventional vehicle shell 11 .
Referring now primarily to FIG. 2 , the parts required for and method of rear assembly 20 of the illustrative embodiment of the present invention are shown. For example, the method can include, but is not limited to, the steps of sliding tube 25 , made of, for example, brass, and available from, for example, K+S®, into right rear bulkhead 31 ( FIG. 9 ) and securing it with tube screw 98 . The method can also include the steps of sliding left rear bulkhead 33 ( FIG. 10 ) onto the other sides of tube 25 , securing rear upper plate 23 ( FIG. 12 ) to right rear bulkhead 31 at right bulkhead recess 97 A, and securing left rear bulkhead 33 at left bulkhead recess 97 B with bulkhead screws 97 . The method can further include the steps of securing this completed assembly to rear wheel assembly mount 35 A ( FIG. 5 ) with rear chassis screws 29 , sliding spur gear 21 , available, for example, from JR®, onto shaft 27 , available, for example, from Du-Bro®, made of, for example, steel, and sliding the assembly is slid into tube 25 .
Continuing to refer primarily to FIG. 2 , the method can still further include the steps of securing the means for powering 60 , such as, for example, conventional motor, to left bulkhead inner side 58 ( FIG. 10 ) with motor screws 30 , and joining conventional rims/hubcap 13 and wheel 19 ( FIG. 11 ), for example, by conventional double-sided tape 101 that is wrapped around the outer circumference of conventional rims/hubcap 13 and wheel 19 . The method can still further include the steps of placing tire 17 , available, for example, from ABC Hobby, around conventional rims/hubcap 13 and wheel 19 , securing tire 17 in place by conventional double-sided tape 101 forming tire assembly 104 , and attaching tire assembly 104 to shaft 27 by inserting wheel screw 29 A, for example a set screw, in wheel 19 . This procedure is followed for both rear tires. The method can still further include the steps of adjusting the alignment of tires 17 and shaft 27 by loosening tube screw 98 , moving brass tube 25 , and retightening tube screw 98 , and when tires 17 are evenly spaced with respect to the center of chassis plate 35 , gluing spur gear 21 to shaft 27 with a self-penetrating glue such as, for example, thin Cyanoacrylate.
Referring now primarily to FIG. 3 , the parts required and method of construction steering assembly 30 A ( FIG. 1 ) of the illustrative embodiment of the present invention are shown. The method of construction can include the steps of threading steering rods 71 A and 71 B, made from, for example, steel, through and centering them in front bulkhead 73 ( FIG. 7 ), and securing steering rods 71 A and 71 B in front bulkhead 73 by top rod screw 74 and bottom rod screw 75 , such as, for example, a set screw. The method can further include the steps of threading steering rods 71 A and 71 B onto lower ball joints 77 , available from, for example, DU-BRO®, to form an assembly, and securing the assembly to steering assembly mount 35 B ( FIG. 6 ) with front screws 79 , for example round-head screws. The method can still further include the steps of pressing axle 81 , made of, for example, brass, available from, for example DU-BRO®, into ball bearing 83 , available, for example, from Dynamite, to form an assembly, and gluing the assembly into wheel 19 from the non-powered vehicle model 10 B. The method can still further include the steps of securing axle 81 in first and second steering arms 87 A and 87 B ( FIG. 8 ) with conventional liquid thread lock, and connecting conventional rims/hubcap 13 , wheel 19 , and tire 17 as described above.
Continuing to refer to FIG. 3 , the method can still further include the steps of inserting screws 93 into lower ball joints 77 and upper ball joints 77 A and first and second steering arms 87 A and 87 B as shown, threading upper threaded rod 95 into upper ball joints 77 A as described above, to form an assembly, and securing the assembly to first and second steering arms 87 A and 87 B with bulkhead screws 97 that pass through lower ball joints 77 and upper ball joints 77 A, and ultimately through nuts 99 .
Referring now primarily to FIG. 4 , the parts of a non-powered vehicle model 10 B that can be used for completing the powered vehicle 10 of the illustrative embodiment of the present invention are shown. In particular, conventional vehicle shell 11 is mounted atop chassis plate 35 ( FIG. 1 ) that has been fitted with the inner workings required to convert a non-powered model vehicle 10 B to a powered vehicle 10 . Conventional rims/hubcaps 13 can also be used to create the same style in a powered vehicle 10 that is provided in the non-powered model vehicle 10 B.
Referring now primarily to FIG. 5 , a schematic diagram of the chassis assembly is shown. The chassis assembly includes chassis plate 35 , right chassis plate wing 35 E, left chassis plate wing 35 C, steering assembly mount 35 B, and rear wheel assembly mount 35 A. Upon steering assembly mount 35 B are mounted, among other things, front bulkhead 73 and first and second steering arms 87 A and 87 B according to the method described in FIG. 3 . Upon rear wheel assembly mount 35 A are mounted left bulkhead inner side 58 and right rear bulkhead 31 , upon which are mounted rear upper plate 23 , and to which are mounted wheel 19 , according to the method shown in FIG. 2 .
Referring now primarily to FIG. 6 , details of chassis plate 35 of the illustrative embodiment of the present invention are shown. Chassis plate 35 is dimensioned illustratively for a wide range of currently available 1/24 and 1/25 scale models. The invention is not limited to these dimensions, which are provided for illustrative purposes only. Nor is the invention limited to 1/24 and 1/25 scale models, but can obviously be up- or down-sized depending on the size and shape of the non-powered vehicle model 10 B of the user's choice. Center chassis plate 35 D, right and left chassis plate wings 35 E and 35 C, steering assembly mount 35 B and rear wheel assembly mount 35 A can be formed of continuous material such as, for example, plastic, or can be provided as separate parts that are made to adhere to each other either fixedly or removably. Steering assembly mount 35 B can include, but is not limited to, front chassis wing 36 A and front attachment recess 36 , which may be any shape and size, or may be multiple recesses, so long as they accommodate the mounting of steering assembly 30 A ( FIG. 1 ). Front chassis wing 36 A forms front angle 36 B with steering assembly mount 35 B. Right and left chassis plate wings 35 E and 35 C form center angle 42 with center chassis plate 35 D. Both front angle 36 B and center angle 42 are preferably 140°, but the invention is not limited to that angle. Rear wheel assembly mount 35 A preferably includes two mounting recesses 38 , but can include any number and shape of mounting recesses 38 to accommodate the mounting of rear assembly 20 ( FIG. 1 ).
Referring now to FIG. 7 , illustrative dimensions are shown for front bulkhead 73 . Front bulkhead 73 is not limited to these dimensions nor this size and shape. Relative positioning of steering rods 71 A and 71 B accommodate mounting on steering assembly mount 35 B. Front bulkhead face 72 can include, but isn't limited to, first threaded rod recess 48 (that extends through the depth of front bulkhead 73 ) to accommodate steering rod 71 A and second threaded rod recess 46 (that also extends through the depth of front bulkhead 73 ) to accommodate steering rod 71 B. Front bulkhead top 74 A includes rod position recess 44 to accommodate rod screw 74 .
Referring now primarily to FIG. 8 , first and second steering arms 87 A and 87 B are shown in detail. In particular, lower steering rods 71 A and 71 B ( FIG. 3 ) are mounted around lower rod recess 111 , while upper threaded rod 95 ( FIG. 3 ) is mounted at upper recess 115 . Axle 81 ( FIG. 3 ) is positioned in axle recess 113 .
Referring now primarily to FIG. 9 , right rear bulkhead 31 is shown in detail. In particular, tube 25 ( FIG. 2 ) is positioned within right tube recess 123 . Bulkhead screw 97 ( FIG. 2 ) is fitted into right bulkhead recess 97 A, and retightening tube screw 98 ( FIG. 2 ) is fitted into retightening recess 121 for maintaining the position of tube 25 .
Referring now primarily to FIG. 10 , left rear bulkhead 33 is shown in detail. In particular, motor screws 30 ( FIG. 2 ) mount means for powering 60 ( FIG. 2 ) onto left bulkhead inner side 58 ( FIG. 2 ) in upper and lower mount recesses 131 and 133 , and motor gear 60 A ( FIG. 2 ) is fitted into motor mount recess 135 . Bulkhead screw 97 ( FIG. 2 ) is fitted into left bulkhead recess 97 B, and tube 25 ( FIG. 2 ) is positioned within left tube recess 141 .
Referring now primarily to FIG. 11 , rear wheel 19 is shown in detail. In particular, shaft 27 ( FIG. 2 ) is positioned through shaft recess 143 , and wheel screw 29 A ( FIG. 2 ) and wheel recess 145 hold wheel 19 in position.
Referring now primarily to FIG. 12 , rear upper plate 23 is shown in detail. In particular, left mounting recess 147 and right mounting recess 149 retain rear upper plate 23 in position above tube 25 ( FIG. 2 ) through bulkhead screws 97 ( FIG. 2 ) that are fitted into right bulkhead recess 97 A and left bulkhead recess 97 B.
FIGS. 5-12 present illustrative measurements that can be useful in constructing the powered vehicle 10 of the present invention. The present disclosure does not preclude a conversion kit that may be constructed of parts having different sizes from the sizes in FIGS. 5-12 , and/or with some parts combined and/or eliminated entirely. The present invention is not limited to the measurements provided, nor to the exact parts disclosed. Nor is the invention limited to the exact method of construction of the powered vehicle 10 using the conversion kit of the present invention.
Although the invention has been described with respect to various embodiments, it should be realized that this invention is also capable of a wide variety of further and other embodiments within the spirit and scope of the appended claims.
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A conversion kit and method for converting a non-powered vehicle model to a powered vehicle, in particular, a radio-controlled vehicle is disclosed. The conversion kit can include a chassis plate, a steering assembly having mountable connection to the chassis plate, a rear assembly having mountable connection to the chassis plate, a device for powering the vehicle model, and a device for attaching the chassis plate to a model shell. Also disclosed is a product produced by the conversion kit and/or method of the present invention.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is the U.S. national phase application under 35 U.S.C. §371 of International Application Ser. No. PCT/DE2012/001090, having an international filing date of 14 Nov. 2012, and designating the United States, the entire contents of which are hereby incorporated by reference to the same extent as if fully rewritten.
BACKGROUND OF THE INVENTION
[0002] The invention concerns a torque transmission device and particularly concerns a permanently engaged starter (PES) for a start-stop system with a change-of-mind function. Already known PES systems include a bearing and a freewheel disposed outside of the engine oil chamber, i.e., in the dry area of the engine. PES systems located in the wet chamber of the engine have also been described, for example in EP 1 748 202 B1.
[0003] An object of the present invention is to provide an improved solution to offer advantages with regard to leak tightness, lubrication, assembly, and costs.
SUMMARY OF THE INVENTION
[0004] For achieving that object, the invention proposes various solutions that include the following features:
[0005] The invention uses a ball bearing for decoupling the differences in rotational speed between the engine and the starter, a freewheel for the speed-controlled coupling of the PES to the drive train of the engine, and two sealing elements for sealing the wet chamber of the engine from the transmission housing. Furthermore, the freewheel outer ring (FRAX) and the bearing inner ring are configured in one piece with each other and are preferably made out of a refinished drawn part. The bearing outer ring and the junctional region with the annular gear (intermediate ring) are likewise configured in one piece with each other and are made preferably out of a refinished blank.
[0006] The following features can be additionally or alternatively provided: The component freewheel outer ring/bearing inner ring is connected by positive engagement and in a leak-proof manner with help of a flange element screwed on the crankshaft (KW), e.g., partially laser welded, and centered with respect to each other through radial surfaces.
[0007] In order to avoid refinishing because of distortion of the bearing raceways during welding, the weld seam is preferably made only partially.
[0008] A sealing element preferably made of an elastomer is arranged on the inner diameter of the bearing inner ring between the component freewheel outer ring/bearing inner ring and the flange element.
[0009] The component freewheel outer ring/bearing inner ring and the flange element are connected through the flex plate by positive engagement, for example riveted, and joined substantially without spacing at least in the region of the flange element.
[0010] The centering of the composite component freewheel outer ring/bearing inner ring and the flange element on the crankshaft is thus achieved with help of the flex plate. The flange element has a radial clearance to the crankshaft seat.
[0011] The annular gear is cold rolled and connected directly to the intermediate ring.
[0012] The connection of the annular gear is realized through positive engagement, optionally by riveting as a low-cost variant. In the case of a positive engagement through a weld joint, it is advantageous that the annular gear can be centered on the outside by welding so that a precise circular running is obtained. For this purpose, it is necessary to provide a spacing between the intermediate ring and the inner diameter of the annular gear carrier.
[0013] The different variants of the embodiment can be combined at least partially with one another.
[0014] An optimized lubricant supply at the freewheel can be achieved through suitable apertures on the component that forms the bearing outer ring and the freewheel inner ring.
[0015] In a torque transmission device using a starter motor for starting an internal combustion engine having an annular gear cooperating with the starter motor, and including a bearing for decoupling the difference in rotational speed between the internal combustion engine and the starter motor. The device further includes a freewheel for the speed-controlled coupling of the starter motor to the internal combustion engine, such that torque transmission takes place between the annular gear and a crankshaft of the internal combustion engine. The device includes still further an annular gear carrier arranged between the annular gear and the freewheel.
[0016] The above-described object is achieved by the fact that the bearing and the freewheel are arranged radially on top of each other such that at least the freewheel and the bearing communicate with an engine oil chamber of the internal combustion engine, and such that a first sealing element and a second sealing element are provided for sealing the engine oil chamber of the internal combustion engine. The freewheel is preferably arranged radially outside of the bearing, this bearing preferably being a rolling bearing, for example a ball bearing. The bearing serves to decouple the differences in rotational speed between the internal combustion engine and the starter motor. The freewheel serves for the speed-controlled coupling of the starter motor to a drive train in which the internal combustion engine comprising the torque transmission device of the invention is arranged. The two sealing elements serve to seal from a transmission housing the engine oil chamber that is also designated as a wet chamber.
[0017] A preferred example of an embodiment of the torque transmission device is characterized in that a bearing outer ring of the bearing and a freewheel inner ring of the freewheel are made in one piece with each other and form an outer bearing freewheel unit. The bearing outer ring and the freewheel inner ring are preferably constituted by a common race ring body. The common race ring body preferably includes radially on an inner side at least one running surface for rolling elements of the bearing. Radially on an outer side, the common race ring body preferably includes at least one running surface for freewheeling elements of the freewheel. Advantageously, the common race ring body is connected particularly integrally to an intermediate ring that constitutes a junction region for the annular gear.
[0018] A further preferred example of an embodiment of the torque transmission device is characterized in that, further, a bearing inner ring of the bearing and a freewheel outer ring of the freewheel are made in one piece with each other and form an inner bearing freewheel unit. The bearing inner ring preferably includes radially on an outer side at least one running surface for rolling elements of the bearing. Radially on an inner side the freewheel outer ring body includes at least one running surface for the freewheeling elements of the freewheel. The freewheel outer ring is made preferably in one piece with the bearing inner ring. The inner bearing freewheel unit preferably possesses a substantially U-shaped cross-section including a base from which two legs protrude at an angle. A radially inner leg of the inner bearing freewheel unit constitutes the bearing inner ring of the bearing. A radially outer leg of the inner bearing freewheel unit constitutes the freewheel outer ring.
[0019] A further preferred example of an embodiment of the torque transmission device is characterized in that a flex plate for torque transmission is provided between the internal combustion engine and a drive train, while being arranged directly adjacent to the inner bearing freewheel unit in an axial direction. The flex plate is preferably configured as a flexible component and serves for torque transmission between the crankshaft of the internal combustion engine and a clutch or a transmission. For this purpose, the flex plate is connected through a radially inner peripheral edge region to the crankshaft.
[0020] A further preferred example of an embodiment of the torque transmission device is characterized in that a radially widening gap is provided between the inner bearing freewheel unit and the flex plate. The flex plate can bear against the inner bearing freewheel unit in a radially inner region. In a radially outer region, the radially widening gap is deliberately arranged between the inner bearing freewheel unit and the flex plate. The radially widening gap is open in a radially outward direction.
[0021] A further preferred example of an embodiment of the torque transmission device is characterized in that the gap is filled at least partially with a material having a low modulus of elasticity, in particular with an elastomer. The material with the low modulus of elasticity advantageously enables the flex plate to be deformed or to move in a limited manner relative to the inner bearing freewheel unit. In this way, if necessary, an offset between the crankshaft and the clutch or the transmission can be compensated for.
[0022] A further preferred example of an embodiment of the torque transmission device is characterized in that the inner bearing freewheel unit is connected to a flange element that is fixed on the crankshaft. The flange element is fixed on the crankshaft with a radially inner peripheral edge region, for example with the help of a fixing means like screws. With a radially outer peripheral edge region the flange element is preferably fixed on the inner bearing freewheel unit.
[0023] A further preferred example of an embodiment of the torque transmission device is characterized in that the inner bearing freewheel unit is centered on an outer periphery of the flange element. For this purpose, the inner bearing freewheel unit is configured, as viewed in cross-section, for example with a step-like shoulder.
[0024] A further preferred example of an embodiment of the torque transmission device is characterized in that the inner bearing freewheel unit is connected to the flange element by fusion of material. The connection by fusion of material is preferably made as a welded joint. However, this welded joint is preferably not made as a continuous but only as a partial weld seam. In this way, an undesired refinishing of the bearing raceways because of distortion caused by welding can be avoided.
[0025] A further preferred example of an embodiment of the torque transmission device is characterized in that a further sealing element is arranged between the bearing inner ring of the inner bearing freewheel unit and the flange element. The further sealing element is preferably made of an elastomeric plastics material. The further sealing element is preferably arranged radially on the inside on the bearing inner ring.
[0026] A further preferred example of an embodiment of the torque transmission device is characterized in that a flex plate, or the flex plate, is fixed on the flange element. Advantageously, the flex plate is connected through positive engagement, for example by riveting on the flange element. A centering of the torque transmission device on the crankshaft is achieved in this case preferably through the flex plate. As a result, the flange element has a radial clearance relative to a crankshaft seat used for centering. A sealing element can be provided between the flange element and the bearing inner ring.
[0027] A further preferred example of an embodiment of the torque transmission device is characterized in that the annular gear is connected through positive engagement to an intermediate ring. In this case, however, attention must be paid to the fact that the concentric running of the annular gear follows the radial tolerances during riveting. Although this is relatively inexact, it has the advantage of being less expensive.
[0028] A further preferred example of an embodiment of the torque transmission device is characterized in that the annular gear is connected by fusion of material to an intermediate ring. The connection of the annular gear to the intermediate ring is realized preferably by welding, particularly by laser welding or by metal active gas welding. The connection by fusion of material offers the advantage that the annular gear, for example during welding, can be centered on the outside. In this way, an exact concentricity of running can be assured. This however makes it necessary to provide a certain spacing between the intermediate ring and an inner diameter of the annular gear carrier.
[0029] A further preferred example of an embodiment of the torque transmission device is characterized in that a further sealing element is arranged between a bearing inner ring of the bearing or the outer bearing freewheel unit and the crankshaft. In this way the sealing of the engine oil chamber relative to the transmission housing is improved.
[0030] A further preferred example of an embodiment of the torque transmission device is characterized in that the bearing and the freewheel are arranged radially within the first sealing element and the second sealing element. As a consequence, both the bearing and the freewheel preferably have a smaller diameter than the first and the second sealing element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Further advantages, features and details of the invention result from the following description in which different examples of embodiment are described in detail with reference to the appended drawings. The drawing figures show:
[0032] FIGS. 1 a to 6 b, altogether six variants of the torque transmission device of the invention, wherein the figures referenced with b are all reduced to PES parts and a flex plate, and
[0033] FIGS. 7 , 8 a, 8 b, 9 , and 10 , five further variants of the torque transmission device of the invention, in a semi-section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] In FIGS. 1 to 10 a torque transmission device of the invention is represented in different variants. The torque transmission device shown in FIGS. 1 a and 1 b and in FIG. 7 includes an annular gear 1 ; 41 that is firmly connected to an annular gear carrier 2 ; 42 by a weld 15 a, as seen in FIGS. 1 a and 1 b. In FIGS. 7 to 10 it can be seen that a starter annular gear 62 of a starter motor 61 is meshed with the annular gear 41 .
[0035] A freewheel 3 ; 43 and a bearing 4 ; 44 are integrated in the torque transmission device. The torque transmission device further includes a flex plate 5 ; 45 that is non-rotatably connected to a crankshaft 6 ; 46 . Through the flex plate 5 ; 45 torque can be transmitted from the crankshaft 6 ; 46 to a transmission (not shown) arranged further downstream in a drive train of an automotive vehicle, or to an intermediately arranged clutch (not shown).
[0036] The bearing 4 ; 44 includes a bearing inner ring 7 ; 47 and a bearing outer ring. The bearing outer ring of the bearing 4 ; 44 is combined with a freewheel inner ring of the freewheel 3 ; 43 in an outer bearing freewheel unit 8 ; 48 . In an inner bearing freewheel unit 9 ; 49 the bearing inner ring 7 ; 47 is combined with a freewheel outer ring 14 ; 54 .
[0037] The inner bearing freewheel unit 9 ; 49 has a substantially U-shaped cross-section with a base from which two legs extend at an angle. The base of the U-shaped cross-section extends substantially in radial direction. The term radial relates to an axis of rotation of the torque transmission device that is indicated through a chain-dotted line.
[0038] The radially inner leg of the U-shaped cross-section is constituted by the bearing inner ring 7 ; 47 . The radially outer leg of the U-shaped cross-section is constituted by the freewheel outer ring 14 ; 54 . The two legs of the U-shaped cross-section extend parallel to each other in axial direction, i.e., parallel to the axis of rotation of the torque transmission device.
[0039] A radially outward extending gap 10 ; 50 is formed between the base of the inner bearing freewheel unit 9 ; 49 and the flex plate 5 ; 45 that includes a matched pot-shaped section. Radially within the gap 10 ; 50 , the flex plate 5 , 45 bears directly, or indirectly with interposition of a further element, against the inner bearing freewheel unit 9 ; 49 .
[0040] A sealing element 11 ; 51 is arranged radially on an inner side on the inner bearing freewheel unit 9 ; 49 . The sealing element 11 ; 51 serves to seal the bearing inner ring 7 , 47 of the inner bearing freewheel unit 9 ; 49 and the crankshaft relative to each other.
[0041] Further, the bearing inner ring 7 ; 47 is combined with a covering disk/a covering sheet metal/a flange element 17 a; 17 b; 17 c or a flange element 57 , into a unit 12 ; 52 . As can be seen for example in FIG. 7 , the flange element 57 is connected through a riveted joint 74 by positive engagement to the flex plate 45 . FIGS. 3 a and 3 b show that the freewheel outer ring 14 can also be combined by a weld joint 15 into a unit 12 made up of bearing inner ring/covering disk.
[0042] A gap filling is indicated at 16 a in FIGS. 3 a and 3 b. In FIGS. 6 a and 6 b the gap filling is referenced as 16 b.
[0043] The annular gear carrier 2 , as can be seen for example in FIGS. 1 a and 1 b, is fixed by a weld joint 15 to an intermediate ring that forms a part of the outer bearing freewheel unit 8 . FIGS. 4 a and 4 b show that the attachment of the annular gear carrier 2 with the intermediate ring of the outer bearing freewheel unit 8 can also be realized through riveted joints 18 .
[0044] For sealing the engine oil chamber from the transmission housing two sealing elements 19 , 20 ; 59 , 60 are integrated in the torque transmission device. The sealing element 20 ; 60 is arranged radially outside of the outer bearing freewheel unit 8 ; 48 . The sealing element 19 ; 59 is arranged in the radial direction between the inner bearing freewheel unit 9 ; 49 and the outer bearing freewheel unit 8 ; 48 .
[0045] In FIGS. 5 a and 5 b it is indicated at 21 that the covering disk 17 c can be connected by positive engagement through a toothed connection to the inner bearing freewheel unit 9 . A sealing element 22 serves for sealing between the crankshaft 6 and the inner bearing freewheel unit 9 .
[0046] In FIGS. 6 a and 6 b it can be seen that the bearing inner ring 7 is connected with help of a toothed connection 21 b by positive engagement to the flex plate 5 . Moreover, the bearing inner ring 7 is connected by the weld joint 15 b by fusion of material to the freewheel outer ring 14 .
[0047] In the variant V 1 of FIG. 1 a and FIG. 1 b, the bearing outer ring and the freewheel inner ring are made in one piece with each other, and the annular gear carrier and the annular gear are made in two pieces and connected to each other by welding. The sealing in the direction of the crankshaft is achieved through a press fit on the bearing inner ring without additional sealing elements.
[0048] In the variant V 2 of FIG. 2 a and FIG. 2 b, the bearing outer ring and the freewheel inner ring are configured in one piece with each other. The bearing inner ring and the freewheel inner ring are likewise made in one piece with each other, with a gap to the flex plate widening in a radially outward direction. The covering disk under the flex plate, the annular gear, and also the annular gear carrier are formed by rolling in one piece with one another and are subsequently welded-on. The sealing in the direction of the crankshaft is achieved through a sealing element (in this case, an O-ring) between bearing inner ring/flex plate/covering disk. The torque of the PES is supported solely through a press fit on the bearing inner ring.
[0049] Variant V 3 , represented in FIG. 3 a and FIG. 3 b, corresponds substantially to variant V 2 except that the bearing inner ring and the covering disk are made in one piece with each other. The freewheel outer ring is connected by fusion of material (in this case, by welding), or by positive engagement to the bearing inner ring/covering disk, the sealing in the direction of the crankshaft being realized with help of a sealing element (here, an O-ring) on the element made up of bearing inner ring/covering disk. The gap between the freewheel outer ring and the flex plate is filled with a material having a low modulus of elasticity, for example an elastomer which can be deformed in correspondence to a movement of the flex plate. The torque of the PES is supported on the screw connection of the crankshaft.
[0050] Variant V 4 of FIG. 4 a and FIG. 4 b corresponds substantially to variant V 2 except that, in this case, the covering disk is omitted. It is solely the flex plate that is screwed to the crankshaft. The annular gear and the annular gear carrier are made in one piece with each other by rolling and are attached by riveting (or by screwing). A sealing element in the direction of the crankshaft (here an O-ring) is arranged between the flex plate and the bearing inner ring. The annular gear carrier secures the sealing from migrating to the exterior.
[0051] Variant V 5 shown in FIG. 5 a and FIG. 5 b corresponds substantially to variant V 2 except that the covering sheet metal for supporting the torque is connected to the bearing inner ring through positive engagement (here in form of a toothed connection). The sealing in the direction of the crankshaft is realized through a sealing element (here an angular ring) arranged on the end of the bearing inner ring facing the engine. The annular gear carrier and the annular gear are made in two pieces and are welded-on.
[0052] Variant V 6 of FIGS. 6 a and 6 b corresponds substantially to variant V 3 except that the flex plate is connected directly to the crankshaft and, for supporting the torque, also by positive engagement (here in the form of a toothed connection) to the bearing inner ring. The sealing in the direction of the crankshaft is realized through a sealing element (here an O-ring) that is arranged radially between the bearing inner ring and the crankshaft screw connection of the flex plate. The gap between the freewheel outer ring and the flex plate is filled up with a material having a low modulus of elasticity (for example an elastomer) which can deform in correspondence to movements of the flex plate.
[0053] The different individual structural variants of embodiments V 1 -V 6 can be combined with one another with regard to the embossing of the annular gear carrier with the starter annular gear and its connection, and also for the sealing of the wet chamber of the engine in the direction of the crankshaft connection geometry. This is indicated in the foregoing text for example, optionally, annular gear carrier and annular gear made to standard in two pieces, or in one piece by shaping through rolling or, for example, optionally, the fixing of the annular gear carrier through a weld joint or by riveting or screwing etc.
[0054] An optimized lubricant supply on the freewheel can be achieved through suitable apertures provided in the component which forms the bearing outer ring and the freewheel inner ring.
[0055] In the exemplary embodiment represented in FIG. 7 , the annular gear 41 is provided with cold-rolled teeth. The annular gear carrier 42 is fixed on the intermediate ring 56 through the riveted joints 55 . The flex plate 45 is provided with a matched pot-shaped section. The inner bearing freewheel unit 49 is made as a refinished drawn part. One point 71 indicates a transition fit between the bearing inner ring 47 and the crankshaft 46 . The transition fit simplifies mounting and demounting.
[0056] At one point 72 , the flex plate 45 bears against the flange element 57 . At one point 74 a riveted joint is indicated between the flex plate 45 and the flange element 57 . The riveted joint 74 serves for the pre-assembly prior to or after a partial welding-on of the flange element 57 to the inner bearing freewheel unit 49 . The partial welding-on is indicated at one point 73 .
[0057] At one point 75 , it is indicated that the centering of the torque transmission device on the crankshaft 46 is achieved through the flex plate 45 . An associated centering diameter is indicated through an arrow 76 . At one point 77 , it is indicated that for sealing between the bearing inner ring 47 , or the flange element 57 , and the crankshaft 46 , a special sealing element made out of an elastomeric plastics material is used.
[0058] It is indicated at one point 81 in FIG. 8 a that the annular gear carrier 42 is connected through fusion of material by a welded joint to the intermediate ring 56 . At one point 82 , is represented a centering gap for the radial centering of the annular gear carrier 42 prior to welding. The connection through fusion of material, for example by laser welding or MAG welding, is made after the external centering when the concentric running of the annular gear 41 is found to be satisfactory.
[0059] In FIG. 8 b is represented a detail out of FIG. 8 a of a further variant. At one point 85 it can be seen that the annular gear carrier 42 bears against the intermediate ring 56 . At one point 86 , is represented a centering gap for the radial centering of the annular gear carrier 42 prior to the welding step. At one point 87 is indicated a weld seam for the connection through fusion of material between the annular gear carrier 42 and the intermediate ring 56 .
[0060] In the exemplary embodiment illustrated in FIG. 9 , it can be seen that the flex plate 45 bears directly against the inner bearing freewheel unit 49 at one point 91 . At one point 92 , it is indicated that the flex plate 45 is connected through fusion of material by a welded joint 51 to the inner bearing freewheel unit 49 . The connection through fusion of material is advantageously configured as a partial weld joint with a low heat input.
[0061] In the exemplary embodiment represented in FIG. 10 , similar to the exemplary embodiment represented in FIG. 9 , the torque transmission device is centered on the crankshaft 46 through the flex plate 45 at the point 75 . At one point 101 , the flex plate 45 bears against the inner bearing freewheel unit 49 . At one point 102 , it is indicated that for a pre-assembly, the flex plate 45 can be riveted to the inner bearing freewheel unit 49 . For the purpose of sealing, a sealing element made of a suitable plastics material can be arranged at one point 103 between the inner bearing freewheel unit 49 and the flex plate 45 .
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A torque transmission device for starting an internal combustion engine using a permanently engaged starter motor for a start-stop system. An annular gear connected with the starter motor includes a bearing for decoupling the starter motor from the engine based upon the rotational speed difference between the internal combustion engine and the starter motor. The device includes a freewheel for the speed-controlled coupling of the starter motor to the internal combustion engine so that torque is transmitted between the annular gear and the engine crankshaft. An annular gear carrier is arranged between the annular gear and the freewheel. The bearing and the freewheel are arranged radially relative to each other so that at least the freewheel and the bearing are in communication with an oil chamber of the engine. First and second seal elements are provided for sealing the engine oil chamber of the internal combustion engine.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of security gate operating systems, and more specifically a method and apparatus for simplifying the driving mechanism for a security gate operating mechanism.
BACKGROUND OF THE INVENTION
[0002] It is well known to operate security gates with a motor driven mechanism, and FIG. 1 shows one form of such a security gate system and FIG. 2 shows another form of such a security gate. FIG. 3 shows in more detail the front installation of a drive chain mechanism associated with the form of security gate operating mechanism shown in FIG. 1. FIG. 4 shows another form of security gate chain drive operating mechanism, a so-called rear installation, which is associated with FIG. 2. Typical security gates have a number of advantages, however, when AC or DC motors are utilized to drive them, these gates retain some problems that need to be overcome. For example, it is often the case that environmental conditions may cause the gate to be heavier at times than normally expected, e.g., if snow or ice in on the gate, or debris from a storm is on the gate, or a person is playing on the gate, as for example, hanging on to the gate for a ride. When moving the gate under such conditions a higher initial torque than usual is needed and may cause problems in operation, such as motor overload for typical AC or DC motors. In addition, this required initial torque can limit the size of gate that can be operated with a given size and power capability for a given motor, because of the initial torque requirements. Further, when the gate operating mechanism does malfunction, which can occur from time to time for any number of different reasons, until the gate operating mechanism is put back into service, there will most likely be a need to position the security gate into a desired position to block ingress and egress or to unblock ingress or egress, as may be appropriate. Without the operation of the drive motor, e.g., the prior art security gates can be very difficult to reposition, due, e.g., to the presence of a reduction gear or gearbox that is typically necessary to reduce the high rpm motor speed to a speed of the driving mechanism that is necessary for a safe and controlled operation of the security gate movement. The presence of the reduction gear or gearbox presents a load opposing manual movement of the security gate, which in some cases may not be able to be overcome, or at least may require extensive manual force to be applied to the security gate for movement without the operation of the drive motor. The security gate operating mechanism of the prior art are, therefore, subject to improvement, which is the subject matter of the present invention.
SUMMARY OF THE INVENTION
[0003] A security gate operating system and method are disclosed, which may comprise a security gate capable of motion between a closed position and an open position; a drive mechanism attached to the security gate and adapted to provide a driving force to the security gate to move the security gate between the closed position and the open position; an electrical drive motor having a drive shaft connected directly to the drive mechanism without a reduction gear between the drive motor and the drive mechanism. The method and system may also comprise the drive motor being a reluctance motor including a switched reluctance motor, and including also a three phase switched reluctance motor. The method and system may also comprise a drive chain operatively connected to the security gate; and a drive sprocket attached directly to the shaft of the drive motor, with the drive sprocket in operative connection to the drive chain. The method and system may also comprise at least one drive arm directly connected to the drive motor shaft and operatively connected to the security gate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] [0004]FIG. 1 (Prior Art) shows a security gate operating system of a type in which the present invention may be utilized;
[0005] [0005]FIG. 2 (Prior Art) shows another form of a security gate system of a type in which the present invention may be utilized;
[0006] [0006]FIG. 3 (Prior Art) shows a security gate drive mechanism of the type useful in the security gate operating mechanism of FIG. 1;
[0007] [0007]FIG. 4 (Prior Art) shows another view of the a security gate drive mechanism of the type useful in the security gate operating mechanism of FIG. 1, with the security gate in a position opposite from that shown in FIG. 3;
[0008] [0008]FIG. 5 (Prior Art) shows a security gate drive mechanism of the type useful in the security gate operating mechanism of FIG. 2;
[0009] [0009]FIG. 6 (Prior Art) shows an exploded view of the security gate drive mechanism shown in FIGS. 1, 3 and 4 ;
[0010] [0010]FIG. 7 (Prior Art) shows an enlarged view of a portion of the security gate drive mechanism shown in FIGS. 1, 3 and 4 ;
[0011] [0011]FIG. 8 shows a perspective view of a security gate operating system according to the present invention; and,
[0012] [0012]FIG. 9 shows another perspective view of a security gate operating system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Turning now to FIG. 1 (Prior Art), there is shown a known form of security gate system 10 . The security gate system 10 shown in FIG. 1 is an example of a so-called front installation security gate system 10 . The security gate system 10 has a sliding gate 12 , which is partially mounted for sliding movement by mounting brackets 14 and 16 to wall sections 18 and 20 , respectively. The sliding gate 12 has a pair of rollers 22 that engage a track 24 . The gate is driven by a security gate drive mechanism 26 , as more fully described in regard to FIG. 3 below. The security gate 12 is driven by a chain drive, more fully described in regard to FIG. 3 between a pair of physical travel stops 28 .
[0014] Turning now to FIG. 2 (Prior Art) there is shown another form of security gate system 10 ′. The security gate system 10 ′ shown in FIG. 2 is an example of a so-called rear installation security gate system 10 ′. The security gate system 10 ′ also has a sliding gate 12 , which is partially mounted for sliding movement by mounting brackets 14 and 16 to wall sections 18 and 20 , respectively. The sliding gate 12 has a pair of rollers 22 that engage a track 24 . The gate is driven by a security gate drive mechanism 26 , as more fully described in regard to FIG. 3 below. The security gate 12 is driven by a chain drive, more fully described in regard to FIG. 3 between a pair of physical travel stops 28 .
[0015] The difference between the security gate system 10 of FIG. 1 and the security gate system 10 ′ of FIG. 2 is that the chain drive for operating the security gate 12 through movement of chain 30 runs along the bottom of the gate 12 in the embodiment of FIG. 1 and is fully behind the respective wall section 20 in the embodiment of FIG. 2, for added security purposes. The chain 30 is also attached to the security gate 12 and security gate drive mechanism slightly differently as explained in more detail in regard to FIGS. 3 and 4.
[0016] Turning now to FIG. 3 (Prior Art) there is shown in more detail a security gate drive mechanism 26 for the embodiment of FIG. 1, as it would appear from a view facing away from the wall section 20 shown in FIG. 1. The security gate drive mechanism has a chain drive sprocket 40 , which engages the drive chain 30 after it passes around a first chain guide 42 . The chain subsequently passes around a second chain guide 44 , as shown in FIG. 3. As also shown in FIG. 3 the chain 30 is attached to the sliding gate 12 by an attachment mechanism 32 . The attachment mechanism 32 includes an attachment bar 34 , which is attached to the sliding gate 12 as shown in FIG. 3, e.g., by welding the attachment bar 34 to the sliding gate 12 in the position shown in FIG. 3. The attachment mechanism 32 is described in more detail below in regard to FIG. 7.
[0017] Turning now to FIG. 4 (Prior Art) there is shown a view of the sliding gate 12 when it is at the opposite end of its travel. The sliding gate 12 is shown in FIG. 4 to be attached to the drive chain 30 by a gate extension arm 50 , to which is attached a mounting bar 52 , e.g., by welding to the gate extension arm 50 . The gate extension arm 50 is itself attached to the sliding gate 12 , e.g., by welding the extension arm 50 to the sliding gate 12 in the position as shown in FIG. 4. The drive chain 30 is in turn connected to the mounting bar 52 by a chain attachment mechanism 54 , which is held on the mounting bar 52 by a nut 56 . The extension arm 50 is cut to a particular size or welded along the lower horizontal portion 12 ″ of the frame of the sliding gate 12 such that the chain is relatively taught when the sliding gate 12 is at the extent of its travel, as shown in FIG. 4, and thereafter the chain attachment mechanism 32 and 54 can be threaded through the respective attachment bar 34 and/or 52 to fully tighten the chain before engaging the chain to the respective chain attachment mechanism 32 and/or 54 .
[0018] Turning now to FIG. 5 (Prior Art) there is shown a security gate drive mechanism 26 of the type shown in the embodiment of FIG. 2. Here the drive chain 30 passes over the drive sprocket 40 and around only the first pulley 42 . One end of the drive chain is attached to the sliding gate by an attachment bar 52 , which is attached to the sliding gate 12 , as by welding the attachment bar 56 to the sliding gate 12 , through an attachment mechanism 54 having a nut 56 . The other end of the chain 30 passes around a sprocket 68 rotatably mounted on a sprocket block 66 , which is in turn mounted to a sprocket block post 58 , e.g., by welding the sprocket block 66 to the sprocket block post 58 . The sprocket block post 58 is in turn mounted to the lower horizontal frame member 12 ″ of the sliding gate 12 , as by welding the sprocket block post 58 to the lower horizontal frame member 12 ″ at such a location that the chain is taught in its extension over the sprocket to the mounting bar 34 , to which it is attached by chain attachment mechanism 32 .
[0019] Turning now to FIG. 6 (Prior Art), there is shown an exploded view of a security gate drive mechanism 26 , as shown in FIG. 1 or FIG. 2. The security gate drive mechanism 26 has a frame 72 . As shown in FIG. 6, the pulley wheels 42 , 44 , which can be, e.g., slotted UHMW rollers adapted to prevent chain slippage off of the drive sprocket 40 , by keeping the drive chain 30 on the chain guide wheels 42 , 44 in their respective slots in alignment with the drive sprocket 40 during operation. The drive chain 30 can be, e.g., a #41 chain. As shown, the pulley wheels 42 , 44 are attached to the frame 72 by respective stationary axels 70 , each having a threaded end attached to a respective nut 71 , which may be attached to the frame 72 , as by welding to the frame 72 . The respective chain guide wheels 42 , 44 are held in place on the respective axles 70 by a washer 74 and a capped nut 76 .
[0020] The security gate drive mechanism of the prior are can include, e.g., a motor 80 , which can be, e.g., a one-half horse power instant reversing 120 VAC, 4 amp, 1625 rpm, parking gate motor, such as that made and sold by Leeson, Model No. 100741.50, which can include high speed ball bearings for smoother and quieter operation. In the alternative, the motor 80 can be a permanent magnet 12V DC motor, e.g. that made and sold by Tru-Torq, Model No. 970-535. The motor 80 has a drive shaft, not shown, that connects to a sprocket wheel 84 , which is part of a sprocket transfer unit 82 . The sprocket transfer unit 82 also has a second sprocket wheel 86 , and a chain or a drive belt 87 , which extends around the sprocket wheels 84 and 86 . The sprocket transfer unit 82 has a typical ratio of 1:1 but the ratio may vary accordingly to match the speed of the motor to the desired speed of the moveable gate. A chain shield 88 covers the sprocket wheels 84 and 86 and the chain 87 . The sprocket wheel 86 is attached to an input shaft 92 of a reduction gear 90 , which also has an output shaft 94 . The reduction gear can be, e.g., a 30-1 worm gear reducer with the gears operating in an oil bath, such as that made and sold by Hampton, Model No. M008. Attached to the output shaft 94 of the reduction gear 90 is the chain drive sprocket 40 and a smaller sprocket 96 , internally mounted on the output shaft 94 in relation to the chain drive sprocket 40 .
[0021] The inner sprocket 96 is connected by a drive chain 98 to a sprocket wheel 100 , which is attached to the end of a limit control spindle 102 , having threads 110 . Moveably mounted on the threads 110 of the motion limit controller spindle 102 is a pair of traveling nuts 112 and 114 . The limit controller spindle 102 is rotatably mounted in a motion limit controller housing 116 , which is in turn attached to the frame 72 . Slideably mounted on the spindle 102 are a pair of adjustably positionable stop members 118 and 120 , which are electrically connected to a controller on a circuit board 132 and can provide a signal indicating that the drive chain 30 has reached one end or the other of its extent of desired motion, as by contact of one or the other of the traveling nuts 112 or 114 with its respective stop member 118 or 120 .
[0022] Also shown in FIG. 6 is a controller circuit board housing 130 , which is attached to the frame 72 and in which is contained the controller circuit board 132 . A cover 134 is attached to the housing 130 and spacers 142 , seat the controller circuit board 132 against input/output electrical signal connections 146 by virtue of being screwed into mounting screws 144 , connected to the interior wall of the housing 130 .
[0023] Turning now to FIG. 7 (Prior Art), there is shown in more detail the connection of the drive chain to the sliding gate, such as in the embodiments of FIGS. 1 and 3. The chain attachment mechanism 32 has a threaded shaft portion 64 , which is threaded into nut 62 after passing through a hole in the attachment bar 34 . The chain attachment mechanism 32 has a flattened attachment extension 60 , to which the chain 30 is attached by passing the pin of the last link of the chain through an opening in the extension 60 .
[0024] It is also well known in the prior art that the motor 80 of a security gate operating system 10 can come with an internal fan and/or an external fan can in addition be supplied, each of which are in operation whenever the motor 80 is in operation.
[0025] Turning now to FIG. 8 and FIG. 9, there is shown perspective views of a security gate driving mechanism according to the present invention. Mounted on the frame 72 is a switched reluctance motor 200 , such as that made for use in industrial sized washing machines, e.g., Neptune washing machines, e.g., one made by Emerson Electric, Model No. M-10816. Such a motor 200 is a type of switched reluctance motor, with the stator and rotor of the motor 200 resembling that of a variable reluctance step motor. Both the stator and rotor (not shown) of the switched reluctance motor 200 have salient poles with phase coils mounted around diametrically opposite stator poles. Power delivered through cables 210 are switched by a controller, not shown, to provide energy to the stator coils of the motor 200 in a fashion that rotates the magnet field through the salient poles of the stator. The rotor will align
[0026] itself to the magnetic field when diametrically opposed stator pole windings are energized. Some of the rotor poles will be aligned and some will be out of alignment with the remaining unaligned stator poles. When the magnetic field in the stator is stepped/rotated to the next stator pole pair, these will attract the unaligned rotor poles and sequentially continuing to perform this stepping/rotating of the magnetic field will result in the rotor continually moving to try to align itself (“catch up”) to the appropriate minimum reluctance position of the energized stator pole windings, thus the term “switched reluctance.” When the rotor is out of alignment to the minimum reluctance position of the energized stator pole windings, the inductance of the windings is proportionally less than maximum inductance to the misalignment thus allowing more current to flow in the windings and creating higher torque. The attainable torque produced is theoretically limited only by the available energy supplied by the controller. Utilization of such a motor 200 provides for very high starting torque as opposed to AC or DC motors. In addition both speed and torque control are more readily managed through the controller supplying power to the stator windings in an appropriate sequence and with appropriate timing, which also makes for similar control properties in both the opening direction movement of the security gate 10 and the closing direction of the security gate 10 . As can be seen from FIG. 8, utilization of a switched reluctance motor 200 also eliminates the need for a reduction gear 90 necessary with AC or DC motors. The drive sprocket 40 can be directly mounted on the shaft 208 of the motor 200 , eliminating a number of pieces of machinery from the prior art security gate drive mechanism, in addition to the reduction gear, and making the space needed much smaller and maintenance more simple. The rotor of the motor can be provided with power in a sequence and timing to achieve the torque and speed relationships required to operate a security gate. This type of drive motor 200 can be utilized with other forms of security gate drive mechanism, e.g., rotary arm drive mechanism, with, e.g., the rotary arm or one of a plurality of pivotally attached rotary arms attached directly to the shaft 94 of the motor 200 , which, of course, can be mounted with the shaft 94 extending generally vertically. While the preferred embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various modifications, in addition to those mentioned above, may be made in these embodiments without departing from the spirit of the present invention. Such modifications, might include the operation of a gate that is hingedly attached for swinging motion between a closed position and an open position, or a gate that is chain driven, but, e.g., opens vertically, as, e.g., a roll-up door commonly used for garage openings and the like. For that reason, the scope of the invention is set forth in the following claims:
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A security gate operating system and method are disclosed, which may comprise a security gate capable of motion between a closed position and an open position; a drive mechanism attached to the security gate and adapted to provide a driving force to the security gate to move the security gate between the closed position and the open position; an electrical drive motor having a drive shaft connected directly to the drive mechanism without a reduction gear between the drive motor and the drive mechanism. The method and system may also comprise the drive motor being a reluctance motor including a switched reluctance motor, and including also a three phase switched reluctance motor. The method and system may also comprise a drive chain operatively connected to the security gate; and a drive sprocket attached directly to the shaft of the drive motor, with the drive sprocket in operative connection to the drive chain. The method and system may also comprise at least one drive arm directly connected to the drive motor shaft and operatively connected to the security gate.
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TECHNICAL FIELD
[0001] Embodiments of the present invention relate generally to the field of acoustic resonators, and more particularly, to temperature compensation of acoustic resonators in the electrical domain.
BACKGROUND
[0002] Acoustic resonators used in radio frequency (RF) filters, such as surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters, typically have a negative temperature coefficient of frequency (TCF) that is caused by a decrease of stiffness of materials when temperature increases. Acoustic velocity decreases with temperature and hence a filter's transfer function shifts toward lower frequencies. There are very few materials that show an irregular behavior in this regard. One example is amorphous silicon oxide. The introduction of amorphous silicon oxide to the propagation path of acoustic waves in a SAW or BAW filter may have a temperature-compensating effect and reduce the overall temperature drift of these devices. However, amorphous silicon oxide also introduces various challenges.
[0003] Amorphous silicon oxide introduces additional propagation loss, and may thwart the objective of achieving low insertion loss in filters. Furthermore, any additional material introduced into a propagation path of an acoustic wave will reduce a coupling coefficient of a resonator, which relates to the efficiency at which the resonator will convert energy between an acoustic wave form and an electrical form. As a consequence, a maximum relative filter bandwidth that a certain piezo-material can provide may decrease steeply.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
[0005] FIGS. 1( a )- 1 ( d ) illustrate temperature-compensated resonator circuits in accordance with some embodiments.
[0006] FIG. 2 illustrates a ladder filter in accordance with some embodiments.
[0007] FIG. 3 illustrates a ladder filter in accordance with some embodiments.
[0008] FIGS. 4( a ) and 4 ( b ) illustrate compensation capacitor pairs in accordance with some embodiments.
[0009] FIG. 5 illustrates a wireless communication device in accordance with some embodiments.
DETAILED DESCRIPTION
[0010] Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that alternate embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific devices and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that alternate embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.
[0011] Further, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present disclosure; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.
[0012] The phrase “in one embodiment” is used repeatedly. The phrase generally does not refer to the same embodiment; however, it may. The terms “comprising,” “having,” and “including” are synonymous, unless the context dictates otherwise.
[0013] In providing some clarifying context to language that may be used in connection with various embodiments, the phrases “A/B” and “A and/or B” mean (A), (B), or (A and B); and the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C) or (A, B and C).
[0014] The term “coupled with,” along with its derivatives, may be used herein. “Coupled” may mean one or more of the following. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements indirectly contact each other, but yet still cooperate or interact with each other, and may mean that one or more other elements are coupled or connected between the elements that are said to be coupled to each other.
[0015] Embodiments of the present invention provide resonator circuits that compensate for temperature drift characteristics of acoustic resonators that may otherwise compromise the effectiveness of the acoustic resonators. In particular, the temperature compensated resonator circuits may be incorporated into filters to prevent filter performance from being adversely affected by temperature drift.
[0016] In many wireless applications there is a critical filter skirt on either the lower or upper side of a filter's transfer function. However, there is rarely a critical filter skirt on both sides of the transfer function. A critical filter skirt, as used herein, may be an operational specification most likely to be violated in the presence of temperature drift.
[0017] Some of the embodiments described herein provide targeted temperature compensation for the elements that have an impact on the portion of the filter's transfer function that is adjacent to the critical filter skirt. By limiting temperature compensation to only a subset of elements in a filter, any negative impact of temperature compensation may have less impact on overall filter performance.
[0018] FIG. 1( a ) illustrates a temperature-compensated resonator circuit 100 in accordance with various embodiments. The resonator circuit 100 may include an acoustic resonator 104 coupled in parallel with a compensating capacitor 108 . The resonator circuit 100 may be incorporated into a radio frequency (RF) filter that is configured to provide a transfer function that exhibits a low in-band insertion loss and a high out-of-band insertion loss.
[0019] The acoustic resonator 104 may be an electromechanical transducer configured to convert energy between an acoustic wave form and an electrical form. The resonator 104 may oscillate at certain frequencies, called resonance frequencies, with a greater amplitude than at other frequencies. The resonator 104 may generate an electrical signal that corresponds to the oscillations, or, conversely, generate oscillations that correspond to an electrical signal.
[0020] The resonator 104 may be associated with a negative temperature coefficient of frequency (TCF) that changes resonance properties associated with the resonator 104 with temperature. In particular, a negative TCF may mean that velocity of acoustic waves will decrease with temperature and, when the resonator 104 is incorporated into an RF filter, this may result in a transfer function shifting toward a lower frequency.
[0021] The compensating capacitor 108 , C_c, may at least partially compensate for temperature drift of the resonance of the resonator 104 . Hereinafter, “C_c” may refer to the capacitor 108 itself, or the capacitance associated with capacitor 108 , depending on the context in which it is used. Temperature compensation will be performed in the electrical domain, without modifying acoustic wave propagation on the resonator 104 .
[0022] The capacitor 108 may be configured to exhibit a negative temperature coefficient of capacitance (TCC), e.g., a capacitance of the capacitor may decrease in response to corresponding increase in temperature. In some embodiments, a negative TCC may be accomplished by using a capacitor having a dielectric material with a high negative temperature coefficient of the dielectric constant (TCK). As used herein, a high negative TCK may refer to a TCK that is more negative than approximately −1,000 ppm/C. In some embodiments, the capacitor 108 may include a dielectric composed of a ceramic formulation that includes calcium titanate (CaTiO3), which may have a TCK of −4,000 ppm/C. The dielectric constant of calcium titanate may be around 160 and the tan-delta may be 0.003.
[0023] An acoustic resonator may be modeled using a Butterworth-van-Dyke (BVD) equivalent circuit in which the resonator is represented by a capacitor, C — 0, coupled in parallel with a series segment that includes a resistor, R_a, a capacitor, C_a, and an inductor, L_a, coupled in series with one another. In the BVD equivalent circuit, temperature drift of a series resonance, which may also be referred to as resonance frequency, f_s, is dominated by C_a and L_a, while temperature drift of parallel resonance, which may also be referred to as anti-resonance frequency, f_p, is dominated by C_a, C — 0, and L_a. R_a models losses of a resonator.
[0024] The addition of C_c may not change the resonance frequency of the resonator circuit 100 , but it may lower the anti-resonance frequency of the resonator circuit 100 . The anti-resonance frequency may be the frequency at which a local maximum of impedance occurs and the resonance frequency may be the frequency at which a local minimum of impedance occurs. The anti-resonance frequency may be given by:
[0000]
f
p
=
1
2
π
1
L
a
(
C
0
+
C
C
)
×
C
a
C
0
+
C
C
+
C
a
.
Equation
1
[0025] The derivative of f_p over C_c may be expressed as:
[0000]
∂
f
p
∂
C
C
=
-
f
p
2
×
C
a
(
C
0
+
C
C
+
C
a
)
(
C
0
+
C
C
)
.
Equation
2
[0026] Equation 2 may be further expressed in relative changes in the approximated by:
[0000]
∂
f
p
∂
f
p
∂
C
C
∂
(
C
0
+
C
C
)
=
1
2
-
C
a
(
C
0
+
C
C
+
C
a
)
≅
1
2
[
(
f
s
f
p
)
2
-
1
]
.
Equation
3
[0027] For an acoustic resonator with an effective coupling coefficient of k 2 _eff, the frequency ratio equals:
[0000]
f
s
f
p
≅
1
-
4
π
2
×
k
eff
2
.
Equation
4
[0028] A temperature dependence of the compensation capacitance itself may be:
[0000] C c (Δ T )= C C0 (1+ TCK×ΔT ), Equation 5
[0029] where C_C0 is an initial, room-temperature capacitance of the capacitor 104 .
[0030] To illustrate the effects of the temperature compensation, consider an example in which the resonator 104 is a BAW resonator with an initial effective coupling coefficient of 6.5%. Initially, it may be assumed that the resonator 104 has no temperature drift at all. For this example, C_c may be ¼ of C — 0. The shift in f_p may then be calculated as follows.
[0000]
∂
f
p
∂
f
p
∂
C
C
∂
(
C
0
+
C
C
)
≅
-
0.02
,
Equation
6
∂
C
C
∂
T
C
C
(
C
0
+
C
C
)
=
TCKC
C
C
0
+
C
C
=
-
4000
ppm
/
C
×
1
5
4
5
+
1
5
=
-
800
ppm
/
C
,
Equation
7
∂
f
p
∂
T
1
f
p
=
(
-
0.02
)
×
(
-
800
ppm
/
C
)
=
+
16
ppm
/
C
.
Equation
8
[0031] Equation 8 shows that f p may shift approximately +16 ppm/C in this scenario. A typical BAW filter may exhibit approximately −15 to −17 ppm/C of TCF. Thus, the anti-resonance frequency of the resonator circuit 100 may become temperature stable in this embodiment.
[0032] The insertion of the capacitor 108 in this embodiment may reduce the effective coupling coefficient to approximately 5.3%, down from the initial effective coupling coefficient of 6.5%. Such a coupling coefficient loss is less than other methods of attempting temperature compensation and is within an acceptable range of loss.
[0033] It may be noted that the temperature drift of the series resonance of the resonator 104 is dominated by C_a and L_a, hence the temperature dependency of C — 0 can be ignored in the above calculations.
[0034] FIG. 1( b ) illustrates a temperature-compensated resonator circuit 112 in accordance with various embodiments. The resonator circuit 112 may include an acoustic resonator 116 coupled in series with a compensating capacitor 120 .
[0035] The temperature compensation of the resonator circuit 112 may be similar to that of resonator circuit 100 except that resonator circuit 112 acts to compensate the temperature drift of the resonance frequency, rather than the temperature drift of the anti-resonance frequency.
[0036] Assuming the resonator 116 is a BAW resonator with characteristics similar to those described above, the compensation capacitance for this embodiment may have a value approximately 4 times the static capacitance, C — 0, of the resonator 116 . In this embodiment, the resonance frequency of the resonator circuit 112 may become temperature stable by placing this compensation capacitance in series with the resonator 116 . Degradation of the coupling coefficient may be similar to that described above.
[0037] FIG. 1( c ) illustrates a temperature-compensated resonator circuit 124 in accordance with various embodiments. The resonator circuit 124 may include an acoustic resonator 128 coupled in series with compensating capacitor 132 and further coupled in parallel with compensating capacitor 136 .
[0038] The temperature compensation of the resonator circuit 124 may compensate for temperature drift of both the resonance frequency and the anti-resonance frequency. However, resonator circuit 124 may be associated with more degradation of the coupling coefficient than resonator circuits 100 and/or 112 .
[0039] FIG. 1( d ) illustrates a temperature-compensated resonator circuit 138 in accordance with various embodiments. The resonator circuit 138 may include an acoustic resonator 140 coupled in series with a variable capacitor 142 and/or coupled in parallel with a variable capacitor 144 . The variable capacitors 142 and/or 144 may be coupled with an active control circuit 146 that controls one or both of the variable capacitors 142 and/or 144 such that they exhibit a TCC similar to that described above. The active control provided by the active control circuit 146 may emulate a similar temperature compensation as that described above with respect to capacitors having high TCK dielectric materials. The active control circuit 146 may include control logic 148 and a sensing device 150 . The sensing device 150 may sense temperature associated with the acoustic resonator 140 , and the control logic 148 may use the sensed temperature to serve as a basis for control of the variable capacitors 142 and/or 144 such that they exhibit desired negative TCC. The variable capacitors 142 and/or 144 may be varactors, tunable capacitors, switched capacitors, etc.
[0040] Each of the resonator circuits 100 , 112 , 124 , and 138 may be specifically suited for particular applications. FIGS. 2 and 3 show examples of some of these particular applications.
[0041] FIG. 2 illustrates a ladder filter 200 in accordance with some embodiments. The ladder filter 200 may be used in an embodiment in which a lower filter skirt is the critical filter skirt. This may be, e.g., when the ladder filter 200 is used as a receive filter for a wireless code division multiple access (WCDMA) band 2 or 25 application. As will be described below, ladder filter 200 may be designed with temperature compensation for elements associated with a lower portion of a transfer function.
[0042] The ladder filter 200 may include a number of series segments, e.g., series segments 204 _ 1 - 5 , with series segments 204 _ 2 - 5 each having at least one of five series resonators 208 _ 1 - 5 of the ladder filter 200 . The series resonators 208 _ 1 and 208 _ 2 may be coupled with one another to form a cascaded pair. The series resonators 208 may each have a common resonance frequency.
[0043] The ladder filter 200 may also include four shunt segments 212 _ 1 - 4 , with each including at least one of four shunt resonators 216 _ 1 - 4 of the ladder filter 200 . Shunt resonators 216 _ 1 and 216 _ 4 may include a common resonance frequency f_s1, while shunt resonators 216 _ 2 and 216 _ 3 include a common resonance frequency f_s2, where f_s2−f_s1=14 megahertz in accordance with some embodiments.
[0044] The ladder filter 200 may also include a number of inductors 218 . These inductors 218 may have small values and may be bond wires or small printed traces on the laminate module.
[0045] The ladder filter 200 may include two compensation capacitors, C_c1 220 _ 1 and C_c2 220 - 2 , each having a negative TCC. The compensation capacitors 220 may include calcium titanate, for example, to provide a strong negative TCK. The values of the compensation capacitors 220 may be set to a fixed factor relative to the static capacitance of the resonator in the corresponding shunt segment. For example, C_c1 may be 4 times the capacitance associated with resonator 216 _ 2 and C_c2 may be 4 times the capacitance associated with resonator 216 _ 3 .
[0046] With application of the ladder filter 200 being only (or at least primarily) concerned with temperature drift in a lower portion of the transfer function, it may be unnecessary to provide temperature compensation for any of the series resonators 208 . Further, it may be that temperature compensation is only desirable on a subset of the shunt segments that provide the largest influence on the portion of the transfer function adjacent the lower, critical skirt. In this embodiment, it may be that shunt segments 212 _ 2 - 3 have the largest impact on the portion of the transfer function of interest. Therefore, only the shunt segments 212 _ 2 - 3 may have temperature-compensated resonator circuits. This may further reduce any coupling coefficient losses that may be associated with temperature compensation.
[0047] FIG. 3 illustrates a ladder filter 300 in accordance with some embodiments. The ladder filter 300 may be used in an embodiment in which an upper filter skirt is the critical filter skirt. This may be, e.g., when the ladder filter 300 is used as a transmit filter for a WCDMA band 2 or 25 application. Therefore, the ladder filter 300 may be designed with temperature compensation for elements associated with an upper portion of the transfer function.
[0048] The ladder filter 300 may include a number of series segments, e.g., series segments 304 _ 1 - 5 , with series segments 304 _ 2 - 5 each having at least one of four series resonators 308 _ 1 - 4 of the ladder filter 300 .
[0049] The ladder filter 300 may also include four shunt segments 312 _ 1 - 4 , with each including at least one of four shunt resonators 316 _ 1 - 4 of the ladder filter 300 .
[0050] The ladder filter 300 may also include a number of inductors 318 . These inductors 318 may have small values and may be bond wires or small printed traces on the laminate module.
[0051] The ladder filter 300 may include two compensation capacitors, C_c1 320 _ 1 and C_c2 320 _ 2 , that have a strong negative TCK. The compensation capacitors 320 may include calcium titanate, for example, to provide the strong negative TCK. The values of the compensation capacitors 320 may be set to a fixed factor relative to the compensation capacitance of the resonator in the corresponding series segment. For example, C_c1 may be ¼ the capacitance associated with resonator 308 _ 3 and C_c2 may be ¼ the capacitance associated with resonator 308 _ 4 .
[0052] With application of the ladder filter 300 being only (or at least primarily) concerned with temperature drift in an upper portion of the transfer function, it may be unnecessary to provide temperature compensation for any of the shunt resonators 316 . Further, it may be that temperature compensation is only desirable on a subset of the series segments that provide the largest influence on the portion of the transfer function adjacent the upper, critical filter skirt. In this embodiment, it may be that series segments 304 _ 3 - 4 have the largest impact on the portion of the transfer function of interest. Therefore, only the series segments 304 _ 3 - 4 may have temperature-compensated resonator circuits. This may further reduce any coupling coefficient losses that may be associated with temperature compensation.
[0053] The compensating capacitors used in the embodiments described herein may be thin-film capacitors integrated onto a filtered chip, thick-film capacitors embedded into a substrate or package, or discrete components. As there may be only two interconnections needed to connect a compensation capacitance to a filter, there may be a wide variety of implementation variations. Furthermore, due to the high relative dielectric constant of calcium titanate, at approximately 160 as mentioned above, the compensation capacitors may be relatively small. This may further facilitate their incorporation into various filter designs without difficulty.
[0054] Materials with strongly negative TCK are usually ferroelectric in nature and tend to exhibit a small electrical field dependency of the dielectric constant, which may result in changes in capacitances occurring as a result of changes in voltage. In order to avoid nonlinear distortion that could result from such a behavior, the compensation capacitors may be used in pairs so that the electrical fields of the two capacitances are inverse. For example, FIG. 4( a ) illustrates a pair of compensating capacitors 404 _ 1 - 2 arranged in a cascade configuration in accordance with an embodiment. The two capacitors 404 are coupled in series with one another with their polarities inversed. In particular, a bottom terminal 408 _ 1 of the capacitor 404 _ 1 is coupled with a bottom terminal 408 _ 2 of the capacitor 404 _ 2 .
[0055] For another example, FIG. 4( b ) illustrates a pair of capacitors 412 _ 1 - 2 arranged in an anti-parallel configuration in accordance with some embodiments. In particular, a top terminal 416 _ 1 of capacitor 412 _ 1 and a bottom terminal 420 _ 2 of capacitor 412 _ 2 are coupled to the same node 424 .
[0056] Filters having temperature-compensated resonator may be used in a number of embodiments including, for example, a wireless communication device 500 as shown in FIG. 5 in accordance with some embodiments. In various embodiments, the wireless communication device 500 may be, but is not limited to, a mobile telephone, a paging device, a personal digital assistant, a text-messaging device, a portable computer, a base station, a radar, a satellite communication device, or any other device capable of wirelessly transmitting and/or receiving RF signals.
[0057] The wireless communication device 500 may have an antenna structure 504 , a duplexer 508 , a transceiver 512 , a main processor 516 , and a memory 520 coupled with each other at least as shown.
[0058] The main processor 516 may execute a basic operating system program, stored in the memory 520 , in order to control the overall operation of the wireless communication device 500 . For example, the main processor 516 may control the reception of signals and the transmission of signals by the transceiver 512 . The main processor 516 may be capable of executing other processes and programs resident in the memory 520 and may move data into or out of memory 520 , as desired by an executing process.
[0059] The transceiver 512 may include a transmitter 524 for transmitting RF signals, communicating outgoing data, through the duplexer 508 and antenna structure 504 . The transceiver 512 may additionally/alternatively include a receiver 528 for receiving RF signals, communicating incoming data, from the duplexer 508 and antenna structure 504 . The transmitter 524 and receiver 528 may include respective filters 532 and 536 . The filters 532 and 536 may have selected temperature-compensated resonator circuits to benefit the functions to which the respective filter is employed. For example, in some embodiments, the filter 532 may be similar to ladder filter 200 , while filter 536 may be similar to ladder filter 300 .
[0060] In various embodiments, the antenna 504 may include one or more directional and/or omnidirectional antennas, including, e.g., a dipole antenna, a monopole antenna, a patch antenna, a loop antenna, a microstrip antenna or any other type of antenna suitable for OTA transmission/reception of RF signals.
[0061] Although the present disclosure has been described in terms of the above-illustrated embodiments, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. Those with skill in the art will readily appreciate that the teachings of the present disclosure may be implemented in a wide variety of embodiments. This description is intended to be regarded as illustrative instead of restrictive.
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Embodiments of apparatuses, systems and methods relating to temperature compensation of acoustic resonators in the electrical domain are disclosed. Other embodiments may be described and claimed.
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BACKGROUND OF THE INVENTION
The present invention relates to a mini-roller cleaning tool and, in particular, to an adapter for enabling a mini-roller to be attached to traditional cleaning devices so as to facilitate cleaning of the mini-roller.
The use of mini-rollers has become common place in painting and other related industries. These rolling paint brushes, often referred to as Seven Inch Rollers and Weenie Rollers, are different from conventional paint rollers in that they have an overall diameter of approximately 1 inch, and a hollow center with a diameter of approximately one-quarter of an inch. The mini-rollers were originally developed for painting in hard to reach areas, such as behind toilets. However, the use of mini-rollers for other painting applications has spread because of their convenient size, and the ease with which they may be used in tight corners, etc.
One major problem with the mini-rollers is that, until the present invention, there has been no practical way to clean the rollers once they are used. Conventional brushes and rollers are usually cleaned by using a paint brush/roller cover spinner. A paint brush/roller cover spinner is typically a hand held device which has a pair of arms which hold a standard sized paint brush handle, or fit within the hollow center of a traditional roller. Once the roller or handle is secured by the arms, a force is applied to the handle causing the paint brush or roller to spin, thereby using centrifugal force to expel left over paint from the brush. The force is usually applied by holding a body of the paint brush spinner and pushing a handle towards the body. A shaft connecting the handle and the body translates axial movement of the handle into radial movement by the arms, and causes the arms to rotate at a high rate of speed.
Another common version of the paint brush spinner utilizes a water pressure from a hose to rotate the arms. By utilizing water pressure, higher rotational velocities can be achieved.
Because of the design of most paint brush/roller cover spinners, it has been impractical before the present invention to use a paint brush spinner to clean mini-rollers. Instead, the mini-roller is usually thrown away, no matter how short the use, because paint cannot be removed from the roller. As the paint dries, the mini-roller becomes unusable. Because mini-rollers tend to be rather expensive, their routine disposal creates both environmental and economic waste.
Thus, there is a need for an device which will enable painters to use a mini-roller with a paint brush spinner to clean the rollers so that they may be reused.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an adapter/tool to enable mini-rollers to be cleaned with conventional paint brush spinners.
It is another object of the present invention to provide an adapter/tool which is inexpensive.
It is yet another object of the present invention to provide an adapter/tool which requires minimal effort to adapt a conventional paint brush spinner for use with mini-rollers.
The above and other objects of the invention are realized in specific illustrated embodiments of a mini-roller cleaning tool including an elongate adapter for disposition adjacent the arms of the paint brush spinner and an elongate shaft for holding a mini-roller coaxially with the elongate shaft such that rotation of the arms of the paint brush spinner causes a corresponding rotation of the mini-roller to thereby use centrifugal force to remove paint from the mini-roller.
In accordance with one aspect of the invention, the elongate adapter has a pair of projections for enabling a user to insert the handle into the arms of the paint brush spinner without damaging his or her hands.
In accordance with another aspect of the invention, the shaft has a retention mechanism for maintaining the mini-roller on the shaft when the paint brush spinner is in use.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of conventional paint brush spinner, such as those used to clean paint brushes and traditional paint rollers, with a paint brush mounted therein.
FIG. 2 is a side cross-sectional view of a mini-roller cleaning tool with a mini-roller attached as would occur in use so to enable a mini-roller to be used with a paint brush spinner.
FIG. 3 is a perspective view of a handle portion of the mini-roller cleaning tool taken along the line A--A shown in FIG. 2.
FIG. 4 is a perspective view of an alternate embodiment of the invention.
DETAILED DESCRIPTION
Reference will now be made to the drawings in which the various elements of the present invention will be given numeral designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. Referring to FIG. 1, there is shown a conventional paint brush spinner, generally indicated at 4. The paint brush spinner 4 has a generally cylindrical body 10. A handle 14 is connected to the body 10 by a grooved shaft 18. On an opposite side of the body 10, a pair of arms 22 extend away from the body in a generally parallel orientation. The arms 22 are maintained in this position by a resilient force, such as a spring, so that when they are rotated, they will not extend radially outward. Between the arms 22 is a base 26. The base 26 has a impression formed therein for receiving a pointed end 30 of a paint brush handle 32. When the paint brush handle 32 is so disposed, the arms 22 hold the handle 32 securely, so that when the paint brush handle will not escape when it is rotated.
In use, the paint brush handle 32 is placed between the arms 22 by sliding the point end 30 through the ends 22a of the arms 22 until it rests in the base 26. As was mentioned previously, the resilient force connected to the arms 22 will hold the handle 32 of the paint brush 34 in place. The paint brush spinner 4 is gripped about the body 10 by one hand and on the handle 14 by the other. As the handle 14 is pushed into and pulled out of the body 10, as indicated by arrow 40, the arms 22 (and the paint brush 34) will rotate at a high rate of speed in the direction indicated by arrows 44. As the paint brush 34 spins, centrifugal force expels most of the paint in the bristles 50 of the paint brush. Once most of the paint has been removed, paint thinner or other cleaner can be used to remove any residual paint. Those skilled in the art will appreciate that the spinning portion of this procedure is usually done while the brush is positioned in a five gallon bucket or some other container so that the paint will not spray onto surrounding persons or structures.
When used with a conventional roller, the spinner 4 is used somewhat differently. Instead of placing a handle between the arms 22, the arms are slid into the hollow cavity inside the roller. As can be seen from FIG. 1, the arms 22 are slightly tapered, so that the roller may slide onto the arms to a point at which the roller is held about the arms. Pumping the handle 14 causes the arms 22, and thus the roller, to rotate, thereby removing excess paint. As will be appreciated, however, such a method would not work with mini-rollers as they have a hollow with a diameter of less than one-quarter of an inch, much smaller than that of a conventional roller.
Referring now to FIG. 2, there is shown a side cross-sectional view of a mini-roller cleaning tool, generally indicated at 60, and a mini-roller 64. The mini-roller cleaning tool 60 includes an adaptation means in the form of an elongate handle portion 70 which will typically be made of a durable plastic, such as PVC, or some other thermosetting material. While such materials will lower cost, those skilled in the art will recognize that the handle portion 70 could be made of numerous durable materials, such as metal, wood, or other composites. As will be discussed in more detail regarding FIG. 3, the handle can have any cross-sectional shape. However, in a preferred embodiment, the handle portion 70 will have a similar shape and cross-section to that of a conventional paint brush. Such a shape guarantees that the handle portion 70 will fit properly within the arms 22 (FIG. 1) of the paint brush spinner 4 (FIG. 1).
One end 74 of the handle portion 70 has a hole 78 formed therein so that the cleaning tool 60 can be hung from a hook, etc., when not in use. At an opposing end 82, a pair of gripping means 84 extend from the handle portion 70. In a preferred embodiment, the gripping means is formed by a generally circular ring providing a finger hold 86 which extends transversely from the handle portion 70. Alternatively, the gripping means may be formed by a semicircular finger hold 88, or even by the base of the handle portion. Typically both gripping means will be the same. The circular finger hold 86 will typically have a diameter of about two-thirds of an inch to accommodate most human fingers. The semicircular finger hold 88 would have a similar curvature. By using the finger holds, the user can insert the handle portion 70 between the arms 22 (FIG. 1) without his or her hand contacting the arms. Because most paint brush spinners 4 (FIG. 1) require significant force to position the handle portion 70 between the arms 22 (FIG. 1), the user's hands could be bruised if handle portion 70 is positioned between the arms too quickly. Those skilled in the art will recognize and appreciate that numerous other gripping means could be used to avoid forceful contact between the user's hand and the arms 22 (FIG. 1).
Partially disposed within the handle portion 70 of the cleaning tool 60 is a retention means in the form of an elongate shaft 90 extending coaxially from the handle portion 70 and holding the mini-roller 64 to the handle portion 70. As with the handle portion 70, the shaft 90 can be made of virtually any rigid material. It is anticipated, however, that the shaft will use a nickel plated steel rod. While the shaft 90 may be solid, as is shown in FIG. 2, the use of nickel and other durable materials will enable the shaft to be hollow, thereby decreasing weight and shipping costs. While discussed as being generally cylindrical, the shaft 90 could have almost any cross-sectional shape.
Near a first end 94 which is disposed within the handle portion 70, a pair of "dog ears" 98 extend from the shaft 90. The dog ears 98 enable the shaft 90 to remain securely held by the handle portion 70 when the handle portion is formed by an injection molding process. Dog ears 98 would also likely be used if the handle portion 70 was formed in two pieces and then attached about the shaft 90.
As is shown in FIG. 2, the shaft 90 is of a generally constant diameter until a short distance from the handle portion 70. The shaft 90 then beings to taper, as shown in FIG. 2 at 102. This tapering of the shaft 90 allows the shaft to fit within the hollow 106 of the mini-roller 64. Ideally, the shaft 90 will taper from a diameter of about 0.37 inches to a diameter of about 0.24 inches over a one to two inch section, after which the final section of the shaft remains of a constant diameter so as to fit securely within the mini-roller 64. The opening 110 of the hollow 106 is usually bevelled on a mini-roller 64. As the tapered section 102 of the shaft 90 slides into the hollow 106 of the mini-roller 64, the opening of the hollow 110 will come to a point at which the frictional force between the tapered section 102 and the opening 110 is sufficient to hold the mini-roller 64 about the shaft 90. To further assist this arrangement, a preferred embodiment has a medium diamond knurl 114 along the tapered section 102 to increase the frictional attachment with the mini-roller 64. This arrangement ensures that the mini-roller 64 will not accidently come off of the shaft 90 while it is being spun clean.
Those skilled in the art will appreciate that the mini-roller 64 can the attached to the shaft 90 before the handle portion 70 is placed between the arms 22 (FIG. 1), or that the handle portion can be placed within the arms 22 prior to attaching the mini-roller. Once the handle portion 70 is between the arms 22 (FIG. 1) so that the end 74 is adjacent the base 26 (FIG. 1) and the mini-roller 64 is attached to the shaft 90, the paint brush spinner 4 (FIG. 1) can be used as described above to remove excess paint from the mini-roller 64. Thus, the cleaning tool 60 quickly and efficiently recycles a mini-roller which otherwise would be thrown away regardless of the length of use.
Referring now to FIG. 3, there is shown a perspective view of the handle portion 70 taken along the line A--A in FIG. 2. As was shown in FIG. 2, the handle portion 70 has a generally rectangular shape. Those skilled in the art, however, will recognize that virtually any shape may be used which will enable the handle portion 70 to be held between the arms 22 of the paint brush spinner 4 (FIG. 1). Preferentially, the end 74 of the handle portion 70 tapers inwardly so as to rest in the base 26 (FIG. 1) of the paint brush spinner 4 (FIG. 1). As shown in FIG. 3, the gripping means 84 are formed by a pair of straight projections 120, instead of the circular finger hold 86 or semicircular finger hold 88 shown in FIG. 2. While straight projections 120 are less desirable than the circular and semicircular holds of FIG. 2, they still enable a user to properly position the handle portion 70 between the arms 22 (FIG. 1) without contacting the arms with his or her hand. Thus, regardless of which gripping means is used, the user's hands are protected against damage by the arms 22 (FIG. 1).
In FIG. 4, there is shown another embodiment of the present invention. Instead of a handle portion as shown at 70 in FIG. 2, the adaptation means includes a generally hollow cylinder 120 having a diameter similar to that of a conventional roller. An opening 124 at one end of the cylinder 120 allows the cylinder to be slid onto the arms 22 (FIG. 1) of the paint brush spinner 4 (FIG. 1) in the manner described regarding FIG. 1. Typically, the cylinder 120 will be made of metal or a durable composite, such as PVC. As with the embodiment discussed regarding FIGS. 2 and 3, an elongate shaft 128 extends coaxially from the cylinder 120. Those skilled in the art will recognize numerous methods for attaching the shaft 128 to the cylinder 120, such as adhesives, welding, or a nut/bolt combination. The shaft 128 has a tapered section 130 which contains diamond knurl 132 to provide adequate friction between the shaft and a mini-roller 138.
As will be appreciated by those skilled in the art, because the cylinder 120 mounts about the outsides of the arms 22 (FIG. 1) of the paint brush spinner 4 (FIG. 1), the need for gripping means, such as those at 84 in FIGS. 2 and 3, is reduced. However, gripping means could easily be added if desired.
When the cylinder 120 is mounted on the paint brush spinner 4 (FIG. 1), the cylinder, the shaft 128 and the mini-roller 138 will rotate about the axis 142, when the handle 14 (FIG. 1) is pushed into or pulled out of the body 10 (FIG. 1). The centrifugal force developed will rid the mini-roller 138 of paint so that the mini-roller may be used repeatedly.
In the manner described, a mini-roller cleaning tool is provided. By using the above described tool, substantial economic and environmental waste can be avoided, as mini-rollers may be used repeatedly, rather than being discarded after any use. It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements.
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A mini-roller cleaning tool is disclosed including an adaptor for positioning adjacent the arms of a paint brush spinner, and a shaft for securing a mini-roller to the adaptor such that when the adaptor handle is rotated, the mini-roller is spun to remove paint from the mini-roller by centrifugal force. In accordance with one aspect of the invention, grips are provided to facilitate positioning the adaptor between the arms of the paint brush spinner without injuring the user's hands.
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This is a division of application Ser. No. 012,151, filed Feb. 14, 1979, now U.S. Pat. No. 4,271,084.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to germanium-containing organic polymers which possess important therapeutic effects as medicine.
2. Description of the Prior Art
In recent years, attention has been drawn to germanium-containing organic compounds in view of their pharmacological activities, which have been disclosed in Japanese Patent Publication No. 2964/71, Japanese Patent Application Laid Open No. 61431/73, Japanese Patent Publication Nos. 21855/71 and 2498/71, etc. The germanium-containing organic compound disclosed in these publications is a low molecular weight compound represented by the formula: (GeCH 2 CH 2 COOH) 2 O 3 .
SUMMARY OF THE INVENTION
As a result of extensive investigations on the synthesis of germanium-containing organic compounds other than the low molecular weight compound represented by the formula:
(GeCH.sub.2 CH.sub.2 COOH).sub.2 O.sub.3
drawing their attention to the pharmacological activities of the germanium-containing organic compound, the present inventors have found novel germanium-containing organic polymers and the process for the production thereof as well as their use as medicine.
The present invention is directed to a germanium-containing organic polymer represented by the formula: ##STR1## wherein A is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, --COOH, --COOR (wherein R is an alkyl group having 1 to 3 carbon atoms), B is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; Z is a hydroxy group, an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms; n is an integer greater than 3, inclusive.
Of the germanium-containing organic polymers represented by the formulae (III) and (IV), particularly preferred are those wherein A is a hydrogen atom, a methyl group, --COOH, B is a hydrogen atom or a methyl group; and Z is a hydroxy group, a methoxy group, an ethoxy group or a methyl group.
Further the present invention is directed to a process for producing the germanium-containing organic polymer represented by the formula (III) or (IV) which comprises reacting halogermanium-phosphoric acid complexes obtained by treating germanium dioxide with hypophosphorous acid or salts thereof in hydrohalogenic acid, with a compound (I) of the formula: ##STR2## wherein A is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, --COOH, --COOR (wherein R is an alkyl group having 1 to 3 carbon atoms), B is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and Z is a hydroxy group, an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms; particularly preferred are in the case where A is a hydrogen atom, a methyl group, --COOH, B is a hydrogen atom or a methyl group; and Z is a hydroxy group, a methoxy group, an ethoxy group or a methyl group, and then polymerizing the resulting compound (II) represented by the formula: ##STR3## wherein A, B and Z have the same meanings as defined above, and X is a halogen atom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Representative examples for preparing the compounds of the present invention are illustratively shown below. ##STR4##
In the reaction schemes (1), (2) and (3), A, B, X and Z have the same meanings as defined above, and the low molecular weight polymer and the high molecular weight polymer shown in the reaction schemes (3) and (4) are germanium-containing organic polymers represented by the formulae (III) and (IV) which are objective compounds of the present invention. Whether the objective compound is of high molecular weight polymer or of low molecular weight polymer is determined by the number of n, more simply, depending upon the solubility of the compound in water.
Based upon the reaction schemes (1), (2), (3) and (4) described above, the process for producing the compounds of the present invention is described below in detail.
Germanium dioxide is reduced with hypophosphorous acid or salts thereof (metal salts or ammonium salts are preferred), whereby the germanium atom becomes di-valent and germanium dihalide is formed. The germanium dihalide is in equilibrium with germanium hydrogen trihalide wherein the germanium atom takes tetra-valence, in hydrohalogenic acid. It is believed that this germanium hydrogen trihalide would be in equilibrium with the dissociation form shown at the right end of the reaction scheme (1), in an aqueous solution (see reaction scheme (1) ). It is likely that phosphoric acid would contribute to this equilibrium system, since this reaction solution is diluted with water to thereby isolate a halogermanium-phosphoric acid complex.
To the thus formed germanium reagent, a polarized unsaturated compound, i.e., a compound represented by the formula: ##STR5## wherein A, B and Z have the same meanings as defined above, is added, then a white crystalline compound represented by the formula: ##STR6## wherein A, B, X and Z have the same meanings as defined above, is formed in high yield (see the reaction scheme (2) ). As described above, the halogermanium-phosphoric acid complex obtained in accordance with the reaction scheme (1) can be stably isolated and, accordingly, this complex can previously be prepared according to the reaction scheme (1), followed by isolation. When it is desired to proceed with the reaction of the reaction scheme (2), this complex is added to an organic solvent or water and the resulting mixture is treated with hydrogen halide. The resulting solution is reacted with the compound of the formula (I) to obtain the compound of the formula (II), alternatively.
The compound represented by the formula (II) is dissolved in acetone or other organic solvents miscible with water (e.g. ethanol, methanol, cellosolve, acetonitrile, tetrahydrofuran, dioxane, dimethoxyethane, digline, dimethylsulfoxide, dimethylformamide) and then water is added to the resulting solution to obtain a low molecular weight polymer which is one of the compounds of the present invention (see the reaction scheme (3) ). In the reaction of the reaction scheme (3), in the case where organic solvents immiscible with water are employed in place of solvents miscible with water, the low molecular weight polymer is obtained by mixing and agitating with water. This low molecular weight polymer is relatively easily soluble in water.
When the water soluble low molecular weight polymer is suspended in a small amount of water and the suspension is allowed to settle, the high molecular weight polymer which is another objective compound of the present invention is obtained (see the reaction scheme (4) ). This high molecular weight polymer is sparingly soluble in water and differs from the low molecular weight polymer in its crystalline form.
Both the low molecular weight polymer and the high molecular weight polymer are compounds of the present invention, and are represented by the formula: ##STR7## wherein A, B, Z and n are the same as defined above. Determination of either the low molecular weight polymer or the high molecular weight polymer can be made by the number of n in the formulae above, more simply, depending upon the solubility in water.
It has been made apparent from the infrared absorption spectrum, x-ray diffraction spectrum of powders, and the like that the compounds in accordance with the present invention are novel compounds different from heretofore known compound:
(GeCH.sub.2 CH.sub.2 CO.sub.2 H).sub.2 O.sub.3
The compounds of the present invention possess important therapeutic effects and exhibit marked effects in use for treating a variety of abnormal physiological symptoms as shown below.
The compounds of the present invention are administered through administration routes such as oral administration, intraveneous administration, subcutaneous administration, intramuscular administration, intrarectal administration, and the like.
These compounds are also used on the skin in a direct form such as ointment.
In the case of oral administration, a sufficient effect is achieved in the daily dose of 0.1 mg/kg/day to 150 mg/kg/day. A sufficient effect is also achieved in the daily dose of 0.02 mg/kg/day to 20 mg/kg/day in intravenous injection, and in the daily dose of 0.04 mg/kg/day to 30 mg/kg/day in subcutaneous as well as intramuscular injections. For rectal use and as ointment, a pharmaceutical preparation which comprises mixing the active ingredient with a variety of bases in a ratio of 0.1 to 5% is obtained.
EXAMPLES OF THE TREATMENT OF ALLERGIC DISEASE
Bronchial Asthma
Side effect or danger due to administration of adrenal corcical hormone in a large dosage can be prevented. If the compounds of the invention are given before onset of asthmatic attack, it is unnecessary to use adrenal cortical hormone. Alternatively, if, after filling the immediate needs with adrenal cortical hormone, the hormone is replaced by the compounds of the present invention, progression could take a sufficiently favorable turn. It is interesting that no side effects are seen.
Toxic Eruption, Urticaria and Collagenic Disease
The low molecular weight polymer (A) was effective in 8 out of 12 cases. The polymer is a very valuable medicine particularly against severe collagenic diseases since it enables administration for a long period of time. Administration at the dose of 60 mg/day at an acute state and at the dose of 30 mg/day after the acute stage is sufficiently effective.
Preparation of the compounds of the present invention will be described in detail with reference to the examples below.
EXAMPLE 1
Preparation of 3-trichlorogermylpropionic acid from germanium dioxide
In 600 ml. of conc. hydrochloric acid was suspended 104.6 g. (1 mol) of germanium dioxide. To the resulting suspension was added 160 ml. (1 mol as the minimum titer) of 50% hypophosphorous acid solution while stirring. The reaction mixture was heated under reflux for about 3 hrs. while stirring to become a transparent solution, all being dissolved therein. With the addition of 72 g. (1 mol) of acrylic acid to the solution under agitation heat generated. Since the reaction was exothermic, the whole amount of acrylic acid was added at such a rate that the reaction temperature did not exceed 50° C. When almost a half amount of acrylic acid was dropwise added, crystals were deposited from the reaction solution by adding a seed for crystallization, etc., which was advantageous. After adding the whole amount of acrylic acid, stirring was continued for further 0.5 to 1 hr. After cooling, the crystals were taken by suction-filtration, followed by drying under reduced pressure. Alternatively, wet crystals were dissolved in ether, methylene chloride, chloroform, benzene, etc. Thereafter, the solution was dried over a drying agent such as MgSO 4 , etc. and the solvent was distilled off to obtain the crystals. As such, 227 g. (90% in yield) of white crystals were obtained. By recrystallization from n-hexane, white needles were obtained. The melting point thereof was 83.5°-86° C. which was identical with that in the literature. Also, elemental analysis, infrared absorption spectrum and NMR spectrum supported the structure of 3-trichlorogermylpropionic acid.
In addition, also in the case where metal salts or ammonium salts of hypophosphorous acid were employed in lieu of hypophosphorous acid, 3-trichlorogermylpropionic acid was similarly obtained.
Further, also in the case where other unsaturated compounds represented by the formula (I) were employed in lieu of acrylic acid, the corresponding compounds represented by the formula (II) were obtained as shown in the Table below.
______________________________________Starting Material Product(Compound of (Compound of Yieldthe formula (I)) the formula (II)) (%)______________________________________CH.sub.2CHCOOC.sub.2 H.sub.5 Cl.sub.3 GeCH.sub.2 CH.sub.2 COOC.sub.2 H.sub.5 70 ##STR8## ##STR9## 79HOOCCHCHCOOH ##STR10## 68CH.sub.3 CHCHCOOH ##STR11## 88CH.sub.2CHCOCH.sub.3 Cl.sub.3 GeCH.sub.2 CH.sub.2 COCH.sub.3 60______________________________________
EXAMPLE 2
Preparation of a low molecular weight polymer (A) of 3-oxygermylpropionic acid
In 1.3 l. of acetone, a solvent compatible with water, was dissolved 252 g. (1 mol) of 3-trichlorogermylpropionic acid. To the solution, 1.3 l. of water was added with stirring. White hairy crystals were precipitated out. The reaction liquid was allowed to stand overnight. Then, crystals were collected by suction-filtration. The so obtained crystals were washed with acetone sufficiently, followed by drying under reduced pressure. White needle-like low molecular weight polymer (A) was obtained in an amount of 144 g. (85% in yield). In addition, also in the case where other solvents which are miscible with water (e.g., ethanol, methanol, cellosolve, acetonitrile, tetrahydrofuran, dioxane, dimethoxyethane, diglime, dimethylsulfoxide, dimethylformamide, etc.) are employed in place of acetone, the low molecular weight polymer (A) can also be obtained likewise. Furthermore, the low molecular weight polymer (A) can also be obtained using solvents which are immiscible with water (e.g., chloroform, methylenechloride, carbon tetrachloride, benzene, ether, etc.). In this case, the low molecular weight polymer (A) was precipitated out when a solution of 3-trichlorogermylpropionic acid was throughly shaked with water. Crystals of this low molecular weight polymer (A) neither decompose nor melt at temperatures below 320° C. It is found that the polymer differs from the germanium-containing organic compound prepared in accordance with the method described in Japanese Patent Publication No. 2964/71 since infrared absorption spectrum and x-ray diffraction spectrum of powders are completely different. In addition, the low molecular weight polymer (A) was relatively easily soluble in water and the solubility in water was about 1 g./100 ml. (25° C.).
EXAMPLE 3
Preparation of high molecular weight polymer (B) of 3-oxygermylpropionic acid
A suspension of 40 g. of the polymer (A) in 400 ml. of water was settled at room temperature until all needles were changed to heavy bright prisms (it required for 1-3 weeks). After suction, the crystals were taken by filtration and dried under reduced pressure. Thus, 33 g. of white prism high molecular weight polymer (B) which was insoluble in water was obtained. This polymer did not decompose or melt at temperatures below 320° C. and its powder x-ray diffraction spectrum as well as infrared absorption spectrum were different from those of the low molecular weight polymer (A). Accordingly, the structure of the polymer (B) was different from that of the polymer (A).
EXAMPLE 4
Isolation of germanium chloride-phosphoric acid complex
As shown in Example 1, a solution obtained by the reaction of germanium dioxide and hypophosphorous acid in conc. hydrochloric acid was poured into 3 l. of cold water while shaking, whereby a white solid germanium chloride-phosphoric acid complex was precipitated out. By suction-filtration, the solid was collected, washed with acetone and then dried under reduced pressure. It is recommended to avoid water-washing since the solid is colored when washed with water.
From 1 mol. (104.6 g.) of germanium dioxide, 136 g. of the complex was obtained. It is assumed that the complex would be a complex of chlorogermanium (Ge II or Ge IV ) and phosphoric acid. The complex is an effective reagent for synthesis of germanium-containing organic compounds.
EXAMPLE 5
Another preparation of organic trichlorogermyl compound from germanium chloride-phosphoric acid complex
The complex isolated in Example 4 was suspended in a solvent such as ethanol, methanol, dichloromethane, chloroform, carbon tetrachloride, ether, or the like. The suspension was saturated under ice cooling by blowing dry hydrogen chloride thereinto. When water was employed, conc. hydrochloric acid was used. The complex gradually disappeared at the same time when hydrogen chloride was blown in the system and a completely transparent solution was formed depending upon solvent. The unsaturated compound represented by the formula (I) was added to the system in an equimolar amount. The mixture was warmed (40°-60° C.) for 1 hr. After post-treatment, the corresponding organic trichlorogermyl compound of the formula (II) was obtained.
In the case of the unsaturated compound (I) to which hydrogen chloride was easily added, the aforementioned treated solution of the complex was provided for use after previously heating the solution at 40°-60° C. for 1 hr. and removing an excess of hydrogen chloride from the system. The corresponding organic trichlorogermyl compounds (II) were thus obtained as shown in the Table below.
______________________________________Starting Material(Compound of Product (Compound Yieldthe formula (I)) of the formula (II)) (%)______________________________________CH.sub.2 ═CHCOOH Cl.sub.3 GeCH.sub.2 CH.sub.2 COOH 80CH.sub.2 ═CHCOOC.sub.2 H.sub.5 Cl.sub.3 GeCH.sub.2 CH.sub.2 COOC.sub.2 H.sub.5 58______________________________________
EXAMPLE 6
Preparation of trichlorogermyl organic acid ester:
Of a variety of organic trichlorogermyl compounds obtained in Examples 1 and 5, the trichlorogermyl organic acids were esterified.
Esters could be obtained by dissolving various trichlorogermyl organic acids into a solvent such as methanol, ethanol, or the like, saturated with hydrogen chloride, and then reacting at temperatures of 0°-60° C. for 2-3 hrs. For example, ethyl-3-trichlorogermyl propionate was obtained in yield of 90% by treating as described above (b.p. 94° C./5 mmHg).
EXAMPLE 7
The organic trichlorogermyl compound shown in the middle column of the table of Example 1, the organic trichlorogermyl compound shown in the middle column of the table in Example 5 and the trichlorogermyl organic acid ester obtained in accordance with Example 6 were treated according to Examples 2 and 3. Thus, the corresponding low molecular weight polymer and high molecular weight polymer were obtained.
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Germanium-containing organic polymers are obtained by polymerizing 3-trichlorogermylpropionic acid obtained by reacting halogermanium-phosphoric acid complexes with acrylic acid. The polymers are markedly effective in treating allergenicities.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of International Application No. PCT/EP2009/003755, filed on May 27, 2009, which claims the benefit of German Application Serial No. 10 2008 026 632.9, filed on Jun. 4, 2008, the contents of both of the foregoing applications are hereby incorporated by reference in their entirety.
FIELD OF DISCLOSURE
The invention relates to a closing machine for closing containers with closures.
BACKGROUND
Units are known for the sterile, and in particular for the aseptic cold filling of bottles or similar containers with a liquid product, for example with a liquid product that spoils easily, for example milk products, and also for the subsequent, again sterile or aseptic cold, closing of the containers. The bottles or containers are, in that case, transported in a sterile chamber during supply to the filling machine, during filling, during transport from the filling machine to a downstream closing machine and during closing. When the unit is running, i.e. on filling and closing, the chamber is flushed with or exposed to a sterile gas and/or vapor-forming medium and from time to time, i.e. within predetermined cleaning and disinfecting cycles or intervals, it is treated with a cleaning and/or disinfection and/or sterilization medium.
Known units suffer from the particular disadvantage that, with the closing machine in question, all of the equipment of that machine and, in particular, the closing tools provided at the closing positions, are arranged in the sterile chamber. This means that the construction of those closing tools, at least at their outer surfaces and/or regions, must also be produced from a material that is resistant to corrosion by the cleaning and disinfection means, for example from stainless steel. Furthermore, the outer surfaces of the closing tools have functionally necessary recesses, slits, indentations, etc. that germs like to colonize. As a result, it has been necessary to use large amounts of cleaning and disinfection materials to clean and disinfect the sterile chamber in the closing machine zone.
SUMMARY
The aim of the invention is to provide a closing machine that is particularly suitable for use in a unit for sterile and thus in particular also for aseptic cold filling of products into bottles or the like as well as for closing such containers in a sterile manner, and that avoids the disadvantages mentioned above, i.e. reduces the risk of contamination, and considerably reduces the means or chemicals required for cleaning, sterilization, and/or for disinfection of the sterile chamber.
A closing machine as described herein solves this problem.
Further embodiments, advantages and applications of the invention will become apparent from the following description of embodiments and from the figures. To this end, all described and/or depicted features, alone or in any combination, constitute the subject matter of the invention, independently of their synopsis in the claims or their dependencies. Further, the contents of the claims form part of the description.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be described in more detail with the aid of FIGS. 1 and 2 , which each show, in simplified form and in partial section, a rotary type closing machine in the region of a sterile chamber.
DETAILED DESCRIPTION
The closing machine 1 shown in FIG. 1 acts in the embodiment shown in this figure to seal bottles 2 , for example plastic bottles, with closures 3 , for example in the form of foils, that can be fastened to the bottles or to the bottle mouth 2 . 1 thereof by welding or sealing, i.e. by the use of heat.
The closing machine 1 includes a rotor 4 that can be driven about a vertical machine axis MA with, on its circumference, an annular channel-like sterile chamber 5 concentrically surrounding the machine axis MA. The sterile chamber 5 is delimited from the surroundings by a plurality of wall sections.
In the embodiment shown, the wall sections are an upper wall section 6 , a lower wall section 7 , a radially inner annular wall section 8 and outer wall sections 9 . An intermediate wall 10 between the wall sections 6 and 7 divides the chamber 5 into an upper chamber part 5 . 1 and a lower chamber part 5 . 2 . In the embodiment shown, the upper wall section 6 , the inner annular wall section 8 , the intermediate wall 10 and the part section 7 . 1 of the lower wall section 7 are mounted on the rotor 4 and thus revolve with it. The outer wall sections 9 , as well as the part section 7 . 2 of the wall section 7 , do not revolve with the rotor 4 . Instead, they are attached to a machine frame of the closing machine 1 .
In order to close bottles 2 with closures 3 , a plurality of closing stations 11 are formed on the circumference of the rotor 4 , one of which is shown in FIG. 1 . These closing stations 11 are distributed at regular angular intervals about the axis MA.
Each closing station 11 includes a closing tool in the form of an induction welding head 12 , of which in FIG. 1 only the inductively heated induction seal 12 . 1 , which extends into the chamber 5 or into both upper and lower chamber parts 5 . 1 and 5 . 2 , is shown. This is guided through an opening 6 . 1 in the upper wall section 6 and can move as shown by the double headed arrow A along its seal axis or along a vertical axis parallel to the machine axis MA between an upper start position and a lowered operational position. In the lowered operational position, the lower seal surface of the induction seal 12 . 1 is applied and pressed against the corresponding closure 3 against the mouth opening 2 . 1 of the bottle 2 to be closed at the closing station 11 so that the closure 3 and the corresponding bottle 2 can be joined by sealing or welding.
The area through which the induction seal 12 . 1 passes through the wall section 6 is sealed off with a suitable material, for example consisting of a bellows-like gasket 13 formed from PTFE (polytetrafluoroethylene).
The induction seal 12 . 1 extends through an opening 10 . 1 in the intermediate wall 10 with its lower end in the lower chamber part 5 . 2 . The outer surface of the induction seal 12 . 1 is made from a material that is as smooth as possible. The induction seal 12 . 1 is formed from a suitable, good heat conductive but corrosion-resistant material to enable it to function as a passive, heat-conductive component. An example of such a material is stainless steel.
All of the other functional elements of the induction welding head 12 , such as the elements for lifting, lowering, and heating the induction seal 12 . 1 , are above the wall section 6 and outside the sterile chamber 5 .
Each closing station 11 is provided with a container carrier that is formed by an opening in the part section 7 . 1 below the induction seal 12 . 1 . The bottle 2 is hung from this container carrier by a mouth flange 2 . 2 below the bottle's mouth 2 . 1 so that only the mouth region above the mouth flange 2 . 2 reaches into the chamber 5 , and in particular into the lower chamber part 5 . 2 .
During operation of the closing machine, i.e. for aseptic closing of the bottles 2 , the chamber 5 is exposed to or flushed with an appropriate gas and/or vapor-forming medium that ensures the sterility of the chamber 5 . A suitable medium is sterile air. This medium is fed into the sterile chamber 5 through lower chamber part 5 . 2 and leaves the sterile chamber 5 at least in part via the upper chamber part 5 . 1 .
For closing, the bottles 2 are individually transferred to an operational position of the closing stations 11 so that there they hang and are retained by their mouth flange 2 . 2 with the bottle mouth 2 . 1 in the lower chamber part 5 . 2 for closing with the closures 3 . The sealed bottles are removed from the closing stations 11 on a container-discharge means.
The particular advantage of the closing machine 1 or the closing stations 11 lies in that only smooth regions of the induction seal 12 . 1 , with no recesses, undercuts or the like that could allow germs to colonize, are arranged in the sterile chamber 5 . This enables the whole chamber 5 to be kept germ-free at a considerably reduced cost. This also increases the time interval between cleaning and/or sterilization cycles, shortens the cycle time, and reduces the quantity of cleaning and/or sterilization media consumed.
FIG. 2 shows the closing machine 1 for closing the bottles 2 with cap-like twist or screw closures 13 . To this end, the individual closing stations 11 are each provided with a screw capper 14 having a construction that is known to the skilled person. The screw capper 14 includes a drive 14 . 1 , a longitudinal and closed capper head 14 . 2 having a spindle or shaft, and a capping cone or capping element 14 . 3 provided at the lower end of the capper head 14 . 2 and connected with the spindle. In the embodiment shown in FIG. 2 , only the part of the length of the screw capper head 14 . 2 having a smooth cylindrically shaped outer surface on each screw capper 14 extends through the wall section 6 into the sterile chamber 5 and thus also through the intermediate wall 10 into the lower chamber part 5 . 2 so that the capping element 14 . 3 that cooperates with the twist or screw closures 3 a is arranged in this lower chamber part 5 . 2 .
The passage of the capping head 14 . 2 through the wall section 6 is again sealed using the bellows gasket 13 . When capping the bottles 2 with the twist or screw closures 3 a , the screw cappers 14 can be moved up and down in a vertical direction (arrow A) and the closing elements 14 . 3 provided on the capping head 14 . 2 are driven in rotation.
Like the embodiment shown in FIG. 1 , the embodiment shown in FIG. 2 has the advantage of allowing entry into the sterile chamber 5 of only those functional elements of the screw capper 14 that have a smooth and easily cleaned and sterilized outer surface. These are arranged within the lower chamber part 5 . 2 . Other functional elements, which are harder to clean and sterilize, are completely outside the chamber 5 . These functional elements would include the drive 14 . 1 and the functional elements that lift and lower the screw capper 14 ,
In one example, the closing machine 1 is a component of a unit for sterile, for example aseptic cold, filling of a liquid product into the bottles 2 or into other containers as well as to seal the bottles 2 with the closures 3 or 3 a . Prior to filling, during filling and sealing, and also over the whole transport path between the filling machine and the closing machine, the bottles 2 are always moved with at least their mouth region 2 . 1 in a sterile chamber.
The closing machine 1 is suitable not only for closing bottles 2 , but also for closing other containers.
The invention has been described using exemplary embodiments. Modifications and deviations are possible without departing from the inventive concept underlying the invention.
Thus, for example, other types of closing tools may be used in the same or similar manner on the closing machine 1 or at its closing stations 11 . Examples of such closing tools include tools for fastening cap-like closures to bottles by application and permanent mechanical deformation of the closures. When using such closing tools only functional elements that cooperate directly with the closures are arranged inside the chamber 5 or the upper and lower chamber parts 5 . 1 and 5 . 2 . Other functional elements, such as functional elements that are hard to clean and/or sterilize, remain outside the sterile chamber 5 . These include, for example drives and/or lifting devices for lifting and lowering the respective closing tools.
Furthermore, it is also possible, instead of using an induction welding head 12 to weld or seal the closures 3 with the opening rim 2 . 1 of the bottles 2 , to use a closing tool employing another manner of fixing or welding the respective closure 3 with the bottle 2 , for example by ultrasound energy and/or using microwave energy.
It was mentioned above that instead of the induction welding head 12 and screw capper 14 , other closing tools could be used. The inventive construction of the closing machine, however, is of particular advantage when using such closing tools wherein the part of the closing tool that extends into the chamber 5 is a purely passive component that has a shaped part with a corrosion-resistant, smooth surface that is free of undercuts, indentations, joints, recesses etc., and that can be cleaned and sterilized without problems. A passive component in this context is the induction seal 12 . 1 and also, for example with a closing tool operating with ultrasound, a seal type tool that transfers ultrasound energy to the closure 3 and the bottle opening or mouth 2 . 1 .
LIST OF REFERENCE NUMERALS
1 closing machine
2 bottle
2 . 1 bottle mouth
2 . 2 mouth flange
3 , 3 a closure
4 rotor
5 sterile chamber
5 . 1 , 5 . 2 upper and lower chamber parts
6 , 7 , 8 , 9 wall section
7 . 1 , 7 . 2 part section of wall section 7
10 intermediate wall
10 . 1 opening
11 closing station
12 induction welding head
12 . 1 induction seal
13 bellows seal
14 screw capper
14 . 1 drive
14 . 2 cylindrical capper head
14 . 3 capping cone or capping element
A lifting motion of closing tool
MA vertical machine axis
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Closing machine for closing bottles or similar containers ( 2 ) using closures ( 3, 3 a ), having a plurality of closing stations ( 11 ) which each have a closing tool ( 12, 14 ) and a container carrier and are formed on the circumference of a rotor ( 4 ), which can be driven in circulation around a vertical machine axis (MA), wherein the rotor ( 4 ) has formed on it, in the region of the closing stations ( 11 ), a sterile chamber ( 5 ) which is bounded in the direction of the surroundings by walls or wall portions ( 6, 7, 8, 9 ) and into which the containers ( 2 ), which are retained in a hanging state on the container carriers, extend by way of their container mouth ( 2.1 ) which is to be closed, and wherein the respective closing tool ( 12, 14 ) extends into the sterile chamber ( 5 ) merely by way of a part which interacts with the container ( 2 ) which is to be closed and/or with the closure ( 3, 3 a ), all the rest of its functional elements being arranged outside the sterile chamber ( 5 ).
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REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of co-pending parent patent application Ser. No. 12/668,498, entitled “Self-Heating Container”, which was a National Stage entry under 35 USC 371 of PCT International Application PCT/ES2007/000425, filed Jul. 13, 2007. The aforementioned application is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a self-heatable container. The field of the invention is that of the preparation of containers intended to contain food products, especially beverages, soups and the like, which can be consumed at a temperature greater than room temperature and in any place, particularly when specific heating means are not available.
[0004] 2. Description of Related Art
[0005] Several types of self-heatable containers provided with incorporated means for the local generation of heat in order to increase the temperature of a beverage up to a certain value are known. Among these are those described in PCT published application WO03/064283.
[0006] The models of containers provided with incorporated heating means which have been disclosed have certain drawbacks, such as their complex structure demanding complicated and therefore expensive manufacturing processes. In addition, some types described in patents have a questionable suitability, given the technical difficulty in maintaining the constitutive parts thereof hermetically joined.
[0007] In other cases, the functional and shape design of the proposed containers is scarcely suitable for the intended purpose.
[0008] There currently exist several models of self-heatable containers, for example Scudder, U.S. Pat. No. 6,266,879, which provides a plastic container with a double bottom which supports the inner body containing the reagent product. At the same time a certain amount of water is placed in another smaller body, which when it comes in contact with the reagent produces an exothermic reaction that causes the inner body to heat at high temperature and that heats the consumable included in the outer container. When the container is made of plastic, it is easy to manufacture, but there is an important risk due to the high temperature reached. Fissures or punctures or distortions might appear in the container containing the reactive product, such that the reactive product might come into contact with the consumable, making it unfit for consumption.
[0009] Metal containers for beer and soft drinks that contain carbon dioxide must work without leakage of any kind, in particular when the container is shaken and the gas fizzes and the pressure increases on the inside. These containers have a closed lid which is fixed by a double fold of both elements about themselves, for example in Beckertgis, U.S. Pat. No. 5,421,472 a closure of this kind is described.
[0010] Therefore, it is desirable to have a container provided with its own heating means, which has a suitable structure and is easy to use and which reaches temperature levels suitable for the type of product contained relatively quickly.
SUMMARY OF THE INVENTION
[0011] The invention relates to a self-heating container and a method of manufacturing the container. The container has a simple structure in which the metallic outer body holds the consumable product, and a metallic inner body and plastic housing contain the two components which react to produce the heat for the self-heating function. A lower lid is crimped over flanges on the lower ends of the inner body and the outer body, forming a double seal. When a flexible portion of the housing is pressed, a seal is punctured, causing the two components to mix and generate heat through an exothermic chemical reaction which heats the contents of the container.
[0012] The inner container fits within a smaller-diameter bottom area of the outer body, and flanges of the inner container and outer container are crimped together with a single bottom lid to form a double seal which closes and supports the elements of the container. The double seal safely seals the two reactive components within the inner container, and the inner container within the outer container.
[0013] Because of the nature of the design, the inner body in which the exothermic reaction occurs is in contact the consumable not only at the bottom of the inner body (as would happen if both the inner body and the outer body were of the same diameter and were fitted without any space between them), but also on its side walls, in the area between the inner body and outer body.
[0014] The flanges of the inner body and outer body match up and overlap each other before the bottom lid is fitted, so that when the lid is placed on the container, both flanges are joined within the lid, forming the double seam. This allows the use of conventional machines for this operation since it is identical to the placement of a lid on a container of soft drinks or beer. This allows ensuring the tightness not only of the container as a whole, but also of the seal between the inner and outer bodies, making sure that there will be no transfer of reagent to the consumable.
[0015] This process takes place with safety and efficiency as a result of the design of the parts forming the container and the associated device thereof. Because both the outer body and inner container are made of metal, the container
BRIEF DESCRIPTION OF THE DRAWING
[0016] FIG. 1 is an exploded view of the container, depicted upright with the upper lid at the top.
[0017] FIG. 2 a is a top view of the housing.
[0018] FIG. 2 b is an exploded, cut-away side view of the housing.
[0019] FIG. 3 is a cut-through view of the container, bottom end upward, prior to crimping the bottom lid.
[0020] FIG. 4 shows a partially cut-through view of the container, showing the operation of the flexible portion of the housing and also how the consumable in the container contacts the inner body.
[0021] FIG. 5 is a side view of the container, bottom end upward, after crimping the bottom lid, with the outer body partially cut away to show the inner body fitting within the outer body.
[0022] FIGS. 6 and 7 are sectional details of the housing.
[0023] FIGS. 8 a and 8 b are details of the crimping process, showing a portion of the outer body, inner body and bottom lid, enlarged from the circled area denoted “ 8 ” in FIG. 5 .
[0024] FIG. 9 shows a flowchart of the method of assembly of the container.
[0025] FIG. 10 shows a detail of the double-seam crimp, in another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Structure of the Container
[0026] As can be seen in FIG. 1 , the container has five major parts: outer body 1 , inner body 9 , housing 10 , upper lid 3 and lower lid 8 .
[0027] The outer body 1 contains the consumable product, such as a beverage, soup or the like. Outer body 1 is preferably cylindrical in shape, and is made of a metallic material of a suitable thickness. The upper edge of the outer body forms a flange 2 , which is crimped together with the periphery of upper lid 3 , as is conventional with beverage cans or the like.
[0028] The lower part 6 of the outer body 1 has a smaller diameter than the upper part 30 of the outer body 1 , with the two sections 6 and 30 joined by tapered area 5 . The bottom edge of lower part 6 forms a flange 7 .
[0029] The inner body 9 , within which the chemicals which heat the can will be contained, consists of a cylindrical metallic body having a closed upper end, and the lower end of the inner body 9 is formed into a projecting flange 9 ′. The inner body 9 has a length greater than the length of the lower part 6 of the outer body, so that when the lower body 9 is inserted into the upper body 10 , the inner body 9 extends from the lower flange 7 past tapered area 5 into the upper part 30 .
[0030] The diameter of the projecting flange 9 ′ of inner body 9 is of approximately the same diameter as the flange 7 of the bottom edge of lower part 6 of the outer body 1 , so that when the inner body 9 is placed into the upper body 1 , the flanges 9 ′ and 7 overlap and are located together as shown in FIGS. 8 a and 8 b.
[0031] As can be seen in FIGS. 2 a and 2 b and FIGS. 6 and 7 , housing 10 is generally cylindrical, and is preferably made of a plastic material. The housing 10 has a diameter which is somewhat smaller than the diameter of inner body 9 , so that the housing 10 will fit within inner body 9 . The length of housing 10 is less than that of inner body 9 , preferably about one-quarter to one-third of the length of inner body 9 , so that when housing 10 is within inner body 9 a chamber 20 is formed within the inner body 9 , as will be discussed further below.
[0032] The side part 11 of housing 10 is are relatively thick so as to have a resistance to deformation, whereas base 12 of housing 10 is of a reduced thickness so as to be flexible in its central part 31 , which is curved to define a dome. On the upper surface 32 of the central portion 31 is a projection 13 . Projection 13 preferably has a square cross-section with four sides meeting at right-angles. Cuts 14 are preferably made in the sides, so as to form four fingers 33 a - 33 d, each with an L-shaped or right-angled shape.
[0033] A thin disc-shaped seal 15 of thin, pierceable aluminum foil or similar material, closes the upper end of the housing 10 , sealed around its edges to the upper rim 16 of the housing 10 . The length of the projection 13 is such that when the domed part 31 of the base 12 is pushed fully upward, the ends of the projection protrude slightly from the upper end of the housing 10 , puncturing the seal.
[0034] The lower end of the housing 10 is formed into a lip 22 , which is closed by filter 17 , a disc of a porous material. The filter 17 is made of a flexible, porous and air-permeable and also moisture-absorbing material. Openings 21 are formed in the lip 22 to provide air passages between the outside atmosphere and the inside of the inner body 9 and assure that the reaction always occurs at atmospheric pressure. Ribs 23 reduce to a minimum the amount of calcium hydroxide in powder form, resulting from the reaction, which could be deposited from the inside of inner body 9 onto the filter 17 .
[0035] When all of the components are assembled, with the inner body 9 inside the outer body 1 and the housing 10 inside the inner body 9 , the lower lid 8 is fixed over the flanges 7 and 9 ′ by the double seam 24 , which closes and holds all the components of the heating module associated with the container.
[0036] FIG. 10 shows another embodiment of the double seam 24 , in which flanges 7 and 9 ′ are bent back over parallel to the sides 6 and 9 and the edge of lid 8 is crimped over to entirely enclose the flanges in the double seam 24 .
[0037] It is preferred to have a protective element for the user's lips, such as a ring made of an insulating material, around the lip 2 of the outer body 1 . The protective element does not form part of the container, and is not shown in the drawing.
Method of Assembly of the Container
[0038] The assembly of the self-heatable container described above can be stated as follows, with reference to FIGS. 3 , 5 and 8 a - 8 b, and as shown in the flowchart of FIG. 9 :
90 . A predetermined amount of water is placed in the housing 10 . 91 . Housing 10 is hermetically closed by fastening seal 15 to the rim 16 of the housing 10 , the inner face of the seal 15 being supported on central projection 13 and its fingers 33 a - 33 d. 92 . Filter 17 is fixed to the opposite end of the housing 10 from the seal 15 . 93 . A predetermined amount of a chemical such as calcium oxide which, upon contact with water, will give rise to an exothermic reaction, is placed in the inside 20 of inner body 9 . 94 . The inner body 9 , loaded with the chemical, is inserted into the smaller-diameter lower part 6 of the outer body 1 . The flange 9 ′ of inner body 9 will seat against flange 7 of outer body 1 . 95 . Housing 10 is inserted into the inner body 9 . 96 . Lower lid 8 is placed on the lower end of the container, with the rim of the lid 8 over flanges 7 and 9 ′, as shown in FIG. 8 a. 97 . The rim of lower lid 8 is crimped over flanges 7 and 9 ′, forming double seal 24 as shown in FIG. 8 b . The double seal 24 assures the hermetic closing of this end part of the container, i.e., the associated edges of the lid 8 , the outer body 1 and the inner body 9 , thus locking inner body 9 and container 10 with respect to the outer body 1 . 98 . Inverting the position of the container to the position of FIG. 1 , the desired amount of the consumable product (food, beverage or the like), the consumption of which will optionally take place after heating, is poured through the upper mouth 2 of the outer body 1 . The product bathes the upper and side part of the container 9 and likewise occupies the area 19 between the outer body 1 and the inner body 9 . 99 . Finally the upper lid 3 is placed over the mouth 2 of the outer body 1 , and upper lid 3 is fixed to the mouth 2 by a conventional peripheral crimp. 100 . Optionally, the finished container (with its heating module incorporated) can be sterilized in an autoclave at a temperature and pressure suitable for the characteristics of the product. The sterilization is possible given the simplified configuration and the metallic nature of the new container. 101 . The container can be finished with the placement of a preferably tubular and laminar label 18 .
Method of Operation of the Container
[0051] In order to heat the consumable product contained in the body 1 , the lower lid 8 is partially removed, with the outer rim of the lower lid 8 being retained by the crimp 24 . This reveals filter 17 and, behind it, the flexible dome 31 or central part of the base 12 of housing 10 is exposed.
[0052] As shown in FIG. 4 , the flexible dome 31 in the base 12 is pressed, whereby the projection 13 moves in an axial direction and its fingers 33 a - 33 d tear seal 15 . This allows the water contained in housing 10 to flow into the interior 20 of inner body 9 . The water contacts the chemical, for example calcium oxide, contained in the interior 20 , initiating an exothermic chemical reaction. This reaction causes a considerable increase of the temperature of the inner body 9 .
[0053] The container with its contents is shaken for a period of time, for example 10 seconds, to facilitate the mixture of the water and chemical in the interior 20 of inner body 9 , and the container is again inverted, leaving it face up as shown in FIG. 1 .
[0054] In less than 30 seconds the heating is noted due to the exothermic chemical reaction, which gives rise to a considerable increase of the temperature of the surface of inner body 9 and, as a result, of the consumable product 40 , which, as can be seen in FIG. 4 , is in contact not just with the end of the inner body 9 , but is also in contact with the cylindrical walls of inner body 9 , in the area 19 between the inner body 9 and the outer body 1 .
[0055] The wall of the outer body 1 is also heated as the contents heat. This could be to a temperature as high as 65-70° C., since the container is designed so that the temperature of the content rises from 38 to 40° C. with respect to the environment. To that end and to prevent the inconvenience and risk of burning for the user when holding the outer body 1 of the container, the label 18 is preferably made of a heat-insulating material, such as polystyrene.
[0056] Finally, the user, in less than 3 minutes, can open the mouth of the container by opening the upper lid 3 and have access to the heated contents.
[0057] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
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A self-heating container and a method of manufacturing the container. The container has a simple structure in which the metallic outer body holds the consumable product, and a metallic inner body and plastic housing contain the two components which react to produce the heat for the self-heating function. A lower lid is crimped over flanges on the lower ends of the inner body and the outer body, forming a double seal. When a flexible portion of the housing is pressed, a seal is punctured, causing the two components to mix and generate heat through an exothermic chemical reaction which heats the contents of the container.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of US Provisional Application Ser. No. 60/953,286, filed 01 Aug. 2007, which is incorporated herein in its entirety.
BACKGROUND
[0002] The process of transferring the Intellectual Property (IP) rights after an acquisition or merger from one entity to another is very complex and time consuming. If you are not familiar with the process and the pitfalls you or your client can lose time, money and rights associated with the IP Portfolio while navigating all the laws and procedural issues that arise during such a transfer.
[0003] Intellectual Property, or IP, has been historically known as the group of legal rights to things people create or invent. Intellectual Property rights typically include patent, copyright, trademark and trade secret rights. An Intellectual Property (IP) Portfolio is defined as all of the Intellectual Property owned by one entity.
[0004] IP portfolios are now being used in many different manners. Portfolios are being used for collateral for loans and are the backbone of many business acquisitions. Unfortunately, in current practice, companies and banks are buying or loaning monies to companies that do not own the properties in the portfolio. The companies are completing sales before they are analyzing the properties and are finding many of the properties abandoned, close to expiration, have assignment encumbrances or the company does not even own the property they are selling due to typographical errors or procedural missteps.
[0005] There is a need for a system and method to categorize an IP portfolio and to transfer the identified portfolio, from one entity to another, in a streamlined manner thus reducing the cost associated and the time it takes to transfer the properties in domestic and foreign patent offices and ensure all properties are transferred in accordance to each countries Intellectual Property laws. There is a need for a system and method to put all the acquired assets in one storage device that contains variables that can be applied when the user answers a series of questions which will then produce the necessary documents and instructions to affect the transfer and track the progress of the properties and produce accurate and timely reports as to the status of the transfer.
[0006] There are many different types of databases and time management systems available, but none that put all of these variables together in one system and method to create a streamlined process to guide a user through the process in a logical manner, which will save the user time, money and preserve the intellectual property rights they have acquired.
[0007] There are also many different methodologies in searching or categorizing the portfolio which is to be bought or sold through different type of database searches by terms such as Assignee, Inventor or classification but there is nothing to direct the actions of the person transferring the portfolio after the acquisition is complete.
SUMMARY
[0008] The present invention relates to production and management of certain documents using template documents, user inputted and stored data and certain international and United States laws and procedures to transfer Intellectual Property from one entity to another.
[0009] The present invention begins with a user accessing the computer program product on a host computer. The computer program product begins with the user answering questions about the Assignor and Assignee companies, e.g., legal address, signer names, etc. The responses are saved into a storage device. The user then enters a US Patent or Trademark number that is stored into a storage device. The next user interface screen directs the user to choose which foreign countries the US Patent or Trademark have been filed in, if any. The next user interface screen shows a table of the selected foreign countries and directs the user to add the foreign property numbers. This information is saved into a storage device.
[0010] This stored information is then categorized per country and is inputted into stored template documents that are legally compliant for each particular country entered. Once the template documents are generated the user is directed to print a document package which contains, the requisite template documents required to transfer the properties in compliance with each countries laws and procedures, an instructional user guide that contains directions for completing the documents and template form cover letters to send with the documents to the different places they need to go.
[0011] When the user begins to complete necessary actions, the user accesses the computer program product and checks off the completed actions whereas the computer program product then directs the user to print a next set of form documents or complete the next required action until all actions are completed, thus successfully transferring the properties.
DETAILED DESCRIPTION
[0012] FIG. 1 , is a schematic diagram of the exemplary system architecture of the present invention.
[0013] FIG. 2 , is a flow diagram of an exemplary process and method, implemented by the information entered by the user.
[0014] FIG. 3 , is an exemplary user interface screen for adding information about the Assignor involved in the IP portfolio transfer and a storage device which stores the user inputted information.
[0015] FIG. 4 , is an exemplary user interface screen for adding information about the Assignee involved in the IP portfolio transfer and a storage device which stores the user inputted information.
[0016] FIG. 5 is an exemplary user interface screen for adding information about the properties to be transferred in the IP portfolio and a storage device that stores the user inputted information.
[0017] FIG. 6 is an exemplary user interface screen for selecting foreign countries that a property is filed in and a storage device that stores the user inputted information.
[0018] FIG. 7 is an exemplary user interface screen for adding application, patent and registration numbers for the properties in each of the user selected foreign countries and a storage device that stores the user inputted information.
[0019] FIG. 8 is an exemplary user interface screen for indicating the user inputted information is complete.
[0020] FIG. 9 is a block diagram illustrating one exemplary method of the present invention accessing the separate storage devices, sorting the application, patent and registration numbers by country, selecting the proper documents for each country and inputting the stored information into the required documents.
[0021] FIG. 10 is a document package.
[0022] FIG. 11 is an exemplary country listing tracking user interface screen where the user can view all countries that have a remaining outstanding actions and countries that have been completed.
[0023] FIG. 12 is an exemplary task management user interface screen for each country that shows which actions are completed and which actions are still pending.
[0024] FIG. 13 is an exemplary user interface instructional pop up window directing the user on any next action that may be required.
DETAILED DESCRIPTION
[0025] The following is a description of the figures and the preferred embodiments relating to the present invention.
[0026] This particular computer program product is to be used after both companies have performed their due diligence on the properties to be transferred. The companies should have already determined that they own the properties to be transferred and that the properties are still in force. The objective of the computer program product is to make preparing the final documents needed to transfer the properties with instructions that are easy to follow and comprehensive for the person transferring the properties.
[0027] A system, method and computer program product for producing certain documents to transfer an IP portfolio is generally described at 10 in FIG. 1 .
[0028] In FIG. 1 , the user 100 accesses a host system 102 , which can be a stand-alone unit or used with a network system. The host system 102 may comprise any type of processor device capable of handling the product. Although the computer program product shown at 10 in FIG. 1 to be executing directly on the host system 102 , it will be appreciated and understood by those skilled in the art that the computer program product 103 may be executed by a remote processor (e.g., a general-purpose computer in communication with 103 the host system via a network.) The user 100 launches the computer program product 103 and then is prompted to input data 104 . The computer program product 103 sorts the data and stores it in the appropriate storage devices 106 , 108 , 110 , 112 on the host system 102 . It is understood that the storage devices 106 , 108 , 110 , 112 could be housed in one storage device, but for clarification, we will refer to each of the devices as a separate unit.
[0029] Once the user 100 has completed inputting the data, the computer program product 103 sorts the information and transfers the information into predefined fields of form template documents that are contained in the template and rules storage device 114 . This can be completed using the principals of any type of mail merge process that is also known in the art. The user 100 is then directed to use a printer 116 to print a document package 118 .
[0030] The host system 102 should run an operating system that can support one or more applications. The host system 102 also has memory to store the information in storage devices 106 , 108 , 110 , 112 , which is known in the art. Host system 102 may be in direct communication with one or all storage devices 106 , 108 , 110 , 112 via cabling or wireless local network technologies, for example, or may be linked to one or all storage devices 106 , 108 , 110 , 112 via wide area network (WAN), Internet, or another type of network implementation. The computer program product 103 , which can be written onto a media or stored directly to the host system's 102 hard drive, can interact directly with the host system's 102 memory or a separate physical device to implement the present invention's applications.
[0031] FIG. 2 , is a flow diagram of an exemplary process and method, implemented by the question and answer information entered by the user 100 into the computer program product 103 . The process and method will be further defined throughout the specification.
[0032] FIG. 3 , is the initial exemplary user interface screen 200 where the user 100 begins inputting information regarding the Assignor Company. Assignor Field 1 202 prompts the user 100 to input the Assignor Company name. Assignor Field 2 204 prompts the user 100 to input the Assignor Company address. Assignor Field 3 206 prompts the user 100 to input the person who will sign the documents on behalf of the Assignor Company. Assignor Field 4 208 prompts the user 100 to input the title of person signing the documents on behalf of the company. The user interface screen 200 will prompt the user 100 to make sure the person signing the documents is either a President or Vice President of the company. This is important in regards to some of the document requirements of different foreign countries. Assignor Field 5 210 prompts the user 100 to input the state of incorporation of the Assignor Company. Assignor Field 6 212 prompts the user 100 to input the official “date of sale” of the intellectual property per the sale agreement. Assignor Field 7 214 prompts the user 100 to input what the actual name on the IP Sale Agreement is, for example, IP Sale and Assumption. This is important in regards to some of the document requirements of different foreign countries.
[0033] Assignor Field 8 220 prompts the user 100 to input the state and county of a notary who will notarize the signature of the Assignor Company. This will prompt the population of several different fields, template documents and instructional user guides. For example, if there are foreign properties to be assigned in Mexico the assignment template will need an “apostille”. Mexico is a participant of “The Hague convention section 12 , Convention abolishing the requirement of legalization” (hereinafter referred to as The Hague convention), which abolishes the need for the hindering process of “legalization” of documents, that some countries still participate in. The answer the user 100 inputs for this field will generate the appropriate notarial certificate (which can change statutory language from state to state and even county to county within a state) that will accompany the assignment template when a document package 118 is printed. The instructional user guide that is printed with the document package 118 will instruct the user 100 to forward the completed executed template documents (with assignor, assignee and notary signatures) to the appropriate Secretary of State office with the appropriate template cover letter and fee (which also varies from state to state.) The information, regarding state and county request procedure, fees and mailing instructions would be saved per state/county in the template and rules storage device 114 .
[0034] Assignor Field 8 220 will also drive information, documents and instructions for countries that are not a part of The Hague convention.
[0035] For Example, Brazil is not a party to The Hague convention. The completed documents to be filed in Brazil first need to be notarized with the appropriate language depending on which state the Notary is commissioned in. Secondly, these documents need to be forwarded to the Secretary of State's office that the Notary is commissioned in with the appropriate cover letter and fee so the documents can be “certified”. Thirdly, these documents need to be forwarded to the US Department of State's office with the appropriate cover letter and fee for certification. Fourthly, these documents need to be forwarded to the foreign embassy of Brazil for “legalization”. After this long process the documents will then be ready for forwarding to your preferred foreign counsel in Brazil for recording. This process is outlined in FIG. 2 .
[0036] Countries have different embassies located in different regions of the United States. In which state the Notary is commissioned, will dictate which embassy the documents need to be forwarded to. For example, if the Notary is commissioned in Utah, the Brazilian foreign embassy that would legalize the documents is in California. The combination of Assignor Field 8 220 and the template and rules storage device 114 will dictate which notarial certificate, cover letter and instructional user guide will be generated.
[0037] Assignor Field Misc. 1 216 prompts the user 100 to answer a YES or NO question regarding whether or not the company has changed its name during the life of the patent. If the user 100 answers NO the user 100 is directed to the next user interface screen. If the user 100 answers YES they will be directed to Misc. Field 1 218 which prompts the user 100 to obtain a copy of the change of name and or company merger as it may be needed to bring the property up to the current name of the company. Certain countries will require this document to be legalized or notarized in the same manner that the other template documents are. Assignor Field 5 210 and the template and rules storage device 114 will then dictate if the documents need legalization or not and will generate the requisite template documents and instructional user guide.
[0038] The instructional user guide will aid the user in regards to information such as, fees, payment requirements or restrictions, and mailing requirements, etc. For example, some embassies will only accept bank checks where other embassies will accept company checks or credit card payments.
[0039] FIG. 4 , is the second user interface screen 300 where the user 100 begins inputting information regarding the Assignee Company that is stored in the Assignee storage device 108 . Assignee Field 1 302 prompts the user 100 to input the Assignee Company name. Assignee Field 2 304 prompts the user 100 to input the Assignee Company address. Assignee Field 3 306 prompts the user 100 to input the person who will sign the documents on behalf of the Assignee Company. Assignee Field 4 308 prompts the user 100 to input the title of person signing the documents on behalf of the company. The user interface screen will prompt the user 100 to make sure the person signing the documents is either a President or Vice President of the company. This is important in regards to some of the document requirements of different foreign countries. Assignee Field 5 310 prompts the user 100 to input the state of incorporation of the Assignee Company.
[0040] Assignee Field 8 320 prompts the user 100 to input the state and county of a notary who will notarize the signature of the Assignee Company. This will prompt several different fields, required documents and instructional user guide as explained above.
[0041] FIG. 5 shows the next user interface screen 400 that asks the user 100 to input the first US property involved in the transfer. This property will be stored in the US properties storage device 110 .
[0042] The system then asks if the US property has been foreign filed. If the user 100 answers NO they will continue to input US property numbers to be stored in US properties storage device 110 until they answer YES.
[0043] FIG. 6 shows a table 500 of all the countries (figure is a sampling) that the property can be foreign filed in with a “radio dial” next to the two-letter country code. The user 100 can then select the foreign countries that the US property is filed in.
[0044] FIG. 7 shows a smaller table of the two letter codes for each of the foreign countries the user 100 has selected as having a foreign counterpart that needs to be transferred. The user 100 then enters the properties numbers (e.g., application no., registration no. etc.) associated with the foreign properties, per country, to be transferred. This information is stored in the foreign property storage device 112 which will be grouped and sorted, per country, and inserted into the stored template documents, i.e., assignment, power of attorney, etc., that are needed to transfer property rights in that particular country.
[0045] The user 100 will continue to add the US and foreign property information until all of the intellectual property has been added. Once the user 100 selects “completed”, as shown at FIG. 8 , the present invention computer program product 103 will access the templates and rules storage device 114 and the different storage devices 106 , 108 , 110 , 112 to merge all of the information into the proper areas of the requisite template documents to process the required documents, cover letters and instructional user guide.
[0046] When the computer program product 103 finishes preparing the template documents as prescribed by the template and rules storage device 114 , the user 100 is instructed to use either a stand-alone or network printer 116 to print a document package 118 as shown at FIG. 10 .
[0047] The document package 118 includes the required template documents for transferring the Intellectual Property rights in each country, a template cover letter and an instructional user guide.
[0048] Once the user 100 sends the document package to the Assignee or completes a required action, the user 100 would access the host system 102 and the computer program product 103 to view the country listing and tracking user interface screen 920 as shown at FIG. 11 . This country listing and tracking user interface screen 920 will help the user track which countries still have actions that need to be taken or which countries have completed all requisite actions to compel a successful transfer of rights from one entity to another. This country listing and tracking user interface screen 920 will also be helpful for the user 100 to quickly determine which properties in which countries have been completely transferred into the name of the Assignee or which properties still have pending actions and remain in the name of the Assignor. This information tends to be difficult to track when a user 100 has multiple countries (or even multiple client portfolios) to monitor that are at different stages of the transfer process. There are some foreign Intellectual Property offices that are severely delayed due to political turmoil, lack of technological advances, and even environmental factors.
[0049] The user 100 would select a country that they have completed an action in. A country task-tracking user interface screen 940 , shown at FIG. 12 , would open showing the user 100 all of the actions that need to be taken to complete that particular country and which actions have already been completed. Some lists will be longer than others due to that countries particular requirements (e.g., legalization or apostille requirements).
[0050] The user 100 would check the box that corresponds with the action taken. The computer program product 103 will automatically generate the date the user 100 checks the box or the user 100 can manually override the date if the perform date precedes the current date the user 100 is inputting the information.
[0051] Once a completion date is generated for a prescribed action, the computer program product 103 will produce the next set of template documents needed to continue the transfer process. The computer program product 103 will generate a “pop-up” instructional window 960 , as shown at FIG. 13 , instructing the user 100 to print the next set of required template documents and instructional user guide, if needed.
[0052] The user 100 will continue with all remaining countries and actions for each country until all actions are completed. Once a country has all actions completed, that country will shift to the completed country list on the country listing and tracking user interface screen 920 . Once all countries are completed, the user 100 has successfully transferred the rights from one entity to the other.
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A system, method and computer program product for a user to produce certain template documents and track the progress of the transfer of an Intellectual Property portfolio. This system, method and computer program product comprises a processor in communication with one or more storage device, where the user would input specific data regarding an Assignee and Assignor, and the bibliographic information regarding the Intellectual Property. The inputted Intellectual Property information is sorted by country. Using the stored inputted information along with the stored template documents, the computer program product generates certain template documents per country. The template documents meet all the legal requirements of that country, listing all of the transferable properties, to affect a transfer of rights.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for transmitting a word (an information representative of the number of spreading codes) representative of transmission parameters respectively allocated to the mobile stations in communication with a base station of a mobile telecommunication system.
The present invention is concerned with mobile telecommunication systems comprising a number of base stations which can communicate with mobile stations. FIG. 1 shows a base station BTS in communication with three mobile stations MS 1 , MS 2 and MS 3 . The communication from a mobile station MSi to the base station BTS is done by means of an up-link UL and the communication from the base station BTS to a mobile station MSi is done by means of a down-link DL.
The present invention is also concerned with telecommunication systems wherein different user signals are separated both in time domain and in code domain. An example of such system is the so called UMTS TDD system or W-CDMA TDD system in which the time domain is represented by the TDD-system component and the code domain by CDMA-system component.
2. Discussion of the Background
More particularly, in time-domain, transmission is for example organised based on radio frames constituted of a number N (for example N=15) of timeslots. The same frequency is used for both the up-link (Mobile Station to Base Station) and the down-link (Base Station to Mobile Station). Furthermore, a time-separation is used to differentiate the down-link and the up-link such that a subset of the N available timeslots per frame is exclusively allocated for down-link transmission and the remaining ones for up-link transmission. In a frame, at least one timeslot is always allocated for each down-link and up-link.
In such a system, different user's signals can be transmitted in separate timeslots, e.g. N different down-link timeslots are allocated to N different down-link user signals. This is the time-domain of the system. Furthermore, several users signals can also be transmitted within one timeslot by using different spreading codes, This is the code-domain mode of the system.
In such a system, all base stations in an area operate synchronously and generally share the same up-link/down-link timeslot configurations.
In both up-link and down-link, user's data is transmitted in a timeslot arranged in a burst B comprising, as illustrated in FIG. 2, a first data field D 1 , a general midamble field M and a second data field D 2 . A midamble is a complex-valued chip sequence and is used by a receiver (the base station BTS in the up-link or a mobile station in the down-link) for channel estimation which is needed for the retrieval of the user's signals.
In the up-link, each mobile station MSi sends a different midamble m (i) , as the base station BTS needs an individual channel estimation for each mobile station transmitting in a particular timeslot.
Note that when a midamble is not explicitly assigned to a mobile station, a default fixed-allocation rule between its assigned spreading code and a particular midamble is used.
In the down-link shown in FIG. 2, generally just one midamble m (j) is used by the base station BTS for all user's signals within a particular timeslot. The reason is that in the down-link, all users experience just one down-link channel to estimate, e.g. from the base station BTS to itself and ignore those of the other users transmitting in the same timeslot. But in some situation, when more than one channel estimation is needed, more that one midamble can be used by a base station BTS. In this cases, the midamble M results in the summation of all these midambles.
A guard period G can be provided to ensure proper separation in time of consecutive timeslots. Also, signalling bits S can be provided.
In the up-link UL, data of a mobile station MSi is spread to the chip rate by a complex valued spreading code ai (or the spreading codes) which is (are) affected to this mobile station MSi by the system.
In the down-link DL, each data di intended for a mobile station MSi is spread to the chip rate by a corresponding spreading code ai (in 11 to 1 k on FIG. 2 ), the results of all these spreading operations being summed (in 20 ) to form the data D 1 and D 2 contained in the burst.
A problem occurs when an advanced detection algorithm such as blind code detection and multiuser detection are used for the retrieval of the user's signals at the receiver side. With such an algorithm implemented, data bits from all users transmitting in a timeslot are simultaneously decoded and decided at receiver-side. For optimal performance of the algorithm, the receiver needs to know amongst several parameters, the number of spreading codes used in the down-link in a particular timeslot.
Generally, when such an algorithm is implemented at a base station-side, the base station can have a knowledge of these parameters because the radio access network to which it belongs controls their usage.
But, the situation is quite different, when the considered algorithm is implemented at the mobile station in the down-link. A mobile station doesn't generally know the number of spreading codes which are allocated to the other user's signals simultaneously present in the same timeslot. This fact seriously impacts the implementation of the algorithm, such the blind code detection and multiuser detection, at the mobile station-side.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for a mobile station to determine the number of spreading codes that have been allocated to the other user's signals simultaneously present in the same timeslot and that are used in the down-link in such a way that this method do not present the underlying problem.
It is a further object of the present invention to provide a method which can be performed without any substantial constraint and, hence, which can be done fast and with only marginal delay.
It is a further object of the present invention to provide such a method that can be carried out in mobile telecommunication system designed in such a way that each mobile station in communication with said base station transmits data in bursts including a midamble or a sum of midambles that are affected to said mobile station and that said or each midamble is used for estimating the channel response between said mobile station and said base station, all said available midambles being derived from an unique basic midamble code by retaining only the elements of said basic midamble code which belong to respective predefined windows shifted one relative to another, said estimations being performed by correlating the received signal with a sequence based on said basic midamble code and channel estimation output being in temporal positions in one-to-one relationship with said available midambles.
The objects of the present invention are achieved by a method for transmitting an information representative of the number of spreading codes that includes the step of:
forming a word, said transmitted word, the content of which is representative of the number of spreading codes allocated,
including in each transmission burst, when data are transmitted from a base station to a mobile station, a general midamble resulting from the sum of selected midambles among all the available midambles, said selection being done by said base station in relation with said transmitted word so that a selected midamble corresponds to a binary element of said transmitted word equal to a first value and a non-selected midamble corresponds to a binary element of said transmitted word equal to second value, considering, at each mobile station side, after having correlated the signal received by said mobile station with a sequence based on the basic midamble code used during the formation of all said midambles, a received word the elements of which are in one-to-one relationship with the temporal positions of the estimations respectively corresponding to said available midambles, an element of said received word being equal to said first value when the corresponding position includes an estimation of the channel between the base station and the mobile station and being equal to said second value when the corresponding position doesn't, said received word equal to the transmitted word enabling said mobile station to have a knowledge of the number of spreading codes the number of spreading codes allocated to the mobile stations in communication with a base station of a mobile telecommunication system.
In accordance with an additional feature of the present invention, the formation of said transmitted word is done in such a way that to each state formed by a number or all of its bits corresponds a number of the allocated spreading codes.
In accordance with an additional feature of the present invention data of each mobile station in communication with said base station being transmitted by means of a plurality of channels, wherein the formation of said transmitted word is done in such a way that for each channel, to each state formed by a number of its bits identical for each channel, corresponds a number of the allocated spreading codes.
In accordance with an additional feature of the present invention, each of said states is equal to the binary value of the number of the allocated spreading codes.
In accordance with an other feature of the present invention, the relation between a state and a number of spreading codes is done in such a way that the number of significant bits of said state is bigger than needed to express the number of spreading codes that can be allocated. For example, to each position of a bit of said state corresponds the number of spreading codes.
In accordance with an other feature of the present invention, the number of spreading codes are grouped in groups of spreading codes, to each position of a bit of a number of significant bits of said state corresponds the number of spreading codes in a group, the other significant bits being in relation with the groups.
In accordance with an additional feature of the present invention, the numbers are grouped in such a way that to one group corresponds a plurality of numbers, the formation of said transmitted word being done in such a way that to one group corresponds one state of a number or all of its bits.
BRIEF DESCRIPTION OF DRAWINGS
The objects and advantages of the present invention become clear to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the following drawings:
FIG. 1 illustrates up-link and down-link in a telecommunication system for mobile stations, in which the present invention finds application,
FIG. 2 illustrates the formation of a burst in a base station of a telecommunication system,
FIG. 3 illustrates the formation of the midambules of a telecommunication system,
FIG. 4 illustrates an example of the result of a correlation process that is performed at the mobile station sides of a telecommunication system,
FIG. 5 illustrates the formation of a burst in a base station of a telecommunication system provided to perform a method according to the present invention,
FIG. 6 illustrates an example of the formation of the word W result of a correlation process that is performed at the mobile station sides of a telecommunication system provided to perform a method according to the present invention,
FIGS. 7 to 11 illustrates the formation of the word W according features of the method of the present invention.
DETAILED DESCRIPTION
The present invention proposes to use the midambles to form a word W which describes the number of spreading codes that are allocated to the mobile stations in communication with a base station by transmitting data in a same burst.
The formation of the midambles is first reminded in relation with FIG. 3 . The midambles are specific of the users who transmit within the same timeslot. They are all derived from a same basic code BMC, “basic midamble code”. The basic midamble code BMC is concatenated with itself in order to form a bloc B and each specific midamble m (i) (i=1 to k for k users) is derived from the basic midamble code BMC by retaining only the elements of the bloc B which belong to a predefined window. The window corresponding to a specific midamble m (i) is shifted of p elements compared to an adjacent window.
In the up-link, each mobile station MSi sends a midamble m (i) different from the others, as the base station BTS needs an individual channel estimation for each mobile station transmitting in a particular timeslot.
When the base station BTS receives a number of bursts transmitted by the mobile stations MS 1 to MSk containing each a midamble m (i) , a correlation with a special sequence based on the basic midamble code BMC is done and gives a channel estimation output for each of the user transmitting bursts in the same timeslot but in time-distinct windows. This is shown in FIG. 4 in the case of two mobile stations MS 1 and MS 2 sending two midambles m (2) and m (8) . The two channel estimation outputs are referenced E 1 and E 2 .
According to the prior art, in the down-link, generally just one midamble m (i) is used by the base station BTS for all user's signals within a particular timeslot. The reason is that in the down-link, all users experience just one down-link channel to estimate, e.g. from the base station BTS to itself and ignore those of the other users transmitting in the same timeslot. But in some situations, when more than one channel estimate is needed, more than one midamble can be used by a base station BTS.
FIG. 5 shows the formation of a burst B according an embodiment of the present invention in a base station BTS communicating with k mobile stations m (l) to m (k) . The processing of the spreading code is identical as the one described in the preamble of the present specification. A spreading process is carried out (in 11 ) with the data d i intended for each mobile station i and all thus spread data is summed (in 20 ) to form the data fields D 1 and D 2 .
Corresponding to each mobile station i, a midamble m (i) is formed according to the method described above in relation with FIG. 3. A selection unit 30 is provided to select some midambles in relation with a word W. The word W has as many elements wi (i=1 to k) as the number of available midambles m (i) so that one element wi of the word W corresponds unequivocally to one midamble m (i) : the first element corresponds to the first midamble, the second element corresponds to the second midamble, etc.
A control unit 40 formed the word W so that it describes the number of spreading codes allocated in the same timeslot to the mobile stations MS 1 to MSk that are in communication with the base station BTS. The formation of the word W will be described later below.
All the selected midambles are summed in a summation unit 50 in order to form the general midamble M of the burst B.
At a mobile station side (one of the mobile stations that are in communication with the base station BTS), a correlation with a special sequence based on the basic midamble code BMC used for the formation of the midambles is performed, the result of which is shown in FIG. 6 . In FIG. 6, each midamble m (i) selected by the control unit 40 of the base station BTS gives an estimation output that is positioned according to the shift of this midamble m (i) . In particular, in FIG. 6, the control unit 40 has selected the midamble m (2) , m (4) and m (8) and three estimation outputs E 1 , E 2 and E 3 appear respectively in the second position, the fourth position and the eighth position.
Note that the estimation outputs E 1 , E 2 and E 3 appearing as a result of the correlation process are identical since they concern the sole down-link DL. Always at the mobile station side, a word Wr is built up as follows. At a given position, when an estimation output appears, a binary information that is equal to a first value, for example 1, is considered and when it does not, a binary information that is equal to a second value, for example 0, is considered. The word Wr is the concatenation of the binary information corresponding to all the positions. At FIG. 6, the word Wr can be written “01010001”.
As each element wri of the word Wr corresponds to a midamble m (i) and as each element wi of the word W corresponds also to the same midamble m (i) , it can be understood that the word Wr is equal to the word W. Therefore, the word Wr describes the number of spreading codes in the same timeslot allocated to the mobile stations MS 1 to MSk in communication with the base station BTS as the word W does.
Note that the words W and Wr are both representative of the number of spreading codes used by all the users.
Each user in this way gets informed of the number of spreading codes that are allocated to all the users in the current timeslot and can take this information as input for a blind code detection algorithm, improving its performing and its efficiency.
Let's assume that N is the number of available midambles in the down-link.
An embodiment of the present invention is now described. A number n (with n≦N) of the bits (said latter the significant bits) of the transmitted word W forms a state composed of a series of bits having a first value (for example 1) and of bits having a second value (for example 0). To each state of these significant bits corresponds a number of spreading codes allocated.
For example, the binary value of each state formed by these significant bits can be equal to the number of the allocated spreading codes. Note that the maximum number of spreading codes can therefore be equal to 2 n−1 .
In FIG. 7, the number of available midambles is N=8 and, as the maximum number of spreading codes that can be allocated is 16=2 4 , the number of significant bits of the transmitted word W is n=5. The example is arbitrarily built over the five most significant temporal positions of the estimation outputs, but it has to be noticed that the temporal position of these used bits can be different. When k channels are used in the down-link (for example when k antennas of the base station transmit signals), the quantity of possible midambles can be split up equally between the channels. Hence, the formation of the word W can be done in such a way that for each channel a number n (with n≦N) of its bits, identical for each channel, forms states to which correspond all the numbers of spreading codes that can be allocated. Advantageously, the binary value of each state is equal to the corresponding number of spreading codes. The maximum number of spreading codes for each channel can therefore be equal to 2 n−1 . Note that the product k×2 n−1 must be lower than 2 N .
In FIG. 8, the number of available midambles is always N=8, the number of channels used is 2 and, as the maximum number, of spreading codes that can be allocated is 15=2 5 −1, the number of significant bits of the word W is n=4.
Note that W can present only 2 N states. In FIG. 8, since the maximum number of spreading codes that can be allocated is 16 and since it represents 16 states +1 state for the case where no code is used, number 15 aud 16 are grouped. This group doesn't imply a big performance degradation.
In case the number of available midambles N gives a word W which can represents a maximum number of states (or value) lower than the number of spreading codes that can be allocated, a plurality of numbers of spreading codes are grouped in one group corresponding to a state of the word W. This is the case in FIG. 9, where only three midambles are available. Hence, the word W can represents only 2 3 −1=7 states. For example, to the state 4, corresponds the group formed by the numbers 7 et 8 of spreading codes allocated.
That means that if 7 spreading codes are allocated, the word W will be 100. The same word W would be used if 8 spreading codes were allocated.
According to another example, state 6 corresponds the group formed by the numbers 11, 12 and 13 of spreading codes allocated. That means that if 11 spreading codes are allocated, the word W will be 110. The same word W 110 would be used if 12 or 13 spreading codes were allocated.
The relation between a state and a number of spreading codes can be done in such a way the number of significant bits of said state is bigger than needed to express the number of spreading codes and, hence, that a minimum of significant bits are used. The advantage of such a feature is that the less midamble shifts used, the more powerful and the easier to detect they are.
An example of such a relation is illustrated in FIG. 10 where the number of available midambles is N=8 and the number of spreading codes that can be allocated is also 8. It can be seen that the position of a significant bit corresponds to the number of spreading codes (For example, third position of the bit 1 of the word W corresponds to the number 3, . . . ).
Another example is illustrated in FIG. 11 where the number of available midambles is N=8 and the number of spreading codes that can be allocated is now 16. The number of spreading codes are grouped in groups (here two), one for number 0 to number 7, the other for number 8 to number 16. In each group, the position of a significant bit corresponds to the number of spreading codes. The remaining significant bits (here eighth) are used to define the groups. In FIG. 11, for the numbers of spreading codes extended from 8 to 16, eighth bit is set to 1 and a second bit is set to a position corresponding to the number of spreading code from number 8 (For example, number 10 corresponds to the state which eighth bit and second bit are equal to 1).
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Method for transmitting an information representative of the number of spreading codes allocated to the mobile stations in communication with a base station of a mobile telecommunication system. The method forms a word to be transmitted, the content of which is representative of the number of spreading codes allocated. In each transmission burst a general midamble resulting from the sum of selected midambles among all the available midambles is included. The selection is done by the base station in relation with the transmitted word so that a selected midamble corresponds to a binary element of the transmitted word equal to a first value and a non-selected midamble corresponds to a binary element of the transmitted word equal to a second value. A received word is considered, the elements of which are in a one-to-one relationship with the temporal positions of the estimations respectively corresponding to the available midambles.
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RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2013-031367 filed on Feb. 20, 2013, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a level shift circuit mounted on a semiconductor device.
[0004] 2. Background Art
[0005] A conventional level shift circuit will be described. FIG. 2 is a circuit diagram illustrating a conventional level shift circuit.
[0006] When an input voltage VIN goes to a high level, namely, a first power supply voltage VDD 1 , then an inverter 51 causes the gate voltage of an NMOS transistor 52 to become a ground voltage VSS. This causes the NMOS transistor 52 to turn off. Meanwhile, an NMOS transistor 53 turns on and an output voltage VOUT goes to a low level, namely, the ground voltage VSS. At this time, a PMOS transistor 54 is on, the voltage of an internal node N 1 is a second power supply voltage VDD 2 , and a PMOS transistor 55 is off
[0007] Further, when the input voltage VIN goes to the low level, namely, the ground voltage VSS, the inverter 51 causes the gate voltage of the NMOS transistor 52 to become the first power supply voltage VDD 1 . Then, the NMOS transistor 52 turns on, the voltage of the internal node N 1 becomes the ground voltage VSS, the PMOS transistor 55 turns on, and the output voltage VOUT goes to the high level, namely, the second power supply voltage VDD 2 . At this time, the NMOS transistor 53 is off (refer to, for example, Patent Document 1).
[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-134690
[0009] However, according to the art disclosed in Patent Document 1, if the first power supply voltage VDD 1 becomes lower than a minimum operating power supply voltage of the level shift circuit, then the circuit malfunctions, inconveniently making the output voltage VOUT unstable.
SUMMARY OF THE INVENTION
[0010] The present invention has been made with a view toward solving the problem described above and an object of the invention is to provide a level shift circuit free from malfunction.
[0011] To solve the problem described above, a level shift circuit according to the present invention is adapted to convert a signal of a first power supply voltage of a first supply terminal, which is supplied to an input terminal, into a signal of a second power supply voltage of a second supply terminal and outputs the converted signal to an output terminal. The level shift circuit includes a control circuit which detects when the first power supply voltage reduces below a predetermined voltage. The voltage of the output terminal of the level shift circuit is fixed to the second power supply voltage or a ground voltage by a detection signal of the control circuit.
[0012] According to the present invention, if the first power supply voltage is lower than the minimum operating power supply voltage, an output voltage of the level shift circuit is forcibly fixed to the second power supply voltage or the ground voltage, thus preventing the level shift circuit from malfunctioning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a circuit diagram illustrating a level shift circuit according to an embodiment of the present invention; and
[0014] FIG. 2 is a circuit diagram illustrating a conventional level shift circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The following will describe an embodiment of the present invention with reference to the accompanying drawings.
[0016] First, the configuration of a level shift circuit will be described. FIG. 1 is a circuit diagram of the level shift circuit. In the figure, the voltage of a first supply terminal is a first power supply voltage VDD 1 , the voltage of a second supply terminal is a second power supply voltage VDD 2 , and the voltage of a ground terminal is a ground voltage VSS. The level shift circuit converts a received signal of the first power supply voltage VDD 1 into a signal of the second power supply voltage VDD 2 and outputs the converted signal.
[0017] The level shift circuit includes a signal processing circuit 10 and a control circuit 20 . The signal processing circuit 10 has an inverter 11 , NMOS transistors 12 and 13 , PMOS transistors 14 and 15 , and switches 16 and 17 . The control circuit 20 has an NMOS transistor 21 , a current source 22 , and an inverter 23 .
[0018] In the level shift circuit, the input terminal of the signal processing circuit 10 is the input terminal of the level shift circuit. The output terminal of the signal processing circuit 10 serves as the output terminal of the level shift circuit. A first control signal terminal of the signal processing circuit 10 and a first control signal terminal of the control circuit 20 are interconnected. A second control signal terminal of the signal processing circuit 10 and a second control signal terminal of the control circuit 20 are interconnected.
[0019] In the signal processing circuit 10 , the input terminal of the inverter 11 is connected to the input terminal of the signal processing circuit 10 and the gate of the NMOS transistor 13 , the output terminal thereof is connected the gate of the NMOS transistor 12 , the supply terminal thereof is connected to the first supply terminal, the ground terminal thereof is connected to a ground terminal. The source of the NMOS transistor 12 is connected to a ground terminal, while the drain thereof is connected to an internal node N 1 . The source of the NMOS transistor 13 is connected to a ground terminal, while the drain thereof is connected to an internal node N 2 . The switch 16 is provided between the internal node N 1 and the ground terminal. The switch 17 is provided between the output terminal of the signal processing circuit 10 and the internal node N 2 . The gate of the PMOS transistor 14 is connected to the output terminal of the signal processing circuit 10 , the source thereof is connected to a second supply terminal, and the drain thereof is connected to the internal node N 1 . The gate of the PMOS transistor 15 is connected to the internal node N 1 , the source thereof is connected to the second supply terminal, and the drain thereof is connected to the output terminal of the signal processing circuit 10 . The switch 16 is controlled by a signal of the first control signal terminal of the signal processing circuit 10 . The switch 17 is controlled by a signal of the second control signal terminal of the signal processing circuit 10 .
[0020] In the control circuit 20 , the gate of the NMOS transistor 21 is connected to a first supply terminal, the source thereof is connected to a ground terminal, and the drain thereof is connected to an internal node N 3 . The current source 22 is provided between the second supply terminal and the internal node N 3 . The input terminal of the inverter 23 is connected to the internal node N 3 and a first control signal terminal of the control circuit 20 , the output terminal thereof is connected to a second control signal terminal of the control circuit 20 , the supply terminal thereof is connected to a second supply terminal, and the ground terminal thereof is connected to a ground terminal.
[0021] The NMOS transistor 21 and the current source 22 constitute a voltage detector circuit. The input terminal of the voltage detector circuit is the gate of the NMOS transistor 21 , while the output terminal thereof is the internal node N 3 . The voltage detector circuit detects when the first power supply voltage VDD 1 becomes a voltage of the total of a minimum operating power supply voltage and a predetermined voltage. The voltage is a threshold voltage of the voltage detector circuit, which is higher by a predetermined voltage than a power supply voltage at which the level shift circuit cannot actually operate, namely, the minimum operating power supply voltage. The predetermined voltage is adjusted, as necessary, according to the specifications of a semiconductor device. More specifically, the threshold voltage of the voltage detector circuit is adjusted by adjusting, as necessary, the threshold voltage and the size of the NMOS transistor 21 and the current amount of the current source 22 .
[0022] A description will now be given of the operation of the level shift circuit in the case where the first power supply voltage VDD 1 is lower than the minimum operating power supply voltage.
[0023] At this time, the first power supply voltage VDD 1 is lower than the threshold voltage of the voltage detector circuit. This causes the NMOS transistor 21 to turn off. The voltage of the internal node N 3 is pulled up by the current source 22 to the second power supply voltage VDD 2 . In other words, the first control signal becomes the second power supply voltage VDD 2 . The switch 16 is composed of, for example, an NMOS transistor, and when the gate voltage reaches the second power supply voltage VDD 2 , the switch 16 turns on, causing the voltage of the internal node N 1 to become the ground voltage VSS. Hence, the PMOS transistor 15 turns on, and the output voltage VOUT is forcibly fixed to the second power supply voltage VDD 2 . Thus, in the case where the first power supply voltage VDD 1 is lower than the minimum operating power supply voltage, the output voltage VOUT of the level shift circuit is forcibly fixed to the second power supply voltage VDD 2 , thus preventing the level shift circuit from malfunctioning.
[0024] The voltage of the internal node N 3 is the second power supply voltage VDD 2 , so that the second control signal is set to the ground voltage VSS by the inverter 23 . The switch 17 is, for example, an NMOS transistor, and the gate voltage is the ground voltage VSS, so that the switch 17 is off.
[0025] Thus, if the first power supply voltage VDD 1 is lower than the threshold voltage of the voltage detector circuit, then the output voltage VOUT of the level shift circuit is forcibly fixed to the second power supply voltage VDD 2 .
[0026] A description will now be given of the operation of the level shift circuit in the case where the first power supply voltage VDD 1 is higher than a voltage of the total of the minimum operating power supply voltage and the predetermined voltage.
[0027] At this time, the first power supply voltage VDD 1 is higher than the threshold voltage of the voltage detector circuit. This causes the NMOS transistor 21 to turn on. The voltage of the internal node N 3 becomes the ground voltage VSS. In other words, the first control signal becomes the ground voltage VSS, so that the switch 16 turns off. Further, the inverter 23 causes the second control signal to be the second power supply voltage VDD 2 , so that the switch 17 turns on.
[0028] Then, when the input voltage VIN goes to the high level, namely, the first power supply voltage VDD 1 , the inverter 11 causes the gate voltage of the NMOS transistor 12 to become the ground voltage VSS. This turns the NMOS transistor 12 off Meanwhile, the NMOS transistor 13 turns on and the output voltage VOUT goes to the low level, namely, the ground voltage VSS. At this time, the PMOS transistor 14 is on, the voltage of the internal node N 1 is the second power supply voltage VDD 2 , and the PMOS transistor 15 is off
[0029] Further, when the input voltage VIN goes to the low level, namely, the ground voltage VSS, the inverter 11 causes the gate voltage of the NMOS transistor 12 to become the first power supply voltage VDD 1 . Then, the NMOS transistor 12 turns on, the voltage of the internal node N 1 becomes the ground voltage VSS, the PMOS transistor 15 turns on, and the output voltage VOUT goes to the high level, namely, the second power supply voltage VDD 2 . At this time, the NMOS transistor 13 is off.
[0030] If the first power supply voltage VDD 1 is higher than the threshold voltage of the voltage detector circuit as described above, then the output voltage VOUT of the level shift circuit depends on the input voltage VIN.
[0031] The current source 22 may use, for example, a resistive element, as long as the pull-up function is implemented.
[0032] Further, the control signal supplied to the switch 16 and the control signal supplied to the switch 17 may be interchanged, and the output terminal and the internal node N 1 of the level shift circuit may be interchanged.
[0033] The gate of the NMOS transistor 21 is directly connected to the first supply terminal. Alternatively, however, the gate of the NMOS transistor 21 may be connected to the first supply terminal through a resistance voltage divider circuit.
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There is provided a level shift circuit free from malfunction. The level shift circuit converts a signal of a first power supply voltage of a first supply terminal, which is supplied to an input terminal, into a signal of a second power supply voltage of a second supply terminal and outputs the converted signal to an output terminal. The level shift circuit has a control circuit that detects when the first power supply voltage reduces below a predetermined voltage. The voltage of the output terminal of the level shift circuit is fixed to the second power supply voltage or a ground voltage according to a detection signal of the control circuit.
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RELATED PATENT APPLICATION
[0001] This application claims benefit of priority to a provisional application, serial No. 60/252,957, filed Nov. 25, 2000, which is hereby incorporated by reference to the same extent as though fully disclosed herein.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] This invention relates to the operation of different types of model electric railroad trains and more particularly, but not by way of limitation, to a system for operating both AC powered three-rail model trains and DCC powered two-rail model trains simultaneously and independently of each other on the same track.
[0004] Model trains have been popular with children and adults since the first railroads were built. Since the beginning, there has been continuous but slow effort to make the model trains more realistic and operation more nearly match fill-sized trains. The earliest model trains were kid's toys pushed by hand across the floor. In the first years of 1900, Joshua Lionel Cowan introduced the first battery powered trains and then trains powered by an AC transformer. Controlling the AC voltage allowed the train speed to be varied. Later, Ives added a stepper relay called an “E-Unit” to their trains. By interrupting the power, the stepper relay would cycle, applying a polarity reversal to the motor and reversing the direction to the train. By 1906 Cowan introduce three-rail track to solve a problem, know as the “reverse-loop problem,” created when a track looped back upon itself, shorting one outside rail to the opposite side.
[0005] The problem of controlling multiple AC powered trains has proven to be intractable. The simple, traditional method has been to divide the track layout into power blocks or “districts.” By switching different transformers to the electrically isolated blocks containing the trains, it is theoretically possible to control as many trains as there are transformers and blocks. In practice, operating more than one train at a time by switching power to different blocks as the train moves about the layout overloads the operator. Yet, because of the lack of a suitable option, block switching is still the primary means to control multiple AC powered trains.
[0006] With the perfection of low cost permanent magnet motors and inexpensive solid-state power supplies in the second-half of the century, Direct Current (DC) became the favorite means to control model trains. These DC powered model trains were predominately the smaller HO and N gauges; all were two-rail. The reverse loop problem was not really solved but the impact was mitigated by solid-state switches that sensed the short caused by a train crossing the phase reversal boundary of a reverse loop. The solid-state switch reversed the polarity of that reverse loop track section. These current reversal switches require the model railroader to understand the track topology that creates a reverse loop and then determine where to put the reverse loop switches.
[0007] In the seventies, numerous schemes were tried to add command control to the two-rail model trains. Because the incompatibility of the different schemes was hurting the industry, the model train manufacturers agreed upon a digital command control protocol known as DCC (Digital Command Control), The National Model Railroad Association formalized the protocol as NMRA specifications S-9.1 and S-9.2. DCC has since become popular for two-rail model trains of all scales. The DCC command control system provides for independent operation of many locomotives and accessories without electrically insulated blocks and toggle switches to control power routing. While it is possible to apply a DCC signal to the center rail of a three-rail track it is seldom done because of incompatibility with other three-rail AC trains and track layouts.
[0008] In the mid-1990s, Lionel introduced a system called the Trainmaster® command control system, also known as TMCC. In the traditional format, the speed is controlled by varying the voltage. With TMCC, the track is supplied with a constant AC voltage and signals are digitally transmitted to the train. However, TMCC is limited to 10 engines per system unit. TMCC uses a proprietary carrier system with a low-level radio signal. The TMCC radio signals travel through the air and are subject to interference. It is common, for instance, for control to be lost when a TMCC train enters a tunnel made of metal mesh. Furthermore even though there is some compatibility with traditional AC controlled trains, it is not possible to independently operate a traditional AC engine and a TMCC engine in the same power block simultaneously.
[0009] Recently Dallee Electronics, Inc. produced a command control system, first used by Atlas, LLC, called Locomatic™, which provides for additional control. The Locomatic™ is a pass-through device wired between the transformer and the track. The Locomatic™ system provides control for sounds, lights, speed, direction and other features. However, the Locomatic™ system is even more limited than the TMCC system since operation is permitted for only one engine of any type per power block.
[0010] MTH Electric Trains has recently demonstrated a different digital command control system. The suggested unique wiring suggests that the system will not operate well on large layouts because of transmission line effects. The company also states that this system is not compatible with Lionel's newest three-rail AC engines. This system suffers the same limitation of the other three-rail command control schemes in that it not possible to independently operate a traditional AC engine and a command control engine in the same power block simultaneously.
[0011] Other developers, notably Severson and Quinn of QSI, Inc., have achieved limited control by changing AC wave shape or by adding DC offsets. These schemes have the advantage that the control information is the same amplitude as the power voltage providing a more robust signal but suffer from having limited bandwidth and offer no other advantages over the systems described above.
[0012] The compatibility restriction is a serious limitation since three-rail AC powered trains have remained essentially unchanged for nearly a century with the existence of enormous numbers of three-rail AC trains. These trains would essentially become obsolete with the widespread acceptance of any of the above AC command control schemes. The incompatibility results because interrupting the power to control the traditional AC trains interrupts power to control the command control trains as well, causing everything to halt.
[0013] A different problem associated with model train power sources is the limited currents that can be safely supplied to heavily loaded model trains. The electrical current, about ten amps, available on the track rails is high enough to start fires in some situations. Yet this current is insufficient to prevent some long, heavy trains from stalling. Manufacturers that have produced AC transformers with higher current capabilities have been unable to get the power supplies UL listed because of the unsafe current levels.
[0014] Another problem found in prior art is that if there is a short circuit on a section of track, all the track and motors are disabled within that electrically isolated block of the track. Accessories tied to that section of track would also be disabled. Thus, most model railroaders wire accessories with entirely separate wiring. This however brings its own problem; the feeder wires complicate and clutter the layout.
[0015] A further problem is that most of the existing schemes of deploying power to the trains use the track rails as the electrical contact to connect adjacent sections with “rail joiners,” electrical contacts that slide on or into the butted rails. The rail joiners often make unreliable electrical contact and cause an additional voltage drop. Many model railroaders solder the rail joiners to improve reliability. However, this step makes the layout less portable and is time consuming to construct.
[0016] None of the above mentioned model train power control systems used with engines and two-rail and three-rail tracks specifically disclose the unique features, structure and function of the subject model railroad train control system as disclosed herein.
SUMMARY OF THE INVENTION
[0017] A primary object of the subject system is to combine one or more traditional AC powered three-rail model trains with one or more modern DCC two-rail model trains to operate simultaneously and independently on the same track.
[0018] Another object of the train control system is through the use of one or more high current drive signal modules connected to the track, power and commands can be sent via the outer two rails of the track while remaining compatible with existing three-rail AC powered trains.
[0019] Yet another object of the system is by combining traditional AC transformer control with the technical advances of the National Model Railroad Association's DCC system, superior performance and vastly expanded capabilities are achieved.
[0020] Still another object of the system is the high current drive signal modules includes power transistors for rapid high voltage output and return current path for the DCC equipped two-rail trains and the AC three-rail model trains.
[0021] The train control system includes one or more current limited voltage source modules connected to the track for providing modulated voltage to each engine. Each module has two identical channels composed of power transistors for a left track power output and two identical channels composed of power transistors for a right track power output. The outputs rapidly switch, alternately, between ground potential (zero volts) and up to 48 volts. The transistors provide a return current path for both the DC or DCC two-rail engine and the AC three-rail engine. The power transistors are individually current limited and have a response time in a range of 1 to 5 microseconds. The fast response time means trains with shorting wheelsets will not cause excessive current from the power supply, since the average current is very low. The action of the current is limited in one phase and does not effect the operation of the other phase.
[0022] These and other objects of the present invention will become apparent to those familiar with different types of model train track systems when reviewing the following detailed description, showing novel construction, combination, and the various embodiments of the invention as herein described, and more particularly defined by the claims, it being understood that changes in the embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings illustrate complete preferred embodiments in the present Invention according to the best modes presently devised for practical application of the principals thereof and in which:
[0024] [0024]FIG. 1 illustrates a top view of a traditional three-rail track system connected to alternating current for driving an AC train engine.
[0025] [0025]FIG. 2. illustrates a top view of a two-rail system track system connected to a digital command control or DCC for driving a DCC train engine.
[0026] [0026]FIG. 3 illustrates a block diagram of the subject invention connected, for example, to four track sections having railroad cars with shorting and non-shorting axles.
[0027] [0027]FIG. 4 illustrates a top view of a track system using one of the current limited voltage source modules connected to the track so that either an AC or DCC controlled train can operate on the track, but not at the same time.
[0028] [0028]FIG. 5 illustrates a top view of another track system using three of the subject modules connected to three section of the track so that the AC train and the DCC controlled train can operate at the same time, but only on separate sections of the track. FIG. 6 illustrates a top view of still another track system having a plurality of modules connected to a number of sections of track whereby the track is laid out so that either AC or DCC trains can run simultaneously on the same track and without restriction.
[0029] [0029]FIG. 7 is a perspective view of a connector with wiring used for attaching the voltage source module to a section of the railroad track.
[0030] [0030]FIG. 8. is a circuit diagram of the current limited voltage source module
[0031] [0031]FIG. 9 is a circuit diagram of a current source module.
[0032] [0032]FIG. 10. illustrates a side view of a model train engine with one of the current limited voltage source modules used as an engine module with the engine to run on either two-rail or three-rail track systems FIG. 11 is a circuit diagram of the engine module used for installing in the model train engine shown in FIG. 10.
[0033] [0033]FIG. 12 is a continuation of the circuit diagram of the module shown in FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] In FIG. 1, a top view of a traditional prior art three-rail track system is illustrated and having general reference numeral 10 . The three-rail track system 10 includes two outer rails 12 and 14 , or left and right rails, connected to ground 16 and a center rail 18 connected to a source 20 of AC voltage for driving an AC train engine. The three-rail system applies the AC voltage to the center rail 18 . This voltage 20 is picked up with a center-rail pick-up roller that powers the train and is then returned through the wheels that are in contact with the outside rails 12 and 14 . The model train is not shown in the drawings. Normally, both outside rails 12 and 14 are grounded but it is only necessary that one rail be grounded, since the metal wheels and axles short the outer rails together.
[0035] In FIG. 2, a top view of a prior art two-rail system track system is illustrated and having general reference numeral 22 . The two-rail track system 22 includes two outer rails 12 and 14 connected to a left digital command control signal 24 or DCC Left and a right digital command control signal 26 or DCC Right. Two-rail track systems 22 apply a differential voltage, DCC or otherwise, across the two rails 12 and 14 . DCC includes a command control protocol for independently controlling any number of trains on a track layout. This differential voltage is picked up by the train wheels for powering the train.
[0036] In FIG. 3 the subject invention includes broadly a current limited voltage source module having a general reference numeral 28 . In this illustration, four of the modules 28 are shown having a left rail output drive lead 30 and a right rail output drive lead 32 connected to the left and right rails of track sections 34 . The left, right and center rail of the track sections 34 are not shown in this drawing. It is important to note that, in this example, the opposite ends of each track section 34 are separated and insulated from each other.
[0037] In this drawing, the two track sections 34 on the left are shown receiving wheels 36 of a first railcar 38 or engine thereon. The first railcar 38 includes shorting axles 37 connected to wheels 36 engaging the left and right rails. A second railcar 40 or engine is shown with wheels 36 engaging the two center track sections 34 . A third train car 42 is shown with wheels 36 engaging the two track sections 34 on the right. The second and third train cars 40 and 42 include non-shorting axles 39 .
[0038] The center rail of the track sections 34 is connected to an AC voltage source by an AC output lead 44 connected to an AC transformer 46 having a ground 48 . Each of the modules 28 are connected to a left rail input lead 50 , a right rail input lead 52 , a 16 volt power lead 54 and ground 48 . The leads 50 , 52 , 54 and 48 are also connected to a power source module 56 . The power source module 56 is connected to a DCC command generator 58 via the left lead 50 and the right lead 52 . The module 56 is also connected to a DC power supply 64 via a 20 volt power lead 66 .
[0039] The module 28 amplify the DCC signals from the DCC command generator 58 to provides a +16 Volts DCC signal, current limited to 5 Amps, to the left and right rail of the track section 34 . These signals will power a DCC engine or an AC engine. If, however, the AC engine or cars with shorting wheelsets is on one of the track section 34 , the module 28 for that particular track section will immediately go into a current limit so that excessive currents will not flow through the wheelset. Only the positive voltage excursions are current limited. The rail held at ground potential is not current limited and can handle AC ground return currents up to 40 Amps.
[0040] In FIG. 4, a top view of a simplified first track system having general reference numeral 68 is illustrated. The first track system 68 includes outer rails 12 and 14 and a center rail 18 connected on one of the current limited voltage source modules 28 shown in FIG. 3. The module 28 is connected to the track system 68 so that either an AC or DCC controlled train can operate on the track, but not at the same time.
[0041] In FIG. 5, a top view of a second track system having general reference numeral 70 is illustrated. In this example, three of the subject modules 28 are connected to three independent track sections 34 of the track system 70 so that an AC train and a DCC controlled train can operate at the same time, but only on separate track sections 34 of the track.
[0042] In FIG. 6, a top view of a third track system having general reference numeral 72 is illustrated. In this drawing, a plurality of the current limited voltage source modules 28 are shown connected to a number of individual track sections 34 . In this example, the track system 72 is laid out so that either AC or DCC trains can run simultaneously on the same track and without restriction and as illustrated in FIG. 3.
[0043] In FIG. 7, a perspective view of a connector block 72 is shown mounted on one of the current limited voltage source modules 28 with electrical leads 44 , 48 , 50 52 and 54 as shown in FIG. 3. The connector block 72 is used for attaching the module 28 to the underside of a portion of a track section 34 as shown
[0044] In FIG. 8, a circuit diagram of the current limited voltage source module 28 is shown. As discussed in FIG. 3, the inputs to the module 28 are the left rail input lead 50 , the right rail input lead 52 , the 16 volt power lead 54 and the ground 48 . The 16 volt power lead 54 and the ground 48 are bypassed with a Capacitor C 4 . Capacitor C 4 supplies the switching transient currents for the module 28 . The DC power supply 64 is only required to supply a steady state of current. The heart of the module 28 is an H-Bridge Driver U 2 . This part, a Harris HIP4082 semiconductor, is powered through Diode D 1 connected to the VDD pin and with the VSS pin connected to ground 48 , Diode D 1 isolates U 2 from the switching transients; Capacitor C 1 holds up the VDD voltage during the transients. This VCC voltage is also connected to the VDD pin of Voltage Comparator U 1 . The VSS pin of U 1 is likewise connected to ground 48 . U 1 is an industry standard dual voltage comparator and is used in this circuit to sense over-currents. The left and right leads 60 and 62 from the DCC command generator 58 are connected to the BLI and ALI pins of U 1 , respectively. These inputs are the left and right low-side driver inputs. The high-side driver inputs, the AHI and BHI pins of U 2 , are connected to the outputs of the Comparator U 1 to take advantage of a unique characteristic of the HIP4082. The AHI and BHI pins of U 2 are interlocked internally with the low-side drive inputs. Thus these inputs can be held high continuously during normal operation. If either comparator output drops due to an over-current condition, the high-side drive is removed for that channel but the low-side drive continues to function. Since the LEFT and RIGHT DCC drive signals are of opposite polarity but have otherwise identical timing, one of either the LEFT TRACK DRIVE or RIGHT TRACK DRIVE signals is always grounded. In this embodiment the DIS pin of U 2 is tied to the ground 48 , continuously enabling U 2 .
[0045] The HIP4082 uses an internal charge pump circuit to provide sufficient drive for N-Channel FETs. Diode D 2 and Diode D 1 rectify the right and left charge pump voltages; Capacitor C 2 and Capacitor C 3 filter the rectified signals. The charge pump voltages are fed into U 2 pins AHB and BHB. The right side, low-side driver, FET Q 4 , is driven by U 2 output ALO through Resistor R 15 . Resistor R 15 combined with the inherent gate capacitance of Q 4 provides a slight delay in Q 4 turn-on and turn-off. FET Q 2 and Resistor R 13 , connected to U 2 output BLO perform the equivalent function for the left side driver. The right side, high-side driver, FET Q 3 , is connected to U 2 output drive pin AHO through Resistor R 14 and paralleled Diode D 7 . Resistor R 14 has a higher value than the corresponding low-side Resistor R 15 . This higher resistance value causes FET Q 3 to turn on much slower than the low-side driver. The delay is set at about one microsecond to allow Comparator U 1 enough time to sense a short circuit on the output before the current becomes excessive. Diode D 7 quickly discharges Q 3 's gate capacitance when the drive signal falls so that Q 3 turns off without significant delay. FET Q 1 , Resistor R 12 , and Diode D 6 perform the equivalent function for the right side, high-side drive. Resistor R 12 and Diode D 6 connect to U 2 output BHO. The DIS input pin of U 2 is an input delay adjustment. Resistor R 11 is selected to create a minimum delay between activation of the high and low side drives without shoot-through current.
[0046] Resistor R 16 and Resistor R 17 are each connected between the 16 volt power lead 54 and high-side FET Q 1 and FET Q 3 , respectively. Resistor R 16 and Resistor R 17 are 0.1 ohm current sense resistors. They are connected to positive inputs of Comparator U 1 through a voltage divider comprised of Resistor R 4 and R 10 for the right side and voltage divider Resistor R 3 and R 9 for the left side. Speed-up Capacitor Cx and Capacitor Cy are paralleled across Resistor R 3 and Resistor R 4 , respectively, to increase the sensitivity of Comparator U 1 to the rapid rise of the current when the left and right rail drive leads 30 and 32 outputs are shorted. Right side Comparator U 1 output is connected back to the positive right side input through Resistor R 5 . This relatively low value resistor causes the comparator to latch up if an over current level is sensed. The latch-up condition is cleared when the drive outputs switch phases by Diode D 4 . Diode D 4 is connected from the right rail drive lead 32 output and the negative input of U 1 . Resistor R 6 is likewise connected between left side comparator output and the positive input of U 1 . Reference voltage divider comprised of Resistor R 2 and Resistor R 8 set the voltage level at the right side comparator input to trip at a right side current level of five Amps. Reference voltage divider comprised of Resistor R 1 and Resistor R 7 set the voltage level for the left side comparator input in a similar manner. Diode D 5 is connected from the left rail drive lead 30 output and the left side negative input of U 1 to clear left side latchups.
[0047] In FIG. 9, a circuit diagram of a current source module is shown and having general reference numeral 74 . The primary function of the current source module 74 is to steer return currents back to their sources. The ground return connections for the AC transformer 46 , the DC power supply 64 , and the DCC command generator 58 are all connected together in the second module 74 . Normally currents from both the AC transformer 46 and the DC power supply 64 flow through the ground connection of the current limiting voltage source module 28 back to their respective sources. However, if one rail of an AC powered train becomes isolated from the wheels, for example due to dirt on the wheels, the transformer 46 will attempt to return current through the 16 volt power lead 54 to the module 28 . This voltage could pump-up the 16 volt power lead 54 and possibly damage the DC power supply 64 and the connected modules 28 . The power buffer, U 3 , in the current source module 74 can both source and sink current. Thus, AC currents appearing on the 16 volt power lead 54 are shunted back to the AC transformer 46 by the output stage of the power buffer. A 16 Volt Zener Diode, provides the reference voltage for the power buffer.
[0048] In FIG. 10, a side view of a profile of a model train engine 76 is shown with an engine module. The engine module is shown having a general reference numeral 77 . The engine module 77 is mounted on the engine 76 . With the engine module 77 incorporated into the engine 76 , the engine is now able to run on either two-rail or three-rail track systems. The engine module 77 is connected to a DCC Decoder 78 and an E-Unit 80 . The Decoder 78 and the E-Unit 80 are connected to a relay 82 connected to the engine's motor 84 .
[0049] In FIGS. 11 and 12, a circuit diagram of the engine module 77 is illustrated. The engine module 77 is not necessary to operate the modules 28 and the track systems described above since one or more modules 28 can run conventional DCC equipped trains as well as unmodified three rail AC trains. In a preferred embodiment, the engine module 77 is used to modify a locomotive to operate on traditional three rail layouts, two rail DCC layouts and, of course, the present invention layouts.
[0050] For example, power enters the engine module 77 through Wipers 1 , 2 , 3 , 4 , 5 , 6 , 7 , and 8 . Wiper 1 and Wiper 2 contact the outer rear wheels 36 of a wheelset 86 . A full-wave bridge rectifier comprised of Diode D 8 , Diode D 9 , Diode D 10 , and Diode D 11 rectify the DCC signal from Wiper 1 and Wiper 2 if a DCC signal is present on the outer rails 12 and 14 . Wipers 3 - 8 and Diodes D 12 -D 23 likewise rectify the DCC signal from the other three wheelsets 86 . The four sets of bridge rectifiers composed of Diodes D 8 -D 23 are connected in parallel. These rectifier outputs are +15VOLTS and +15VRET. The +15VOLT signal powers the standard decoder 78 and the coil of relay 82 . Power to the relay 82 transfers power from the decoder 78 and the normally closed contacts of the relay to the wipers of relay 82 . Engine motor 84 , connected to the wipers of relay 82 is thus powered by the decoder 78 . Wipers 1 , 3 , 5 , and 7 are also connected to the anodes of Diodes D 24 , D 25 , D 26 , and D 27 to obtain a replica of one polarity of the DCC signal. The cathodes of Diodes D 24 , D 25 , D 26 , and D 27 to the Red input pin of the Decoder 9 to supply the serial digital commands to the decoder 78 . Resistor R 18 acts as a pull-down current sink to prevent the signal on the cathodes of Diodes D 24 , D 25 , D 26 , and D 27 from floating during the low intervals of the DCC signal.
[0051] Inductor L 1 is also connected between Wipers 1 and 2 ; Inductor L 2 is connected between Wipers 3 and 4 . Inductor L 3 is connected between Wipers 5 and 6 . Inductor L 4 is connected between Wipers 7 and 8 . These center-tapped inductors have sufficient inductance that they appear as essentially an open circuit at DCC frequencies. However, in the absence of a DCC signal on the wipers, and if an AC signal is present on wheelsets 86 , AC current flows from the wipers through the inductors to the center tap pins of those inductors. The currents in the two sides of the inductors generate opposing magnetic fields and cancel, making the inductors appears as short circuits to the AC current. These center-tapped inductor pins form the return path for the AC current that flow from the wheelsets 86 , through the E-Unit 80 (stepper relay of a type common in the industry) back to the inductor center-taps. The output of the E-Unit 80 is connected to the normally open contacts of unenergized relay 82 . Thus, engine motor 84 obtains power from the E-Unit 80 in the absence of a DCC signal.
[0052] Should one side of an inductor become disconnected from its side of the track, the inductance at of the inductor at 60 Hertz is sufficiently low that the inductor rapidly saturates and appears to the AC current as a short circuit. Therefore only one roller of rollers 88 on the wheelset 86 needs to make contact with the track section 34 for normal operation of the engine module 77 .
[0053] As illustrated in FIG. 3, each track section 34 is independently powered by a separate modules 28 . Straight sections of standard three-rail track are commonly 10 inches long. Curve sections may be slightly longer or shorter. In any case, this is normally less than the length of standard railroad cars and engines. Since each wheelset 86 on a car can independently pick-up power from the rails, it is only necessary that a single wheelset 86 be unshorted to power that car or engine. The left-most car 38 in FIG. 3 is a traditional railroad car with shorting wheelsets. These wheels bridge the two first track sections 34 , shorting the module 28 and causing it to go into current limit. The second car's left most wheelsets are setting on the shorted track section 34 and therefore does not get power. However, because the track sections 34 are short enough, the right most wheelset of the center car 40 can get power from the unshorted third track section 34 . Therefore, with most combinations of traditional railroad cars with shorting wheelsets and DCC decoder equipped cars with non-shorting wheelsets, the traditional cars do not inhibit operation of the decoder equipped cars.
[0054] The crossed left and right rail drive leads 30 and 32 shown in FIG. 3 and connecting the track section on the right to one of the modules 28 represent a phase reversal of the DCC signals from one track section to the adjacent section. This situation will occur if the track layout topology connected one outside rail 12 to the opposite rail 14 is a “Reverse Loop” or “Wye” track configuration. In the example shown, the left-most wheelset of the car 42 on the right senses a different polarity DCC signal than the other three wheelsets. In this example, the DCC signals would cancel and not be sensed by the DCC Decoder as the car is crossing the phase reversal. Normally, this would not be a concern since phase reversals only occur in a few places on a layout. However, the bridge rectifiers would independently generate the voltage to operate any functions, such as lights, that had been commanded earlier.
[0055] While the invention has been particularly shown, described and illustrated in detail with reference to the preferred embodiments and modifications thereof, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention as claimed except as precluded by the prior art.
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A model railroad train control system for supplying power to at least one DCC two-rail operated train engine and/or at least one AC three-rail operated train engine. The train control system used for operating the engines simultaneously and independently on the same railroad track or separate train section blocks making up the track. The control system includes one or more current limited voltage source modules connected to the track for providing modulated voltage to each engine. Each module has two identical channels composed of power transistors for a left track power output and two identical channels composed of power transistors for a right track power output. The outputs rapidly switch, alternately, between ground potential (zero volts) and as high as 48 volts. The transistors provide a return current path for the DCC two-rail engine and the AC three-rail engine. The power transistors are individually current limited and have a response time in a range of 1 to 5 microseconds. The fast response time means trains with shorting wheelsets will not cause excessive current from the power supply, since the average current is very low. The action of the current is limited in one phase and does not effect the operation of the other phase.
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This is a continuation of application Ser. No. 07/619,956, filed Nov. 30, 1990 now abandoned.
This U.S. patent application is related to U.S. Disclosure Document Number 257504 filed Jul. 12, 1990.
BACKGROUND OF THE INVENTION
The growing emphasis on the state of the environment requires the development of accurate, inexpensive testing methods to detect organic contaminants in soils and water. The effective pollution management of our lakes, other waterways, subsoils and the subterranean water table demands regular and stringent testing. The effectiveness of such testing is enhanced when the tests are simple, inexpensive, can be operated on site and give a rapid result. In this way, the progress of the toxic clean-up from the waterway can be monitored to see if clean-up efforts are meeting existing state or federal guidelines. Very often soil assays must be made before land sales can be completed if the presence of a contaminant once existed on the site or suspected to be present. The detection of the adverse effects from leaking underground storage tanks can be enhanced if convenient tests can be routinely run on soil and water samples taken directly from near the buried storage tanks. The extent to which a toxic spill has penetrated and thus contaminated the subsoil and/or the groundwater can be more effectively determined, assayed and monitored if the subsoil and/or the groundwater can be collected, sampled and tested directly on-site.
Further, the safety of workers in enclosed working facilities which handle potentially harmful organic compounds could be enhanced if simple testing kits were available to test routinely and accurately for the presence of contaminants in the air or water being consumed by the work force. For example, factory air could easily be bubbled through an aqueous solution which in turn could be tested for the presence of the harmful organic compounds. Alternatively, absorptive charcoal badges as are known in the art and used in the workforce, could be worn by the workers, collected after a specified period, treated with suitable extraction liquid and assayed.
However, it has been difficult accurately to assess the presence, especially on a quantitative basis, of certain volatile non-polar organic compounds such as, for example, benzene, toluene, xylene, perchloroethylene and trichloroethylene, that have limited solubility in polar solvents e.g., in water. Some organic compounds are so volatile that even short delays in testing a sample can result in their evaporating from the sample completely, or at very least, sufficiently to significantly alter the true value of the actual contaminant concentration in a particular environment. This problem is exacerbated when the contaminant being tested for is non-polar and only minimally soluble in common polar solvents such as water.
Water is an important source for the purpose of detecting organic contaminants since large and small bodies of water, both above and below ground level are often found to contain various contaminants, and hence are the target of contaminant testing. In addition, water is an inexpensive, safely transportable, non-volatile solvent and can easily be used to wash contaminated soil samples, thus obtaining soluble and partially soluble organic contaminants in aqueous solution.
Quick, inexpensive and accurate qualitative and quantitative tests are needed for the detection of certain organic compounds directly from water or soil. The present invention is an improvement upon known environmental immunoassay tests involving the collection and sampling of water, soil, or air followed by the testing of the water, soil, or air samples, for various contaminants including volatile organic compounds. The improvement according to this invention comprises improving immunoassay accuracy by eliminating all separate sampling steps and testing samples, as collected, on site, for the presence of suspected contaminants. It is contemplated that the air may be tested by dissolving the air sample in a suitable solvent such as, e.g. water or methanol, or absorbing air in activated charcoal that is then extracted with suitable solvent such as, e.g. methanol.
Related immunoassays are disclosed in the commonly assigned and related U.S. patent application, Ser. No. 059,721 filed Jun. 9, 1987 and now abandoned, and its copending, commonly assigned continuation-in-part U.S. application Ser. No. 200,952 filed Jun. 1, 1988. As taught in these U.S. patent applications, many techniques are known for determining the presence of volatile organic compounds in the workplace and the environment, such as gas chromatography, mass spectrophotometry, and high performance liquid chromatography. One drawback to these detection and testing methods is the need to transport the collected samples to an off-site laboratory for further analysis. The vessels containing the samples to be tested must be carefully packaged and shipped to off-site laboratory facilities which in turn raises the overall testing costs. Even the least porous containers suffer the drawback of losing some of the contained volatile materials when the sample containers are opened and prepared for testing such as, e.g., during the preparation of dilutions, or transfer to testing receptacles. The volatile contaminants thus evaporate from the collected sample, inevitably adversely affecting the accuracy of the test result. Certain especially volatile contaminants may leave the sample altogether, resulting in false negative test results indicating a false absence of potentially hazardous compounds at a particular testing site, or drastically understating the true volatile contaminant concentration.
Immunoassays have been commonly used in connection with diagnostic testing, and in conjunction with monitoring drug levels in humans and various animals. However, the use of immunoassay techniques to ascertain the extent to which certain contaminants are present in the environment is relatively new. The use of immunoassays to detect aromatic ring-containing hydrocarbon compounds in soil and aqueous solutions has been disclosed in the aforementioned commonly assigned U.S. patent applications.
The immunoassays according to the invention of this application, are normally assembled in the form of field test kits to be brought directly to the site to be tested. Such tests and test kits are relatively inexpensive, and can be designed to give accurate and immediate results. Soil and aqueous samples suspected of containing various volatile organic contaminants, such as, for example, benzene, toluene, xylene, perchloroethylene and trichloroethylene may thus be tested immediately on-site, before any substantial evaporation of the hazardous volatile contaminant can occur. Therefore, immunoassay testing protocols according to this invention which allow for direct, inexpensive, on-site testing for volatile organic contaminants from samples as collected, which are suspected of containing such contaminants, provide superior overall volatile organic compound detection capabilities.
Further, highly volatile organic compounds, such as benzene, toluene, xylene, perchloroethylene and trichloroethylene begin evaporating to a substantial extent within the first few minutes following collection, from aqueous solutions in which they are only marginally soluble in the first instance. According to heretofore accepted testing methods commonly used in the art, sources suspected of containing the volatile organic compound being tested for are initially sampled, and are often further sampled into aliquots of various volumes in order to preserve the original sample in the event further testing is needed. This aliquot sampling allows the volatile organic compound being assayed for to evaporate from the sample. Further, it has heretofore been customary in the field of immunoassays that extremely small sample volumes when performing an immunologically based test yield the best results. These small volumes usually range between 10 and 500 microliters. In addition, separating such a small volume from the entirety of the sample and transferring this small amount to the ultimate immunoassay reaction vessel, results in another opportunity for volatile organic contaminants to escape from the sample being tested. As a result, a certain percentage of volatile compound evaporation during these aforementioned laboratory procedures is inevitable. Such evaporation, or volatile compound escape invariably affects the final accuracy of the test. Therefore, to conduct an accurate assay for volatile organic compounds, the assay must be initiated as soon as possible after collection.
The degree of volatilization of organic compounds during testing is affected by various ambient conditions during testing such as temperature, solubility of the volatile organic compound in the aqueous solution, and surface area of the sampling receptacle, or testing vessel, etc. While field testing must be conducted at ambient temperatures, the testing receptacles into which the sample is introduced have heretofore been conventionally chilled to temperatures between 2° and 8° C. in a specific attempt to reduce the evaporation of volatiles from the sample. As already discussed, the sample sizes have heretofore been usually restricted and limited to the relatively small volume capacity of the reaction receptacles designed to be used in the accepted testing procedures known in the art. The volume capacity of these receptacles is typically less than approximately 5 mls. It has heretofore been widely believed in the field of immunoassays that sample concentration, rather than sample size, determines sensitivity of the assay. In fact, most prior art immunoassay protocols call for a minimum total test volume in order to measure the analyte at its highest possible concentration when compared to the sample volume. The art has not heretofore appreciated the effect of the sample size, or volume, on the overall accuracy and sensitivity of the assay for volatile compounds. There has to now been concern in the field that the integrity of samples containing volatiles is compromised prior to analysis due to volatile evaporation from the sample solvent. Such volatile evaporation continues to remain a significant cause of inaccurate testing results.
As mentioned previously, the sample volume has oftentimes been limited by design. Conventional practice often calls for use of a sample volume which is equivalent to or less than the volume of the antibody-coated portion of the receptacle device. For example, the use of 4 to 5 ml. cuvettes are common in the immunoassay field. Usually, only the bottom of the cuvette, up to only the 1 ml. mark is coated with antibody. Under these conditions, it is common for samples of not more than about 0.5 to 1.0 ml. to be introduced into the cuvette and assayed. It has now been found according to this invention that, in principle, when assaying for volatile compounds, the volume of the test sample should not be constrained by the amount of antibody coating present at the bottom of the sample vessel nor should the size of the collection vessel deter direct testing in that vessel.
As this invention contemplates, one can coat only the lower portion of a relatively large volume sample collection receptacle with an immunologically coated surface while assaying a total volume of sample that exceeds, by at least about double, the volume that can be contained within the coated portion of the receptacle. Alternatively, if it is cost prohibitive to coat the receptacle with expensive antibody preparation due to the size of the receptacle, then antibody coated insertable insoluble solid-phase devices can be used. Such devices may be of any desired shape or size, but are commonly in the form of wands, sticks, finned sticks, paddles, balls, beads, hoops, loops, meshes, baskets, spiral, etc. The use of such inserts is also contemplated regardless of the area of the surface exposed in the sample collection receptacle. It is further contemplated that the antibody-coated insert devices have a sufficient density to sink to, and remain at the bottom of the collection vessel. When the coated insert device is in the form of a stick, paddle or wand, it is contemplated that the coated portion of the device is completely depressed in the collection vessel so that it comes into contact with, and is held against the bottom of the collection vessel. In this way, the sample volume assayed would cover the antibody coated portion of each insert device to a significant excess.
SUMMARY OF THE INVENTION
The present invention relates to an improved method for detecting volatile organic compounds in soil or aqueous solutions including, but in no way limited to toluene, benzene, xylene, perchloroethylene and trichloroethylene. The essence of this invention is based upon the unexpected discovery that the sensitivity of assays for non-polar organic compounds in aqueous solutions and other polar media, is enhanced by dispensing with sampling via the aliquot approach and testing only an unsegregated lower portion of the entire sample as collected, just as soon after collection as possible. Volatile organic contaminants have been found to display a heightened level of detectability when only a lower layer of sample was tested while in contact with a confining sample overlayer of at least the same volume as the lower layer and preferably several times that volume. When the size of the opening of the collection vessel and hence the sample area exposed to the atmosphere, was kept as small as possible, results are also enhanced. We have found that our immunoassays for the detection and quantification of organic compounds in soil and aqueous solutions and other polar solvent-containing mixtures display a significantly pronounced, unexpected increase in accuracy of detection and quantification when the overall sample size is increased while holding the available evaporation surface area of the sample to a minimum and only the confined lower layer of sample is assayed. This increased detection capability, results in a greatly enhanced immunoassay result.
In addition, it was further discovered that an increase in the total sample size accompanied by assay of only a lower layer sample fraction will also lead to an increased assay sensitivity, whether or not accompanied by concomitant restriction of the exposed surface area at the collection vessel's opening. Therefore, it is believed that the sensitivity increase is somehow due to the increase in sample integrity resulting from the reduced total evaporation of volatile organic materials contained in the sample. In other words, this larger sample appears to retain intact the total volatile organic compound in its lower layer, and also to retain a greater amount of the volatile organic compound being tested for as compared with a small volume of sample, at least when the sample surface area exposed to evaporation is held constant in each instance. This results in an unexpected increase in the overall sensitivity of the immunoassay. It was discovered that such a result occurs even though the concentration of the volatile organic contaminant in both the large and small volume samples was identical at the outset of the testing protocol. While we do not intend to be in any way bound by the theoretical explanations that follow, it is believed that when the reaction vessel is coated essentially only at the very bottom, but is then filled to a level at least twice the volume contained within the antibody coated region, and preferably more, the volatile evaporation begins to take place nearest the top of the sample. The volatile compound will apparently first escape from the sample closest to the surface. The vapor pressure equilibrium then forces some of the volatile compound that had originally been in a lower level of sample to rise through the sample and replace the volatile compound which had left the sample. Eventually this "replacement" volatile compound will also evaporate from the sample. Over a sufficient period of time, even the volatile compound which was present at the bottom of the collection vessel will leave the container. However, the improved assays of the present invention are designed to be completed within a short time period while evaporation of volatile organic compound from the protective sample overlayer is still proceeding. In essence, the protective sample layer in contact with and above the antibody coated level acts as a protective layer which temporarily shields the volatile compound in the assay region (the antibody-coated region) so that it reacts with antibody preferentially over migrating to a higher sample layer.
This invention embraces the further aspects of controlling volatile compound evaporation during an immunoassay procedure including rapid, preferably virtually simultaneous testing and collection of samples, selecting collection/reaction receptacles with restricted available evaporation surface area, filling the collection vessel to at least twice the volume of sample containable within a coated portion of the collection vessel and collecting the sample in such a fashion as to minimize volatile evaporation, e.g. by completely filling the collection vessel with sample and/or capping or sealing the collection vessel immediately after filling. Significantly, it was also discovered, that immediate immunoassay testing in accordance with this invention, before evaporation of the contained organic contaminant occurs, will also result in enhanced detection sensitivity, regardless of the size of the evaporation surface area at the collection vessel's opening.
In quantitative terms, assume that various factors known to affect volatility, (e.g. agitation during sampling, mixing, temperature, relative humidity, ambient vapor pressure, solubility of the contaminant in the solvent, etc.) and available evaporation surface area from which a volatile contaminant in partial solution may evaporate into the atmosphere, are held constant. If a 500 microliter and a 2 milliliter aqueous sample both contain a 10 ppm concentration of a non-polar volatile organic compound such as, for example, benzene, the larger sample contains four times as much mass of benzene as does the smaller sample. If both samples are placed in identical testing receptacles or cuvettes which therefore have the same diameter and internal contour, the same available evaporation surface area results. Under these conditions, the evaporation rate of the volatile compound will be constant. In addition, it should be assumed that the receptacles have each been coated with an amount of antibody such that the antibody-coated surface area covers the same depth of the vessel and has the same antibody concentration per unit volume of sample. Alternatively, if the antibody is instead used to coat a device which is to be inserted into the receptacle, assume the identical device, with the same depth of coating at the lower end and the same antibody concentration per unit volume of sample, is inserted into each receptacle.
In terms of mass of volatile contaminant remaining in the solution, there will be approximately four times the mass of benzene left in the larger sample as compared to the smaller sample. In other words, the constant rate of evaporation affects the larger mass of the volatile organic compound to a reduced degree. This may in part be because of the reduced evaporation surface area per unit volume exposed to the atmosphere and in part because of the greater depth of protective sample layer above and in contact with the sample portion actually assayed. Although the evaporation of the benzene occurs at a constant rate in both samples, since the larger sample begins with a greater mass of benzene in solution, or partial solution, the larger sample retains a greater net amount of organic volatile contaminant over time. This, in turn, has been found to increase the sensitivity of the assay test system.
This unexpectedly enhanced assay sensitivity which coincides with an overall increase in sample size while holding a predetermined volume of about half or less of the total sample the sample portion actually subjected to immunoassay, has led to a change according to the present invention, in the heretofore conventional procedures regarding sample size used to conduct immunoassays and in other detection testing techniques.
When the vessel itself is to be coated, it is contemplated that a suitable receptacle have an opening no larger than about 4 sq. in., and preferably less. In practice, due to the amount of antibody coating required to coat the bottom of a receptacle and the concomitant expense, containers having a maximum volume of about 5 to 100 mls. in the form of test tubes are most commercially feasible and are preferred, although this invention contemplates use of containers that are wider at the bottom and that hold a volume exceeding 25 gallons. In certain cases, the diameter of the container at the opening and below it may be very small, such as 2 to 3 millimeters for a pipette. Alternatively, the diameter of the container opening and its body may be slightly wider; such as 1 to 3 centimeters for test tubes and graduated cylinders. Further, this invention contemplates the use of containers that have necked in openings with body diameters greater than the diameter of the necked in opening, such as common gallon and half-gallon jugs or flasks.
When the receptacle is coated at the bottom with antibody, it is contemplated in one preferred embodiment of the invention that the assay will commence immediately upon contact of the sample with the antibody coating.
In another preferred embodiment, where the antibodies are coated on a solid-phase device to be inserted into the receptacle, the actual assay cannot begin until the coated solid-phase device is brought into contact with the sample. The coated solid-phase device may simply remain at the bottom of the collection vessel in stationary condition, or in another embodiment the coated solid-phase device may be used to agitate the sample.
It is further contemplated that the accuracy of an assay performed in accordance with the process of the present invention will enable one to ascertain and quantify the presence of volatile organic compounds in aqueous solutions at extremely low concentrations in a range as low as about 5 parts per billion or even lower.
As already mentioned, one preferred immunoassay method comprises immersing an insoluble solid-phase device insert into the contaminant-containing sample. In this embodiment, the collection vessel used may have its evaporation surface area defined by a neck narrower than the body of the sample vessel. However, the advantages of the present invention according to this embodiment are realized even if the collection vessel has an opening essentially the same size as the body of the vessel, so long as the reaction time needed for the antibody coated on the insoluble solid-phase device to react with the contaminant is not outrun by the rate of evaporation of contaminant. In other words, the advantages of the present invention are realized, even if the evaporation surface area is relatively unrestricted, so long as large sample volumes are present with a sufficiently deep protective layer of sample covering the bottom layer being assayed and the testing procedures are performed with sufficient dispatch to assure minimal evaporation of volatile organic components from the sample. In this way, this embodiment of the present invention further contemplates that the coated solid-phase device either may be used as a stirrer, or may otherwise be moved evenly throughout the mass of the sample. The movement of the antibody coated solid-phase device can shorten the time it takes to assay the volatile organic contaminant as compared to an assay wherein the device is maintained in a static position since the antibodies more rapidly come into contact with the volatile organic compound contained in the sample.
It is further contemplated that the process of the present invention as already described may be used with immunoassays designed for antibodies which react specifically with only one particular organic contaminant.
It is also contemplated in the present invention that antibodies which are cross-reactive to more than one organic contaminant at one time may be used. The cross-reactive antibodies used in connection with the process of the present invention, are those antibodies harvested from rabbits injected with a conjugate of 6-aminohexyl-p-tolylacetamide with Bovine Serum Albumin (BSA) according to methods well-known in the art. Such cross-reactive antibodies which are able to detect both ring-containing aromatic compounds and aliphatic compounds will shortly, be made the subject of a co-pending U.S. patent application. Immunoassays using these extremely sensitive, cross-reactive antibodies in this invention, allow for the direct sampling of e.g. ground water, soil and air in the form of aqueous or other solutions containing one or more volatile organic compounds, at sample sizes in the order of at least about 0.5 ml. and higher, preferably at least about 1.0 ml. and even more preferably at least about 30 mls. when the antibody-coating (either on the inside walls of the collection vessel or on the inserted coated solid-phase devices) reaches a depth of about 0.25 to about 1.0 ml. of an appropriately scored test tube or graduated cylinder. Larger sample volumes are also contemplated according to this invention. It is recognized that collection receptacles having standard large volume capacities of 1-5 mls. (pipettes), 10-25 mls. (test tubes), 10-500 mls. (graduated cylinders) or 1000 mls. (liter jugs), etc. will be used, due to their widespread availability, in the performance of the present invention.
BRIEF DESCRIPTION OF DRAWINGS
For the purpose of illustrating the invention, there shown a drawing of a form which is presently preferred; it being understood however, that this invention is not limited to precise arrangements and instrumentalities as shown.
FIG. 1 is a perspective view of an embodiment of a test tribe in accordance with the present invention.
DETAILED DESCRIPTION OF THE DRAWING
Referring to the drawing in detail, FIG. 1 shows a test tube (1) having a total volume of 15 mls. The bottom of the inside surface (2) of the tube (1) has been covered with an immunologically active coating (3) up to the 1 ml. mark (4) on the tube (1). The tube (1) is further marked at the 10 ml. level (5) as an indication of the sampling level to which the tube is filled with sample. The line (6) indicates the boundary between the lower sample layer (7), which remains at all times in contact with the immunologically active coating (3), and the 9 ml. of sample acting as the protective overlayer (8).
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to improved immunoassay methods for ascertaining the presence of and quantifying the concentration of volatile organic contaminants present in aqueous and other polar solvent-containing samples obtained from natural water bodies, soil or air. In such immunoassays, the organic contaminant/antibody reaction which occurs can be detected by a variety of methods, using various markers to label the enzyme conjugate, thereby permitting detection of the reaction product. Various methods of quantification or measurement may be used as are well known in the art. Furthermore, immobilization of the antibody will facilitate detection of the contaminant in many cases. It is contemplated that the present invention may be used, e.g., with either competitive or competitive inhibition immunoassays such as are well-known in the field.
It is contemplated that the immunoassay according to the present invention may use monoclonal or polyclonal antibodies, mixtures of the two, and multiple monoclonal or multiple polyclonal antibodies in order to have the broad spectrum screening capabilities needed to detect and quantify the presence of certain volatile organic contaminants, depending upon whether or not one, or more than one, contaminant is being assayed for at any one time.
In the contemplated preferred embodiment of this invention, a known 15 ml. test tube is used as the collecting vessel. The bottom of the tube is coated with antibody by conventional immunoassay methods well-known in the field to a depth of 1 ml. at the bottom end. The sample suspected of containing a volatile contaminant is then introduced into the collecting vessel until the vessel is filled to a preexisting mark representing 10 mls. of volume. The assay is allowed to proceed as in Example 2 below. In this way the layer of sample present above the 1 ml. mark will act as a protective layer for the sample layer surrounded by antibody coating and inhibit the evaporation of volatile compound from the thus trapped lower layer, thus facilitating complete reaction with the antibody coating of the volatile compound in the lowest layer. This enables full detection and quantification of the volatile compound in the lowest layer of the collecting vessel and leads to an enhanced sensitivity level of at least about 5 to 500 ppb of volatile compound.
In another preferred embodiment, the antibody-coated insoluble solid-phase surface may be selected from the group consisting of wands, sticks, finned sticks, paddles, balls, beads, hoops, loops, meshes, baskets, spirals and other immersible objects of convenient shape and size. These devices are sufficiently dense so as to immediately migrate to and remain at the bottom of a collected sample. In a further embodiment, said devices may be placed within the collection vessel prior to the collection of sample.
In still another embodiment, pipettes having a total volume capacity of about 0.5 to 10 mls. have only the lower 10% of the inside walls coated with the antibody. The sample is then drawn out of the source until the pipette is filled to a level of about 20% to 100% capacity of the pipette. In this way, the sample layer containing the volatile compound which is in contact with the antibody coated portion of the pipette will act as a protective layer from which volatile compound preferentially evaporates while the volatile compound layer being assayed reacts with the antibody.
Immunoassay labels that can be used in the practice of the present invention to detect the presence or absence of organic compounds in a sample include enzyme, fluorescent chemiluminescent, and dyed particles as well as radiolabels. In enzyme-linked immunoassays (ELISA), large organic compound(s) can be detected by methods well-known in the art where competition for available immunological binding sites occurs between the organic compound(s) of interest and similar enzyme-labelled compounds. The enzyme activity is typically detected by formation of a colored reaction product, i.e. a colored end-point that may easily be detected by eye or measured by spectroscopic or reflectance means. Several enzymes, including alkaline phosphatase, horseradish peroxidase (HRP) and glucose oxidase have heretofore been coupled to both antigens and antibodies. HRP is commonly used in the field. For visual detection and quantification of the volatile organic compounds contained within the suspect samples, a chromogen will usually comprise a solution of a peroxide and tetramethylbenzidine which manifests a color upon oxidation, the intensity of which can be calibrated to quantify the presence of the volatile organic compounds sought.
The assays of the present invention are applicable to detect any volatile organic contaminant in water, soil, and various polar solvent-containing mixtures. Exemplary volatile organic contaminants include, but are in no way limited to toluene, benzene, xylene, perchloroethylene and trichloroethylene.
As indicated from the examples listed below, the amount of hydrocarbon compound detected in the aqueous or other polar solvent such as e.g. methanol, ethanol, isopropanol, can vary over a wide range. For example, immunoassays in accordance with the process of the present invention are contemplated to detect volatile hydrocarbon compounds down to a range as low as about 5 parts per billion, or even lower.
Monoclonal and polyclonal antibodies to the hydrocarbon compounds sought to be detected in the contaminated samples, for use in the present invention are made using immunization techniques well known in the art. Heterospecific antibodies are particularly useful in conducting tests, according to the present invention, for general or non-specific screening purposes such as, for example detecting the presence of gasoline in a water or soil sample, since a variety of hydrocarbon compounds, together, comprise the liquid hydrocarbon mixture known as gasoline. In addition, several different contaminants often occur in soil or water samples being tested at a particular site or in a particular industrial environment.
One hapten used to obtain the preferred antibody in accordance with the process of the invention, consists of 6-aminohexyl-p-tolylacetamide conjugated to Bovine Serum Albumin (BSA) and injected into a rabbit which is bled after a suitable period of time, usually at least 18 days, followed by extraction of the desired antibody from the blood sample according to methods well known in the art. In accordance with one embodiment of the invention, the resulting antibody is used to coat an insoluble solid phase which is contacted with a sample. This antibody binds toluene and may also bind a number of other organic contaminant compounds such as, but not limited to benzene, as well as a number of aliphatic, straight-chain hydrocarbon compounds. When the insoluble solid-phase antibody coated matrix is a solid phase insert, such insert may be of any shape, size or dimension such as, but is in no way limited to wands, sticks, finned sticks, paddles, balls, beads, hoops, loops, meshes, baskets, spirals, membranes, etc. The sample is collected in a vessel, or receptacle which may or may not have an opening narrower than its main body to minimize evaporation at the surface of the volatile organic compounds contained in the sample. The insoluble solid-phase device is then inserted into the collected sample. The antibody-coated solid-phase device may then remain stationary, or may be moved around throughout the lower layer of the sample so that its volatile organic content may be assayed. The insoluble solid phase matrix itself may, for example, be reacted with certain reactants and "read" to determine and quantify the presence of volatile organic compounds in the collected sample.
It is known that to conduct an accurate assay for volatile organic compounds, the assay must be conducted as soon as possible after collection. The present invention, unlike heretofore used test systems, takes account of this need. Further, the use of an antibody-coated container with an opening no greater than approximately 4 sq. in. where the opening is equal to or less than the widest portion of the collection vessel, serves to additionally inhibit the evaporation of the volatile compound from the sample. The antibody coating on the inside of the collection vessel therefore immediately reacts with the sample. If the antibody is coated on the inside of the collection vessel so as to react with the sample immediately, this, too, aids in overcoming volatility problems.
It is contemplated that a colorimetric or other perceptible and easily determined reaction will occur to signify the presence or absence of volatile organic compounds in the sample. In effect, when the assay system comprising the antibody-coated vessel is lowered into a body of surface, or subterranean water, or filled with a soil sample which is subsequently washed with aqueous solution, the assay system can ascertain the presence or absence of volatile organic compounds in virtually simultaneous fashion. It is therefore contemplated that the assay can be completed in the time it takes to bring, e.g., a soil sample to the surface.
In a further embodiment of the present invention it is contemplated that, an absorptive material such as, e.g. activated charcoal may absorb a volatile organic compound directly from the air and can then be treated with appropriate solvent such e.g. methanol, to remove the volatile compound from the charcoal. The solvent is then immediately assayed in accordance with the invention as already described.
In accordance with the present invention, various labels may be used to further assist in the detection of the hydrocarbon compounds. Such labels may include, but are in no way limited to radioactive labels, enzymes, fluorochromes or luminogens, dye particles and colored latex. Such labels may be attached to antigens or antibodies by methods which are well-known in the art. At present, enzymes are a preferred label. Peroxidases and phosphatases are preferred classes of enzymes and especially preferred are horseradish peroxidase (HRP) and alkaline phosphatase (AP). However, any enzyme which can be conjugated to an antibody, or antigen is contemplated by the process of the present invention. The chromogen contemplated is capable of undergoing a color change in the presence of an enzyme. The chromogen is preferably 3,3',4,5-tetramethylbenzidine (TMB) when horseradish peroxidase is the enzyme.
The following preparation schemes and outlines are presented as further illustrations of the details of the present invention, and only illustrate preferred embodiments of the invention.
Preparation of the Immunogen
The preparation of desired immunogen, (6-aminohexyl-p-tolylacetamide-BSA) according to the preferred embodiment requires the preparation of 6-aminohexyl-p-tolylacetamide by methods known in the art, and the subsequent coupling of the activated compound to the desired protein which in this preferred embodiment is Bovine Serum Albumen (BSA). 6-aminohexyl-p-tolylacetamide is covalently linked to the protein, BSA.
Synthesis Scheme for the (6-aminohexyl-p-polylacetamide)-BSA Immunogen
The following synthesis is performed to obtain the desired hapten-protein complex used for immunization to produce antibodies by the method already described which is well-known in the art: ##STR1##
The resulting immunogen is used in animal immunization procedures with rabbits or mice in methods which are well known in the art, and are fully disclosed in the commonly assigned U.S. patent applications, Ser. No. 059,721 filed Jun. 9, 1957 and now abandoned, and Ser. No. 200,952 filed Jun. 1, 1988 (which is a continuation-in-part of U.S. Ser. No. 059,721 and currently co-pending). In short, the animals were immunized via injections prepared with Complete Freunds' Adjuvant while subsequent injections (boost) were prepared with incomplete Freunds' Adjuvant. Subsequent bleeding techniques as are well known in the art were then conducted to harvest antibodies from these animals.
Conjugate Labelling Procedure
One preferred embodiment of the invention further contemplates the following labelling procedure for the conjugate which is well-known in the art.
Horseradish Peroxidase Oxidation
Horseradish peroxidase (HRP) in the amount of 4 mg was dissolved in 1 ml of water. The solution was cooled to 4° C. and 200 microliters of cold 0.1 M NaIO 4 was added. The solution was then stirred for 90 minutes in the dark at 4° C. Ethylene glycol in the amount of 104 microliters was then added followed by continued stirring for 30 minutes. The resulting solution was then dialyzed overnight at 4° C. against 4 liters of 1 M acetate buffer at pH 4.0.
Coupling the Oxidized Horseradish Peroxidase to 4-methylbenzyl-6-aminohexamide
An amount of 4-methylbenzyl-6-aminohexamide was dissolved in methanol to make a solution in the concentration of 2.85 mg/ml. Next, 175 microliters of the 4-methylbenzyl-6-aminohexamide was added to the oxidized HRP. This was followed, by adding 200 microliters of 0.1 M Na 2 CO 3 , pH 9.5, with the solution then stirred for 2 hours at 4° C. Next, 200 microliters of 4 mg/ml NaBH4 in water was added followed by continued stirring for an additional 30 minutes. The mixture was then dialyzed against 61 ml of 0.01 M phosphate buffer, 0.15 M NaCl at pH 6.0 at 4 overnight. The dialysis was repeated with fresh buffer.
The following examples use the enzyme-labelled conjugate as described above and are presented as further illustrations of the present preferred embodiments of the present invention which are in no sense intended to limit the invention.
EXAMPLE 1
In various embodiments of the present invention, the following stepwise testing protocols were used; as more fully indicated in relation to the ensuing tables of data:
Procedure for Assay with 30 ml. Reaction Volumes with Antibody-Coated "Probes"
1. Mark one tube "S" for sample and the other tube "R" for reference.
2. Add 30 ml. of 4° C. deionized water to each tube.
3. Add 0.5 ml. of 3M tris-(hydroxymethyl) amino methane buffer (pH 7.4) to each tube.
4. Prepare toluene standards in methanol and add 10 microliters. of this standard to the "S" tube and mix. Add 10 microliters of pure methanol to the "R" tube.
5. Add 4 drops of horseradish peroxidase conjugate as disclosed hereinabove to each tube and mix.
6. Insert an antibody coated probe into each tube.
7. Incubate at 4°-10° C. for one minute.
8. Remove probes and wash with water.
9. Insert probes into clean tubes containing 4 drops of urea hydrogen peroxide to each tube as a first color developer, then add 4 drops of tetramethyl benzidine to each tube as a second color developer.
10. Incubate at room temperature for one minute.
11. Remove probes and discard.
12. Add 1 ml. of 1N sulfuric acid to each tube to terminate the reaction.
13. Read the absorbance from the tubes on a spectrophotometer at 450 nm.
EXAMPLE 2
Procedure for Assay with 15 mls. Reaction Volumes
1. Coat two reaction tubes with antibody. Mark one tube "S" for sample and the other tube "R" for reference.
2. Add 15 mls. of cold (4°-10° C.) deionized water to each tube.
3. Add 0.5 ml. of 3M tris-buffer (pH 7.4) to each tube.
4. Add 10 microliters of a 500 ppb standard prepared in methanol to the "S" tube and mix. Add 10 microliters of pure methanol to the "R" tube and mix.
5. Add 4 drops of horseradish peroxidase to each tube and mix.
6. Incubate at 4°-10° C. for one minute.
7. Wash tubes 4 times with deionized water.
8. Add 4 drops of urea hydrogen peroxide to each tube as a first color developer, then add 4 drops of tetramethyl benzidine to each tube as a second color developer.
9. Incubate at room temperature for one minute.
10. Add 1 ml. of 1N sulfuric acid to each tube to terminate the reaction.
11. Read the absorbance from the tubes on a spectrophotometer at 450 nm.
EXAMPLE 3
Procedure for Assays with 0.5, 1.0, and 2.0 mls Reaction Volumes
1. Coat two reaction tubes with the antibody produced from the rabbit as already disclosed. Mark one tube "S" for sample and the other tube "R" for reference.
2. Add appropriate amount of cold (4°-10° C.) deionized water (either 0.5, 1.0 or 2.0 mls.) to each tube.
3. Add 4 drops of 3M tris-buffer (pH 7.4) to each tube.
4. Add 10 microliters of a 10 ppm standard prepared in methanol to the "S" tube and mix. Add 10 microliters of pure methanol to the "R" tube and mix.
5. Add 4 drops of horseradish peroxidase to each tube and mix.
6. Incubate at 4°-10° C. for one minute.
7. Wash tubes 4 times with deionized water.
8. Add 4 drops of urea hydrogen peroxide to each tube as a first color developer, then add 4 drops of tetramethyl benzidine to each tube as a second color developer.
9. Incubate the tubes at room temperature for one minute.
10. Add 1 ml. of 1N sulfuric acid to each tube to terminate the reaction.
11. Read the absorbance from the tubes on a spectrophotometer at 450 nm.
In the following tables, the S/R value is the sample tube (S) to reference tube (R) ratio of absorbance values as read on a spectrophotometer at 450 nanometers. Theoretically, if the sample and reference tubes had the same contents and were run against each other, the tubes and their contents would nave identical absorbance values and the S/R ratio would equal 1.0. However, in practical analytical terms, running two such tubes against each other a number of times and taking readings of each run actually establishes a range which instead only approaches the theoretical value of 1.0. For example, it was determined that for a 0.5 ml sample the S/R value for two tubes containing identical standard contents run at 450 nanometers on a spectrophotometer may range from 0.85 to 1.15, with two standard deviations. This means that when the "S" tube contains an actual sample and is then run against the "R" tube, to positively determine the presence of an organic contaminant, the analyte in the "S" tube must be sufficiently readable such that the value of the "S/R" ratio is lower than 0.85.
By using laboratory methods well-known in the immunochemistry field to carefully establish the relationship between known organic compound concentration in the sample and the S/R ratio absorbance reading on the spectrophotometer, a standard curve, for 0.5 ml. samples containing toluene can be constructed. Through the use of this curve it was further determined that, for 0.5 ml. samples, when the resulting S/R ratio is greater than 0.85, the sample must contain less than 5 parts per million of toluene, or, in other words the S/R ratio is within the range at which positive readings cannot be detected due to the precision limitations on the assay as already described. However, if the S/R ratio produces a value that is between 0.50 and 0.85, it was determined that the sample contains 5 to 10 parts per million of toluene. Finally, if the S/R ratio produces a value that is less than 0.50, it was determined that the toluene concentration of the sample is greater than 10 parts per million.
While the standard curve derived as described above, and the following data presented were specifically evaluated with reference to the standard curve for toluene presence in a 0.5 ml. sample, it is clear that similar curves can be created for other volatile organic compounds and mixtures thereof, as well as for various other sample volumes, using the technique described. Moreover, examples of such volatile organic compounds include but are in no way limited to benzene, xylene, perchloroethylene, trichloroethylene and mixtures including volatile organic compounds such as, for example, gasoline.
The data in Table 1 represents the assay sensitivity differences of aqueous toluene as the sample sizes (volumes) are progressively increased. The protocol as described in Example 3 when 0.5, 1.0 and 1.5 mls. samples are tested was followed to obtain the results stated. In Table 1, "PPM" is parts per million of toluene in solution, "S" is the sample tube, and "R" is the reference tube. The "Observed % Increased Sensitivity" shows the enhanced sensitivity of the 1.0 ml sample as compared to the 0.5 ml. sample when the concentration of toluene in the sample is held constant (5 ppm) . This increase, therefore, represents the change in S/R ratio value that is observed as the volume is increased from the 0.5 ml. "baseline", on which the toluene standard curve is based. All tests were run on the spectrophotometer at an absorbance setting of 450 nanometers.
TABLE 1______________________________________Toluene ObservedSample S/R % IncreasedVol. (ml.) PPM Ratio Sensitivity______________________________________0.5 5 0.770 1001.0 5 0.550 1421.5 5 0.378 207______________________________________
The data in Table 1 shows that as the overall volume of aqueous toluene samples is doubled and tripled, the immunoassy S/R ratio dropped significantly in value, resulting in an observed sensitivity increase, even though the actual concentration of the toluene per unit volume remained constant throughout.
The comparative data in Table 2 further shows the immunoassay sensitivity differences of aqueous toluene as the volume of the sample is increased. When the volume of the toluene sample was held to 0.5 ml, the immunoassay was only able to detect the toluene at approximately a 2 PPM concentration. However, when the volume was increased to 15 ml samples, the toluene was detectable at concentrations as low as 0.167 PPM. Similar data was collected for the detection of benzene in aqueous solution.
All reagents were used, and the assays were performed at ambient conditions. The "S" and "R" tubes were stored prior to the assay in ice water and therefore maintained at the 2°-8° C. range. The protocol used is the protocol described in Examples 2 or 3 depending upon the volume of the sample tested. In Table 2, "PPM" is parts per million of toluene in solution, "S" is the sample tube, "R" is reference tube, "S/R" is the sample to reference ratio as already described, and "n" is the number of test runs made on each sample. All tests were run on the spectrophotometer at an absorbance setting of 450 nanometers. The "Range" column reflects the "high" and "low" values from the 3 runs made.
TABLE 2______________________________________ Assay Vol PPM S/RAnalyte (ml) Analyte Ratio n Range______________________________________Toluene 0.5 0.2 0.972 3 0.79-1.16Toluene 0.5 0.5 1.090 3 1.00-1.18Toluene 0.5 1 1.040 3 1.03-1.05Toluene 0.5 2 0.888 3 0.87-0.91Toluene 15 0.067 0.966 3 0.87-1.06Toluene 15 0.167 0.732 3 0.69-0.77Toluene 15 0.333 0.685 3 0.66-0.71Toluene 15 0.670 0.568 3 0.41-0.73______________________________________
The data in Table 2 shows that when the volume of toluene is increased significantly (15 mls. as compared to 0.5 ml.), the observed sensitivity of the assay is apparently markedly increased.
The comparative data in Table 3 shows the immunoassay sensitivity differences of aqueous toluene as the volume of the sample is increased. All reagents were used, and the assays were performed at ambient conditions. The "S" and "R" tubes were stored prior to the assay in ice water and therefore maintained at the 2°-8° C. range. The protocol used, is basically the protocol described in Examples 2 or 3 depending upon the sample volumes used. In Table 3, "PPM" is parts per million of tolune in solution, "S" is the sample tube, "R" is reference tube, "S/R" is the sample to reference ratio as already explained, and "n" is the number of test runs made on each sample. All tests were run on the spectrophotometer at an absorbance setting of 450 nanometers.
TABLE 3______________________________________TolueneVolatile Sample (S) (R)Cmpd. PPM Vol. 450 nm 450 nm S/R n______________________________________Tol. 10 0.5 ml 0.282 0.623 0.453Tol. 10 0.5 ml 0.297 0.618 0.481Tol. 10 0.5 ml 0.347 0.744 0.466 mean = 0.467 3Tol. 2 0.5 ml 0.464 0.828 0.560Tol. 2 0.5 ml 0.533 0.789 0.676Tol. 2 0.5 ml 0.550 0.658 0.835 mean = 0.690 3Tol. 1 0.5 ml 0.336 0.398 0.844Tol. 1 0.5 ml 0.300 0.461 0.651Tol. 1 0.5 ml 0.271 0.373 0.727 mean = 0.744 3Tol. 1 1.0 ml 0.192 0.288 0.667Tol. 1 1.0 ml 0.181 0.259 0.699Tol. 1 1.0 ml 0.144 0.237 0.608 mean = 0.658 3Tol. 0.5 1.0 ml 0.219 0.326 0.672Tol. 0.5 1.0 ml 0.182 0.260 0.700Tol. 0.5 1.0 ml 0.230 0.250 0.920 mean = 0.764 3Tol. 0.25 1.0 ml 0.160 0.227 0.705Tol. 0.25 1.0 ml 0.184 0.221 0.833Tol. 0.25 1.0 ml 0.199 0.210 0.948 3 mean = 0.829Tol. 0.5 2.0 ml 0.123 0.159 0.774Tol. 0.5 2.0 ml 0.166 0.220 0.755Tol. 0.5 2.0 ml 0.207 0.293 0.706 mean = 0.745 3Tol. 0.25 2.0 ml 0.199 0.318 0.626Tol. 0.25 2.0 ml 0.199 0.293 0.679Tol. 0.25 2.0 ml 0.203 0.278 0.730 mean = 0.678 3Tol. 0.25 4.0 ml 0.155 0.158 0.981Tol. 0.25 4.0 ml 0.109 0.123 0.886Tol. 0.25 4.0 ml 0.130 0.170 0.765 mean = 0.877 3Tol. 0.333 15 ml 0.351 0.484 0.725Tol. 0.333 15 ml 0.331 0.480 0.690Tol. 0.333 15 ml 0.439 0.537 0.818 mean = 0.744 3Tol. 0.167 15 ml 0.113 0.236 0.479Tol. 0.167 15 ml 0.594 0.655 0.907Tol. 0.167 15 ml 0.506 0.458 1.100Tol. 0.167 15 ml 0.650 0.742 0.876Tol. 0.167 15 ml 0.602 0.739 0.815 mean = 0.835 5______________________________________
While the present invention has been described with respect to its various and preferred embodiments, it is not intended to limit such invention by the description here given. Various alternative ways of proceeding and various embodiments not specifically described will be readily apparent to those skilled in the art, and it is intended that they be embraced within the scope of the invention, insofar as the appended claims may permit.
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The invention pertains to an immunoassay method for determining the presence of volatile organic compounds in aqueous, soil and air samples by simultaneously collecting and testing a sample volume suspected to contain such organic compounds. As a major problem in the assay of such materials is their rapid evaporation, the present immunoassay is specifically designed to eliminate or minimize the evaporation of the volatile organic analyte during sample handling as well as during the assay process itself. The immunoassay method is based on an assay vessel which has a lower portion, in which the immunoassay actually takes place, and an inert upper portion, which can hold a sufficiently large volume of sample to prevent or minimize evaporation of the organic compound from the smaller volume in the lower portion. The assay is performed by: (1) coating the vessel's lower portion with an antibody specific for the organic analyte; (2) adding the sample to the vessel, wherein the volume of the sample added is between about two to about thirty times the volume of the vessel's lower portion; (3) adding a conjugate between a detectable label and an organic compound for which the antibody is specific; (4) allowing the organic analyte and the added conjugate to compete for binding to the immobilized antibody; and (5) detecting the binding of the detectable label to the immobilized antibody. In another embodiment of the immunoassay, the lower portion of the vessel has inserted therein a solid phase device whose surface is coated with an immobilized antibody specific for the organic analyte.
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FIELD OF THE INVENTION
The present invention relates to a speed control device for a motor of an electric sewing machine, and more particularly to a speed setting device therefor.
BACKGROUND OF THE INVENTION
In an electric sewing machine having so-called hand controller system which is provided with a speed selecting device for a machine motor and a stop device, there are embodiments, where a machine body is, as shown in FIG. 4, provided with switches of low speed, middle speed, high speed and a stop switch (these switches are exclusive of one another), or where a machine body is, as shown in FIG. 5, provided with switches for in advance selecting low speed, middle speed and high speed (these switches are exclusive of one another) and a switch located near a needle bar of the sewing machine to designate the drive or stop of the motor.
The former embodiment has the stop switch, and an operator must confirm therewith a switch to be pushed when stopping the machine motor. The latter embodiment requires the two operations for selecting speed and stop.
SUMMARY OF THE INVENTION
The present invention provides a flat switch having a plurality of switch components arranged in line and marked with rotation speed numbers on an outer surface thereof, in a region of the needle bar of the sewing machine. Pushing on any component part of the flat switch will designate the drive or stop of the machine motor. A control logic circuit (which realizes a program in accordance with this invention) is designed such that, after initiating the drive, a constant rotation speed of an upper shaft of the sewing machine corresponds to the rotation number shown at a position of the pushed component part, and the machine motor is stopped by pushing any component part of the flat switch, and therefore it is not necessary to confirm it by an additional operation. The switch has the speed selection and the drive stop designed for easy operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electric sewing machine embodying the invention;
FIG. 2(a) is a front view of a flat switch in the machine of FIG. 1;
FIG. 2(b) is a sectional side view of the flat switch of FIG. 2(a);
FIG. 3A is connection with FIG. 3B illustrate a block diagram showing a first embodiment of the control circuit according to the invention;
FIGS. 4 and 5 are front views of electric sewing machines having conventional hand operated controller systems;
FIG. 6A in connection with FIG. 6B illustrate a block diagram showing a second embodiment of the control circuit according to the invention; and
FIG. 7 shows a table of set rotation speed numbers when a switch component part is pushed.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be explained with reference to the attached drawings.
FIG. 1 shows the sewing machine provided in a place near to a needle bar 2 at a head 1 of the sewing machine with a flat or membrane-type switch 3 (called as "switch" hereinafter) having switch components formed in line. The switch is marked on its outer surface with numbers indicative of the speed of rotation of a non-illustrated upper shaft of the sewing machine.
FIG. 2(a) shows the switch 3 having four switch components SW1 to SW4 disposed vertically in line. As shown in the cross sectional view of FIG. 2(b), a U-shaped resilient sheet 4 keeps an insulation sheet 5 therebetween to separate the contacts of respective switch components. The rear side B is protected by a reinforcing plate 6, and an outer sheet 7 printed with rotation speed numbers is attached by an adhesive to the front side A of sheet 4. The outer sheet 7 in a film and is bendable by a finger pushing so that A side and B side of the sheet 4 is deformed to close selected switch components. When the finger is released, the sheet 4 resumes its original shape due to its elasticity, and contacts on the A and B sides are again separated by the thickness of the insulation sheet 5.
In the illustrated embodiment, the switch 3 is composed of four aligned switch components (SW1), (SW2), (SW3), (SW4). By pushing an intermediate part of outer sheet 7 between (SW1) and (SW2) for example, both switch components are closed, and the B side of the elastic sheet 4 is extended to a base (not shown) of a speed controller and connected thereto via a connector.
FIG. 3 is a block diagram of a control logic circuit of this invention, and main parts of relative controls are realized by a program of a micro computer.
A speed setting data store or memory (VDATA) supplies at its output terminal (OUT2) speed sitting data addressed by an input terminal (A) to a calculator (ACC), and also supplied at its output terminal (OUT1) data (speed reading-in cycle data) designating cycle number of a speed detecting signal to a speed detecting device (CACC).
The speed detecting device (VACC) keeps detecting rotation speed number of an upper shaft of the sewing machine and counts clock pulses (from a oscillator, now shown) in several cycles of the speed signals, and gives the clock count as actual speed data to the calculator (ACC).
When a "H" drive signal is issued, the calculator (ACC) controls conduction time of a semi-conductor element in a machine drive circuit (DV) by the above mentioned speed setting data and actual speed data, and feeds back so that the upper shaft is set at a designated rotation speed number. Detailed description of this operation is taught in Japanese Pat. No. 8789 (Laid Open Jan. 16, 1987).
The speed setting data memory (VDATA) stores speed read-in cycle data and speed setting data whose address values are 100 rpm, 200 rpm, 300 rpm . . . 800 rpm in response to 0, 1, 2 . . . 7.
T type flip-flop (TFF) inverts its output Q each time when its input terminal (T) is supplied with a pulse.
(TFF) is reset by a source signal detecting circuit (Ds) when a source pulse is supplied, and Q output is at L level and Q is at H level. (DR1) is a rise detecting circuit, and if any one of the switches (SW1) and (SW4) is pushed and a corresponding pulse from the power source is supplied via resistors R1-R4, inverters (INV1) to (INV4), OR gate (OR1) and (DR1) to the input terminal (T) of the T type flip-flop (TFF), and the output of (TFF) is inverted. The output signal of OR gate (OR3) is a drive signal to operate the calculator (ACC) and drive the machine motor (M). The drive signal is output by OR gate (OR3) when any one of the switches (SW1) to (SW4) is pushed and when the output Q of (TFF) is H. An output signal of AND gate (AND9) is a stop signal to stop the calculator (ACC) and the machine motor (M). The stop signal is issued when Q output of (TFF) is H and when the switch 3 is not pushed and no pulse is applied to OR gate (OR1) and inverter (INV6).
AND gates (AND1) to (AND7) and flip-flops (FF1) to (FF7) are means which discriminate which component part of switch 3 has been pushed.
AND gate (AND8) and flip-flop (FFO) are means for disciminating and storing signals generated when more than one of the four switch components (SW1) to (SW4) of the switch 3 has been pushed, or the adjacent two switch component parts are pushed and corresponding pulses are applied to OR gate (OR1) and inverters (IN11) to (IN17), that is, for example, when three switch component parts are pushed or alternate two component parts are pushed.
When the input terminals (IN0) to (IN7) are H, the decoder (DC) in response to these high levels gives an address value to the speed setting data memory (VDATA). OR gates (OR1) (OR2), the inverter (INV5) and AND gates (AND11) to (AND 17) are logic means which designate the low speed rotation to the decoder (DC). When the switch 3 is pushed, only the input terminal (IN0) of the decoder (DC) is H, and the flip-flops (FF0) to (FF7) are reset by the stop signal.
The set rotation speed numbers (rpm) when the switch 3 is pushed are shown in the table of FIG. 7.
The actuation of the speed setting device will be explained below with reference to the structure of FIG. 3.
(a) Supply of the source signals
Before actuation of the switch 3, the T type flip-flop (TFF) is reset (Q is L) by the source signal detecting circuit (DS), and its Q output terminal is H. Since the switch 3 is not pushed, the output of OR gate (OR1) is L, and the stop signal is issued from the output terminal of AND gate (AND9) to stop the calculator (ACC) and the machine motor (M). The flip-flops (FF0) to (FF7) are reset by the stop signal.
(b) Pushing simultaneously two switch components, e.g. (SW2) and (SW3)
After pushing switch components (SW2) and (SW3), the output of the OR gate (OR1) changes from L to H, the T type flip-flop (TFF) is supplied with a source pulse at its input terminal (T) via the rise detecting circuit (DR1), and its output is inverted such that Q is H level and Q is L level. The drive signal from (OR3) is applied to the calculator (ACC) and the machine motor (M) is started. Only the input terminal (IN0) of decoder (DC) is set to H level by or gate (OR2), and via the inverter (INV5) the AND gates (AND11) to (AND17) are reset. The decoder (DC) gives the address value "0" to the speed setting data memory (VDATA). The speed setting data equivalent to 100 rpm is applied to the calculator (ACC), and the speed read-in cycle data is applied to the speed detecting device (VACC). Then, the upper shaft of the sewing machine is rotated at 100 rpm. Since (SW2) and (SW3) are pushed, the output of AND gate (AND4) is H, and only the flip-flop (FF4) is set and its output Q is H level.
(c) Releasing of (SW2) and (SW3)
Upon releasing the switch components (SW2) and (SW3), the output of OR gate (OR1) is L level, and since the flip-flop (FF0) is not set, the output of the inverter (INV5) is H level. Therefore, only the input terminal (IN4) of the decoder (DC) is H level, and the decoder (DC) gives the address value "4" to the speed setting data memory (VDATA), and the speed setting data equivalent to 500 rpm is given to the calculator (ACC) and the speed read-in cycle data is given to the speed detecting device (VACC). Then, the upper shaft is rotated at 500 rpm.
(d) Pushing of a single switch component only, e.g. (SW2)
When pushing any of the switch components, the output of OR gate (OR1) changes from L to H, the output of the T type flip-flop (TFF) is inverted, and Q is L level and Q is H level. Consequently, the stop signal is not issued via the inverter (INV6) and AND gate (AND9), and the drive signal is continuously issued by OR gate (OR3). Since OR gate (OR1) is H level, the input terminal (IN0) of the decoder (DC) is H level, and the upper shaft is rotated at 100 rpm as long as the (SW2) is pushed and the flip-flop (FF3) is set.
(e) Releasing of (SW2)
Since OR gate (OR1) is reset to L level, the stop signal is issued to stop the calculator (ACC) and the machine motor (M). The flip-flops (FF3) (FF4) are reset.
As having stated above, the flat switch 3 has a plurality of the switched components disposed vertically in line, and is provided in a region of head 1 near the needle bar 2. When switch 3 is pushed, the drive and stop are designated alternately, and by selecting a pushing position, the set rotation number may be selected in seven steps.
FIG. 6 illustrates an embodiment where a delay means (MM) is added between (OR1) and DR1 of FIG. 3. The delay means (MM) delays by a delay time T (about 1 second) the switching time of L to H, but "H to L" is switched over together with the output of OR gate.
In such a manner, if the speed is changed during driving the machine motor, a desired speed indicating position of the switch 3 is pushed in a time shorter than the above mentioned T time.
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A flat touch switch having plural switch components with rotation speeds of the sewing machine shaft indicated on each component is positioned in the region of the needle bar. Pushing a component part of the switch drives the machine at the indicated speed. A control logic circuit senses the pushed component and by sensing the speed of the driven shaft, drives the machine at the selected speed.
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BACKGROUND OF THE INVENTION
This invention relates to the isomerization of cycloalkanes.
The use of supported aluminum chloride catalysts for alkane isomerization is known. The present invention is directed to the use of novel, effective AlCl 3 -containing catalyst materials for cycloalkane isomerization.
SUMMARY OF THE INVENTION
It is an object of this invention to employ materials prepared from aluminum chloride and select boron compounds as catalysts for isomerizing cycloalkanes. Other objects and advantages will be apparent from the detailed description of the invention and the appended claims.
In accordance with this invention, a process for isomerizing cycloalkanes comprises contacting, at a reaction temperature of about 0°-100° C., at least one cycloalkane containing 5-10 carbon atoms per molecule with a solid catalyst composition at effective isomerization conditions;
wherein said catalyst composition bas been prepared by a method comprising the steps of (I) heating in the substantial absence of water, at a temperature of about 40°-90° C., a mixture comprising (a) aluminum chloride, (b) at least one solid boron-containing material selected from the group consisting of boron phosphate on silica, boron phosphate on carbon and boron sulfate on silica, and (c) at least one cblorinated hydrocarbon having a normal boiling point (i.e., the boiling point at 1 atm. pressure) of about 40°-90° C., wherein the weight ratio of AlCl 3 to said at least one solid boron-containing material is at least about 0.25:1; and (II) separating the solid material contained in the reaction mixture obtained in step (I) from said at least one chlorinated hydrocarbon under a dry gas atmosphere.
In one preferred embodiment, the weight of AlCl 3 to the solid boron-containing material is about 0.5:1 to about 1.0:1. In another preferred embodiment, the isomerization reaction temperature is about 20°-50° C. In a further preferred embodiment, the feed cycloalkane is methylcyclopentane, which is isomerized to cyclohexane at a high selectivity (about 90-100%).
DETAILED DESCRIPTION OF THE INVENTION
Preparation step (I) can be carried out in any suitable manner. Generally, substantially dry agents (a), (b) and (c), which are all defined above, are thoroughly mixed under a dry gas atmosphere (preferably a dry inert gas atmosphere, e.g., N 2 , He, Ar and the like), and the obtained mixture is then heated under a dry inert gas atmosphere at a temperature of about 40°-90° C., preferably about 70°-80°C., for a time period of about 4 to about 120 hours, preferably about 10-30 hours. It is preferred to carry out step (I) with agitation, either mechanically (e.g., by means of a stirrer) or ultrasonically. The weight ratio of (a) to (b) generally is about 0.25:1 to about 1.5:1. When material (b) is BPO 4/ SiO 2 or B 2 (SO 4 ) 3 /SiO 2 , this weight ratio preferably is about 0.25:1 to about 1.0:1. When material (b) is BPO 4/ carbon, this weight ratio preferably is about 0.5:1 to about 1.0:1.
In one embodiment, the solid material (b) contains about 20 to about 80 weight-% (preferably about 23-65 weight-%) BPO 4 and/or B 2 (SO 4 ) 3 and about 20-80 weight-% silica carrier (preferably about 35-73 weight-% SiO 2 ). In another embodiment, BPO 4 is the boron compound and activated carbon is used as the carrier (in lieu of silica), generally at a level of 20-80 weight-% carbon (preferably about 50-80 weight-% carbon). The surface area (measured by the BET method by Brunauer, Emmett and Teller employing nitrogen) of these solid materials (b) generally is in the range of about 100 to about 1000 m 2 /g (preferably about 200-500 m 2 /g). Preferably, the support particles have a size in the range of smaller than 20 mesh and larger than 60 mesh.
Preferably, the solid BPO 4 -containing materials are prepared by the reaction of a boric acid ester, B(OR) 3 , wherein each R can be independently selected from the alkyl radicals containing 1-5 carbon atoms (more preferably tri-n-propyl borate), and orthophosphoric acid (H 3 PO 4 ), in the presence of silica or, alternatively, activated carbon, which are present during this reaction in an amount as to provide a material containing about 20-80 weight-% SiO 2 or, alternatively, 20-80 weight-% activated carbon. When a solid B 2 (SO 4 ) 3 -containing material is used as material (b), it is preferably prepared by the reaction of a boric acid ester (such as tri-n-propyl borate) and sulfuric acid, in the presence of silica at an amount to provide a level of about 80 weight-% SiO 2 in the B 2 (SO 4 ) 3 /SiO 2 material. The thus-obtained solid materials are then separated from the liquids by distillation, substantially dried and calcined (generally for about 2-5 hours at a temperature of about 250°-500° C., either in air or in a N 2 atmosphere) before they are employed in step (I).
Agent (c) used in step (I) is a chlorinated hydrocarbon or a mixture of two or more chlorinated hydrocarbons having a normal boiling point in the range of about 40°-90° C., preferably about 70°-80° C. Preferred chlorinated hydrocarbons are chlorine derivatives of paraffins. Non-limiting examples of suitable chlorinated hydrocarbons are dichlorometbane, chloroform (trichloromethane), carbon tetrachloride, 1,1-dichloroethane, 1,2-dicbloroethane, 1,1,1-trichloroethane, 1,1-dichloropropane, 2,2-dichloropropane, 1-chlorobutane, 2-chloro-2-methylbutane, and mixtures thereof. The preferred chlorinated hydrocarbon is carbon tetrachloride. Generally the ratio of the weight of the cblorinated hydrocarbon(s) to the combined weight of materials (a) and (b) employed in step (I) is about 4:1 to about 20:1.
Separation step (II) can be carried out in any suitable manner. Preferably, the finished reaction mixture obtained in step (I) is filtered, and the solid filter cake is substantially dried at any suitable conditions, preferably at subatmospheric (i.e., vacuum) conditions, at a temperature of about 25°-60° C. Preferably, step (II) is carried out under a dry inert gas atmosphere (N 2 , He, Ar, and the like). The finished/dried catalyst particles should be stored under a dry inert gas atmosphere.
The catalyst composition prepared by the above-described preparation method is employed as a catalyst for isomerizing C 5 -C 10 cycloalkanes, preferably methyl-substituted cycloalkanes, to product cycloalkanes (i.e., cycloalkanes having the same number of carbon atoms as the feed cycloalkanes by different structural formulas). Nonlimiting examples of suitable feed cycloalkanes are methylcyclobutane, methylcyclopentane, 1,1-dimetbyleyclopentane, 1,2-dimethylcyclopentane, 1,3-dimetbylcyclopentane, metbylcyclohexane, 1,1-dimethylcyclohexane, 1,2-dimethyleyclohexane, 1,3-dimethylcyclohexane, ethylcyclobexane, methylcyclobeptane, 1-methyl-2-ethylcyclopentane, 1,1-dimethylcycloheptane, 1,2-dimethylcycloheptane, 1,3-dimetbylcyclobeptane, ethylcycloheptane, 1-methyl-2-etbylcyclohexane, methylcyclooctane, 1,1-dimetbylcyclooctane, 1,2-dimethylcyclooctane, 1,3-dimethylcyclooctane, and mixtures thereof. The preferred cycloalkane is methylcyclopentane which is substantially completely converted to cyclohexane.
The process for isomerizing C 5 -C 10 cycloalkanes with at least one of the above-described catalyst compositions can be carried out under any suitable reaction conditions at a relatively low temperature of up to about 100° C., more preferably about 20°-50° C. (most preferably about 30°-40° C.), generally at about 1-5 atm. pressure, for about 0.1-8 hours. The feed hydrocarbon(s) can be contacted with the catalyst composition in any suitable mode, such as in a slurry operation in which the catalyst is dispersed in the feed hydrocarbon(s), or in a fixed catalyst bed operation in which the hydrocarbon feed flows upward or downward through a solid catalyst layer (or several catalyst layers). The time of contact between the feed hydrocarbon(s) and the catalyst composition generally is in the range of about 5 minutes to about 8 hours, preferably about 1-2 hours. Each isomerization process can be carried out as a batch operation or as a continuous operation. Moisture is to be substantially absent during the isomerization process.
Since the isomerization process of this invention may generate more than one hydrocarbon product, it is generally necessary to separate the various formed hydrocarbons from one another and also from unconverted feed cycloalkane(s). This separation can be carried out in any suitable manner, generally by fractional distillation (possibly in the presence of an extractant, i.e., by extractive distillation), as is easily determined by persons skilled in the various liquid-liquid separation technologies.
The following examples are presented to further illustrate the invention and are not to be construed as unduly limiting the scope of the invention.
EXAMPLE I
This example illustrates the preparation of catalyst materials which were employed in cycloalkane isomerization tests.
Control Catalysts A1-A6 were prepared by beating various amounts of dry AlCl 3 and G-57 silica (20-40 mesh; BET/N 2 surface area: 340-350 m 2 /g; marketed by Davison Catalyst Division of W. R. Grace and Company, Baltimore, MD, under the product designation of G-57; calcined for 4 hours at 550° C.) and 30 mL of dry CC1 4 for 18 hours under reflux conditions in the dark, under a N 2 gas atmosphere. The thus-heated mixture was cooled and then dried at about 30° C. under vacuum conditions. The amounts of AlCl 3 and SiO 2 were as follows: 0.373 g AlCl 3 and 1.50 g SiO 2 for Catalyst A1, 0.640 g AlCl 3 and 1.50 g SiO 2 for Catalyst A2, 0.896 9 AlCl 3 and 1.50 g SiO 2 for Catalyst A3, 1.78 g AlCl 3 and 2.50 g SiO 2 for Catalyst A4, 1.493 g AlCl 3 and 1.50 g SiO 2 for Catalyst A5, and 2.240 g AlCl 3 and 1.5 g SiO 2 for Catalyst A6.
Control Catalysts B1--B4 were prepared by heating various amounts of dry AlCl 3 and 1.50 grams BPO 4 (20-40 mesh; prepared by adding tri-n-propyl borate dropwise to phosphoric acid containing 85 weight-% H 3 PO 4 and 15 weight-% H 2 O, at a (C 3 H 5 ) 3 B:H 3 PO 4 molar ratio of about 1:1, maintaining the reaction mixture at about 65°-80° C. for about 1 hour under a N 2 gas atmosphere, followed by distillation at about 110° C. for the removal of n-propanol and of water, and drying the solid BPO 4 reaction product under vacuum conditions at 120° C. for 3 hours) and 30 mL of dry CCl 4 for 18 hours under reflux conditions, followed by drying as described above for Catalysts A1--A6. The amounts of employed AlCl 3 were: 0.373 grams, 0.640 grams, 0.896 grams and 1.493 grams, respectively, for Catalysts B1, B2, B3 and B4, respectively.
Catalysts C1-C4 were prepared as follows. First, a BPO 4 /SiO 2 materials containing 27 weight-% BPO 4 was prepared by mixing 34.35 grams of calcined 20-40 mesh G-57 silica (described above) and 1-3.8 grams of a mixture of aqueous 85 weight-% H 3 PO 4 (described above), heating the mixture to about 80° C. under a N 2 atmosphere, adding dropwise with stirring 22.70 g tri-n-propyl, beating the entire reaction mixture for 2 hours under reflux conditions, thereafter distilling off essentially all liquids (mainly formed propanol and water) at a temperature of about 120° C., and finally drying the solid BPO 4 residue for 3 hours at a temperature of about 150° C. under vacuum conditions. 2.50 grams of the thus obtained BPO 4 on SiO 2 Material (containing 27 weight-% BPO 4 ) was then heated with AlCl 3 and CCl 4 and dried (as described for Catalysts A 1-A6). The amounts of AlCl 3 were 0.622 grams, 1.245 grams, 1.867 grams and 2.489 grams, respectively, for Catalysts C1, C2, C3 and C4 respectively.
Catalysts D1-D3 were prepared as follows. First, a BPO 4 /SiO 2 support material containing 75 weight-% BPO 4 was prepared essentially in accordance with above-described procedure for preparing BPO 4 /SiO 2 (containing 27 weight-% BPO 4 ), except that the amount of added silica was adjusted to about 25 weight-% SiO 2 of the entire support material, which was heated for 2 hours at 300° C. in air. 1.50 grams of this BPO 4 /SiO 2 material containing 75 weight-% BPO 4 was then heated with various amounts of AlCl 3 and CCl 4 and dried, as described for Catalysts A1-A6. The amounts of AlCl 3 were 0.373 grams, 0.747 grams and 1.120 grams, respectively, for Catalysts D1, D2 and D3, respectively.
Catalysts E1-E3 were prepared as follows. First 36.35 grams of Nuchar® C activated carbon (Grade WV-B 14×35; obtained from Westvaco Chemical Division, Covington, VA; calcined under N 2 at 400° C. overnight) was mixed with 27.9 grams of aqueous 85 weight-% H 3 PO 4 (described above), heating this mixture with stirring to 80° C. for 1 hour, adding dropwise 45.14 grams of tri-n-propyl borate to the hot mixture, increasing the temperature of the entire mixture to 120° C. over a 4 hour period, distilling of formed n-propanol and water at 130° C. for 1 hour, and finally drying the BPO 4 /carbon material containing about 25 weight-% BPO 4 and about 75 weight-% C. 1.50 grams of this BPO 4 /C material was heated with various amounts of AlCl 3 and 30 mL dry CCl 4 and then dried, as described for Catalysts A1-A6. The amounts of AlCl 3 were 0.373 grams, 0.747 grams and 1.120 grams, respectively, for Catalysts E1, E2 and E3, respectively.
Catalysts F1-F3 were prepared as follows. First, a B 2 (SO 4 ) 3 /SiO 2 support material containing 35 weight-% B 2 (SO 4 ) 3 , was prepared by mixing and beating (with stirring) 22.70 grams of tri-n-propyl borate, 17.76 grams of 100% H 2 SO 4 and 34.35 grams of G-57 silica (described above) for about 2 hours at 80° C., then heating the reaction mixture to 120° C., distilling off liquids (mainly formed propanol) at about 120° C., and heating the solid residue in air at 275° C. for 2 hours. 1.50 grams of this B 2 (SO 4 ) 3 /SiO 2 material (containing 35 weight-% B 2 (SO 4 ) 3 and 65 weight-% SiO 2 ) was then heated with various amounts of AlCl 3 and CCl 4 and finally dried, as described for Catalysts A1-A6. The amounts of AlCl 3 were 0.373 grams, 0.747 grams and 1.120 grams, respectively, for Catalysts F1, F2 and F3, respectively.
EXAMPLE II
This example illustrates the isomerization of methylcyclopentane to cyclohexane in the presence of the Catalyst materials described in Example I. All reactions were carried out at about 38°-40° C. in sealed ampules under a dry nitrogen atmosphere, employing about 10 mL of the feed hydrocarbon (methylcyclopentane) and about 0.5 grams of each of the catalysts. The reaction mixtures were slightly agitated for about 1-2 hours by means of an ultrasonic vibrator, and were analyzed by means of a gas chromatograph. Test results obtained after a reaction time of 1 hour are summarized in Table I.
TABLE I__________________________________________________________________________Catalyst Preparation Method % ConversionCatalyst Grams AlCl.sub.3 of SelectivityEmployed Support per Gram Support Methylcyclopentane to Cyclohexane.sup.3__________________________________________________________________________A1 SiO.sub.2 0.25 4.4 85.2%B1 BPO.sub.4 " 8.8 92.7%C1 BPO.sub.4 /SiO.sub.2.sup.1 " 14.7 96.0%D1 BPO.sub.4 SiO.sub.2 " 13.3 95.2%E1 BPO.sub.4 /C " 2.2.sup.4 53.2%.sup.4F1 B.sub.2 (SO.sub.4).sub.3 /SiO.sub.2 " 5.5 87.9%A2 SiO.sub.2 0.43 12.0 94.4%A3 SiO.sub.2 0.60 10.4 93.4%B2 BPO.sub.4 0.50 11.5 94.5%C2 BPO.sub.4 /SiO.sub.2.sup.1 " 16.5 96.2%D2 BPO.sub.4/ SiO.sub.2.sup.2 " 31.7 97.9%E2 BPO.sub.4 /C " 35.5 95.4%F2 B.sub.2 (SO.sub.4).sub.3 /SiO.sub.2 " 25.0 97.0%A4 SiO.sub.2 0.71 3.4 86.3%B3 BPO.sub.4 0.75 8.6 92.7%C3 BPO.sub.4 /SiO.sub.2.sup.1 " 11.6 94.5%D3 BPO.sub.4/ SiO.sub.2.sup.2 " 31.8 97.9%E3 BPO.sub.4 /C " 60.0 97.5%F3 B.sub.2 (SO.sub.4).sub. 3 /SiO.sub.2 " 21.1 96.7%A5 SiO.sub.2 1.00 11.9 94.6%B4 BPO.sub.4 " 11.2 94.1%C4 BPO.sub.4 /SiO.sub.2.sup.1 " 17.0 96.0%__________________________________________________________________________ .sup.1 containing 27 weight% BPO.sub.4 .sup.2 containing 65 weight% BPO.sub.4 .sup.3 %yield of cyclohexane divided by %conversion of methylcyclopentane × 100 .sup.4 results believed to be erroneous (likely reason: contamination of catalyst or feed)
Test data in Table I clearly show that the AlCl 3 /BPO 4 SiO 2 , AlCl 3 /B 2 (SO 4 ) 3 /SiO 2 and AlCl 3 /BPO 4 /C catalyst materials were generally more effective (in terms of feed conversion and selectivity to cyclohexane) than AlCl 3 /SiO 2 and AlCl 3 /BPO 4 , in particular at the more preferred AlCl 3 :support weight ratio of 0.50:1 to 1.00:1.
Reasonable variations, modifications and adaptations for various conditions and reactants can be made within the scope of the disclosure and the appended claims without departing from the scope of this invention.
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C 5 -C 10 cycloalkanes (preferably methylcyclopentane) are isomerized in the presence of a catalyst comprising aluminum chloride and at least one of the following materials: boron phosphate on silica, boron phosphate on activated carbon, boron sulfate on silica.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Application Ser. No. 62/326,133, entitled “APPARATUS AND METHOD FOR TREATING AND PREVENTING ODORS,” filed Apr. 22, 2016, which is incorporated herein in its entirety.
TECHNICAL FIELD
[0002] This disclosure relates to the sanitization and cleaning industries. In particular, this disclosure relates to an apparatus and methods for cleaning and sanitizing bathrooms and toilets.
BACKGROUND
[0003] On average, people eliminate fecal waste between 1 to 3 times per day. Usually people eliminate their fecal waste into a toilet or similar waste disposal system. This fecal elimination process often brings about unwanted odors on account of metabolic byproducts that are contained in feces and/or accompany the evacuation process. These odors originate from the toilet area, where the fecal evaluation takes place and the waste is collected for subsequent disposal. Left untreated, the waste generates odors, which diffuse into the air and adjacent areas.
[0004] Popular remedies for toilet related odors include air circulation systems and air fresheners. Air circulation systems, such as fans, replace the contaminated air with fresh air. Air fresheners typically introduce pleasant fragrances to mask unwanted toilet odors. Air fresheners are available in many forms, such as sprays, heated oils, solids, and gels.
[0005] Despite existing products for treating bathroom air, the state of art suffers from several limitations. For example, sprays that are used in bathrooms typically treat only the air around the toilet, i.e., the ambient atmosphere. Such sprays do not target the source of the problem, which is the fecal waste in the toilet and odorous volatile molecules emanating from that waste. Most sprays only cover the odor by dispersing fragrances into the area with the unwanted odor. Such air fresheners do not treat the source of the odor itself.
[0006] No existing systems or methods treat both the source of the odor problem and also resulting odors. Accordingly, there exists a need to target both the source of the odor and the ambient atmosphere affected by the odor. In particular, there exists a need to treat both the odor source and the affected surrounding air with compositions targeting both the source of the odor problem and the unwanted odors themselves. Accordingly, there exists a need for systems, methods, and devices, for deploying multiple targeted compositions to multiple different places in and around a toilet.
DETAILED DESCRIPTION
[0007] Disclosed herein is a new apparatus for dispensing chemical compositions, for example dispensing multiple compositions into two or more spaces. Disclosed herein is a new apparatus for eliminating bathroom odors. Also disclosed herein are new methods for eliminating bathroom odors.
[0008] Disclosed herein is a new apparatus. Also disclosed herein is a new device, which may be used independently or in concert with the disclosed apparatus. Accordingly, in one embodiment, the apparatus disclosed herein includes the device disclosed herein.
[0009] Disclosed here is a new apparatus comprising:
a First Container; a Second Container; a Third Container; a First Composition; a Second Composition; a First Dispenser; a Second Dispenser; a surrounding ambient atmosphere; wherein the First Dispenser expels the First Composition from within the First Container into the Third Container; wherein the Second Dispenser expels the Second Composition from within the Second Container into the ambient atmosphere.
[0020] In one embodiment, the Third Container comprises water and air. In one embodiment, the Third Container is open to the ambient atmosphere. In one embodiment, the First Composition is held within the First Container and the Second Composition is held within the Second Container.
[0021] As used herein, the term “First Container” means a storage device that can be either left open to the atmosphere or closed. In one example, the First Container is a can, bag, bladder, or bottle.
[0022] As used herein, the term “Second Container” means a storage device. Within the context of this disclosure the Second Container can be left open to the atmosphere or closed. In one example, the Second Container is a can, bag, bladder, or bottle.
[0023] As used herein, the term “Third Container” means a storage device that can be either left open to the atmosphere or closed. In one example, the Third Container is a can, bag, bladder, or bottle. In one example, the Third Container is a tank, chamber, or bowl, such as a toilet or urinal.
[0024] As used herein, the term “First Composition” means a chemical or chemical mixture. In one example, the First Composition is an oil and natural oil. In one example, the First Composition is a perfume. In another example, the First Composition is a surfactant. In another example, the First Composition is an oil. In one example, the First Composition is an alcohol. In one example, the First Composition is an antiseptic.
[0025] As used herein, the term “Second Composition” means a chemical or chemical mixture. In one example, the Second Composition is an odor absorber. In one example, the Second Composition is a soap. In one example, the Second Composition is a natural oil. In one example, the Second Composition is a perfume. In one example, the Second Composition is an alcohol. In one example, the Second Composition is an antiseptic.
[0026] As used herein, the term “First Dispenser” means a device through which a substance can be delivered. In one example, the First Dispenser is a pump system. In one example, the First Dispenser is a nozzle system.
[0027] As used herein, the term “Dispenser” includes pressurized or unpressurized delivery systems, such as pressurized spray systems, or gravity mediated drip systems.
[0028] As used herein, the term “Second Dispenser” means a device through which a substance can be delivered. In one example, the Second Dispenser is a pump system. In one example, the Second Dispenser is a nozzle system. In one example, the Second Dispenser is an atomizer.
[0029] As used herein, the term “ambient atmosphere” means the surrounding atmosphere in which the device or apparatus resides. In one example, the ambient atmosphere is the air within a bathroom or vestibule, which contains a toilet.
[0030] As used herein, the term “expels” means to ejecting or causing a material to move out of the container from which it is expelled. In one example, the First Dispenser expels the First Composition from the First Container.
[0031] In one embodiment, the First Composition is held within the First Container and the Second Composition is held within the First Container. In one embodiment, at least one of the First Container and the Second Container is a bag on valve container.
[0032] As used herein, the term “bag on valve” refers to a pressurized container with a filled bag inside. In one example, the bag inside is a welded bag. In one example, the bag is filled with a composition on the inside and subjected pressure of greater than one atmosphere on the outside. In one embodiment, the bag is contained within a rigid container and a gas having a pressure of greater than one atmosphere fills the space between the bag and rigid container. In one example, the gas creates a pressure on the bag, which expels the composition from the bag.
[0033] In one embodiment, at least one of the First Container and the Second Container is a pump bottle.
[0034] As used herein, the term “pump bottle” means a bottle with a dispensing mechanism inserted therein. For example, a “pump bottle,” within the context of this disclosure includes conventional trigger spray bottles which can squirt, spray or mist fluids. In some embodiments, the term “pump bottle” includes a bottle with a nozzle, said bottle having a dip tube inserted therein and a means for pumping liquid from within the bottle, up through the dip tube, and out of the nozzle.
[0035] In one example, the First Dispenser is attached to the First Container.
[0036] In one embodiment of the disclosed apparatus, the First Composition includes one or more ingredients chosen from an oil, a natural oil, a perfume, an oxidant, a soap, an acid, a base, a surfactant, an odor absorber, a cyclodextrin, and an antioxidant.
[0037] As used herein the term “oil” refers to a nonpolar liquid that can be viscous at ambient temperatures. Within the context of this disclosure, an “oil” can be characterized as being both hydrophobic and lipophilic, and having high carbon and hydrogen content. In one embodiment, the term “oil” refers to a substance that is substantially immiscible with water, creating distinct layers of material as opposed to a single solution.
[0038] As used herein, the term “natural oil” refers to oils containing compounds which may be found in plants or animals as opposed to oils which exist only through man-made synthesis. Examples of natural oils within the context of this disclosure include vegetable oils with ethereal salts of glycerin, organic acids such as stearic acid, oleic acid, and palmitic acid forming stearin, olein and palmitin, respectively.
[0039] As used herein the term “perfume” refers to one or more fragrant volatile molecules, such as aromatic compounds.
[0040] As used herein the term “oxidant” can refer to a chemical species that can either remove an electron or transfer electronegative atoms to a substrate. An oxidant can also be referred to as an oxidizing agent. Within the context of this disclosure, examples of oxidants include, chlorinating agents, halogenating agents, peroxides, nitrates, oxygen, ozone, and hypohalite.
[0041] As used herein the term “soap” refers to a salt of a fatty acid often characterized for being able to allow insoluble particles to be soluble in water. In one example, the term soap refers to sodium stearate with the following structure:
[0000]
[0042] As used herein the term “acid” refers to a chemical substance with a pH of less than 7. In one example, an acid has the ability to turn blue litmus red. In one example, an acid has the ability to react with bases and certain metals to form salts. Within the context of this disclosure, examples of acids include acetic acid, citric acid, phthalic add, sodium hydroxymethylglycinate, hydrochloric acid, and formic acid.
[0043] As used herein the term “surfactant” refers to compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid.
[0044] As used herein the term “odor absorber” refers to a substance, such as a solid or gel, that neutralizes smells. Within the context of this disclosure, one example of an odor absorber is a cyclodextrin.
[0045] As used herein the term “cyclodextrin” refers to a family of compounds made up of sugar molecules bound together in a ring. Some examples, but not limited to, are α (alpha)-cyclodextrin (6-membered sugar ring molecule), β (beta)-cyclodextrin (7-membered sugar ring molecule), and γ (gamma)-cyclodextrin (8-membered sugar ring molecule).
[0000]
[0046] As used herein the term “antioxidant” refers to a chemical agent that lessens oxidation. Within the context of this disclosure, examples of antioxidants include beta carotene, lutein, lycopene, Vitamin C, thiosulfate, Vitamin A, Vitamin E, etc., including salts and derivatives thereof in any proportion.
[0047] In one embodiment of disclosed apparatus, the Second Composition includes one or more ingredients chosen from an oil, a natural oil, a perfume, an oxidant, a soap, an acid, a base, a surfactant, an odor absorber, a cyclodextrin, and an antioxidant.
[0048] Disclosed herein is a new device comprising:
a Rigid Pressurized Container comprising a First Bladder and Second Bladder; an Outlet; wherein said First Bladder comprises a composition having a First Bladder Vapor Pressure; wherein said Second Bladder comprises a composition having a Second Bladder Vapor Pressure; wherein said Pressurized Container comprises a vapor pressure greater than one atmosphere of pressure; and wherein said Pressurized Container comprises a vapor pressure greater than said First Bladder Vapor Pressure.
[0054] As used herein the term “Rigid Pressurized Container” refers to a container that is sturdy enough withstand pressures higher than 1 atmosphere without compromising the structure of the container. One example of a “Rigid Pressurized Container” is a can or bottle. In one embodiment, the Rigid Pressurized Container is made of plastic. In one embodiment, the Rigid Pressurized Container is made of metal.
[0055] As used herein the term “Bladder” mean an inflatable flexible container (e.g., a bag) made of a material capable of holding a liquid composition and capable of bending when exposed to a force, such as a pressure differential. In one example, the bladder is made of rubber. In one example, the bladder is made of plastic. In one example, the bladder is made of metal.
[0056] In one embodiment, the Rigid Pressurized Container comprises a First Chamber and a Second Chamber;
[0057] wherein the First Bladder is contained within the First Chamber; and
[0058] wherein the Second Bladder is contained within the Second Chamber.
[0059] In one embodiment, the apparatus disclosed herein comprises a Third Composition. In one embodiment, the Third Composition is expelled into the Third Container. In one embodiment, the Third Composition is expelled into the ambient atmosphere. In one embodiment, the Third Composition activates the First Composition.
[0060] As used herein the term “activates” refers to reacting with a composition, such as the First Composition, thereby making the composition differently (e.g., more) reactive towards other molecules or chemical reactions.
[0061] In one embodiment, the Third Composition activates the Second Composition.
[0062] In one embodiment, the Third Composition neutralizes the First Composition.
[0063] As used herein the term “neutralizes” refers to lessening the chemical reactivity of a molecule. For example, neutralizing a composition, such as the First Composition, includes reacting with that composition, thereby rendering the composition less reactive towards other molecules or chemical reactions.
[0064] In one embodiment, the Third Composition neutralizes the Second Composition.
[0065] In one embodiment, the First Container is a different volume from the Second Container.
[0066] In one embodiment, each of the First Dispenser and the Second Dispenser is independently chosen from a spray nozzle, an atomizer, and a tube.
[0067] As used herein the term “spray nozzle” refers to a device that facilitates dispersion of liquid into a spray.
[0068] As used herein the term “atomizer” refers to a device, which forms a dispersion of fine solid particles or liquid droplets upon passing a material through the device.
[0069] In one embodiment, the apparatus is coated with an antibacterial.
[0070] As used herein the term “antibacterial” refers to a compound that either inhibits bacterial growth or kills bacteria.
[0071] In one embodiment, the Third Container is a toilet.
[0072] As used herein, the term “toilet” means a sanitation fixture used to collect or dispose of human feces or urine. Examples within the context of this disclosure include conventional toilet bowls, urinals, outhouses, and portable toilets.
[0073] In one embodiment, the toilet has a water holding tank. In one embodiment, the First Container is positioned inside the water holding tank.
[0074] As used herein, the term “water holding tank” means a tank which holds a cached volume of water for later use, wherein the tank may be filled at a rate that is independent of the rate at which the tank is emptied. In one embodiment, the term “water holding tank” includes a container which holds water along with devices and plumbing for a toilet.
[0075] In one embodiment, the toilet has a water holding tank and the First Container is positioned adjacent to the water holding tank.
[0076] As used herein, the term “positioned adjacent to the water holding tank” means the First Container is located next to the water holding tank but not inside of the water holding tank.
[0077] In one embodiment, the apparatus comprises a First Fill Level Indicator.
[0078] In one embodiment, the apparatus comprises a UV light, positioned to radiate the surrounding ambient atmosphere.
[0079] In one embodiment, the apparatus comprises a UV light, positioned to radiate the apparatus.
[0080] In one embodiment, the toilet has a toilet seat. In one embodiment, the toilet is equipped with a Sensor. In one embodiment, the Sensor triggers deployment of the First Composition.
[0081] As used herein, the term “First Fill Level Indicator” means a display means, which provides visible information about the amount of material present within one or more containers. In one embodiment, the “First Fill Level Indicator” is a light, such as an LED light. In one embodiment, the “First Fill Level Indicator” is a display screen.
[0082] As used herein, the term “toilet seat” means a hinged unit consisting of a seat (and optionally a lid), which is connected onto a toilet bowl for a toilet used in a sitting position.
[0083] As used herein, the term “Sensor” means a device that detects stimuli in its surrounding environment. Within the context of this disclosure the term “Sensor” includes infrared, electrical conductance, weight, and/or light sensors.
[0084] In one example, the Sensor activates the First Dispenser to deploy the First Composition. In one example, the Sensor detects the presence of a person sitting on a toilet seat of the apparatus. In one example, the apparatus deploys a First Composition into a toilet upon detecting the presence of a person sitting on a toilet seat.
[0085] As used herein, the term “trigger” means a stimulus which causes another event to occur. For example, the term “triggers deployment” means that an event (such as a Sensor detection) causes the First Composition to become deployed.
[0086] In one embodiment, the Sensor detects a water level in the toilet. In one embodiment, the Sensor detects gravitational force on the toilet set. In one embodiment, the Sensor detects electrical conductance on the toilet seat. In one embodiment, the Sensor triggers deployment of the Second Composition.
[0087] Although the present invention herein has been described with reference to various exemplary embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. Those having skill in the art would recognize that various modifications to the exemplary embodiments may be made, without departing from the scope of the invention.
[0088] Moreover, it should be understood that various features and/or characteristics of differing embodiments herein may be combined with one another. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the scope of the invention.
[0089] Furthermore, other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a scope and spirit being indicated by the claims.
[0090] Finally, it is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent, and vice versa. As used herein, the term “include” or “comprising” and its grammatical variants are intended to be non-limiting, such that recitation of an item or items is not to the exclusion of other like items that can be substituted or added to the recited item(s).
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This disclosure relates to new methods and compositions for dispensing multiple compositions into a plurality of containers or atmospheres. In one embodiment, this disclosure pertains to treating and preventing offensive odors arising from toilets.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a national phase entry under 35 U.S.C. §371 of International Application No. PCT/SE2010/050266 filed Mar. 9, 2010, published in English, which claims priority from Swedish Application No. 0900351-8, filed Mar. 19, 2009, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to treatment of cellulose pulp and in particular to a screening arrangement for cellulose pulp and a system and a method for screening of cellulose pulp.
BACKGROUND OF THE INVENTION
[0003] In the course of preparing a cellulose pulp to be used for further processing, such as for example in papermaking or the like, a number of “standard” operations are often performed. For chemical pulp, lignin from wood chips is dissolved in a digester in order to separate the fibers within the wood chips from each other. The cooked pulp is then transported to washing and screening devices. During cooking, not all of the wood chips are equally well digested, and the resulting pulp thus contains not only individually separated fibers, but also pieces of uncooked wood chips, knots and fiber bundles known as shives. The shives, knots and other impurities (e.g. sand, bark, etc.) still remaining in the pulp may cause problems in later stages of the pulp processing, and thus need to be removed. There are a number of well-known operations used, separately or in combination, to separate impurities from the pulp, including sedimentation, screening and vortex cleaning operations.
[0004] Screening refers to an operation in which fibers in a pulp suspension pass through a perforated plate with holes or slots, while the impurities are retained. The fraction of pulp passing the plate is referred to as the accept fraction or simply the accept. The fraction of pulp not passing through the openings of the plate is referred to as the reject fraction or simply the reject. The pulp fraction fed to the perforated plate is referred to as the inject fraction or simply the inject. An inject can thus be said to be a pulp flow about to be divided into an accept and a reject. Instead of a perforated plate, slots for separation may be created in other ways, e.g. through forming a screen basket of longitudinal bars.
[0005] In a pulp mill, there are often several screening operations at different locations throughout the process. For example, there is often a primary screening operation, in connection with the pulp being washed and dewatered, and an after-screening operation after bleaching of the pulp. Each screening operation can, and often will be, performed in several stages. One single screening apparatus is often not sufficient to separate all impurities in one stage. In order to achieve good screening efficiency, the reject flow has to be sufficiently large to make sure that the impurities not passing through the screen are removed from the screening apparatus. In case the reject flow is too small, impurities may be retained in the screening chamber where they can cause unnecessary wear to the screen. Since the reject flow must therefore be of a certain magnitude, this implies that a large number of “good” fibers (i.e. fibers that would belong to the accept) is not given enough time to pass the perforated plate or through slots between longitudinal bars, but instead becomes a part of the reject. The accept portion from the screening stage is passed to the next processing step, while the reject portion is passed to a subsequent screening stage, in order to be screened again. In order to minimize fiber losses, the accept from the subsequent screening stage is then returned to the inject of the preceding screening stage. In that way, most of the “good” fibers are recovered.
[0006] There are several different kinds of screening apparatuses. One commonly used screening apparatus is a so-called combi-screen, meaning that two or more screening stages are combined within the same screen housing. An example of such an apparatus is disclosed in European Patent No. 1,165,882, where a first screening means is located at least partly within a second screening means. Combi-screens have been developed in order to provide a cheaper process in which two different screening apparatuses are combined into one apparatus, eliminating the need for e.g. a separate knotter. There are also other kinds of multistage screens in which several screening stages are combined within the same apparatus. For example, the separate screening stages may be arranged by means of screens on top of each other, or by one high screening basket being divided into separate screening sections
[0007] While using a combi-screen, it is not possible to return the accept from a subsequent screening stage after the combi-screen to its directly preceding screening stage, such as e.g. a fine screen contained within the combi-screen. The accept portion from the subsequent screening stage (at this stage not containing any larger particles), when returned to a combi-screen, will have to pass both screening stages within the combi-screen again, which implies an unnecessary load on the coarse screen. Part of the pulp entering the coarse screen has then already been screened for larger impurities, and does not require the coarse screening stage. The return flow from the subsequent screening stage can submit to about 15-20% of the main flow into the combi-screen. This implies that the pump before the combi-screen must be dimensioned to handle a larger flow, in case the return flow is to be added before the pump. Even if the flow is added after the pump, the coarse screen still has to be dimensioned to be able to handle the larger flow. All of these measures render a more expensive process.
[0008] One object of the present invention is thus to provide an improved system and arrangement for the screening of cellulose pulp. Another object of the present invention is to achieve a more efficient way of screening while minimizing fiber losses, and at the same time keeping the number of individual screening apparatuses as low as possible, in order to minimize the total investment cost. Another object of the present invention is to provide a screening system and an arrangement where the screening means and associated equipment does not have to be overdimensioned, also in order to minimize the investment cost.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, these and other objects have now been realized by the discovery of apparatus for screening a cellulose pulp stream comprising a housing, a first screen member contained within the housing including screen openings for permitting a first predetermined accept portion to pass therethrough and for creating a first reject portion, a second screen member contained within the housing including screen openings for permitting a second predetermined accept portion to pass therethrough and for creating a second reject portion, a primary inlet for directing the cellulose pulp stream into the housing, an accept outlet for withdrawing the second predetermined accept portion from the housing, a reject outlet for withdrawing at least one of the first and second reject portions from the housing, a first screening chamber for receiving the cellulose pulp stream from the primary inlet for transfer to the first screen member, a first accept chamber for receiving the first predetermined accept portion of the cellulose pulp stream which has passed through the first screen member, a second screen chamber for directing the first predetermined accept portion of the cellulose pulp stream from the first accept chamber to the second screen member, a secondary pulp inlet for receiving a second cellulosic pulp feed stream comprising a screened cellulose pulp accept fraction and directing the second cellulose pulp feed stream to the second screen member, whereby the second predetermined accept fraction is delivered to the accept outlet. In a preferred embodiment, the screen openings in the first screen member and the second screen member have different sizes.
[0010] In accordance with one embodiment of the apparatus of the present invention, the first and second screen members are coaxially disposed within each other within the housing, and the first screen member is rotatably mounted within the second screen member.
[0011] In accordance with another embodiment of the apparatus of the present invention, the screen openings in the first screen member comprise coarse screen openings and the screen openings in the second screen member comprise fine screen openings smaller than the coarse screen openings.
[0012] In accordance with another embodiment of the apparatus of the present invention, the second cellulose pulp feed stream merges with the first predetermined accept fraction before entering the second screen member.
[0013] In accordance with another embodiment of the apparatus of the present invention, the secondary pulp inlet is disposed in the lower portion of the housing.
[0014] In accordance with another embodiment of the apparatus of the present invention, the apparatus includes a secondary pulp inlet chamber for directing the secondary cellulose pulp feed stream from the secondary pulp inlet to the second screen member. In a preferred embodiment, the secondary pulp inlet is disposed in the lower portion of the housing below the first screen member, whereby the secondary cellulose pulp feed stream flows from the secondary pulp inlet into the secondary pulp inlet chamber from below. In another embodiment, the apparatus includes a bearing unit centrally disposed within the first screen member and a stator disposed between the first screen member and the bearing unit, the secondary pulp inlet chamber being disposed between the bearing unit and the stator. In a preferred embodiment, the secondary inlet chamber and the first accept chamber are connected to each other. In yet another embodiment, the secondary inlet is disposed in the largest diameter portion of the housing.
[0015] In accordance with another embodiment of the apparatus of the present invention, the secondary pulp inlet is disposed in the upper portion of the housing. In a preferred embodiment, the housing includes a cover, and the secondary pulp inlet is disposed in the cover.
[0016] In accordance with the present invention, a system has also provided including the apparatus set forth above, as well as a separate housing including a third screen member for screening a separate cellulose pulp stream and producing a third accept portion thereby, and conduit means for passing the third accept portion to the secondary pulp inlet. In a preferred embodiment, the secondary pulp inlet includes mixing means for mixing the third accept portion with the first predetermined accept portion for feeding into the second screen member.
[0017] In accordance with the present invention, a method has also been devised for screening a cellulose pulp stream in a housing including an inlet, a first screen member including screen openings for permitting a first predetermined accept portion to pass therethrough, and a second screen member including screen openings for admitting a second predetermined accept portion to pass therethrough, the method including directing the cellulose pulp stream into the inlet in the housing, directing the cellulose pulp stream from the inlet to the first screen member, screening the cellulose pulp stream in the first screen member to produce a first accept portion of the cellulose pulp stream and a first reject portion thereof, receiving the first accept portion of the cellulose pulp stream which has passed through the first screen member, screening the first accept portion of the cellulose pulp stream in the second stream member to produce a second accept portion of the cellulose pulp stream and a second reject portion thereof, withdrawing the second accept portion from the housing, withdrawing at least one of the first and second reject portions from the housing, providing a second cellulose pulp stream comprising a screened cellulose pulp stream, and directing the second cellulose pulp stream to the second screen member. In a preferred embodiment, the method includes mixing the second cellulose pulp feed stream with the first accept portion before screening in the second screen member.
[0018] In accordance with the present invention a screening arrangement, a system and a method for screening are proposed in which a fiber fraction can be returned from at least one subsequent screening arrangement to a first screening arrangement, the first screening arrangement being an arrangement in which at least two screening stages, e.g. a coarse screen and a fine screen, are combined in one apparatus in such a way that the returned fiber fraction or fiber fractions from the at least one subsequent screening arrangement enters as inject to a second screening means (e.g. a fine screen) of the first screening arrangement and is screened only through the second screening means of the first screening arrangement.
[0019] In accordance with the present invention an arrangement for screening of cellulose pulp in several stages is proposed comprising at least two screening means within the same apparatus, where the screening means have openings for allowing certain fractions of cellulose pulp to pass through the screens. The screening means are enclosed in a housing, and the arrangement further comprises a main inlet for input of pulp to the screening arrangement, at least one outlet for output of an accept fraction of pulp from the screening arrangement, and at least one outlet for output of a reject fraction. The arrangement further comprises a first screening chamber being arranged to receive pulp from the main inlet for input of pulp, a first accept chamber arranged to receive pulp passing through a first screening means and a second screening chamber arranged to receive pulp at least from the first accept chamber before screening through a second screening means, and the screening arrangement further comprises a secondary pulp inlet for input of pulp from a subsequent screening arrangement to be screened through the second screening means.
[0020] More specifically, in accordance with the present invention a screening arrangement, a system and a method for screening are provided in which the first screening arrangement is provided with a secondary pulp inlet separated from a main pulp inlet, and the secondary pulp inlet is arranged so that pulp entering the mentioned inlet is merged with the accept fraction of the first screening means in order to form an inject to be fed to the second screening means.
[0021] According to one embodiment of the present invention, the screening means are arranged co-axially and the first screening means is rotatably arranged at least partly within the second screening means. According to another embodiment, the size of the openings of the first and second screening means are different for the respective screening means.
[0022] According to another embodiment of the present invention, the first screening means is a coarse screen and the second screening means is a fine screen with openings smaller than the first screening means, and the main inlet for input of pulp is arranged so that the pulp from the main inlet is fed to the coarse screen.
[0023] The secondary pulp inlet may be arranged in the lower part of the screen, e.g. through a gable of the screen housing. Alternatively, the secondary pulp inlet may be arranged in the upper part of the screening arrangement, e.g. arranged to go through a cover of the housing enclosing the screening means.
[0024] According to another embodiment of the present invention, a secondary pulp inlet chamber is arranged to receive the pulp entering the secondary pulp inlet. The secondary pulp inlet can be arranged below the first screening means so that, in operation, a secondary pulp flow will enter the secondary inlet chamber from below. The secondary inlet chamber may be arranged, as seen in a circumferential direction, between a bearing unit centrally placed in the screening arrangement and a stator enclosed within the first screening means.
[0025] According to another embodiment of the present invention, the secondary inlet chamber and the first accept chamber are in connection with each other.
[0026] The secondary pulp inlet may consist of a connection piece arranged to fit within the largest diameter of the screening arrangement. In that way, any extra piping or the like sticking out of the screening arrangement is avoided. The screening arrangement thus maintains a compact design.
[0027] The present invention further relates to a system comprising a first screening arrangement as described above and further at least one subsequent screening arrangement, the respective screening arrangements being arranged, during operation, to allow an accept fraction/accept fractions of at least one subsequent screening arrangement to be returned to the first screening arrangement by means of the secondary pulp inlet. Several accept fractions from different subsequent screening arrangements could thus be returned to the first screening arrangement. According to a further embodiment of the system of the present invention, the secondary pulp inlet is arranged so as to enable mixing of the accept fraction from at least one subsequent screening arrangement with the accept fraction of the first screening means of the first screening arrangement to form an inject fraction to the second screening means of the first screening arrangement.
[0028] The present invention also relates to a method for screening a cellulose pulp suspension, using the system described above, in which an accept fraction from at least one subsequent screening arrangement is returned to an inject fraction to a second screening means of a first screening arrangement by means of a secondary pulp inlet, the accept fraction from the subsequent screening arrangement being screened only through the second screening means. It is to be understood that several accept fractions from different subsequent screening arrangements could be returned, as well as only the accept fraction of a particular subsequent screening arrangement. According to an embodiment of the method of the present invention, the accept portions of at least one of the subsequent screening arrangements and the first screening stage of the first screening arrangement are mixed before entering the second screening means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The present invention, together with further objects and advantages thereof, may best be understood by reference to the following detailed description which, in turn, refers to the appended drawings, in which:
[0030] FIG. 1 is a side, elevational, schematic cross-sectional view of a screening arrangement according to a preferred embodiment of the present invention;
[0031] FIG. 2 is a top, elevational, transverse, cross-sectional view of the screening arrangement illustrated in FIG. 1 , taken along cross-section A-A of FIG. 1 ;
[0032] FIG. 3 is a side, elevational, schematic, cross-sectional view of an alternative embodiment of the screening arrangement of the present invention;
[0033] FIG. 4 is a diagrammatic block diagram of a screening system comprising a screening arrangement as illustrated in FIGS. 1-3 ; and
[0034] FIG. 5 is a diagrammatic block diagram of another screening system comprising a screening arrangement as illustrated in FIGS. 1-3 .
DETAILED DESCRIPTION
[0035] Referring to the drawings, similar or corresponding elements will be denoted by the same reference numbers. It should be noted that, although the following description primarily refers to a combined screening arrangement in which a fine screen is located outwardly of a coarse screen, seen from the center of the screening arrangement, the teachings are also applicable to “inside-out” arrangement, i.e. where the fine screen is located on the inside of the coarse screen. Inside-out arrangements with the coarse screen located on the outside of the fine screen hence lie within the scope of the present invention. It is also to be noted that the teachings are applicable to all kinds of such combi-screens combining a coarse screen and a fine screen within the same apparatus, as well as other multi-stage screens where several screening stages are performed in the same arrangement. The teachings hereof are thus applicable irrespective of whether the multi-stage screening apparatus contains a coarse screen or not. The screening means in the different stages may, for example, be of the same kind with openings of the same size. The screening means could also be located on the same diameter, i.e. on top of each other.
[0036] The screening apparatus 100 shown in FIG. 1 comprises a screen housing 1 with an upper portion 2 and a lower portion 3 . The housing can preferably be pressurized. The lower portion 3 ends in a gable 29 which is placed on a frame 30 . In the screen housing, a first screening means 4 is arranged on a rotor means 5 which is rotatable about a rotor shaft 6 contained in a bearing unit 7 . The first screening means has a cylindrical shape and is located partially in the lower portion 3 of the screening arrangement. The first screening means 4 is arranged to rotate with the rotor means 5 . A second screening means 8 is located in the upper portion 2 of the screening arrangement 100 . The second screening means 8 is arranged coaxially with the first screening means 4 and has a greater diameter than the first screening means 4 . At least a part of the first screening means 4 is arranged within at least a part of the second screening means 8 . The first and second screening means may also be located vice versa. They may further be arranged on the same diameter, in that case none within the other but instead on top of each other.
[0037] A first screening chamber 9 is formed with a guide surface 10 being one limiting surface, outwardly in the circumferential direction, and the screening means 4 being the other, in the inward direction. The guide surface 10 is a cylindrical tubular means arranged coaxially with the first screening means 4 , having a diameter larger than the first screening means 4 so that a space is formed between the screening means and the guide surface. The guide surface 10 is arranged to extend in an upward direction so that a substantial part of the first screening means 4 is surrounded by the guiding surface. This arrangement forces the pulp flow from a main pulp inlet 11 to enter the first screening chamber mainly in the vicinity of the upper part of the first screening means 4 . In this way, a downward flow is created, which aids the reject flow since a reject from the first screening means 4 is to be taken out from the lower part of the screening arrangement through a first reject outlet 15 .
[0038] In operation, a pulp flow to be screened enters the first screening chamber 9 through the main pulp inlet 11 and the pulp is then fed towards the first screening means 4 . The pulp inlet in the illustrated embodiment is placed in the lower portion 3 of the screening arrangement, although near the middle of the screening arrangement. As previously described, the pulp is forced to flow upwardly due to the guide surface 10 in order for the pulp to enter the first screening means 4 at its uppermost location. Fibers of a size smaller than the size of the openings in the perforated screen plate pass through the screening means 4 and enter a first accept chamber 12 . The accept chamber 12 is limited by the screening means 4 and by a stator 13 located inside the screening means 4 . The stator is a stationary part, preferably cylindrical and provided with at least one pulse means 14 . The pulse means 14 are arranged upon rotation of the rotary screening means 4 to create pressure pulses for clearing the first screening means 4 . The screening is performed from the outside-in, which is preferable due to the centrifugal force preventing large and heavy particles from being in close contact with the screening means. This first screening stage can preferably perform the task of separating mainly larger impurities (e.g. knots), such a screening stage being commonly known as a knotter.
[0039] The reject portion, i.e. the particles not passing through the screen, is taken out through a reject outlet 15 . This reject portion is also denoted the coarse reject in case the first screening means is a coarse screen. The accept fraction is further fed to a second screening chamber 16 to form an inject to the second screening means 8 . The pulp passing the second screening means 8 is taken out through an accept outlet 26 while the reject portion is taken out through at least one reject outlet 27 .
[0040] A secondary pulp inlet 17 is arranged so that pulp flowing through the secondary inlet is mixed with the accept portion from the first screening means 4 before entering the second screening means 8 . The pulp entering the secondary inlet 17 consists of an accept fraction from a subsequent screening arrangement (not illustrated in this figure) in which the reject from the second screening means 8 has been screened again. The accept portion of the subsequent screening arrangement, together with the accept portion from the first screening means 4 in the screening arrangement 100 , forms the inject to the second screening means 8 . In this way, the “good fibers” contained in the reject portion from the second screening means 8 is brought back to the pulp flow moving along in the process and fiber losses are minimized.
[0041] Pulp from the secondary inlet 17 enters a secondary pulp inlet chamber 18 . The secondary pulp inlet chamber 18 is limited inwardly, as seen in the circumferential direction, by the bearing unit 7 and outwardly by the stator 13 . The secondary pulp inlet chamber 18 could also be arranged within the bearing unit 7 , with the secondary inlet 17 placed below the bearing unit. In such a case, at least one opening will be provided in the outward wall of the bearing unit for transport of the pulp towards the second screening chamber 16 . In the embodiment shown in FIG. 3 , the secondary inlet chamber 18 at least partly coincides with the second screening chamber 16 .
[0042] In a preferred embodiment of the present invention, the first screening means is a coarse screen and the second screening means is a fine screen. By the term coarse screen is meant a screen designed primarily to separate larger impurities such as knots. Typically the openings may be about 6-10 mm, normally about 8-10 mm in diameter. By the term fine screen is meant a screen designed to primarily separate skives from fibers. For a slotted fine screen, the slots may be in the range of about 0.15-0.60 mm, typically about 0.15-0.40 mm. Slots or holes may be used dependent on which process parameters are to be optimized.
[0043] In FIGS. 1 and 2 the secondary pulp inlet 17 is located in the lower portion of the screening apparatus 100 , e.g. below the gable 29 of the screen housing 1 . Preferably, the inlet consists of a connection piece adapted to fit within the largest diameter of the screening arrangement. This placement gives the advantage of eliminating any extra piping protruding from the screening arrangement. The secondary pulp inlet 17 is located in such a way that pulp flowing through the inlet is fed into the secondary inlet chamber 18 . For example, the secondary pulp inlet 17 may be arranged to have an inlet opening 19 below an opening 28 in the gable 29 of the screen housing 1 . From the secondary inlet chamber 18 the pulp is transported to the second screening chamber 16 to be passed through the second screening means 8 . In one embodiment, the secondary inlet chamber 18 and the first accept chamber 12 are connected to each other at their respective lower portions by means of a connection portion 20 , as well as at their respective upper portions by means of a second connection portion 25 . At least a part of the accept from the first screening stage in the first screening arrangement can thus flow into the secondary inlet chamber 18 from below and merge with the accept from the subsequent screening stage of the second screening arrangement (not shown). A part of the accept from the first accept chamber 12 will enter the second screening chamber 16 directly, flowing upwardly in the screening arrangement. However, due to the connection portion the flow from the first accept chamber 12 going in an upward direction will also be at least partly mixed with the flow from the secondary inlet chamber 18 before entering the second screening chamber 16 . Since the flow entering the secondary pulp inlet 17 and the flow in the first accept chamber 12 may differ in concentration, it is preferable to merge the flows before entering the second screening chamber in order to create a homogeneous flow to the second screening means 8 .
[0044] FIG. 2 illustrates a cross-section A-A of a screening arrangement according to the embodiment shown in FIG. 1 . The secondary pulp inlet 17 in this case is arranged as a connection piece comprising an outer connection flange 21 and an inner inlet opening 19 . The inlet opening 19 is in communication with the secondary inlet chamber 18 , and may also be in communication with the first accept chamber 12 . In the figure the inlet opening is placed mainly underneath the first accept chamber 12 . In this case, the first accept chamber 12 and the secondary inlet chamber 18 are in communication by means of the connection portion 20 . The flow through the secondary pulp inlet 17 thus enters the secondary inlet chamber 18 through the connection portion 20 . The inlet opening 19 may, however, be placed such that direct access is made to the secondary inlet chamber 18 .
[0045] FIG. 3 shows a screening arrangement where the secondary pulp inlet 17 is located in the cover 22 of the screen housing 1 . The accept from at least one subsequent screening arrangement is fed through the secondary pulp inlet 17 in the cover 22 of the screening housing 1 and enters the screening chamber 16 . According to this illustrated embodiment, a connection piece 23 a is arranged within the cover and pulp fed through the secondary pulp inlet 17 is mixed in the second screening chamber 16 mixed with the accept portion from the first accept chamber 12 flowing up through the rotor means 5 . The rotor means is preferably arranged with rotor pulse means 24 in order to create suction pulses to clean the second screening means 8 . Alternatively, a connection piece 23 b , located in the center of the cover 22 may be used as a secondary pulp inlet 17 . The location of the secondary pulp inlet 17 should be chosen to optimize mixing with the flow from the first accept chamber 12 in order to create a homogeneous flow to the second screening means 8 .
[0046] FIG. 4 is a block diagram showing a system comprising two separate screening arrangements in which the first screening arrangement 100 is a combined screening arrangement comprising two screening stages, a first screening stage 101 and a second screening stage 102 . Pulp is fed to the first screening arrangement as a first inject I 1 . In the first screening stage 101 , pulp is separated into a first accept portion A 1 and a first reject portion R 1 . The first reject portion R 1 is taken out of the screening arrangement to be handled separately. The first accept portion A 1 is fed within the first screening arrangement 100 to the second screening stage 102 , where it is separated into a second accept portion A 2 and a second reject portion R 2 . The second accept portion A 2 is fed forward in the processing line to the next processing step. The system further comprises a second screening arrangement 200 , which is arranged to follow subsequently upon the first screening arrangement 100 , meaning that a reject portion R 2 from the second screening stage 102 is fed as an inject 13 to the second screening arrangement 200 . The second screening arrangement 200 is normally a screen with finer slots or holes than the second screening stage 102 , or about the same. The pulp is in the second screening arrangement 200 separated into a third accept portion A 3 and a third reject portion R 3 . According to the invention, the third accept portion A 3 is returned to the first screening arrangement 100 and together with the first accept portion A 1 fed as a second inject 12 (A 1 +A 3 ) to the second screening stage 102 .
[0047] FIG. 5 is a block diagram showing a system comprising three separate screening arrangements in which the first screening arrangement 100 is a combined screening arrangement comprising two screening stages. In this embodiment, accept may also be returned from a subsequent third screening arrangement 300 . This screening arrangement is used to screen the reject portion R 1 from the first screening stage 101 of the first screening arrangement 100 . The reject portion R 1 is thus divided into an accept portion A 4 and a reject portion R 4 . The accept portion A 4 may, as illustrated, be returned to the second screening stage 102 of the first screening arrangement 100 . It is possible to return only the accept A 4 from the third screening arrangement 300 , excluding the accept A 3 from the second screening arrangement 200 , but more preferably both accepts A 3 and A 4 are returned to be screened through the second screening stage 102 of the first screening arrangement 100 .
[0048] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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Apparatus for screening cellulose pulp streams is disclosed including first and second screens contained in a housing, and a primary inlet for directing the cellulose pulp stream into the housing, an accept outlet for withdrawing an accept portion from the housing, a reject outlet for withdrawing a reject portion from the housing, a first accept chamber for receiving the accept portion which has passed through the first screen, a second screen chamber for directing the first accept portion to the second screen, and a secondary pulp inlet for receiving a second cellulose pulp feed stream comprising a screened cellulose pulp accept fraction and directing it to the second screen whereby the second accept fraction is delivered to the accept outlet. Methods and systems for screening cellulose pulp systems are also disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The instant application claims priority to U.S. Provisional Application 61/064,337 filed on Feb. 28, 2008, the disclosure of which is expressly incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a connection methodology. More specifically, the present invention relates to methodologies for connecting hybrid chips to printed wiring boards where the chips contain both leads and leadless contacts.
[0004] 2. Discussion of Background Information
[0005] An integrated circuit (“IC”) typically comes in two varieties. One variety includes ICs with metal leads extending therefrom that carry power, ground, input and output signal. The metal leads are often rigid and bent into a shape known as a “gull wing.” The other variety uses “leadless” contacts, in which conductive pads are integrated into the surface of the IC. Varieties of methods are known for connecting the leads, leaded ICs, or conductive pads of leadless ICs to printed circuit boards.
[0006] Recently a hybrid chip has been introduced that utilizes both gull wing leads and leadless contact pads on the bottom of the chip. FIGS. 1A-1C show an example of such a hybrid chip 102 . It is difficult to mount hybrid chip 102 to a printed circuit board, as known connection methodologies for the gull wing and the leadless pads can conflict with each other.
SUMMARY OF THE INVENTION
[0007] According to an embodiment of the invention, a method for preparing an integrated circuit for connection to a surface, the integrated circuit including lead contacts and leadless contacts, is provided. The method includes providing the integrated circuit, applying a first solder paste to the leadless contacts, forming solder balls on the applied solder paste, heating the solder balls, thereby removing at least a portion of the first solder paste and bringing the solder balls into electrical contact with the leadless contacts, the base of the solder balls being generally aligned in a plane, and bending the lead contacts into gull wings, the base of the gull wings being substantially coplanar with the plane, wherein the base of the gull wings and the base of the at least one of the solder balls collectively generally define a contact plane.
[0008] The above embodiment may include various features. The method may include: determining, before the bending and after the heating, a lateral distance between the lead contacts and the base of at least one of the solder balls; and/or electrically connecting the lead contacts and leadless contacts to the surface. The electrically connecting may include applying a second solder paste to the surface, soldering the base of the gull wings to the surface, and heating the solder balls, thereby removing at least a portion of the second solder paste and bringing the solder balls into electrical contact with the surface, wherein the integrated circuit will be in electrical contact with the surface through both the leadless contacts and the lead contacts. The providing the integrated circuit may include providing an integrated circuit with the lead contacts attached to the body of the integrated circuit and extending laterally away from the body. The forming solder balls may include forming solder balls of about 10 mils in diameter and/or forming solder balls of substantially equal size.
[0009] According to another embodiment of the invention, a method for preparing an integrated circuit for connection to a surface, the integrated circuit including lead contacts and leadless contacts, is provided. The method includes providing the integrated circuit, applying a first solder paste to the leadless contacts, connecting bent leads to the applied solder paste, soldering the bent leads, thereby removing at least a portion of the first solder paste and bringing the bent leads into electrical contact with the leadless contacts, the base of the bent leads being generally aligned in a plane, and bending the lead contacts into gull wings, the base of the gull wings being substantially coplanar with the plane, wherein the base of the gull wings and the base of the at least one of the bent leads collectively generally define a contact plane.
[0010] The above embodiment may have various features. The method may include: determining, before the bending and after the soldering, a lateral distance between the lead contacts and the base of at least one of the bent leads; and/or electrically connecting the lead contacts and leadless contacts to the surface. The electrically connecting may include applying a second solder paste to the surface, soldering the base of the gull wings and the base of the bent leads to the surface, thereby removing at least a portion of the second solder paste and bringing the bent leads into electrical contact with the surface, wherein the integrated circuit will be in electrical contact with the surface through both the leadless contacts and the lead contacts. The providing the integrated circuit may include providing an integrated circuit with the lead contacts attached to the body of the integrated circuit and extending laterally away from the body. The bent leads may be either S-leads or C-leads. The connecting may include providing the bent leads on a fixture, and orientating the fixture to bring the bent leads into alignment with the leadless contacts; the bent leads made be removed from the fixture after the bent leads are connected to the integrated circuit.
[0011] According to yet another embodiment of the invention, a method for preparing an integrated circuit for connection to a surface, the integrated circuit including lead contacts and leadless contacts, is provided. The method includes providing the integrated circuit, applying a conductive epoxy to the leadless contacts, the base of the epoxy being generally aligned in a plane, and bending the lead contacts into gull wings, the base of the gull wings being substantially coplanar with the plane, wherein the base of the gull wings and the base of the at least one of the bent leads collectively generally define a contact plane.
[0012] The above embodiment may include various optional features. The method may include: determining, before the bending and after the applying, a lateral distance between the lead contacts and the base of at least one of the bent leads; and/or electrically connecting the lead contacts and leadless contacts to the surface. The electrically connecting may include applying a second solder paste to the surface, soldering the base of the gull wings to the surface, curing the conductive epoxy, wherein the integrated circuit will be in electrical contact with the surface through both the leadless contacts and the lead contacts. The providing the integrated circuit may include providing an integrated circuit with the lead contacts attached to the body of the integrated circuit and extending laterally away from the body.
[0013] According to still yet another embodiment of the invention, a method for preparing an integrated circuit for connection to a surface, the integrated circuit including lead contacts and leadless contacts, is provided. The method includes providing the integrated circuit, applying a first solder paste to the leadless contacts, placing preformed conductive metal pieces on the first solder paste, soldering the metal pieces, thereby removing at least a portion of the first solder paste and bringing the metal pieces into electrical contact with the leadless contacts, the base of the metal pieces being generally aligned in a plane, and bending the lead contacts into gull wings, the base of the gull wings being substantially coplanar with the plane, wherein the base of the gull wings and the base of the at least one of the metal pieces collectively generally define a contact plane.
[0014] The above embodiment may have various optional features. The method may include: determining, before the bending and after the soldering, a lateral distance between the lead contacts and the base of at least one of the metal pieces; and/or electrically connecting the lead contacts and leadless contacts to the surface. The electrically connecting may include applying a second solder paste to the surface, soldering the base of the gull wings and the metal pieces to the surface, wherein the integrated circuit will be in electrical contact with the surface through both the leadless contacts and the lead contacts. The providing the integrated circuit may include providing an integrated circuit with the lead contacts attached to the body of the integrated circuit and extending laterally away from the body.
[0015] Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of certain embodiments of the present invention, in which like numerals represent like elements throughout the several views of the drawings, as follows.
[0017] FIGS. 1A-1C are top, side and bottom views of a hybrid integrated circuit with leads and leadless contacts in which the leads have been bent into gull wings.
[0018] FIG. 2 is a side view of the steps of an embodiment of the invention for attaching a hybrid chip to a printed wiring board.
[0019] FIG. 3 is a flow chart of the process steps of FIG. 2 .
[0020] FIG. 4 is a side view of the steps of an embodiment of the invention for attaching a hybrid chip to a printed wiring board.
[0021] FIG. 5 is a flow chart of the process steps of FIG. 4 .
[0022] FIG. 6 is a side view of the steps of an embodiment of the invention for attaching a hybrid chip to a printed wiring board.
[0023] FIG. 7 is a flow chart of the process steps of FIG. 6 .
[0024] FIG. 8 is a side view of the steps of an embodiment of the invention for attaching a hybrid chip to a printed wiring board.
[0025] FIG. 9 is a flow chart of the process steps of FIG. 8 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0026] The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
[0027] Referring now to FIGS. 2 and 3 , a methodology for attaching a hybrid chip 202 is shown. At step 302 , a hybrid chip 202 is provided that includes a plurality of leads 204 in a first orientation and a plurality of contact pads 206 ( FIG. 1C ). The initial orientation (for this embodiment and the later embodiments below) is preferably a connection to the body of chip 202 and extending laterally away from chip 202 without bends. However, other initial orientations may be used.
[0028] Solder paste 208 (thickness exaggerated for illustration) is applied to conductive contact pads 206 at step 304 . At step 306 , solder balls 210 are then applied on top of solder paste 208 . The solder balls 210 are then heated to bond with conductive pads 206 at step 308 ; this tends to remove solder paste 208 , such that it is no longer shown in FIG. 2 .
[0029] Each solder ball 210 is preferably about 10 mils in diameter when deposited, although they are expected to expand as solder flows during soldering. Each solder ball 210 is preferably made from a material with a melting point of 290 degrees or above. Pure copper or a 10/90 alloy of tin and lead are suitable for this environment.
[0030] The lower surface of the solder balls 210 will roughly define a base plane 212 at which the solder balls 210 will later connect to a printed wiring board. At step 310 the distance between that plane and leads 204 is then determined, and at step 312 the leads 204 are bent into a second orientation that includes gull wings 214 . The lateral wing portions 216 of gull wings 214 lie in the base plane 212 , thus forming a collective contact plane.
[0031] At step 314 , solder paste 218 is applied using a stencil at the appropriate locations on a printed wiring board 220 . At step 316 , wings 214 are then soldered onto their respective portions of solder paste 218 , while the solder balls 210 are heated to form connections onto the printed circuit board 220 . The connections at step 316 can be simultaneously or in any order.
[0032] Solder balls 210 tend to have minimal compliancy and tend to crack under stress. The connections of FIG. 2 are thus preferable for environments with minimal thermal expansion and/or minimal thermal expansion cycles.
[0033] FIGS. 4 and 5 show another embodiment of the invention. At step 502 , a hybrid chip 402 is provided that includes a plurality of leads 404 in a first orientation and a plurality of contact pads 406 (as in FIG. 1C ). Solder paste 408 (thickness exaggerated for illustration) is applied to contact pads 406 at step 504 . At step 506 , a plurality of pre-bent conductive leads 410 , such as copper alloy C-leads or S-leads, are then secured in fixtures and pressed against solder paste 408 . Solder is then applied to connect the bent leads 410 to pads 406 at step 508 . Once bent leads 410 are attached, the connection to the securing fixture can be removed.
[0034] Each bent lead is preferable 0.40 mils high, and made from a copper alloy. In the alternative, small form factor bent leads of the type shown in co-pending U.S. patent application Ser. No. 11/979,487 (filed on Nov. 7, 2007, the disclosure of which is herein incorporated by reference in its entirety) can be used.
[0035] The lower portion of the connected bent leads will roughly define a base plane 412 at which the bent leads 410 will later contact the printed wiring board. At step 510 the distance between that plane and leads 404 is then determined, and at step 512 the leads 404 are bent into a second orientation that includes gull wings 414 . The wing portions 416 of gull wings 414 lie in the base plane 412 , thus forming a collective contact plane.
[0036] At step 514 , solder paste 418 is applied using a stencil at the appropriate locations on a printed wiring board 420 . At step 516 , wings 414 and leads 410 are then soldered onto their respective portions of solder paste 218 . The connections at step 516 can be made simultaneously or in any order.
[0037] Bent leads have a compliancy that allows them to shift during thermal stress. This makes the connection of FIG. 4 particularly useful for harsh environments subject to considerable thermal expansion and/or repeating thermal expansion cycles.
[0038] FIGS. 6 and 7 show another embodiment of the invention. At step 702 , a hybrid chip 602 is provided that includes a plurality of leads 604 in an initial orientation and a plurality of contact pads 606 (as in FIG. 1C ). Conductive epoxy 608 is applied to contact pads 606 at step 704 . The lower portion of the epoxy will roughly define a base plane 612 at which the epoxy 608 will later contact the printed wiring board. At step 710 the distance between that plane and leads 604 is then determined, and at step 712 the leads 604 are bent into a second orientation that includes gull wings 614 . The wing portions 616 of gull wings 614 lie in the base plane 612 , thus forming a collective contact plane.
[0039] At step 714 , solder paste 618 is applied using a stencil at the appropriate locations on a printed wiring board 420 that correspond to the contact points for wing portions 616 . At step 716 , wings 614 are soldered onto their respective portions of solder paste 618 . At step 718 , the epoxy is cured. The connections at steps 716 and 718 can be made simultaneously or in any order.
[0040] Conductive epoxy is more compliant than solder but less compliant than bent leads. It is thus suitable for use in environments with moderate to high thermal expansion and/or cycles of thermal expansions, although not to the same extent as bent leads. Thus, for example, this connection methodology is not preferable for avionics applications.
[0041] Referring now to FIGS. 8 and 9 , another methodology for attaching a hybrid chip 202 is shown. At step 902 , a hybrid chip 802 is provided that includes a plurality of leads 804 in an initial orientation and a plurality of contact pads 806 ( FIG. 1C ). Solder paste 808 (thickness exaggerated for illustration) is applied to contact pads 806 at step 904 . At step 906 , pre-slugs of conductive metal 810 are then applied on top of solder paste 808 . Solder is applied at step 908 ; this tends to remove the solder paste, such that it is no longer shown in FIG. 8 .
[0042] Each slug 810 is preferably about 5 mils in height, although other heights could be used. FIG. 8 shows slug 810 as rectangular, but other shapes, such as cylindrical, could be used. Each slug 810 is preferably made from a material with a higher melting point than the solder. A copper alloy with a sufficiently high melting point so as not to melt during the soldering process is sufficient for this.
[0043] The lower portion of the slugs 810 will roughly define a base plane 812 at which the slugs 810 will contact the printed wiring board. At step 910 the distance between that plane and leads 804 is then determined, and at step 912 the leads 804 are bent into a second orientation that includes gull wings 814 . The wing portions 816 of gull wings 814 lie in the base plane 812 , thus forming a collective contact plane.
[0044] At step 914 , solder paste 818 is applied using a stencil at the appropriate locations on a printed wiring board 820 . At step 916 , wings 814 are then soldered onto their respective portions of solder paste 818 , while the slugs 810 are heated to form connections onto the printed circuit board 820 . The connections at step 916 can be made simultaneously or in any order.
[0045] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to certain embodiments, it is understood that the words that have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of any current or future claims.
[0046] Various claims below recite terms for which the following additional discussion may be relevant. For example:
“base” is a relative term generally referring to the lower ends of structures when in the orientation shown in FIG. 1 . “before” and “after” refer to the order of steps, but do not require (nor exclude) that the identified order of steps follow directly or indirectly via intervening steps. “lead” is used in the context of a lead of a circuit a circuit, as opposed to the metal Pb. This does not require nor exclude that the lead may be made of Pb or include Pb.
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A method for preparing an integrated circuit for connection to a surface, the integrated circuit including lead contacts and leadless contacts, is provided. The method includes providing the integrated circuit, applying a first solder paste to the leadless contacts, forming solder balls on the applied solder paste, heating the solder balls, thereby removing at least a portion of the first solder paste and bringing the solder balls into electrical contact with the leadless contacts, the base of the solder balls being generally aligned in a plane, and bending the lead contacts into gull wings, with the base of the gull wings being substantially coplanar with the plane. The base of the gull wings and the base of the at least one of the solder balls collectively generally define a contact plane for potential future contact with the surface.
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This invention relates to a vehicle disabling device and more particularly to a device and method for disabling the electronic functions of a vehicle and causing that vehicle to slow down or stop.
BACKGROUND OF THE INVENTION
In this litigious society, even a police chase after a criminal can prove dangerous to the municipality, which sponsors the police department. Such a high speed police chase sometimes causes injury to the pursuing police officer or innocent victims, in addition to the offending motorist or other criminal.
Not only does an innocent party suffer improperly, he or she is also hurt substantially for merely being at the wrong place at the wrong time. This problem has become so severe that a number of states are even restricting high speed police chases by statute.
From both a military and civilian standpoint, it can be desirable to disable a vehicle, in a simple fashion without creating a danger to the surrounding area. Various known electronic devices are most ineffective. These devices can flatten tires or disable engines.
Known devices exist which can flatten or incapacitate a vehicle tire. If this occurs at a high speed, the driver may lose control of the vehicle. An uncontrolled vehicle is extremely dangerous. Whether the tire flattening device is electronically or mechanically actuated, it is highly desirable to disable the vehicle and incapacitate the escape mechanism without this danger of losing control of the vehicle.
In addition to the tire flattening device, an electronic device can disable a vehicle engine by attacking various vehicle systems. One such system is an electronic engine control computer. The second is the electronic sensors, which feed information to the electronic engine control computer. The third system is a set of sensors in the vehicle's signal processing modules. Damage to or destruction of the electronic engine control computer or electronic engine module will stop the vehicle by disabling the fuel delivery or ignition pulses. Damage to various sensors will usually cause activation of a redundant (also known as the limp home) mode where vehicle performance is drastically reduced.
A device in this class is generically known as an anti-vehicle electronic counter measure (AVECM). The high burst of pulsed microwave energy from one type of an electronic engine disabling device, while it may disable the criminal vehicle, can also disable adjacent computers and unintended vehicles. The microwave energy lacks control so severely, that the advantages of using the high microwave energy or similar disabling devices are far outweighed by the disadvantages.
Especially problematical is the production of the high burst of pulsed microwave energy by an electromagnetic pulse generating system. The transmission of this cannot be specifically directed to only desired target. This lack of direction can very adversely affect unintended vehicles as well as computers in nearby buildings.
Typically, a vehicle disabling device is desired to be of a type referred to as a man-portable barrier. In other words, the device may be carried by a man. Present man-portable barrier systems have significant technical shortcomings, because they must dissipate fully the kinetic energy of the target vehicle. This places severe technical constraints on any man-deployable system, requiring that they be light-weight, safe, rapidly deployable, and easy to operate by a small unit or patrol.
It is difficult for light-weight systems to sustain the kinetic energy dissipation rate required to stop a typical vehicle traveling at moderate to high speeds. A vehicle weighing 6,800 kilograms (15,000 pounds) and traveling at 80 kilometers per hour (50 miles per hour) has a kinetic energy of over 170,000 newton-meters (1.25 million foot-pounds), for example. The development of a system light enough to be man-deployable and able to sustain the mechanical forces required to dissipate that force is extremely difficult to realize.
In an attempt to avoid the direct dissipation of these immense kinetic forces, the traditional approach is to disable the target vehicle or operator by various means. These typically involve severe damage to the vehicle, driver, occupants, and even bystanding personnel. These means are, therefore, of questionable use in a civilian law enforcement environment.
Tire deflation and related techniques can be easily circumvented by current commercially available deflation-resistant, runflat, tire technology and means such as expanded cell polymer foam tire fillers. Even when tires are successfully deflated, forward progress can be maintained for a long distances, because the vehicle drive train is still operational.
Arresting the vehicle by mechanical disruption is extremely hazardous. Typical mechanical disruption is by small arms or ballistic projectiles. This method is intrinsically hazardous, especially in urban or populated areas and is not very reliable, as the projectiles must impact either a critical vehicle component or the driver, either of which presents considerable target acquisition problems because of target speed and maneuverability.
It is desired to avoid these dangers and such methods. In response, police and military security agents often pursue the target vehicles at high speeds which result in extreme hazards to these personnel and also to innocent bystanders, besides being frequently ineffective in arresting the target vehicle and its occupants.
Local, state, and federal police agencies are especially concerned with reducing or eliminating high speed pursuits or target vehicles because of the potentially disastrous effects on public and/or private property and the personal welfare of non-involved third parties. In addition to the almost unacceptable chance of hurting an innocent party, the financial costs thereof can be immense.
Civilian, private, and public security agencies and commercial organizations are equally concerned with prevention of unauthorized suspect or terrorist vehicle penetration. Therefore, development of AVECM technology and devices has great commercial as well as military applications, both domestically and internationally.
Other vehicle penetration systems also have shortcomings. Mechanical disruption of the vehicle by stationary and associated attached penetration is also hazardous and often ineffective. These systems attempt to use the vehicle's own kinetic energy to produce mechanical damage. These systems typically employ spikes, pikes, turnstiles, hooks, cables, or related kinetic pendulum-type devices.
The effectiveness of these devices is overly dependent on the vehicle's weight, physical design and configuration, speed vector of approach; which have, in fact, exhibited variable results in actual field use. These systems are also not readily deployable by a single man in the majority of cases.
Some non-traditional methods are developed in an attempt to overcome these problems. These include chemical agents, adhesives, and foams. These are also of questionable and unproven effectiveness and are potentially hazardous, non-selective. Additionally, these methods may pose a toxic or environmental hazard.
The methods of deployment of these chemical-based compounds require complex equipment. Typical parts of this equipment include, but are not limited to; nozzles, hoses, and pressure vessels. This complex equipment can malfunction or suffer damage from the chemicals themselves.
The effectiveness of these chemicals themselves may be compromised by environmental conditions, such as precipitation, temperature, humidity, wind, road surface characteristics and other factors. The use of caustic and toxic materials may also violate United States and international laws and regulations covering the use of chemicals in warfare.
SUMMARY OF THE INVENTION
Therefore, among the many objectives of this invention is to provide a remotely activatable vehicle disabling device and method capable of disabling a vehicle.
A further objective of this invention is to provide a vehicle disabling device fixed in the road.
A still further objective of this invention is to provide a mobile vehicle disabling device.
Yet a further objective of this invention is to provide a vehicle disabling device, which dissipates the kinetic energy of a vehicle.
Also an objective of this invention is to provide a vehicle disabling device, with a limited activation range in order to limit the effect to the one vehicle desired to be stopped.
Another objective of this invention is to provide a vehicle disabling device to minimize damage from a high speed chase.
Yet another objective of this invention is to provide a vehicle disabling device to minimize injury from a high speed chase.
Still another objective of this invention is to provide a vehicle disabling device, which avoids the use of chemicals.
A further objective of this invention is to provide a method for disabling the electronic engine controls of a vehicle.
A still further objective of this invention is to provide a method for reducing the vehicle to a redundant operating mode.
Yet a further objective of this invention is to provide a method to safely dissipate the kinetic energy of a vehicle.
Also an objective of this invention is to provide a method for disabling a vehicle having a reduced undesirable impact on the environment.
Another objective of this invention is to provide a method for disabling a vehicle active in a restricted area.
Yet another objective of this invention is to provide a method for disabling a vehicle to minimize injury from a high speed chase.
Still another objective of this invention is to provide a vehicle disabling device, which avoids the use of chemicals.
These and other objectives of the invention (which other objectives become clear by consideration of the specification, claims and drawings as a whole) are met by providing a vehicle disabling device, which can contact a vehicle, send a capacitive discharge therethrough, and disable at least one electric system of a vehicle.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 depicts a vehicle mounted anti-vehicle electronic counter measure device 100 in use.
FIG. 2 depicts a vehicle mounted anti-vehicle electronic counter measure device 100 in block diagram form.
FIG. 3 depicts a vehicle circuit diagram 118 for vehicle mounted anti-vehicle electronic counter measure device 100.
FIG. 4 depicts a modification of FIG. 3 to a roadway mounted circuit diagram 116 for vehicle mounted anti-vehicle electronic counter measure device 100.
FIG. 5 depicts a portable anti-vehicle electronic counter measure device 300 in block diagram form.
FIG. 6 depicts a stationary anti-vehicle electronic counter measure device 370 in block diagram form.
FIG. 7 depicts a stationary circuit diagram 310 for stationary anti-vehicle electronic counter measure device 370.
FIG. 8 depicts a partial block diagram of mortar-launched, anti-vehicle electronic counter measure device 400 of this invention.
FIG. 9 depicts a partial block diagram of traction-motor launched, anti-vehicle electronic counter measure device 500 of this invention.
FIG. 10 depicts a crimped wire guidance system 600 for vehicle mounted anti-vehicle electronic counter measure device 100.
FIG. 11 depicts a hose wire guidance system 650 for vehicle mounted anti-vehicle electronic counter measure device 100.
FIG. 12 depicts a splitable wire guidance system 700 for vehicle mounted anti-vehicle electronic counter measure device 100.
Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a more modern vehicle, like an automobile, there are three systems, which control the operation of the vehicle. In order to stop or slow the vehicle, any one of these systems may be disrupted. With the destruction of any of these systems, the automobile will either be unable to proceed at great speed or be stopped. In either case, the loss of power is less dangerous than the flat tire or other stopping device.
An electromagnetic pulse generator can be placed close to a vehicle desired to be disabled. The pulse generator generator can then be activated. The resulting damage occurs only in the pursued vehicle. An inductance based generator is especially useful. However, a capacitance based generator is preferred.
Of primary importance to the anti-vehicle electronic counter measure device of this invention is a capacitor discharge device. The capacitor discharge device can apply a current to the undercarriage of a vehicle, which will disable or destroy any one or all of these critical systems.
It is also possible to mount the capacitor discharge device on a police squad car or similar vehicle. Included in that vehicle mounted device is a launch mechanism for launching a platform including the capacitor discharge device. The platform is positioned under the pursued vehicle. As that platform reaches the vehicle pursued, and particularly the undercarriage, the platform may then be activated from the squad car. Contact by two electrodes with the undercarriage of the vehicle at the appropriate points results in the appropriate electrical systems being deactivated.
Most police officers are highly skilled drivers. Those skilled drivers indicate that it is no problem to maintain a position behind a pursued vehicle in range of a launched device. With two wires forming the arms of an isosceles triangle, the front bumper of the pursuit vehicle forming the base of the triangle and the platform forming the vertex thereof, the platform is easily guided under the pursued vehicle. The isosceles triangle basis of the wire guiding of this device permits the platform to adjust with the speed of the vehicle. As the platform proceeds under the vehicle, the platform may be activated and disable the vehicle being pursued.
With regard to a fixed vehicle disbling device, current police tactics can permit a herding or a guiding of the pursued vehicle to a fixed disabling device of this invention. This structure permits certain areas to have at least one of these devices secured to a particular, to be activated as the pursued vehicle is herded thereover.
The wire system may also be modified to a parallelogram by attaching the guide wires further apart on the platform. This is possible by providing an extension bar across the front, rear or mid section of the platform.
Determination of vehicle electrical system and subsystem susceptibility to electronic-based vehicle disablement means indicates the platform of this invention is highly operable. This conclusion results from an investigation of the effects of overvoltages, current pulses, and electromagnetic field interactions with vehicle electronic engine controls (EEC) and sensors. Testing, simulation, and modeling do confirm the susceptibility thresholds and parameters. Typical of these parameters are amplitudes, waveform characteristics, and overall energy levels required to disrupt or disable target vehicles.
Commercial automotive electronics designers are aware that the increased use of microelectronics in automotive control and communications systems makes commercial automobile systems susceptible to electromagnetic disruption, failure, or upset. Currently, standards are being developed by the industry and concerned agencies that require automotive vehicle susceptibility to electromagnetic and electrostatic effects to be tested (for example SAE J1595, "Electrostatic Discharge Tests for Vehicles" and SAE "Electromagnetic susceptibility Measurement Procedures for Vehicle Components Except Aircraft!").
Other proprietary test programs are also conducted by all of the major automotive manufacturers. All of these tests use low to moderate energy levels. Typical electronic static device (ESD) test levels are 2 to 15 kilo volts, with up to 250 picofarads of capacitance (charge storage) limited by a 1 to 2 kilo ohm resistance, which result in less than 0.03 Joules of energy with current limited to 15 amperes. Electromagnetic field strengths are nominally around 200 volts per meter (V/m) or less using continuous wave (CW) testing.
These test levels are sufficient to simulate the inadvertent discharges caused by an electrostatically-charged driver or occupant, or driving under most power lines and transmission towers. They are also adequate to provide compatibility with automobile citizens band and cellular communications systems, but do not even come close to matching the disruptive effect caused by high energy electrical pulses (EMP) of the type used in military test programs or the inventive subject matter herein.
These levels must be exceeded in order to disable a vehicle. Yet, the excess level must be insufficient to damage surrounding vehicles or electronic devices, which are most desirably maintained in their normal functions. This factor occurs within certain parameters.
The vehicle disabling device preferably provides a charge to the vehicle of about 20 to about 450 kilo volts to the vehicle. More preferably, the vehicle disabling device preferably provides a charge to the vehicle of about 30 to about 400 kilo volts to the vehicle. Most preferably, the vehicle disabling device preferably provides a charge to the vehicle of about 40 to about 350 kilo volts to the vehicle to be disabled.
The vehicle disabling device further provides up to about 5 microfarads of capacitance limited by about a 1 to about 2 ohm resistance, which results in less than 1000 Joules of energy with current limited to about 15,000 amperes. More preferably, the vehicle disabling device further provides up to about 4 microfarads of capacitance. Most preferably, the vehicle disabling device further provides up to about 3 microfarads of capacitance.
The vehicle disabling device further provides an electromagnetic field strength of about 100,000 to about 900,000 volts per meter. More preferably, the vehicle disabling device further provides an electromagnetic field strength of about 150,000 to about 800,000 volts per meter. Most preferably, the vehicle disabling device further provides an electromagnetic field strength of about 200,000 to about 750,000 volts per meter.
With regard to a static or stationary device, remote activation is preferred. A remote line-of-sight or cell area radio link is used to effect stand-off or remote control. A coded transmission is received through a small internal antenna and directional coupler means. The receiver acquires (tunes) and demodulates the radio frequency (RF) remote link control signal, which compares the receiving command to a prestored digital validation code and which, in turn, is contained in the decode key.
This method, for activating a stationary device, provides a level of protection against unauthorized operation or intentional spoofing or jamming. The two basic decoded commands are "arm" and "fire". Upon receipt of a valid "arm" command, a link-enable output is produced which provides the charge-enable signal to the charge generator section.
The charge generator is any suitable voltage multiplier. Preferably a Kocroft-Walton voltage multiplier available from any electrical supply source, which is driven by a switchmode power supply and high frequency set-up transformer configuration which produces a voltage charging ramp across the high voltage charge storage capacitors contained in the charge storage circuit block.
The critical automotive electronic systems subject to electrical disruption/destruction are very well protected against normal electrical system transients ranging from "alternator load dump" to static electricity discharges from passengers sliding across plastic seats. Such transients normally involve peak power levels in the range of tens to perhaps a few thousands of watts, and energies ranging from a few thousandths of a joule to a few joules. To reliably disrupt an automotive electrical system, energy levels of at least an order of magnitude greater than the maximums stated above must be effectively coupled into the "victim" modules or platform.
Two methods of accomplishing this desired result are known. The first method involves direct electrical contact with the offending vehicle, while the second employs inductive or capacitive coupling to the same. Both methods involve an energy storage means (preferably a high voltage capacitor), which is discharged to provide a very brief about 30 to about 400 kilo volt, but very energetic current flow through the automobile frame and therefore through attached electronic modules.
The direct contact preferentially pumps the electrical contents of the energy storage capacitor between the engine/transaxle and the vehicle under carriage/unibody. As the vehicle passes over the contact block, an arcing contact occurs to the vehicle parts mentioned, inducing a current flow limited only by the impedances involved; namely:
Z=(L/C).sup.0.5 +R
and I=V/Z
with L being the sum of the inductance for the bonding wire, the contact block, and the feeder cable inductance; R being the sum total of the arc resistance and the capacitor equivalent series resistance; C being the capacitance of the energy storage capacitor (ESR), I being the current in amps, and V being the voltage.
Assuming equal inductance in the three items above and small total resistance, nearly one-third of the capacitor charge voltage will appear across the bonding wire between engine and body and therefore between engine-mounted modules (such as the engine control computer). The available current is limited only by the circuit impedance described above. Typical circuit values are: ##EQU1## So Z=(L/C) 0 .5 +R=(5×10 -6 /5×10 -6 ) 0 .5 +0.2=1.2 ohms. Assuming 30 kilo volts direct current (KVDC) capacitor charge potential, peak currents may reach 24,000 amps. Under the conditions given above a "tank circuit: with resonant frequency of F= 2pi(L/C)! -1 =30 kilohertz results.
The frequency or "Q" of this circuit is X L /R=5 causing a "damped wave" oscillation to result which dies away in a few cycles. This brief, high level oscillatory current has been found to short, open or actually vaporize electronic components used in typical automotive modules, including the protective components used to attenuate normal transients such as zener diodes and metal oxide varistors.
Another operable method is identical to first method except that instead of direct arcing contacts ohmically transferring energy to the vehicle a wire loop of similar dimension to vehicle length and width is placed on the pavement, and when the offending vehicle is driven over same, a high voltage (H.V.) switch means (for example, triggered spark gap) is closed discharging the energy storage capacitor and setting up a powerful damped wave current oscillation in the loop, which sets up a similar current in the vehicle body, by transformer action (magnetic field interface). However, not all flux lines from the loop (primary) impinge upon the vehicle body (secondary). Similarly, a capacitively coupled system can be used.
More energy is needed in this method by a factor of roughly ten from experiments to date. System cost, of course, rises with energy storage level. An additional complication of this method is that some external vehicle position sensor must accurately and quickly trigger energy release when the vehicle is directly over the loop or capacitive coupled device. This can take the form of an optical, capacitive inductive or even pneumatic sensor.
The first method is entirely self-triggering. No energy discharge occurs until the vehicle in question physically completes the electrical circuit. Clearly the second method is not only more expensive but more complicated as well.
The true worth of this second method can only be realized in a situation where electrical safety is an overriding concern. Since all high voltage components including the exposed delivery loop can be well insulated accidental electrocution of the operator, innocent by-standers, for example, are virtually eliminated. Regardless, safety precautions such as radio or fiber optic-isolated control and ground-fault interrupter circuitry to quickly "dump" the stored energy safely into a resistor are considered mandatory for total safety from the lethal energies used within either method.
Waveform Generation and Target Vehicle Coupling Electrodes trigger the platform. The trigger command signal enables the pulse switching circuits in the waveform generator and applies a very high voltage potential to the coupling electrode and return electrode. As the leading edge of the target vehicle passes over the electrodes, a series of high energy discharges are coupled to the engine, transmission, oil pan, and frame, creating a high electrical potential between the engine block and the vehicle frame.
Each discharge pulse has a rapid rise and fall time of about 30 nanoseconds and a duration of less than 3 microseconds. The peak power level of each discharge is over 1 megawatt and the total energy delivered to the target vehicle is a nominal 100 Joules at peak currents exceeding 5,000 amperes. As the high voltage discharge occurs, the combined inductance and capacitance of the engine compartment structures, such as the engine-to-frame/body grounding strap, battery return cable, and sensor leads, will cause electrical "ringing" or secondary waveforms to be coupled to the automobile electrical system. The oil pan and frame structure will also behave as electromagnetic radiating structures that will couple electromagnetic near-field radiation to the sensor leads.
The EEC module of the target is located on the firewall or other vehicle location, is electrically connected to the engine block and sensors, and will experience high amplitude overvoltages and false sensor inputs. The EEC module will either be destroyed or will function incorrectly and halt the vehicle.
Even if the EEC module resets itself and recovers, if critical engine sensors have been destroyed, its embedded software will shut down the engine and prevent vehicle restart. Other systems, such as the ignition switching and electronic transmission controls, may be disabled as well. As the power train is disabled, the vehicle will either roll to a stop as its kinetic energy dissipate, or traditional barrier means may be employed to limit forward travel distance and to reduce penetration range.
Preferably, the platform or AVECM device is housed in a light-weight, high-strength polycarbonate low-profile case. The configuration and coloring of this case makes it appear non-threatening to an oncoming vehicle operator; it appears as a mere "bump" in the road. The high voltage electrodes are thin and difficult to see. Their protrusion above the case is minimal (FIG. 4). The use of modern electronics and engineering material can make the AVECM device compact and light, weighing only approximately 20 kg. The power supply of the AVECM device can be light in weight and portable by using modern battery technology. For single-use systems, a thermal battery may be used with the battery "ignited" by the arming command upon approach of the target vehicle.
The light weight and compact configuration of the proposed AVECM device makes it truly man-deployable, unlike traditional barrier technology. The AVECM device can be carried in a light vehicle or small helicopter, ready to be deployed on a roadway, making strike evasion difficult or unlikely. Gates, vehicles, or other roadway impediments may be used to restrict the path of the vehicle and to guide it toward the AVECM device strike zone.
The AVECM device described above is only one of many design alternatives. The means of coupling energy can be capacitive or inductive, and discharge electrodes can also be employed. For installed perimeter defense systems, power can be provided by base power utilities and control can be by fiber optic or coaxial cables.
The vehicle energy-coupling means can actually be placed in the road surface by embedding metal capacitive "plate" or similar elements into thin composite materials made to look like common paving material, giving a blanket, wide-area effect. These plates can be organized into a matrix or array, allowing only specified areas to be energized selectively in order to target a specific vehicle in a line of traffic flowing past a check point.
Check points can even be automated using a radio frequency car security "tag" issued to authorized vehicles which respond with a coded message when interrogated with the modulated electromagnetic field of predetermined frequency and strength. If the tag response in incorrect, a lighted warning to stop could be issued concurrently with arming the AVECM charging circuits. If the vehicle continues forward progress and reached the restricted zone, the AVECM device could be triggered, automatically disabling the vehicle. Unlike conventional check points, vehicles can be "cleared" without even requiring authorized vehicles to come to a complete stop.
AVECM technology minimizes the hazards associated with traditional barrier technology and/or high-speed pursuits by law enforcement personnel. The AVECM device requires neither the physical disruption of the target vehicle nor injury to its driver or occupants. The use of coded control signal would make unauthorized operation difficult. The short duration of pulses and brief duty cycle of operation required limits electromagnetic interference with collocated communications systems. The AVECM device uses only near-field coupling and will not affect even sensitive electronics systems, such as radiated micro systems, located only a few meters away.
Ignition of fuel tanks is very unlikely, as minimal heating effects are produced. Pre-detonation of on-board explosives is possible, but very unlikely, as the AVECM device is to be designed to couple its energy to the engine compartment and not to the payload of a vehicle. Unless the explosives were actually wired into the automotive electrical system, sufficient energy is not available to trigger most electronic bomb detonation systems.
The voltage and current amplitudes used by a typical AVECM device do pose an electrical shock hazard to any personnel or bystanders making direct contact with coupling electrodes. For this reason, the preferred design incorporates a charge dissipation circuit to remove rapidly the hazardous stored energy after the arming or fire sequence is performed.
In particular the static or stationary automobile killer, or the vehicle disabling device includes a battery, a radio controller, a DC to AC inverter, a step up transformer, a voltage multiplier, two resistors, a safety or bleeder resistor, a storage capacitor, and a pair of car electrodes. More particularly, the battery is connected to the radio receiver in a standard fashion. The radio controller operably connected to the DC inverter and provides for control and operation of the static car killer. The DC to AC inverter is connected to the step up transformer to provide five to ten kilo volts of alternating current.
That current is then multiplied into a negative and positive kilo voltage through isolation resistors. Preferably, the voltage is about 30 kilo volts to about 400 kilo volts. More preferably, the voltage is about 50 kilo volts to about 140 kilo volts. Most preferably, the voltage is about 90 kilo volts to about 110 kilo volts.
The isolation resistors have a resistance in a range of about five to about forty kilo ohms. More preferably, the isolation resistors have a resistance in a range of about ten to about thirty kilo ohms. Most preferably, the isolation resistors have a resistance in a range of about ten to about twenty kilo ohms.
A safety bleeder resistor connects the two resistors from the voltage multiplier. An energy storage capacitor is connected in parallel with the safety bleeder resistor and in series with each isolation resistor. A spark gap is connected to each car electrode. As the automobile closes the gap between the electrodes, the disabling current is fired through the automobile.
This device can fire immediately on contact with the vehicle. It fires repeatedly and quickly so that eventually critical disabling contact can be made with the underside of the vehicle. Thus, the device does not require precise positioning before fired. Similarly, a stationary device can fire repeatedly within fractions of a second and have the same results.
Any suitable method may be used to launch the anti-vehicle electronic counter measure. It may be launched by a spring mechanism, a hydraulic ram, or expanding gas. The platform may also be launched by mortar device or a traction motor device. Most preferred, however, is a rocket based launch with wire controls. The rocket is preferably a solid state fueled single use rocket. Such a rocket is a commonly available item and easily adapted for the use herein.
In the vehicle launch embodiment, the device is mounted on a platform; which, is in turn, mounted on the vehicle. Upon activation of a launch device, a rocket can fire the platform containing the anti-vehicle electronic counter measure device. The position platform is controlled by cables.
The cable is mounted in any suitable fashion. Preferably two cables are used and proceed from each end of the front bumper of the pursuit vehicle. Each cable may be mounted on a double reel, with a centrifugal brake to control the speed of the required substantially equal payout of each cable. The two cables may also be formed by splitting a joined cable and ejecting the platform as required.
In this vehicle launched mode, the platform for the electrode assembly has a rocket mounted thereon and is mounted on wheels. The rocket is wire guided to the desired target. Information from various police officers indicate that it is no problem to stay an appropriate distance behind the vehicle being followed, for the required period of time, usually about three to five seconds.
The sled or platform containing the vehicle disabler is mounted on wheels and guided by a wire control. The sled is propelled by a rocket. A mechanical or fuse link release system releases the platform and ignites the rocket. The five second timer arms the rocket and permits the fire switch to ignite the rocket. Upon igniting of the rocket, the power is provided through an inverter to a dual cable reel.
Each cable forms an arm of a isosceles triangle with the disabling device at the front portion thereof. In this particular case the inverter remains with the automobile while the step up transformer is mounted on the rocket platform. This is the basic division of the switch activation to control activation of the disabling device. With the inverter and the multiplier, there is a voltage regulator and bleeder resistors operationally connected to the isolation resistors and the energy storage capacitor.
Each cable may also form parallel sides of a parallelogram. The front bumper of a pursuit vehicle and the launched platform form the other pair of parallel sides.
The voltage regulator permits control of the voltage and prevents excess voltage from reaching the capacitors. By this means, an electronic switch is opened, when the regulator detects adequate capacitor voltage, and acts to reduce energy passing to the voltage regulator and thence to the capacitor.
Referring now to FIG. 1, the anti-vehicle electronic countermeasure device 100 is launched from pursuit vehicle 110 toward a pursued vehicle 112. Preferably the front bumper of the pursuit vehicle 110 forms the base of an isosceles triangle while the anti-vehicle electronic countermeasure 100 forms the vertex of the isosceles triangle. A first wire guide mechanism 120 and a second wire guide mechanism 122 form the arms of the isosceles triangle. As the pursuit vehicle 110 changes position, the anti-vehicle electronic countermeasure 100 form can be maneuvered toward the pursued vehicle 112. After the vehicle mounted device 100 is under the pursued vehicle 112, the device 100 may be activated and the pursued vehicle 112 disabled.
Now adding FIG. 2 to the discussion, the structure of the vehicle mounted anti-vehicle electronic countermeasure device 100 is more clearly defined. The launching mechanism 130 is depicted in block diagram form. The launching mechanism 130 is wired to the battery 114 of the pursuit vehicle 110.
Wired in series with or otherwise connected to the battery 114 is a safety switch 132 and a timer 134. These devices are wired to an inverter 136 which can convert the 12 volt DC from the battery 114 to 500 volts AC current at 2 amps. The inverter 136 is, in turn, connected to a cable 138 through dual cable reel 140. Dual cable reel 140 is, in turn, controlled by a centrifugal brake 142.
The dual cable reel 140 provides a coil of cable 138 connected to a rocket sled 146. The rocket sled 146 has mounted thereon the anti-vehicle electronic activation system 148 of FIG. 3 for the anti-vehicle electronic countermeasure 100. The cable 138 is fed out as the rocket motor 150 ignites burns and propels the sled 146 on wheels 152. Cable 138 divides into first wire guide mechanism 120 and second wire guide mechanism 122.
Within the pursuit vehicle 110 and wired to the five (5) second timer 134 is a fire switch 154 connected to a rocket igniter 156. This five (5) second timer 134 controls the duration of power delivery to the rocket sled 146.
Adding FIG. 3 to the consideration, the actual structure of the anti-vehicle electronic activation system 148 on the rocket sled 146 may be seen. The battery 114 within the pursuit vehicle 110 provides power to the system. Radio controller 162 is connected to the inverter 136. The inverter 136 is connected to a step up transformer 164 and a voltage multiplier 166, which increases the voltage to about 100 kilo volts direct current.
A FIG. 4 modification shows that the high voltage direct current is fed through a pair of isolation resistors 168 from platform battery 128. The isolation resistors 168 are connected a safety bleeder resistor 170 and to the energy storage capacitor 172. Leading from the energy capacitor 172 are first car electrode 174 and a second car electrode 176. As the rocket sled 146 goes under the pursued vehicle 110, the electrodes 174 and 176 contact the undercarriage thereof. The radio controller 162 may then activate the electrodes and disable the electronics within the pursued vehicle 112.
Most preferably the step up transformer 164 drives a Kocroft Walton voltage multiplier. The voltage multiplier 166 takes the 5 to 10 kilo volts AC out of the step up transformer 164 and increases the voltage level to 100 kilo volts. In this fashion, enough energy is created to permit the electronic engine controls (EEC) of pursued vehicle 112 to be disabled.
As depicted in FIG. 5, portable anti-vehicle electronic counter measure device 300 may placed in a roadway and used as desired. The structure is very similar to FIG. 3. Radio receiver 302 or a similar device is connected to the battery 128, which operates the initial voltage input 306. The initial voltage input 306 is connected to a step up transformer 164 and a voltage multiplier 166, which increases the voltage to about 100 kilo volts direct current.
The kilo volts are fed through a pair of isolation resistors 168. The isolation resistors 168 are connected to a safety bleeder resistor 170 and to the energy storage capacitor 172. Leading from the energy capacitors 172 are first car electrode 174 through first spark gap 310 and a second car electrode 176 through spark gap 312. The radio receiver 302 may then activate the electrodes, and disable the electronics within the pursued vehicle 112, when it passes thereover.
The stationary anti-vehicle electronic counter measure device 400 of FIG. 6 is similar to FIG. 5. Glue assembly 402 or spikes 404 in frame 406 lock stationary device 400 in place. The radio receiver 162 may be activated by remotely operated device from pursuit vehicle 110 or an officer in a vehicle or on foot, in a standard fashion.
FIG. 7 depicts a stationary circuit diagram 310 for a capacitively coupled anti-vehicle electronic counter measure device 400. A metal plate 350 causes a capacitive coupling and thus current to flow to a pursued vehicle 112. The spark gap and capacitor 172 with the isolation resistors 168 are encased in a plastic coating 352. The device 400 may then be placed as desired and activated when necessary.
Referring now to FIG. 8, the mortar launched anti-vehicle electronic countermeasure device 450 is depicted. This device 450, while operable, is not as efficiently controlled as the rocket launched vehicle mounted anti-electronic countermeasure device 100. The mortar 452 provides for a faster acceleration. However, the accurate speed control of device 100 is more usually preferred. Again this mortar launch device 450 is mounted on the police car or pursuit vehicle 110.
It is controlled by a typical mortar launch device 450 mounted in a mortar 452 attached to pursuit vehicle 110, capable of providing for more accurate firing mechanism. The mortar device 450 includes a nickel cadmium battery pack 454 which is charged by through charger 470 by the battery 114 on the pursuit vehicle 110 until the device 450 is launched.
The launch tube 456 for mortar 452 is mounted on a sabot 458 in an angled mounting bracket 462. There is an appropriate propellant charge 464 for launching the disabling device 450. High pressure gases generated from the ignition of propellant charge 464 are sealed by sabot 458.
The mortar-caused acceleration activates the timer 412 and the other features of the device by an impact switch 468 or similar device. The timer 412 activates elements similar to elements on the rocket launched electronic device 100. Thus, the kilo volt inverter 136, the step up transformer 164 and the voltage multiplier 166 used herein are similar.
The timer 412 also effects the activation of the electrodes. This launch must be timed, as the electrodes are activated by the timer 412 and the appropriate vehicle contact. Once launched, this mortar device 400 has greater speed than the device 100. However, the mortar device 400 lacks the control, maneuverability and flexibility of the device 100.
In FIG. 9, traction-motor launched, anti-vehicle electronic counter measure device is depicted. Traction motor device 500 is distinguished by four traction drive wheels 502 on each corner of the traction sled 504 to carry the electronic disabling device 100. The four traction drive wheels 502 are mounted in a typical vehicle fashion and spaced equivalently apart.
The first traction drive wheel 506 is operated by first motor 508. The second traction drive wheel 510 is operated by second motor 512. The third traction drive wheel 514 is operated by third motor 516, while the fourth traction drive wheel 518 is operated by fourth motor 520. Constant torque controller 522 is operably connected to each motor to provide torque control and to keep the motors at a constant torque output independent of speed. Vehicle speed is regulated by the centrifugal brake.
The cable reel 524 of this device includes a joined cable 526. Mounted adjacent to the cable reel 524 is a knife 528 for separating the joined cable 526 into separated cable 530 to form the above described isosceles triangle or parallelogram with first cable arm 532 and second cable arm 534. The separated cable 530 passes through a first solid mounted, tetrafluoroethylene-coated (sold under TEFLON a registered trademark of E. I. dupont, Wilmington, Del.) low friction sleeve 536 and a second low friction sleeve 538 (FIG. 10).
Within the joined cable 526, of course, is the control of the traction motor device 500 and power delivery for the electronic disabling device. Control of the traction sled 504 then becomes similar to device 100 in that the first cable arm 532 and second cable arm 534 feed into a step-up voltage transformer 164, which in turn go to a voltage multiplier 166 and then to a voltage regulator 536. The voltage regulator 536 is connected to the capacitor 172, which reaches the car electrodes and provides for the firing power to stop the pursued vehicle 112. Joined cable 526 and the structure therewith may also be used with other embodiments disclosed herein.
FIG. 10 provides a crimped wire guidance system 600 for good wire control related to vehicle mounted anti-vehicle electronic counter measure device 100. Two strand wire 602 is mounted on a reel 604. As the platform fires, wire 602 passes through a pair of crimping wheels 606 then to a blade 608. The blade 608 splits the wire 602 to form the parallelogram or isosceles triangle. The split wire passes through a pair of tubes 610 and to the platform. The crimping simplifies the wire payout control with a centrifugal brake 616 standardly mounted on one crimping wheel 606.
FIG. 11 depicts a hose wire guidance system 650 for vehicle mounted anti-vehicle electronic counter measure device 100. The wire 660 is not on a reel, but is coiled in an S-coil 660 like a fire hose.
FIG. 12 depicts a splitable wire guidance system 700 for vehicle mounted anti-vehicle electronic counter measure device 100. Due to a bar 702 on the platform, a parallelogram of guidance is achieved. The other structure is similar to FIG. 10. However, no splitting knife such as knife 528 FIG. 9 is required
This application--taken as a whole with the abstract, specification, claims, and drawings--provides sufficient information for a person having ordinary skill in the art to practice the invention disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure.
Because of this disclosure and solely because of this disclosure, modification of this method and apparatus can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.
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A vehicle disabling device is positioned under a vehicle desired to be stopped, sends a capacitive discharge therethrough, and disables at least one electric system of the vehicle.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a friction clutch to be arranged in the power train of a motor vehicle.
2. Description of the Prior Art
A conventional friction clutch to be arranged in the power train of a motor vehicle includes a flywheel which is rotatable about an axis of rotation. The flywheel can be coupled to one end of a crankshaft of an internal combustion engine and has a friction surface facing away axially from the crankshaft. A friction facing of a clutch disk connectable with a transmission input shaft is connected in a frictional engagement with the friction surface of the flywheel when the friction clutch is engaged. A pressure plate unit is provided in order to apply the contact pressure force needed for the frictional engagement between the friction facing of the clutch disk and the friction surface of the flywheel. The pressure plate unit comprises a clutch housing which is rigidly connected with the flywheel radially outside the friction facing and extends radially inward so as to partially surround the clutch disk. A contact-pressure plate is supported axially against the clutch housing via a clutch spring. The contact-pressure plate is provided with a friction surface which is located opposite the friction surface of the flywheel facing the crankshaft and communicates with a friction facing of the clutch disk in a frictional connection when the friction clutch is engaged. Frictional forces of roughly equal magnitudes are transmitted to the clutch disk by the friction surface of the contact-pressure plate and the friction surface of the flywheel given an identical construction of these two friction surfaces. Torque is accordingly transmitted from the crankshaft to the clutch disk connected with the transmission input shaft via two separate torque transmission paths. The first torque transmission path extends from the flywheel, via the friction surface of the flywheel, directly to the clutch disk. The second torque transmission path extends from the flywheel to the clutch disk via the clutch housing, clutch spring, contact-pressure plate and friction surface provided at the latter. Torques of approximately equal magnitude are transmitted via both torque transmission paths.
In addition to the torques to be transmitted by the friction clutch during normal driving and shifting operation, peak torques which are generated, for example, by incorrect operation such as engaging the clutch in a jerking manner, are also transmitted to the clutch disk by the frictional engagement between the flywheel and clutch disk. In this connection, there exists the risk that these peak torques can damage components of the friction clutch itself, as well as components of the gearbox or transmission. In order to withstand these peak torques, which only occur occasionally, these components must exhibit a mechanical strength and robustness beyond that required for normal operation.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a friction clutch which makes it possible to limit the torques transmitted by the friction clutch.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a friction clutch to be arranged in the power train of a motor vehicle, the friction clutch comprising a flywheel mass arrangement to be fastened to an input shaft rotating about an axis of rotation, especially to a crankshaft of an internal combustion engine, a pressure plate unit with a clutch housing held at the flywheel mass arrangement, and a contact-pressure plate which is guided so as to be axially displaceable relative to the clutch housing and the flywheel mass arrangement. A clutch spring arrangement is provided so as to axially spring-load the contact-pressure plate toward the flywheel mass arrangement. A clutch disk with friction facings projects between, on the one side, friction surfaces of the flywheel mass arrangement which are located axially opposite one another and, on the other side, the contact-pressure plate. The clutch disk is connectable with an output shaft extending coaxial to the input shaft, especially of a transmission input shaft.
The friction clutch according to the invention is characterized in that the flywheel mass arrangement and the contact-pressure plate are coupled with one another in a torsionally elastic manner with reference to the axis of rotation.
In contrast to the conventional friction clutch in which the flywheel mass arrangement and the contact-pressure plate are connected with one another rigidly with respect to rotation, the torsionally elastic connection of these two components according to the invention makes it possible to limit the torque transmitted by the friction clutch. This means that when torques of corresponding magnitude occur, the contact-pressure plate can rotate relative to the flywheel mass arrangement and can thus decrease the torque transmitted by the friction surface of the contact-pressure plate to the clutch disk corresponding to this rotating movement. In so doing, the total torque transmitted by the friction clutch is reduced at the same time.
The torsionally elastic coupling of the flywheel mass arrangement and the contact-pressure plate is preferably realized in that two components succeeding one another in the torque transmission path between the friction surface of the flywheel mass arrangement and the friction surface of the contact-pressure plate are connected with one another in a torsionally elastic manner via at least one spring and so as to be rotatable relative to one another about the axis of rotation. This torque transmission path is formed by portions of the flywheel mass arrangement, the clutch housing, the clutch spring arrangement and the contact-pressure plate. The rotatable connection between two successive components ensures the possibility in at least one location of the torque transmission path, for components to rotate relative to one another and accordingly for a relative rotation between the flywheel mass arrangement and the contact-pressure plate, so that it is possible to limit the torque which can be transmitted by the friction clutch. In addition, the use of the spring for the torsionally elastic connection of the two successive components makes it possible to proportion the use of the torque-limiting action of the friction clutch and to define this in a reproducible manner. The spring is preferably a pressure spring.
The two components which succeed one another in the torque transmission path and are rotatable relative to one another preferably have stops located opposite one another in the circumferential direction. At least one spring is arranged between the steps. In this way, the torsionally elastic coupling between the flywheel mass arrangement and the contact-pressure plate can be realized in a simple manner.
The spring, of which there is at least one, is preferably fitted with pretensioning between the stops located opposite one another in the circumferential direction, so that the contact-pressure plate rotates relative to the flywheel mass arrangement only when a torque corresponding to the pretensioning of the installed springs is exceeded.
A particularly favorable and robust construction is achieved when the clutch housing is held at the flywheel mass arrangement so as to be rotatable and is coupled in a torsionally elastic manner with the flywheel mass arrangement via a spring, of which there is at least one. The components of the conventional friction clutch can be taken over in large part. The conventional rigid connection between the flywheel mass arrangement and the clutch housing need only be replaced by a torsionally elastic coupling of these two components, which can be accomplished at a relatively low cost in terms of construction.
In this respect, an axially acting spring preferably holds the clutch housing in a frictional engagement with the flywheel mass arrangement so that a portion of the driving torque to be transmitted by the friction clutch is transmitted from the flywheel mass arrangement to the clutch housing, from which it is further transmitted to the clutch disk via the clutch spring arrangement and the contact-pressure plate.
The axially acting spring is preferably designed so that it holds the clutch housing and the flywheel mass arrangement in a frictional engagement when the friction clutch is engaged, but at least partially relieves this frictional engagement when the friction clutch is disengaged. In so doing, the strength of the frictional engagement and accordingly the degree of torque which can be transmitted between the flywheel mass arrangement and the contact-pressure plate depends upon the coupling state of the friction clutch. This functionality is achieved in a particularly simple manner in that the axially acting spring is formed by the clutch spring arrangement or the clutch spring arrangement is at least a component part of the axially acting spring.
The flywheel mass arrangement is preferably constructed as a two-mass flywheel in which the first flywheel mass can be fastened to the input shaft and the second flywheel mass comprises the friction surface. The first and second flywheel masses are coupled with one another via a torsional vibration damper. In this way, a friction clutch is realized in which the variations in torque which are caused, for example, by rough running of the internal combustion engine are reduced by means of the torsional vibration damper and are accordingly kept away from the components succeeding the friction clutch in the power train. On the other hand, this friction clutch is also capable of absorbing torque peaks caused, e.g., by improper operation, via the torsionally elastic coupling of the flywheel mass arrangement with the contact-pressure plate and is accordingly able to protect the components following the friction clutch in the power train from these torque peaks.
In conjunction with the design of the flywheel mass arrangement as a two-mass flywheel, the torsionally elastic coupling of the flywheel mass arrangement with the contact-pressure plate results in a friction clutch which not only solves the problem of limiting the peak torques transmitted by the friction clutch, but which is also capable of solving a completely separate problem familiar from the field of conventional two-mass flywheels. The two flywheel masses of the two-mass flywheel which are coupled in a torsionally elastic manner form a spring-mass system having a resonant frequency. Normally, the torsionally elastic coupling of the two flywheel masses and their inert masses are so adapted to one another that this resonant frequency lies outside the speed range of the friction clutch during normal operation. In operating states not corresponding to normal operation of the friction clutch, e.g., when starting or stopping the internal combustion engine, it is possible nevertheless for resonances to be excited in the spring-mass system of the two-mass flywheel, which are considered undesirable and under unfavorable circumstances can even lead to destruction of the two-mass flywheel.
When the friction clutch is disengaged, i.e., when the frictional engagement of the flywheel mass arrangement with the contact-pressure plate via the clutch disk is interrupted, the flywheel mass arrangement, together with the contact-pressure plate which is coupled therewith in a torsionally elastic manner, forms a vibratory or oscillatory spring-mass system which can be considered as a "three-mass flywheel" in combination with the flywheel mass arrangement designed as a two-mass flywheel. The spring-mass system which is formed in this way when the friction clutch is disengaged, in contrast with the simple two-mass flywheel, has two resonant frequencies and accordingly a completely different resonant behavior. Given a suitable arrangement of the torsional vibration damper between the first flywheel mass and the second flywheel mass and an appropriate arrangement of the torsionally elastic coupling of the flywheel mass arrangement with the contact-pressure plate, this resonant behavior can be influenced such that the possibilities for exciting resonances are appreciably reduced in comparison with the conventional two-mass flywheel. The combination of these two functions--limiting the transmitted peak torque when the friction clutch is engaged and damping resonances when the friction clutch is disengaged--is achieved in a particularly effective manner in that a frictional engagement between the flywheel mass arrangement and the contact-pressure plate, such as that described between the clutch housing and flywheel mass arrangement, is reinforced when the friction clutch is engaged and is at least partially released when the friction clutch is disengaged.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a friction clutch according to the present invention in a sectional view along the axis of rotation; and
FIG. 2 shows the friction clutch in a partial sectional view vertically to the axis of rotation along line II--II from FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The friction clutch 1 shown in FIG. 1 comprises a flywheel mass arrangement 3 which can be fastened to a crankshaft of an internal combustion engine, not shown, a pressure plate unit 5, and a clutch disk 7 which can be fastened to an input shaft of a transmission, likewise not shown. The flywheel mass arrangement 3, the pressure plate unit 5, and the clutch disk 7 are rotatable about a common axis of rotation 9.
In the embodiment shown in the drawing, the flywheel mass arrangement 3 is constructed as a two-mass flywheel and, in this connection, comprises a hub 11 which can be fastened to the crankshaft by screws 13. A first flywheel 15 is fixedly mounted at the hub 11 and a second flywheel 17 is supported via a bearing 19 so as to be rotatable about the axis of rotation 9. The first flywheel 15 is formed of a plurality of parts and includes a radially extending primary disk 21 which is fixedly connected with the hub 11, supports a starter ring gear 23 at its outer rim, and is fixedly connected, likewise at its outer rim, with a cover disk 25 which extends at a distance axially from the primary disk 21 to an inner rim 27 of the cover disk 25. The inner rim 27 is arranged radially outside of the bearing 19. The second flywheel 17 comprises a hub disk 29 which is arranged axially between the primary disk 21 and the cover disk 25. The hub disk 29 is connected, by means of rivets 31, with a counter-pressure plate 33 radially between the inner rim 27 of the cover disk 25 and the bearing 19. The counter-pressure plate 33 extends radially outward from the bearing 19 such that the cover disk 25 is arranged axially between the counter-pressure plate 33 and the hub disk 29.
The first flywheel 15 and the second flywheel 17 are coupled with one another in a torsionally elastic manner via a set of springs. The spring set is formed by a plurality of springs 35 which are oriented in the circumferential direction of the friction clutch 1. The springs 35 are loaded in the circumferential direction between, on the one side, stops 37 provided at the primary disk 21 and the cover disk 25 and, on the other side, edges of windows 39 provided in the hub disk 29. For the purpose of damping torsional vibrations between the first flywheel 15 and the second flywheel 17, a friction disk 41 is provided at the inner rim 27 of the cover disk 25. The friction disk 41 is in frictional contact with a friction facing 43 provided at the hub disk 29.
An annular clutch friction surface 45 is formed at the counter-pressure plate 33 on its side axially remote of the crankshaft and the first flywheel 15. The counter-pressure plate 33 is connected with the pressure plate unit 5 radially outside the clutch friction surface 45 such that the counter-pressure plate 33 and the pressure plate unit 5 are rotatable relative to one another about the axis of rotation 9.
The pressure plate unit 5 comprises a clutch housing 47 whose outer surface region 49 first extends axially away from the counter-pressure plate 33 and then passes into a clutch spring retaining region 51 which extends inward radially and is thus arranged at a distance axially from the clutch friction surface 45 of the counter-pressure plate 33. An annular contact-pressure plate 53 with a clutch friction surface 55 facing the clutch friction surface 45 of the counter-pressure plate 33 is arranged axially between the counter-pressure plate 33 and the clutch spring retaining region 51. The contact-pressure plate 53 is centered around the axis of rotation 9 and is axially displaceable. Friction facings 56 of the clutch disk 7 are arranged between the two clutch friction surfaces 45, 55 which are thus located opposite one another axially. These friction facings 56 are connected by rivets 57 with a hub part 59 of the clutch disk 7, the hub part 59 being provided for fastening to the transmission input shaft.
In order to apply the contact pressure force required for the frictional engagement between the clutch friction surfaces 45, 55 and the friction facings 56 when the friction clutch 1 is engaged, the pressure plate unit 5 comprises a clutch spring unit 61 with an annular diaphragm spring 63 which is held in the circumferential region and radially close to the inner rim of the clutch spring retaining region 51 by a holder 64. In so doing the spring 63 is clamped swivelably between two tilting rings 65. The diaphragm spring 63 contacts the contact-pressure plate 53 radially outside the tilting rings 65 accompanied by pretensioning so as to load the contact-pressure plate 53 in the direction of the counter-pressure plate 33. In order to release the frictional engagement between the clutch friction surfaces 45, 55, on the one hand, and the friction facings 56, on the other hand, the contact pressing force exerted by the pretensioned diaphragm spring 63 on the contact-pressure plate 53 can be canceled by actuating a release bearing, not shown, which acts on tongues 67 of the diaphragm spring 63 radially inside the tilting rings 65.
The outer surface region 49 of the clutch housing 47 has, at its end facing the counter-pressure plate 33, an annular flange 69 extending radially outward and projecting into an annular groove 71 provided in the counter-pressure plate 33. The clutch housing 47 is centered around the axis of rotation 9 relative to the counter-pressure plate 33 in that an outer rim 73 of the annular flange 69 contacts a cylindrical inner surface 75 of the annular groove 71. An annular spring 79 is inserted into another annular groove 77 recessed into the cylindrical inner surface 75 so that the annular flange 69 is arranged axially between this annular spring 79 and the base of the annular groove 71. As a result, the clutch housing 47 is fixed axially relative to the counter-pressure plate 33. The annular flange 69 of the clutch housing 47, on the one hand, and the annular groove 71 and annular spring 79, on the other hand, accordingly form a swivel bearing which enables the rotation of the clutch housing 47 relative to the counter-pressure plate 33.
The rotation of the clutch housing 47 relative to the counter-pressure plate 33 is held in the neutral position shown in detail in FIG. 2 by a set of springs. The spring set comprises a plurality of helical springs 83 arranged around the axis of rotation 9 so as to be distributed in the circumferential direction and oriented in the circumferential direction in each instance. The helical springs 83 are arranged in chambers 87 which are formed radially between the inner wall of the outer surface region 49 of the clutch housing 47 and an annular flange 85 provided at the pressure plate 33. The chambers 87 are defined in the circumferential direction by stop faces 89 which are provided at the inner side of the outer surface region 49 and which project radially inward, and by associated stop faces 91 which are provided at the annular flange 85 and project radially outward. In the neutral position, as is shown in FIG. 2, each of the helical springs 83, under pretensioning, makes contact at each end with the stop faces 89 constructed at the clutch housing 47 and with the stop faces 91 formed at the counter-pressure plate 33. A rotation of the clutch housing 47 relative to the counter-pressure plate 33, i.e., a deflection out of the neutral position shown in FIG. 2, accordingly leads to a further compression of the helical springs 83 and accordingly to a restoring force which tries to return the clutch housing 47 to the neutral position relative to the counter-pressure plate 33. The clutch housing 47 is rotatable relative to the counter-pressure plate 33 while the helical springs 83 are increasingly compressed until the helical springs 83 lock up, thus limiting the rotation of the clutch housing 47 relative to the counter-pressure plate 33.
The construction described above accordingly results in a friction clutch 1 in which the clutch housing 47 is held in a torsionally elastic manner at the counter-pressure plate 33, wherein adjustment of the curve of the restoring force as a function of the rotation path and adjustment of the maximum possible rotation path can be effected by means of the dimensioning of the helical springs 83 and the chambers 87.
When the friction clutch 1 is closed, driving torque is transmitted from the crankshaft of the internal combustion engine, via the hub 11, to the first flywheel 15 and from there to the second flywheel 17 via the springs 35, wherein the springs 35 together with the friction disk 41 and friction facing 43 lead to a damping of torsional vibrations of the internal combustion engine. The driving torque is transmitted from the second flywheel 17 to the friction facings 56 of the clutch disk 7 and accordingly via the hub part 59 to the transmission input shaft. The driving torque is transmitted from two sides to the friction facings 56 of the clutch disk 7, namely from the friction surface 45 at the counter-pressure plate 33 on the one hand and from the friction surface 55 at the contact-pressure plate 53 on the other hand. At a given contact pressure force of the contact-pressure plate 53 against the friction facings 56 and accordingly of the friction facings 56 against the pressure plate 33, the driving torque is correspondingly divided into two torque transmission paths. The first torque transmission path leads from the second flywheel 17 via its counter-pressure plate 33 and the clutch friction surface 45 provided at the counter-pressure plate 33 to the clutch disk 7. The second torque transmission path leads from the second flywheel 17 via the counter-pressure plate 33 to the clutch housing 47 and then, via the springs 63 and the contact-pressure plate 53, to the clutch disk 7.
Accordingly, in the second torque transmission path the contact-pressure plate 53 and the clutch housing 47 are connected with one another so as to be rigid against rotation. However, the clutch housing 47 is connected with the counter-pressure plate 33 in a torsionally elastic manner.
The counterforce corresponding to the contact pressure force of the contact-pressure plate 53 exerted by the diaphragm spring 63 in the direction of the counter-pressure plate 33 when the friction clutch 1 is closed is transmitted via the clutch housing 47 to the counter-pressure plate 33, wherein the annular flange 69 comes into contact with the annular spring 79 under axial pressure. If the driving torque transmitted to the second torque transmission path exceeds a value given by the pretensioning of the helical springs 83 and the friction force acting between the annular flange 69 and the annular spring 79 accompanied by axial force loading, the clutch housing 49 rotates relative to the counter-pressure plate 33. In so doing, the contact-pressure plate 53 stays back as viewed in the rotating direction of the counter-pressure plate 33 and participates to a correspondingly lesser degree in the transmission of driving torque to the clutch disk 7 and accordingly in its slip. This results in a limiting of the peak torque which can be transmitted by the friction clutch 1.
When the friction clutch 1 is disengaged, no driving torque is transmitted from the crankshaft of the internal combustion engine to the clutch disk 7, but the flywheel mass arrangement 3 and pressure plate unit 5 rotate together with the crankshaft of the internal combustion engine about the axis of rotation 9 and, in so doing, form a spring-mass system which is formed of three inert masses coupled with one another via two springs in series.
The first mass is formed by the first flywheel 15, described above, which is coupled via the springs 35 with the second inert mass of the spring-mass system, namely the second flywheel 17, in a torsionally elastic manner. The third inert mass of this spring-mass system is formed by the clutch housing 47, the diaphragm spring 63, its holder 64 and the contact-pressure plate 53 and is coupled in a springing manner to the second flywheel 17 by the torsionally elastic coupling between the clutch housing 47 and the counter-pressure plate 33. Since the contact pressure force of the contact-pressure plate 53 is canceled in the direction of the counter-pressure plate 33 by the clutch release, not shown, in the disengaged state of the friction clutch 1, the annular flange 69 also does not contact the annular spring 79 under axial force. When suitably designed, the annular flange 69 can be held with a slight axial and radial play relative to the counter-pressure plate 33 so that there is essentially no frictional force acting between these two components so as to impede rotational movement about the axis of rotation 9.
Thus, when the friction clutch 1 is disengaged the spring-mass system described above forms a "three-mass flywheel" which, with a suitable design of the springs 35 and the helical springs 83 and an appropriately dimensioned distribution of mass between the first flywheel 15, the second flywheel 17 and the pressure plate unit 5, leads to a marked improvement in the resonance behavior of the spring-mass system in comparison to the conventional two-mass flywheel.
The type of torsionally elastic coupling between the flywheel mass arrangement 3 and the contact-pressure plate 53 can be modified not only by means of the selection of the spring strength of the springs 83, but also by the influence of the frictional force acting between the flywheel mass arrangement 3 and contact-pressure plate 53 during rotation. For example, a relatively large peak torque can be transmitted in that the torsionally elastic coupling makes use of relatively strong, especially heavily pretensioned springs for the torsionally elastic coupling or in that a relatively large frictional force acts between the components which are rotatable relative to one another.
The springs 83 need not be arranged, as was described above, in chambers formed between the inner wall of the outer surface region 49 of the clutch housing 47 and the annular flange 85 at the counter-pressure plate 33. Rather, the springs 83 can be held by means of disks which are arranged at a distance from one another axially or radially and provided with windows or projections for supporting the springs 83. The holder for the spring 35 of the two-mass flywheel between the disks 21, 25 and 29 can serve as a model for such a construction.
Further, instead of the torsionally elastic connection between the clutch housing 47 and the counter-pressure plate 33, a torsionally elastic connection can be provided between two other components following one another in the second torque transmission path described above so that a limiting of the peak torques transmitted by the friction clutch can be achieved. For example, the connection between the clutch housing 47 and the contact-pressure plate 53 can be effected in a torsionally elastic manner by means of a suitable design of the holder 64.
On the other hand, in contrast to the construction of the flywheel mass arrangement 3 in the above-described embodiment as a two-mass flywheel, it is also conceivable to connect the counter-pressure plate 33 with the crankshaft of the internal combustion engine such that it is fixed with respect to rotation relative thereto and to provide a corresponding torsional vibration damper in the clutch disk 7, e.g., by means of a divided hub part 59 of the clutch disk 7 that is coupled via springs. In so doing, the torsional vibration damper in the clutch disk 7 can protect the transmission gearing downstream thereof from torque fluctuations of the internal combustion engine when the friction clutch 1 is in the engaged state, and peak torques are suppressed as a result of the ability of the clutch housing 47 to rotate relative to the counter-pressure plate 33. In the disengaged state of the friction clutch 1, the counter-pressure plate 33 and the pressure plate unit 5, which is coupled to the latter in a torsionally elastic manner, form a spring-mass system which can be viewed as a two-mass flywheel with corresponding resonance behavior.
A pushed friction clutch was described in the preceding embodiment. However, it is also easily possible to realize the torsionally elastic coupling between the flywheel mass arrangement and the contact-pressure plate as a pulled friction clutch.
The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims.
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A friction clutch for arrangement in the power train of a motor vehicle. The friction clutch includes a flywheel mass arrangement to be fastened to an input shaft rotating about an axis of rotation. A pressure plate unit with a clutch housing is held at the flywheel mass arrangement. A contact-pressure plate is guided so as to be axially displaceable relative to the clutch housing and the flywheel mass arrangement. A clutch spring arrangement axially spring loads the contact-pressure plate toward the flywheel mass arrangement. A clutch disk with friction facings projects between, on the one side, friction surfaces of the flywheel mass arrangement which are located axially opposite one another and, on the other side, the contact-pressure plate. The flywheel mass arrangement and the contact-pressure plate are coupled with one another in a torsionally elastic manner with reference to the axis of rotation in order to limit the peak torque transmitted through the friction clutch. For this purpose, the flywheel mass arrangement is preferably constructed as a two-mass flywheel.
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RELATED APPLICATIONS
[0001] This application claims priority to provisional application Ser. No. 61/105,619 filed Oct. 15, 2008, the contents of which are incorporated herein by reference.
FEDERALLY SPONSORED RESEARCH
[0002] National Institutes of Health (NIH) R01GM085457 Institute for Collaborative Biotechnologies from the U.S. Army Research Office
BACKGROUND OF THE INVENTION
[0003] This invention relates to methods and apparatus for measuring a property such as mass, size or density of target particles, and more particularly to such measurements using a Suspended Microchannel Resonator (SMR).
[0004] Precision measurements of nanometer- and micrometer-scale particles, including living cells, have wide application in pharmaceuticals/drug delivery, disease studies, paints and coatings, foods, and other major industries and fields of research. This need is growing due to the expanding use of particulate engineering across these industries, to emerging nano- and micro-particle manufacturing techniques, to the need to better understand and treat diseases, and to recent regulations governing quality control in the pharmaceutical industry.
[0005] A variety of particle sizing and counting techniques, such as light scattering, Coulter Counters and others are known in the art. These techniques are embodied in commercial instruments and are used in industrial, medical, and research applications. Although such techniques have proven utility, they have limitations, which limit their applicability. Relatively recently, particle detection and measurement based on the use of SMR's has been developed, and shows promise of going beyond some of the limitations of conventional techniques. The SMR uses a fluidic microchannel embedded in a resonant structure, typically in the form of a cantilever or torsional structure. Fluids, possibly containing target particles are flowed through the sensor, and the contribution of the flowed material to the total mass within the sensor causes the resonance frequency of the sensor to change in a measurable fashion. SMR's are typically microfabricated MEMS devices. Using microfabricated resonant mass sensors to measure fluid density has been known in the literature for some time [P. Enoksson, G. Stemme, E. Stemme, “Silicon tube structures for a fluid-density sensor”, Sensors and Actuators A 54 (1996) 558-562]. However, the practical use of resonant mass sensors to measure properties of individual particles and other entities suspended in fluid is relatively recent, as earlier fluid density sensors had insufficient resolution to detect and measure individual particles at the micron and submicron scale.
[0006] In a body of work by common inventors and owned by the assignee of the current application, miniaturization and improvement of several orders of magnitude in mass resolution has been demonstrated. Development in the microfabrication recipes, the fluidics design, and measurement techniques are described in a number of co-pending patent applications and scientific publications. In particular U.S. patent applications, Ser. Nos. 11/620,320, 12/087,495, and 12/305,733 are particularly relevant and are incorporated by reference in their entirety. Also of relevance is a publication by some of the current inventors, [T. P. Burg, M. Godin, S. M. Knudsen et al., “Weighing of biomolecules, single cells and single nanoparticles in fluid,” Nature 446 (7139), 1066-1069 (2007)] By using the microfabrication techniques described in the references, SMR sensors have been fabricated with mass resolution of less than 1 femtogram (10 −15 g). This resolution is sufficient to detect and measure the mass of individual particles in the range of several nanometers up to many microns in size, including living cells.
[0007] Despite the progress made in SMR design and measurement techniques, further improvements are desirable, particularly for applications involving small numbers of, or individual, particles or cells. Signal to noise can still limit the application of the technique, and both for better signal characteristics as well as expanding the range of applications, it is desirable to control the positioning of particles within the resonator. In addition it is highly desirable to measure the density of a particle, as discussed in the earlier references for characterization purposes. The present invention discloses apparatus and methods for improved particle measurement utilizing SMR's.
SUMMARY OF THE INVENTION
[0008] In one embodiment, the invention is an SMR with a main channel and an additional channel with it's own pressure controlled port. The additional channel is in fluid communication with main SMR channel and has a particle trap. The pressure can be controlled in the additional channel to either cause flow from the main channel into the trap to trap a particle, or to cause flow away from the trap into the main channel to release the particle.
[0009] In various aspects of the embodiment, the trap may be a slit or a sieve of any orientation, but preferably oriented horizontally or vertically to the plain of the SMR. In typical implementations, the channel dimensions are in the range of 10 20 microns in cross section, while the trap dimensions are on the order of one micron.
[0010] In other embodiments, one or more posts leaving small gaps, preferably on the order of a micron are disposed across a region of the flow channel to trap a particle.
[0011] In other embodiments the invention is a method of measuring the density of a particle by measuring the particle's effect on the resonant behavior of SMR's in fluid carriers of differing fluid densities. In one aspect, two (or more) SMR's are plumbed in series. A target particle is flowed through a first SMR in a fluid of a first density and the resonant effect is measured. In between the first and a second SMR, the carrier fluid density is changed and the resonant effect is measured on the second SMR with the particle in the modified density carrier, and the density is computed from the two measurements.
[0012] In another aspect using an SMR with a particle trap, a particle is trapped in the SMR, allowing the carrier fluid density to be changed with the particle remaining trapped, enabling difference measurements as above. A preferred technique to change carrier density is to mix in fluid with a different density with the first density fluid between measurements.
[0013] In another embodiment, an SMR is used as a Coulter Counter. Electrodes are placed in two electrolyte reservoirs connected by the micro channel of an SMR. Current is measured between the reservoirs. A particle that enters the SMR will reduce the current level by an amount that depends on the particle's volume. The same particle introduced into the SMR carried by the electrolyte will affect the resonant behavior proportional to their total buoyant mass. Thus particle density may be directly calculated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will be better understood by referring to the following figures:
[0015] FIG. 1 is a schematic illustration of a Suspended Microchannel Resonator configured with an additional channel and particle trap.
[0016] FIG. 2 depicts other trap geometries compatible with the SMR of FIG. 1 .
[0017] FIG. 3 is a schematic illustration of post traps according to the invention.
[0018] FIG. 4 is schematic of a set-up utilizing serial SMR's and a capability to change carrier fluid density between the SMR's.
[0019] FIG. 5 is a graph showing sample data obtainable from the set-up of FIG. 4 .
[0020] FIG. 6 is schematic of a set-up utilizing an SMR with a particle trap and a capability to change carrier fluid density between measurements.
[0021] FIG. 7 is a graph showing sample data obtainable from the set-up of FIG. 6 .
[0022] FIG. 8 is a diagram of a set-up where an SMR is used as the bypass channel for a coulter counter.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The embodiments described herein are improved apparatus and methods that can be implemented using the microfabrication techniques and fluidics disclosed in the documents referenced and other publications available at the time the invention was made. Since those aspects of the invention do not contribute to the novelty, they are not described in detail. For instance novel versions of the SMR's may be produced with mask changes in the microfabrication process. Similarly the fluidics, data acquisition, and data processing steps can be accomplished with straightforward changes to set-ups previously disclosed. The novelty of the current invention lies in the arranging of the physical SMR geometries and measurement steps to achieve significantly improved results. Also the term particle is interchangeably used in this application to mean any particulate substance, including cells, and particularly live cells in a suitable carrier fluid. Thus particular embodiments may be described in terms of cells and others in terms of particles, but it is to be understood that no embodiments herein disclosed are restricted to a particular type of particle.
[0024] Referring to FIG. 1 , a typical cantilever shaped SMR 1 has a microfluidic channel 2 with ports P 1 and P 3 , whose pressure is controllable to cause fluid flow through the channel 2 . A novel additional channel 3 , which connects with channel 2 , with it's own Port P 2 , is added for this embodiment of the invention. The pressure of Port P 2 can be adjusted relative to P 1 and P 3 to either divert flow into channel 3 , or cause flow from channel 3 into channel 2 . Thus when a particle 4 is introduced into the carrier fluid in channel 2 , the pressure at P 3 may be adjusted to cause particle 4 to divert into channel 3
[0025] As shown, channel 3 may include a trap geometry smaller than the channel dimensions, sized to trap particles in a size range of interest. Thus particle 4 may be held within the SMR 1 for a long period, which enables a wide variety of potential applications which will be described herein and in other co-pending applications. When desired, the pressure at P 3 may be adjusted to push particle 4 away from the trap and into the flow in channel 2 carrying the particle out of the SMR 1 . This the novel SMR provides precise trapping control without the need to back flush the SMR to remove the particle as is the case in previously disclosed SMR particle traps.
[0026] FIG. 1 depicts the trap as a vertical slit. FIG. 2 shows other trap arrangements such as a vertical sieve and a horizontal slit. Other possible shapes and orientations for traps would also work from a functional standpoint as long as it is sized appropriately. However the micro fabrication processes used favor rectilinear features, which are oriented either vertically or horizontally to the plane of the SMR, so such arrangements are preferred. Although dimensions of the channels and traps may vary as needed within the microfabrication process design rules, channel cross section dimensions on the order of 10-20 microns, and trap dimensions with openings on the order of 1 micron have been found to be useful, particular for cells. For the case of a cantilever shaped SMR, the most sensitive measurement region is near the free end, so the traps and channels should be arranged accordingly as shown. However one skilled in the art will recognize that there is latitude in the precise placement of the structures. For other SMR geometries, the trap should be placed near the measurement sensitive region as appropriate for the geometry.
[0027] FIG. 3 shows another novel trap geometry used in a conventional single channel 2 , two port SMR 1 . In this embodiment the trap consists of one or more posts spanning a dimension of channel 2 . The posts are advantageous because it's harder for softer particles such as cells to be pushed through by the applied pressure.
[0028] Trapping a particle has many obvious measurement advantages, such as allowing multiple measurements with the particle in a repeatable location, providing benefits such as the ability to average measurements, or observe particle characteristics change over time. Another desired improvement is to take data in a fashion that allows density to be measured. A method to accomplish this measurement is shown in FIG. 4 . Two (or more) SMR's 1 a and 1 b are plumbed serially such that fluid flow passes through them sequentially. A fluid of a first density 5 is introduced into channel 2 along with particle (or cell) 4 . A resonator measurement is made while particle 4 is in SMR 1 a. Between the resonators, the fluid density is changed. A preferable technique to change the fluid density is to mix at 7 a fluid 6 of a different density at at least one known ratio, thus providing a fluid flowing in SMR 1 b of a known different density than flows in 1 a. When particle 4 is in 1 b, the resonant measurement is repeated. Assuming SMR's 1 a and 1 b are nearly identical or any disparities are calibrated out, the measurement of the buoyant mass from each cantilever can be used to determine the particle's density, volume and absolute mass (as depicted in FIG. 5 ).
[0029] Sample data obtained from a set-up such as in FIG. 4 is shown in FIG. 5 for the case where the particles are cells. FIG. 5 shows that by measuring the cell's buoyant mass in solutions of two different densities (in the case shown, the cell has either a positive or negative buoyant mass), it is possible to calculate its density, total mass, and volume.
[0030] FIG. 6 depicts another set-up for practicing the buoyant mass differential fluid density method, utilizing an SMR 1 with a trap. The particle 4 is trapped, and then measurement(s)are made at a first fluid density 5 , the density is changed and the measurements are repeated. Again the mixing at 7 of Fluid 6 with fluid 5 is a preferred technique to change the density of the fluid in channel 2 . FIG. 7 shows corresponding sample results from this set-up to the results in FIG. 5
[0031] Another novel SMR set-up for measuring density is shown in FIG. 8 . Two reservoirs containing an electrolyte have electrodes placed in them. The electrodes are connected to Coulter Counter electronics, known in the art. The fluidics channel of an SMR is plumbed as the Coulter bypass channel as shown. Particles, in this case cells, introduced into the SMR will have their total buoyant mass measured by their effect on the resonant behavior. The same particles will have their total volume measured by the Coulter effect. Thus particle density can be directly calculated as shown in the Figure.
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Methods and apparatus for improving measurements of particle or cell characteristics, such as mass, in Susppended Microchannel Resonators (SMR's). Apparatus include in particular designs for trapping particles in SMR's for extended measurement periods. Methods include techniques to provide differential measurements by varying the fluid density for repeated measurements on the same particle or cell.
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FIELD OF THE INVENTION
The invention relates to a method for monitoring yarn run/stop conditions.
BACKGROUND
According to a method as known from DE-A4 417 222 (U.S. Pat. No. 5,477,892) the working sensitivity level of each of a group of weft yarn feelers is adjusted by inputting the yarn quality into a selector device having pre-set sensitivity level adjustments associated to different yarn qualities. Any set working sensitivity level is used unchanged during operation of the weaving machine. Although yarn quality is decisive for the working sensitivity level adjustment a predetermined and unchangeable adjustment of the sensitivity level has to be a compromise and does not consider further parameters also of influence for the needed working sensitivity level. For example, for a given yarn quality (yarn number) the response behaviour of an electronic weft yarn feeler varies depending from the surface quality, material flexibility and roughness of the yarn, the linear specific mass of the yarn, yarn tension and yarn speed, and moreover varies due to other parameter variations arising during weaving from the weaving behaviour or special design of the weaving machine. Such parameters are e.g. yarn tension variations, braking variations, yarn oiling, temperature, humidity, etc. A predetermined working sensitivity level strictly associated to the yarn quality precautionary has to consider all said parameters with their worst possible influence and thus is far too high. An unnecessarily high working sensitivity level, however, leads to missing stop signals because the best sensitivity level adjustment is the lowest sensitivity level that can avoid false stop signals.
Furthermore, it is known from practice on some rapier weaving machines to provide a possibility on the main control panel to select and vary different working sensitivity levels or amplification factors for the piezo-electric weft yarn feelers. Each working sensitivity level can be adjusted by the operator. However, this needs advanced skill and attention by the operator but only can lead to a working sensitivity level adjustment which for safety reasons has to be higher than actually needed.
It is a task of the invention to provide a method of the kind as disclosed allowing to reliably operate the weaving machine with an optimum working sensitivity level for each weft yarn feeler without the necessity to carry out remote adjustments.
Each respective weft yarn feeler is automatically and continuously adjusted to an optimum working sensitivity level for the respective weft yarn. Due to the automatic adjustments of the working sensitivity level not only the yarn quality but all other effectively occurring and varying parameters are considered continuously. According to the method the effectively used working sensitivity level is oscillating about an optimum adjustment level in the most decisive moments of an insertion cycle. This means that the sensitive level is permanently adjusted to the summary of all influencing parameters such that it fits to the instantaneous conditions and will follow any developments for better or worse. This eliminates false stop signals and avoids stops of the weaving machine only caused by a too low sensitivity level.
According to the invention the periodic procedures of the weft insertion is taken care of by carrying out adjustments on the basis of sampling the detected run output signals synchronised with said periods. It can be convenient to monitor the run output signal and to control the amplifier's gain individually for the feeler by multiplexing the signals and by assigning a time slot for each channel. Alternatively, it is even safer to observe the run output signal of the weft yarn feeler in two different time slots and by using two different sensitivity levels, namely the higher working sensitivity level used to confirm the run/stop conditions and the lower observation sensitivity level to observe if said lowered sensitivity level could lead to a stop.
According to the invention the lower observation sensitivity level is used to investigate safely if the lowered sensitivity level would not generate a false stop. If it turns out at the lower observation sensitivity level that the observed run output signal is stable this is taken as the confirmation that both sensitivity levels now can be lowered without the danger of a false stop. This is continued until the output run signal starts to become unstable at the observation sensitivity level. This then is taken as a proof sign to not further lower both sensitivity levels, but to now raise both sensitivity levels for a predetermined amount in order to stay on the safe side. Since the adjustment method is carried out continuously the effectively used working sensitivity level will oscillate around an optimum sensitivity level for the weft yarn in question and with consideration of all further influencing parameters.
Advantageously the difference between the present working and the observation sensitivity level is maintained essentially constant and just big enough to avoid undesirable machine stops.
In order to avoid extreme sensitivity level adjustment behaviour, it is advantageous to lower both sensitivity levels only after a predetermined number of consecutive insertion cycles have occurred with the run output signal at the lower observation sensitivity level maintaining stable. Only after having registered said number of consecutive insertions cycles with stable output signal behaviour both sensitivity levels commonly are lowered by a certain amount.
Advantageously both sensitivity levels are raised, also by a predetermined amount only, in case that an observation confirms an instability of the run output signal. In combination this means that lowering both sensitivity levels only is only carried out after first confirming a predetermined number of correct insertion cycles, but both sensitivity levels immediately are raised in case of occurring signal instability. As long as the run output signal at the lower observation sensitivity level remains stable both sensitivity levels are lowered step by step in order to approach an optimum working sensitivity level as soon as possible.
Both sensitivity levels may either be raised and lowered always by one step or for a predetermined time interval.
In order to maintain the effectively used working sensitivity level close to an optimum sensitivity level it is expedient to have only one step difference between the working sensitivity level and the observation sensitivity level.
In order to achieve a high resolution of the adjustment it is preferred to use about 32 steps. Each step represents an individual signal amplification factor meaning that the adjustments carried out actually is a step-wise variation of the amplification factor.
According to a preferred embodiment of the method the run output signal within the restricted observation interval of each insertion cycle is sampled in different adjacent time slots for both sensitivity levels. Said method can easily be carried out with a microprocessor or microcontroller using the same circuitry for the observation as is used for gaining the working signal output. This means that the microprocessor of the weft yarn feeler is consecutively switching back and forth between both sensitivity levels without the danger of losing any significant run output signal variations.
Preferably the observation interval is restricted to an angle range of a full revolution of the rapier weaving machine beginning at about 220° to 280° and ending at about 280° to 310°. This means that the observation is carried out within essentially the angle range used to evaluate the correct run/stop conditions as well. Within said angle range in a rapier machine relatively smooth speed and tension variations are occurring in the yarn, which is advantageous for the reliability of the method.
In case that a weft yarn feeler device consisting of several weft yarn feelers is used, either each individual weft yarn feeler is controlled individually or the result of the observation of one of the weft yarn feelers is used to also adjust the working sensitivity level of other weft feelers processing an equal yarn or the same yarn quality.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with the help of the drawing.
FIG. 1 is a schematic view of a yarn processing system containing a weft yarn feeler device.
FIG. 2 is a block diagram, schematically indicating the line-up of an essential part of a yarn feeler.
FIG. 3 is a diagram with signal chains.
DETAILED DESCRIPTION
A yarn processing system in FIG. 1 includes a weaving machine M, particularly a rapier weaving machine, further at least one yarn feeding device F, and a weft yarn feeler device W e.g. consisting of several parallel weft feelers S. Said rapier weaving machine M includes a shed 1 , a bringer rapier 2 and a receiver rapier 3 , both driven by drive mechanism 4 , a main control and/or monitoring unit C and a weaving machine control panel 5 . Close to the entrance of shed 1 a yarn selecting device 6 is provided which is controlled by e.g. control unit C. Weft yarn feeler device W is connected e.g. to control unit C and/or to the feeder's control or a so-called stop-motion relay.
Each weft yarn feeler S in FIG. 2 can be in the form of a yarn guiding element 7 containing e.g. a piezo-electric sensor 8 . The weft yarn Y is penetrating said weft yarn feeler S and is exciting the piezo-electric sensor 8 by friction forces or vibrations to which sensor 8 responds by generating an electric run signal. Said run signal is amplified by an amplifying component A, 9 , outputting a run output signal as long as the yarn keeps on running through element 7 . As soon as the weft yarn Y becomes slack or breaks no run signal will be output. A microprocessor MP for evaluating the run output signal is connected to a signal evaluation or responding component C′. e.g. a stop switch. Microprocessor MP is provided with e.g. 32 steps representing different sensitivity levels in a table or a storing part D, which. e.g. via a driver or shift register is connected to amplifier component A, 9 in order to set or vary the amplification factor or sensitivity level by consecutive positive or negative steps as +1 or −1. Furthermore, microprocessor MP or any advanced circuitry 10 is connected to amplifier component A, 9 in order to selectively operate amplifier component A, 9 with one of two different sensitivity levels Hi, Lo, i.e. a higher working sensitivity level Hi and a lower observation sensitivity level Lo out of the e.g. 32 available levels. Furthermore, microprocessor MP can be equipped with a clock, a counter and a setting section for setting several different parameters like a sync-setting depending on the weaving machine operation, an angle setting for cutting out a restricted angle range of a full 360° revolution only, e.g. of the main shaft of the weaving machine, a yarn quality setting YQ and a counter setting for a predetermined number of consecutive insertion cycles Nmin.
FIG. 3 shows in diagrammatic form in upper curve 12 how the run output signal is behaving over a 360° insertion cycle of the weaving machine. A higher level in curve 12 indicates the correct yarn run, the lower level of curve 12 represents a yarn stop or extreme deceleration. Signal chain 12 is used to trigger e.g. switch component C′ in FIG. 2 in order to confirm a correct weft yarn run and stop condition during an insertion cycle. Curve 12 is derived at said higher present working sensitivity level Hi. This can be done by additionally considering a sync-signal indicating when said weft yarn Y is expected to run and when not.
Lower curve 11 indicates how the same run output signal is evaluated at a lower observation sensitivity level Lo in order to observe and find out whether the run output signal is stable within a restricted observation range X. Said observation range X may be restricted to an angle range between 220° and 310° of a full 360° weaving machine cycle. In the first part of the same insertion cycle, e.g. between 0° and 220° neither of both signal chains 11 , 12 is considered or evaluated for the actuation of switch component C′ or to observe whether the run output signal is stable.
Curve 11 is shown in FIG. 3 when the lower observation sensitivity level Lo has been lowered too much, i.e. is too low in order to gain a stable run output signal. This is indicated by signal chain variations or instabilities 13 indicating that within observation range X the signal quality is not satisfactory.
The effectively used working sensitivity level Hi according to one of the available steps is adjusted to an optimum but nevertheless safe sensitivity level as follows:
The weaving machine M starts operating and is consuming weft yarn Y as monitored by weft yarn feeler S. The parameters as indicated in FIG. 2 are set in microprocessor component MP, 10 . Weft yarn feeler S first is adjusted to operate with a high working sensitivity level Hi. Provided that for Nmin consecutive insertion cycles run output signal 11 does not show instabilities 13 within range X both sensitivity levels are lowered by one step. It then is observed over the next consecutive number Nmin whether instabilities 13 occur. If not, both sensitivities again are lowered by one step. This is continued until instabilities 13 occur during observation in range X. If yes, both sensitivity levels immediately are raised by one step. Then again it is observed whether for Nmin consecutive insertion cycles instabilities 13 will occur. If no instabilities occur again both sensitivity levels are lowered by one step and so on. Said method is carried on during the operation of the weaving machine M such that the effectively used working sensitivity level Hi always will oscillate around an optimum sensitivity level.
The end point or angle of the observation range X has to be the same angular position at which the weaving machine control unit C stops to consider the output of weft yarn feelers to generate a weaving machine stop signal. Said end position furthermore is related to the position where the receiver rapier 3 releases the weft yarn Y. The weft feeler S with its control circuit is using two different sensitivity levels, namely the higher working sensitivity level Hi and the lower observation sensitivity level Lo, both preferably differing by one step only. However, it is possible to use other bigger and smaller differences as well. Said observation can be carried out for one weft feeler S only and can be used to adjust the sensitivity levels of other adjacent weft feelers as well, provided that they are processing the same yarn quality. However, alternatively each weft feeler provided can be adjusted individually. If the weft yarn is broken, the output run signal (curves 11 and 12 ) will drop within the observation interval or range X and a machine stop will be commanded by the machine control unit C or the stop motion relay. The continuous adjustment of the sensitivity level effectively used is necessary to compensate for parametric fluctuations during the weaving operation. The run output signal is checked in different and adjacent time slots at two different sensitivity levels. A run output signal is still found to be stable at the observation sensitivity level if all samples within the defined observation interval confirm that the yarn is running. The stability observation is done by the same circuitry as used for the normal monitoring of the weft yarn run. Said circuitry however is used with two different sensitivity settings in different times. It is useful to use a high number of different sensitivity levels, e.g. 32, for a better resolution. The microcontroller or microprocessor MP as used should be powerful enough for carrying out the method throughout the entire operation of the weaving machine. Parametric variations causing signal fluctuation during weaving might occur due to yarn tension variations, braking variations, varying yarn oiling conditions, varying temperatures and varying humidity. The run output signal is observed between e.g. 220° and 310° of a 360° weaving machine cycle due to the fact that the most critical phase of the weft yarn monitoring is the end phase of the weft yarn control, usually set near the opening position of the receiver rapier gripper which causes the yarn speed to decrease to zero. Incidentally, in this range a relatively moderate speed profile is present. However, it is not necessary to concentrate on this small range, because the method uses more cycles or consecutive numbers of correct insertions to decide whether a sensitivity level downshift is justified, instead of basing the decision only on a single signal evaluation. The working sensitivity level is lowered step by step together with the observation sensitivity and must not be held at the start level until a convenient lower sensitivity level has been adjusted.
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A method of monitoring the weft yarn run/stop conditions during each insertion cycle in a shuttle-less weaving machine like a rapier or projectile weaving machine by means of an electronic weft yarn feeler generating run output signals representing said weft yarn run condition, said weft yarn feeler including means to adjust the working sensitivity level, comprises that the present working sensitivity level effectively used for confirming run output signals continuously and automatically is adjusted during operation of the weaving machine to oscillate about an optimum and safe working sensitivity level by observing within a predetermined restricted observation interval of each insertion cycle the signal stability at an observation sensitivity level lower than the present working sensitivity level and by lowering or raising both said present working and observation sensitivity levels in dependence from output signal stability.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the art of doors, windows and other closures. More particularly, the present invention relates to a rigid construction (and the method for making that construction) for sliding closures designed to avoid difficulties previously experienced with such closures during sliding.
2. Description of the Prior Art
Sliding doors and windows are typically fabricated from extruded aluminum formed in a rectangular configuration. It is conventional to form a corner for such closures by cutting two lengths of the aluminum channel material with a bevel and butting the beveled cuts together to form an L-shaped corner. The corner may be fastened by L-shaped brackets on either (or both) the inside or the outside of the corner, with fasteners joining the bracket to each side of the corner.
It is also known to provide an insert having an outer diameter configured to the inner diameter of the channel, and sliding the insert into the channel to bridge the slot between the two lengths of channel material forming the corner material. The insert is then held in place by a mating extrusion or similar means.
There are certain uses of sliding closures where the above-described corner constructions have proven to be unsatisfactory. Of particular significance are uses for screened patio and porch doors designed to slide along horizontal tracks. Such doors typically have rather long vertical and horizontal dimensions, and carry a flexible material (i.e. screen) which does not impart any rigidity to the overall structure. As a result, such doors are particularly susceptible to twisting and distorting forces caused by any binding in the bottom of the track (where the weight of the door is supported). Since such doors are usually outside, binding frequently results from leaves, dust and the like which are lodged in the bottom track. When this happens, the twisting and distortion may cause the corners of the door to become out of square, resulting in binding.
SUMMARY OF THE INVENTION
The present invention contemplates a rigid construction for sliding closures which is designed to overcome the problems discussed above.
The method of the present invention is designed to make a rigid closure construction for a sliding door, window or other closure from a length of channel material, and includes the steps of forming a lateral V-shaped slot in the channel, leaving an outer web of the channel material between the sides of the slot. The channel is then bent laterally along the web so that one side of the slot abuts the other side, while extending a corner lock through the channel and bridging the slot. Fastening means are provided extending through the channel and the corner lock for rigidly connecting the two sides of the corner together with the corner lock.
Preferably, the corner lock is provided with an expander operable to expand the lock into a tight fit within the aluminum length upon insertion of a fastener.
In a preferred embodiment of the method of the present invention, the door is fabricated from a length of extruded tubular aluminum channel material through which four mitered cuts are made in order to create all four corners of the door. The extruded tubular aluminum channel has two parallel screw bosses extruded integrally therewith and extending along the inner surface of one side. The fasteners for interconnecting the opposite sides of each mitered corner and the corner lock extend into one or the other of these screw bosses.
The present invention is also directed to a particular sliding door construction incorporating the rigid corner construction, and further contemplates that at least two of the corners, along the bottom of the door, are provided with wheels positioned in close proximity to a respective bottom corner.
In a preferred embodiment of the construction of the present invention, the corner lock is provided with a screw boss extending parallel with the expander, permitting an additional fastener to be extended through that screw boss for further rigidity.
THE DRAWING
The present invention will be described in detail below with respect to the accompanying drawing.
FIG. 1 is a front view of a length of aluminum channel material prior to fabrication of a screen door in accordance with the present invention.
FIG. 2 is a cross-section of the length of channel shown in FIG. 1.
FIGS. 3 and 4 are front and cross-sectional views, respectively, of the corner lock in accordance with the present invention.
FIG. 5 is a front view of a portion of the construction of FIG. 1, illustrating one step in the method of manufacture.
FIG. 6 is a front elevation, partially cut away, of a sliding screen door manufactured in accordance with the present invention.
FIG. 7 is a perspective view illustrating a corner portion of the sliding door of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the rigid closure construction in accordance with the present invention will now be described, and with specific reference to the preferred method of manufacture.
Noting FIGS. 1 and 2, the starting material for the screen door comprises an elongated length of extruded aluminum channel, referred to by the reference numeral 10, formed in a generally rectangular cross-section configuration. The channel includes two opposing side walls 12, 14 with a screen spline 22 extruded with the channel 10 along the outside surface of side 12, and with a pair of parallel, longitudinal screw bosses 16, 18 extruded along the inside surface of the side 12. A pair of rails 20 extend outwardly and are extruded integrally with the second side 14 (note FIG. 2).
Initially, the length of channel 10 is provided with four 90° miter cuts laterally through the channel at predetermined spaced intervals along its length, each cut extending through the one side 12, and forming opposing sides of the respective miter cut which are identified in FIG. 1 as follows: a first cut obtains mitered sides 24, 26; a second cut, sides 28, 30; a third cut, sides 32, 34; and a fourth cut, sides 36, 38. Each mitered cut is extended through the channel 10 but short of the side 14, so as to leave a web 25, 29, 33 and 37 bridging the opposing sides of the respective cut. A vertical cut 27, 31, 35 and 39 is then made in the railings 20 to leave the respective web 25, 29, 33 and 37 as an interconnection between adjacent portions of the channel 10. As is shown in FIG. 1, these portions of the channel 10 are identified by reference numerals 11, 13, 15, 17 and 19.
A next step in the manufacture of the sliding patio door according to the present invention contemplates the insertion of at least two corner locks into the mitered cuts which form the two corners along the bottom of the door after construction. For purposes of this disclosure, these corners are arbitrarily selected as being the corners defined by mitered sides 24, 26 and 36, 38; however, as will be understood by those skilled in the art, the bottom corners may be fabricated at other locations along the channel 10. It will also be understood that the preferred construction will include a corner lock in all four corners of the door.
The particular features of the corner lock in accordance with the present invention are shown in FIGS. 3 and 4. One of the corner locks, referred to by the reference numeral 40, includes a first end 42. As is shown in the cross section of FIG. 4, the corner lock 40 is formed from a length of extruded material having opposing sides 50, 52 with an extension 53 extending normal from the surface 50 into the space between the two surfaces 50, 52. The extremity of the extension has a bevel 55 thereon which forms an expander opening 56 with the opposing side 52. A screw boss 54 is extruded on the outside surface of the extension 53. Preferably, the outside dimensions between the surfaces 50, 52 permit the corner lock 40 to slide through the hollow core of the channel length 10; the precise dimensions of the corner lock 40 are not critical, as the expander 56 provides a means by which the dimension between the opposing sides 50, 52 may be expanded to permit a tight fit. Fastener holes 57 and 59 are also provided in the face 51 between the opposing sides 50, 52 to accommodate fasteners designed to rigidly fasten the corner lock 40 into the corner of the door construction.
Reference is again made to FIG. 1, which shows the two corner locks 40, 44 positioned in the channel 10 adjacent the respective mitered sides 24, 26 and 36, 38. As is there shown, the one end 42, 46 of each corner lock 40, 44, respectively, lies approximately along the center line of the mitered cut. A fastener 41, 45 is then extended through the side 14 of the channel 10 and through the corner lock 40, 44 and then through the expander 56 to effectuate the expansion of the dimension between the sides 50, 52 of the corner lock 40. It will be appreciated that the corner lock 44 on the right side of FIG. 1 is cut from the same extrusion as the corner lock 40, and thus the fastener 45 likewise extends to an expander portion identical to the expander 56 associated with the corner lock 40.
In the next step, the four corners of the door are then formed by bending the channel 10 around the webs 25, 29, 33 and 37. The corner lock (such as corner locks 40, 44) serves as a mandrel during the bending operation.
FIG. 5 shows the bending of the corner formed by mitered sides 36, 38 during this bending operation. It is noted that the corner lock 44 is rendered rigidly joined to the channel portion 11 by the fastener 45.
After the bending of all four corners in a manner similar to that shown in FIG. 5, the resulting door is formed in a generally rectangular configuration such as that shown in FIG. 6.
The steps in the completion of the construction of the sliding patio door in accordance with the present invention will now be described with reference to FIGS. 6 and 7.
Initially, it will be noted that the first two fasteners 41, 45 inserted through the side 14 of the channel lock 10 and into the respective corner locks 40, 44 remain in place; however, for descriptive purposes, the fastener 41 is shown in an exploded view in FIG. 7 which more clearly illustrates the manner in which that fastener 41 extends through the side 14 of the channel 10, through the hole 59 and into the expander 56 of the corner lock 40.
Each corner of the door having a corner lock associated therewith is then provided with three additional fasteners to provide extreme rigidity between the opposite sides of the corner and the corner lock. These three additional fasteners are referred to in FIGS. 6 and 7 by reference numerals 60, 62 and 64. Fastener 60 extends through the side 14 of the channel 10 and thence through hole 57 in face 51 of the corner lock 40, through expander 56 and into screw boss 16. Fastener 62 extends through the side 14 in section 19 of the channel 10 and then into the screw boss 54 of the channel lock 40. Fastener 64 extends through the side 14 of the section 19, between the sides 50, 52 of the corner lock 40 and into that portion of screw boss 18 associated with section 17 of the channel 10. Holes (not shown) along side 14 in section 17 of the channel 10 are positioned between the rails 20, and are indexed with holes 57, 59 of the corner lock to permit access of the fasteners 41, 60. Holes 61, 63 are provided in the side 14 of section 19 outside the rails 20 to permit access by fasteners 62, 64 to the screw boss 61 and screw boss 18 in section 17. As is illustrated, all of the fasteners 41, 60, 62 and 64 comprise threaded sheet metal screws.
Referring now to the bottom right hand portion of FIG. 6, there are three additional fasteners associated with fastener 45, and referred to by reference numerals 66, 68 and 70 correspond to the three additional fasteners associated with corner lock 40, namely fasteners 60, 62 and 64 respectively. The fasteners 66, 68 and 70 serve to rigidly join the sections 11, 13 with the corner lock 44 associated with that corner. Additional fasteners (shown but not numbered with respect to the upper two corners of the door in FIG. 6) may be provided to complete the construction of the door.
Openings along the upper section 15 and the lower sections 11, 19 may be provided to permit the installation of conventional wheel assemblies referred to generally by the reference numeral 72.
It will be noted that the extremities of channel 10 denoted by reference numerals 74 and 76 in FIG. 1 abut each other along the bottom side of the door. Sections 11, 19 of the channel 10 are locked together by a splice gusset 77 having an identical extrusion configuration to that of the corner locks 40, 44 but being somewhat longer. Fasteners 78, 81 extend through the expander section of the splice gusset 77 to firmly lock the gusset in place within the sections 11, 19 of the channel 10.
The patio door shown in FIG. 6 is completed by adding screening 82 locked in the screen spline 22, and a conventional latch 84.
The patio screen door construction of the present invention provides a highly rigid structure not susceptible to the twisting and bending distortions frequently encountered in prior art patio screen doors. It will be noted that the webs 25, 29, 33 and 37 provide a structural strength between adjoining sections of the channel 10, and that the fasteners lock the corner locks 40, 44 to each abutting section in a rigid manner.
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A screen or patio door adapted for sliding along a track in a doorway or other opening includes a generally rectangular frame of extruded aluminum channel having four generally L-shaped corners, at least two of the corners positioned along the bottom of the door and adapted to slide along the track. Each corner is formed by a 90° miter cut leaving a web of aluminum material bridging the cut, and thereafter bending the channel about the web to form the corner. The corners all include a corner lock extending through the channel and bridging the miter, with fasteners extending through the channel. The fasteners extend through and expand the corner lock to fill the channel, thereby forming an inside wall bridging the miter cut and unitizing the corner construction.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to carbonaceous materials that have enhanced properties. More particularly, the present invention is related to carbon material that is made oxidation resistant to temperatures of 900° C. The oxidation resistant carbon materials have an electrically non-conducting surface with significantly enhanced surface hardeness.
[0002] Carbonaceous materials, such as carbon, graphite, carbon-carbon composites, glassy carbon, and the like have many uses. In particular they are useful at high-temperatures where they have excellent mechanical strength. The oxidation of carbonaceous materials in air or oxygen-containing environments at temperatures of 400 to 500° C. has limited its use in high-temperature applications. Otherwise, the easy machinability, low density, good strength, and other properties would lead to carbonaceous materials being the obvious choice.
[0003] Oxidation protection of carbonaceous materials has been directed to coatings and layers that are utilized to reduce the reaction of oxygen with the materials. Exemplary teachings are provided in U. S. Pat. Nos. 4,711,666 and 4,769,074. Often such layers contain silicon or aluminum to help form glasslike coatings during oxygen attack, whereby the glassy layer or glaze will reduce any additional oxidation of the substrate. An inherent concern with coatings is the thermal expansion mismatches between the substrate and coating that often cause delamination and complete coating spallation.
[0004] Another example of oxidation improvement for carbonaceous materials is U.S. Pat. No. 5,368,938, wherein described is the reaction of carbon with gaseous boron oxide to form boron carbide. Still another method of oxidation protection for carbonaceous materials, described in U.S. Pat. No. 5,356,727, is based on “boron carbonitride” designated as CBN, or CBNO if it contains oxygen. CBN is produced by chemical vapor deposition at 700° C. with a mixture of hydrocarbons, boron trichloride and ammonia along with nitrogen or hydrogen carriers at a low as a small fraction of atmospheric pressure, such as a few hundred to a few thousand pascals. The CBN, as described therein, typically has a “metallic appearance” at 50 micrometers thickness.
[0005] Graphite has been coated with “pyrolytic boron nitride” to form boats for metal vaporization, as described in U.S. Pat. No. 4,264,803. In such cases, the boron nitride coating was deposited at 1750 to 2300° C. to a thickness of about 250 micrometers or 0.010 inches. It was found that the geometry of the boat cavity and nearly total encapsulation of the boat held the coating onto the substrate. The tendency of the coating of “pyrolytic boron nitride” to delaminate seems to be the main problem with this type of boat.
[0006] None of the known technologies for improving the oxidation resistance of carbonaceous materials produces a carbon material that is not a coated surface. Integral materials have been heretofore been thought to be difficult to prepare due to the differences in crystal lattice between dissimilar materials. Any blending of materials would generate a unique crystalline lattice which is dissimilar from either starting material. This typically leads to crystallographic defects and dislocations which can create additional, often uncontrollable and unpredictable, crystallographic phases.
BRIEF SUMMARY OF THE INVENTION
[0007] A particular feature of the present invention is the ability to form carbonaceous materials with a hardened exterior that is non-conducting.
[0008] Another feature is the ability to form a relatively soft carboneous item in a desired shape and configuration after which the item can be treated to form an oxidative resistant hard surface without altering the dimensions or structural components of the carbonaceous item.
[0009] These and other advantages, as would be realised to one of ordinary skill in the art, are provided in a carbon material produced by heating a carbonaceous material embedded in a boron nitride precursor.
[0010] Another embodiment is provided in a process for manufacturing a carbon material that has enhanced oxidation resistance and an electrically non-conducting surface. The process involves the steps of embedding a carbonaceous material in a boron nitride precursor and heating the embedded carbonaceous material to a temperature in the range of from about 1600° C. to about 2000° C. at one atmosphere pressure with flowing nitrogen.
[0011] Yet another embodiment is provided in a surface hardened carbonaceous tool prepared by a process comprising machining a carbonaceous blank into a tool precursor, embedding the tool precursor in a boron nitride precursor to form an envelope and heating the envelope to a temperature of at least 1000° C. at one atmosphere of flowing nitrogen to form the carbonaceous tool.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The inventors of the present application have developed, through diligent research, a process for forming an integral oxidation resistance region on the exterior of the carbon and the material formed thereby.
[0013] Essential to this invention is a means of heat-treating carbonaceous materials in a boron nitride production process. Boron nitride production processes are well known in the art, typically involving reaction of boric acid, borates, or boron oxides or the like with ammonia gas or with nitrogen containing compounds such as melamine, urea, dicyandiamide etc. that yield ammonia during heating in nitrogen atmosphere. These processes have been referred to in U.S. Pat. Nos. 4,562,050; 4,784,978; 4,749,556; 5,854,155. A filler, such as calcium phosphate, may be used, as well as additives such as carbon or boron to affect final purity of the boron nitride powder. However, these processes all involve heating to temperatures of around 1000° C. to produce a “turbostratic” boron nitride that then requires further heating to temperatures of 1600 to 2200° C. to obtain good crystallinity and to reduce residual boron oxide.
[0014] The present invention provides a new carbon material. This carbon material is likely a composition of B—N—O—C, resulting from the reaction of those phases present during boron nitride production with the carbonaceous material buried in the reaction mixture. The type of carbonaceous material can be carbon, carbon-carbon composite, glassy carbon, any type of graphite, or virtually any type of carbon material. The interaction of the reactive products of boron nitride precursors, such boron oxides and ammonia or melamine, typically results in incompletely reacted boron nitride that contains considerable oxygen and has varied stoichiometry and crystallinity along with unreacted boron oxide. In the presence of nitrogen, boron carbide does not form. Boron oxides vaporize at temperatures above 1300° C. By heat-treating the carbonaceous material in the reaction mixtures used for making boron nitride, a carbon material is produced with visually the same dimensions and no weight changes from its initial condition. The surface is light grayish-white in appearance. Machined dimensions are retained. Yet the initial carbonaceous material transforms into a distinctly different carbon material, with superior oxidation resistance and an electrically non-conductive surface. The final material is uniquely produced at one atmosphere pressure with flowing nitrogen.
[0015] According to the present invention, a new carbon material is provided that has many advantages over the prior art. The new carbon material exhibits almost no reaction with air to temperatures of 900° C. for many days. The material is distinctly not a coating but an integral surface treatment that is married to the substrate whereby the dimensions are essentially unchanged from their initial dimensions. Any carbonaceous material can be heat-treated in a standard boron nitride powder production process mixture in the presence of nitrogen gas at one atmosphere pressure. The converted surface has an affected depth of about 200 micrometers whereas the first 100 micrometers seem to have mostly changed. Visually the surface is light grayish-black.
[0016] The procedure is similar to metal heat-treating. Any shaped part or component of a carbonaceous material is placed in a powder mixture that is a precursor material for boron nitride. For example, boric acid is normally blended with melamine in a ratio of 2.5 pounds of melamine to 3.5 pounds of boric acid. The carbonaceous material is placed into the mixture so that it is completely covered with the mixture. A graphite boat or container is used to hold this material. Typically, it is heated from room temperature up to 1000° C. for approximately 2 hours immediately followed by heating to 1900° C. for 2 hours. During this period of heating in a nitrogen atmosphere, gases evolve. The gases are mostly ammonia but also include water, carbon monoxide, carbon dioxide, hydrogen, hydrogen cyanide, boron oxide(s), and other species.
[0017] The precursor material for boron nitride comprises a boron 1 compound and a nitrating compound which, when heated together, react to form boron nitride. Preferred boron compounds include boric acid, borates, borax, boron oxides, orthoboric acid, metaboric acid, tetraboric acid, lithium borate, potassium borate, sodium perborate, boron trichloride and ammonium borate. It is most preferred that the boron compound be solid. Boron oxides are particularly preferred as the boron compound.
[0018] Preferred nitrating compounds include ammonia gas, ammonium chloride, urea, melamine, melam, melem, melon, dicyandiamide, ammelide, guanamines such as acetoguanamine, and nitrogen-compound containing salts such as guanidine hydrochloride, melamine hydrochloride, melamine phosphate or malamine oxalate. Melamine is a particularly preferred nitrating compound.
[0019] For graphite parts subjected to the above procedure, weight changes are minimal as are any visual changes in dimensions. Edge retention and shape retention are excellent. Graphite parts have been tested in an air furnace for oxidation to 10% weight loss. This is a standard measurement used to compare effectiveness with graphite oxidation improvements. Oxidation was essentially stopped at 750° C., with no observable weight change after 400 to 500 hours. At 900° C., weight loss reached 10% after 18 to 20 days.
[0020] By post-heating in air for 1000° C. for 1 hour and then testing the oxidation at lower temperatures, such as 750° C., the oxidation resistance is enhanced. At 750° C., the time to reach 10% weight loss was approximately 2000 hours or 80 to 90 days.
[0021] Testing of the heat-treated carbon material in vacuum at 1500° C. showed no weight, dimensional, or visual changes. The surface remained electrically nonconductive in all cases.
[0022] The surface of the new carbon material is not soluble in water or methyl alcohol. While not restricted to any theory regarding the actual chemical composition of the surface and immediate interior the insolubility indicates that the inventive phase is different chemically from boron oxide/boric acid phases. The lack of vaporization at 1500° C. also indicates significant differences from boron-oxygen compounds. The oxidation stability in air greatly exceeds boron nitride. The visual appearance suggests that the new carbon material is probably likely a composition of B—N—O—C, which results from the reaction of those phases present in the boron nitride production processes reacting with the carbonaceous material that is buried in the reaction mixture.
[0023] Any type of carbonaceous material is similarly affected, whether it is carbon, carbon-carbon composite, glassy carbon, carbon or graphite felt, flexible graphite foil (grafoil) such as described in U.S. Pat. No. 3,404,061, or any type of graphite. It appears that the reactive phases from boron nitride production processes react with carbon to produce a carbon material that is unique and not yet characterized herein. The many phases of boron-nitrogen-oxygen-carbon that can be present in liquid, vapor, or gaseous states prohibit the determination of the mechanism of the production of this new carbon material. Since boron carbide does not form in the nitrogen atmosphere that is used for boron nitride production processes, that may drive the composition towards a boron-nitride-like phase. This would account for the observed light grayish-white color, definitely not metallic appearing. Visually, there is no change in the outer dimensions or shape which suggest, without limiting the scope herein, some type of substitution reaction within the crystal lattice of the carbon. Even screw threads are not affected by the heat-treatment and transformation to the new carbon material. The final carbon material does not act in any way like a coated part.
[0024] The observed properties of this new carbon material greatly enhance the potential utility of carbonaceous materials. The surface created with this invention is like a “deep-case” treatment for metals, where the treated surface is integrally bonded to the substrate, essentially married to the substrate and not acting as an independent layer or coating. The underlying carbon has the properties of normal carbon and thus has electrical conductivity that is characteristic of whatever species of carbon is utilized, enabling both electrically conductive and nonconductive surfaces to be available. The affected surface region from the heat-treatment is electrically nonconductive, but that layer can be machined down to leave material that has the characteristics of the un-heat-treated substrate carbonaceous material. For graphite, the substrate is highly electrically conductive.
[0025] It should be noted that the affected surface is much harder than normal graphite or carbon materials or normal hexagonal boron nitride. The surface is easily ground down with silicon carbide wheels, thus indicating it to be softer than silicon carbide.
[0026] Graphite electrodes used for steelmaking have significant consumption due to surface oxidation. This can be prevented with the carbon material of this invention. Electrical conductivity can be achieved by clamps that penetrate the surface to achieve electrical contact with the underlying electrically conductive graphite substrate which remains chemically unaltered in the present process.
[0027] Evaporation boats can be made that are usable in vacuum conditions to 1500° C. and above due to the stability of the surface of this carbon material. There are no problems with delamination since the surface is tightly bonded to the substrate, essentially as if there is no coating but just an extension of the material. Areas needing electrical conductivity, such as where clamping is desired, can be made electrically conductive by machining away the electrically nonconductive affected surface region to expose the electrically conductive graphite substrate.
[0028] For electrical-discharge machining (EDM) electrodes used for hole-drilling, the sides need to be electrically nonconductive while the cutting surface needs to be electrically conductive. This is also achieved by machining away the electrically nonconductive affected surface region to expose the electrically conductive graphite substrate.
[0029] For greatly extended life, pump components, injection tubes, paddles, stalk tubes, etc. used for nonferrous metal melting and casting can be made of this new carbon material. The enhanced oxidation resistance, hardness, and electrical nonconduction of the affected surface provide new usefulness for carbonaceous materials.
[0030] A flash evaporator was prepared in accordance with the invention described herein. The heating cycle was about 2 hours at 950° C. and about 2 hours at about 1900° C. The flash evapator was cross-sectioned for visible inspection. The visible appearance indicated that the chemical transformation was about 200 to 300 micrometers into the carbon. Increasing the time, temperature and exposure is expected to increase the thickness of the converted layer.
[0031] A graphite sample was embedded in melamine and borix acid mix. The coupon was heated to 950° C. for 2 hours. The resulting product oxidized like normal graphite indicating that the reaction did not occur under these conditions.
[0032] Braided graphite, available as braided flexible graphite packing, was treated in accordance with the present invention. The material became less flexible yet the shape and appearance were substantially unchanged. Oxidation properties were consistent with the present invention.
[0033] A sample of 0.1 to 0.125 thick piece of grafoil was treated in accordance with the present invention. The oxidation properties were improved without loss of shape or size.
[0034] While preferred embodiments have been shown and described, it will be understood that it is not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and the scope of the invention as defined in the appended claims.
[0035] The invention has been described with particular emphasis on the preferred embodiments. It would be realized from the teachings herein that other embodiments, alterations, and configurations could be employed without departing from the scope of the invention which is more specifically set forth in the claims which are appended hereto.
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A carbon material is formed by heat-treating a carbonaceous material in a reaction mix of boron oxide or its precursors and ammonia-generating phases such as melamine or its like in a nitrogen atmosphere to temperatures of 1600 to 2000° C. The surface of the carbonaceous material is transformed into a carbon material that is resistant to oxidation to temperatures of 900° C., enabling machined components to be utilized for weeks at that temperature. The carbon material also is stable in inert or vacuum environments to temperatures in the range of 1500 to 2000° C., enabling its use as aluminum evaporative boats and the like.
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FIELD OF INVENTION
[0001] The present invention relates to a device for attaching steel cable sometimes referred to as safety cable (or lock wire or wires) to releasable fasteners and, more particularly, to an adaptable device for tensioning, locking and terminating safety cable while simultaneously ejecting the device from the attached steel cable-fastener assembly.
BACKGROUND OF THE INVENTION
[0002] Various types of machinery are subject to vibration that can loosen nuts and bolts. Lock wire has long been used as protection to resist such loosening. Lock wire secures two or more elements together so that the loosening of one element is counteracted by the tensioned wire running through the elements. Most often in a lock wire configuration, two wire strands are wrapped together and then separated such that one strand goes through the bolt or nut head and the other strand goes around the bolt or nut head; the rejoined ends are twisted together, again, on the exiting side of the nut or bolt and so on. Once the wire strands have been inserted through and around all of the nuts or bolts in a particular grouping, the remaining free ends of the wire strands are secured by twisting the terminated ends of the wire strands together.
[0003] In large part in the area of machinery vibration, the lock wire method of grouping bolts together has been replaced with steel cable (also referred to as safety cable). Steel cable is made from an assembly of steel wire laid (or twisted) into a helix to produce a strong resilient material. Notwithstanding the strength of steel cable, the termination of a steel cable often results in ends which easily fray. Further, the resultant resiliency of the steel cable makes it difficult to secure the terminated ends by twisting the steel cable ends together. As such, the terminated ends of steel cable passed through holes in a series of nuts or bolts subject to operational vibration is usually secured by a ferrule crimped onto the free end of the cable to secure the cable to the assembly.
[0004] In this arrangement, it is often necessary to obtain a predetermined tension on the steel cable looped through the holes in a grouping of nuts and bolts before securing the free end of the steel cable with a ferrule and terminating the excess safety cable. Prior art devices use a pocket into which the ferrule sits where the crimping occurs. This arrangement often requires twisting or other manipulation by the operator to remove the device from the crimped cable-bolt assembly. This movement often compromises the pre-set tension limit on the crimped cable-bolt assembly. It is an object of the present invention to provide a device that allows tensioning of the steel cable to a predetermined limit, ferrule crimping, steel cable free end termination and ejection of the device from the crimped steel cable secured grouping of nuts or bolts without compromising the pre-set tension of the safety cable.
SUMMARY OF THE INVENTION
[0005] A device used for tensioning steel cable to a mechanically set limit (typically on a grouping of bolts on a machine subject to vibration) and crimping a ferrule onto the cable while simultaneously terminating the excess cable and ejecting the device from the crimped ferrule-steel cable assembly when the steel cable has been tensioned to the mechanically set tension limit. The device includes a manual actuator for gripping and pulling the steel cable to the desired tension limit. A mechanical configuration implemented for crimping the ferrule onto the steel cable when the tension limit has been reached. The mechanical configuration being operative to sever the free end of the steel cable and eject the device from the crimped ferrule-steel cable assembly concurrent with crimping the ferrule onto the terminated end of the steel cable.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a top plan view of the prior art bolt head lock wire configuration;
[0007] FIG. 2 is a top plan view of a safety cable system applied using the device according to the present invention;
[0008] FIG. 3 is a top planar view of a device according to the present invention;
[0009] FIG. 4 is an enlarged partial cut away view along axis A-A of the tip portion of the device depicted in FIG. 3 ;
[0010] FIG. 4 a is a partial enlarged top plan view of the tip portion of the device depicted in FIG. 5 ;
[0011] FIG. 4 b is a cross-sectional view of the partial cut away view depicted in FIG. 4 taken along line B-B;
[0012] FIG. 5 is a side plan view of the nose portion of the device according to the present invention;
[0013] FIG. 6 is a side plan view of the tool body portion of the device according to the present invention;
[0014] FIG. 7 is an isometric view of the tensioning assembly associated with the present invention;
[0015] FIG. 8 is a planer view of the tension gripper shaft of the tensioning system associated with the present invention;
[0016] FIG. 9 is a side view of the tension gripper shaft of the tensioning system associated with the present invention;
[0017] FIG. 10 is an isometric view of the tensioning mechanism housing associated with the present invention;
[0018] FIG. 11 is a side view of the tensioning mechanism housing associated with the present invention;
[0019] FIG. 12 is an enlarged planner view of the ratchet mechanism associated with device according to the present invention;
[0020] FIG. 13A-13C are views of the operation of the ratchet mechanism of the device according to the present invention;
DETAILED DESCRIPTION OF INVENTION
[0021] The Present invention will now be described in terms of the presently preferred embodiment thereof as illustrated in the drawings. Those of ordinary skill in the art will recognize that many obvious modifications may be made thereto without departing from the spirit or scope of the present invention.
[0022] A lock wire 18 applied in accordance with the prior art is illustrated in FIG. 1 wherein threaded fasteners 10 , 12 and 14 are engaged with a portion 16 of a rotating apparatus (not otherwise shown). The lock wire 18 comprises two wire strands 18 a and 18 b twisted together at one end are separated such that strand 18 a passes through a transverse opening in fastener 10 while strand 18 b passes around the exterior of the fastener 10 . The strands are twisted together on the opposite side of fastener 10 and, again, one strand passes through a transverse opening formed in fastener 12 while the other strand passes around fastener 12 . The lock wire 18 continues until the last fastener, in this particular instance fastener 14 , whereupon one strand passes through a transverse opening in the fastener, while the other strand passes around the exterior of the fastener. The strands are twisted together on the opposite side of the fastener 14 .
[0023] FIG. 2 illustrates a safety cable system applied using the apparatus according to the present invention. Threaded fasteners 10 , 12 and 14 are once again engaged with the machinery portion 16 . Safety cable 20 comprises a multi strand cable having a motion stop ferrule 22 affixed to end 20 a . Safety cable 20 passes through transverse openings formed in the threaded fasteners 10 , 12 and 14 until ferrule 22 bears against one side of fastener 10 . At this point, ferrule 24 is inserted over the end of cable 20 against the side of fastener 14 , a tension is applied to the safety cable 20 and the ferrule 24 is crimped onto the safety cable such that it bears against a side of the fastener 14 thereby securing the cable to the series of fasteners through which it is threaded. Safety cable 20 is then automatically trimmed. The pre-determined tension is maintained in safety cable 20 by the contact of ferrules 22 and 24 with the sides of the threaded fasteners 10 and 14 , respectively.
[0024] As best illustrated in FIG. 5 & FIG. 6 , the device according to the present invention comprises a pair of handle members 26 and 28 pivotally attached together via pivot pins 32 and 34 so as to pivot about the longitudinal axis of the pivot pins 32 and 34 toward and away from each other as illustrated by arrows 31 . The handle members 26 and 28 may have cushioned or coated hand gripping areas 26 a and 28 a , respectively.
[0025] The elongated nose portion 46 ( FIG. 5 ) is pivotally attached via pivot pins to handles 26 and 28 at location 32 and 34 . Plunger 50 is captured in the inner cavity of 46 by a spring loaded set screw mechanism FIG. 5 . The proximal end of Plunger 50 sits on the flat of pin 30 pivotally attached to handle members 26 and 28 . Pin 30 engages 50 b . See FIGS. 5 and 6 .
[0026] Elongated nose portion 46 also has a distal end portion 46 b which includes a ferrule receiving opening 48 , the outer most portion of which is open as illustrated in FIG. 5 , the opening including a proximal end 46 adjacent punch driving member 50 and an opposed distal opening 46 b . FIG. 5 . Elongated nose portion 46 has a longitudinally extending, central opening which slidably accommodates crimping punch driving member 50 . FIG. 5 . Driving member 50 has an end 50 a which sits on the flat portion of pin 30 which provides for it to be extended by manipulation of handle members 26 and 28 by pivot pins 32 and 34 . As will be hereinafter explained in more detail, the driving member 50 is movable between a retracted position at which a crimping punch distal end 50 a does not extend significantly into opening 48 and a crimping position at which punch 50 a extends into the opening 48 effectively pushing through into the opening and forcing the ferrule through the opening 46 c so as to crimp the ferrule onto a safety cable extending through the ferrule. FIG. 4A . As will be described below, a cable receiving aperture 70 extends into the bottom of opening 48 . FIG. 4 and FIG. 4B .
[0027] In order to use the device according to the present invention, the safety cable must first be threaded through a ferrule as well as the aperture 70 ; a tension must be applied to the safety cable to a predetermined value; and the ferrule must be permanently crimped onto the safety cable.
[0028] The first portion of the operational procedure may be carried out with the assistance of a ferrule holding cartridge as is generally known to those of ordinary skill in the art. Generally, the ferrule holding member may have a magazine portion defining a storage chamber adapted to accommodate a plurality of ferrules 24 .
[0029] Once the desired amount of safety cable 20 has been pulled through the threaded member 14 , the ferrule 24 and the nose portion 46 , the ferrule holding member, if employed, is removed. At this point, it is necessary to apply a predetermined tension to the safety cable 20 before permanently attaching ferrule 24 to the cable by crimping. This is accomplished by attaching the end of safety cable 20 to a tensioning device, generally indicated in FIG. 7 . The tensioning mechanism is illustrated in FIGS. 7-11 . The tensioning mechanism according to the present invention comprises a one-way rotation mechanism, which may be any known, commercially available device. FIG. 8 . The tension gripper shaft 84 has four slots so that the cable may be locked by being inserted into two of the slots in a 90 degree configuration. FIG. 8 . The winding member 86 is attached to the tension gripper shaft by way of a one-way bearing press fit into a housing 85 . FIG. 8 . The winding member 86 will operate only in one direction so that it can only apply tension to the cable and cannot operate to loosen the cable once the cable is engaged onto the tension gripper shaft. FIG. 7 and FIG. 8 . The winding member is rotated to apply tension to the cable. FIG. 7 . When the desired tension is reached, the one way bearings in the tensioning mechanism prohibits the cable from unwinding from its tensioned position while the ferrule is crimped onto the cable. The winding mechanism is contained in a housing 85 with two set screws 87 which allow the entire tensioning mechanism to slide along the elongated nose piece. FIG. 10 and FIG. 11 .
[0030] Once the proper tension has been applied to the safety cable 20 , the ferrule 24 may be crimped onto the safety cable. This is achieved by manually urging handle members 26 and 28 towards each other. As illustrated in FIG. 6 , such movement of the handle members 26 and 28 will cause pivot pins 32 and 34 to move around their respective axis points and thereby urging pin 30 against which crimping punch driver 50 sits at 50 b . FIG. 5 and FIG. 6 . Such movement causes relative movement between the nose portion 46 and the crimping punch driver 50 . FIG. 5 .
[0031] As best seen in FIGS. 4A and 6 , moving the handles 26 and 28 towards each other will cause driver 50 to move toward the left with respect to nose portion 46 from the retracted position to the crimping position. As specifically shown if FIG. 4A , the extending motion of the crimp punch 50 a , forces the ferrule-cable assembly through restriction 46 d which deforms the ferrule 24 so as to be crimped and permanently attached to safety cable 20 . The restriction 46 d is defined by two flats 46 c . The flats 46 c initially engage the ferrule 24 as it is pushed through the restriction 46 d in order to start the crimping process and reduce the stress experienced in the area of 46 d . This process allows the ferrule 24 to be crimped to the cable 20 before the cable 20 is engaged by a cutting plate 250 shown in FIG. 4 and as described below. The nose piece 46 is plated with a material with a high Rockwell Hardness to facilitate the crimping function and to provide wear resistance, such as HRC 55-66. Specifically, as the ferrule 24 is pushed toward the distal end of 46 , it is initially engaged by the two flats 46 c at the entrance to the restriction 46 d which deforms the outer ring of the ferrule 24 , so that the ferrule 24 and the cable 20 running through it can be pushed through restriction 46 d and thereby crimped and joined together. FIG. 4 and FIG. 4A .
[0032] The detail of the ferrule crimping portion of the tool is illustrated in FIGS. 4 , 4 A and 4 B. The tip of the ferrule crimping punch 50 a (that will come into contact with the ferrule when extended) is slightly angled to an edge at the portion of the tip of the crimping punch 51 a in contact with the cutting plate 250 as shown in FIG. 4 . The tip of the plunger 51 a is fabricated from hard wear resistant material such as carbide; alternatively, this area can be coated with a hard wear resistant coating to improve the wear characteristics of the crimping and cutting portion of the device.
[0033] The crimping punch 50 a slides over hole 70 in nose portion 46 when the punch is extended in the direction of the crimping position towards the distal opening in 46 to assist in the shearing action used to cut the free end of cable 20 away from the ferrule during crimping. As shown in cross section FIG. 4B , hole 70 in nose portion 46 forms a pocket angled toward the direction that the safety cable 20 will enter the device to facilitate the advancement of the safety cable through hole 70 during the drive stroke of the crimp punch 50 . Crimping forces the ferrule 24 to be pushed through opening 46 d in nose portion 46 as it is being forced out of the tool by the crimp punch 50 as shown in FIG. 4A . The relative movement as described above causes shearing of the cable 20 protruding through hole 70 on 46 b by the plate 250 . FIG. 4A . Specifically, a replaceable cutting plate 250 preferably made of hardened metal such as tool steel is provided at the bottom of opening 48 to improve the wear characteristics of the crimping and cutting portion of the tool. FIG. 4A . The plate 250 provides a sharpened edge against which the cable 20 is urged by ferrule 24 during crimping to thereby cause shearing of the cable adjacent the lower surface of the ferrule 24 . FIG. 4B . The plate 250 may be constructed so as to be replaceable to increase service life of the tool.
[0034] In accordance with the embodiment of FIG. 4 , the crimping punch 50 a includes a flattened bottom section 51 b that slides over plate 250 when the punch is extended towards the crimping position to assist in the shearing action used to cut the free end of cable 20 away from the ferrule during crimping. The crimping punch 50 a , of course, is also located so as to be closely adjacent to the bottom of opening 48 next to the cutting plate 250 when the ferrule 24 is being deformed by restriction 46 d by the urging of the crimping plunger. FIG. 4 .
[0035] To ensure that the ferrule 24 is disposed contiguous with hole 70 in the nose portion 46 during crimping, the depth of opening 48 is selected such that the height of a ferrule 24 to be crimped by the tool is always slightly greater than the depth of the opening 48 to ensure that the ferrule, which is disposed between fastener 14 and plate 250 , is pressed through restriction 46 d when the tool is operated as shown in FIG. 4 . The outer flange of the ferrule 24 is disposed in the opening shown in FIG. 4A and gently rests against the sides of the opening 48 in the elongated nose portion 46 before crimping. FIG. 4A .
[0036] An alternative embodiment of nose portion 46 allows for the nose piece to be removed and accepted by many different tool bodies. FIG. 5 . For example, tool bodies operated manually, tool bodies operated electrically or by battery power, tool bodies operated by hydraulic means and tool bodies powered by pneumatic means.
[0037] During the drive stroke of crimp punch 50 , in order to prevent the movement of handle members 26 and 28 away from each other before the ferrule 24 has been permanently attached to the safety cable 20 , ratchet mechanism 112 is provided. As best seen in FIGS. 6 , 12 and 13 A- 14 C, ratchet mechanism 112 comprises a ratchet body 114 attached to handle member 26 via pivot pin 116 . It also comprises a support body 118 attached to handle member 28 via pivot pin 120 . Ratchet member 124 is attached to the support body 118 via threads 126 . Ratchet member 124 also extends through the ratchet body 114 and defines a plurality of ratchet teeth 128 extending over a length of the ratchet member 124 . Ratchet member 124 also defines ratchet grooves 130 located at either end of the ratchet teeth 128 . The depth of ratchet teeth 130 is greater than that of ratchet teeth 128 as illustrated in FIG. 12 .
[0038] Pawl 132 is pivotally attached to ratchet body 114 via pivot pin 134 . Resilient biasing members 136 a and 136 b are located on opposite sides of pawl 132 and exert a biasing force thereon urging it to the central position illustrated in FIG. 12 . Compression spring 138 is operatively interposed between the ratchet body 114 and support body 118 so as to normally urge these elements apart.
[0039] The operation of the ratchet mechanism can be seen from FIGS. 13A-13C . Movement of handle members 26 and 28 towards each other will cause ratchet body 114 and support body 118 to also move towards each other. Thus, ratchet body 114 moves in the direction of arrow 138 in FIG. 13A relative to ratchet member 124 . Pawl 132 defines an engagement edge 140 which, when the ratchet body 114 is displaced towards support body 118 , engages ratchet teeth 128 . The movement of ratchet body 114 will cause pawl 132 to pivot about pivot pin 134 so as to compress resilient biasing member 136 a . This compression will increase the force urging the pawl 132 toward its central position illustrated in FIG. 13 . However, the depth of the ratchet teeth 128 is insufficient to allow the pawl 132 to return to this position.
[0040] Thus, once the engagement edge 140 engages ratchet teeth 128 , it is impossible for ratchet body 114 to move in any direction other than that indicated by arrow 138 in FIG. 14A . This prevents the handles 26 and 28 from being moved apart as long as pawl 132 is engaged with ratchet teeth 138 to prevent partial crimping of a ferrule. Once the handles 26 and 28 have been moved towards each other sufficiently for the crimping punch 50 to have fully crimped the ferrule 24 onto the safety wire 20 , the ratchet body 14 and the support body 118 will be in the positions illustrated in FIG. 13B . In this position, engagement edge 140 of pawl 132 enters the lower ratchet groove 130 which has a depth sufficient to allow the pawl 132 to be returned to its central position due to the biasing force of resilient biasing member 136 a . FIG. 13B .
[0041] Once the engagement edge 140 enters the groove or ratchet tooth 130 , ratchet 114 and support body 118 may move away from each other, as illustrated in FIG. 13C . Movement of ratchet body 114 relative to support body 118 in the direction of arrow 142 will bring engagement edge 140 once again into contact with ratchet teeth 128 . The depth of the ratchet teeth 128 will cause the pawl 132 to pivot about pivot pin 134 and compress resilient biasing member 136 b . This depth, however, is insufficient to allow the pawl 132 to return to its center position. This prevents movement of ratchet body 114 in any direction except that indicated by arrow 142 . Once ratchet body 114 reaches the position illustrated in FIG. 12 , the upper ratchet groove 130 will enable the pawl 132 to be returned to its center position by resilient biasing members 136 a and 136 b.
[0042] Those of ordinary skill in the art will recognize that the embodiments just described merely illustrate the principles of the present invention. Many obvious modifications may be made thereto without departing from the spirit or scope of the invention as set forth in the appended claims.
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An adaptable device for tensioning safety cable to a predetermined tension limit, crimping a ferule onto the cable, cutting the excess cable and ejecting the device from the crimped ferrule-cable assembly. The device compromises a tool body, a cable tensioner and an elongated nose. The cable tensioner comprises a handle for applying tension to a cable inserted into the tension gripper mechanism and a one-way clutch to prohibit movement in a direction which would unwind the cable or lessen the tension applied. The elongated nose has a ferrule receiving aperture for receiving a ferrule and passing the safety cable there through. A plunger is reciprocally operative in the nose piece to crimp the ferrule onto the cable, cut the excess cable and eject the device from the crimped ferrule-cable assembly. The Plunger is actuated either manually or by means of an attached power assisted tool. The elongated nose piece is removable so it can be interfaced with different tool bodies.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the enhanced recovery of oil and more specifically, to a chemically enhanced process for recovering oil in which a gas is injected into an oil bearing formation prior to the injection of the displacement fluid.
2. Description of the Prior Art
The use of gas injection in conjunction with conventional secondary recovery methods such as waterflooding is known. For example, U.S. Pat. No. 3,525,395 describes a process in which the field is subjected to cycles of gas pressurization, production, waterflooding and production until oil recovery becomes uneconomical. The gas injection is intended to restore reservoir pressure and drive oil to the production system. U.S. Pat. No. 3,599,717 describes the formation of a free-gas phase followed by a gas/waterflood which process may take place in cycles.
Carbon dioxide is frequently the gas injected since it is miscible with petroleum, particularly relatively high viscosity petroleum. U.S. Pat. No. 3,586,107 discloses that when a reservoir is swept with carbon dioxide followed by a water drive, a portion of the carbon dioxide is trapped in pores reducing the amount of carbon dioxide available for oil displacement. This undesirable trapping of the miscible slug can be avoided by interposing a slug of inert gas between the carbon dioxide and waterflood.
U.S. Pat. No. 3,599,716 teaches an air slug followed by a slug of water containing a surfactant. The air results in oxidation of crude oil to form in-situ surface active components which are adsorbed on reservoir rock in place of the surfactants in the aqueous flood. U.S. Pat. No. 3,811,501 relates to the injection of carbon dioxide and an inert gas in order to form a miscible transition zone followed by a driving agent which may be water containing a surfactant. U.S. Pat. No. 3,893,511 employs alternating slugs of a gas and a foaming agent.
Finally, an improved tertiary oil recovery process is described in U.S. Pat. No. 3,882,940 wherein a gaseous slug is injected after subjecting the formation to a chemical tertiary recovery step such as a surfactant or micellar flood.
Because of the expense of surfactants and other additives such as thickening agents, the additional oil recovered as a result of chemically enhanced recovery techniques is usually insufficient to offset the added production costs. It would, therefore, be highly desirable to improve the efficiency of surfactant or micellar floods while at the same time being able to employ common surfactants even in hostile environments such as high brine concentration and eliminate the need for thickeners in pusher slugs.
SUMMARY OF THE INVENTION
It has been discovered that the effectiveness of chemically enhanced oil recovery in watered-out reservoirs can be substantially improved by injecting a gas into the formation prior to commencing chemically enhanced oil recovery. Accordingly, the present invention relates to a process for the enhanced recovery of oil from an oil-bearing formation which comprises injecting a gas into the formation in an amount sufficient to attain trapped gas phase saturation, injecting a fluid containing an effective amount of a surfactant to displace oil, driving the fluid through the formation and recovering the displaced oil.
Gases have been injected into oil-bearing formations for purposes such as restoring or maintaining formation pressure, displacement fluids and forming free-gas phases. Carbon dioxide alone or in combination with other gases has found use as a mobilizing aid in high viscosity oil fields. The present pre-injection of minor amounts of gases results in a trapped gas phase which is not displaced by any subsequent liquid floods. The amount of gas which will form a saturated trapped gas phase depends on the nature of the rock and varies from 3 to 30 pore volume %, preferably 10 to 20 pore volume %. Larger amounts may be employed, but gas substantially in excess of about 20 pore volume % is usually displaced by subsequently injected fluids.
The pre-injection of gas before a surfactant or micellar flood has surprisingly beneficial effects on flood performance. Among the factors improved are minimum surfactant slug size, greater residual oil recovery, earlier banking of oil and improved fractional oil flow. The use of a gas pre-injection step permits the injection of low-cost salt sensitive microemulsions directly into high brine reservoirs without fresh water purging and also permits the use of a polymer-free; i.e., unthickened, brine pusher. Moreover, no alternating gas-liquid cycles are required to achieve maximum oil displacement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of the effect of CO 2 and N 2 pre-injection on oil recovery from a Berea sandpack;
FIG. 2 is a graph of the effect of N 2 pre-injection on oil recovery from a Berea sandstone core;
FIG. 3 is a graph of the effect of air pre-injection on oil recovery from a Berea sandstone core with equalized pressure gradients;
FIG. 4 is a graph of the effect of air pre-injection on oil recovery using a brine sensitive microemulsion in a high brine environment;
FIG. 5 is a graph of the effect of air pre-injection on oil recovery from a high brine Berea sandstone core using a salt-sensitive microemulsion and an unthickened or thickened, high brine pusher;
FIG. 6 is a graph of the effect of air pre-injection on oil recovery from a high brine Berea sandstone core using a brine sensitive microemulsion and an unthickened, 1.5% NaCl aqueous pusher;
FIG. 7 is a graph of the effect of air pre-injection on fractional oil recovery from a high brine Berea sandstone core using a brine sensitive microemulsion.
DETAILED DESCRIPTION OF THE INVENTION
In watered-out reservoirs, the oil present is largely immobilized or trapped in the formation by capillary and wettability forces. In order to displace this trapped oil, surfactant floods, especially micellar floods, have been used. The injection of a gas into the formation prior to the surfactant flood substantially improves the performance of the latter. This gas is tightly held in the porous formation since it is not displaced by any subsequent flood under practical flow-rates. Any gas can in principle be used for pre-injection. Such gases are, e.g., air, nitrogen, ammonia, oxygen, carbon dioxide, carbon monoxide, sulfur dioxide, flue gas, exhaust gas, methane, ethane, propane, butane, liquified petroleum gas, natural gas and mixtures thereof.
The gases are preferably nitrogen, exhaust gas or flue gas, which are especially non-corrosive and non-combustible.
The surfactant floods are those known in the art which contain an effective amount of surfactant to displace oil. The surfactants are generally anionic, cationic, nonionic, amphoteric or mixtures thereof.
Anionic surfactants are carboxylates, sulfonates, sulfates and esters of phosphorus acid. Sulfonate and sulfate surfactants are preferred. Ethoxylated and/or propoxylated sulfonates and sulfates are especially preferred because of their increased ability to function at high brine and elevated temperatures.
Suitable cationic surfactants are amines, polyamines and quaternary ammonium salts. Preferred cationics are ethoxylated primary or secondary amines. Quaternary ammonium salts derived from the above cited primary or secondary amines are also preferred.
Nonionic surfactants are ethoxylated derivatives of phenols, amines, carboxylic acids, alcohols, and mercaptans as well as polyhydroxy compounds. Ethoxylated phenols and amines are preferred.
Amphoteric surfactants usually contain an amino group as the basic function and carboxylate or sulfonate group as the acidic function. These surfactants may also be ethoxylated. Preferred amphoterics contain a quaternary ammonium moiety and a sulfonate or carboxylate moiety.
Combinations of anionic surfactants with nonionic or cationic surfactants are preferred, especially combinations of sulfonates or sulfates with ethoxylated amines or ethoxylated quaternary ammonium salts.
The displacing fluid is preferably a micellar solution. A preferred form of micellar solution is that in which the surfactant is combined with oil and water or brine to form a microemulsion. Preferred microemulsions are water-external and derived from the surfactants set forth above.
The surfactant floods may optionally contain conventional additives such as co-surfactants or thickeners. These additives assist in functions such as formulation, brine or temperature tolerance and viscosity control. Examples of co-surfactants include alcohols, phenols, ethoxylated alcohols or phenols which may be sulfated or sulfonated and synthetic sulfonates. Typical thickeners are water soluble polymers such as polysaccharides, biopolymers, and partially hydrolyzed polyacrylamides, fatty acids soaps, alignates, sucrose and the like.
The techniques of surfactant flooding are well-known and are generally initiated after primary and waterflooding procedures have been completed. These methods usually involve a preflush to displace or remove materials which could interfere with the surfactant. A surfactant slug, a thickened pusher, and an unthickened drive water, are then sequentially injected.
In the present process, the preflush step is optional, even when salt-sensitive microemulsions are used. Whether or not a preflush is employed, a gas injection step is interposed immediately before the injection of the surfactant flood. The actual rate of injection is not critical. A rate of between 10 and 30 MMcf/day at a suitable pressure, e.g., 10 2 -10 4 psig is preferred in order to achieve maximum trapped gas phase saturation. The pressure should be maintained at a point below that at which fracturing could occur. Pressures in slight excess of the hydrostatic pressure are preferred; e.g., from 1.1 to 2.5 times the formation hydrostatic pressure.
The surfactant flood may be injected either continuously or in slug mode, and micellar floods are typically employed. The flood is conventionally driven through the field with a thickened pusher slug and may be followed by formation brine.
Surfactant flooding requires a thickened brine pusher in order to provide mobility control so as to avoid fingering effects at the pusher/surfactant flood interface. The process of the present invention differs in that the polymers usually added to provide mobility control may be omitted. This is a further beneficial result of the gas pre-injection step.
Because of the size of a typical oil field, in order to achieve a trapped gas phase over a significant fraction of the field, the use of multiple single completions over the entire formation thickness for gas injection is preferred. The gas is more preferably injected through dual completions with gas being injected through both intervals to facilitate an equalized gas saturation. Most preferably, gas may be injected initially in the lower interval simultaneously with an initial injection of water in the upper interval, followed by gas in both intervals.
One of the factors affecting the performance of gas pre-injection is the configuration of the field. The presence of permeable sands near the bottom of the pay-zone may facilitate gas input. Also a low effective ratio of vertical to horizontal permeability is desirable since this may control the rate at which gas migrates to the top of the sand as it travels from the injection site towards the production site. Finally, a close spacing of wells would be desirable.
It is presently thought that the injection of gas into watered-out reservoirs displaces water from pores and isolates an equivalent amount of pore space. In these depleted reservoirs, all of the oil remaining is largely immobilized, i.e., trapped by wettability and capillary forces. On the other hand, the water or brine which is present can be classified as either immobile or mobile. It is the mobile component of the formation water which is displaced by gas pre-injection, and the gas is effectively trapped as small bubbles by interfacial forces up to the point of trapped gas phase saturation.
When a chemical flood is injected, the surfactant lowers the interfacial tension of the immobilized oil permitting its movement. The trapped gas phase, however, is not affected and continues to isolate a portion of the total pore space available.
The breakthrough of oil occurs earlier by an amount roughly equivalent to the trapped phase saturation. While not wishing to be bound by any particular theory, it is possible that this trapped gas blocks the most water-wet channels and the flow of the flood is through the more oil-wet paths thus permitting increased fractional oil flow and greater recovery. Retrapping of oil may also be minimized. The use of a salt-sensitive microemulsion in a high brine field is possible in the instant process without a preflush. This is probably indicative of a reduced communication and co-mingling of the microemulsion with formation water.
One possible explanation of why an unthickened brine pusher slug can be used in the present process is that the usual tendency of aqueous pusher to move with greater ease in water-wet channels and override the slug of microemulsion in the preferentially oil-wet channels which contain the residual oil is greatly reduced. Thus the trapped gas phase may focus the flow of drive water through pores which transport microemulsion and residual oil.
The observed result is that gas pre-injection can increase the "effective" size of a surfactant slug by a much larger proportion than the pore volume isolated by trapped gas saturation. For any given surfactant slug, substantially more oil will be recovered with than without gas pre-injection which means that optimum oil recovery may be achieved using smaller slug sizes. This is expected to be especially important when dealing with relatively expensive surfactants. By focusing the flow of surfactant through selective oil-containing pores, the effective size (length) of the surfactant bank is increased. While erosion at the rear of the bank is expected to occur due to surfactant mixing with formation brine, the increased effective slug size will permit recovery of recoverable oil before collapse of the entire slug.
The gas pre-injection step and effects on oil recovery are further described by reference to the following examples.
EXAMPLES
Sample Preparation
The sand packs and cores used in the following examples were prepared according to the procedures outlined below:
A. Berea Sand Packs--crushed Berea sandstone was sieved (-40+100 mesh) three times, each for ten-minute intervals. A graduated 100 ml burette was prepared and a filter paper placed at the bottom. Seventy-five grams of sieved sand was continuously added while vibrating and rotating the vertically mounted burette. After capping the packed sand with filter paper, the weight and volume of the sand pack were measured. Following a CO 2 purge, the burette was flooded from the bottom with 40 ml of aqueous phase at 0.20 ml/min and after removing excess liquid, the pore volume can be determined from the weight and known density of the resident aqueous phase. In a similar manner, the burette was flooded with 35 ml of oil and the initial oil saturation (S oi ) determined. A second aqueous flood was then conducted, and the residual oil saturation (S or ) calculated by measuring the volume of oil displaced. After removing excess liquids, the sand pack is ready for tests.
B. Consolidated Berea Sandstone Cores--the core was purged with CO 2 , weighed, and horizontally positioned on a lab jack. The core was flooded with aqueous phase at 10 ft/day and the pressure recorded after steady state flow has been achieved for permeability determination. The weight gain at saturation is then recorded and the core flooded with oil. The initial oil phase saturation can be calculated from the amount of aqueous phase displaced. A second aqueous flood is carried out until no further oil is displaced, and the volume of oil measured for calculation of the residual oil saturation. The relative permeability to the aqueous phase at residual oil saturation is then determined.
EXAMPLES 1-4
These examples demonstrate the effect of gas injection on oil recovery using a microemulsion as displacing fluid. The microemulsion employed to flood the sand pack contained 2 wt.% surfactant, 1 wt.% of a branched 20,000 M.wt. polyethylene oxide (PG20M manufactured by Union Carbide Corp.), 7 vol. % of n-decane and the balance Tar Springs Brine (TSB), which is a high brine aqueous solution containing 92.07 g/l NaCl, 7.89 g/l CaCl 2 , 4.98 g/l MgCl 2 , 0.113 g/l BaCl 2 .2H 2 O, 0.195 g/l NaHCO 3 . The surfactant designated C 18 TAS has the formula: ##STR1## in which x+y=7 and 8, and the weight ratio of a blend of 7:8 ethoxylated surfactants is 20:28.
A watered-out sand pack or core prepared as set forth above is first injected with gas at a rate of about 2 cc/hr with an injection pressure of about 5 psi.
After gas bubbles emerge from the top of the sand pack or core, the volume of brine displaced is carefully noted. A measured volume of Tar Springs Brine is then re-injected and the amount of brine produced recorded. If the latter quantities are equal, then the volume of brine originally displaced by the injected gas is equal to the trapped gas saturation, S rg . If less brine is produced than injected, the original volume of brine displaced is reduced accordingly to calculate S rg .
The microemulsion is then injected at about 1-2 ft./day with the amount of fluid injected, the total fluid displaced, and the amount of oil produced being measured. The injection is usually terminated after 1 pore volume of total fluids have been produced. For comparative purposes, the microemulsion is injected without a gas injection step. The data are summarized in Table I.
TABLE 1__________________________________________________________________________ MicroemulsionTest Injection Surfactant/ PG20M.sup.a Oil/ Aqueous Rate PVExampleSubstrate Gas Amount Amount Phase Injection S.sub.oi S.sub.or S.sub.rg__________________________________________________________________________1 Sand Pack CO.sub.2 C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 1 ft/day 0.62 0.22 0.09 2 wt. % 7 vol. %Sand Pack None C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 1 ft/day 0.56 0.23 0.00 2 wt. % 7 vol. %2 Sand Pack N.sub.2 C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 2 ft/day 0.49 0.18 0.09 2 wt. % 7 vol. %Sand Pack None C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 2 ft/day 0.56 0.23 0.00 2 wt. % 7 vol. %3 Berea N.sub.2 C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 1 ft/day 0.58 0.30 0.22Sandstone 2 wt. % 7 vol. %CoreBerea None C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 1 ft/day 0.62 0.33 0.00Sandstone 2 wt. % 7 vol. %Core4 Berea Air C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 0.98 ft/day 0.48 0.33 0.21.sup.dSandstone 2 wt. % 7 vol. %CoreBerea None C.sub.18 TAS/ 1 wt. % n-decane/ TSB.sup.c 1.70 ft/day 0.54 0.42 0.00.sup.dSandstone 2 wt. % 7 vol. %Core__________________________________________________________________________ .sup.a Branched 20,000 M. Wt. polyethylene oxide. .sup.b Ethoxylated octadecylammonium salt of idodecyl-o-xylene sulfonic acid. .sup.c Tar Springs Brine .sup.d The characteristic permeabilities with and without air preinjectio are 443 and 613 millidarcies, respectively.
FIG. 1 shows that with either a CO 2 or N 2 gas pre-injection (GPI) step, production of oil occurs earlier and is essentially complete by the time one pore volume of microemulsion is injected. In contrast, without gas injection, oil production is delayed and only about 75% of the residual oil is recovered as compared to a 100% recovery with gas pre-injection.
In Example 3, a Berea sandstone core is substituted for a sand pack and as illustrated in FIG. 2, initial oil production commenced at 0.05 pore volume and oil recovery was essentially complete by the time 0.85 pore volume of microemulsion had been injected. Without N 2 pre-injection, oil was not produced until 0.27 pore volume and only about 76% of the residual oil was recovered at microemulsion breakthrough which occurs at 0.93 pore volume.
Also displayed in FIG. 2 are the injection pressures observed upon continuous introduction of microemulsion at the frontal velocity of 1 ft/day. (The injection pressure usually exceeds the pressure that would be sensed 1 inch downstream from the entry face by about 1.5 psi.) The higher pressure recorded for microemulsion flow following N 2 pre-injection is consistant with the decrease in permeability that would attend the isolation of pore space by the trapped gas phase.
In Example 3, the higher oil recoveries achieved with gas pre-injection could conceivably be attributed to the increased pressure gradient which develops at constant flow rate. Example 4, therefore, matches the pressure gradients by adjusting flow rates. FIG. 3 demonstrates that with pressure gradients maintained at approximately the same values for both systems, the core with residual gas phase saturation shows a final oil recovery of 70% compared with a 51% recovery without gas pre-injection even though the former had a 56% lower frontal advance rate (0.98 vs. 1.70 ft/day). The improvement in oil recovery therefore is not due to pressure gradients.
EXAMPLE 5
This example illustrates the effect of gas pre-injection on a brine sensitive microemulsion in a high brine environment. The microemulsion was formulated from 2 wt.% of the monoethanolamine salt of i-dodecyl-o-xylene sulfonic acid (PDM-388), 1 wt.% tertiary amyl alcohol, 7 vol.% of synthetic Loudon crude and the balance 1.5 wt.% NaCl. Synthetic Loudon crude is a 90:10 blend of Isopar M and Heavy Aromatic Naphtha, which are trade names for paraffinic and aromatic oils, respectively, manufactured by Exxon Co.
The above microemulsion is known to perform well in a low salt environment, e.g., 1.5 wt.% NaCl, but poorly at high salt concentrations such as are found in Tar Springs Brine. The tests were conducted in Berea sand packs as described in Example 1. The S oi and S or parameters with and without air pre-injection (API) were 0.63, 0.21 and 0.65, 0.23, respectively. The residual gas phase saturation was found to be 0.08 pore volume.
In FIG. 4, the dotted line shows microemulsion performance under ordinary ideal laboratory conditions; i.e., 1.5 wt.% NaCl (a compatible brine) without gas pre-injection. As can be seen from this figure, even under high brine conditions, this salt sensitive microemulsion performed almost as if it had been injected into a compatible, low salt environment. In contrast, without gas pre-injection (GPI), the results obtained are very poor.
EXAMPLE 6
This example further illustrates the effect of gas pre-injection on a brine-sensitive microemulsion in a high brine environment using Berea sandstone cores. The microemulsion was formulated from 2 wt.% monoethanolamine salt of iso-dodecylorthoxylene sulfonic acid, 7 vol.% n-decane, and the balance 1.6 wt.% NaCl.
The above microemulsion performs well in slug mode in a hostile environment, provided it is pushed with a low salinity, thickened drive solution. If the salinity of the drive solution is comparable to that of the hostile formation water, e.g., 84% Tar Springs Brine, much lower oil recovery results. However, if gas pre-injection is employed, the same hostile drive solution recovers twice as much oil.
In FIG. 5, the dotted line shows that about 30 percent of the residual oil in the Berea sandstone core watered-out with Tar Springs Brine is recovered upon injection a 35 pore volume % salt-sensitive microemulsion slug directly into the hostile environment and driving with 84% Tar Springs Brine solution thickened with 600 ppm of xanthan biopolymer (XCP).
The experiment was repeated, only air pre-injection was used to establish a trapped gas phase saturation of 17 pore volume % before introduction of the microemulsion slug. As shown in FIG. 5, oil production commenced 0.17 PV earlier and 60% of the residual oil was recovered by the time 0.7 pore volume of fluids had been produced.
In a further experiment, air pre-injection was used to establish a trapped gas phase saturation of 23 pore volume percent before introduction of 0.35 PV of the salt-sensitive microemulsion. The microemulsion slug was driven with unthickened Tar Springs Brine and 65 percent of the residual oil was recovered, as much as if a thickened high brine drive solution had been employed in conjunction with air pre-injection, as described above. These results show that for a Berea sandstone core using gas pre-injection, a salt sensitive microemulsion slug can be injected directly into a hostile environment and driven with the unthickened, hostile formation brine, There is no need to add water soluble polymer to the drive water.
EXAMPLE 7
The pusher slug typically employed in enhanced oil recovery is a thickened brine so as to avoid fingering between the microemulsion and pusher. As previously shown in Example 6, above, the use of gas pre-injection permits driving the microemulsion with an unthickened slug, and this is further demonstrated in the following example using a low salinity pusher.
The microemulsion system was the same as that described in Example 5. In the Berea sand pack, 1.5 wt.% NaCl replaced Tar Springs Brine as the resident aqueous phase. The S oi and S or values were approximately the same as those set forth in Example 5, i.e., 0.61, 0.23 and 0.65, 0.23, respectively, and the residual trapped gas phase (S rg ) with air pre-injection was only 0.03 pore volume. The microemulsion slug size was 21 pore volume % and this was driven by a slug of 1.5 wt.% NaCl which did not contain added polymer as thickening agent.
FIG. 6 shows that an air pre-injection step substantially improves oil recovery for a given microemulsion slug while permitting the use of an unthickened pusher slug. The pre-injection step results in a final oil recovery of 100% at 0.98 pore volume whereas the same microemulsion and pusher without pre-injection produces only a 54% recovery at 1.00 pore volume.
EXAMPLE 8
Gas pre-injection permits the use of low cost salt-sensitive surfactants in high brine fields without a pre-flush step. Moreover, the size of the slug can be substantially reduced due to an increased effectiveness in surfactant displacement of recoverable oil.
Varying pore volumes of a microemulsion containing 2 wt.% of the monoethanolamine salt of i-dodecylorthoxylene sulfonic acid (PDM-388), which is an incompatible surfactant in a high brine environment, 7 vol.% n-decane and the remainder 1.2 wt.% aqueous NaCl are injected directly into a Berea sandstone core containing Tar Springs Brine. The surfactant slug is then driven through the core using a 100% TSB pusher. An air pre-injection step is then interposed prior to injecting 0.35 PV of the salt-sensitive surfactant slug to establish a trapped gas phase saturation (S rg ) of 0.21 PV.
The results are shown in FIG. 7, which is a graph of the effect of air pre-injection on the fractional oil recovery (f or ) versus surfactant slug size using a salt-sensitive surfactant in a hostile brine medium. As can be seen from the figure, when an 0.35 PV slug is injected directly into the core containing TSB, only 23% (f or =0.23) of the residual oil available in the prepared core is recovered. Using an air pre-injection step, the same 0.35 PV slug recovered 64% of the available residual oil. By extrapolation, it can be determined that in order to achieve a 64% oil recovery without air pre-injection, an 0.88 PV slug would have been necessary. This represents a 150% increase in effective slug size even though the pore volume was reduced only 21% by the trapped air.
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A method for the chemically enhanced recovery of oil in which a gas is injected into the oil-bearing formation prior to the commencement of any surfactant flood. The pre-injection of gas allows the chemical flood to function more effectively and also permits the use of unthickened pushers and smaller surfactant banks.
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FIELD OF THE INVENTION
[0001] The invention relates to carbon fibers, processes of preparing the carbon fibers and the use of the carbon fibers in various applications.
BACKGROUND OF THE INVENTION
[0002] Carbon fibers are generally defined as a fiber containing at least about 92 wt-% of carbon. Carbon fibers containing 99 wt-% or more of carbon are often referred to as graphite fibers. Carbon fibers (CFs) are used in various applications owing to their excellent tensile properties, thermal and chemical stabilities (in absence of oxidizing agents) and thermal and electrical conductivities. The conventional applications of CFs include aircraft frames, turbine blades, automobile panels, sporting goods and industrial components.
[0003] Currently, the carbon fiber market is dominated by carbon fiber derived from polyacrylonitrile (PAN), with the balance being made up of fibers from pitch and rayon. CFs with distinct properties result from the processing of different precursor fibers. In a typical process in the art for converting organic polymer fibers into carbon fibers, the organic polymer fiber is first heat-stabilized in air in an oxidation process conducted at a temperature of 200 to 400° C. The thus stabilized precursor fibers then undergo controlled pyrolysis, i.e., a carbonization step, comprising heat-treating in an inert atmosphere such as nitrogen to a temperature of from about 300° C. to about 3000° C., which removes non-carbon elements such as hydrogen, oxygen and nitrogen from the oxidized fiber. It is known in the art that heating at the higher end of the temperature spectrum, e.g., between about 1000° C. and about 3000° C. may achieve higher carbon content, thereby producing CFs with higher Young's modulus values.
[0004] For automotive applications, desired mechanical properties for carbon fibers include tensile strength of >1.72 GPa, tensile modulus of >172 GPa and elongation at break of about 1%.
[0005] In addition to the limited mechanical properties of conventional CFs, the currently used methods of preparing CFs can be costly. For example, the cost of the precursor fiber amounts to approximately 40% to 50% of the total cost of preparing the carbon fiber. Therefore, there is a need in the art for lower cost precursor fibers that yield carbon fibers of excellent quality would significantly reduce the cost of CFs. An additional benefit would be to enable the expansion of CF applications to industries and markets such as those related to the automotive industry.
[0006] Furthermore, it is desirable to provide a source of carbon fibers that derives from a renewable source that does not contribute to global warming.
[0007] Polysaccharides have been known since the dawn of civilization, primarily in the form of cellulose, a polymer formed from glucose by natural processes via β(1→4) glycoside linkages; see, for example, Applied Fibre Science , F. Happey, Ed., Chapter 8, E. Atkins, Academic Press, New York, 1979. Numerous other polysaccharide polymers are also disclosed therein.
[0008] Only cellulose among the many known polysaccharides has achieved commercial prominence as a fiber. In particular, cotton, a highly pure form of naturally occurring cellulose, is well-known for its beneficial attributes in textile applications.
[0009] It is further known that cellulose exhibits sufficient chain extension and backbone rigidity in solution to form liquid crystalline solutions; see, for example O'Brien, U.S. Pat. No. 4,501,886. The teachings of the art suggest that sufficient polysaccharide chain extension could be achieved only in β(1→4) linked polysaccharides and that any significant deviation from that backbone geometry would lower the molecular aspect ratio below that required for the formation of an ordered phase.
[0010] More recently, glucan polymer, characterized by α(1→3) glycoside linkages, has been isolated by contacting an aqueous solution of sucrose with GtfJ glucosyltransferase isolated from Streptococcus salivarius , Simpson et al., Microbiology, vol 141, pp. 1451-1460 (1995). Highly crystalline, highly oriented, low molecular weight films of α(1→3)-D-glucan have been fabricated for the purposes of x-ray diffraction analysis, Ogawa et al., Fiber Diffraction Methods, 47, pp. 353-362 (1980). In Ogawa, the insoluble glucan polymer is acetylated, the acetylated glucan dissolved to form a 5% solution in chloroform and the solution cast into a film. The film is then subjected to stretching in glycerine at 150° C. which orients the film and stretches it to a length 6.5 times the original length of the solution cast film. After stretching, the film is deacetylated and crystallized by annealing in superheated water at 140° C. in a pressure vessel. It is well-known in the art that exposure of polysaccharides to such a hot aqueous environment results in chain cleavage and loss of molecular weight, with concomitant degradation of mechanical properties.
[0011] Polysaccharides based on glucose and glucose itself are particularly important because of their prominent role in photosynthesis and metabolic processes. Cellulose and starch, both based on molecular chains of polyanhydroglucose are the most abundant polymers on earth and are of great commercial importance. Such polymers offer materials that are environmentally benign throughout their entire life cycle and are constructed from renewable energy and raw materials sources.
[0012] The term “glucan” is a term of art that refers to a polysaccharide comprising beta-D-glucose monomer units that are linked in eight possible ways, Cellulose is a glucan.
[0013] Within a glucan polymer, the repeating monomeric units can be linked in a variety of configurations following an enchainment pattern. The nature of the enchainment pattern depends, in part, on how the ring closes when an aldohexose ring closes to form a hemiacetal. The open chain form of glucose (an aldohexose) has four asymmetric centers (see below). Hence there are 2 4 or 16 possible open chain forms of which D and L glucose are two. When the ring is closed, a new asymmetric center is created at C1 thus making 5 asymmetric carbons. Depending on how the ring closes, for glucose, α(1→4)-linked polymer, e.g. starch, or β(1→4)-linked polymer, e.g. cellulose, can be formed upon further condensation to polymer. The configuration at C1 in the polymer determines whether it is an alpha or beta linked polymer, and the numbers in parenthesis following alpha or beta refer to the carbon atoms through which enchainment takes place.
[0000]
[0014] The properties exhibited by a glucan polymer are determined by the enchainment pattern. For example, the very different properties of cellulose and starch are determined by the respective nature of their enchainment patterns. Starch or amylose consists of α(1→4) linked glucose and does not form fibers among other things because it is swollen or dissolved by water. On the other hand, cellulose consists of β(1→4) linked glucose, and makes an excellent structural material being both crystalline and hydrophobic, and is commonly used for textile applications as cotton fiber, as well as for structures in the form of wood.
[0015] Like other natural fibers, cotton has evolved under constraints wherein the polysaccharide structure and physical properties have not been optimized for textile uses. In particular, cotton fiber is of short fiber length, limited variation in cross section and fiber fineness and is produced in a highly labor and land intensive process.
[0016] O'Brien, U.S. Pat. No. 7,000,000 discloses a process for preparing fiber from liquid crystalline solutions of acetylated poly(α(1→3) glucan). The thus prepared fiber was then de-acetylated resulting in a fiber of poly(α(1→3) glucan).
[0017] The inventive method described herein, results in carbon fibers meeting these desired mechanical benchmarks and would further reduce the costs making CFs available to additional industrial sectors.
SUMMARY OF THE INVENTION
[0018] A process comprising
subjecting one or more filaments of poly(α(1→3) glucan) to a tension below the breaking strength of the one or more filaments at 350° C.; subjecting the thus tensioned one or more filaments to a first thermal exposure by heating said one or more filaments to a temperature in the range of 160 to 200° C. in air for a duration in the range of 5 to 15 minutes; subjecting the thus heated one or more filaments to a second thermal exposure by further heating said one or more filaments at a heating rate, still under tension, from a first temperature in the range of 200 to 250° C. to a second temperature in the range of 300 to 350° C., said heating rate being in the range of 0.1 to 1° C. per minute, thereby preparing one or more thermally stabilized filaments; subjecting said one or more stabilized filaments in a zero tension state to a third thermal exposure by heating said one or stabilized filaments to a temperature in the range of 700 to 1500° C. in an inert atmosphere for a duration in the range of 0.5 to 5 minutes, thereby preparing one or more carbonized filaments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 depicts a side view of the fiber spinning apparatus employed in the specific embodiments hereof.
[0024] FIG. 2 depicts a side view of the tube furnace arrangement used in the thermal stabilization step of the process hereof as executed in the specific embodiments thereof.
[0025] FIG. 3 depicts a side view of the carbonization apparatus used in the specific embodiments hereof.
[0026] FIG. 4A depicts a top view, and FIG. 4B depicts a front view of the winding frame used to prepare the filament skeins employed in the specific embodiments hereof.
DETAILED DESCRIPTION OF THE INVENTION
[0027] When a range of values is provided herein, it is intended to encompass the end-points of the range unless specifically stated otherwise. Numerical values used herein have the precision of the number of significant figures provided, following the standard protocol in chemistry for significant figures as outlined in ASTM E29-08 Section 6. For example, the number 40 encompasses a range from 35.0 to 44.9, whereas the number 40.0 encompasses a range from 39.50 to 40.49.
[0028] As used herein, the term “filament” encompasses a thread-shaped compact unit comprising one or more molecules of a polymer comprising poly(α(1→3) glucan). The filament can further comprise additional polymers added, for example, order to control the morphology of the carbon fiber produced according to the process hereof. Such additives as are commonly employed in the art of carbon fiber production to enhance the properties or processing of organic polymers undergoing solution spinning and subsequent carbonization can also be included.
[0029] In the present invention, the term “fiber” and the term “filament” are used interchangeably. The present invention is directed to the preparation of high strength, high modulus carbon fibers from a fiber precursor comprising poly(α(1→3) glucan). Suitable poly(α(1→3) glucan) fibers are in the form of continuous filaments. Staple fibers are not well suited for the practice of the present invention.
[0030] According to the present invention a process is provided for the preparation of carbon fiber from a precursor fiber comprising poly(α(1→3) glucan), the process comprising
subjecting one or more filaments comprising poly(α(1→3) glucan) to a tension below the breaking strength of the one or more filaments at 350° C.; subjecting the thus tensioned one or more filaments to a first thermal exposure by heating said one or more filaments to a temperature in the range of 160 to 200° C. in air for a duration in the range of 5 to 15 minutes; subjecting the thus heated one or more filaments to a second thermal exposure by further heating said one or more filaments at a heating rate, still under tension, from a first temperature in the range of 200 to 250° C. to a second temperature in the range of 300 to 350° C., said heating rate being in the range of 0.1 to 1° C. per minute, thereby preparing one or more thermally stabilized filaments; subjecting said one or more stabilized filaments in a zero tension state to a third thermal exposure by heating said one or stabilized filaments to a temperature in the range of 700 to 1500° C. in an inert atmosphere for a duration in the range of 0.5 to 5 minutes, thereby preparing one or more carbonized filaments.
[0035] One benefit of the present invention over the known art is that the carbon fiber resulting from the process hereof is a “green” product—that is, it is biologically sourced because the poly(α(1→3) glucan) upon which it is based is produced by fermentation, and not from petroleum.
[0036] If the first thermal exposure is conducted at a temperature below 160° C., it may be ineffective. If the first thermal exposure is conducted at a temperature above 200° C., it can cause water molecules trapped within fiber pores to evaporate too quickly and rupture the fiber, causing points of weakness where the fiber can break. The duration of exposure less than 5 minutes is not highly effective. An exposure of greater than 15 minutes is not deleterious, but is unnecessary. In one embodiment of the process hereof, the first thermal exposure is effected at a temperature in the range of 175 to 185° C. for a duration of 7.5 to 12.5 minutes.
[0037] Thermal stabilization of the poly(α(1→3) glucan) fiber is effected in a second thermal exposure, which involves heating from a first temperature in the range 200 to 250° C., preferably 230 to 250° C., to a second temperature in the range of 300 to 350° C., preferably 310 to 330° C. At a temperature below 200° C., thermal stabilization does not occur or occurs at a rate that is impractically slow. At a temperature above 350° C., the fiber can melt and break.
[0038] In one embodiment of the process hereof, said second thermal exposure is effected in a series of well-defined steps between the first temperature and the second temperature, with a hold period between steps, and a heating rate from step to step in excess of 10° C. per minute.
[0039] The first and second thermal exposures are conducted in air or an oxygen containing atmosphere. If the first and second thermal exposures are conducted in an oxygen containing atmosphere other than air, the same sequence of steps will still be operative, but will be modified in detail to accommodate the atmosphere in question.
[0040] The third thermal exposure, the carbonization step, is effected in an inert environment. Any inert environment is satisfactory. A heavy nitrogen purge, as described in the specific embodiments infra, has been found to be satisfactory. The third thermal exposure is conducted in the temperature range of 700 to 1500° C., preferably 800 to 1000° C. At a temperature below 700° C., the necessary level of pyrolysis and carbonization does not occur. At temperatures above 1500° C., the resulting carbon fiber can undergo such deleterious changes as loss of integrity, melting and others.
[0041] When the third thermal exposure is conducted for a period of time less than 0.5 minutes, insufficient carbonization takes place. For a period of time more than 5 minutes, the resulting carbon fiber may undergo deleterious changes, particularly in the higher range of carbonization temperatures. In one embodiment, the third thermal exposure is effected in the temperature range of 800 to 1000° C. for a period of time of 1 to 2 minutes.
[0042] The resulting carbon fiber is strong, very stiff, and tough.
[0043] The invention is further described in, but not limited by, the following specific embodiments.
EXAMPLES
Materials
[0044]
[0000]
MATERIAL
Description
Vendor
Dialysis
Spectrapor 25225-226, 12000
VWR (Radnor, PA).
tubing
molecular weight cut-off
Sucrose
15 wt-% solids aqueous solution
VWR.
(#BDH8029)
Dextran
T-10 (#D9260)
Sigma Aldrich.
Ethanol
Undenatured (#459844)
Sigma Aldrich
Antifoam
Suppressor 7153
Cognis Corporation
(Cincinnati, OH).
[0045] All other chemicals were obtained from commonly used suppliers of such chemicals.
[0000] Preparation of Glucosyltransferase (gtfJ) Enzyme
Seed Medium
[0046] The seed medium, used to grow the starter cultures for the fermenters, contained: yeast extract (Amberex 695, 5.0 grams per liter, g/L), K 2 HPO 4 (10.0 g/L), KH 2 PO 4 (7.0 g/L), sodium citrate dihydrate (1.0 g/L), (NH 4 ) 2 50 4 (4.0 g/L), MgSO 4 heptahydrate (1.0 g/L) and ferric ammonium citrate (0.10 g/L). The pH of the medium was adjusted to 6.8 using either 5N NaOH or H 2 SO 4 and the medium was sterilized in the flask. Post sterilization additions included glucose (20 mL/L of a 50% w/w solution) and ampicillin (4 mL/L of a 25 mg/mL stock solution).
Fermenter Medium
[0047] The growth medium used in the fermenter contained: KH 2 PO 4 (3.50 g/L), FeSO 4 heptahydrate (0.05 g/L), MgSO 4 heptahydrate (2.0 g/L), sodium citrate dihydrate (1.90 g/L), yeast extract (Amberex 695, 5.0 g/L), Suppressor 7153 antifoam (0.25 milliliters per liter, mL/L), NaCl (1.0 g/L), CaCl 2 dihydrate (10 g/L), and NIT trace elements solution (10 mL/L). The NIT trace elements solution contained citric acid monohydrate (10 g/L), MnSO 4 hydrate (2 g/L), NaCl (2 g/L), FeSO 4 heptahydrate (0.5 g/L), ZnSO 4 heptahydrate (0.2 g/L), CuSO 4 pentahydrate (0.02 g/L) and NaMoO 4 dihydrate (0.02 g/L). Post sterilization additions included glucose (12.5 g/L of a 50% w/w solution) and ampicillin (4 mL/L of a 25 mg/mL stock solution).
[0000] Construction of Glucosyltransferase (gtfJ) Enzyme Expression Strain
[0048] A gene encoding the mature glucosyltransferase enzyme (gtfJ; EC 2.4.1.5; GENBANK® AAA26896.1, SEQ ID NO: 3) from Streptococcus salivarius (ATCC 25975) was synthesized using codons optimized for expression in E. coli (DNA 2.0, Menlo Park Calif.). The nucleic acid product (SEQ ID NO: 1) was subcloned into pJexpress404® (DNA 2.0, Menlo Park Calif.) to generate the plasmid identified as pMP52 (SEQ ID NO: 2). The plasmid pMP52 was used to transform E. coli MG1655 (ATCC47076™) to generate the strain identified as MG1655/pMP52. All procedures used for construction of the glucosyltransferase enzyme expression strain are well known in the art and can be performed by individuals skilled in the relevant art without undue experimentation.
[0000] Production of Recombinant gtfJ in Fermentation
[0049] Production of the recombinant gtfJ enzyme in a fermenter was initiated by preparing a pre-seed culture of the E. coli strain MG1655/pMP52, expressing the gtfJ enzyme, constructed as described infra. A 10 mL aliquot of the seed medium was added into a 125 mL disposable baffled flask and was inoculated with a 1.0 mL culture of E. coli MG1655/pMP52 in 20% glycerol. This culture was allowed to grow at 37° C. while shaking at 300 revolutions per minute (rpm) for 3 hours.
[0050] A seed culture, for starting the fermenter, was prepared by charging a 2 L shake flask with 0.5 L of the seed medium. 1.0 mL of the pre-seed culture was aseptically transferred into 0.5 L seed medium in the flask and cultivated at 37° C. and 300 rpm for 5 hours. The seed culture was transferred at optical density 550 nm (OD 550 )>2 to a 14 L fermenter (Braun, Perth Amboy, N.J.) containing 8 L of the fermenter medium described above at 37° C.
[0051] Cells of E. coli MG1655/pMP52 were allowed to grow in the fermenter and glucose feed (50% w/w glucose solution containing 1% w/w MgSO 4 .7H 2 O) was initiated when glucose concentration in the medium decreased to 0.5 g/L. The feed was started at 0.36 grams feed per minute (g feed/min) and increased progressively each hour to 0.42, 0.49, 0.57, 0.66, 0.77, 0.90, 1.04, 1.21, 1.41 1.63, 1.92, 2.2 g feed/min respectively. The rate was held constant afterwards by decreasing or temporarily stopping the glucose feed when glucose concentration exceeded 0.1 g/L. Glucose concentration in the medium was monitored using a YSI glucose analyzer (YSI, Yellow Springs, Ohio).
[0052] Induction of glucosyltransferase enzyme activity was initiated, when cells reached an OD 550 of 70, with the addition of 9 mL of 0.5 M IPTG (isopropyl β-D-1-thiogalacto-pyranoside). The dissolved oxygen (DO) concentration was controlled at 25% of air saturation. The DO was controlled first by impeller agitation rate (400 to 1200 rpm) and later by aeration rate (2 to 10 standard liters per minute, slpm). The pH was controlled at 6.8. NH 4 OH (14.5% weight/volume, w/v) and H 2 SO 4 (20% w/v) were used for pH control. The back pressure was maintained at 0.5 bars. At various intervals (20, 25 and 30 hours), 5 mL of Suppressor 7153 antifoam was added into the fermenter to suppress foaming. Cells were harvested by centrifugation 8 hours post IPTG addition and were stored at −80° C. as a cell paste.
[0000] Preparation of gtfJ Crude Enzyme Extract from Cell Paste
[0053] The cell paste obtained above was suspended at 150 g/L in 50 mM potassium phosphate buffer pH 7.2 to prepare a slurry. The slurry was homogenized at 12,000 psi (Rannie-type machine, APV-1000 or APV 16.56) and the homogenate chilled to 4° C. With moderately vigorous stirring, 50 g of a floc solution (Aldrich no. 409138, 5% in 50 mM sodium phosphate buffer pH 7.0) was added per liter of cell homogenate. Agitation was reduced to light stirring for 15 minutes. The cell homogenate was then clarified by centrifugation at 4500 rpm for 3 hours at 5-10° C. Supernatant, containing crude gtfJ enzyme extract, was concentrated (approximately 5×) with a 30 kilo Dalton (kDa) cut-off membrane. The concentration of protein in the gftJ enzyme solution was determined by the bicinchoninic acid (BCA) protein assay (Sigma Aldrich) to be 4-8 g/L.
Enzymatic Synthesis of Poly(α(1→3) Glucan)
[0054] Several batches of poly(α(1→3) glucan) polymer were prepared by combining the materials listed in Table 1 in the amounts shown. The pH was adjusted to pH 6.8-7.0 by addition of 10% KOH. De-ionized water was then added to bring the volume up to level specified in Table 1. The buffer concentration in the thus prepared solution was 50 mM.
[0055] The thus prepared pH-adjusted solution was then charged with the enzyme extract prepared supra in an amount sufficient to bring the enzyme concentration to 0.30% by weight in each batch. Each thus prepared reaction mixture was then allowed to stand at ambient temperature for 144 hours. The resulting poly(α(1→3) glucan) solids were collected on a Buchner funnel using a 325 mesh screen over 40 micron filter paper. The filter cake was re-suspended in deionized water and filtered twice more as above to remove sucrose, fructose and other low molecular weight, soluble by-products. Finally two additional washes with methanol were carried out, the filter cake was pressed out thoroughly on the funnel and dried in vacuum at room temperature, yielding a white flaky solid in the amounts shown in Table 1.
[0000]
TABLE 1
Batch
KH2PO4
Batch
size
Sucrose
Dextran
Buffer
Ethanol
Number
(L)
(g)
T-10 (g)
(mL)
(mL)
Yield
1
20
1000
4.0
1000
0
120.0
2
20
1000
4.0
1000
0
114.5
3
20
1000
4.0
1000
0
113.0
4
20
1000
4.0
1000
0
86.0
5
3
450
2.4
150
150
47.3
6
3
450
3.0
150
300
32.1
7
3
450
6.0
150
300
49.0
8
3
450
9.0
150
300
56.6
Preparation of 1,3 Alpha Glucan Triacetate
[0056] The several batches of poly(α(1→3) glucan) as shown in Table 1 were combined in the amounts shown, respectively, in Table 2 to make three 130 g blends for subsequent acetylation.
[0057] The blends were boiled for one hour in deionized water. Each thus boiled blend was then added to a mixture containing 890 mL of methylene chloride, 600 mL of acetic acid and 870 mL of acetic anhydride in a 4 L reaction kettle provided with a nitrogen blanket. Mixing was effected with an egg beater style mixing blade that covered the entire depth of the liquid. The resulting mixture was then cooled to approximately −5° C. Separately, a catalyst mixture was prepared by addition of 9 mL of 70% aqueous perchloric acid to 370 mL of chilled acetic anhydride. The catalyst mixture was then added dropwise to the rapidly stirred reaction mixture at −5° C. Subsequent to catalyst addition, the reaction kettle was immersed in a hot water bath contained in a 2 gallon plastic bucket, and heated to 30° C. When the temperature of the reactants was observed to exceed 32° C., the reaction kettle was removed from the hot water bath and suspended in the air until the reaction temperature was observed to reach 27° C. at which point the reaction kettle was again immersed in the hot water bath. This procedure was continued for a period of 2-4 hours until reaction was complete. The reaction was deemed to be complete when no particulate matter was observed by visual inspection of the translucent reaction mixture.
[0058] In small aliquots, the mixture was coagulated in methanol in a Waring blender, the resultant suspension was filtered, washed with methanol twice more, water washed until neutral pH was obtained, and then washed with methanol and dried under vacuum. Yield of the resulting triacetate is shown in Table 2
[0000]
TABLE 2
Blend
Polymer Batches
Wt. (g)
Triacetate Yield (g)
1
1/2
30/100
190.4
2
3/4
43.7/86.3
204.6
3
5/6/7/8
25/20/40/45
207.94
Spinning Solution
[0059] Spinning solutions A and B were prepared from the thus prepared acetylated poly(α(1→3) glucan). 100 parts by weight of trifluoroacetic acid were diluted with 8 parts by weight of water. The thus prepared solution was added to two 1-quart zip-lock bags, each containing 120 g of the respective acetylate poly(α(1→3) glucan) blends, as indicated in Table 3, in an amount sufficient to prepare a 37.5% solids solution in each case. Each bag was then sealed, and was subject to hand kneading to homogenize. The bag was allowed to stand at ambient conditions overnight. In order to dissolve the polymer therein, the mixture of polymer and solvent was first stirred by hand using a stainless steel spatula in order to homogenize the mixture. The homogenized mixture was then pumped back and forth through 13 cycles between two syringes connected by a short length of 3 mm ID stainless steel tubing.
[0000]
TABLE 3
Spinning
Glucan Triacetate Blend
Solution
#
Weight (g)
A
1
94
2
26
B
3
120
Fiber Spinning of Glucan Triacetate
[0060] The thus prepared spinning solutions were solution-spun into continuous filaments using the spinning apparatus depicted in FIG. 1 . The spinning solution was charged to the cell ( 13 ) that was provided with a piston ( 11 ) connected to ram ( 12 ) which pushed solution through a spin pack containing a screen pack ( 14 ) provided with stainless steel support screens including 100 mesh support screen and a 325 mesh filter screen, and a 20-hole spinneret ( 15 ). Each spinneret hole was characterized by a diameter of 0.005 in. and a length to diameter ratio of 6. The piston ( 11 ) was driven by a drive screw (not shown) that drove the ram at a metered rate. The filaments ( 16 ) emerging from the spinneret ( 15 ) were directed into a coagulation bath ( 17 ) consisting of 100% methanol. The fiber was passed around Teflon guide pins ( 18 ) within the coagulation bath and exiting the bath to a traverse ( 19 ) with a guide pin ( 110 ) distributing the fiber evenly across a width to a windup ( 111 ) where the fiber is collected on a bobbin. The bobbins so prepared were soaked overnight in methanol. Spinning conditions are provided in Table 4. The yarns so produced are herein designated GYA-1 and GYA-2.
[0000]
TABLE 4
Spin-
Jet
Wind
ning
Veloc-
Bath
Bath
Air
up
Spin
Solu-
ity
Temp
length
Gap
speed
Stretch
tion
(fpm)
(° C.)
(ft)
(in)
(fpm)
Factor
GYA-1
A
17
−1
11.8
0.3
52
3.1
GYA-2
B
22
−19
11.8
0.75
60
2.7
Saponification
[0061] 0.54 g of sodium methoxide were added to 100 mL of methanol. The bobbin of GYA-2 yarn was placed into the solution so formed for a period of 48 hours to regenerate glucan fiber from the glucan triacetate fiber. The so-treated bobbin was then rinsed with methanol, and soaked for an additional 24 hours in neat methanol, and allowed to air dry. The resulting regenerated glucan fiber yarn is herein designated GY-1.
Oxidation Treatment
[0062] Referring to FIG. 2 , a tube furnace ( 21 ) having an entry port ( 22 ) and an exit port ( 22 ′) was equipped with an air supply fan ( 23 ) that flowed air, at rates stated in Table 5, infra, into the entry port ( 22 ) and through the furnace to the exit port ( 22 ′). A skein of fiber ( 24 ) was fed end-wise through the tube furnace. The skein was disposed to pass over a pulley ( 25 ) at each end of the tube furnace. Each end of the skein was formed into a loop ( 26 ), through which a hook ( 27 ) was passed. Affixed to the hook was a weight ( 28 ). The weight employed is stated in the examples, infra. The heated section of the tube inside the tube furnace was a 2 inch schedule 5 tube with an inner diameter of 57 mm and a length of 54 inches. Each specimen was subject to a temperature of 180° C. in air for 10 minutes. The temperature was then increased in a series of steps, as described in the thermal profile provided in the examples, infra. It took less than 1 minute to make the temperature changes between adjacent steps in the thermal profile.
Carbonization Treatment
[0063] Referring to FIG. 3 , nitrogen was provided to the tube furnace ( 21 ) at six locations ( 33 ): one at the entry port ( 22 ) and one at the exit port ( 22 ′) of the tube furnace, two at the tubing before the entrance port and two at the tubing before the exit port ( 22 ′). The nitrogen was fed through six flow meters ( 34 ). The oxidized fiber skein ( 35 ) was attached to an Inconel® transport wire 0.9 mm in diameter ( 36 ) using metal crimps ( 37 ) in order to keep the fiber skein in a zero tension state. The Inconel® wire was wrapped around pulleys ( 25 ) located at the entry port ( 22 ) and exit port ( 22 ′) in order to move the fiber skein into and out of the furnace. The fiber skein thus disposed was then subject to heating according to the schedule disclosed in the specific embodiments infra.
Preparation of Filament Skeins.
[0064] Referring to FIG. 4 , a skein of filaments having more than 20 ends was prepared by winding the skein around four posts ( 41 ) that were set at the corners of a square ( 42 ), 24 inches apart from each other. A fiber skein was wrapped around the posts until the skein contained the desired number of filaments. The skein was cut at one post, resulting in a length of 8 feet.
Example 1
[0065] Two 60-inch skeins, consisting each of 20 filaments of GY-1 were prepared for oxidation as described supra. To each skein, herein designated GY-1-A and GY-1-B, a 3.5-gram weight was affixed at each end as shown in FIG. 2 . Under an air flow rate of 6 standard cubic feet per minute (scfm), each skein was individually heated to 230° C., held for 60 minutes, then heated to 250° C., held for 60 minutes, then heated to 270° C., held for 60 minutes, then heated to 290° C., held for 60 minutes, then heated to 310° C., held for 60 minutes. No breakage had occurred at the end of the five-hour thermal exposure process. The resulting oxidized skeins are herein designated GY-1-AO and GY-1-BO.
[0066] The GY-1-AO oxidized skein was prepared for carbonization as described supra. The skein was heated at 800° C. for 90 seconds under a nitrogen purge of 120 scfh. The skein, herein designated GY-1-AC, was removed from the oven and spooled. The skein was black in color, pliable enough to be spooled, but fragile. If the skein was wrapped tightly, filaments would break.
[0067] The GY-1-BO oxidized skein was prepared for carbonization as described supra. The skein was heated to 1000° C. for 90 seconds under a nitrogen purge of 120 scfh. The skein was black in color. The filaments seemed stronger than GY-1-AC, but upon removal from the oven, many filaments were caught on the equipment and broken.
Example 2
[0068] Referring to FIG. 4 , a 440 filament skein was prepared by wrapping a 20-filament length of GY-1 around the posts 22 times. A second skein was prepared in the same manner. The skeins so prepared were cut at one post, resulting in two lengths of 8 feet each, designated GY-1-C and GY-1-D.
[0069] Each of GY-1-C and GY-1-D were prepared for oxidation as described, supra. Each was oxidized separately. To each skein a 50-gram weight was affixed at each end as shown in FIG. 2 . Under an air flow rate of 10 scfm, each skein was heated to 250° C., held for 40 minutes, then heated to 270° C., held for 40 minutes, then heated to 290° C., held for 40 minutes, then heated to 310° C., held for 40 minutes, then heated to 330° C., held for 40 minutes. No breakage occurred at the end of the 200-minute temperature profile. The resulting oxidized skeins are herein designated GY-1-CO and GY-1-DO.
[0000] c. Carbonization
[0070] Oxidized skein GY-1-CO was prepared for carbonization as described supra. The skein was heated to 800° C. under a nitrogen flow rate of 120 standard scfh for 120 seconds. The thus heated skein, herein designed GY-1-CC, was removed from the furnace. The skein was black in color, pliable, and easy to spool.
[0071] Oxidized skein GY-1-DO was treated in a manner identical to that of GY-1-CO except that the temperature was 1000° C. The thus heated skein, herein designed GY-1-DC, was removed from the furnace. The skein was black in color, very pliable, and very easy to spool.
[0072] In the thus carbonized skeins fiber diameter was determined by scanning electron microscopy; denier, using a TexTechno Vibromat ME denier testerand (TexTechno H.Stein GMBH & Co.); and, mechanical properties, using an Instron® Universal Testing Machine. Results are shown in Table 5.
[0000]
TABLE 5
GY-1-CC
GY-1-CD
Diameter (micrometers)
17.0 ± 0.4
19.6 ± 1.7
Denier
3.581 ± 0.789
3.076 ± 0.674
Tenacity (gpd)
1.3 ± 0.5
2.0 ± 1.0
Tensile Strength (MPa)
189 ± 79
203 ± 100
Tensile Modulus (GPa)
28 ± 4
27 ± 6
Comparative Example A
[0073] One 60-inch skein consisting of 20 filaments of glucan triacetate GYA-1 was prepared for oxidation as described supra. A 4.5 g weight was affixed to each end of the skein as shown in FIG. 2 . Under an air flow rate of 6 scfm, the bundle was heated to 230° C. After one minute, the skein broke.
Comparative Example B
[0074] Two 200 filament skeins were prepared by wrapping the 20-filament glucan triacetate GYA-1 ten times around the posts of the apparatus in FIG. 4 . Each skein was cut at one post, resulting in two lengths of 8 feet.
[0075] A 60-inch skein was cut from each of the thus prepared 8 foot lengths, herein designated GYA-1-1 and GYA-1-2. Each 60-inch skein was prepared for oxidation as described supra. Each skein was oxidized separately. A 16 g weight was affixed to each end of the GYA-1-1 skein, and a 40 g weight was affixed to each end of GYA-1-2. The skeins were heated for 10 minutes at 180° C. under an air flow rate of 6 scfm. skeins broke after 10 minutes at 180° C.
Comparative Example C
[0076] PANOX® Thermally Stabilized Textile Fiber, an oxidized poly(acrylonitrile) fiber was obtained from The SGL Group, Ross-Shire, UK. Three PANOX fiber skeins, herein designated PANOX-1, PANOX-2, and PANOX-3, consisting of approximately 12,000 filaments per skein were prepared for carbonization as described supra. Three 60-inch length skeins were heated to 800° C. under a nitrogen atmosphere of 120 scfh. PANOX-1 was held for 60 seconds, PANOX-2 was held for 90 seconds, PANOX-3 was held for 120 seconds. PANOX-1 caught on the furnace during removal and was bunched up. No further testing was performed. PANOX-2 was frayed and could not be spooled. PANOX-3 was removed from the oven, herein designed PANOXC-3, and spooled.
[0077] A further 12,000 filament 60 inch skein of PANOX, herein designated PANOX-4, was heated to 1000° C. under a nitrogen atmosphere of 120 scfh for 120 seconds. PANOX-4 was removed from the oven, herein designated PANOXC-4 and spooled.
[0078] PANOXC-3 and PANOXC-4 were analyzed in the manner of the specimens in Example 2. Results are shown in Table 6.
[0000]
TABLE 6
PANOXC-3
PANOXC-4
Diameter (micrometers)
8.0 ± 0.3
9.9 ± 0.3
Denier
0.779 ± 0.040
1.111 ± 0.070
Tenacity (gpd)
9.4 ± 2.1
2.7 ± 1.7
Tensile Strength (MPa)
1440 ± 317
387 ± 247
Tensile Modulus (GPa)
85 ± 6
15 ± 8
|
A process is provided for preparation of carbon fibers based from fibers of poly(α(1→3) glucan). The method comprises three thermal exposures at progressively higher temperatures to drive off volatiles, thermally stabilize the glucan fiber, and carbonize the thermally stabilized fiber. The carbon fibers prepared according to the process hereof are strong, stiff, tough, and easily handled.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of and claims the benefit of priority to co-pending U.S. application Ser. No. 13/431,291, filed on Mar. 27, 2012, which in turn claims the benefit of priority to U.S. Provisional Application No. 61/475,791, filed Apr. 15, 2011, the disclosures of both of which are incorporated herein by reference in their entireties for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to recurring payment cancellation services and, more particularly, to a system and method for upgrading cancellation services relating to the identifying of cancelled recurring payments.
[0003] Recurring payments are common in the marketplace. A cardholder preauthorizes a merchant to automatically bill a credit or debit card at a preset interval (e.g., monthly, quarterly or annually). This is typically done for a matter of convenience for both the cardholder and the merchant. These payment transactions typically occur without incident.
[0004] However, changes in the merchant/cardholder relationship can introduce challenges into the process. For example, the cardholder may revoke preauthorization to bill his account due to either a change in payment type or discontinuation of a merchant relationship. Although most merchants quickly honor the change in the recurring payment billing arrangement, there are times when the merchant does not make the requested change in a timely fashion. In this case, the cardholder continues to incur the periodic charge. He then contacts the card issuer, and requests a refund. This request for a refund results in the issuing bank seeking a chargeback from the merchant bank.
[0005] Although a payment network such as the MasterCard Worldwide Network includes a procedure for chargebacks, this process nevertheless results in cost to the participants, as well as a potential loss of goodwill between the issuing back and the cardholder. Continued billing to a cardholder's account results in complaints to the issuer's customer service department, and may even result in the cardholder asking to have his or her account closed.
[0006] To reduce the frequency of chargebacks resulting from cancelled recurring payments, as well as to maintain the relationship between the issuing bank and its cardholder, a cancellation service can be provided whereby a database is maintained of unauthorized recurring payments associated with particular cards. An issuing bank can participate in such a cancellation service by inputting information associated with a particular card into the database to prevent future unauthorized billing from a selected merchant. In this way, the recurring charge is blocked before it can appear on the cardholder's bill, thus eliminating complaints from the cardholder, as well as the need for a chargeback by the issuing bank.
[0007] Although databases of cancelled recurring payments are effective in blocking unauthorized recurring payments, the existing systems require the issuing bank (or some other authorized entity) to provide the database with the necessary financial data, e.g., account number, merchant identity, merchant bank identity and transaction amount. Typically, this data is manually entered into the database by an employee of the issuing bank. As a result, the entry of data into the cancellation database can be delayed and/or never completed due to the time and effort involved with inputting such data.
[0008] In addition, some charges are not properly identified as recurring payments by the submitting merchant. This failure to identify the payment as a recurring payment can result in the bypassing of the cancellation database during the authorization/clearance process.
[0009] There is therefore a need in the art for a system and method for providing an updated database of cancelled recurring payments for comparison during the authorization and/or clearance process. There is a further need in the art for a system and method of identifying cancelled recurring payments even when the submitted charge is not properly identified as a recurring payment.
SUMMARY OF THE INVENTION
[0010] The present invention involves a method of reducing chargebacks due to a cancelled recurring payment, wherein the payment occurs within a card-based financial network, and wherein the network includes a database of unauthorized recurring charges and a defined chargeback procedure. The method generally includes the step of creating an entry within the database during the chargeback procedure when the chargeback procedure is related to a cancelled recurring payment, whereupon the cancelled recurring payment is subsequently identified in the database as an unauthorized recurring charge.
[0011] In a preferred embodiment, the method further includes the step of extracting predefined data associated with the cancelled recurring payment, wherein the creating step includes the further step of populating a field associated with the database with the predefined data. Also, the creating step preferably includes the further steps of comparing the predefined data associated with the cancelled recurring payment to file data contained within the database and inputting at least one item from the predefined data into the database in accordance with predefined parameters.
[0012] The present invention also involves a method of reducing chargebacks due to a cancelled recurring payment, wherein the payment occurs within a card-based financial network, and wherein the network includes a database of unauthorized recurring charges and a defined automatic billing updating procedure for assigning a new account number to a cardholder. The method generally includes the step of updating the database during the automatic billing updating procedure when the network identifies an unauthorized recurring charge in said database associated with said cardholder.
[0013] In a preferred embodiment, the method includes the further step of extracting predefined data associated with the automatic billing updating procedure, and the updating step includes the further step of populating a field associated with the database with the predefined data. When the unauthorized recurring charge is associated with an old account number, the updating step preferably includes the further step of associating the new account number with the old account number in the database, wherein a file is created containing both the old account number and the new account number for subsequent comparison.
[0014] The present invention further involves a method for reducing chargebacks due to a cancelled recurring payment, wherein the payment occurs within a card-based financial network, and wherein the network includes a cancellation service, which includes a database of unauthorized recurring charges. The method generally includes the steps of receiving a financial processing request identifying a card-based payment without a recurring payment code, determining whether the issuing bank associated with the request is a participant within the cancellation service, comparing data associated with the request to the unauthorized recurring charges contained within the database and determining a response to the processing request in accordance with predefined parameters.
[0015] In a preferred embodiment, the comparing step provides a plurality of authorization comparisons and includes the further step of assigning values to each of the authorization comparisons. The authorization comparisons are preferably related to selected secondary criteria, which includes information relating to at least one of a merchant identity, a merchant size, a length of time a merchant has been doing business, a number of cancelled recurring payments associated with a merchant, a number of chargebacks associated with a merchant or a billing date. The determining step preferably includes the further step of combining the values, and rejecting the processing request when the combination of values exceeds a predefined threshold, wherein the predefined threshold is determined by an issuing bank.
[0016] In another method for reducing chargebacks due to a cancelled recurring payment, the method generally includes the steps of receiving a financial processing request identifying a card-not-present (CNP) transaction, determining whether the issuing bank associated with the request is a participant within the cancellation service, comparing data associated with the request to the unauthorized recurring charges contained within the database and determining a response to the processing request in accordance with predefined parameters.
[0017] In a preferred embodiment of this method, the comparing step again provides a plurality of authorization comparisons, and includes the further step of assigning values to each of the authorization comparisons, wherein the authorization comparisons are related to selected secondary criteria. The determining step again preferably includes the further step of combining the values, and rejecting the processing request when the combination of values exceeds a predefined threshold, wherein the predefined threshold is determined by an issuing bank. This method is also carried out when the financial processing request is received without a recurring payment code.
[0018] A preferred form of the method according to the present invention, as well as other embodiments, objects, features and advantages of this invention, will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematical diagram of a card-based payment system;
[0020] FIG. 2 is a flow diagram of a file maintenance process for a cancellation listing system;
[0021] FIG. 3 is a flow diagram of an authorization and clearance process for a card-based transaction;
[0022] FIG. 4 is a flow diagram depicting the updating of a recurring payment cancellation service (RPCS) file during a chargeback process;
[0023] FIG. 5 is a flow diagram depicting the updating of a RPCS file during an automatic billing updating process;
[0024] FIG. 6 is a flow diagram of an alternative authorization and clearance process for a card-based transaction; and
[0025] FIG. 7 is a flow diagram of still another alternative authorization and clearance process for a card-based transaction.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring first to FIG. 1 , in a typical card-based payment system transaction, a cardholder 10 presents his credit/debit card to a merchant 12 for the purchase of goods and/or services. This transaction is indicated by arrow 14 . It will be understood that prior to the occurrence of transaction 14 , cardholder 10 was issued a card by issuing bank 16 . Moreover, it will be understood that merchant 12 established a relationship with a merchant bank 18 , thereby allowing merchant 12 to receive credit/debit cards as payment for goods and/or services. The merchant banks and issuing banks may participate in various payment networks, including payment network 20 . One such payment network is referred to as the MasterCard Worldwide Network.
[0027] After presentation of a card to merchant 12 by cardholder 10 , merchant 12 sends an authorization request (indicated by arrow 22 ) to bank 18 . In turn, bank 18 communicates with network 20 (indicated by arrow 24 ), and network 20 communicates with the issuing bank 16 (indicated by arrow 26 ) to determine whether the cardholder is authorized to make the transaction in question. An approval or disapproval of the authorization request is thereafter transmitted back to merchant 12 (indicated by arrows 28 , 30 and 32 ). Merchant 12 thereafter either completes or cancels the transaction based upon the response to the authorization request.
[0028] If transaction 14 is approved, the transaction amount will be sent from issuing bank 16 through network 20 to bank 18 . This transaction amount, minus certain fees charged by both network 20 and bank 18 , will thereafter be deposited within a bank account belonging to merchant 12 . Issuing bank 16 thereafter bills cardholder 10 (indicated by arrow 34 ) for the amount of such transaction, and cardholder 10 follows by a submission of payment(s) (as indicated by arrow 36 ) to issuing bank 16 . This submission of payment(s) (as indicated by arrow 36 ) by cardholder 10 may be automated (e.g., in the case of debit transactions), may be initiated by the cardholder for the exact amount matching costs of purchases during the statement period (e.g., charge cards or credit balances paid in full), and/or may be submitted (in part or in whole) over a period of time that thereby reflects the costs of the purchases plus financing charges agreed upon beforehand between the cardholder and the cardholder's issuing bank (e.g., revolving credit balances.)
[0029] When cardholder 10 receives an unauthorized recurring charge, (whether a one-time, or a recurring charge), on his statement, the cardholder contacts issuing bank 16 (indicated by arrow 38 ) and requests a refund. Issuing bank 16 then initiates a chargeback (indicated by arrows 40 , 42 ), requesting a refund of the payment from merchant bank 18 . This refund is provided back to the cardholder (as indicated by arrows 44 , 46 , 48 ).
[0030] Network 20 preferably includes at least one server 49 and at least one database 50 . Server 49 may include various computing devices such as a mainframe, personal computer (PC), laptop, workstation or the like. The server can include a processing device and be configured to implement an authorization and clearance process, which can be stored in computer storage associated with the server. The authorization and clearance process can be implemented by the server to prevent and/or reduce unauthorized recurring payments. Database 50 may include computer readable medium storage technologies such as a floppy drive, hard drive, tape drive, flash drive, optical drive, read-only memory (ROM), random access memory (RAM), and/or the like.
[0031] Referring now to FIG. 2 , a cancellation listing system 51 of the present invention is shown. System 51 is preferably implemented by network 20 , and is preferably maintained by the network provider, e.g., MasterCard, or by an independent authorized third party. System 51 preferably includes an account management system (AMS) file 52 , a recurring payment cancellation service (RPCS) file 54 and a billing service file 56 . AMS file 52 , RPCS file 54 and billing service 56 are preferably stored in database 50 of network 20 , and processed by server 49 . Although FIG. 2 depicts AMS file 52 , RPCS file 54 and billing service file 56 as separate discrete files, these separate files could be contained within one larger file. In one preferred application, the mentioned files are stored within a single storage device as separate files. In another preferred application, RPCS file 54 is a sub-file of AMS file 52 .
[0032] AMS file 52 is preferably a database of cards which have been flagged for non-authorization, e.g., lost or stolen cards, cards in collection and cards participating in the recurring payment cancellation service. In other words, the AMS file is essentially a negative database. AMS file 52 preferably communicates with both RPCS file 54 and billing service file 56 . File 56 is associated with the billing of an issuing bank for each card entered into RPCS file 54 .
[0033] Entering data into AMS file 52 , and ultimately into RPCS file 54 , may be accomplished in at least two ways. In the first way, a written request 58 is forwarded to the operator of system 51 . The written request 58 includes the necessary data (e.g., account number, merchant identity, merchant bank identity, transaction amount) to be entered into RPCS file 54 . The data is thereafter entered into RPCS file 54 by authorization support 60 . The second method of inputting data into the RPCS file 54 involves the direct input of data by issuing bank 16 (or an authorized entity). More particularly, issuing bank 16 communicates with a system input 62 , which then forwards the data through an issuer file 64 . The input of the data into AMS 52 is depicted by arrows 66 , 68 , and the confirmation of the input of such data is depicted by arrows 70 , 72 . It is contemplated herein that system input 62 can be accomplished by various computing devices such as a mainframe, personal computer (PC), laptop, workstation, handheld device, or the like.
[0034] As will be recognized by those skilled in the art, the transaction processing of card-based payments include both an authorization side and a clearance side. The authorization side involves the process of confirming that the cardholder has a sufficient line of credit to cover the proposed payment. The clearance side of the transaction involves the process of moving funds from the issuing bank to the merchant bank. FIG. 3 depicts a transaction processing flow chart showing both the authorization side and the clearance side of the card-based payment.
[0035] Referring to FIG. 3 , and to the authorization side of the transaction, an authorization request 74 is submitted by a merchant bank to network 20 . Network 20 first considers whether the charge included in authorization request 74 is a recurring payment ( 76 ). In this regard, merchants and/or merchant banks preferably indicate a recurring payment as such by utilizing defined criteria, e.g., an identifying code. If the proposed charge is not a recurring payment transaction, then the processing of the authorization request continues at step 78 in ordinary fashion. However, if the proposed charge is indicated to be a recurring payment, then network 20 determines whether the issuing bank is an issuer participant ( 80 ). If the issuing bank is not an issuer participant, then the processing of the transaction continues at step 78 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the proposed charge defined in the authorization request matches a recurring account charge (RAC) blocking criteria ( 82 ). This step is indicated at 84 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the processing of the authorization request continues in step 86 in ordinary fashion. If RAC blocking criteria are found, then the authorization request is rejected, as indicated by steps 88 and 90 .
[0036] Turning now to the clearance side of the transaction, a clearing presentment 92 is submitted to network 20 . Network 20 determines whether clearing presentment 92 involves a recurring payment ( 94 ), and if not, directs network 20 to continue processing the clearing presentment at step 96 in ordinary fashion. If clearing presentment 92 involves a recurring payment, then network 20 determines whether the issuing bank is an issuer participant ( 98 ). If the issuing bank is not an issuer participant, then network 20 continues processing the clearing presentment at step 96 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the charge defined in the clearing presentment matches the RAC blocking criteria ( 100 ). This step is indicated at 102 in FIG. 3 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the processing of the clearing presentment continues at step 104 in ordinary fashion. If RAC blocking criteria are found, then the clearing presentment is rejected at step 106 .
[0037] At present, the RPCS file maintenance described in FIG. 2 is isolated from the typical chargeback process described with respect to FIG. 1 . In other words, unless the issuing bank ensures that the appropriate data is entered into RPCS file 54 (by either input 62 or written request 58 ), then the process described in FIG. 3 will be ineffective in identifying unauthorized recurring charges, and will be unable to reject such charges.
[0038] Accordingly, one aspect of the present invention is to associate the chargeback process with the RPCS file such that the process of performing a chargeback results in the creation of an entry within RPCS file 54 which will be available for future comparison during steps 82 and 100 of the transaction process. This entry in RPCS file 54 can be created because the chargeback process requires the input of the same or similar data required to flag an unauthorized recurring payment, e.g., the account number, merchant identity, merchant bank identity and transaction amount.
[0039] When issuing bank 16 initiates a chargeback within network 20 , the chargeback is preferably associated with RPCS file 54 whereby the server(s) (e.g., server 49 ) and database(s) (e.g., database 50 ) involved in the chargeback process communicate with RPCS file 54 , either directly or through AMS file 52 , to add and/or update the data contained in RPCS file 54 . The association between the chargeback process and RPCS file 54 is shown in greater detail in FIG. 4 . More particularly, in addition to the normal steps incurred during a typical chargeback 108 , the present invention adds the additional step ( 110 ) of contacting RPCS file 54 and determining whether a match is found in the stored data for the payment associated with the chargeback. Step 110 is preferably initiated when the chargeback 108 includes a predefined code indicating that such chargeback is due to a “cancelled recurring” charge. If a match is found in RPCS file 54 for the payment associated with the chargeback, then the updating process of RPCS file 54 is discontinued at step 112 . If no match is found in RPCS file 54 for the payment associated with the chargeback , then RPCS file 54 is updated at step 114 to add the data associated with the chargeback to RPCS file 54 , e.g., account number, merchant identity, merchant bank identity and transaction amount.
[0040] It is contemplated herein that network 20 may also include an automatic billing updater (ABU) platform 200 . ABU platform may be stored in database 50 , and processed by server 49 . ABU platform 200 is used to automatically maintain the accuracy of account data for account-on-file payments, including recurring payments, between participating issuers, acquirers and merchants. Another aspect of the present invention is to associate ABU platform 200 with the RPCS file 54 such that the process of performing an ABU account number change results in the updating of RPCS file 54 . More particularly, the RPCS file 54 can be updated to also include the new account number provided through the ABU account number change. In other words, RPCS file 54 will now include both the old and new account numbers, such that if a merchant attempts to process an unauthorized recurring payment using the new card number, the transaction will be flagged and subsequently rejected.
[0041] Thus, as shown in FIG. 5 , ABU platform 200 creates a file 202 containing both the old and new account numbers associated with a cardholder. The system then communicates with RPCS 54 to determine whether a listing exists for the old account number ( 204 ). If a listing 206 exists, then the system can either create a new RPCS listing with the duplicate information ( 208 ), or update the existing RPCS listing with the new account number ( 210 ). If no existing RPCS listing is found in step 204 , then the process is terminated at step 212 .
[0042] Although merchants and merchant banks are supposed to indicate recurring charges by coding such charges in a particular manner, this coding is not always associated with a recurring payment. The failure to properly code a payment can result from oversight, error or even intentional omission. Existing cancellation listing services require the payment to be identified as a “recurring payment” to trigger the RPCS file inquiry. Accordingly, a merchant may intentionally omit the recurring payment designation to avoid having the transaction denied. The present invention further contemplates at least two authorization and clearance processes (as shown in FIGS. 6 and 7 ) which consider the possibility that payments have been improperly labeled, i.e., that a recurring payment has not been labeled as such.
[0043] Turning to the first embodiment shown in FIG. 6 , an authorization request 116 is submitted to network 20 , which then considers whether the payment associated with the request is a recurring payment ( 118 ). If the submitted payment is identified as a recurring payment, then the process continues at step 120 as discussed hereinabove with respect to step 76 in FIG. 3 . However, if the payment associated with authorization request 116 is not identified as a recurring payment, then network 20 considers whether the issuing bank is an issuer participant ( 122 ). If the issuing bank is not an issuer participant, then the transaction is continued at step 124 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the proposed charge defined in the authorization request matches the RAC blocking criteria ( 126 ). This step is indicated at 128 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the processing of the transactions continues at step 130 in ordinary fashion. If RAC blocking criteria are found, then the process considers certain secondary criteria ( 131 ).
[0044] In this first embodiment, network 20 considers selected secondary criteria in step 131 before approving or denying the authorization request. More particularly, the process can be configured to deny the authorization request at 132 when a predefined number of secondary criteria are matched, or when a particular weighting of all criteria has been reached. These secondary criteria can include the identity of the merchant, the size of the merchant, the length of time such merchant has been doing business, the number of cancelled recurring payments associated with such merchant, the number of chargebacks associated with such merchant, the billing date, etc. It is contemplated that different secondary criteria can be assigned different values. It is also contemplated that the number of matches necessary to cause an authorization request to be denied can be targeted and specific to a particular issuing bank. This can provide the issuing bank with an additional degree of control over the cards and accounts issued to its customers. Considering these additional criteria before denying an authorization request can reduce the likelihood that a legitimate charge is denied.
[0045] Inasmuch as a card based payment also involves a clearance process, this provides the issuing bank with a second opportunity to identify an unauthorized charge. As shown in FIG. 6 , clearing presentment 134 is submitted to network 20 . If the payment associated with clearing presentment 134 is a recurring payment, then the process continues at step 136 as discussed hereinabove with respect to FIG. 3 . However, if the payment associated with clearing presentment 134 is not identified as a recurring payment then the network considers whether the issuing bank is an issuing participant ( 138 ). If the issuing bank is not an issuer participant, then the process continues at step 140 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the charge defined in the clearing presentment matches the RAC blocking criteria ( 142 ). This step is indicated at 144 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the process continues at step 146 in ordinary fashion. If RAC blocking criteria are found, then the clearing process considers certain secondary criteria ( 147 ).
[0046] In this first embodiment, network 20 considers selected secondary criteria before approving or denying the presentment request. More particularly, the process can be configured to deny the presentment at 148 when a predefined number of secondary criteria are matched, or when a particular weighting of all criteria has been reached. These secondary criteria can include the identity of the merchant, the size of the merchant, the length of time such merchant has been doing business, the number of cancelled recurring payments associated with such merchant, the number of chargebacks associated with such merchant, the billing date, etc. It is contemplated that different secondary criteria can be assigned different values. It is also contemplated that the number of matches necessary to cause a presentment to be denied can be target and specific to a particular issuing bank. This can provide the issuing bank with an additional degree of control over the cards and accounts issued to its customers. Considering these additional criteria before denying a payment request can reduce the likelihood that a legitimate charge is denied.
[0047] Turning to the second embodiment shown in FIG. 7 , an authorization request 150 is submitted to network 20 , which then considers whether the payment associated with the request is a card-not-present (CNP) transaction ( 152 ). CNP transactions include, among others, the recurring payments discussed herein. If the submitted payment is not identified as a CNP transaction, then the process continues at step 154 in ordinary fashion. However, if the payment associated with authorization request 150 is identified as a CNP transaction, then network 20 considers whether the issuing bank is an issuer participant ( 156 ). If the issuing bank is not an issuer participant, then the transaction is continued at step 154 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the proposed charge defined in the authorization request matches the RAC blocking criteria ( 158 ). This step is indicated at 160 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the processing of the transactions continues at step 162 in ordinary fashion. If RAC blocking criteria are found, then the authorization request is rejected at step 164 .
[0048] Inasmuch as a card based payment also involves a clearance process, this provides the issuing bank with a second opportunity to identify an unauthorized charge. As shown in FIG. 7 , clearing presentment 166 is submitted to network 20 , which then considers whether the payment associated with the presentment is a CNP transaction ( 168 ). If the payment associated with clearing presentment 166 is not identified as a CNP transaction, then the process continues at step 170 in ordinary fashion. However, if the payment associated with clearing presentment 134 is identified as a CNP transaction, then the network considers whether the issuing bank is an issuer participant ( 172 ). If the issuing bank is not an issuer participant, then the process continues at step 170 in ordinary fashion. If the issuing bank is an issuer participant, then network 20 determines whether the data associated with the charge defined in the clearing presentment matches the RAC blocking criteria ( 174 ). This step is indicated at 176 , and is accomplished by accessing RPCS file 54 . If RAC blocking criteria are not found, then the process continues at step 178 in ordinary fashion. If RAC blocking criteria are found, then the clearing presentment is rejected at step 180 .
[0049] Thus, in this second embodiment, network 20 identifies all CNP transactions, and automatically checks for matching blocking criteria for participating issuers—irrespective of how the transaction is coded. In this way, an issuer is more likely to “catch” unauthorized recurring charges which have not been properly coded as such, whether done innocently or intentionally. In other words, if the data associated with the proposed transaction matches the RAC blocking criteria in the RPCS file, and the transaction is a CNP transaction, then the authorization request or presentment will be denied.
[0050] It will be appreciated that the present invention has been described herein with reference to certain preferred or exemplary embodiments. The preferred or exemplary embodiments described herein may be modified, changed, added to or deviated from without departing from the intent, spirit and scope of the present invention, and it is intended that all such additions, modifications, amendments and/or deviations be included in the scope of the present invention.
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A method of reducing chargebacks due to a cancelled recurring payment, wherein the payment occurs within a card-based financial network, and wherein the network includes a database of unauthorized recurring charges and a defined chargeback procedure. The method generally includes the step of upgrading a recurring payment cancellation services file based on predefined occurrences relating to the identifying of cancelled recurring payments.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of magnetic resonance imaging and more specifically to the field of imaging moving matter with magnetic resonance.
2. Description of Related Art
Motion, particularly that of fluids, is an important parameter in many systems. Information of the gradients in velocity and acceleration is useful in design and analysis of fluid flow systems. Gradients in velocity and acceleration indicate regions of potential turbulence, and stagnant areas. These may lead to corrosion in metal pipes, areas of blockage, etc. Also, regions of slow flow through vessels of living subjects have been shown to play a central role in the in-vivo development of arteriosclerotic disease.
A traditional fluid flow analysis method, known as ink streamlining, requires introducing a contrast agent into a flowing fluid and observing the motion of the contrast agent.
Another method of measuring motion of materials employs laser Doppler technique. This requires a laser beam to be reflected from particles suspended in the material which is to be measured, and determining the displacement of each particle over a short interval thereby indicating the velocity of the material at the chosen location.
Both of these methods are invasive, or destructive, and require direct access to the material being tested. If the material is in inside a tube or deep within a living subject, these methods will not be useful. Furthermore, they are not suited for in-vivo, or non-destructive testing applications.
A number of methods for the detection and measurement of fluid motion with magnetic resonance have been previously disclosed. These methods use either a bolus tracking approach in which the magnetization of a bolus of moving fluid is changed and followed, or they use approaches in which motion-encoding magnetic field gradient pulses are used to induce a phase shift which is proportional to a desired component of motion such as velocity, acceleration and jerk. Prior methods for the detection of motion with magnetic resonance are limited in their application since only a single component of motion can be detected at a time.
It would be useful to have a method which non-invasively measures several components of motion simultaneously.
SUMMARY OF THE INVENTION
Methods employing magnetic resonance (MR) pulse sequences for the acquisition of images containing information from more than one component of motion are disclosed. These pulse sequences are comprised of a slice-selective RF pulse and a conventional readout gradient pulse for spatial encoding. At least two motion encoding gradient pulses are incorporated into the pulse sequence. Motion encoding gradient waveforms can be bipolar to encode velocity as a phase shift in the resulting image, tri-polar to encode acceleration as a phase shift in the resulting image, or have a higher number of lobes to encode higher orders of motion.
The motion encoding gradients are applied in one of two ways. The first motion encoding gradient is applied with a selected amplitude, but is modulated in polarity during subsequent acquisitions. Data acquired responsive to this modulation is processed by computing differences, to extract the component of data arising from the first motion encoding gradient. The second motion encoding gradient pulse (as well as all additional motion encoding pulses, if present) are applied with varying amplitudes to form a phase-encoding dimension of the image.
Motion encoded in this form is resolved by the application of a Fourier transformation with respect to the changing pulse amplitudes. A motion dimension provides a means of assessing the distribution of a motional parameter such as velocity within a subject.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a method for the simultaneous detection and display of two or more selected component of motion within a subject. It is another object of the present invention to provide a method for the detection and display of two orthogonal components of velocity within a subject.
It is another object of the present invention to provide a method for the detection and display of velocity and acceleration within a subject.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a simplified block diagram of a magnetic resonance (MR) imaging system suitable for use with the present invention.
FIG. 2 is a more detailed diagram of the magnet assembly of FIG. 1.
FIG. 3a is a graphical illustration of one embodiment of a velocity-encoding magnetic field gradient pulse sequence which is incorporated into a shear imaging pulse sequence.
FIG. 3b is a graphical illustration of a second embodiment of a velocity-encoding magnetic field gradient pulse sequence.
FIG. 4a-4c are vector illustrations of the effect of bipolar magnetic field gradient pulses on stationary spin magnetization.
FIG. 4d-4f are vector illustrations of the effect of bipolar magnetic field gradient pulses on moving spin magnetization.
FIG. 5 is a graphical illustration of the formation of an acceleration-encoding magnetic field gradient pulse by combining two velocity-encoding magnetic field gradient pulses.
FIG. 6 is pulse sequence diagram of a third embodiment of the present invention which can be used to measure velocity and acceleration, where the velocity measurement defines one dimension of the image.
FIG. 7 is a set of MR images collected using the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the present embodiment of the invention, a subject is placed within the magnet of a magnetic resonance imaging system. The region over which a motional component image is desired is then identified by an operator, perhaps with the assistance of a conventional MR imaging sequence. A pulse sequence is then applied and the data analyzed.
FIG. 1 is a simplified block diagram of the major components of a magnetic resonance (MR) imaging system suitable for use with the invention described herein. The system is made up of a general purpose mini-computer 2 which is functionally coupled to a disk storage unit 2a and an interface unit 2b. A radiofrequency (RF) transmitter 3, signal averager 4, and gradient power supplies 5a, 5b and 5c, are all coupled to computer 2 through interface unit 2b. Gradient power supplies 5a, 5b and 5c energize gradient coils 12-1, 12-2 and 12-3 to create magnetic field gradients Gx, Gy and Gz, respectively, in the "X", "Y" and "Z" directions respectively, over a subject to be imaged. RF transmitter 3 is gated with pulse envelopes from computer 2 to generate RF pulses having the required modulation to excite an MR response signal from a subject. The RF pulses are amplified in an RF power amplifier 6 to levels varying from 100 watts to several kilowatts, depending on the imaging method, and applied to a transmitter coil 14-1. The higher power levels are necessary for large sample volumes, such as in whole body imaging, and where short duration pulses are required to excite larger NMR frequency bandwidths.
The MR response signal is sensed by a receiver coil 14-2, amplified in a low noise preamplifier 9 and passed to receiver 10 for further amplification, detection, and filtering. The signal is then digitized for averaging by signal averager 4 and for processing by computer 2. Preamplifier 9 and receiver 10 are protected from the RF pulses during transmission by active gating or by passive filtering.
Computer 2 provides gating and envelope modulation for the MR pulses, blanking for the preamplifier and RF power amplifier, and voltage waveforms for the gradient power supplies. The computer also performs data processing such as Fourier transformation, image reconstruction, data filtering, imaging display, and storage functions (all of which are conventional and outside the scope of the present invention).
Transmitter coil 14-1 and receiver RF coil 14-2, if desired, may comprise a single coil. Alternatively, two separate coils that are electrically orthogonal may be used. The latter configuration has the advantage of reduced RF pulse breakthrough into the receiver during pulse transmission. In both cases, the coils are orthogonal to the direction of a static magnetic field B0 produced by a magnet means 11. The coils may be isolated from the remainder of the system by enclosure in an RF shielded cage.
Magnetic field gradient coils 12-1, 12-2 and 12-3 are necessary to provide gradients Gx, Gy and Gz, respectively, that are monotonic and linear over the sample volume. Multi-valued gradient fields cause a degradation in the MR response signal data, known as aliasing, which leads to severe image artifacts. Nonlinear gradients cause geometric distortions of the image.
Magnet assembly 11, shown schematically in FIG. 2, has a central cylindrical bore 11a which generates a static magnetic field B0, typically in the axial, or Z Cartesian coordinate direction. A set of coils 12, such as coils 12-1, 12-2 and 12-3 of FIG. 1, receive electrical signals via input connections 12a, and provide at least one gradient magnetic field within the volume of bore 11a. Also situated within bore 11a is an RF coil 14, which receives RF energy via at least one input cable 14a, to provide an RF magnetic field B1, typically in the X-Y plane.
FIGS. 3a and 3b show two embodiments of velocity-encoding magnetic field gradient pulse sequences. In FIG. 3a the magnetic field gradient has substantially zero intensity until time t=0. Beginning at t=0 and ending at t=a, a first magnetic field gradient pulse 300 is applied. Beginning at t=b and ending at t=c a second magnetic field gradient pulse 310 having substantially the same duration and intensity of the first gradient pulse, but having opposite polarity, is applied. The time interval between the two gradient pulses is T.
An alternative embodiment of this velocity-encoding gradient pulse is shown in FIG. 3b. This embodiment is similar to the embodiment shown in FIG. 3a with the exception of the addition of a refocusing RF pulse 340 placed between the gradient waveforms 320, 330 and the second waveform 330 having a polarity identical to that of the first gradient pulse 320.
The application of magnetic field gradient pulse sequences such as those of FIGS. 3a and 3b results in a phase shift in transverse spin magnetization which is directly proportional to velocity, the area of each lobe of the pulse sequence being Ag, the gyromagnetic ratio of the nuclear species being γ and the time interval between successive gradient lobes being T. This relationship is well known to those skilled in the art and can be expressed as:
Φ=γVTAg [1]
where Φ is the velocity-induced phase shift and V is the velocity component of the nuclear spin parallel to the applied magnetic field gradient. The effect of a velocity-encoding magnetic field gradient pulse on a body of stationary spin magnetization is shown in FIGS. 4a-4c. For the purpose of illustration, only vectors corresponding to the transverse magnetization of two spins at different positions in the direction of the applied velocity-encoding gradient are shown. After the generation of transverse spin magnetization by an RF pulse, all the spins have the same phase and can be represented as a single vector 400 at time t=0, as shown in FIG. 4a. At time t=a, however, each spin has acquired a phase shift which is directly proportional to its position along the magnetic field gradient, as shown in FIG. 4b. These individual vectors 410, 420 arise from spins which do not change position and thus, when the second gradient pulse is applied the phase shifts generated by the first gradient pulse are exactly cancelled by the second gradient pulse. Consequently, the phase shifts at time t=c for each spin is identical, and the two vectors coincide and are represented as a single vector 430 in FIG. 4c. The phase shift at time t=c is substantially identical to the phase shift found at time t=0.
The effect of a velocity-encoding magnetic field gradient pulse on a body of moving spin magnetization shown in FIGS. 4d-4f differs from that on a body of stationary spin magnetization shown in FIGS. 4a-4c. For the purpose of illustration, only vectors corresponding to the transverse spin magnetization of two spins traveling at the same velocity, but at different positions in the direction of the applied velocity-encoding gradient, are shown. After the generation of transverse spin magnetization by an RF pulse, all the spins have the same phase and can be represented as a single vector 450 at time t=0, as shown in FIG. 4d. At time t=a, however, each spin has acquired a phase shift which is directly proportional to its position along the magnetic field gradient as shown by vectors 460, 470 in FIG. 4e. These individual vectors arise from spins which change position with time and thus, when the second gradient pulse is applied, the phase shifts generated by the first pulse are not entirely cancelled by the second gradient pulse. Consequently, the phase shift at time t=c, represented by the single vector 480 as shown in FIG. 4f, differs from the phase shift found at time t=0 by an amount Φ. This phase shift is directly proportional to velocity V of equation 1.
FIG. 5 illustrates how higher order motion-encoding magnetic field gradient pulses can be constructed from the velocity-encoding magnetic field gradient pulses shown in FIG. 3. Since acceleration is defined as the change in velocity with respect to time, acceleration can be measured by applying a first velocity-encoding gradient pulse 510 followed by a second velocity-encoding gradient pulse 520. Second velocity-encoding gradient pulse 520 has a polarity opposite to that of first velocity-encoding pulse 510. Consequently, for spin magnetization having constant velocity, the velocity-induced phase shifts created by first velocity-encoding pulse 510 will be cancelled by the velocity-induced phase shifts created by second velocity-encoding pulse 520. If the velocity of the detected spin magnetization changes in the interval between the first and second velocity-encoding pulses, however, the cancellation of phase will be incomplete and the residual phase shift will be directly proportional to acceleration
First velocity-encoding pulse 510 and second velocity-encoding pulse 520 are combined in two different ways in FIG. 5 to generate acceleration-encoding gradient pulses. When the velocity-encoding pulses are combined and the amplitude of the gradient waveforms are conserved, an equal amplitude acceleration-encoding gradient pulse 530 is generated. If, however, the velocity-encoding pulses are combined and the lobe duration of the waveforms is conserved, an equal duration acceleration-encoding pulse 540 is generated. Note that the acceleration-induced phase shifts of equal amplitude acceleration-encoding pulse 530 are twice that of equal duration acceleration-encoding pulse 540, where the phase shift Φ acc observed with gradient 530 is:
Φ.sub.acc =4γAT.sup.2 A.sub.g ; [2]
and the the phase shift observed with gradient 540 is:
Φ.sub.acc =2γAT.sup.2 A.sub.g. [3]
FIG. 6 is a pulse sequence diagram of radio frequency (RF) pulses and magnetic field gradients employed in a third embodiment of the present invention which may be executed by the MR imaging system of FIGS. 1 and 2. Pulse sequence 800 is comprised of an excitation RF pulse 830 which is applied in the presence of a slice selective magnetic field gradient pulse 840. Excitation pulse 830 nutates spin magnetization in a selected portion of the subject. The amount of nutation can be selected by selecting the duration and amplitude of detection pulse 830. The location and size of the selected portion can be adjusted by appropriate selection of the frequency and bandwidth of RF pulse 830 and the amplitude of slice selective magnetic field gradient pulse.
After the excitation RF pulse 830 and slice selective magnetic field gradient pulse 840 are applied, a slice refocusing magnetic field gradient pulse 850 is applied. Slice refocusing gradient pulse 850 has an amplitude and duration which is selected to cause all transverse spin magnetization within the selected portion of the subject to be substantially in phase after the application of slice refocusing gradient pulse 840. In the present embodiment the product of the amplitude and duration of slice refocusing gradient pulse 850 is substantially half that of the negative of the product of the amplitude and duration of slice selective gradient pulse 840 in a manner well known to those skilled in the art.
After excitation RF pulse 830 and slice selection gradient pulse 840 have been applied, a tripolar acceleration-encoding magnetic field gradient pulse is applied in a selected direction. The acceleration-encoding pulse consists of a first acceleration-encoding magnetic field gradient pulse lobe 855a, a second acceleration-encoding magnetic field gradient pulse lobe 855b and a third acceleration-encoding magnetic field gradient pulse lobe 855c. The product of the pulse duration and amplitude of third acceleration-encoding pulse lobe 855c is substantially equal to the product of the pulse duration and amplitude of the first velocity-encoding pulse lobe 855a as described in FIG. 5. The product of the pulse duration and amplitude of second acceleration-encoding pulse lobe 855b is substantially equal to the negative of twice the product of the pulse duration and amplitude of the first velocity-encoding pulse lobe 855a as described in FIG. 5.
Successive application of first acceleration-encoding pulse lobe 855a, second acceleration-encoding pulse lobe 855b and third acceleration-encoding pulse lobe 855c to transverse spin magnetization causes a phase shift in the magnetization which is proportional to the acceleration component of the magnetization parallel to the direction of the acceleration-encoding magnetic field gradient. This phase shift can be used to distinguish accelerating from stationary and constant velocity transverse spin magnetization.
After excitation RF pulse 830 and slice selection gradient pulse 840 have been applied, a bipolar phase encoding magnetic field gradient pulse of a selected amplitude is applied. The bipolar phase-encoding pulse consists of a first phase-encoding magnetic field gradient pulse lobe 860a and a second phase-encoding magnetic field gradient pulse lobe 860b. Phase encoding gradient pulse lobes 860a, 860b are applied in a direction independent of acceleration-encoding gradient pulses 855a, 855b, 855c and can be applied simultaneously with slice refocusing pulse 850 if desired. For the sake of clarity, phase encoding pulse lobes 860a, 860b, acceleration-encoding pulses 855a, 855b, 855c and slice refocusing pulse 850 are not shown to be simultaneous in FIG. 7, but it is possible to apply combinations of these pulses simultaneously.
After excitation RF pulse 830 and slice selective gradient pulse 840 have been applied, a readout dephasing magnetic field gradient pulse 870 of a selected amplitude is applied. Readout dephasing gradient pulse 870 is applied in a direction substantially orthogonal to slice selective gradient pulse 840. Readout dephasing pulse 870 can be applied simultaneously with either slice refocusing pulse 850 or phase encoding pulse lobes 860a, 860b if desired. Readout dephasing pulse 870 causes transverse magnetization at different positions along the direction of the readout dephasing magnetic field gradient to obtain phase shifts which are proportional to position in the readout direction.
Following the application of slice refocusing pulse 850, phase encoding pulse lobes 860a, 860b and readout dephasing pulse 870, a readout magnetic field gradient pulse 880 is applied. Readout pulse 880 is applied in the same direction as readout dephasing pulse 870, but is given the opposite polarity. The amplitude and duration of readout pulse 880 is selected so that substantially all transverse spin magnetization has an identical phase shift at a selected point during readout pulse 880.
Substantially simultaneously with readout pulse 880, a data acquire signal pulse 890 is sent to a data acquisition subsystem which is part of the imaging system. MR signals are digitized during data acquire pulse 890. Since the MR signals coming from transverse spin magnetization within the selected portion of the subject are acquired during readout magnetic field gradient 880, each detected MR signal will have a frequency which is proportional to the location of the position of the transverse spin magnetization which generated said signal. The location of each signal source can be determined by applying a Fourier transformation to the acquired signal data in a fashion well known to those skilled in the art.
In the present invention pulse sequence 800 is repeated a plurality, N, times to form a single frame of data which has sufficient information to permit the measurement of at least one component of motion. The acquisition of a frame is repeated a plurality, Y, times. In each frame acquisition, phase encoding pulse lobes 860a, 860b are given a different amplitude. Phase encoding pulse lobes 860a, 860b cause phase shifts in the detected MR signals which are proportional to the velocity of transverse spin magnetization in the direction of phase encoding magnetic field gradient lobes 860a, 860b. Data acquired responsive to different amplitudes of phase encoding gradient lobes 860a, 860b can be Fourier transformed to give the velocity (in the direction of phase encoding gradient lobes 860a, 860b) of the signal producing transverse spin magnetization in a manner well known to those skilled in the art.
In the present embodiment of the present invention, each frame consists of N=2 applications of pulse sequence 800. In the first application, acceleration-encoding gradient pulses 855a, 855b, 855c are applied with a selected polarity. This causes the phase of the transverse spin magnetization to be proportional to the component of acceleration in the direction of acceleration-encoding gradient pulses 855a, 855b, 855c. The phase of each portion of transverse spin magnetization, however, will also have contributions from sources other than acceleration. These sources may include transmitter offsets, chemical shift effects and eddy currents.
In order to remove contributions from all components other than acceleration, pulse sequence 800 is applied a second time and a second data set is acquired. The RF and magnetic field gradient pulses of the second application are identical to that of the first with the exception of first acceleration-encoding pulse lobe 855a, second acceleration-encoding pulse lobe 855b and third acceleration-encoding pulse lobe 855c. In their place a fourth acceleration-encoding pulse lobe 855d followed by a fifth acceleration-encoding pulse lobe 855e and a sixth acceleration-encoding pulse lobe 855f are applied. Fourth, fifth and sixth acceleration-encoding pulse lobes 855d, 855e, 855f are identical to first, second and third acceleration-encoding pulse lobes 855a, 855b, 855c respectively, except that they have opposite polarity. Data collected in the first application is then subtracted from data collected in the second application to give a difference data set. Phase shifts induced by the fourth, fifth and sixth acceleration-encoding gradient lobes have opposite polarity relative to the phase shifts induced by the first, second and third acceleration-encoding gradient lobes. When the phase of data acquired responsive to the first application of pulse sequence 800 is subtracted from the phase of the data acquired responsive to the second application of pulse sequence 800, phase contributions from all non-acceleration sources are substantially canceled, leaving only a phase shift arising from acceleration. This phase shift is directly proportional to acceleration and can be used to quantify acceleration.
FIG. 7 shows the MR response signals for one application of the present invention. These images were obtained from a phantom constructed with a rigid tube. Non-steady flow of water in the tube was accomplished by attaching the phantom to an oscillating pump. The oscillating pump caused the velocity of water within the phantom to accelerate and decelerate with a period of approximately one second. A series of nine images, each acquired afar a selected delay from a trigger signal generated by the pump, were obtained.
In the images of FIG. 7, the horizontal axis of each image is a spatial dimension across the diameter of the tube. The vertical axis of each image is velocity in the axial direction of the tube. The MR response signals are complex in nature and each image in FIG. 7 has two parts. The first part, shown in each upper frame, is the magnitude of the MR response signal. Pixels in the magnitude image have an intensity proportional to the number of nuclear spins having the velocity and location corresponding to the pixel. Pixels in the phase image, lower frame of each, however, have an intensity proportional to the acceleration of the nuclear spins having the velocity and location corresponding to the pixel. Note that in the sixth frame, the water in the tube exhibits simultaneously regions of acceleration and deceleration.
The present invention has several applications in medical imaging. For example, it may be used to examine the velocity profile within a selected blood vessel. Pulsatile flow in a normal vessel is known to be very different of that having stenosis. Simultaneous detection of both velocity and acceleration may be particularly useful in measuring the physiological state of the blood vessel. This may be very useful in predicting arteriosclerotic disease.
Numerous additional embodiments of the present invention should be apparent to those skilled in the art. For example, the velocity and acceleration encoding gradient pulses used in the previously described embodiments can be replaced with encoding gradient pulses which induce phase shifts from higher orders of motion such as jerk. These gradient pulses can be constructed by taking linear combinations of velocity and acceleration encoding gradients in a manner analogous to that illustrated in FIG. 5. Other embodiments of the present invention can be created by adding additional phase-encoding gradient pulses to form additional dimensions in the resulting image. These dimensions can be spatial, velocity, acceleration or higher order components of motion.
While several presently preferred embodiments of the novel MR motion imaging method have been described in detail herein, many modifications and variations will now become apparent to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations as fall within the true spirit of the invention.
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A motion imaging method uses magnetic resonance to detect acceleration, and an velocity distribution within moving materials in a subject. Acceleration encoding is performed by computing differences of data obtained with modulated motion-encoding magnetic field gradient pulses. Distributions of velocity are measured responsive to a motion sensitive phase-encoding gradient pulse.
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TECHNICAL FIELD
The present disclosure relates to an EGR device having a diffusing device for an internal combustion engine of a vehicle. The present disclosure further relates to an EGR mixer for the EGR device.
BACKGROUND
A vehicle may be equipped with an exhaust gas recirculation system (EGR system). The EGR system is to reduce emission contained in exhaust gas discharged from an internal combustion engine. The EGR system may recirculate a part of exhaust gas into fresh air to produce mixture gas containing recirculated exhaust gas and fresh air. Recirculated exhaust gas may be unevenly mixed with fresh air to reduce combustion efficiency of the engine consequently.
SUMMARY
The present disclosure addresses the above-described concerns.
According to an aspect of the preset disclosure, an EGR device comprises a housing defining an inner passage internally and having an EGR inlet. The EGR device further comprises a diffusing device extended from the EGR inlet into the inner passage. The diffusing device is a hollow member having at least one wall, a root end, and a tip end defining an interior. The at least one wall has a plurality of through holes communicating the interior with the inner passage. The tip end is twisted relative to the root end.
According to another aspect of the preset disclosure, an EGR mixer is configured to be accommodated in a housing of an EGR device. The housing defines an inner passage internally and having an EGR inlet. The EGR mixer comprises a diffusing device body configured to be extended from the EGR inlet into the inner passage. The diffusing device body is a hollow member having a wall, a root end, and a tip end defining an interior. The wall has a plurality of through holes configured to communicate the interior with the inner passage. The tip end is twisted relative to the root end.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:
FIG. 1 is a block diagram showing an EGR system for an internal combustion engine of a vehicle;
FIG. 2 is a partially sectional view showing an EGR device for the EGR system, according to a first embodiment;
FIG. 3 is a sectional view showing the EGR device, the sectional view corresponding to a section taken along the line III-III in FIG. 2 ;
FIG. 4 is a view showing the EGR device viewed from a downstream side;
FIG. 5 is a view showing a diffusing device of the EGR device;
FIG. 6 is a schematic view showing the diffusing device viewed along the arrow VI in FIG. 5 ;
FIG. 7 is a perspective view showing the EGR device; and
FIG. 8 is a partially sectional view showing an EGR device according to a second embodiment.
DETAILED DESCRIPTION
First Embodiment
In the following description, a radial direction is along an arrow represented by “RADIAL” in drawing(s). An axial direction is along an arrow represented by “AXIAL” in drawing(s). A circumferential direction is along an arrow represented by “CIRCUMFERENTIAL” in drawing(s). A vertical direction is along an arrow represented by “VERTICAL” in drawing(s). A horizontal direction is along an arrow represented by “HORIZONTAL” in drawing(s). A width direction is along an arrow represented by “WIDTH” in drawing(s). A length direction is along an arrow represented by “LENGTH” in drawing(s). A flow direction is along an arrow represented by “FLOW” in drawing(s).
As follows, a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 7 . As shown FIG. 1 , according to the present example, an internal combustion engine 150 is connected with an intake manifold 148 and an exhaust manifold 142 .
The engine 150 is combined with an intake and exhaust system. The intake and exhaust system includes an intake valve 110 , an intake passage 112 , an EGR device 10 , a mixture passage 122 , a turbocharger including a compressor 130 and a turbine 160 , a charge air passage 142 , and an intercooler 140 . The intake and exhaust system further includes a combustion gas passage 158 , an exhaust passage 162 , an EGR passage 172 , an EGR cooler 180 , and an EGR valve 90 .
The intake passage 112 is equipped with the intake valve 110 . The intake passage 112 is connected with the EGR device 10 . The EGR device 10 is connected with the compressor 130 through the mixture passage 122 . The compressor 130 is connected with the intake manifold 148 through the charge air passage 142 . The charge air passage 142 is equipped with the intercooler 140 . The exhaust manifold 142 is connected with the turbine 160 through the combustion gas passage 158 . The turbine 160 is connected with the exhaust passage 162 . The EGR passage 172 is branched from the exhaust passage 162 and connected with the EGR device 10 . The EGR passage 172 is equipped with the EGR cooler 180 and the EGR valve 90 .
The intake passage 112 conducts fresh air from the outside of the vehicle through the intake valve 110 into the EGR device 10 . The intake valve 110 regulates a quantity of fresh air flowing through the intake passage 112 into the EGR device 10 . The EGR device 10 draws fresh air from the intake passage 112 and draws exhaust gas from the exhaust passage 162 through the EGR passage 172 . The EGR device 10 includes an EGR mixer to blend the drawn fresh air with the drawn exhaust gas to produce mixture gas. The mixture passage 122 conducts the mixture gas from the EGR device 10 into the compressor 130 .
The compressor 130 is rotatably connected with the turbine 160 via a common axis. The compressor 130 is driven by the turbine 160 to compress the mixture gas. The charge air passage 142 conducts the compressed mixture gas to the intake manifold 148 . The intercooler 140 is a heat exchanger to cool the compressed mixture gas conducted through the charge air passage 142 .
The engine 150 draws the cooled mixture gas. The engine 150 forms air-fuel mixture with the drawn mixture gas and injected fuel in each cylinder and burns the air-fuel mixture in the cylinder to drive a piston in the cylinder. The engine 150 emits combustion gas (exhaust gas) through the exhaust manifold 142 into the combustion gas passage 158 . The combustion gas passage 158 conducts the combustion gas into the turbine 160 . The turbine 160 is driven by the exhaust gas to drive the compressor 130 thereby to cause the compressor 130 to compress mixture gas and to press-feed the compressed mixture gas through the charge air passage 142 and the intercooler 140 into the engine 150 .
The exhaust passage 162 conducts exhaust gas (combustion gas) from the turbine 160 to the outside of the vehicle. The EGR passage 172 is branched from the exhaust passage 162 at the downstream side of the turbine 160 to recirculate a part of exhaust gas from the exhaust passage 162 into the EGR device 10 . The EGR cooler 180 is a heat exchanger to cool exhaust gas flowing though the EGR passage 172 into the EGR device 10 . The EGR device 10 is located at a connection among the intake passage 112 , the EGR passage 172 , and the mixture passage 122 . The EGR passage 172 is merged with the intake passage 112 in the EGR device 10 . The EGR valve 90 regulates a quantity of EGR gas recirculated through the EGR passage 172 into the EGR mixer.
As described above, the EGR system is configured to recirculate a part of exhaust gas from the exhaust passage 162 into the intake passage 112 . The circulated exhaust gas may contain oxygen at a lower percentage compared with oxygen contained in fresh air. Therefore, circulated exhaust gas may dilute mixture of exhaust gas and fresh air thereby to reduce peak temperature of combustion gas when burned in the combustion chamber of the engine 150 . In this way, the EGR system may reduce oxidization of nitrogen, which is caused under high temperature, thereby to reduce nitrogen oxide (NOx) occurring in the combustion chamber.
Subsequently, the configuration of the EGR device 10 will be described in detail. As shown in FIGS. 2 to 4 , the EGR device 10 includes a housing 20 accommodating a diffusing device (diffusing device body) 60 . The diffusing device 60 may function as an EGR mixer. The housing 20 and the diffusing device 60 are formed of a metallic material such as stainless steel and/or an aluminum alloy.
The housing 20 includes an air inlet 22 , a housing body 40 , an outlet 26 , and an EGR inlet 28 . The air inlet 22 is connected with the intake passage 112 . The outlet 26 is connected with the mixture passage 122 . The housing body 40 is located between the air inlet 22 and the outlet 26 . In the present example, the air inlet 22 , the housing body 40 , and the EGR inlet 28 are integrally formed with each other, and the outlet 26 is affixed to the housing body 40 by, for example, welding. The housing body 40 has an inner periphery, which defines an inner passage 42 communicated with the intake passage 112 and the mixture passage 122 .
The EGR inlet 28 is connected with the EGR passage 172 . The EGR inlet 28 defines an EGR channel 46 internally. The EGR channel 46 extends along the radial direction through the EGR inlet 28 . The EGR channel 46 is directed substantially at 90 degrees relative to a center axis 40 AX of the housing body 40 . The EGR channel 46 is defined with a curvature surface, which is in a funnel shape gradually reducing in cross section toward the inner passage 42 .
The diffusing device 60 is inserted through the EGR channel 46 into the inner passage 42 . The diffusing device 60 is affixed to the housing 20 at a root end 62 (one end) by, for example, welding or crimping, such that an opening 62 A of the diffusing device 60 is communicated with the EGR channel 46 . The diffusing device 60 may be in contact with the inner periphery of the housing body 40 at a tip end 66 (other end). In this case, the diffusing device 60 may be supported at the root end 62 and the tip end 66 .
The diffusing device 60 is projected from the EGR channel 46 radially inward into the inner passage 42 . The diffusing device 60 is extended into the inner passage 42 and inclined from the EGR inlet 28 toward the downstream side. That is, the diffusing device 60 is inclined relative to a center axis 46 AX of the EGR channel 46 .
The diffusing device 60 is a twisted hollow object having multiple through holes 68 . The diffusing device 60 may be formed by, for example, deep-drawing a metallic plate into a bottomed hollow case, forming the through holes 68 on walls, and twisting the bottomed hollow case. Alternatively, the diffusing device 60 may be formed by, for example, forming twisted metallic plates, forming through holes 68 in the twisted plates, and combining the twisted plates by, for example, welding into the twisted hollow object. The diffusing device 60 may be formed by various methods such as injection molding or 3D-printing of a resin or metallic material.
The diffusing device 60 has an intermediate portion 64 between the root end 62 and the tip end 66 . The intermediate portion 64 is formed with an upstream wall 52 , lateral walls 54 and 56 , and a downstream wall 58 . The upstream wall 52 is located on the upstream side of the lateral walls 54 and 56 relative to the fresh air flow. The downstream wall 58 is located on the downstream side of the lateral walls 54 and 56 relative to the mixture gas flow. The root end 62 , the intermediate portion 64 , and the tip end 66 define an interior 60 A inside the diffusing device 60 . The interior 60 A of the diffusing device 60 communicates with the EGR channel 46 through the opening 62 A of the root end 62 . The tip end 66 forms the bottomed end of the diffusing device 60 . The tip end 66 has a convex cross section projected toward the inner periphery of the housing body 40 . The tip end 66 may have a curvature along the inner periphery of the housing body 40 to enable the tip end 66 to be fitted to the housing body 40 . The inner periphery of the housing body 40 may be equipped with a bracket and/or a dent to retain the tip end 66 .
In FIG. 4 , the housing body 40 has a cross section having a vertical center 40 V, a horizontal center 40 H, and a center point 40 C, which is an intersection between the vertical center 40 V and the horizontal center 40 H. The downstream wall 58 has through holes 68 arranged in one row along an imaginary line 58 B. The imaginary line 58 B may be substantially in parallel with sidelines 58 A of the downstream wall 58 . The imaginary line 58 B may be a centerline of the downstream wall 58 and may extend along the vertical center 40 V at the root end 62 to be veered from the vertical center 40 V toward the tip end 66 .
FIG. 5 is a side view showing the diffusing device 60 . In FIG. 5 , the upstream wall 52 and the lateral walls 54 and 56 form sidelines 52 A therebetween. The lateral walls 54 and 56 and the downstream wall 58 form the sidelines 58 A therebetween. Each of the sidelines 52 A and 58 A is defined by, for example, a combination of two or more arcs. In the present example, the sideline 52 A includes an upper sideline 52 A 1 and a lower sideline 52 A 2 , and the sideline 58 A includes an upper sideline 58 A 1 and a lower sideline 58 A 2 . Each of the upper sidelines 52 A 1 and 58 A 1 is in an arc shape convex downward (in one direction) in the drawing. Each of the lower sidelines 52 A 2 and 58 A 2 is in an arc shape convex upward (in another direction) in the drawing. The diffusing device 60 having the upper sidelines 52 A 1 and 58 A 1 and the lower sidelines 52 A 2 and 58 A 2 may form the interior 60 A, which is bent twice from the root end 62 toward the tip end 66 while being twisted.
The lateral wall 54 has the through holes 68 arranged in two rows along imaginary lines 54 A and 54 B respectively. The lateral wall 56 has the through holes 68 arranged in two rows along imaginary lines (not shown) respectively, similarly to the lateral wall 54 . That is, the through holes 68 are arranged substantially along the length direction of the diffusing device 60 . Each of the imaginary lines 54 A and 54 B may be in parallel with the sidelines 52 A and 58 A. The through holes 68 adjacent to each other in the width direction are arranged alternately. That is, the through holes 68 are arranged in a zigzag form from the root end 62 toward the tip end 66 .
FIG. 6 is a schematic top view showing the diffusing device 60 . In FIG. 6 , the tip end 66 is hidden by the lateral walls 54 and 56 and the downstream wall 58 and is shown by dotted lines. In FIG. 6 , through holes 68 are omitted. In the present example, the shape of the tip end 66 is substantially identical to the shape of the root end 62 . The upstream wall 52 has a convex cross section projected toward the upstream side of fresh air. Each of the downstream wall 58 and the lateral walls 54 and 56 substantially has a flat cross section. In FIG. 6 , the root end 62 has a centerline (root center) 62 C shown by a chain line, and the tip end 66 has a centerline (tip center) 66 C shown by a chain line. The tip center 66 C is inclined relative to the root center 62 C by a twisted angle A. The twisted angle A may be, for example, about 30 degrees. The twisted angle A may be in a range between 0 degree and 45 degree or may be in a range between 15 degree and 40 degree. The twisted angle A may be determined in consideration of a mixing effect of fresh air and EGR gas and blockage of the inner passage 42 caused by the lateral wall 54 faced to the upstream side of the mixture gas flow.
In FIG. 7 , the EGR inlet 28 may have screw holes 28 A screwed with the EGR passage 172 . The present configuration enables to flow EGR gas from the EGR passage 172 ( FIG. 1 ) to pass through the EGR channel 46 into the interior 60 A of the diffusing device 60 . The diffusing device 60 enables EGR gas to further flow from the interior 60 A through the through holes 68 into the inner passage 42 . The through holes 68 extend through the lateral walls 54 and 56 and the downstream wall 58 ( FIG. 5 ). The present configuration enables to flow EGR gas from the interior 60 A of the diffusing device 60 through the through holes 68 into the inner passage 42 . After passing through the through holes 68 , EGR gas may be expanded and diffused into fresh air passing through the inner passage 42 . Thus, the present configuration may enable EGR gas to be homogeneously and evenly blended with fresh air in the inner passage 42 to produce uniform mixture gas.
The diffusing device 60 has the twisted configuration to form the interior 60 A twisted from the upstream to the downstream in the flow direction. The present configuration may cause turbulence in the EGR gas flow through the interior 60 A of the diffusing device 60 and through holes 68 . In addition, the lateral walls 54 and 56 being twisted may deflect fresh air to cause turbulence in the fresh air.
In the present example, the upstream wall 52 does not have a through hole. Therefore, the upstream wall 52 may baffle EGR gas flow incoming from the opening 62 A, thereby to reflect the EGR gas flow toward the lateral walls 54 and 56 and the downstream wall 58 . In this way, the diffusing device 60 may rectify the EGR gas flow toward the downstream side lengthwise in the diffusing device 60 . Thus, the diffusing device 60 may rectify the EGR gas flow and to diffuse EGR gas through the through holes 68 . The diffusing device 60 may enable to lead EGR gas beyond the center of the inner passage 42 to the radially opposite side of the EGR channel 46 . That is, the diffusing device 60 may enable EGR gas to access the opposite side of the diffusing device 60 from the EGR channel 46 .
Second Embodiment
As shown in FIG. 8 , according to the present second embodiment, a diffusing device 260 is shorter than the diffusing device 60 in the first embodiment. The housing 20 is substantially identical to that of the first embodiment.
The diffusing device 260 according to the present second embodiment extends to the center of the inner passage 42 . The diffusing device 260 has a tip end 266 distant from the inner periphery of the housing body 40 . The diffusing device 260 is cantilevered at a root end 262 . The tip end 266 is located around the center axis 40 AX of the housing body 40 .
Similarly to the first embodiment, the diffusing device 260 has an intermediate portion 264 between the root end 262 and the tip end 266 , and the intermediate portion 264 is formed with an upstream wall 252 , lateral walls 254 and 256 , and a downstream wall 258 . The diffusing device 260 has a twisted configuration.
In the present example, the diffusing device 260 has through holes 68 selectively around the tip end 266 . More specifically, the through holes 68 form an array centered around the center axis 40 AX of the housing body 40 . That is, the diffusing device 260 does not have the through holes 68 at the side of the root end 262 . According to the present embodiment, the through holes 68 are selectively (mainly) formed around the tip end 66 located close to the center of the inner passage 42 . The present configuration may concentrate the EGR gas flow around the center of the inner passage 42 to diffuse EGR gas radially from the center of the inner passage 42 .
The through holes 68 are located selectively on the downstream side in the lateral walls 254 and 256 . For example, in the lateral walls 254 and 256 , the number of the through holes 68 on the downstream side may be larger than the number of the through holes 68 on the upstream side. For example, in the lateral walls 254 and 256 , the through holes 68 may be located only on the downstream side relative to a center of the diffusing device 260 in the width direction.
Other Embodiment
The shape of the diffusing device is not limited to the above examples, and may be in various forms. The upper sideline and the lower sideline may not be arc lines and may be in various shapes.
The tip end may be different in shape from the root end. The tip end may be reduced in cross section relative to the root end.
Various combinations of the features such as the arrangement of the through holes and the twisted angle according to the above-described embodiments may be arbitrary employed.
The through holes may employ various forms. For example, the through holes may employ various numbers, various sizes, various arrangements, and/or various shapes. For example, the through holes may employ various shapes such as an oval shape, a polygonal shape, or a star shape. Various combinations of the through holes of the above-described embodiments may be arbitrary employed. The through holes may be unevenly arranged.
It should be appreciated that while the processes of the embodiments of the present disclosure have been described herein as including a specific sequence of steps, further alternative embodiments including various other sequences of these steps and/or additional steps not disclosed herein are intended to be within the steps of the present disclosure.
While the present disclosure has been described with reference to preferred embodiments thereof, it is to be understood that the disclosure is not limited to the preferred embodiments and constructions. The present disclosure is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, which are preferred, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the present disclosure.
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A housing has an housing body. An inner pipe is accommodated in the housing body. The inner pipe defines an inner passage internally. The inner pipe defines an annular passage externally with the housing body. The inner pipe has through holes 68 communicating the inner passage with the annular passage. The housing internally defines an EGR channel communicating with the annular passage. The EGR channel accommodates a diffusing device 60 partitioning the EGR channel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to warp knitting machines and, in particular, to machines having a jacquard arrangement.
2. Discussion of the Relevant Art
The invention concerns warp knitting machines for producing patterned goods. This machine has thread guides which are movable by a jacquard arrangement along their longitudinal axis at an acute angle relative to the guide bar carrying them.
In a known warp knitting machine of this type (U.S. Pat. No. 3,099,921) the thread guides having eyelets, are caused to move in a vertical plane. Threads run directly from the eyelet of the guides to the needle bed. Since the eyelet of the guide has a determinable height with respect to the needle bed during the swinging motion of the guide bar, the thread may be placed in a determinable passage between the needles. Unfortunately, it has been observed that many pattern errors occur at this step. These errors increase in proportion to the speed of the machine and the narrowness of the gap between the needles.
U.S. Pat. No. 3,834,193 discloses the use of thread guides which are laterally displaced by interaction with jacquard controlled dropper bars. However, with this technique similar pattern errors also occur.
A further type of warp knitting machines is known (DE-PS No. 1585536) wherein each needle passage is provided with a thread positioning sinker having an angled surface on its leading edge which has the task of laying the threads, which run diagonally in front of the needles, directly into the appropriate needle passage. The threads are led via eyelets in steel bands whose sideward displacement produces the pattern. Unfortunately, the number of patterning possibilities in this mode is limited and may only be increased by the provision of a substantial number of steel bands. It also has been noted that the diagonal portion of the sinker causes substantial damage to the threads by friction, sideward displacement and cutting.
U.S. Pat. No. 2,480,231 further discloses an alternative for the thread guide and is eyelet which avoids running the thread through an S-shaped path. This mode utilitzes thread guiding sinkers in the form of an upwardly open hook wherein the free ends of the hooks are protected by a U-shaped rail.
SUMMARY OF THE INVENTION
Therefore, it is one object of the present invention to provide a warp knitting machine arranged in such a way as to avoid the patterning errors heretofore observed with jacquard controlled thread guides.
It is another object of the present invention to provide a reciprocatable thread guide moving relative to a needle bed and to thread positioning sinkers in such a way that threads are rapidly and accurately laid between adjacent needles.
A warp knitting machine according to the principles of the present invention has a needle bed and a jacquard arrangement for producing patterned wear from a plurality of threads. The machine also has a thread positioning bar and a plurality of thread positioning sinkers mounted on the thread positioning bar. The sinkers are spaced to allow the sinkers to pass between the needles of the needle bed. The machine also includes at least one guide bar and a plurality of thread guides mounted on each guide bar. The guides can separately guide the threads and can be operated by the jacquard arrangement to move longitudinally relative to the guide bar, with a component of motion in a plane alongside the needle bed. This component is sized to allow each of the threads to reciprocate between and be pulled against the interior sides of a corresponding, neighboring pair of the sinkers.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a cross sectional view through the working portion of a warp knitting machine according to the teachings of the present invention;
FIG. 2 is a schematic and perspective representation of the working area of FIG. 1 together with a jacquard arrangement;
FIG. 2A is an elevational view of the apparatus of FIG. 2;
FIG. 3 is a detailed cross sectional view of a portion of the apparatus of FIG. 1 showing the thread guide in its lowest position during the passage of the hook of the sinker through the needle passage;
FIG. 4 is another detailed cross sectional view of a portion of the apparatus of FIG. 1, showing the thread guide raised at the peak of its swing;
FIG. 5 is a cross sectional view of a guide bar which is an alternate to that of FIG. 1;
FIG. 6A is a partially sectioned view of a thread guide which is an alternate to that of FIG. 1; and
FIG. 6B is a side view of the guide of FIG. 6A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the working area of a warp knitting machine is shown including a needle bar 1 supporting a plurality of latch needles 2 (one of them being illustrated). A plurality of knock over sinkers 3 (one of them being illustrated) are attached to a bar 4. Needles 2 can vertically reciprocate in a conventional manner. Two pluralities of thread guides 9 and 10 (one from each plurality being illustrated) are attached to guide bars 5 and 6, respectively, which are arranged to swing past needles 2. A plurality of thread guides 11 (one of them being illustrated) shaped as rods ending with transverse eyelets are slidably mounted in matching holes in guide bar 12. Guides 11 can reciprocate, as described hereinafter, by the action of a jacquard arrangement. A plurality of thread positioning sinkers 13 (one of them being illustrated) are affixed to a thread positioning bar 14. The thread positioning sinkers 13 are provided in the form of an upwardly open hook, whose free end has a rearwardly directed protrusion. As explained further hereinafter, the purpose of the protrusion is to help maintain thread within the hook when guide bar 14 makes a substantial movement, notwithstanding forces from the guides in front of sinkers 13. Sinkers 13 are spaced preferably with the same center to center spacing as needles 2 and guide 11. Bars 5,6,12 and 14 are all mounted so they can swing past needles 2 with the motion indicated by arrow 15.
Referring to FIGS. 2 and 2A, the working area of a warp knitting machine is shown including some of the apparatus of FIG. 1, but excluding guide bars 5 and 6 and their associated guides. Guide bar 12 is a channel-shaped member having a plurality of apertures along both of its legs into which guides 11 are slidably mounted. Guides 11 are laid at an acute angle, preferably 45°, to the length of guide bar 12 so, when moved, they have a component of motion along the axis of needle bed 1.
Threads 21 are shown passing through eyelets 20 of guides 11, between a corresponding space between sinkers 13 and past needles 2. Each of the guides 11 have two extreme positions, illustrated herein as positions A and B. Guides 11 are urged into position A by a spring (not shown) within bar 12. With such construction, threads 21 can be displaced along the longitudinal axis of needle bed 1 by thread guides 11. By this means threads 21 can, to a certain extent, be directed into passages between needles 2. The path constituting the transition of each of the guides 11 from its position A to B, contains a directional component parallel to the longitudinal axis of needle bed 1 of such an order of magnitude that each of threads 21 at one extreme position of thread guide 11 can lay against the side of a given one of thread positioning sinkers 13 and at the other extreme position lay against the side of a neighboring thread positioning sinker facing that given one.
Each of the guides 11 have attached to their upper ends control cords 16 which are colinear with the extension of the longitudinal axis of each of the guides 11. Thus aligned, guides 11 are not biased by a force acting perpendicular to their bearings. Cords 16 run through eyelets 17 of eyelet bar 18 and thereafter terminate in and are controlled by conventional jacquard arrangement 19.
The motion of the jacquard control threads in the eyelet board is no source of problems. Jacquard arrangement 19 can draw or release individual ones of the cords 16 according to a predetermined pattern. By means of jacquard arrangement 19, guides 11 and their eyelets 20 can be moved from lower, right hand position A to upper, left hand position B. By sending guides 11 from position A to B, the associated thread 21 moves from one passage between neighboring needles to the next one on the left (and vice versa).
In the area of the hook of sinker 13, the displacement of thread 21 is not 100% of the inter-needle spacing but somewhat less. The horizontal component of the displacement of guide 11, on the other hand, is somewhat greater than one needle space. Because of their registration with the spaces between needles 2, thread positioning sinkers 13 can readily lead thread 21 between needles 2 and thereby avoid misplacement and patterning errors.
Bars 12 and 14 are mounted so they can reciprocate in a direction parallel to the length of needle bed 1 but are biased to the right by unillustrated springs. Two pattern wheels 24 and 25 having a radius that varies along their circumferences are mounted on a common shaft 23 which rotates in proportion to the number of knitting cycles of the machine of FIG. 2. Push rods 26 and 27 are mounted on bars 12 and 14, respectively, and terminate in rollers. The rollers of push rods 26 and 27 ride the periphery of pattern wheels 24 and 25, causing the bars to move in a predetermined pattern. The extent of travel produced by wheels 24 and 25 can be one or more needle spaces. In particular cases, it may be desirable to displace positioning bar 14 with respect to the guide bar 12 a predetermined amount. This has the consequence that all of the threads are laid on the same side of the appropriate sinkers 13 irrespective of whether guides 11 are in position A or B.
For some embodiments the additional guide bar 12a, shown herein in phantom, can be employed. Second guide bar 12a is also provided with jacquard controlled, angled, thread guides (not shown) and is similarly controlled by a pattern wheel and push rod, neither of which are illustrated. In these circumstances, the separate threads handled by bars 12 and 12a can be positioned by the same sinkers 13, one sinker possibly receiving more than one thread. Thus bar 12a, having the same structure as bar 12 makes it possible for sinkers 13 to operate not only the system of threads 21 but a second entirely independent thread system.
The motion produced by the jacquard arrangement is equivalent to moving threads 21, one needle space. This displacement can be in addition to the motion provided to the guide bar itself by pattern wheels 24 and 25. This thus provides a multiple patterning possibility. An even greater choice is provided by the use of additional guide bars 12a with jacquard-controlled guides.
It is clear that the range of travel of the thread guide 11 can be kept rather small. It can, in fact, be reduced to the order of about 8 mm so that it is possible to work even with rather high machine speeds.
Thread positioning sinker 13 has the form of a hook 28 having an upwardly directed opening (FIGS. 3 and 4) and a rearwardly directed protrusion 29 at its free end. An eyelet 30 is provided in this protrusion through which wire 31 may be run along the entire breadth of the machine to provide additional security against thread misplacement. The protrusion assists in holding thread 21 in place when a substantial swing to the right is required. For example, when several guide bars are present and thus the thread 21 is turned through an angle (See FIG. 4). (In contrast, in the position of FIG. 3, the thread (not illustrated) runs to needle 2 without a substantial amount of turning from eyelet 20.) Thread 21 lies in front of bar 12 and behind wire 31. Wire 31, however, is not critical and need not be present in all embodiments. While the purpose of wire 31 is a safeguard against the slipping of the thread from the space between the sinkers 13, the threads are usually pulled into the hook space of sinkers 13 and the wire plays almost no part in setting up a frictional effect.
In operation the thread guides 11 swing between the front and the back of needle bed 1 to execute an lapping or a laying motion about needles 2. To effect such motion, thread guide bar 12 can move laterally a number of needle spaces determined by pattern wheel 24 during the course of the knitting cycle. It is presently assumed that control strings 16 have not retracted thread guides 11 so that each is in its "A" position. It is also assumed that pattern wheel 25 is in an interval wherein push rod 27 does not move. Accordingly, the machine of FIG. 2 can produce knitted goods having a consistent pattern.
In response to patterning action from jacquard arrangement 19, certain ones of the thread guides 11 are drawn causing them to move from position A to B. Consequently, selected ones of threads 21 can shift to an adjacent (left in this view) passage between needles 2. This retraction of guide 11 can change the net motion undertaken by selected threads, thereby altering the texture of the knitted goods at certain positions to produce a predetermined pattern in the wear produced by the machine of FIG. 2. This readjustment by the jacquard arrangement 19 of thread guides 11 can persist for one or more machine cycles and then change again to produce a varying pattern.
It is also desirable that under some circumstances, sinkers 13 move relative to thread guide bar 12 so that all of the threads 21 are driven to the left (or alternatively to the right) side of sinker 13. This results in threads 21 being uniformly distributed throughout the knitted wear and, in effect, overrides any pattern that might otherwise be produced by jacquard arrangement. It will be appreciated, therefore, that the extent to which threads 21 are moved is a combination of the relative motion of guide bars 12 and 14 as well as thread guides 11.
It is important to note that by moving threads 21 against the side of thread positioning sinkers 13, the threads can be accurately held in a predetermined position. Therefore, threads 21 can swing through the spaces between needles 2 accurately and with little chance of thread misplacement. Thus, disturbances ordinarily encountered with jacquard controlled thread guides are avoided since, even at high speeds, such disturbances from the jacquard arrangement are not transferred to that portion of the thread which passes between needles 2 because the thread is held against thread positioning sinkers 13.
FIG. 5 shows a cross section of a particular mode of guide bar. The bar has a substantially U-shaped profile 32, whose lower arm is extended to form the thread guiding bar 14 so that both bars comprise a single structural unit which may be driven by a single pattern wheel. The thread guide 11 is surrounded by a biasing spring 34 which bears against striker portion 33 to urge guide 11 downwardly. An aperture at the upper end of guide 11 for the connection thereto of jacquard cord 16 can draw guide 11 to an upper position, shown in phantom.
The foregoing unitary construction achieves the desirable feature of keeping thread positioning sinkers 13 at a fixed position with respect to guide bar 12, even as it carries out a patterning displacement in the direction of the longitudinal axis of the needle bed. In this manner, a preset arrangement is maintained in the direction of the needle bed axis. Also for swinging motions, attachment of thread positioning bar 14 to guide bar 12 achieves an optimal mutual arrangement between them which, once set, persists regardless of whether these parts swing with respect to a fixed needle bed or, conversely, the needle bed swings with respect to a fixed guide bar and thread patterning bar.
In FIGS. 6A and 6B, thread guide 36 is shown as an alternate to guide 11 (FIG. 2). Guide 36 includes a cylindrical shaft 38 leading to a flattened (or narrowed) tip 37. The narrowed portion 37 is preferably made stiff. Thus arranged, eyelet 20 can be threaded with a conventional insertion comb even when thread guides 36 are very closely spaced. Such a comb has a plurality of spaced, parallel hook needles which can be pushed through eyelets 20. Once inserted, the hooks grab hold of each thread and in the backward movement of the comb, pull them through the appropriate hole.
In other possible embodiments, the illustrated thread guide sinkers may be replaced by other forms thereof, for example, hooks whose free ends are covered by a shoe running in the direction of the length of the machine or, when no substantial thread turning is to be expected, simple pegs.
Hereinbefore has been disclosed an efficient device for rapidly, simply and accurately positioning warp threads in the needle bed of warp knitting machine. It will be understood that various changes in the details, materials, arrangement of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principles and scope of the instant invention.
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A warp knitting machine has a needle bed and a jacquard arrangement for producing patterned wear from a plurality of threads. The machine includes a thread positioning bar and a plurality of thread positioning sinkers mounted on the thread positioning bar. The sinkers are spaced to allow the sinkers to pass between the needles of the bed. The machine also includes at least one guide bar and a plurality of thread guides mounted on each guide bar for separately guiding the threads. The thread guides are operable by the jacquard arrangement to move longitudinally relative to said guide bar and with a component of motion in a plane alongside the needle bed. This component is sized to allow each of the threads to reciprocate between and be pulled against the interior sides of a corresponding, neighboring pair of the sinkers.
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PRIORITY
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/510,194, entitled “Vertically Actuated Vehicle Barrier System,” filed Jul. 21, 2011, the disclosure of which is incorporated by reference herein.
BACKGROUND
[0002] Versions of the present invention relate to systems and devices that may be used to provide a barrier to prevent the passage of vehicles and the like. Some barriers may be installed in a fixed configuration, such that the barrier system constantly prevents the passage of vehicles and the like. Other barriers may be selectively deployable, such that vehicles may pass during selected times (e.g., when the barrier is present but not deployed); while vehicles may be prevented from passing during other selected times (e.g., when the barrier is deployed). Some vehicle barriers are shown and described in U.S. Pub. No. 2010/0098486, entitled “Vertically Actuated Vehicle Barrier System,” published Apr. 22, 2010, the disclosure of which is incorporated by reference herein. Additional vehicle barriers are shown and described in U.S. Pat. No. 7,641,416, entitled “Vehicle Barrier Deployment System,” issued Jan. 5, 2010, the disclosure of which is incorporated by reference herein. While a variety of systems and methods have been made and used to provide a barrier, it is believed that no one prior to the inventor has made or used the invention described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:
[0004] FIG. 1 depicts a perspective view of an exemplary vehicle barrier system in an undeployed position;
[0005] FIG. 2 depicts a perspective view of the system of FIG. 1 in a deployed position;
[0006] FIG. 3 depicts a top plan view of the system of FIG. 1 ;
[0007] FIG. 4 depicts a front elevation view of the system of FIG. 1 ;
[0008] FIG. 5 depicts an end view of the system of FIG. 1 ;
[0009] FIG. 6 depicts a top plan view of a vault portion of the system of FIG. 1 ;
[0010] FIG. 7 depicts a front elevation view of a vault portion of FIG. 6 ;
[0011] FIG. 8 depicts a cross-sectional end view of the vault portion of FIG. 6 , taken along line 8 - 8 of FIG. 7 ;
[0012] FIG. 9 depicts another cross-sectional end view of the vault portion of FIG. 6 , including part of the barrier and a cover closing assembly;
[0013] FIG. 10 depicts a front elevation view of the system of FIG. 1 , showing components of an exemplary drive system;
[0014] FIG. 11 depicts an elevational view of the drive system of FIG. 10 ;
[0015] FIG. 12 depicts a cross-sectional end view of the drive system of FIG. 10 ;
[0016] FIG. 13 depicts a partial elevational view of some of the components of the drive system of FIG. 10 , within a longitudinally central region of the system of FIG. 1 ;
[0017] FIG. 14 depicts a partial elevational view of components of the drive system of FIG. 10 , at a first longitudinal end of the system of FIG. 1 ;
[0018] FIG. 15 depicts a partial end view of components of the drive system of FIG. 10 , including a shaft driving chain but omitting a lifting chain, from a cross-section taken along line 15 - 15 of FIG. 14 ;
[0019] FIG. 16 depicts a partial end view of components of the drive system of FIG. 10 , including a lifting chain but omitting a shaft driving chain, from a cross-section taken along line 16 - 16 of FIG. 14 ;
[0020] FIG. 17 depicts an elevational view of components of a counterweight assembly of the system of FIG. 1 ;
[0021] FIG. 18 depicts a partial elevational view of support features of the counterweight assembly of FIG. 17 ;
[0022] FIG. 19 depicts a top plan view of components of the counterweight assembly of FIG. 17 ;
[0023] FIG. 20 depicts a top plan view of an exemplary cover plate assembly of the system of FIG. 1 ;
[0024] FIG. 21 depicts a partial cross-sectional view of the cover plate assembly of FIG. 20 , taken along line 21 - 21 of FIG. 20 ;
[0025] FIG. 22 depicts an elevation view of cover plate guide features for the cover plate assembly of FIG. 20 ;
[0026] FIG. 23 depicts a cross-sectional view taken along line 23 - 23 of FIG. 22 , showing a pair of the cover plate guide features of FIG. 22 ;
[0027] FIG. 24 depicts a front elevational view of a cover plate rotation restriction feature for the cover plate assembly of FIG. 20 , viewed from the exterior of the system of FIG. 1 ;
[0028] FIG. 25 depicts an enlarged rear elevational view of the cover plate rotation restriction feature of FIG. 24 , viewed from the interior of the system of FIG. 1 ;
[0029] FIG. 26 depicts an exemplary alternative form that the exemplary vehicle barrier system of FIG. 1 may take;
[0030] FIG. 27 depicts another exemplary alternative form that the exemplary vehicle barrier system of FIG. 1 may take;
[0031] FIG. 28 depicts yet another exemplary alternative form that the exemplary vehicle barrier system of FIG. 1 may take;
[0032] FIG. 29 depicts a cross-sectional end view of an exemplary electrical component compartment in a barrier wall; and
[0033] FIG. 30 depicts a cross-sectional end view of an exemplary alternative form that the features shown in FIG. 9 may take.
[0034] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown. While some of the drawings include specific dimensions, etc., it should be understood that those dimensions are mere examples. Any other suitable dimensions, proportions, etc., may be used.
DETAILED DESCRIPTION
[0035] The following description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
[0036] I. Overview of Exemplary Vehicle Barrier with Beams
[0037] FIGS. 1-25 show an exemplary vehicle barrier system ( 10 ) that includes horizontal gate beams ( 110 , 112 ) and that is selectively retractable into a vault or housing ( 20 ), which is embedded within reinforced concrete ( 12 ) in the ground. A plurality of vertical posts ( 40 , 42 ) are operable to reciprocate relative to housing ( 20 ) to selectively raise and lower gate beams ( 110 , 112 ) relative to housing ( 20 ). A pair of hinged cover plates ( 310 ) are coupled with housing ( 20 ) and are configured to substantially close posts ( 40 , 42 ) and gate beams ( 110 , 112 ) within housing ( 20 ) when posts ( 40 , 42 ) and gate beams ( 110 , 112 ) are retracted downward. Barrier system ( 10 ) is shown as being positioned between a pair of barrier walls ( 650 ), with static guides ( 600 ) being interposed between barrier system ( 10 ) and barrier walls ( 650 ). A counterweight sprocket cap ( 620 ) spans across the top of each static guide ( 600 ) and the adjacent barrier wall ( 650 ), as will be described in greater detail below.
[0038] Posts ( 40 , 42 ) include passive posts ( 40 ) and lifting posts ( 42 ), as will be described in greater detail below. Gate beams ( 110 , 112 ) are coupled with posts ( 40 , 42 ) via collar assemblies in the present example. Such collar assemblies may be constructed in accordance with the teachings of U.S. Pub. No. 2010/0098486. Alternatively, gate beams ( 110 , 112 ) may be coupled with posts ( 40 , 42 ) in any other suitable fashion. It will be appreciated that any suitable number of passive posts ( 40 ) and/or lifting posts ( 42 ) may be used in any suitable arrangement. In the present example, posts ( 40 , 42 ) comprise steel I-beams, though it should be understood that any other suitable structures (e.g., steel square tubes, etc.) or combinations of different structures may be used. It should also be understood that posts ( 40 , 42 ) may be formed of any suitable material(s) and may have any suitable cross sectional form(s). Furthermore, in some versions posts ( 40 ) are omitted entirely, such that only posts ( 42 ) are included. In some such versions, posts ( 42 ) are coupled together via one or more gate beams ( 110 , 112 ) and/or other components.
[0039] As will be described in greater detail below, posts ( 40 , 42 ) are connected by gate beams ( 110 , 112 ) and a horizontal member ( 114 ) such that posts ( 40 , 42 ) move vertically substantially simultaneously. In some versions, a single horizontal member ( 114 ) spans across all posts ( 40 , 42 ) (e.g., along the tops of posts ( 40 , 42 )), while separate horizontal gate beams ( 110 , 112 ) span between adjacent posts ( 40 , 42 ). While barrier system ( 10 ) of the present example comprises three beams ( 110 , 112 ), it should be understood that any other suitable number of beams ( 110 , 112 ) may be used. It should also be understood that various structures other than beams ( 110 , 112 ) may be used. Several structures that may be used as an alternative to horizontal gate beams ( 110 , 112 ) are described elsewhere herein, while others will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0040] FIG. 2 shows posts ( 40 , 42 ) and gate beams ( 110 , 112 ) in a deployed configuration, with cover plates ( 310 ) open. In this configuration, posts ( 40 , 42 ) and gate beams ( 110 , 112 ) are substantially positioned above ground level, and are configured to provide a barrier against passage of vehicles and the like. Barrier system ( 10 ) may therefore be provided within a road, median, sidewalk, or elsewhere to selectively prevent passage of vehicles and the like. Various suitable locations and ways in which barrier system ( 10 ) may be positioned and used will be described in greater detail below, while other suitable locations and ways in which barrier system ( 10 ) may be positioned and used will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0041] In some versions, barrier system ( 10 ) may stop a vehicle that is traveling at a high rate of speed, even if the driver of the vehicle is intent on passing through the barrier provided by barrier system ( 10 ). For instance, posts ( 40 , 42 ) and gate beams ( 110 , 112 ) may be sufficiently anchored such that they provide little or no “give” when struck by a vehicle (e.g., a car or truck, etc.). By way of example only, some versions of barrier system ( 10 ) may meet a Department of State “K” certification requiring that the front line of cargo of a 15,000 pound vehicle traveling 50 mph must not go further than 1 meter past the line defined by barrier system ( 10 ). In addition or in the alternative, some versions of barrier system ( 10 ) may satisfy the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) criteria. In some instances with some versions of barrier system ( 10 ), posts ( 40 , 42 ) and/or gate beams ( 110 , 112 ) may essentially destroy a vehicle that strikes posts ( 40 , 42 ) and/or gate beams ( 110 , 112 ), with relatively little damage being done to barrier system ( 10 ). For instance, barrier system ( 10 ) may be constructed such that no portions of barrier system ( 10 ) are released as projectiles when barrier system ( 10 ) is struck by a heavy vehicle moving at a high rate of speed.
[0042] As shown in FIGS. 6-9 , housing ( 20 ) of the present example comprises sidewalls ( 22 ) and a floor ( 24 ). A plurality of electrical components may be provided within a compartment ( 26 ) of housing ( 20 ), within barrier wall ( 650 ), and/or elsewhere. A merely illustrative example of how compartment ( 26 ) (or at least some electrical components) may be incorporated into barrier wall ( 650 ) are shown in FIG. 29 . Other suitable locations and structures in which electrical components may be provided will be apparent to those of ordinary skill in the art in view of the teachings herein. Such electrical components may include, among other things, an electrical junction box, a transformer, a DC/AC inverter, a battery, a battery charger, and/or a limit switch (not shown). Of course, each and every one of these components is merely optional, and any of them may be varied, substituted, supplemented, or omitted as desired. In the present example, these components provide electricity to other components within housing ( 20 ), as will be described in greater detail below. Various ways in which these components may be selected and coupled will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0043] It should be understood that compartment ( 26 ) may be provided at either or both ends of housing ( 20 ), in addition to or in lieu of being incorporated into barrier wall ( 650 ). Alternatively, compartment ( 26 ) may be provided at any other suitable location; or may be omitted altogether (e.g., components separated and located at various positions within housing ( 20 ), etc.). By way of example only, one or more batteries ( 43 ) may be mounted to gate beam ( 112 ). In some versions, battery ( 43 ) is rechargeable by solar power via a solar panel (not shown). In some other versions, a battery is omitted, and an external power line is fed to housing ( 20 ). It will be appreciated, therefore, that a variety of alternative components may be used to provide and/or regulate electricity to other components within housing ( 20 ). It will also be appreciated that, in some versions, barrier system ( 10 ) may be modified such that no external power source is required at all. A sump pump may also be provided within housing ( 20 ), below housing ( 20 ), or elsewhere, such as to purge water from housing ( 20 ). For instance, a perforated drainage pipe or “French drain” may be located at the bottom of housing ( 20 ) (e.g., below floor ( 24 )), and may be coupled with a sump pump. Of course, as with various other components described herein, a sump pump is merely optional. Housing ( 20 ) may also be structurally reinforced in various ways, including but not limited to using any of the reinforcement structures described in U.S. Pat. No. 7,641,416 and/or U.S. Pub. No. 2010/0098486, the disclosures of which are incorporated by reference herein.
[0044] As shown in FIGS. 6-9 , a plurality of post guides ( 50 ) extend upwardly from floor ( 24 ) of housing ( 20 ). In some versions, at least a portion of each post guide ( 50 ) is hingedly coupled with housing ( 20 ). For instance, such a hinged coupling may allow the hinged portions of post guides ( 50 ) to be folded over to reduce the overall height of barrier system ( 10 ) when barrier system ( 10 ) is transported from one location to another location. With reference to FIG. 6 , outermost post guides ( 50 ) are positioned in notches at the outer ends of housing ( 20 ); while interior post guides ( 50 ) are positioned in openings formed through floor ( 24 ) of housing ( 20 ). Post guides ( 50 ) of the present example comprise steel tubes having a square cross section. In some versions, reinforced concrete ( 12 ) is formed to itself provide/define post guides ( 50 ) and/or drainage system features as described elsewhere herein. Alternatively, post guides ( 50 ) may be formed of any other suitable material(s) and may have any other suitable cross section. In the present example, outermost post guides ( 50 ) are also engaged with static guides ( 600 ), such as by being welded to an associated static guide ( 600 ).
[0045] As shown in FIGS. 8-9 , each post guide ( 50 ) includes a reinforcement collar ( 52 ) about the part of the post guide ( 50 ) that protrudes upwardly from floor ( 24 ) of housing ( 20 ). Such collars ( 52 ) may be configured in accordance with the teachings of U.S. Pub. No. 2010/0098486 and/or otherwise. Of course, reinforcement collars ( 52 ) may be joined with post guides ( 50 ) and/or floor ( 24 ) in any other suitable fashion using any other suitable types of devices, components, features, or techniques. Optionally, post guides ( 50 ) may include “I-beams” or other suitable structures secured within their interior for reinforcement.
[0046] Post guides ( 50 ) are configured to slidably receive posts ( 40 , 42 ). In particular, posts ( 40 ) are inserted in interior post guides ( 50 ); while posts ( 42 ) are inserted into outermost post guides ( 50 ). Post guides ( 50 ) are configured to restrict lateral movement of posts ( 40 , 42 ), while permitting posts ( 40 , 42 ) to move vertically (e.g., reciprocate) within post guides ( 50 ). While five posts ( 40 ) and two posts ( 42 ) are shown in the present example, it should be understood that any desired number of posts ( 40 , 42 ) may be used. Likewise, any suitable number of post guides ( 50 ) may be used. It should also be understood that one or more shim plates and/or other components/features may be used to regulate the space between the exterior of a post ( 42 ) and the adjacent surface of static guide ( 600 ). Similarly, one or more shim plates and/or other components/features may be used to regulate the space between the exterior of posts ( 40 , 42 ) and post guides ( 50 ). For instance, shim plates may be placed at different vertical heights along each post ( 40 , 42 ). Some examples of such uses of shim plates are described in U.S. Pub. No. 2010/0098486, while other examples will be apparent to those of ordinary skill in the art in view of the teachings herein. As yet another merely illustrative example, posts ( 42 ) and/or static guides ( 600 ) may include freely rotating rollers, rub plates (e.g., formed of ultra high molecular weight material, etc.), and/or various other structures to facilitate vertical movement of posts ( 42 ) relative to static guides ( 600 ).
[0047] Post guides ( 50 ) may have a height that is greater than the height of sidewalls ( 22 ), though post guides ( 50 ) do not extend above sidewalls ( 22 ) in this example. For instance, while the upper rims of post guides ( 50 ) may be positioned below the upper rims of sidewalls ( 22 ), the lower portions of post guides ( 50 ) may extend below floor ( 24 ) of housing ( 20 ). In particular, the lower portions of post guides ( 50 ) may be embedded in concrete ( 12 ) or in the ground, below floor ( 24 ). FIGS. 1-2 and 4 - 5 show a lower portion ( 19 ) of concrete ( 12 ) that encases post guides ( 50 ). Alternatively, post guides ( 50 ) may have any other desired length and position relative to housing ( 20 ). In addition, the lower end of each post guide ( 50 ) may communicate with a drainage system, as described in U.S. Pub. No. 2010/0098486 or otherwise. Of course, a variety of other types of drainage systems may be provided; or barrier system ( 10 ) may even lack a drainage system.
[0048] As noted above, a pair of static guides ( 600 ) are positioned outside of housing ( 20 ), on opposite ends of housing ( 20 ). Static guides ( 600 ) of the present example comprise steel I-beams having flanges that extend transversely from a central web member. The lower ends of static guides ( 600 ) extend through concrete ( 12 ), below floor ( 24 ) of housing ( 20 ), such that the lower ends of static guides ( 600 ) are encased in concrete ( 12 ); while the upper ends of static guides ( 600 ) protrude above the ground. In the present example, a portion of the upper end each static guide ( 600 ) is attached with an adjacent concrete barrier wall ( 650 ) (e.g., a “Jersey Barrier” wall), such that the concrete barrier wall ( 650 ) is inserted between opposing flanges and abuts the central web member of static guide ( 600 ). Static guide ( 600 ) may thus act as a cap piece for the end of barrier wall ( 650 ). For instance, when barrier system ( 10 ) is installed in a gap between preexisting concrete barrier walls ( 650 ), upper ends of static guides ( 600 ) may be bolted to or otherwise secured to adjacent such preexisting concrete barrier walls ( 650 ) (e.g., a bolt inserted through opposing flanges ( 602 ) and through concrete barrier wall ( 650 ), etc.). As another merely illustrative example, when barrier system ( 10 ) is installed with new adjacent concrete barrier walls ( 650 ), the new concrete barrier walls ( 650 ) may be formed around or adjacent to static guides ( 600 ) such that static guides ( 600 ) are embedded in the new concrete barrier walls ( 650 ). Still other suitable ways in which the upper portions of static guides ( 600 ) may be laterally restrained will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0049] As best seen in FIGS. 1-2 , each static guide ( 600 ) of the present example includes a pair of foot portions ( 612 ). In particular, foot portions ( 612 ) extend outwardly from the outer faces of the flanges of static guide ( 600 ). Foot portions ( 612 ) have a profile configured to mimic the profile of foot portion ( 652 ) of concrete barrier ( 650 ). Foot portions ( 612 , 652 ) thus provide a substantially smooth transition from concrete barrier ( 650 ) to static guide ( 600 ). In some versions, foot portions ( 612 ) include beveled edges and/or other structural features that are configured to avoid snow plow blades or the like getting snagged on foot portions ( 612 ). Of course, as with other components described herein, foot portions ( 612 ) are merely optional, and static guides ( 600 ) may have a variety of alternative components, features, and configurations. As best seen in FIG. 9 , the lowermost gate beam ( 112 ) of the present example is wider than the rest of the gate beams ( 110 ). This configuration and arrangement provides a profile collectively presented by gate beams ( 110 , 112 ) and cover plates ( 310 ) that substantially mimcs the profile of concrete barrier ( 650 ). Thus, static guides ( 600 ) and barrier system ( 10 ) both present a profile that is substantially similar to the profile of concrete barrier ( 650 ). Again though, any other suitable sizes, arrangements, and configurations may be used. For instance, some versions of barrier system ( 10 ) may include gate beams ( 110 , 112 ) that all have approximately the same width.
[0050] FIG. 30 shows one merely illustrative variation of the components described above. In particular, post guides ( 50 ) and lower portion ( 19 ) of concrete ( 12 ) are completely omitted in this version. In addition, posts ( 40 , 42 ) are shortened such that they terminate at central web member ( 113 ) of gate beam ( 112 ). A plurality of upper footers ( 53 ) are secured to floor ( 24 ) of housing ( 20 ) in a spaced apart fashion, in the same locations where post guides ( 50 ) are shown in FIG. 6 . Upper footers ( 53 ) comprise I-beam segments in the present example, though it should be understood that any other suitable structures may be used. In some variations, a single footer ( 53 ) is used. Such a single footer may extend the full length of housing ( 20 ), and its ends may be further secured to static guides ( 600 ).
[0051] Continuing with the example shown in FIG. 30 , a lower footer ( 55 ) is positioned underneath floor ( 24 ), further underneath upper footers ( 53 ). Lower footer ( 55 ) also comprises an I-beam in this example, though again any other suitable structures may be used. In some versions, lower footer ( 55 ) extends along the full length of housing ( 20 ). In some other versions, lower footer ( 55 ) comprises a plurality of discrete segments corresponding to the segments forming upper footers ( 53 ). It should be understood that the variation of barrier system ( 10 ) shown in FIG. 30 may function identically to the exemplary version of barrier system ( 10 ) described below. In other words, in some versions of the variation of barrier system ( 10 ) shown in FIG. 30 , the absence of post guides ( 50 ) and lower portion ( 19 ), and the shortening of posts ( 40 , 42 ) will not impact performance or functionality; and will not otherwise require any changes to any other components of barrier system ( 10 ). Furthermore, the absence of post guides ( 50 ) and lower portion ( 19 ) may significantly reduce the size, cost, installation time, and/or excavation depth for barrier system ( 10 ).
[0052] It should be understood that any of the components described above may be modified, substituted, supplemented, relocated, or omitted in any suitable fashion as desired.
[0053] II. Exemplary Deployment and Retraction System
[0054] A. Exemplary Drive System
[0055] In the present example, barrier system ( 10 ) is selectively actuated from a retracted configuration ( FIG. 1 ) to a deployed configuration ( FIG. 2 ) by a system that includes a winch ( 200 ), a series of sprockets ( 210 , 212 , 214 , 216 , 218 , 220 , 224 , 226 , 228 ), drive shafts ( 230 , 232 , 234 ), and roller chains ( 240 , 242 , 244 ). These components are shown in FIGS. 10-16 . It should be understood that lowermost gate beam ( 112 ) is shown in cross-section (the cross-section being taken along a vertical plane) in FIGS. 10-11 in order to improve the view of certain components. In the present example, each sprocket ( 210 , 212 , 214 , 216 , 218 , 220 , 224 , 226 , 228 ) includes oil impregnated bushings to facilitate rotation, though it should be understood that this is merely optional. Winch ( 200 ) is fixedly mounted to and above central web member ( 113 ) of lowermost gate beam ( 112 ) in the present example, though it should be understood that winch ( 200 ) may alternatively be located elsewhere. Main drive shaft ( 230 ) is also mounted to central web member ( 113 ) of lowermost gate beam ( 112 ) in the present example. In particular, a plurality of bearing assemblies ( 222 ) are used to mount main drive shaft ( 230 ) to gate beam ( 112 ), providing support for main drive shaft ( 230 ) while facilitating rotation of drive shaft ( 230 ) relative to gate beam ( 112 ). Main drive shaft ( 230 ) extends along nearly the entire length of gate beam ( 112 ) in the present example, though it should be understood that any other suitable length may be used. As best seen in FIG. 13 , winch ( 200 ) includes a first drive sprocket ( 210 ), which is mounted to the drum of winch ( 200 ). First drive sprocket ( 210 ) is coupled to a first driven sprocket ( 212 ) of main drive shaft ( 230 ) via a roller chain ( 240 ). Thus, winch ( 200 ) rotates main drive shaft ( 230 ) via sprockets ( 210 , 212 ) and roller chain ( 240 ) when winch ( 200 ) is activated. In the present example, central web member ( 113 ) of lowermost gate beam ( 112 ) defines a slot that provides clearance for passage and free movement of roller chain ( 240 ).
[0056] As best seen in FIG. 11 , a second drive sprocket ( 214 ) is provided at one end of main drive shaft ( 230 ) while a third drive sprocket ( 218 ) is provided at the other end of main drive shaft ( 230 ). Second drive sprocket ( 214 ) is coupled with a second driven sprocket ( 216 ) via a roller chain ( 242 ) (see FIGS. 14-15 ). Similarly, third drive sprocket ( 218 ) is coupled with a third driven sprocket ( 220 ) via a roller chain (not shown). Second driven sprocket ( 216 ) is coupled with a second drive shaft ( 232 ), which also includes an end sprocket ( 224 ). Similarly, third drive sprocket ( 218 ) is coupled with a third drive shaft ( 234 ), which includes an end sprocket ( 236 ). Drive shafts ( 232 , 234 ) are secured to gate beam ( 112 ) via bearing assemblies ( 222 ) in the present example, providing support for drive shafts ( 232 , 234 ) while allowing drive shafts ( 232 , 234 ) to rotate relative to gate beam ( 112 ). In particular, as best seen in FIG. 14 , drive shafts ( 232 , 234 ) are secured above the central web member ( 113 ) of gate beam ( 112 ) while main drive shaft ( 230 ) is secured below central web member ( 113 ) of gate beam ( 112 ). It should be understood that slots may be formed in central web member ( 113 ) in order to provide free passage of roller chains ( 242 ) through central web member ( 113 ). Of course, any other suitable components, configurations, and arrangements may be used. The following discussion will focus mainly on the components at the end of barrier system ( 10 ) where second drive shaft ( 232 ) is located. It should be understood that the components at the other end of barrier system ( 10 ) (i.e., the end where third drive shaft ( 234 ) is located) are substantially identical in operation and arrangement in the present example.
[0057] As best seen in FIGS. 12 and 16 , a lifting roller chain ( 244 ) is engaged with end sprocket ( 224 ). Lifting roller chain ( 244 ) is also engaged with a pair of idler sprockets ( 226 , 228 ), which are mounted to a central web portion ( 43 ) of post ( 42 ). Sprockets ( 224 , 226 , 228 ) are all mounted such that sprockets ( 224 , 226 , 228 ) are all positioned along a common vertical plane. FIG. 16 best shows the routing of lifting roller chain ( 244 ) around sprockets ( 224 , 226 , 228 ). One end of lifting roller chain ( 244 ) is secured to a bolt ( 260 ), which is adjustably secured to a plate ( 262 ). Plate ( 262 ) is fixedly secured to the top of static guide ( 600 ), as shown in FIGS. 10 and 12 . In the present example horizontal member ( 114 ) includes a notch (not shown) that is configured to provide clearance for lifting roller chain ( 244 ) and bolt ( 260 ) as barrier ( 10 ) is raised to the deployed position.
[0058] As best seen in FIG. 12 , the other end of lifting roller chain ( 244 ) passes around a redirector sprocket ( 252 ), which redirects roller chain ( 244 ) approximately 180°, to reach a bolt ( 256 ). Roller chain ( 244 ) is fixedly secured to bolt ( 256 ). Bolt ( 256 ) is adjustably secured to a bracket ( 258 ), which is fixedly secured to a bottom region of static guide ( 600 ). It should be understood that the effective length or tension in lifting roller chain ( 244 ) may be adjusted by selectively adjusting the position of bolt ( 260 ) relative to plate ( 262 ), by selectively adjusting the position of bolt ( 256 ) relative to bracket ( 258 ), and/or by removing/adding links from/to roller chain ( 244 ). Providing such adjustability of roller chain ( 244 ) at each end may eliminate the need for rotating winch ( 200 ) and/or drive shafts ( 230 , 232 , 234 ), etc. for positioning or tensioning of roller chain ( 244 ) in order to get sprockets ( 210 , 212 , 214 , 216 , 218 , 220 , 224 , 226 , 228 ), drive shafts ( 230 , 232 , 234 ), and roller chains ( 240 , 242 , 244 ) in proper synchronization. Bolt ( 256 ) and bracket ( 258 ) may be positioned at a depth within housing ( 20 ) such that they may be readily accessed by a person reaching in through the top of housing ( 20 ) (e.g., at less than a person's arm length). Of course, any other suitable features may be provided for adjustability as will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0059] In use, winch ( 200 ) is activated to rotate sprocket ( 210 ) in one direction to raise barrier ( 10 ) to a deployed position; or in the other direction to lower barrier ( 10 ) to a retracted position. In particular, such activation of winch ( 200 ) ultimately rotates both end sprockets ( 224 , 236 ), which causes end sprockets ( 224 ) to “climb” up or down their associated lifting roller chains ( 244 ). As described in greater detail below with reference to FIGS. 17-19 , a counterweight system may be used to assist in the raising of barrier ( 10 ), thereby reducing the power that would otherwise be required of winch ( 200 ) to raise barrier ( 10 ). Of course, as with other features described herein, a counterweight system is merely optional. Furthermore, various other suitable types of systems may be used to selectively raise and lower barrier ( 10 ). Several exemplary alternative systems are described in greater detail below, while other exemplary alternative systems will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0060] B. Exemplary Counterweight System
[0061] In the present example, barrier system ( 10 ) includes a counterweight ( 400 ) that reduces the load on winch ( 200 ) as barrier ( 10 ) is raised to a deployed position. Counterweight ( 400 ) may thus reduce power consumption, reduce demand/wear on drive components, and provide for generally smoother operation of barrier ( 10 ) during raising and lowering. While FIGS. 17-19 illustrate counterweight ( 400 ) and associated components at just one end of barrier system ( 10 ), it should be understood that another counterweight ( 400 ) and associated components may be located at the other end of barrier system ( 10 ). It should also be understood that horizontal member ( 114 ) is omitted from FIG. 19 in order to improve the view of other components.
[0062] Counterweight ( 400 ) of the present example comprises a steel drum ( 402 ) filled with concrete, though counterweight ( 400 ) may of course take any other suitable form. An anchor ( 404 ) is embedded in the concrete and extends a substantial depth into steel drum ( 402 ). The combined weight of counterweight(s) ( 400 ) and anchor(s) ( 404 ) may be selected to approximate the weight of barrier ( 10 ), may be slightly greater than the weight of barrier ( 10 ), or may be slightly less than the weight of barrier ( 10 ). In the present example, the combined weight of counterweight(s) ( 400 ) and anchor(s) ( 404 ) is selected to permit barrier ( 10 ) to be raised manually (e.g., by one or two people) without any assistance from winch ( 200 ) (e.g., in the event of a power failure) and without the assistance of other mechanical means. Similarly, such a selection may permit barrier ( 10 ) to be lowered manually while reducing the risk of barrier ( 10 ) falling violently. By way of example only, an emergency rope, cable, lever, and/or other feature may be provided that is accessible from outside of barrier ( 10 ) and that selectively disengages a clutch in winch ( 200 ). With the clutch disengaged, winch ( 200 ) and other components of the drive system may rotate freely, allowing barrier ( 10 ) to be selectively raised or lowered manually. As noted above, counterweights ( 400 ) may greatly facilitate such manual raising or lowering.
[0063] A roller chain ( 406 ) is secured to anchor ( 404 ) via a linking bar ( 403 ). As will be described in greater detail below, roller chain ( 406 ) is also secured to gate beam ( 110 ). It should be understood that a cable or other structure may be used in addition to or in lieu of roller chain ( 406 ). Counterweight ( 400 ) is disposed in a chamber ( 410 ) that is adjacent to housing ( 20 ) underground (e.g., under barrier wall ( 650 ), etc.). Chamber ( 410 ) is sized to permit counterweight ( 400 ) to travel vertically during vertical travel of barrier ( 10 ). In particular, counterweight ( 400 ) is raised to an upper position in chamber ( 410 ) as barrier ( 10 ) is lowered to a retracted position. Conversely, counterweight ( 400 ) descends to a lower position in chamber ( 410 ) as barrier ( 10 ) is raised to a deployed position. A pipe ( 412 ) extends upwardly from chamber ( 410 ) and provides a path for roller chain ( 406 ) to reach a sprocket ( 420 ). Sprocket ( 420 ) is mounted at the top of barrier wall ( 650 ).
[0064] As best seen in FIG. 18 , roller chain ( 406 ) further extends from sprocket ( 420 ) to another sprocket ( 422 ), which is mounted at the top of static guide ( 600 ). After passing over sprocket ( 422 ), roller chain ( 406 ) is directed downward to yet another sprocket ( 424 ). Sprocket ( 424 ) is mounted to post ( 42 ) by a bracket ( 426 ). Bracket ( 426 ) may be mounted to gate beam ( 110 ) in addition to or in lieu of being mounted to post ( 42 ), if desired. After passing over sprocket ( 424 ), roller chain ( 406 ) is secured to a bolt ( 430 ). Bolt ( 430 ) is adjustably secured to a bracket ( 432 ), which is fixedly secured to the central web member ( 111 ) of gate beam ( 110 ). Counterweight ( 400 ) is thus adjustably secured to gate beam ( 110 ) by roller chain ( 406 ). Bolt ( 430 ) may be adjusted relative to bracket ( 432 ) in order to adjust the effective length of roller chain ( 406 ).
[0065] It should be understood that slots or other openings may be provided in horizontal member ( 114 ) and/or in other components to accommodate the free passage of roller chain ( 406 ) therethrough. It should also be understood that sprocket caps ( 620 ), referred to above and shown in FIGS. 1-2 , are configured to cover sprockets ( 420 , 422 ) and the portion of roller chain ( 406 ) extending over sprockets ( 420 , 422 ). As with other components described herein, sprocket caps ( 620 ) are merely optional. Still other suitable components, features, and configurations that may be used for a counterweight system for barrier ( 10 ) will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0066] C. Exemplary Alternative Systems
[0067] While the above described examples include the use of counterweights, sprockets, roller chains, drive shafts, etc. to selectively raise and lower barrier ( 10 ). It should be understood that various other types of systems may be used to selectively raise and lower barrier ( 10 ). For instance, various combinations of folding arms, pulleys, and cables may be used as taught in U.S. Pat. No. 7,641,416, the disclosure of which is incorporated by reference herein. As another merely illustrative alternative, various combinations of arms, pulleys, and/or cables may be used as taught in U.S. Pub. No. 2010/0098486, the disclosure of which is incorporated by reference herein. It should therefore be understood that various teachings of U.S. Pat. No. 7,641,416 and U.S. Pub. No. 2010/0098486 may be combined together and with the teachings herein in numerous ways. As yet another merely illustrative example, barrier ( 10 ) may be selectively raised and/or lowered hydraulically, pneumatically, and/or in any other suitable fashion. Other suitable ways in which barrier ( 10 ) may be selectively raised and/or lowered will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0068] III. Exemplary Cover Plates
[0069] Cover plates ( 310 ) are pivotally engaged relative to flanges ( 9 ) of housing ( 20 ), such that cover plates ( 310 ) may provide a selectively openable “lid” for barrier system ( 10 ). In particular, as best seen in FIGS. 20-21 , cover plates ( 310 ) are each mounted to a respective set of hinges ( 13 ), each of which is mounted to a corresponding flange ( 9 ). While each cover plate ( 310 ) has a plurality of associated hinges ( 13 ) in the present example, some versions may provide just a single hinge (e.g., a continuous hinge or piano hinge) for each cover plate ( 310 ). As shown in FIG. 1 , when cover plates ( 310 ) are down, cover plates ( 310 ) are configured to cover the opening defined by sidewalls ( 22 ) of housing ( 20 ). While a pair of pivoting cover plates ( 310 ) are shown, it will be appreciated that cover plate ( 310 ) may be varied or modified in a number of ways. For instance, a single hinged cover plate may be used. Furthermore, cover plates ( 310 ) may be modified to slide open, to swing downward into housing ( 20 ), or to open in any other suitable way. Other variations of cover plate ( 310 ) and methods of opening cover plate ( 310 ) will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0070] Horizontal member ( 114 ) of the present example is configured to cooperate with cover plates ( 310 ) to cover the opening defined by sidewalls ( 22 ) of housing ( 20 ), when barrier system ( 10 ) is in the undeployed configuration shown in FIG. 1 . For instance, horizontal member ( 114 ) may provide structural support underneath closed cover plates ( 310 ). In addition or in the alternative, horizontal member ( 114 ) may substantially fill a gap between closed cover plates ( 310 ). In the present example, cover plates ( 310 ) and horizontal member ( 114 ) (along with other load bearing components of barrier system ( 10 )) may cooperate to fully bear the weight of numerous vehicles driving over cover plates ( 310 ) when cover plates ( 310 ) are in the retracted position as shown in FIG. 1 , without causing any damage to cover plates ( 310 ) and horizontal member ( 114 ), etc. As shown in FIGS. 20-21 , a metal strip ( 116 ) is secured to the top of horizontal member ( 114 ) to assist in partially filling the gap between closed cover plates ( 310 ), though metal strip ( 116 ) is of course merely optional. As another merely illustrative example, cover plates ( 310 ) may be omitted, such that horizontal member ( 114 ) itself substantially covers the opening defined by sidewalls ( 22 ) of housing ( 20 ), when barrier system ( 10 ) is in the undeployed configuration. Other suitable relationships between horizontal member ( 114 ) and cover plates ( 310 ) will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0071] As yet another merely illustrative variation, barrier system ( 10 ) may include an integral cover plate (not shown) that is not hinged. For instance, an integral cover plate may span across the tops of posts ( 100 , 101 ), and may have a width that is configured to overlay at least a portion of flanges ( 9 ) on both sides of housing ( 20 ). Thus, such an integral cover plate may fully cover or substantially cover the entire top opening defined by housing ( 20 ) when posts ( 100 , 101 ) are in a retracted/undeployed position Like closed cover plates ( 310 ), such a “closed” integral cover plate may also be substantially flush with the ground when posts ( 40 , 42 ) are in a retracted/undeployed position. Such an integral cover plate may also raise unitarily with posts ( 40 , 42 ) as posts ( 40 , 42 ) are raised to the deployed position. Still various other suitable ways in which the top opening defined by housing ( 20 ) may be fully covered or substantially covered will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0072] Some versions may also include plates (not shown) on each side of hinges ( 13 ). Such plates may be configured to deflectingly force snow plow blades or the like to be raised above hinges ( 13 ), to avoid snow plow blades or the like getting snagged on hinges ( 13 ). For instance, such plates may wrap over at least part of the “knuckle” (e.g., the part that contains the hinge pin) of each hinge ( 12 ). As one merely illustrative alternative, each hinge ( 12 ) may be installed facing down such that the knuckles of hinges ( 13 ) are covered. To the extent that flanges ( 9 ) of housing ( 20 ) are exposed, such flanges ( 9 ) may include a beveled edge to also reduce the likelihood of snow plow blades or the like getting snagged on flanges ( 9 ). To the extent that tread plates or other components are positioned above flanges ( 9 ) and obscure flanges ( 9 ), such tread plates or other components may have such a beveled edge to also reduce the likelihood of snagging. In addition, cover plates ( 310 ) may each include a beveled edge to also reduce the likelihood of snow plow blades or the like getting snagged on cover plates ( 310 ). Of course, these features and configurations are merely optional, and may be varied, substituted, supplemented, or omitted as desired.
[0073] FIGS. 9 and 22 - 23 show examples of features that may be used to assist with opening of cover plates ( 310 ) as barrier ( 10 ) is raised to the deployed position; and to prevent cover plates ( 310 ) from snagging on gate beams ( 110 ) and horizontal member ( 114 ) as barrier ( 10 ) is lowered to the retracted position. In particular, FIGS. 9 and 22 - 23 show a plurality of cover guide plates ( 320 , 330 ) that are vertically positioned between gate beams ( 110 , 112 ) and horizontal member ( 114 ). Each cover guide plate ( 320 , 330 ) fixedly secured to a respective bracket ( 322 ), which is pivotally coupled to post ( 40 ) via a respective hinge ( 324 ). As best seen in FIG. 20 , hinges ( 324 ) are positioned on opposing sides of each post ( 40 ) and are aligned along a longitudinally extending vertical plane defined by barrier system ( 10 ). In the present example, each post ( 40 ) has a set of six cover guide plates ( 320 , 330 ), brackets ( 322 ), and hinges ( 324 ) mounted thereto. Posts ( 42 ) do not have any plates ( 320 , 330 ), brackets ( 322 ), or hinges ( 324 ) mounted thereto in the present example.
[0074] Cover guide plates ( 320 ) have angled outer edges that deflect the free edges of cover plates ( 310 ) outwardly as barrier ( 10 ) is lowered to the retracted position, such that the outer edges of cover guide plates ( 320 ) prevent cover plates ( 310 ) from snagging on gate beams ( 110 ) and horizontal member ( 114 ) as barrier ( 10 ) is lowered to the retracted position. Cover guide plates ( 320 ) each thus define a non-rectangular trapezoidal shape in the present example. In the present example, cover guide plate ( 320 ) has a rectangular shape, though it should be understood that cover guide plate ( 320 ) may alternatively have a non-rectangular shape. It should also be understood that the configuration of gate beam ( 110 ) and cover guide plate ( 320 ) may still prevent cover plates ( 310 ) from snagging on the lowermost gate beam ( 110 ) as barrier ( 10 ) is lowered to the retracted position, even when cover guide plate ( 320 ) has a rectangular shape as shown in FIG. 22 .
[0075] As best seen in FIG. 23 , each cover guide plate ( 320 , 330 ) also includes a bend ( 321 ), which is configured to orient the outermost portions of cover guide plates ( 320 , 330 ) transversely relative to post ( 40 ) when cover guide plates ( 320 , 330 ) are positioned as shown in FIGS. 9 and 22 - 23 . As also best seen in FIG. 23 , a spring ( 326 ) biases each cover guide plate ( 320 , 330 ) to the position shown in FIGS. 9 and 22 - 23 . One end of each spring ( 326 ) is secured to a respective cover guide plate ( 320 , 330 ); while the other end of each spring ( 326 ) is secured to a respective block ( 328 ). Blocks ( 328 ) associated with the uppermost cover guide plates ( 320 ) are secured to the underside of horizontal member ( 114 ). Blocks ( 328 ) associated with the lower cover guide plates ( 320 ) are secured to the underside of central web member ( 111 ) of the upper gate beam ( 110 ). Blocks ( 328 ) associated with cover guide plates ( 330 ) are secured to the underside of central web member ( 111 ) of the lower upper gate beam ( 110 ).
[0076] Hinges ( 324 ) and springs ( 326 ) permit cover guide plates ( 320 , 330 ) to pivot at hinges ( 324 ), such as when a vehicle strikes barrier ( 10 ) at an oblique angle. In settings where barrier system ( 10 ) is installed in the median of a highway (e.g., such that barrier system ( 10 ) runs parallel to the roadways), hinges ( 324 ) and cover guide plates ( 320 , 330 ) are located on the sides of posts ( 40 ) that are downstream of the direction of traffic on the respective sides of barrier system ( 10 ). In other words, when cover guide plate ( 320 , 330 ) is struck obliquely by a vehicle traveling along a first direction, hinge ( 324 ) permits cover guide plate ( 320 , 330 ) to responsively pivot away from that vehicle and toward the opposite side of barrier system ( 10 ). In the event that cover guide plates ( 320 , 330 ) are struck, springs ( 326 ) are biased to return cover guide plates ( 320 , 330 ) to the position shown in FIGS. 9 and 22 - 23 . Springs ( 326 ) and hinges ( 324 ) thus provide a degree of impact absorption, reducing the likelihood that cover guide plates ( 320 , 330 ) and brackets ( 322 ) will be destroyed by vehicles striking barrier ( 10 ).
[0077] In addition to preventing cover plates ( 310 ) from snagging on gate beams ( 110 , 112 ) and horizontal member ( 114 ) as barrier ( 10 ) is lowered to the retracted position. Cover plates ( 310 ) may also act as cams urging cover plates ( 310 ) outwardly as barrier ( 10 ) is raised to the deployed position. Once barrier ( 10 ) reaches the fully deployed position, gate beam ( 112 ) holds cover plates ( 310 ) in the substantially open position.
[0078] FIGS. 24-25 show a merely illustrative example of a feature that may be used to restrict the degree to which cover plates ( 310 ) may be opened. In particular, FIGS. 24-26 show a locking member ( 350 ) that is secured to the underside of each cover plate ( 310 ) at each end of cover plate ( 310 ). Locking member ( 350 ) is a rectangular piece of metal in this example, though any other suitable configuration may be used. Locking member ( 350 ) is secured to cover plate ( 310 ) by a pair of bolts ( 352 , 354 ). Bolts ( 352 , 354 ) may be countersunk in cover plate ( 310 ) such that the flat heads of bolts ( 352 , 354 ) do not protrude past the outer surface of cover plate ( 310 ). Bolt ( 352 ) is configured to pivotally secure locking member ( 350 ), such that locking member ( 350 ) may pivot about bolt ( 352 ) and relative to cover plate ( 310 ) when bolt ( 354 ) is removed. For instance, bolt ( 352 ) may include a nylon nut (not shown). Bolt ( 354 ) is configured to lock the rotational position of locking member ( 350 ) about bolt ( 352 ) and relative to cover plate ( 310 ). When bolt ( 354 ) is secured to locking member ( 350 ) (e.g., in complementary threading formed in locking member ( 350 ), etc.), locking member ( 350 ) extends in a direction that is substantially parallel to the direction along which cover plate ( 310 ) extends, such that locking member ( 350 ) and cover plate ( 310 ) are substantially parallel. In this position, locking member ( 350 ) extends past the end of cover plate ( 310 ) and under foot portion ( 612 ) of static guide ( 600 ) (e.g., by approximately one inch). Thus, engagement between locking member ( 350 ) and foot portion ( 612 ) of static guide ( 600 ) restricts the degree to which cover plate ( 310 ) may be opened. In particular, locking member ( 350 ) ensures that cover plates ( 310 ) do not open past planes defined by foot portions ( 612 ) of static guides ( 600 ), such that locking members ( 350 ) assist in keeping a substantially smooth transition from foot portions ( 612 ) to cover plates ( 310 ) when cover plates ( 310 ) are opened.
[0079] In the event that cover plates ( 310 ) need to be opened further (e.g., to perform maintenance or inspections in housing ( 20 ), etc.), bolt ( 354 ) may be removed, allowing locking member ( 350 ) to pivot as shown in FIG. 25 to a position where it will not engage foot portion ( 612 ) of static guide ( 600 ) as cover plate ( 310 ) is opened. In particular, the absence of bolt ( 354 ) and the pivotal relationship provided by bolt ( 352 ) and the nylon nut (not shown) allows locking member ( 350 ) to rotate to a position where it is oriented transversely relative to cover plate ( 310 ). After the maintenance/inspection/etc. is complete, cover plate ( 310 ) may be rotated back toward a position where it is no longer “hyperextended” relative to foot portion ( 612 ) of static guide ( 600 ), then locking member ( 350 ) may be rotated back to a position where it is substantially parallel to cover plate. Bolt ( 354 ) may then be secured to cover plate ( 354 ) and locking member ( 350 ) to hold locking member ( 350 ) in this position. It should be understood that locking member ( 350 ) may be modified, substituted, or supplemented in numerous ways. It should also be understood that locking member ( 350 ) may be readily incorporated into virtually any form of barrier described herein. Of course, as with other components described herein, locking member ( 350 ) may simply be omitted if desired.
[0080] FIGS. 9 and 21 show additional features that assist with closure of cover plates ( 310 ) as barrier ( 10 ) is lowered to the retracted position. In particular, the upper end of a closure beam ( 370 ) is pivotally secured to the underside of each cover plate ( 310 ). The lower ends of closure beams ( 370 ) are pivotally coupled to a shared cross-beam ( 372 ). By way of example only, beams ( 370 , 372 ) may comprise angle irons or any other suitable structures. When cover plates ( 310 ) are opened during deployment of barrier ( 10 ), closure beams ( 370 , 372 ) are raised to and held in the position shown in FIG. 9 . As barrier ( 10 ) is subsequently being lowered to the retracted position, gate beam ( 112 ) eventually engages cross-beam ( 372 ). As barrier ( 10 ) continues to be lowered, gate beam ( 112 ) pushes downwardly on cross-beam ( 372 ), which pulls cover plates ( 310 ) closed via closure beams ( 370 ). While barrier ( 10 ) remains in the retracted position, gate beam ( 112 ) and beams ( 370 , 372 ) cooperate to hold cover plates ( 310 ) in the closed position. While just one set of beams ( 370 , 372 ) are shown in the present example, it should be understood that any suitable number of sets of beams ( 370 , 372 ) may be incorporated into barrier system ( 10 ). By way of example only, one end of barrier system ( 10 ) may have one set of beams ( 370 , 372 ) while the other end of barrier system ( 10 ) may have another set of beams ( 370 , 372 ).
[0081] Of course, there are a variety of other structures, components, and techniques that may be employed to provide opening, holding open, closing, and/or closing of cover plates ( 310 ), in addition to or in lieu of those described above. By way of example only, lift assist springs (not shown) may be provided to assist in opening of cover plates ( 310 ). Similarly, a spring or other resilient member may bias cover plates ( 310 ) to a closed position. It should also be understood that, in versions where at least one limiting chain, cable rod, and/or linkage is used to restrict the degree to which cover plates ( 310 ) may be opened, completely separate chain(s), cable(s), rod(s), and/or linkage(s) may be used to assist in closing cover plates ( 310 ). Numerous examples of alternative features that may be used to assist with opening and/or closing of cover plates ( 310 ) are disclosed in U.S. Provisional Patent Application No. 61/510,194, the disclosure of which is incorporated by reference herein; U.S. Pub. No. 2010/0098486, the disclosure of which is incorporated by reference herein; and U.S. Pat. No. 7,641,416, the disclosure of which is incorporated by reference herein. Still other suitable structures, components, and techniques for opening, holding open, and/or closing cover plates ( 310 ) will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0082] IV. Exemplary Alternative Barrier Configurations
[0083] In the examples shown in FIGS. 1-25 , a barrier is provided by gate beams ( 110 , 112 ) and horizontal member ( 114 ). However, it should be understood that a barrier system may include various other kinds of barrier features. By way of example only, FIG. 26 shows a barrier system ( 700 ) that includes conventional guardrails ( 702 ) to provide a barrier. FIG. 27 shows a barrier system ( 800 ) that includes a plurality of chains ( 802 ) to provide a barrier. FIG. 28 shows a barrier system ( 900 ) that includes a plurality of steel cables ( 902 ) to provide a barrier. It should be understood that various teachings provided herein with respect to barrier system ( 10 ) may be readily incorporated into any of these types of alternative barrier systems ( 700 , 800 , 900 ), among others. Other suitable types of barrier systems into which at least some of the teachings herein may be incorporated will be apparent to those of ordinary skill in the art.
[0084] It should also be understood that numerous versions of the barrier systems ( 10 , 700 , 800 , 900 ) described herein may be readily integrated into pre-existing conventional fixed barrier systems, such as pre-existing conventional jersey barriers, pre-existing conventional guardrail barriers, pre-existing conventional chain barriers, and pre-existing conventional cable barriers. For instance, one or more of the barrier systems ( 10 , 700 , 800 , 900 ) described herein may provide a selective pass-through in such conventional barrier systems, enabling people and/or vehicles to retract the barrier system ( 10 , 700 , 800 , 900 ) to pass through a gap in the conventional barrier then subsequently redeploy the barrier system ( 10 , 700 , 800 , 900 ) to close the gap after passing through. Several examples of how barrier systems such as those taught herein may be incorporated into a pre-existing conventional fixed barrier systems are described in U.S. Pub. No. 2010/0098486, the disclosure of which is incorporated by reference herein, and U.S. Pat. No. 7,641,416, the disclosure of which is incorporated by reference herein, while still other suitable examples will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0085] V. Exemplary Control
[0086] Control of barrier system ( 10 ) may be provided in a variety of ways, and may include one or more microprocessors and/or various other types of control module components that will be apparent to those of ordinary skill in the art in view of the teachings herein. In some versions, control is provided locally. For instance, a switchbox or other device may be located proximate to barrier system ( 10 ) to permit selective activation of winch ( 200 ). Such a switchbox may include any of a variety of security features, including but not limited to keyed control, a card reader (e.g., using a magnetic strip, RFID technology, EAS technology, etc.), a keypad for entry of a code, a biometrics reader, or any other suitable security feature. Barrier system ( 10 ) may also be triggered by an in-road sensor or other device. Furthermore, barrier system ( 10 ) may be capable of manual operation, such as in the case of a power loss or under other circumstances.
[0087] In some versions, control is provided remotely. For instance, in some versions, winch ( 200 ) is in communication with a small portable remote control device, similar to a conventional garage door opener controller. In particular, a receiver (not shown) may be coupled with winch ( 200 ), and may be configured to receive commands from a remote control device, and translate such commands into corresponding operation of winch ( 200 ) to deploy or retract posts ( 40 , 42 ) and gate beams ( 110 , 112 ). Such communication may be encrypted using a rolling code or any other suitable techniques, such that the receiver only responds to a particular remote control device or particular group of remote control devices. By way of example only, suitable personnel such as firefighters, ambulance drivers, highway patrol, etc., may be provided with such remote control devices. Alternatively, to the extent that a building is wholly or partially surrounded by a barrier system ( 10 ), a building manager, building security, or other personnel may be provided with such a remote control device. Still other suitable personnel and other ways in which a portable remote control device may be used with barrier system ( 10 ) will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0088] As another merely illustrative example of remote control, winch ( 200 ) may be in communication with a network, such that a user may selectively activate winch ( 200 ) from a remote location, via wire or wirelessly. Such a network may be a dedicated closed network, the Internet, or any other communication structure. It will be appreciated that any of the security features noted above with respect to local control of barrier system ( 10 ) may also be implemented for remote control of barrier system ( 10 ). It will also be appreciated that one barrier system ( 10 ) may be in communication with one or more other barrier systems ( 10 ). For instance, one barrier system ( 10 ) may act as a “master” system, such that other barrier systems ( 10 ) will automatically deploy or retract in response to deployment or retraction of the “master” system. Alternatively, one barrier system ( 10 ) may act as a relay for data or commands to and/or from other barrier systems ( 10 ). To the extent that a barrier system ( 10 ) is in communication with some type of network, operational data may be communicated to a remote location via the network. For instance, the charge left in the battery, the operability of winch ( 200 ), the presence of water or debris in the vault or housing ( 20 ), the striking of posts ( 40 , 42 ) and/or gate beams ( 110 , 112 ) by a vehicle, or any other type of data may be communicated via a network.
[0089] Barrier system ( 10 ) may also include safety or warning features such as lights or horns when barrier system ( 10 ) is activated. For instance, one or more limit switches or proximity sensors, etc. may be used to stop winch ( 200 ) when posts ( 40 , 42 ) have reached a fully raised/deployed and/or a fully lowered/retracted position. By way of example only, limit switches may comprise at least one metal tab or other structure mounted to at least one of the posts ( 40 , 42 ) that provides contact with another switch position when posts ( 40 , 42 ) have reached a fully raised/deployed and/or a fully lowered/retracted position. Alternatively, limit switches may take any other suitable form, to the extent that limit switches are even used. In addition, barrier system ( 10 ) may include a kill switch to prevent deployment of barrier system ( 10 ) when a person or obstacle is detected in the path of barrier system ( 10 ); and/or when there is a limit switch failure. Suitable components and arrangements for providing such sensor and kill switch systems will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0090] As yet another merely illustrative variation, barrier system ( 10 ) may include a control module and/or other component that monitors the amount of electrical current drawn by winch ( 200 ). Such a control module and/or other component may be configured to shut down winch ( 200 ) in response to detecting the drawn electrical current exceeding a threshold value (e.g., a value that would indicate an overload on winch ( 200 ), etc.). This may prevent components of barrier system ( 10 ) from being damaged when winch ( 200 ) is overloaded. Still other ways in which barrier system ( 10 ) may be controlled or monitored will be apparent to those of ordinary skill in the art in view of the teachings herein. Similarly, various other suitable components, features, configurations, operabilities, and uses of barrier system ( 10 ) will be apparent to those of ordinary skill in the art in view of the teachings herein. By way of example only, a substitute or supplement for gate beams ( 110 , 112 ) may include guardrails, chains, cables, rods, bars, rails, ropes, netting, plates, or any other suitable structures, including combinations of such structures, and including any suitable material or combination of materials.
[0091] VI. Exemplary Uses
[0092] It will be appreciated by those of ordinary skill in the art that each barrier system described herein may be used in a variety of ways. In one merely exemplary use, a barrier system is positioned in a median of a multi-lane highway or interstate, between a pair of preexisting median barriers such as preexisting guardrails, cables, Jersey barriers, or concrete walls, etc. For instance, a barrier system may be constructed into a new concrete barrier wall, positioned in a preexisting gap between preexisting barrier walls, or “cut into” a preexisting barrier wall, etc. Guide plates or other features may be mounted to the preexisting median barriers in order to guide or reinforce one or more portions of barrier system (e.g., guardrails, etc.). Concrete of the barrier system or any other component of the barrier system may also be anchored with a preexisting concrete median wall. In this example, the barrier system is oriented substantially parallel to the flow of traffic on a roadway, and is configured to restrict passage across a highway median rather than restricting passage across a lane of a roadway. It will be appreciated that having a barrier system in such a location may be useful for emergency vehicles that need to cross the median of a highway or interstate, etc., who may otherwise need to travel substantial distances out of the way just to get to the other side of the highway. Furthermore, a barrier system may be installed where gaps already exist between median barriers (e.g., where such gaps were created for use by patrol cruisers or emergency vehicles), and may be set in a deployed configuration by default to prevent unauthorized use of such gaps by non-state and non-emergency vehicles, such that obstructive portions of the barrier system may be lowered when authorized vehicles need to cross the median.
[0093] Similar to the example above, a barrier system may be positioned in the median of a highway that does not have guardrails or walls in the median. In particular, a barrier system may be positioned in the median of a highway that uses cables and posts to prevent vehicles from crossing the median. For instance, some such medians may currently have openings in the cable and post lines to permit emergency vehicles to cross the median. A barrier system may be positioned in such paths to prevent non-emergency vehicles from crossing such paths while permitting emergency vehicles to lower the barrier to permit passage through the paths. In versions that use horizontally oriented cables to present a barrier to vehicles, the cables of the retractable barrier system may tie into the preexisting system of cables and posts in the median. For instance, the cables of the barrier system may be coupled with whichever posts or cables are immediately adjacent to each end of barrier system. As yet another alternative, a barrier system may be retrofitted to a preexisting cable median barrier system such that the posts are coupled directly with a span of the preexisting cables, and such that the posts and the horizontal member may be used to selectively raise and lower the preexisting cables. It should also be understood that a barrier system as described herein may be overlapped with a preexisting barrier system, such that neither system is struck by a vehicle at its upstream termination point. For instance, such overlap may result in a vehicle first striking a barrier as described herein and then sliding into the preexisting barrier. Still other ways in which a barrier system may be used in conjunction with a preexisting system of posts and cables in a highway median will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0094] In another merely exemplary use, a barrier system is provided in a roadway (not shown). The barrier system may have a length such that it extends across the width of the roadway to any suitable length (e.g., across one or more traffic lanes in the roadway, across the entire width of the roadway, etc.). To permit normal passage of traffic across the roadway, the barrier system may be kept in a retracted configuration. When the provision of a barrier is desired, winch ( 200 ) (or some other type of component) may be activated to transition the barrier system to a deployed configuration. Such a deployed barrier system may provide a barrier substantially preventing passage of vehicles approaching the barrier system from either direction. If a vehicle strikes one or more obstructive portions of the barrier system, the barrier system may quickly bring such a vehicle to a stop. Alternatively, if a vehicle does not strike the barrier system, and if a barrier is no longer desired, winch ( 200 ) (or some other type of component) may be activated again to transition the barrier system back to the retracted configuration to once again permit passage of vehicular traffic.
[0095] While barrier systems have been described as being capable of spanning across an entire width of a roadway, it will be appreciated that a barrier system may span across any other suitable length. For instance, a barrier system may span across only one lane of traffic. Alternatively, a barrier system may be configured to span across distances that far exceed the width of a roadway. For instance, a barrier system may be constructed to span across the entire width of the face of a building, park, or other location, or may be constructed to span around the entire perimeter of such a location.
[0096] In another exemplary use, a barrier system is installed behind a pre-existing gate (not shown) that it is used to selectively restrict access to a road, driveway, or the like. The barrier system may therefore provide reinforcement or a “back up” for existing barriers (e.g., where existing barriers are less able to prevent passage of a moving vehicle intent on passing through the barrier). The barrier system may thus be used to provide security for non-authorized vehicle entry. As another merely exemplary use, a barrier system may be used by the military to provide checkpoints, by police to provide blockades, or by other persons or entities for a variety of purposes.
[0097] It should also be understood that a barrier system may be constructed such that it spans around corners, such as at right angles, along a curve, or otherwise (e.g., to conform to property lines or desired security perimeter, etc.). For instance, one or more cables or chains could easily be extended around a corner using a pulley or other component. Similarly, any suitable number of cables may be coupled with a deployment cable or a retraction cable via a clevis or other component, and such additional cables may be extended around a corner using a pulley or other component. Thus, even if several deployment posts are used at different positions about one or more corners, such deployment posts may all be simultaneously deployed using a single winch in some implementations. For instance, a single barrier system may be arranged in a rectangle or square surrounding the perimeter of an entire building, and a single winch may be used to simultaneously raise and/or simultaneously lower posts on all four sides of the building perimeter. Such posts could be positioned at each side of each corner and/or elsewhere.
[0098] It will also be appreciated that, in many situations, length may be added to a barrier system simply by lengthening guardrails, chains, cables, gate beams, etc., and possibly adding additional vertical posts. For instance, a barrier system with chains and/or a barrier system with cables may be used to protect areas that span 200 feet or more (e.g., as opposed to just one traffic lane spanning 12 feet). Furthermore, in many situations, all posts may still be deployed by a single drive mechanism (e.g., winch). To the extent that increasing the length of barrier system requires the addition of more posts additional cables may be easily coupled with cables described herein, and additional pulleys may be provided, as desired.
[0099] It should be understood that any barrier system described herein may include an audio and/or visual warning system that may be activated when the barrier system is transitioning from an extended position to a retracted position; and or when barrier system is transitioning from a retracted position to an extended position. For instance, such a warning system may include a horn/klaxon, bell, or other type of alarm and/or a flashing light, etc. Such a warning system may thus provide a warning to traffic that the barrier system is changing its position.
[0100] Of course, a barrier system may be used in a variety of other contexts and for a variety of other purposes. Various other contexts and purposes in which a barrier system may be used, as well as various other techniques for using a barrier system, will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0101] It will be understood in view of the above that a deployed barrier system may provide a bi-directional barrier. Furthermore, barrier system is operable to provide such a barrier with a single drive mechanism (e.g., winch). In some versions as described above, the drive mechanism that is used to deploy a barrier is mechanical or electromechanical, such as a winch or some other mechanical/electromechanical device. It will be appreciated that, where a mechanical or electromechanical drive mechanism is used, the barrier system may be substantially free of any hydraulic or pneumatic devices. In other words, a drive mechanism need not rely on hydraulics or pneumatics to operate, which may be preferable in certain situations. In other situations, hydraulics or pneumatics may be preferred, and a hydraulic or pneumatic device may be incorporated into a barrier system, either for a drive mechanism or otherwise.
[0102] Barrier systems have been described herein as deploying obstructive components in a manner that does not require a sweeping motion that is transverse to a longitudinal plane defined by the barrier system. Instead, obstructive components of the barrier system (e.g., guardrail, chains, cables, gate beams, etc.) simply move up and down along the longitudinally extending vertical plane defined by the barrier system during deployment and retraction. It will be appreciated that the absence of transverse sweeping by such components for deployment of such components may permit the barrier system to occupy a relatively short portion of a lane of a roadway. Those of ordinary skill in the art will recognize that the narrow profile achieved by relying on deployment motion that is along a longitudinally extending vertical plane of the barrier system (and therefore transverse to roadway—vertically transverse and/or horizontally transverse as opposed to parallel) may ease installation of the barrier system or provide other benefits. Alternatively, a barrier system may be modified to have a deployment motion that spans across any other suitable plane, including those transverse to a longitudinal plane defined by the barrier system or those that are parallel with the roadway.
[0103] Any version of a barrier system may include a heavy canvas, rubber sheeting or strips, sheet metal, and/or any other suitable structures or material(s) to substantially cover and protect the interior of the vault or housing from debris and/or snow, etc. when the barrier system is in the fully deployed position. Such a protective covering may even be provided in versions where cover plates already provide some degree of protection to the interior of the vault or housing. Such a protective covering may be secured to one or more portions of the vault or housing and/or to any other suitable components of the barrier system.
[0104] It should also be understood that a barrier system may be configured to substantially prevent or at least reduce the likelihood of a vehicle's wheel getting snagged on the barrier system when a vehicle strikes the barrier system. For instance, components of barrier system may be sized, spaced, and otherwise arranged (relative to each other and relative to surrounding structures such as the ground) to substantially prevent or at least reduce the likelihood of wheel snagging. Various ways in which a barrier system may be configured to substantially prevent or at least reduce the likelihood of wheel snagging will be apparent to those of ordinary skill in the art in view of the teachings herein. It should also be understood that posts (or portions thereof) may be configured to break away from other components of the barrier system upon sufficient impact by a vehicle, such as to prevent or reduce snagging.
[0105] Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometric s, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims, and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.
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A vehicle barrier system comprises a housing, substantially vertical members, a barrier member, and an actuation assembly. The barrier member is coupled with the substantially vertical members. The barrier member is configured to stop a moving vehicle when the substantially vertical members are in a raised position relative to the housing. The actuation assembly is operable to selectively raise and lower the substantially vertical members relative to the housing to selectively deploy and retract the barrier member relative to the housing. The actuation assembly comprises a powered rotary actuator mounted to the barrier member. The actuation assembly is operable to convert rotary motion from the rotary actuator into linear movement of the barrier member. A counterweight provides opposing mass and vertical motion relative to the barrier member.
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This is a Continuation of application Ser. No. 08/127,551, filed Sep. 28, 1993 which was abandoned upon the filing hereof.
FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a method for recovering an ammonia adsorbent. In particularly, the present invention relates to a method for recovering an ammonia adsorbent disposed on the downstream side of a dry exhaust gas denitrating device using ammonia as a reducing agent. This ammonia adsorbent is preferably disposed in a temperature region of 200° C. or less on the above-mentioned downstream side. In the present invention, this adsorbent is recovered, when the ammonia adsorbent adsorbs remaining ammonia in the above-mentioned dry exhaust gas denitrating device and it is saturated with ammonia.
Ammonia remaining in the exhaust gas from the dry exhaust gas denitrating device utilizing ammonia as a reducing agent is adsorbed by the adsorbent, but the amount of adsorbed ammonia is limited and therefore in order to use the adsorbent repeatedly, a suitable adsorbent recovery treatment is necessary. As an adsorbent recovery means, there have been known a method in which temperature is elevated for desorbing ammonia, and another method in which pressure is lowered to a level in the vicinity of vacuum so that ammonia can be desorbed.
However, for the sake of the adsorbent recovery by heat, a high-temperature gas or a heating device is necessary, and for the sake of the adsorbent recovery by vacuum, it is necessary to decrease the pressure by vacuum suction. Both methods have the drawback that a large amount of energy is consumed. In addition, a long period of time is required for the recovery. Since an adsorption process is not carried out during the recovery period, a capacity of the apparatus must be increased so as to overcome such an inconvenience. Particularly for the desorption of adsorbed components present in trace amounts, a degree of vacuum must be increased, so that a great deal of energy and a heating device or a vacuum pump are required, which makes the system more complicated. Therefore, a technique for securely recovering the adsorbent in a short period of time under a low energy consumption has been desired. If this technique is attained, the dry exhaust gas denitrating device in which the adsorption technique can be utilized using the ammonia adsorbent can be applied to many fields, and the energy saving of the whole apparatus can be expected.
OBJECT AND SUMMARY OF THE INVENTION
In view of the above-mentioned technical level, an object of the present invention is to provide a method for recovering an ammonia adsorbent in response to the above-mentioned technical demand.
The gist of the present invention resides in a method for recovering an ammonia adsorbent which comprises the steps of adsorbing remaining ammonia in an exhaust gas by an ammonia adsorbent layer disposed on the downstream side of a dry exhaust gas denitrating device into which ammonia is injected as a reducing agent, to saturate the adsorbent layer with ammonia, and then introducing and streaming an NO x -containing exhaust gas at 300°-600° C. drawn from an upstream side of the dry exhaust gas denitrating device.
In the present invention, an NO x -containing exhaust gas at 300°-600° C. or an NO x -containing hot air at 300°-600° C. is used as a heat source required for the recovery of the ammonia adsorbent. In the case that the heat source does not include NO x , the desorption of ammonia from the ammonia adsorbent is carried out only by the effect of an elevated temperature, and therefore a long time is taken to achieve desorption and recovery. However, when NO x is added, NO x itself reacts rapidly with adsorbed ammonia as shown by the following formula, whereby the ammonia adsorbent can be promptly recovered:
4NO+4NH.sub.4 +O.sub.2 →4N.sub.2 +6H.sub.2 O
Thus, in the present invention, the removal of ammonia by the reaction of NO x and ammonia and the desorption of ammonia by the effect of high temperature are simultaneously carried out to remove ammonia promptly and efficiently from the ammonia adsorbent, whereby the ammonia adsorbent can be recovered.
At a temperature of 300° C. or less, the exhaust gas or air containing NO x does not react with ammonia adsorbed by the ammonia adsorbent, and at a temperature of 600° C. or more, the ammonia adsorbent deteriorates. Therefore, the temperature of the exhaust gas or air containing NO x should be in the range of from 300° to 600° C.
One example of the ammonia adsorbent which can be used in the present invention is an adsorbent comprising 75% of titania, 5% of vanadium pentoxide and a molding auxiliary agent which will be described in the undermentioned embodiment, and other usable examples of the ammonia adsorbent include alumina, zeolite, silica.alumina, molecular sieve and titania.
In the present invention, a gas released from an ammonia adsorbent layer at the time of the recovery of the ammonia adsorbent is preferably circulated through a position on the upstream side in the exhaust gas flow of the dry exhaust gas denitrating device and on the downstream side of a dividing/drawing portion of the NO x -containing exhaust gas for the recovery.
In the present invention, it is preferable that a plurality of systems of the ammonia adsorbent layers are formed and the adsorption of ammonia and the recovery of the ammonia adsorbent are mutually alternated on each ammonia adsorbent layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating an embodiment of a method for recovering an ammonia adsorbent regarding the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
One embodiment of the present invention will be described in reference to, for example, a denitration system of an exhaust gas from a gas turbine 1 equipped with an exhaust gas boiler 2 shown in FIG. 1. This exhaust gas boiler 2 is provided with an ammonia injector 3 and a denitrating device 4 in addition to a heat exchanger (not shown). A gas duct 7 extending from the downstream side of the denitrating device 4 is divided into a duct 10 extending to an ammonia adsorbing tower 5 and a duct 11 extending to another ammonia adsorbing tower 6, and the exhaust gases coming from the ammonia adsorbing towers 5, 6 join into the gas duct 7 again and the joined gas is then discharged into the atmosphere through a chimney 9.
Furthermore, the system of the present invention is provided with an NO x -containing gas duct 12 and a recovery gas duct 13. This NO x -containing gas duct 12 divides and draws the exhaust gas on the upstream side of the ammonia injector 3 of the exhaust gas boiler 2 and then introduces this NO x -containing exhaust gas into the ammonia adsorbing towers 5, 6. On the other hand, the above-mentioned recovery gas duct 13 introduces the recovery gases coming from the ammonia adsorbing towers 5, 6 into a position on the upstream side of the denitrating device 4 of the exhaust gas boiler 2 and on the downstream side of the above-mentioned exhaust gas dividing/drawing position.
The exhaust gas of the thus constituted gas turbine 1 is heat-exchanged in the exhaust gas boiler 2, so that the temperature of the exhaust gas lowers, and ammonia is injected through the ammonia injector 3 and the exhaust gas is then denitrated by the denitrating device 4. However, in the thus treated exhaust gas, ammonia is kept remaining. This exhaust gas containing ammonia is introduced into the ammonia adsorbing tower 6, in which ammonia is adsorbed, and the exhaust gas is introduced into the gas duct 7 again and then discharged through the chimney 9. At this time, dampers D 1 , D 2 of the duct 11 are opened.
On the other hand, dampers D 3 , D 4 of the duct 10 extending to the ammonia adsorbing tower 5 which is another system are closed, but the NO x -containing exhaust gas at a high temperature (300°-600° C.) forwarded through NO x -containing gas duct 12 is introduced into the ammonia adsorbing tower 5 via a damper D 5 . In this ammonia adsorbing tower 5, ammonia adsorbed by the ammonia adsorbent is desorbed and then returned to an upstream side of the denitrating device 4 of the exhaust gas boiler 2 through the recovery gas duct 13.
The dampers D 1 to D 6 are switched suitably in accordance with the adsorbing state of ammonia or when a certain time has passed, so that these ammonia adsorbing towers 5, 6 are alternated to adsorb or desorb ammonia.
COMPARATIVE EXAMPLE
(Example 1)
An ammonia adsorbent comprising 75% of titania, 5% of vanadium pentoxide and a molding auxiliary agent was molded into pellets having a diameter of 3 mm, and a combustion exhaust gas containing 20 ppm of ammonia at a gas temperature of 100° C. was then introduced into the pellets to adsorb ammonia sufficiently.
Afterward, the feed of the combustion exhaust gas was stopped, and hot air having a gas temperature adjusted to 100° C. was introduced thereinto. At this time, an ammonia concentration change with time at the outlet of the ammonia adsorbent was measured. Furthermore, changes with time at air temperatures of 200° C., 300° C. and 400° C. were measured in the same manner, and the results are shown in Table 1.
TABLE 1______________________________________Ammonia Concentrations at Outlet of AdsorbentGasTemp. after after after after after(°C.) 10 min 20 min 30 min 60 min 120 min______________________________________100 2-3 ppm 2-3 ppm 2-3 ppm 2-3 ppm 2-3 ppm200 3-5 ppm 5-10 ppm 5-10 ppm 5-10 ppm 5-10 ppm300 60 ppm 100 ppm 100 ppm 50 ppm 10 ppm400 120 ppm 180 ppm 140 ppm 20 ppm <1 ppm______________________________________
It can be understood from Table 1 that ammonia is rapidly desorbed at a temperature of 300° C. or more. Moreover, the ammonia adsorbents after a passage of 120 minutes were ground and then analyzed to inspect ammonia concentrations, and as a result, it was confirmed that in the cases of 100° C. and 200° C., ammonia remained at high concentrations in the ammonia adsorbents. In the case of 300° C., it was confirmed that a small amount of ammonia remained in the ammonia adsorbent and most of ammonia was desorbed.
EXAMPLE IN ACCORDANCE WITH THE PRESENT INVENTION
(Example 2)
The same ammonia adsorbents as in Example 1 were used, and ammonia was adsorbed by the same treatment as in Example 1. Afterward, hot air to which NO x was added at a concentration of 30 ppm and which was adjusted to 300° C. was introduced, and an ammonia concentration at an outlet was measured. The results are shown in Table 2.
TABLE 2______________________________________Ammonia Concentrations at Outlet of AdsorbentGas after after after after afterTemp. 10 min 20 min 30 min 60 min 120 min______________________________________300° C. 20 ppm 30 ppm 10 ppm <1 ppm <1 ppm______________________________________
It can be understood from Table 2 that in Example 2 regarding the present invention, the ammonia concentration at the outlet lowers more rapidly as compared with Example 1. In addition, the ammonia adsorbents 60 minutes or 120 minutes had passed were ground and then analyzed to inspect ammonia concentrations in the ammonia adsorbents, and as a result, any ammonia was not detected.
In Example 2 described above, the results in the case of using the hot air containing NO x are exhibited, but also with the use of an exhaust gas containing NO x , about the same results have been obtained.
As is apparent from the foregoing, according to the present invention, an ammonia adsorbent on which ammonia is adsorbed can be rapidly recovered, and in a dry exhaust gas denitration using ammonia as a reducing agent, the present invention can be advantageously applied to a process in which ammonia remaining in a denitrated exhaust gas is desorbed and removed. In addition, when two or more systems having ammonia adsorbing towers are provided and desorption and adsorption are alternated, ammonia in the exhaust gas can be continuously treated.
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A method for recovering an ammonia adsorbent which comprises streaming an NO x -containing gas at 300°-600° C. through an ammonia adsorbent layer which adsorbs ammonia and which is saturated with ammonia.
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RELATED APPLICATIONS
The invention disclosed in this application is related to that in patent application U.S. Pat. application, Ser. No. 08/761,042 now U.S. Pat. No. 5,744,024 filed of even date herewith.
RELATED APPLICATIONS
The invention disclosed in this application is related to that in patent application U.S. Pat. application, Ser. No. 08/761,042 now U.S. Pat. No. 5,744,024 filed of even date herewith.
FIELD OF THE INVENTION
This invention relates generally to the field of polarizers for liquid crystal display applications, and specifically to liquid crystal polymer-based polarizers.
BACKGROUND OF THE INVENTION
Polarizers are important components of liquid crystal displays. Liquid crystal displays (LCDs) are widely used components in applications such as, for example, Notebook Personal Computers (PCs), calculators, watches, liquid crystal color TVs, word processors, automotive instrument panels, anti-glare glasses and the like. A useful review article, for example, is "Digital Displays" by in Kirk-Othmer Encyclopedia of Chemical Technology, Third edition, Volume 7, page 726 (1979), Wiley-lnterscience Publication, John Wiley & Sons, New York. Typically, Polarizers are used in the form of film, the polarizer film (also called polarizing film). In an LCD, the liquid crystal elements are generally sandwiched between two layers of polarizing films.
Traditional polarizing films comprise a stretched polymer film such as, for example, polyvinyl alcohol (PVA), a dichroic absorber and other optional layers. The dichroic absorber is usually iodine or a dichroic dye that is absorbed in the polymer film. However, there are several disadvantages with such films that make them unsuitable for advanced and sophisticated applications. Some such disadvantages include, for example, non-uniformity, separation of the absorber over time, susceptibility to moisture and the like. For this reason, liquid crystalline polymer-based polarizers are being developed for polarizers. The process of molding or extrusion generally achieves a high degree of stable orientation in such polymers.
Pending U.S. Pat. application, Ser. No., 08/460,288, filed Jun. 2, 1995, now U.S. Pat. No. 5,672,296 discloses novel liquid crystalline polymer compositions useful in polarizer applications. Illustrative compositions disclosed therein are liquid crystalline polyesters which comprise repeat units corresponding to the formula:
- P.sup.1 !m- P.sup.2 !n- P.sup.3 !q-
wherein P 1 , P 2 and P 3 represent monomeric moieties with P 1 being an aromatic hydroxy carboxylic acid, P 2 being an aromatic dicarboxylic acid and P 3 being a phenol; and m, n and q represent mole percent of the respective monomers ranging from 5-70 mole percent individually. Additional monomers may also be present. A preferred composition in the same patent is a film-forming wholly aromatic thermotropic liquid crystal polyester which comprises five monomeric moieties derived from 4-hydroxybenzoic acid, terephthalic acid, 4,4'-dihydroxybiphenyl, 6-hydroxy-2-naphthoic acid, and resorcinol in a molar ratio 30:20:10:30:10 respectively. Such LCPs are converted to polarizing films by combining them with suitable dichroic absorbers and then melt extrusion to yield the films. After melt extrusion, the polarizer films are subjected to further processing steps which include lamination to an optically transparent polymeric layer which is generally a thermoplastic. This lamination may require the use of adhesives depending on the adhesion of the polymeric layer to the melt extruded polarizer film.
Melt extruded LCP films, however, typically exhibit a degree of machine direction-oriented surface texture and therefore need polishing prior to further use. In the case of LCPs for polarizers, the films, especially in the required thickness of 1 mil (25 μm) or less, easily fibrillate and are also damaged easily during processes such as, for example, slitting and winding operations. Subsequent lamination of the polarizer films to the optically transparent polymeric layer preserves these defects and hence substantially reduces the utility of the film in devices where surface quality is critical for optical applications. Furthermore, preparing a polarizing film followed by further lamination to a thermoplastic involves extra steps which make the process uneconomical in addition to possible creation of additional defects.
One way to reduce the defects would be to coextrude the polarizer film with the optically transparent cover layer. This would avoid the separate lamination step later as well as the creation of additional defects on the polarizing LCP film. Coextruded laminates of LCPs containing other LCPs as surface layers on both sides are known. For example, U.S. Pat. No. 5,248,530 discloses such laminates prepared by coextrusion. Copending U.S. Pat. application, Ser. No. 08/761,042, now U.S. Pat. No. 5,744,204 filed of even date herewith, describes a coextrusion process for LCPs. In that case, the cover layers are non-adherent, and are peeled off after the coextrusion. A typical LCP for polarizer applications, on the other hand, is a mixture of an LCP polymer and a dichroic dye, where the dye has been dissolved in, blended with or absorbed in the LCP. A suitable process that provides a laminate from which the cover layers need not be peeled off will be highly useful for such LCPs.
There is a need for an improved polarizer laminate with improved surface characteristics.
It is an objective of this invention to provide improved quality LCP-polarizer laminates.
It is an additional objective of this invention to provide polarizing films with improved surface quality.
It is a further objective of this invention to provide LCP films which contain surface protecting films thereon that need not be delaminated during further processing steps.
It is a further objective of this invention to provide polarizer films which contain surface protecting films thereon that need not be delaminated but may be suitable for processing to a device by conventional processing methods.
It is a still further objective of this invention to provide polarizer laminates prepared by fewer number of steps and with fewer defects.
Other objectives and advantages of the present invention will be apparent to those skilled in the art as well as from the following description and Examples.
SUMMARY OF THE INVENTION
One or more of the foregoing objectives are achieved by the provision in the present invention of improved polarizer laminates. The laminates comprise an LCP-based polarizer film in intimate contact with surface layers of a suitable non-peelable, non-liquid crystalline polymer sheath on both sides of the polarizer film. The LCP-based polarizer film comprises a mixture of a suitable LCP and a dichroic absorber. Such improved laminate is prepared by a process comprising lining an LCP-based polarizer on both sides with the non-liquid crystalline polymer by a process of coextrusion. In one illustration, a suitable LCP-based polarizer is melted in a suitable extruder. The non-LCP polymer is also converted into a melt stream and coextrusion is performed such that the LCP film is lined on both sides by the non-LCP film to produce the inventive laminates. The external layers in the laminate provide sufficient strength to the LCP film during any subsequent processing steps such as, for example, winding, slitting and transport. The external layers are also suitable for further processing of the laminate to make liquid crystal display ("LCD") devices since those layers need not be peeled off (delaminated) and are compatible with such further processing steps.
DESCRIPTION OF THE INVENTION
In one embodiment, the present invention discloses improved polarizer laminates. The laminates comprise a polarizer film located between two integral layers of a non-liquid crystalline polymer. The term "integral" herein refers to the fact that the layers are not peeled off after lamination but stay as attached part of the polarizer. The polarizer film comprises a mixture of a liquid crystalline polymer and a dichroic absorber wherein the dichroic absorber is not covalently linked to he liquid crystalline polymer chain. The non-liquid crystalline polymer used for the cover layer (alternately referred to as the glazing layer or surface layer, or sheath herein) is preferably a thermoplastic polymer. The laminate is prepared by coextruding the polarizing film with the non-liquid crystalline polymer film. The coextruded laminates show a remarkable and significant improvement over conventional polarizer laminates. The latter are prepared by conventional monolayer extrusion, which is described, for example, in pending application, Ser. No. 08/460,288, now U.S. Pat. No. 5.672,296 followed by a separate lamination to a thermoplastic layer. The improved quality of the inventive laminates are clearly seen by optical micrograph examination.
The invention is particularly suitable for LCP-based polarizers. Examples of suitable LCP-based polarizers are disclosed in the above-mentioned pending patent application, Serial No. 08/460,288. The liquid crystal polymers in such polarizers may be liquid crystalline polyester, polyamide, polyesteramide, polyketone, polyether and the like. Liquid crystalline polyesters are preferred. A suitable LCP disclosed in the '288 application comprises repeat units corresponding to the formula:
- P.sup.1 !m- P.sup.2 !n- P.sup.3 !q- P.sup.4 !r- P.sup.5 !s-
wherein P 1 , P 2 , P 3 , P 4 and P 5 represent monomeric moieties with P 1 being an aromatic hydroxy carboxylic acid, P 2 being an aromatic dicarboxylic acid, P 3 being a phenol, P 4 being a second aromatic hydroxy carboxylic acid and P 5 being a second phenol; and m, n, q, r and s represent mole percent of the respective monomers with m, n and q ranging from 5-70 mole percent individually, while r and s range from 5-20 mole percent individually. Such liquid crystal polymers are combined with a suitable dichroic absorber suitably in order to form the polarizer. The dichroic absorber may be organic or inorganic; organic is preferred. A suitable organic dichroic absorber is a dye. Suitable dyes are selected from, for example, straight chain dyes, branched dyes, direct dyes, disperse dyes, solvent dyes and acidic dyes. Dyed LCP layers practiced in this invention are generally in the 4 to 40 μm thickness range.
A suitable non-liquid crystalline polymer which forms the cover layers for the inventive laminates is a non-liquid crystalline polymer, preferably a thermoplastic. Suitable thermoplastics include, for example, polyesters, polycarbonates, polyolefins, polyacrylates, polyestercarbonates, polyamides, polyketones, polyethers, cyclic olefin homopolymer, cyclic olefin copolymer ("COC") and the like. Important criteria for their selection include their optical clarity, low birefringence, as well as their thermal and mechanical properties. Preferred are the polyesters, many of which are well-known thermoplastics. Examples are polyethylene terephthalate ("PET") and polybutylene terephthalate ("PBT"). The cover layer thickness is generally in the 0.5 mil to 2 mil (2.5-50 μm) range in the practice of the present invention. The cover layer polymer on either side of the LCP may be the same or different polymer provided they have suitable optical, thermal and the like properties as noted above.
It is preferable that the surface polymer films possess good adhesion to the liquid crystal polymer film in the laminate. In such a case, one need not use an adhesive layer in between. If, however, the layers do not adhere well, or if one prefers still better adhesion, a suitable adhesive tie layer may also be present in the laminate, prepared in the same extrusion process. Suitable adhesives are commercially available such as, for example, the ADMER brand adhesive supplied by Mitsui Petrochemical Industries Limited, Tokyo, Japan. Suitable thickness for the adhesive tie layers are generally in the range 0.5 to 1 mil (2.5-25 μm). When an adhesive tie layer is used, the laminate construction would be surface layer/adhesive/LCP polarizer/adhesive/surface layer. Again, the same or different adhesives may be used provided they have suitable optical, thermal as well as curing properties.
The process of preparing an inventive laminate is illustrated in the Examples section below. The invention is illustrated with PET as the surface layers and a polarizer based on an LCP material disclosed in the '288 application and referred to as COTBPR therein. COTBPR comprises repeat units from 4-hydroxybenzoic acid, terephthalic acid, resorcinol, 4,4'-biphenol and 6-hydroxy-2-naphthoic acid in the respective molar ratio 30:20:10:30:10. COTBPR was blended with the dichroic dye Methylene Violet Bernthsen™ (from Aldrich Chemical Co., Milwaukee, Wis.) in order to make the polarizing material. The same PET material (a bottle grade PET resin from Hoechst Celanese Corporation, Somerville, N.J.) was used for the cover layer. Coextrusion was performed using the equipment and conditions described in the Examples section below to obtain the inventive laminate where the cover layers were integral parts of the laminate. The laminate was suitable for further processing steps as in conventional methods to fabricate devices such as, for example, liquid crystal display devices.
The present invention has several key advantages over prior known (monolayer extruded and then laminated) polarizer laminates and processes for preparing them. The advantages include ease of operation as well as cost advantages arising from the single coextrusion step versus multi-step production of polarizer film followed by lamination. Surface imperfections are significantly reduced. Quality advantages also exist due to the elimination of multiple steps where contaminates can be introduced into the laminate structure.
The following Examples are provided to further illustrate the present invention, but the invention is not to be construed as being limited thereto.
EXAMPLES
Example 1. Preparation of COTBPR
This example illustrates the preparation of COTBPR polyester from a 1 mole reaction mixture of 4-hydroxybenzoic acid ("HBA"), 6-hydroxy-2-naphthoic acid ("HNA"), terephthalic acid ("TA"), 4,4'-biphenol ("BP"), and resorcinol ("R") in the ratio 30:30:20:10:10.
To a 500 ml 3-neck flask equipped with a half-moon shaped TEFLON™ stirrer blade, gas inlet tube, thermocouple, a Vigreux column attached to a condenser and receiver were added the following:
a) 41.440 grams of 4-hydroxybenzoic acid (0.3 moles);
b) 56.456 grams of 6-hydroxy-2-naphthoic acid (0.3 moles);
c) 33.226 grams of terephthalic acid (0.2 moles);
d) 18.600 grams of 4,4-biphenol (0.1 moles);
e) 11.012 grams of resorcinol (0.1 moles);
the flask was immersed in an oil bath and provided with means to accurately control the temperature. The flask was thoroughly purged of oxygen by evacuation and then flushed with nitrogen three times, and slowly heated in the oil bath; and
f) 0.02 grams of potassium acetate was added as a catalyst along with 105.48 grams of acetic anhydride (2.5% excess). Acetic acid began to distill over and was collected in a graduated cylinder.
The contents of the flask were heated while stirring at a rate of 2000 rpm to 200° C. over a period of 60 minutes at which time 10 ml of acetic acid had been collected. The reaction temperature was then gradually raised at a rate of about 1° C./ min to 320° C. at which time 96 ml of acetic acid had been collected. The flask was heated at 320° C. for another 60 min. A total of 110.5 ml of acetic acid had been collected. The flask was then evacuated to a pressure of 1.0 mbar at 320° C. while stirring. During this period the polymer melt continued to increase in viscosity while the remaining acetic acid was removed from the flask. The flask and its contents were removed from the oil bath and were allowed to cool to the ambient temperature. Polymer was then removed from the flask and a total of 120 grams of polymer was obtained.
The resulting polyester had an inherent viscosity (IV) of 2.0-2.4 dl/g as determined in a pentafluorophenol solution of 0.1 percent by weight concentration at 60° C. and a melt viscosity (MV) of 550 poise at a shear rate of 10 3 sec -1 measured at 230° C. in a capillary rheometer using an orifice of 1 mm diameter and 30mm length.
When the polymer was subjected to differential scanning calorimetry (10° C./ min heating rate), it exhibited a glass transition temperature (Tg) of 106° C. When the polymer was examined by hot-stage cross-polarized optical microscopy, it has a transition temperature from solid to liquid crystalline (Ts->lc) at 170° C. The polymer melt was optically anisotropic.
Example 2. Preparation Of Dye Blended COTBPR By Melt Blending
60 grams of the COTBPR from Example 1 and 0.3 gram of Methylene Violet Bernthsen were charged into the mixing chamber of a Haake Mixer (Model # 3042309 from Haake Company, Paramus, N.J.). The mixing ball and its contents were heated to 240° C. over about 30 minutes and then the charge was blended at a rotational speed of 100 rpm for 10 minutes at the temperature. The mixture of polymer and dye was removed from the ball and allowed to cool to the ambient temperature.
Example 3. Coextrusion Experiments
A coextrusion was performed using a 2 inch extruder to extrude the dyed COTBPR in Example 2 and a 3.5 inch Egan extruder (from Egan Davis Standard, Somerville, N.J.) to extrude a bottle resin grade polyethylene terephthalate. The two melt streams were combined in a commercial ABA ("A" refers to the PET layers, and "B" refers to the dyed COTBPR layer) configuration feedblock (from Cloeren, Inc., Orange, Tex.) and extruded through a commercial 12" wide coathanger die (from Extrusion Dyes, Inc., Chippewa Falls, Wis.). Extrusion conditions are provided in Table
TABLE 1__________________________________________________________________________ Extrusion Feedblock Die Temp Rate Line SpeedExtruder Material Temp (°C.) Temp (°C.) (°C.) (pph) (fpm)__________________________________________________________________________3.5 inch PET 285° C. 280° 260° C. 75 601.5 inch Dyed 210° C. 280° C. 260° C. 2.7 60 COTBPR__________________________________________________________________________
Under these conditions, a laminate with the structure of 1.4 mil PET/0.17 mil dyed COTBPR/1.4 mil PET was produced. The laminate structure exhibits good integrity under normal handling conditions. The inner COTBPR layer had a Hermans Orientation Factor (gaussion fit) of 0.88 and a dichroic ratio of 4, as measured by standard techniques. The PET glazing layers are unoriented.
Example 4. Coextrusion using an intermediate adhesive layer
PET, dyed COTBPR, and an adhesive tie layer (the ADMER brand adhesive supplied by Mitsui Petrochemical Industries Limited, Tokyo, Japan) are coextruded similar to the procedure in Example 3 to produce a PET/tie layer/dyed LCP/tie layer/PET structure having improved adhesion between the PET glazing layers and the LCP layer.
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This invention discloses laminates comprising dyed liquid crystalline polymer based polarizers in the middle with a non-peelable, non-liquid crystalline polymeric cover layers, prepared by a process of coextrusion. The laminates are suitable to prepare liquid crystal display devices therefrom. An illustrative laminate comprises a dyed liquid crystal polymer as the polarizing film with polyethylene terephthalate as the cover layers.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/094,456 filed Dec. 19, 2014, the contents of which are incorporated by reference herein in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with government support under grant No. W81XWH-11-2-0054 awarded by the United States Defense Medical Research Development Program. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] Millions of patients worldwide suffer from hip, knee, and ankle joint disorders, including quadriceps weakness, Patellofemoral Pain Syndrome, or from injuries, stroke, post-polio, multiples sclerosis, or SCI. An improvement in lower extremity assistive devices will benefit some or all of these patients. However, with few exceptions, orthotic options for this population are limited to technologies that cannot provide assistance necessary to replicate the function of an unaffected limb. Accordingly, there is great potential for the development of orthosis devices to drastically increase the quality of life of this population. Gait pathologies and musculoskeletal disorders are often stabilized using a leg orthosis, typically consisting of a crude hard piece of material formed to the wearer's leg. Recently, new orthotic technologies have been introduced that employ external actuators and powered systems to rigidly lock the knee during the stance phase and unlock it during the swing phase of the gait. External actuators and powered systems are generally bulky and often result in low gait speed, joint pain due to additional load, and/or an unnatural gait. Powered systems require a power source, and are prone to faulty operation if the power system dies or malfunctions. Furthermore, powered orthotic devices require sensors and electronics, which have not shown the level of reliability and endurance that is required for medical applications. Thus, there is a need in the art for a small-size purely mechanical orthotic device that does not require an external power source, sensors and electronics.
SUMMARY OF THE INVENTION
[0004] The invention is a purely mechanical passive orthotic joint that utilizes a friction-based latch manipulated by a tri-state mechanism. The orthotic joint allows for impedance modulation in that the knee joint is compliantly supported during the weight acceptance phase and dampens downward forces for the user, and the knee joint is allowed free rotation during the swing phase. The present invention solves issues associated with powered and electronic orthoses, has a small size and light weight, it can be used bilaterally, is passive and mechanical and can be used in any environment of the daily life, and has high endurance and reliability. Moreover, the device according to aspects of the invention can be used for prosthetic applications as a knee-ankle-foot or knee-ankle prosthesis.
[0005] In one aspect, the present invention relates to a friction-based impedance module, comprising: an engagement fixture, a locking mechanism, a chassis, and a lower frame, wherein the chassis is connected to the lower frame by a pivoting joint, wherein the module is configured to lock the pivoting joint responsive to an increased torque load, and wherein the module is configured to unlock responsive to a decreased torque load.
[0006] In one embodiment, the locking mechanism is at least partially housed within the engagement fixture. In one embodiment, the locking mechanism comprises a plunger, a friction trail, and a friction lever with a trail slot. In one embodiment, the friction trail passes through the trail slot of the friction lever. In one embodiment, the alignment of the trail slot with respect to the friction trail is controlled by the engagement fixture. In one embodiment, the trail slot contacts the friction trail to lock the pivoting joint. In one embodiment, the friction trail has a protrusion or void at an angle that prompts the engagement fixture into an engaged configuration. In one embodiment, the friction lever is released from the engaged configuration by a magnet, a spring, a solenoid, gravity, a motor, or movement of a user's limbs. In one embodiment, the friction-based impedance module further comprises a mechanism for delaying the unlocking of the friction-based impedance module in response to a decreased torque load.
[0007] In one embodiment, the locking mechanism is selected from the group consisting of: a ratchet and pawl mechanism, a roller clutch mechanism, a hydraulic mechanism and a wrap spring clutch mechanism. In one embodiment, the friction-based impedance module further comprises at least one of a safety lock, configuration lock, dials, adjustment knobs, range of motion limits, dampers, and lubricating system. In one embodiment, the spring is replaced by a rubber band or other elastic material.
[0008] In another aspect, the present invention relates to a hip-knee-ankle-foot orthosis (HKAFO), hip-knee-orthosis (HKO), knee-ankle-foot orthosis (KAFO), ankle foot orthosis (AFO), hip orthosis (HO), shoulder orthosis (SO), elbow orthosis (EO), wrist orthosis (WO), or knee orthosis (KO) comprising the friction-based impedance module of the present invention.
[0009] In another aspect, the present invention relates to a serpentine spring device comprising a two-dimensional plate having at least one S-shaped region. In one embodiment, the serpentine spring is composed of at least one material selected from the group consisting of: carbon fiber, a metal, and a composite material. In one embodiment, the serpentine spring further comprises at least one additional stacked plate to modulate the flexibility of the device.
[0010] In another aspect, the present invention relates to an orthotic device, comprising: an impedance module including a chassis, a lower frame, and a walking member; wherein the chassis is coupled to the lower frame by a pivoting joint; and wherein the walking member is coupled to the lower frame by a serpentine spring.
[0011] In one embodiment, the spring comprises at least one of a carbon fiber, metal, or composite material. In one embodiment, the impedance module further comprises an engagement fixture and a locking mechanism, such that the module is configured to lock the pivoting joint responsive to an increased torque load, and wherein the module is configured to unlock responsive to a decreased torque load.
[0012] In one embodiment, the locking mechanism is at least partially housed within the engagement fixture. In one embodiment, the locking mechanism comprises a plunger, a friction trail, and a friction lever with a trail slot. In one embodiment, the friction trail passes through the trail slot of the friction lever. In one embodiment, the alignment of the trail slot with respect to the friction trail is controlled by the engagement fixture. In one embodiment, the trail slot contacts the friction trail to lock the pivoting joint. In one embodiment, the friction trail is released by a magnet, a spring, a solenoid, gravity, a motor, or movement of a user's limbs. In one embodiment, the locking mechanism is selected from the group consisting of: a ratchet and pawl mechanism, a roller clutch mechanism, a hydraulic mechanism and a wrap spring clutch mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following detailed description of preferred embodiments of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments, which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.
[0014] FIG. 1 depicts an exploded view of a friction-based impedance module incorporating a locking mechanism according to an exemplary embodiment of the invention.
[0015] FIG. 2 depicts a schematic of a plunger for use with the exemplary friction-based impedance module.
[0016] FIG. 3 depicts a schematic of a chassis for use with the exemplary friction-based impedance module.
[0017] FIG. 4 depicts a knee-ankle-foot orthosis equipped with the exemplary friction-based impedance module.
[0018] FIG. 5A through FIG. 5D depict the operation of an exemplary friction-based impedance module through different phases of the gait cycle.
DETAILED DESCRIPTION
[0019] It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in typical orthosis devices. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.
[0020] Unless defined elsewhere, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.
[0021] As used herein, each of the following terms has the meaning associated with it in this section.
[0022] The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
[0023] “About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, and ±0.1% from the specified value, as such variations are appropriate.
[0024] Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6, and any whole and partial increments therebetween. This applies regardless of the breadth of the range.
[0025] The present invention includes a mechanical friction-based impedance modulation device (weight acceptance control orthosis) for orthotic applications. The device can function in parallel with any upper or lower extremity joints, such as the elbow or knee joint for example, to replace or supplement the function of an impaired joint. The device locks in response to a torque, such as a torque caused by rotation or a user's weight load on a joint, and subsequently unlocks upon removal of the torque to restore full range of motion to the joint. The device is capable of locking at any angle in response to a torque.
[0026] Referring now to FIG. 1 , an exploded view of an exemplary friction-based impedance module 10 is shown. The friction-based impedance module 10 includes an engagement fixture 14 , a locking mechanism 20 , and a chassis 12 . As shown, the engagement fixture 14 includes side frame components 1 and 3 , and a rear frame component 2 . The distal portion of friction-based impedance module 10 includes a stopper rod 56 , and a lower frame component 54 connected to a serpentine spring 18 . Locking mechanism 20 includes a plunger 22 , a plunger spring 50 , a posterior rod 40 , an anterior rod 42 , a rubber band anchor rod 52 , at least one rubber band 24 , a magnet 16 , a friction lever 26 , a leaf spring 28 , a friction trail 30 , and a pin 38 . Friction lever 26 and rear frame component 2 each include a trail slot 53 .
[0027] Referring now to FIG. 2 , a schematic of plunger 22 is shown. Plunger 22 includes a short notch 44 and a long notch 46 , thereby forming a posterior ridge 47 between short and long notches 44 and 46 . At the opposing end of long notch 46 is an anterior ridge 48 .
[0028] Referring now to FIG. 3 , a schematic of chassis 12 is shown. Chassis 12 includes one or more orthotic attachment holes 76 , a spring attachment hole 68 , a tunnel 70 , a slot 60 , one or more adjustment holes 66 , one or more magnet slots 62 , a stopper slot 64 , and a hole 34 to form a joint. Attachment points 76 are located on the proximal end of chassis 12 for securing chassis 12 to, for example, an orthotic device 100 as shown in FIG. 4 . Tunnel 70 runs through chassis 12 and is open on both the anterior and posterior ends. Slot 60 includes plunger rod guides 72 and friction lever guide 74 .
[0029] As illustrated, side frames 1 and 3 , and rear frame 2 are connected to each other via pin 38 engaging holes 36 , such that engagement fixture 14 moves as a single unit. In such an embodiment, at least one rubber band 24 loops around anterior rod 42 and rubber band anchor 52 . The position of rubber band anchor 52 may be adjustable by inserting it in any one of adjustment points 66 of chassis 12 . Accordingly, adjusting the position of rubber band anchor 52 also adjusts the force that the at least one rubber band 24 exerts upon anterior rod 42 .
[0030] Leaf spring 28 is attached to the distal end of friction lever 26 , such that leaf spring 28 and friction lever 26 move as a single unit. Accordingly, pin 38 resists the range of movement by leaf spring 28 when pin 38 is engaged with holes 36 . Further, friction lever 26 is positioned to engage with chassis 12 such that it fits into friction lever guide 74 of slot 60 . Thus, the proximal edge of friction lever 26 rests against posterior rod 40 and anterior rod 42 . The selected magnet slot 62 holds or otherwise engages magnet 16 . Accordingly, the position of magnet 16 is also adjustable by inserting it in any of magnet slots 62 . Once in position, magnet 16 magnetically attracts friction lever 26 .
[0031] As shown, friction trail 30 is attached to the extended arms of lower frame 54 , thereby allowing friction trail 30 and frame 54 to move as a single unit. In this configuration, friction trail 30 passes through trail slot 53 of friction lever 26 . Accordingly, engagement fixture 14 , chassis 12 , and lower frame 54 may be joined together at joint 34 . As shown, engagement fixture 14 , chassis 12 , and lower frame 54 pivot independently about joint 34 . For example, lower frame 54 may pivot in flexion to move friction trail 30 in an anterior direction, or lower frame 54 may pivot in extension to move friction trail 30 in a posterior direction. As such, stopper rod 56 limits the range of pivot by lower frame 54 .
[0032] Friction trail 30 provides the friction for locking exemplary friction-based impedance module 10 depicted in FIG. 1 , as described elsewhere herein. It should be appreciated that the present invention may be locked with any suitable mechanism that provides a friction. Non-limiting examples of suitable mechanisms include: a ratchet and pawl; a roller clutch, a wrap spring clutch, hydraulic mechanisms, and the like.
[0033] As shown in FIG. 1 , serpentine spring 18 is attached to the distal end of lower frame 54 . In one embodiment, the distal end of serpentine spring 18 is attached to, for example, an orthotic or prosthetic device, such that serpentine spring 18 dampens the force exerted on a wearer while using the orthotic or prosthetic device. Accordingly, serpentine spring 18 enables torsion in, for example, an orthotic device as shown in FIG. 4 . Serpentine spring 18 can be made of any suitable material. For example, non-limiting materials include carbon fiber, metals, composites, and the like. In certain embodiments, the serpentine spring is S-shaped, and includes two two-dimensional S-shaped plates sandwiching the lower frame 54 . In other embodiments, the serpentine spring may comprise a plate having a plurality of S-shaped regions in linear succession to increase the length of the serpentine spring. In other embodiments, additional plates may be any desired shape, meaning the additional plates may or may not be S-shaped. The spring constant can be modified by either adding more plates, or customizing the constant of each of the base plates. In certain embodiments, the torque of the serpentine spring can be modified by adding one or more spring laminae. For example, spring laminae may be stacked onto the serpentine spring to adjust the torque based on spring laminae orientation and constraint. The spring laminae may be any desired length and shape, depending on the position of laminae when stacked. Accordingly, the serpentine spring device may be modified with any number of additional plates and/or laminae, to effectively modulate the flexibility of the spring, to facilitate adjustment of torque or differentiation of torque for clockwise verses counterclockwise rotations. As shown in FIG. 1 and FIG. 4 , the exemplary embodiment provides for easy switch-out, replacement, customization and installation of serpentine springs without the need for disassembling the engagement fixture 14 .
[0034] In one embodiment, plunger 22 is housed within tunnel 70 of chassis 12 , and the posterior end of plunger 22 rests against rear frame component 2 . Further, a spring wraps around the proximal edge of rear frame 2 and is anchored to chassis 12 by spring attachment 68 . Accordingly, the spring anchored by spring attachment 68 maintains the contact between rear frame 2 and the posterior end of plunger 22 . In one embodiment, the anterior end of tunnel 70 is plugged by a threaded screw. In one embodiment, plunger spring 50 is compressed within tunnel 70 between plunger 22 and a threaded screw.
[0035] Posterior rod 40 and anterior rod 42 fit into plunger rod guides 72 of slot 60 . In one embodiment, plunger rod guides 72 are dimensioned such that they permit posterior rod 40 and anterior rod 42 to move in only the proximal and distal directions. In this configuration, posterior rod 40 holds the position of plunger 22 . For instance, posterior rod 40 may rest in short notch 44 against posterior ridge 47 to maintain plunger 22 in an anterior position. In another instance, posterior rod 40 may rest in long notch 46 against anterior ridge 48 to maintain plunger 22 in a posterior position. Alternatively, anterior rod 42 holds the position of plunger 22 . For instance, anterior rod 42 may rest in long notch 46 against anterior ridge 48 to maintain plunger 22 in a medial position.
[0036] Friction-based impedance module 10 is amenable for use in any application wherein the function of a joint, such as an impaired joint, is in need of having its function replaced or supplemented. In particular, friction-based impedance module 10 can be used in an orthosis to replace or supplement the function of a joint. Friction-based impedance module 10 can also be used to replicate the function of a joint in a prosthetic. Suitable joints include those of the lower extremities and the higher extremities, such as the hip, the knee, the ankle, the wrist, the elbow, the shoulder, and the like. Accordingly, any embodiment of friction-based impedance module 10 , any embodiment of serpentine spring 18 , either separately or in combination, may be incorporated into any type of orthosis device. Example orthoses include hip-knee-ankle-foot orthoses (HKAFO), hip-knee-orthoses (HKO), hip-knee-ankle orthoses (HKAO), knee-ankle-foot orthoses (KAFO), knee-ankle orthoses (KAO), ankle-foot orthoses (AFO), knee orthoses (KO), hip orthoses (HO), shoulder orthoses (SO), elbow orthoses (EO), wrist orthoses (WO), and the like.
[0037] It should be understood that the devices of the present invention may comprise any additional elements that enhance the function or safety of the devices. For example, the additional elements may improve device performance, customization, and ease of use. Non-limiting examples of such elements include safety locks, configuration locks, dials, adjustment knobs, range of motion limits, dampers, lubricating systems, and the like.
[0038] FIG. 5A through FIG. 5D track the operation of an exemplary friction-based impedance module 10 through different phases of the gait cycle (with details of certain elements described below shown in FIG. 1 through FIG. 3 ). In a first state that starts exactly after the weight acceptance phase ends around ˜40% through the gait cycle and ends in the swing phase when the knee maximally flexes, the friction-based impedance module 10 is unlocked. At the start of this phase and with reference to FIG. 5A , the proximal edge of friction lever 26 rests against the bottom of posterior rod 40 , raising posterior rod 40 to the uppermost limit allowed by plunger rod guide 72 . Anterior rod 42 is lowered to the lowermost limit allowed by plunger rod guide 72 due to tension from rubber band 24 . Posterior rod 40 rests in long notch 46 against anterior ridge 48 to maintain plunger 22 in a posterior position. In a posterior position, plunger 22 extends out of tunnel 70 and holds rear frame 2 in a posterior position. Accordingly, engagement fixture 14 and pin 38 are also held in posterior positions. In this configuration, magnet 16 pulls friction lever 26 into an upright position. Friction lever 26 in an upright position aligns trail slot 53 perpendicular to friction trail 30 .
[0039] Accordingly, friction lever 26 does not impede the movement of friction trail 30 in this configuration. For instance, friction trail 30 is free to move in an anterior direction, such as when lower frame 54 pivots in flexion, and friction trail 30 is free to move in a posterior direction, such as when lower frame 54 pivots in extension. Now with reference to FIG. 5B , when lower frame 54 pivots to its limit in flexion, the posterior arm of lower frame 54 pushes against rear frame 2 . Accordingly, engagement fixture 14 , pin 38 and plunger 22 are pushed as well. Plunger 22 is depressed into tunnel 70 and friction-based impedance module 10 enters a second configuration.
[0040] In a second state that starts in the swing phase when the knee maximally flexes and ends at the beginning of the stance phase when the knee starts flexing, friction-based impedance module 10 is primed and is ready to lock in response to a torque, such as from a rotation or weight load. At the start of this second state, and still with reference to FIG. 5B , the proximal edge of friction lever 26 rests against the bottom of posterior rod 40 , raising posterior rod 40 to the uppermost limit allowed by plunger rod guide 72 . Anterior rod 42 is lowered to the lowermost limit allowed by plunger rod guide 72 due to tension from rubber band 24 . Posterior rod 40 rests in short notch 44 against posterior ridge 47 to maintain plunger 22 in an anterior position. In an anterior position, plunger 22 extends out of tunnel 70 and holds rear frame 2 in an anterior position. Accordingly, engagement fixture 14 and pin 38 are also held in anterior positions. Pin 38 in an anterior position holds friction lever 26 in an angled position, where the distal edge is anterior to the proximal edge. Friction lever 26 in an angled position also angles trail slot 53 .
[0041] In this second state, the angled position of trail slot 53 allows friction trail 30 to move unimpeded in a posterior direction, such as when lower frame 54 pivots in extension. Now with reference to FIG. 5C , if friction trail 30 moves in an anterior direction, such as when lower frame 54 pivots in flexion, trail slot 53 catches friction trail 30 and friction-based impedance module 10 enters a third configuration.
[0042] In a third state that starts at the beginning of the stance phase and ends at the end of the weight acceptance phase around ˜40% through the gait cycle when the device is unloaded, friction-based impedance module 10 has locked in response to a weight load. As shown in FIG. 5D , the wearer's weight bearing upon the primed friction-based impedance module 10 applies a torque to cause lower frame 54 to pivot in flexion, moving friction trail 30 in an anterior direction. Trail slot 53 catches friction trail 30 and causes the proximal edge of friction lever 26 to undergo an anterior shift. The proximal edge of friction lever 26 pushes anterior rod 42 from underneath to the uppermost limit allowed by plunger rod guide 72 . Posterior rod 40 falls by gravity to the lowermost limit allowed by plunger rod guide 72 . Anterior rod 42 rests in long notch 46 against anterior ridge 48 to maintain plunger 22 in a medial position. In a medial position, plunger 22 extends slightly out of tunnel 70 and holds rear frame 2 in a medial position. Accordingly, engagement fixture 14 and pin 38 are also held in medial positions.
[0043] In this third state, as long as the wearer's weight remains upon friction-based impedance module 10 and maintains the torque, flexion by lower frame 54 will be locked. Removing the weight load removes the torque and shifts friction-based impedance module 10 back into the first configuration. Without the torque provided by the weight load, anterior rod 42 is pulled distally by the at least one rubber band 24 . Posterior rod 40 is now pushed proximally by the proximal edge of friction lever 26 . Plunger 22 , having been released by the distal motion of anterior rod 42 , is now pushed posteriorly by plunger spring 50 . Plunger 22 stops posterior movement once posterior rod 40 seats in long notch 46 and rests against anterior ridge 48 . Friction-based impedance module 10 has returned to the first configuration.
[0044] In some embodiments, the friction-based impedance module of the present invention further comprises a delay mechanism for delayed unlocking. For example, the mechanism may delay the friction-based impedance module from shifting from the third configuration to the first configuration upon the decrease or removal of a torque, such that friction-based impedance module remains locked for a brief period of time. A delay mechanism may be advantageous to enhance a user's ability to recover from a stumble in a lower extremity orthosis, or for tremor suppression in an upper extremity orthosis. In a moment of imbalance or weakness, the torque on a locked friction-based impedance module may be inadvertently removed. A delay mechanism allows the device to be able to provide a user with a brief period of time where the friction-based impedance module stays locked, giving the user the structural support needed to regain balance or suppress tremor.
[0045] In certain embodiments, the delay mechanism allows a limited range of motion in the friction-based impedance module upon the decrease or removal of a torque. For example, it may be advantageous for a user to have a functional range of motion for stumble recovery. The delay mechanism may restrict the friction-based impedance module to a safe range of motion for a brief period of time following the decrease or removal of a torque.
[0046] The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety.
[0047] While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.
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In certain aspects, the present invention is a purely mechanical stance control orthosis, or stated differently, a weight acceptance control orthosis, as it stabilizes the impaired knee joint during the first 40% of the gait cycles termed as the weight acceptance phase. The device employs a tri-stable fixture to lock/unlock a friction-based latch to provide two levels of stiffness. The device is locked during the weight acceptance phase to stabilize the impaired knee joint for an orthotic application or avoid collapse for a prosthetic application, and is unlocked during the rest to allow free rotation. The device includes an engagement fixture, a locking mechanism, a chassis, and a frame. The engagement fixture controls the locking mechanism to lock and unlock movement in the chassis and frame in response to a wearer's weight load and is capable of locking at any angle.
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BACKGROUND OF THE INVENTION
[0001] Surgical site infections (SSI) occur following about 2-3 percent of surgeries in the United States with an estimated 500,000 incidents of SSI occurring annually, which can lead to significant patient morbidity and mortality. In addition to the negative impact of such infections on patient health, these potentially avoidable infections contribute significantly to the financial burden experienced by the health care system. SSIs result when an incision becomes contaminated by bacteria, and for most surgeries the primary source of these infection-causing microorganisms is the skin (an exception being surgeries in which the gastrointestinal tract is penetrated).
[0002] Various compositions are used to prepare the skin prior to surgery. Skin preparations or “preps” are used to remove some level of microbial load on the skin prior to making an incision. Skin sealant materials are used to protect patients from bacterial infections associated with surgical site incisions and insertion of intravenous needles. Skin preps are applied to the skin and allowed to dry to maximize effectiveness for reducing microorganisms. After the skin prep has dried, the sealant may be applied directly to the skin in liquid form. The sealant forms a coherent film with strong adhesion to the skin through various techniques based on the chemistry of the sealant composition.
[0003] Skin preps currently are predominantly povidone-iodine or chlorhexidine gluconate based formulations and may contain alcohol for fast drying and more effective killing of organisms. Time constraints in the operating room and the lack of an indicator that the prep has dried often result in the skin remaining wet when draping and/or surgery begin, creating the possibility of infection. The lack of an indicator can also negatively impact infection since the users cannot know with certainty where the prep and sealant have been applied.
[0004] Skin sealants now use a polymer composition that dries to form a film through evaporation of a solvent, for example. Other skin sealants contain monomeric units that polymerize in situ to from a polymeric film. Cyanoacrylate sealants containing alkyl cyanoacrylate monomer are an example of the latter type wherein the monomer polymerizes in the presence of a polar species such as hydroxide, water or protein molecules to form an acrylic film. The resulting film formed serves to immobilize bacterial flora found on the skin and prevents their migration into an incision made during a surgical procedure or skin puncture associated with insertion of an intravenous needle.
[0005] Skin sealants may contain additives such as plasticizing agents to improve film flexibility and conformance, viscosity modifiers to aid in application of the liquid composition, free radical and anionic scavengers to stabilize the product prior to use, biocidal agents to kill immobilized bacteria under the film, and the like.
[0006] Skin sealants have also been formulated with colorants to help the user apply the liquid composition uniformly to the skin, especially when large areas are to be covered. There are several problems, however, with existing colorants; addition of a colorant directly to the liquid skin sealant composition can negatively impact both in situ polymerization rates and the conversion reaction, in the case of cyanoacrylate compositions, or evaporation rates and the coalescence process in the case of polymer solution compositions. In addition, known colorants do not provide a visual cue to indicate curing of the composition has been completed. Lastly, after completion of the surgical procedure, the colorant in the sealant can obscure the wound site, making it difficult to detect redness associated with surgical site infections, bruising or leakage.
[0007] It is clear that there exists a need for a colorant that provides a visual cue to indicate coverage area and/or curing and that does not obscure the wound site.
SUMMARY OF THE INVENTION
[0008] In response to the foregoing difficulties encountered by those of skill in the art, we have discovered that compositions including color changing tannates may be used to indicate that the composition has dried and the area of coverage. Iron tannate changes color in response to an acidic environment. The iron tannate may be added to a skin prep, for example, and the color discharged by a slightly acidic coating like a skin sealant. The tannate may be added either directly to a composition, incorporated into a sponge on the applicator through which the composition is dispensed and applied, applied separately or applied simultaneously from a separate reservoir. The amount of tannate in the composition can be adjusted to provide a visual cue to the user of the application area and the extent of cure.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Tannic acid occurs in the bark and fruit of many plants, notably the bark of the oak species, in sumac and myrobalan. Commercial uses include sizing paper and silks, clarifying beer and wine. Medical uses include external use as an astringent for burns and internally as an astringent and as a heavy metal antidote.
[0010] Skin preparations or “preps” are used to remove some level of microbial load on the skin prior to making an incision. Skin preps are applied to the skin and allowed to dry to maximize effectiveness for reducing microorganisms. Skin preps currently are predominantly povidone-iodine or chlorhexidine, gluconate based formulations and may contain alcohol for fast drying and more effective killing of organisms. Povidone iodine, available commercially as Betadine® is estimated to be used in 80 percent of surgeries as a skin preparation. Betadine® skin prep is an aqueous solution of 10 percent povidone iodine having 1 percent titratable iodine content. When Betadine® skin prep is applied to the skin, it imparts and orange-brown color.
[0011] Skin sealant materials are used to protect patients from bacterial infections associated with surgical site incisions and insertion of intravenous needles. Skin sealants are often applied directly over or on top of (Betadine®) skin preps. The sealant forms a coherent film with strong adhesion to the skin through various techniques based on the chemistry of the sealant composition. The skin sealants used herein contain a film former and a plasticizer and other optional ingredients like viscosity modifiers to aid in application of the liquid composition, free radical and anionic scavengers to stabilize the product prior to use, biocidal agents to kill immobilized bacteria under the film, and the like.
[0012] One film former available in a skin sealant composition is commercially known as InteguSeal® and is available from Medlogic Global, Ltd of Plymouth, England. InteguSeal® skin sealant contains medical grade n-butyl cyanoacrylate monomer (80% w/w). Medical grade cyanoacrylate is double distilled. Non-medical grade cyanoacrylate, in contrast, is single distilled and is typically marketed as a “super glue” type adhesive for gluing a wide variety of substrates together.
[0013] It would be useful to medical personnel to know exactly where the skin sealant and prep were applied so that they could be sure that the appropriate area was covered. The inventors believe that providing a skin sealant and/or skin prep which will change color as it dries will provide valuable information for the medical professional. The authors identified the vivid color change potential of tannic acid through laboratory research. The invention discussed herein uses tannic acid and metal salts to give a vivid color which is discharged by the acid nature of the skin sealant. Several variations have been developed using this methodology:
[0014] 1) Iron tannate in the skin prep with the color discharged by the application of the skin sealant (deep blue to colorless)
[0015] 2) Tannic acid in the sealant and iron salts on the applicator sponge or in a separate vial within the applicator so that the tannic acid and iron salt react to form iron tannate as the sealant is applied to the skin and the iron tannate has its color discharged by the skin sealant and;
[0016] 3) Iron salt in the skin prep and tannic acid in the skin sealant to give a timed color development and color discharge during the application process.
[0017] The amount of iron tannate in the skin prep or sealant should be between about 0.09 and 10 weight percent. This may be calculated by one skilled in the art based upon the volume of the skin prep or sealant to be used. It should be noted that the term “ppm” or parts per million as used herein denotes one particle of a given substance for every 999,999 other particles. This is roughly equivalent to one drop of ink in a 150 liter (40 gallon) drum of water, or one second per 280 hours (11 days, 16 hours). One part in 10 6 —a precision of 0.0001%.
[0018] Tannic add of use in commerce occurs in the bark and fruit of many plants, notably in the bark of the oak species, in sumac and myrobalan. It is produced from Turkish or Chinese nutgall, the former containing 50-60%, the later about 70% tannic acid. The chemistry of tannins is quite complex and non-uniform. Tannins may be divided into two groups: (a) derivatives of flavinols, so-called condensed tannins and (b) hydrolysable tannins (the most important group) which are esters of a sugar, usually glucose, with one or more trihydroxybenzenecarboxylic acids. Tannic add is used for clarifying beer and wine and also as an astringent. It has also been used internally for treatment of diarrhea.
[0019] The intensity or brightness of light is expressed in lux (lx), for example, an over cast summer day is estimated to between 30,000 lx and 40,000 lx and a mid-winter day is estimated to be about 10,000 lx. The British Standards Institution Code of Practice for Day-lighting, BS 8206 Part 1 deals in general terms with the code of practice for artificial light. The following gives some general guidance for the light requirements for the work place.
[0020] General office, laboratories, kitchen—500 lx
[0021] Drawing offices—750 lx
[0022] Tool rooms and paintwork—1000 lx
[0023] Inspection of graphic reproduction—1500 lx.
[0000] Accordingly, for purposes of the present invention “normal light conditions” refers to light conditions of between about 500 lx and 2000 lx, more desirably, from about 750 lx to about 1500 lx as determined in accordance with BS 8206 part 1.
[0024] As noted above, there a number of ways to use the color change components with a skin prep/skin sealant system: it may be mixed with the skin sealant, it may be impregnated onto a sponge or wipe which is used to apply the sealant, it may be applied separately from a separate reservoir and it may be applied simultaneously from a separate reservoir in a manner similar to the application of an epoxy.
[0025] The application of a tannate to a carrier may be done by the “dip and squeeze” method, known to those skilled in the art. In this method, the carrier (e.g., sponge, nonwoven fabric (wipe), cotton ball or other) is placed in a bath of the tannate and allowed to absorb the tannate. After absorbing the tannate, the carrier is squeezed between, for example, a pair of rollers, to force out excess tannate.
[0026] Another method to apply tannate to a carrier is to spray the tannate onto the carrier. Spraying generally does not penetrate the carrier with tannate as well as the dip and squeeze method, though it is generally faster and simpler.
[0027] Yet another method to apply a tannate to, for example, a stack of wipes in a storage box, is to add the tannate to the box with the wipes. U.S. Pat. Nos. 4,775,582 and 4,853,281, commonly assigned and incorporated by reference in their entirety. These patents concern a method of maintaining relatively uniform moisture in a stack of wipes. The wipes may be made from polyolefinic microfibers that have been extruded and gathered like spunbond or meltblown fibers, or a combination of both. Common materials for construction of wipers include spunbond and meltblown fibers and fabrics in various arrangements.
[0028] The term “spunbond fibers” refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to Hartman, and U.S. Pat. No. 3,542,615 to Dobo et al. Spunbond fibers are generally not tacky when they are deposited onto a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, more particularly, between about 10 and 20 microns. As used herein the term “meltblown fibers” means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al. Meltblown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally tacky when deposited onto a collecting surface. Laminates of spunbond and meltblown fibers may be made, for example, by sequentially depositing onto a moving forming belt first a spunbond fabric layer, then a meltblown fabric layer and last another spunbond layer and then bonding the laminate in a manner described below. Alternatively, the fabric layers may be made individually, collected in rolls, and combined in a separate bonding step.
[0029] Such fabrics usually have a basis weight of from about 0.1 to 12 osy (6 to 400 gsm), or more particularly from about 0.75 to about 3 osy. Multilayer laminates may also have various numbers of meltblown (abbreviated as “M”) layers or multiple spunbond (abbreviated as “S”) layers in many different configurations and may include other materials like films (abbreviated as “F”) or coform materials (see U.S. Pat. No. 4,100,324 for descriptions of exemplary “coform” materials), e.g. SMMS, SM, SFS, etc.
[0030] Applying the sealant from a separate reservoir may involve the use of dispensers developed for that purpose. One exemplary dispenser has the liquid sealant held in at least one oblong glass ampoule within a rigid nylon housing. The housing has a body and a cap that are slidably connected and it is the cap which holds the ampoule(s). In use, the two parts are moved toward each other to dispense the liquid; the cap moving into the body. Moving the parts together results in breakage of the glass ampoule(s) and dispensing of the liquid. A detent-type locking mechanism holds the body and cap together once they are moved. The locking mechanism consists of slots formed in the cap into which fits a slight protuberance or knoll of plastic formed on the inside surface of the body. Once the ampoule is broken, the liquid travels through a small piece of foam which catches any glass shards that may have been formed by the breakage of the ampoule and thence on to the tip portion of the body. The tip has a number of small holes in it to allow the liquid to pass through. The body tip has a piece of foam on the outside, held in place with a rigid plastic oval-shaped ring that snaps in place on the tip. The outer foam contacts the skin of the patient when the liquid is dispensed. Other types of dispensers may be found in U.S. Pat. Nos. 4,854,760, 4,925,327 and 5,288,159, incorporated herein by reference.
[0031] In another embodiment the skin sealant and tannate may be applied separately to the area containing a skin prep. U.S. Pat. No. 5,928,611 describes a dispenser having a skin sealant reservoir and an active ingredient such as a cross linking accelerator or initiator disposed on a foam piece through which the sealant must pass. One could envision the use of such a dispenser having the tannate disposed on the foam piece and the sealant passing though it as it is about to be deposited onto the skin. See also U.S. Pat. No. 6,322,852.
[0032] In yet another embodiment, U.S. Pat. No. 6,340,097 describes a dispenser having at least one crushable ampoule within the body of the dispenser which could hold more than one. This would permit one ampoule to hold skin sealant and a second to hold the tannate. When the dispenser was used, it would break both ampoules and the sealant and tannate would mix just before application to the skin.
[0033] In addition to being used as a traditional skin sealant, i.e. as a film forming barrier through which a surgical incision is made, the tannate and skin sealant composition may also be used like a bandage to close and/or cover wounds, abrasions, burns, acne, blisters and other disruptions in the skin to protect them from subsequent contamination. The use of the skin sealant composition would therefore not be limited to medical personnel.
[0034] Wound protection is critical in permitting the healing process to take place. Traditional adhesive bandages and gauze wound dressings have been used by the consumer to treat/dress acute wounds or skin irritations. Such adhesive bandages are generally passive, in that they offer little or no chemical treatment for wound healing. Rather, they primarily serve to exert low levels of pressure on the wound, protect the wound from exposure to the environment, and absorb any exudates, which are produced from the wound site. Such bandages generally include a base layer, which is the layer seen by the consumer following application of the bandage to the wound. Such a layer is typically formed from a polymeric material such as a film, nonwoven web, or combination thereof, and may be perforated in some fashion to allow for flexibility and/or further breathability. This layer often includes a film component, having a top side surface which is seen by the consumer after application of the bandage to the wound site, and a bottom side surface (skin contacting surface). A skin-friendly adhesive is usually placed over the base layer bottom side surface to provide a means for attaching the bandage to the consumer. Alternatively, a separate adhesive tape is used to attach the bandage/wound dressing to the wound site, if the bandage/wound dressing is of the nonadhesive type. In the center of the base layer bottom side surface is traditionally positioned an absorbent pad for absorbing exudates from the wound. Finally, a non-stick perforated film layer is normally positioned over the absorbent pad layer, to provide a barrier between the absorbent pad and the wound itself. This allows the wound fluid to move through the perforated layer without sticking to the wound site. Typically the absorbent pad in such bandage does not include any medicinal components, although comparatively recently, bandage manufacturers have started including antibiotic agents on or within bandages to encourage wound healing.
[0035] The skin sealant composition of this invention can replace this seemingly complicated bandage construction with a single liquid treatment that will dry to a flexible coating that protects a wound much like a bandage would. Additionally, medicaments such as antibiotic agents may be blended in effective amounts with the composition to provide additional benefits in the area of microbial inhibition and the promotion of wound healing. The sealant may be applied to provide an effectively thick coating over the surface of the superficial wound, burn or abrasion. Because the to-be-treated wound is superficial and does not extend beyond the dermal layer, any polymeric residues diffusing into or forming in the wound will be naturally extruded from the skin. Generally, the sealant provides an adhesive film coating over the wound area which when set is satisfactorily flexible and adherent to the tissue without premature peeling or cracking. The coating generally has a thickness of less than about 0.5 millimeter (mm).
[0036] Sealant coatings of such thicknesses form a physical barrier layer over superficial wounds which provide protection for the wound in the same manner as a conventional bandage. Specifically, the coating provides an almost airtight, waterproof seal around the wound which does not need to be replaced when the wound gets wet. Once applied, the coating prevents bacterial and contaminant entry into the wound, thus reducing the rate of secondary infection. Generally, the adhesive coating does not limit dexterity and promotes faster wound healing. Additionally, unlike conventional bandages, the sealant naturally sloughs off the skin within 2-3 days after application and, accordingly, avoids the discomfort associated with removal of conventional bandages from the skin. However, if early removal of this polymeric coating is desired, such can be achieved by use of solvents such as acetone. Further discussion of this use may be found in U.S. Pat. No. 6,342,213.
[0037] By way of elaboration it should be noted that several wound care products are currently being marketed which contain an antiseptic benzalkonium chloride and an antibiotic mixture of polymixin B-sulfate and bacitracin-zinc. Patents in this area of technology have described the use of commonly known antiseptics and antibiotics, such as those described in U.S. Pat. Nos. 4,192,299, 4,147,775, 3,419,006, 3,328,259, and 2,510,993. U.S. Pat. No. 6,054,523, to Braun et al., describes materials that are formed from organopolysiloxanes containing groups that are capable of condensation, a condensation catalyst, an organopolysiloxane resin, a compound containing a basic nitrogen, and polyvinyl alcohol. U.S. Pat. No. 5,112,919, reported a moisture-crosslinkable polymer that was produced by blending a thermoplastic base polymer, such as polyethylene, or a copolymer of ethylene, with 1-butene, 1-hexene, 1-octene, or the like; a solid carrier polymer, such as ethylene vinylacetate copolymer (EVA), containing a silane, such as vinyltrimethoxysilane; and a free-radical generator, such as an organic peroxide; and heating the mixture. The copolymers could then be cross-linked by reaction in the presence of water and a catalyst, such as dibutyltin dilaurate, or stannous octoate. U.S. Pat. No. 4,593,071 to Keough reported moisture cross-linkable ethylene copolymers having pendant silane acryloxy groups.
[0038] A polyurethane wound coating is described by Tedeshchl et al., in EP 0992 252 A2, where a lubricious, drug-accommodating coating is described that is the product of a polyisocyanate; an amine donor, and/or a hydroxyl donor; and an isocyanatosilane adduct having terminal isocyanate groups and an alkoxy silane. A water soluble polymer, such as poly(ethylene oxide), can optionally be present. Cross-linking causes a polyurethane or a polyurea network to form, depending upon whether the isocyanate reacts with the hydroxyl donors or the amine donors. U.S. Pat. No. 6,967,261 describes the use of chitosan in wound treatment. Chitosan is a deacetylated product of chitin (C 8 H 13 NO 5 ) n , an abundant natural glucosamine polysaccharide. In particular, chitin is found in the shells of crustaceans, such as crabs, lobsters and shrimp. The compound is also found in the exoskeletons of marine zooplankton, in the wings of certain insects, such as butterflies and ladybugs, and in the cell wall of yeasts, mushrooms and other fungi. Antimicrobial properties of chitosan have been reported against Gram positive and Gram negative bacteria, including Streptococcus spp., Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Pseudomonas, Escherichia, Proteus, Klebsiella, Serratia, Acinobacter, Enterobacter and Citrobacter spp. Chitosan has also been described in the literature to induce repair of tissue containing regularly arranged collagen bundles.
[0039] The composition may also be used to close wounds much like stitches or bandages. To be used in such a way, the composition is applied to at least one skin surface of the opposed skin sections of, for example, a suturable wound of a mammalian patient (e.g., human patient). The opposed skin sections are contacted with each either before or after application of the composition. In either case, after application of the composition, the wound area is maintained under conditions wherein the composition polymerizes to join these skin sections together. In general, a sufficient amount of the composition may be employed to cover the wound and the adjacent the skin surface of at least one of the opposed skin sections of the suturable wound. Upon contact with skin moisture and tissue protein, the composition will polymerize or, in the case of compositions utilizing partially polymerized monomers, will further polymerize, at ambient conditions (skin temperature) over about 10 seconds to 60 seconds to provide a solid polymeric film which joins the skin sections, thereby closing the wound. Generally, the composition can provide a polymeric film over the separated skin sections thereby inhibiting infection of the wound while promoting healing. Further discussion of this use may be found in U.S. Pat. No. 6,214,332.
[0040] The composition may be packaged in a “kit” form for use in medical facilities and bundled with the appropriate skin prep solution for ease of use and the convenience of the medical personnel. Kits may also include a container holding the skin sealant composition and another separate container for the tannate as previously described. The kit may also include an applicator and means for mixing the contents of the two containers. Alternatively the tannate may be impregnated onto a sponge which is used to apply the sealant and through which the skin sealant flows when it is dispensed. In addition, various complimentary or “mating” containers and different packaging schemes have been used for some time and are known in the art.
[0041] The following examples show the efficacy of the instant approach.
EXAMPLE 1
Iron Tannate in Skin Prep
[0042] Water and alcohol (70% isopropanol) solutions were prepared containing 0.2% wt/wt tannic acid or iron (III) chloride. When these solutions were mixed a deep blue colored solution was generated. When this deeply colored solution was mixed with acid or skin sealant the color was discharged to leave a very pale yellow solution.
[0043] Iron tannate solution (0.3% wt/wt) in 70% isopropanol (IPA) was swabbed onto Vitroskin® artificial skin and allowed to dry to yield a blue colored patch. Vitroskin® is available from IMS Inc., of Orange, Conn and is hydrated over glycerol/water for 12 hours before use as described in the product instructions. A sample of InteguSeal® skin sealant was applied to this area and the skin sealant discharged the color in <1 min.
EXAMPLE 2
Iron Tannate in the Patient Preoperative Skin Preparation (“Skin Prep”) with the Color Discharged by the “Acidic” Sealant
[0044] Iron tannate was dissolved into an alcohol-based chlorhexidine (2% w/v chlorhexidine in isopropanol, 70% w/v) solution (100 mg in 20 ml of solution) to yield a blue-black solution. This skin prep solution was applied to Vitroskin® artificial skin via a sponge application to yield a black colored square 4″×4″ (10.2 cm by 10.2 cm). After allowing for the skin prep to dry, cyanoacrylate skin sealant was applied via the InteguSeal® applicator foam tip. The acidic nature of the skin sealant was sufficient to discharge the black color to yield a colorless and transparent coating.
EXAMPLE 3
Tannic Acid (Aldrich Chemical Co., Milwaukee, Wis.) in the Skin Sealant with Iron Chloride in the Foam Applicator
[0045] To 10 ml of the InteguSeal® skin sealant was dissolved 500 ppm tannic acid and placed in a glass ampoule. The foam tip of the applicator was dip coated with 3% wt/wt solution of iron chloride in isopropanol and allowed to air dry in a fume hood. The applicator was then assembled by first placing the ampoule containing the tannic acid and sealant into the body of the applicator and then fitting the foam tip onto the end of the applicator. The applicator was then activated and the skin sealant applied to a sheet of Vitroskin® artificial skin. The skin sealant turned blue-black on coming through the foam (due to the formation of iron tannate) and went onto the skin to initially produce a black coating which slowly became pale blue-black on curing. This loss of color was due to the acidic nature of the skin sealant reacting with the iron tannate, resulting in significant discharge the color.
EXAMPLE 4
Iron Tannate in the Foam Applicator Tip with Citric Acid in the Alcohol-Based Skin Preparation
[0046] The foam applicator tip of the InteguSeal® applicator was soaked in a solution of iron tannate (500 ppm) in isopropanol and then allowed to air dry. The applicator was then reassembled and the foam fitted. To a 10 ml solution of 2% w/v chlorhexidine in isopropanol, 70% w/v skin prep was added 100 mg of citric acid and stirred to dissolve. This solution was then applied to a sheet of Vitroskin® skin in a 6″×6″ (15.2 cm by 15.2 cm) square area using a foam applicator. The InteguSeal® applicator was then activated and sealant applied to the skin prep area. The blue-black skin sealant coated the skin prep area and within 20 seconds the was completely colorless and transparent. The citric acid shortened the time to discharge the color of the sealant containing the iron tannate.
[0047] As will be appreciated by those skilled in the art, changes and variations to the invention are considered to be within the ability of those skilled in the art. Such changes and variations are intended by the inventors to be within the scope of the invention. It is also to be understood that the scope of the present invention is not to be interpreted as limited to the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing disclosure.
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A composition having various color changing tannates may be used to indicate that the composition has dried. The tannates change color in contact with an acid. The composition may be, for example, a skin prep, skin sealant, food product, paint or other building material or other product that undergoes a phase change. The tannate may be added either directly to the composition, incorporated into a sponge on an applicator through which the composition is dispensed and applied, applied separately or applied simultaneously from a separate reservoir. The amount of tannate in the composition can be adjusted to provide a visual cue to the user of the application area and the extent of cure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a trailer that can be towed behind a vehicle and used on railroad tracks for transporting rail sections that are to be replaced in a railroad track.
2. Description of the Prior Art
Various trailer type vehicles have been used for hauling railroad ties and rail sections, as well as other equipment on railroad tracks, and which are adapted for use either on tracks or on the road.
A track trailer of this general type is sold by The Nolan Company of Bowerston, Ohio. The Nolan track trailer has steel wheels for supporting it on a railroad track, as well as a pair of wheels having tires for road use. The track trailer includes a bed, a winch, and a roller support at the rear, as well as rail section clamps at the front and rear. The Nolan trailer also includes removable end gates. In the normal operation, rail sections will be clamped onto the trailer bed and the outer end of the rail sections will be used for attaching a hitch or towing tongue directly to the rail section. Then a pickup truck or vehicle suitably equipped with steel wheels for running on rails in a normal manner will be hitched to the leading end of the rail section and the trailer located at the midsection of the rail, will support the rail section as the trailer is towed down the railroad track. One of the problems is that the curves on railroad tracks sometimes vary, and the rigid connection of the rail sections to the trailer may cause the wheels of the trailer to jump the tracks, causing the need for retracking, and not only tying up the track, but also delaying replacement of rail sections. In the prior art the rails are fixedly secured relative to the trailer bed, and if the curve of the track is too sharp, one set of the steel wheels will jump the track because the rails are rigidly connected to the trailer.
The winch in prior art trailers is low down, on a level of the trailer bed, and does not provide a good mechanical advantage for lifting rails, nor is it positioned so that it is out of the way for operation when the rails are extended along the bed and extend out beyond the winch itself in a forwardly direction.
The prior art trailers have removable end gates, which are placed on the trailer bed while rail sections are being moved. They are in the way, and can be lost. The present device overcomes the problems associated with using this type of a trailer for hauling rails.
SUMMARY OF THE INVENTION
The present invention relates to a track trailer for operation on a railroad track to support a pair of rail sections which extend a substantial distance fore and aft of the trailer bed, and which then may be towed at the leading end with a suitable hitch assembly. The rail sections are supported on the trailer bed, and are permitted to move slightly sideways with respect to the bed due to the mounting of one of the rail clamps, to accommodate variations in the railroad track curvature and irregularities in the railroad track construction.
The present device further includes means for storing removable tail gates in a secure position, automatically, and has a pair of support rollers at the rear over which the rails will be rolled when they are being loaded. The rollers are easily cammed from a working position to a nonworking position. In the nonworking position of the rollers the tracks are supported directly on the trailer bed and clamp members at the rear, but in the working position the rollers extend above the trailer bed to provide a rolling support for the rail sections as they are loaded onto the trailer bed.
The supports for storing the end gates comprise racks positioned below the trailer bed and accessible from the rear of the trailer. Retainer members which overlie the end of the rack when the rollers are retracted are provided to prevent the end gates from slipping out of the racks, but when the rollers are in usable position, the retainer members clear the racks so that the end gates can be removed or inserted with ease. The retainer members that prevent removal of the tail gate include the operating handle for the cam for controlling the rollers, as well as a tab also operated simultaneously with the roller cam, so that when the rail sections are secured it is assured that the end gates will be held in position and cannot be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a track trailer made according to the present invention having rail sections supported thereon and being towed along a railroad track by a vehicle;
FIG. 2 is an enlarged top plan view of the front portion of the track trailer of FIG. 1 shown with the track engaging wheels in their retracted position;
FIG. 3 is a side elevational view of a track trailer made according to the present invention with the track engaging wheels in their retracted position;
FIG. 4 is a top plan view of FIG. 3 with parts in section and parts broken away;
FIG. 5 is a rear end view of the device in FIG. 3 shown with rail sections in towing position on the trailer bed;
FIG. 6 is a sectional view taken generally along line 6--6 in FIG. 5;
FIG. 7 is a fragmentary view taken along line 7--7 in FIG. 2; and
FIG. 8 is a fragmentary enlarged sectional view generally along the same line as FIG. 6 showing a cam shaft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A track trailer made according to the present invention is shown generally at 10, and in FIG. 1 the track trailer is shown supported on a railroad track 11 (the ties are not shown) and the trailer is supported for movement along the railroad track 11 in a conventional manner.
As shown, the track trailer 10 has a body portion 12, including frame members as will be explained, which support retractable steel railroad wheels indicated generally at 13, that are in their working position as shown in FIG. 1 engaging the rail forming track 11. The trailer body 12 is usable for supporting a pair of elongated rail sections indicated at 15,15 that are supported in a suitable manner on the trailer body, and a hitch assembly 16 is bolted to the ends of the rail section 15 at the forward end thereof in a conventional manner. The hitch assembly in turn is attached to a hitch tongue 17 on a vehicle 18, such as a pickup truck, that also has retractable railroad wheels 20,20 operatively engaging the railroad track 11 for a movement along the track. By using the hitch assembly 16, the trailer body 12 of the track trailer 10 and the rail sections 15 are capable of being towed along the railroad track 11 to a remote location. The track trailer 10 is primarily used for transporting rail sections to locations where rail sections of the railroad track 11 are to be replaced.
The railroad track trailer body 12, as shown in FIG. 3, has longitudinally extending side frame members 23,23 that are used for supporting an axle assembly indicated generally at 24 that has wheels with rubber tires 25 thereon for permitting the trailer to be towed on the road when rail wheels 13 are retracted using a hitch pole 26. The hitch assembly 16 is used at the forward end of the hitch pole 26 in FIG. 3 for towing the trailer over roads. The hitch assembly 16 bolts to the hitch pole 26 for use, after it has been removed from the rail sections 15. When rail sections 15 are to be transported, hitch assembly 16 is removed from the hitch pole and again bolted to the ends of the rail sections on the trailer. The axle assembly 24 can be any desired type of axle, and as shown in the prior art, this arrangement is well known.
The side frame members 23 have suitable supports shown at 30 attached thereto for supporting front and rear pivoting rail wheel axle assemblies indicated generally at 31 for the steel wheels 13. These axle assemblies have a cross shaft 32 pivotally mounted on the trailer bed and have struts 33,33 at an opposite end that extend outwardly from the main pivot axis and rotatably support the steel wheels 13. A separate hydraulic cylinder 36 is connected between the trailer body 12, in the center portions thereof, to a suitable arm 37 fixed to the respective cross shaft as shown in FIG. 6 so that the axle assemblies 31, and the struts 33 can be pivoted to a working position as shown in FIG. 1 and in dotted lines in FIG. 3 and to a retracted position as shown in solid lines in FIG. 3. The hydraulic cylinders 36 can be operated with a valve 40, and pump 41 that can either be a manual pump, or an electrically driven pump if desired driven from the battery of the towing vehicle.
It should be noted that when the axle assemblies 31 are pivoted to a working position, the struts and the wheels 13 go over center, and will rest against suitable stops or supports to remove the load from the cylinders 36 while the trailer is supported on the rails. Also, with the device of the present invention the wheels 13 support the trailer bed so that the rubber tires 25 clear the tracks 11, eliminating any tendency of the rubber tires 25 to drag on the track rails, which dragging may also cause problems on curves when transporting rails.
In addition to the longitudinally extending frame members 23, the trailer frame has front suitable cross frame members, at both the front and the rear, for example, a rear cross member 42 is shown in FIGS. 5 and 6. Fenders 43 are used over the rubber tires 25. The trailer body 12 is provided with a box formed of upright side panels 44 suitably mounted to the side frame members 23, and a floor or bed plate 45 is mounted on the frame members of the trailer. The side panels 44 may be removable, if desired.
Suitable end gates 46 are also provided at the front and rear of the trailer. These end gates 46 are pivotally mounted for movement about a horizontal axis to pivot from open to closed (vertical) positions and are removable from the trailer body. The removability of the end gates is well known in pickup trucks and the like, and any desired mounting structure that permits the end gates to be pivoted and removed can be utilized. As shown, pivot mounting brackets for the end gates are shown generally at 47.
When the trailer is to be used to transport rail sections 15, the end gates 46,46 are removed. This leaves the bed 45 defining a plane from the front to the rear of the box between the upstanding side panels 44 on the trailer frame, and a clear space in which to support rail sections 15,15.
In order to store the end gate sections, as shown in FIGS. 4, 5 and partially in FIG. 6, a pair of end gate racks are supported below the trailer bed. These racks, as shown perhaps best in FIGS. 5, each comprise a separate pair of elongated rack guides 50,50 that extend fore and aft and which are spaced laterally apart sufficiently to receive an end gate 46. The rack guides are supported on the framework of the trailer, and are just above the rear cross axle shaft 32, as shown. The end gates 46,46 fit into and slide along rack guides, and are stopped in forward direction with a cross member 51, as shown in FIG. 4 schematically. The racks and end gates are also shown partially in FIG. 6. The rack guides can be made of channel iron or angle iron as desired, and the tail gates will slide along these racks quite easily. The racks are accessible from the rear of the trailer, except when the retainers for holding the tail gates 46 in position are lowered.
At the rear of the trailer there are a pair of rollers 55, mounted for rotation about a horizontal axis, on individual roller support plates 56. The roller support plates 56 are pivotally mounted relative to the rear cross member 42 on pins 57 that in turn are rotatably mounted in hubs 58 that are fixed to a rear cross member of the frame assembly. The rear cross member 42 as can be seen supports the deck 45, and is connected to the side frame members 23. The rollers 55 are mounted on a suitable shaft indicated at 62 that may extend through all three of the roller support plates 56, and the rollers 55 can be mounted on such shaft on suitable bushings in any conventional manner. The roller support plates 56 are made so that the cams pivot downwardly about pins 57 under gravity, and each plate has a camming edge surface shown at 56A in FIG. 6 that rides against a cam shaft 65. The cam shaft 65 in turn is rotatably mounted in suitable hubs 66 also attached to the rear cross member 42. There can be two or three or more hubs 66 along the length of the cam shaft, so that the cam shaft is supported for rotation about its axis. The cam shaft 65 is also shown in FIG. 8. The cam shaft may be mounted in suitable bearings for ease of operation.
As shown in FIG. 8, and also as shown in FIGS. 5 and 6, the cam shaft 65 has three portions formed therein, by recessing or cutting away a portion of the shaft as shown at 70 in FIG. 8 to form a cam surface 71 that is a planar surface forming a chordal plane that is closer to the axis of rotation, or center of the shaft, than the outer peripheral (cylindrical) surface.
A cam actuator handle indicated at 72 is mounted adjacent one end of the cam shaft 65 (see FIG. 5) and can manually be moved from its solid line position shown in FIG. 5 wherein the cam shaft will be in the position shown in FIGS. 6 and 8 in solid lines to a position substantially 90° from the solid line position. As shown in FIG. 8 when the handle is in its down position, the cam surface 71 formed by the recesses 70 will permit the camming edges 56A of the roller support plates 56 to move about the axis of the pins 57 so that the cam surface 56A is closer to the cross member 42. This lowers the center of the roller shaft 62, and thus the upper edge of the rollers 55, so that the upper edge of the rollers, in the solid line position of FIG. 6 is below the plane 75 of the trailer bed 45. When the cam actuating lever 72 is lifted upwardly, to the second position shown in FIG. 6 with the lever 72 extending generally horizontally, (the dotted line position shown in FIG. 5) the cam shaft 65 will rotate so that the camming edges 56A of the roller support plates 56 will be moved away from the center of the cam shaft generally as shown by the dotted lines in FIG. 8, to lift the shaft 62 supporting the rollers 55 and thus lift the upper edge of the rollers 55 above the plane 75. As will be explained, when the rail sections 15 are being loaded, the cam shaft will be in the position lifting the rollers so that the upper edge of the rollers is above the plane of the trailer or platform 45 so that the rails can be rolled onto the platform across the rollers 55 for a substantial distance without having a high friction load on the rail sections.
Thus, the working position of the rollers 55 is with the cam shaft 65 lifting the rollers 55 so that the upper edge of the rollers 55 is above the plane 75 of the bed 45 of the trailer.
When the rail sections are supported for transport shown in FIG. 1, they must be clamped in position to prevent them from sliding across the bed 45. At the rear of the trailer bed, with the present invention using the pivoting support rollers 55, standard rail clamp means indicated generally at 80 are supported on the shaft 62 for the rollers. A pair of arms 81 are mounted on opposite ends of the shaft 62, outside of the outer roller support plates 56, and these arms are mounted on suitable hubs so that they can pivot about the axis of the shaft 62. The arms 81, when they are not in use, will pivot downwardly out of the way about the axis of the shaft 62 and hang below the rollers 55. However, when they are to be used, they will be moved to the position shown in FIGS. 5 and 6. The arms 81 have outer end portions that are sufficiently long to clear the outer edges of the roller support plates 56, and these outer ends of arms 81 in turn mount a threaded cross rod 82 that extends between the arms 81,81. This threaded cross rod can be pinned to suitable hub members 83 on the arms 81. The threaded rod 82 is part of a conventional rail clamping assembly, and as shown in FIG. 5, the clamping assembly includes lower clamp members of substantially identical construction but arranged in pairs. These clamp members shown at 85 slide on the threaded rod 82. After the rail sections 15 are in position on rollers 55 when first loaded, the rollers can be lowered by operating cam shaft 65 and arms 81 can be pivoted upwardly with the clamp members 85 arranged in the first and second pairs and separated sufficiently to grip flanges 15A of the rail sections as shown in FIG. 5. Suitable nuts 86 can be threaded against the outer edges or surfaces of the clamp members 85 to push the clamp members together and clamp against the flanges 15A on the rail sections 15. The clamp members have overhanging lips that fit over the flanges. A spacer 88 is positioned on the threaded rod 82 in the center to space the first pair of clamp members holding a first rail section 15 from the second pair of clamp members.
The nuts 86 can be tightened down as desired to hold the rails in the proper location.
Normally the rail sections 15 will not be clamped until the cam shaft 65 has been moved to retract the rollers (to their retracted position) with the handle 75 down so that the rail sections 15 are supported on the surface of the track bed and then clamped in position. The rail sections 15 can be clamped while they are still supported on the rollers 55, if desired.
It should also be noted that when the cam shaft handle 72 is in its down position, it will retain one of the tail gates 46 on the right hand side rack of the trailer as shown in FIG. 5, and as a further retainer member for the other tail gate, a radially extending arm 87 is fixed to the cam shaft 65 near the left hand end as shown in FIG. 5, on the outside of the roller support plate 56 on that side of the trailer. The arm member 87 is mounted to be substantially parallel to the handle 72, and is of sufficient length so that when the handle 72 is in its down position as shown in FIG. 5 the arm 87 also blocks the space between the supports 50 for the second tail gate 46, so that both tail gates are securely held in position when the rollers 55 are retracted. The weight of the rollers 55 and their support plates 56 is sufficient to keep the cam shaft handle 72 and arm 87 in the down positions and hold the tail gates in the racks even if no rail sections are supported on the trailer. Of course when the rail sections are supported, the arm 87 and handle 72 are positively locked so that the tail gates cannot be removed. When the rail sections are to be removed, or have been removed, and the cam shaft handle 72 is rotated to lift the rollers 55, by operating the cam sections against the camming edge 56A of the roller plates 56, the handle 72 and the arm 87 move to a clearing position so that the tail gates can either be removed or reinserted in the rack guides.
The arms 81 for the rear rail clamps, will normally depend or hang downwardly when there are no rails on the trailer, but the arms can be pivoted up out of the way to permit the tail gates to be inserted or removed.
As stated previously in discussing the prior art, problems have arisen with towing these long rail sections because of the curves of the railroad tracks are not within acceptable limits. The leverage on the rail section is such that the front steel wheels can jump off the track, as the rails are not permitted to shift at all relative to the trailer body in the prior art device. To solve this problem, front rail clamping assembly illustrated generally at 90 is provided to permit slight shifting of the rails relative to the bed 45. The clamping assembly 90, as shown includes a threaded cross rod 91 that has suitable end slide members shown at 92 in FIG. 7, attached thereto. These end slide members 92 as shown are comprised of blocks that are fixed to the rod and are slidably mounted in an outer slide support section 93. The slide support section 93 is elongated in the fore and aft direction so that the blocks 92 and their respective ends of the threaded rod 91 can shift fore and aft a distance sufficient to compensate for normal rail curvature according to railroad standards, and also shift endwise of the rod (transverse to the trailer).
As shown, the threaded rod 91 supports rail clamp members 95 which are identical to those shown as clamp members 85, and when the rail sections 15 are in position on the trailer bed they will be held in sets of clamp members 93, and then clamped together with suitable nuts 96 that hold the rails in these clamp members. Additionally, adjustable nuts 96 are positioned just to the interior of the slide members 93, so that the amount of endwise movement of the threaded rod 91 can be controlled as well.
The sliding mount in the slide members 93 permits a horizontal movement of the rails, because the slide members or blocks 92 can slip fore and aft and side to side to permit the rail sections to move in the horizontal plane to twist if the curves encountered require a slight shifting of the rail sections from their towed end relative to the supports on the steel wheels 13. In this manner, accommodation is made for differences in the curves as shown by the dotted line representation of the threaded rod 91 in FIG. 2, and also this movement is shown by the dotted line representation of the block 92 and the rod 91 in FIG. 7.
Without the present invention, because of the long lever arm of the rail between the towed end and the trailer, the curvature of curves in railroad tracks cause the trailer to derail.
An additional feature of the present invention is the ability to utilize the winch for providing a lifting component to the rails that are being loaded from the rear of the trailer. As shown, a winch assembly indicated generally at 100 is a typical manually operated winch having a manual handle 101, on one side thereof, and a winch drum 102 that controls a cable 103. The winch assembly is mounted onto a tubular pipe support member 104 that in turn is mounted into a tubular socket 105 fixed to the hitch pole assembly 26 in substantially the center of the trailer. The bottom of the tubular pipe 104 has a cutout notch that engages a cross pin or bar 106 at the bottom of the socket 105 to detent the pipe 104 in position for working. The notch is on both sides of the pipe so it will detent in two positions 180° apart.
The upright pipe support 104 is capable of being moved axially in and out of the socket 105 with a slip fit, and it can be seen that the support raises the winch 100 up above the plane 75 of the bed 45 to provide an angle of lift tending to lift up from the rollers 55, so that the rail section will be lifted when the cable 103 is threaded over the rollers. As the rail sections are winched on there will be a further lifting action so that the rails can be rolled on relatively easily.
Additionally, the removability of the support pipe permits the winch to be rotated 180° and detented in position so it can be used in two positions. There are situations where the first end portions of the rail sections will both be winched up partially onto the trailer bed, and the ability to rotate the winch 180° puts the operating handle 101 clear of the one rail section that is in position or is being moved into position, so the winching job for the second rail section is easier than with conventional winches. The dotted line position handle 101 in FIG. 4 shows the alternate position. Conventional winches that mount close to the plane of the trailer bed 45 do not provide the lifting action, the cables get in the way of the rail sections being loaded, and in general the ability to lift and move the rail sections onto the trailer bed is restricted.
Additionally, the pipe support 104 can be removed from socket 105 for transport. When the rail sections are supported on the trailer bed and are to be clamped with the front clamp assembly, the winch can be removed and put into the trailer body for transport.
It also should be noted that the adjustment nuts 95 for the threaded rod 91 can be placed in any desired location to permit sufficient axial movement along the length of the rod 91 (transverse to the direction of movement of the trailer) to accommodate the shifting that is shown in dotted lines. The clamp assembly 90 can be used for only one rail section if desired, as well as two rail sections as shown.
The present trailer thus solves the problems associated with moving rail sections for repairing railroad tracks.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A railroad track trailer for carrying replacement rail sections along a railroad track, which reduces the problems of having a trailer which will tend to jump off the track, when going around curves, and which includes support systems that ease the ability of workers to load and unload rail sections from the trailer.
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This application is a division of application Ser. No. 741,727, filed June 6, 1985, now U.S. Pat. No. 4,624,620, issued Nov. 25, 1986; which is a division of application Ser. No. 634,694, filed July 26, 1984, now abandoned; which is a division of application Ser. No. 493,141, filed May 9, 1983, now U.S. Pat. No. 4,482,286, issued Nov. 13, 1984.
BACKGROUND OF THE INVENTION
This invention relates to improvements in pushpull slipsheet handlers for forklift trucks.
Load push and push-pull devices have long been used on materials handling lift trucks. Prior to the popularity of slipsheets for handling loads, some forklift trucks were equipped with load push assemblies similar to that shown in Anderson, Jr., U.S. Pat. No. 3,885,692 to push loads off of standard load-handling forks. Later, when the ues of thin, flexible slipsheets came into prominence, platens having a substantially greater load-supporting surface area than standard forks were used, such as those shown in Vander Wal U.S. Pats. Nos. 3,180,513 and 3,310,189, respectively.
Still later, combiantion push-pull and platen assemblies were developed, such as that shown in Frees U.S. Pat. No. 4,300,867, Brudi U.S. Pat. No. 3,640,414, or those currently manufactured by Cascade Corporation of Portland, Oreg. under the designations 30C and 34C. Many of these have a two-piece, or split, platen so that the platen can, at least theoretically, be inserted into the end of a standard rigid wooden pallet if it becomes necessary to handle rigid pallets as well as slipsheets. Some units, such as the aforementioned Cascade 30C and 45C devices, have transversely adjustable split platen sections capable of handling slipsheet-supported loads of different widths. Such transversely-adjustable platen sections can be either manually adjusted or hydraulically adjusted.
Other types of units have been developed featuring platens mounted on the standard forks of a truck, but for different purposes such as the swivel-type platen shown in Brennaman U.S. Pat. No. 2,957,594.
A drawback of devices such as that shown in the aforementioned U.S. Pat. No. 3,885,692, wherein a push plate is used in connection with standard, relatively narrow, pallet-handling forks, is that the forks have insufficient surface area to support loads with underlying slipsheets. Conversely, early fork-mounted platens having sufficient surface area for slipsheet handling, such as those shown in U.S. Pats. Nos. 3,180,513 and 3,310,189, are likewise unsatisfactory because they have no slipsheet pulling capability and are therefore limited to engaging a slipsheet-supported load only by knifing their platens beneath the slipsheet.
Alternatively, more modern slipsheet-handling devices such as those shown in U.S. Pats. Nos. 4,300,867 and 3,640,414, or the aforementioned CASCADE 30C and 45C push-pull devices, although quite adequate for slipsheet handling, and although employing split platens and even transversely-adjustable split platens, are most difficult to use for handling rigid pallets. This is because the platens, in order to provide the necessary supporting surface area, are so wide that a lift truck driver cannot use them to engage a rigid pallet unless he approaches the end of the pallet virtually parallel to its longitudinal dimension. Any substantial angularity in the approach makes it impossible to insert the wide platens fully into the spaces provided in the pallet. Moreover, such platens cannot engage a standard rigid pallet along one of its longer sides as standard forks can. Standard rigid wooden pallets are 40 inches by 48 inches in size and are designed to be engaged on either their ends or longitudinal sides by trucks having standard load-handling forks.
The above-described difficulties of a truck with standard forks attempting to handle slipsheets and, conversely, the difficulties of a slipsheet handler attempting to handle standard rigid pallets, have led to severe equipment problems in the materials handling industry. Many shippers or goods prefer to use slipsheets rather than rigid pallets, primarily because slipsheets are expendable and do not have to be returned. On the other hand, most warehouse establishments which receive such shipments prefer to use rigid pallets to facilitate stacking and handling of loads. Accordingly such warehouses must have at least two different types of lift trucks on hand to handle loads received from shippers: push-pull slipsheet-handling trucks to remove slipsheet-supported loads from highway trucks and transfer them to rigid pallets; and lift trucks equipped with standard load-handling forks to handle and stack the loads once they have been transferred to the rigid pallets.
This places an unduly high requirement, with respect to capital expenditures for materials handling equipment, on warehousemen and other receivers of goods, since the size of their lift truck fleets is effectively twice what it might otherwise be. Unfortunately, the lift trucks cannot be converted quickly or easily from slipsheet-handling capability to pallet-handling capability, and vice versa. This is because conversion to pallet handling requires not only removal of a complete push-pull assembly from the lift truck carriage, but also installation of standard forks, with the reverse procedure being necessary for the opposite conversion. There is insufficient time in the hectic scheduling of a warehousing operation to make such conversions repeatedly. Even where the push-pull assemblies are mounted compatibly with forks, as for example in the aforementioned U.S. Pats. Nos. 3,885,692 and 4,300,867, the push-pull assemblies are so reliant for their vertical support upon the lift-truck carriage or frame (rather than upon the upwardly-facing load-supporting surfaces of the forks) that they are substantially permanently mounted to the carriage or frame so as to be incapable of rapid attachment and detachment.
SUMMARY OF THE PRESENT INVENTION
The present invention is directed to push-pull slipsheet-handling appparatus which permits extremely rapid conversion of a lift truck between slipsheet-handling capability and pallet-handling capability.
As an added significant advantage, the push-pull slipsheet handler of the present invention is actually less expensive to maufacture than previous push-pull slipsheet handlers which did not provide such rapid convertibility of the lift truck.
The foregoing combination of advantages is achieved by making the push-pull assembly mountable on a standard lift truck hook-type carriage compatibly with standard pallet-handling forks, i.e. such that both may be supported on the lift truck carriage concurrently. Moreover, the push-pull assembly and its associated platen is vertically supported by the upper load-supporting surfaces of the forks, rather than by the lift truck carriage or frame as is the conventional practice. This permits the carriage-mounting structure of the push-pull assembly to be less permanent and less substantial than is normally required, thereby facilitating attachment and detachment of the push-pull slipsheet handler while also reducing the weight and expense thereof.
In addition, the push-pull slipsheet handler of the present invention is designed so as to permit convertibility of the lift truck by different alternative processes, thereby giving the operator utmost flexibility. By one conversion process, merely the platen of the slipsheet handler need be detached or attached, as the case may be, without any manipulation whatsoever of the pushpull assembly. In an alternative conversion process, the entire push-pull assembly and platen may be removed and installed as an integral unit. The first alternative, i.e. merely platen manipulation, is obviously quicker. However the latter alternative increases the load-handling capacity of counterbalanced lift trucks since the removal of the push-pull assembly permits the center of gravity of the load to be positioned more rearwardly relative to the truck.
For further versatility, despite the fact that the platen acts as part of the vertical support system for the push-pull assembly, the platen is nonetheless not only removable independently of the push-pull assembly but is also laterally adjustable with respect thereto.
Accordingly it is a principal objective of the present invention to provide a push-pull slipsheet handler of a type which improves the rapidity and facility of converting a lift truck between slipsheet handling and pallet-handling capability.
It is a further objective of the present invention to provide such rapidity and facility of lift truck conversion while also reducing the manufacturing cost of the slipsheet handler, by making such handler both compatible with, and supportable by the load-supporting surfaces of, a standard pair of pallet-handling forks mounted on the lift truck.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an exemplary embodiment of the push-pull slipsheet handler of the present invention shown mounted on a standard lift truck hook-type carriage together with a pair of load-handling forks, with a central portion of the nearest fork broken away to reveal the underlying structure of the slipsheet handler.
FIG. 2 is an extended top view of a portion of the slipsheet handler taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged, extended sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a rear view of a lower side portion of the slipsheet handler shown in relation to the lift truck carriage lower transverse mounting member, a load-handling fork and an exemplary wooden pallet (all shown in phantom), wherein the platen of the slipsheet handler has been inserted longitudinally into the end of the pallet.
FIG. 5 is a schematic diagram of the hydraulic circuit of the slipsheet handler.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, an exemplary embodiment of the push-pull slipsheet handler of the present invention, indicated generally as 10, is shown mounted on a vertically-movable lift truck carriage 12 on a mast 14 of a lift truck 16. The carriage 12 has a pair of transverse mounting members 18 and 20 thereon to which are mounted a pair of forwardly-extending, transversely-spaced load-lifting forks 22a and 22b respectively, each having upwardly-facing load-supporting surfaces 24 thereon. Each fork 22a, 22b has an upstanding rear portion having a downwardly-opening hook such as 26 interlocked with an upwardly-protruding lip 18a on the upper transverse mounting member 18, together with an upwardly-opening hook 28 (FIGS. 2 and 4) interlocked with a downwardly-protruding lip 20a on the lower transverse mounting member 20. The upwardly and downwardly-protruding lips 18a and 20a of the respective transverse mounting members may extend either continuously or discontinuously across the respective mounting member.
The push-pull slipsheet handler 10 includes a push-pull assembly composed of a rear frame 30, a forwardly-extensible and retractable push plate 32 and a conventional scissors linkage 34 powered by a transversely-spaced pair of selectively-extensible and retractable double-acting hydraulic cylinders 36. The push plate has a selectively openable and closable transverse jaw along the lower edge thereof including a fixed jaw member 38 and a cooperating vertically-extensible and retractable jaw member 40 under the control of a pair of vertically-oriented hydraulic cylinders 108 (FIG. 5) conventionally mounted on the push plate 32. In operation, the push plate 32 is extended as shown in FIG. 1 adjacent to a load lying on a slipsheet such that the fixed jaw 38 lies beneath a protruding tab of the slipsheet, and the movable jaw 40 is then extended to grasp the slipsheet tab between the jaws 38 and 40. Thereafter, by retraction of the cylinders 36, the scissors linkage 34 retracts the push plate 32 thereby pulling the slipsheet and its load onto a platen composed of twin platen sections 42 and 44 (FIG. 2), respectively, to be described more fully hereafter. To deposit the load, the cylinders 36 are extended, thereby extending the scissors linkage 34 and push plate 32 to push the load off of the platen.
The platen sections 42 and 44 also form a portion of the push-pull slipsheet handler 10. As best seen in FIG. 2, they are of much greater surface area than that of the standard load-lifting forks 22a and 22b, respectively, to give adequate underlying support to the load since the slipsheet is made of a relatively thin, flexible material.
If it were desired that the lift truck 16 handle a load supported by a conventional rigid wooden pallet such as 46 as shown in phantom in FIG. 4, the large surface area of the platen sections 42 and 44 would be unnecessary because of the inherent rigidity of the pallet 46. In fact, although the platen sections 42 and 44 are narrow enough to be insertable into the end of a pallet 46 as shown in FIG. 4, their large size is a detriment for pallet handling purposes because the extreme width of the platen sections forces the lift truck operator to approach the end of the pallet substantially parallel to its longitudinal dimension, with little tolerance for any angular deviation in the approach. Accordingly, for handling rigid pallets such as 46, it is much more desirable from an operating point of view that the platen sections 42 and 44 be removed such that the relatively narrow load-lifting forks 22a and 22b can engage the pallet 46. The use of the forks 22a and 22b also enables the truck to engage a pallet such as 46 not only at its end but also, if desired, at one of its longitudinal sides through narrow fork pockets which are conventionally provided in such pallets, this latter maneuver being impossible with wide platen sections such as 42 and 44.
Moreover, when handling rigid pallets such as 46, the presence of the push-pull assembly may be a detriment even though the push plate 32 is completely retracted with respect to the rear frame 30. This is because the presence of the push plate and rear frame tends to limit the rearward extent to which a palletized load may be positioned on the forks, thereby limiting the extent to which the center of gravity of the load may be positioned in proximity to the front axle of the lift truck 16. This limitation in turn limits the load-carrying capacity of the truck 16 if it is of the counterbalanced type.
It is therefore highly desirable for the lift truck 16 to be rapidly convertible between slipsheet-handling capability and rigid pallet-handling capability. The slipsheet handler 10 of the present invention accomplishes this primarily by being mountable on the lift truck compatibly with the standard forks 22a and 22b so that the forks are always present and do not have to be mounted and demounted, and by vertically supporting both the push-pull assembly and the platen sections primarily on the upwardly-facing load-supporting surfaces 24 of the forks 22a and 22b.
Turning now to the specific structure of the slipsheet handler 10, the rear frame 30 of the push-pull assembly has welded to its bottom edge a forwardly-protruding tongue 48 of substantial thickness and rigidity, but of less thickness than that of one of the forks 22a or 22b. With reference to FIGS. 2 and 3, the tongue has a pair of transversely-spaced rear interlocking members 50 and a pair of forward interlocking members 52 for detachably supportably connecting the tongue to each of the platen sections 42 and 44 respectively and suspending it therefrom. As can be seen in FIG. 3, the rear interlocking member 50 overlies the rear edge of the platen section 42, while the forward interlocking member 52 is inserted into a hanger 54 bolted to the underside of the platen section 42. A similar interlocking arrangement exists with respect to platen section 44. Thus, with the platen sections 42 and 44 overlying the forks 22a and 22b respectively and supported vertically by the upwardly-facing load-supporting surfaces 24 of the forks, the tongue 48 and thus the rear frame 30 of the push-pull assembly are likewise vertically-supported by the upwardly-facing load-supporting surfaces 24 of the forks.
Since vertical support for the entire slipsheet handler 10 is thus provided by the forks, there is need for very little connecting structure between the slipsheet handler 10 and the lift truck carriage 12. The only connection to the carriage 12 which is really necessary is a connection between the bottom of the frame 30 of the push-pull assembly and the lower transverse mounting member 20 of the lift truck carriage 12 in order to restrain the frame 30 against forward movement while the scissors linkage 34 is being retracted to pull a load onto the platen. This restraint is provided by a pair of transversely-spaced upwardly-opening hooks 56 (only one of which is shown) pivotally mounted to the frame 30 for rotation about a respective pivot bolt 58. When pivoted upwardly, as shown in FIG. 3, the hooks 56 detachably matingly engage the downwardly-protruding lip 20a of the carriage lower transverse mounting member 20 to prevent forward movement of the frame 30 relative to the lift truck carriage 12. The hooks 56 are retained in their upwardly-pivoted positions by insertion of a spring-biased locking pin 60 into a matching aperture 62 of the hook 56. Detachment of the hooks 56 from the carriage 12 to permit removal of the slipsheet handler 10 as an integral unit from the forks 22a and 22b is accomplished by retracting the locking pin 60 by twisting a cammed retractor member 64 and permitting the respective hooks 56 to pivot downwardly about the pivot bolt 58 as shown in phantom in FIG. 3.
A second aperture 66 is also provided in the hook 56 for insertion of the locking pin 60 to lock the hook in its downwardly-pivoted position, such position extending below the bottom of each fork as seen in FIG. 3. This enables each hook 56, by contact with the floor, to support the slipsheet handler 10 at a sufficiently elevated position to provide clearance for withdrawal of the forks by backing the lift truck away from the slipsheet handler when it is desired to demount the slipsheet handler as an integral unit. The same clearance facilitates insertion of the forks for remounting.
Because the slipsheet handler 10 is easily and rapidly mountable and demountable with respect to the lift truck 16 as an integral unit including the push-pull assembly and platen sections, it would be acceptable, and within the scope of the present invention, for the platen sections 42 and 44 to be permanently connected to the frame 30 by means of the tongue 48. However, to add a degree of flexibility to the process by which the lift truck 16 may be converted from slipsheet-handling to pallet-handling capability, and vice versa, the platen sections 42 and 44 are preferably detachable with respect to the tongue 48 and frame 30 by means of a quick-disconnect interlocking structure.
As seen in FIGS. 2 and 3, the forward interlocking member 52 of the tongue 48, and the mating hanger 54 on the underside of the platen 42, are interconnected by a quick-disconnect pin 68. When inserted as shown in FIG. 3, the pin 68 is prevented from withdrawal from aperture 70 of hanger 54 by a small locking stud 72 protruding therefrom. However the pin 68 may be withdrawn by lifting the bail 74 through an aperture 75 in the platen and rotating the pin 68 so that the stud 72 is aligned with a pair of slots 76 formed at the top of the aperture 70. The slots 76 provide clearance for the stud 72 such that the pin 68 may be withdrawn. Upon withdrawal of the pin 68, the respective platen section 42 may be detached from the tongue 48 by forward movement of the platen section until it clears the rear interlocking member 50 and front interlocking member 52 of the tongue 48. The other platen section 44 is removable in the same manner.
With platen sections 42 and 44 thus removed, rigid wooden pallets such as 46 (FIG. 4) can be easily handled in most applications. Although the tongue 48 remains in position, it protrudes forwardly only a relatively short distance and therefore does not interfere with the insertion of the forks into the pallet spaces, even during an angular approach to a pallet. The fact that the tongue 48 is bifurcated as shown in FIG. 2, with an elongate, centrally-located slot formed therethrough which is open and somewhat rounded at its forward extremity 48a, permits the full insertion of the forks into the end of a rigid pallet to the point where the pallet contacts the push-plate 32, the slot in the tongue 48 being wide enough to accept insertion of the pallet's central stringer. Although the push-plate 32 limits somewhat the rearward positioning of a palletized load on the forks, it should be noted that the placement of the unusually narrow frame 30 of the push-pull assembly between the forks 22a and 22b, so that the frame 30 overlaps the upstanding rear portions of the forks in a rearward direction as best seen in FIG. 2 rather than being positioned in front of the forks, minimizes the protrusion of the retracted push-plate 32 and thus maximizes the load carrying capacity of a counterbalanced truck with the push-pull assembly in place. Moreover, for relatively light palletized loads (relative to the capacity of the lift truck 16) pallets may even be engaged by the forks along their longitudinal sides by insertion of the forks up to the forward extremity of the tongue 48.
Because the platen sections 42 and 44 normally furnish vertical support for the tongue 48 and the attached frame 30 of the push-pull assembly, there should be some substitute means of vertical support if the platen sections are to be removed from the lift truck independently of the push-pull assembly and tongue 48. This substitute vertical support may be provided either by lugs such as 78 connected to the frame 30 and extending transversely therefrom so as to overlie the forks as best seen in FIG. 2 or, alternatively, by upper carriage hooks such as 80 (shown in phantom in FIG. 3) on the frame 30 for engaging the lip 18a of the upper carriage mounting member 18. Neither of these substitute support structures need be substantial because they are not relied upon for vertical support of the platen sections 42 and 44 nor, under operating circumstances, even for vertical support of the push-pull assembly.
Another feature providing added flexibility to the slipsheet handler is the provision of a transversely-adjustable connection between the platen sections 42 and 44 and the tongue 48. As seen in FIG. 2, the tongue 48 has multiple transversely-spaced apertures 82 extending through its forward interlocking member 52 for accepting insertion of the pin 68 at different transverse positions of the platen section 42 relative to the tongue 48. The transversely elongate nature of interlocking member 52 and hanger 54 permits transverse adjustment of the platen section relative to the tongue to provide alignment of the pin 68 with any of the apertures 82. Likewise, the rear interlocking member 50 of the tongue has a plurality of transversely-spaced positioning members 84 which mate with a plurality of transversely-spaced recesses 86 formed in the rear edge of the platen section 42. Thus by withdrawing the pin 68 and sliding the platen section forwardly with respect to the tongue, the platen section 42 may be transversely slidably adjusted on the forks relative to the tongue 48, primarily for the purpose of supporting wider loads on slipsheets. Similar transverse adjustment structure exists with respect to the other platen section 44.
In view of the fact that the platen sections are detachable from the tongue 48, it is convenient also to provide them in different interchangeable widths for accommodating different-sized loads.
FIG. 5 is a schematic diagram of the hydraulic circuit of the slipsheet handler 10. A pump 88 draws fluid from a reservoir 90 and feeds it to an operator-controlled selector valve 92. These components, together with a standard relief valve 94, are mounted on the lift truck 16 and are connected by a pair of quick-disconnect line couplers 100 and 102 to hydraulic lines 104 and 106 respectively of the slipsheet handler. The couplers 100 and 102, respectively, are disconnected whenever the slipsheet handler 10 is removed as an integral unit, i.e., including both platen and push-pull assembly.
The hydraulic actuating system of the slipsheet handler 10 is conventional except with respect to the manner in which the hydrualic cylinders 108 which selectively extend and retract the jaw member 40 are sequenced with respect to the cylinders 36. Such sequencing is necessary to ensure that the jaw member 40 is extended into engagement with the fixed jaw member 38 prior to any retraction of the cylinders 36 to retract the scissors linkage 34. Without such sequencing, it is possible that a slipsheet will not be grasped by the jaw 40 prior to the retraction of the scissors linkage to draw the load onto the platen.
Since the fluid line, such as 106 in FIG. 5, which extends the jaw-actuating cylinders 108 and retracts the scissors-actuating cylinders 36 is usually connected to these two sets of cylinders in parallel as shown in FIG. 5, it has often been necessary that some type of valve be interposed in the retraction line 110 of cylinders 36 to delay their retraction until the cylinders 108 have been fully extended. In the past, such valve has taken two different forms. One form of the valve has been a simple relief valve which remains closed until line pressure reaches a predetermined level indicating full extension of the cylinders 108, at which time the valve opens and permits pressurized fluid to be fed to cylinders 36 to retract them. A second form of the valve has been a time delay type, i.e., where the valve opens to permit retracting pressure to cylinders 36 only in response to line pressure sensed through a restricted pilot line.
Both of these prior forms of valves, however, have had serious drawbacks. The pressure-relief form of valve can be triggered prematurely under cold ambient conditions by high line pressures resulting from high hydraulic fluid viscosity or, alternatively, by high pressures due to the operator's rapid actuation of the selector valve 92. On the other hand, the time delay form of valve can cause too long a delay when operating under cold conditions which high fluid viscosity.
These same two types of valves have in the past also been used to control an opposite sequencing between the cylinders 108 and cylinders 36 respectively. In this second type of sequencing, the objective is to ensure that the cylinders 108 have retracted the jaw 40 prior to extension of the cylinders 36 to extend the scissors linkage. This ensures that the jaw 40 is open in preparation for an approach to a slipsheet-supported load and is particularly important if, in the process of pulling a load onto a platen, the slipsheet slips from the grasp of the jaw 40 and the scissors linkage has to be extended to regain contact with the slipsheet.
In the present invention, the two above-mentioned forms of valves previously used to accomplish the described sequencing operations are replaced by check valves mechanically responsive to the actual position of the jaw 40. For example, when selector valve 92 is actuated to introduce pressurized fluid to line 106 to extend the cylinders 108 and jaw 40 and retract the cylinders 36 and the scissors linkage 34, the jaw 40 is extended first while the cylinders 36 are prevented by check valve 112 from receiving retracting fluid through line 110 until jaw 40 has been extended into contact with jaw 38, at which time a contact member 40a engages a valve-unseating member 112a which opens the valve and permits retracting fluid to pass through line 110. Conversely, if the selector valve 92 is actuated to deliver pressurized fluid through line 104 to retract the cylinders 108 and jaw 40 and extend the cylinders 36 and the scissors linkage 34, an opposite check valve 114 prevents any exhaust of fluid from cylinders 36 while cylinders 108 are retracting the jaw 40, until such time as the jaw 40 is fully retracted at which time contact member 40b engages a valve-unseating member 114a which opens the valve to pemit the exhaust of fluid from cylinders 36 through line 110, thereby permitting extension of the cylinders 36 and thus extension of the scissors linkage 34. It will be appreciated that this form of sequencing valve arrangement will not permit premature extension or retraction of the cylinders 36 under conditions which cause excessive line pressure, nor will it cause excessively retarded actuation of the cylinders 36 under cold, high-viscosity conditions.
It should also be noted that it is within the scope of the invention for valves 112 and 114, rather than being interposed in line 110, alternatively to be interposed in the opposite line leading to cylinders 36 such that valve 112 prevents the exhaust of fluid from cylinders 36 during extension of cylinders 108 until engaged by contact member 40a. In such case valve 114 would prevent the supply of fluid to cylinders 36 during retraction of cylinders 108 until engaged by contact member 40b.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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A push-pull slipsheet handler mountable on a standard hook-type lift truck carriage compatibly with load-handling forks mounted on the carriage. The slipsheet handler comprises a push-pull assembly and split platen, both of which receive their vertical support from the load-supporting surfaces of the forks. Attachment of the push-pull assembly to the lower hook-type bar of the carriage provides resistance against fore-and-aft movement of the slipsheet handler. To convert the truck rapidly to a fork-type truck capable of handling standard rigid pallets rather than slipsheets, the platen may be quickly removed leaving the push-pull assembly in place or, alternatively, the push-pull assembly and platen may be removed as an integral unit.
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FIELD OF THE INVENTION
[0001] This invention relates to equipment for generating a force in a wellbore and more particularly but not limited to setting and retrieving tools for use in oil and gas wells.
BACKGROUND OF THE INVENTION
[0002] The structure of a wellbore of an oil or gas well generally consists of an outer production casing and an inner production tubing installed inside the production casing. The production tubing extends from the surface to the required depth in the wellbore for production of the oil or gas. Various tools such as plugs, chokes, safety valves, check valves, etc. can be placed in landing nipples in the production tubing to allow for different production operations or the downhole control of fluid flow. Also, tools like bridge plugs, packers and flow control equipment are placed in the production casing to control production or stimulation operations. Force generating tools are needed both to exert a pushing force to set tools in the production tubing or casing and to provide a pulling force to retrieve these tools. It is preferable to have the force generating tools wellbore pressure balanced so that the same force may be applied both in pulling and in pushing operations, irrespective of the pressure in the wellbore.
[0003] A downhole force generator is disclosed in U.S. Pat. No. 6,199,628. A downhole force generator is disclosed in U.S. Pat. No. 5,070,941. A locator and setting tool is disclosed in Canadian Patent No. 2,170,711. These 3 patents describe virtually the same technology, in different variations. None of these prior art tools are pressure balanced to provide equal force in pulling and pushing operations. As detailed in the article published by Halliburton Energy Services in the June 1996 edition of the SPE Drilling & Completion magazine, “Any pressure differential increases the available force with the DPU in tension and decreases the setting force in the extension mode. This is because (1) the DPU is sealed to the well pressure through redundant sealing elements maintaining internal parts at near-atmospheric pressure, and (2) the well pressure acts on the power rod's sealed diameter.” This is a disadvantage, especially in high-pressure wells. A high enough downhole pressure will render these tools unusable. Additionally, none of these tools provide a simple mechanical tool, particularly for the retrieving of downhole tools.
SUMMARY OF THE INVENTION
[0004] According to one broad aspect, the invention provides a well tool for applying a pulling or a pushing force to an object in an interior of a well bore comprising: a) a drive mandrel; b) an engaging mandrel; c) an actuation means; d) a housing sealing a portion of the drive mandrel and a portion of the engaging mandrel within an interior space, the drive mandrel and the engaging mandrel extending from opposite ends of the housing; e) a drive mandrel piston area defined at a drive mandrel end portion of the housing between an outside diameter of the housing and a sealed diameter of the drive mandrel; and f) an engaging mandrel piston area defined at an engaging mandrel end portion of the housing between the outside diameter of the housing and a sealed diameter of the engaging mandrel; wherein the actuation means is adapted to reversibly move the housing longitudinally relative to the drive mandrel and the engaging mandrel and wherein the drive mandrel piston area and the engaging mandrel piston area are substantially equal and external pressure acting on these two piston areas, generates two opposing forces that are substantially balanced during relative movement.
[0005] According to another broad aspect, the invention provides a well tool for applying a pulling or a pushing force to an object in an interior of a well bore comprising: a) an inner elongated member; b) an outer elongated member; c) a sealed interior defined between the inner elongated member and the outer elongated member; and d) an actuation means defined at least partially within the sealed interior; wherein the actuation means is adapted to reversibly move the outer elongated member longitudinally over the inner elongated member and wherein the inner elongated member and the outer elongated member are arranged such that a volume of the sealed interior occupied by the inner elongated member remains substantially constant as the inner elongated member and the outer elongated member move relative to each other.
[0006] According to a further broad aspect, the invention provides a well tool for applying a pulling or a pushing force to an object in an interior of a well bore comprising: a) an inner elongated member; b) an outer elongated member encircling an intermediate segment of and longitudinally moveably engaged with the inner elongated member; c) a screw component of the inner elongated member, the screw component being coupled for rotation about a longitudinal axis; and d) a threaded component of the outer elongated member engaged with the screw component; wherein rotation of the screw component reversibly moves the outer elongated member relative to the inner elongated member.
[0007] According to a still further broad aspect, the invention provides a well tool for applying a pulling or a pushing force to an object in an interior of a well bore comprising: a) an inner member comprising a first elongated member, a second elongated member and an actuation means axially interconnecting the first elongated member and the second elongated member; b) an outer elongated member longitudinally moveably engaged with the inner member; c) a first seal defined between the first elongated member and the outer elongated member; d) a second seal defined between the second elongated member and the outer elongated member; e) a first piston area defined at a first end portion of the outer elongated member between an outer diameter of the outer elongated member and a sealed outer diameter of the first elongated member; f) a second piston area defined at a second end portion of the outer elongated member between the outer diameter of the outer elongated member and a sealed outer diameter of the second elongated member; and g) a sealed chamber defined between the first seal and the second seal, the sealed chamber including a fluid at a fluid pressure; wherein operation of the actuation means axially reversibly moves the outer elongated member relative the inner member while the fluid pressure remains constant; and wherein the first piston area and the second piston area are substantially equal and external pressure acting on these two pistons areas, generates two opposing forces that are substantially balanced during relative movement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Preferred embodiments of the invention will now be described with reference to the attached drawings in which:
[0009] FIGS. 1A , 1 B and 1 C are partial schematic cross-sectional views of a first embodiment of the invention;
[0010] FIGS. 2A , 2 B and 2 C are detailed upper, middle and lower cross-sectional views, respectively, of the first embodiment of the invention in a first position;
[0011] FIGS. 3A , 3 B and 3 C are detailed upper, middle and lower cross-sectional views, respectively, of the embodiment of FIGS. 2A , 2 B and 2 C in a second position;
[0012] FIGS. 4A , 4 B and 4 C are detailed upper, middle and lower cross-sectional views, respectively, of the embodiment of FIGS. 2A , 2 B and 2 C in a third position;
[0013] FIGS. 5A , 5 B and 5 C are detailed upper, middle and lower cross-sectional views, respectively, of a second embodiment of the invention;
[0014] FIGS. 6A , 6 B and 6 C are detailed upper, middle and lower cross-sectional views, respectively, of a third embodiment of the invention; and
[0015] FIGS. 7A , 7 B and 7 C are partial cross-sectional views of a forth embodiment of the invention in first, second and third positions, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] FIG. 1A shows cross-sectional view of a simplified embodiment of the invention. A tool 10 has an inner elongated member which includes a drive mandrel 50 , a screw 62 and an engaging mandrel 66 . The engaging mandrel may be a setting or a retrieving mandrel. The drive mandrel 50 and the screw 62 are axially coupled for both rotational and longitudinal movement. The engaging mandrel 66 and the screw 62 are preferably coupled for longitudinal movement only. The cross-sectional area of the drive mandrel 50 is substantially equal to the cross-sectional area of the engaging mandrel 66 .
[0017] The tool 10 also includes an outer elongated member or main housing 64 . The outside diameter of the main housing 64 is preferably constant. Fixed to the interior of the main housing 64 is a threaded component or nut 58 . The nut 58 is threaded on the screw 62 . One end of the main housing 64 is sealed to the drive mandrel 50 by a seal 48 . The other end of the main housing 64 is sealed to the engaging mandrel 66 by a seal 70 . The sealed interior of the main housing 64 is preferably equalized with the wellbore pressure. The connection between the screw 62 and the nut 58 is not fluid tight, i.e. chambers 65 and 67 on either side of the nut 58 are enclosed by the main housing 64 and are in fluid communication through gaps between the screw 62 and nut 58 and/or channels milled on the outside of the nut 58 .
[0018] The drive mandrel 50 is coupled at its other end to a motor 24 . The motor 24 is contained within a motor housing 14 . A connector 12 is provided at the other end of the motor for electrically and mechanically connecting the tool 10 . Cap screws 44 are provided in a guide sleeve 38 formed at the end of the motor housing 14 which encircles the drive mandrel 50 and an electronics seal 46 is provided around the drive mandrel 50 which seals the guide sleeve to the mandrel 50 to protect the inside of the motor housing 14 from the environment. A guide housing extension 40 of the main housing 64 slidably encompasses a portion of the guide sleeve 38 . The cap screws 44 travel in slots in the guide housing extension 40 and prevent rotation of the main housing 64 .
[0019] In operation, the connector 12 is electrically and mechanically connected to a wireline. The motor 24 rotates the drive mandrel 50 . Rotation of the drive mandrel 50 causes the screw 62 to rotate. The main housing 64 is held against rotation so that rotation of the screw 62 causes the main housing 64 to move longitudinally over the inner elongated member. At all times, the volume of the drive mandrel entering/exiting the interior space is the same as the volume of the engaging mandrel exiting/entering the interior space so that the free volume, and therefore also the pressure, in the interior space remains constant. The seals 48 and 70 , define two hydraulic pistons between the outside diameter of the main housing 64 and the outside diameter of the drive mandrel 50 and the outside diameter of the engaging mandrel 66 respectively. The two piston areas, shown schematically in FIGS. 1B and 1C , have the same area. Any outside well pressure P acting on these two hydraulic piston areas will create two equal opposing forces that cancel each other. The constant volume in the interior and the matched piston areas enable the same force to be applied by the tool in both the pushing and the pulling operations. The main housing 64 and/or the engaging mandrel 66 are coupled to engaging tools for setting or retrieving of downhole tools.
[0020] In greater detail, FIGS. 2A to 4C depict a well tool, in particular a wireline retrieving tool for applying a pulling force to an object in the interior of a wellbore. The wireline retrieving tool 110 is generally tubular in shape. A connector 112 is located at the proximal end of the wireline retrieving tool 110 . The proximal end is the upper or trailing end when the wireline retrieving tool 110 is inserted into a wellbore. The connector 112 allows for mechanical and electrical connection of the wireline retrieving tool 110 to a wireline. The connector 112 connects to a proximal end of a tubular electronics housing 114 . Seals 116 are provided at the interface between the connector 112 and the electronics housing 114 to seal the interior of the electronics housing 114 from the environment. The electronics housing 114 houses an electronics carrier 118 , a printed circuit board 120 , a digital positioning encoder 122 and a gear motor 124 . The electronics carrier provides mechanical support for the printed circuit board 120 . The connector 112 is connected to the printed circuit board 120 to provide power to the printed circuit board from the wireline. The printed circuit board 120 provides control for the operation of the digital positioning encoder 122 and the gear motor 124 . The digital positioning encoder 122 is connected at one end of the gear motor 124 . The digital positioning encoder 122 counts the rotation of the gear motor 124 to allow precise calculation and control of the movement of the distal end, i.e. lower or leading end, of the wireline retrieving tool 110 .
[0021] A distal end of the electronics housing 114 is connected to a guide sleeve 138 . The guide sleeve is generally tubular. Seals 116 are provided between the guide sleeve 138 and the electronics housing 114 to seal the interior from the environment. A drive mandrel 150 extends at least partially through the guide sleeve 138 . The drive mandrel 150 is generally an elongated solid member with a circular cross-section. The drive mandrel 150 is interconnected to the gear motor 124 through a spline adapter 130 . The spline adapter 130 interconnects the gear motor 124 to the drive mandrel 150 through axial splines so that rotation of an output of the gear motor 124 results in rotation of the drive mandrel 150 at the same speed. The spline adaptor 130 is threaded to the drive mandrel 150 . Set screws 136 hold the drive mandrel 150 in position relative to the spline adaptor 130 .
[0022] Thrust bearings 134 are provided at support ends of the spline adapter 130 to facilitate smooth rotation of the drive mandrel 150 relative to the guide sleeve and the electronics housing. A drive mandrel lock nut 132 is provided to retain the bearings 134 and the spline adaptor in the guide sleeve 138 and cap screws 128 are provided to fasten the gear motor to the distal end of the electronics housing 114 .
[0023] Cap screws 144 are provided at a distal end of the guide sleeve 138 . The heads of the cap screws 144 project outward from the surface of the guide sleeve 138 . An upper guide housing 140 slidably encompasses a portion of the guide sleeve 138 . Longitudinal slots are defined in the upper guide housing 140 . The cap screws 144 travel within the longitudinal slots in the upper guide housing 140 when the upper guide housing 140 slides relative to the guide sleeve 138 . The cap screws 144 rest against the ends of the longitudinal slots to retain the upper guide housing 140 in contact with the guide sleeve 138 at the limits of relative travel and prevent relative rotation between the guide housing 138 and the upper guide housing 140 .
[0024] A glide ring 142 is also provided adjacent the cap screws 144 between the guide sleeve 138 and the drive mandrel 150 to facilitate the smooth rotation of the drive mandrel 150 . An electronics seal 146 is provided around the drive mandrel 150 at the distal end of the guide sleeve 138 . The electronics seal 146 seals the electronic section from external contaminants and keeps it at atmospheric pressure.
[0025] The distal end of the upper guide housing 140 mates with a proximal end of an upper housing 152 . The upper housing 152 is also generally tubular. The upper guide housing 140 and the upper housing 152 are retained relative to one another by a threaded connection. An upper interior area seal 148 is provided at a proximal end of the upper housing 152 and seals the upper housing 152 to the drive mandrel 150 . The upper internal area seal 148 seals the interior of the upper housing 152 . The electronics seal 146 and the upper internal area seal 148 allow for rotation of the drive mandrel 150 .
[0026] A distal end of the upper housing 152 is coupled to a proximal end of an actuator housing 160 . The actuator housing 160 is generally tubular. An actuator nut 158 is non-rotatably held within the actuator housing 160 . An actuator screw 162 extends through the actuator nut 158 . The actuator screw 162 is coupled to a distal end of the drive mandrel 150 . The coupling is provided by an anti-rotational lug so that the actuator screw 162 rotates with the drive mandrel 150 . A drive mandrel retainer 154 is provided within the upper housing 152 which maintains the drive mandrel 150 in contact with the actuator screw 162 . Glide rings 156 are provided around the circumference of the drive mandrel retainer 154 to allow smooth rotation of the drive mandrel retainer 154 within the upper housing 152 .
[0027] Upper chambers 165 A and 165 B ( FIGS. 3B and 3C ) are defined within the upper housing 152 which accommodate the drive mandrel retainer 154 when the upper housing 152 moves longitudinally relative to the drive mandrel 150 . Upper chambers 165 A and 165 B are in permanent communication.
[0028] Seals 116 are provided at the interface of the upper housing 152 and the actuator housing 160 to protect the interior of the upper chambers from the environment. A bottom housing 164 connects to the distal end of the actuator housing 160 . Seals 116 are provided between bottom housing 164 and the actuator housing 160 to protect the interior from the environment.
[0029] The actuator screw 162 extends through the bottom housing 164 . The actuator nut 158 is engaged with the actuator screw 162 such that rotation of the actuator screw 162 moves the actuator nut 158 relative to the actuator screw 162 . Other screw components and threaded components may be utilized.
[0030] The distal end of the actuator screw 162 is coupled to a retrieving mandrel 166 . The retrieving mandrel 166 is generally an elongated solid member with a circular cross-section of substantially the same diameter as the drive mandrel 150 . The actuator screw 162 is coupled to the retrieving mandrel 166 by a retrieving mandrel retainer 168 . The proximal end of the retrieving mandrel 166 adjacent to the actuator screw 162 has a shoulder 177 . On either sides of the shoulder 177 are thrust bearings 134 . The thrust bearings 134 allow longitudinal movement of the actuator screw 162 to be transmitted to the retrieving mandrel 166 but rotational movement of the actuator 162 is not transmitted to the retrieving mandrel 166 such that retrieving mandrel 166 moves longitudinally but does not rotate. Glide rings 156 are positioned between the retrieving mandrel retainer 168 and the bottom housing 164 to allow smooth longitudinal and rotational movement of the retrieving mandrel retainer 168 relative to the bottom housing 164 .
[0031] Bottom chambers 167 A and 167 B ( FIGS. 3B and 3C ) are defined within the bottom housing 164 which accommodate the retrieving mandrel retainer 168 when the bottom housing 164 moves longitudinally relative to the retrieving mandrel 166 . The bottom chambers 167 A and 167 B are in permanent communication.
[0032] A distal end of the bottom housing 164 is coupled to a setting cone 174 . Seals 116 are provided between the bottom housing 164 and the setting cone 174 . A lower internal area seal 170 is provided between the setting cone 174 and the retrieving mandrel 166 . A lower secondary interior area seal 172 is provided between the bottom housing 164 and the retrieving mandrel 166 . The lower internal seal 170 provides a primary seal to seal the interior of the bottom housing 164 from the external environment. The lower secondary interior seal 172 provides a backup seal.
[0033] A slip cage 178 holds a set of slips 180 on the setting cone 174 . Cap screws 176 connect the slip cage 178 to the setting cone 174 . The slip cage 178 is moveable relative to the setting cone 174 by movement of the cap screws 176 in slots defined in the slip cage 178 . The slips 180 are biased inward by springs 182 .
[0034] A C-ring 190 is provided which sits in a circumferential recess in the retrieving mandrel 166 . The C-ring 190 sits inside a C-ring housing 186 which is connected to the setting cone 174 by cap screws 184 . The C-ring 190 is retained within the C-ring housing 186 by a C-ring retainer 192 . A segment of the production tubing or casing 188 is shown to facilitate the explanation of the operation of the wireline retrieving tool 110 .
[0035] The drive mandrel 150 and the retrieving mandrel 166 are of substantially the same diameter so that the volume of either mandrel entering the sealed interior defined by the upper housing 152 , the actuator housing 160 , and the bottom housing 164 is substantially the same as the volume of the other mandrel exiting the sealed interior so that the free volume within the sealed interior remains substantially constant. A hydraulic piston defined between the outside diameter of the upper housing 152 and the outside diameter of the drive mandrel 150 and a hydraulic piston defined between the outside diameter of the bottom housing 164 and the outside diameter of the retrieving mandrel 166 are equal in area. Any outside well pressure acting on these two hydraulic piston areas will create two equal opposing forces that cancel each other. This provides the same power availability for pushing and pulling.
[0036] The operation of the wireline retrieving tool 110 is explained with reference to FIGS. 2A to 2C , 3 A to 3 C and 4 A to 4 C which show the wireline retrieving tool 110 in three different positions. The same reference characters are used in all three figures to refer to the same elements. In operation, the wireline retrieving tool 110 is connected by connector 112 to a wireline, both electrically and mechanically. The wireline retrieving tool is lowered into a segment of the production tubing or casing 188 to a desired location. At that location, the gear motor 124 is operated via the printed circuit board 120 . The digital positioning encoder 122 counts the rotations of the gear motor 124 so that an exact position of the retrieving mandrel 166 can be obtained. Rotation of the gear motor 124 is translated to the drive mandrel 150 to provide rotation of the drive mandrel 150 .
[0037] In the initial position depicted in FIGS. 2A to 2C , only chambers 165 A and 167 A are open. The drive mandrel 150 is coupled to the actuator screw 162 as noted above so that rotation of the drive mandrel 150 provides rotation of the actuator screw 162 at the same rate of rotation. Rotation of the actuator screw 162 moves the actuator nut 158 downward along the actuator screw 162 as seen in FIGS. 3A to 3C . This opens up chambers 165 B and 167 B at the same rate that chambers 165 A and 167 A are closed. The movement of the actuator nut 158 in turn moves the upper guide housing 140 , the upper housing 152 , the actuator housing 160 and the bottom housing 164 downward. The bottom housing 164 in turn pushes the setting cone 174 downward.
[0038] The C-ring housing 186 is held against downward movement by the C-ring 190 seated in the recess on the retrieving mandrel 166 . This also holds the slips 180 stationary relative to the retrieving mandrel 166 . The setting cone 174 slides relative to the slips 180 . The setting cone 174 has a narrower end initially within the slips 180 and expands along a shoulder 181 to a wider section. As the shoulder 181 is forced through the slips 180 , the slips are moved outward, the springs 182 are compressed and the slips bite into the segment of production tubing or casing 188 and hold the slips stationary relative to the production tubing or casing 188 (see FIGS. 3A to 3C ). Further rotation of the actuator screw 162 no longer moves the housing downwardly, instead, further rotation of the actuator screw 162 will force the expansion and release the C-ring 190 from the retrieving mandrel 166 and the proximal end of the wireline retrieving tool 110 moves upwardly to the upper limit of travel shown in FIGS. 4A to 4C . In this final position, chambers 165 A and 167 A are completely closed and chambers 165 B and 167 B are completely open.
[0039] All of chambers 165 A, 165 B, 167 A and 167 B are in fluid communication through gaps between the actuator screw 162 and the actuator nut 158 and gaps between the coupling assemblies interconnecting the actuator screw 152 to the mandrels 150 and 166 and the housings 152 and 164 . The mandrels 150 and 166 have substantially the same cross section. As a result, the combined free volume of the chambers 165 A, 165 B, 167 A and 167 B remains substantially constant throughout the relative movement of the housings so that the pressure within the sealed interior of the tool 110 remains constant. Also, because the mandrels 150 and 166 have the same cross section, any outside well pressure acting on the two opposing hydraulic pistons defined by the outside diameters of the housings 152 and 164 and the outside diameters of the mandrels 150 and 166 , would generate two equal opposing forces that would cancel each other and would not affect the function of the tool in pushing or pulling operations.
[0040] In operation, a fishing tool is attached to the distal end of the wireline retrieving tool 110 . The further rotation of the actuator screw 162 pulls the fishing tool upward against the holding force of the slips against the segment of production tubing or casing 188 . Thus, the pulling force is not provided by the wireline but instead by the action of the retrieving mandrel 166 against the slips 180 .
[0041] To reset the tool, the actuator screw 162 is rotated in the opposite direction causing the upper guide housing 140 , the upper housing 152 , the actuator nut 158 , the actuator housing 160 , the bottom housing 164 and the setting cone 174 to move upward. The withdrawal of the shoulder 181 of the setting cone 174 from the slip 180 results in the springs 182 retracting the slips 180 from contact with the segment of production tubing or casing 188 . The wireline retrieving tool 110 can then be withdrawn from the production tubing or casing. Alternatively, if the object to be retrieved is not completely free, the wireline retrieving tool 110 can be partially withdrawn up the production tubing or casing 188 and reset to perform a second or other subsequent pulling operations in the same manner as described above.
[0042] FIGS. 5A to 5C depicts a wireline setting tool 198 . The same reference characters are used in FIGS. 5A to 5C for the same components as identified in FIGS. 2A to 4C . It can be seen that the only difference between the wireline retrieving tool 110 of FIGS. 2A to 4C and the wireline setting tool 198 of FIGS. 5A to 5C is the assembly at the distal end. In particular, the wireline setting tool 198 does not contain a slip assembly. Instead, a setting housing 194 is connected at the distal end of the bottom housing 164 . As with the wireline retrieving tool 110 , a lower internal area seal 170 seals against a mandrel, in this case a setting mandrel 169 , of substantially the same diameter as the upper interior seal 148 which seals against the drive mandrel 150 . A setting adapter 196 is fixed to the distal end of the setting mandrel 169 . A tool to be set is fixed to the end of the setting housing 194 and the setting adapter 196 . When the wireline setting tool 198 is actuated in the manner as described with regard to the wireline retrieving tool 110 , the housings 140 , 152 , 160 , 164 and 194 move downward over the setting mandrel 169 and the force thus exerted is used to set a tool to be placed in the production tubing or casing (not shown). In FIGS. 5A to 5C , the wireline setting tool 198 is shown with the actuator nut 158 in an intermediate position such that the housings are partly but not fully extended.
[0043] The tools depicted in FIGS. 1A to 5C are intended to be deployed by a wireline. A wireline is flexible and uses gravity to lower a tool into position. For horizontal or highly deviated wells, a wireline alone may not allow a tool to be properly positioned in the well. Instead coiled tubing with a wireline installed inside it, also known as stiff wireline, is used. Coiled tubing consists of a hollow tube that surrounds the wireline and can be used to push a tool into a horizontal well. Coiled tubing is typically relatively thin walled. As a result, to prevent the tubing from collapsing under well pressure and mechanical forces, it is necessary to allow pressurized completion fluids to flow through the coiled tubing and through the tool.
[0044] FIGS. 6A to 6C depict an embodiment of a retrieving tool that has been adapted for use with coiled tubing. FIGS. 6A to 6C use the same reference characters that are used in FIGS. 2A to 4C for the same components. FIGS. 6A to 6C will be described only in respect to how they differ from FIGS. 2A to 4C . FIGS. 6A to 6C depict a retrieving tool 200 . A flow path is defined through the retrieving tool 200 to allow fluid to flow through the coiled tubing as detailed in the following description.
[0045] At a proximal end of the retrieving tool 200 there is the connector 112 for connecting to a wireline as explained above. FIG. 6A depicts additional components at a proximal end of the connector 112 , not shown in FIGS. 2A to 4C . In particular, an electrical contact sub 208 and a rubber boot 204 are shown as interconnecting between a segment of wireline 202 and the connector 112 . The electrical contact sub 208 and the rubber boot 204 do not form part of the retrieval tool 200 . They serve to mechanically and electrically interconnect the connector 112 to the wireline 202 .
[0046] The connector 112 is connected at its distal end to the electronics housing 114 as in FIGS. 2A to 4C . However, in FIG. 6A , the electronics housing 114 is surrounded by a bypass sleeve 218 . A proximal end of the bypass sleeve 218 is connected to a coiled tubing connector 206 . The bypass sleeve 218 and the coiled tubing connector 206 are both hollow, and may be tubular. The coiled tubing connector 206 is adapted to connect to the coiled tubing at its free end so that the coiled tubing can be used to position the retrieving tool 200 in the well.
[0047] As can be seen in FIG. 6A , the combination of the coiled tubing connector 206 and the bypass sleeve 218 define an outer hollow member in fluid connection with the coiled tubing. The wireline 202 , the rubber boot 204 , the electrical contact sub 208 , the connector 112 , and the electronics housing 114 define an inner member surrounded by the outer hollow member. An elongated fluid chamber or conduit 212 is defined between the inner member and the outer member which allows fluid to flow down the coiled tubing and around the electronics. The electronics remain sealed from the fluid chamber 212 .
[0048] FIGS. 6A to 6C also depict an inner elongated member comprised of a drive mandrel 250 , an actuator screw 262 and a retrieving mandrel 266 comparable the drive mandrel 150 , the actuator screw 162 and the retrieving mandrel 166 . The difference between the inner elongated member of FIGS. 6A to 6C , from the inner elongated member of FIGS. 2A to 4C , is that the inner elongated member of FIGS. 6A to 6C has a fluid flow port or conduit 224 defined longitudinally therethrough. The drive mandrel 250 the actuator screw 262 and the retrieving mandrel 266 are connected to each other in a fluid tight manner by the seals 234 at either end of the actuator screw 262 . This prevents any fluid exchange between the fluid flow port 224 and the chambers 165 A, 165 B, 167 A and 167 B.
[0049] The elongated fluid chamber 212 is in fluid communication with the fluid flow port 224 such that fluid entering the coiled tubing can exit through the distal end of the retrieving mandrel 266 . In particular, the distal end of the bypass sleeve 218 is attached to the proximal end of the guide sleeve 138 through a threaded connection and the connection is sealed with the seals 116 . Interconnection ports 244 are defined between where the elongated fluid chamber 212 ends adjacent to the end of the bypass sleeve 218 and where the fluid flow port 224 begins at the proximal end of the drive mandrel 250 . These interconnection ports extend through the guide sleeve 138 and the drive mandrel 250 generally perpendicular to the direction of the elongated fluid chamber 212 and the fluid flow port 224 . Fluids pumped through the coiled tubing will flow through the space (i.e. chamber 212 ) between the bypass sleeve 218 and the outside diameter of the tool (i.e. electronics housing 114 ) then it will cross over to the inside of the tool through the ports 244 in the guide sleeve 138 and the drive mandrel 250 to the fluid flow port 224 . Although the coiled tubing connector 206 and the bypass sleeve 218 are depicted as separate from the electronics housing 114 , it will be appreciated that they may be interconnected such that flow passages, rather than a complete chamber 212 , may be defined.
[0050] The flow path through the tool may be used for other purposes. For example, fluids may be pumped through to perform clean-outs for fishing jobs or for formation stimulation. Another option is to pump fluids, particularly cold fluids, around the electronics. If the tool is being run into a hot well whose temperature exceeds the temperature rating of the tool, by pumping cold fluids through the tool, the electronics section will be cooled thereby enabling the tool to perform.
[0051] FIGS. 2A to 4C and 6 A to 6 C depict the slips 180 as the means of fixing the tool 110 in place. Other means may also be used. FIG. 7 provides an example of a portion of a retrieving tool 300 . The tool 300 is shown within three segments of tubing or casing 388 , 386 and 384 . The middle segment of tubing or casing 386 is a landing nipple which has a profile 390 defined around the interior surface.
[0052] The tool 300 comprises a bottom housing 364 comparable to bottom housing 164 previously described. The bottom housing 364 is connected to a retrieving housing 374 which in turn connects to a locking lug holder 326 . Locking lugs 350 are movably held within the locking lug holder 326 . The outer contour of the locking lugs 350 matches the profile 390 so that the locking lugs 350 fit into the profile 390 .
[0053] A retrieving mandrel 366 extends axially through the centre of the bottom housing 364 , the retrieving housing 374 , the locking lug holder 326 , and the locking lugs 350 . The retrieving mandrel 366 has an essentially constant circular diameter. However, the retrieving mandrel 366 has two necked down portions 327 and 328 which are used to position and release the locking lugs. Springs or other biasing means 352 are positioned between the retrieving mandrel 366 and the locking lugs 350 . The locking lugs 350 are movable inwards and outwards perpendicular to the direction of travel of the retrieving mandrel 366 . The springs 352 bias or push the locking lugs 350 in the outwards direction.
[0054] In use, the springs 352 are initially positioned in the necked down portion 327 of the retrieving mandrel 366 . The tool 300 is inserted into the well with the mandrel 366 held in this position until the locking lugs 350 reach the profile 390 of the landing nipple 386 . The locking lugs 350 are forced outward and locked in position in the profile 390 as shown in FIG. 7A . Actuation of the tool 300 will cause the retrieving mandrel 366 to move upward (to the left in the FIGS. 7A to 7C ) relative to the locking lugs 350 and the housings 364 and 374 to perform its retrieving function. A larger diameter portion of the mandrel 366 , as shown in FIG. 7B will come between the locking lugs 350 and further compress the spring 352 . The larger diameter portion of the mandrel 366 will lock the locking lugs 350 in place. As the retrieving function is performed, the retrieving mandrel 366 is moved upwards relative to the locking lugs 350 until the second necked down portion 328 of the mandrel is positioned under the lugs 350 and the springs 352 . The locking lugs 350 can now be forced inward in the second necked down portion 328 of the retrieving mandrel 366 so that the locking lugs 350 are drawn out of the landing nipple 386 and the tool 300 can be withdrawn from the well. Other locking means may also be used.
[0055] In addition to the setting and retrieving applications already described, the tools described herein can also be used for other applications such as shifting of sleeves and measuring the location of an object in the well. For example, if the tool is locked in a known position in the well, the mandrel can be extended and the positioning encoder 122 or other counter can be used to precisely determine the location of the end of the tool and therefore the location of an object contacted by the tool.
[0056] Extended reach slip assemblies can be used to perform retrieving, shifting or measuring operations in through tubing applications.
[0057] The number of housings and configurations depicted in FIGS. 2A to 7C is based, at least in part, on manufacturing concerns. The invention encompasses tools having more or fewer housings. The tubular shape of the housings is preferred but not essential.
[0058] Although seals are depicted throughout the figures, seals may be unnecessary between the relatively stationary parts if a sufficiently tight fit is present.
[0059] The mechanical means of interconnecting the various components of the tool shown in the figures are exemplary only. Other known mechanical means of interconnecting the various components are contemplated by the invention.
[0060] Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A well tool for applying a pulling or a pushing force to an object in an interior of a well bore comprising: a) an inner member comprising a first elongated member, a second elongated member and an actuation means axially interconnecting the first elongated member and the second elongated member; b) an outer elongated member longitudinally moveably engaged with the inner member; c) a first seal defined between the first elongated member and the outer elongated member, d) a second seal defined between the second elongated member and the outer elongated member; e) a first piston area defined at a first end portion of the outer elongated member between an outer diameter of the outer elongated member and a sealed outer diameter of the first elongated member, f) a second piston area defined at a second end portion of the outer elongated member between the outer diameter of the outer elongated member and a sealed outer diameter of the second elongated member, and g) a sealed chamber defined between the first seal and the second seal, the sealed chamber including a fluid at a fluid pressure; wherein operation of the actuation means axially reversibly moves the outer elongated member relative the inner member while the fluid pressure remains constant; and wherein the first piston area and the second piston area are substantially equal and external pressure acting on these two piston areas, generates two opposing forces substantially balanced during relative movement.
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BACKGROUND OF THE INVENTION
The present invention relates to a cassette loading mechanism for a cassette type magnetic recording/reproducing apparatus, and, more particularly, to a cassette loading mechanism capable of using a plurality of types of cassettes of different sizes.
Magnetic recording/reproducing apparatuses (VTRs) have been proposed which include a cassette loading mechanism capable of loading cassettes regardless of the size or type of the cassette, with the loading mechanism being capable of using a small cassette by arranging the structure of the cassette loading mechanism in such a manner that the small cassette is inserted into an adapter cassette whose size is the same as that of the large size cassette and the adapter is inserted into the cassette loading mechanism. However, another cassette loading mechanism has been disclosed in, for example, Japanese Patent Laid-Open No. 63-146263 in which the small cassette is directly inserted into the cassette loading mechanism.
However, in the cassette loading mechanism of the type described above, the passage through which the cassette holder moves is the same in both the case where the large cassette is used and the case where the small cassette is used. Therefore, the position at which the cassette holder stops finally during the cassette ejection operation is also nearly the same in both the case where the large cassette is used and the case where the small cassette is used.
The cassette loading mechanism of the type described above is arranged in such a manner that the small cassette pro]ects over the cassette insertion port by a proper length with which at least the small cassette can be readily held and pulled out of the cassette insertion port after the cassette holder has stopped its movement when it is desired to pull out the cassette.
As described above, the passage through which the cassette holder moves is the same in both the case where the large cassette is used and the case where the small cassette is used. Therefore, a user feels uneasiness and is concerned about the reliability of the mechanism since the cassette projects excessively over the cassette insertion port when the large cassette is used.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a cassette loading mechanism capable of overcoming the above-described problem by properly determining the length of projection of the cassette over the cassette insertion port.
In order to overcome the above-described problem, there is provided a cassette loading mechanism comprising means for detecting that a cassette holder reaches a specific position in a passage arranged between a first position to which a cassette is inserted and a second position at which the cassette is loaded, with the detection being made during the movement of the cassette holder from the second position to the first position, whereby a driving member for moving the cassette holder is controlled in accordance with an output from the detection means and the cassette holder is stopped at the specific position.
Furthermore, according to the present invention, there is provided a cassette loading mechanism comprising cassette pull out detection means for detecting that the cassette has been pulled out of the cassette holder which has been stopped at the specific position, whereby the driving member is controlled in accordance with an output from this cassette pull out detection means, and the cassette holder from which the cassette has been pulled out is moved back from the specific position to the first position.
By suitably setting the above mentioned specific position, it is possible to make the cassette which is placed on the cassette holder to project appropriately out of the cassette insertion port when the cassette holder stops at this specific position. Therefore, if the specific position is set according to the size of a cassette, it is possible to select the amount of projection of the cassette so as to permit an easy grasping by fingers, without making it project too great. Accordingly, it is possible to make the amount of projection of different size cassettes nearly the same.
Further, the cassette holder is made to move back to the first position after the cassette is pulled out of the cassette holder at the specific position, whereby the position of the cassette holder can be made nearly the same regardless of the size of the cassette, and the amount necessary for pushing the cassette in may be made substantially the same.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features and advantages of the invention will appear more fully from the following description.
FIG. 1 is an exploded perspective view of a portion of a cassette loading mechanism according to the present invention;
FIG. 2 is a cross sectional view which illustrates a state in which a small cassette has been placed in a cassette holder of the cassette loading mechanism shown in FIG. 1;
FIG. 3 is a cross sectional view which illustrates a state in which the small cassette shown in FIG. 2 has been moved to a position at which it is arranged to be loaded;
FIG. 4 is a cross sectional view which illustrates a state in which a large cassette has been placed in the cassette holder of the cassette loading mechanism shown in FIG. 1;
FIG. 5 is a cros sectional view which illustrates a state in which the large cassette shown in FIG. 4 has been moved to a position at which it is arranged to be loaded;
FIG. 6 is a cross sectional view which illustrates a state in which the large cassette shown in FIG. 5 has been ejected to a position at which it is arranged to be pulled out;
FIG. 7 is a cross sectional view which illustrates a state in which the large cassette shown in FIG. 6 has been pulled out;
FIG. 8 is a cross sectional view which illustrates a state in which the cassette holder has been moved to its normal position after the large cassette had been pulled out as shown in FIG. 7; and
FIG. 9 is a flow chart showing an operation for ejecting a cassette performed by the cassette loading mechanism shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In a cassette loading mechanism shown in FIG. 1, a tray 3 is secured to a cassette holder 4. A rib 3a formed in a direction of an arrow F is disposed in the central portion of the tray 3. A projection 3b is disposed in the inner portion of the tray 3. A groove la is formed in the central portion of the bottom of a large cassette 1, while a groove 2a is formed in the central portion of the bottom of a small cassette 2. The large or small cassette 1 or 2 is pushed from a position shown in FIG. 1 in the direction of the arrow F so as to be inserted into the cassette holder 4. The cassette holder 4 is arranged to have its width which is substantially the same as that of the large cassette 1. The distance from the upper surface of the cassette holder 4 to the tray 3 is arranged to be substantially the same as the height of the large cassette 1 and that of the small cassette 2. When the large cassette 1 is pushed in the direction of the arrow F and it is inserted between the tray 3 and the cassette holder 4, the rib 3a formed on the tray 3 is fitted within the groove 1a formed in the bottom of the large cassette 1 with a certain play allowed. As a result, the large cassette 1 can be laterally located. When the small cassette 2 is pushed in the direction of the arrow F, the rib 3a of the tray 3 is fitted within the groove 2a formed in the small cassette 2 with a certain play allowed. As a result, the small cassette 2 can be laterally located. When the large cassette 1 o the small cassette 2 is inserted between the cassette holder 4 and the tray 3 in the direction of the arrow F, the front surface of the large cassette 1 or that of the small cassette 2 comes contact with the projection 3b provided on the tray 3. Thus, the cassette 1 or 2 is placed in the cassette holder 4.
Guide shafts 6, 7 and 8 are embedded in the right side surface of the exterior portion of the cassette holder 4. Similarly, guide shafts (not shown) are embedded in the left side surface of the same. Furthermore, side plates 5 and 5' running parallel to each other are secured to a chassis (not shown). Guide grooves 5a, 5b and 5c are formed in the side plate 5, with each of the guide grooves 5a, 5b and 5c including a horizontal portion) running parallel to the surface of the chassis and a perpendicular portion bent perpendicularly with respect to the horizontal portion. The guide shaft 6 embedded in the cassette holder 4 is fitted within the guide groove 5a, the guide shaft 7 is fitted within the guide groove 5b, and the guide shaft 8 is fitted within the guide groove 5c, with a certain play allowed. Similar guide grooves are formed in the guide groove 5' and guide shafts embedded in the left side surface of the exterior portion of the cassette holder 4 are fitted within the guide grooves with a certain play.
As described above, the cassette holder 4 is supported by the side plates 5 and 5' and it can be moved along the guide grooves 5a, 5b and 5c. The guide grooves 5a, 5b and 5c are arranged to be in the form of the same shape, and their positional relationship on the side plate 5 is arranged to correspond to the positional relationship of the guide shafts 6, 7 and 8 on the right side surface of the exterior portion of the cassette holder 4, with the side plate 5' being arranged similarly). As a result, posture of the cassette holder 4 can always be maintained constant during its movement.
A shaft 35 is secured to the outer surface of the side plate 5. A gear arm 17 is rotatably fastened to the shaft 35. An elongated groove 17b is formed in an arm portion 17a of the gear arm 17 in the direction along the arm portion 17a. The guide shaft 6, embedded in the cassette holder 4 and penetrating the guide groove 5a, is fitted within the elongated groove 17b. The side plate 5' is similarly provided with the gear arm 17'.
A rotatable synchronizing-shaft 18 is provided so as to penetrate the side plates 5 and 5', with the synchronizing shaft 18 having a worm wheel 15 and a gear 16 secured to the right end portion thereof and having a gear 16' secured to the left end portion thereof. The gear of the gear arm 17 is engaged with the gear 16, while the gear of the gear arm 17' is engaged with the gear 16'. A worm 14 with secured to the rotary shaft of a motor 36 with is engaged with the worm wheel 15.
Therefore, when the motor 36 is driven in a direction of an arrow A, the worm wheel 15 is rotated in the direction of an arrow B, causing the gears 16 and 16' to be rotated in a direction designated by an arrow C, that is, in the same direction as the arrow B). Thus, the gear arms 17 and 17' are rotated in the direction designated by an arrow D. As a result, the guide shaft 6 is pushed along the guide groove 5a (similarly to the side plate 5'), causing the cassette holder 4 to be first moved horizontally and lowered perpendicularly along the guide grooves 5a, 5b and 5c in the direction of an arrow E in such a manner that the cassette holder 4 is moved from the first position shown in FIG. 2 to the second position shown in FIG. 3. When the motor 36 is driven in a reverse direction the cassette holder 4 is first raised perpendicularly from the second position and is then horizontally moved toward the first position in a reverse direction with the movement being made along the guide grooves 5a, 5b and 5c.
The cassette holder 4 is moved in the direction designated by the arrow E as the motor 36 is driven so as to feed the large cassette 1 or the small cassette 2 to a predetermined position at which the, cassette is arranged to be loaded. On the contrary, when the motor 36 is driven in a reverse direction the cassette holder 4 is moved in the reverse direction so as to eject the cassette 1 or 2 from the cassette loaded position. The above-described operations are controlled in accordance with the output from sensors described more fully hereinbelow.
A downwardly projecting shaft 32 is embedded in the inner end portion of the tray 3. A sensor arm 31, formed in a bent shape is rotatably secured to the shaft 32 at the central portion of the sensor arm 31, with the sensor arm 31 having a cylindrical projection portion 31a at an end portion thereof. The sensor arm 31 is urged clockwise by a spring 34 when viewed from a position above it. A photosensor 33 is disposed in the vicinity of the shaft 32 formed at the end portion of the tray 3. The photo-sensor 33 comprises a U-shaped package facing side, a light emitting diode and a photo-transistor. The light emitting diode is disposed at either of the projection portions of the package, and the photo-transistor is disposed at another projection of the package so that the light emitting diode and the photo-transistor confront each other. As a result, light emitted from the light emitting diode is received by the photo-transistor. The photo-sensor 33 is placed in such a manner that an end portion of the sensor arm 31 at which the cylindrical projection portion 31a is not provided is introduced between the two projections of the package of the photo-sensor when the sensor arm 31 is rotated. In this state, since light emitted from the light emitting diode is shielded by the sensor arm 31, the photo-transistor does not receive light or is in a light shielded state. However, the sensor arm 31 is urged by the spring 34, causing the cylindrical pro]ection portion 31a to come contact with an end portion of the tray 3. Therefore, the end portion of the sensor arm 31 is positioned away from the photo-sensor 33. As a result, the photo-transistor of the photo-sensor 33 receives light emitted from the light emitting diode so as to be in a light non-shielded state.
When the large cassette 1 or the small cassette 2 is inserted into the cassette holder 4, the front surface of the large cassette 1 or the small cassette 2 pushes the cylindrical projection portion 31a before the front end surface of the large cassette 1 or the small cassette 2 comes contact with the projection 3b of the tray 3. As a result, the sensor arm 31 is rotated counterclockwise relative to the shaft 32, causing the photo-sensor to be brought into the light shielded state. Thus, a fact that the large cassette 1 or the small cassette 2 has been placed in the cassette holder 4 can be detected, causing the motor 36 to be driven in the direction of the arrow A. As a result, the cassette holder 4 is moved in the direction of the arrow E.
Shafts 10, 11, 12 and 13 are embedded in the inner surface of the side plate 5 (in the surface adjacent to the cassette holder 4), with the shafts 10, 11, 12 and 13 being rotatably provided with corresponding sensor arms 19, 20, 21 and 22. The sensor arm 19 is urged counterclockwise, when viewed from the side plate 5, by a torsion spring 27 secured to the shaft 10. The sensor arm 19 is positioned on a passage through which the large cassette 1, to be inserted into the cassette 4, moves, with the passage being positioned between the cassette holder 4 and the cassette insertion port when no cassette has been inserted into the cassette holder 4. The sensor arm 19 is usually erected substantially perpendicularly upon contacting a projection 5d provided on the surface of the side plate 5. When the cassette holder 4 is positioned adjacent to the cassette insertion port in a case where no cassette has been inserted, a cut is formed in the tray 3 and, if necessary, a cut is also formed on the side wall of the cassette holder 4 adjacent to the side plate 5, so as to form a space in which the side arm 19 is positioned. A photo-sensor 23 having the same structure as that of the photo-sensor 33 is fastened to the inner surface of the side plate 5 at a position lower than the position of the shaft 10. When no force is applied from outside to the sensor arm 19 and the sensor arm 19 is substantially perpendicularly, the photo-sensor 23 is brought into the light shielded state by the sensor arm 19. When the large cassette 1 is inserted into the cassette holder 4, the sensor arm 19 is pushed by the large cassette 1 so as to be rotated clockwise relative to the shaft 10. As a result, the light shielded state of the photo-sensor 23 is released. When the small cassette 2 is inserted into the cassette holder 4, the small cassette 2 does not contact the sensor arm 19. As a result, it is determined that the large cassette 1 has been inserted into the cassette holder 4 or the small cassette 2 has been inserted into it. Thus, the sensor arm 19 and the photo-sensor 23 constitute a cassette determining means.
The sensor arm 20, fastened to the shaft, 11 embedded in the side plate 5, is urged in a clockwise direction by the spring 28 when viewed from the side plate 5. A photo-sensor 24, having the same structure as that of the photo-sensor 33, is disposed lower than the shaft 11 but adjacent to the same on the inner surface of the side plate 5. The photo-sensor 24 is switched between th light shielded state and the light non-shielded state due to the rotation of the sensor arm 20. In the initial state in which no cassette has been inserted into the cassette holder 4, the sensor arm 20 is pushed by a pin 9 embedded in the right side surface on the exterior portion of the cassette holder 4 and the sensor ar 20 is thereby brought into a state in which it has been rotated counterclockwise. As a result, the light non-shielded state of the photo-sensor 24 is maintained. When the cassette holder 4 to which the cassette is inserted has been moved in the direction of the arrow E, the sensor arm 20 is released from the urging from the pin 9 so that it is rotated clockwise relative to the shaft 11 until it comes in contact with a projection 5e provided for the side plate 5. Thus, the photo-sensor 24 is brought into the light-shielded state.
The shaft 12 is disposed away from the shaft 11 along in the direction designated of the arrow E. The sensor arm 21, fastened to the shaft 12, is urged clockwise by a spring 29 when viewed from the side plate 5. A photo-sensor 25 having the same structure as that of the photo-sensor 33 is also disposed lower than the shaft 12 but ad]acent to the same on the inner surface of the side plate 5. The photo-sensor 25 is switched between the light shielded state and the light non-shielded state due to the rotation of the sensor arm 21. In an initial state in which no cassette has been inserted into the cassette holder 4, the sensor arm 21 is urged counterclockwise by the pin 9 and the photo-sensor 25 is in the light non-shielded state. When the cassette holder 4 to which the cassette has been inserted moves in the direction of the arrow E, the urging force applied to the sensor arm 21 by the pin 9 is reduced and, as a result, the sensor arm 21 rotates in a clockwrse direction. When the urging force from the pin 9 has been completely lost, the sensor arm 21 comes contact with a projection 5f provided for the side plate 5. As a result, the sensor arm 21 brings the photo-sensor 25 into the light shielded state.
The shaft 13 is disposed adjacent to the perpendicular portion of the guide groove 5a but lower than the same. The sensor arm is rotatably fastened to the shaft 13. The sensor arm 22 is urged in a clockwise direction by a spring 30 when viewed from the side plate 5. A photo-sensor 26 having the same structure as that of the photo-sensor 33 is disposed lower than the shaft 13 but adjacent to the same which is provided on the inner surface of the side plate 5. The photo-sensor 26 is switched between the light shielded state and the light non-shielded state due to the rotation of the sensor arm 22. The rotation of the side arm 22 is restricted by a projection 5g provided on the side plate 5, causing the photo-sensor 22 to be brought into the light shielded state. When the cassette holder 4, to which the cassette has been inserted, is moved in the direction of the arrow E and it is lowered along the perpendicular portions of the guide grooves 5a, 5b and 5c until it reaches a predetermined position, with the pin 9 provided on the side surface of the cassette holder 4 pushing the sensor arm 22. As a result, the sensor arm 22 is rotated in a counterclockwise direction relative to the shaft 13 so that the photo-sensor 26 is brought into the light non-shielded state.
The photo-sensor 25 acts to detect whether the cassette has been fed to a predetermined position by the cassette holder 4. When the photo-sensor 26 has been brought into the light non-shielded state, the motor 36 is stopped. The above-described sensor arm 22 and the photo-sensor 26 constitute first detection means.
The sensors 24 and 25 act to detect the position of the moving cassette holder 4, the outputs from the sensors 24 and 25 being used when the cassette is fed so as to be ejected.
Then, the operation for loading the small cassette 2 performed according to this embodiment will be described with reference to FIGS. 1, 2 and 3.
Referring to FIG. 1, when the small cassette 2, pushed in the direction designated by the arrow F, is placed in the cassette holder 4, the sensor arm 31 rotates in a counterclockwise direction when viewed from a position above the sensor arm 31, and, as a result, the photo-sensor 33 is brought into the light shielded state.
The light shielded state is shown in FIG. 2, where the small cassette 2 pro]ects outwards by a length l 2 over a cassette insertion port 38 formed in the case 37 of a VTR. Since the small cassette 2 does not come in contact with the sensor arm 19 when it is inserted into the cassette insertion port 28, the photo-sensor is in the light shielded state. The photo-sensors 24 and 25 are in the light non-shielded state since the sensor arms 20 and 21 have been rotated by the pin 9 of the cassette holder 4. On the other hand, the photo-sensor 26 is in the light shielded state.
Referring to FIG. 1, when the photo-sensor 33 has been brought into the light shielded state, the motor 36 rotates in the direction of the arrow A. As a result, the cassette holder 4 moves from the position shown in FIG. 2 in the direction of the arrow E so that the small cassette 2 is fed. Simultaneously, the sensor arms 20 and 21 rotate clockwise, when viewed in FIG. 2, so that the photo-sensors 24 and 25 are brought into the light shielded state.
When the cassette holder 4 is moved horizontally and lowered perpendicularly until it is brought to a state, shown in FIG. 3, the pin 9 of the cassette holder 4 rotates the sensor arm 22 in a counterclockwise direction. As a result, the photo-sensor of the first detection means is brought into the light non-shielded state, causing the motor 36 (FIG. 1) to be stopped. Therefore, the small cassette 2 is positioned at a predetermined loading position.
It is detected that the cassette 4 has been inserted into the cassette holder 4 from a fact that the photo-sensor 33 has been switched to the light shielded state. Furthermore, it is detected that the loaded cassette is the small cassette 2 from a fact that the photo-sensor 23 of the cassette determining means has been maintained at the light shielded state.
When the operation for ejecting the small cassette 2 is conducted in the state shown in FIG. 3, the cassette holder 4 moves, in the reversed manner to that described above, namely, horizontally in the direction toward the cassette insertion port 38 after it has been raised perpendicularly. As a result of this horizontal movement, the pin 9 of the cassette holder 4 first pushes the sensor arm 21 so as to rotate it counterclockwise. As a result, the photo-sensor 25 is brought into the light non-shielded state. However, the cassette holder 4 does not respond to this but moves in the horizontal direction as it is. The action that the cassette holder 4 does not respond to the above-described state is determined by a fact that the photo-sensor 23 has been maintained at the light shielded state, that is, a fact that the small cassette 2 has been inserted into the cassette holder 4. Then, the pin 9 of the cassette holder 4 pushes the sensor arm 20 so as to rotate the sensor arm 20 in the counterclockwise direction. As a result, the photo-sensor 24 is brought into the light non-shielded state, and the motor (FIG. 1) is stopped and a state is realized in which the small cassette 2 projects over the cassette insertion port 38 by length l 2 (FIG. 2). Therefore, the small cassette 2 can be pulled out by holding the portion projecting over the cassette insertion port 38. The sensor arm 20 and the photo-sensor 24 constitute a second detection means.
In order to make length l 2 of the projection suitable to easily hold the small cassette 2 but to prevent excessive length, the positions of the sensor arm 20 and the photo-sensor 24 are determined.
FIG. 4 illustrates a state in which the large cassette 1, inserted into the cassette insertion port 38, has been placed in the cassette holder 4. This state corresponds to the state shown in FIG. 2 where the small cassette 2 has been placed. In this state, since the large cassette 1 projects by length l 1 (>l 2 ) over the cassette insertion port 38 and the large cassette 1 comes contact with the sensor arm 19 of the cassette determining means, the sensor arm 19 rotates in clockwise direction upon insertion of the large cassette 1. As a result, the photo-sensor 23 is brought into the light non-shielded state, thereby detecting that the large cassette 1 has been placed in the cassette holder 4 is detected.
When the photo-sensor 33 has been shifted to the light stopped state, the motor 36 is driven in the direction of the arrow A (FIG. 1) and the cassette holder 4 moves in the direction as designated by an arrow in FIG. 4. Accordingly, the sensor arms 20 and 21 rotate in a clockwise direction as described with reference to FIGS. 2 and 3 so that the photo-sensors 24 and 25 are brought into the light shielded state. When the cassette holder 4 is lowered perpendicularly after it has moved horizontally, the sensor arm 19 comes contact with the rear surface of the large cassette 1 and then it further rotates in a clockwise direction.
As shown in FIG. 5, when the cassette holder 4 is lowered, the pin 9 rotates the sensor arm 22 of the first detection means in a counterclockwise direction. When the photo-sensor has been thus brought into the light non-shielded state, the motor 36 (FIG. 1) is stopped. As a result, the large cassette 1 is positioned at a predetermined loading position. At this time, since the sensor arm 19 has been rotated in a clockwise direction by the large cassette 1, the photo-sensor 23 is in the light non-shielded state.
When the operation for ejecting the cassette is conducted in a state shown in FIG. 5, the cassette holder 4 horizontally moves to the cassette insertion port 38 after it has been perpendicularly raised in the reversed manner to that described above. Accordingly, the sensor arm 22 rotates in a clockwise direction. As a result, the photo-sensor 26 is brought into the light shielded state. When the moving direction of the cassette holder 4 is changed from the perpendicular direction to the horizontal direction, the sensor arm 19 rotates in a counter-clockwise direction by about 90°. However, the photo-sensor 23 is in the light non-shielded, state since the sensor arm 19 has been rotated in the clockwise direction by the bottom of the large cassette 1.
When the cassette holder 4 moves horizontally, the pin 9 first pushes the sensor arm 21 as shown in FIG. 6 so as to rotate it in a conterclockwise direction. As a result, the photosensor 25 is brought into the light non-shielded state. Therefore, the motor 36 (FIG. 1) is stopped since the photo-sensor 23 is in the light non-shielded state, causing the cassette holder 4 to be stopped at a predetermined position. The large cassette 1 projects over the cassette insertion port 38 by length l 11 at (FIG. 6) the predetermined position. The projection length l 11 be optionally determined in accordance with the distance from the sensor arm 21 and the photo-sensor 25 to the cassette insertion port 38. The position of the sensor arm 21 with respect to the position of the sensor arm 20 and the position of the photo-sensor 25 with respect to the position of the photo-sensor 24 are determined so as to make the projection length l 11 substantially the same as the projection length l 2 of the small cassette 2 shown in FIG. 2.
As described above, the sensor arm 21 and the photo-sensor 25 constitute means for detecting a specific position for the large cassette.
FIG. 7 illustrates a state in which the large cassette 1 has been pulled out from a state shown in FIG. 6. As seen, when the large cassette is pulled out, the sensor arm 19 rotates in a counterclockwise direction so that the photo-sensor 23 is brought into the light shielded state. Therefore, the sensor arm 19 and the photo-sensor 23 constituting the cassette determining mean also constitute cassette pull out detection means for detecting the fact that the cassette was pulled out and the cassette holder 4 has been emptied. As a result, the motor 36 which has been stopped is driven again so that the cassette holder 4 is horizontally moved to the cassette insertion port 38. Then, the pin 9 of the cassette holder 4 further rotates the sensor arm 20 in a counterclockwise direction as shown in FIG. 8, causing the photo-sensor 24 to be brought into the light non-shielded state. As a result, the motor 36 (FIG. 1) is stopped, causing the cassette holder 4 to be stopped. Since the position at which the cassette holder 4 has been moved at this time is the same as that shown in FIGS. 2 and 4, the operation for loading the large cassette 1 or the small cassette 2 can be started again. If the cassette holder 4 is maintained at the position shown in FIG. 7, it is inconvenient when the small cassette 2 is inserted at the next operation since the small cassette 2 must be inserted deeply into the cassette insertion port 38 so as to rotate the sensor arm 31. However, according to the invention, since the cassette holder 4 moves to the position shown in FIG. 8, the insertion of the small cassette can also be conducted easily.
The sensor arm 19 is always positioned between the cassette holder 4 and the cassette insertion port 38. Therefore, when the large cassette 1 is to be pulled out of the cassette holder 4, the cassette holder 4 moves after the large cassette 1 has been pulled out and sensor arm 19 has thereby brought the photo-sensor 23 into the light shielded state. Therefore, the moving cassette holder 4 does not come in contact with the pulled out large cassette 1. Accordingly, the safety of the cassette holder 4 and other related elements can be secured. Furthermore, when the cassette is held so as to be pulled out, a problem, arising from the fact that it cannot be pulled out easily due to the fact that the cassette is pushed by the cassette holder 4, can be prevented.
As described above, according to the present invention, the length of projection of the cassette over the cassette insertion port at the time of ejection of the cassette can be properly determined. Therefore, the length of projection can be determined in accordance with the size of the cassette. As a result, all of the cassettes of various sizes project over the cassette insertion port by a proper length. Therefore, the cassettes can easily be pulled out without any fear of an instable functioning of the cassette loading mechanism.
Furthermore, according to the present invention, even if the length of projection of the cassette over the cassette insertion port has been optionally determined so as to correspond to the size of the cassette, the cassette holder can be always properly maintained at a predetermined position when the next cassette is inserted. As a result, cassettes of different sizes can be readily and reliably be mounted on the cassette holder.
In addition, according to the present invention, the determination of the length of the projection of the ejected cassette over the cassette insertion port can be properly determined. Furthermore, the position of the cassette holder at the time of the loading of the cassette can be properly conducted. These determinations can be conducted only by additionally providing the cassette holder position determining means, the cassette pull out detection means and the cassette size detection means. Furthermore, a increase in the number of the elements can be minimized since the cassette pull out detection means also serves as the cassette size detection means. Therefore, any increases in the space for accommodating and additional elements can be substantially ignored. Furthermore, since the above-described detection means can be stably fastened, wiring for establishing these detection means can be easily conducted.
Furthermore, according to the present invention, the cassette pull out detection means causes the cassette holder to move to a predetermined initial position after the cassette pull out detection means has detected the fact that the cassette was pulled out and the cassette holder has been emptied. Therefore, the problem arising from the fact that the cassette which has not been pulled out completely is inevitably pushed by the moving cassette holder can be prevented.
As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
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A cassette loading mechanism comprising a cassette holder for holding a cassette positioned at a first position, with a support member for supporting the cassette holder so that the cassette holder is movable from a first position to a second position at which the cassette is loaded along a predetermined path. A first detector detects that the cassette holder has been moved from the first position to the second position, with a second detector detecting that the cassette holder has been moved from the second position to the first position. A specific position detector detects that the cassette holder has reached a specific position on the path with the specific position being a position different from the first position and the second position so that the moving member is controlled by an output from the specific position detector during movement of the cassette holder from the second position to the first position and the cassette holder is stopped at the specific position, whereby the cassette can be pulled out from the cassette holder.
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BACKGROUND OF THE INVENTION
The spinning machines to which this invention relates are preferably of the type known as "ring spinning machines", however, the invention can be used to advantage on other long spinning machines that have drawing frames, such as cannister spinning machines, flyers or the like, that have several lower rollers.
Rotatably supported upper rollers are pressed onto the driven lower rollers of the drawing frame of such spinning machines, and by means of the varying circumferential speeds of the lower rollers fiber strands supplied thereto and which are squeezed between the upper and lower rollers are drawn therethrough. The lower rollers of the drawing frame which are arranged lengthwise of the machine are formed by very long roller lines, which extend along all of the drawing frames. It is common practice to drive the roller lines that form the output lower rollers of this drawing frame at both of its ends by a motor, and further to drive the other roller lines on the machine by means of this roller line by step-down gear transmissions at stepped-down, lower rpm's. The ends of these roller lines opposite the drive side thereof have ended up free in the conventional spinning machines i.e., they have never been driven at each end. Because of the great length of the roller lines it is thus impossible to prevent them from twisting during operation, with the torsion on the free ends of the rollers being caused to increase from one line to the next and consequently being the greatest at the last drawing frame. The torsion of the roller lines is caused by the drive power which is transferred by these lines to the upper rollers, and by the friction in the numerous roller line supports.
The torsion in the roller lines causes draw malfunctions and has therefore disadvantageous effects on the quality of the produced yarns or unfinished yarns. Such torsion can lead to torsion variations in the bottom roller lines and as a consequence the uniform operation of the drawing process is prevented and periodic thickness variations of the yarn or unfinished yarn can thus result, from such machine operation which in extreme cases can lead to unusable yarns or unfinished yarns. The resulting average values of the torsion in the roller lines during operation of the machine regardless of whether they are overlapped by torsion variations or not, can be extremely disadvantageous, especially in connection with periodic idleness of the machine, which is necessary occasionally to exchange the empty spools or cartridges. Th torsions present during operation of the machine decay when the machine is idle and can thereby cause draw malfunctions and naturally this will lead to thread breaks when the machine is again started. Thus the next-to-last roller line in the thread supply feeding device of a drawing frame has a higher torsion than the roller line which forms the lower supply roller located on the output side of the drawing frame, which can lead to a temporary interruption of the thread feed to the supply roller pairs and thereby ultimately to thread breaks.
The drawing malfunctions caused by torsion and/or torsion fluctuations of the roller lines have been solved in the past by limiting the length of the spinning machine and by using roller lines of the greatest possible diameter. The diameter of the roller lines depends, however, on technical spinning factors, and one cannot enlarge them too much for reasons of space. It is also desirable in many cases to diminish the diameter of the roller lines, in order to be able to spin fiber strands with a shorter stacking length, which accordingly require a smaller field of distortion, without having to have a shorter spinning machine for this purpose. It would be much more desirable, on the other hand, to be able to lengthen the spinning machine, since the economy of a spinning machine increases with the increased number of its drawing frames.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore the principal object of this invention, to overcome the drawing malfunctions caused by the torsion of the roller lines of the drawing frame, in a structurally simple, reliable manner, so that the spinning machine is longer than conventional known machines with a significant increase in the number of its drawing means and/or which can lower the number of drawing malfunctions caused by the torsion of the roller lines.
Another object of this invention is to provide a spinning machine in which at least two of the roller lines of the drawing system that are arranged lengthwise of the machine are associated with another by gear transmissions that have step up and step down ratios.
Still another object of the invention is to provide the improved spinning machine with gear transmissions that are positioned substantially medially of the drawing system.
A further object of the invention is to provide the spinning machine with a booster motor that is adapted to exert torque on the roller line at a distance removed from the gear transmission assembly to reduce torsion.
Yet another object of the invention is to increase the length of the drawing area of the spinning machine and to decrease the drawing malfunctions naturally caused by torsion of the roller lines as well as decrease the diameter of the roller lines.
Numerous other advantages result from the use of this invention e.g. it is extremely economical because it has not been conceivable heretofore to construct spinning machines with long roller lines.
Especially high economical advantages result, when one constructs the spinning machine significantly longer than has been common previously. Also by such an assembly as taught herein the high fixed costs of the drive and control elements of the spinning machine are then divided over a significantly greater number of drawing frames, for example, double the number. Further, by having the gear transmission associated with the ends of the roller lines lengthening of the drawing area of the machine can be more readily achieved up to several times the lengths conceivable heretofore, depending on the arrangement of the gear drive.
Normally it is expedient to positively connect all roller lines at one point of each along the length of the machine adjacent to an outer drawing means or between two drawing means by means of gear drives. In many cases in fact, it is sufficient to connect only two roller lines, preferably those that border on the drawing field with the highest draft, on one additional point by another special gear drive, so that in case one or more other roller lines are present, preferably a roller line on the input side of a pre-draw region these other roller lines are paired with only a single gear drive. Indeed, torsion or torsion fluctuations can cause more disturbance when the draft is greater in the draw region which they border. And this does not even touch on the fact that it is naturally optimal and therefore advantageous because of the additional expenses that do not constitute the greater percentage of the total price of the spinning machine, if all roller lines on the length of the machine involved are connected with each other by gear drive means at at least two points spaced from each other by a significant distance.
The drive of the roller lines on one or both sides of the machine can be accomplished in a known manner by a single drive motor, which can include an electric motor employed only for these roller lines or an electric motor employed also for the spindles and/or other machine elements, such as the rail ring, spool stand and the like.
Especially with extremely long spinning machines it can be advantageous to provide two motors for the drive of the roller lines, which drive the roller line arranged at the drawing system output at two points greatly separated from each other, and thus reduce the absolute roller line torsion. One of these two motors can be less powerful than the other that is less powerful than the main drive motor e.g. this motor could be actually a booster motor. The booster motor can be an asynchronous motor or a synchronous motor, preferably a motor having a rotating magnetic field. In some instances, a non-electric motor could be provided, for example one having an hydraulic motor.
Structurally, it is especially favorable to provide gear drive means on both ends of the roller line. In many cases it can be advantageous if at least one gear drive connection of the roller line is provided between two drawing means. Thus, in this manner the torsion and torsion fluctuations of the roller lines can be even further reduced, so that among other things the spinning machine can be even longer. If, in such a case the roller lines are also connected to each other on both ends by gear transmissions, the gear transmissions located between two drawing means can engage at the middle of the roller lines. If only one end of the roller lines is connected by the gear transmission, it can be advantageous to arrange the gear transmissions located between the drawing means at a distance of approximately 0.6 to 0.7 times the length of the roller lines from the end of the roller lines that are connected together by the gear drives, since this arrangement produces a minimum of torsion. As also disclosed in detailed hereinafter the connecting of the roller lines of the side of the machine concerned by gear drives occurs exclusively approximately in the center of the roller lines, so that the torsions of the roller lines at the two outer drawing means are only about half as large as with the common one sided gear drive arrangement, thus in this way the length of the drawing means area of this novel machine can be doubled.
The drive motor in many cases can be advantageously arranged in the center of the long side of the machine near the gear transmissions, or it is also possible to have the drive motor operate on one end of a roller line, preferably that of the roller line with the highest rpm. Also, two or more drive motors can be provided. The roller lines can extend through the gear drive, but it is also possible at a greater expense to interrupt them at the point of drive.
It is also structurally simple and reliable, to produce a substantial reduction of the torsions of the roller lines driven by booster motors, with all of the resultant advantages as will be described later. Preferably each roller line would have its own booster motor. As non-electrical booster motors, one preference is hydraulic motors, also called hydromotors. Motors having a rotating magnetic field are rotational current fed asynchronous motors, which are not designed for a specific performance, but rather for a maximum torque, which they can deliver depending on their position when stopped and can remain switched on when stopped. Such motors having a rotating magnetic field are produced, for example, by SSB-Electromachines GmbH & Co. KG., Salzbergen, West Germany.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed description when taken in conjunction with the drawings and finally claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings several exemplary embodiments of the invention are schematically shown.
FIG. 1 is a fragmentary front elevational view of the improved spinning machine according to the first exemplary embodiment of the invention,
FIG. 2 is a fragmentary front elevational view of another spinning machine according to a second exemplary embodiment of the invention, and
FIG. 3 is a partial fragmentary view of one side of the machine showing another embodiment according to FIG. 1.
In the drawings, corresponding parts are provided with the same numerals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematically illustrated spinning machines 10, 10', and 10", that are shown in FIGS. 1, 2, and 3, are particularly concerned with ring spinning machines, which have about double the number of drawing means 11 arranged the length of the machine than was possible heretofore. The drawing means 11 in these exemplary embodiments have the common preliminary drawing field 12 and a main drawing field 13, through which extend in the direction of the arrow A the fiber strands to be drawn. After leaving the drawing means 11 the drawn fiber strands are twisted into yarn and wound onto a spool by means of known devices, in the case of ring spinning machines by means of runners and spindles.
The drawing means 11 have common upper roller carriers, not-shown which press the upper roller 14 onto the lower rollers formed by three roller lines 15, 16, 17 (FIGS. 1, 3 i.e. 15', 16', 17' (FIG. 2) extending along all of the drawing means on this side of the machine, in order to grip and transport the fiber strands to be drawn.
In the following description of the exemplary embodiment according to FIG. 1 the roller lines 15, 16, 17 are of the common construction.
The spinning machine according to FIG. 1 has a common drive means 19 with an electric motor 20 to drive the roller lines 15, 16, and 17. This drive motor 20, besides driving the roller lines 15, 16, 17, can also serve to drive the roller lines arranged on the other long side of the machine. The motor 20 can, if necessary, also serve to drive other machine elements, such as spindles and ring rails. The drive motor 20 directly drives the shaft 22 of the roller line 17, which is arranged at the output end of the drawing means 11, and which forms the lower feed rollers, and though the drive is direct, a transmission can be also utilized. This roller line 17 operates at a much higher rpm than the other two roller lines 15, 16, which causes only a limited drawing power in the preliminary drawing fields 12, which they in part delimit, because of the high pull in the main drawing fields 13.
On both ends of each roller line 15, 16, 17 there is a gear attached as shown, these being connected to each other by intermediate gears which engage with them, so that four gear drives 21, 23, 24, 25 are present. In this manner the left end of the roller line 17 as viewed in the drawing is positively connected with the middle roller line 16 at its drive by the gear drive 21, and this roller line 16 is positively connected with the roller line 15 at its drive by the gear drive 23. The right end of the roller lines 15, 16, 17 (as seen in FIG. 1) are also positively connected in predetermined rpm relationships by means of the gear drives 24, 25, the step-down of which correspond to those of the gear drives 21 i.e. 23. The diameter of the gears of the transmissions 21, 23, 24, 25 are not according to scale. This is also true of other details in both exemplary embodiments. Further gears can also be provided for whatever speed control is deemed necessary.
The draw malfunctions caused by the unavoidable torsions of the roller lines 15, 16, 17 are the greatest in the middle of the drawing area of the machine 10 because of the gear drives 21, 23, 24, 25, but they are only half as great as those on the right side of these roller lines 15, 16, 17 as viewed when looking at the drawings. The draw malfunctions decrease progressively from the middle of the drawing area toward both sides i.e., from drawing means to drawing means, until is is practically zero at both ends, since the roller lines 15, 16, 17 are driven by transmissions 24, 25 at the ends, where the roller lines 15, 16, 17 remain precise and uninfluenced by the torsions because of their proximity to the transmissions 24, 25. Accordingly, the draw malfunctions caused by the torsions of the roller lines 15, 16, 17 in the drawing fields 12, 13 are at most only about half as great as if the transmissions 24, 25 were not present, and one can therefore make the length of the drawing area of this machine, for example, twice as long as in a conventional, comparable machine. Because of the low draw pressure in the preliminary drawing fields 12 and the resultant low torsions in the roller lines 15, 16, it is not necessary in all instances to connect the roller lines 15, 16, as viewed in FIG. 1 by a gear transmission, so that it is possible where desired to leave out the gear transmission 25. It can be also advantageous to provide a second drive motor 26, as shown by the broken lines, which motor would drive the roller lines 17, as viewed in FIG. 1, whereby the torsions of the roller lines 15, 16, 17 become substantially smaller, so that the draw malfunctions caused by torsion in these roller lines can be even further reduced with the attendant advantages. This also causes a substantial decrease in the load on these roller lines, which is very important. The motor 26 and the transmissions 24, 25 are arranged in a housing, shown by the broken line.
In the exemplary embodiment of the invention according to FIG. 2, the lower rollers of the drawing system 11 formed by the roller lines 15', 16', and 17' are connected with each other in the middle of the drawing area of this machine 10' by means of gear drives 21', 23'.
In the area of the transmissions 21', 23', arranged in the housing 27 shown by the broken line, the diameters of the roller lines 15', 16', 17' are smaller.
Although it is normally advantageous for structural reasons to provide only the transmissions 21', 23' in such an embodiment, in extreme cases the outer ends of the roller lines 15', 16', and 17' can be connected with each other by gear drives in a manner not shown, so that the torsion-dependent draw malfunctions can be reduced even further, or the spinning machine can be lengthed even more.
The drive of these draw roller lines 15', 16', 17' in this embodiment of the invention is accomplished by a single drive motor 20', which preferably can simultaneously be the main drive motor of the spinning machine 10' and perhaps also can be arranged at other positions on the spinning machine, for example, on one end of the machine, driving a gear 29 arranged on the roller line 17. In order to decrease the torsion of the roller lines 15', 16', and 17' even further, their outer ends can be connected with additional booster drive motors 20", which are not as powerful as the main drive motor 20'.
The outer ends of the roller lines 15', 16', 17', are supported in support plates 31. Of course, the long roller lines in both FIGS. 1 and 2 are supported by such support plates at several points along their lengths.
The spinning machine 10", shown schematically in FIG. 3, is a further variation of the spinning machine 10 of FIG. 1. In this embodiment the machine differs from that of FIG. 1 in that a special booster motor 20'", instead of the gear transmissions 24 and 25, is arranged on each of the ends of the roller lines 15, 16, 17 opposite the main drive motor 20 and gear transmissions 21, 23 are not further shown in FIG. 3. The roller lines 15, 16, 17 are thus connected with each other on the left as viewed in the drawing in FIG. 1 by gear transmissions and are driven by a main drive motor. Thus, besides the main drive motor, there are less powerful booster motors 20'" present for each roller line 15, 16, 17, which booster motors drive the right side of the roller lines 15, 16, 17 (as viewed in the drawing) independently of one another, in order to decrease the torsions of these roller lines 15, 16, 17 and thereby also decrease the draw malfunctions of the drawing system caused by such torsions. Their torque must thus be selected so that the main drive motor exerts a driving torque on the roller lines 15, 16, 17 which can preferably correspond to the torque of the respective booster motors 20'". In this preferred embodiment, the drive shaft of each booster motor 20'" is directly connected to its corresponding roller line end in such a manner as to rotate with it, yet under certain circumstances a transmission also can be interposed. These booster motors 20'" are preferably electric motors. Either synchronous or asynchronous motors would be acceptable, but preferably a motor having a rotating magnetic field would be provided. It is also conceivable, that non-electrical motors 20'" could be provided, for example, hydraulic motors.
The purpose of the booster motors 20'" of FIG. 3 is the same as that of the booster motors 20" and described in connection with the embodiment according to FIG. 2.
The spinning machine according to FIG. 3 has the same advantages as the spinning machine according to the FIGS. 1 and 2.
In the spinning machine according to FIG. 3, the gear transmissions connecting the roller lines 15, 16, 17, are arranged on the ends of the roller lines opposite the ends which are driven by the booster motors 20'", but under certain circumstances they could have a different arrangement, for example, they could be located at about 2/3 of the roller line length from the end of roller line shown in FIG. 3, whereby the torsions would be even further reduced.
In some instances it can be sufficient not to provide all of the roller lines with such booster motors 20'", but rather only one or two roller lines, preferably the roller lines 16 and 17. It is also possible and in many cases advantageous, to allow these booster motors 20'" to engage not on an end of the roller lines 15, 16, 17, but rather between two drawing means in operating connection with the concerned roller lines, and to do it preferably at places as discussed above in connection with the additional gear transmissions, that is, preferably at a distance of about 2/3 of the roller line length from the roller line ends connected with each other by the gear transmissions. In some cases each of the roller lines concerned advantageously can be arranged with two or more such booster motors, which engage the roller line at substantial distances from each other. Preferably, a first booster motor at the center of the roller line and a second booster motor at the end of the roller line opposite the gear transmissions can exert driving torque on the roller line.
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A long spinning machine, preferably a ring spinning machine, with a plurality of drawing means, which serve to draw the fiber strands with the drawing means being arranged adjacent to each other and extending lengthwise of the machine the drawing lower rollers of the drawing means formed by a plurality of long roller lines positively connected together at one point by drive gear transmissions which provide predetermined rpm ratios between the roller lines with some of the roller lines connected together by additional drive gear transmission at least at one additional point spaced from the one point to eliminate or substantially reduce torsion in the roller lines.
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This application is a continuation of application Ser. No. 09/338,706 filed Jun. 23, 1999 which is a division of application Ser. No. 09/128,873 filed Aug. 4, 1998 which claims priority from provisional application 60/055,472 filed Aug. 11, 1997.
FIELD OF INVENTION
This invention relates to the fields of pharmaceutical and organic chemistry and provides novel benzothiophene compounds which are useful for the treatment of the various medical conditions associated with postmenopausal syndrome, as well as estrogen-dependent diseases including cancer of the breast, uterus, and cervix.
BACKGROUND OF THE INVENTION
“Postmenopausal syndrome” is a term used to describe various pathological conditions which frequently affect women who have entered into or completed the physiological metamorphosis known as menopause. Although numerous pathologies are contemplated by the use of this term, three major medical conditions of postmenopausal syndrome are the source of the greatest long-term medical concern: osteoporosis, cardiovascular effects such as hyperlipidemia, and estrogen-dependent cancer such as breast and uterine cancer.
Osteoporosis, which generally includes a group of disorders which arise from diverse etiologies, is characterized by the net loss of bone mass per unit volume.
The consequence of this loss of bone mass and resulting bone fracture is the failure of the skeleton to provide adequate structural support for the body. One of the most common types of osteoporosis is that associated with menopause. Most women lose from about 20% to about 60% of the bone mass in the trabecular compartment of the bone within three to six years after the cessation of menses. This rapid loss is generally associated with an increase of bone resorption and formation. However, the resorptive cycle is more dominant and the result is a net loss of bone mass.
Osteoporosis is a common and serious disease among postmenopausal women. There are an estimated 25 million women in the United States who are afflicted with this disease. The results of osteoporosis disease's sequelae are personally harmful and often result in the need for extensive and long term medical support (hospitalization and nursing home care). This is especially true in elderly patients. Additionally, although osteoporosis is not generally thought of as a life threatening condition, a 20% to 30% mortality rate is related with hip fractures in elderly women. A large percentage of this mortality rate can be directly associated with postmenopausal osteoporosis.
The trabecular tissue is the most vulnerable bone tissue to the effects of postmenopausal osteoporosis. This tissue is often referred to as spongy or cancellous bone and is particularly concentrated near the ends of the bone (near the joints) and in the vertebrae of the spine. The trabecular tissue is characterized by small osteoid structures which inter-connect with each other, as well as the more solid and dense cortical tissue which makes up the outer surface and central shaft of the bone. This interconnected network of trabeculae gives lateral support to the outer cortical structure and is critical to the biomechanical strength of the overall structure. In postmenopausal osteoporosis, it is loss of the trabeculae which leads to the failure and fracture of bone. In light of the loss of the trabeculae in postmenopausal women, it is not surprising that the most common fractures are those associated with bones which are highly dependent on trabecular support, e.g., the vertebrae and the neck of the weight bearing bones, such as the femur and the fore-arm. Indeed, hip fracture, collies fractures, and vertebral crush fractures are hallmarks of postmenopausal osteoporosis.
At this time, the generally accepted method for treatment of postmenopausal osteoporosis is estrogen replacement therapy (ERT). Although ERT is generally successful, patient compliance with this therapy is low primarily because estrogen treatment frequently produces undesirable side effects.
Prior to menopause, most women have less incidence of cardiovascular disease than age-matched men. Following menopause, however, the rate of cardiovascular disease in women, such as hyperlipidemia, increases to match the rate seen in men. This rapid increase in the incidence of cardiovascular disease has been linked, in part, to the loss of estrogen and to the loss of estrogen's ability to regulate serum lipids. The nature of estrogen's ability to regulate serum lipids is not well understood, but evidence to date indicates that estrogen can upregulate the low density lipid (LDL) receptors in the liver to remove excess cholesterol. Additionally, estrogen appears to have some effect on the biosynthesis of cholesterol, as well as other beneficial effects on cardiovascular health.
It has been reported in the literature that postmenopausal women undergoing estrogen replacement therapy have a return of serum lipid levels to concentrations similar to those of the premenopausal state. Thus, estrogen would appear to be a reasonable treatment for this condition. However, the side-effects of ERT are not acceptable to many women, thus limiting the use of this therapy. An ideal therapy for this condition would be an agent which would regulate the serum lipid levels like estrogen, but would be devoid of the side-effects and risks associated with estrogen therapy.
The third major pathology associated with, but not limited to, postmenopausal syndrome is estrogen-dependent cancer, primarily breast and uterine cancer. Although such neoplasms are not solely limited to postmenopausal women, they are more prevalent in the older postmenopausal population. Current chemotherapy of these cancers has relied heavily on the use of estrogen agonist/antagonist compounds, such as tamoxifen. Although such mixed agonist/antagonists have beneficial effects in the treatment of these cancers, the estrogenic side-effects are tolerable in only acute life-threatening situations. These agents have stimulatory effects on certain cancer cell populations in the uterus due to their estrogenic (agonist) properties and therefore, are contraproductive in some cases. A better therapy for the treatment of these cancers would be an agent which is an antiestrogenic compound in cancerous tissue, having negligible or no estrogen agonist properties on other reproductive tissues.
In response to the clear need for new pharmaceutical agents which are capable of alleviating the symptoms of, inter alia, postmenopausal syndrome, the present invention provides new compounds, pharmaceutical compositions thereof, and methods of using such compounds for the treatment of postmenopausal syndrome and other estrogen-related pathological conditions such as those mentioned herein.
SUMMARY OF THE INVENTION
The present invention relates to compounds of formula I:
wherein:
R and R 1 are independently hydrogen, halo, hydroxy, or O—Pg;
R 2 is CHR 3 OR 4 , CO 2 R 5 , CHOHCH 2 NR 6 R 7 , or a heterocycle;
X is C═O, CH—OH, CH 2 , O, or S;
Pg is independently at each occurrence a hydroxy protecting group;
R 3 is hydrogen or CH 2 OH;
R 4 is hydrogen, C 1 -C 6 alkyl, or COR 8 ;
R 5 is hydrogen, C 1 -C 6 alkyl, or aryl;
R 6 and R 7 are independently at each occurrence hydrogen or C 1 -C 6 alkyl, or R 6 and R 7 together with the nitrogen to which they are attached form a 3,5-dimethylpiperidino, 3-methylpiperidino, pyrrolidino, piperidino, or a hexamethyleneimino ring;
R 8 is hydrogen, C 1 -C 6 alkyl, or aryl; or a pharmaceutically acceptable salt or solvate thereof.
The present invention further relates to pharmaceutical formulations containing compounds of formula I and the use of such compounds for alleviating the symptoms of postmenopausal syndrome, particularly osteoporosis, cardiovascular-related pathological conditions, and estrogen-dependent cancer.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term “C 1 -C 4 alkyl” represents a methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, cyclobutyl, s-butyl, or a t-butyl group. The term “C 1 -C 6 alkyl” includes “C 1 -C 4 alkyl” groups in addition to straight, branched or cyclic alkyl groups having from five to six carbon atoms which would include, but not be limited to, pentyl, isopentyl, hexyl, 2-methylpentyl, cyclopentyl, cyclohexyl, and like groups. The term “C 1 -C 4 alkoxy” represents a methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, or a s-butoxy group. The term “halo” refers to fluoro, chloro, bromo, or iodo.
The term “aryl” represents phenyl, benzyl, substituted phenyl, and substituted benzyl groups.
The term “heterocycle” refers to a 3 or 4 membered saturated, partially unsaturated, or aromatic optionally substituted ring, which contains one heteroatom chosen from oxygen or sulfur, and also refers to a 5 or 6 membered saturated, partially unsaturated, or aromatic optionally substituted ring, which contains one or two heteroatoms chosen from oxygen or sulfur.
The terms “substituted phenyl”, “substituted benzyl”, and “optionally substituted heterocycle” represent a phenyl, benzyl, or heterocyclic group, respectively, substituted with one to three moieties chosen from the group consisting of halo, hydroxy, nitro, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, trichloromethyl, and trifluoromethyl. Examples of a substituted phenyl group include 4-chlorophenyl, 2,6-dichlorophenyl, 2,5-dichlorophenyl, 3,4-dichlorophenyl, 3-chlorophenyl, 3-bromophenyl, 4-bromophenyl, 3,4-dibromophenyl, 3-chloro-4-fluorophenyl, 2-fluorophenyl, 4-hydroxyphenyl, 3-hydroxyphenyl, 2,4-dihydroxyphenyl, 3-nitrophenyl, 4-nitrophenyl, 2,4-dinitrophenyl, 4-methylphenyl, 4-ethylphenyl, 4-methoxyphenyl, 4-propylphenyl, 4-n-butylphenyl, 4-t-butylphenyl, 3-fluoro-2-methylphenyl, 2,3-difluorophenyl, 2,6,difluorophenyl, 2,6-dimethylphenyl, 2-fluoro-5-methylphenyl, 2,4,6-trifluorophenyl, 2-trifluoromethylphenyl, 2-chloro-5-trifluoromethylphenyl, 3,5-bis-(trifluoromethyl)phenyl, 2-methoxyphenyl, 3-methoxyphenyl, 3,5-dimethoxyphenyl, 2-methyl-4-nitrophenyl, 4-methoxy-2-nitrophenyl, and the like. Examples of a substituted benzyl group would include all the compounds named when the word “benzyl” is substituted for the word “phenyl” in all the previously mentioned examples of a substituted phenyl group. The substitution of a heterocycle is similar to that of phenyl and benzyl group.
The term “hydroxy protecting group” denotes a group understood by one skilled in the organic chemical arts of the type described in Chapter 2 of “Protective Groups in Organic Synthesis, 2nd Edition, T. H. Greene, et al., John Wiley & Sons, New York, 1991, hereafter “ Greene”.
Representative hydroxy protecting groups include, for example, C 1 -C 4 alkyl and substituted C 1 -C 4 alkyl, including methyl, ethyl, or isopropyl ether, methoxymethyl ether, methylthiomethyl ether, tert-buylthiomethyl ether, (phenyldimethylsilyl)methoxymethyl ether, benzyloxymethyl ether, p-methoxy-benzyloxymethyl ether, and tert-butoxy-methyl ether; substituted ethyl ether groups such as ethoxyethyl ether, 1-(2-chloroethoxy)ethyl ether, 2,2,2-trichloroethoxymethyl ether, and 2-(trimethylsilyl)ethyl ether; phenyl and substituted phenyl ether groups such as phenyl ether, p-chlorophenyl ether, p-methoxyphenyl ether, and 2,4-dinitrophenyl ether; benzyl ether groups such as benzyl ether; and alkylsilyl ether groups such as trimethyl- triethyl- and triisopropylsilyl ethers, mixed alkylsilyl ether groups such as dimethylisopropylsilyl ether, and diethylisopropylsilyl ether; ester protecting groups such as those of the general formula COC 1 -C 6 alkyl or COAr, or a formate ester, benzylformate ester, mono- di- and trichloroacetate esters, phenoxyacetate ester, and p-chlorophenoxyacetate and the like; and carbonates of the general formula COOC 1 -C 6 alkyl, or COOAr, where Ar is phenyl or substituted phenyl. The species of hydroxy protecting group employed is not critical so long as the derivatized hydroxy group is stable to the condition of subsequent reaction(s) on other positions of the intermediate molecule and can be selectively removed at the appropriate point without disrupting the remainder of the molecule including any other hydroxy protecting group(s). It is within the knowledge of one skilled in the art to select appropriate hydroxy protecting group(s) for a given set of reaction conditions given the guidance provided by Greene cited above.
The term “carbonyl activating group” refers to a substituent of a carbonyl that promotes nucleophilic addition reactions at that carbonyl. Suitable activating substituents are those which have a net electron withdrawing effect on the carbonyl. Such groups include, but are not limited to, esters and amides such as hydroxybenzotriazole, imidazole, a nitrophenol, pentachlorophenol, N-hydroxysuccinimide, dicyclohexylcarbodiimide, N-hydroxy-N-methoxyamine, and the like; acid anhydrides such as acetic, formic, sulfonic, methanesulfonic, ethanesulfonic, benzenesulfonic, or p-tolylsulfonic acid anhydride, and the like; and acid halides such as the acid chloride, bromide, or iodide.
Although the free-base form of formula I compounds can be used in the methods of the present invention, it is preferred to prepare and use a pharmaceutically acceptable salt form. Typical pharmaceutically acceptable salts include those salts prepared by reaction of the compounds of the present invention with a mineral or organic acid. Such salts are known as acid addition salts. Thus, the term “pharmaceutically acceptable salt” refers to acid addition salts of a compound of formula I which are substantially non-toxic at the doses administered and are commonly used in the pharmaceutical literature. See e.g. Berge, S. M, Bighley, L. D., and Monkhouse, D. C., J. Pharm. Sci., 66, 1, 1977.
Examples of such pharmaceutically acceptable salts are the iodide, acetate, phenylacetate, trifluoroacetate, acrylate, ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, methylbenzoate, o-acetoxybenzoate, naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate, g-hydroxybutyrate, b-hydroxybutyrate, butyne-1,4-dioate, hexyne-1,4-dioate, hexyne-1,6-dioate, caproate, caprylate, chloride, cinnamate, citrate, decanoate, formate, fumarate, glycollate, heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate, malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate, oxalate, phthalate, terephthalate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, propiolate, propionate, phenylpropionate, salicylate, sebacate, succinate, suberate, sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate, benzenesulfonate, p-bromophenylsulfonate, chlorobenzenesulfonate, propanesulfonate, ethanesulfonate, 2-hydroxyethanesulfonate, methanesulfonate, naphthalene-l -sulfonate, naphthalene-2-sulfonate, p-toluenesulfonate, xylenesulfonate, tartarate, and the like of a compound of formula I.
By “pharmaceutically acceptable” it is also meant that in a formulation containing the compound of formula I, the carrier, diluent, excipients, and salt must be compatible with the other ingredients of the formulation, and not deleterious to the recipient thereof.
The term “solvate” represents an aggregate that comprises one or more molecules of the solute, such as a formula I compound, with one or more molecules of solvent.
As used herein, the term “effective amount” means an amount of compound of the present invention which is capable of alleviating the symptoms of the various pathological conditions herein described.
The terms “treatment” or “treating” bear their usual meaning which includes prohibiting, inhibiting, ameliorating, halting, restraining, slowing or reversing the progression, or reducing the severity of a pathological symptom related to or resultant from post menopausal syndrome. As such, these methods include both medical therapeutic (acute) and/or prophylactic (prevention) administration as appropriate.
When any of the following substitutions occur:
X is CH—OH; and/or
R 2 is a heterocycle; and/or
R 2 is CHR 3 OR 4 and R 3 is CH 2 OH; and/or
R 2 is CHOHCH 2 NR 6 R 7 ;
the compounds of the invention contain chiral centers. All enantiomers, diastereomers, and mixtures thereof, are included within the scope of the present invention. While all diastereomers, both enantiomers, and mixtures thereof, are useful, single enantiomers or single diastereomers are preferred.
While all of the compounds of the present invention are useful, certain of the compounds are particularly interesting and are preferred. The following listing sets out several groups of preferred compounds. It will be understood that each of the listings may be combined with other listings to create additional groups of preferred compounds.
aa) R is halo;
ab) R is fluoro;
ac) R is chloro;
ad) R is bromo;
ae) R is hydrogen;
af) R is hydroxy;
ag) R is O—Pg;
ah) R 1 is halo;
ai) R 1 is fluoro;
aj) R 1 is chloro;
ak) R 1 is bromo;
al) R 1 is hydrogen;
am) R 1 is hydroxy;
an) R 1 is O—Pg;
ao) R and R 1 are both hydroxy;
ap) R and R 1 are both O—Pg;
aq) Pg is methyl;
ar) Pg is benzyl;
as) Pg is isopropyl;
at) R 2 is CHR 3 OR 4 ;
au) R 2 is CO 2 R 5 ;
av) R 2 is CHOHCH 2 NR 6 R 7 ;
aw) X is C═O;
ax) X is O;
ay) R 3 is hydrogen;
az) R 3 is CH 2 OH;
ba) R 4 is hydrogen;
bb) R 4 is C 1 -C 4 alkyl;
bc) R 4 is t-butyl;
bd) R 4 is ethyl;
be) R 4 is COR 8 ;
bf) R 5 is hydrogen;
bg) R 5 is C 1 -C 4 alkyl;
bh) R 5 is methyl;
bi) R 5 is phenyl;
bj) R 5 is benzyl;
bk) R 6 hydrogen;
bl) R 7 is hydrogen;
bm) R 7 is C 1 -C 6 alkyl;
bn) R 7 is n-hexyl;
bo) R 7 is isopropyl;
bp) R 7 is n-butyl;
bq) R 6 and R 7 together with the nitrogen to which they are attached form a 3,5-dimethylpiperidino ring;
br) R 6 and R 7 together with the nitrogen to which they are attached form a 3-methylpiperidino ring;
bs) R 6 and R 7 together with the nitrogen to which they are attached form a pyrrolidino ring;
bt) R 6 and R 7 together with the nitrogen to which they are attached form a piperidino ring;
bu) R 8 is C 1 -C 6 alkyl;
bv) R 8 is t-butyl;
bw) R 8 is methyl;
bx) R 8 is cyclohexyl;
by) R 8 is phenyl;
bz) the compound of formula I is a salt;
Synthesis
Specific preparations of compounds of the present invention are described herein, in Examples 1-39. Modification to the methods described below may be necessary to accommodate reactive functionalities of particular substituents. Such modification would be both apparent to, and readily ascertained by, those skilled in the art. The following schemes generally illustrates the preparation of compounds of formula I.
The compounds of formula I where R and R 1 are not hydroxy, X is C═O, O, or S, R 2 is CHR 3 OR 4 , CO 2 R 5 , or a heterocycle, R 3 is hydrogen, and R 4 is C 1 -C 6 alkyl may be prepared from compounds of formula II as illustrated in Scheme 1 below where R′ and R 1′ are independently at each occurrence hydrogen, halo, or O—Pg, R 9 is CH 2 O(C 1 -C 6 alkyl), CO 2 R 5 , or a heterocycle, X′ is C═O, O, or S, Y is hydroxy or a leaving group and R 3 , R 5 , and heterocycle are as described supra.
Generally, a phenol intermediate of formula II is reacted with an alkylating agent of formula III, IV, or V under various protocols known in the art to give compounds of formula Ia. In one such procedure, intermediate II is reacted with an alcohol of the formula III, IV, or V under Mitsunobo conditions (Y is hydroxy). The reaction may be accomplished by combining an appropriate alcohol of formula III, IV, or V, a dialkylazodicarboxylate, and a triaryl or trialkylphosphine in a polar organic solvent. Preferred reagents include diethyl azodicarboxylate and triphenylphosphine and the preferred solvents are typically tetrahydrofuran or toluene. Preferred heterocyclic alcohols of formula V are those which contain an oxygen or sulfur atom at least two carbons removed from the alcohol group e.g. 2-hydroxymethyl-2,3,5,6-tetrahydropyrans or 2-thiophenemethanol. The reaction is generally carried out by dissolving the reagents in a suitable solvent between 0° C. and the reflux temperature of the reaction mixture and allowing the reaction to proceed until it is complete, generally in less than 24 hours.
Alternatively, when Y is a leaving group in compounds of formula III, IV, or V, displacement of the leaving group by a compound of formula II is accomplished by heating that compound of formula III, IV, or V and a compound of formula II in the presence of an appropriate base, such as potassium bicarbonate or triethylamine, in a polar organic solvent such as N,N-dimethyformamide. The reaction can be conducted at room temperature or, preferably, at 80° C. to 120° C. where the reaction is typically complete in less than 6 hours. The leaving group can be, but is not limited to, halides such as chloride, bromide, or iodide or other functionalities capable of being displaced, such as sulfonates e.g. tosylate and mesylate. The preferred leaving group is bromide.
When R 9 in compounds of formula Ia is CO 2 R 5 and R 5 is not hydrogen (esters) such compounds may be converted to their corresponding acids by standard saponifications procedures. This transformation is preferably accomplished through treatment of the ester with aqueous bases such as sodium hydroxide, lithium hydroxide, or potassium hydroxide, followed by acidification with a proton source such as 5N hydrochloric acid.
Compounds of formula I where X is C═O, O, or S, R 2 is CHR 3 OR 4 , R 3 is hydrogen, and R 4 is hydrogen or COR 8 may be prepared from compounds of formula Ia where R 9 is CH 2 O(C 1 -C 6 alkyl) as shown in Scheme 2 below where Z is a carbonyl activating group and R, R 1 , R 9 , and X′ are as described supra.
Compounds of formula Ib, prepared as described in Scheme 1, may be converted to compounds of formula Ic using standard hydroxy deprotection conditions known in the art. (See Greene at 14). Compounds of formula Ic may then be esterified using standard conditions well known in the art by treatment with a suitable base and a compound of formula VI. See e.g. Larock, “Comprehensive Organic Transformations”, VCH Publishers, Inc., New York, N.Y., 1989, pgs. 978-979. Preferred reagents for this transformation include trialkylamine bases, such as triethylamine, and alkyl or aryl acid chlorides. The reaction is generally carried out in an organic solvent, such as tetrahydrofuran, at room temperature or below and is typically complete in less than 24 hours.
Compounds of formula I where X is C═O, O, or S and R 2 is CHOHCH 2 NR 6 R 7 may be prepared from compounds of formula Ia where R 9 is a heterocycle where that heterocycle is an epoxide. This transformation is shown in Scheme 3 below where R, R 1 , R 6 , R 7 , and X′ are as described supra.
Compounds of formula Ie, prepared as described in Scheme 1, may be reacted with a primary or secondary amine of formula VII e.g. 1-butylamine, pyrrolidine, or piperidine, to provide compounds of formula If. Preferred reaction conditions for this process include reaction of the amine and epoxide in a polar organic solvent, such as methanol or ethanol, at the reflux temperature of the mixture for a period of about 30 minutes to about 4 hours.
The compounds of formula I where X is C═O, O, or S, R 2 is CHR 3 OR 4 , R 3 is CH 2 OH, and R 4 is hydrogen may be prepared from compounds of formula Ia where R 9 is a heterocycle where that heterocycle forms a 1,2-diol protecting group e.g. 2,2-dimethyldioxalan-4-yl. This transformation is illustrated in Scheme 4 below where n is 1 or 2 and R, R 1 , and X′ are as described supra.
Compounds of formula Ig, prepared as described in Scheme 1 may be converted to compounds of formula Ic using standard 1,2-dihydroxy deprotection conditions known in the art. See Greene at 118.
The compounds of formula I where X is CH—OH or CH 2 may be prepared from compounds of formula Ia—Ih where X is C═O essentially as described in U.S. Pat. No. 5,484,798, the teachings of which are hereby incorporated by reference.
When any of R, R′, R 1 , or R 1′ are hydroxy protecting groups in compounds of formula Ia—Ih, they may be removed by well known methods in the art to give the compounds of formula I where R and R 1 are both hydroxy. Numerous reactions for the formation and removal of hydroxy protecting groups are described in a number of standard works including, for example, Protective Groups in Organic Chemistry, Plenum Press (London and New York, 1973); The Peptides, Vol. I, Schrooder and Lubke, Academic Press (London and New York, 1965), and Greene. Preferred protecting groups are C 1 -C 4 alkyl groups and especially preferred are methyl groups.
The pharmaceutically acceptable acid addition salts are typically formed by reacting a compound of formula I in its free base form with an equimolar or excess amount of acid. The reactants are generally combined in a polar organic solvent such as methanol or ethyl acetate. The salt normally precipitates out of solution within about one hour to 10 days and can be isolated by filtration, or the solvent can be stripped off by conventional means.
The pharmaceutically-acceptable salts generally have enhanced solubility characteristics compared to the compound from which they are derived, and thus are often more amenable to use in pharmaceutical formulations.
The compounds of formula II may be prepared by a number of well known routes. For example, compounds of formula II where X is C═O and compounds of formula II where X is O, or S can be prepared from m-methoxythiophenol and an appropriately substituted a-bromoacetophenone as taught respectively in U.S. Pat. Nos. 4,133,814 and 5,510,357, the teaching of which are hereby incorporated by reference.
The optimal time for performing the reactions of Schemes 1-4 can be determined by monitoring the progress of the reaction via conventional chromatographic techniques. Furthermore, it is preferred to conduct the reactions of the invention under an inert atmosphere, such as, for example, argon, or, particularly, nitrogen. Choice of solvent is generally not critical so long as the solvent employed is inert to the ongoing reaction and sufficiently solubilizes the reactants to effect the desired reaction. Intermediate and final products may be purified, if desired by common techniques such as recrystallization or chromatography over solid supports such as silica gel or alumina.
Compounds of formula III, IV, V, VI, and VII are either commercially available or may be prepared by methods well known in the art.
The synthetic steps of the routes described herein may be combined in other ways to prepare the formula I compounds. The discussion of the synthesis is not intended to be limiting to the scope of the present invention, and should not be so construed. Application of the above chemistry enables the synthesis of the compounds of formula I, which would include, but not be limited to:
1) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(butoxyethoxy)phenyl]methanol,
2) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(ethoxyethoxy)phenyl]sulfide,
3) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(carboethoxyethoxy)phenyl]ether,
4) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-([tetrahydrofuran-2-yl]methoxy)phenyl]methane,
5) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-([tetrahydro-2H-pyran-2-yl]methoxy)phenyl]methanol,
6) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2,3-dihydroxypropoxy)phenyl]sulfide,
7) (R)-[6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2,3-dihydroxypropoxy)phenyl]ether,
8) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(cyclohexanoyloxyethoxy)phenyl]methane
9) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-([benzoyloxy]ethoxy)phenyl]methanol,
10) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-([acetoxy]ethoxy)phenyl]sulfide,
11) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-([trimethylacetoxy]ethoxy)phenyl]ether,
12) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-butylaminopropoxy)phenyl]methane,
13) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-pyrrolidinylpropoxy)phenyl]methanol,
14) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-piperidinylpropoxy)phenyl]sulfide,
15) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl-[4-(2-hydroxy-3-isopropylaminopropoxy)phenyl]ether,
16) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[(3a, 5b)-3,5-dimethylpiperidinyl]propoxy)phenyl]methane,
17) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[(3a, 5a)-3,5-dimethylpiperidinyl]propoxy)phenyl]methanol,
18) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[3-methylcyclohexyl]propoxy)phenyl]sulfide, and
19) [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-pentylaminopropoxy)phenyl]ether.
The following examples further illustrate the processes of the present invention. The examples are not intended to be limiting to the scope of the invention in any respect, and should not be so construed. All experiments were run under positive pressure of dry nitrogen. All solvents and reagents were used as obtained. The percentages are generally calculated on a weight (w/w) basis; except for HPLC solvents which are calculated on a volume (v/v) basis. Proton nuclear magnetic resonance ( 1 H NMR) spectra were obtained on a Bruker AC-300 FTNMR spectrometer operating at 300.135 MHZ.
EXAMPLES
Example 1
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][(4-t -Butoxyethoxy)phenyl]methanone
To a mixture of [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (1.0 g, 2.6 mmol), ethylene glycol mono t-butyl ether (0.6 g. 5 mmol), and triphenylphosphine (1.02 g, 3.9 mmol) stirring in tetrahydrofuran (40 mL) at 0° C. was added diethyl azodicarboxylate (0.61 mL, 3.9 mmol) dropwise over a 10 minute period. After 2 hours at room temperature, the reaction was concentrated and the resulting residue purified by flash chromatography (silica gel, 3:1 hexanes/ethyl acetate) to give 1.37 g of the title compound as a thick syrup.
Yield: 94%.
Example 2
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][(4-Hydroxyethoxy)phenyl]methanone
An aqueous solution of sodium hydroxide was added to 1.37 g of [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-t-butoxyethoxy)phenyl]methanone stirring in dioxane at room temperature. The mixture was then heated to reflux. After a sufficient time, the mixture was cooled to room temperature and the solution made acidic by addition of 1N hydrochloric acid then extracted with ethyl acetate. The combined organic extracts were washed with brine, dried (sodium sulfate), filtered, and concentrated. This material was purified by flash chromatography (silica gel, ethyl acetate) resulting in 3.0 g of the title compound as a thick syrup.
Example 3
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][(4-Hydroxyethoxy)phenyl]methanone
To [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-hydroxyethoxy)phenyl]methanone (3.0 g, 6.9 mmol) stirring vigorously in methylene chloride (200 mL) at room temperature was added ethanethiol (3 mL, 40 mmol) followed by aluminum chloride (5.3 g, 40 mmol). After 1 hour, sodium bicarbonate (saturated aqueous solution) and methanol were added. The mixture was then extracted throughout with ethyl acetate. The combined organic extracts were washed with brine, dried (sodium sulfate), filtered, and concentrated. The resulting material was purified by flash chromatography (silica gel, ethyl acetate) to give 2.4 g of the title compound as a yellow solid.
Yield: 85%. 1 H NMR (C 3 D 6 O) d 8.6-8.7 (m,2H), 7.72 (d, J=9.0 Hz, 2H), 7.27 (d, J=8.9 Hz, 2H, 6.84-6.96 (m, 3H), 6.73 (d, J=9.0 Hz, 2H), 4.8 (t, J=3.1 Hz, 2H).
Example 4
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Ethoxyethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (0.39 g, 1.00 mmol) and ethylene glycol mono ethyl ether (2 mmol) were converted to 350 mg of the title compound by the procedure of Example 1 using 520 mg (2.0 mmol) of triphenylphosphine and 2.0 mmol of diethyl azodicarboxylate the only difference being that the total reaction time was 18 hours.
Example 5
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(Ethoxyethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(ethoxyethoxy)phenyl]methanone (0.35 g, 0.76 mmol) was converted to 2.4 g of the title compound by the procedure of Example 3 using 0.28 mL (3.79 mmol) of ethanethiol and 0.61 g (4.6 mmol) of aluminum chloride.
Yield: 43%. 1 H NMR (MeOD): d 7.68-7.71 (d, 2H, J=9.2 Hz), 7.39-7.42 (d, J=8.8 Hz, 1H), 7.25-7.26 (d, 1H, J=2.2 Hz), 7.17-7.19 (d, 2H, J=8.5 Hz), 6.83-6.88 (m, 3H), 6.61-6.64 (d, 2H, J=9.0 Hz), 4.09-4.12 (m, 2H), 3.72-3.75 (m, 2H), 3.52-3.58 (q, 2H, J=7.0 Hz), 1.15-1.20 (t, 3H, J =7.0 Hz).
Example 6
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-Carbomethoxymethoxyphenyl]methanone
To [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (5.0 g, 12.8 mmol) stirring in dimethylformamide at room temperature was added potassium carbonate (5.3 g, 38.4 mmol) followed by methyl bromoacetate (8 mL, 84.5 mmol). The solution was stirred at 80° C. for 1 hour then cooled to room temperature and poured into brine/ethyl acetate (300 mL, 1:1). The mixture was extracted with ethyl acetate (3×100 mL) and the combined organic extracts washed thoroughly with brine, dried (magnesium sulfate), and filtered. Concentration gave a yellow syrup which was further dried in vacuo to give 5.33 g of the methyl ester as a white crystalline solid which was used without further purification.
Yield: 90%.
Example 7
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-Carbomethoxymethoxyphenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-carbomethoxymethoxyphenyl]methanone (250 mg, 0.54 mmol) was converted to the title compound by the procedure of Example 3 using 0.24 mL (3.25 mmol) of ethanethiol and 505 mg (3.79 mmol) of aluminum chloride except the total reaction time was 0.5 hours and the workup of the reaction went as follows: the mixture was poured into a mixture of brine/ethyl acetate and extracted with ethyl acetate. The residual solid remaining in the reaction vessel was dissolved in a minimal amount of methanol and added to the ethyl acetate extracts. The combined organic extracts were washed thoroughly with brine, dried (magnesium sulfate), filtered, and concentrated. Purification by radial chromatography (2 mm, silica gel, 40% methanol in ethyl acetate) gave 140 mg methyl ether cleaved product as a yellow solid.
Example 8
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-Carboxymethoxyphenyl]methanone
To [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-carbomethoxymethoxyphenyl]methanone (132 mg, 0.30 mmol) stirring in methanol (5 mL) was added sodium hydroxide (0.43 mL of a 5 N aqueous solution, 2.13 nmol). The red mixture was heated to reflux for 0.5 hour, cooled to room temperature, and made acidic with hydrochloric acid (0.70 mL of a 5N aqueous solution). The mixture was then poured into brine and extracted with ethyl acetate. The combined organic extracts were washed thoroughly with brine, dried (magnesium sulfate), and filtered. Concentration afforded the title compound as a yellow solid.
1 H NMR(C 3 D 6 O): d 8.70 (br s, 2H) 7.76 (d, 2H, J=8.8 Hz), 7.39 (m, 2H), 7.28 (d, 2H, J=9.0 Hz), 6.84-6.94 (d, 2H, J=9.0 Hz), 4.74 (s, 2H).
Example 9
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Tetrahydropyran-2-yl)methoxyphenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (0.39 g, 1.00 mmol) and 2-hydroxymethyltetrahydropyran (174 mg, 1.5 mmol) were converted to the title compound by the procedure of Example 1 using 390 mg (1.5 mmol) of triphenylphosphine and 0.24 mL (1.5 mmol) of diethyl azodicarboxylate the only difference being that the total reaction time was 3 hours giving a thick syrup.
Example 10
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(Tetrahydropyran-2-yl)methoxyphenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(tetrahydropyran-2-yl)methoxyphenyl]methanone (0.32 g, 0.66 mmol) was converted to the title compound by the procedure of Example 3 using 0.24 mL (3.31 mmol) of ethanethiol and 530 mg (3.97 mmol) of aluminum chloride.
Yield: 62%. 1 H NMR(d 6 -DMSO): d 9.76 (br s, 2H), 7.65 (d, 2H, J=9.0 Hz), 7.35 (d, J=2.0 Hz, 1H), 7.27 (d, J=9.0 Hz, 1H), 7.19 (d, 2H, J=9.0 Hz), 6.85-6.92 (complex, 3H), 6.85 (d, J=9.0 Hz, 2H) 3.85-3.95 (complex, 3H), 3.60 (m, 1H), 1.20-1.82 (complex, 6H).
Example 11
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-([Tetrahydrofuran-2-yl]methoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo [b]thiophen-3-yl](4-hydroxyphenyl)methanone (390 mg, 1 mmol) and 2-hydroxymethyl tetrahydrofuran (153 mg, 1.50 mmol) were converted to 297 mg of the title compound by the procedure of Example 9 using 393 mg (31.5 mmol) of triphenylphosphine and 0.24 mL (1.5 mmol) of diethyl azodicarboxylate the only differences being that the chromatography eluent was 3:7 ethyl acetate:hexanes.
Yield: 83%.
Example 12
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-([Tetrahydrofuran-2-yl]methoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-([tetrahydrofuran-2-y])methoxy)phenyl]methanone (297 mg) was converted to 189 mg of the title compound by the procedure of Example 3 using 0.24 mL (3.31 mmol) of ethanethiol and 530 mg (3.97 mmol) of aluminum chloride except that 1:1 ethyl acetate:hexanes was used as chromatography eluent.
1 H NMR(d 6 -DMSO): d 9.74 (br s, 2H), 7.65 (d, 2H, J=9.1 Hz), 7.35 (d, J=2.5 Hz, 1H), 7.25 (d, 1H, J=9.0 Hz), 7.15 (d, 2H, J=9.3 Hz), 6.93 (d, 1H, J=8.9 Hz), 6.83 (dd, 1H, J=9.0 Hz, 2.3 Hz), 6.70 (d, 2H, J=8.9 Hz), 4.13 (m, 1H), 3.96 (m, 2H), 3.38 (complex, 2H), 1.75-2.0 (complex, 3H), 1.60 (m, 1H).
Example 13
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-([2,2-Dimethyl-1,3-dioxolan-3-yl]methoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone and 2,2-dimethyl-1,3-dioxolane-4-methanol were converted to the title compound by the procedure of Example 9 using triphenylphosphine and diethyl azodicarboxylate.
Example 14
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2,3-Dihydroxypropoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-([2,2-dimethyl-1,3-dioxolan-3-yl]methoxy)phenyl]methanone was converted to the title compound by the procedure of Example 3 using ethanethiol and aluminum chloride.
Example 15
(R)-[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-([2,2-Dimethyl-1,3-dioxolan-3-yl]methoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (0.39 g, 1.00 mmol) and (R)-2,2-dimethyl-1,3-dioxolane-4-methanol (0.18 ml, 1.5 mmol) were converted to the title compound by the procedure of Example 13 using 390 mg (1.5 mmol) of triphenylphosphine and 0.24 mL (1.5 mmol) of diethyl azodicarboxylate.
Example 16
(R)-[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2,3-Dihydroxypropoxy)phenyl]methanone
(R)-[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-([2,2-dimethyl-1,3-dioxolan-3-yl]methoxy)phenyl]methanone (0.39 g, 0.77 mmol) was converted to the title compound by the procedure of Example 14 using 0.28 mL (3.84 mmol) of ethanethiol and 610 mg (4.61 mmol) of aluminum chloride.
Yield: 82%. 1 H NMR(d 6 -DMSO): d 9.75 (br s, 2H), 7.68 (d, 2H, J=9.0 Hz), 7.15-7.35 (complex, 4H), 6.82-6.92 (complex, 3H), 6.70 (d, J=9.1 Hz, 2H) 4.98 (d, J=3.1 Hz, 1H), 3.78 (m, 1H), 3.40 (m, 2H).
Example 17
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Cyclohexanoyloxyethoxy)phenyl]methanone
To [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-hydroxyethoxy)phenyl]methanone (0.77 g, 1.8 mmol) stirring in tetrahydrofuran (200 mL) was added triethylamine (0.36 g, 3.6 mmol) followed by cyclohexane carbonyl chloride (0.26 g, 1.8 mmol). After 18 hours, the mixture was filtered and concentrated. The resulting material was taken up in ethyl acetate, washed with 1N hydrochloric acid, dried (sodium sulfate), filtered, and concentrated to give 1.25 g of the title compound as a thick oil.
Example 18
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(Cyclohexanoyloxyethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(cyclohexanoyloxyethoxy)phenyl]methanone (1.25 g, 2.3 mmol) was converted to the title compound by the procedure of Example 3 using 400 mg (7.0 mmol) of ethanethiol and 920 mg (7.00 mmol) of aluminum chloride (0.92 g, 7.00 mmol).
Yield: 48%. 1 H NMR(d 6 -DMSO): d 9.75 (app d, 2H), 7.63 (d, 2H, J=8.5 Hz), 7.23 (s, 1H), 7.20-7.23 (m, 1H), 7.13-7.16 (m, 2H), 6.89-6.92 (m, 2H), 6.81-6.83 (m, 1H), 6.64-6.66 (m, 2H), 4.27-4.29 (s, 2H), 4.18-4.20 (s, 2H), 1.62-1.80 (m, 2H), 1.40-1.62 (m, 3H), 1.01-1.39 (m, 6H).
Example 19
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Benzoyloxyethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-hydroxyethoxy)phenyl]methanone (0.76 g, 1.8 mmol) and benzoyl chloride (0.25 g, 1.8 mmol) were converted to 1.14 g of the title compound by the procedure of Example 17 using 360 mg (3.6 mmol) of triethylamine.
Example 20
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[fb]thiophen-3-yl][4-(Benzoyloxyethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(benzoyloxyethoxy)phenyl]methanone (1.14 g, 2.10 mmol) was converted to the title compound by the procedure of Example 3 using 400 mg (7.0 mmol) of ethanethiol and 920 mg (7.0 mmol) of aluminum chloride.
Yield: 20%. 1 H NMR(d 6 -DMSO): d 9.71-9.76 (d, 2H), 7.90-7.92 (m, 2H), 7.64-7.66 (m, 2H), 7.45-7.47 (m, 2H), 7.31 (s, 1H), 7.14-7.23 (m, 4H), 6.95-6.98 (d, 2H), 6.64-6.67 (d, 2H), 4.56-4.57 (d, 2H), 4.34-4.35 (m, 2H).
Example 21
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Acetoxymethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-hydroxyethoxy)phenyl]methanone (1.07 g, 2.5 mmol) and acetyl chloride (200 mg, 2.5 mmol) were converted to 1.7 g of the title product by the procedure of Example 17 using 500 mg (5.00 mmol) of triethylamine except that the total reaction time was 72 hours.
Example 22
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(Acetoxymethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(Acetoxymethoxy)phenyl]methanone (1.7 g, 2.5 mmol) was converted to the title compound by the procedure of Example 3 using 500 mg (7.5 mmol) of ethanethiol and 1.0 g (7.5 mmol) of aluminum chloride except that the total reaction time was 4 hours.
Yield: 29%. 1 H NMR(d 6 -DMSO): d 9.71-9.75 (app d, 2H), 7.63 (d, 2H), 7.32 (s, 1H), 7.23 (d, 1H), 7.15 (d, 2H), 6.90 (d, 2H), 6.83 (d, 1H), 6.64 (d, 2H), 4.28-4.29 (m, 2H), 4.18-4.19 (m, 2H), 1.98 (s, 3H).
Example 23
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Trimethylacetoxymethoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][(4-hydroxyethoxy)phenyl]methanone (1.22 g, 2.8 mmol) and trimethyl acetyl chloride (0.34 g, 2.8 mmol) were converted to the title compound by the procedure of Example 21 using 600 mg (5.6 mmol) of triethylamine (0.60 g, 5.6 mmol).
Example 24
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(Trimethylacetoxymethoxy)phenyl]methanone
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(Trimethylacetoxymethoxy)phenyl]methanone (760 mg, 1.5 mmol) was converted to the title compound by the procedure of Example 3 using 300 mg (4.5 mmol) of ethanethiol and 600 mg (4.5 mmol) of aluminum chloride.
Yield: 69%. 1 H NMR(d 6 -DMSO): d 9.69 (d, 2H), 7.63 (d, 2H), 7.31 (d, 1H), 7.22 (d, 1H), 7.17 (d, 2H), 6.91 (d, 2H), 6.80 (d, 1H), 6.65 (d, 2H), 4.22-4.28 (m, 2H), 4.20 (m, 2H), 1.04-1.06 (m, 9H).
Example 25
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][O -Epihydrin)-4-Hydroxyphenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl](4-hydroxyphenyl)methanone (10 g, 25.6 mmol) and epibromohydrin (3.3 mL, 38.0 mmol) were converted to 2.0 g of the title compound by the procedure of Example 6 except that the reaction was performed for 16 hours at room temperature and the work up was as follows: the reaction mixture was filtered and the filtrate was concentrated. The residue was taken up in ethyl acetate and washed with saturated sodium bicarbonate. The organic portion was dried over sodium sulfate and concentrated to give a yellow solid which was recrystallized from ethyl acetate.
Example 26
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Butylaminopropoxy)phenyl]methanone
To a suspension of [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][O-epihydrin)-4-hydroxyphenyl]methanone (2.0 g, 4.5 mmol) in ethanol (50 mL) was added butylamine (0.98 g, 13.0 mmol) and the reaction mixture was heated to reflux. After 3 hours, the mixture was cooled to room temperature and concentrated. Purification by radial chromatography (silica gel, 4 mm, 50% ethyl acetate in hexanes) provided 1.56 g of the title compound as a yellow oil.
Yield: 67%. 1 H NMR(CDCl 3 ): d 7.76 (d, 2H, J=8.4 Hz), 7.52 (d, 1H, J=9.0 Hz), 7.33 (m, 3H), 6.95 (m, 1H), 6.75 (m, 4H), 3.94 (m, 3H), 3.87 (s, 3H), 3.74 (s, 3H), 2.70 (br m, 6H), 1.39 (br m, 4H), 0.90 (t, 3H, J=7.1 Hz).
Example 27
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Pyrrolidinylpropoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl[O -epihydrin)-4-hydroxyphenyl]methanone (0.5 g, 1.1 mmol) and pyrrolidine (0.5 mL, 5.0 mmol) were converted to the title compound by the procedure of Example 26 except that 6:4 ethyl acetate/methanol was used as chromatography eluent.
Example 28
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Pyrrolidinylpropoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-pyrrolidinylpropoxy)phenyl]methanone (250 mg, 0.50 mmol) was converted to 164 mg of the title compound by the procedure of Example 32 using 0.18 mL (2.48 mmol) of ethanethiol (0.18 mL, 2.48 mol) and 398 mg (2.98 mmol) of aluminum chloride except that 6:4 ethyl acetate/methanol gradient was used as the chromatography eluent.
1 H NMR(d 6 -DMSO): d 7.62 (d, 2H, J=9.0 Hz), 7.10-7.50 (complex, 4H), 6.80-6.90 (complex, 3H), 6.67 (d, 2H, J=9.0 Hz), 4.12 (m, 1H), 4.00 (m, 1H), 3.81-3.91 (complex, 2H), 2.35-2.60 (complex, 4H), 1.58-1.61 (complex, 4H).
Example 29
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Piperidinylpropoxy)phenyl]methanone
To a solution of [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][O-epihydrin)-4hydroxyphenyl]methanone (0.5 g, 1.1 mmol) stirring in ethanol at room temperature was added potassium carbonate (300 mg, 2.0 mmol) followed by piperidine hydrochloride (200 mg, 1.5 mmol). The mixture was heated to reflux and maintained at that temperature for 1 hour then cooled to ambient temperature. The solution was concentrated and the resulting mixture dissolved in ethyl acetate and extracted with water. The organic extract was dried over magnesium sulfate to give a brown oil which was purified by radial chromatography (silica gel, 2 mm, 8:2 ethyl acetate/methanol (v/v) to give 210 mg of the title compound as an off-white foam.
Example 30
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Piperidinyl)propoxy]phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-piperidinylpropoxy)phenyl]methanone (210 mg, 0.41 mmol) was converted to 151 mg of the title compound by the procedure of Example 32 using 0.15 mL (2.03 mmol) of ethanethiol and 326 mg (2.44 mmol) of aluminum chloride.
1 H NMR(d 6 -DMSO): d 7.64 (d, 2H, J=8.8 Hz), 7.34 (d, 1H, J=2.5 Hz 4H), 7.16 (d, 1H, J=9.0 Hz), 6.93 (d, 2H, J=8.7 Hz), 6.84 (dd, J=9.0 Hz, 2.4 Hz), 6.63 (d, 2H, J=8.7 Hz), 3.90-4.10 (complex, 2H), 2.23-2.60 (complex, 6H), 1.45-1.56 (complex, 4H), 1.35-1.45 (complex, 2H).
Example 31
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Isopropylamino]propoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][O -epihydrin)-4-hydroxyphenyl]methanone (0.50 g, 1.1 mmol) and isopropylamine (0.48g, 5.6 mmol) were converted to the title compound by the procedure of Example 26.
Example 32
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Isopropylamino]propoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-isopropylamino]propoxy)phenyl]methanone (0.42 g, 0.8 mmol) was converted to 200 mg of the title compound by the procedure of Example 7 using 0.30 mL (4.2 mmol) of ethanethiol and 850 mg (6.4 mmol) of aluminum chloride except that the workup was performed as follows: the reaction was quenched by slow addition of saturated sodium bicarbonate. To the resulting solution was added sufficient methanol to dissolve all remaining yellow residue. This mixture was extracted with ethyl acetate, the combined organic extracts were dried over sodium sulfate, filtered, and concentrated. Purification by radial chromatography (silica gel, 2 mm, 6:2:1.5:0.5 ethyl acetate: hexanes: methanol: triethylamine) provided the desired compound as a yellow solid.
Yield: 52%. 1 H NMR (CDCl 3 ) d 7.62 (d, 2H, J=8.7 Hz), 7.30 (s, 1H), 7.26 (m, 1H), 7.15 (m, 4H), 6.84 (m, 4H), 6.64 (dd, 2H, J=6.9 Hz, 1.8 Hz), 3.88 (m, 3H), 2.64 (m, 3H), 0.95 (d, 6H, J=6.3 Hz).
Example 33
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(3-[2-Hydroxy-(3a, 5b)-3,5-Dimethylpiperidinyl]propoxy)phenyl]methanone, and [6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-[(3a, 5a)-3,5-Dimethylpiperidinyl]propoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzoz[b]thiophen-3-yl][O -epihydrin)-4-hydroxyphenyl]methanone (2.0 g, 4.5 mmol) and 3,5-dimethylpiperidine (2.97, 22.0 mmol) were converted to 670 mg of the trans title product and 1.67 g of the cis title product by the procedure of Example 26.
(93% total yield).
Example 34
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-[(3a, 5b)-3,5-Dimethylpiperidinyl]propoxy)phenyl]methanone, and [6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-[(3a, 5a)-3,5-Dimethylpiperidinyl]propoxy)phenyl]methanone
A mixture of [6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[(3a, 5b)-3,5-dimethylpiperidinyl]propoxy)phenyl]methanone 670 mg) and [6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[(3a, 5a)-3,5-dimethylpiperidinyl]propoxy)phenyl]methanone (1.67 g) were converted to the title compounds by the procedure of Example 3 to give 500 mg of the trans product and 1.22 g of the cis product.
Yield (trans): 78%. Yield (cis): 78%. 1 H NMR (CDCl 3 ) trans d 7.61 (d, 2H, J=8.7 Hz), 7.29 (d, 1H, J=2.1 Hz), 7.16 (dd, 3H, J=21 Hz, 8.9 Hz), 6.83 (m, 3H), 6.63 (d, 2H, J=8.4 Hz), 4.79 (br m, 1H), 4.00 (m, 1H), 3.84 (t, 1H, J=6.2 Hz), 3.28 (s, 2H), 3.12 (s, 1H), 2.34(m, 4H), 1.99 (m, 1H), 1.73 (m, 1H), 1.15 (t, 1H, J=5.4 Hz), 0.88 (m, 6H).
1 H NMR (CDCl 3 ) cis d 7.61 (d, 2H, J=8.7 Hz), 7.29 (d, 1H, J=2.1 Hz), 7.16 (dd, 3H, J=21 Hz, 8.9 Hz), 6.83 (m, 3H), 6.63 (d, 2H, J=8.4 Hz), 4.78 (br m, 1H), 3.84 (m, 4H), 3.29 (s, 2H), 3.12 (d, 2H, J=2.6 Hz), 2.72 (m, 2H), 2.45 (m, 2H), 2.31 (m, 2H), 1.462 (m, 4H), 0.94 (m, 6H).
Example 35
[ 6 -Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-[3-Methylpiperidinyl]propoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][O -epihydrin)-4-hydroxyphenyl]methanone (500 mg, 1.1 mmol) and 3-methylpiperidine (0.65 mL, 5.6 mmol) were converted to 340 mg of the title compound by the procedure of Example 26.
Example 36
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-[3-Methylpiperidinyl]propoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-hydroxy-3-[3-methylpiperidinyl]propoxy)phenyl]methanone (540 mg, 1.0 mmol) was converted to 340 mg of the title compound by the procedure of Example 32 using 360 mg (4.9 mmol) of ethanethiol and aluminum chloride.
Yield: 66%. 1 H NMR (CDCl 3 ) d 7.13 (d, 2H, J=8.4 Hz), 6.84 (m, 3H), 6.63 (dd, 2H, J=8.4 Hz), 3.91 (m, 3H), 2.69 (m, 2H), 2.31 (m, 2H), 1.901 (m, 2H), 1.52 (m, 5H), 0.75 (d, 6H, J=5.4 Hz).
Example 37
[6-Methoxy-2-(4-Methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-Methoxy-3-Hexylaminopropoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][O -epihydrin)-4-hydroxyphenyl]methanone (500 mg, 1.1 mmol) and n-hexylamine (0.74 mL, 5.6 mmol) were converted to 540 mg of the title compound by the procedure of Example 26.
Yield: 90%.
Example 38
[6-Hydroxy-2-(4-Hydroxyphenyl)benzo[b]thiophen-3-yl][4-(2-Hydroxy-3-Pentylaminopropoxy)phenyl]methanone
[6-Methoxy-2-(4-methoxyphenyl)benzo[b]thiophen-3-yl][4-(2-methoxy-3-hexylaminopropoxy)phenyl]methanone (340 mg, 0.62 mmol) was converted to 200 mg of the title compound by the procedure of Example 32 using 0.23 mL (3.1 mmol) of ethanethiol 660 mg (5.0 mmol) of aluminum chloride.
Yield: 62%. 1 H NMR(d 6 -DMSO): d 7.61 (d, 2H, J=8.7 Hz), 7.30 (d, 1H, J=2.1 Hz), 7.20 (d, 1H, J=8.7 Hz), 7.13 (d, 2H, J=8.7 Hz), 6.84 (m, 3H), 6.63 (d, 1H, J=8.7 Hz), 3.89 (m, 3H), 2.50 (m, 2H), 1.19 (m, 8H), 0.80 (t, 3H, J=6.5 Hz).
Experimental Assays
Representative compounds of the present invention have been biologically tested to demonstrate their efficacy for treating the effects of post menopausal syndrome. In the examples illustrating the methods, a post menopausal model was used in which effects of different treatments upon circulating lipids were determined.
General Preparation Procedure
Seventy-five day old female Sprague Dawley rats (weight range of 200 g-225 g) were obtained from Charles River Laboratories (Portage, Mich.). The animals were either bilaterally ovariectomized (OVX) or exposed to a Sham surgical procedure at Charles River Laboratories, and then shipped after one week. Upon arrival, these rats were housed in metal hanging cases in groups of three or four animals per cage, and had ad libitum access to food (calcium content approximately 0.5%) and water for one week. Room temperature was maintained at 22.2° C.±1.7° C. with a minimum relative humidity of 40%. The photoperiod in the room was twelve hours light and twelve hours dark.
Dosing Regimen Tissue Collection
After a one-week acclimation period (two weeks post-OVX), daily dosing with test compound was initiated. The test compounds or 17a-ethynylestradiol (Sigma Chemical Co., St. Louis, Mo.) were given orally, unless otherwise stated, as a suspension in 1% carboxymethylcellulose or dissolved in 20% cyclodextrin. Animals were dosed daily for four days. Following the dosing regimen, animals were weighed and anesthetized with a ketamine:xylazine (2:1, v:v) mixture and a blood sample was collected by cardiac puncture. The animals were then sacrificed by asphyxiation with CO 2 , the uterus was removed through a midline incision, and a wet uterine weight was determined.
Serum Cholesterol Analysis
Blood samples were allowed to clot at room temperature for two hours, and serum was obtained following 10 centrifugation for ten minutes at 3000 rpm. Serum cholesterol was determined using a high-performance cholesterol assay (Boehringer Mannheim Diagnostics, Indianapolis, Ind.). Briefly, the cholesterol was oxidized to produce cholest-4-en-3-one and hydrogen peroxide. The hydrogen peroxide was then reacted with phenol and 4-aminophenazone in the presence of peroxidase to produce a p-quinoneimine dye, which was read spectrophotometrically at 500 nm. Cholesterol concentration was then calculated against a standard curve.
Uterine Eosinophil Peroxidase (EPO) Assay
Uteri were kept at 4° C. until time of enzymatic analysis. The uteri were then homogenized in 50 volumes of 50 nM Tris buffer (pH=8.0) containing 0.005% Triton X-100. Upon addition of 0.01% hydrogen peroxide and 10 nM o-phenylenediamine (final concentrations) in Tris buffer, the increase in absorbance was monitored for one minute at 450 nm. The presence of eosonophils in the uterus was taken as an indication of estrogenic activity of a compound. The maximal velocity of a fifteen second interval was determined over the initial, linear portion of the reaction curve.
Representative compounds of the present invention were tested in a four day ovariectomized rat model to study their estrogenicity. In particular, the effect on the uterus and the cholesterol lowering characteristics were studied. Comparative data were obtained between untreated ovariectomized rats, ovariectomized rats treated with 17a -ethynylestradiol (EE 2 ), and ovariectomized rats treated with certain compounds of the present invention. Although EE 2 caused a decrease in serum cholesterol when orally administered at 0.1 mg/kg/day, it also exerted a stimulatory action on the uterus so that EE 2 uterine weight was substantially greater than the uterine weight of untreated ovariectomized test animals. This uterine response to estrogen is well recognized in the art. Representative compounds of the present invention reduced serum cholesterol compared to the ovariectomized control animals. Also, relative to EE 2 , representative compounds of the present invention have a diminished effect on uterine weight.
Compared to estrogenic compounds known in the art, the benefit of serum cholesterol reduction without as adverse of an affect on uterine weight is rare and desirable.
As is expressed in the in vivo data, estrogenicity also was assessed by evaluating the adverse response of eosinophil infiltration into the uterus. Relative to EE 2 , which caused a substantial, expected increase in eosinophil infiltration, the representative compounds of the present invention did not increase the eosinophil infiltration, and in most cases had a significantly diminished effect.
In addition to the demonstrated benefits of these representative compounds of the present invention, especially when compared to estradiol, the compounds tested were not estrogen mimetic.
MCF-7 Proliferation Assay
The affinity of a representative sample of the compounds of the present invention for the estrogen receptors was tested in a MCF-7 receptor proliferation assay. MCF-7 breast adenocarcinoma cells (ATCC HTB 22) were maintained in MEM (minimal essential medium, phenol red-free, Sigma Chemical Co., St. Louis, Mo.) supplemented with 10% fetal bovine serum (FBS) (v/v), L-glutamine (2 mM), sodium pyruvate (1 mM), HEPES [N-(2-hydroxyethyl) piperazine-N′-2-ethanesulfonic acid 10 mM], non-essential amino acids and bovine insulin (1 mg/mL) (maintenance medium). Ten days prior to assay, MCF-7 cells were switched to maintenance medium supplemented with 10% dextran-coated charcoal stripped fetal bovine serum (DCC-FBS) assay medium) in place of 10% FBS to deplete internal stores of steroids. MCF-7 cells were removed from maintenance flasks using cell dissociation medium (Ca +2 /Mg +2 free HBSS (phenol red-free) supplemented with 10 mM HEPES and 2 mM EDTA). Cells were washed twice with assay medium and adjusted to 80,000 cells/mL. Approximately 100 mL (8,000 cells) were added to flat-bottom microculture wells (Costar 3596) and incubated at 37° C. in a 5% CO 2 humidified incubator for 48 hours to allow for cell adherence and equilibration after transfer. Serial dilutions of drugs or DMSO as a diluent control were prepared in assay medium and 50 mL transferred to triplicate microcultures followed by 50 mL assay medium for a final volume of 200 mL. After an additional 48 hours at 37° C. in a 5% CO 2 humidified incubator, microcultures were pulsed with tritiated thymidine (1 mCi/well) for four hours. Cultures were terminated by freezing at −70° C. for 4 hours followed by thawing and harvesting of microcultures using a Skatron Semiautomatic Cell Harvester. Samples were counted by liquid scintillation using a Wallac BetaPlace b-counter. Relative to 17b-estradiol's known effects on the proliferation of MCF-7, the representative compounds of the present invention demonstrated significantly less stimulatory activity. In most cases, no effect was observed at the highest concentrations tested, and in some cases an inhibitory effect was observed.
Administration and Formulation
For the majority of the methods of the present invention, compounds of formula I are administered continuously, from 1 to 3 times daily. However, cyclical therapy may especially be useful in the treatment of endometriosis or may be used acutely during painful attacks of the disease. In the case of restenosis, therapy may be limited to short (one to six months) intervals following medical procedures such as angioplasty.
The specific dose of a compound administered according to this invention will, of course, be determined by the particular circumstances surrounding the case including, for example, the compound administered, the route of administration, the state of being of the patient, and the pathological condition being treated. A typical daily dose will contain a nontoxic dosage level of from about 5 mg to about 600 mg/day of a compound of the present invention. Preferred daily doses generally will be from about 15 mg to about 100 mg/day.
The compounds of this invention can be administered by a variety of routes including oral, rectal, transdermal, subcutaneous, intravenous, intramuscular, and intranasal, the selection of which will be decided by the attending physician. These compounds preferably are formulated prior to administration. Thus, another aspect of the present invention is a pharmaceutical composition comprising an effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof, optionally containing an effective amount of estrogen or progestin, and a pharmaceutically acceptable carrier, diluent, or excipient. The total active ingredients in such formulations comprises from 0.1% to 99.9% by weight of the formulation.
Pharmaceutical formulations of the present invention can be prepared by procedures known in the art using well known and readily available ingredients. For example, the compounds of formula I, with or without an estrogen or progestin compound, can be formulated with common excipients, diluents, or carriers, and formed into tablets, capsules, suspensions, powders, and the like. Examples of excipients, diluents, and carriers that are suitable for such formulations include the following: fillers and extenders such as starch, sugars, mannitol, and silicic derivatives; binding agents such as carboxymethyl cellulose and other cellulose derivatives, alginates, gelatin, and polyvinyl-pyrrolidone; moisturizing agents such as glycerol; disintegrating agents such as calcium carbonate and sodium bicarbonate; agents for retarding dissolution such as paraffin; resorption accelerators such as quaternary ammonium compounds; surface active agents such as cetyl alcohol, glycerol monostearate; adsorptive carriers such as kaolin and bentonite; and lubricants such as talc, calcium and magnesium stearate, and solid polyethyline glycols.
The compounds also can be formulated as elixirs or solutions for convenient oral administration or as solutions appropriate for parenteral administration, for example, by intramuscular, subcutaneous, or intravenous routes. Additionally, the compounds are well suited for formulation as sustained-release dosage forms and the like. The formulations can be so constituted that they release the active ingredient only or preferably in a particular physiological location, possibly over a period of time. The coatings, envelopes, and protective matrices may be made, for example, from polymeric substances or waxes.
The following formulation examples are illustrative only and are not intended to limit the scope of the present invention.
FORMULATIONS
In the formulations which follow, “active ingredient” means a compound of formula I, or a salt thereof.
Hard gelatin capsules are prepared using the following:
Formulation 1
Gelatin Capsules
Ingredient
Quantity (mg/capsule)
Active ingredient
0.1-1000
Starch, NF
0-650
Starch flowable powder
0-650
Silicone fluid 350 centistokes
0-15
The formulation above may be changed in compliance with the reasonable variations provided.
A tablet formulation is prepared using the ingredients below:
Formulation 2
Tablets
Ingredient
Quantity (mg/tablet)
Active ingredient
2.5-1000
Cellulose, microcrystalline
200-650
Silicon dioxide, fumed
10-650
Stearate acid
5-15
The components are blended and compressed to form tablets.
Alternatively, tablets each containing 2.5 mg-1000 mg of active ingredient are made up as follows:
Formulation 3
Tablets
Ingredient
Quantity (mg/tablet)
Active ingredient
25-1000
Starch
45
Cellulose, microcrystalline
35
Polyvinylpyrrolidone
4
(as 10% solution in water)
Sodium carboxymethyl cellulose
4.5
Magnesium stearate
0.5
Talc
1
The active ingredient, starch, and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders which are then passed through a No. 14 mesh U.S. sieve. The granules so produced are dried at 50° C.-60° C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 60 U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets.
Suspensions each containing 0.1 mg-1000 mg of medicament per 5 ml dose are made as follows:
Formulation 4
Suspensions
Ingredient
Quantity (mg/5 ml)
Active ingredient
0.1-1000
mg
Sodium carboxymethyl cellulose
50
mg
Syrup
1.25
mg
Benzoic acid solution
0.10
mL
Flavor
q.v.
Color
q.v.
Purified water to
5
mL
The medicament is passed through a No. 45 mesh U.S. sieve and mixed with the sodium carboxymethyl cellulose and syrup to form a smooth paste. The benzoic acid solution, flavor, and color are diluted with some of the water and added, with stirring. Sufficient water is then added to produce the required volume.
An aerosol solution is prepared containing the following ingredients:
Formulation 5
Aerosol
Quantity (% by
Ingredient
weight)
Active ingredient
0.25
Ethanol
25.75
Propellant 22 (Chlorodifluoromethane)
70.00
The active ingredient is mixed with ethanol and the mixture added to a portion of the propellant 22, cooled to 30° C., and transferred to a filling device. The required amount is then fed to a stainless steel container and diluted with the remaining propellant. The valve units are then fitted to the container.
Suppositories are prepared as follows:
Formulation 6
Suppositories
Ingredient
Quantity (mg/suppository)
Active ingredient
250
Saturated fatty acid
2,000
glycerides
The active ingredient is passed through a No. 60 mesh U.S. sieve and suspended in the saturated fatty acid glycerides previously melted using the minimal necessary heat. The mixture is then poured into a suppository mold of nominal 2 g capacity and allowed to cool.
An intravenous formulation is prepared as follows:
Formulation 7
Intravenous Solution
Ingredient
Quantity
Active ingredient
50
mg
Isotonic saline
1,000
mL
The solution of the above ingredients is intravenously administered to a patient at a rate of about 1 mL per minute.
Formulation 8
Combination Capsule I
Ingredient
Quantity (mg/capsule)
Active ingredient
50
Premarin
1
Avicel pH 101
50
Starch 1500
117.50
Silicon Oil
2
Tween 80
0.5
Cab-O-Sil
0.25
Formulation 9
Combination Capsule II
Ingredient
Quantity (mg/capsule)
Active ingredient
50
Norethynodrel
5
Avicel pH 101
82.50
Starch 1500
90
Silicon Oil
2
Tween 80
0.50
Formulation 10
Combination Tablet
Ingredient
Quantity (mg/capsule)
Active ingredient
50
Premarin
1
Corn Starch NF
50
Povidone, K29-32
6
Avicel pH 101
41.50
Avicel pH 102
136.50
Crospovidone XL10
2.50
Magnesium Stearate
0.50
Cab-O-Sil
0.50
The preferred embodiment of the present invention is now fully described. Nothing in this description is intended to limit the scope or spirit of this invention.
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This invention provides novel benzothiophene compounds of the formula I:
which are useful for the treatment of the various medical conditions associated with postmenopausal syndrome, as well as estrogen dependent diseases including cancer of the breast, uterus, and cervix. The present invention further relates to pharmaceutical formulations of compounds of formula I.
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FIELD OF THE INVENTION
The present invention relates to polyolefin-based sealing element compositions particularly suitable for forming sealing elements, for example gaskets and cap liners, that surprisingly also provide desirable oxygen barrier properties and are especially useful for sealing containers having products such as liquids or food-stuffs therein. The compositions when formed as sealing elements do not appreciably contribute taste and/or odor to a packaged product including the sealing element. The compositions have desirable rheological properties and are thus readily processable at various temperatures.
BACKGROUND OF THE INVENTION
Many different polymer-based compositions have been utilized to form sealing elements for applications such as foodstuff applications both liquid and dry commodities, medical products and nutritional products. Examples of such polymers are polyolefins, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, elastomers and, various rubbers such as EPDM, polyesters, polycarbonate. Techniques used to manufacture sealing elements are set forth, for examples, in U.S. Pat. Nos. 3,183,144; 3,300,072; 3,414,938; 3,493,453; 3,779,965; 3,786,954; 4,085,186; 4,619,848; 4,717,034; 4,939,859; 4,981,231; 4,984,703; 5,000,992; 5,104,710; 5,137,164; and 5,215,587 all herein incorporated by reference.
In one embodiment, sealing elements in the form of a single layer or liner are made by extruding a polymer composition, cutting and placing a quantity of the extrudate at a desired location, such as in the center of a cap, followed by compression molding the extrudate into a gasket or liner. In other embodiments, injection molding can be utilized to form a sealing element in the form of a seal ring, for example, in a cap.
Properties required of the sealing elements can vary depending upon individual applications. For example, sealing elements subject to retort conditions, such as relatively high temperatures and pressures, are generally required to withstand the retort process without failing, maintain a suitable oxygen barrier for a desired lifespan of the product and also be easily removable from the container when desired by a consumer or other user. Regardless of whether or not retort conditions are encountered, the sealing element should provide for adequate sealing at a wide range of temperatures, especially high temperatures. Various sealing elements should also provide desirable sealing properties during stacking and a reasonable oxygen barrier property when required to preserve freshness of a packaged item, such as a foodstuff. Some sealing elements must be resistant to acids or bases. Sealing elements whether designed for a single use or a multiple use item should retain their integrity and not shred or tear in order to prevent contamination of the packaged products. Further, seal elements should have good compression set to impart sealing capability and not lose seal integrity. Numerous attempts to provide sealing elements had been disclosed.
U.S. Pat. No. 7,960,007 and U.S. Patent Publication No. 20110204016 relate to retort liners and containers including a container body such as a bottle or jar, a closure, and the retort liner, wherein the retort liners exhibit attractive properties such as low compression set under retort conditions, desirable adhesion to a polymeric closure such as a cap or lid, and beneficial oxygen barrier properties. In particular, the retort liners are thermoplastic elastomers formed from compositions including one or more styrenic block copolymers, one or more polyolefins and a softener. In a preferred embodiment, the retortable containers are all plastic packages, wherein the bottle or jar and the closure are thermoplastic compositions and the liner is a thermoplastic elastomer composition.
U.S. Pat. No. 4,807,772 relates to a polypropylene compression molded closure with an elastomer liner that is removable, the elastomer being a blend of polyethylene and a rubbery copolymer, containing oil.
U.S. Pat. No. 4,872,573 relates to a moldable plastic closure comprising a selectively foamed, unitarily molded layer and at least one layer of barrier resin adapted to retard the migration of oxygen-containing gasses through the closure.
U.S. Pat. No. 5,000,992 relates to a plastic container closure, such as a bottle cap liner or tamper evident seal, formed from a coextruded multilayer foamed film. The coextruded multilayer foamed film has at least one solid film layer of a first polyolefin blend containing linear low density polyethylene, low density polyethylene, and, optionally high density polyethylene, and at least one foamed layer of a second polyolefin blend containing linear low density polyethylene, low density polyethylene, and optionally ethylene vinyl acetate. The multilayer foamed film may be coextruded using a blown film or cast film extrusion process under defined conditions. The coextruded multilayer foamed film may be laminated to other materials such as polyester film, thermoplastic adhesive films or metallic films and used as a plastic container closure, or may be applied as a liner to a plastic bottle cap.
U.S. Pat. No. 3,786,954 relates to a cap liner disclosed for use with a closure cap in sealing a container. The liner is cut from a foamed polyethylene sheet material. It reportedly provides a seal for products such as fine powdered products where leakage has been experienced with prior liners. The foamed liner material reportedly has dynamic cushioning properties so that a tight seal is maintained at all times including handling and shipping operations of the sealed package. One embodiment of the closure is a laminate of the foamed sheet material and a thin air impervious film.
U.S. Pat. No. 5,104,710 relates to a gasket of thermoplastic material moulded in a polypropylene cap, wherein the adhesion of the gasket to the cap at temperatures below 200° C. is reportedly improved by including an adhesion-promoting polymer of propylene in the thermoplastic composition.
U.S. Pat. No. 4,529,740 relates to hot melt compositions disclosed from which foamed products having a fine and uniform void structure therein can be obtained. The compositions include a thermoplastic polymer preferably an elastomer such as a styrene-butadiene block copolymer, and a small amount of a salt of a sulfonated styrene polymer. Plasticizing processing aids, tackifying agents and antioxidants can be included in the compositions, as well as in addition surfactants such as dodecylbenzene sulfonate. The composition can be mixed with gaseous blowing agents by suitable means and dispensed to produce foamed products reportedly suited for example as sealants in closures for containers.
U.S. Pat. No. 4,744,478 relates to a molded polymeric container closure comprising at least one substantially unfoamed polymer layer and an integrally molded foamed layer of the same polymer.
Numerous olefin block copolymers and olefin block copolymer containing compositions are described in U.S. patent and Publication Nos. U.S. Pat. Nos. 7,671,106; 7,608,668; 6,566,446; 6,545,088; 6,538,070; 6,448,341; 5,869,575; 5,844,045; 2010/0298515; 2010/0069574; and 2007/0219334. These disclosures set forth a plethora of various potential applications, end uses, and general components that can be combined therewith.
U.S. Pat. No. 7,671,106 relates to cap liners, closures and gaskets for multi-block polymers, i.e. olefin block copolymers. The polymer composition comprises at least an ethylene/alpha-olefin interpolymer and at least one other polymer. The other polymer can be selected from a second ethylene/alpha-olefin interpolymer, an elastomer, a polyolefin, a polar polymer, and an ethylene/carboxylic acid interpolymer or ionomer thereof. The ethylene/alpha-olefin interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comonomers than the hard block. The block interpolymer has a number of unique characteristics disclosed here. Also provided are gaskets, bottle cap liners, and closures that comprise or are obtained from a composition comprising at least one ethylene/alpha-olefin interpolymer and at least one polyolefin. The gaskets are reportedly capable of compression sealing various containers, without contaminating the contents. Liquid containers reportedly particularly benefit from the use of the novel gasket materials disclosed herein.
In view of the above, a problem still exists as economical sealing elements especially polyolefin-based sealing elements, are needed that are formed from compositions providing broad processing windows for depositing a sealing element bead, for example in a closure or cap, and further forming a sealing element, such as a liner, having desirable barrier properties, particularly when using a container and/or closure formed from a substantially homopolymer polyolefin. It is a difficult challenge to meet the processing requirements to make a sealing element, as well as the performance requirements needed when the sealing element is in a packaged state. Additionally, there is a need for sealing elements that are formed from polyolefin compositions that are readily processable under desired conditions that do not contribute to one or more of taste and odor of the packaged product, provide desirable compression set properties to ensure good sealing, provide good adhesion to a polymeric cap or closure, and provide oxygen barrier properties, which are especially useful in foodstuff applications.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention to provide polyolefin-based sealing element compositions that can be processed at a wide range of temperatures to form sealing elements.
An additional object of the present invention is to provide sealing elements and sealing element compositions that are polyolefin-based and comprise a greater amount of polyolefin(s), preferably substantially homopolymer polyolefins(s), compared to any other polymeric component present such as an elastomer and olefin block copolymer, yet provide desirable oxygen barrier properties.
Still another object of the present invention is to provide sealing element compositions and sealing elements that do not appreciably contribute to the taste and/or odor of the packaged product. A further object of the present invention is to provide sealing elements that can be used in both retort and non-retort applications, for example, hot fill.
An additional object of the present invention is to provide sealing element compositions and sealing elements formed therefrom utilizing a variety of different polyolefins having different properties, for example melt indices that contribute to the various desirable properties of the formed sealing elements.
Yet another object of the present invention is to provide sealing elements offering pleasing natural color characteristics, for example in the form of translucent-like sealing elements.
A further object of the present invention is to provide sealing elements that can be formed by one or more of compression molding and injection molding.
An additional object of the present invention is to provide a polyolefin-based sealing element composition and sealing elements therefrom that contain in one embodiment, considering all polymeric components, a greater amount of one or more polyolefins compared to any other polymeric components, and a greater amount of an olefin block copolymer in relation to a styrenic block copolymer.
Still another object of the present invention is to provide sealing elements and compositions having less than 50 parts, or less than 40 parts or less than 37 parts by weight of an olefin block copolymer based on 100 parts by weight of all polymeric components in the composition.
Another object of the present invention is to provide sealing elements and compositions having less than 40 parts by weight or less than 35 parts by weight of an olefin block copolymer based on 100 parts by weight of the total composition.
Another object of the present invention is to provide sealing elements and compositions having less than 50 parts, or less than 40 parts or less than 30 parts by weight of a styrenic block copolymer based on 100 parts by weight of all polymeric components in the composition.
Yet an additional object of the invention in one embodiment is to provide a sealing element composition including one or more polyolefins, a styrenic block copolymer, an olefin block copolymer and a friction reducing agent.
In one aspect of the present invention, a polymeric sealing element comprising or obtainable from a composition is disclosed, comprising a styrenic block copolymer; an olefin block copolymer; polyolefin polymers comprising a first polyolefin polymer having a melt index less than 10 grams per 10 min; a second polyolefin polymer having a melt index greater than 10 grams per 10 min, and a softener, wherein the olefin block copolymer and the styrenic block copolymer are each present in an amount of less than 50 parts by weight per 100 parts by weight of the total polymer of the polyolefin polymers, the olefin block copolymer and the styrenic block copolymer and wherein the polyolefin polymer is present in an amount by weight greater than each of the amounts of the styrenic block copolymer and olefin block copolymer, wherein melt index is determined according to ASTM D-1238.
In a further aspect of the present invention, a polymeric sealing element comprising or obtainable from a composition is disclosed, comprising a polyolefin polymer; an olefin block copolymer; a styrenic block copolymer; and a softener, wherein the olefin block copolymer and the sytrenic block copolymer are each present in an amount of less than 50 parts by weight per 100 parts by weight of the total polymer of the polyolefin polymer, the olefin block copolymer and the styrenic block copolymer, wherein the polyolefin polymer is present in an amount greater than each of the amount of the styrenic block copolymer and the olefin block copolymer, and wherein the olefin block copolymer is present in an amount less than 40 parts per 100 parts by weight of the composition.
In another aspect of the present invention, a sealing element is disclosed comprising a polymeric layer having a first side and a second side, the polymeric layer comprising a polyolefin polymer; an olefin block copolymer; a styrenic block copolymer; and a softener, wherein the olefin block copolymer and the sytrenic block copolymer are each present in an amount of less than 50 parts by weight per 100 total parts of the total polymer of polyolefin polymer, olefin block copolymer and styrenic block copolymer, wherein the polyolefin polymer is present in an amount greater than the amount of the styrenic block copolymer and the olefin block copolymer, and wherein the olefin block copolymer is present in an amount less than 40 parts per 100 parts by weight of the sealing element.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other features and advantages will become apparent by reading the detailed description of the invention, taken together with the drawings, wherein:
FIG. 1 is a cross-sectional side elevational view schematically illustrating one embodiment of a container sealed with a sealing element of the present invention that is located inside of a closure of the container; and
FIGS. 2A-2C are side perspective views illustrating embodiments of different sealing, elements of the present invention, wherein FIG. 2A illustrates a sealing element formed as a liner pad having a relatively thick rim portion, wherein FIG. 2B illustrates a sealing element formed as a sealing ring having an aperture or a hollow center, and wherein FIG. 2C is a sealing element formed as a liner pad having a substantially constant thickness.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the Figures, one embodiment of a container 10 with a sealing element 20 is shown in FIG. 1 and sealing elements 20 are shown in FIGS. 2A-2C . The container 10 has a body 40 that is adapted to be filled with a beverage, foodstuff, or another desired item, and sealed with a closure 30 , wherein a sealing element 20 is provided to seal an opening 44 in the container body 40 . Preferably, the sealing element 20 is situated between the closure 30 and the opening 44 in the container body 40 in one embodiment, when the closure 30 is connected to the body 40 .
The closure 30 of the container 10 is generally a cap or lid which, in a preferred embodiment, is adapted to have the liner adhered to a surface thereof, with or without the use of one or more adhesives. The closure 30 illustrated in FIG. 1 includes a generally annular or circular top portion 32 having an upper surface 34 and a lower surface 36 , with the sealing element 20 being in contact with at least a portion of the lower surface 36 . The closure 30 has a substantially cylindrical skirt 37 extending downwardly from the top portion and integrally formed therewith. The skirt includes an interior surface and an exterior surface, with the exterior surface being provided with ribs, protrusions or indentations in one embodiment which can aid in sealing the closure 30 to the container 10 . In one embodiment, a thread 38 is formed in the inner wall of the skirt that mates with a thread 46 formed on the outer wall of the neck portion of the container body 40 shown in FIG. 1 . Although threads are shown in the drawings and utilized in one preferred embodiment, those of ordinary skill in the art will recognize that other methods of securing the closure 30 and sealing element 20 contained therein to the container body 40 may also be utilized, such as a snap-on configuration. The thread 46 may have one of a variety of thread configurations, such as a single helix, double helix, triple helix, or other multiple helixes, as are known in the art.
In one embodiment of the present invention, a tamper evident band 39 may be formed on the lower portion of the skirt and may include ratchet teeth that engage mating ratchet teeth formed in the neck of the container.
The sealing element 20 in one embodiment has a lower surface 26 adapted to contact a portion of the container body 40 and an upper surface 24 that abuts the top interior lower surface 36 of the closure and is sized to fit firmly within the closure. In one embodiment such as shown in FIG. 2A , the diameter or peripheral edge 22 of the sealing element is large enough that the sealing element 20 can be held within the cap without the need for a bonding material. In other embodiments, the sealing element may be optionally adhered, if desired, such as on its upper surface 24 , to the closure by a variety of means such as known in the art, for example a thin layer of adhesive, glue or similar bonding material. The composition of the sealing element should be sufficient that the material be pliable or elastic and can be compressed between the closure and the container, but also sufficiently resilient so that the material can recover from a compressed state at ambient temperature and pressure conditions as well as under stress temperature in pressure conditions, such as are present during a retort process. The sealing element should have sufficient elasticity so it can conform to any distortions in the container body, such as at the container lip 48 , for example molding nubs or small divots or voids, or distortions in the closure.
In some embodiments, the sealing element is a liner pad formed in the shape of a planar seal ring, and generally formed with a thickened rim 28 which is shown in FIG. 2A . The central area of the sealing element has a thickness which is less than a thickness of rim 28 . In the embodiment illustrated in FIG. 2B , the sealing element is in the form of a seal ring having an aperture or a hollow central area which is bounded by an inner edge 29 of the sealing element 20 . The sealing element 20 illustrated in FIG. 2C is a liner pad in the form of a seal ring that has a substantially constant thickness between upper surface 24 and lower surface 26 . While the sealing elements illustrated in FIGS. 2A through 2C are illustrated as circular, it is important to understand that the form thereof is not limited thereto and the sealing elements can be formed in generally any imaginable shape and size as desired by the end user.
The container body 40 comprises a base (not shown) and outer side walls 50 extending upwardly from the base. The base and outer side walls define a void 60 in the body portion of the container for receiving one or more products such as described herein. In one embodiment, the outer side walls form shoulders 52 at an upper end which lead to a neck portion that terminates in an opening, defining lip 48 having a periphery. As shown in FIG. 1 , the neck has an exterior portion adapted to allow the container body to receive and engage the closure 30 . The configuration of the container body 40 illustrated in FIG. 1 is generally a bottle. It should be understood that containers useful in the prevent invention can be made in a variety of other configurations suitable for the particular application.
In some embodiments of the invention, it is desired that the sealing elements formed are able to withstand a heat treatment process such as sterilization or heat treatment utilizing a retort process or a hot fill process. For the sake of clarity, it is to be understood that the sealing elements can also be used in processes that are performed generally at room temperature or even below room temperature.
Various retort systems are known in the art, such as retort batch systems and retort continuous processes. Examples of further retort systems include continuous hydrostatic retort systems and continuous agitating retort systems. Both types of systems include a conveyor for carrying foodstuff packaged in containers, a container feeder for delivering packaged foodstuff to the conveyor, a retort chamber for treating the packaged foodstuff with elevated temperature and pressure, and a discharge system for discharging the retorted packaged foodstuff for further packaging and handling. The hydrostatic retort systems include water columns for maintaining elevated pressure in the retort chamber and agitating retort systems include agitators for agitating the foodstuff within its container as the packaged foodstuff travels through the retort system. Such continuous retort systems are often large and expensive and require a large capital investment for the packaged foodstuff manufacturer.
In a typical retort process, the filled container is transported through or placed in a high pressure overheated water bath, wherein the container is heated for a predetermined period of time, generally about 1 to about 50 minutes and preferably from about 1 to about 40 minutes at a temperature generally from about 121° C. (249° F.) to about 130° C. (266° F.) or more, and preferably from about 121° C. (249° F.) to 125° C. (257° F.). As the exterior surface of the container is heated, the packaged contents are heated and the internal pressure within the container increases. Concurrently, in one embodiment the container is submerged to greater depths in a water bath resulting in a counteracting external pressure increase. After the retorting process, the container is cooled, such as in a water bath. The rate of movement in the retort process and in subsequent cooling steps is designed to minimize variations in the internal pressure of the container. After a predetermined period of time, the container is removed from the retort system and allowed to cool to room temperature.
Hot fill processes are relatively inexpensive and utilized as a conventional filling technology that provides extended service life at room or ambient temperature to perishable beverage and liquid food products, such as soft drinks, fruit and vegetable juices, teas, and water containing additives. During a hot fill process, the liquid to be packaged is pasteurized in one embodiment. The container is filled with the product at an elevated or “hot” temperature, such as from about 90° C. to about 100° C. Afterwards, the container is sealed with the closure, with the sealing element located there between and the assembly is cooled, preferably rapidly, which can in some embodiments aid in maintaining product taste and vitamin integrity.
The liner or sealing element cooperatively functions with the container body and the closure to provide an added measure of protection for seal integrity as the container contents are sterilized or heat treated such as by the retort or hot fill process. More specifically, the sealing element functions cooperatively with the closure to provide a pressure against the container body, specifically the container lip. When the closure is attached to the container body at ambient temperature and pressure conditions, the closure may be tightened on the container such that the sealing element is compressed slightly between the container body and the top interior surface of the closure. A sealing area is formed where the sealing element is compressed or sandwiched between the closure and the container lip. When the sealed container is exposed to retort or hot fill conditions, the seal integrity is challenged by the pressure increases within the container.
The sealing element compositions of the present invention utilized to form a desired sealing element include one or more and preferably a plurality of polyolefins, one or more styrenic block copolymers and one or more olefin block copolymers as polymeric components of the compositions. An various embodiments, one or more other components are present in the compositions, for example softeners, friction modifying agents, and other additives.
Polyolefins
In one embodiment, the compositions of the present invention include one or more polyolefins, which as utilized herein are defined as one or more of a polyolefin polymer and a polyolefin copolymer unless otherwise indicated. The term “polyolefin” as used herein excludes olefin block copolymers, which are defined hereinbelow. Polyolefins suitable for use in the compositions of the present invention comprise amorphous or crystalline homopolymers or non-olefin block copolymers of two or more same or different monomers derived from alpha-monoolefins having from 2 to about 12 carbon atoms, and preferably from 2 to about 8 carbon atoms. Examples of suitable olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene, and combinations thereof. Polyolefins include, but are not limited to, low-density polyethylene, high-density polyethylene, linear-low-density polyethylene, polypropylene (isotactic and syndiotactic), ethylene/propylene copolymers, and polybutene. Polyolefin copolymers can also include the greater part by weight of one or more olefin monomers and a lesser amount of one or more non-olefin monomers such as vinyl monomers including vinyl acetate, or a diene monomer, etc. Generally, a polyolefin copolymer includes less than 40 weight percent of a non-olefin monomer, desirably less than 30 weight percent, and preferably less than about 10 weight percent of a non-olefin monomer.
In a further embodiment, the polyolefin may optionally include at least one functional group per chain or can be a blend of non-functionalized polyolefins and functionalized polyolefins Functional groups can be incorporated into the polyolefin by the inclusion of for example, one or more non-olefin monomers during polymerization of the polyolefin. Examples of functional groups include, but are not limited to, anhydride groups such as maleic anhydride, itaconic anhydride and citraconic anhydride; acrylates such as glycidyl methacrylate; acid groups such as fumaric acid, itaconic acid, citraconic acid and acrylic acid; epoxy functional groups; and amine functional groups. Functional group-containing polyolefins and methods for forming the same are well known to those of ordinary skill in the art. Functionalized polyolefins are available commercially from sources such as Uniroyal, Atofina, and DuPont. Epoxy modified polyethylenes are available from Atofina as LOTADER®. Acid modified polyethylenes are available from DuPont as FUSABOND®.
In one embodiment, a single polyolefin can be utilized in the sealing elements in compositions of the present invention, for example polypropylene. In other embodiments of the present invention, at least two or at least three different polyolefins are utilized in the sealing element compositions to impart desirable properties thereto. Various polyolefins can be utilized to improve properties such as tensile strength, compression set, and hardness. Preferred polyolefins have the ability to flow under pressure to aid in forming a sealing element in a molten state, but also allow the finished, formed sealing element to have sufficient mechanical strength. Polyolefins also aid in reducing viscosity of the compositions thereby improving the processability thereof. Moreover, when a polyolefin is utilized as a closure or cap, polyolefins also aid in improving adhesion of the sealing element to the closure or cap.
The polyolefins of the present invention can be characterized in one embodiment using melt indices. Therefore, in one embodiment the sealing element compositions include a polyolefin having a melt index greater than 10 grams of polymer per 10 minutes and desirably greater than 11 grams of polymer per 10 minutes and at least one polyolefin having a melt index less than 10 grams per 10 minutes and desirably less than 9 grams per 10 minutes. Melt flow index or melt index when utilized herein is measured according to ASTM D-1238.
For example, in one embodiment a polypropylene having a melt index greater than 10 grams per 10 minutes and desirably greater than 11 grams per 10 minutes is utilized in combination with at least one polyethylene having a melt index less than 10 grams and desirably less than 9 grams per 10 minutes. In a further embodiment, a second polyethylene having a melt index greater than 10 grams and desirably greater than 11 grams per 10 minutes is utilized in combination with the previously mentioned polypropylene and polyethylene.
As the relatively high melt index polyolefins are believed to provide at least the above indicated benefits to the sealing element compositions and sealing elements of the present invention, in various embodiments one or more polyolefins having a melt index greater than 10 grams or 11 grams of polymer per 10 minutes are present in an amount generally from about 60 to about 99 parts, desirably from about 75 to about 98 parts, and preferably from about 80 to about 97 parts based on 100 parts by weight of total polyolefins present. That said, the at least one polyolefin present having a melt index less than 10 grams or 9 grams per 10 minutes is present in an amount generally from about 1 to about 40, desirably from about 2 to about 25 parts and preferably from about 3 to about 20 parts by weight based on 100 parts by weight of total polyolefins present. When two or more different polyolefins are utilized having a melt index greater than 10 grams of polymer per 10 minutes, in various embodiments polypropylene is utilized as one of the relatively high melt index polymers and is present in an amount generally from about 40 to about 85 parts and preferably from about 50 to about 75 parts based on 100 parts by weight of the total polyolefins polymer present having a melt index greater than 10 or 11 grams per 10 minutes. When polyethylene is utilized as a second relatively high melt index polyolefin the amount thereof ranges generally from about 15 to about 60 and preferably from about 25 to about 50 parts based on 100 parts by weight of the total polyolefins polymer present having a melt index greater than 10 or 11 grams per 10 minutes.
Of the polyolefins, substantially homopolymer polyolefins are preferred and polypropylene and polyethylene are desirable. Polypropylene is utilized in a major amount based on the total weight of polyolefins present in at least one embodiment due to the ease of molding, a processability, resistance to chemicals, and desirable mechanical properties.
Polyolefin polymers and copolymers are commercially available from sources including, but not limited to, Chevron, Dow Chemical, DuPont, Exxon Mobil, Huntsman Polymers, Ticona and Westlake Polymer under various designations.
The total amount of polyolefin(s) utilized in the sealing elements and compositions of the present invention ranges generally from about 30 to about 60 parts, desirably from about 35 to about 55 parts, and preferably from about 35 to about 50 parts based on 100 parts by weight of total polyolefin, styrenic block copolymer and olefinic block copolymer. As indicated herein, in a preferred embodiment, regardless of the total amount of polyolefin(s) utilized in the sealing element compositions, the total polyolefin content, on a weight basis, is greater than the total weight of any other class of polymers utilized in the composition. For example, the total weight of polyolefin is greater than the total weight of any styrenic block copolymers utilized in the sealing element composition. Likewise, the polyolefin content by weight is greater than the total weight of any olefinic block copolymers present in the compositions.
Styrenic Block Copolymers
The sealing element compositions of the present invention include one or more styrenic block copolymers. In a preferred embodiment, the styrenic block copolymers have a hard block (A) including aromatic vinyl repeat units and at least one soft polymer block (B) containing two or more repeat units, that are the same or different, and independently derived from olefin monomers. The styrenic block copolymer can be, for example, a triblock copolymer (A-B-A); or a tetrablock or higher multiblock copolymer. In a preferred embodiment, the styrenic block copolymer is a triblock copolymer (A-B-A) having two hard blocks.
Each hard polymer block (A) can have two or more same or different aromatic vinyl repeat units. For example, the block copolymer may contain (A) blocks which are styrene/alpha-methylstyrene copolymer blocks or styrene/butadiene random or tapered copolymer blocks so long as a majority of the repeat units of each hard block are aromatic vinyl repeat units. The (A) blocks are aromatic vinyl compound homopolymer blocks in one embodiment. The term “aromatic vinyl” is to include those of the benzene series, such as styrene and its analogs and homologs including o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, alpha-methylstyrene and other ring alkylated styrenes, particularly ring-methylated styrenes, and other monoalkenyl polycyclic aromatic compounds such as vinyl naphthalene, vinyl anthracene and the like. The preferred aromatic vinyl compounds are monovinyl monocyclic aromatics, such as, styrene and alpha-methylstyrene, with styrene being most preferred. When three or more different repeat units are present in hard polymer block (A), the units can be combined in any form, such as random form, block form and tapered form.
Optionally, the hard polymer block (A) can comprise small amounts of structural units derived from other copolymerizable monomers in addition to the structural units derived from the aromatic vinyl compounds. The proportion of the structural units derived from other copolymerizable monomers is desirably 30% by weight or less and preferably 10% by weight or less based on the total weight of the hard polymer block (A). Examples of other copolymerizable monomers include, but are not limited to, 1-butene, pentene, hexene, conjugated dienes such as butadiene or isoprene, methyl vinyl ether, and other monomers.
The soft polymer block (B) of the styrenic block copolymer includes two or more same or different structural units. Soft polymer block (B) can be derived from olefin monomers generally having from 2 to about 12 carbon atoms and can include, for example, ethylene, propylene, butylene, isobutylene, etc. When the soft polymer block (B) has structural units derived from three or more repeat units, the structural units may be combined in any form such as random, tapered, block or any combination thereof. In one embodiment, the soft polymer block does not contain any unsaturated bonds.
In additional embodiments of the present invention, the styrenic block copolymer can have at least one soft polymer block (B) including two or more repeat units that are the same or different, independently derived from one or more of an olefin monomer and a diene monomer. When the diene monomer is present, the styrenic block copolymer is preferably hydrogenated or substantially hydrogenated. The conjugated diene monomers preferably contain from 4 to about 8 carbon atoms with examples including, but not limited to, 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene (piperylene), 1,3-hexadiene, and the like. Therefore, in one embodiment, the soft polymer block (B) can have structural units derived from one or more of an olefin monomer(s) and diene monomer(s). As indicated hereinabove, when the soft polymer block (B) has structural units derived from three or more repeat units, the structural units may be combined in any form.
The styrenic block copolymers may be prepared utilizing bulk, solution or emulsion or other techniques as known in the art. In one embodiment, the amount of hard block ranges from about 10% to about 40% by weight based on the total weight of the styrenic biotic copolymer.
Optionally, the soft polymer block (B) can include small amounts of structural units derived from other copolymerizable monomers in addition to the structural units described. In this case, the proportion of the other copolymerizable monomers is generally 30% by weight or less, and preferably 10% by weight or less based on the total weight of the soft polymer block (B) of the styrenic block copolymer. Examples of other copolymerizable monomers include, for example, styrene, p-methylstyrene, α-methylstyrene, and other monomers that can undergo ionic polymerization.
In various embodiments, the styrenic block copolymers are styrene-ethylene/propylene (SEP) styrene-ethylene/propylene-styrene (SEPS), styrene-ethylene/butylene-styrene (SEBS), styrene-ethylene/ethylene/propylene-styrene (SEEPS), styrene-isobutylene-styrene (SIBS), styrene-butadiene-styrene (SBS), and styrene-isoprene-styrene (SIS), or a combination thereof.
Styrenic block copolymers are available in the art from sources such as Kraton Polymers of Houston, Tex., as Kraton G-1641, G-1642, G-1651, G-1633; Kuraray Co., Ltd. of Tokyo, Japan as SEPTON™ styrenic block copolymers, for example SEPTON™ 4033, 4044, 4055, 8004, 8006, TSRC Corporation of Taiwan as Taipol 6151, 6154, and Danasol Elastomers LTD of Houston, Tex. as Calprene 6170WS.
The amount of the one or more styrenic block copolymers utilized in the sealing elements and compositions of the present invention ranges generally from about 5 to less than 50 parts, desirably from about 10 to about 40 and preferably from about 15 to about 30 parts based on 100 parts by weight of total polyolefin, polymer, styrenic block copolymer, and olefin block copolymer.
In addition to imparting good mechanical properties and compression set, styrenic block copolymers also provide for good retention of softener oil and minimize the exudation oil in the sealing elements and compositions of the present invention.
Olefin Block Copolymers
In a further embodiment of the present invention, the thermoplastic elastomer composition comprises an olefin or olefinic block copolymer (OBC). Olefin block copolymers provide a balance of flexibility and high temperature resistance as well as desirable elastic recovery and compression set properties at both ambient and elevated temperatures in the formulations of the invention. Improved abrasion resistance can also be achieved utilizing olefin block copolymers in the sealing element compositions. The olefin block copolymer contains therein two or more, and preferably three or more segments or blocks. Generally olefins having from 2 to about 12 carbon atoms and preferably from about 2 to about 8 carbon atoms are utilized. The olefin block copolymers can comprise alternating blocks of hard and soft segments. As known in the art, chain or catalytic shuttling technology allows variable yet controllable distribution of block lengths to be produced. Olefin block copolymers are characterized by having a broader molecular weight distribution compared to traditional anionic block copolymers made by a living polymerization.
Olefin block copolymers are available for example DOW as INFUSE™ Further description of olefin block copolymers is set forth in WO 2005/090425; WO 2005/090427; WO 2005/090426; U.S. 2007/0219334; U.S. 20100069574; U.S. 20100298515; U.S. Pat. No. 5,844,045; U.S. Pat. No. 5,869,575; U.S. Pat. No. 6,448,341; U.S. Pat. No. 6,538,070; U.S. Pat. No. 6,545,088; U.S. Pat. No. 6,566,446; U.S. Pat. No. 7,608,668; and U.S. Pat. No. 7,671,106 herein fully incorporated by reference.
The olefin block copolymers as indicated herein are present in an amount less than the total amount of polyolefins present, by weight. Accordingly, the olefin block copolymers are present in the sealing elements and compositions in an amount less than 50 parts, generally from about 10 to about 45 parts, desirably from about 20 to about 40 parts and preferably from about 25 to about 40 parts by weight per 100 parts by weight of the total polymer of polyolefin polymer, styrenic block copolymer and olefin block copolymer. Moreover, the olefin block copolymers are present in an amount less than 40 parts by weight, desirably less than 30 parts by weight and preferably less than 25 parts by weight based on 100 total parts by weight of the composition or sealing element formed therefrom.
Softeners
The sealing element compositions of the present invention in various embodiments include a softener such as a mineral oil softener, or synthetic resin softener, a plasticizer, a vegetable oil, or combinations thereof. The softener can beneficially reduce the temperatures at which the compositions are processable. Oil softeners are generally mixes of aromatic hydrocarbons, naphthene hydrocarbons and paraffin, i.e., aliphatic, hydrocarbons. Those in which carbon atoms constituting paraffin hydrocarbons occupy 50% by number or more of the total carbon atoms are called “paraffin oils”. Those in which carbon atoms constituting naphthene hydrocarbons occupy 30 to 45% by number of the total carbon atoms are called “naphthene oils”, and those in which carbon atoms constituting aromatic hydrocarbons occupy 35% by number or more of the total carbon atoms are called “aromatic oils”. In one embodiment, paraffin oils and/or plasticizers are preferably utilized as a softener in compositions of the present invention. Examples of synthetic resin softeners include, but are not limited to, polyisobutylene, and polybutenes. When present, the softeners range in an amount from about 10 to about 50 parts, and preferably from about 20 to about 40 parts by weight based on 100 total parts by weight of the composition.
Other Components
The sealing element compositions and sealing elements of the present invention may optionally include additional additives including, but not limited to lubricants, light stabilizers, pigments, heat stabilizers, processing aids, mold release agents, flow enhancing agents, platelet fillers and non-platelet fillers. Examples of fillers for use in the compositions include, but are not limited to, one or more of starch, calcium carbonate, talc, clay, silica, titanium dioxide, barium sulfate, mica, glass fibers, whiskers, carbon fibers, magnesium carbonate, glass powders, metal powders, kaolin, graphite, and molybdenum disulfide. All additives should be screened to ensure that they are approved by various regulatory authorities for use in direct food contact, when necessary.
In one embodiment of the present invention, the sealing element compositions include talc. Talc functions as an agent in the compositions that reduces the friction between the composition and another surface the composition contacts. Stated in another manner, the talc aids in sliding of the sealing elements in relation to another surface, such as the rim of a container. The talc, when present, is utilized in an amount from about 0:1 to about 30 parts and preferably from about 10 to about 20 per 100 parts by weight of the composition.
The hardness of the compositions and sealing elements formed therewith generally range from Shore A 50 to Shore A 90, desirably from Shore A 55 to 85, and preferably from Shore A 60 to 80, measured according to ASTM D-2240.
In one embodiment of the present invention, the composition, a sealing element, has a compression set greater than 60% at 7 days and 70° C. according to ASTM D-395. The compositions and sealing elements in some embodiments have a tensile strength greater than 600 psi and elongation to break greater that 600% measured according to ASTM-412.
In one embodiment, the sealing element is formed as a cap liner pad having a melt index (200° C., 5 Kg) from about 25 to about 30 grams per 10 minutes measured according to ASTM D-1238.
In a further embodiment, the sealing element is a seal ring having a melt index of from about 30 to about 50 grams per 10 minutes (200° C., 5 Kg) as measured according to ASTM D-1238.
In a preferred embodiment, the sealing element compositions of the present invention are characterized as having desirable peak melting temperature ranges and peak crystallization temperature ranges. In one embodiment the sealing element compositions have a first peak melting temperature that ranges from about 60° C. to about 85° C., and preferably from about 65° C. to about 80° C., and a second peak melting temperature that ranges from about 110° C. to about 125° C., and preferably from about 115° C. to about 120° C. Due to the presence of polypropylene, a third melting temperature generally ranges from about 145° C. to about 165° C. and preferably from about 150° C. to 160° C.
The compositions can have a first peak crystallization temperature that has split peaks from about 90° C. to about 125° C. and preferably from about 95° C. to about 110° C. due to the presence of an olefin block copolymer. A second peak crystallization temperature ranges from about 50° C. to about 65° C. and preferably from about 54° C. to about 60° C. As evident from the melting and crystallization temperature ranges, the sealing element compositions of the present invention provide broad processing windows that are desirable to sealing element manufacturers. As utilized herein the melting and crystallization temperatures were measured on a DSC Q2000 instrument from TA Instruments, New Castle, Del., measured according to ASTM D3418-08 with rates of cooling and heating at 10° C. per minute, and sample sizes varying from 5 to 10 milligrams.
The compositions and sealing elements formed therefrom exhibit low gas permeability and therefore are particularly useful in sealing food and liquid containers where the low permeability values prevent or lessen unintended gases from contacting the contents within the container. The compositions and sealing elements of the present invention desirably exhibit average permeability values less than 450, desirably less than 350, and preferably less than 350 or 300 CM 3 -MM/[M 2 -D-ATM] as measured according to ASTM F1927 using a MOCON® Ox-Tran 2/61 manufactured by MOCON Inc., Minneapolis, Minn.
As indicated herein, the closure is designed to form a seal with a container body, with the sealing element being disposed therebetween. In a preferred embodiment, the closure is a thermoplastic or thermoset material. In one embodiment, the closure is a thermoplastic and comprises one or more of a polyolefin and a polyester. Suitable polyolefins have been described hereinabove with respect to the sealing element compositions. Polypropylene closures are preferred in one embodiment. Examples of suitable polyesters include polyethylene terephthalate (PET) and polyethylene naphthalate.
The container may be manufactured from a wide variety of materials such as known in the art for container use. Preferably the container is a rigid or semi-rigid thermoplastic polymeric material. Preferred materials for the container body are those thermoplastics approved by the FDA or regulatory body for contact with food or foodstuffs. In a preferred embodiment, the container body is a thermoplastic and comprises one or more of a polyolefin and PET.
The sealing element compositions of the present invention are useful to form a wide variety of sealing elements having different dimensions or forms. For example, as illustrated in FIGS. 2A-2C the sealing elements can be formed in the form of a ring, disc, or any other desired shape, for example in a square or rectangular form, etc. Depending upon the configuration of the container and closure to be sealed, one or more different portions of the sealing element can have a thickness greater than another portion of the sealing element, see FIG. 2A for example which illustrates a sealing element 20 having a rim 24 of greater thickness than a central area of the sealing element.
The sealing elements of the present invention can be utilized in generally any application where a sealing element is required as known to those of ordinary skill in the art. Examples of suitable applications include, but are not limited to, closure liners for foodstuff and liquid containers as well as containers designed to house non-foodstuff items.
The sealing element compositions of the present invention can be produced utilizing in any of numerous processes known, in the art including, but not limited to, extrusion, injection molding, compression molding, and calendaring.
Methods for producing sealing elements of different forms have been disclosed hereinabove and are incorporated by reference. Other methods of manufacturing sealing elements are known to those of ordinary skill in the art as well. In one particularly useful embodiment, a sealing element is formed by extruding a quantity of a sealing element composition and then forming the extrudate into a sealing element, such as by stamping or compressing the extrudate into a desired form. In one embodiment, the extrudate can be dropped or placed in a closure and subsequently stamped or compressed there against in order to mold the extrudate into the desired sealing element shape within the closure at a desired location. As one non-limiting example of a viable manufacturing process, these steps are repeated at a rate to form 200 to 1800 sealing elements per minute. The melt rheology of the sealing element composition has to meet the manufacturing rate. Obviously, the amount of the sealing element composition extrudate will vary depending upon the size of the sealing element to be formed, thickness thereof, and the like.
EXAMPLES
The examples set forth in the following tables were prepared by melt mixing the indicated components using a twin screw extruder at a temperature of about 220° C. The properties were measured using samples injection molded at 210° C. prepared from the respective formulations.
TABLE 1
Com-
Com-
Ex-
Ex-
Ex-
parative
parative
ample
ample
ample
1
2
1
2
3
STYRENIC BLOCK
—
—
40
50
40
COPOLYMER 1
OLEFIN BLOCK
100
90
60
55
55
COPOLYMER 2
STYRENIC BLOCK
—
10
—
—
—
COPOLYMER 3
POLYPROPYLENE 4
35
23
45
40
40
12 MI
POLYETHYLENE 5
—
—
20
25
15
12 MI
POLYETHYLENE 6
—
—
10
10
13
MI = 8
ETHYLENEVINYL
—
—
—
—
7
ACETATE
SOFTENER 7
70
62.5
85
85
30
CRODAMIDE ER
1.8
0.9
1.8
1.8
6.40
CRODAMIDE VR
1
0.9
1
1
—
IRGANOX 1010
0.19
0.19
0.19
0.19
0.5
POLYISOBUTYLENE
—
—
—
—
60.00
OIL
TOTAL
207.99
187.49
262.99
267.99
266.90
(parts by weight)
HARDNESS,
63/58
60/55
74/69
80/75
77/72
Shore A 8 (inst./5 sec)
MI 200° C., 5KG 9
38
26
28
31
28
(g/10 min)
COMPRESSION SET 10
27
25
—
23° C. 7 DAYS (%)
COMPRESSION SET 10
—
—
25
25
—
23° C. 22 HRS (%)
COMPRESSION SET 10
46
45
—
70° C. 7 DAYS (%)
COMPRESSION SET 10
—
—
52
52
—
70° C. 22 HRS (%)
COMPRESSION SET 10
—
—
37
39
—
85° C. 30 MIN (%)
TENSILE
850
990
900
960
740
STRENGTH 11 (psi)
300% MODULUS 12
320
300
—
—
536
(psi)
% ELONGATION 13
1430
1350
850
760
650
1 st LOW T MELTING
63
77
68
63
—
POINT 14 (° C.)
2nd MELTING POINT
116
115
119
119
—
PEAK 14 (° C.)
3 rd MELTING POINT
158
158
155
159
—
PEAK 14 (° C.)
1 st high temp
103/94
102/90
106/100
109/95
—
CRYSTALLIZATION
PEAK 1 15 (° C.)
2 nd high temp
60
58
58
60
—
CRYSTALLIZATION
PEAK 1 15 (° C.)
PERMEABILITY 16
—
—
254
274
—
AVG CM 3 -MM/[M 2 -D-
ATM]
1 Kurraray, Septon 4055;
2 Dow Infuse D9000;
3 Calprene 6170 WS;
4 Ineos Polypropylene;
5 Exxon Mobil L6202;
6 Exxon Mobile polyethylene;
7 Krystol 550;
8 ASTM D-2240;
9 ASTM D-1238;
10 ASTM D-395;
11 ASTM 412;
12 ASTM 412;
13 ASTM 412;
14 ASTM D-3814-08, at a rate of heating 10° C./min.;
15 ASTM D-3814-08, at a rate of cooling 10° C./min;
16 ASTM F1927 using Mocon Ox-Tran 2/21.
Comparative examples 1 and 2 include relatively high amounts of an olefin block copolymer which were found more difficult to process due to the observed viscosity at about 200° C. being too low. Examples 1 and 0.2 of the invention include a high amount of polypropylene, yet have desirable seal properties as indicated in Table 1 as well as viscosities and also desirable processability. The compositions of the invention also exhibit beneficial permeability values as also set forth in Table 1. The compositions according this invention are further characterized with multiple melting temperatures and also multiple crystallization temperatures. The first melting temperature around 63 to 77° C. is due the presence of friction reducing agents. The second melting temperature around 116 to 119° C. is due the presence of OBC. The third melting temperature around 152 to 159° C. is due the presence of polypropylene. The presence of OBC in the compositions according to this invention is further characterized with the presence of split or double crystallization peaks from 95 to 110° C.
TABLE 2 Example 3 Example 4 Example 5 Example 6 STYRENIC BLOCK 40 40 50 50 COPOLYMER 1 OLEFIN BLOCK 60 55 55 55 COPOLYMER 2 POLYPROPYLENE 4 12 MI 45 45 40 40 POLYETHYLENE 5 12MI 20 20 20 20 POLYETHYLENE 6 MI = 8 10 10 10 10 TALC 17 10 20 10 20 SOFTENER 7 90 85 95 95 CRODAMIDE ER 1.8 1.8 1.8 1.8 CRODAMIDE VR 1 1 0.5 0.5 IRGANOX 1010 0.19 0.19 0.19 0.19 TOTAL (parts byweight) MI 200° C., 5KG 9 28 27 22 22 (g/10 min) HARDNESS (inst.) 75. 80 77 80 Shore A 8 COMPRESSION SET 10 24 25 23 25 23° C. for 22 hours (%) COMPRESSION SET 10 47 50 46 45 70° C. for 22 hours (%) COMPRESSION SET 10 41 40 34 35 85° C. for 30 min (%) TENSILE 1140 1145 1065 1067 STRENGTH 11 (psi) 300% MODULUS 12 (psi) 595 608 532 534 % ELONGATION 13 800 797 791 805 17 MICROTUFF 9103 W, from Minelco Specialties. 17 MICROTUFF 9103 W, from Minelco Specialties.
Table 2 shows examples of compositions and properties containing talc that are prepared according to this invention. The properties such as hardness, melt flow, compression set, tensile strength and elongation are desirable as specified in this invention. The incorporation of a filler, e.g. talc, to the compositions as specified in this invention is suitable for forming a sealing element. It further offers an alternative solution for making sealing elements for applications where a translucent color is not a critical concern.
While in accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
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Polyolefin based sealing element compositions with good oxygen barrier properties particularly suitable for forming sealing elements, for example gaskets and cap liners that are especially useful for sealing containers having products such as liquids or food-stuffs therein. The compositions when formed as sealing elements do not appreciably contribute taste and/or odor to a packaged product including the sealing element. The compositions have desirable rheological properties and are thus readily processable at various temperatures.
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[0001] This Application claims priority to U.S. Provisional Application Ser. No. 60/522,490, filed Oct. 6, 2004.
BACKGROUND OF THE INVENTION
[0002] Many people now routinely carry mobile devices such as mobile phones, personal digital assistants, integrated phones/PDAs or other mobile devices with calendar functions. Existing calendars and personal information management systems are useful to leave reminders for appointment dates and times, but are ignorant of physical location. The lives of everyone, from a busy business executive to a salesperson to a student are not dictated solely by date and time. How much time is wasted when you search for you car in a large parking lot? How often do you pass by an important building, only to make another trip later? How many trips past the grocery store does it take to remember to pick up that required ingredient? Outstanding tasks in our lives are almost always tied to a physical location, yet we have no simple way to leave reminders.
[0003] A need exists for help to organize our lives around both time and space. A device and/or service that takes advantage of its location can remind us when we need to pick up an important item from the approaching store, allow us to quickly recall notes about a client site, and allow us to keep track of useful information associated with specific places.
SUMMARY OF THE INVENTION
[0004] The number of mobile devices is increasing rapidly. The spatial calendar of the present invention utilizes these mobile devices as platform to address the need for a personal information management system that is aware of the path it travels through both space and time. The spatial calendar utilizes these currently deployed handheld tools to augment both our memory and our perception. Reminders will be provided when you approach an important location, notifications will be sent when you need to do something nearby, and you will be able to easily track down difficult to find items.
[0005] The system is mainly a software module that can deliver the functionality described herein as long as it is executed on a device that can supply it with GPS (or other source) reading of its current location. For example, the device can be a GPS-enabled phone, a car navigation system, a cellular phone that can obtain GPS location using cellular-GPS capabilities, a laptop, desk computer, pocket computer, a Palm or BlackBerry Device.
[0006] Utilizing the spatial calendar, the user can associate an event reminder to a location in space (Space to Event Association (SEA)). The location can be fed into the device manually, from the map unit, GIS address book unit, or from the current reading of the GPS unit, as well as any other source of GPS location media.
[0007] An event reminder can be text and/or audio to remind the user of a specific thing to do or pick once he or she approaches the location. Examples: once at the parking lot of an airport (inside the car or in the vicinity of the car), the user can activate the SEA function to associate a reminder (text, audio, or visual) to the location of his/her vehicle at the airport. In this case the system will automatically read the GPS location of the car and will prompt the user to enter an audio or text event reminder.
[0008] The user can create a library of audio and text event reminders and use them in association with geographical locations.
[0009] As another example, at home the user can associate an event reminder to the address of a store in his/her way. The reminder message can be simply to pickup milk from a grocery store once the system realizes that the user is in the vicinity of any grocery store or a specified grocery store (specified from map, address, or GPS).
[0010] Reminder Triggering: The system keeps a memory of event reminders in conjunction with their GPS locations. The user can specify at what distance from the location of an event the reminder should be triggered. For example, the user can specify that the event reminder “car parking” be triggered once the user is within 500 m from the car. Another example, the user can specify that if he is driving with 2 km distance from a given grocery store a reminder of the event “Pick up diapers on your way home”.
[0011] The user provides a functionality that allows the user to combine temporal (time) events with location events. For instance, the user can specify triggering a certain location event reminder can only happen after 7 PM. The same for time events.
[0012] Navigation to location events: The invention includes a navigation module which guides the user towards a location event. For instance, the module can guide the user using an onboard map, directional arrow, or clock numbering system (e.g., “the car is at 1 O'clock from you”).
[0013] Reminders Retrieval and Display: The invention includes a module that allows the user to display, and scan through stored event reminders, to delete or modify them.
[0014] Location Labeling and Storing: The user can label his/her current location with a text description of the location (e.g, Toronto airport, my-favorite JC Penny-), or an audio or visual description. This information is stored in the system's Location Address Book.
[0015] Location Address Book: Contains locations labeled and stored by the user, or acquired from other sources (e.g., Locations of places such as parking areas, hotels, parks, gas stations, grocery stores, press stands, etc., or Location Address Books supplied by other users of similar device)
[0016] For example, if you open the last bag of milk while preparing breakfast, a few quick taps on your mobile device serves as a reminder to yourself. Later that day, on the way home from work, your mobile device notices that you are approaching a grocery store. It has been a long day and you forgot all about breakfast. A pleasant reminder is spoken to you about the milk you need to pick up, with simple directions to the approaching grocery store. You conveniently make a stop at the store to pick up the required milk.
[0017] As another example, you return from a pleasant flight, only to be faced with the daunting task of finding your vehicle. As you walk outside, you turn to your mobile device for a little help, and ask it where your vehicle is located. It quickly notifies you to turn left and find your vehicle about 500 m ahead. Your mobile device continues to assist with a “radar” display as you walk toward your destination.
[0018] As yet another example, as you enjoy the road ahead, you completely forget about the remaining fuel in your vehicle. Luckily, your mobile device reminds you about the approaching gas station far enough ahead of time for you to exit the highway and stop for gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Other advantages of the present invention can be understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0020] FIG. 1 is a schematic of a spatial calendar system implemented with a limited function mobile phone.
[0021] FIG. 2 is a schematic of the spatial calendar system of FIG. 1 implemented with a full function mobile phone/PDA.
[0022] FIG. 3 illustrates a space-time event stored in the spatial calendar of FIG. 1 or FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] One embodiment of the spatial calendar system 10 of the present invention is shown in FIG. 1 for use with a limited capability mobile device 12 (e.g. simpler cell phone). The spatial calendar system 10 is shown in FIG. 2 in use with a more capable and independent mobile device 12 a , where some of the services previously performed by the server 24 are performed on the mobile device 12 a . Except where otherwise indicated, the following description applies to both embodiments of the system 10 , 10 a , which will be referenced generically as system 10 , for use with limited and full capability mobile devices 12 , 12 a , which will be referenced generically as mobile device 12 .
[0024] The proposed modular architecture of the spatial calendar system 10 shown in FIGS. 1 and 2 is designed to support a simple, transparent user interface on everything from a limited capability mobile device 12 (such as a traditional mobile phone) ( FIG. 1 ) to an integrated PDA/phone to a standalone PDA/GPS device 12 a ( FIG. 2 ).
[0025] User Interface: The primary user interface 14 for the user is the mobile device 12 itself, where space-time events can be created, located, and used for automatic notification. The mobile device 12 user interface 14 should be as simple as or simpler than a pen and a pad of paper. The user interface 14 presents notifications from the event management service 16 in addition to event creation, modification, and search.
[0026] Event Management Service: The event management service 16 is responsible for monitoring the state of space-time events. This service is also responsible for sending reminders to the user interface 14 at the appropriate places and times when event conditions are satisfied. Knowledge of the maximum speed, time, location, and active space-time events allows the event management service to put the device into low-power mode when event conditions are guaranteed to be false for extended periods of time.
[0027] Locator Service: The locator service 18 is responsible for estimating the position of a mobile device 12 (and ideally, the associated user). The physical source 19 of position information is abstracted by this service to both keep the system flexible and robust. Flexibility to incorporate additional or alternate sources of position is important to improve accuracy and coverage. Robustness is achieved by decoupling the decision process from the physical source of position information. The locator service 18 will provide estimates of both position and a measure of accuracy when a physical position source is temporarily unavailable. This service provides both current and historical location information to the event management service 16 . The sources 19 of position information can include: AFLT (Advanced Forward Link Trilateration), or other methods for determining mobile device location using cell towers on a mobile phone network; AGPS (Assisted Global Positioning System), where a bare minimum of data (i.e. one satellite) is received by the phone and sent to the wireless network provider, where cell site location information and phone details are combined to reduce time required for the initial position lock and minimize mobile device power consumption; GPS and Bluetooth (i.e. proximity to other Bluetooth devices with known positions, or where proximity to these devices is relevant in itself). Other sources of position information could be used and will no doubt be implemented in the future.
[0028] Database: All space-time event information must be reliably maintained in a personal space-time database 20 for effective notification and future use. Required information can be grouped by visibility: public information 22 a available to everyone, and private information 22 b . The space-time database 20 is maintained on a fixed server 24 in wireless communication with the mobile device 12 .
[0029] Public Information 22 a is available to everyone and includes the locations of relevant buildings (grocery store, gas station, post office), and street address details. This public information 22 a may be provided by a third party database or service, such as Microsoft Location Services.
[0030] Guaranteed privacy of private information 22 b is very important to most end-users. Space-time event information for one individual will be maintained in isolation from other individuals unless explicit permission is granted.
[0031] Mobile Service Components in this architecture are not tied to a specific processor or machine. To take advantage of the full spectrum of mobile devices, from low-end mobile phone to high-end PDA, the event management and locator services are distributed between a fixed hardware platform and the mobile device 12 itself. Operating the event management service 26 and locator service 28 locally on the fully-capable mobile device 12 a results in improved coverage where wireless network connectivity is not available ( FIG. 2 ). Operating the event management services 26 and locator services 28 on the fixed server 24 ( FIG. 1 ) is required to provide notification capabilities on mobile devices 12 with limited capabilities (J2ME/Bell).
[0032] In FIG. 2 , an intermediate mobile space-time data cache 30 is used to keep the logic between mobile event management service 26 and locator service 28 consistent with their counterparts on the server 24 . This mobile data cache 30 also helps to minimize response time by avoiding wireless communication when local memory permits. Queries against large datasets, including address lookups may be passed directly through to the fixed server 24 .
[0033] A space-time event 40 is shown in FIG. 3 . A simple set of outstanding space-time events 40 is maintained for each individual in the personal space-time database 20 ( FIGS. 1 and 2 ). Each space-time event 40 may be associated with any combination of location region and/or time interval for future notification. Examples of these space-time event descriptions include; pick up cereal whenever you are near a grocery store (associated with any grocery store—i.e. the event is associated with a generic category of locations, not a specific geographic location), pick up prototype from Bob the next time you visit (associated with Bob at your remote office), or visit the fireworks if you are in Niagara Falls on a Friday night.
[0034] Each space-time event 40 is associated with a specific user 42 (or with a specific mobile device 12 ( FIGS. 1 and 2 )) and includes a simple human-readable description 44 . This description 44 does not have to be meaningful to the software, only to the user. The description 44 can be text, an audio clip, video clip, image and or combination of these.
[0035] The space-time event 40 also includes space condition(s) 46 , which can be a single physical location or a set or category of locations. A fixed location is defined by latitude, longitude, and a description of the surrounding region. In the disclosed embodiment, the space conditions 46 may be circles centered on a location 48 (the latitude+longitude) and described by a radius 50 . A space condition 46 is considered satisfied when a predefined region around the mobile device 12 overlaps the region (defined by the radius 50 ) surrounding the fixed location 48 . A fixed location 48 can optionally include a human readable description or address used to resolve the latitude+longitude. Examples of fixed locations include a specific store (i.e. Zehrs #45), one office, or a known address, a set of locations defined by a human readable description (i.e. “Grocery stores”, or “Gas stations”) and one or more fixed locations. When measuring the distance or finding directions to a set of locations, the closest fixed location 48 is considered.
[0036] Each space-time event 40 can optionally include time conditions 56 . Time conditions 56 can be specified as a fixed absolute time interval, relative time interval (do this event AFTER some other event is completed), or sets of time intervals. Time intervals require at least one bound (i.e. anytime after Nov. 2, 2004). A relative time interval is specified using an offset from the completion time of another space-time event 40 . (i.e. go back to collect a soil sample 7 days after the last time you collected a sample). A set of time intervals can be used to define recurring or regular events. Arbitrary sets of time intervals can be defined, in addition to time intervals that are repeated after fixed durations (i.e. weekly, daily). Repeated time intervals can include “repeat until” and “start repeating from” times.
[0037] Each space-time event 40 includes a status 60 (Completion). The number of times an event has been triggered is maintained, along with the corresponding dates and times. This information distinguishes events just entered into the system from old events, and may be useful for the user to filter information and also for the trigger type logic. The date and time the event was created or modified is also maintained.
[0038] The user configures the notification rules 62 of the space-time event 40 to notify the user: a) the first time all of its conditions are satisfied; b) each time all of its conditions are satisfied; or c) never.
[0039] The space-time event 40 can include associated notes 66 . A note 66 is useful to leave a long reminder for a future visit. The note 66 can be text, audio, image and/or video.
[0040] The user can create, remove, and modify all space-time events 40 directly from the mobile device 12 .
[0041] The user can create a “thumbtack on the map,” or location marker at the user's current location with minimal user interaction (this is particularly useful to remember where you left your car). This action creates a space-time event 40 with a space condition 46 , a reasonable default radius 50 , and no trigger for notification in the notification rules 62 . Uses for an event 40 with only a space condition 46 include helping to remember where a vehicle was parked in an airport or other large parking space, and also to leave location specific notes 66 as useful reminders for future visits. More complex events can be created by completing the space-time event 40 description 44 . An event 40 must have at least one of: description 44 , space condition 46 , time condition 56 . All other event information is optional.
[0042] Space conditions 46 can be entered: a) Automatically using the current location+a reasonable default radius 50 that the user can override and modify; b) Resolved from an address or range of addresses (postal code)+a reasonable default radius (perhaps based on building density) that the user can override and modify; c) Selected on a map (including radius), or d) Selected from known locations or location sets (presented in a way to minimize effort—perhaps ordered by favorites, most frequently used, most recently used, proximity to current location, and/or some combination of these). Known locations will include a default radius. The user can override a default radius 50 with a few predefined alternate values or with a manually specified radius.
[0043] An event 40 can be modified either directly when its conditions are met and the user is notified, or indirectly by first searching for the event. Events 40 can be sorted by name, proximity, date entered, date last triggered, time condition, and filtered by: a) Freeform text (in description, address, or notes); b) Proximity to a given location (specify location as address or using a map). The relative age of locations on a map will be indicated (i.e. brighter=newer, darker=older). c) Date entered; d) Date triggered; e) Time condition (an interval). Once an event is located, any of its details can be modified or the event itself can be removed. If the conditions of an event are modified, the event is considered a new event for the purposes of the trigger type “the first time all the conditions are met.”
[0044] The user will be notified as soon as all of the space conditions 46 and time conditions 56 of an event 40 are satisfied. Notification methods include optional audible prompts, vibration, and visual details about the space-time event 40 . An event 40 with no trigger, such as a location marker where you left your car in the parking lot, will only generate passive visual messages when its conditions are satisfied. Events with triggers may also generate audible prompts or vibration when their conditions are satisfied. The desired notification rules 62 (audible, silent, display only) can be set by the user and remain in effect for all future notifications until changed. When an event's conditions are met, the user can (easily): a) Silence/Acknowledge.; b) Postpone. (Postponing an event will notify the user again after either a user specified reasonable time duration (e.g. 15 minutes) or when the conditions are about to change from true to false, whichever occurs first); c) Do nothing; d) Change the event's trigger type (fire the next time, always, never); e) Delete; or f) Edit or view further event details (notes, last trigger, etc.)
[0045] Unnecessary notifications are avoided to prevent false alarms, by using hysteresis around space conditions 46 and/or a minimum time or distance between successive notifications. The velocity of the user and precision of location measurements may also be used to determine if space conditions 46 are satisfied. Velocity and precision is important to accommodate both travel by foot and travel by vehicle. A region around the user that includes a predicted path over a short time period will be considered. If any part of the region around the user overlaps with any part of the region defined in a space condition, the space condition 46 is satisfied. When event notifications occur at the same time (all conditions are met for more than one event), the most recent event is shown to the user with an indication that multiple events occurred.
[0046] Lost (but previously marked) locations are found using the same mobile device interface. The same search options exist whether modifying an event or trying to find a lost location. Events with associated space conditions are included in the search, along with known locations (gas stations, grocery stores, other points of interest). Once a location is selected, either relative arrows and distance or cardinal direction and distance will be provided, depending on availability of orientation information. The user can then request map directions (obtained using an existing navigation application). Depending on accuracy and availability of location information, the mobile device can also be used to help find a marker with a regular audible (i.e. “Geiger counter mode”) or visual (“radar mode”) indication of proximity while the user is moving. An event can be directly modified or removed at any time after it is selected. A map with road directions can be provided on traditional mobile phones by integrating with Microsoft's Map Location Service.
[0047] The user does not need to sift through unnecessary information. Predefined sets of locations are provided, including grocery stores, gas stations, and hotels, but the user can: a) Define personal sets of locations. This can be useful for a real-estate agent to add sets of houses they are trying to push, or an individual that prefers certain types of grocery stores. b) Hide/remove predefined sets that are of no use to the individual c) Define aliases or abbreviations for commonly used locations (“Moe's”, or “office”) d) Define aliases or abbreviations for commonly used time intervals (“morning” or “after dinner” have different meanings depending on an individual's schedule) Aliases and custom/personal sets of locations can be used to minimize data entry time.
[0048] Preferably, the management of space-time events 40 can also be done using a desktop PC and/or a web interface.
[0049] A space condition 46 can be added that is tied to another mobile device 12 (phone, vehicle), not to a fixed longitude/latitude. For privacy reasons, the user of a mobile device 12 must explicitly grant permission to expose their location to other mobile devices 12 . Uses for mobile locations include specifying events as “remember to pick up the briefcase the next time you are in the car” (with an appropriate bluetooth-enabled car), or notification when a delivery vehicle arrives for a pick-up or delivery. Minor adjustments to this can also provide virtual fence functionality for pets/hunters/people.
[0050] The user can also send or share some or all of his personal space-time events 40 with others. For example, by choosing to “Share an Event,” shared events allow any person in a group of mobile device 12 users to accomplish the task. Some form of task selection/assignment should be possible, and once a shared item is marked completed, it should be marked completed for everyone.
[0051] The user can also send a space-time event 40 to another user, so that the space-time event 40 will be added to their personal space-time events 40 . The user can also send location details via SMS, instant messaging, or email to users without direct access to the system 10 . The user can also leave a virtual note in a public place for future interested visitors (e.g. graffiti without property damage, or food reviews left at the restaurant by previous customers).
[0052] Realistically, a person will not spend the time and effort to manage more than one organizer/PIM system. Synchronizing space-time events with existing desktop applications (e.g Outlook) is one option to reduce double-entry. It may be difficult to preserve the space information of events 40 , but use of contact names is useful for address lookups by name.
[0053] The system 10 also may utilize predictive reasoning. Knowing the location and time of events 40 allows your mobile device 12 to also predict how long it will take for you to travel to a meeting or other scheduled appointment from the user's current location. Reminders should take this time into consideration and notify the user, giving enough time for the user to actually travel to their appointment. One approach to include predictive reasoning is to add a new trigger type for an appointment or meeting, and include relevant logic in the event notification service.
[0054] The system 10 also provides inter-device communication. Modern phones and vehicles communicate without user intervention to use the vehicle sound system for hands free communication. The device 12 can also take advantage of passing devices to help determine location. For example, the device keeps track of when the user leaves their vehicle and automatically stores a “thumbtack” to help find it later (no user effort/time).
[0055] With an integrated camera, the mobile device 12 can also take images with embedded location information. store and find images based on where they were taken.
[0056] In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. Alphanumeric identifiers in method steps are for ease of reference in dependent claims and do not signify a required sequence unless otherwise specified.
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Utilizing a spatial calendar device and service, the user can associate an event reminder to a location in space. The location can be fed into the device manually, from the map unit, GIS address book unit, or from the current reading of the GPS unit, as well as any other source of GPS location media. An event reminder can be text and/or audio to remind the user of a specific thing to do or pick once he or she approaches the location. Examples: once at the parking lot of an airport (inside the car or in the vicinity of the car), the user can associate a reminder (text, audio, or visual) to the location of his/her vehicle at the airport. In this case the system will automatically read the GPS location of the car and will prompt the user to enter an audio or text event reminder.
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BACKGROUND OF THE INVENTION
This invention concerns a method for the removal of at least one heavy metal, e.g., arsenic, lead, tin and the like, from water in which it is dissolved, by the precipitation of a salt thereof in multiple steps. More particularly, it concerns a multi-stage process for the removal of one or more heavy metals from contaminated water wherein the metal is precipitated from solution in the form of a salt and the filtrate reprocessed one or more times at progressively higher pH to further precipitate metal therefrom. The process is useful for the treating of industrial, surface and underground wastewater to produce potable water and solid metal salts which may be reused for industrial purposes, such as copper arsenate to make wood preservatives.
PRIOR ART
It is known to remove heavy metals from water contaminated therewith, by various means. Precipitation of their salts is known and disclosed, for example, in U.S. Pat. No. 4,959,203 which teaches the precipitation of copper arsenate from a solution of copper sulfate to which a water-soluble arsenate solution is added and the resulting solution mixture neutralized to precipitate copper arsenate. The precipitation technique is preferred, in some instances, because it is possible to process water contaminated with heavy metals and provide useful products which do not cause waste disposal problems. For example, arsenic containing groundwater can be treated to form copper arsenate, for use in making wood preservatives, and potable water. The present invention is an improvement on the precipitation process wherein the facile production of potable drinking water is realized from the processing of heavy metal contaminated water.
THE DRAWINGS
FIG. 1 is a diagrammatic representation of the multi-stage process of this invention carried out in multiple reactors, and
FIG. 2 is a diagrammatic representation of the multi-stage process of this invention carried out in a single reactor.
STATEMENT OF THE INVENTION
This invention is a process for the removal of at least one heavy metal from an aqueous solution contaminated therewith wherein said metal is formed into a water-soluble salt in said solution at a mildly acid pH and then precipitated by adjusting the pH of said solution upward, the improvement comprising adjusting the pH upward until precipitation begins to form a first precipitate, separating said first precipitate from said solution, further adjusting the pH upward to form a second precipitate, separating said second precipitate from said solution, and optionally, further adjusting the pH upward to form a third precipitate and separating said third precipitate from said solution. The process may be carried out in a single reactor or multiple reactors as depicted in the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
This invention is a process for the removal of at least one heavy metal from an aqueous solution contaminated therewith wherein said metal is formed into a water-soluble salt in said solution at a mildly acid pH and said salt is precipitated by adjusting the pH of said solution upward. The improvement in such process comprises treating said solution in multiple stages wherein the pH of the solution containing the dissolved salt is adjusted upward until precipitation begins and a first precipitate is formed. The first precipitate is separated from the aqueous solution and the pH of said solution is further adjusted upward until precipitation occurs again and a second precipitate is formed. The second precipitate is separated from the aqueous solution and, optionally, the previous step is repeated to form a third precipitate which is also separated from the aqueous solution.
Optionally, the solution to be treated is oxidized, prior to salt formation, to convert any heavy metal of lower valency to a higher and more reactive metal ion. For example, trivalent arsenic, if present, will be converted to pentavalent arsenic by the oxidizing agent. This preoxidation will also serve to oxidize any organic impurities in the aqueous solution which could interfere with the precipitation of the formed metal salts. Organics which act as chelating agents to bind the heavy metal and prevent precipitation are especially in need of oxidation. Oxidizing agents are used which will accomplish the intended purpose and not themselves interfere with the relevant reaction or precipitation in the amounts employed. That is, the oxidizing agents should not raise the pH of the metal-containing solution to the degree that precipitation will occur on the addition of the salt-forming agent. Oxidizing agents which are useful for this process include, for example, ozone, hydrogen peroxide, sulfuric acid, nitric acid, hydrochloric acid, and the like. These agents are used in amounts sufficient to convert lower valent heavy metals to a higher valency and to oxidize organic contaminants sufficiently to prevent their interference with precipitation by the metal salt on pH adjustment in the process. In general, amounts of sulfuric acid or nitric acid as oxidizing agents to be added to the heavy metal-containing aqueous solution range from 1 g/L to 5g/L; preferably 1.5 to 2.5 g/L based on the volume of water in the aqueous solution to be treated.
Of course, if all heavy metal present in the solution is in its higher valency form and no organics are present in the solution, the oxidizing step may be omitted.
A precipitation-enhancing agent may also be used in the process of the present invention to provide improved and quicker filtration of the formed precipitate. The step of mixing this agent with the solution maximizes the particle size and can be accomplished either before, during or after the heavy metal is converted to the water-soluble salt at acid pH. Preferably, the enhancing agent is added before the heavy metal is converted or before the contaminated solution is pumped to the reactor. Any inorganic salts with a crystal structure similar to that of the precipitate can be used as the precipitation-enhancing agent. Preferred precipitation-enhancing agents include, for example, sulfuric acid, calcium sulfate, arsenic trioxide, and calcium arsenate. If the enhancing agent is the same as the oxidizing agent, e.g., sulfuric acid, its addition will accomplish both purposes.
To facilitate description of this invention, arsenic will be used hereinafter to represent heavy metals which also include, for example, lead, chromium and tin. These materials will exist in ionic form in the aqueous solution.
Arsenic is removed from water containing it by reacting the arsenic in solution with an inorganic water-soluble metal salt wherein the metals are those, for example, of the Groups Ib, IIa, IIb, VIIb and VIII of the periodic table. Preferred salts are cupric nitrate, cupric chloride, copper sulfate, zinc nitrate and the like which form water-soluble metal arsenates in solution at an acid pH, e.g., from about 1 to 2. The amount of copper or equivalent salt introduced into the arsenic-containing solution is determined by the arsenic content of the solution and, based on a stoichiometric ratio of metal to arsenic, will be from about 1.3:1 to about 2:1 and preferably from about 1:4:1 to 1.6:1. The typical pH of most underground water is between 5 and 8. On addition of the water-soluble salt to the arsenic solution, the pH of the solution will be lowered to about 1-2 and is generally maintained between 1 to 3, preferably about 2 during the reaction stage. The reaction stage is preferably carried out for 5 minutes to two hours, more preferably about 10-20 minutes, at a temperature of about 30° C. to below the boiling point of the reaction solution, more preferably between about 35° to about 60° C.
The pressure at which the process is operated is not critical, ambient or atmospheric being preferred.
The reaction is generally carried out with agitation in either a batch or continuous system, e.g., continuous stirred tank reactor. It is preferable to have a ditched bottom reactor with an agitator diameter-to-reactor vessel diameter being about 0.4 to about 0.55. Agitation during the reaction will be mild with mostly axial flow and low shear force to avoid shearing of precipitate particles when precipitation occurs. Examples of the agitators include, but are not limited to hydrofoil agitators, such as Lightnin A310 and A315, and profiles agitators, such as Mixel Profile propellers TT, TTP and TTM. It is preferable to locate the injection ports for inorganic metal salt slightly above the agitator blades. It is also preferred to have a tubular anchor close to the bottom of the reactor in order to avoid the accumulation of precipitate in the bottom of the reactor.
In accordance with the present invention, in a first stage, the arsenate is preferably precipitated by adjusting the pH of the aqueous solution upward from about 1-2 to about 2.5-4.5 causing the formation of a first precipitate. This precipitate is separated from the aqueous solution as a solid metal arsenate, preferably copper arsenate, in a conventional liquid/solid separator, e.g., a filter press.
Following separation of the first precipitate, the pH of the aqueous solution (or filtrate) is again adjusted upward from 2.5-4.5 to 4.5-7 to cause the formation of a second precipitate, most likely a mixture of Cu 3 (AsO 4 ) 2 , CuHAsO 4 , etc., which is separated, as above, from the aqueous solution. If desired and if residual metal arsenate is present, the pH of the aqueous solution (new filtrate) may again be raised (e.g., above 7) to produce additional precipitate, most likely a mixture of CuHAsO 4 , CuHAsO 3 , etc.
Adjustment of the pH upward in the reaction system is accomplished by adding an alkali or alkaline earth metal hydroxide, ammonia or equivalent base material to the arsenate-containing aqueous solution. The base material may be in solid or solution form as desired. Addition of the basic material is preferably accomplished over an extended period at each stage, e.g. 10 to 30 minutes, to obtain optimum precipitation at each stage.
To further describe the multi-stage process of this invention, reference is made to FIG. 1 of the drawing which represents a multiple reactor embodiment. Lines 2, 4, 6 and 8 deliver wastewater, sulfuric acid, inorganic metal salt and caustic, respectively, to the reactor 10 at the direction of the operator. Reactor 10 may be heated by external or internal means to maintain the reactor at the desired temperature, at least about 100° F. (37.8° C.), preferably 130°-140° F. (54.4°-60° C.), and contains agitator means, e.g., an electric stirrer. Wastewater (ground water as hereinafter described) is pumped into the reactor while the reactor temperature is raised to 130°-140° F. and then sulfuric acid is incorporated in the appropriate amount as the mixture is mildly agitated. When the pH is lowered to the desired level (e.g., 1.2-1.5) a water soluble salt, e.g., cupric nitrate is pumped to the reactor in at least a stoichiometric amount based on the arsenic content of the wastewater, and the reaction is carried on for about 10-20 minutes. On completion of the reaction, caustic is slowly incorporated into the reactor preferably in the form of NaOH solution or granulates to raise the reactor pH to about 2.5-4.5 with mild agitation. Precipitate forms and the slurry containing it is passed to a liquid/solid separator 12 which may be, for example, a filter press, and the precipitate is removed at 14 while the filtrate flows into reactor 18 through line 16. Reactor 18 may be substantially the same type of reactor as reactor 10. The filtrate from separator 12 is treated in reactor 18 with additional caustic through line 20 to further adjust the pH of the solution upward to 4.5 to 7 under similar heating and agitation conditions as in reactor 10. Precipitate forms and the slurry containing it is passed to a liquid-solid separator 22 which may consist of equipment similar to separator 12. The precipitate from separator 22 is removed through line 24 and the filtrate may be discharged directly into municipal sewage or pumped underground thru line 26.
Optionally, should it be desired to further treat the filtrate, it can be passed to reactor 28 and more caustic added to the reactor via line 30 to adjust the pH above 7 to produce additional precipitate. The slurry containing this precipitate is passed to liquid/solid separator 32 and solids are discharged through line 34 and filtrate liquid through line 36. The precipitates may be collected and, in the case of copper arsenate, used to produce chromated copper arsenate for wood preservative.
Alternatively, the multi-stage process is carried out in the system depicted in FIG. 2 of the drawings which is a single reactor 50. Wastewater is charged to the reactor through line 42 and sulfuric acid may be injected through line 44. Water-soluble salt is fed through line 46 and caustic through line 48 into the reactor, as activated by the operator. In the first stage, the reaction is continued for about an hour at the initial low pH caused by the incorporation of sulfuric acid and water-soluble salt into the wastewater in the reactor 50. As in FIG. 1, the reactor is equipped with heating and agitating means. On completion of the reaction, caustic, preferably NaOH granulars or solution, is slowly incorporated into the reactor via line 48 to increase the pH upward to about 2.5-4.5. This forms a precipitate in the wastewater and this slurry is passed into a liquid/solid separator 52. The precipitate is discharged through line 54 and the filtrate flows through lines 56 and 58 back to reactor 50. Additional caustic is brought into the filtrate through line 48 to bring the pH to between 4.5 and 7 to form more precipitate. The slurry produced by precipitate formation is passed to the liquid/solid separator 52 and, after separation, the precipitate discharged through line 54. The filtrate may be discharged to municipal sewage or pumped underground via line 60. Optionally, the filtrate may be recycled through line 58 back to the reactor and subjected to further upward pH adjustment, if desired.
EXAMPLES
The following examples are set forth to demonstrate the invention but are not to be construed as narrowing the breadth thereof.
Wastewater, or groundwater, as used herein has the following typical content and concentrations.
______________________________________Chemicals Concentration (wt.)______________________________________Arsenic approx. 4000 ppmCalcium approx. 1000 ppmChloroform 160 ppbChlorobenzene 94 ppbAlpha BHC* 490 ppbGramma BHC 740 ppbBeta BHC 95 ppbDelta BHC 410 ppb______________________________________ *benzene hexachloride ppm = parts per million ppb = parts per billion The pH of this typical wastewater is 5.5-5.7
EXAMPLE 1
Single Stage Reaction (Comparative Example)
Eight hundred grams of groundwater (with typical chemical contents of Table 1) was added to a stirred glass reactor. The reactor temperature was slowly raised to about 130°-140° F. and was maintained at 130°-140° F. throughout the run. 3.0 grams of concentrated sulfuric acid (>95%) was added into the reactor and the reactor pH dropped to about 1.4, followed by the addition of 16.3 grams of cupric nitrate salt, Cu(NO 3 ) 2 .2.5 H 2 O. The reactor pH further dropped to 1.1. After addition of the salt, the reaction was allowed to proceed for about forty minutes. 6.9 grams of NaOH granulars were slowly added over fifteen minutes to the reactor and the reactor pH increased to 7.3. The reactor slurry was filtered and the filtrate was found to have 2.45 ppm arsenic.
EXAMPLE 2
Multi-Stage Reaction
Five hundred grams of the groundwater was added into a stirred glass reactor. The reactor temperature was slowly raised to about 130°-145° F. and maintained within this range through out the run. 1.9 grams of concentrated sulfuric acid (>95%) was added to the reactor and the reactor pH dropped to about 1.2. 10.3 grams of cupric nitrate salt, Cu(NO 3 ) 2 .2.5 H 2 O, was then added to the reactor. The reactor pH further dropped to about 1. After addition of the salt, the reaction was allowed to proceed for 5 minutes. 3.7 grams of NaOH granulars were slowly added into the reactor and the reactor pH increased to about 4. The resulting precipitate formed a slurry in the reactor and the slurry was filtered. This first filtrate was found to have 948 ppm arsenic. The pH of the first filtrate was further adjusted to about 6 by adding 1.1 grams of NaOH granulars and the resulting slurry was filtered again. The resulting second filtrate contained less than 0.05 ppm arsenic. The pH of the second filtrate was further adjusted with 0.1 gram of NaOH granulars to 12.5 and the formed slurry was filtered again. The arsenic content of this third filtrate was less than 0.05 ppm. Typically, a two-stage operation should be sufficient to reduce the concentrations of heavy metals to meet the national drinking water standards.
Compared to Example 1, the arsenic removal efficiency with the two or three-stage precipitation process was much higher. As far as arsenic is concerned, the filtrates from the multi-stage precipitation process should meet the discharge regulations imposed by governmental regulations. The filtrate from the single stage precipitation process outlined in Example 1 contained 2.45 ppm arsenic which is far above the arsenic level 0.05 ppm allowed in the national drinking water standards.
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In the process of removing heavy metals from aqueous solutions by precipitation of a salt thereof at increased pH, multiple stage precipitation by upward stepwise pH adjustment and solid separation at each stage is used to facilitate the manufacture of a product of high purity.
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This application is a continuation of application Ser. No. 08/508,564, filed Jul. 28, 1995, now abandoned.
FIELD OF THE INVENTION
This invention relates to a process for producing a thermoplastic resin foams which comprise adding a blowing agent to a thermoplastic resin, mixing the two components and extrusion foaming the mixture. The invention also relates to an apparatus for implementing the process. In particular, the invention relates to a process capable of producing thermoplastic resin foams consistently by this method, as well as an apparatus for implementing the process.
BACKGROUND OF THE INVENTION
Process for producing thermoplastic resin foams by adding a blowing agent and other necessary additives to a thermoplastic resin, mixing the respective components and extrusion foaming the mixture, as well as apparatus for implementing the processes are widely known. Among those processes, the approach of using an extruder having a rotating screw in a barrel finds extensive commercial use because of its capability for continuous production of desired foams in large volumes. This approach typically comprises the following steps: heating a thermoplastic resin to melt in an extruder with a blowing agent and other necessary additives are forced into the melt; mixing the respective components uniformly under pressure; cooling the mixture to a temperature suitable for expansion; extruding the cooled mixture through a specified die; and allowing the molded part to expand in the reduced atmosphere thereby producing desired foams in a continuous manner.
For uniform expansion, it is important that the blowing agent be uniformly mixed with the thermoplastic resin and that the molten resin be uniformly cooled to the temperature suitable for expansion. To meet these needs, various methods and apparatus have been proposed that are capable of both uniform mixing of the resin feed with the blowing agent and uniform cooling of the molten resin composition. One of these proposals is described in JP-B-54-42026 (the term "JP-B" as used herein means an "examined Japanese patent publication") and it uses a cooler that has a rotating shaft in a barrel that can be cooled; the shaft has a plurality of vanes or blades in a plate form that are provided on the circumference in a staggered pattern in both an axial and a circumferential direction, with the length of each vane being parallel to the axis of the shaft. Each vane has a plurality of holes that extend through the plate thickness. The through-holes in adjacent vanes are oriented in two different directions, one being from the inner to the outer circumference and the other being vice versa. According to JP-B-54-42026, this arrangement enables the molten foamable resin to be mixed and cooled uniformly. However, the cooler under consideration has no ability to thrust the resin and in order to prevent the loss of extrusion force, the diameter of the rotating shaft has to be increased to such an extent that the resulting equipment is difficult to install adjacent the extruder and adjust for proper operation.
Another proposal is made in JP-B-60-52926 (corresponding to U.S. Pat. No. 4,454,087) and it consists of providing a cooler of the above-described type and a zigzag mixer which is a kind of static mixers. A problem with this proposal is that a loss in the extrusion force occurs in the zigzag mixer and in order to compensate for the resulting loss in extrusion output, a sufficient thrust force must be secured by installing two extruders behind the cooler but then the overall production equipment becomes complex.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process for the production of a thermoplastic resin foam that uses a simple apparatus and which yet is capable of satisfactory extrusion molding of a thermoplastic resin after addition and mixing of a blowing agent, as well as the apparatus used to implement the process.
Another object of the invention is to provide a process for the production of a thermoplastic resin foam that is capable of extrusion molding of a thermoplastic resin after a blowing agent is added to and uniformly mixed with a thermoplastic resin, as well as an apparatus used to implement the process.
A further object of the invention is to provide a process for the production of a thermoplastic resin foam that is capable of extrusion molding of a thermoplastic resin after a blowing agent is added to and uniformly mixed with a thermoplastic resin, with the mixture being subsequently cooled uniformly, as well as an apparatus used to implement the process.
Yet another object of the invention is to provide a process for the production of a thermoplastic resin foam that enables a blowing agent to be added to and uniformly mixed with a thermoplastic resin while the mixture is uniformly cooled, whereby the cooled mixture can be extruded and expanded to a desired shape in a consistent manner, as well as an apparatus used to implement the process.
Still another object of the invention is to provide a process for the production of a thermoplastic resin foam that enables a blowing agent to be added to and uniformly mixed with a thermoplastic resin while the mixture is uniformly cooled, whereby the cooled mixture can be extruded to a desired shape in a consistent manner and in large quantities, as well as an apparatus used to implement the process.
In essence, the present invention relates to a process for the production of a thermoplastic resin foam by adding a blowing agent to a thermoplastic resin and mixing them in an extruder, characterized in that the thermoplastic resin is rendered in a molten state by means of the extruder and allowed to travel through a barrel as it passes between the inner surface of the barrel and the outer surface of a rotating shaft which has a plurality of perforated plates provided on the circumference such that the thermoplastic resin is mixed with the blowing agent under agitation, the mixture being then passed through a metering zone around the rotating shaft, extruded through a die and expanded to a foamed shape.
The invention also relates to an apparatus for the production of a thermoplastic resin foam, characterized in that an extruder for heating a thermoplastic resin and a blowing agent to melt is combined with an extruding unit comprising a kneading zone and a metering zone of a screw structure, said kneading zone comprising a barrel, a rotating shaft in it, and a plurality of perforated plates mounted on the shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section showing, in partial view, an example of the apparatus according to the invention;
FIG. 2 is a section showing, with part taken away, another example of the invention;
FIG. 3 is a section showing, with part taken away, yet another example of the kneading zone in the apparatus of the invention;
FIG. 4 is a section of the kneading zone taken on line IV--IV of FIG. 3;
FIG. 5 is a fragmentary view of the rotating shaft in still another example of the kneading zone for use in the invention;
FIG. 6 is a fragmentary view of the rotating shaft in a further example of the invention;
FIG. 7 is a section of the rotating shaft taken on line VII--VII of FIG. 6; and
FIG. 8 is a fragmentary view of the rotating shaft in another example of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Thermoplastic resins are used in the invention. For example, polyolefine resins such as polyethylene resins and polypropylene resins, styrenic resins, polyester resins such as polyethylene terephthalate, and polyvinyl chloride resins may be extruded and expanded to desired shapes. Among these, polystyrenic resins, polyolefin resins and polyester resins are particularly preferred for mixing with blowing agents and subsequent extrusion and expansion to produce foams.
In the invention, blowing agents are added to and mixed with thermoplastic resins. Examples of blowing agents include a decomposable blowing agent, volatile compounds such as hydrocarbons and fluorinated hydrocarbons, and inert gases such as carbon dioxide and nitrogen gases.
The invention also permits the mixing of thermoplastic resins with various additives that provide them with specified characteristics and exemplary additives include nucleating agents, foam-controlling agents, flame retardants, fillers, colorants and heat stabilizers.
The process according to the invention and the apparatus for implementing that process will now be described with reference to the accompanying drawings.
In FIG. 1, numeral 1 designates an extruder, 2 a connecting pipe, 3 a kneading zone, 4 a metering zone, 5 an auxiliary mixing zone, and 6 is a die. Extruder 1 consists of a barrel 11 and a screw 12 provided rotatably in the barrel. Connecting pipe 2 is so adapted that a resin extruded from extruder 1 is directed to the entrance 34 of kneading zone 3. Kneading zone 3 consists of a barrel 31 and a rotating shaft 32, with a passageway for the resin being formed between the inner surface of the barrel 31 and the outer surface of the rotating shaft 32. The rotating shaft 32 is provided with a plurality of plates 33 each having three holes. Stated more specifically, a set of perforated plates 33 are spaced apart at equal distances in the circumferential direction and a plurality of such sets are arranged side by side on the shaft 32 in its axial direction to make the kneading zone. Two adjacent sets of plates are so positioned that they virtually contact end to end in the longitudinal direction; however, in the circumferential direction, the plates are staggered in such a way each of the plates in one set virtually lies between two plates in the adjacent set. Each plate 33 has three through-holes and it is provided on the shaft 32 in such a way that its thickness is substantially parallel to the direction in which the shaft 32 rotates. The thus constructed kneading zone 3 occupies 30 to 90% of the length of the shaft 32, which begins from the area right beneath the entrance 34 to the front end of the metering zone 4. Cooling jackets 35 are provided on the circumference of the barrel 31 and channels for the passage of a cooling medium extend through each cooling jacket. One end of the rotating shaft 32 extends behind the barrel 31 into a drive mechanism.
The shaft 32 in the metering zone 4 is of a screw structure that is in a cylindrical form of a uniform outside diameter and which has a uniform channel depth and flight pitch. Cooling jackets 35 are also provided on the circumference of the barrel 31 in the metering zone 4. The auxiliary mixing zone 5 is provided at the front end of the metering zone 4 and the rotating shaft in this zone has a smaller outside diameter and is provided with a multiple number of projections on the surface. The auxiliary mixing zone may be designed to have other structures such as a Dulmage structure and a static mixer.
The process of the invention is described below more specifically with reference to FIG. 1. A thermoplastic resin to which a blowing agent and other necessary additives have been added is melted in the extruder 1 and extruded into the connecting pipe 2, from which it passes through the entrance 34 to enter the kneading zone 3, through which it is allowed to travel by the extrusion force created by the extruder 1.
In the kneading zone 3 having the rotating shaft 32 in the barrel 31, the resin travels between the inner surface of the barrel 31 and the outer surface of the rotating shaft 32. Since the rotating shaft 32 has a multiple of perforated plates 33 that project radially outward and which extend along the axis, the resin is mixed under agitation as it travels through the kneading zone 3. At the same time, the resin is cooled with a cooling medium that is supplied into and discharged from the coolant channels through the cooling jackets 35. If desired, the resin may be cooled with a cooling means provided in the rotating shaft 32 in the kneading zone. The cooling means may have a dual-wall structure 37 consisting of an inner tube and an outer tube as shown in FIG. 1. A cooling medium for the cooling means may be supplied into the inner tube and discharged from the outer tube. Because of these arrangements, the resin is cooled by means of the barrel 31 and the rotating shaft 32 as it travels through the interior of the kneading zone 3. At the same time, the resin is thoroughly agitated by means of the perforated plates 33 to provide a uniformly mixed composition; the resulting uniformly mixed and cooled resin composition is transferred from the kneading zone 3 to the similarly cooled metering zone 4, where it travels in a consistent manner. The resin emerging from the metering zone 4 has been controlled to a temperature appropriate for expansion and is subsequently fed into the auxiliary mixing zone 5, where it is rendered to be more uniform.
The resin leaving the auxiliary mixing zone 5 is then directed to the die 6. The resin in the die 6 has a uniform temperature suitable for expansion; therefore, even if the passage in the die 6 is large enough to enable the extrusion of a shaped part having a large cross-sectional area, the extruded resin will expand uniformly throughout and there will be no differences between the surface area and the interior in such aspects as the expansion ratio, the size of cells and their distribution within the foam. In other words, there can be produced thick foams having consistent physical properties.
FIG. 2 shows another example of the apparatus of the invention, in which the rotating shaft 32 is provided rotatably within the barrel 31. The barrel 31 has heating bands 36 and cooling jackets 35 provided on the surface so as to effect heating or cooling as required. The barrel 31 is also fitted with an entrance 34 for resin supply. The front end portion of the shaft 32 is shaped as a cylinder having a uniform outside diameter and has a screw structure having provided thereon a flight 41. The screw structure is formed on the surface with a uniform channel depth and flight pitch to create a metering zone 4. A feed zone 21 is also formed that starts just beneath the entrance 34 and which ends part of the length of the rotating shaft 32. At the end portion of the feeding zone 21, a gas injection hole 38 is provided for injecting a blowing agent. In the present invention, a blowing agent may be added to the thermoplastic resin at any time before kneading zone. A flight 40 is provided around the rotating shaft 32 in the feed zone 21. The channel depth of the feed zone 21 is maximal just beneath the entrance 34 and decreases progressively toward the front end. The metering zone 4 accounts for 10 to 30% of the overall length of the shaft 32 and the feed zone 21 accounts for 30 to 50% of the same overall length.
The extruding machine shown in FIG. 2 differs structurally from the conventional type in terms of the kneading zone 3 formed behind the metering zone 4. Stated more specifically, the kneading zone 3 shown in FIG. 2 has no screw structure but is provided with plates 33 having a multiple of holes.
In the kneading zone 3 shown in FIG. 2, the shaft 32 also assumes a cylindrical form as in the metering zone 4 but its outside diameter of the cylinder is made smaller than that of the cylinder which connects the bottoms of screw channels in the metering zone 4. The outside diameter of the shaft in the kneading zone 3 is preferably uniform but permits some variations. The shaft in the thus formed kneading zone 3 has four perforated plates 33 provided on the surface. The plates 33 extend from end to end of the kneading zone 3 and each has a multiple number of holes that penetrate its thickness. The plates 33 extend along the length of the shaft 32, with the thickness of each plate being substantially parallel to the direction in which the shaft 32 rotates. The plates 33 are fixed to the surface of the shaft 32, being offset by 90 degrees in the direction of width to be spaced equidistantly over the shaft 32 in its circumferential direction. The kneading zone 3 accounts for 30 to 60% of the overall length of the shaft 32; the length of the kneading zone 3 is preferably 15 to 30 times the major diameter d (as shown in FIGS. 5 to 8) of the kneading member including the rotating shaft and the perforated plates. In the present invention, the major diameter of the kneading member means a distance of two times the distance from the center of the rotating shaft to the edge of the plate apart from the center. The length of the metering zone is preferably 5 to 10 times the major diameter of the external thread.
In addition, the feed zone, the kneading zone and the metering zone preferably account for 30 to 50%, 30 to 60% and 10 to 30%, respectively, of the overall length of the shaft; these dimensions insure that the extruding machine shown in FIG. 2 suffices to achieve thorough kneading of the resin to produce a uniform melt, which can therefore be extruded to a shape in a simple, easy and consistent manner.
Another feature of the example shown in FIG. 2 is that the outside diameter of the shaft 32 in the kneading zone 3 is adjusted to be smaller than that of the shaft in the metering zone; this helps increase the capacity of the channels for the passage of the resin and, hence, the residence time of the molten resin which has been added to and mixed with the blowing agent is sufficiently prolonged to accomplish thorough mixing of the resin under agitation by means of the rotation of the perforated plates secured to the surface of the shaft 32.
In the present invention, as shown in FIGS. 1 and 2, (i) the extruder for heating a thermoplastic resin and (ii) the extruding unit comprising a kneading member and a metering member may be rotated independently of each other or in synchronization with each other.
Still another example of the kneading zone 3 is described below with reference to FIG. 3 and FIG. 4 which is a section taken on line IV--IV of FIG. 3. As shown, the shaft 32 in the kneading zone 3 is also shaped in a cylindrical form; the outside diameter of the cylinder is desirably uniform but permits some variations. Plates 331 to 334 are identical in shape and size and each has three holes that penetrate its thickness; the plates are fixed onto the shaft 32 along its length in such a way that the thickness of each plate is substantially parallel to the direction x in which the shaft 32 rotates whereas the length is parallel to the axial direction of the shaft.
The plates 331 to 334 are spaced equidistantly on the shaft 32 in both its axial and circumferential directions. Stated more specifically, a plurality of plates 331 are spaced equidistantly in a straight line on the shaft 32 and so are the plates 332, 333 and 334. As shown in FIG. 4, the line of plates 331 is spaced from the line of plates 332 in the circumferential direction by a central angle of 60 degrees and the same relationship is satisfied by the lines of plates 332 and 333 and the lines of plates 333 and 334. Thus, taken as a whole, the plates 331 to 334 are fixed to the shaft 32 as they are spaced equidistantly in both its axial and circumferential directions. In addition, the axial arrangement of these plates is staggered such that a plate 332 is located between adjacent plates 331 and this allows the plates 331 to 334 to be distributed even more uniformly on the entire surface of the shaft.
As is clear from FIG. 4, the projecting end of each of the plates 331 to 334 is in close proximity to the inner surface of the barrel 31 and this insures that as the shaft 32 rotates within the barrel 31 in the direction of arrow x, the resin moving through the space between the inner surface of the barrel 31 and the outer surface of the shaft 32 is thoroughly mixed by means of the plates 331 to 334.
Each of the plates 331 to 334 has a plurality of holes 335. The openings provided by holes 335 in each plate preferably occupy 10 to 70% of the surface area of the plate. Adjacent plates in the same line are preferably spaced apart by a distance y which is 0.5 to 2 times the diameter of the hole 335. The plates are preferably arranged in 2 to 8 lines in the circumferential direction. If desired, each line may consist of one continuous plate rather than a plurality of spaced plates.
In the example shown in FIG. 3, three holes 335 are provided in one plate but this is not the sole case of the invention and each plate may have only one hole. Alternatively, a great number of holes are provided in a continuous plate. If desired, the density of hole 335 may be changed as shown in FIG. 5 such that more holes are provided in the base portion of a plate 33 which is close to the shaft 32 and in the projecting end portion which is close to the barrel 31 than in the middle portion. In another modification, the direction of the respective holes may be changed with respect to the travel of the resin such that the holes in the projecting end portion of the plate 33 are inclined toward the shaft 32 whereas the holes in the base portion are inclined toward the barrel 31.
In the case shown in FIGS. 3 and 4, the plates are provided perpendicular to the circumferential surface of the shaft 32 in such a way that the width of each plate is substantially parallel to the radial direction of the shaft. This is not the sole case of the invention and the plates may be provided such that the width of each plate is parallel to the tangential direction of the shaft and this can be accomplished by bolting the plates to the circumferential surface of the shaft.
The plates to be used in the invention are by no means limited to a flat form and may have a generally U-shaped cross section as indicated by 33 in FIG. 6 which is a side view and in FIG. 7 which is a section taken on line VII--VII of FIG. 6. The plate 33 consists of two legs 336 and 337 which are fixed onto the shaft 32 and which are connected at the projecting ends by means of a bar 338. As is clear from FIG. 7, the bar 338 is inclined with respect to legs 336 and 337 and opposite ends of the tie-bar in the direction of its width project beyond the legs 336 and 337 when seen in the circumferential direction of the shaft 32. The structure of the plate 33 is such that the open space surrounded by the legs 336 and 337 and the bar 338 serves as a hole. The shaft 32 furnished with at least one plate 33 is preferably rotated in the direction indicated by arrow x in FIG. 7.
The plate 33 shown in FIG. 5 may be positioned at an angle with respect to the axial direction of the shaft 32 as shown in FIG. 8 and this arrangement is effective in reducing the load on the extruding machine, particularly its feed zone. The angle the plate 33 forms with the axial direction of the shaft 32 is preferably 10 degrees and less. This angle should be large enough to insure that the molten resin is given the necessary moving force in the kneading zone but should preferably not exceed 10 degrees in order to prevent heat generation and ensure against extrusion surging.
The barrel 31 in the extruder according to the present invention is commonly adapted to be capable of being heated or cooled as required. To this end, heating bands 36 or cooling jackets 35 may be provided on the surface of the barrel 31 as shown in FIG. 2. Alternatively, the barrel 31 may be designed to have a dual-wall structure consisting of an inner tube and an outer tube as shown in FIG. 3, with a heating or cooling medium being supplied into the space between the two tubes so as to heat or cool the barrel. Although not shown, the shaft 32 may be formed as a hollow member, into which a heating or cooling medium is supplied to heat or cool the shaft as required.
The method and apparatus of the invention will now be described more specifically by reference to an example, which is given here for illustrative purposes only and is by no means intended to be limiting.
EXAMPLE 1
A hundred parts by weight of polystyrene (ESBRITE 7M of Sumitomo Chemical Co., Ltd.) as a thermoplastic resin was mixed with 0.5 parts by weight of a fine talc powder as a foam-controlling agent and 2.0 parts by weight of a flame retardant (SR 103 of Dai-ichi Kogyo Seiyaku Co., Ltd.). The resulting composition was thoroughly mixed and fed into an extruder having an inside barrel diameter of 150 mm and a length of 5,100 mm and the polystyrene was melted with the barrel adjusted to a temperature of 180° C. The barrel had an inlet provided part of its length, through which a blowing agent was forced into the molten polystyrene. The blowing agent consisted of a mixture of 30 parts by weight of monochlorodifluoroethane and 70 parts by weight of methyl chloride. The mixture was forced into the molten polystyrene composition in an amount of about 12 parts by weight per 100 parts by weight of the latter.
The thus prepared resin composition was fed into an extruder (inside barrel diameter: 200 mm), in which it was subjected to mixing and cooling actions; thereafter, the cooled mass was extruded through a die and allowed to expand. The kneading zone of the extruder was of the type shown in FIG. 3; the rotating shaft 32 had a diameter of 140 mm; each of the plates 331 to 334 was 30 mm high and 150 mm long; the kneading zone had an axial length of 4,400 mm; the shaft 32 was rotated at a speed of 14 rpm; and the barrel 31 was cooled to a temperature of about 70° C. The metering zone had triple flights on the screw with a channel depth of 15 mm; the flight pitch was 110 mm; the axial length of the metering zone was 2,000 mm; and the barrel 31 was cooled to a temperature of 70° C. A zigzag mixer was installed ahead of the metering zone and it consisted of four mixing units of a Model SMX (Sulzer AG, Switzerland) connected in tandem, each being 152.4 mm in both outside diameter and length. With the extruder of this design, the resin composition was extruded through the die for expansion at a rate of 800 kg/h. A pressure of 70 kg/cm 2 developed between the metering zone and the zigzag mixer and the temperature at the entrance of the die was 106° C.
The die had a rectangular nozzle 500 mm wide and 4.0 mm thick at the exit end. The extruded resin expanded and was trimmed to produce a foamed board having a density of 29 to 30 kg/m 3 , a width of 1,000 mm and a thickness of 120 mm. The foam had a substantially uniform cellular structure in both close to the skin and the interior, with the cells being distributed uniformly ranging in size from about 0.6 to about 0.8 mm.
Comparative Example
A resin composition was supplied into an extruder having an inside screw diameter of 150 mm and a length of 5,100 mm. With the barrel heated at 180° C., a blowing agent was injected into the resin feed through an inlet provided on the barrel part of its length. Subsequently, the resin composition was supplied into a second extruder having an inside screw diameter of 200 mm and a length of 6,400 mm; it had triple flights on the screw with a channel depth of 15 mm; the flight pitch was 110 mm. The temperature in the barrel was reduced progressively from 120° C. in the feed zone to 70° C. at the exit end and the resin feed was subjected to mixing and cooling actions with the screw rotating at a speed of 10 rpm.
The thus prepared resin composition was subsequently fed into a third extruder having a kneading zone that consisted of a barrel with an inside screw diameter of 300 mm and a rotating shaft with a diameter of 200 mm and a length of 3,600 mm which was equipped with a multiple of plates of the design shown in FIG. 6 and no metering zone was provided. The barrel was cooled to a temperature of 70° C. as the shaft was rotated at a speed of 3 rpm. Extrusion foaming was effected with the resin composition, a zigzag mixer and the die being designed in substantially the same manner as in Example 1, except that an extrusion pressure of 80 kg/cm 2 developed between the kneading zone and the zigzag mixer, that the temperature at the entrance of the die was 107° C.
The rate of extrusion foaming through the die was 820 kg/h and the foam had substantially the same physical properties as the product of Example 1.
Thus, the throughput of extrusion in the comparative example was a little bit higher than in Example 1 but this could only be achieved by using three units of extruding machine.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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An improved process and apparatus for producing a thermoplastic resin foam by mixing a thermoplastic resin, a blowing agent and other necessary components in a molten state and extruding the mixture to expand. The apparatus comprises a metering zone provided at the front end of the rotating shaft in an extruder, a kneading zone provided closer to the rear end than the metering zone, and a plurality of perforated plates mounted on the surface of the shaft in the kneading zone. The outside diameter of said shaft is made smaller than that of the screw in the metering zone as measured at the bottom of channels. This feature combines with the perforated plates to insure uniform mixing and consistent extruding operations.
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FIELD OF THE INVENTION
This invention relates to submerged barges for transporting cargo, and more particularly, is concerned with a boom arrangement for towing a submerged cargo container from a surface vessel.
BACKGROUND OF THE INVENTION
With the increasing movement of oil over the world's oceans, there has developed a need for ever larger tankers to move the oil. Increase in tanker size presents a number of problems, including structural problems of designing the vessel to withstand the surface wave action encountered, the docking problem difficulties in loading and unloading, and maneuvering over existing navigable waterways. While the use of barges or floating cargo containers has been proposed to permit existing tankers to effectively increase their capacity, towing at sea is a hazardous undertaking. Conventionally the tow lines must be made relatively long to permit damping of the relative movement between the two vessels, and give the barge room to maneuver without colliding with the towing vessel. Also, the barge or container must be far enough back to be outside the influence of the propeller wake of the towing vessel.
SUMMARY OF THE INVENTION
The present invention provides an arrangement for towing a cargo container from the stern of a tanker or other conventional cargo ship in a manner which provides close coupling and control of the towed barge while providing effective damping of the relative movement between the barge and the towing vessel. This arrangement includes a semi-rigid boom which extends from the stern of the towing vessel to the nose of an elongated submersible container. The boom is coupled to the stern of the vessel through a hydraulically controlled linkage system which holds the boom in a downward angle so that the connection of the boom to the towed container is at a submerged depth below that of the propeller wake of the towing vessel. The buoyancy of the loaded container and the attitude of the container in the water are controlled remotely from the towing vessel. The towing boom includes a structural rod of an epoxy or other resin or composite material with longitudinally aligned reinforcing fibers which give it great strength while allowing it to flex substantially to compensate for relative motion of the stern of the towing vessel relative to the container.
DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference should be made to the accompanying drawings, wherein:
FIG. 1 is an elevational view of a preferred embodiment of the invention;
FIG. 2 is a sectional view taken on the line 2--2 of FIG. 1; and
FIG. 3 is a partial top view of the stern of the surface vessel.
DETAILED DESCRIPTION
Referring to the drawing in detail, the numeral 10 indicates generally a surface vessel such as an oil tanker or the like, only the stern portion of the vessel being shown in the figure. The bridge and cabin area of the vessel, indicated at 12, are provided in the aft portion of the vessel. A submergible cargo container 14 is designed to operate as much as 80 to 100 ft. below the surface of the water. This submersible container 14 has a surrounding outer wall 16 which is divided by bulkheads 18 into a series of compartments in which can be stored oil or other liquid cargo or ballast. The compartments can also be used to hold air to control the buoyancy of the system. The cargo container 14 preferably is provided with a plurality of longitudinal flotation-cargo tubes 22 and ballast-cargo tubes 24 which interconnect the fore and aft compartments 26 and 28. The tubes may be filled with air or with water or a higher specific gravity slurry to control the overall buoyancy of the container. Preferably the container is trimmed so as to have a slightly positive buoyancy which causes the container to rise slowly to the surface in the event it becomes free of the towing vessel. The towed vessel or a container may employ a structure substantially as set forth in U.S. Pat. No. 3,296,994 incorporated herein by reference.
The container 14 is towed from the surface vessel 10 through a faired semi-rigid boom 30 extending from the stern of the vessel downwardly at an abrupt angle to the surface of the water to a Universal coupling 31 at the bow of the submerged container 14. The coupling 31 may be a ball joint connection, for example, which allows the container 14 to freely adjust its attitude about the point of coupling.
The upper end of the boom 30 is coupled to the stern of the vessel 10 by a pair of linkage arms 32 and 34 which are anchored to the deck of the surface vessel by hinge supports 36 and 38, respectively. The outer ends of the arms 32 and 34 are connected by a pin 39 which passes through the upper end of the boom 30 and provides a hinged support therefor.
The downward angle of the boom 30 is controlled by a pair of hydraulic actuators 40 and 42. The linear actuators are connected at one end to the stern of the vessel by hinge supports 44 and 46, respectively. The other ends of the actuators 40 and 42 are connected to the boom 30 at a point below the pin 39. Thus operation of the linear actuators 40 and 42 moves the boom 30 from a substantially horizontal position, as shown by the broken lines in FIG. 1, to the operative position in which the boom extends downwardly at substantially 45° or greater to the surface of the water. The linkage arms 36 and 38 and the actuators 40 and 42 forms a parallelogram type of support which allows the stern of the vessel 10 to move up and down relative to the boom 30. A hydraulic actuator 48 may be connected between the pin 39 and the stern of the vessel 10 to dampen or control the relative vertical movement between the boom 30 and the stern of the vessel.
As shown by the sectional view of FIG. 2, the boom includes a rigid structural member 50 which preferably is constructed of an epoxy or other resin material reinforced with glass fibers or other suitable fibers which are aligned longitudinally of the boom. A suitable material for this purpose is described in U.S. Pat. No. 3,686,048. The structural member 50 forms the leading edge of the boom and is rounded in the leading edge to reduce resistance to the flow of water around the boom. The trailing edge of the boom is formed from a hollow fairing 52 through which hydraulic lines, electrical cable and air lines for controlling ballast may extend between the surface vessel and the container. The power cable control lines and ballast lines are indicated generally at 54 and extend out the upper end of the boom 30 to a control room in the bridge section 12 of the surface vessel. They connect with the stern compartment 28 of the container vessel 14 through one of the tubes 22.
To control the trim of the container, horizontal control vanes 56 are provided at the stern of the container 14. The angle of the vanes about a transverse horizontal axis is controlled by a suitable motor drive (not shown) within the stern compartment 28 of the container 14. The control motors in turn may be controlled by signals from the surface vessel through the cable 54. The control vanes 56 are normally set to keep the stern from rising due to the positive buoyancy, thereby maintaining a level trim of the container beneath the water, the level of the bow of the container being controlled by the angle of the boom 30.
In circumstances where water depth may be insufficient or other conditions make it necessary to bring the container 14 to the surface and tow it in conventional manner from the surface vessel, the boom 30 is raised to the horizontal position by extending the actuators 40 and 42. The boom 30 may then be used as a guide for a cable extending from a suitable windlass on the vessel 10 through the boom to the bow of the container 14, as indicated by the dashed line in FIG. 1. The cable 58 is played out to allow the container 14 to fall astern by a sufficient distance so as to be unaffected by the wake of the vessel, as in any conventional towing operation.
From the above description it will be seen that a towing arrangement is provided which maintains the container in close coupled relationship to the towing vessel. By holding the container in a submerged position, even though closely coupled to the vessel, it is below the influence of the propeller wake or surface wave action. The hydraulic actuators 40, 42, and 48 permit the towing load of the container to be transferred to the surface vessel 10 while permitting the vessel 10 to pitch and roll under the influence of the surface wave action. Because the structural member 50 of the boom 30 is relatively thin in a transverse direction, considerable sideways flexing of the boom 30 takes place with the rolling of the surface vessel 10 without any adverse affect on the towing action. The container 14 can be relatively simple and inexpensive in terms of the cargo volume compared to a conventional tanker. All power for moving and controlling the trim of the container 14 is derived from the surface vessel 10, although the container 14 may be provided with independent thrust generating means, if desired.
Since the control surfaces or vanes 56 on the container 14 only function effectively when the ship is underway and the vanes are moving through the water, it may be desirable to provide both vertical and horizontal thrusters, such as indicated at 62 and 64, respectively, which can be driven in conventional manner to provide either vertical or horizontal thrust to the stern of the container 14. The thrusters can be used to particular advantage when it is desired to back up the towing vessel 10 so that the container vehicle 14 is moved ahead of the towing vehicle 10. By providing the thrusters, the boom 30 may be extended from the bow of a tug or other surface vessel so as to push the load in front of the surface vessel rather than towing it in the rear, as is sometimes preferable in negotiating more restricted bodies of water, canals, rivers, and the like.
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An arrangement for transporting in which a self-propelled surface vessel tows a submergible elongated cargo container by means of a semi-rigid boom extending from the stern of the vessel to the nose of the cargo container. The position of the boom is controlled from the stern of the vessel to hold the nose of the container at a level below the wake of the towing vessel.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2012-0041085 filed Apr. 19, 2012, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an antibacterial composition comprising titanium oxide immobilized with an antibody having affinity and cognitive power to a microorganism of interest, and a method for sterilizing the microorganism by using the same. In particular, the present invention relates to a method for preparing functional titanium oxide particles wherein an antibody capable of recognizing a microorganism or a virus of interest is immobilized on the surface thereof, and a method for selectively and efficiently sterilizing the microorganism or virus of interest by using the functional titanium oxide particles.
BACKGROUND
[0003] Generally, various methods such as a filtering method using a filter (U.S. Pat. No. 6,780,332), a high/low temperature treatment method (U.S. Pat. No. 5,366,746; U.S. Pat. No. 6,086,936), an antibiotic treatment method (U.S. patent Ser. No. 10,415,219), a disinfectant method (U.S. Pat. No. 6,583,176) and a UV irradiation method (U.S. Pat. No. 7,396,459) have been widely used in the art for inactivating a microorganism (a bacteria or a virus) or preventing a subject from being infected therewith. Recently, it has been developed a method for sterilizing a microorganism by using superoxide (O 2 − )/hydroxyl radical (OH) generated from photoreaction of a photocatalyst such as titanium oxide (U.S. Pat. No. 6,387,844; U.S. Pat. No. 6,777,357). The photocatalyst accelerates a chemical reaction by absorbing light from the outside. Among the photocatalysts, titanium oxide is a stable substance, but under ultraviolet (UV) light, it loses electrons and holes are formed thereon, leading to the excitation into an unstable state. At this time, superoxide (O 2 − ) or hydroxyl radical (OH) generated from the excitation exerts antibacterial activities by inducing the oxidization or degradation of microorganisms and viruses around. Due to such strong oxidizing power, the attempts for applying titanium oxide to the sterilization by coating the same onto the surface of a support or spreading it in underwater have been remarkably increased. Because said method of coating the support with titanium oxide or dispersing it in an aqueous solution does not have selectivity to a microorganism of interest, the most cases are to merely utilize radicals generated from titanium oxide itself. Further, there is no systemic research on the correlation between the number of microorganisms and the concentration of titanium oxide, and the consideration of UV strength and a period of time being irradiated. For example, in a water system, there are problems in that the residence time of radicals generated from titanium oxide is not last long, and its antibacterial activities is lowered when the distance between the microorganism of interest and the titanium oxide is not extremely close. U.S. patent application Ser. No. 12/743,340 discloses a method for immobilizing titanium oxide particles with a biomolecule, but it provides only the information on sensor application of the immobilized complex and not antibacterial activities thereof.
[0004] Sakai et al. reported that a microelectrode comprised of titanium oxide can be used in killing T24 human bladder cancer cells. They also reported that if the microelectrode comprised of titanium oxide is 10 cm or longer distant from the cells, there is no effect of killing the cells. In this research, such poor antibacterial activities are because that direct oxidation is not actively occurred on the surface of the cells due to a very short life span of radicals generated from titanium dioxide (Sakai et al., Chemistry Letter, 1995, 185). In case of using the titanium oxide particles having no selectivity, there is a possibility of sterilizing normal useful microorganisms as well as target microorganisms being sterilized. Further, as suggested in the previous research, because the radicals generated by UV irradiation cannot be delivered to the microorganism, there is a disadvantage in that its antibacterial activity is not strong. The study for utilizing titanium oxide as an antibacterial composition has been actively pursued and relating products have been manufactured. But, there is no report on the development of titanium oxide photocatalytic particles having selectivity to a microorganism of interest as disclosed in the present invention.
SUMMARY OF THE INVENTION
[0005] The present inventors have therefore endeavored to overcome the above problems in the art, and developed a method for preparing titanium oxide photocatalytic particles by immobilizing titanium oxide having no selectivity to a microorganism of interest with an antibody capable of recognizing the microorganism. Because the titanium oxide photocatalytic particles of the present invention can selectively bind to the microorganism of interest and generate radicals at the position which is closest thereto, it is possible to effectively show antibacterial activities and thus sterilize the microorganism. Therefore, the present invention is characterized by providing a method for sterilizing a microorganism of interest by using the titanium oxide immobilized with an antibody.
[0006] Other objects and advantages of the present invention will be apparent upon consideration of the following specification, with reference to the accompanying drawings and claims.
[0007] It is an object of the present invention to provide titanium oxide particles immobilized with a bioreceptor capable of specifically binding to a microorganism of interest, in which the bioreceptor is immobilized onto the titanium oxide particle through the binding between a functional group linked to the titanium oxide particle and the functional group of the bioreceptor.
[0008] It is another object of the present invention to provide a method for selectively sterilizing a microorganism of interest by using titanium oxide particles immobilized with an antibody specific to the microorganism, comprising the following steps:
[0009] (i) bringing into contact the titanium oxide-antibody complex with the microorganism for a period of time; and
[0010] (ii) sterilizing the titanium oxide-antibody complex by UV irradiation.
[0011] According to the method of the present invention, it is possible to selectively sterilize a microorganism of interest depending on the kind of an antibody immobilized on the titanium oxide particles.
[0012] The method of immobilizing titanium oxide particles with an antibody is characterized by forming a carboxyl (—COOH) group through the reaction between the titanium oxide particles and polyacrylic acid (PAA), treating the titanium oxide particles to which PAA is linked with EDC (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride) and sulfo-NHS (N-hydroxysulfosuccinimide) so as to induce the binding between the carboxyl group of the titanium oxide particles and an amine (—NH 2 ) group of the antibody, separating thus prepared titanium oxide particles by centrifugation, and immobilizing the antibody onto the titanium oxide particles. Here, the linking method for the immobilization of an antibody onto titanium oxide particles is not limited to that using PAA, EDC or sulfo-NHS.
[0013] According to one preferred embodiment, the present invention provides a titanium oxide- E. coli specific antibody complex in which an E. coli specific polyclonal antibody is immobilized onto the surface of the titanium oxide particle. Further, according to another embodiment, the present invention provides a method for sterilizing E. coli , comprising the steps of:
[0014] (i) bringing into contact the titanium oxide-antibody complex with E. coli by mixing the titanium oxide particle immobilized with the E. coli specific antibody with an E. coli containing solution, and
[0015] (ii) exposing the mixture to UV irradiation.
EFFECT OF THE INVENTION
[0016] The features and advantages of the present invention are summarized as follows:
[0017] (i) the titanium oxide-bioreceptor particle of the present invention can exhibit excellent antibacterial activity by generating oxidized free radicals under the condition that a microorganism of interest is close to the titanium oxide particle through cross-linkage between a functional group linked to titanium oxide and a functional group of the bioreceptor, and
[0018] (ii) the titanium oxide-bioreceptor particle of the present invention can more effectively sterilize a microorganism of interest in a smaller amount for a shorter period of time than conventional titanium oxide particles being not immobilized with a microorganism specific antibody.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0020] FIG. 1 is a schematic diagram illustrating the method of immobilizing a microorganism specific antibody to titanium oxide particles according to the present invention, in which the principle of enhancing antibacterial activities of the titanium oxide particle immobilized with the antibody is illustrated;
[0021] FIG. 2 is the result of analyzing the surface of titanium oxide particles before and after the introduction of a carboxylic group by Fourier transform infrared spectroscopy (FTIR);
[0022] FIG. 3 is the result of comparing the sterilizing effects on E. coli after an E. coli containing PBS buffer is treated with the titanium oxide particles to which an E. coli specific antibody is immobilized or with the titanium oxide particles not being immobilized with the antibody, followed by UV irradiation. As a control, the E. coli containing PBS buffer is subjected to only UV irradiation; and
[0023] FIG. 4 is the result of comparing the sterilizing effects on Staphylococcus epidermidis after a Staphylococcus epidermidis containing PBS buffer is treated with the titanium oxide particles to which an E. coli specific antibody is immobilized or with the titanium oxide particles not being immobilized with the antibody, followed by UV irradiation.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Hereinafter, the present invention will be described in more detail.
[0025] According to one aspect of the present invention, it is provided a titanium oxide particle immobilized with a bioreceptor in which the bioreceptor is capable of specifically binding to a microorganism of interest through the binding between a functional group linked to the titanium oxide particle and a functional group of the bioreceptor.
[0026] According to a preferred embodiment of the present invention, the binding between a functional group of the titanium oxide particle and a functional group of the bioreceptor is achieved by a cross-linkage between a carbonyl group and an amine group. Especially, it is preferable to be a cross-linkage between a carboxylic acid and an amine group. In particular, an amide linkage, a sulfhydryl-amine linkage, a hydrogen-amine linkage, an amine-amine linkage and a carbonyl-sulfhydryl linkage can be used in the method of the present invention.
[0027] In the following Table 1, specific examples of the sulfhydryl-amine linkage, hydrogen-amine linkage, amine-amine linkage and carbonyl-sulfhydryl linkage besides the amide linkage are described.
[0000]
TABLE 1
Possible linkage between titanium oxide particles and bioreceptors
Linkage
Reaction scheme
Sulfhydryl- Amine
Hydrogen- Amine
Amine- Amine
Carbonyl- Sulfhydryl
[0028] It is preferable to add carbodiimide as a coupling reagent in order to facilitate the direct linkage between a carboxylic acid and an amine, and carbodiimide such as DCC, EDC, DIC and the like can be used.
[0029] According to a preferred embodiment of the present invention, the functional group linked to the titanium oxide particle is a carbonyl group, and the functional group linked to the receptor is an amine group.
[0030] According to a preferred embodiment of the present invention, the carbonyl group can include acyl chloride, acid anhydride, ester and carboxylic acid, but is not limited thereto. More preferably, the carbonyl group is carboxylic acid.
[0031] According to a preferred embodiment of the present invention, the bioreceptor can be one of a protein antibody, DNA as a nucleic acid molecule, and a RNA-based aptamer.
[0032] As used herein, the term “nucleic acid molecule” is intended to inclusively mean DNA molecules (gDNA and cDNA) and RNA molecules. Nucleotides are molecules that, when joined, make up the individual structural units of the nucleic acids RNA and DNA, and include analogues having altered sugar or nucleobases as well as naturally occurring nucleotides (Scheit, Nucleotide Analogs, John Wiley, New York (1980); Uhlman and Peyman, Chemical Reviews, 90: 543-584, 1990).
[0033] The aptamers are DNA or RNA oligonucleotides that are folded into a certain conformation so as to bind to a target antigen with high specificity and affinity. Such aptamers can be obtained according to a SELEX (Systemic Evolution of Ligands by Exponential Enrichment) method (Tuerk and Gold, Science, 249: 505-510, 1990).
[0034] The microorganism specific binding according to the present invention may be applied to all kinds of microorganisms that are being subjected to the binding of the present invention, and thus there is no limitation to the kind of a microorganism.
[0035] More preferably, the microorganism specific binding according to the present invention is characterized by showing E. coli specific binding.
[0036] According to the other aspect, the present invention provides a method of selectively sterilizing a microorganism of interest depending on the type of an antibody immobilized onto the surface of a titanium oxide particle by using the titanium oxide particle immobilized with the antibody, comprising the following steps of:
[0037] (i) bringing into contact the titanium oxide-antibody complex with the microorganism for a period of time in order to increase antibacterial effects on the microorganism having a specificity to the antibody by using the titanium oxide particle immobilized with the antibody according to claim 1 or 5 ; and
[0038] (ii) sterilizing the microorganism by UV irradiation to the titanium oxide-antibody complex.
[0039] According to a preferred embodiment of the present invention, the UV irradiation of step (ii) is carried out for 5 to 15 min, preferably for 10 to 15 min.
[0040] FIG. 1 is a schematic diagram illustrating the method of immobilizing a microorganism specific antibody to the titanium oxide particle according to the present invention. The method of immobilizing the antibody to the titanium oxide particles can be carried out by reacting the titanium oxide particle with polyacrylic acid (PAA) to form a carboxylic group (—COOH), treating the titanium oxide particle into which the carboxylic group is introduced with EDC (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride) and sulfo-NHS (N-hydroxysulfosuccinimide), to thereby introduce NHS-ester which is capable of biding to an amine group (—NH 2 ) of the antibody, and immobilizing the antibody thereon. This method is described in detail as follows.
[0041] First, 0.1 g of the titanium oxide particles are dispersed in 20 mL of a DMF (N,N-dimethylformamide) solution, followed by mixing with 2 mL of a polyacrylic acid solution in dimethylformamide (100 mg PAA/1 mL DMF). The mixed solution obtained above is kept at 150° C. for 5 hrs in a thermostat. After keeping it in the 150° C. thermostat for 5 hr, the mixed solution is cooled down to room temperature and 38 mL of an acetone solution is added thereto. The resulting mixed solution is kept at room temperature for 1 hr. After that, the resulting mixed solution was centrifuged at 4000 rpm for 20 min to separate titanium oxide particles coated with polyacrylic acid. Thus separated titanium oxide particles are washed with 40 mL of ethanol three times, subjected to centrifugation, and dried at room temperature for 24 hr, to thereby the titanium oxide particles coated with polyacrylic acid. The carboxylic group that is introduced into the surface of the titanium oxide particle through the coating of polyacrylic acid can be analyzed by Fourier transform infrared spectroscopy (FTIR). FIG. 2 is the FTIR analysis result of comparing PAA-coated titanium oxide particles and PAA-uncoated titanium oxide particles. The PAA-coated titanium oxide particles show a peak at about 1730 cm −1 . Such a peak represents the presence of C═O, which suggests that the carboxylic group is successfully introduced into the titanium oxide particles through PAA coating. Thus dried titanium oxide particles are dissolved in a MES buffer (2-[morpholino]ethanesulfonic acid buffer, pH 5.9) to adjust its concentration to 25 mg/mL. To 2 mL of the MES buffer in which the titanium oxide particles are dissolved (pH 5.9) was added EDC and sulfo-NHS at a concentration of 80 mM and 20 mM, respectively. After reacting for 1 hr at room temperature, the titanium oxide particles are isolated by centrifuging at 4000 rpm for 20 min, followed by re-dissolving in 1 mL of the MES buffer. To the resulting solution is added 0.2 mg of an E. coli polyclonal antibody and kept at 4° C. for 12 hr. After that, 0.5 mL of an ethanolamine solution (0.1 M) is added to the resulting solution to interfere the NHS-ester being not adhered to the antibody. After keeping it at room temperature for 30 min, the resulting solution is kept at 4° C. for 30 min again. Last, the titanium oxide particles immobilized with the E. coli specific antibody are washed with a PBS buffer (pH 7.0) three times, followed by dissolving in 1 mL of the PBS buffer (pH 7.0). The antibacterial activity of the titanium oxide particles immobilized with the E. coli specific antibody can be proved in the following Examples.
[0042] The present invention is further illustrated by the following examples. However, it shall be understood that these examples are only used to specifically set forth the present invention, rather than being understood that they are used to limit the present invention in any form.
Example 1
[0043] After E. coli was cultured in 100 mL of a LB medium until the OD 600 reached 0.4, 12 mL of the culture solution was collected therefrom and subjected to centrifuging so as to separate E. coli . Thus separated E. coli was washed with 12 mL of a PBS buffer (pH 7.0) and dispersed in 5 mL of a PBS buffer (pH 7.0) in a 20 mL glass bottle. Three such samples were prepared in the same way. Titanium oxide particles immobilized with an E. coli specific antibody were added to a Bottle 1 and non-immobilized titanium oxide particles were added to a Bottle 2 in each amount of 0.25 mg. There was no added to a Bottle 3 . All three bottles were put into a rotator shaking incubator which was set at 25° C., 200 rpm and subjected to shaking culture for 15 min. After 15 min, a 355 nm UV lamp (15 W) was installed at intervals of about 10 cm therefrom, and then UV was irradiated thereto. Before the UV irradiation (0 min) and after UV was irradiated for 15 min and at thirty-minute intervals thereafter, 100 uL of a sample was collected from each bottle. Thus collected sample was diluted by 1000 times, plated onto each of agar plates, and then incubated in a 37° C. thermostat for 17 hr. After the incubation was completed, the number of E. coli cells existed in each bottle was determined by counting the number of colonies formed on the agar plate.
[0044] The results of measuring the number of E. coli cells are shown in FIG. 3 based on the number of E. coli cells existed in each bottle at 0 min Generally, under UV irradiation, E. coli was killed. At this time, when UV was irradiated in the presence of the titanium oxide particles, titanium oxide generated active oxygen, leading to the increase in antibacterial activity. When compared the death rate of E. coli 15 min after the titanium oxide particles were added, in case of adding the titanium oxide particles immobilized with the E. coli specific antibody, the death rate of E. coli was 90% or higher, and in case of adding the non-immobilized titanium oxide particles, the death rate thereof was only 20%. These results have confirmed that the antibacterial activity of the titanium oxide particles immobilized with the E. coli specific antibody was increased by about 4.5-fold. Further, the titanium oxide particles immobilized with the E. coli specific antibody shortened the time for completely sterilizing E. coli cells by 1 hr. In the case that the titanium oxide particles immobilized with the E. coli specific antibody adhered to E. coli cells and UV was then irradiated thereto, activated oxygen generated from the titanium oxide particles was delivered more easily to the E. coli cells, and thus their antibacterial activity was further enhanced.
[0045] This Example is merely illustrative of some methods for assessing the efficiency of the titanium oxide particles immobilized with the E. coli specific antibody, and there is no limitation to the methods of culturing E. coli , irradiating UV and the like so as to assess its antibacterial activity.
Example 2
[0046] It was confirmed in Example 1 that the antibacterial activity of the titanium oxide particles immobilized with the E. coli specific antibody was significantly increased. In this Example, whether the titanium oxide immobilized with the E. coli specific antibody exhibited antibacterial activity to other cells besides E. coli was investigated. For this, Staphylococcus epidermidis cells were cultured according to the same method as E. coli . As a result of irradiating the cultured Staphylococcus epidermidis cells with UV, there was no difference in antibacterial activity between the addition of titanium oxide particles only and that of titanium oxide particles immobilized with the E. coli specific antibody ( FIG. 3 ). This was because that the antibody immobilized to the titanium oxide particles was not specific to Staphylococcus epidermidis , and thus unlike E. coli , the titanium oxide particles did not adhere thereto, which results in dispersing the antibody titanium oxide particles in the culture solution of Staphylococcus epidermidis . In case of adding the same amount of the titanium oxide particles, there was no difference in antibacterial activity due to the lack of antibody specificity.
[0047] This Example is merely illustrative of some methods for assessing the efficiency of the titanium oxide particles immobilized with the E. coli specific antibody, and there is no limitation to the methods of culturing E. coli , irradiating UV and the like so as to assess its antibacterial activity.
Example 3
[0048] From Examples 1 and 2, it was found that the titanium oxide particles immobilized with the E. coli specific antibody exhibited increased antibacterial activity to E. coli . In Examples 1 and 2, two kinds of microorganisms were cultured in a separate cultivator and the antibacterial activities thereon were investigated independently. In order to investigate whether the titanium oxide particles immobilized with the E. coli specific antibody can selectively sterilize E. coli when two kinds of microorganisms are existed, the antibacterial activity of the titanium oxide particles immobilized with the E. coli specific antibody to E. coli was measured in the presence of E. coli and Staphylococcus . After E. coli was cultured in 100 mL of a LB medium until the OD 600 reached 0.4, 12 mL of the culture solution was collected therefrom and subjected to centrifuging so as to separate E. coli cells. After Staphylococcus was cultured in 100 mL of a LB medium until the OD 600 reached 0.25, 20 mL of the culture solution was collected therefrom and subjected to centrifuging so as to separate Staphylococcus cells. Thus isolated E. coli and Staphylococcus cells were dispersed in a 25 mL PBS buffer, respectively, and 10 mL of the resulting E. coli solution was mixed with 10 mL of the resulting Staphylococcus solution. After that, the antibacterial activities to E. coli and Staphylococcus were measured according to the same method as described in Example 1. At this time, the antibacterial activity was compared 5 min after UV irradiation. As a result, in case of E. coli , when the titanium oxide particles immobilized with the E. coli specific antibody was added, about 30% of E. coli was killed. When the non-immobilized titanium oxide particles were added only, there was no difference in the death rate of E. coli . In case of Staphylococcus , there was about 10% of difference in the death rate between the addition of the titanium oxide particles immobilized with the E. coli specific antibody and the addition of the non-immobilized titanium oxide particles. The same level of death rate was observed irrelevant to the action of the titanium oxide particles immobilized with the E. coli specific antibody and the non-immobilized titanium oxide particles. Therefore, it was confirmed that the titanium oxide particles immobilized with the E. coli specific antibody selectively acts to only E. coli even in the co-presence of E. coli and Staphylococcus , leading to the increase in antibacterial activity ( FIG. 4 ).
[0049] This Example is merely illustrative of some methods for assessing the efficiency of the titanium oxide immobilized with the E. coli specific antibody, and there is no limitation to the methods of culturing E. coli , irradiating UV and the like so as to assess its antibacterial activity.
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Disclosed is an antibacterial composition comprising titanium oxide particles immobilized with an antibody having affinity and cognitive power to a microorganism of interest, and a method for sterilizing the microorganism by using the same. In particular, the present invention relates to a method for preparing functional titanium oxide particles capable of recognizing a microorganism or a virus of interest, and a method for selectively and efficiently sterilizing the same by using the functional titanium oxide particles, and not for randomly sterilizing microorganisms or viruses by using conventional titanium oxide particles having no recognition power to a microorganism or a virus of interest.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Patent Application No. 16176994.8, which was filed on Jun. 29, 2016. The entirety of this European patent application is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of providing a recent call list, and also relates to a software product, a telecommunications device and a telecommunications system.
BACKGROUND OF THE INVENTION
[0003] A telecommunication device can provide a recent call list that includes calls recently received or initiated by the telecommunications device. A recent call list is generally understood as a list including calls recently received and/or initiated using a telecommunications device, and generally allows a user to select particular entries, and initiate further calls based on such selection. The recent call list typically identifies telephone calls that were previously made by the device. In other words, a recent call list as generally known in the art is limited to showing the history of past calls.
[0004] For example, WO 2014/187288 A1 relates to a call log invoking method. A call log invoking request sent by a client comprises an action field for indicating an invoking operation and a type field for indicating that a data type is a call log. WO 2008/130101 A1 relates to providing various call services by using a hot key. EP 1 621 983 A2 relates to more easily find an item within a plurality of items of the same kind such as communications, contacts, folders, files, messages, applications, or the like, by providing a recent item list of items that were recently used. Correspondences (incoming and outgoing) may be matched to a corresponding contact stored in a device. A recent item may be shown only once in the recent items list.
SUMMARY OF THE INVENTION
[0005] A technical problem underlying the present invention is enhancing functionality of a recent call list. A further problem underlying the present invention is enhancing control of an integrated system facility management, surveillance, and monitoring by use of a telecommunications device.
[0006] The problem(s) mentioned above are at least in parts solved by the features of the appended independent claims. Further developments and advantageous embodiments of the invention are set forth in the dependent claims.
[0007] A first aspect, or embodiment, of the present invention relates to a method of providing a recent call list of calls recently received or initiated by a telecommunications device. Information on recent services which are services recently handled by or using said telecommunications device other than calls are incorporated as entries in a recent call list of said telecommunications device. Each entry of said recent call list is formed by a data structure including a plurality of data fields, wherein each data field includes a data value. An entry representing a recent service other than a call in said recent call list includes a service code identifying said recent service, as a data value. In the above aspect, recently generally means in the past. Handling of a service may include, without being limited to, initiating, controlling, monitoring, receiving reports about. A value may generally be comprised of or interpretable as any sort of character string, numeral, logical, or whatsoever, or even an array thereof. A service other than a call may be a service other than a telecommunications service at all such as door opening, facility management or surveillance, entry control, environmental surveillance, machine control, or others.
[0008] It should be understood that a call as used herein to describe embodiments of the present innovation described in this patent application can include a telephone call, but can also include other telephoning communication events such as fax, SMS (text messaging, short message service messaging, etc.) and can also include other types of telecommunications exchanges or messaging by email, skype, twitter, facebook, xing, a blog, or the like, and may include audio, video, text, or other content. A call may therefore include a telecommunications exchange involving the telecommunications device that may be defined by use of an application stored on that device and use of a service accessible via an application programming interface (“API”) or other type of interface with a remote service hosted by one or more remote servers (e.g. remote computer devices having hardware including a processor, memory, and at least one transceiver type device) accessible via a network (e.g. the internet, etc.) that may be utilized via that application. A call in the sense of the application can be understood to be represented by a call identifier of another side of the call and preferably includes other contact information, in the recent call list.
[0009] In preferred embodiments, a data field may include a data field identifier identifying its respective data value (e.g. each entry may be understood as a data set wherein a place intended for a specific kind of data value is a data field which is uniquely identified by a respective data field identifier). A kind of data value may be any data in relation to a call, such as date/time, duration, other party (called, calling), direction of call (in, out, incoming, outgoing, etc.), and absolute call count in device, etc. The sum of entries may thus be provided in the form of a database or other type of datastore. As an example, the data structure may be predefined by JavaScript Object Notation (JSON), or other data exchange format. In any of such data exchange formats, the data values of each data field are information used for clearly and unambiguously identifying a call, and providing further information thereon. At least, such information allows to identify another side of the call, in particular to an extent to be able to initiate a further call with said other side. Preferably, such information also includes other aspects of a call such as date and/or time of the call. A data field identifier may be a mere field count, or be a character string including a name or shortcut of a specific kind of data value such that a data field identifier indicates a place intended for a specific kind of data value, i.e., for a specific information relating to a call. Thereby, call information may be found, interpreted and used by a call handling device or software stored in non-transitory memory of that device that is run by a processor of that device.
[0010] In preferred embodiments, said service code may be included at a place intended in said entry for a call identifier of another side of a call, and include a distinguisher allowing for distinguishing a service code from a call identifier. Said distinguisher may be a prefix or suffix, and may include a character or text not expected for a call identifier. It will be noted that each type of service may be addressed by a unique service code just like a certain other party may be addressed by a unique call identifier. It will be noted that a call identifier may include, without being limited to, any of a telephone number, a telefax number, an email address, or any other type of electronic address.
[0011] In preferred embodiments, an entry representing a recent service other than a call in said recent call list may include a plain text description of said recent service as a data value. Said plain text description may be included at a place intended in said entry for contact information of another side of a call, said contact information including at least a name and a call identifier, and be in a format expected at that place.
[0012] In preferred embodiments, an entry representing a recent service other than a call in said recent call list may include a second level detail of said recent service as a data value. Said second level detail may be included at a place intended in said entry for a second level detail of a call, and be in a format expected at that place. Second level detail of a call may for example include, without being limited to, detail of whether a call was answered, not answered, rejected, or ran into a busy terminal. Second level detail of a service other than a call may for example include, without being limited to, a result of the service.
[0013] In preferred embodiments, an entry representing a recent service other than a call in said recent call list may include a service type of said recent service as a data value. Said service type may be included at a place intended in said entry for a call type of a call, and be in a format expected at that place. A type of a call may for example include, without being limited to, detail of whether a call was outgoing or incoming.
[0014] In preferred embodiments, an entry representing a recent service other than a call in said recent call list may include follow-up service information on a follow-up service which is a service to be activated upon selection of said entry by a user, as a data value. Said follow-up service information may include a service code identifying said follow-up service.
[0015] In preferred embodiments, said recent call list may be displayed or displayable upon user choice on a display device, and if an entry representing a recent service other than a call is found in said recent call list, at least one of the service code of said recent service, and a plain text description assigned to said service code, is displayed for such entry in displaying said recent call list. In other words, just data fields which are used for displaying call details are also used to display contents of a recent service other than a call. The appearance in a displayed recent call list would be quite the same format for recent calls and recent services other than calls.
[0016] In preferred embodiments, said recent call list is sorted or sortable upon user choice by at least one of a date, call identifier of another side of a call, name and/or other contact information, and service code.
[0017] In preferred embodiments, said entries regarding one same service functionality are grouped or groupable together upon user choice in said recent call list. In preferred embodiments, said telecommunications device may be a telecommunications terminal device. Said recent service and/or a follow-up service may be executed or executable by a telecommunications server such as a PBX or the like. As an alternative or additional option, remote services may address or be addressable by a telecommunications server such as a private branch exchange (PBX) of telecommunication switch device via a local area network (LAN) or a wide area network (WAN). Such networks may be wireless, wired, or include transmission paths that include both wired and wireless transmission paths involving a plurality of intermediate nodes (e.g. gateways, base stations, access points, routers, etc.).
[0018] In preferred embodiments, a data structure may be provided comprising assignments of service codes and additional information for identifying and/or describing a service or kind of service. Said additional information may comprise at least one of a plain text description, service type, service code of a follow-up service. Said data structure may be provided in the form of a database, table, or the like.
[0019] A second aspect, or embodiment, of the present invention relates to a software product for providing a recent call list of calls incoming to and outgoing from a telecommunications device, said software product being stored on a non-transitory computer-readable medium, preferably being directly loadable into an internal memory of a computer. The software product of this aspect comprises program code for performing the steps of the method of the afore-described first aspect of the present invention at said telecommunications device when said software product is executed by said computer. Said computer may be embodied by said telecommunications device or a server connected to said telecommunications device. It will be noted that the software product may be embodied by, without being limited to, a stand-alone software, software package, plug-in, add-on, app or the like to be included in or used by or co-executed with or enabling or enhancing functions of a telecommunications software, or may constitute or be part of or include a basic operating program of a telecommunications device, unit, server, system, or the like.
[0020] A third aspect, or embodiment, of the present invention relates to a telecommunications device, preferably a telecommunications terminal device (e.g. a computer, a desktop computer, a personal computer, a laptop computer, a telephone, a smart phone, an electronic tablet device, televisions, or other type of endpoint device having hardware that includes non-transitory memory (e.g. flash memory, a hard drive, etc.), a processor (e.g. a central processing unit, a microprocessor, etc.) configured for use by a user to initial calls and/or receive calls for engaging in telecommunications activities with others, and at least one transceiver unit (e.g. at least one receiver and at least one transmitter). The telecommunications device of this aspect is adapted to execute the method of the afore-described first aspect of the present invention. Adaptation may be provided by implementing the program code of the software product of the afore-described second aspect of the present invention. It will be noted that the telecommunications terminal device in some embodiments may be any kind of device suitable to perform telecommunication events, such as a mobile phone, smart phone, portable computer, desktop computer, a telecommunications server such as a PBX, or the like.
[0021] A fourth aspect, or embodiment, of the present invention relates to a telecommunications system comprising at least one telecommunications device, preferably at least one telecommunications terminal device. The telecommunications system of this aspect is adapted to execute the method of the afore-described first aspect of the present invention. Adaptation may be provided by implementing the program code of the software product of the afore-described second aspect of the present invention on at least one instance included in said telecommunications system. The telecommunications system may comprise at least one server for executing services other than telecommunications services. The server may be or included in or comprise a PBX. Said services other than telecommunications services may include at least one of a door opening service, door monitoring service, facility management service, surveillance or monitoring services, or the like. The telecommunications system may further comprise at least one of a telecommunications server for executing telecommunications services. It will be noted that the server and the telecommunications server may be, but need not to be, the same device.
[0022] Embodiments (or aspects) of the present invention may as well be embodied by a computer program including instructions configured for storage within memory of a device to cause that device to o perform the steps of the afore-described method of the first aspect when said computer program is loaded in or executed by said device, or by a digital data carrier having electrically readyble control signals which are designed to operate with a programmable device, said control signal being designed and adapted to cause the device to perform the steps of the method of the afore-described first aspect of the present invention. In any such cases, the device may also be embodied by the telecommunications device of the afore-described third aspect.
[0023] With embodiments of the present invention, a concept is introduced that services activated or addressed via service codes can be incorporated within a recent call list so that such services appear just like telephone calls in the call history. In other words, the functionality of a well-known recent call list is enhanced in that it may be understood as a recent-calls-and-services history, and each service event appearing as an entry in the history may be selected just as a call so as to inspect its details, or activate some follow-up service which may be predefined or suggested as part of the same entry of the recent call list. This also enhances control of an integrated system facility management, surveillance, and monitoring by use of a telecommunications device.
[0024] Further aspects (or embodiments), objects, advantages, and details of the present invention will become more apparent from the following description of specific exemplary embodiments of the invention and respective illustration thereof in the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Exemplary embodiments of a software product stored in non-transitory memory, a telecommunications device, and a telecommunications system, and methods of making and using the same are shown in the drawings included herewith. It should be understood that like reference numbers used in the drawings may identify like components.
[0026] FIG. 1 shows a general example of a telecommunications environment including a telecommunications system and a telecommunications device according to an exemplary embodiment of the present invention.
[0027] FIG. 2 shows an excerpt of a recent call list provided by a method according to an exemplary embodiment of the present invention as showing up on a display of a telecommunications device.
[0028] FIG. 3 shows a flowchart of a process in a method according to an exemplary embodiment of the present invention.
[0029] FIG. 4 shows a flowchart of another process in a method according to an exemplary embodiment of the present invention.
[0030] FIG. 5 shows an example of an recent call entry of a recent call list provided by a method according to an exemplary embodiment of the present invention.
[0031] FIG. 6 shows an example of an recent service entry of a recent call list provided by a method according to an exemplary embodiment of the present invention.
[0032] Next, the invention will be described with reference to specific exemplary embodiments in view of the appended drawings. It will be noted however that the illustrations in the drawings are purely schematic, need not to be to scale, and may be limited to features that are believed to be useful for a person of skill in the art to understand principles that may be incorporated into embodiments of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] FIG. 1 shows a general example of a telecommunications environment 100 according to an exemplary embodiment of the present invention.
[0034] As shown in FIG. 1 , the telecommunications system includes a number of communications terminal devices 102 . Each terminal device 102 may in general be understood as a computer device that includes a CPU, ROM, RAM, internal and/or external busses, interfaces and controllers, power supply etc. and is connected to (or includes) a display unit 104 for displaying contents as results of software running on terminal device 102 . For instance, software stored in non-transitory memory can be executed by a processor of the terminal device 102 such that the device performs a method defined by the code of the software. Graphical user interface information can be displayed based on such software via the display unit to facilitate displaying of output to a user and receipt of input from a user utilizing one or more input devices of the terminal device (e.g. touch screen feature of the display unit 104 , stylus, button, keypad, keyboard, pointer device, mouse, etc.).
[0035] In the present example, a recent call list 106 is displayed on display unit 104 of one of the terminal devices 102 . Each terminal device 102 may also be connected to (or include) I/O facilities such as a writing unit 108 such as a keyboard, a pointing unit 109 such as a mouse, and a voice unit 110 such as a head set. Terminal devices 102 are connected to a PBX 112 directly or via a local area network (not explicitly shown), or implemented in PBX 112 .
[0036] Moreover, a door opening service 114 and a facility management service 116 are connected to a PBX 112 directly or via the local area network, or implemented in PBX 112 . PBX 112 is connected or connectable to a wide area network (WAN) 118 such as the internet or the like. For connecting to WAN 118 , PBX 112 may be assumed to be connected to or include some routing/gateway facility (not explicitly shown) which may also manage the local area network mentioned above. Via WAN 118 , PBX 112 is further connected to a telecommunications provider 120 and a remote facility management system 122 . The terminals 102 and the PBX 112 may be understood as a telecommunications system in the sense of the present invention.
[0037] FIG. 2 shows an excerpt of recent call list 106 as it shows up on display 104 of a telecommunications device 102 used by a user (see FIG. 1 ), including typical examples of the features introduced according to the present invention. The recent call list 106 includes a number of entries which will be generally addressed by reference sign 202 , in the following. In the excerpt showing up in FIG. 2 seven individual entries 202 . 1 , . . . , 202 . 7 are visible of which entries 202 . 1 , 201 . 2 , 202 . 5 and 202 . 7 relate to recent calls, entries 202 . 4 and 202 . 6 relate to telecommunication services other than telephone calls, and entry 202 . 3 relates to a service other than a telecommunication service (and, obviously, other than a telephone call).
[0038] Each entry 202 displayed in the excerpt of the recent call list 106 is divided into several display areas as exemplarily indicated by dotted border lines in the first entry 202 . 1 , including a name area 204 , a number area 206 , a date area 208 , a time area 210 , and a selection area 212 . If an entry relates to a call such as, e.g., entry 202 . 1 , 202 . 2 and others, the name area 204 shows a name of a person (or more generally, of a party which also may be a company, society or whatever entity) to which or from which the call was directed, the number area 206 shows a number (or more generally, a party identifier) of the party to which or from which the call was directed, the date and time areas 208 , 210 show a date and time of when the call was made or received, and selection area 212 includes some selection symbol which is selectable by, e.g., pointing unit 109 of FIG. 1 . If an entry relates to a service other than a call as exemplified by entry 202 . 3 , the name area 204 shows a short description 214 of the service, the number area 206 shows a service code 216 , and the date and time areas 208 , 210 show a date and time when the service event has happened. In any case, selecting the section symbol in selection area 212 leads to a further action associated with the entry, such as showing its details or executing some follow-up service being prescribed by default or varying depending on a situation, or being selectable by user choice.
[0039] As shown in FIG. 2 , a service code 216 showing up in the number area 204 of entries 202 . 3 , 202 . 4 and 202 . 6 has a format clearly showing that the number is not a telephone number or other call identifier. In the present example, a service code is prefixed by a “*” character (asterisk sign). It will be noted that the invention is not limited to a “*” prefix for this purpose.
[0040] The excerpt of recent call list 106 shown in FIG. 2 is sorted by date and time such that the most recent entry shows up first. However, there is no limitation in this regard. In particular, the list may be generated as a pure data structure, each entry identified by some entry identifier or count not showing up when displayed, and may be sorted by any other criteria automatically, by default, or upon user choice for display.
[0041] The concept of introducing service codes 216 inside recent call list 106 opens a new view in presenting recent calls in telephone systems (herein, an entry of a recent call list may also be addressed as a “recent”, for ease of language). This can enable users to see their activated features such as opening a door, forwarding a call, transferring a call, granting access to a user to reach an outside line, parking a call etc. In that essence, recents become a more common history of exactly what a user has done with his or her device.
[0042] In the following, an approach on the method of how service codes of any kind can be incorporated in recents of a recent call list so a user can handle them in the same way as recent calls, will be described. This description is oriented for showing the different attributes that can be deducted from such an approach:
showing the service codes and translating to the actual code listing up the history; what happens when the user selects a recent entry that in fact is a service other than a call or, more generally, other than a telecommunication service; and how service codes can be grouped depending on type.
<Showing Services Codes in Recents>
[0046] First of all, an exemplary principle data structure of an entry in recent call list 106 will be described by way of example. FIG. 3 shows a data structure 300 representing a recent call list entry 106 as shown in FIG. 1 . The data structure 300 may be understood as a listing in JSON format. An overview of the JSON data interchange format may be found in “The JSON Data Interchange Format”, Standard ECMA-404, 1st Edition/October 2013, ecma international, with further references. The listing in FIG. 3 includes a JSON response showing how a recent call entry 106 may be represented in an PBX system. It will be noted however that JSON is just one example of a data structure to describe the way data is received. Other forms may apply as well. The JSON format is used, for example, in Asterisk which is a common telephone system. Of course, the present invention is not limited to this application.
[0047] In JSON as in many other data interchange formats, a data structure (which may also be referred to as a data set or object) may be listed in text form which is written in lines. In the present example as shown in FIG. 3 , the data structure 300 includes lines 302 - 326 counted in even numbers. The first and last lines 302 , 326 include an opening token 354 and a closing token 356 , respectively (here, left and right curly brackets) while lines 304 - 324 include respective data fields 352 . It will be noted that data fields 352 are separated from each other by a data field separator (here, a comma). Each data field 352 is composed of a data field identifier 358 (the “name” of the data field) and a data value 360 . Data field identifiers 358 and data values 360 are character strings (words) framed by quotation signs (double inverted commas). A data filed identifier 358 is followed by a data value 360 , separated by a separator (colons). If a data value 360 includes more than one item such as for the destination field in line 312 , the items are separated from each other by another separator (backslash). It will be noted that listing in lines is only for the human reader for ease of recognition but is not necessary for automatic interpretation of the data structure 300 . In the following, a specific one of data fields 352 may also be referred to by its line count within the data structure 300 .
[0048] As seen in FIG. 3 , a JSON response of a recent call may include the data fields shown in table 1 below:
[0000]
TABLE 1
Data fields in recent call entry
IDENTIFIER
CONTENT
id
object identifier (call count)
start
starting date and time of call (predefined
date and time format)
src
source of call (number only)
dst
destination of call (number only)
destination
destination of call (name and number)
duration
duration of call (time information on
duration of call, etc. (date of call and time
indicating entirety of the duration of the
call, etc.)
disposition
ANSWERED, NO ANSWER, BUSY, or other
disposition identifier
answer
date and time of answering the call
end
date and time of end of the call
direction
direction of the call (in; out, etc.)
callerid
call identification (e.g. caller ID, etc.)
[0049] It is noted however that the above identifiers and contents are exemplary and may be defined as needed in a telecommunications device, system, or software, and even by a user.
[0050] To include recent services other than calls in a recent call list, service codes can be incorporated in a recent call entry. A table which matches the service code activated with the actual service code can write in the recents the actual service in text mode. Recent's date and time are the same as any other recent call.
[0051] FIG. 4 shows an example of a data structure 400 representing a recent call list entry 106 referring to a recent service other than a call, in a recent call list. This data structure 400 includes lines 402 - 428 where lines 404 - 426 include data fields and lines 402 , 428 include opening and closing tokens, respectively. For further details on the data structure 400 which is similar to data structure 300 of FIG. 3 , see the afore description. In this data structure 400 , the fields “dst” (line 410 ), “destination” (line 412 ), “disposition” (line 416 ), and “direction” (line 422 ) have been re-used for including content relating to the recent service, and a new data field “action” is included in line 426 . The “action” field 426 may be understood as a user-defined data field. Below table 2 includes how data fields match with a service code entry.
[0000]
TABLE 2
Matching of data fields in recent service entries
IDENTIFIER
CONTENT FOR RECENT SERVICE
dst
The actual service code activated from
user at the “start time”
destination
The service code in text mode as it is
obtained by the database
disposition
Second level details from the service
action
direction
The actual type of the entry (“service”)
action
Further action on selecting an entry
[0052] In the “direction” field 422 an application can decide if this entry is a service code or an actual call and it can handle the information likewise.
[0053] All other fields remain the same as in recent calls. So even an application that does not distinguish the difference between call and service will show this information irrespectively of the content.
[0054] In the listing of data structure 400 shown in FIG. 4 , the number in the “src” field is the number of a user of the terminal device where the recent call list is provided, and the service code of a service initiated using this device is found in the “dst” field. However, it can be vice versa such that in case that the service is initiated by another side the service code is found in the “src” field, and the own number is found in the “dst” field in such case.
[0055] FIG. 5 shows a flowchart of a process 500 of matching incorporating service codes in recent call list. As shown in FIG. 5 , process 500 starts by recognizing a user action in step 502 . Then, in step 504 , a judgment is made as to whether a call or a service was included in the user action recognized in step 502 . If the judgment 504 leads to a call, an incoming/outgoing call handling is made in step 506 . If the judgment 504 leads to a service other than a call, a service code handling is made in step 508 which implies data exchange with a database 510 . Thereafter, the branches via steps 506 , 508 are reunited, and a recent call list is provided in step 512 .
<Service Code Selection>
[0056] When selecting a recent call either details are displayed or the selected number is called back. Similarly these two options will be applied when a service other than a call is selected. In case details are to be shown all information is obtained from the response. This is up to the application how to handle this information. It will be noted that selection of an entry may be done by touching a screen area (e.g., selection area 212 in FIG. 2 ), pushing or pressing a key, expressing speech or gesture or whatever input option the employed terminal device may offer. In case user selects an entry of a recent service other than a call then not all same rules do apply as in the case of recent call. The differentiation is due to the fact that a dialing the same service code combination is not necessarily the same action required for all cases.
[0057] For example, a user selects a feature code to open a door via use of an input device for providing the selection. This entry is registered as an open door action. When user selects this entry in the recent call list, then it makes little sense if the door opens again. It would make sense if the user watches the door from a video monitor or opens the speaker call of the door etc. The above example shows the necessity to define an additional field namely the “action” field shown in FIG. 4 that can define another action (so-called follow-up action) from the one additionally registered. The information of whether a different action is necessary is held in a local database of the underlined communication system.
[0058] FIG. 6 shows a flowchart of a process 600 on writing onto the “Action” field. The flowchart is an excerpt relating to steps 508 and 512 of process 500 shown in FIG. 5 and analyzes in more detail one of the functions of service codes handler step 508 , as indicated by steps 602 , 604 , and 606 which are part of service code handler step 508 .
<Grouping Service Codes>
[0059] One additional functionality that can be provided is the grouping of consecutive service codes. Again in this case this functionality differs from the one of the consecutive calls. Taking as example the door opener feature there are many times that service codes might differ for the same functionality. For example, service code may contain a secret key. Different users can open the door with different keys from the same device. In that case the recent call list will differentiate the two service codes for the same function and will list up two different entries. Hence the field “destination” may become very important since this is the one that can generically provide the information of the actual feature code. In this point it is to be made clear that “destination” and “dst” are two levels of decision given in the application which can be used openly. In other words, is up to the application whether it would use the information provided from the JSON listing, since the latter's content could be taken as redundant information.
[0060] The invention has been described above based on specific exemplary embodiments, and variations and modifications thereof. Obviously, any features, objects, advantages, and details of any specific exemplary embodiment, its variations and modifications apply to any other embodiment, variation or modification mutatis mutandis unless such application obviously violates technical constraints or laws of nature. Embodiments, variations and modifications may be combined with any other embodiment, variation or modification, and any combination as a whole or in terms of single feature may be assumed to constitute an embodiment of the invention.
[0061] It should be understood that while certain exemplary embodiments of the ZZZ methods of making and using the same have been shown and described above, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.
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A method of providing a recent call list of calls recently received or initiated by a telecommunications device where information on recent services which are services recently handled by or using the telecommunications device other than calls are incorporated as entries in a recent call list of the telecommunications device. Each entry can be formed by a data structure being composed of a plurality of data fields. Each data field can include a data value. An entry representing a recent service other than a call in the recent call list can include a service code identifying a recent service as a data value. A device, system, and apparatus can be configured to utilize or execute the method.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the priority of German Patent Application, Serial No. 10 2009 030 632.3, filed Jun. 25, 2009, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference in its entirety as if fully set forth herein.
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a catalytic converter having a monolith wrapped in a mat and a housing, and an apparatus for producing a catalytic converter
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Catalytic converters are used for post-treatment of exhaust gases in vehicles having a combustion engine. The catalytic converters typically include a housing, in which a monolith, for example a ceramic substrate, is arranged. The monolith is wrapped in a mat, which fills a gap between the monolith and the housing, thereby securing the position of the monolith. The housing may be made, for example, from a tube as a single piece made or may be made of several housing parts, which are connected to each other with screws or by welding. The mat is used to secure the position of the monolith inside the housing and to ensure the alignment in this position over various temperatures when operating under different loads. The monolith also protects the mat from damage because the monolith is by far one of the most expensive components of the catalytic converter. The monolith has typically a cylindrical geometry, wherein the diameter of the monolith can vary for production-related reasons. It is easier to adapt the housing to the overall dimensions of the monolith in production by taking into account the average diameter of the monolith.
Several methods are used in the art for enclosing a monolith for a catalytic converter in a housing. One of these methods is described in EP 1 445 443 A1. In this method, a sheet metal piece is cut to a predetermined size commensurate with the dimensions of the monolith and formed into a housing. The edges are connected by soldering. The outside dimensions of the monolith are determined by a contact-less measurement performed in a measuring station, wherein the monolith is scanned with a laser at defined measurement positions and an average diameter of the monolith is determined from the measured diameters. Disadvantageously, optical measurement systems with the required higher accuracy a relatively expensive and susceptive to failure; moreover, the exact positioning of monolith and laser as well as setting the measurement points increases the complexity.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide a simplified method for producing a catalytic converter as well as an apparatus for producing the catalytic converter.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a method for producing a catalytic converter, which includes a monolith wrapped in a mat and is disposed in a housing, includes the steps of determining an average diameter of the monolith by introducing the monolith in a measurement space having an interior volume, filling a gap between the measurement space and the monolith with a fluid, measuring a quantity of fluid which corresponds to a volume difference between the monolith and the interior volume of the measurement space, and calculating the average diameter of the monolith from the volume difference. The method further includes the steps of determining a thickness of the mat, wrapping the monolith in the mat; forming a housing blank into a housing; and enclosing the wrapped monolith in the housing.
According to another aspect of the invention, an apparatus for determining an average diameter of a monolith includes a base plate configured to support the monolith, a measuring cylinder configured to receive the monolith supported on the base plate, a limiter configured to limit a measurement space to a length of the monolith, a flexible measuring tubing disposed in an intermediate space bounded by the base plate, an interior wall of the measuring cylinder, the limiter, and the monolith, means for filling the flexible measuring tubing, means for determining a filled-in fluid quantity, and means for calculating a volume difference between the monolith and an interior space of the measuring cylinder.
According to yet another aspect of the invention, a method for producing a stepped fold on a longitudinal side of a housing blank for a catalytic converter, which includes a monolith wrapped in a mat, includes the steps of arranging an inner electrode pair with a first positive electrode and a first negative electrode on an inner side of the housing blank with a first distance between the first positive electrode and the first negative electrode, arranging an outer electrode pair with a second positive electrode and a second negative electrode on an outer side of the longitudinal side with a second distance between the second positive electrode and the second negative electrode which is identical to the first distance, wherein the outer electrode pair has an offset relative to the inner electrode pair corresponding to at least a thickness of the housing blank. The method further includes the steps of applying a voltage to both the inner and the outer electrode pairs; and moving the first positive electrode relative to the first negative electrode and the second positive electrode relative to the second negative electrode, so that the first distance between the positive and negative electrodes of the corresponding first and second electrode pair is steadily reduced, while simultaneously moving the first and second positive electrodes and the first and second negative electrodes perpendicular to the housing blank.
According to still another aspect of the invention, an apparatus for producing a stepped fold on a longitudinal side of a housing blank includes an inner electrode pair with a first positive electrode and a first negative electrode having a first distance between the first positive electrode and the first negative electrode; and an outer electrode pair with a second positive electrode and a second negative electrode arranged in parallel with the first electrode pair and having a second distance between the second positive electrode and the second negative electrode which is identical to the first distance, wherein electrodes with identical polarity of the first and second electrode pairs are arranged next to each other, and wherein all electrodes are arranged for relative movement to one another.
According to yet another aspect of the invention, a catalytic converter includes a monolith wrapped in a mat and disposed inside a housing constructed of a formed housing blank having longitudinal edges which are joined with one another in a joining region, wherein a first of the longitudinal edges has in the joining region a stepped fold, with a second of the longitudinal edges abutting a radially outwardly oriented section of an inner side of the first longitudinal edge of the fold.
For producing a catalytic converter, a monolith is wrapped in a mat and arranged in a housing. The mat is provided for protecting and positioning the monolith. Because of the dimensions of the monoliths exhibit production-related variations, but the monoliths represent by far the most expensive component of the catalytic converter, the housing is adapted to the dimensions of the monolith.
For this purpose, the average diameter of the monoliths is determined in a first step. Also determined is the thickness of the mat in a compressed state, and the mat is wrapped around the monolith. The required inside diameter of the housing can then be determined from the average diameter and the thickness of the mat. The housing is formed from a housing blank which is cut to a size adapted to the average diameter and the thickness of the mat. In a last step, the monolith wrapped in the mat is enclosed by the housing blank which is, for example, formed into a tubular housing and welded.
The average diameter of the monolith is determined by introducing the monolith into the measuring space, positioning the monolith on a base plate and securing the monolith in position on the side facing the base plate with a pressure piston. The pressure piston may include means for determining the position of the monolith. The measurement space may be implemented, for example, as a hollow measuring cylinder having a known interior volume.
For measuring the volume of the monolith, the intermediate space between the measurement space and the monolith is filled with a fluid. The introduced quantity of fluid corresponds to a volume difference between the monolith and the interior volume of the measurement space and is used for calculating the average diameter of the monolith.
Preferably, a flexible measurement tubing filled with the fluid is arranged between an outer face of the monolith and an inside wall of the measurement space. This prevents contact between the monolith and the fluid and obviates the needs for an additional cover. The flexible measurement tubing is designed to make two-dimensional contact with both the outer circumferential side of the monolith and an interior wall of the measuring cylinder. By using a flexible material for the flexible measurement tubing, the flexible measurement tubing can contact the contour of the outer circumferential side of the monolith and the interior wall of the measuring cylinder during filling.
Limiters may be provided surrounding the pressure piston which delimit the annular intermediate space between the monolith and the interior wall of the measuring cylinder at an end face, i.e., in the longitudinal direction of the monolith facing the base plate. Alternatively, the pressure piston itself may simultaneously be used as a limiter. In this case, the cross-sectional surface area of the pressure piston corresponds to the cross-sectional area of the measuring cylinder, minus any necessary tolerances.
In addition, means are provided for filling the flexible measurement tubing with the fluid and for determining the filled fluid quantity. In addition, means are provided for calculating the volume difference between the monolith and the interior space of the measurement space, by which of the average diameter of the monolith can be determined. Most accurate results are produced by including the wall thickness of the flexible measurement tubing in the calculations.
The thickness of the mat in the compressed, i.e., installed state between the housing and the monolith must be added to the average diameter determined in this way. The thickness is determined by compressing the mat between two flat plates in contact with their lateral faces, until a predetermined force is attained. As soon as this force is reached, the distance between the plates is measured, with the distance corresponding to the thickness of the mat. The required interior diameter for the housing is obtained from the thickness of the mat at the determined average diameter of the monolith.
The housing is produced by forming a housing blank. The housing blank is cut to a size corresponding to the values determined for the average diameter of the monolith and the thickness of the mat, and formed into a tubular housing. The longitudinal edges of the housing blank can be joined in abutting relationship. Because the longitudinal edges are joined directly above or adjacent to the mat, a molybdenum foil is advantageously arranged in the joining region between the mat and the housing to prevent melt from a welding process or solder from a soldering process from making contact with the mat.
Advantageously, the longitudinal edges of the housing blank are joined with a mutual overlap, wherein one longitudinal side is folded with a step before joining. The stepped fold is produced by using an apparatus having two electrode pairs. With this apparatus, a positive electrode and a negative electrode from an inner electrode pair are arranged on an inner side of the housing blank along an end of the longitudinal side so that a first, for example the positive, electrode is arranged facing the longitudinal edge, and a second, for example the negative, electrode is arranged on the side of the first electrode facing away from the longitudinal edge. The electrodes of the outer electrode pair are arranged mirror-symmetrically relative to the inner electrode pair on an outer side face of the housing blank, so that electrodes with the same charge are always adjacent to one another and separated by the housing blank. In an initial position, the electrodes of both electrode pairs have the same distance from one another. The outer electrode pair is arranged on the outside of the housing blank with a relative offset from the inner electrode pair corresponding to a distance which is at least equal to the thickness of the housing blank. This produces an offset in the gap between the opposing end faces of the electrodes.
Before the longitudinal side is bent, the material of the housing blank is heated in the region of the gap by applying a voltage to both electrode pairs. The material is thereby softened in the region of the gap to the yielding point and can be more easily deformed.
For producing a step-shaped fold, the positive electrodes and the negative electrodes are moved against each other in such a way that the gap between the electrodes of the inner electrode pair and the electrodes of the outer electrode pairs is uniformly reduced. At the same time, a movement perpendicular to the housing blank produces the step-shaped fold. In an end position, a radially outwardly oriented region of the outer longitudinal side of the fold abuts an end face of the second electrode of the outer electrode pair, and a radially outwardly oriented region of the inner longitudinal side of the fold abuts an end face of the first electrode of the inner electrode pair. After forming, the step of the fold has a height which corresponds approximately to the thickness of the housing blank.
The position of the fold on the housing blank depends on the determined dimensions of the mat and the monolith. Decisive is the average diameter. Accordingly, the housing blank is folded only after the average diameter has been determined. The dimensions of the folded housing blank can thereby be optimally matched to the dimensions of the monolith. As a result, when the monolith wrapped in the mat is enclosed, one longitudinal edge of the housing blank directly abuts the inner side face of the radially outwardly oriented region of the longitudinal side. The monolith with the mat is then peripherally enclosed without a gap.
Advantageously, the mat is already compressed before the wrapped monolith is enclosed. This prevents creasing of the mat when the longitudinal sides are joined into joining region. To this end, for example, a thread is tightly wound around the mat. This can be accomplished with an apparatus in which the monolith with the mat is clamped, wherein either the monolith is rotated and the thread wound around the mat, or the thread is moved around the monolith for winding the thread around the mat.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
FIG. 1 shows in cross-section a catalytic converter enclosed in a housing;
FIGS. 2 to 2 c show an apparatus for determining the average diameter of a monolith;
FIG. 3 shows plates for determining a thickness of a mat;
FIGS. 4 a and 4 b show an apparatus for wrapping the mat;
FIGS. 5 a and 5 b show housing variants;
FIG. 6 shows a fold of a housing blank (state-of-the-art);
FIGS. 7 a to 7 e illustrate method steps for folding a housing blank; and
FIGS. 8 a to 8 c show housing blanks with folds.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to FIG. 1 , there is shown in cross-section the basic configuration of a catalytic converter 1 . A monolith 2 is arranged in the center of the catalytic converter 1 . The monolith 2 is wrapped in a mat 3 , by which the monolith 2 is fixed in position and protected. The monolith 2 and the mat 3 are enclosed in a cylindrical or tubular housing 5 formed from a housing blank 4 . The inside diameter Dg of the housing 5 is matched to an average diameter Dm of the monolith 2 and a thickness M of the mat 3 .
FIG. 2 illustrates the structure of an apparatus 6 for determining the average diameter Dm of the monolith 2 before the monolith 2 is wrapped in a mat and before being enclosed in a housing. The apparatus 6 includes a base plate 7 and a measuring cylinder 8 . The monolith 2 is positioned on the base plate 7 inside the measurement space of the measuring cylinder 8 . The inside diameter Di of the measuring cylinder 8 is dimensioned so that there is always a gap 11 between the outer peripheral side 9 of the monolith 2 and an interior wall 10 of the measuring cylinder 8 . A flexible measurement tubing 12 is arranged in this gap 11 . The flexible measurement tubing 12 is made of a flexible material and is configured for abutment with the entire outer peripheral side 9 of the monolith ( FIG. 2 a ). The flexible measurement tubing 12 is filled by means 13 arranged on the wall of the measuring cylinder 8 . A pressure piston 14 is arranged in the longitudinal direction LR of the measuring cylinder 8 on a side of the monolith 2 facing the base plate 7 . The pressure piston 14 fixes the position of the monolith 2 on the base plate 7 , and a length L of the monolith 2 can be determined from the position of the pressure piston 14 .
Before the flexible measurement tubing 12 is filled, the gap 11 between the monolith 2 and the measuring cylinder 8 is delimited by limiters 15 which are arranged around the pressure piston 14 on the side of the monolith 2 facing the base plate 7 . This ensures that the flexible measurement tubing 12 can expand only within the gap 11 bounded by limiters 14 , the base plate 7 , the interior wall 10 of the measuring cylinder 8 , and the outside 9 of the monolith 2 , with only this gap 11 being filled with fluid.
When a certain pressure is established at the fluid inlet, the filled fluid quantity is measured and the volume of the monolith 2 is calculated from the volume difference between the known interior volume of the measuring cylinder 8 and the quantity of fluid filled in. Based on this calculated volume, the average diameter Dm of the monolith 2 is calculated from the length L determined with the pressure piston 14 .
The thickness M of the mat 3 is determined by applying a force, as shown schematically in FIG. 3 . In this embodiment, the side faces of the mat 3 are compressed by flat plates 16 until a defined force Fm is reached. A thickness M of the mat is then measured in this compressed state. The surface pressure for determining the defined force is a value defined by the manufacturer of the mat.
A required inside diameter Dg of the housing 5 is determined from the determined average diameter Dm of the monolith 2 and the determined thickness M of the mat 3 according to the equation
Dg= 2 M+Dm.
Starting from this required diameter Dg, the dimensions of the housing blank 4 are then calculated and the housing blank 4 is cut to size.
The catalytic converter 1 is manufactured by wrapping the monolith 2 in the mat 3 and then enclosing the monolith 2 in the housing 5 . The mat 3 is compressed when the monolith 2 is enclosed in the housing 5 . Creases may develop in the mat 3 in the region of a gap 19 between the longitudinal edges 17 , 19 when the longitudinal edges 17 , 18 ( FIG. 1 ) of the housing blank 4 are joined. In order to achieve uniform contact between, on one hand, the mat 3 and the monolith 2 and, on the other hand, between the mat 3 and an inner side 20 of the housing 5 , the mat 3 is advantageously uniformly compressed by winding a thread 21 around, before the monolith 2 and the mat 3 are enclosed by the housing blank 4 .
This can be done, for example, by using the winding apparatus 22 illustrated in FIGS. 4 a and 4 b . The end faces of a monolith 2 wrapped in a mat 3 are clamped in a holder 23 . The holder 23 may be supported for rotation on one end of a shaft 24 and is, for example, rotated relative to a thread guide 25 about a longitudinal axis LA of the monolith 2 . The thread 21 is wound around the mat 3 , compressing the mat 3 . Alternatively, the clamped monolith 2 may be stationary, while a thread guiding apparatus with the thread 21 is moved around the monolith 2 and the mat 3 , thereby placing the thread 21 around the mat 3 and compressing the mat 3 . Alternatively, the holder 23 and the thread guide 25 may rotate concurrently in opposite directions. For realizing the rotation of the thread guide 25 or the holder 23 , a manual or automatic drive can be provided on the shaft 24 .
When producing a housing 5 from a housing blank 4 , the longitudinal edges 17 , 18 of the housing blank 4 may be butt-joined ( FIG. 5 a ). Advantageously, however, they are joined with a mutual overlap ( FIG. 5 b ). The wall of the housing 5 is then advantageously arranged between the weld seam and the mat, thus protecting the mat during welding. To this end, a stepped fold 26 is provided in the region of the longitudinal edge 18 . With conventional methods, the fold 26 is produced by cold-forming. Disadvantageously, this approach produces relatively large negative radii of curvature R 1 , as illustrated in FIG. 6 . This may produce a leak between the longitudinal edge 17 and the fold 26 , through which exhaust gases may escape.
With the process illustrated in FIGS. 7 a to 7 d , a stepped fold 26 can be produced which reduces or even completely eliminates leaking of exhaust gases, FIG. 7 e.
To this end, two electrode pairs 28 , 29 are provided. An inner electrode pair 28 is hereby arranged on the inner side 20 of a longitudinal side 18 a of the housing blank 1 , with the longitudinal side 18 a extending along the longitudinal edge 18 . An outer electrode pair 29 is arranged on the outer side 30 of the longitudinal side 18 a of the housing blank 4 . The distance A 1 between the positive electrode 31 and the negative electrode 3234 is identical to the distance between the positive electrode 33 and the negative electrode 34 , thereby forming a gap 35 of constant width between the electrodes 31 , 32 ; 33 , 34 .
The electrode pairs 28 , 29 are mutually offset in the direction of the longitudinal edge 18 by a distance A 2 , which corresponds at least to a thickness S of the housing blank 4 .
Before the forming process starts, a voltage U is applied between the positive electrode 31 and the negative electrode 32 , and an identical voltage U is applied between the positive electrode 33 and the negative electrode 34 of the respective electrode pairs 28 , 29 , producing current flow through the housing blank 4 in the region of the gap 35 between the electrodes 31 , 32 ; 33 , 34 . The material of the housing blank 4 heats up and softens in this region. By moving the positive electrodes 31 , 33 relative to the negative electrodes 32 , 34 in the X-direction, the identical gap 35 between the individual electrodes 31 and 33 and between the individual electrodes 32 and 34 , respectively, of the electrode pairs 28 , 29 decreases. At the same time, the positive electrodes 31 , 33 are moved relative to the housing blank 45 in the vertical direction Y to produce a vertical offset between the electrodes 31 and 32 and between the electrodes 33 and 34 , respectively, which also corresponds at least to a thickness S of the housing blank 4 ( FIG. 7 b ). The gap 35 between the electrodes 31 and 32 and commensurately between the electrodes 33 and 34 is the further decreased while maintaining the vertical offset ( FIGS. 7 c and 7 d ), thereby deforming the material in the gap region 35 so as to form a defined step. The softened material of the housing blank 4 adapts to the geometry of the gap 35 between the opposing side faces so that a segment of the inner side 20 oriented perpendicular to the housing blank 4 abuts a side face 33 a and a segment of the outer side 30 oriented perpendicular to the housing blank 4 abuts a side face 32 a . This minimizes the radii R 2 of the step of the fold 26 .
When the housing blank 4 is formed into the housing 5 around the monolith 2 with the mat 3 , the longitudinal edge 17 abuts a radially outwardly oriented section of the fold 26 when the housing blank 4 is joined, with the small radius R 2 of the step leaving no free space through which exhaust gases could escape ( FIG. 7 e ).
FIGS. 8 a to 8 c each show the housing 5 with a folded housing blank 4 . The folds 26 a , 26 b , 26 c are positioned depending on a previously determined average diameter of a monolith so that the inner diameter Dg of the closed housing 5 matches the average diameter of the respective monolith. It is evident that the folds 26 a , 26 b , 26 c are arranged at different distances from the respective longitudinal edge 18 . FIG. 8 a shows a housing 5 for a monolith with a small average diameter. FIG. 8 b shows a housing 5 for a monolith with a normal average diameter, while FIG. 8 c shows a housing 5 for a monolith with a large average diameter.
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein:
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A method for producing a tubular catalytic converter, which includes a monolith wrapped in a mat and is disposed in a housing, includes forming a stepped longitudinal fold on a longitudinal side of a housing blank, wherein the longitudinal side on both sides of the fold to be formed is clamped by electrodes of opposite polarity across the fold. Electrode pairs on one side of the fold to be formed are then offset with respect to electrodes on the other side of the fold and the electrodes of opposite polarity move closer together, while a current is flowing between the electrodes of opposite polarity, heating the material in the fold. Opposing longitudinal sides of the tubular housing are then materially joined along the stepped longitudinal fold with the overlap to produce the housing for the tubular catalytic converter.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to concrete screeds. Specifically, the invention is concerned with a double-bearing shaft for a vibrating screed that is particularly suitable for a relatively small size, portable vibrating screed.
2. Description of the Related Art
Concrete floor and/or slab construction normally involves several steps, including pouring, compacting, puddling, screeding and surface finishing. A screed is run along the upper surface of the wet concrete to smooth and settle the concrete. Oftentimes, a screed includes a vibrating mechanism to expedite the settlement of the concrete.
Many job sites require relatively small size, lightweight and less expensive screeds that can be easily manuveured and operated. These small size vibrating screeds in some instances utilize different types of vibrating devices than larger and heavier screeds. The vibrating force for a lightweight screed is preferably uniformly spread along the length of the screed irrespective of where the vibration device is mounted on the screed. A relatively large size, portable vibrating screed with a semi-flexible shaft loosely supported in spaced apart single bearings is illustrated in U.S. Pat. No. 4,030,873. Examples of relatively small size, portable vibrating concrete screeds can be found in applicant's U.S. Pat. Nos. 4,386,901, 4,650,366 and 4,701,071.
A particular problem for relatively small size, portable vibrating screeds involves premature failure of bearings which loosely support a motor-driven rotating shaft as a vibrating device. Conventional rotating shafts include a plurality of single, relatively wide bearings loosely mounted on the shaft. Because of the vibrations and relatively heavy duty, the single bearings tend to wear out and fail prematurely, resulting in substantial maintenance expense and down time. A single bearing failure typically puts the entire small size screed machine out of service.
The art continues to seek improvements. It is desirable that bearings which loosely or otherwise support a vibrating rotating shaft in relatively small size portable screeds be able to withstand the vibrations transmitted to the shaft with minimum failure and down time.
SUMMARY OF THE INVENTION
The present invention relates to a vibrating shaft loosely supported on sets of uniquely mounted double bearings for imparting vibrations to a vibrating screed and to a screed employing such a shaft. The shaft is mounted within and rotates within a plurality of the uniquely mounted double-bearing assemblies which substantially extend the operating time of the screed as compared to a screed in which the shaft is mounted in single bearing assemblies. The double-bearing assemblies of the invention each include a pair of spaced apart, independently mounted, relatively narrow bearing elements which permit the semi-flexible shaft to flex between the bearing assemblies. The double bearing elements are preferably mounted loosely on the shaft and loosely within mating bearing housings or supports. However, the double bearing elements are also useful and substantially extend screed life when not loosely mounted on the shaft or within the bearing supports and employed with eccentric weights or the like on the shaft to impart vibration.
In a first preferred embodiment, a vibrating screed includes a driven rotatable shaft assembly mounted on a frame equipped with means for screeding the concrete. The shaft assembly includes a rotatable shaft having a plurality of the invention bearing assemblies. Each bearing assembly includes a pair of bearing elements separately mounted on the shaft. Pin screws retain the bearing elements on the shaft and the bearing assemblies spaced apart lengthwise along the shaft. Each bearing assembly is mounted in a bearing support on the frame assembly. Vibration is enhanced by mounting the bearing elements loosely on the shaft and by sizing the bearing supports so as to provide clearance for the bearing elements and thus a loose support within the bearing supports thereby further enhancing the vibration effect.
In a second preferred embodiment, the shaft assembly having the invention bearing assemblies is mounted within a tubular elongated section of a screed frame. Vibration is enhanced by sizing the inner diameter of the tubular section slightly larger than the diameter of the bearing elements so as to provide for clearance and a loose fit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of a dismounted double-bearing shaft assembly for a vibrating screed.
FIG. 2 is an enlarged elevational view of a double-bearing assembly for the shaft assembly of FIG. 1 and with the bearing housing clearance exaggerated for purpose of illustration.
FIG. 3 is an enlarged sectional view of a double-bearing assembly taken along line 3--3 of FIG. 1 and with the bearing shaft clearance exaggerated for purposes of illustration.
FIG. 4 is a perspective view of a first embodiment of a portable screed utilizing the shaft assembly of FIG. 1.
FIG. 5 is a rear elevational view of the central frame section of the screed of FIG. 4.
FIG. 6 is a front elevational view of the central frame section of FIG. 5.
FIG. 7 is a partial perspective view of a second embodiment of a portable screed frame section utilizing the shaft assembly of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A perspective view of a double-bearing shaft assembly according to the invention, indicated generally at 10, is illustrated in FIG. 1. The shaft assembly 10 includes a semi-flexible shaft 12 and a plurality of double bearing assemblies 14. For purposes of the drawings only, five bearing assemblies 14 are illustrated on the shaft 12 of FIG. 1.
Each bearing assembly 14 includes a first relatively narrow width bearing element 14A and a second relatively narrow width bearing element 14B. As illustrated best in FIG. 2, bearing elements 14A and 14B are spaced apart on the shaft 12. If desired, a spacer (not illustrated) can be inserted between bearing elements 14A and 14B to maintain a desired distance between the bearing elements 14A and 14B. Each bearing element 14A and 14B is constructed from a suitable conventional bearing, e.g., a sealed roller bearing. A pair of pin screws 16 are mounted on shaft 12 to retain bearing elements 14A and 14B. Pin screws 16 or other suitable retainers are mounted on shaft 12 in any desired manner. While not illustrated, shaft 12 is typically slightly bent to enhance the vibration. The invention construction both facilitates and reduces the amount of such bending. In one embodiment incorporated in the type of screed shown in the referenced U.S. Pat. No. 4,386,901, the bearing elements 14A, 14B were approximately 7/16" wide, 1 9/16" in diameter and were spaced apart about 5/16". Shaft 12 was 5/8" diameter steel.
As illustrated in FIG. 3, the shaft opening for each bearing element 14A and 14B is preferably larger than the diameter of shaft 12. A clearance 15 is thus provided between shaft 12 and bearing elements 14A and 14B. Because of clearance 15, bearing elements 14A and 14B are mounted loosely on shaft 12 and thereby permit vibration and play of shaft 12 as it is rotated. In a preferred embodiment, bearing elements 14A and 14B are mounted with a clearance 15 of, for example, twenty to sixty thousandths of an inch between shaft 12 and bearing elements 14A and 14B. Such clearance also facilitates slight bending of shaft 12 to enhance vibration while retaining the desired loose fit in both bearings of each set.
A screed 20 utilizing shaft assembly 10 is illustrated in FIG. 4. The shaft assembly 10 is particularly adaptable for use with applicants' portable vibrating concrete screed disclosed in U.S. Pat. No. 4,386,901 the description of which is hereby incorporated by reference.
Screed 20 is illustrated as being formed of three separate frame sections 22, 24 and 26. Frame sections 22 and 24 are removably connected by turnbuckle nut 25A and plates 27A. Frame sections 24 and 26 are removably connected by turnbuckle nut 25B and plates 27B. It will be understood that the frame sections 22, 24 and 26 can be formed as a unitary member or as a plurality of sections as desired.
It is preferred that in the illustrated embodiment screed 20 have a frame 21 of triangular cross section formed by screed blades 28 and 30 and ridge member 32. A plurality of frame supports 33 are connected between screed blades 28 and 30. A plurality of braces 34 are connected between the screed blades 28 and 30 and the ridge member 32.
Screed 20 includes bearing supports 35 formed as castings which transversely bridge the distance between screed blades 28 and 30. Castings 35 are connected to screed blades 28 and 30 by bolts or other suitable means. Each casting 35 is shaped to receive both elements of a double bearing assembly 14 of shaft assembly 10. Castings 35 are preferably formed with bearing support inner diameters slightly larger than the outer diameters of bearing assemblies 14 and may, for example, provide a clearance 36 (FIG. 2) of between twenty to sixty thousands of an inch. Such clearance provides a loose fit between the support surfaces of castings 35 and bearing elements 14A and 14B to enhance vibration and play of bearing elements 14A and 14B as shaft 12 is rotated.
A pulley 40 is mounted on shaft 12 at a selected position between bearing assemblies 14. A variable speed drive source 42, illustrated as a lightweight engine in FIGS. 4-6, is mounted on screed 20 by engine mount 44. Engine mount 44 is mounted on frame 21 by any suitable means.
A drive pulley 46 is fixed on the shaft of engine 42 and drives a belt 50 which in turn drives pulley 40. Shaft 12 rotates in a counter-clockwise direction as viewed in FIG. 4 as indicated by arrow C in FIG. 4 and the shaft vibration tends to cause screed 20 to creep in the forward direction. This movement substantially reduces the force required to move the screed 20 over the concrete.
To facilitate movement of the screed 20, a pair of vertical posts 52 and 54, mounted to frame 21, mount telescoping L-shaped handles 56 and 58. Handles 56 and 58 permit operators 100 and 102 to move the screed 20 over the surface of the concrete.
A second embodiment of a portable screed frame section, indicated generally at 60, is illustrated in FIG. 7. Screed frame section 60 includes a tubular section 62 joined to a bottom screeding plate 64 by a set of lower ribs 65, 66 and 67. A top flat plate 68 is joined to tubular section 62 by a set of upper ribs 69 and 70. A support 72 and threaded rod 74, mounted on the top flat plate 68, are used with conventional turnbuckle nuts (not illustrated) to connect frame sections of a screed. A portable screed having a frame section of the type of screed frame section 60 is disclosed in applicant's U.S. Pat. No. 4,701,071 which is hereby incorporated by reference. The applicant's portable vibrating concrete screed disclosed in U.S. Pat. No. 4,701,071 is particularly adaptable for use with shaft assembly 10.
Shaft assembly 10 is inserted into tubular section 62. The inner diameter of tubular section 62 is preferably slightly larger than the outer diameter of bearing elements 14A and 14B to provide a clearance similar to clearance 36 provided between bearing elements 14A and 14B and castings 35 (FIG. 2). Such a clearance, in combination with clearance 15 between bearing elements 14A and 14B and shaft 12 (FIG. 3), provides a loose fit of shaft assembly 10 in tubular section 62 to enhance vibration and play of shaft assembly 10 as it is rotated by suitable means. The clearance between the bearing elements 14A and 14B and tubular section 62 can range, for example, between twenty and sixty thousandths of an inch.
Each bearing element 14A or 14B of each bearing assembly 14 is sized and selected with a load carrying capability of performing independently of the other bearing element 14A or 14B. Such capability thus permits continued operation of the screed 20 when one bearing element 14A or 14B in a particular assembly 14 fails. In other words, if bearing element 14A fails, bearing element 14B of the same assembly 14 provides the load carrying requirement of the assembly 14 to keep the screed 20 in operation until the job is finished at which time all necessary repairs can be made without having to stop work on the job because of a single bearing failure. It has also been observed that the double-bearing assemblies 14 each of which is made up of a pair of single width bearings each operating independent of the other tends to eliminate or at least substantially reduce casting 35 failures which typically occur when a single bearing fails. Enhanced vibration is also obtained since each bearing in each assembly is free to vibrate independent of the other bearing in the same assembly.
As previously mentioned, another discovered advantage of the double-bearing shaft assembly 10 is that less bend is required in shaft 12 than in single-bearing shaft assemblies in order to obtain the same vibrating effect in the shaft 12 when rotated.
While the double bearing assemblies of the invention are preferably loosely mounted as described many advantages of the invention are derived when the bearings are snugly mounted on the shaft and in th bearing housings with eccentric weights, shaft bend or the like employed to impart vibration.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A portable vibrating screed includes a driven, vibratory rotatable shaft assembly mounted on an elongated frame equipped with means for screeding concrete. The shaft assembly includes a plurality of bearing assemblies spaced along the length of the shaft. Each bearing assembly includes a pair of separate bearing elements mounted on the shaft and supported in bearing supports secured to the frame. Failure of any single bearing element allows a companion bearing element in the same assembly to absorb all of the load imposed on such assembly to prevent shutdown and without impairing the needed vibration.
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BRIEF SUMMARY OF THE INVENTION
1. Technical Field
This invention relates to a process for preparing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (aldicarb) as an aqeuous wet cake by reacting 2-methyl-2-(methylthio) propionaldehyde oxime (aldicarb oxime) with methyl isocyanate in an aqueous medium. This invention also relates to an aqueous wet cake composition containing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime.
2. Background of the Invention
The carbamoylation reaction of an oxime compound with an isocyanate compound in an organic solvent such as dichloromethane is known and practiced in the art.
U.S. Pat. No. 3,217,037 describes a process for preparing 2-hydrocarbylthio-sulfinyl and sulfonylalkanal carbamoyloximes including 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime which involves reacting an oxime compound with an isocyanate compound in an inert organic solvent. The inert organic solvents described in the patent which can be employed are those inert to isocyanates in general, i.e., those free of radicals such as hydroxy or amine radicals. Illustrative solvents described in the patent are aliphatic and aromatic hydrocarbons such as hexane, heptane, octane, benzene, toluene and the like, and ethers such as diethyl ether, ethyl propyl ether and the like.
U.S. Pat. No. 3,506,698 describes a process for preparing thiolhydroxamate carbamates which involves the reaction of thiolhydroxamate esters such as methyl thiolacetohydroxamate esters with a carbamylating agent such as isocyanic acid or its methyl ester in an aqueous medium at a temperature of between 0° C. and the boiling point of the reaction mass to obtain the corresponding thiolhydroxamate carbamates. At column 1, lines 58-60 of this patent, it is pointed out that thiolhydroxamates are not oximes.
It is therefore an object of this invention to provide a process for preparing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime by reacting 2-methyl-2-(methylthio) propionaldehyde oxime with methyl isocyanate in an aqueous medium, and thereby eliminating the need for organic solvents. It is another object of this invention to provide a water-wet cake composition containing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime.
DISCLOSURE OF THE INVENTION
This invention relates to a process for preparing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime by reacting 2-methyl-2-(methylthio) propionaldehyde oxime with methyl isocyanate in the presence of an aqueous medium for a period sufficient to form 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime. This invention further relates to a water-wet cake composition containing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime.
DETAILED DESCRIPTION
As stated above, the process for this invention is carried out in the presence of water rather than an organic solvent. This is a significant discovery for several reasons. The use of water provides for increased safety in comparison with certain organic solvents which may exhibit toxic properties or pose other health and safety hazards. In addition, the use of water avoids any adverse environmental aspects such as air and water pollution which may be associated with certain organic solvents. Further, in comparison with certain orgnic solvents, the use of water is economically advantageous in that is is inexpensive and no recycle is necessary.
The process of this invention can be carried out by contacting 2-methyl-2-(methylthio) propionaldehyde oxime with methyl isocyanate in the presence of an aqueous medium for a period sufficient to form 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime as a solid in an aqueous slurry which is then filtered to give a water-wet cake.
2-Methyl-2-(methylthio) propionaldehyde oxime is a known material which can be prepared according to the procedure described in U.S. Pat. No. 3,217,036. Methyl isocyanate is a known material which can be prepared by conventional methods. 2-Methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime is a known material which is the active ingredient in various TEMIK® brand aldicarb pesticides available from Union Carbide Agricultural Products Comapny, Inc., Research Triangle Park, N.C.
The amount of 2-methyl-2-(methylthio) propionaldehyde oxime and methyl isocyanate used in the process of this invention can vary over a wide range. In general, the molar ratio of methyl isocyanate to 2-methyl-2-(methylthio) propionaldehyde oxime can range from about 0.25:1 to about 2:1. Preferably, an equimolar amount or slight excess of methyl isocyanate is employed to ensure that 2-methyl-2-(methylthio) propionaldehyde oxime is completely reacted.
The amount of water used in the process of this invention is not narrowly critical and can vary over a wide range. In general, the molar ratio of 2-methyl-2-(methylthio) propionaldehyde oxime to water can range from about 1:1 or less to about 1:50 or greater, preferably from about 1:10 to about 1:40. The amount of water used in the process of this invention is in general influenced primarily by reaction equipment including heat removal capability and solids handling capability.
A catalyst can optionally be used in the process of this invention to facilitate the carbamoylation reaction. Suitable catalysts include a tertiary amine or an organotin catalyst. Other suitable catalysts include alkali metal and alkaline earth metal oxides, carbonates, bicarbonates or basic ion exchangers and carboxylic acid derivative salts. Illustrative tertiary amine catalysts include, for example, triethylamine, trimethylamine and the like. Illustrative organotin catalysts include, for example, dibutyltin diacetate, dibutyltin dichloride, dibutyltin dimethoxide, dibutyltin dilaurate, dibutyltin maleate, dibutyltin di-2-ethylhexenoate, stannous octanoate, stannous oleate and the like. Such catalysts are conventional materials known in the art.
The amount of catalyst which can be used in the process of this invention is a catalytically effective amount and can vary over a wide range. Generally, the amount of catalyst employed can range from about 0.01 weight percent to about 1.0 weight percent or higher based on the total weight of methyl isocyanate and 2-methyl-2-(methylthio) propionaldehyde oxime.
The reaction temperature is not critical and can be varied over a wide range. The process of this invention is normally conducted at a temperature in the range of from about 0° C. to about 30° C., preferably from about 5° C. to about 25° C. The reaction temperature is in general limited primarily by physical constraints such as vaporization or freezing of the reactants or other ingredients. At temperatures below about 0° C., 2-methyl-2-(methylthio) propionaldehyde oxime tends to freeze out while the temperatures in excess of about 30° C. the reaction of methyl isocyanate with water is favored over the reaction of methyl isocyanate with 2-methyl-2-(methylthio) propionaldehyde oxime. The reaction of methyl isocyanate with 2-methyl-2-(methylthio) propionaldehyde oxime proceeds significantly faster than the reaction of methyl isocyanate with water at temperatures from about 0° C. to about 30° C.
Reaction pressures are not critical. The process of this invention can be conducted at either subatmospheric, atmospheric or superatmospheric pressure. For convenience, the reaction is usually conducted at atmospheric or autogenous pressure.
The reaction time period is not narrowly critical and can vary from second(s) or instantaneous to as long as several hours. The process of this invention is effected over a period of time sufficient to produce 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime. Generally, when operating in the preferred temperature range, reaction times of from about one-half hour or less to about 4 hours are sufficient to complete the reaction of methyl isocyanate with 2-methyl-2-(methylthio) propionaldehyde oxime. Reaction time is influenced by the reaction temperature, the concentration and choice of catalyst and other factors known to those skilled in the art.
The process of this invention can be conducted by mixing 2-methyl-2-(methylthio) propionaldehyde oxime with water at a temperature of from about 0° C. to about 30° C. after which a catalyst is optionally added to the mixture. While maintaining the reaction temperature between about 0° C. and 30° C., methyl isocyanate is added with vigorous stirring over a sufficient period of time to provide for substantially complete conversion of 2-methyl-2-(methylthio) propionaldehyde oxime to 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime as a solid in aqueous slurry which is then filtered to give a water-wet cake. The process of this invention can provide 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime on a yield basis in excess of 90 percent based on the weight of 2-methyl-2-(methylthio) propionaldehyde oxime.
The methyl isocyanate addition period can range from seconds to hours or longer, and can occur over one, two or even more separate addition periods, i.e., batchwise, continuously or intermittently introduced into the reaction mixture. Generally, the methyl isocyanate addition period can range from about one-half hour or less to about 2 hours or longer depending upon the amount of 2-methyl-2-(methylthio) propionaldehyde oxime and catalyst employed in the process and the ability to control the reaction temperature. The stirring period can also range from seconds to hours or longer and can be approximately co-extensive with the methyl isocyanate addition period. However, the stirring period is generally longer than the methyl isocyanate addition period in order to effect substantially complete conversion of 2-methyl-2-(methylthio) propionaldehyde oxime to 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime.
Other ingredients can optionally be employed in the process of this invention. An organic or inorganic acid can be used to quench the reaction (tie up the catalyst and raise the reaction pH to about 4 or 5) and also provide additional stability to the water-wet cake product. Suitable organic and inorganic acids include phosphoric acid, hydrochloric acid, sulfuric acid, acetic acid and the like. The amount of acid which can be employed is not narrowly critical and is dependent upon the amount of catalyst and reactants used in the process. The amount of acid can range from 0.0001 weight percent or less to about 1.0 weight percent or greater based on the weight of the entire reaction mass.
Antifoaming agents and surfactants can optionally be employed in the process of this invention. Such antifoaming agents and surfactants are conventional materials known in the art. Suitable antifoaming agents include, for example, SAG 10 and SAG 30 which are available from Union Carbide Corporation, Danbury, Conn. and Q-132, which is available from SWS Silicones Corporation, Adrian, Mich. Suitable surfactants include conventional ionic and nonionic materials such as Tergitol 15-S7 available from Union Carbide Corporation, Danbury, Conn. and Pluronic L-61 and L-101 available from BASF. The amount of antifoaming agent and surfactant employed in the process of this invention can range from about 0.0001 weight percent or less to about 1.0 weight percent (based on the weight of the entire reaction mass) or greater for each ingredient.
The process of this invention can be conducted in a batch, semicontinuous or continuous fashion. The reaction can be conducted in a single reaction zone or in a plurality of reaction zones, in series or in parallel or it may be conducted intermittently or continuously in an elongated tubular zone or series of such zones. The materials of construction employed should be inert to the reactants during the reaction and the fabrication of the equipment should be able to withstand the reaction temperatures and pressure. Means to introduce and/or adjust the quantity of reactants or ingredients introduced, either intermittenly or continuously into the reaction zone during the course of the reaction can be conveniently utilized in the process especially to maintain the desired molar ratio of the reactants.
The process is preferably conducted in either glass lined, stainless steel or similar type reaction equipment. The reaction zone can be fitted with one or more internal and/or external heat exchanger(s) in order to control undue temperature fluctuations, or to prevent any possible "runaway" reaction temperatures. In preferred embodiments of the process, agitation means to vary the degree of mixing the reaction mixtures can be employed. Mixing by vibration, shaking, stirring, rotation, oscillation, ultrasonic vibration or the like are all illustrative of the types of agitation means contemplated. Such means are available and well known to those skilled in the art.
As stated above, a water-wet cake product is prepared by the process of this invention. The water-wet cake product generally contains from about 70 weight percent to about 95 weight percent or greater of 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime, less than about 0.1 weight percent to about 15 weight percent of residual 2-methyl-2-(methylthio) propionaldehyde oxime and from about 5 weight percent or less to about 30 weight percent of water (weight percent based on the total weight of the product). Amounts of water greater than about 30 weight percent tend to provide a slurry product rather than a water-wet cake product. Other ingredients such as an organic or inorganic acid, an antifoaming agent and a surfactant as described above and certain impurities, e.g., methacrolein oxime carbamate, can be present in the water-wet cake product in minor amounts, e.g., individual amounts from about 0.0001 weight percent or less to about 1 weight percent.
The water-wet cake product prepared by the process of this invention is useful in formulating various TEMIK® brand aldicarb pesticides available from Union Carbide Agricultural Products Company, Inc., Research Triangle Park, N.C.
The following examples are illustrative of the process of this invention.
EXAMPLE 1
Into a one liter glass resin kettle equipped with an air-driven stirrer, a pressure-equalizing dropping funnel with Teflon® tube for subsurface addition, a thermometer and a dry ice/acetone cold condenser was added 66.5 grams (0.50 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime (aldicarb oxime) and 266 milliliters of water. After cooling the mixture to a temperature of 5° C. with a water/salt/ice bath, 0.52 grams (0.005 mole) of triethylamine was added to the kettle under a nitrogen atmosphere. A stoichiometric amount of methyl isocyanate (29.5 milliliters, 0.50 mole) was then added over a period of 30 minutes at a temperature of 5° C.-10° C. with vigorous stirring. The water/salt/ice bath was removed and the mixture was stirred for an additional 60 minutes at a temperature of 15° C.-20° C. after which an additional 2.0 milliliters (0.03 mole) of methyl isocyanate was added and the mixture stirred for an additional period of 30 minutes. The water/salt/ice bath was then put back in place and 2.9 grams of phosphoric acid in 10 milliliters of water was added in a slow stream subsurface. The resulting solid product was filtered off on a sintered glass funnel to give 107.1 grams (wet weight) of a fluffy white powder. High pressure liquid chromatographic analysis (internal standard) indicated the following: 76.00 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (aldicarb) (89percent yield based on aldicarb oxime) and 0.36 percent 2-methyl-2-(methylthio) propionaldehyde oxime (aldicarb oxime); 23.64 percent water content was determined by Karl Fischer titration.
EXAMPLE 2
Into a one liter glass resin kettle equipped with a metal pitched-blade agitator, a pressure-equalizing dropping funnel with Teflon® tube for subsurface addition, a thermometer and a dry ice/acetone cooled condenser was added 66.5 grams (0.50 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime and 112 milliliters of water. After cooling the mixture to a temperature of 2° C.-3° C. with a water/salt/ice bath, 0.52 grams (0.005 mole) of triethylamine was added to the kettle under a nitrogen atmosphere. A stoichiometric amount of methyl isocyanate (29.5 milliliters, 0.50 mole) was then added over a period of 30 minutes at a temperature of 4° C.-14° C. with vigorous stirring. The water/salt/ice bath was removed and the mixture was stirred for an additional 75 minutes at a temperature of 10° C.-18° C. after which an additional 2.0 milliliters (0.03 mole) of methyl isocyanate was added and the mixture stirred for an additional period of 30 minutes. The water/salt/ice bath was then put back in place and 2.9 grams of phosphoric acid in 10 milliliters of water was added in a slow stream subsurface. The resulting solid product was filtered off on a sintered glass funnel and rinsed with hexane to give 104.4 grams (wet weight) of a fluffy white powder. High pressure liquid chromatographic analysis (internal standard) indicated the following: 84.00 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (89.1 percent yield based on aldicarb oxime) and 2.38 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 13.62 percent water content was determined by Karl Fischer titration.
EXAMPLE 3
Into a one liter glass resin kettle equipped with an air-driven stirrer, a pressure-equalizing dropping funnel with Teflon® tube for subsurface addition, a thermometer and a dry ice/acetone cooled condenser was added 66.5 grams (0.50mole) of 2-methyl-2-(methylthio) propionaldehyde oxime and 266 milliliters of water. After the mixture was cooled to a temperature of 5° C. with a salt/water/ice bath, 0.52 grams (0.005mole) of triethylamine was added to the kettle under a nitrogen atmosphere. A stoichiometric amount of methyl isocyanate (29.5 milliliters, 0.50 mole) was then added in a slow stream subsurface over a period of 30 minutes at a temperature of 5° C.-12° C. with vigorous stirring. The mixture was stirred for an additional 45 minutes at a temperature of 10° C.-20° C. after which the reaction mixture was transferred to a Waring Blendor® using water to flush out the resin kettle. The mixture was then blended at high speed for a period of 30 seconds to give uniformly small particles after which an additional 3.0 milliliters (0.05 mole) of methyl isocyanate was added as the mixture was blended at high speed for another 30 second period. The reaction temperature rose to 21° C. The reaction mixture was then transferred back into the glass resin kettle and 1.0 milliliter (0.02 mole) of methyl isocyanate was added with vigorous stirring at a temperature of 20° C. The mixture was then stirred for a period of 30 minutes after which 2.9 grams of phosphoric acid in 10 milliliters of water was added in a slow stream subsurface. The resulting solid product was filtered off on a sintered glass funnel to give 97.88 grams (wet weight) of a fine white powder. High pressure liquid chromatographic analysis (internal standard) indicated the following: 91.88 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (87.9 percent yield based on aldicarb oxime) and 0.34 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 12.66 percent water content was determined by Karl Fischer titration.
EXAMPLE 4
Into a jacketed blender-reactor similar to a Waring Blendor® equipped with rotor blades, a pressure-equalizing dropping funnel with Teflon® tube, a thermometer and a dry ice/acetone cooled condenser was added 66.5 grams (0.50 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime and 266 milliliters of water. Because of heat generated by the blender motor, the rotor blades were used only in 10 second bursts. A paddle-type stirrer was inserted halfway into the blender and used continuously for agitation. After cooling the mixture to a temperature of 15° C. with a water/salt/ice bath, 0.3 grams (0.005 mole) of trimethylamine was added to the blender under a nitrogen atmosphere. An amount of methyl isocyanate slightly in excess of stoichiometric (32.4 milliliters, 0.55 mole) was then added over a period of 30 minutes at a temperature of 15° C. with vigorous stirring. The water/salt/ice bath was removed and the mixture was stirred for an additional 90 minutes. The water/salt/ice bath was then put back in place and 2.9 grams of phosphoric acid in 10 milliliters of water was added in a slow stream subsurface. The resulting solid product was filtered off on a sintered glass funnel to give 91.62 grams of a white powder. High pressure liquid chromtographic analysis (internal standard) indicated the following: 97.12 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (93.7 percent yield based on aldicarb oxime) and 1.78 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 1.10 percent water content was determined by Karl Fischer titration.
EXAMPLE 5
Into a 5-liter Morton flask equipped with an air-driven paddle stirrer, a pressure-equalizing dropping funnel, a thermometer and a dry ice/acetone cooled condenser vented through two traps to a caustic scrubber was added 319.7 grams (2.4 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime, 1279 milliliters of water, 2.4 grams (0.024 mole) of triethylamine, 16.0 grams of SAG 10® antifoam (10 percent solution) available from Union Carbide Corporation, Danbury, Conn., and 0.4 grams of Pluronic L-61 surfactant available from BASF Corporation, under a nitrogen atomosphere. After cooling the mixture to a temperature of 8° C.-10° C. with a salt/water/ice bath, 143.8 grams (2.52 mole) of methyl isocyanate was added over a period of 35 minutes with vigorous stirring. At this time an additional 1.2 grams of Pluronic L-61 surfactant was added and the mixture was stirred for an additional period of 95 minutes at a temperature of 15° C.-25° C. The resulting solid product was filtered off on a sintered glass funnel to give 555.3 grams of a white powder. High pressure liquid chromatographic analysis (internal standard) indicated the following: 70.8 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (86.2 percent yield based on aldicarb oxime), 4.7 percent 2-methyl-2-(methylthio) propionaldehyde oxime and 9.1 percent water.
Into a jacketed one liter reaction vessel equipped with an electric stirrer, a thermocouple, a condenser vented through two traps to a caustic scrubber, a sample port, four baffles and a Teflon® tube for subsurface addition was added 640 grams of water and 4.0 grams of Pluronic L-101 surfactant. After cooling the mixture to a temperature of 2° C.-3° C., 160.0 grams (1.20 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime was added to the reaction vessel under a nitrogen atmosphere. A slight excess stoichiometric amount of methyl isocyanate (82.0 grams, 1.44 mole) was then added in a slow stream subsurface over a period of 20 minutes at a temperature of 2° C.-11° C. with vigorous stirring. The mixture was then stirred for an additional 45 minutes at a temperature of 10° C.-12° C. The resulting solid product was filtered off on a sintered glass funnel to give 230.83 grams of a white powder. High pressure liquid chromatographic analysis (internal standard) indicated the following: 73.2 percent 2-methyl-2-(methylthio) propionaldehyde O-(methyl-carbamoyl) oxime (77.0 percent yield based on aldicarb oxime) and 8.1 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 18.7 percent water content was determined by Karl Fischer titration.
EXAMPLE 6
Into a jacketed one liter reaction vessel equipped with an electric stirrer, a thermocouple, a condenser vented through two traps to a caustic scrubber, a sample port, four baffles and a Teflon® tube for subsurface addition was added 160.0 grams (1.20 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime and 4.0 grams of Pluronic L-101 surfactant. After cooling the mixture to a temperature of 2° C.-3° C., 640 grams of water was added to the reaction vessel under a nitrogen atmosphere. An amount of methyl isocyanate slightly in excess of stoichiometric (82.0 grams, 1.44 mole) was then added in a slow stream subsurface over a period of 20 minutes at a temperature of 2° C.-11° C. with vigorous stirring. The mixture was then stirred for an additional 40 minutes at a temperature of 5° C.-12° C. The resulting solid product was filtered off on a Buchner funnel to give 226.22 grams of a white powder. High pressure liquid chromatographic analysis (external standard) indicated the following: 74.0 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (76.1 percent yield based on aldicarb oxime) and 7.4 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 16.5 percent water content was determined by Karl Fischer titration.
EXAMPLE 7
Into a jacketed one liter reaction vessel equipped with an electric stirrer, a thermocouple, a condenser vented through two traps to a caustic scrubber, a sample port, four baffles and a Teflon® tube for subsurface addition was added 640 grams of water and 4.0 grams of Pluronic L-101 surfactant. After the mixture was cooled to a temperature of 2° C.-3° C., 160.0 grams (1.20 mole) of 2-methyl-2-(methylthio) propionaldehyde oxime was added to the reaction vessel under a nitrogen atmosphere. An amount of methyl isocyanate slightly in excess of stoichiometric (82.0 grams, 1.44 mole) was then added in a slow stream subsurface over a period of 20 minutes at a temperature of 2° C.-11° C. with vigorous stirring. The mixture was then stirred for an additional 45 minutes at a temperature of 5° C.-12° C. The resulting solid product was filtered off on a Buchner funnel to give 230.83 grams of a white powder. High pressure liquid chromatographic analysis (external standard) indicated the following: 73.2 percent 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime (77.0 percent yield based on aldicarb oxime) and 8.1 percent 2-methyl-2-(methylthio) propionaldehyde oxime; 18.7 percent water content was determined by Karl Fischer titration.
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This invention relates to a process for preparing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime as an aqueous wet cake by reacting 2-methyl-2-(methylthio) propionaldehyde oxime with methyl isocyanate in the presence of an aqueous medium. This invention also relates to an aqueous wet cake composition containing 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl) oxime.
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