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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of currently pending U.S. patent application Ser. No. 10/908,749 filed May 25, 2005, which is a continuation of International Application No. PCT/US03/37480, filed Nov. 25, 2003 which claims the benefit of U.S. patent application Ser. No. 10/303,522, filed Nov. 25, 2002, and U.S. patent application Ser. No. 10/319,683, filed Dec. 13, 2002, which are all herein incorporated by reference.
STATEMENT OF GOVERNMENT INTEREST
[0002] This invention was made with Government support under Grant No. ONR-N0014-98-1-0848 awarded by the Department of the Navy. The Government has certain rights in the invention.
FIELD OF INVENTION
[0003] This invention relates to the analysis of biological or chemical, particle or physical species contained in fluid milieus that include trace amount of the species; more specifically, the invention relates to an analytical system having a conveyance system to convey the analytical system through a liquid medium to collect and/or detect desired components and a related method of analyzing the collected components.
BACKGROUND
[0004] In recent years the presence of contaminants in bodies of water, both fresh and salt varieties, has become an issue of both public and governmental interest. In addition, air quality with respect to pollution from industrial or bellicose activities deeply affects the daily lives of most of the world's population. With the changing political situation in the world as well as concern over contamination from industrial and agricultural activity, a new intense interest has developed in monitoring water and air sources for pollutants and trace quantities of materials. As technology progresses, it has become increasingly important to know immediately the content of a body of water or air, thus necessitating the development of new analytical systems to give precise information on the presence and/or quantities of microbial and chemical contaminants.
[0005] To date, the available methods and devices have been concerned with “capturing” a sample for transportation to a laboratory for analysis and, in the case of trace quantities, concentration of the suspect species for that analysis. In addition, many of the available devices include sophisticated sensors and pumping apparatus that make the devices cumbersome as well as expensive to assemble and to maintain. Even though towed or tethered samplers are known in the art, their uses have been limited to physical characteristics and not the monitoring of chemical or biological species.
[0006] U.S. Pat. No. 3,537,316 to Stewart et al. shows a towed underwater sampler having an internal cavity that houses sensor circuits. In this device, water is permitted to flow through the analysis chamber so that temperature and pressure may be evaluated. However, the sensors here are measuring physical parameters and not the chemical or biological content of the water passing through the sensor cavity. In fact, there is no actual sample reading made by the instrument because only the desired parameters of temperature and pressure are immediately evaluated, and the actual sample is captured in a bottle for later analysis.
[0007] Another towed sensor system is disclosed in U.S. Pat. No. 4,713,967 to Overs et al. Again the sensors are only concerned with physical properties—temperature and water speed. The temperature and speed are then equated to the presence of fish bait, but no information is obtained about any compositional make-up of the environment or the nature of the fish bait itself.
[0008] Inner chambers in contaminant sensing devices for water analysis are described previously as well. One example is U.S. Pat. No. 6,272,938 to Baghel et al. Baghel et al. describes an inner chamber formed by a semi-permeable membrane in communication with an inner chamber containing a sensor that monitors contaminants in a tethered-style apparatus. Water diffuses through the membrane until a threshold is reached and then the diffusion is stopped. In this system, the quantity of contaminants is a function of diffusion time and, thus, is controlled by an unpredictable parameter.
[0009] U.S. Pat. No. 6,306,350 to Mereish et al. describes a portable water sampling device that captures the sample in a chamber that is then removed and sent to a lab for analysis. The concentration of the sample is determined as a function of time, because a timer is used to determine the sample collection period. A pump is also used to force the water being tested into the system and past the extraction membrane.
[0010] Similar devices that incorporate sampling chambers are described in U.S. Pat. Nos. 5,844,147 to Fiedler et al. and 5,167,802 to Sandstrom et al. Again, the samples are collected and sent to a remote lab for analysis.
[0011] In addition to aquatic environments, similar devices have been used in the atmosphere.
[0012] Examples of these are U.S. Pat. No. 6,321,609 to Mengel et al. and U.S. Pat. No. 6,354,135 to McGee et al. Again, these systems include suction devices or pumps to facilitate the flow of effluent through the monitoring apparatus.
[0013] A system for immediate analysis of contaminants in situ is needed to overcome the disadvantages of the previously available systems. There is also a need for a system that incorporates reliability and sensitivity in performing the necessary analyses that is low-cost and easy to maintain. It is, therefore, to the provision of such an instrument that the instant invention is directed.
SUMMARY
[0014] The present invention includes a self-propelled apparatus for analysis of a component contained in a fluid medium. The apparatus includes an analytical system and a conveyance system to move the analytical system through the fluid medium and facilitate fluid flow through the fluid conduit of the analytical system.
[0015] The analytical system includes a fluid inlet that receives fluid from the fluid medium and a fluid outlet, which is connected to the fluid inlet via a fluid conduit. The fluid conduit defines a fluid pathway. The fluid outlet dispels at least a portion of the fluid medium received by the fluid inlet. The analytical system further includes an analysis chamber, which is connected to the fluid conduit and positioned intermediate to the fluid inlet and the fluid outlet in the fluid pathway. The analytical system further includes a reagent system located within the analysis chamber to isolate the component. The analytical system also includes a sensor system, which is positioned within the analysis chamber and in communication with the fluid pathway, to sense the component.
[0016] The conveyance system may be removably attached to the analytical system. The conveyance system may include a propulsion system.
[0017] The self-propelled apparatus may further include a power source located within the conveyance system for providing power to the analytical system.
[0018] The analytical system may further include a means for transferring data.
[0019] The self-propelled apparatus may further include a tether connecting the analytical system and the conveyance system. The tether may be a transmission cable for transmitting data from the analytical system to the conveyance system. The tether may also be a power cable for providing power to the analytical system from a power source located in the conveyance system.
[0020] The sensor system may determine the concentration of the component. The sensor system may be an optical system, an electromechanical system, an electrical system, a gravitational system, a mass loading system, an ion trap system, a molecular trap system, or a particle trap system. The sensor system may also include a light source and a detector.
[0021] The self-propelled apparatus may also further include a pre-extractor connected to the fluid inlet of the analytical system to receive fluid from the fluid medium and transport the fluid to the fluid inlet.
[0022] The self-propelled apparatus may further include a burst reservoir located adjacent to the analysis chamber and in fluid communication with the analysis chamber.
[0023] The present invention also includes a method of using the self-propelled apparatus to analyze a component contained in a fluid medium. The method includes providing a self-propelled apparatus as described above, introducing the analytical system into the fluid medium to permit the flow of the fluid medium through the analytical system, and recording data on the component contained in the fluid medium using the sensor system.
[0024] The method may further include transmitting data from the analytical system to a remote location. As used herein, the term “remote” means that the data is transmitted to an apparatus not in immediate contact with the analytical system.
[0025] The method may also include determining the concentration of the component of the fluid medium.
[0026] The method may further include capturing the component contained in the fluid medium in the reagent system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
[0028] FIG. 1 is a diagram of a first configuration of the analytical system according to an embodiment of the present invention.
[0029] FIG. 2 is a diagram of the analysis chamber of the analytical system according to an embodiment of the present invention.
[0030] FIG. 3 is a diagram of a first configuration of the sensor system of the analytical system according to an embodiment of the present invention.
[0031] FIG. 4 is a diagram of a second configuration of the sensor system of the analytical system according to an embodiment of the present invention.
[0032] FIG. 5 is a diagram of a second configuration of the analytical system according to an embodiment of the present invention.
[0033] FIG. 6 is a diagram of the third configuration of the analytical system on board a projectile according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.
[0035] The present invention includes a submersible, self-propelled apparatus for analysis of a component contained in a liquid medium. The apparatus includes an analytical system and a conveyance system to move the analytical system through the liquid medium and facilitate liquid flow through the liquid conduit of the analytical system.
[0036] In an embodiment, as shown in FIG. 1 , analytical system 100 includes detection portion 115 connected to support system 130 . In an embodiment, detection portion 115 and support system 130 are encased in a housing (not shown) that may be any suitable housing as known to those of ordinary skill in the art for the environment of use. Detection portion 115 and support system 130 may be detachably connected, a single unit, or arranged to allow for reuse of desired components. Any desired geometry for the overall system may be chosen by one of ordinary skill in the art. FIG. 1 represents only one embodiment.
[0037] Detection portion 115 includes fluid inlet 121 for ingress of the fluid to be examined. Fluid inlet 121 may be co-extensive with the housing, protrude therefrom, or be recessed within the interior confines of the housing. Pre-extractor 120 may be also present at the proximal end of fluid inlet 121 if desired to separate deleterious material from entering detection portion 115 . Detection portion 115 also includes fluid outlet 124 , which dispels fluid from detection portion 115 . Fluid inlet 121 , as well as fluid outlet 124 , may be formed of any suitable material as known to those of ordinary skill in the art. For example, a non-porous plastic that is inert to the environment can be used.
[0038] Fluid inlet 121 is connected to fluid outlet 124 via fluid conduit 190 , which defines a fluid pathway. Fluid flows in the direction shown by arrows 180 . Fluid is received at pre-extractor 120 (if present) and then moves through fluid inlet 121 and analysis chamber 135 , and then exits through fluid outlet 124 .
[0039] Located at the distal end of fluid inlet 121 is first separator 122 that blocks, at least temporarily, unwanted material from entering analysis chamber 135 . First separator 122 may be any suitable separator, such as a filter, a screening material, or a semi-permeable membrane. First separator 122 is chosen for the milieu of use and for optimizing the effectiveness of performing a concentrating and screening function.
[0040] Second separator 123 is located in fluid communication with first separator 122 with the intermediate portion of the fluid conduit defining analysis chamber 135 . Second separator 123 , at least temporarily, prevents the component of interest from exiting analysis chamber 135 . In addition, both first separator 122 and second separator 123 may have coatings applied to them to assist in the detection of the component, such as, but not limited to, reflective coatings that enhance optical characteristics of the analytical system 100 . The fluid of interest exits analytical system 100 via fluid outlet 124 .
[0041] Analysis chamber 135 , by virtue of first separator 122 and second separator 123 , also acts to concentrate the component of interest. Thus, the component of interest is substantially trapped within the confines of analysis chamber 135 so that sensor system 125 is able to respond to its presence. Sensor system 125 may be designed to respond to a threshold value of the component or may be chosen to actually quantify the concentration of the component contained in analysis chamber 135 . In addition, sensor system 125 may be constructed to react to a plurality of components of interest.
[0042] Optionally, burst reservoir 126 may be included in detection portion 115 . Burst reservoir 126 introduces a chemical enhancement into the analysis chamber 135 to aid the performance of sensor system 125 . If a plurality of analyses are performed, burst reservoir 126 may be compartmentalized and serve to introduce a plurality of enhancements.
[0043] Support system 130 includes the electronic components necessary to support the function of the sensor system 125 . This may include power supplies, either battery or cable supplied, as well as the support electronics necessary to run sensor system 125 . In addition, any other necessary or desired support equipment may also be contained within this structure, including, but not limited to, telemetry devices, GPS units, and data storage units. Optionally, the power source and/or other support electronics are contained within conveyance system 195 . Additionally, the self-propelled apparatus may also include a second power source. This second power source may be contained within conveyance system 195 .
[0044] The self-propelled apparatus of the present invention further includes conveyance system 195 . Analytical system 100 may be removably attached to conveyance system 195 by line 140 . Line 140 may be a tethering line only or may also include a means for communication and a power source to analysis system 100 and means for feedback for the retrieval of data or other information from analysis system 100 . For example, line 140 may be a transmission cable for transmitting data from analytical system 100 to conveyance system 195 . As another example, line 140 may be a power cable for providing power to analytical system 100 from a power source located on conveyance system 195 . Conveyance system 195 itself may be a tether. If conveyance system 195 is a tether, it may be connected to a second conveyance system (not shown). Any suitable means known to those of ordinary skill in the art may be used for any of the desired embodiments as described above. Conveyance system 195 may be a watercraft or aircraft of any description, either manned or remote controlled, suitable as a means for transporting analytical system 100 through the fluid to be analyzed.
[0045] In an embodiment of the present invention, conveyance system 195 is a propulsion system. The propulsion system may be any either an integral system to the overall device or a detachable propulsion system that may even be replaceable if the overall system is intended to be reusable. The propulsion system may be a renewable system. Examples of propulsion system include, but are not limited to: bullets, artillery shells, torpedoes, drop projectiles, fired projectiles, missiles, and other munition systems. The propulsion system may also be detachable from the remainder of the apparatus. In addition, telemetry systems may be included for relaying the desired data back to a monitoring station. In one embodiment, analytical system 100 is connected to propulsion system. In another embodiment, analytical system 100 is on-board propulsion system 450 , as shown in FIG. 6 . In this embodiment, as propulsion system 450 moves through a fluid medium in the direction shown by arrow 485 , fluid flows into and through analysis system 400 in the direction shown by arrows 480 .
[0046] Conveyance system 195 (and the propulsion system) serves not only to transmit analytical device 100 to the location of interest, but also to provide the fluid flow within analytical system 100 to effect the analytical functions. The sampling function may occur while the propulsion system is actively powering the device, or after the propulsion system is spent in a free-drift mode.
[0047] Additional power sources may also be present for telemetry, GPS, electronic controls and other communication purposes. Further instrumentation may also include receivers, steering devices, and other ground or ship communication devices, so that adjustments may be made to the flight path of the apparatus after it is deployed. In addition, a second propulsion system may be incorporated into the apparatus so that it may be transmitted after a period of time to a further location, such as a pick-up location. An aerial-type device, such as a kite, balloon, or aircraft, may be used for overland applications. Flotation devices such as a watercraft may be used for aquatic applications.
[0048] Conveyance system 195 may be detachable so that analytical system 100 may be released and gravity acts to propel it through the fluid medium. In this embodiment, telemetry may also be used to transmit the data or other results back to a monitoring station or the analytical system 100 may be retrieved. Also contemplated is the use of balloons or kites, with sampling taking place during ascent and travel. If detachable cords are used, sampling may also occur during gravitational descent.
[0049] Because gravity or the motion of conveyance system 195 are used to impel the flow of fluid through analytical system 100 , the need for the auxiliary pumps of the prior art is obviated. This enables the instant device to be reduced in size and simplifies the power requirements of the analytical system 100 . In addition, analysis chamber 135 may be a micro-sized portion of the overall system, so that minute or trace amounts of a component of interest may be captured and detected.
[0050] Analysis chamber 135 may be constructed in any geometry necessary to enhance the performance of sensor system 125 , the component of interest, and the fluid medium. Three example geometries for an optical sensor detection system are shown in FIGS. 2 through 5 . In each of these examples, light source 200 emits a light beam through analysis chamber 135 to detector 210 . Other geometries are also available and are considered as design variations to one of ordinary skill in the art, including a linear arrangement as shown in FIG. 5 .
[0051] In addition to a single detection system, it is contemplated that a flow splitting arrangement may also be incorporated so that multiple discreet detections of the same or different component may be made simultaneously. In addition, either one or both of separators 122 and 123 may be omitted depending on the sensor system used. Reagent systems that trap the component of interest or assist in the detection of the component may also be used. A diagram of an embodiment using reagent trap 350 is shown in FIG. 5 in conjunction with a linear, non-membrane detection system 300 . Here, reagent trap 350 is used for isolation of the desired component.
[0052] In addition to optical sensors, various other types of sensors may be employed. Example sensors include, but are not limited to, electrical, electrochemical, gravimetric, mass loading and ion or molecular and particle traps. Various configurations of analysis chamber 135 to accommodate these types are systems are considered within the scope of knowledge of one of ordinary skill in the art. In addition, a threshold-type of sensor may also be incorporated into analytical system 100 , with comparison to a pre-determined level being the output of choice.
[0053] Modification and variation can be made to the disclosed embodiments of the instant invention without departing from the scope of the invention as described. Those skilled in the art will appreciate that the applications of the present invention herein are varied, and that the invention is described in one preferred embodiment. Accordingly, additions and modifications can be made without departing from the principles of the invention. Particularly with respect to the claims it should be understood that changes may be made without departing from the essence of this invention. In this regard it is intended that such changes would still fall within the scope of the present invention. Therefore, this invention is not limited to the particular embodiments disclosed, but is intended to cover modifications within the spirit and scope of the present invention as defined in the appended claims.
[0054] It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0055] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall there between. | A self-propelled apparatus for analyzing a component contained in a fluid medium. The self-propelled apparatus uses kinetic energy of the apparatus to drive a fluid under analysis through the apparatus. This is accomplished by use of a conveyance system that is attached to the analytical system of the apparatus. A sensor system is used to analyze the component collected within the confines of an analysis chamber, a part of the analysis system. The invention also includes a method of using the analytical apparatus. | 8 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a display apparatus for a sewing machine and, more particularly, to technology for displaying the sewing order of a stitch pattern selected from a plurality of sewable stitch patterns.
2. Description of Related Art
A conventional sewing machine with a display displays a plurality of sewable stitch patterns to allow an operator to select a desired stitch pattern therefrom, as a stitch pattern to be sewn, and also displays at least part of the selected stitch pattern to notify the operator of the selected stitch pattern.
As the selected stitch pattern displayed alone on a display does not provide sufficient information about sewing the selected stitch pattern, many of the sewing machines are designed to display more information including the size of the selected stitch pattern (such as the stitch width and the stitch length) and the thread tension during sewing.
As shown in FIG. 12, in a sewing machine the applicants have put to practical use, when a straight stitch pattern key 102 is pressed on a utility stitch pattern selection screen 101 displayed on a display 100 , a straight stitch pattern is selected as the stitch pattern to be sewn. At the top of the display 100 , a horizontal straight stitch pattern and the stitch pattern name “Straight (Left)” are displayed. Below a plurality of stitch patterns displayed on the display 100 , the needle bar oscillating width (stitch width) “0.0 mm”, the stitch length “2.5 mm”, and the thread tension are displayed as the sewing information of the selected stitch pattern.
In addition, when an “ADVICE” key 104 is pressed on the utility stitch pattern selection screen 101 of FIG. 12, advice on sewing the selected stitch pattern can be displayed on the display 100 . If a “HOW TO SEW” key 103 is pressed when the stitch pattern to select is unknown, a sewing position selection screen, a work cloth type selection screen and the like can be displayed on the display 100 to allow an operator to selectively enter the sewing position, the work cloth type, and the like on the respective screens and set a stitch pattern suitable for a particular use.
In some of conventional machines, a selected stitch pattern, sewing information of the selected stitch pattern, such as the pattern size and the thread tension during sewing, and advice on sewing the selected pattern can be displayed. However, to date there is no sewing machine that can display the sewing order of the selected stitch pattern from start to finish of sewing.
The sewing order of relatively simple stitch patterns, such as a straight stitch pattern and a zigzag stitch pattern, is obvious and unnecessary to be displayed. On the other hand, if the sewing order is not displayed on the display when a complex stitch pattern is selected as the stitch pattern to be sewn, an operator cannot check the sewing order of the selected stitch pattern on the display. In this case, it is difficult to judge if the pattern being sewn is the selected pattern by only seeing the pattern being sewn (unfinished pattern). In the worst case, an operator may misjudge that the pattern being sewn is a wrong one and stop sewing.
There is a conventional sewing machine that displays, on a display, a stitch pattern and one arrow indicating the sewing direction at the start of sewing. However, a sewing machine that displays the sewing order of a stitch pattern from start to finish of sewing has not yet been available. In such a conventional machine, it is difficult to judge if the pattern being sewn is the selected one by only seeing the pattern being sewn (unfinished pattern).
When a selected stitch pattern is a continuously- and repeatedly-sewn pattern, it is conceivable to display an essential part, that is, a unit pattern of the selected stitch pattern in an enlarged scale and to show a plurality of needle drop positions of the enlarged unit stitch pattern. However, when a complex stitch pattern is selected, the sewing order is not easy to recognize even if a unit pattern of the selected stitch pattern is displayed in an enlarged scale. Particularly, when the selected pattern is made up of intersecting stitches, the sewing order is more difficult to recognize.
Therefore, the invention provides a display apparatus for a sewing machine that can display the sewing order of a stitch pattern selected from a plurality of sewable stitch patterns to allow an operator to judge if a pattern being sewn (an unfinished pattern) is the selected one, and providing a storage medium storing a stitch pattern display program that enables a display used in a sewing machine to display such sewing order.
SUMMARY OF THE INVENTION
The invention provides a display apparatus for a sewing machine that can indicate a sewing order of substantially an entire stitch pattern using a display.
In this regard, the display apparatus for a sewing machine of the embodiment of the invention may include a display that displays a stitch pattern thereon, and a sewing order indicator that indicates a sewing order of substantially the entire stitch pattern.
According to the display apparatus structured as described above, the sewing order indicator indicates a sewing order of substantially the entire stitch pattern. Therefore, an operator can recognize the sewing order of substantially the entire stitch pattern by means of the display.
In a preferred aspect of the invention, the display apparatus may further include a selecting device that selects the stitch pattern, the display may display the stitch pattern selected by the selecting device, and the sewing order indicator may indicate the sewing order of the stitch pattern selected by the selecting device. According to the display apparatus structured as described above, even when the operator selects, as a stitch pattern, a complex stitch pattern, such as a buttonhole stitch pattern, the operator can easily judge if the stitch pattern being sewn is exactly what the operator has selected before the stitch pattern is finished. Accordingly, the apparatus can prevent the operator from misjudging that a wrong stitch pattern is sewn and from stopping the sewing machine.
In a preferred aspect of the invention, the sewing order indicator may include a sewing direction indicator that indicates a sewing direction at least at a starting portion and an ending portion of the stitch pattern. According to the display apparatus structured as described above, the operator can easily recognize the sewing order of substantially the entire stitch pattern by means of the display.
In a preferred aspect of the invention, the sewing direction indicator may include a mark display device that displays at least one mark indicating the sewing direction. According to the display apparatus structured as described above, the mark display device can indicate the sewing direction in a simple manner.
In a preferred aspect of the invention, the mark display device may display a plurality of marks. According to the display apparatus structured as described above, the mark display device can indicate the sewing direction of substantially the entire stitch pattern in detail.
In a preferred aspect of the invention, the sewing order indicator may include a forming process indicator that indicates a forming process of the stitch pattern. According to the display apparatus structured as described above, the operator can recognize the sewing order of substantially the entire stitch pattern through the forming process of the stitch pattern using the display.
In a preferred aspect of the invention, the forming process indicator may display an animation of the forming process. According to the display apparatus structured as described above, the operator can recognize the realistic image of the forming process of the stitch pattern by the animation displayed on the display.
In a preferred aspect of the invention, the forming process indicator may display each picture included in a series of pictures showing the forming process one by one at intervals of a predetermined period. According to the display apparatus structured as described above, the operator can recognize each step of the forming process of the stitch pattern by the series of pictures displayed on the display.
In a preferred aspect of the invention, the sewing order indicator may include a thread path indicator that indicates a thread path for at least one part of the stitch pattern. Further, the display apparatus may include an enlargement device that enlarges the stitch pattern on the display. Further, the thread path indicator may include a mark display device that displays at least one mark indicating the thread path. According to the display apparatus structured as described above, the operator can easily recognize the stitch pattern enlarged on the display by the enlargement device and the thread path and also the sewing order in detail through the thread path indicated by the thread path indicator.
In a preferred aspect of the invention, the display apparatus may include a needle drop position display device that displays needle drop positions included in the stitch pattern. According to the display apparatus structured as described above, for example, when the fagotting stitch pattern is selected, the displayed needle drop positions of the stitches allow the operator to clearly know the needle drop positions and facilitate the operator to trace a plurality of needle drop positions in the vicinity of a joining part of two work cloths. Thus, workability during sewing can be improved.
In a preferred aspect of the invention, the display apparatus may include a needle drop position numbering device that displays a plurality of numbers indicating an order of the needle drop positions or may include a path numbering device that displays a plurality of numbers indicating an order of the thread path. According to the display apparatus structured as described above, the operator can recognize the sewing order through the numbers indicating the order of the needle drop positions or the thread path on the display.
In a preferred aspect of the invention, the thread path indicator may indicate the thread path for at least one unit of repeated patterns included in the stitch pattern. According to the display apparatus structured as described above, even when a continuous and repeated stitch pattern is selected, the operator can recognize the sewing order of the stitch pattern adequately.
In a preferred aspect of the invention, the thread path indicator may indicate the thread path so that when two stitches cross each other, a lower stitch is not displayed in a vicinity of an upper stitch. According to the display apparatus structured as described above, even when two stitches cross each other in the selected stitch pattern, the operator can recognize the upper/lower positional relationship of the two stitches clearly.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described in detail with reference to the following figures wherein:
FIG. 1 is a perspective view of an electronically controlled sewing machine according to a preferred embodiment of the invention;
FIG. 2 is a block diagram showing the control system of the electronically controlled sewing machine;
FIG. 3 is a diagram showing the structure of part of the data contained in a ROM;
FIG. 4 is a pattern selection screen displayed on a display;
FIG. 5 is a pattern confirmation screen displayed on the display;
FIG. 6 is a flowchart (first half) of a control sequence including pattern display control;
FIG. 7 is a flowchart (second half) of the control sequence including pattern display control;
FIG. 8 is a pattern confirmation screen displayed on a display according to a second embodiment of the invention;
FIG. 9 is a pattern confirmation screen displayed on a display according to a third embodiment of the invention;
FIG. 10 is a pattern confirmation screen displayed on a display according to a fourth embodiment of the invention;
FIG. 11 illustrates a stitch pattern forming process according to fifth and sixth embodiments of the invention; and
FIG. 12 is a pattern selection screen displayed on a prior art display.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A first preferred embodiment according to the invention as applied to an electronically controlled sewing machine will now be described with reference to the accompanying drawings. The electronically controlled sewing machine has a removable embroidery unit, and can sew embroideries when the embroidery unit is mounted and sew normal stitches (utility stitches, such as straight stitches and zigzag stitches) when the embroidery unit is removed. As shown in FIG. 1, an electronically controlled sewing machine M has a bed 1 , a standard portion 2 extending upwardly from the right end portion of the bed 1 , an arm 3 extending leftwardly from the top of the standard portion 2 so as to face the bed 1 , and a head 4 located at the left end of the arm 3 .
The bed 1 is provided with a feed dog (not shown), a feed dog up/down moving mechanism (not shown) that moves the feed dog up and down, a feed dog back/forth moving mechanism (not shown) that moves the feed dog back and forth, and a rotary hook (loop taker) (not shown) that accommodates a bobbin and forms stitches in cooperation with a vertically moving needle 11 . When normal stitches are sewn, an auxiliary bed 5 is detachably attached to the bed 1 . The embroidery unit 6 (FIG. 2) can be mounted/dismounted to/from the bed 1 when the auxiliary bed 5 is not attached to the bed 1 .
The standard portion 2 has a card slot 2 a into which a ROM card 7 is inserted to be connected with an internal card connector 29 (FIG. 2 ). Below the card slot 2 a, a floppy disk drive (FDD) 9 for receiving a floppy disk (FD) 8 is built in the standard portion 2 . In this embodiment, embroidery pattern data of a plurality of sewable embroidery patterns is stored in the ROM card 7 and the floppy disk 8 .
A needle bar 10 is supported on the head 4 so as to be vertically movable. The needle 11 is mounted at the lower end of the needle bar 10 . Provided inside the head 4 and the arm 3 are a needle bar driving mechanism (not shown) that vertically moves the needle bar 10 , a needle bar oscillating mechanism (not shown) that oscillates the needle bar 10 right and left, and a thread take-up lever driving mechanism (not shown) that vertically moves a thread take-up lever in a timed relationship with the vertical motion of the needle bar 10 .
A presser foot 12 is provided to the head 4 so as to press, in the vicinity of the needle 11 , a work cloth against the upper surface of the bed 1 . A start/stop switch 13 for commanding the sewing machine M to start and stop sewing is provided at the front face of the head 4 . The feed dog up/down moving mechanism, the needle bar driving mechanism, and the thread take-up lever driving mechanism are driven by a sewing motor 30 , the needle bar oscillating mechanism is driven by a needle bar oscillating stepping motor 31 , and the feed dog back/forth moving mechanism is driven by a feed dog back/forth driving stepping motor 32 (FIG. 2 ).
A vertically elongated color liquid crystal display (LCD) 15 is attached to the front face of the standard portion 2 . At the front face of the display 15 , a plurality of touch keys 16 (FIG. 2) made of transparent electrodes are arranged in a matrix form. The functions of the touch keys 16 are displayed on the display 15 . A desired stitch or function can be selected from the displayed information by pressing the touch key 16 associated with the desired stitch or function.
As shown in FIG. 2, when an embroidery frame (not shown) is mounted on the embroidery unit 6 , a first stepping motor 6 a for driving the embroidery frame in the X direction (right and left direction) and a second stepping motor 6 b for driving the embroidery frame in the Y direction (back and forth direction) are also mounted thereon. When the embroidery unit 6 is mounted on the bed 1 , the first and second stepping motors 6 a, 6 b are electrically connected to a control unit C of the sewing machine M through a connector 28 .
The control system of the electronically controlled sewing machine M will now be described.
As shown in FIG. 2, the control unit C has a computer including an input interface 20 , a CPU 21 , a ROM 22 , a RAM 23 , and a flash memory 24 that is nonvolatile and electrically rewritable, an output interface 25 , and a floppy disk controller (FDC) 26 for driving the FDD 9 . These devices are connected using a bus 27 , such as a data bus.
The start/stop switch 13 , the touch keys 16 , and a timing signal generator 17 that detects rotation phases of a main shaft of the sewing machine M are connected to the input interface 20 . The motors 30 - 32 and a display controller (LCDC) 33 for the LCD 15 are connected to the output interface 25 . The first and second stepping motors 6 a, 6 b of the embroidery unit 6 are connectable to the output interface 25 through the connector 28 , and a ROM 7 a of the ROM card 7 is connectable to the bus 27 through a connector 29 .
As shown in FIG. 3, the ROM 22 stores pattern data of a plurality of utility stitch patterns (first stitch pattern, second stitch pattern, third stitch pattern, . . . ) including straight stitches, buttonhole stitches used to form a buttonhole, and fagoting stitches used to join two work cloths.
The pattern data of each stitch pattern includes pattern display data, accompanying data for pattern display data, sewing data, and accompanying data for sewing data. As shown in FIG. 3, the ROM 22 also stores display data of a set of stitch patterns for displaying the stitch patterns at a time. Such a display allows an operator to select a desired stitch pattern from the plurality of stitch patterns. In addition, the ROM 22 stores pattern data of a plurality of embroidery patterns.
Further, the ROM 22 stores a pattern display program, which is unique to the invention, and other programs. The pattern display program includes a pattern display routine for displaying the plurality of stitch patterns on a screen (a pattern selection screen 40 of FIG. 4) of the display 15 , based on the display data of a set of stitch patterns, a pattern selection routine for selecting a desired stitch pattern from the plurality of stitch patterns displayed, by the pattern display routine, on the screen of the display 15 , and a sewing order display routine for displaying the selected stitch pattern and its sewing order on a screen (a pattern confirmation screen 50 of FIG. 5) of the display 15 , based on the pattern display data and the accompanying data for pattern display data (FIG. 3 ).
Particularly, in this embodiment, as shown in the pattern confirmation screen 50 of FIG. 5, when buttonhole stitches are selected, for example, buttonhole stitches 52 as well as a plurality of arrows indicating the sewing direction are displayed by the sewing order display routine.
A control sequence including a control routine executed by the pattern display program run by the control unit C will now be described with reference to flowcharts shown in FIGS. 6 and 7. An exemplary case will be described where a pattern of buttonhole stitches for forming a buttonhole is selected from the plurality of stitch patterns. Si (i=1, 2, 3 . . . ) shown in the flowcharts represents each step.
As shown in FIG. 6, the control sequence starts when the power of the sewing machine M is turned on, and initialization of the sewing machine M including clearing memories in the RAM 23 is executed (S 1 ). Then, when the embroidery unit 6 is not mounted on the sewing machine M, a pattern type selection screen (not shown) appears on the display 15 to allow an operator to select the type of stitch pattern (S 2 ).
When utility stitches are selected as the stitch pattern type by pressing a utility stitch pattern selection key (S 3 : Yes), the pattern selection screen 40 appears on the display 15 (S 4 ). On the pattern selection screen 40 , a plurality of stitch patterns (for example, 15 stitch patterns), including straight stitches, buttonhole stitches, and fagoting stitches, are displayed in a plurality of columns and rows (for example, in a 3×5 matrix), based on the display data of a set of stitch patterns.
In addition, below the plurality of stitch patterns on the pattern selection screen 40 , sewing information including the stitch width (WIDTH), the stitch length (LENGTH), and the thread tension (TENSION), along with stitch width changing keys 44 a, 44 b, stitch length changing keys 45 a, 45 b, and thread tension changing keys 46 a, 46 b are displayed. Below them, a help key 42 is displayed.
When the pattern selection screen 40 is displayed for the first time after the power of the sewing machine M is turned on, straight stitches are initially selected, as shown in FIG. 4, and a horizontal straight stitch pattern and the stitch pattern name “Straight (Left)” are displayed at the top of the display 15 . In addition, the sewing information, that is, the stitch width (WIDTH) being “0.0 mm”, the stitch length (LENGTH) being “2.5 mm” and the thread tension (TENSION) are displayed below the plurality of stitch patterns, based on the additional sewing data about straight stitches.
When a buttonhole key 41 a is pressed on the pattern selection screen 40 while the help key 42 is not on (S 5 : No), buttonhole stitches are selected as the stitch pattern used for sewing (S 6 : Yes). After that, when a predetermined key is operated, stitch pattern selection processing (S 7 ) is executed, and then the pattern confirmation screen 50 shown in FIG. 5 is displayed (S 8 ).
On the pattern confirmation screen 50 , a pattern display area 51 is displayed so as to overlap a generally central part of the pattern selection screen 40 . In the pattern display area 51 , a buttonhole stitch pattern 52 is displayed based on the pattern display data, and a plurality of arrows 53 are displayed, based on the accompanying data for pattern display data, to indicate the sewing direction of the buttonhole stitch pattern 52 .
In the pattern display area 51 , the stitch pattern name “Buttonhole” is displayed above the buttonhole stitch pattern 52 , and a piece of advice on sewing and an explanation of the sewing order, which start with “Used for jeans and thick fabric . . . ” are displayed on the right side of the buttonhole stitch pattern 52 . Together with the pattern selection screen 40 of FIG. 4 and the pattern confirmation screen 50 of FIG. 5, a horizontal buttonhole stitch pattern 55 is displayed outside the pattern display area 51 , that is, at the top of the display 15 .
At this time, if a predetermined key is operated, the pattern display area 51 disappears. In this state, if any one of the WIDTH changing keys 44 a, 44 b, the LENGTH changing keys 45 a, 45 b, and the TENSION changing keys 46 a, 46 b is pressed to change the sewing condition (S 9 : Yes), sewing condition update is executed (S 10 ) to change the previously set sewing condition to the newly set sewing condition.
After that, when the start/stop switch 13 is turned on (S 11 ), sewing is executed (S 12 ). The motors 30 - 32 are driven, based on the sewing data of the selected buttonhole stitch pattern and the above-described sewing condition, and a buttonhole pattern is sewn on a work cloth set on the bed 1 . Then the control sequence returns to S 9 .
When no utility stitch pattern is selected in S 3 (S 3 : No) and any key other than a utility stitch pattern selection key is pressed (S 15 : Yes), processing associated with the other key is executed (S 16 ), and the control sequence returns to S 2 . When no stitch pattern is selected (S 6 : No) and any other key than a stitch pattern selection key is pressed (S 20 : Yes), processing associated with the other key is executed (S 21 ), and the control sequence returns to S 4 . When no other key is pressed (S 20 : No), the control sequence also returns to S 4 .
When the help key 42 is pressed and turned on in S 5 (S 5 : Yes), the help screen is displayed as shown in the flowchart of FIG. 7 (S 22 ). The help screen is the same as the pattern selection screen 40 except that it is entirely shaded to inform the operator the system is in the help mode. When the buttonhole key 41 a is pressed on the help screen to select the buttonhole stitch pattern (S 23 ), stitch pattern selection is executed (S 24 ). Then, a pattern confirmation screen, which is substantially the same as the pattern confirmation screen of FIG. 5, is displayed (S 25 ). Doing so allows the operator to review the stitch without actually making a selection, thereby determining the best stitch for the job.
When any other key than the buttonhole key 41 a is pressed on the help screen (S 23 : No, S 27 : Yes), a description of the other key is displayed (S 28 ), and the control sequence returns to S 23 . Then, when the help key 42 is pressed again and turned off (S 26 : Yes), the control sequence returns to S 4 .
As described above, when an operator selects, as a stitch pattern, a complex stitch pattern such as a buttonhole stitch pattern, a plurality of arrows indicating the sewing direction of the stitch pattern are displayed. Such display allows the operator to know the sewing order of the stitch pattern and to judge if the stitch pattern being sewn is exactly what he/she has selected even when the stitch pattern is unfinished, and prevents the operator from misjudging that a wrong stitch pattern is being sewn and stop the sewing machine M.
The above-described pattern display routine corresponds to S 2 and S 21 , the pattern selection routine corresponds to S 7 and S 24 , and the sewing order display routine corresponds to S 8 and S 25 .
Referring now to FIG. 8, a second embodiment of the invention will be described.
The sewing order display routine in the first embodiment may be modified such that stitches in an enlarged scale (hereinafter referred to as enlarged stitches) of an essential part, that is, a unit pattern of a selected stitch pattern, a plurality of arrows indicating the thread path, and needle drop positions of the enlarged stitches may be displayed. Further, when stitches cross each other, the lower stitch may not be displayed in the vicinity of the upper stitch so as to make clear the upper/lower positional relationship of the crossed stitches.
For example, when a fagoting key 41 b is pressed on the pattern selection screen 40 (FIG. 4) displayed on the display 15 , a fagoting stitch pattern is selected and a pattern confirmation screen 50 A is displayed as shown in FIG. 8 . On the pattern confirmation screen 50 A, enlarged stitches 60 of an essential part, that is, a unit pattern of the fagoting stitch pattern, a plurality of arrows 61 indicating the thread path, and needle drop positions 60 a of the enlarged stitches are displayed based on the pattern display data.
The arrows 61 displayed to indicate the thread path of the enlarged stitches 60 allow an operator to clearly know the sewing order of the selected fagoting stitch pattern. The additionally displayed needle drop positions 60 a of the enlarged stitches allow the operator to clearly know the needle drop positions 60 a and to enable the operator to trace a plurality of needle drop positions 60 a in the vicinity of an joining part of two work cloths. Thus, workability during sewing can be improved.
When stitches cross each other, the lower stitch is not displayed in the vicinity of the upper stitch. Such a display makes clear the upper/lower positional relationship of the crossed stitches. In addition, the stitch pattern name “Fagoting” is displayed in the pattern display area 51 of the pattern confirmation screen 50 A of FIG. 8, and a horizontal fagotting stitch pattern 62 is displayed outside the pattern display area 51 , that is, at the top of the display 15 .
Referring now to FIG. 9, a third embodiment of the invention will be described.
The sewing order display routine in the first embodiment may be modified such that a plurality of arrows indicating the thread path of enlarged stitches of an essential part, that is a unit pattern of a selected stitch pattern, and a plurality of numbers indicating the order of sewing along the thread path are displayed. For example, when a fagoting stitch pattern is selected, a plurality of arrows 61 indicating the thread path of enlarged stitches 60 of an essential part, that is, a unit pattern of the fagoting stitch pattern, and a plurality of numbers “1, 2, 3, . . . ” associated with the arrows 61 are displayed on a pattern confirmation screen 50 B as shown in FIG. 9 . Accordingly, the sewing order of the fagoting stitch pattern can be displayed clearly. Alternatively, the plurality of arrows 61 may be omitted.
Referring now to FIG. 10, a fourth embodiment of the invention will be described.
The sewing order display routine in the first embodiment may be modified such that a plurality of arrows indicating the thread path of enlarged stitches of an essential part, that is a unit pattern of a selected stitch pattern, and a plurality of numbers indicating the order of sewing by tracing a plurality of needle drop positions are displayed. For example, when a fagoting stitch pattern is selected, a plurality of arrows 61 indicating the thread path of enlarged stitches 60 of an essential part, that is, a unit pattern of the fagoting stitch pattern, and a plurality of numbers “1, 2, 3, . . . ” added to a plurality of needle drop positions 60 a are displayed on a pattern confirmation screen 50 C as shown in FIG. 10 . Accordingly, the sewing order of the fagoting stitch pattern can be displayed clearly. Alternatively, the plurality of arrows 61 may be omitted.
Referring now to FIG. 11, a fifth embodiment of the invention will be described. The sewing order display routine in the first embodiment may be modified such that a forming process of a selected stitch pattern is displayed using an animated picture. For example, following the selection of a buttonhole stitch pattern, or following a predetermined key operation after the selection of a buttonhole stitch, an animated picture as shown in FIG. 11 may be displayed in the pattern display area 51 . Although FIG. 11 illustrates the forming process as divided into nine steps, the animated picture is a single continuous picture. Accordingly, the sewing order of the buttonhole stitch pattern can be displayed very clearly.
Alternatively, the sewing order display routine in the first embodiment may be modified such that a forming process of a selected stitch pattern may be displayed in steps using a plurality of frame pictures. For example, following the selection of a buttonhole stitch pattern, or following a predetermined key operation after the selection of a buttonhole stitch, a buttonhole stitch forming process may be displayed in the pattern display area 51 by changing, at predetermined intervals, frame pictures corresponding to each or some of the nine forming steps of FIG. 11 . Accordingly, the sewing order of a buttonhole stitch pattern can be displayed very clearly.
Although, in the above-described embodiments, the pattern display program including the pattern display routine, the pattern selection routine, and the sewing order display routine are stored in the ROM 22 , it may be stored in the ROM card 7 or in the FD 8 . Thereby, the pattern display program stored in the ROM card 7 or the FD 8 can be used in sewing machines with a display, other than the electronically controlled sewing machine M, if they support the use of a ROM card or a FD. A sewing machine using such a ROM card or an FD produces the same effects as the sewing machine M of the above-described embodiments do.
Although not shown, the sewing machine M may be connectable to the internet directly via a modem or a ISDN line or may be connected to a computer, such as a personal computer or server, that stands alone or, in turn, is connected to the internet.
The invention further includes as an aspect, the programs described above that can be executed by the controller of the sewing machine, or by an attached computer, to control the sewing machine as described above. The control program can be implemented in an application specific integrated circuit (ASIC). Alternatively, the control program and/or the stitch data can be transmitted by a carrier wave over a communications network, such as, for example, the World Wide Web, and/or transmitted in a wireless fashion, for example, by radio waves or by infrared waves. The control program can also be transmitted by a carrier wave from a remote storage facility to a local control unit, either in the sewing machine or attached thereto. In such an arrangement, the local control unit interacts with the remote storage facility to transfer all or part of the program or data, as needed, for execution by the local unit. Accordingly, the local unit does not require a large amount of memory capacity. Additionally, or alternatively, the programs can be fixed in a computer-readable recording medium such as, for example, a CD-ROM, a computer hard drive, RAM, or other types of memories that are readily removable or intended to remain fixed within the sewing machine or an attached computer. Thus, as another aspect, the invention relates to a computer program product such as a carrier wave or a recording (or storage) medium that embodies or stores the control program.
While the invention has been described with reference to specific embodiments, it is not restricted to the specific details set forth. Various modifications or changes may be made by those skilled in the art without departing from the spirit and scope of the invention. | The display apparatus for a sewing machine of the invention includes a display that displays a stitch pattern thereon, and a sewing order indicator that indicates a sewing order of substantially an entire stitch pattern. Therefore, even when the operator selects, as a stitch pattern, a complex stitch pattern such as a buttonhole stitch pattern, the operator can easily judge if the stitch pattern being sewn is exactly what the operator has selected before the stitch pattern is finished. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to the containment of aerofoil blades and in particular to the containment of gas turbine engine rotor aerofoil blades.
Gas turbine engines typically include large numbers of aerofoil blades that are mounted for rotation within the engine. Normally such aerofoil blades are extremely reliable and present no problems during normal engine operation. However in the unlikely event of one of the blades becoming detached from its mounting, measures must be taken to ensure that the detached blade causes as little damage as possible to the structures surrounding the engine.
One way of limiting such damage is to manufacture the casing that normally surrounds the blades so that it is sufficiently robust to contain a detached blade. Unfortunately this results in a casing that is very thick, and therefore undesirably heavy.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lightweight aerofoil blade containment structure.
According to the present invention, an aerofoil blade containment structure includes a continuous woven sleeve for positioning externally of a gas turbine engine casing enclosing rotor aerofoil blades, the woven sleeve is folded to define a plurality of interconnected secondary sleeves arranged in coaxial superposed relationship with each other. The sleeve is woven from fibres that are capable both of withstanding the operational temperatures externally of such a gas turbine engine casing without suffering significant thermal degradation and of containing any failed rotor aerofoil blades released from within the casing radially inwardly of the sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a sectioned side view of a ducted fan gas turbine engine having an aerofoil blade containment structure in accordance with the present invention.
FIG. 2 is a view on an enlarged scale of a portion of the aerofoil blade containment structure of the ducted fan gas turbine engine shown in FIG. 1.
FIG. 3 is a view of a part of the aerofoil blade containment structure of the ducted fan gas turbine engine shown in FIG. 1 prior to its mounting on that gas turbine engine.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, a ducted fan gas turbine engine generally indicated at 10 is of conventional construction and operation. Briefly it comprises, in axial flow series, a-ducted fan 11, an intermediate pressure compressor 12, a high pressure compressor 13, combustion equipment 14, high, intermediate and low pressure turbines 15,16 and 17 respectively and an exhaust nozzle 18. The fan 11 is driven by the low pressure turbine 17 via a first shaft 19. The intermediate pressure compressor 12 is driven by the intermediate pressure turbine 16 via a second shaft 20. Finally the high pressure compressor 13 is driven by the high pressure turbine 15 via a third shaft 21. The first, second and third shafts 19,20 and 21 are concentric.
During the operation of the engine 10, air initially compressed by the fan 11 is divided into two flows. The first and major flow is exhausted directly from the engine 10 to provide propulsive thrust. The second flow is directed into the intermediate pressure compressor 12 and high pressure compressor 13 where further compression takes place. The compressed air is then directed into the combustion equipment 14 where it is mixed with fuel and combustion takes place. The resultant combustion products then expand through, and thereby drive, the high, intermediate and low pressure turbines 15,16 and 17, before being exhausted through the nozzle 18 to provide additional propulsive thrust.
The low pressure turbine 17 comprises three axially spaced apart annular arrays of rotor aerofoil blades 22. The aerofoil blades 25 are mounted for rotation about the longitudinal 26 axis of the engine 10 on discs (not shown) in the conventional manner. The rotor aerofoil blades 22 are enclosed by the low pressure turbine casing 27.
The low pressure turbine casing 27 is in turn partially enclosed by a lightweight annular support member 28 (which can be seen more easily if reference is now made to FIG. 2). The support member 28 is radially spaced apart from the turbine casing 27 by a plurality of radially extending feet 29. This results in the definition of an annular passage 30 between the casing 27 and support member 28. During operation of the gas turbine engine 10, some of the air exhausted from the fan 11 is directed to flow through the passage 30. This ensures adequate cooling of both the casing 27 and the support member 28.
The support member 28 carries a lightweight containment sleeve 31 that is knitted from glass fiber. Glass fiber is used in this particular application because of its ability to withstand the high temperatures that it is likely to encounter in this area of the turbine casing 27 without suffering significant thermal degradation. However other suitable high temperature resistant materials could usefully be employed if so desired. Moreover in certain circumstances it may be desirable to mount the containment sleeve 31 directly on the casing 27 without the use of the support member 28.
The containment sleeve 31 is initially knitted in the form of an elongate sleeve narrowed at regular intervals 32. Such narrowing 32 of the sleeve 31 is not essential but it assists in the folding of the sleeve 31 to the final configuration shown in FIG. 2. In that final configuration, the sleeve 31 defines a plurality of interconnected secondary sleeves 33 that are arranged in coaxial superposed relationship with each other.
Although in this particular case, the sleeve 31 is knitted, it will be appreciated that other suitable forms of weave could be employed if so desired.
The sleeve 31 is woven to such dimensions that when folded in the manner described above to define the secondary sleeves 33, it can be deformed so as to be a snug fit on the support member 28.
As can be seen from FIG. 2, the support member 28 is generally of frusto-conical configuration so as to approximately correspond in configuration with the turbine casing 27. However the knitted weave of the sleeve 31 enables the sleeve 31 to deform to such an extent that the previously mentioned snug fit on the support member 28 is achieved.
In the event of one of the turbine blades 22 becoming detached from its supporting disc during the operation of the engine 10, it will pass through the turbine casing 27. This is because the casing 27 is made only sufficiently thick for it to carry out its normal functions. However as soon as the detached turbine blade 22 reaches the support member 28 and glass fiber sleeve 31, it passes through the support 28 but is constrained by the sleeve 31. Thus the multiple layers defined by the secondary sleeves 33 are sufficiently strong to capture and retain the detached blade 22.
Since the multiple layers defined by the secondary sleeves 33 are composed of substantially continuous glass fibers, the capture of a detached turbine blade is more effective than would be the case if discontinuous fibers were used. Such discontinuous fibers would be present if, for instance, the secondary sleeves 33 were discrete and discontinuous.
If the glass fiber sleeve 31 were not to be utilized, the turbine casing 27 would have to be sufficiently thick to ensure containment of detached turbine blades 22. This typically would mean that the casing 27 would have to be some 35% heavier than when used in conjunction with the sleeve 31.
The present invention is not specifically restricted to the containment of turbine aerofoil blades 22. It will be appreciated that it could be applied in other areas of the engine 10 where aerofoil blade containment could be a problem. If those other areas are in cooler parts of the engine 10 then fibers which are sufficiently strong but that do not have high temperature resistance could be employed. For instance a sleeve of knitted Kevlar (registered trade mark) fibers could be provided around one of the compressor regions of the engine 10. | An aerofoil blade containment structure that is adapted to surround the low pressure turbine casing of a gas turbine engine includes an annular support member upon which is mounted a glass fiber knitted sleeve. The knitted sleeve is folded to define a plurality of interconnected secondary sleeves that are arranged in coaxial superposed relationship. Use of the containment structure obviates the use of thick, and therefore undesirably heavy, turbine casings. | 5 |
RELATED APPLICATIONS
This application is a continuation-in-part application of Ser. No. 484,367, filed Apr. 12, l983. now issued as U.S. Pat. No. 4,598,013.
BACKGROUND OF THE PRESENT INVENTION
The present invention relates to reinforcing materials used in flexible "V"-type belts and the methods for producing same. More particularly, the invention relates to a V-belt construction having, as one component thereof, a fiber-loaded seamless industrial fabric produced from the treatment of a non-woven fabric, whereby the fabric has a high percentage of either "chopped" or "staple length" fibers oriented in the "cross-machine" (fill) direction. i.e., perpendicular to the non-woven fabric length.
Conventional raw edge V-belts produced from fabrics containing chopped fibers, as well as large "full-wrapped" V-belts, are typically manufactured by combining the chopped fibers with a rubber compound, milling and then calendering the resultant mixture to form fiber-loaded sheets which are used to form the inside portion of the belt--that is, the portion which undergoes considerable stress (both axially and longitudinally) during normal use in, for example, high speed pulley arrangements. Almost all conventional V-belts also utilize one form or another of a strength member incorporated in the body of the belt.
It has long been known that the addition of chopped fiber adds stability widthwise and allows the belt to flex and elongate in the lengthwise direction. Known chopped fiber constructions are also intended to hold the belt in a "V" shape, and to thereby reduce abrasion at the contact points between the belt and any associated pulleys or other friction surfaces.
A critical limitation of conventional prior art V-belt constructions is that the equipment used to compound and calender the rubber/fiber mixtures are not generally capable of forming sheets having a chopped fiber concentration of over 10% by weight. Although it is known that a rubber to fiber ratio of over 25% would considerably improve belt stability and increase belt life, the conventional compounding methods have not been capable of achieving such a high percentage of fiber concentration.
In addition, conventional compounding methods are not capable of orienting the fibers in the cross-machine direction in sufficiently high concentrations to avoid cutting and splicing the fiber-loaded sheets. For example, a known method used by V-belt manufacturers to compound rubber and thereafter orient chopped fibers in a widthwise direction includes the following basic steps. First, the chopped fibers (approximately 1/4 inch in length) are added to a base rubber composition with additional mixing to break the fibers into individual components. The composition is then processed on a rubber mill and "slabbed" (generally in 1/2 inch thick sheets) which are then calendered to sheets approximately 60 inches wide and 0.060 inches thick. The calendering step orients 60% to 80% of the chopped fibers in the lengthwise direction of each sheet. The 60 inch sheets are then cut to 41 inch lengths and combined by splicing individual sections crosswise to form a continuous roll (generally 41 inches wide) for belt makeup purposes. This step is necessary in order for 80% of the fibers to be oriented in the crosswise direction relative to the longitudinal axis of the finished V-belt.
Likewise, a known method for manufacturing "full-wrapped" V-belts consists of the following steps. First, a layer of cushion fabric, commonly referred to as a "bias fabric", is placed on the belt makeup drum followed by layers of a fiber-loaded sheet previously calendered (as described above) to a specified thickness. A continuous strength element (generally consisting of one or more rubberized cord fabrics) is placed on top of the calendered sheets, followed by a rubberized laminate fabric. The V-belt is then slit to the desired size and shape and "wrapped" with a bias fabric (generally 45° or more) by one ore more complete wraps. The bias fabric overlaps on the underside of the narrow portion of the V-belt and the resultant "wrapped" construction is then cured in a conventional oven at a temperature and for a period of time sufficient to vulcanize the rubber components, thereby forming a cohesive structure.
Although conventional prior art V-belt constructions are acceptable for most moderate stress applications, they suffer from having a limited amount of chopped fiber within the base rubber compound and a lack of fiber orientation in the cross-machine (widthwise) direction. V-belts having a high percentage (i.e. greater than 10%) of fiber in the widthwise direction are, in fact, very difficult to manufacture because of the natural tendency of the fibers to become oriented in a lengthwise direction (relative to the longitudinal axis of the belt) during milling or calendering operations. Such limitations reduce overall belt stability and life span, particularly in high stress applications. In addition, conventional prior art V-belt constructions are relatively expensive, particularly in the larger sizes, due to the additional cutting and splicing steps required to achieve a higher percentage of fibers in the cross-machine direction.
Thus, it is an object of the present invention to provide an improved V-belt construction having a higher percentage of stability-improving fibers (i.e. more than 10 percent) incorporated into the belt in an oriented manner to provide sufficient flexibility in the lengthwise direction, but good stability widthwise.
It is a further object of the present invention to provide for a method of manufacturing a "seamless" V-belt reinforcing fabric having a higher percentage of stability-improving fibers oriented in a crosswise direction.
It is still a further object of the present invention to provide a simplified and improved V-belt having high flexibility but greater stability and a longer life-span than conventional constructions.
These and other objects of the invention will become evident from the detailed description, drawings and appended claims.
It has now been found that the foregoing objects regarding overall strength, utility and life-span of V-belts can be accomplished by a unique construction whereby a seamless, i.e., endless and non-spliced, fabric is produced from a non-woven fabric having an increased percentage of either chopped or "staple length" fibers oriented perpendicular to the non-woven fabric length. More particularly, it has now been found that the application of solvent and rubber compositions to the non-woven fabric by way of an initial impregnation and a "re-impregnation" of the fabric, followed by an expansion of the fabric, permits the fibers to be reoriented in the crosswise direction while in a "solvated state" during a subsequent tentering operation. Thus, exemplary V-belt constructions in accordance with the present invention contain a higher percentage of stability-improving fibers incorporated into the belt in an oriented manner to thereby provide sufficient flexibility in the lengthwise direction, but good stability widthwise. It has also been found that both conventional "chopped" fibers (usually about 1/4 inch in length) and "staple length" fibers may be used in fiber-loaded non-woven fabrics and V-belt constructions according to the invention.
The staple length fibers may be from 1/4 inch to 6 inches, preferably 1 inch to 11/8 inches.
The fibers may be cotton, polyester, nylon, nomex, kevlor, rayon or blends of two or more of these fibers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block-flow diagram depicting the basic process steps for producing the fiber-loaded non-woven fabric according to the present invention.
FIG. 2 is a perspective view, taken in cross-section, of a "cut edge" V-belt construction in accordance with the invention.
FIG. 3 is a perspective view, also taken in cross-section, of a "full wrapped" V-belt construction in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the foregoing objects, a preferred form of the process for producing the fiber-loaded non-woven fabric according to the invention involves the following basic steps: (1) entangling the chopped or staple length fibers in a non-woven fabric by way of a conventional needle punch; (2) impregnating the non-woven fabric with a neoprene/organic solvent/isocyanate composition; (3) reimpregnating the fabric with a neoprene/organic solvent composition; (4) drawing the impregnated non-woven fabric on a tentering frame; and (5) drying the fabric in a conventional oven. The product so produced can then be layered to form a V-belt construction of desired size and length. A specific illustration of a V-belt constructed in accordance with the invention is set forth in Example 1 below.
EXAMPLE 1
A "cut edge" V-belt was produced by using a starting material of 100% polyester fabric, non-woven greige Style No. 75051, at 4.79 ounces per square yard. The non-woven fabric was needle-punched using a conventional needle punch in order to "entangle" the chopped fibers in the fabric matrix.
Thereafter, in order to "reorient" the fibers in the 75051 greige sample in accordance with the invention, the fabric was first impregnated with a mixture of 20% (by weight) neoprene rubber compound, 5% isocyanate and 70% solvent (toluene), by dipping it in the impregnating solution and passing the fabric through a set of rollers to remove any excess composition. The percentage of wet pickup following the initial impregnation was found to be approximately 60%. The fabric was then passed through a conventional textile applicator and reimpregnated with a compounded mixture comprised of neoprene rubber and 58% solvent (toluene), wherein the non-woven fabric was coated on both sides. The fabric was then overfed onto tenter frame pins at 40% over frame pin chain speed and the width of the fabric expanded from a 60 inch greige width to 86.5 inches (approximately 44% increase in width). Finally, the fabric was dried in a conventional oven for approximately 5 minutes at 150° F. The drying operation was done only for a period of time sufficient to remove any excess solvent (water in an aqueous systems). That is, the drying must be short enough to avoid any vulcanization of the rubber compounds. In this regard, it has been found that a solvent-based system (as described above) requires approximately 5 minutes of drying in a conventional oven at 150° F.; aqueous systems generally require 5 minutes at 250° F.
The V-belt construction produced in accordance with the foregoing example was then tested using known analytical techniques, with the following results:
______________________________________ Finished Greige Uncured Cured______________________________________Grab Tensile:Machine Direction 50 Lbs. 80 Lbs. 138 Lbs.Cross Machine direction 45 Lbs. 155 Lbs. 225 Lbs.Weight/Square Yard: 4.79 oz. 38.42 oz. 38.42 oz.Adhesion Pounds per inch:Fabric/Fabric -- -- 37 Lbs.Fabric/.050 Neoprene/ -- -- 52 Lbs.Fabric Fabric BreakElongation:Machine direction (Warp)20-Lb. Load 29.9% 9.99%30-Lb. Load 76.6% 23.30%40-Lb. Load -- 36.60%Cross Machine direction(Fill)20-Lb. Load 3.33% 1.66%30-Lb. Load 6.66% 4.90%40-Lb. Load 13.30% 6.66%Width: 60 in. 86.5 in. --Gauge: .020 .060 .040Percent Rubber Add-on: 702% 702%Ratio Fiber to Rubber: 12.47% Fiber; 87.53% Rubber______________________________________
At the time in which the non-woven fabric is overfed (relative to the frame pin chain speed) and its width expanded, the fibers are in a "solvated" state and become reoriented with a high percentage (approximately 70-100%) in the cross-machine direction. Thus, the wet coating acts as a lubricant which allows the fibers to move freely within the fabric matrix while they are in the solvated state. The net effect of such reorientation is shown by the test results of the finished fabric tensile strength and elongation. That is, the machine direction grab tensile strength increased approximately 60% over the untreated greige fabric, while the cross-machine direction tensile strength increased approximately 244%.
Thus, as those skilled in the art can readily appreciate, non-woven "reoriented" fabric constructions in accordance with the invention have extremely high elongation in the machine direction but very low elongation in the cross-machine direction thereby resulting in excellent flexibility in the lengthwise direction of a finished V-belt, but good stability widthwise. In this regard, it has been found that the high flexibility and strength characteristics are achieved when the width is expanded in the range of 20 to 60%. The elongation of the fabric is also high enough to prevent any interference with strength members (such as rubberized cords) that are incorporated in a typical construction.
With particular reference to FIG. 1 of the drawings, FIG. 1 depicts a block-flow diagram of the basic process steps for producing fiber-loaded non-woven fabrics according to the invention. A preferred embodiment utilizes a non-woven polyester starting material that has been subjected to a conventional needle punch operation to incorporate and "entangle" the chopped fibers within the fabric matrix. As indicated above, both conventional "chopped" fibers (usually about 1/4 inch in length) and staple length fibers may be used to form the fiber-loaded fabrics and V-belt constructions in accordance with the invention. The staple length fibers may be standard polyester/cotton fibers ranging in size from 1/2 inch to 11/2 inches, within a preferred length of about 1 inch to 11/8 inches.
The "punched" fabric is then subjected to a first impregnation with a neoprene/isocyanate/solvent solution by immersing (dipping) the fabric into the solution. It is then reimpregnated on both sides with a Neoprene/solvent composition using a standard textile pad. The two impregnation steps place the chopped or staple length fibers in a "solvated", i.e. mobile, state within the fabric structure. The impregnated fabric is then overfed to a tentering frame where it is stretched and extended in a widthwise direction in order to reorient the fibers in the cross-machine direction. Finally, the "reoriented" fabric is dried in a conventional oven to remove any excess solvent.
With particular reference to FIG. 2, an exemplary cut edge V-belt construction in accordance with the present invention is shown generally at 10. The narrow bottom portion of the V-belt (shown generally at 13) is comprised of a first layer consisting of a bias cushion fabric 12, followed by one or more layers of a fiber-loaded non-woven polyester fabric 17 having its fibers "reoriented" in accordance with the present invention. A continuous strength rubberized cord, shown as 15 on FIG. 2, is placed on top of the fiber-loaded non-woven fabric, followed by a second layer of "reoriented" fabric 16. Finally, a second layer of bias cushion fabric 11 forms the top portion of the V-belt and defines edge 14.
With particular reference to FIG. 3, an exemplary "full wrapped" V-belt utilizing a "reoriented" fiber-loaded fabric in accordance with the invention is shown generally at 30. Again, a bottom layer comprised of bias cushion fabric (shown at 32) forms the bottom portion of the belt, followed by reoriented fiber-loaded material 38 and a strength element in the form of a rubberized cord 36. A second layer of fiber-loaded material 37 is added on top of the strength element together with a second bias cushion fabric 31. The entire V-belt is then "wrapped" with a second bias fabric 33 by way of one or more complete wraps. As FIG. 3 makes clear, bias fabric 33 overlaps the underside of the narrow portion of the V-belt at 35. Once the belt is fully wrapped, the entire construction is cured in a conventional oven at a temperature and period of time sufficient to accomplish vulcanization.
The "reoriented" fabric products according to the present invention can be produced by using either a solvent rubber solution or an aqueous latex-resin solution as the impregnating solvent. Although neoprene is the preferred polymer, blends of the various generic types of neoprene may be employed. An example of one such blend of natural rubber with a neoprene polymer is shown below as merely one or many available recipes for producing a seamless "reoriented" fabric in accordance with the invention.
______________________________________ Preferred Composition Composition Range______________________________________Neoprene GNA 90 0-100Neoprene GRT -- 0-100#1 Smoke Sheet 10 0-30Scorchguard "0" 3.5 3-5Antixodant 2246 1.0 1-3Naugha White 1.5 1-3Stearic Acid 0.5 0-2Plasticizer 4141 12.5 5-20N-220 30 15-60N-774 30 15-60ZNO 4.5 3-5MBTS 1.2 0-3______________________________________
Other polymers that are useful as the major portion of the compound include polyurethane, Buna-N, Hypalon, natural rubber, EPDM and mixtures of such polymers (up to 30%) blended with neoprene rubber. The end products produced from such compositions may range in fiber to rubber concentration of 5% fiber/95% rubber to 95% fiber/5% rubber. Thus, the non-woven fabric weights can be adjusted for various fiber/rubber ratios to obtain a desired finished gauge thickness.
It has also been found that the fiber-loaded (reoriented) non-woven fabrics in accordance with the invention can be made from either virgin or reclaimed natural or man-made blends of different fibers. Further, the width of the expanded non-woven fabric over greige may be as high as 70% to ensure that a higher percentage of the fibers will be properly oriented. As indicated above, because the process according to the invention orients the fiber in the cross-machine direction (contrary to the conventional processes) it avoids the step of orienting the fibers by cutting, turning and splicing the fiber-loaded fabric. In addition, the fact that the belt is seamless avoids any weight variations in the V-belt which tend to cause "belt slapping" and/or reduced wear due to improper belt balance. The process according to the invention thus allows the manufacturer to produce a V-belt having improved balance by using a seamless raw material that can be applied in any number of layers without fear of weight variations in the finished product.
While the invention herein is described in what is presently believed to be a practical, preferred embodiment thereof, it will be apparent that many modifications may be made within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent methods, fabrics and V-belt constructions. | A reinforced V-belt and method relating to same in which the V-belt comprises bottom, middle and top portions, the bottom portion consisting of a layer of bias cushion fabric and one or more layers of a seamless "fiber-loaded" non-woven fabric which has been impregnated with first and second solvent solutions and a plurality of chopped or staple length fibers generally oriented in the cross-machine direction relative to the longitudinal axis of the non-woven fabric; the middle portion consists of rubberized cord and a layer of non-woven fabric disposed on top of the rubberized cord; the top portion consists of bias cushion fabric. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 146,510 filed Jan. 21, 1988, which is a continuation of U.S. Ser. No. 6/835,493 filed Mar. 3, 1986, now U.S. Pat. No. 4,792,336 issued Dec. 20, 1988; and also is related to U.S. Ser. No. 6/929,577 filed Dec. 24, 1986, now U.S. Pat. No. 4,871,365 issued Oct. 3, 1989, which is a continuation application of U.S. Ser. No. 727,326 filed Apr. 25, 1985, now U.S. Pat. No. 4,652,264 issued Mar. 24, 1987.
BACKGROUND OF THE INVENTION
This invention relates to a prosthetic article and specifically to a vascular graft containing texturized absorbable or absorbable/nonabsorbable biomaterial. The use of the vascular graft is for repair of the peripheral vascular system and for coronary bypass.
The absorbable material fosters increased tissue ingrowth into the graft as compared to nonabsorbable grafts. Increased tissue ingrowth leads to greater patency through formation of a vascularized neointima and less tendency to be aneurysmal through formation of a suitable adventitia.
The absorbable material can vary and includes polyglycolic acid (hereafter PGA), and a copolymer comprising glycolic acid ester and trimethylene carbonate linkages, e.g. the copolymer in the MAXON™ (American Cyanamid Company, Wayne, N.J. 07470 U.S.A.) suture.
The nonabsorbable material (which is used as the backbone) can be proprietary materials, e.g. a Hytrel™ (E. I. DuPont and Co., Wilmington, Del. U.S.A.) polymer, such as the polymer in the NOVAFIL™ (American Cyanamid Company, Wayne, N.J.) suture. Alternatively, the nonabsorbable material can be more conventional polymers including a polyester, polyamide or polypropylene.
There has been a long felt need in the vascular graft art to develop a small diameter graft which will be generally acceptable to essentially all of the surgical community. The reasons for this long felt need are many and relate both to the biological requirements for a small diameter graft and to the limitations of the biomaterials generally used for these applications. Consequently, prior art small diameter vascular grafts, e.g. at or less than 8 mm diameter to even smaller diameter grafts, e.g. at or less than 4 mm diameter, have not been universally accepted by the surgical community.
Further discussion of the development of this long felt need is disclosed in U.S. Pat. No. 4,652,264 issued Mar. 24, 1987 at column 1 line 43 to column 2 line 12, which patent is incorporated herein by reference.
For a discussion of the background of this invention in a connective tissue repair or augmentation device, see U.S. Ser. No. 06/835,493 filed Mar. 3, 1986 page 1 to page 7 line 3 which is incorporated herein by reference.
SUMMARY OF THE INVENTION
A tubular article useful in prosthetic surgery has been invented. The article has a plurality of texturized fibers manufactured from an absorbable polymer. The polymer comprises at least one trimethylene carbonate linkage. In one embodiment, the absorbable polymer is a copolymer. In another embodiment, the article is manufactured on a warp knitting machine. The absorbable polymer comprises more than about 50% by weight of the article. The remainder of the article, if any, comprises a plurality of texturized fibers manufactured from a nonabsorbable polymer.
Another embodiment is an article manufactured on a weft knitting machine. The absorbable polymer comprises more than about 50% by weight of the article. The remainder of the article, if any, comprises a plurality of fibers manufactured from a nonabsorbable polymer.
Yet another embodiment is a woven article. The absorbable polymer in the texturized warp and weft yarns comprises more than about 50% by weight of the article. The remainder, if any, comprises a plurality of texturized fibers manufactured from a nonabsorbable polymer.
A generic embodiment of all of the above is a tubular article comprising a vascular graft.
A vascular graft has also been invented. The vascular graft has a plurality of texturized fibers which are manufactured from an absorbable copolymer. The copolymer comprises up to about 50% by weight of trimethylene carbonate linkages. The copolymer in the MAXON™ (American Cyanamid Company, N.J. U.S.A.) suture contains a copolymer having trimethylene carbonate linkages. MAXON™, which is a poly(gly-colide-co-trimethylene carbonate), has superior and unexpected properties when contrasted to other absorbable fibers. It is long-lasting. A portion of its original strength is retained out to 56 days; 50% of the strength remains through 28 days. The absorption rate of MAXONT™ is approximately equal to PGA.
A MAXON™ fiber is more compliant than polyglycolic acid (herein PGA). A graft containing 75% MAXON™ in combination with Dacron™ has a measured compliance of 3.03. A similarly constructed PGA/Dacron™ graft has a compliance of 2.45. Compliance is measured as a percentage of diametral change per 100 mm Hg internal pressure change. Finally, the bending modulus of MAXON™ is approximately 325,000 p.s.i., indicating that MAXON™ is a much more flexible fiber than other absorbable fibers.
In one embodiment, the copolymer comprises about 50% by weight of glycolic acid ester linkages. In another embodiment, the copolymer consists of at least one glycolic or lactic acid ester linkage.
Another embodiment is a graft which is manufactured on a warp knitting machine. The absorbable polymer comprises more than about 50% by weight of the article. The remainder, if any, comprises a plurality of texturized fibers manufactured from a nonabsorbable polymer. In a specific embodiment, the graft is manufactured on a Raschel knitting machine. In another specific embodiment, the plurality of texturized nonabsorbable polymer fibers of the graft comprises about 20 to 35% by weight of the graft.
The plurality of absorbable and nonabsorbable fibers are separately texturized by either a false twist or a knit/deknit process. In a most specific embodiment, the nonabsorbable polymer is Hytrel®. Another most specific embodiment is wherein the nonabsorbable polymer is polyethylene terephthalate.
Hytrel™ is a trademark of E. I. DuPont de Nemours & Co., Wilmington, Del. U.S.A. for a class of polymers having the following generic formula: ##STR1## The values for a, x and y are known from the prior art, e.g. as disclosed in "Thermoplastic Copolyester Elastomers: New Polymers For Specific End-Use Applications", M. Brown, Rubber Industry 9 102-106 (1978), and the references (footnote numbers 1b 1c 1d 2 and 3) cited therein; Encyclopedia of Polymer Science and Technology, Supplement, 2 485-510, see particularly pages 486 to 493, Interscience N.Y. 1977; and U.S. Pat. No. 4,314,561 issued Feb.9, 1982. All of this prior art is incorporated herein by reference. A specific embodiment of Hytrel® which is useful in this invention is a grade of Hytrel® having a 72 durometer D hard.
The polymer in the Novafil™ (American Cyananid Company, N.J., U.S.A.) suture contains Hytrel®. Novafil™, which is a polybutester, has superior and unexpected properties when contrasted to other nonabsorbable fibers. It is more flexible than other convention-al-type graft fibers, e.g. Dacron™. Novafil™ has a bending modulus of approximately 230,000 p.s.i. Also, the compliance of a Novafil™ containing graft measures 4.20 in combination with MAXON™. A similar graft manufactured from Dacron™ and Maxon™ has a compliance of 3.03. Compliance is measured as a percentage of diametral change per 100 mm Hg internal pressure change.
Finally, a tubular article useful in prosthetic surgery and having a plurality of texturized fibers manufactured from a nonabsorbable polymer has been invented. In a specific embodiment, the nonabsorbable polymer is Hytrel®.
A concentric knit relationship, wherein PGA comprises the inner tube, Maxon™ comprises the middle tube, and either Dacron™ Novafil™ comprises the outer tube, has the following synergistic advantages:
(1) Dacron™ is known from the prior art to incite a thrombogenic reaction.
(2) Dacron™ or Novafil™ fibers can be shielded from blood by inner layers of PGA and MAXON™, thereby minimizing the tendency to thrombose and occlude the graft.
(3) As PGA and then MAXON™ degrade and are absorbed, the inner capsule becomes larger and, hence, has a higher probability of remaining patent in small diameter applications.
(4) Based upon animal studies, a PGA- and MAXON™- containing graft tends to have greater patency than a commercial graft material.
The concentric relationship can be a plurality of single tubes attached together by sewing, gluing, or merely held together by frictional contact between the layers.
The texturized MAXON™ and/or PGA absorbable components of the graft become absorbed and are replaced by natural tissue. This leaves a skeletal structure of texturized nonabsorbable Dacron™ Novafil™ fibers which is encapsulated in healthy collagenous tissue. The inside wall or neointima of the skeletal structure develops into an endothelial-like growth. The outside wall has been shown to be comprised of a matrix of mature, highly vascularized granulation tissue.
This invention also relates to a nonabsorbable vascular graft manufactured from a Hytrel™ polymer, such as the polymer in the Novafil™ suture.
A method has been invented for texturizing a hydrolytically degradable, bioabsorbable fiber or yarn, or combination of biodegradable and nonabsorbable yarn without significantly degrading the bioabsorbable polymer structure. The purpose of the texturization is to form a plurality of fibers or yarn for use in a vascular graft or other surgical implant that will (1) encourage tissue ingrowth and (2) improve conformability and compliance.
This invention relates to the method of texturizing the absorbable or absorbable/nonabsorbable plurality of fibers or yarn. The method comprises:
(1) twisting, knitting, crimping or otherwise mechanically deforming the plurality of bioabsorbable or combination of absorbable and nonabsorbable thermoplastic fibers or yarn; and
(2) setting the plurality of fibers or yarn from step (1) by
(a) heating them to their glass transition or softening temperature in a dry atmosphere under a vacuum of up to about 5 torr at a temperature of from about 100° to 190° C., preferably at or less than about 1 torr and a temperature of about 120° to 140° C.; and
(b) cooling the fibers or yarn to ambient temperature.
Following cooling, the twist or other mechanical deformation is removed from the yarn by the same means in which it was inserted. Because of the heat setting step, the deformation imparted to the yarn is permanently set causing a textured, open, bulky appearance. The mechanical deformation can be removed by reversing the direction of an upstroke twisting (or uptwisting) machine. Such a machine is known in the prior art, e.g. see Man-Made Textile Encyclopedia, Textile Book Publishers, N.Y., 1959 pages 222, 223 and 238 to 240. This prior art is incorporated herein by reference.
This texture can further be modified to a lower degree, in the case of twisted heat set fibers, by subsequently rewinding the yarn onto another package (spool, aluminum tube, paper tube, etc.) under a lower winding tension, reheating the yarn and subsequently cooling it.
For a description of the relative humidity to be used in texturizing a plurality of fibers or yarn manufactured from a glycolic acid homopolymer or copolymer, see U.S. Pat. No. 3,422,181 entitled "Method for Heat Setting . . ." which issued to L. Chirgwin on Jan. 14, 1969, which patent is incorporated herein by reference. For a description of general process conditions useful in manufacturing a glycolic acid homopolymeric or copolymeric suture, see U.S. Pat. Nos. 3,626,948 entitled ". . . Enhanced In-Vivo Strength Retention" which issued Dec. 14, 1971 and 3,772,420 entitled "Method for Improving the In-Vivo Strength . . ." which issued Nov. 13, 1973, both to A. Glick, and both incorporated herein by reference.
A drawing which describes the shape and/or geometrical configuration of the texturized plurality of fibers or yarns is not necessary for an understanding of this invention. That is, any person skilled in the texturization art will know how to manufacture and how to use the invention by reading this specification, generally and the examples, specifically.
It is to be understood that the term carrier yarns as disclosed in this specification is synonymous with the term sleeve yarns.
For a description of manufacturing the Hytrel™ polymer, see e.g., U.S. Pat. Nos. 3,766,146; 3,763,109; 3,023,192; and Great Britain Patent No. 1,458,341; for a description of manufacturing the Novafil™ suture, see, e.g., U.S. Pat Nos. 4,224,946 and 4,314,561. All of these patents are incorporated herein by reference.
The materials can be constructed into vascular grafts in several ways: (1) as woven single tubes, (2) as warp or weft knit single tubes, (3) as double triple, etc. concentric tubes, and (4) as single woven or knit tubes that are externally supported. The materials can also be constructed from a fabric having a changing composition, e.g. a graded transition section in a fabric or a bicomponent filament. See U.S. Pat. No. 3,463,158 issued Aug. 26, 1969 entitled Polyglycolic Acid Prosthetic Devices, which is incorporated herein by reference. The graft structures can be either straight or bifurcated (branched) tubes.
A knitted tube can be manufactured on a Raschel knitting machine. The number of needles per inch can be about 25 to 35. The gauge (which is twice the number of needles per inch) can therefore be about 50 to 70. Prior art Raschel knitting machines are commercially available in a 56, 60 or 64 gauge.
A surgical repair device having a length to width ratio of greater than one has been invented. The device comprises a plurality of fibers. The majority of the fibers are in a direction essentially parallel to the device length.
The device has an absorbable component comprising from about 10 to 100 percent of polymer having a glycolic or lactic acid ester linkage. The remainder of the device, if any, has a nonabsorbable component.
In one embodiment of the device, the absorbable polymer is a copolymer having a glycolic acid ester linkage. In a specific embodiment, the copolymer comprises glycolic acid ester and trimethylene carbonate linkages.
A connective tissue repair device having a length to width ratio of greater than one has also been invented. The device comprises a plurality of fibers. The majority of the fibers are in a direction essentially parallel to the device length. The device has an absorbable component comprising from about 10 to 100 percent of a copolymer. The copolymer has glycolic acid ester and up to about 50 percent by weight of trimethylene carbonate linkages. The remainder of the device, if any has a nonabsorbable component. Embodiments of the repair device include a knitted, woven, braided and flat braided device. In one embodiment, the longitudinally oriented majority of the fibers comprises about 80 to 95 percent. In a specific embodiment, the longitudinally oriented majority of the fibers comprises about 90 percent.
In another embodiment, the device has an absorbable component comprising at least about 80 percent. In a specific embodiment, the device has a nonabsorbable component selected from the group consisting of a poly(C 2 -C 10 alkylene terephthalate), poly(C 2 -C 6 alkylene), polyamide, polyurethane and polyether-ester block copolymer. In a more specific embodiment, the device consists of poly(ethylene terephthalate) or poly(butylene terephthalate) as the poly(C 2 -C 10 alkylene terephthalate), and a polybutester as the polyether-ester block copolymer. In a most specific embodiment, the device consists of Hytrel™ as the polybutester.
A polybutester can be defined as a polytetramethylene glycol. polymer with terephthalic acid and 1, 4-butanediol. See. e.g.. the definition of polybutester in USAN and the USP dictionary of drug names, U.S. Pharmacopeial Convention, Inc., Md. 20852 U.S.A., 1985.
A flat braided ligament or tendon implant device having a length to width ratio of greater than one has been invented. The device comprises a plurality of fibers. The majority of the fibers are in a direction essentially parallel to the implant length. The braid has about 5 to 100 carrier and up to about 50 warp yarns.
The implant has an absorbable component comprising from about 10 to 100 percent of a copolymer. The copolymer has glycolic acid ester and from about 20 to 40 percent by weight of trimethylene carbonate linkages. The remainder of the implant, if any, has a nonabsorbable component.
In one embodiment of the implant, the braid has about 13 carrier and about 6 warp yarns. In a specific embodiment, the implant consists of about 100 percent of the absorbable component. In a more specific embodiment, the carrier yarns consist of about 100 percent of the absorbable component and the warp yarns comprise about 80 percent of the absorbable component. In a most specific embodiment, the nonabsorbable component in the warp yarns is selected from the group consistent of a poly(ethylene terephthalate) and polyether-ester block copolymer.
In other embodiments of the implant, the yarns are texturized or heat treated. In a further embodiment of the implant. the braid is heat treated.
The bioabsorbable filaments may be comprised of man-made polymers including glycolide-trimethylene carbonate (GTMC), polyglycolic acid, polydioxanone, poly(L-Lactic) acid, poly(DL-Lactic) acid and copolymers or physical combinations of the components of these polymers. Natural bioabsorbable polymers such as regenerated collagen or surgical but may also be used. The biocompatible (nonabsorbable) components include poly(ethylene terephthalate) (PET). poly(butylene terephthalate) (PBT), polyether-ester multi-block copolymers, polypropylene, high strength/modulus polyethylene, polyamide (including polyaramid). or polyether type polyurethanes. Once spun into filaments, the properties of the above materials may be improved for this application by various temperature/time/stress treatments.
The device shall be braided, woven or knitted so that the structure has the desired strength and stiffness in the primary (axial) loading direction. It also has adequate interfibrillar space and minimized thickness to promote the ingrowth of tissue. The end(s) of the device may be compressed inside biocompatible metal sleeve(s) to which swivel end-caps(s) and surgical needle(s) are attached in such a way as to permit rotation of the needle(s) about the longitudinal axis of the device.
In use, an appropriate number of plies of the device are implanted to match the biomechanical properties of the tissue being repaired. This permits an early return to normal function post-operatively. As the ligament or tendon begins to heal, the implant continues to bear any applied loads and tissue ingrowth commences. The mechanical properties of the bioabsorbable component(s) of the implant then slowly decay to permit a gradual transfer of loads to the ingrown fibrous tissue, stimulating it to orient along the loading direction. Additional ingrowth continues into the space provided by the absorbed components of the implant. This process continues until the bioabsorbable component(s) are completely absorbed and only the newly formed tissue remains, or the bicompatible (nonabsorbable) component(s) are left in situ to provide long-term augmentation of the newly formed tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of the device described as the preferred embodiment, except that two different possible ends are shown.
FIG. 2 is an enlarged view of the flat surface of the preferred embodiment showing the braided construction in greater detail.
FIG. 3 is an anterior view of a knee showing the device as positioned for repair of the excised patellar ligament in animal (canine) studies.
FIG. 4 is an anterior view of a knee showing the device as positioned for augmentation of the medial third of the patellar ligament in an Anterior Cruciate Ligament reconstruction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
I.
The following steps are followed when preparing knit vascular grafts starting from the appropriate yarns. The proper denier texturized yarns for the specific construction have to be knit. If the denier to be used can only be obtained by using three or mote ends. the texturized yarn must be ply-twisted together. For example, if the construction is a 330-denier PGA and 100-denier textured Dacron™, and the only available PGA is 110-denier, it is necessary to twist three ends of 110-denier PGA and the one end of 100-denier Dacron™. Other variations can be used, depending on the type of construction called for. After ply-twisting onto a king spool, the twisted yarn is transferred to a model 50 cone, using a coning machine. It is preferred that any material that is not twisted and is to be used for knitting be transferred to a cone, or to a similar type package from which the texturized yarn may easily be removed. The method of texturization is described above under "SUMMARY OF THE INVENTION". The texturized yarn is then set up on the knitting machine.
The knitting machine can be commercially available. It can be a floor-type self-contained unit, completely assembled, with exception of the yarn tension or stop-motion assembly. A direct V-belt drive from a fractional horsepower motor to the knitting head allows for a quiet knitting speed up to about 1100 r.p.m. A variable speed take-down assures minimum breakdowns and absolute quality stitch control. Operating speeds can vary depending on cylinder size and also the type of yarn or fibers used.
The proper density of the graft construction is obtained by changing the stitch cam and take-down setrinqs. The stitch cam controls the length of the stitch, and the take-down controls the tension of the tubular fabric being knit.
After knitting, the graft material is scoured in xylene under ultrasonic agitation for two ten-minute baths. The material is allowed to dry in a fume hood until no xylene odors can be detected. The graft material is then cut to appropriate lengths (e.g. 4 mm×60 mm; and/or 8 mm×80 mm) and then reversed.
Reversing involves turning the graft inside out to have a smooth inner surface, and a rougher outer surface to promote ingrowth. Any graft containing PGA is then post-treated on stainless steel mandrels at temperatures of about 115° C. to 150° C., under a vacuum approximately equal to 1 torr or lower. The post-treatment process seems to increase the tensile strength retention for the absorbable component, up to about 60 days after implant. A graft that does not contain PGA may not undergo the post-treatment process.
The ends of the graft may then be heat-sealed on a hot surface to prevent unravelling. During heat-sealing, the ends of the graft are melted only slightly.
Following scouring in xylene or another medically approved nonaqueous solvent and drying, the graft is then packaged in a polycarbonate folding container, which is then placed in a foil inner pouch. The graft is then sent through an absorbable device EtO-sterilization cycle. After sterilization, the graft is repacked in a 2-web TYVEK® (a spun bonded polyolefin manufactured by E. I. DuPont Co., Wilmington, Del., U.S.A.)/Mylar™ (a polyethylene terephthalate also manufactured by E. I. DuPont & Co.) pouch, sealed and EtO-sterilized a second time.
A series of in vivo studies with woven vascular grafts in several configurations was completed. The following materials although not exclusive, were included:
(a) PGA/Dacron™ 80/20 low and high porosity. 4 and 6 mm in diameter
(b) PGA/copolymer having glycolic acid ester. and trimethylene carbonate linkages. 4 mm
(c) Woven non-crimped Dacron™ 4 and 6 mm; and
(d) Gore-Tex (a Trademark of Wil-Gore & Associates. Inc.) 4, 8 and 10 mm.
The overall patency rate for PGA containing grafts was substantially higher than controls: 58% vs. 41%.
Bi- and tri-component vascular grafts made of biodegradable and non-degradable fibers have been studied in the beagle. Observations carried out from ˜30 days to ˜7 months showed that as the absorbable component left the textured graft structure, organized and oriented tissue invaded the graft approximating the location of the degraded material. The tissue ingrowth appeared to mobilize as a neointima with the luminal surface covered by cells strongly resembling endothelium. The non-degradable texturized component exhibited dispersed fibers within a matrix of mature, highly vascularized granulation tissue. This rich blood supply persisted for the period of maximum observation.
The graft structures were provided in two diameters: 4 and 8 mm ID. The former were studied as interpositional grafts in both carotids of the host; the latter as interpositional grafts in the thotacic aorta. The 4 mm grafts (40-60 mm in length) were examined at 1 and 2 months and showed high degrees of patency. The tissue reaction showed progressively increasing tissue incorporation although endothelization was absent at 1 month and only partially manifest at 2 months. The 8 mm grafts examined at ˜3-˜7 months were uniformly patent and showed uninterrupted complete endothelization of the graft lumen and complete replacement of the degradable material by the tissue elements noted above.
The present invention is illustrated by the following examples which can be useful in peripheral vascular surgery, as coronary artery bypasses or in general arterial or venous grafting.
EXAMPLE 1
This graft is a double-walled structure consisting of a 100% PGA woven inner tube and a 100% texturized knit Dacron™ velour outer tube. The structure was designed so that the inner wall, being PGA, would become absorbed and be replaced by a smooth, well-organized tissue at least partially consisting of endothelial cells. This inner wall would become the new intima. The outer wall, being constructed of porous nonabsorbable Dacron™ material would allow tissue and capillary ingrowth and at the same time, add support to the newly-grown neointima to prevent aneurysms. The Dacron™ outer wall material is a Sauvage Filamentous Veloure fabric supplied by U.S.C.I., a division of C. R. Bard Co., Inc., Billerica, Mass. U.S.A. The inner wall fabric is a woven tube having a 1×1 plain weave construction using 5-ply. 46-denier. 21 filament (PGA) polyglycolic acid yarn in both the warp and filling direction.
The graft materials were scoured in xylene in an ultrasonic bath--2 baths of fresh xylene for 10 minutes each--to remove fiber spin finish.
The outer and inner tubes for the 4 mm I.D. grafts were cut to approximately 45 mm in length. The tubular woven PGA material was mounted on stainless steel rods, placed in a vacuum chamber and treated at 130° C. for 3 hours under a vacuum of less than 1 torr (a similar treatment was done for the 8 mm tubes, except they were cut to 80 mm length).
Next, the inner and outer tubes were stitched together by placing either 3 (4 mm I.D.) or 4 (8 mm I.D.) longitudinal rows of stitches between inner and outer wall. The double tube shafts were then packaged and EtO-sterilized prior to use as implants.
Following graft construction and sterilization, the 4 mm grafts were implanted in the left and right carotid arteries of thoroughbred beagle dogs. The 8 mm I.D. grafts were implanted in the thoracic aorta. The grafts were left in the animal for periods of up to 90 days, at which time the dogs were sacrificed, and the grafts were dissected and removed for subjective and histological examination.
Examination of the implant sites revealed absorption of the PGA fiber and replacement with a smooth, glistening endothelial-like neointima. The Dacron™ outer wall was ingrown with tissue and small blood vessels. There was little, if any, indication of aneurysmal dilation. Exclusive of technical error during implant, grafts Were patent and blood flow, as determined by Doppler recordings. Was satisfactory.
EXAMPLE 2
A 3-ply yarn, consisting of 110-denier/50-filament PGA, 105-denier/25-filament MAXON™ (a copolymer having glycolic acid ester and trimethylene carbonate linkages. e.g as described in U.S. Pat. No. 4,429,080 issued Jan. 31, 1984 and incorporated herein by reference), and 100-denier texturized Dacron™, was plied together at approximately 2 turns per inch of twist and knit into (a) 4 mm and (b) 8 mm inside diameter (I.D.) tubes. The knitting machine used was a Lamb ST3A circular weft knitting machine. The needle cylinder used had 25 needles per inch of circumference.
Following knitting the tubular graft material was scoured, cut, post-treated, packaged and sterilized as described in Example 1.
The tricomponent structure, being comprised of both MAXON™ (glycolide-TMC) and polyglycolic acid yarns after post-treatment attains a tighter, more pebbly velour-like appearance, due to the differential shrinkage between the two absorbable fibers in the presence of textured Dacron™.
The 4 mm and 8 mm grafts were implanted in beagle dogs, as described under Example 1.
Examination of the implant sites following sacrifice revealed partial to complete absorption of the bioabsorbable yarns, excellent patency, no noticeabIe aneurysmal formation and a uniform granular tissue forming the neointima and extending through the wall to the advential surface.
Table 1 is a summary of the in vivo animal data for the knit grafts constructed according to Example 2.
TABLE 1__________________________________________________________________________SUMMARY OF ANIMAL DATA ON KNIT GRAFTS AneurysmalGraft Number Number Tendency Number NumberComposition Implanted Implant Site Patent 0123.sup.a Occluded Unsacrificed__________________________________________________________________________33/33/33 PGA/ 6 Thoracic Aorta 5 0041 -- 1MAXON ™/Textured 4 Left Carotid Artery 3 2010 1 --DACRON ® 6 Right Carotid Artery 3 0031 2 1__________________________________________________________________________ .sup.a Rating: 0 = None 1 = Possible 2 = Slight 3 = Significant
EXAMPLE 3
A 4-Ply yarn consisting of three ends of 105-denier DAXON™ (as described in the Background and in Example 2 above) and one end of 100-denier texturized Dacron™ was plied together at a twist level of approximately 2 turns/inch. The yarn was knit into 4 and 8 mm I.D. tubes on separate Lamb ST3A circular weft knitting machines, using 25-needle per inch knitting cylinders. These grafts had wall thicknesses of between 650 and 850 microns.
Following knitting the graft material was scoured, cut to 45 and 80 mm lengths, heat-set at 110° C. for 1 to 3 minutes on stainless steel sizing rods. helically wrapped with 2-0 monofilament MAXON™ suture material as a means of external support packaged and sterilized.
The external support material was attached to the outside surface of the vascular graft, using polymeric glycolide/trimethylene carbonate (TMC) dissolved in methylene chloride as an adhesive. Alternatively. poly-TMC dissolved in methylene chloride can be used as an adhesive. Table 2 is a summary of the in vivo animal data for the knit grafts constructed according to Example 3.
TABLE 2__________________________________________________________________________SUMMARY OF ANIMAL DATA ON KNIT GRAFTS AneurysmalGraft Number Number Tendency Number NumberComposition Implanted Implant Site Patent 0123.sup.a Occluded Unsacrificed__________________________________________________________________________75/25 MAXON ™/ 6 Thoracic Aorta 6 2022 -- --Textured DACRON ® 3 Left Carotid Artery 2 1010 1 --with External 4 Right Carotid Artery 4 0112 -- --Support*__________________________________________________________________________ .sup.a Rating: 0 = None 1 = Possible 2 = Slight 3 = Significant *External support of monofilament MAXON ™ absorbable suture material.
EXAMPLE 4
A 4-ply yarn consisting of two ends of 46-denier PGA, one end of 62-denier PGA and one end of 100-denier texturized NOVAFIL® was assembled at approximately 2 turns per inch of twist. The texturized NOVAFIL® yarn was false-twist texturized, using the Helanca® (trademark of Heberlein Corp., Wattwil, Switzerland) Process in order to provide a surface texture that would encourage maximum tissue ingrowth. The combined yarn was knit into 4 and 8 mm I.D. tubes similar to Example 3, except that the cylinder had a needle spacing of 33 needles per inch.
Following knitting, the graft materials were scoured, cut to 45 and 80 mm length tubes, post-treated on stainless steel rods under vacuum of 1 torr at 130° C. for 3 hours, cooled, helically wrapped with 3-0 MAXON™ monofilament suture material attached to the surface of the graft using poly-TMC as an adhesive and, finally, packaged and sterilized.
EXAMPLE 5
In this warp knit example, 70-denier texturized Dacron™]was combined with 105-denier MAXON™ multifilament yarn on a 48-gauge Raschel knitting machine in the following construction:
______________________________________Front Bar 2/0 2/4 70-denier textured Dacron ™Back Bar 2/0 4/6 105-denier MAXON ™______________________________________
EXAMPLE 6
This construction is similar to Example 5, except that the stitch construction is reversed as follows:
______________________________________Front Bar 2/0 4/6 105-denier MAXON ™Back Bar 2/0 2/4 70-denier textured Dacron ™______________________________________
Examples 5 and 6, although formed on a 48-gauge Raschel machine can be made on a 56-, 60- or 64-gauge Raschel machine, having 14 or more guide bars, positive feeds and stitch combs.
In preferred embodiments the elongated textile structure 1 of the implant comprises a flat braid having primarily axial (quoit) yarns of an absorbable polymer such as GTMC. The number and denier of quoit and sleeve yarns are varied to provide devices having a range of properties that are biomechanically compatible with any likely implant site. Swivel end cap(s) 3 and surgical needle(s) 4 may be attached at the end(s) of the device to facilitate placement and attachment.
The procedures described below are followed when preparing flat braids to be used as artificial ligaments/tendons starting from the appropriate yarns. To begin, the proper denier yarns for the specific braid construction are required. This example describes a typical construction designed to fit a particular animal model--repair/replacement of the canine patellar ligament (FIG. 3). An application that had a tensile strength/stiffness requirement three times higher than that described in the example would require three times as much yarn. This could be accomplished by simply tripling the final total braid denier, either by increasing the yarn denier or increasing the number of sleeve and quoit (stuffer yarns) or both.
To produce a braid for canine patellar ligament repair (FIG. 3), a final braid denier between 13,000 and 24,000 is tarqeted. In the preferred construction, approximately 90% of the fiber is contained in the parallel quoit or warp yarns 2.
The sleeve yarns 5, which consist completely of absorbable material, are generally about 130 denier. On transfer they are given a nominal 1.4 turn per inch (TPI) `Z` or `S` twist before further processing. This facilitates handling and minimizes fiber breakage.
The quoit (stuffer or warp) yarns can be 100% absorbable or they may contain a nonabsorbable component. They are much heavier than the sleeve, generally ranging from 2100 to 2700 denier. This necessitates two passes on a six position ply twister. A 130 denier yarn would normally be 5-plied 2.8 TPI `S` or `Z`, then 4 ends of the 5-ply yarn would be twisted 1.4 TPI in the reverse direction. This would result in a final quoit yarn denier of 2600, mechanically balanced from the reverse twist operation (no tendency to twist or unravel).
Nonabsorbable components 6, if included, are blended into the quoit yarns during the 1st ply twisting operation. For instance, a J MAXON™/NOVAFIL® (American Cyanamid Co., N.J. 07470 U.S.A.) bicomponent yarn consisting of 18-22% nonabsorbable fiber would be made by running 1 yarn of 130 denier NOVAEIL® with 4 yarns of 130 denier MAXON™ in the 5-ply operation. The preparation and polymeric composition of MAXON™ is disclosed in U.S. Pat. Nos 4,423,660; 4,300,565 and 4,243,775; the preparation and polymeric composition of NOVAFIL® is disclosed in U.S. Pat. Nos. 4,314,561; 4,246,904; and 4,224,946. All of these patents are incorporated herein by reference. The exact proportion of NOVAFIL® is determined by the yarn deniers involved and the proportion of quoit yarns in the braid construction.
An important processing step for some absorbable yarns is post treatment (a vacuum annealing step which upgrades the implant tensile values). Generally speaking, for a construction that is to be 100% absorbable, the yarns are post treated after ply twisting: for an absorbable/nonabsorbable bicomponent construction, the absorbable yarns are post treated prior to ply twisting. There is another option and that is to post treat the final braid, providing it does not have a deleterious effect on a nonabsorbable component.
After ply twisting and post treatment, the yarns are ready for braiding. The best results to date are obtained with a construction that is made on a 13 carrier flat braider, which has 6 quoit gap feed. About 90% of the construction is composed of the heavy parallel quoit yarns held loosely together by the sleeve yarns at 12.3 picks (yarn cross over points) to the inch. After braiding, the ligament is ready for further processing. It is cut to length and sleeved on both ends with a 1/4" aluminum or silver sleeve. A stainless steel overcap 3 with a small metal swivel pin 7 is then attached.
The end capped ligaments are now ultrasonically washed in xylol to remove any residual finishing oils (6 min residence in each of 4 baths). After the implants are air dried, appropriate needles 4 are attached to the metal pins to allow the implant to swivel in use. They are then packaged in preformed plastic trays with a lid and in open aluminum foil laminate envelopes. They are sterilized in an Ethylene Oxide cycle which includes an elevated temperature vacuum drying step. The foil laminate envelopes containing the dry ligaments are then heat-sealed in an aseptic glove box hood fed by dry air. Any interim storage needed between vacuum drying and heat sealing is carried out in an aseptic sealed box fed, again, by dry air.
Devices, as described above, may be surglcally implanted to bridge a defect in a ligament, as a replacement for an excised damaged ligament (FIG. 3) or as an augmentation (FIG. 4) for autogenous tissue graft (or allograft) ligament reconstruction. In those surgical procedures requiring passage through and/or attachment to soft tissue 9, implants having the end-cap 3 and swivel needle(s) 4 at the end(s) would be used. For those applications in which the implant only needs to be passed through an open joint space 10 or through pre-drilled tunnels in bone 11, the swivel needles would not be required. Implants provided for such procedures may instead have either: (a) melt-fused ends to prevent fraying, or (b) ends stiffened by surrounding tubes 8 that are melt-fused or heat-shrunk onto the material of the device itself.
The invention can be described by the following examples.
EXAMPLE 7
This embodiment consisted of 100% MAXON™ in a flat braid construction. It differs from constructions described in previous examples in that it was airjet texturized prior to the initial twisting steps. The sleeve yarn consisted of 149d texturized MAXON™. This was made by overfeeding 2 yarns of 66 denier MAXON™ into the airjet chamber-one by 15% and the other by 8%. This material was then twisted to 1.4 TPI `Z`. The quoit yarn started with 219 denier texturized MAXON™. This was made by overfeeding 1 ; end of 66d MAXON™ at 15% into the airjet along with 1 end of 130d MAXON™ at 8%. The 219 denier yarns were then 3-plied at 2.8 TPI `S`. Four yarns of the 3-ply material were then reverse twisted at 1.4 TPI `Z` to give a final denier of 2523.
This material was braided on a 13 carrier flat machine at 12.3 picks per inch. Its final denier measured 17.693 with 88.7% of the construction in the quoits.
The straight pull to break averaged 130 lbs (3.3 gms per denier) with an extension at break of 26.7%. As expected, its surface appearance resembled that made of yarns spun from a natural, staple fiber such as cotton or wool. Optically, the braid could be characterized as having a loose, single fil looped appearance. Subsequent processing of the braid is as described above under the heading `Description of the Preferred Embodiment`.
EXAMPLE 8
This design is identical to Example 11 except that in the initial 3-plying of the quoit yarns one end of a 245 denier MAXON™/NOVAFIL® texturized bicomponent yarn was substituted for one of 219 denier texturized MAXON™ yarns. This MAXON™/NOVAFIL® bicomponent was made by overfeeding a 66d MAXON™ yarn at 55% and two 69d NOVAFIL® yarns at 11% into the airjet chamber. The denier of the 12 ply quoit yarn was measured to be 2667d.
This material was braided on a 13 carrier flat machine at a 12.3 pick. Its final denier was 18,467 of which 89.2% was quoit yarn and 19.1% was the nonabsorbable NOVAFIL® component.
The final non-sterile ligament had a breaking strength of 122 lbs (3.00 grams per denier) and an extension at break of 25.9%. Hydrolytic data indicates that this will make a viable product with a residual strength of 29.5 lbs.
Subsequent processing of the braid is as described above under the heading `Description of the preferred Embodiment`.
EXAMPLE 9
This implant design is identical to Example 11 except that in the initial 3 plying of the quoit yarns one end of a 226 denier MAXON™/Heat Stretched Texturized DACRON® bicomponent yarn was substituted for one of the 219 denier MAXON™ yarns. This MAXON™/Heat Stretched DACRON® bicomponent was made by overfeeding a 66 denier MAXON™ yarn at 55% and a 127 denier heat stretched MACRON® yarn at 11% into the airjet chamber. The denier of the 12 ply quoit yarn measured 2613.
This material was braided on a 13 carrier flat machine at a 12.3 Pick. Its final non-sterile denier was 18.054, of which 89.0% was quoit yarn and 20.7% was the nonabsorbable heat stretched DACRON®
The final non-sterile ligament had a breaking strength of 97 lbs (2.43 grams per denier) and an extension at break of 21.7%. Hydrolytic data indicated it would remain unchanged in strength for 14 days and would have a residual strength of 34.7 lbs.
Subsequent processing of the braid is as described above under the heading `Description of the preferred Embodiment `.
EXAMPLE 10
This construction consists of 100% MAXON™ in a flat braid construction. It differs from previous constructions in that it is braided on a 21 carrier machine.
The sleeve yarn consists of 66 denier MAXON™ yarn twisted to 1.4 TPI `Z`. The 130 denier quoit yarns are first 2-plied at 2.8 TPI `S`--then 5 yarns of this 2-ply construction are reverse twisted at 1.4 TPI `Z`. The final denier of the 10 ply quoit yarn is 1300.
The above yarns are then braided on a 21 carrier machine with 10 quoit yarns set at a 12 picks/inch. The final construction measures 16,986 denier, of which 91.8% is quoit yarn.
Samples are expected to have a non-sterile breaking strength of 124 lbs (equivalent to 3.31 grams per denier) with an extension at break of 35.2%.
EXAMPLE 11
This construction consists of 100% MAXON™ in a flat braid construction. It differs from previous constructions in that it is braided on a 15 carrier machine.
The sleeve yarn consists of 98 denier MAXON™ twisted to 1.4 TpI Z. The 130 denier quoit yarns are 5-plied at the same level of twist to give a total denier of 650. All yarns are post treated after plying.
The above yarns are braided on a 45 carrier machine. Only 15 out of 45 available carriers are used for the sleeve yarns. All of the available 22 quoit positions are used. The braider is set for a 4.1 pick. The final construction measures 15,770 denier, of which 90.7% is parallel quoit yarn.
Straight pull tensile strength is expected to average approximately 68 lbs (4.83 grams/denier) with a 37.2% elongation at break.
EXAMPLE 12
This implant design is similar to Example 15 except that 1 yarn of heat stretched DACRON™ is substituted in ply twisting the quoit yarns. Also, all MAXON™ yarns are post treated prior to twisting.
The final braid denier is 15,700, of which 90.7% is parallel quoit yarn. Approximately 18.1% of the total construction is the nonabsorbable DACRON® component.
Straight pull tensile strength is expected to be approximately 127 lbs (3.67 grams/denier) with a breaking elongation of 29.3%. Hydrolytic data from similar constructions indicate that this design would make a viable product with a residual strength of 29 lbs due to the nonabsorbale component.
EXAMPLE 13
This design consists of 100% MAXON™ in a flat braid construction. Although braided on a 45 carrier machine, it differs from Sample 15 in that it is 3.3 times heavier.
The sleeve yarns consist of 130 denier MAXON™ twisted to 1.4 TPI `Z`. The 130 denier quoit yarns were first 4-plied to 2.8 TPI `Z`, then four 4-ply yarns are reverse plied to 1.4 TPI `S` to give a final quoit yarn denier of 2080. All yarns are post treated after twisting.
The above yarns are then braided on a 45 carrier machine using all available carriers for the sleeve and all of the available 22 quoit yarn positions. The braider is set for a 12.3 pick. The final construction measures 51.610 denier, of which 88.7% is parallel quoit yarn.
Straight pull tensile strength is expected to average 525 lbs (4.61 grams/denier) with a breaking elongation of 31.6%.
Although the following example, and variations thereof, may be suitable for some soft tissue orthopedic (i.e. tendon) repair/reconstruction applications, it has been found to be inappropriate as a ligament implant and therefore not part of this invention. It is disclosed for its comparative value to examples 7 to 13, and as a contribution to the state of the art.
Comparative Example A
This implant design was 100% DEXON® (PGA) in a flat braid configuration and again consisted of heavy denier quoit or warp yarns held together by light denier sleeve yarns. However, all the yarns were post treated: then air jet texturized prior to twisting and braiding.
a. The quoit (warp) yarn consisted of a 6 ply construction using 357 denier texturized DEXON® yarn to give a total 2142 denier yarn. This 357 denier yarn was made by entangling 3 ends of 110 denier DEXON® yarn - 2 yarns with a 24% overfeed and one with a 6% overfeed.
b. The sleeve yarn was made similarly except it was a 152 denier, texturized DEXON® yarn. This was made by entangling 2 yarns of 62 denier DEXON®--one yarn with a 24% overfeed and the other with an 11% overfeed.
c. The braid was made on a thirteen carrier braider, each carrier containing the 152 denier yarn described in section b above. These sleeve yarns were braided about the 2142 denier warp yarns fed through all six available quoit positions. The total pick count was estimated at 12.3 per inch.
The total braid denier was 14.800. Tensile strength measured 152 lbs. with a 23.2% elongation-to-break.
Connective tissue devices of this construction were evaluated in-vivo. Upon sacrifice at 2 months, these implants were found to have better tissue ingrowth/organization than non-texturized PGA devices. However, the results achieved with implants made using the longer lasting GTMC yarns were consistently, significantly improved over those obtained with the devices of this comparative example. | The invention involves a method to texturize absorbable or absorbable/nonabsorbable components that are to be used to fabricate textile grafts of all sizes, and specifically for repair of the peripheral vascular system and for coronary bypass use. The bioabsorbable component of the graft fosters increased tissue ingrowth into the graft as compared to conventional 100% nonabsorbable grafts. Increased tissue ingrowth leads to greater patency through formation of a vascularized neointima and less tendency to be aneurysmal through formation of a suitable adventitia. The absorbable component can be a variety of materials, including PGA, the polymer used to manufacture the MAXON™ suture, etc., whereas the nonabsorbable component (to be used as the backbone) can be new materials, e.g. the polymer used to manufacture the NOVAFIL® suture, or more conventional polymers, including polyester, polyamide or polypropylene. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention concerns a method of treating a pneumatic tire, and more particularly a method of treating a pneumatic tire for making the tire disposable by taking out the pneumatic tire without oozing a repair agent for a punctured tire from a punctured pneumatic tire with a rim wherein the repair agent for punctured tire is introduced into the inside of the punctured tire.
[0003] 2. Background Art
[0004] As a temporary repair method in case of puncture of a pneumatic tire, there is a method for injecting a liquid repair agent for punctured tire into the pneumatic tire, and obstructing the puncture hole from the tire inside. The repair agent for punctured tire used for this method is composed of a latex of O/W dispersion emulsion type wherein natural rubber or the like is dispersed in water, and alkalized with ammonium. This repair agent for punctured tire is injecting in the tire on the order of 500 ml, for obstructing a puncture hole made by sticking a nail or the like with latex.
[0005] The repair by this liquid repair agent for punctured tire being temporary, a regular puncture repair shall be performed in a repair shop such as gas station or the like after this temporary repair, or the tire be discarded. However, the repair agent for punctured tire included in the inside of the tire being liquid, there was a problem that the repair agent for punctured tire soils the surroundings by dripping down or otherwise, when the tire with a rim is removed from the wheel for such puncture repair or discard.
SUMMARY OF THE INVENTION
[0006] The present invention has an object to provide a method of treating a pneumatic tire composed not to soil the surroundings, when the puncture treated pneumatic tire with a rim is removed from the wheel, by introducing a repair agent for a punctured tire comprising a latex into the inside of a punctured tire, followed by sealing.
[0007] The method of treating a pneumatic tire of the present invention to achieve the aforementioned object is characterized in that it comprises introducing the repair agent for punctured tire comprising a latex into the inside of a punctured tire with a rim, followed by sealing, and then introducing a polymer coagulating agent into the inside of the punctured tire to coagulate the repair agent.
[0008] Thus, as the polymer coagulating agent being introduced into the inside of a puncture repaired pneumatic tire wherein the repair agent for punctured tire comprising the latex is sealed to coagulate the repair agent for punctured tire, the repair agent for punctured tire would not drips down when the pneumatic tire is removed from the wheel, allowing not to soil the surroundings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic illustrative drawing showing a method of treating a pneumatic tire according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] Now, a composition of the present invention shall be described in detail referring to an attached drawing.
[0011] In FIG. 1, the numeral 1 indicates a punctured pneumatic tire, which is integrated into a rim 2 . This pneumatic tire 1 is, as a temporary measure for the puncture, injected into the inside thereof with a liquid repair agent 3 for punctured tire comprising a latex through a valve 6 .
[0012] Conventionally, the puncture repaired pneumatic tire 1 as mentioned above, was removed from the rim 2 (wheel) at the repair shop to, for instance, discard in a state where the repair agent 3 for punctured tire in the interior had been eliminated beforehand.
[0013] In the present invention, the aforementioned puncture repaired pneumatic tire 1 is left integrated into the rim, and a polymer coagulating agent 5 is dropped and injected through a valve 6 into the interior (insie) of the pneumatic tire from a syringe 4 filled with the polymer coagulating agent. This dripping coagulates the repair agent 3 for punctured tire and the coagulate coagulated in gel deposits on the tire inner wall face and so on.
[0014] Thus, the repair agent for a punctured tire becomes a gelled coagulum and deposits for instance on the tire inner wall face, the repair agent for punctured tire will not ooze and soil the surroundings, when the pneumatic tire 1 is removed from the rim 2 .
[0015] The repair agent for punctured tire may include an organic solvent such as freeze proofing agents including ethylene glycol, propylene glycol or the like; however, such organic solvent can also be prevented from soiling, as it will be included in the gel when it coagulates taking a gel structure.
[0016] In the present invention, those repair agents for punctured tire made of a latex comprising a natural rubber or a synthetic rubber dispersed in the water, and alkalized by ammonia are used preferably. This repair agent for punctured tire is injected in the inside of the tire by the order of 500 ml through an air valve, during the puncture repair of a pneumatic tire with a rim. As for rubber of the latex to be used, butyl rubber, styrene-butadiene rubber and so on are used among synthetic rubbers.
[0017] The polymer coagulating agent is not particularly limited, provided that it can coagulate the repair agent for punctured tire including liquid components (for instance, mixture components such as ethylene glycol, propylene glycol and so on). For instance, it is at least one kind of polymer or copolymer selected from acrylamide, methacrylamide, acrylic acid, acrylic ester and methacrylate ester and others. More particularly, it is, for instance, an imine type polymer coagulating agent comprising polyethylene imine, an amine type polymer coagulating agent, an acrylamide type polymer coagulating agent comprising acrylamide, a methacrylamide type polymer coagulating agent polymethacryl amide, an acryacryl ester type polymer coagulating agent comprising polyacryl ester, a methacrylate ester type polymer coagulating agent comprising polymethacryl ester or the like. Also, the mixture of a plurality of polymer coagulating agents selected from these polymer coagulating agents may be used. One which is especially preferable among them is the imine type polymer coagulating agent comprising polyethylene imine.
[0018] The polymer coagulating agent is injected in the inside of the tire through for instance an air valve of a tire, in the form of aqueous dispersion. As injector of the injection thereof, those of dropping pipette type or syringe type can be used, and they can be sized according to the addition amount of the polymer coagulating agent.
[0019] The polymer coagulating agent is preferably injected in the inside of the tire as aqueous dispersion of 20 to 30 weight %. In case of aqueous dispersion less than 20 weight %, the quantity of polymer coagulating agent to be added is too little, making the coagulation difficult, or the produced gel becomes too soft that it hardly deposits on the tire inner wall surface. On the other hand, in case of that more than 30 weight %, the concentration is too high that the viscosity becomes to high, making difficult to inject from the valve 6 and further, in some cases, making difficult to blend with the repair agent for punctured tire.
[0020] As for the injection quantity of the polymer coagulating agent into the inside of the tire, it is preferably to make the proportion of aqueous dispersion of the aforementioned polymer coagulating agent 0.5 to 3 weight % to the repair agent for punctured tire. In case of aqueous dispersion less than 0.5 weight %, the quantity of polymer coagulating agent to be added is too little, making the coagulation difficult, or the produced gel becomes too soft that it hardly deposits on the tire inner wall surface. In case of that more than 3 weight %, the quantity of polymer coagulating agent being excessive, in some cases, the repair agent for punctured tire is inhibited to coagulate, and further, it too much, aqueous dispersion of polymer coagulating agent remain as they are in the tire, in some cases.
[0021] When the polymer coagulating agent is added to the repair agent for punctured tire, intermolecular attraction and electrostatic attraction act among the polymer coagulating agent and rubber particulates in the repair agent for punctured tire, and the polymer coagulating agent will be absorbed on the surface of the rubber particulate. Then, the polymer coagulating agent absorbed by the rubber particulate will also be absorbed by the other rubber particulates, a rubber network is formed through the polymer coagulating agent by the chain generation of this absorption, and this will deposit on the tire inner wall surface as a gelled coagulum. At this time, liquid substances such as moisture and ethylene glycol included in the repair agent for punctured tire being also included in the network made of polymer coagulating agent and rubber, it becomes possible to make the liquid substance difficult to flow out.
[0022] As mentioned hereinabove, according to the present invention, as a repair agent for a punctured tire comprising a latex is introduced and sealed into the inside of a punctured pneumatic tire with a rim, and then a polymer coagulating agent that can coagulate the latex is introduced into the inside thereof to coagulate the repair agent for punctured tire, the repair agent for punctured tire would not drip down when the pneumatic tire is removed from the wheel, allowing not to soil the surroundings. | A method of treating a pneumatic tire, which comprises introducing a repair agent for a punctured tire comprising a latex into the inside of a punctured tire with a rim, followed by sealing, and then introducing a polymer coagulating agent into the inside of the punctured tire to coagulate the repair agent. | 1 |
FIELD OF THE INVENTION
The present invention relates to a device for the presettable calendering of tubular knitted fabric.
BACKGROUND
The calendering of tubular knitted fabric is a finishing operation which is performed during the end stage of the processing cycle, and which has the purpose of drafting the tubular fabric, in general by means of a steaming and flattening between heated cylinders, after previously expanding and overfeeding it.
Such an operation allows the width of the tubular knitted fabric to be brought back to the required value, by determining the dimensions thereof, and allows the same tubular fabric to be given a commercially acceptable appearance and touch.
Normally, expander devices for the tubular knitted fabric are used, which are equipped with width adjustment systems, based on principles and elements of mechanical character, which require a manual intervention by the operator, and are, e.g., of the sliding-guide type, with blocking by means of screws; when it is necessary to act on the width control device inside the tubular knitted fabric, the textile finishing machine must be stopped.
It is evident that such a procedure causes time and production losses, an additional use of manpower, machine stoppage and cost increases, besides the undoubted difficulty of the intervention.
Furthermore, single machines or calenders of various types are used, which are different from each other essentially because of the usable cylinder types, as well as due to the different mechanical action they perform on the tubular knitted fabric. Thus, devices exist, which are equipped with drafting calenders, polishing calenders, friction calenders, and so forth.
The selection of the equipment to be used depends both on the type of tubular knitted fabric to be processed, e.g., determined by the different fibrous compositions and interlacing patterns of the knitted fabric, and on the finishing effect to be given, so that, according to the different cases, different calender types are used in sequence, which requires replacement of, the calender or equipment being used to be replaced.
The selection of the equipment is also a function of its installation in a processing line including downstream machines of different types, e.g., a dryer.
The case frequently occurs furthermore, in which the same article of tubular knitted fabric must be calendered with two different machines, and, hence, by two sequential passages, e.g., by first using a polishing calender equipped with a polished cylinder, and then a drafting calender, equipped with cylinders coated with a textile material.
Another problem which occurs frequently with some types of tubular knitted fabric, is in obtaining the required end width of the flattened tubular fabric by means of only one calendering passage. Namely, due to the deformations of the tubular knitted fabric during preceding wet-treatments, such as mercerization, bleaching, and/or dyeing, an excessive decrease in the original width is produced.
In such case, both the expansion and the overfeeding of the tubular knitted fabric must be performed gradually and progressively at least two sequential passages through the calendering machine.
It is evident that a double calendering passage, whatever the reasons requiring it may be, and whether it is carried out on the same calendering machine, or on two different calendering machines, causes a considerable decrease in productivity, higher than 50%, and a corresponding increase in production costs.
SUMMARY OF THE INVENTION
An object of the present invention is provide a system for solving all of these problems of calendering variety, of cylinder replacement and of related times for carrying it out, so as to reduce the costs of production and of machine engagement.
A further object is to provide a single, extremely flexible machine, easily adaptable to different knitted fabrics which must be calendered, and to different calendering treatments to be performed on the same knitted fabric. Furthermore, such equipment must be suitable for incorporation in a treatment facility, so as to reduce the production and machine servicing costs, the operating costs and the dead times due to material transport lags.
Still a further object of the present invention is to provide an expander device for tubular knitted fabric, which allows width control without stopping the machine, and which may even act during the processing, in an autonomous and continuous way, to correctly adjust the exact width of the tubular knitted fabric, without any manual interventions being necessary.
These and further objects are achieved, according to the present invention, by providing equipment for the calendering of tubular knitted fabric comprising, on a support frame, an expander device for the tubular knitted fabric being fed, a device for feeding the fabric towards a steaming chamber, and at least one pair of calendering cylinders for the fabric, characterized in that on said support frame a second pair of calendering cylinders is provided, installed sequentially with respect to said at least one pair of calendering cylinders.
Preferably, on said support frame, first and second calendering units are provided sequentially with both calendering units being provided with said second pair of calendering cylinders.
Preferably, said expander device for tubular knitted fabric is of the type comprising one pair of side expander elements provided on related support bars sliding relatively to each other, and adjustable in position, with an elastic element interposed between said expander elements, and is characterized in that said elastic element is a gas spring hinged to the two ends of said two support bars, and guide means are provided between the support bars for said pair of side expander elements for their mutual travel transversely of said tubular knitted fabric.
BRIEF DESCRIPTION OF THE DRAWING
Characteristics and advantages of a calendering device according to the present invention will be better understood from the following exemplifying and nonlimitative disclosure, which refers to the attached schematic drawings, wherein;
FIG. 1 is a schematic elevation view of a device according to the invention;
FIG. 2 is a schematic elevation view of a further device according to the invention;
FIG. 3 shows an elevation view of an expander device according to the invention, and
FIG. 4 is a sectional view taken along line IV--IV in FIG. 3.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As it can be seen from FIG. 1, a calendering device comprises a support frame 11, suitable to be inserted, e.g., in a processing facility for tubular knitted fabric 13 which must be calendered, and is supplied with fabric 13, for example from a dryer outlet (not shown).
On said support frame 11, an expander device 16 is installed in a vertical position for expanding the tubular knitted fabric 13 which is then fed by a feeding device 17 to a steam chamber 18.
Downstream of said steam chamber 18, whereat the expander device 16 ends, there are provided, in sequence, a first pair of calendering cylinders 19, e.g., of the type with polished surface, and a second pair of calendering cylinders 20, e.g., of the type provided with a coating of a textile material.
On frame 11, at least one return roller 21 is positioned so to lead the tubular knitted fabric 13 towards the outlet, for supply to a collecting unit or a stacking machine.
In the disclosed embodiment, the first pair of calendering cylinders 19 is provided with a polished surface in engagement with the tubular knitted fabric as a function of the treated fabric type and of the calendering characteristics to be given.
When, either due to the use of a different type of processed fabric, or due to different end characteristics to be given to the fabric, it is sufficient to disengage the first pair of calendering cylinders 19, and engage the second pair of calendering cylinders 20 whose surfaces are provided with the coating of textile material, or the like.
According to the embodiment shown in FIG. 2, a reel 12 is mounted on support frame 11 for the tubular knitted fabric 13 to be calendered; alternatively, the fabric is supplied from a stack provided on a bench.
On support frame 11 there are provided, vertically, and substantially parallel to each other, both a first calendering unit, generally indicated by numeral 14, and similar to that shown in FIG. 1, and a second calendering unit, indicated by numeral 15.
In FIG. 2, the elements which constitute the first calendering unit are designated by the same reference numerals as in FIG. 1.
A set of return rollers 21, and a compensator element 22, e.g., of swinging type, which controls the tension of the tubular knitted fabric 13, are provided on the frame 11, so as to feed the tubular knitted fabric 13, are provided on the frame 11, so as to feed the tubular knitted fabric 13 to the second calendering unit 15.
The second calendering unit 15 is essentially composed of a set of components similar to those of the first calendering unit 14. Downstream of the compensator element 22, a further expanding device 23 is provided, which operates on the tubular knitted fabric 13 during its passage through both a further feeding device 24, and a further steaming chamber 25.
In sequence, a further first pair of calendering cylinders 26 and a further second pair of calendering cylinders 27 are provided. The first pair can be provided with a textile-material surface, and the second pair with a polished surface.
The tubular knitted fabric, after passing over a further return roller 28, is subsequently discharged by an outlet wind-up cylinder 29, which allows, and cooperates with, the winding up of the fabric on a wind-up reel 30, or delivers it to a stacking unit.
In the embodiment of FIG. 2, the first pair of calendering cylinders 19 and the further pair of calendering cylinders 27 are both of the polished-surface type. This however does not exclude the possibility that the various pairs of calendering cylinders can be constructed to act on the tubular knitted fabric in different combinations, so that different characteristics may be obtained in the calendered fabric, e.g., by using both of said pairs with cylinders of the type coated with a textile material, and/or selectively using first a pair with polished surfaces, and subsequently a pair with surfaces coated with textile material, and/or vice-versa.
This wide range of combinations, together with the possibility of variation of all of the other operating parameters, i.e., increase in operating speed of the feeding devices 17, 24 with over-feed, variation in steam volume in chambers 18, 25, allow many calendering effects to be obtained, so to fit a wide variety of fibers and weaving interlacing patterns.
It should be noted that functional changes in the operation of the equipment in FIGS. 1 and 2 is simply performed by means of the shifting, and the consequent engagement and disengagement of the various pairs of cylinders, in extremely short operating times, whereby production costs are considerably reduced.
A further very favorable advantage is that for one single calendering equipment only, it is possible to perform at least two different calendering operations in only one passage.
A further advantage is the elimination of cylinder replacements, or of the necessary presence of a plurality of different cylinder machines selectively insertable on line according to the requirements.
The positioning inside the equipment, in the reverse sequence, first of cylinders with surfaces coated with a textile material, and then of cylinders with polished surfaces, is within the scope of the present invention.
The calendering equipment according to the present invention as shown in FIG. 2 has the advantageous characteristics of allowing, on one single operating line, a double expansion and a double feed or progressive overfeed of the tubular knitted fabric.
Such an innovative operating concept enables the textile finisher to comply with many needs, and to solve at the same time the production and financial problems arising from the need for a plurality of sequential calendering passages.
Preferably, the expander device for tubular knitted fabric denoted at 16 or 23 in FIGS. 1 and 2 can be advantageously constructed as shown in FIGS. 3 and 4.
The expander device is generally designated by numeral 111 and is generally positioned on a support frame 112 of a textile finishing machine (not shown), between feed devices 113, e.g., motor-driven rollers, on which a tubular knitted fabric, schematically shown at 114, runs.
The expander device 111 is constituted by two side expander elements 115, each fixed-on a related support bar 116, with the two support bars 116 being slidable relative to each other.
Each support bar 116 has, on its side opposite the other bar, a pair of guide grooves 117 in which related guide rollers 118 are engaged, which are fixed to the opposite end portion of the other bar 116.
The two bars 116 can thus slide on each other, up to a maximum extended position, as shown in FIG. 3, of the right-hand expander element 115.
The two side expander elements 115, occupy a position of maximum width as indicated by La, and they can approach each other up to the position of minimum width, as indicated by Lc, the relevant stroke length being indicated by C.
An elastic element 119, such as a gas spring, has its ends hinged at 120 and 121 respectively to the two bars 116.
The gas spring 119, of known type, is constituted by a small cylinder 122 containing a pressurized gas, and a stem 123 which enters one of the two base ends of the cylinder. The two free and opposite ends of the cylinder 122 and of stem 123 are each fastened, as said, to its own bar 116, respectively at 121 and 120.
Each side expander element 115 supports two return wheels 124, slightly projecting from the element 115, on which a belt element 125 is wound for advancing the tubular knitted fabric. Furthermore, in correspondence with a lower inlet portion 126 of each side expander element 115, which has a shape convergent towards the interior of the device, two wheels 127 are furthermore provided, which cooperate to accompany the tubular knitted fabric 114 during the slipping thereof on the expander device 111 between the motor-driven wheels 113.
It should be observed that on the support frame 112, slots 128 may be provided, inside which the drive shafts 129 for the motor-driven rollers 113 can slide, so to allow the distance between the centers of the rollers to be modified, to adapt to varying widths of the tubular knitted fabric 114.
The operation of expander device 111 will explained hereafter.
In its working position, the expander device for the tubular knitted fabric is housed between the motor-driven wheels 113 of the finishing machine, in such a way that each of the wheels 113 abuts against the lower wheel 124 and the upper wheel 127.
The motor-driven wheels 113 can perform a lateral approaching or separating movement by sliding of their shafts 129 inside the slots 128.
When the two side expander elements 115 of the expander device are in their position of maximum width La, the stem 123 of the gas-spring 119 is in its extracted position from the cylinder 122, and the gas inside the cylinder exerts a thrust force Fa on the stem which applies the two side expander elements 115 against the motor-driven wheels 113.
Due to the transverse movement of the two motor-driven wheels 113 towards one another, the side expander elements 115 of the expander device progressively approach each other, causing the two bars 116 to slide on each other, with guidance by the guide rollers 118, thus compressing the gas spring 119 by retraction of stem 123 in the cylinder 122.
When the position of minimum width Lc is reached, the gas inside the cylinder 122 applies to the stem 123 a thrust force Fc, which keeps the side expanders 115 always against the motor-driven wheels 113 and allows them to follow the wheels, in the event of an opposite transverse movement, in the direction of opening of the tubular knitted fabric expander device.
The transverse movement of the motor-driven wheels 113 is electrically controlled by the operator attending the finishing machine, in accordance with the different fabric widths, thus causing the continuous and progressive opening and/or closure of the expander device 111, without any need for stopping the finishing machine, or for any manual interventions.
As compared to the width control devices known in the prior art, which use spiral springs or pneumatic pistons, the expander device of the invention has the following advantages:
the possibility of supplying an initial preload Fa, when the gas spring is in its released position, determined by the initial pressure of the gas contained inside the cylinder, thereby without affecting the useful length of stroke C;
very long useful stroke "C" of the gas spring, which reaches values as high as 40% of the length of the gas spring when this is in its released position, without causing any excessive increases in the thrust force, generally indicated by F;
change in the thrust force between the released position (Fa) and the compressed position (Fc) of the gas spring is limited to only 15-20%, which guarantees uniformity in the gas spring response, for all positions thereof; simplicity in structural, operative and application characteristics, with no need for connection to external power supplies, such as, compressed air. | Equipment for the calendering of tubular knitted fabric (13) which, in the end step of a processing cycle, allows, by means of a cloth expander device (16), a steaming cxhamber (18) and a flattening, the width of the tubular fabric to be determined and fixed, besides giving the tubular fabric a commercially acceptable appearance. A plurality of calenders (19, 20, 26, 27) are disposed in series for being selectively used in engagement with the tubular knitted fabric (13) to effect a finishing treatment suitable for the individual type of tubular knitted fabric (13) which is undergoing treatment. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a separator for removing particulate from an airflow carrying particles of different densities and more specifically to a separator accomplishing separation by a sudden change in airflow velocity and thereafter an upward, slowed flow through an enlarged separator chamber.
In the manufacture of various wood products such as plywood, dimensioned lumber, etc., the products are subjected to sanding or the like to provide the desired surface thereon. Provision is normally made in the manufacturing facility for the automatic and continuous removal of the resulting sander dust and other residue from such operations. Commonly, pneumatic conveyor systems are used to transfer the dust and other particulate to a remote collection point.
In the interest of better utilization of wood resources, such dust is commonly reclaimed and used as a constituent of other manufactured wood products. Undesirably, some abrasive particles such as those dislodged from a sander belt also become mixed with the dust and become part of the later manufactured wood product. Subsequently, the amount of abradant particles in the manufactured wood product constitutes a significant factor in the wear of machinery and tools performing various operations on the wood product.
The minute, abrasive particles have a cumulative effect on saws, planer, sanders, etc., with resulting excessive wear and replacement of such equipment adding to product manufacturing costs over a period of time.
Also undesired in the reclaimed wood material are oversize wood particles or rejects which alter the desired homogenous constituency of the finished product.
SUMMARY OF THE PRESENT INVENTION
The present invention is embodied in a separator for use in a pneumatic conveyor system for removing particles, such as abradants or oversize wood particle rejects from an airstream carrying particles of different densities and/or aerodynamic characteristics.
A walled structure includes fixed walls with which a movable wall member jointly defines a variable size chamber into which an airflow is discharged. The chamber is of greater crossectional area than a communicating inlet duct. Impingement of the airflow against the chamber structure and reduced airflow velocity in the structure may be regulated so as to affect the precipitation of heavier particles, such as abradants or oversize wood particle rejects for collection within a hopper or the like. The movable wall member is positionable by adjustment means which may be a scissor linkage. An outlet duct receives chamber airflow for routing to additional particle collection means.
Important objects of the present separator include the provision of a separator and method for removing the heavier particles from a conveyor airflow without impeding same by momentarily subjecting the airflow to a rapid velocity drop and a slowed upright flow; the provision of a separator having movable wall means which is positionable relative the fixed walls of the separator structure to define a chamber the crossectional area of which may be varied to alter airflow velocity and hence particle precipitation therein; and, the provision of movable wall means within a particle separator said means being transversely disposed to the axis of an incoming airflow.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a side elevational view of the present separator; and
FIG. 2 is a horizontal sectional view taken downwardly along line 2--2 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With continuing attention to the drawings, the reference numeral 1 indicates generally a box-like fixed walled structure including walls 2, 3, 4 and 5 joined at their common edges. Corner mounted legs are at 8. The lower end of walled structure 1 is closed by a later described collector.
An inlet 10 normally carries a sub-atmospheric pressure airflow as, for example, induced by a blower B (shown schematically) both of which may be part of a pneumatic conveyor system. Such conveyor systems are used to collect and convey various mixed types of particulate which, in a wood products manufacturing plant, primarily consists of fine wood dust. Conveyed along with the dust, as earlier noted are dislodged abrading particles usually of a mineral nature and of heavier density than the wood dust.
Inlet means 10 discharges the airflow so as to move along a projected axis A into a chamber 11 and impinge against movable wall means at 12. A flared duct segment 10A disperses the airflow across the width of the movable wall means. Said wall means desirably includes an inclined segment at 12A swingably mounted at 13 and weighted at 14 for rested, sealing engagement with wall means 12. Along the side edges of wall means 12 are neoprene seals as at 16.
Outlet means at 15 receives an upward airflow from the upper portion of chamber 11 and may direct same to blower B and to a second particle separator such as one of the cyclone type as shown schematically, a filter collector device or another one of the present type separator.
With attention again to movable wall means 12, the same is positionable in a substantially parallel manner relative to opposite separator wall 4 to enable varying of the crossectional area of chamber 11.
Upper and lower pairs of guide bars at 17 slidably support guides 18, the latter integral with wall means 12 to enable forward advancement of same toward wall 4 or, conversely, rearward retraction toward the left hand side of the separator as shown in FIG. 1.
Adjustment means acts on wall means 12 and may be, for example, of the scissors type including upper and lower pairs of scissor linkages at 20 and 21 controlled by a screwshaft 22 and an operator actuated hand wheel 23.
Disposed below upright chamber 11 is a collector 19 which is embodied in a hopper type structure having inclined walls defining a discharge opening at their lower extremities, said opening normally closed by movably mounted plates 24 which permit periodic emptying of the collector. A latch mechanism 25 retains the plates in upward abutment with the hopper walls. Obviously, other types of collector arrangement may be utilized to receive precipitated particulate P from chamber 11.
In operation, the sub-atmospheric pressure airflow within duct 10 is discharged into the lower portion of chamber 11 so as to impinge against and across movable wall means 12 resulting in a turbulent area within the lower portion of the chamber. The axis A of the inlet airflow is substantially normal or perpendicular to wall means 12 resulting in wall impingement of the airflow and some particle separation from the airflow. Subsequent passage of the airflow is upwardly through chamber 11 at a reduced velocity (relative to duct velocity) during which passage particle precipitation occurs with higher density particles gravitating into the collector. Positioning of wall member 12 so as to decrease the crossectional area of chamber 11 will increase chamber velocity resulting in less particle precipitation. To enable precise control of chamber velocity, pressure gauges at 26-27 read respectively duct and chamber pressures while a window at 28 provides for operator surveillance of separator operation and wall member positioning.
In one embodiment, wall means 12 when positioned to effect a crossectional area of chamber 11 somewhat greater than twice the like dimension of inlet duct 10 provides a suitable reduction in the chamber airflow for particle precipitation. The area ratio between chamber 11 and inlet duct 10 will be determined primarily according to the CFM flow of the conveyor system and the nature of the particles to be separated.
While we have shown but one embodiment of the invention it will be apparent to those skilled in the art that the invention may be embodied still otherwise without departing from the spirit and scope of the invention.
Having thus described the invention, what is desired to be secured under a Letters Patent is: | A separator for a pneumatic conveyor system having fixed wall and a movable wall jointly defining a chamber of greater crossection than a conduit supplying a particulate carrying airflow. An inlet discharges the airflow into the chamber and into impingement with the movable wall to initiate particle separation. | 1 |
BACKGROUND OF THE INVENTION
The present invention is directed toward a pharmaceutical composition containing a renal vasodilator and antihypertensive agent; more particularly, an angiotensin converting enzyme inhibitor.
Antihypertensive agents are known (see e.g., U.S. Pat. Nos. 4,129,571, 4,154,960, 4,052,511, 4,374,829). A particularly preferred class of these compounds are those disclosed in U.S. Pat. No. 4,374,829.
Recently, a novel class of prostanoic acid type compounds having pharmacological activity have been disclosed (see e.g., U.S. Pat. Nos. 4,225,609 and 4,260,771). These compounds are racemic mixtures of interphenylene-9-thia-11-oxo-12-azaprostanoic acid and are especially effective renal vasodilators. More recently, a process was developed for separating these interphenylene racemates to obtain derivatives of interphenylene-9-thia-11-oxo-12-azaprostanoic acid as optically pure enantiomers (see commonly assigned U.S. application Ser. No. 276,117 filed June 22, 1981) and it is these optically pure enantiomers that are the preferred renal vasodilators in the composition of this invention.
It has been discovered that the combination of these preferred renal vasodilator compounds and the preferred antihypertensive agents produces a composition having enhanced pharmacological activity.
SUMMARY OF THE INVENTION
A pharmaceutical composition containing an interphenylene-9-thia-11-oxo-12-aza-prostanoic acid type renal vasodilator and a carboxyalkyl dipeptide antihypertensive agent.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention is a pharmaceutical composition useful for treating hypertension which comprises:
(i) a renal vasodilator compound of the formula ##STR1## wherein the asterisk (*) marks the asymmetric carbon;
X is chlorine or methyl;
r is 0, 1 or 2;
n is 3 or 4;
R 1 is hydrogen, deuterium or methyl;
Z is ethylene, trimethylene, cis or trans-propenylene or propynylene;
y is 0, 1 or 2; and,
W is polymethylene of 2-6 carbon atoms; and,
(ii) an antihypertensive compound of the formula: ##STR2## wherein R and R 6 are the same or different and are hydroxy,
lower alkoxy,
lower alkenoxy,
dilower alkylamino lower alkoxy (dimethylaminoethoxy),
acylamino lower alkoxy (acetylaminoethoxy),
acyloxy lower alkoxy (pivaloyloxymethoxy),
aryloxy, such as phenoxy,
arloweralkoxy, such as benzyloxy,
substituted aryloxy or substituted arloweralkoxy
wherein the substituent is methyl,
halo or methoxy,
amino,
loweralkylamino,
diloweralkylamino,
hydroxyamino,
aryloweralkylamino such as benzylamino;
R 1 is
hydrogen,
alkyl of from 1 to 20 carbon atoms which include branched and cyclic and unsaturated (such as allyl) alkyl groups,
substituted loweralkyl wherein the substituent can be halo, hydroxy, lower alkoxy, aryloxy such as phenoxy, amino, diloweralkylamino, acylamino, such as acetamido and benzamido, arylamino, guanidino, imidazolyl, indolyl, mercapto, loweralkylthio, arylthio such as phenylthio, carboxy or carboxamido, carboloweralkoxy,
aryl such as phenyl or naphthyl,
substituted aryl such as phenyl wherein the substituent is lower alkyl, lower alkoxy or halo,
arloweralkyl, arloweralkenyl, heteroarlower alkyl or heteroarlower alkenyl such as benzyl, styryl of indolyl ethyl,
substituted arloweralkyl, substituted arloweralkenyl, substituted heteroarlower alkyl, or substituted heteroarlower alkenyl,
wherein the substituent(s) is halo, dihalo, lower alkyl, hydroxy, lower alkoxy, amino, aminomethyl, acylamino (acetylamino or benzoylamino) diloweralkylamino, loweralkylamino, carboxyl, haloloweralkyl, cyano or sulfonamido;
arloweralkyl or heteroarloweralkyl substituted on the alkyl portion by amino or acylamino (acetylamino or benzoylamino);
R 2 and R 7 are the same or different and are hydrogen or lower alkyl;
R 3 is hydrogen, lower alkyl, phenyl lower alkyl, aminomethyl phenyl lower alkyl, hydroxy phenyl lower alkyl, hydroxy lower alkyl, acylamino lower alkyl (such as benzoylamino lower alkyl, acetylamino lower alkyl), amino lower alkyl, dimethylamino lower alkyl, halo lower alkyl, quanidino lower alkyl, imidazolyl lower alkyl, indolyl lower alkyl, mercapto lower alkyl, lower alkyl thio lower alkyl;
R 4 is hydrogen or lower alkyl;
R 5 is hydrogen, lower alkyl, phenyl, phenyl lower alkyl, hydroxy phenyl lower alkyl, hydroxy lower alkyl, amino lower alkyl, quanidino lower alkyl, imidazolyl lower alkyl, indolyl lower alkyl, mercapto lower alkyl or lower alkyl thio lower alkyl;
R 4 and R 5 may be connected together to form an alkylene bridge of from 2 to 4 carbon atoms, an alkylene bridge of from 2 to 3 carbon atoms and one sulfur atom, an alkylene bridge of from 3 to 4 carbon atoms containing a double bond or an alkylene bridge as above substituted with hydroxy, loweralkoxy, loweralkyl or diloweralkyl;
and the pharmaceutically acceptable salts thereof.
Examples of Formula I compounds are:
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycyclopentyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycycloheptyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxy-4,4-dimethylcyclohexyl)ethyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-benzoic acid;
4-{3-[3-[2-(9-hydroxy-9-bicyclo[3.3.1]nonyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-benzoic acid;
4-{4-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]butyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)propyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)-trans-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)-cis-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)-2-propynyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-chlorobenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-2-chlorobenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-methylbenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-5,5-dimethyl-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-5,5-dideuterio-4-oxo-2-thiazolidinyl]propyl}benzoic acid and the like.
Examples of Formula II compounds are:
N-(1-carboxy-3-phenylpropyl)-L-alanyl-L-proline;
N-(1-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-proline;
N-(1-ethoxycarbonyl-4-methylpentyl)-L-alanyl-L-proline;
N-(1-carboxy-5-aminopentyl)-L-alanyl-L-proline;
N-α-(1-carboxy-3-phenylpropyl)-L-lysyl-L-proline;
N-α-(1-ethoxycarbonyl-3-phenylpropyl)-L-lysyl-L-proline;
N-α-[1-carboxy-3-(3-indolyl)-propyl]-L-lysyl-L-proline;
N-α-[1-carboxy-3-(4-chlorophenyl)-propyl]-L-lysyl-L-proline;
N-α-[1-carboxy-2-phenylthioethyl]-L-lysyl-L-proline;
N-α-[1-carboxy-3-(4-chlorophenyl)-propyl]-L-lysyl-trans-4-methoxy-L-proline;
N-α-[1-carboxy-5-aminopentyl]-L-lysyl-L-proline;
N-α-(1-carboxy-3-phenylpropyl)-L-ornithyl-L-proline;
Ethyl N-(1-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-prolinate hydrochloride;
N-[1-(ethoxycarbonyl)-3-(4-imidazolyl)propyl]-L-alanyl-L-proline.
N-[1-carboxy-3-(4-imidazolyl)propyl]-L-lysyl-L-proline;
N-(1(S)-carboxy-3-phenylpropyl)-L-alanyl-L-proline;
N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-proline;
N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-proline maleate salt;
N-α-(1(S)-carboxy-3-phenylpropyl)-L-lysyl-L-proline; and, ethyl N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanyl-L-prolinate hydrochloride;
N-α-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-lysyl-L-proline.
The above described Formula II compounds, their use, and methods for their preparation are disclosed in U.S. Pat. No. 4,374,829 which is incorporated herein by reference.
The above-described Formula I compounds, their use and the method of preparation thereof are disclosed in U.S. Pat. No. 4,225,609 which is incorporated herein by reference.
The resolution of the Formula I diastereomeric compounds into their preferred optically pure enantiomers is disclosed in commonly assigned U.S. patent application Ser. No. 276,117 filed June 22, 1981 which is incorporated herein by reference.
This resolution process comprises
(a) protecting the benzoic acid function of the Formula I compound e.g., by treating the acid with an alcohol or an alkyl halide in the presence of a catalyst to form an ester;
(b) treating the product from step (a) with an optically active esterifying agent in the presence of a catalyst and a base to form at least one separable diastereomeric ester;
(c) separating the diastereomeric esters into individual diastereoisomers; and
(d) recovering the Formula I enantiomer from the individual corresponding diastereoisomers e.g., by hydrolysis in the presence of a catalyst in a suitable solvent.
The following flow sheet, illustrates the resolution process to obtain optically pure enantiomers of Formula I compounds: ##STR3##
As outlined above in the flow scheme, the present process consists of four steps:
Step A--Protection of the benzoic acid
The benzoic acid is generally protected as an ester which can be removed easily via hydrolysis under mild conditions. Thus interphenylene-9-thia-11-oxo-12-azaprostanoic acid is treated with an esterifying agent such as, for example, an alcohol or an alkyl halide in the presence of a catalyst to form a benzoate of the structural formula ##STR4## wherein R 2 is as described in, the following (1) Description which summarizes the scope of esterification with an alcohol; and
(2) Description which summarizes the scope of esterification with a halide.
(1) Esterification of the Benzoic Acid with an Alcohol Alcohol (R 2 OH)
(a) C 1-5 alkanol wherein R 2 is methyl, ethyl, isopropyl, tertiary butyl; isoamyl or the like; or
(b) phenyl-substituted methanol, e.g., benzyl alcohol, benzhydryl, or diphenylmethyl alcohol.
Catalyst under acidic conditions
(a) sulfuric acid alone or in the presence of molecular sieves or arylsulfonic acids such as phenylsulfonic acid;
(b) hydrochloric acid or hydrobromic acid; or
(c) boron trifluoride-etherate.
Catalyst under neutral or basic conditions
N,N'-dicyclohexylcarbodiimide;
β-trichloromethyl-β-propiolactone;
N,N'-carbonyldiimidazole;
triphenylphosphine and diethylazodicarboxylate;
1-methyl-2-chloropyridinium iodide; or
6-chloro-1-p-chlorobenzenesulfonyloxybenzotriazole.
The preferred alcohol to be used is methanol or benzyl alcohol. The reaction is usually carried out in an excess amount of an alcohol in the presence of a catalyst. Under acidic conditions, the preferred catalysts are boron trifluoride etherate and sulfuric acid-molecular sieve. A typical procedure involves the refluxing of the benzoic acid, for example, compound 1, in an alcohol with a suitable catalyst under anhydrous conditions. The refluxing continues with or without stirring until a substantial amount of the acid is converted to the ester. Usually it requires about 0.5 to 48 hours, preferably about 2 to 6 hours to obtain optimal yield. Generally, reaction temperatures vary with the boiling point of the alcohol being used but can be adjusted to a range from about 25° C. to about 120° C. with the optional addition of an inert solvent, for example, diethyl ether, methylene chloride, benzene, toluene or xylene. The preferred temperatures are about 35° C. to about 80° C., since the thiazolidine ring of the compounds of this invention normally survives at such mild temperatures.
(2) Esterification with an Alkyl Halide (R 3 X)
As to esterification with alkylhalides, the benzoic acid is treated with a base to form a salt before subsequent treatment with an alkylhalide.
(a) C 1-5 alkylhalides wherein R 3 is methyl, ethyl, n-propyl, n-butyl or isoamyl; and X is chloro, bromo or iodo; or
(b) benzyl chloride or the like.
Base for converting the benzoic acid to a salt
(a) a mineral base such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate or potassium carbonate; or
(b) an organic base such as ammonium hydroxide, quaternary ammonium hydroxide, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide or phenyltrimethylammonium hydroxide.
The reaction is preferably carried out in a polar, aprotic solvent such as dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), dimethylsulfoxide (DMSO), or hexamethylphosphoramide (HMPA). Other polar solvents may also be used. To minimize elimination, primary alkyl halides preferably methyl iodide or benzyl chloride are usually used and prolonged heating at high temperatures should be avoided. In most cases the reaction is conducted at about 0°-100° C. preferably at about 10°-40° C. For example, the reaction is stirred and maintained at about 25° C. until it is substantially complete, usually in about 1 to 48 hrs, preferably about 2 to about 10 hours under optimal conditions.
Step B--Formation of diastereoisomers
Esterification of the sterically hindered cyclohexyl hydroxyl group is accomplished by treating the product from Step A with an optically active acid generally in the presence of a base and a catalyst. Useful optically active acids, catalysts and bases are described below:
1. Optically active acids
(+) or (-)-camphanic acid
(+) or (-)-camphanyl anhydride
(+) or (-)-camphorcarboxylic acid
2. Reagents for Esterification Involving Camphanic Acid or Camphorcarboxylic Acid In the Presence of An Organic Base
Catalyst
N,N'-dicyclohexylcarbodiimide (DCC)
β-tri-chloromethyl-β-propiolactone
N,N'-carbonyldiimidazole
1-methyl-2-halopyridinium iodide
(halo=F, Cl, Br or I)
Base
a trialkylamine (R 3 N) wherein R is alkyl especially C 1-5 alkyl such as methyl, ethyl or butyl
pyridine
4-dimethylaminopyridine
2,4,6-collidine
2,6-lutidine
quinoline
Step C--Separation of the diastereoisomers
Fractional recrystallization is used to separate the diastereoisomers from Step (B) having the structural formula ##STR5##
Typically, a suitable organic solvent is selected for successive recrystallization until an optically pure diastereoisomer is isolated. The solvents usually include water, acetonitrile, C 1-3 alkanol such as methanol or ethanol, acetone, methylacetate, ethylacetate, methylene chloride, ethyl ether, chloroform, dioxane, carbon tetrachloride, toluene, benzene, petroleum ether, n-pentane, n-hexane, cyclohexane or a mixture thereof. The preferred solvent for the camphanyl or camphorcarbonyl esters of the present invention is methylene chloride, chloroform, ethylacetate or a mixture thereof.
Step D--Hydrolysis
Hydrolysis of the highly hindered esters, for example, camphanyl esters, (-,-)-3 is difficult. A few representative hydrolysis procedures which are useful are described below:
TABLE VI______________________________________HydrolysisCatalyst Solvent______________________________________(1) sodium hydroxide tetrahydrofuran- (aqueous solution) methanol-water(2) potassium hydroxide tetrahydrofuran- (aqueous solution) methanol-water(3) potassium hydroxide toluene or benzene (pellets) and dicyclo- hexyl-18-crown-6 (naked hydroxide ion) or sodium hydroxide pellets with other crown ethers(4) lithium tetrahydroboron tetrahydrofuran, or hexamethyl phosphor- amide (HMPA) or mixture thereof______________________________________
The hydrolysis is usually conducted at about 25° C. to about 120° C. depending on the solvent being used. For example, hydrolysis involving the naked hydroxyl ion (KOH-crown ether) is carried out preferably at about 40° C. to about 60° C. The reaction is continued with vigorous agitation until it is substantially complete, usually about 2 to 48 hours, preferably about 5 to about 24 hours.
The following example illustrates but does not limit the process of the present invention. The underlined numbers in the example identify the products as shown in the Flow Sheet above.
EXAMPLE 1
Resolution of Racemic 4{3-[3-[2-(1-hyroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic Acid
Step A. Preparation of (±)-Methyl 4-{3-[3-[2-(1-Hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoate (2)
To a freshly-prepared solution of (±)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid (1) (10 g, 25.6 mmol) in dry N,N-dimethylformamide (86 ml) contained in a 250 ml round bottom flask is added finely-ground potassium carbonate (3.54 g, 25.6 mmol) followed by methyl iodide (1.6 ml, 25.6 mmol). The resulting suspension is protected from atmospheric moisture with a magnesium sulfate drying tube and is stirred at room temperature for 19.5 hours. The reaction mixture is poured into water (175 ml) contained in a separatory funnel and then is extracted with ether (3×40 ml). The organic extracts are combined, washed with saturated aqueous sodium bicarbonate (3×30 ml), dried over sodium sulfate and filtered. Evaporation (in vacuo) of the filtrate leaves the desired ester 2 as a pale yellow oil (10.55 g): tlc, R f =0.4 (homogeneous, UV detection) on silica gel with ethyl acetate:hexane (7:3; v:v) as eluent; ir (2% solution in chloroform) 3400 (w), 1710 (s), 1600 (s) and 1280 (s) cm -1 .
Step B. Preparation of Methyl 4-{3-[3-[2-(1-(-)-camphanyloxy)cyclohexyl)-ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoate (3)
To a solution of (±)-methyl 4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoate (2) (38.37 g, 94.6 mmol) in methylene chloride (189 ml) are added (-)-camphanic acid (20.64 g, 104.1 mmol) and 4-dimethylaminopyridine (5.77 g, 47.3 mmol). The resulting solution is cooled to 0° C. and treated with a solution of N,N'-dicyclohexylcarbodiimide (23.38 g, 113.52 mmol) in methylene chloride (180 ml) added slowly with stirring over 15 min. Thereby is obtained a heterogeneous mixture which is stirred at ambient temperature for 22 h. The reaction mixture is filtered to remove the insoluble solid (N,N'-dicyclohexylurea). The filtrate is washed with 0.2N hydrochloric acid (2×60 ml) and water (2×80 ml), dried over sodium sulfate and filtered. Evaporation (in vacuo) of the filtrate affords a brown, oily residue (semi-solid): tlc on silica gel with chloroform:methanol (98:2; v:v) indicates that the product 3, R f =0.3, is accompanied by starting material 2 (ca. 5%) and traces of 4-dimethylaminopyridine.
The oily residue is "flash chromatographed" on silica gel (600 g, 230-400 mesh, E. Merck) using chloroform-methanol (98:2; v:v) as eluent and a flow rate sufficient to move the solvent front at of 1" per min. Thereby is eluted product 3 (ca. 55 g as a yellow solid) which is contaminated with N-((-)-camphanyl)-N,N'-dicyclohexylurea (4). Product 3 is used as such in Step C described below.
Step C. Separation of Mixture 3 Into Diastereomeric Components (-,-)-3 and (+,-)-3
(a) Isolation of (-,-)-3--Yellow solid 3 (ca. 55 g from Step B above) is triturated with ethyl acetate: hexane (1:1, v:v; 300 ml) at room temperature for 1 h to provide a heterogeneous mixture which is filtered. The collected, pale yellow solid (ca. 25 g of impure (-,-)-3) is recrystallized six times from ethyl acetate to afford pure diastereomer 1 (-,-)-3 as colorless crystals (8.85 g), mp 163°-164° C.; [α] D 22 =-47.3° (c 0.58, CHCl 3 ).
(b) Isolation of (+,-)-3--The trituration filtrate from Step C (a) above is evaporated in vacuo to provide a residue 2 (ca. 24 g) consisting essentially of (+,-)-3 and byproduct 4. This residue is "flash chromatographed" in two separate 12 g portions as described below. A 12 g portion is applied in chloroform to a silica gel column (ca. 350 g, 230-400 mesh, E. Merck, 60 mm in diameter×10" in length) which is eluted first with 30% ethyl acetate in hexane (2.4 L) at a flow rate sufficient to move the solvents front of 1" per min to remove the byproduct 4. Continued elution at the same flow rate with 40% ethyl acetate in hexane (1 L), 50% ethyl acetate in hexane (2 L) and 60% ethyl acetate in hexane (1 L) provides (+,-)-3. From the two "flash chromatographies" is obtained a pale yellow solid (15 g), [α] D 22 =+26.5° (c 0.57, CHCl 3 ). This solid is recrystallized from ethyl acetate to constant rotation. Thereby is obtained pure diastereomer (+,-)-3 3 as colorless crystals (10.55 g), mp 130°-132° C.; [α] D 22 =+37.2° (c 0.61, CHCl 3 ).
Step D. Hydrolysis of (+,-)-3 and (-,-)-3
(a) Preparation of (+)-4-{3-[3-[2-(1-Hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]-propyl}benzoic Acid
To toluene (102 ml) contained in a 250 ml round bottom flask is added crushed solid potassium hydroxide (3.83 g, 68.3 mmol). The resulting heterogeneous mixture is heated at reflux until ca. 20 ml of distillate is collected 4 and then is cooled to room temperature. To the cooled heterogeneous mixture is added (+,-)-3 (4 g, 6.83 mmol) followed by dicyclohexyl-18-Crown-6 (12.72 g, 34.2 mmol). The resulting reaction mixture is protected from atmospheric moisture with a magnesium sulfate drying tube and is vigorously stirred and heated at 40° C. (oil bath) for 1 h. Then the drying tube is removed, water (80 ml) is added to the brown reaction mixture and stirring and heating at 40° C. are continued for 45 h. After cooling to room temperature, the reaction mixture is poured slowly into cold, excess N hydrochloric acid (200 ml) with vigorous stirring. The acidic, 5 aqueous mixture is transferred to a separatory funnel and the layers are allowed to separate. The aqueous layer (acidic phase) is extracted with chloroform (4×100 ml). The toluene and chloroform layers are combined, washed with water (2×100 ml), dried over sodium sulfate and filtered. Evaporation (in vacuo) of the filtrate leaves an oily residue which is triturated with ether at room temperature to afford an insoluble, colorless solid. The solid is collected, washed with ether and dried to give 2.04 g (76%) of (+)-1: tlc, R f =0.26 (homogeneous, UV detection) with chloroform: methanol (9:1; v:v) on silica gel; identical by tlc to 1. Recrystallization from methanol affords pure enantiomer (+)-1 as colorless crystals (1.1 g), mp 139.5°-140.5° C.; [α] D 22 +70.0° (c 0.47, CHCl 3 ); ir (KBr pellet) 3270, 1690, 1640 and 1260 cm 1 ; pmr (CDCl 3 ) δ8.05 (2H, d), 7.28 (2H, d), 6.49 (2H, bs, OH and CO 2 H), 4.75 (H, bm), 3.56 (2H, s), 2.68 (2H, t) and 1.60 (bc envelope).
Anal. Calcd. for C 21 H 29 NO 4 S: C, 64.42; H, 7.47; N, 3.58. Found: C, 64.57; H, 7.81; N, 3.51.
(b) Preparation of (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic Acid
The hydrolysis of the pure diastereomer (-,-)-3 is carried out exactly as described above for (+,-)-3 in Step D (a). Thereby is obtained pure enantiomer (-)-1 as colorless crystals (1.24 g), mp 140°-141° C. (from CH 3 OH); [α] D 22 -68.7° (C 0.47, CHCl 3 ); tlc, ir and pmr data identical with those recorded for (+)-1.
Anal. Calcd. for C 21 H 29 NO 4 S: C, 64.42; H, 7.47; N, 3.58: Found: C, 64.48; H, 7.72; N, 3.72.
Using substantially the same procedure as in Example 1 but substituting an equivalent amount of camphorcarboxylic acid for the camphanic acid, the corresponding camphor carbonyl esters are obtained and after separation and hydrolysis, comparable yields of the enantiomers of the azaprostanoic acid are obtained.
Substantially the same procedure as described in Example 1 was followed, but the following unresolved compounds were substituted for the racemic combinations used therein:
4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycyclopentyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycycloheptyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxy-4,4-dimethylcyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(9-hydroxy-9-bicyclo[3.3.1]nonyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{4-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]butyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)propyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)-trans-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-(1-hydroxycyclohexyl)-cis-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[3-(1-hydroxycyclohexyl)-2-propynyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)-ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-chlorobenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)-ethyl]-4-oxo-2-thiazolidinyl]propyl}-2-chlorobenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)-ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-methylbenzoic acid;
4-{3-[3-[2-(1-hydroxycyclohexyl)-ethyl]-5,5-dimethyl-4-oxo-2-thiazolidinyl]propyl}benzoic acid; or
4-{3-[3-[2-(1-hydroxycyclohexyl)-ethyl]-5,5-dideuterio-4-oxo-2-thiazolidinyl)propyl}benzoic acid.
From the foregoing unresolved compounds, there were obtained the following corresponding enantiomers:
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclopentyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycycloheptyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxy-4,4-dimethylcyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[2-(9-hydroxy-9-bicyclo[3.3.1]nonyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{4-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]butyl}benzoic acid;
(+) or (-)-4-{3-[3-[3-(1-hydroxycyclohexyl)propyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[3-(1-hydroxycyclohexyl)-trans-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[3-(1-hydroxycyclohexyl)-cis-2-propenyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[3-(1-hydroxycyclohexyl)-2-propynyl]-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-chlorobenzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl-4-oxo-2-thiazolidinyl]propyl}-2-chlorobenzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2-thiazolidinyl]propyl}-3-methylbenzoic acid;
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-5,5-dimethyl-4-oxo-2-thiazolidinyl]propyl}benzoic acid; and
(+) or (-)-4-{3-[3-[2-(1-hydroxycyclohexyl)ethyl]-5,5-dideuterio-4-oxo-2-thiazolidinyl]propyl}benzoic acid;
The composition of the invention can contain varying amounts of the Formula I (i) renal vasodilator and Formula II (ii) antihypertensive compounds. The weight ratio of (i):(ii) can range from about 1 to 25; preferably from about 1 to 10; more preferably from about 1 to 15. In addition to the active ingredients of (i) and (ii), the composition can also contain other conventional pharmaceutically acceptable compounding ingredients, as necessary or desired. Such ingredients are generally referred to as carriers or diluents. Conventional procedures for preparing such compositions in appropriate dosage forms can be utilized. Whatever the dosage form, it will contain a pharmaceutically effective amount of the present composition.
The present compositions can be administered orally or other than orally; e.g., parenterally, by insufflation, topically, rectally, etc.; using appropriate dosage forms; e.g., tablets, capsules, suspensions, solutions, and the like, for oral administration; suspension emulsions, and the like, for parenteral administration; and ointments, and the like, for topical administration.
Treatment dosage for human beings can be varied as necessary. Generally, daily dosages of the composition of the invention can range from about 550 to about 25 mg; preferably, from about 400 to about 60 mg; more preferably from about 200 to about 120 mg, using the appropriate dosage form and mode of administration.
The composition of this invention inhibits angiotensin converting enzyme and thus blocks conversion of the decapeptide angiotensin I to angiotensin II. Angiotensin II is a potent pressor substance. Thus blood-pressure lowering can result from inhibition of its biosynthesis especially in animals and humans whose hypertension is angiotensin II related. Furthermore, converting enzyme degrades the vasodepressor substance, bradykinin. Therefore, inhibitors of angiotensin converting enzyme may lower blood-pressure also by potentiation of bradykinin. Although the relative importance of these and other possible mechanisms remains to be established, inhibitors of angiotensin converting enzyme are effective antihypertensive agents in a variety of animal models and are useful clinically, for example, in many human patients with renovascular, malignant and essential hypertension. See, for example, D. W. Cushman et al., Biochemistry 16, 5484 (1977).
The evaluation of converting enzyme inhibitors is guided by in vitro enzyme inhibition assays. For example, a useful method is that of Y. Piquilloud, A. Reinharz and M. Roth, Biochem. Biophys. Acta, 206, 136 (1970) in which the hydrolysis of carbobenzyloxyphenylalanylhistidinylleucine is measured. In vivo evaluations may be made, for example, in normotensive rats challenged with angiotensin I by the technique of J. R. Weeks and J. A. Jones, Proc. Soc. Exp. Biol. Med., 104, 646 (1960) or in a high renin rat model such as that of S. Koletsky et al., Proc. Soc. Exp. Biol. Med., 125, 96 (1967).
Thus, the compositions of the invention are useful in treating hypertension. They are also of value in the management of acute and chronic congestive heart failure, in the treatment of secondary hyperaldosteronism, primary and secondary pulmonary hypertension, renal failure and renal vascular hypertension, and in the management of vascular disorders such as migraine or Raynaud's disease. The application of the compounds of this invention for these and similar disorders will be apparent to those skilled in the art.
In vivo testing of the composition of this invention in test animals (dogs) has demonstrated that this composition is pharmaceutically effective in lowering mean arterial pressure, reducing blood pressure, increasing heart rate, and increasing plasma renin activity.
The combination composition of the invention was administered to test animals (dogs) and the results obtained and the methods employed are described in Example 2 below.
EXAMPLE 2
Each of 6 female beagles was anesthetized and, under sterile conditions, one kidney was wrapped with cellophane. Two weeks later a contralateral nephrectomy was performed so that perinephritic hypertension developed. The surgical preparation of the dogs was completed at least one year prior to the administration of the combination composition of the invention. The dogs were trained to lie quietly on a table during puncture of a femoral artery with a 26 guage needle attached to a Micron pressure transducer. The output from the transducer was recorded on a 1-channel Gilson strip chart writer. The needle was left in the artery until a clear pulsatile pressure trace of at least 15 seconds duration was obtained. Heart rate was counted and mean arterial pressure (MAP) was calculated by adding the diastolic pressure to one-third of the pulse pressure. Five consecutive daily measurements were made in untreated hypertensive dogs. Subsequent statistical testing of the data by analysis of variance indicated that the blood pressure was constant over the course of the control week; an average of the 5 measurements for each dog was therefore used as the control MAP for that animal. During the following week, each dog received a gelatin capsule containing either 1 mg/kg of the antihypertensive compound of the invention, 0.2 mg/kg of the renal vasodilator compound of the invention or a combination of the 2 compounds at 9 a.m. and at 4:30 p.m. daily for 5 days. Blood pressure was measured immediately before and then 2 hours after the morning treatment.
Plasma samples for plasma rein activity (PRA) determinations were drawn on the first day of the treatment before the first dose (the control sample) and on the final day of that week 2 hours after the morning dosing. On each occasion, 5 ml of blood was withdrawn from the jugular vein and delivered into a chilled test tube containing ethylenediaminotetraacetate (EDTA). Plasma was separated by centrifugation at 4° C. and was stored at -20° C. until PRA was determined by use of the Clinical Assay Gamma Coat 125 I radioimmunoassay kit. After each week of compound administration, 2 weeks in which no measurements were made and no treatments were given were allowed to assure that the animals had fully recovered. The protocol of 5 days of control observations and 5 days of treatment was then repeated until each dog had received each treatment once.
The data were subjected to analysis of variance for repeated measures. Differences between means were identified by application of the Newman-Keuls procedure. The results are set forth below in Tables I and II wherein the antihypertensive compound of the invention is identified as "A-H" and the renal vasodilator compound of the invention is identified as "RV".
TABLE I__________________________________________________________________________Mean arterial pressures (MAP) and heart rates (HR) of hypertenivebeagles* Day of TreatmentTreatment Control 1 2 3 4 5__________________________________________________________________________MAP A-H 125 ± 6 119 ± 7 123 ± 7 120 ± 5 123 ± 5 122 ± 6(mm Hg)RV 130 ± 4 125 ± 4 128 ± 4 124 ± 5 127 ± 4 141 ± 4RV + A-H 123 ± 3 120 ± 4 114 ± 7 113 ± 4 119 ± 6 118 ± 5HR A-H 129 ± 9 135 ± 17 145 ± 6 133 ± 9 128 ± 7 129 ± 10(bpm)RV 135 ± 9 136 ± 10 149 ± 5 137 ± 6 133 ± 4 132 ± 6RV + A-H 129 ± 9 123 ± 8 144 ± 6 144 ± 6 135 ± 7 140 ± 9__________________________________________________________________________ *Data presented as mean ± standard error of the mean.
TABLE II______________________________________Plasma renin activities (PRA) of hypertensive beagles before andafter treatment. PRA (mg/ml/hr)Treatment Control Day 5______________________________________A-H 0.99 ± 0.29 8.19 ± 0.68*RV 1.14 ± 0.44 5.58 ± 1.39*RV + A-H 0.58 ± 0.16 17.69 ± 2.98*.sup.+______________________________________ Data presented as mean ± standard error of the *p 0.01, control vs. day 5 .sup.+ p 0.01, RV + AH compared to AH and to RV
The data in Table I reveal that during the first 4 days of concurrent administration of the A-H compound and RV compound, MAP was significantly less in the treated dogs than in the untreated beagles. In contrast, administration of either compound alone produced no statistically significant effect on MAP when compared to controls. Statistical comparisons among the effects of the 3 treatments on a given day indicated that the A-H compound in combination with the RV compound lowered blood pressure to levels significantly less than those produced by either compound alone during the first 3 days and, on day 4, to a pressure less than the average of the dogs treated with the RV compound alone. Concurrent administration of the A-H compound with the RV compound to these mildly hypertensive beagles clearly reduced blood pressure to within the normotensive range, an effect which was not produced with either compound alone.
From Table I, it can also be seen that administration of the RV compound alone and in combination with the A-H compound significantly increased heart rate above the control levels on the first 3 days of compound administration. The A-H compound had no significant effect on pulse rate. The heart rates attained when the RV compound was administered singularly were significantly greater than those measured in dogs treated only with the A-H compound on the first 3 days of treatment. When the effects of the combination of the A-H and RV compounds were compared to those of A-H compound alone, significant differences were found on days 2 and 3 of treatment.
As shown in Table II, plasma renin activities (PRA) were similar at the end of each of the 3 control weeks. As expected all 3 treatments significantly increased PRA above the control levels. There was no significant difference between the renin level attained during treatment with the A-H comound and that measured during the RV compound treatment. The effects of the 2 compounds on renin release appeared to be additive since PRA during administration of the combination of the compounds was significantly higher than the activities measured during either treatment alone.
From the data shown in Tables I and II, it can be seen that mean arterial pressure (MAP) was significantly decreased only when the combination of the antihypertensive (A-H) and renal vasodilator (RV) compounds were administered. It can also be seen that administration of the renal vasodilator compound either alone or in combination with the antihypertensive compound significantly increased heart rate and also elevated plasma renin activities. | A pharmaceutical composition is disclosed which comprises the combination of interphenylene 9-thia-11-oxo-12-aza prostanoic acid derivatives and carboxyalkyl dipeptide derivatives. | 2 |
CONTINUING APPLICATION DATA
This application is a Continuation-In-Part application of International Patent Application No. PCT/EP98/05374, filed on Aug. 25, 1998, which claims priority from Federal Republic of Germany Patent Application No. 197 39 366.7, filed on Sep. 9, 1997. International Patent Application No. PCT/EP98/05374 was pending as of the filing date of the above-cited application. The United States was an elected state in International Patent Application No. PCT/EP98/05374.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates first of all to a disk milling cutter for the milling of a crankshaft journal, including the two oil collar cheeks associated with it, and of recesses that act as oil grooves between the oil collar cheeks, with plate-shaped cutting inserts on its milling cutter periphery in the peripheral direction on its left and right sides.
2. Background Information
Using such disk milling cutters, crankshaft journals are machined as the workpiece is driven synchronously so that it rotates around its axis, together with both associated oil collar cheeks and together with the recesses in between that act as oil grooves, flank the cylindrical journal surface on both sides and maintain an appropriate distance from the oil collar cheeks. This milling is appropriately done using a single feed motion of the disk milling cutter, i.e. in one single operating process. The disk milling cutter is equipped or studded on its periphery in the peripheral direction, alternately on the left and right sides, with plate-shaped cutting inserts. On the disk milling cutter claimed by the present invention, the cutting inserts with their cover surfaces that contain the faces or chip faces are oriented essentially radially with respect to the axis of the milling cutter.
Crankshaft journals generally have only a limited diameter. The curvature of the surface of the crankshaft journals to be formed by the milling cutter into a cylindrical jacket is correspondingly severe. Consequently, on conventional disk milling cutters for this application only one milling cutter cutting edge is engaged at a time. This engagement occurs alternately on the left and on the right sides of the periphery of the disk milling cutter. This type of operation causes rough operation, which in turn results in the risk of an adverse effect on the surface quality.
OBJECT OF THE INVENTION
The initial object of the present invention is therefore to improve the smoothness of operation of the disk milling cutter and thus to optimize the result of the milling operation.
SUMMARY OF THE INVENTION
The present invention teaches that the cutting inserts can be located on the periphery of the milling cutter with such close spacing, or narrow or tight pitch, that the length of the arc of contact between the beginning of the cut and the end of the cut of a cutting insert on the crankshaft journal is greater than one-half the spacing of the arrangement of the cutting inserts on the periphery of the milling cutter. In this context, one whole space, pitch, or spacing can be defined, either on the left side or on the right side of the periphery of the milling cutter, as the distance between two sequential cutting inserts in the peripheral direction of the milling cutter. The present invention consequently can make possible such a close spacing that the length of the arc of contact of the milling cutter is greater than one-half the milling cutter spacing on its right or on its left side. The length of the arc of contact is defined as the arc that is traveled by each milling cutter cutting edge between the beginning of the cut and the end of the cut on the crankshaft journal. Because the cutting inserts that are located on the left and right sides on the periphery of the milling cutter can be offset from each other by one-half space, which means that the left cutting inserts are in the centers of the spaces between the cutting inserts that are located on the right side (and vice versa), one-half of the space equals the peripheral arc of the milling cutter between a cutting edge on the left side and a neighboring cutting edge on the right.
The present invention teaches that more than just one cutting edge can essentially always be in contact with the workpiece. Thus there can be a cutting force load that is always pulsating between a bottom value and a top value. There are essentially no loads that alternate between zero and maximum. This feature is also an advantage in terms of machine dynamics and promotes a longer useful life of the equipment.
In at least one possible embodiment according to the present invention, the cutting force load can be kept substantially constant by the precise spacing of the cutting inserts. The precise spacing, as discussed above, can permit more than one cutting insert to be in contact with the workpiece, i.e. the crankshaft, in order to achieve a substantially smooth operation of the disk milling cutter. The smooth operation can essentially avoid the undulations or vibrations caused by the application of uneven cutting force loads. In at least one possible embodiment, the inserts can be spaced so that, during operation of the disk milling cutter, the preceding cutting insert, in the direction of rotation of the milling cutter, will disengage from the crankshaft while the following cutting insert, which is preferably located on the opposite side of the periphery of the milling cutter, begins engaging the crankshaft. Further, the degree of force applied by the preceding cutting insert can begin to decrease during disengagement, while the degree of force applied by the following cutting insert can begin to increase during disengagement at a rate and amount preferably substantially equivalent to the rate and amount of decrease of the force during disengagement of the preceding cutting insert. This balance between decreasing and increasing cutting force loads can provide for a substantially smooth operation of the milling cutter by substantially eliminating unbalanced force loads that can cause vibrations or undulations in the milling process.
In at least one further possible embodiment according to the present invention, the cutting inserts may not alternate from side to side about the periphery and may all be substantially similar in position.
In at least one other possible embodiment according to the present invention, the diameter of the workpiece to be machined, the diameter of the disk milling cutter, the spacing of the cutting inserts, and the depth at which the inserts are to cut into the workpiece all must be precisely calculated and measured for substantially optimal performance during the milling process. Each one of these measurements affects each one of the other measurements. If, for example, the cutting inserts were spaced improperly with relationship to the workpiece, unbalanced cutting force loads could occur. If the spacing were too small, the cutting force applied by the multiple inserts contacting the workpiece could cause an improper cut. If the spacing were too large, only one insert may contact the workpiece at any given time, which could also result in variations in the cutting force load from none to maximum, and thereby cause rough or imprecise cuts.
The disk milling cutter as described by the present invention takes advantage of the low wear on the peripheral length of the disk milling cutter by each individual cutting insert. This low wear on the peripheral length is made possible by the exclusive use of plate-shaped cutting inserts, which with their cover faces form a face or chip face and thereby—with reference to their plate-shaped configuration—can be oriented essentially radially on the periphery of the milling cutter. In one embodiment, the present invention teaches a disk milling cutter of a type in which the milling cutter can be equipped both on the left side and on the right side of its periphery with identically configured cutting inserts, which also—regardless of whether it is used on the left side or on the right side of the periphery of the milling cutter—are realized in the form of indexable cutting inserts, which make available cutting edges that can be placed in more than one cutting position. The cost advantages of using such indexable cutting inserts are generally known. In this document, when the term “indexable insert” is used, it should be understood in the sense of a “double indexable insert” because the indexing capability makes it possible to use the same insert on the left side and also on the right side of the milling cutter, and the other rotation is available for an additional cut on the left or on the right side. The term “cutting edge” as used here relates to a complete reproducing or matching, namely a combined or otherwise dual-function diameter and recessing cutting edge, which either on the left or on the right side of the crankshaft journal creates the complete final shape with a single feed motion. All these capabilities are made possible in a disk milling cutter according to at least one embodiment of the present invention, wherein each of the cutting inserts is an indexable insert with at least two cutting edges on the same side of the milling cutter that can be brought into the cutting position one after the other, and wherein each cutting insert is shaped and indexable so that it can be used on the same disk milling cutter both on its left side as well as on its right side.
The above discussed embodiments of the present invention will be described further hereinbelow with reference to the accompanying figures. When the word “invention” is used in this specification, the word “invention” includes “inventions”, that is, the plural of “invention”. By stating “invention”, the Applicants do not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicants hereby assert that the disclosure of this application may include more than one invention, and, in the event that there is more than one invention, that these inventions may be patentable and non-obvious one with respect to the other.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention further relates to the more detailed configuration of the general indexable cutting inserts described above for the intended use described above. Claim 3 discloses their basic configuration. The indexable cutting insert is characterized by a series of variant configurations, which are described in greater detail below with reference to the exemplary embodiments illustrated in the accompanying figures, in which:
FIG. 1 is a schematic side view of the journal milling process which takes place in synchronization on the basis of a peripheral segment of the milling cutter which is located in the journal periphery in the contact position.
FIG. 2 shows a cross section along Line II—II in FIG. 1, whereby the completely reproducing cutting edge of the cutting insert is shown in cross section by the broken line, although it forms a continuous cutting edge.
FIG. 3 is a plan view of the peripheral segment of the disk milling cutter as shown in FIG. 2 .
FIG. 4 shows one exemplary embodiment of the indexable cutting body for the disk milling cutter in an overhead view, and in three partial sections A—A, B—B and C—C, shown in FIGS. 4A, 4 B, and 4 C respectively. In the overhead view, in turn, the closed completely reproducing cutting edges are shown in broken lines, although they are one continuous, visible edge.
FIG. 5 shows, in a plan view, in a side view and in two partial sections A—A and B—B, shown in FIGS. 5A and 5B respectively, a modified exemplary embodiment of the indexable insert. Here again, the information relating to FIGS. 2 and 4 above also applies to the cutting edges illustrated in broken lines.
FIG. 6 is a drawing in partial section of the crankshaft journal to be machined by the disk milling cutter in its pre-machining condition, whereby the surface area of the crankshaft journal to be removed by the milling process is highlighted for purposes of the drawing by means of dot-shading.
FIG. 7 is a partial section through the crankshaft journal as illustrated in FIG. 6, with indexable inserts of the type illustrated in FIG. 5 shown schematically in their contact position.
FIGS. 7A and 7B show expanded views of portions of the crankshaft journal shown in FIG. 7 .
FIG. 8 is a plan view of a peripheral segment of the disk milling cutter, which is equipped or studded with indexable inserts of the type illustrated in FIG. 5, and to achieve a particularly close spacing is provided with an insert clamping device that differs from the arrangement illustrated in FIGS. 1 and 2.
FIG. 9 is a plan view, and in three partial sections A—A, B—B and C—C, shown in FIGS. 9A, 9 B, and 9 C respectively, with enlarged details X, Z, and Y, shown in FIGS. 9D, 9 E, and 9 F respectively, of an additional modified exemplary embodiment of an indexable insert, basically of the type illustrated in FIG. 4 . Here again, the comments made with regard to FIGS. 2 and 4 relate to the cutting edges illustrated in broken lines.
FIG. 10 shows an additional modified exemplary embodiment of an indexable insert that has the basic design illustrated in FIG. 4, as well as three partial sections A—A, B—B and C—C, as shown in FIGS. 10A, 10 B, and 10 C respectively, as well as enlarged details Z and X, as shown in FIGS. 10E and 10D respectively. Here again, the comments made with regard to FIGS. 2 and 4 relate to the cutting edges illustrated in broken lines.
FIG. 11 shows an overhead view and a side view, as shown in FIG. 11B, as well as, in two partial sections shown in FIGS. 11A and 11C, an additional modification of the indexable insert having the basic design illustrated in FIG. 4 . Here again, the comments made with regard to FIGS. 2 and 4 relate to the cutting edges illustrated in broken lines.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The disk milling cutter 1 , which is illustrated only in the form of a peripheral segment, is used to mill the workpiece, a crankshaft journal 2 , in a single feed motion, together with the two oil collar cheeks 3 , 4 and with the recesses 5 , 6 (FIGS. 2, 6 ) acting as oil grooves, between them.
The disk milling cutter 1 is equipped on its periphery 7 in the peripheral direction or direction of rotation 8 alternately on its left and right sides with plate-shaped cutting inserts 9 , which are oriented with their tool faces 10 containing the faces or chip faces essentially radially to the milling cutter axis (not shown). The machining of the crankshaft journal is preferably done in synchronization or climb milling or cut down milling. The direction of rotation 11 of the workpiece is therefore in the same direction as the direction of rotation 8 of the disk milling cutter, as shown in FIG. 1 .
The cutting inserts 9 are located at a spacing 12 (FIG. 3) uniformly on the periphery 7 in the peripheral direction 8 on the left and on the right side of the milling cutter. The location of the cutting inserts 9 on the left side is symmetrical and offset by one-half a space 12 with respect to the location on the right side (FIG. 3 ). The spacing 12 is tight enough that the length 13 of the arc of contact between the beginning of the cut and the end of the cut of the cutting insert 9 on the workpiece 2 is greater than one-half the spacing 14 of the arrangement of the cutting inserts 9 on the periphery of the milling cutter 1 .
The cutting inserts 9 are indexable inserts with at least two cutting edges 15 , 16 which can be brought into the cutting position one after the other on the same side of the milling cutter. To emphasize their characteristic as a closed, completely reproducing cutting edge, they are highlighted by cross-hatching in the figures, although they of course form continuous, visible cutting edges.
Each cutting insert 9 is provided with a peripheral contour of its cover faces 10 which contain the cutting faces such that a cutting insert always shapes one half of the crankcase journal 2 with its neighboring oil collar cheek 3 or 4 and the recess 5 or 6 between them. Each cutting insert 9 is illustrated in the vicinity of its two cover faces, of which only the upper, visible cover face 10 is shown in FIGS. 2 and 4, with two closed completely reproducing cutting edges 15 , 16 . Each cutting insert 9 therefore carries a total of four cutting edges 15 , 16 . Two of these cutting edges are thereby suitable or designed for use on the left side and two for use on the right side of the periphery 7 of the milling cutter 1 .
The basic shape of the indexable insert used as the cutting insert 9 is illustrated in FIGS. 4, 4 A, 4 B, and 4 C. This indexable insert is characterized by the approximate shape of a cuboid with somewhat rhombus-shaped or diamond-shaped or rhomboid cover surfaces which contain the chip faces 17 , 18 , the cover face of which, viewed from above, is numbered 10 . The vertical or standing or projecting plate corners in the direction of the longer rhombus diagonal 19 (FIG. 4) each have, in an extension of the two facing cover face sides, each of which forms a cutting edge 20 , 21 , a lug-like carrier projection 22 and 23 respectively with a recessing cutting edge 24 , 25 to form a recess 5 , 6 on the crankshaft journal 2 . The carrier projections 22 , 23 are also active on the side opposite the illustrated cover face 10 , namely in the vicinity of the chip face 18 , as the carrier of a recessing cutting edge 26 and 27 (FIGS. 4A and 4B) respectively located there. Each cutting edge 15 , 16 of one of the two cover faces 10 of the cutting insert 9 therefore forms—and in the exemplary embodiment illustrated in FIG. 4 they merge into each other—a recessing cutting edge 24 or 25 and adjacent to it a diameter cutting edge 28 or 29 , and analogously on the underside of the indexable insert a recessing cutting edge 26 or 27 and a diameter cutting edge 30 or 31 .
The clearance faces 32 (FIG. 5A) of the cutting inserts 9 form a right angle with the cutting or chip surfaces 16 , 18 . In the exemplary embodiment illustrated in FIG. 4, each diameter cutting edge 28 , 29 makes a continuous transition into the associated recessing cutting edge 24 or 25 . The two cutting edges lie in the same cover face 10 or in the same chip face 17 , 18 . The cutting rake γ is 0 degrees. Standing in the cut it is negative.
In contrast to the cutting insert 9 illustrated in FIG. 4, on the cutting insert 9 illustrated in FIGS. 5, 5 A, 5 B, and 5 C, the recessing cutting edges 24 , 25 and 26 , 27 are each stepped underneath the corresponding diameter cutting edges 28 , 29 or 30 , 31 . The respective, completely matching overall cutting edge 15 , 16 is thereby formed by a diameter cutting edge 28 , 29 or 30 , 31 and by a recessing cutting edge 24 , 25 or 26 , 27 which is recessed with respect to it opposite to the direction of rotation 8 . The overall cutting edge 15 or 16 is divided or split. Therefore, there is a splitting of the cutting force into two smaller parts, which do not reach their peak levels simultaneously. Thus lower cutting force plays or clearances are achieved. This is an effective active geometry with, once again, a negative cutting rake γ of 0 degrees.
The cutting insert illustrated in FIG. 9 represents a modification of the cutting insert illustrated in FIG. 4, to the extent that each cutting edge 15 , 16 , consisting of a diameter cutting edge 28 , 29 or 30 , 31 and a recessing cutting edge 24 , 25 or 26 , 27 which merge seamlessly into each other, is provided with a chip forming shoulder 33 for the formation of positive cutting edges. The chip forming shoulder 33 has a trough-shaped or hollow cross section. The cutting rake γ is therefore positive. The trough-shaped cross section of the chip forming shoulder is shown in sectional drawings A—A (FIG. 9 A), B—B (FIG. 9B) and C—C (FIG. 9 C), in which the areas Z (FIG. 9 E), Y (FIG. 9F) and X (FIG. 9D) are shown on an enlarged scale. It is therefore apparent that in the vicinity of the recessing cutting edges 24 , 25 in the chip discharge direction behind the chip forming shoulder 33 , an island-like plateau surface 34 is formed which is recessed with respect to the chip face 17 or 18 . The cutting rake γ, which is associated with the cutting edge 20 or 21 , is also positive. The cutting insert with a chip shaping shoulder along the entire cutting edge as illustrated in FIG. 5 is particularly well suited for materials that form long chips, as well as for a reduction of cutting and passive forces. There is an effective active geometry with positive cutting rakes on the diameter cutting edges and on the recessing cutting edges.
In the embodiment illustrated in FIG. 10, the diameter cutting edges 28 , 29 and 30 , 31 are positive, while on the other hand, the recessing cutting edges 24 , 25 and 26 , 27 are negative. The trough-shaped chip forming shoulders 35 of the diameter cutting edges 28 , 29 stand in a straight line tapering or inward toward the vicinity of the carrier projections 22 , 23 of the recessing cutting edges 24 , 25 and 26 , 27 . The different geometries of recessing cutting edges and of the diameter cutting edges are illustrated by way of example by the partial sections A—A (FIG. 10A) and B—B (FIG. 10 B), with the enlargement of A—A in the detail drawing Z (FIG. 10 E), using the example of a diameter cutting edge 29 and of the associated recessing cutting edge 25 . This exemplary example shows, on the basis of the diameter cutting edge 29 , that the diameter cutting edges are graduated or stepped back with respect to the recessing cutting edge in the direction of the main cutting pressure, and namely by the dimension h. The cutting geometry in the vicinity of the carrier projections 22 , 23 is illustrated by way of example, with reference to partial section C—C (FIG. 10 C), with the enlargement X (FIG. 10 D).
The exemplary embodiment illustrated in FIG. 10 is particularly well-suited for materials that throw off long chips,because it promotes chip breaking. This cutting geometry is also suitable for reducing the cutting force and the passive force. An effective active or cutting geometry is achieved by the positive cutting rake on the diameter cutting edges 28 , 29 and 30 , 31 and by the negative cutting rake, which stabilizes the cut, on the recessing cutting edges 24 , 25 and 26 , 27 .
On the indexable insert illustrated in FIGS. 11, 11 A, 11 B, and 11 C, the carrier projections 22 , 23 of the recessing cutting edges 24 , 25 and 26 , 27 are hollowed out on their outer flanks 36 , 37 to form clearance faces. The troughs 38 , 39 are in the shape of a V, with the peak 40 of the V lying approximately in the center plane of the cutting plate 9 . The depth of the troughs 38 , 39 decreases steadily from the carrier projections 22 , 23 toward the center of the cutting insert.
The troughs 38 , 39 extend to the center of the outside of the cutting insert 9 . In a plan view of the outer flanks 36 , 37 , too, the troughs 38 , 39 have a V-shape that opens toward the carrier projections 22 , 23 (FIG. 11 ). The troughs 38 , 39 in the clearance faces below the outsides of the recessing cutting edges 24 , 25 and 26 , 27 are designed to ensure a sufficiently large clearance angle ± α when there are rather flat axial angles of inclination of the cutting insert 9 . This feature is used or is necessary if, at the transition from the recessing cutting edge 24 , 25 or 26 , 27 to the diameter cutting edge 28 , 29 or 30 , 31 , as the result of a transition angle at an insufficiently small or too small clearance angle, a flatter axial angle of inclination is required. The troughs 38 , 39 ensure an effective active or cutting geometry with negative cutting rakes on the diameter cutting edges 28 - 31 and on the recessing cutting edges 24 - 27 .
Additional troughs 41 , 42 with a similar V-shape extend inward at an angle 43 toward the previous trough in the vicinity of the clearance faces of the recessing cutting edges 24 , 25 or 26 , 27 .
FIGS. 7A and 7B show a partial section through the crankshaft journal as illustrated in FIG. 6, with indexable inserts of the type illustrated in FIG. 5 shown schematically in their contact position.
FIG. 8 is a plan view of a peripheral segment of the disk milling cutter, which is equipped or studded with indexable inserts of the type illustrated in FIG. 5 . An insert clamping device that differs from the arrangement illustrated in FIGS. 1 and 2 is provided to achieve a particularly close spacing.
One feature of the invention resides broadly in the disk milling cutter 1 for the milling of a crankshaft journal 2 , including the two oil collar cheeks 3 , 4 associated with it, and with recesses 5 , 6 that act as oil grooves between the oil collar cheeks, with plate-shaped cutting inserts 9 on its milling cutter periphery 7 in the peripheral direction 8 on its left and right sides, characterized by the fact that each of the cutting inserts 9 with its cover face 10 containing the chip faces 17 , 18 is oriented essentially radially with respect to the axis of the milling cutter, and each shapes one-half of the crankshaft journal 2 with its neighboring oil collar cheeks 3 and 4 respectively as well as the recesses 5 and 6 respectively, whereby these cutting inserts 9 are located on the periphery 7 of the milling cutter, are separated from one another on each side of the milling cutter by one space 12 , and are offset with respect to one another on the two sides of the milling cutter by one-half space.
Another feature of the invention resides broadly in the disk milling cutter characterized by the fact that each of the cutting inserts 9 is an indexable insert with at least two cutting edges 15 , 16 on the same side of the milling cutter that can be brought into the cutting position one after the other and that each cutting insert 9 is shaped and indexable so that it can be used on the same disk milling cutter 1 both on its left side as well as on its right side.
Yet another feature of the invention resides broadly in the indexable insert for use on a disk milling cutter, in particular characterized by the shape of approximately a cuboid with approximately rhombus-shaped or rhomboid cover faces 10 which contain the chip faces 17 , 18 , with two carrier lugs 22 , 23 diagonally opposite each other, and each with a recessing cutting edge 24 , 25 for the recess 5 or 6 ,
whereby the carrier lugs 22 , 23 are each an extension of cover face sides that are opposite each other and each of which forms a cutting edge 20 , 21 ,
whereby both carrier lugs 22 , 23 extend over a portion of the other cutting edges 15 , 16 associated with the same cover face 10 , each of which cutting edges 15 , 16 forms a diameter cutting edge 28 , 29 , and
whereby the carrier lugs 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 are hollowed out or have a trough on-their outer flanks 36 , 37 to form clearance or tool faces with a positive clearance or tool angle.
Still another feature of the invention resides broadly in the indexable cutting insert characterized by a trough 38 , 39 with a V-shaped cross section with the point of the V 40 lying approximately in the center plane of the cutting insert 9 .
A further feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the depth of the troughs 38 , 39 decreases steadily toward the center of the cutting insert.
Another feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the troughs 38 , 39 extend to the center of the outer edge 36 , 37 of a cutting insert 9 that supports them.
Yet another feature of the invention resides broadly in the indexable cutting insert characterized by a V-shape of the troughs 38 , 39 which, when the cutting insert flanks 36 , 37 are viewed from overhead, opens toward the carrier lug 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 .
Still another feature of the invention resides broadly in the indexable cutting insert characterized by at least one additional trough 41 , 42 that runs at an angle 43 with respect to the trough 38 , 39 that lies behind it, extends under the carrier lug 22 , 23 and tapers in its clearance or tool face.
A further feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the clearance or tool faces 32 of the cutting inserts 9 form a right angle with the cover faces 10 or with the chip faces 17 , 18 .
Another feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the carrier lug 22 , 23 with the recessing cutting edge 24 , 25 is stepped with respect to the adjacent diameter cutting edge 28 , 29 .
Yet another feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the diameter cutting edges 28 , 29 and/or the recessing cutting edges 24 , 25 are-provided with a chip forming shoulder 33 , 35 to form positive cuts.
Still another feature of the invention resides broadly in the indexable cutting insert characterized by a trough-shaped cross section of the chip forming shoulder 33 , 35 .
A further feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the trough-shaped chip forming shoulders 35 of the diameter cutting edges 28 , 29 project inward into the vicinity of the carrier lugs 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 .
Another feature of the invention resides broadly in the indexable cutting insert characterized by the fact that the diameter cutting edges 28 , 29 lie lower in the direction of the main cutting pressure than the recessing cutting edges 24 , 25 or 26 , 27 .
Yet another feature of the invention resides broadly in the cutting insert characterized by the fact that the diameter cutting edges 28 , 29 are positive and the recess cutting edges 24 , 25 are negative.
One feature of the invention resides broadly in the disk milling cutter 1 equipped with cutting inserts for the milling of a crankshaft journal 2 that can be done in a single feed motion, together with the two oil collar cheeks 3 , 4 associated with it, and together with recesses 5 , 6 that act as oil grooves between them,
which milling disk cutter 1 carries on its periphery 7 , alternating in the peripheral direction 8 on its left side and on its right side, plate-shaped cutting inserts 9 , which are oriented with their cover faces 10 which contain the chip faces essentially radially with respect to the milling cutter axis,
characterized by the fact
that the cutting inserts 9 are located on the periphery of the milling cutter 1 with a spacing 12 that is so close or tight that the length 13 of the arc of contact between the beginning of cut and the end of cut of a cutting insert 9 on the workpiece 2 is greater than one-half of the spacing 14 of the layout of the cutting inserts 9 on the periphery of the milling cutter 1 .
Another feature of the invention resides broadly in the disk milling cutter,
characterized by the fact
that the cutting inserts 9 are indexable inserts with at least two cutting edges 15 , 16 on the same side of the milling cutter that can be brought into the cutting position one after the other,
that each cutting insert 9 is provided with a peripheral contour of its cover faces 10 which contain the chip faces, such that a cutting insert 9 always shapes one-half of the crankshaft journal 2 with its neighboring oil collar cheek 3 or 4 and the recess 5 or 6 in between, and
that each cutting insert 9 is shaped and indexable so that it can be used on the same disk milling cutter 1 both on its left side as well as on its right side.
Yet another indexable insert for use on a disk milling cutter, in particular,
characterized by
the shape of approximately a cuboid with approximately rhombus-shaped or rhomboid cover faces 10 which contain the chip faces 17 , 18 , of which preferably the cutting insert corners standing in the direction of the longer rhombus diagonal 19 each have, as an extension of two facing cover faces sides each forming a cutting edge 20 , 21 , have a lug-shaped projection as a carrier of the recessing cutting edge 24 , 25 to shape the recess 5 , 6 , whereby both lugs extend with their width beyond a portion of the two other cutting edges 15 , 16 associated with the same cover face 10 and each forming a diameter cutting edge 28 , 29 or 30 , 31 .
Still another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the clearance or tool faces 32 of the cutting inserts 9 form a right angle with the cover faces 10 or with the chip faces 17 , 18 .
A further feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the carrier lug 22 , 23 with the recessing cutting edge 24 , 25 or 26 , 27 is stepped with respect to the adjacent diameter cutting edge 28 , 29 or 30 , 31 .
Another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the diameter cutting edges 28 , 29 or 30 , 31 and/or the recessing cutting edges 24 , 25 or 26 , 27 are provided with a chip forming shoulder 33 to form positive cuts.
Yet another feature of the invention resides broadly in the cutting insert,
characterized by
a trough-shaped cross section of the chip forming shoulder 33 .
Still another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that only the diameter cutting edges 28 , 29 or 30 , 31 are positive, but the recessing cutting edges 24 , 25 or 26 , 27 are negative.
A further feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the trough-shaped chip forming shoulders 35 of the diameter cutting edges 28 , 29 or 30 , 31 project inward into the vicinity of the carrier lugs 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 .
Another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the diameter cutting edges 28 , 29 or 30 , 31 lie lower in the direction of the main cutting pressure than the recessing cutting edges 24 , 25 or 26 , 27 .
Yet another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the carrier lugs 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 are hollowed out or have a trough on their outer flanks 36 , 37 to form clearance or tool faces with a positive clearance or tool angle.
Still another feature of the invention resides broadly in the cutting insert,
characterized by
a trough 38 , 39 with a V-shaped cross section with the point of the V 40 lying approximately in the center plane of the cutting insert 9 .
A further feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the depth of the troughs 38 , 39 decreases steadily toward the center of the cutting insert.
Another feature of the invention resides broadly in the cutting insert,
characterized by the fact
that the troughs 38 , 39 extend to the center of the outer edge 36 , 37 of a cutting insert 9 that supports them.
Yet another feature of the invention resides broadly in the cutting insert,
characterized by
a V-shape of the troughs 38 , 39 which, when the cutting insert flanks 36 , 37 are viewed from overhead, opens toward the carrier lug 22 , 23 of the recessing cutting edges 24 , 25 or 26 , 27 .
Still another feature of the invention resides broadly in the cutting insert,
characterized by
at least one additional trough 41 , 42 that runs at an angle 43 with respect to the trough 38 , 39 that lies behind it, extends under the carrier lug 22 , 23 and tapers in its clearance or tool face.
A further feature of the invention resides broadly in a method for milling with a disk milling cutter a crankshaft journal including the two oil collar cheeks associated with it, as well as the recesses that act as oil grooves between the oil collar cheeks, which disk milling cutter having plate-shaped cutting inserts on its milling cutter periphery disposed in the peripheral direction on its left and right sides, said method comprising the steps of: measuring a diameter of the crankshaft journal; determining a desired depth of the milling cuts for the crankshaft journal; determining a diameter of the disk milling cutter relative to the diameter of the crankshaft journal and the desired depth of the milling cuts; positioning the cutting inserts on the periphery of the disk milling cutter; said step of positioning the cutting inserts further comprising: positioning the cutting inserts radially with respect to the axis of the disk milling cutter; alternating the cutting inserts on the left and right sides about the periphery of the disk milling cutter in a direction of rotation of the disk milling cutter; determining a spacing between each of the cutting inserts relative to the diameter of the crankshaft journal, the desired depth of the cut, and the diameter of the disk milling cutter; positioning the cutting inserts with the spacing between each of the cutting inserts located on the right side of the periphery of the disk milling cutter; positioning the cutting inserts with the spacing between each of the cutting inserts located on the left side of the periphery of the disk milling cutter; and positioning the cutting inserts so that the spacing between each alternating left-side and right-side cutting insert is one half the distance of the spacing between adjacent cutting inserts on the left side or the right side; rotating the disk milling cutter and the crankshaft in the same direction of rotation; engaging the crankshaft with a first cutting insert upon rotation of the disk milling cutter, said step of engaging the crankshaft with the first cutting insert comprising: contacting the crankshaft to cut said crankshaft by applying a cutting load force to said crankshaft; engaging the crankshaft over a predetermined arc of rotation, which arc of rotation is greater in length than the length of one-half of the spacing; and disengaging from the crankshaft upon completion of the arc of rotation; engaging the crankshaft with a second cutting insert, which cutting insert follows the first cutting insert in the direction of rotation of the disk milling cutter, said step of engaging the crankshaft with the second insert comprising: contacting the crankshaft to cut said crankshaft by applying a cutting load force to said crankshaft; engaging the crankshaft over a predetermined arc of rotation, which arc of rotation is greater in length than the length of one-half of the spacing; and disengaging from the crankshaft upon completion of the arc of rotation; said step of engaging the crankshaft with the second cutting insert begins as the first cutting insert begins disengaging from said crankshaft, whereby the cutting load force applied by the second cutting insert during engagement increases at a rate substantially equivalent to the rate at which the cutting load force applied by the first cutting insert decreases during disengagement; and applying a substantially constant cutting load force throughout the milling process to produce milling cuts having the desired depth in the crankshaft.
Some examples of milling cutters and components thereof which may be utilized or adapted for use in at least one embodiment of the present invention may be found in the following U.S. Pat. No. 5,454,671, issued on Oct. 3, 1995 to inventor Qvarth; No. 5,071,291, issued on Dec. 10, 1991 to inventor Kaminski; No. 4,488,839, issued on Dec. 18, 1984 to inventors Wermeister, et al.; No. 6,004,080, issued on Dec. 21, 1999 to inventors Qvarth, et al.; No. 5,810,517, issued on Sep. 22, 1998 to inventor Bostic; No. 5,593,255, issued on Jan. 14, 1997 to inventors Satran, et al.; No. 4,285,618, issued on Aug. 25, 1981 to inventor Shanley, Jr.; No. 5,984,599, issued on Nov. 16, 1999 to inventor Janssen; No. 5,707,187, issued on Jan. 13, 1998 to inventor Arnold; No. 5,551,814, issued on Sep. 3, 1996 to inventor Hazama; No. 4,444,533, issued on Apr. 24, 1984 to inventors Riley, et al.; and No. 4,326,323, issued on Apr. 27, 1982 to inventors Kralowetz, et al.
The following patents, patent applications, or publications were cited in the International Search Report for International Patent Application No. PCT/EP98/05374, and are hereby incorporated by reference as if set forth in their entirety herein: International Application WO 96/39269; European Application EP 0 156 780 A; and Federal Republic of Germany Application DE 195 19 951.
The components disclosed in the various publications, disclosed or incorporated by reference herein, may be used in the embodiments of the present invention, as well as, equivalents thereof.
The appended drawings in their entirety, including all dimensions, proportions and/or shapes in at least one embodiment of the invention, are accurate and to scale and are hereby included by reference into this specification.
All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein.
All of the patents, patent applications and publications recited herein, and in the Declaration attached hereto, are hereby incorporated by reference as if set forth in their entirety herein.
The corresponding foreign and international patent publication applications, namely, Federal Republic of Germany Patent Application No. 197 39 366.7, filed on Sep. 9, 1997, having inventors Gebhard Muller and Horst Jager, and DE-OS 197 39 366.7 and DE-PS 197 39 366.7 and International Application No. PCT/EP98/05374 as well as their published equivalents, and other equivalents or corresponding applications, if any, in corresponding cases in the Federal Republic of Germany and elsewhere, and the references cited in any of the documents cited herein, are hereby incorporated by reference as if set forth in their entirety herein.
The details in the patents, patent applications and publications may be considered to be incorporable, at applicant's option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention. | A side milling cutter with cutting inserts, by which side milling cutter a crank pin can be cut with a single feed motion. The plate-shaped cutting inserts are arranged on the periphery of the side milling cutter alternating between the left and right side in a peripheral direction, and are oriented essentially radially with their cover surfaces in relation to the cutter axis, which cover surfaces contain the tool faces. The cutting inserts are also arranged so as to form a gap on the periphery of the cutter which is so narrow that the length of the arc of action between the point of entry and the point of exit of cutting is greater than the half of the gap of the arrangement of cutting inserts on the periphery of the cutter. The present invention also relates to the configuration of the cutting inserts as indexable inserts which can be used on the left and on the right. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present utility application claims priority and is related to U.S. Provisional Application Ser. No. 60/719,560, filed September 23, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method and system for runtime dynamic management of running applications and the communications among them. Specifically, the present invention relates to the graphical presentation of instantiated objects and the creation of connections among them, at the selection of the user, while the instantiated objects are running.
[0004] 2. Background of the Related Art
[0005] One problem in the software industry today is that it is not practicable to provide dynamic common access and/or a dynamic common interface to source code programs authored by different software developers, while the programs are running. Traditionally, software has been created by programmers as a finite solution for end users. User-specified customization or other changes in the original software typically require the changes to be made in the source code by a software developer, reassembly and recompilation of the software, and redistribution of the customized program to the end user. Any such customization requires at least the following: (a) involvement by a skilled and trained software developer; (b) recompilation of the software; and (c) interruption in program execution.
[0006] There are known in the art methods and systems that enable an end user, rather than a software developer, to perform software customization. For example, graphical or iconic programming languages (also known as “environments”) permit an end user, through manipulation of a graphical diagram, to instruct a system to create and/or generate software code of behalf of the user, thus requiring little low level text-based programming experience. Examples of such graphical programming environments include Visual Basic, Delphi, Vee, LabView and DT Measure Foundry, including Visual Basic—made by Microsoft® Corporation of Redmond, Wash., Delphi—made by Borland—Software Corporation of Cupertino, Calif., Vee—made by Agilent Technologies, Inc., of Palo Alto, Calif., LabVIEW—made by National Instruments® Corporation of Austin, Tex., and DTMauseure Foundry—made by Data Translation®, Inc., of Marlboro, Mass., among others. All of these environments, however, require at least two modes: a development mode and a runtime mode, during which the developed and assembled program is compiled for loading and running (e.g., on a computer operating system, micro device, instrument, embedded hardware, virtual device or virtual operating system). Thus, while these graphical environments purport to allow end users to perform customization of existing programs by in essence providing a substitute for a trained software developer, they fail to avoid the necessity for pre-runtime recompilation of software upon making changes, and for program execution interruption to make the changes and recompile the program.
[0007] An additional shortcoming of these graphical programming environments is that they are not attractive to traditional software developers, being typically limited by pre-defined graphical representations of instructions. Furthermore, while these environments purport to allow end users to create complete solutions, these solutions are frequently inefficient. In addition, such environments require end users to learn some traditional programming constructs, such as loops, conditionals, and variables, among others. Moreover, all graphical programming environments involve creation of software code in the background, on behalf of the end user, without permitting the end user to take advantage of the actual knowledge, experience and skill of trained software developers in resolving a particular problem.
[0008] Other shortcomings of known graphical software environments include the fact that most graphical languages are proprietary and require translation from an existing algorithm to a specific iconic language implementation. Also, making changes to a program typically requires switching from a runtime mode for execution of the program, to a development mode for manipulation of the program flow, and vice versa. In addition, any program in a runtime mode must be terminated prior to switching to the development and assembly mode to make changes in the software.
[0009] There is a general need in the art, therefore, for methods and systems that provide dynamic common access and/or a dynamic common interface to source code programs authored by different programmers at runtime. There is a further need in the art for methods and systems that enable making changes to existing software programs without the need for recompilation. There is yet a further need for methods and systems that enable making changes to existing running software solutions without the need for interrupting the execution of the software. Finally, there is a need in the art for methods and systems that permit end users to take advantage of the skills of software developers in resolving specific problems by combining different available software applications, while the software applications are in a state of execution, thereby providing an attractive solution to beginners and skilled software developers alike.
SUMMARY OF THE INVENTION
[0010] The present invention solves the above identified needs, and others, by providing a method and system for runtime dynamic management of running applications and the communications among them. The present invention permits runtime dynamic assembly of running applications by providing graphical representations of the running software applications in, e.g., block form, and dynamically connecting the blocks in a block diagram, each application being instantiated into a running object upon inclusion in the diagram. One of ordinary skill in the art will appreciate, however, that the graphical representation of compiled software applications may, besides in block form, be represented in any shape, form, or visual element.
[0011] Embodiments of the method and system of the present invention provide dynamic common access and/or a dynamic common interface to source code programs authored by different programmers at runtime. In addition, embodiments of the present invention enable making changes to, including adding and subtracting, existing software applications without the need for recompilation of the code. Further, embodiments of the present invention enable making changes to existing running software solutions without the need for interrupting the execution of the software. Moreover, embodiments of the present invention permit end users to take advantage of the skills of software developers in resolving specific problems by combining different available software applications, while the software applications are in a state of execution.
[0012] Other objects, features, and advantages will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0013] For a more complete understanding of the present invention, the needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following description taken in connection with the accompanying drawings.
[0014] FIG. 1 presents a flow diagram of functions performed in accordance with an embodiment of the present invention.
[0015] FIGS. 2A-2P show Graphical User Interface (“GUI”) screens depicting an example scenario for the task of performing a calculator from the point of view of a user of the system, in accordance with an embodiment of the present invention.
[0016] FIGS. 3A-3G show GUI screens depicting an example scenario for the task of performing a pong game from the point of view of a user of the system, in accordance with an embodiment of the present invention.
[0017] FIGS. 4A-4B show GUI screens depicting an example scenario for the task of performing a statistical stock chart, in accordance with an embodiment of the present invention.
[0018] FIG. 5 contains a block diagram of various computer system components for use with an exemplary implementation of a system for runtime dynamic management of running applications and the communications among them, in accordance with an embodiment of the present invention.
[0019] FIG. 6 presents an exemplary system diagram of various hardware components and other features in accordance with an embodiment of the present invention.
[0020] FIG. 7 presents an example open system architecture, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0021] Preferred embodiments of the present invention and their features and advantages may be understood by referring to FIGS. 1-7 , like numerals being used for like corresponding parts in the various drawings.
[0022] In one embodiment, the system and method of the present invention for dynamic assembly of running applications and the connections among them while running, may be implemented as an Internet-based or other network-based system that allows the end user unlimited or virtually unlimited flexibility in terms of the types of compatible source code applications that may be connected to each other to form a graphical assembly of one or more instantiated objects or running blocks and the connections among them (alternatively referred to herein as a diagram, flow chart or graphical representation), and in terms of connecting functioning (previously or simultaneously created) diagrams, such as by nesting diagrams within each other and/or connecting blocks and flow charts in a number of possible ways. To facilitate the understanding of the description that follows, it is assumed that each source code application is previously compiled by its respective developer. One of ordinary skill in the art will understand, however, that such applications may be compiled at any point prior to their inclusion in a diagram as instantiated objects while running.
[0023] An example flow diagram of functions performed in accordance with an embodiment of the present invention will now be described in reference to FIG. 1 . After locating compatible classes of compiled code 110 , one embodiment of the method for dynamically managing running applications and their connections while running includes creating a list of available compiled codes 120 for inclusion into diagrams in the form of graphical blocks. It will be recognized by those skilled in the art that the compiled code may be supplied from or in any device or system capable of supplying compiled code, such as a network (e.g., the Internet), a server, or any local, wired or wireless storage medium. It will also be recognized by those skilled in the art that a class is a definition of an object, and is made up of the software code. To use an object, a user must instantiate an instance of the class. Therefore, if 50 television objects are needed, 50 instances of the television class should be provided. Each of the 50 instances is created by instantiation. According to accepted terminology in the art, to reduce ambiguity, classes are “created,” while objects are “instantiated.” Class creation is performed at design time when the software is being built, and involves writing the actual software code. Objects are instantiated at runtime when the program is being used. See, e.g., Thearon Willis, Jonathan Crossland & Richard Blair, Beginning VB.NET 2003 327 (Wiley Publishing, Inc.) (2004).
[0024] Referring now to FIG. 1 , upon creation of a list of available compiled codes 120 , a user (e.g., an “end user”) defines one or more tasks to be performed by one or more diagrams 130 to be created through any combination of the available compiled codes (interchangeably referred to herein as “blocks”).
[0025] One or more compatible classes from compiled code or blocks are then selected from the list for inclusion into the diagram 140 . Upon selection and inclusion of each block into the diagram, the block is instantiated into an object and begins to execute 150 . Graphical connections may then be created between/among the instantiated blocks, whereupon communications are established between/among the instantiated blocks 160 , while the blocks are executing. It will be recognized by those skilled in the art that the graphical connections may be created by any available user input device, such as a keyboard or mouse. It will also be recognized by those of ordinary skill in the art that communications among the instantiated objects may be established by creating one or more references among the objects, such as execution address pointers. Further, references may be established among diagrams, if one or more diagrams are being connected to complete a task, or may be brokered by a first instantiated object to facilitate an indirect connection between a second and a third instantiated objects.
[0026] In one embodiment, upon creating the graphical connections among instantiated objects to establish communication 160 , the method of the present invention is complete, if the task to be performed by the diagram has been completed 190 and the user does not wish to save 195 the current diagram configuration, or saves the configuration 185 , but does not wish to reload it 170 . Furthermore, the diagram and connections may be saved in XML format, or in any other format capable of storing the type of data represented by the objects and connections. The instantiated objects may be saved, for example, as instance identifiers, such as Globally Unique Identifiers (“GUID”). The graphical connections may be saved as connector names, defined by the instance identifiers of the saved instantiated objects. It will be appreciated by those of ordinary skill in the art that the references may be stored by each connected instantiated object or by one of the connected objects, depending on the type of the connection (e.g., one-to-one, one-to-many, many-to-one or many-to-many).
[0027] If the task to be performed by the diagram is not complete 190 and does not have to be re-defined 180 , in one embodiment, the method of the present invention continues with selecting blocks for inclusion in the diagram 140 . In one embodiment, if the task needs to be re-defined 180 , the method of the present invention continues with defining the tasks to be performed by the diagram 130 . As the diagram is being constructed by instantiating blocks 150 and creating the graphical connections to establish communication among the instantiated blocks 160 , the corresponding phase of the task to be performed by the diagram, if capable of being visually represented, may be made displayed on, e.g., a computer monitor, printed out, captured as a series of images, or made available by any other means to the end user.
[0028] To further illustrate the operation of system of the present invention for dynamic assembly of running applications and the communications among them while running, an example scenario will now be described from the point of view of a user of the system, in reference to the GUI screens shown in FIGS. 2A-2P . In the example scenario of this embodiment, the user-defined task to be performed by a diagram is a selected function performed by a calculator.
[0029] Referring now to FIG. 2A , shown therein are two exemplary windows, a first window 202 , for dynamically creating and displaying a diagram or flow chart, and a second window 201 , for dynamically displaying the output 203 of the diagram as it is being created. In this embodiment, upon clicking the mouse or otherwise making a selection, represented by indicator 204 in the flow chart window 202 , a block selection option 205 appears in flow chart window 202 , as shown in FIG. 2B . Upon selecting the “Select Block” option 206 , a third window 209 appears on the screen, containing a list 207 of available blocks (compatible classes of compiled code) for inclusion into a diagram, as shown in FIG. 2C . It will be recognized by those skilled in the art that the blocks may be categorized or grouped according to relevant factors, so that only certain categories or groups of blocks are displayed in list 207 . In the example scenario shown in FIGS. 2A-2P , the list of available blocks 207 represents available compiled codes corresponding to different functions that a calculator performs, e.g., addition, subtraction, multiplication and square root, among others.
[0030] Upon scrolling down the list of available blocks 207 , a graphical representation of each block 208 is shown in window 209 . Assuming that the task to be performed by the diagram is addition, for example, the user may select the “Add” block 208 from list 207 (e.g., by clicking on it with a mouse), upon which the “Add” block 208 is instantiated as an object 210 , as shown in FIG. 2D . The output of instantiated (alternatively referred to herein as “running” or “executing”) object 210 , shown in the flow chart window 202 of FIG. 2D , is connected to the diagram output 203 . It should be noted that, consistent with its function, instantiated “Add” object 210 has two inputs and one output. As shown in FIG. 2D , the two inputs are for integer numbers; however, the number format may be changed by the user if the author of “Add” block 208 has provided that the type of inputs to block 208 may be changed to different number formats.
[0031] As shown in FIG. 2E , upon graphically connecting (e.g., by using a mouse) the two inputs of instantiated object 210 to blocks 211 and 212 that provide numbers, each containing a value of 0.00, the diagram output 203 , as displayed in data display window 201 , is 0 (zero). When the inputs into running object 210 are changed to 3.00 and 2.00, as shown by blocks 211 and 212 , respectively in FIG. 2F , the diagram output 203 immediately changes value to 5, as shown in data display window 201 of FIG. 2F .
[0032] Another example of using functions performed by a calculator will now be described in reference to FIG. 2G . In this example, the user-defined task is to calculate the result of a multiplication of two numbers, a first number and the sum of a second number and the first number. In this example, upon selection of the “Multiply” block from the list of available blocks 207 (as described above in reference to FIG. 2C ), the block is instantiated into object 213 , which begins to run. Upon creating the graphical connection between the output of instantiated object 210 and one input to instantiated object 213 , and providing as a second input to instantiated block 213 the value in block 212 , the diagram output 203 is displayed in the data display window 201 , which is 10 (3.00+2.00=5.00×2.00=10), in the example shown in FIG. 2G . It should be noted that once a block is selected from the list of available blocks 207 , it is instantiated into an object and begins to run, regardless of the values (or if there are no values) on its inputs and outputs. When connections are created between blocks, the thus assembled blocks continue to run, without the necessity of compiling the assembled blocks.
[0033] The process of selecting and adding blocks to the diagram, thus instantiating them into running objects, continues until the user is satisfied that the task is completed. It bears mention that each block is instantiated into a running object while the instantiated objects that have already been included in the diagram continue to run; that is, it is not necessary to stop the execution of the connected blocks prior to adding more blocks.
[0034] For example, the user may choose to redefine the task by selecting a second “Add” block 208 from the list of available blocks 207 shown in FIG. 2C . Upon selection, the second “Add” block is added as instantiated object 214 , shown in FIG. 2H . Upon creating, for example, a graphical connection connecting the first input of object 214 with the output of object 213 , and providing as the second input of object 214 , the value of block 212 , the diagram output 203 is displayed in data display window 201 , in this case the value 12 .
[0035] FIG. 2I shows the selection of a numeric selector block 215 , and FIG. 2J shows its addition to the diagram as object 216 . In FIG. 2I , dragging so as to provide a connector to the numeric selector 215 adds an existing block 216 , which the numeric selector 215 has instantiated to the diagram, and connects block 216 to block 210 . Therefore, the block 216 is “owned by” (e.g., provides input to) the numeric selector 215 and will always provide the current value of block 216 to selector 215 .
[0036] In FIG. 2K , the value of numeric selector 215 is set to 4, and object 216 is connected to provide one input each to instantiated objects 210 and 213 . The second input into instantiated object 210 is the value of block 212 , while the second input into instantiated object 213 is the output of instantiated object 210 . The value of block 212 is provided as one input into instantiated object 214 , while the second input into instantiated object 214 is the output of instantiated object 213 . Upon creating the connections, the diagram output 203 , in this case 26 , is displayed in data display widow 201 .
[0037] FIG. 2L shows an output of 37 in data display window 201 , upon changing the value of numeric selector 215 to 5 . In FIG. 2M , no value is displayed in data display window 201 , as the connection between instantiated objects 213 and 214 is severed. As there is only one input into instantiated object 214 , the diagram does not provide an output 203 , as object 214 is waiting to receive a value on its second input.
[0038] FIG. 2N shows recreating the graphical connection between instantiated objects 213 and 214 by, for example, dragging with a mouse cursor 204 from one input of instantiated object 214 to the output of instantiated object 213 . It will be appreciated that nothing will be displayed in data display window 201 until the connection is complete, despite the fact that all objects shown in flow chart window 202 are instantiated and running. Upon completing the connection, however, a value of 50 is displayed in data display window 201 , as shown in FIG. 20 , as the value of numeric selector 215 is 6.
[0039] In one embodiment, upon establishing graphical connections among instantiated objects, references among the connected objects are established, as shown in FIG. 2P . For example, FIG. 2P shows how the connectors are defined in code. Upon creating a graphical connection, the reference provided by the output blocks simultaneously or approximately simultaneously obtains a property that is flagged to be provided, and this property is passed to the input block's set property, which has been flagged as requiring an input. A reference between the objects is thereby established.
[0040] Referring now to FIGS. 3A-3G , therein shown is an example scenario for the task of performing a pong game from the point of view of a user of the system, in accordance with an embodiment of the present invention. FIG. 3A shows a screen shot prior to initiating a diagram or flow chart, and the pong ball is immobile, as shown in data display window 201 . The diagram outputs 301 and 302 , are respectively configured to show the next position of the pong ball and the next targets. The diagram inputs 303 and 304 , are respectively configured to show the current position of the pong ball and the current targets. Upon selecting a block of code implementing a “law” to be applied (not shown), thereby instantiating this law into object 305 (here entitled “Newton's 3 rd Law,” which states that an object in motion remains in motion; in this example, when the game is started, the ball is provided an initial velocity vector, but does not move because it needs a block to make it move) and graphically connecting it as an output of Current Position input 303 and an input to Next Position output 301 , as shown in flow chart window 202 in FIG. 3B , the pong ball in display window 201 begins to move down towards the paddle.
[0041] FIGS. 3C-3G show the progressive implementation of a pong game according to this example scenario of one embodiment of the present invention. Following the principles and procedures described above, FIG. 3C introduces a paddle 306 and an Angle Paddle instantiated object 307 , which causes the pong ball to bounce off the paddle; FIG. 3D introduces Wall Collision instantiated object 308 , which causes the pong ball to bounce off the walls; FIG. 3E introduces PongBlockDestroyer instantiated object 309 , connected to the output of Current Targets input 304 and the input of Next Targets output 302 , which causes the pong ball to destroy bricks it comes into contact with (and bounce off of them), as shown in data display window 201 ; and FIGS. 3F and 3G introduce Wall Shy and Newton's 3 rd Law instantiated objects 310 and 311 , each of which respectively causes the pong ball to become accelerated/delayed by a variable factor when approaching the bottom or the walls shown in data display window 201 .
[0042] Referring now to FIGS. 4A and 4B , therein shown is an example scenario for the task of creating a statistical stock chart, in accordance with an embodiment of the present invention. FIG. 4A depicts the data display window showing variations of user-selected stocks according to user-selected criteria (e.g., minimum, maximum, average, and median values, with such values being provided once an hour, once a day, every two days, or at any selected interval). The exemplary diagram shown in flow chart window 202 in FIG. 4B causes the results displayed in the data display window 201 , shown in FIG. 4A .
[0043] The present invention may be implemented using hardware, software or a combination thereof and may be implemented in one or more computer systems or other processing systems. In one embodiment, the invention is directed toward one or more computer systems capable of carrying out the functionality described herein. An example of such a computer system 500 is shown in FIG. 5 .
[0044] Computer system 500 includes one or more processors, such as processor 504 . The processor 504 is connected to a communication infrastructure 506 (e.g., a communications bus, cross-over bar, or network). Various software embodiments are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art(s) how to implement the invention using other computer systems and/or architectures.
[0045] Computer system 500 can include a display interface 502 that forwards graphics, text, and other data from the communication infrastructure 506 (or from a frame buffer not shown) for display on the display unit 530 . Computer system 500 also includes a main memory 508 , preferably random access memory (RAM), and may also include a secondary memory 510 . The secondary memory 510 may include, for example, a hard disk drive 512 and/or a removable storage drive 514 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive 514 reads from and/or writes to a removable storage unit 518 in a well known manner. Removable storage unit 518 , represents a floppy disk, magnetic tape, optical disk, etc., which is read by and written to removable storage drive 514 . As will be appreciated, the removable storage unit 518 includes a computer usable storage medium having stored therein computer software and/or data.
[0046] In alternative embodiments, secondary memory 510 may include other similar devices for allowing computer programs or other instructions to be loaded into computer system 500 . Such devices may include, for example, a removable storage unit 522 and an interface 520 . Examples of such may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an erasable programmable read only memory (EPROM), or programmable read only memory (PROM)) and associated socket, and other removable storage units 522 and interfaces 520 , which allow software and data to be transferred from the removable storage unit 522 to computer system 500 .
[0047] Computer system 500 may also include a communications interface 524 . Communications interface 524 allows software and data to be transferred between computer system 500 and external devices. Examples of communications interface 524 may include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. Software and data transferred via communications interface 524 are in the form of signals 528 , which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface 524 . These signals 528 are provided to communications interface 524 via a communications path (e.g., channel) 526 . This path 526 carries signals 528 and may be implemented using wire or cable, fiber optics, a telephone line, a cellular link, a radio frequency (RF) link and/or other communications channels. In this document, the terms “computer program medium” and “computer usable medium” are used to refer generally to media such as a removable storage drive 514 , a hard disk installed in hard disk drive 512 , and signals 528 . These computer program products provide software to the computer system 500 . The invention is directed to such computer program products.
[0048] Computer programs (also referred to as computer control logic) are stored in main memory 508 and/or secondary memory 510 . Computer programs may also be received via communications interface 524 . Such computer programs, when executed, enable the computer system 500 to perform the features of the present invention, as discussed herein. In particular, the computer programs, when executed, enable the processor 504 to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system 500 .
[0049] In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 500 using removable storage drive 514 , hard drive 512 , or communications interface 524 . The control logic (software), when executed by the processor 504 , causes the processor 504 to perform the functions of the invention as described herein. In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components, such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s).
[0050] In yet another embodiment, the invention is implemented using a combination of both hardware and software.
[0051] FIG. 6 presents an exemplary system diagram of various hardware components and other features in accordance with an embodiment of the present invention. As shown in FIG. 6 , in an embodiment of the present invention, each source code author 630 , 639 and 640 creates a stand alone source code application, and makes it available, via network 634 , to user 643 . User 643 , via the system of the present invention residing on terminal 644 , creates a flow chart by connecting the source codes provided by users 630 , 639 and 640 . The terminal 644 is coupled to a server 633 , on which portions of the data used by the created flow chart are stored, via a network 634 , such as the Internet, via couplings 635 , 636 .
[0052] Each of the terminals 631 , 637 , 641 , 644 is, for example, a personal computer (PC), minicomputer, mainframe computer, microcomputer, telephone device, personal digital assistant (PDA), or other device having a processor and input capability. The terminal 631 is coupled to a server 633 , such as a PC, minicomputer, mainframe computer, microcomputer, or other device having a processor and a repository for data or connection to a repository for maintained data.
[0053] In one exemplary embodiment, the system for dynamic assembly of running applications and the connections among them while running may be implemented, for example, as a Microsoft.net® desktop application program (Microsoft.net® is made by Microsoft® Corporation of Redmond, Wash.), which may reside on a computer hard drive, database or other repository of data, or be uploaded from the Internet or other network (e.g., from a personal computer (PC), minicomputer, mainframe computer, microcomputer, telephone device, personal digital assistant (PDA), or other device having a processor and input capability). It will be recognized by those skilled in the art, however, that any available software tool capable of implementing the concepts described herein may be used to implement the system and method of the present invention.
[0054] One embodiment of the present invention is based on an open system architecture 700 , as shown in FIG. 7 . In this embodiment, the system for dynamic assembly of running applications and the connections among them while running includes an Available Code/Block List module 710 , a Task Diagram module 720 , and a Runtime Memory module 730 . After identifying a task to be performed, a user selects the blocks needed to complete the task, instantiates these blocks into running objects 740 . . . 750 in Running Memory module 730 , while adding them to Task Diagram Module 720 and creating graphical connections to enable communications among the instantiated objects to complete the task while the objects are running, and without causing interruption in program execution.
[0055] In one embodiment, the end user of the method and system of the present invention may be the ultimate consumer of data created as a result of the functioning of the system, such as a data analyst. An end user of the system, in another embodiment, may be a programmer, who creates flow charts based on the blocks that are available to the system. In yet another embodiment, the end user may be a user that provides the data to the system of the present invention, to be processed and manipulated by others. Those of ordinary skill in the art will appreciate the unlimited spectrum of end users of the system and method of the present invention.
[0056] While the present invention has been described in connection with preferred embodiments, it will be understood by those skilled in the art that variations and modifications of the preferred embodiments described above may be made without departing from the scope of the invention. Other embodiments will be apparent to those skilled in the art from a consideration of the specification or from a practice of the invention disclosed herein. It is intended that the specification and the described examples are considered exemplary only, with the true scope of the invention indicated by the following claims. | A method and system for dynamic management of running applications and the communications among them at runtime. Runtime dynamic assembly of running applications is achieved by providing graphical representations of the running software applications in block form, and dynamically connecting the blocks into a flow chart, each application being instantiated into a running object upon inclusion in the flow chart. The method and system of the present invention provide dynamic common access and/or a dynamic common interface to source code programs authored by different programmers at runtime, while enabling changing of existing software applications without the need for recompilation of the code. Further, the method and system of the present invention enable changing of existing running software solutions without the need for interrupting the execution of the software. | 6 |
BACKGROUND OF THE INVENTION
The invention described herein is generally related to electrical lighting apparatus, and more specifically is related to decorative electrical lighting devices which simulate candles or other natural flames.
It has previously been known to provide decorative electrical lighting devices which automatically switch on and off in a manner intended to simulate a flickering flame. Various electrical circuits and electromechanical means have been used to achieve this effect in a simplified form. However, the characteristic appearance of a natural flame arises from certain illumination intensity variations and gas turbulence effects which are not easily reproduced in simple lighting devices of the type previously known. To some extent these effects have been sought to be reproduced in multi-filament light bulbs which flicker on and off in various ways. However, there has not been previously available a lighting apparatus containing multiple lighting elements which flicker in a manner that realistically simulates both the gas turbulence and the illumination intensity distribution that are characteristic of a burning flame.
Accordingly, it is the object and purpose of the present invention to provide an improved electrical lighting apparatus for simulating a natural flame.
It is a more specific object of the present invention to provide a lighting apparatus which simulates both the turbulent gas flow and the illumination intensity distribution of a natural flame, particularly a candle flame.
It is another object of the present invention to provide a lighting apparatus which includes, in a single bulb unit, multiple lighting elements which are arranged and independently actuated to switch on and off in a random manner which simulates both the gas turbulence and illumination intensity distribution of a natural flame.
It is also an object of the present invention to provide digitally controlled electronic circuitry to drive the multiple lighting elements of the above-mentioned lighting apparatus.
SUMMARY OF THE INVENTION
The foregoing as well as other objects and purposes are attained in the lighting apparatus of the present invention, which includes a bulb assembly consisting of a plurality of vertically spaced electric lamps which are preferably enclosed in a suitable translucent bulb having the general shape of a natural flame. Each lamp is actuated under the control of a control signal which turns the lamp on and off in a pseudo-random manner described further below. The control signals are generated by a control signal generator circuit which produces a different control signal for each lamp. The control signals applied to the lamps are different in certain characteristics which result in the assembly of lamps simulating both the illumination intensity distribution and the gas turbulence of a natural flame. The illumination intensity distribution is obtained by varying the control signals such that the average proportion of time during which the lamps are actuated increases toward the lowermost of the lamps. This results in the average illumination intensity increasing toward the base of the assembly, just as the average illumination intensity increases toward the base of a natural flame where the combustion rate is greatest. At the same time, the control signals are also varied so as to randomly and intermittently turn the lamps off for periods of time which are of varying frequency and duration, but which, on the average, are of progressively increasing duration toward the top of the assembly. This results in a flickering effect which is more pronounced toward the top of the assembly, just as the flickering of a natural flame is more pronounced toward the top of the flame where the gas turbulence is greatest.
In the preferred embodiment, and in accordance with other aspects of the invention, the control signals are generated in part by means of a multi-stage static shift register which is employed in a feedback mode to produce a pseudo-random pulse train of suitable average frequency and pulse width. The shift register is tapped at several stages, corresponding to the number of lamps in the assembly, so as to produce a set of pulse trains which are delayed with respect to one another, and which are used to form the control signals for the lamps. In the preferred embodiment, one of the pulse trains is used directly to control the uppermost lamp of the assembly. The other pulse trains are combined with a set of assymetric clock signals having progressively increasing duty cycles so as to produce a set of control signals that are biased toward progressively increasing average duty cycle duration, yet which retain an element of randomness as a result of the pseudo-random pulse train component. The latter control signals are applied to other lamps of the assembly, with the control signals having the longest average duty cycle duration being applied respectively to the lowest lamps in the assembly.
These and other aspects of the present invention will be more apparent upon consideration of the following detailed description and accompanying drawings of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated in and constitute a part of the specification. The drawings illustrate various aspects of a preferred embodiment of the invention, and are provided for the purpose of accompanying the following detailed description of the invention and its operation. In the drawings:
FIG. 1 is a pictorial illustration of an electronic candle made in accordance with the present invention;
FIG. 2 is a schematic electrical circuit diagram of the internal circuitry used to drive the lamps of the electronic candle; and
FIG. 3 is a timing diagram illustrating the nature of the control signals which drive the lamps of the candle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention illustrated in the Figures and described in detail below is the best mode of the invention contemplated by the inventor and is described for the purpose of enabling one of ordinary skill in the art to make and use the invention.
Referring to FIG. 1, the electronic candle includes a generally tubular housing 10 which is designed to resemble a candle and which encloses all of the electronic circuitry described below and illustrated schematically in FIG. 2. Atop the housing 10 is a hollow translucent bulb 12 having an elongated free-form shape generally resembling that of a candle flame. The bulb 12 encloses three lamps 14, 16 and 18. The lamps 14, 16 and 18 are positioned in a spaced-apart vertical arrangement, with the the lamp 14 being near the base of the bulb 12, lamp 16 being near the middle, and lamp 18 being near the upper tip of the bulb 12. As discussed below, the three lamps are driven by the electronic circuitry so as to flicker on and off in a manner which simulates both the gas turbulence and the illumination intensity distribution of a natural candle flame.
The circuitry described below and illustrated in FIG. 2 is driven by a 6-volt dc power supply which may be of any suitable configuration. All of the circuitry shown in FIG. 2 can be conveniently incorporated on a printed circuit board approximately 1×1.5 inches in dimension, using commercially available miniature integrated circuits, thereby enabling the circuitry to be completely contained in a candle such as that shown in FIG. 1.
Referring to FIG. 2, the circuitry that drives the lamps 14, 16 and 18 includes a clock circuit 20 which consists of two exclusive OR gates 22 and 24, two 330 kilohm resistors 26 and 28, two 0.1 microfarad capacitors 30 and 32, and a 180 kilohm resistor 34. These components are arranged in the manner of an assymetrical multivibrator to provide two clock signals, which are discussed below. The exclusive OR gates 22 and 24 are embodied as two gates (accessed by pins 1 through 6, as indicated in FIG. 2) of a four-gate integrated circuit (IC) which is identified in the industry by the designation CD4070B and which is commercially available from a number of major electronics manufacturers. The third and fourth gates of the IC are utilized in a start-up circuit described below.
The gate 22, resistor 26, and capacitor 30 operate to produce an approximately 40 Hz clock signal at the output of the gate 22, which is pin 4 of the CD4070B IC. The gate 24, resistor 28 and capacitor 32 likewise operate to produce a 40 Hz clock signal at the output of the gate 24, which is pin 3 of the IC. The resistor 34 operates to render each of the clock signals assymetrical. More specifically, the output of gate 22 is a long-duty-cycle clock signal, having a duty cycle of approximately 75 percent, and the output from gate 24 is a short-duty-cycle clock signal, having a duty cycle of approximately 25 percent. These clock signals are illustrated in the timing diagrams of FIGS. 3(c)(i) and 3(b)(i), respectively, and are further discussed below. The long- and short-duty-cycle clock signals are applied in the manner described below to control both the periodicity and intensity of illumination of the three lamps 14, 16 and 18.
The circuitry of FIG. 2 further includes an 18-stage static shift register (or delay line) 36, which is embodied in a commercially available integrated circuit identified in the industry by the designation CD4006B. The shift register 36 operates at the 40 Hz frequency of the clock circuit 20, with the short-duty-cycle clock signal from clock gate 24 being applied to the clock input (pin 3 of the CD4006B IC) of the shift register.
The shift register receives as an input a signal (high or low logic state) on input pin 1 and produces output pulse trains on pins 8, 10 and 13. The pulse train emitted at pin 8 represents a 17-stage delay tap; the pulse train emitted at pin 10 represents a 13-stage delay tap; and the pulse train at pin 13 represents a 4-stage delay tap. Thus, a signal (high or low) applied at pin 1 is emitted at pin 8 after a period of 17 clock cycles (approximately half a second); and is emitted at pin 10 after 13 clock cycles; and is emitted at pin 13 after 4 clock cycles.
The input signal that is applied to pin 1 of the shift register 36 is generated by a feedback-controlled start-up circuit 38, which consists of a pair of exclusive OR gates 40 and 42, a one-megohm resistor 44, and a 0.1 microfarad capacitor 46. The OR gates 40 and 42 are embodied in the four-gate CD4070B integrated circuit described above with reference to the clock circuit 20, and are accessed through pins 8 through 13 of the IC.
The OR gate 40 receives as one input the constant +6 volt power supply signal (at pin 13) and as its other input the pulse train (at pin 12) from the 13-stage tap of the shift register 36 (pin 10 of the shift register). The output of the OR gate 40 is applied through the one-megohm resistor 44 to the input pin 1 of the shift register. The OR gate 42 receives as inputs the pulse trains from the 17-stage tap (pin 8) and the 13 stage tap (pin 10) of the shift register 36. The output of the OR gate 42 is applied through the 0.1 microfarad capacitor 46 to the input pin 1 of the shift register 36. In this manner, the logical outputs of the gates 40 and 42 are summed to produce the input signal to the shift register.
The start-up circuit 38 serves three purposes. First, it provides an initial start-up signal to the shift register when the system is turned on. Secondly, it functions as a pseudo-random signal generator to apply a pseudo-random pulse train to the input of the shift register. Finally, the start-up circuit ensures that, in the event the output signals from the 17- and 13-stage taps of the shift register are both low, the input signal to the shift register does not go low and stay low. More specifically with regard to the latter function, if the outputs of the 17- and 13-stage taps are both low, the combination of the OR gates 40 and 42 operates to provide a high signal to the input of the shift register 36, thereby preventing the shift register outputs from thereafter remaining low.
It will be recognized that the output pulse trains from the 4-, 13- and 17-stage taps of the shift register 36 are identical in their respective random sequences of logical high and low logic states, but are delayed with respect to one another by constant periods of time which are represented by the different delay times of the taps. The output of each tap consists of a pseudo-random pulse train of logical high and low signals, with the signals changing in a random fashion between high and low at the clock frequency of approximately 40 Hz.
The output of the 17-stage tap at pin 8 is applied through a 3-kilohm resistor 48 to the base of an npn switching transistor 50, which may be a PN3642 transistor. The emitter of the transistor 50 is grounded and the collector is connected through a 10-ohm resistor 52 to the upper candle lamp 18. Thus, the upper lamp 18, representing the tip of the candle flame, is turned randomly on and off under the control of the pseudo-random output pulse train from the 17-stage tap of the shift register. An example of this pulse train is shown in FIG. 3(a). It will be recognized that the upper lamp is actuated, on the average, approximately half the time as a consequence of the random on-and-off nature of the pulse train control signal.
The output pulse train from the 13-stage tap at pin 10 of the shift register 36 is applied through a 3-kilohm resistor 54 to the base of a second switching transistor 56 (also a PN3642). The collector of the second transistor 56 is connected to the middle candle lamp 16. The short-duty-cycle clock signal from OR gate 24 is also passed through a 3-kilohm resistor 58 to the base of the transistor 56. In this manner the short-duty-cycle clock signal and the pseudo-random pulse train from the shift register are summed to produced a control signal for the middle lamp 18. The short-duty-cycle clock signal and a representative example of the shift register output pulse train are shown in FIGS. 3(b)(i) and 3(b)(ii), together with the control signal (FIG. 3(b)(iii)) that is formed by summing the former two signals.
In a similar fashion, the output pulse train from the 4-stage tap of the shift register is applied through a 3-kilohm resistor 60 to the base of a third switching transistor 62 (also a PN3642). The collector of the transistor 62 is connected to the lower candle lamp 14. The long-duty-cycle clock signal is also applied through a 3-kilohm resistor 64 to the base of the transistor 62, such that the control signal for the lower lamp consists of the sum of the long-duty-cycle clock signal and the pseudo-random output pulse train from the shift register. The long-duty-cycle clock signal, a representative example of the the shift register pulse train, and the summed control signal are illustrated in FIGS. 3(c)(i), 3(c)(ii) and 3(c)(iii), respectively.
It will be noted upon examination of FIG. 3 that the lamp control signals (FIGS. 3(a), 3(b)(iii) and 3(c)(iii)) have certain characteristics which result in illumination levels and flickering effects that simulate a natural flame. For example, the control signal for the upper lamp is in a logical high state, on the average, exactly half the time. The control signals for the lower and middle lamps are in the logical high state a greater proportion of the time, since they are formed by summing the shift register output signal with the clock signals. In this regard, the lower lamp control signal is, on the average, in the logical high state the greatest proportion of time, since it is the sum of the shift register output signal and the long-duty-cycle clock signal. Further, the average time period between successive high logic states decreases from the upper lamp to the lower lamp. This results in the lower lamp being on most of the time, with only relatively occasional and brief periods during which it is off. In actuality, the flicker rate of the lower lamp is nevertheless sufficiently high that it appears to flicker between a bright state and a somewhat less bright state, rather than flickering distinctly on and off. The middle lamp is also on most of the time, but not as much as the lower lamp, and has relatively longer and more frequent periods during which it is off. Again, however, because of the relatively high average frequency of the control signal, the middle lamp in actuality appears to flicker between an intermediate intensity level and a somewhat higher intensity level, with the average rate of the flickering being somewhat higher than that of the lower lamp. The upper lamp appears to flicker on and off more distinctly than either the lower or middle lamp, with the average lengths of the periods during which the upper lamp is on and off being approximately equal in duration, and with the duration of the periods during which it is off being, on the average, longer than the average periods during which the lower and middle lamps are off. Additionally, the power to the upper lamp is reduced somewhat by the 10-ohm resistor 52, so that the average intensity of the upper lamp is somewhat less than that of the lower and middle lamps for this reason as well as for the reason that the average duration of the periods during which the upper lamp is off is somewhat longer for the upper lamp than for the other lamps. As a result, the upper lamp is less bright but is characterized by a more pronounced flickering effect than the lower and middle lamps.
The net result is a set of three lamps which simulate both the illumination intensity distribution and the gas turbulence of a a natural flame. The average illumination intensity increases toward the base of the apparatus, thus simulating the actual intensity distribution in a flame, which occurs as a result of the greater combustion rate near the base of the flame. At the same time, the flickering effect becomes more pronounced toward the top of the flame, thus simulating the greater gas turbulence that exists near the top of the flame.
The foregoing detailed description of a preferred embodiment of the invention is provided to enable one of ordinary skill in the art to make and use the present invention, and is not intended to limit the invention to the actual embodiment illustrated and described. Various modifications, alterations and substitutions which may be apparent to one of ordinary skill in the art may be made without departing from the spirit of the invention. Accordingly, the scope of the invention is defined by the following claims. | An electronic lighting device for simulating a flame, particularly a candle flame. In the preferred embodiment a set of three vertically spaced lamps are enclosed in a translucent bulb and are controlled by a signal generator circuit which independently turns three lamps on and off in a manner which simulates both the illumination distribution and the gas turbulence in a natural flame. The circuit includes a multistage static shift register which is used in a feedback mode to produce three mutually delayed pseudo-random pulse trains. One pulse train is used directly to control the uppermost lamp. The other pulse trains are combined with assymetric long-duty-cycle and short-duty-cycle clock signals. The resulting combined signals are used to drive the lower and middle lamps, respectively. The net result is that the lowermost lamp is brightest and flickers only dimly; the middle lamp is of intermediate brightness and appears to flicker more distinctly; and the upper lamp is on half the time and off half the time, on average, with the average brightness being less than either of the lower lamps and the flickering effect being more pronounced than that of either the lower or middle lamps. | 8 |
FIELD OF THE INVENTION
This invention relates to fastener accessories, more particularly to retainers used to prevent the undesired disengagement of nuts from spindles.
BACKGROUND OF THE INVENTION
Retaining nuts are used to secure devices, for example a hub, upon a spindle. Typically both the spindle and nut are threaded. Devices are secured upon the spindle before the nut is screwed onto the spindle, the nut abutting the exterior side of the device. Vibration, associated with the rotation of the spindle, may cause the nut to unscrew and disengage from the spindle. The device is no longer secured and may detach itself from the spindle.
Numerous devices have been used to secure the nut to the spindle. Simple versions of these devices include lock washers, jam nuts, self-locking nuts and slotted nuts used in conjunction with a cotter pin. More advanced versions of securing devices include the controlled axle nut system of U.S. Pat. No. 5,795,037 to Hagelthorn and the nut and bolt locking system of U.S. Pat. No. 5,967,723 to Duran. Hagelthorn provides a retainer member which must be threaded onto the spindle. The threading process can be difficult, especially in cases where the parts are being assembled by machine. Potential assembly difficulties are cross-threading and the need to protect the internal threads of the retainer from damage. Duran provides a nut and washer locking combination where the washer deforms to form an interference fit with flats on the face of the nut as the nut is tightened upon a bolt. Locking contact between the nut and washer occurs only at one end of the nut.
A system which can be easily assembled and which provides a strong locking connection between the spindle nut and the nut retainer is desired.
SUMMARY OF THE INVENTION
The present invention overcomes these and other disadvantages of the prior art by providing a spindle nut retainer which is easily attached to a spindle/nut system and which creates a strong connection between the nut and spindle.
The invention provides in one aspect a spindle nut retainer which prevents a nut from unthreading and becoming detached from a spindle. The spindle nut retainer includes both a base section and peripheral section which together form a cup shape. The base section includes a hole through which the spindle passes. The peripheral section provides a plurality of fingers which form windows within the peripheral section. The fingers also include nut engaging surfaces which engage the corners of the nut to provide a locking connection.
The invention provides in another aspect a spindle nut retainer which includes both a base section and peripheral section which together form a cup shape. The base section includes a hole through which the spindle passes, and the peripheral section includes a plurality of fingers which create one or more longitudinal windows therebetween, the fingers including a flared end bent towards the center of the spindle nut retainer.
The spindle nut retainer of the present invention may be easily attached over the nut without having to be threaded upon the spindle. Further, the spindle nut retainer creates a strong locking connection along the corners of the spindle nut. These and other aspects of the invention are herein described in particularized detail with reference to the accompanying Figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a cutaway view of a spindle nut locking system;
FIG. 2 is a front view of a spindle nut retainer;
FIG. 3 is a side view of the spindle nut retainer; and
FIG. 4 is a perspective view of an alternate embodiment of the spindle nut retainer.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 illustrates a preferred spindle assembly 10 according to the invention. The assembly 10 prevents a nut 60 from becoming disengaged from a spindle 50 . Disengagement typically occurs as a result of vibration of the spindle 50 . The spindle assembly 10 as described in more detail below, comprises a spindle nut retainer 20 , a nut 60 , and a spindle 50 . In the illustrated embodiment, the spindle assembly 10 also comprises a hub 70 , one or more bearings 90 and one or more washers 80 .
Embodiments of the spindle nut retainer 20 are shown in FIGS. 2 , 3 and 4 and comprise an integral base section 22 and peripheral section 28 in a cup-shaped configuration. In separate embodiments the spindle nut retainer 20 is made from materials such as steel as shown in FIG. 4 , or a polymer as shown in FIGS. 2 and 3 . The base section 22 may be flat, having an interior face 24 and an exterior face 26 . The base section 22 includes a centrally located aperture 34 . The area of the base section 22 around the aperture 34 may be of increased thickness for structural reinforcement. In an embodiment wherein the spindle nut retainer is made of steel, the base section 22 may include a bent tab 25 . The bent tab 25 may be integrally formed with the base section 22 and bent to extend from the base section 22 perpendicularly. The aperture 34 may be D-shaped. Throughout the specification, the term “D-shaped” refers to a truncated circular shape. A flat portion of the base section forming the flat section of the “D” is an interference surface 27 . The interference surface 27 is transverse to the interior face 24 and exterior face 26 of the base section 22 . As a result, there is rotational interference when the retainer 20 is positioned upon an area of the spindle 50 having a D-shaped cross section. In an embodiment wherein the spindle nut retainer is made of steel, the surface of bent tab 25 may be the interference surface 27 . The base section 22 may include a manufacturer's brand name.
The peripheral section 28 comprises the walls of the cup-shaped configuration of the spindle nut retainer 20 . The peripheral section 28 includes an exterior surface 30 and an interior surface 32 . The exterior surface 28 may be circular in shape. A first end 31 of the peripheral section is integral with the base section 22 . The peripheral section 28 of the spindle nut retainer 20 may include a series of longitudinal windows 36 aligned in an alternating manner with and defined by solid fingers 38 of the peripheral section 28 . The number of windows 36 on a spindle nut retainer 20 may be related to the number of corners on the nut 60 , for example two times the number of corners. This allows the spindle nut retainer 20 to be easily fit over the nut 60 , without having to rotate the nut 60 into a position of exact alignment. In any position upon the peripheral section 28 , an oversized window 37 may be created by removing a finger 38 . The windows 36 and fingers 38 allow for increased flexibility of the spindle nut retainer 20 and ease in the manufacturing process. The longitudinal windows 36 also allow the passage of one or more corners 64 of the nut through the spindle nut retainer 20 .
The longitudinal windows 36 may extend all the way to the first end 31 of the peripheral section, thus, creating notches 35 within the exterior surface 30 of the base section 22 . A second end 33 of the peripheral section, opposite the base section 22 , may be a continuous ring. The longitudinal windows 36 , when the ring is continuous do not extend completely to the second end 33 of the peripheral section 28 . In an embodiment wherein the spindle nut retainer is made of steel, the second end 33 of the peripheral section is not a ring but instead is comprised of the flared ends 39 of each individual finger 38 .
In an embodiment wherein the spindle nut retainer 20 is made of polymer, the second end 33 of the peripheral section 28 may have an internal diameter which is smaller than the internal diameter of the remainder of the peripheral section 28 . The second end 33 of the peripheral section 28 will then snap over the nut 60 and be locked in place as shown in FIG. 1 . In an embodiment wherein the spindle nut retainer 20 is made of steel, the flared ends 39 of each finger 38 may be bent internally to create a locking function. Additionally or alternatively in either embodiment, the corners 64 of the nut 60 which pass through the longitudinal windows 36 may be locked in place by the end surfaces 46 of the windows.
In an embodiment wherein the spindle nut retainer is made of polymer, the peripheral section 28 defines a plurality of nut engaging surfaces 40 . Each nut engaging surface 40 is angled. Each finger 38 includes two adjacent nut engaging surfaces 40 angled to form a point on the interior surface 32 of the peripheral section 28 . The nut engaging surfaces 40 may extend along the entire length of the interior surface 32 of the peripheral section 28 . The nut engaging surfaces 40 create rotational interference between the nut 60 and retainer 20 when the retainer 20 is overlapping the nut 60 . In embodiments wherein the spindle nut retainer is made of polymer the end surfaces 46 of the longitudinal windows 36 work in conjunction with the nut engaging surfaces 40 to lock the nut 60 in place. The nut engaging surfaces 40 will interfere with the corners 64 of the nut 60 if the nut is rotated in relation to the spindle nut retainer 20 or vise versa. The end surface 46 of the longitudinal window 36 will interfere with the corner of the nut 60 when the spindle nut retainer 20 is moved axially. In an embodiment wherein the spindle nut retainer is made of steel, the nut 60 is locked in place by the window side surfaces 48 , as opposed to the nut engaging surfaces, as well as window end surfaces 46 .
Referring to FIG. 1 , the spindle assembly 10 further comprises the nut 60 which includes exterior flats 62 and corners 64 . The nut 60 is commonly formed of steel. The nut 60 functions to hold a hub 70 upon the spindle 50 . The nut 60 is threadedly engaged to the spindle 50 . As previously described the nut 60 is locked in place by the spindle nut retainer 20 . The spindle assembly 10 may further comprise a hub 70 . The hub 70 circumscribes the spindle 50 and rotates freely about the spindle 80 . One or more bearings 90 are used between the hub 70 and spindle 50 to allow free rotational engagement. The hub 70 is located on the interior side of the nut 60 and is restrained from disengagement from the spindle 50 by the nut 60 . The spindle assembly 10 may further comprise one or more washers 80 . In an embodiment, a washer 80 is between the hub 70 and the nut 60 . The washer 80 is flat and provides a surface which abuts both the hub 70 and the nut 60 .
The spindle assembly 10 further comprises a spindle 50 . In an embodiment, the spindle 50 is part of an automobile. The spindle 50 has multiple sections around which components are circumscribed. The spindle 50 includes a threaded section 51 and a non-threaded section 53 . In an embodiment, the sections of the spindle 50 have varying diameters. The spindle has two ends. In an embodiment, a section adjacent to one end 52 of the spindle 50 has a D-shaped cross section. This section allows a spindle nut retainer 20 having a D-shaped cross section to circumscribe the spindle 50 which resists rotational movement. One section of the spindle 50 is threaded, allowing engagement with a nut 60 which is similarly threaded.
Although the invention has been shown and described with reference to certain preferred and alternate embodiments, the invention is not limited to these specific embodiments. Minor variations and insubstantial differences in the various combinations of materials and methods of application may occur to those of ordinary skill in the art while remaining within the scope of the invention as claimed and equivalents. | A spindle nut retainer is provided for preventing a nut threaded upon a spindle from unthreading and detaching from the spindle. The spindle nut retainer includes an integral base section and peripheral section maintaining a cup-shaped configuration. The base section includes an aperture through which the spindle may pass and the peripheral section includes a plurality of fingers which form windows therebetween used to form a locking connection between the spindle nut retainer and the nut. | 5 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] Exemplary aspects of the present disclosure relate to a headrest of a vehicle to increase the comfort of a user during prolonged use.
[0003] 2. Description of the Related Art
[0004] Seats of a vehicle such as an automobile are provided with a headrest for the safety and comfort of an occupant (user). The headrest provides protection to the occupant in the event of a crash by helping to prevent head, neck, or spinal injuries by limiting the rearward movement of the occupant's head. A headrest also provides comfort to a user by providing a place to rest one's head especially for a long drive.
[0005] Headrests may be provided in special arrangements to enhance the comfort of the user. For example, certain materials such as foam may be used to provide a soft cushion. Also, the shape of the headrest may be designed to enhance comfort. See, for example, U.S. Pat. No. 7,717,517 B2. However, U.S. Pat. No. 7,717,517 B2 has a drawback in that the side wings do not go all the way back, which does not give the appearance of a normal headrest when the side wings are not in use.
SUMMARY
[0006] The present disclosure is designed to address issues in the related art. In particular, a headrest according to an exemplary embodiment of the present disclosure provides passengers with the convenience of a pillow like cushion that can be adjusted to provide support for the back and the side of the head of the passenger. This additional support provides extra comfort to passengers during long drives.
[0007] The vehicle headrest includes a center portion, two side members that attach to opposite ends of the center portion and extends forward and retracts backward and a locking mechanism in each side member locks each side member independent of the other side member in multiple positions relative to the center portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0009] FIG. 1 illustrates a front view of an extendable comfort headrest assembly in accordance with one example;
[0010] FIG. 2 illustrates a top view of an extendable comfort headrest assembly in accordance with one example;
[0011] FIG. 3 illustrates a back view of an extendable comfort headrest assembly in accordance with one example;
[0012] FIG. 4 illustrates a side view of an extendable comfort headrest assembly in accordance with one example;
[0013] FIG. 5 illustrates a top section view of an extendable comfort headrest assembly in accordance with one example;
[0014] FIG. 6 illustrates a front view of an extendable comfort headrest assembly with side member extended in accordance with one example;
[0015] FIG. 7 illustrates a top view of an extendable comfort headrest assembly with side member extended in accordance with one example;
[0016] FIG. 8 illustrates a side view of the center portion of the extendable comfort headrest assembly with the side member removed in accordance with one example; and
[0017] FIG. 9 illustrates a side view of a side member of the extendable comfort headrest assembly in accordance with one example.
DETAILED DESCRIPTION
[0018] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views. Further, as used herein, the words “a,” “an” and the like generally carry a meaning of “one or more,” unless stated otherwise.
[0019] FIGS. 1-9 depict various aspects of an extendable comfort headrest for a vehicle seat. Here a vehicle refers to a land vehicle exemplified by an automobile. However, the present disclosure is also applicable to any similar type vehicle, such as but not limited to, a sport utility vehicle, a pickup truck, a commercial vehicle, airplane, train, or the like.
[0020] FIG. 1 illustrates a front view of an extendable comfort headrest 100 according to one embodiment in its retracted position. The extendable comfort headrest 100 includes a center portion 102 , and two side members 104 and 106 . In the retracted position, the two side members, 104 and 106 , are flush with the center portion 102 . The side members can be manipulated by a user to extend the side members 104 and 106 out past the front surface of the center portion 102 .
[0021] FIG. 2 illustrates a top view of the extendable comfort headrest 100 in the retracted position according to one embodiment. The sides 202 and 204 of the center portion 102 are angled from the front 206 of the center portion 102 to the back 208 of the center portion. The corresponding interior sides 210 and 212 of the two side member 104 and 106 are angled at the same angle as the sides 202 and 204 . Therefore, the width W 1 of the front 206 of the center portion 102 is wider than the width W 2 of the back 208 of the center portion 102 . The angled sides 202 and 204 of the center portion 102 provide angled positions for the side members 104 and 106 when extended. The angle of the angled sides of the center portion 102 is fixed. The current angle shown in the figures merely demonstrates a possible embodiment and not meant to be exclusive. The angle of the angled sides of the center portion 102 could be any possible angle.
[0022] FIG. 3 illustrates a back view of the extendable comfort headrest 100 in the retracted position according to one embodiment. The center portion 102 has a smaller width in the back 208 of the headrest than in the front 206 of the headrest.
[0023] FIG. 4 illustrates a right side view of the extendable comfort headrest 100 in the retracted position according to one embodiment with side member 106 visible. In the center of the side member 106 , a button 402 is illustrated. The button 402 is surrounded by trim 404 . The trim 404 adds stability to the button 402 . A corresponding button and trim are found on side member 104 of the left side of the extendable comfort headrest 100 . The button 402 , as discussed below, activates the locking mechanism, and allows the user to manipulate the position of the side member 106 by extending the side member 106 forward, or retracting the side member 106 backwards.
[0024] FIG. 5 illustrates a top cross-sectional view of the interior structure of the extendable comfort headrest 100 according to one embodiment. The view is based on the cross-section line A in FIG. 1 . The front 206 of the extendable comfort headrest 100 is at the bottom of the FIG. 5 , and the back 208 is at the top of FIG. 5 . A locking mechanism 502 is disposed within each side member 104 and 106 . The locking mechanism 502 includes a pin 504 that rotates about a pivot point 506 , an inner sliding wall 508 , a retracted locking position 510 , and an extended locking position 512 . The locking positions are slots in the inner sliding wall 508 .
[0025] As the locking mechanisms 502 for each side member 104 and 106 are substantially the same, the locking mechanism 502 in side member 106 will be explained. A bias force acts on the pin 504 to force the pin 504 toward the inner sliding wall 508 . The bias force locks a first end 514 of the pin 504 locked in a slot, such as the retracted locking position 510 shown in FIG. 5 . When the user pushes on the button 402 , the button 402 depresses and exacts a force on a second end 516 of the locking mechanism pin 504 , which causes the pin 504 to rotate about the pivot point 506 in a clockwise direction as shown in the figures, although the pin 504 does not need to rotate clockwise. The force exacted by the button 402 on the pin 504 counteracts the bias force. Correspondingly, the pin 518 in the side member 104 rotates counter-clockwise when the button 402 is depressed.
[0026] As the pin 504 rotates, the first end 514 of the pin 504 is released from the retracted locking position 510 . Once the first end 514 of the pin 504 is released from the retracted locking position 510 , the user is able to slide the side member 106 forward. As soon as the first end 514 of the pin 504 engages with the inner sliding wall 508 outside the slot, the user no longer needs to press the button 402 and exact a force on the second end 516 of the pin 504 . Here, the bias force presses the first end 514 of the pin 504 against the inner sliding wall 508 and the first end 514 is configured to slide along the inner sliding wall 508 . The first end 514 of the pin 504 continues to slide along the inner sliding wall 508 until the first end 514 encounters a new locking position or slot, such as the extended locking position 512 . When the first end 514 encounters a new locking position or slot, the bias force pushes the first end 514 into the slot and locks the pin 504 into the new locking position.
[0027] FIG. 5 merely illustrates two locking positions, but the present disclosure is not so limited. The extended comfort headrest could have multiple locking positions to enable the user to adjust the length of the side members 104 and 106 according to the user's preferences or needs. The present disclosure is also not limited by the type of locking mechanism used as long as the locking mechanism 502 allows the user to lock the side members 104 and 106 in more than one location relative to the center portion 102 .
[0028] The present disclosure allows for easy operation by the user because the user can simply push a button and extend the side member forward until it locks into position.
[0029] FIG. 6 illustrates a front view of the extended comfort headrest 100 with side member 104 and 106 in the extended position according to one embodiment. Side member 104 and 106 are extended out past the front surface of the center portion 102 . With the side member 104 and 106 fully extended, the width W 1 of the center portion 102 is sufficient to accommodate the 95 th percentile male head size. However, the present disclosure is not so limited, and the width could be larger or smaller than W 1 to accommodate larger or smaller head sizes.
[0030] The extension or retraction of one side member is not dependent on the other side member. The user can extend either one or both of the side members, depending on personal preference or need. The inner surface 602 of the side members 104 and 106 are only exposed when the side members are extended. The inner surface 602 contains padding to ensure the user will be comfortable. The padding could be foam or any other material known to one skilled in the art. Further, multiple layers of foam and padding could be used to ensure the comfort of the user.
[0031] FIG. 7 illustrates a top view of the extendable comfort headrest 100 with the side member 104 and 106 in the extended position according to one embodiment. The front 206 of the extendable comfort headrest 100 is at the bottom of the FIG. 7 , and the back 208 is at the top of FIG. 7 . The extended position length L is sufficient accommodate the 95 th percentile male head size. However, the present disclosure is not so limited, and the length could be larger or smaller than L to accommodate larger or smaller head sizes.
[0032] FIG. 8 illustrates a side view of the center portion 102 of the extendable comfort headrest 100 with the side member removed according to one embodiment. Slides 802 and 804 are attached to the side member 104 . The slides 802 and 804 control the linear movement of the side members 104 and 106 relative to the central portion 102 by moving through the channels 806 and 808 , respectively. When the user unlocks the pin 504 , the user is able to slide the side member 104 between the retracted locking position 510 and the extended locking position 512 . Although, there could be multiple locking positions or slots, not just two. The first end 514 of the pin 504 also slides along the inner sliding wall 508 , as the user slides the side member 104 with the help of the slides 802 and 804 in the slide channels 806 and 808 .
[0033] As discussed earlier, when the extendable comfort headrest 100 is in the retracted position, the pin 504 is locked in the retracted locking position 510 . Further, when the extendable comfort headrest 100 is extended forward, the pin 504 is locked in the extended locking position 512 .
[0034] The embodiment shown in FIG. 8 illustrates two slides and two sliding channels, but the present disclosure is not so limited. Additional channels and slides could be added to control the linear movement of the side members. The slide mechanism used could be any known slide mechanism to one skilled in the art.
[0035] FIG. 9 illustrates a side view of the inner structure of the side member 104 of the extendable comfort headrest 100 according to one embodiment. Slides 802 and 804 can be seen through a cut away view. The slides 802 and 804 are attached to the side members 104 , and engage with the channels 806 and 808 of the center portion 106 . The area 902 houses the button 402 .
[0036] Obviously, 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. | A vehicle headrest, including a center portion, two side members that attach to opposite ends of the center portion and that extend forward and retract backward and a locking mechanism in each side member that locks each side member independent of the other side member in multiple positions relative to the center portion. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates to a display unit. More particularly the invention is concerned with a display unit of the kind in which a blind printed with display material is windable between a pair of rollers for presenting a selected area of the blind for display in a frame or window area.
BACKGROUND TO THE INVENTION
[0002] Roller blind displays have been widely used for many purposes including advertising and presentation of information. In such displays a blind carries a sequence of displays along its length. It is wound between a pair of parallel spaced rollers through a display window area, the blind being wound off one roller onto the other. Various controllable drive mechanisms have been used conventionally driven by an electric motor. Such drive mechanisms including indexing means to halt the drive when a selected portion of the blind is in the display window area. The present invention seeks to provide a drive mechanism which is reliable and easy to use and, in particular, one which can be manually actuated.
[0003] The present invention is applied to a display apparatus of the kind comprising first and second rollers rotatably mounted in spaced parallel relationship for winding a blind carried by the rollers therebetween through a display area to locate a selected portion of the blind thereat; and drive means for rotating one or other roller to cause lengthwise movement of the blind.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention in display apparatus of the above kind, the drive means comprises first and second drive portions rotatable with said first and second rollers respectively, said first and second drive portions being located at opposite sides of the rollers as seen from the display area.
[0005] A flexible elongate drive element is terminated at one end at the first drive portion, and is wound in a plurality of turns about the first drive portion. The drive element is terminated at the other end at the second drive portion and is wound in a plurality of turns about the second drive portion so as to be wound thereon when the drive element is wound off the first drive portion and vice versa. The is drive element has an intermediate section-supported for lengthwise movement thereof in a predetermined path between the turns wound on the first and second portions and the predetermined path includes a portion at which the intermediate section is manually actuable to apply a drive force to one or other of the rollers.
[0006] The blind carried by the rollers may be a carrier for graphics, e.g. a printed display blind attached to the carrier blind. The carrier blind acts to transmit drive from the roller to which drive is applied to wind the carrier thereon to the other roller from which the blind is being wound off. The display apparatus may be constructed in the form of a light box in which the carrier blind is back lit. To this end the carrier blind is made light transmissive.
[0007] In a preferred embodiment of the display apparatus of the invention the above-mentioned portion of the predetermined path is substantially parallel to and in the plane of said first and second rollers outside the space between the rollers occupied by the blind. More particularly the rollers are supported in a rectangular housing parallel to and adjacent respective ones of two opposed sides thereof and the portion of the predetermined path lies external to one of said two opposed sides to be manually accessible. One of these two opposed sides contains first and second apertures through which the flexible element extends to the external portion of the predetermined path. Manually-engageable (e.g. graspable) means is carried by the flexible element at the external portion of said predetermined path.
[0008] The manually-engageable means is sized to be unable to pass through the apertures and thereby limits the extent of movement of the manually-engageable means. Preferably the manually-engageable means is a spring-loaded device acting to maintain tension on the flexible element. In the preferred embodiment of the invention the flexible element extends from the first drive portion in a direction past the second roller and extends from said second drive portion to engage a part acting as a guide pulley rotatable with the first drive roller and return towards and past the second drive portion.
[0009] Furthermore in the preferred embodiment of the display apparatus the ratio of the diameter of each of the first and second rollers to the diameter of each of the first and second drive portions respectively is such that a movement of the flexible element through a distance between said apertures causes the blind to be wound over a length that is at least twice the dimension of said display area in the lengthwise direction of the blind.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a front elevation of a display unit embodying the invention with the front cover removed;
[0011] [0011]FIG. 2 is an illustration to a larger scale of the means for rotatably supporting the rollers at each end, the illustration of FIG. 2 particularly pertaining to the right-hand end of the upper roller as seen in FIG. 1; and
[0012] [0012]FIG. 3 is an axial section of a handle/tensioning device for the drive cord.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] There will be described an embodiment of the invention in which the invention is applied to what is known as a light-box type of display unit. A light-box provides back lighting of the displayed portion of a blind carrying display material. It will be assumed that the blind that is moved to change the display is movable in a vertical path between upper and lower rollers. Reference to the “left” and “right” and “upper” and “lower” refer to the display unit as seen in FIG. 1. The unit to be described could be mounted to provide a display in which the blind is moved horizontally.
[0014] [0014]FIG. 1 shows a display unit having a housing 10 formed to provide a rectangular tray in which the mechanism of the display unit is mounted. That is the housing includes a rear wall 12 and side vertical walls 14 and horizontal side walls 16 upstanding from the rear wall. Mounted in the housing parallel to and adjacent respective side walls 16 is an upper roller assembly 20 and a lower roller assembly 30 parallel to the upper roller and spaced from it. Both rollers are rotatably mounted to releasable plain bearings 18 supported on the opposed vertical side walls 14 for rotation about a horizontal axis. The structure is shown simplified in FIG. 1. A preferred arrangement for the support and rotation of the roller assemblies 20 and 30 (including their respective drive means) is described below with reference to FIG. 2. The rollers 20 and 30 receive a graphic carrier 40 which is in the form of a blind and which is windable from one roller to the other to present a portion of the blind in a display window area 22 indicated in dashed line. The display window area 22 is defined by a front cover or surround (not shown) attachable to the housing 10 . The end portions of the graphic carrier 40 are secured to respective rollers, as by pop type rivets. The carrier 40 transmits the drive applied to one roller to the other and serves to carry a display blind (not shown) on which the advertising or information to be displayed is printed. The display blind is attached to the outer surface of the carrier 40 by releasable means (not shown) such resilient plastic tongue and groove arrangements such as are well known. The front cover screens the rollers and their operating mechanism from external view so that only the wanted display portion of the blind is seen at display area 22 . The housing 10 and the front cover provide what is known as a light box. The graphics carrier 40 extends between the outer portions of the rollers, i.e. away from rear wall 12 . The carrier 40 is a translucent plastics web which supports both the tension generated in the web between the rollers 20 and 30 during movement of the carrier and diffuses light to allow back lighting of the display blind. To this end, back lighting is provided by lamps such as elongate fluorescent lamps (not shown), carried by the rear wall 12 behind the display window area 22 . The depth of the tray that is the height of the side walls 14 and 16 from the base 12 , is sufficient to allow the rollers 20 and 30 to be accommodated within the tray such that the plane of the carrier 14 therebetween is a little within the tray. This is not essential but is of advantage in the provision of a front cover or surround of straight forward construction.
[0015] The roller assemblies 20 and 30 are conveniently of identical construction as exemplified by the following description of roller assembly 20 . The assembly 20 has a larger diameter portion 24 onto which the carrier 40 is wound and an integral reduced diameter portion 26 at each end of the larger diameter portion which is mounted to rotate in a plain bearing aperture of a respective bearing 18 in a construction to be described with reference to FIG. 2. All the parts of a roller assembly rotate as a unit. Not all the parts are used in the drive arrangement: it is convenient, however, to manufacture the roller assemblies to be identical and for each to be symmetrical.
[0016] In order to rotate the two rollers simultaneously, a manually-operable cord drive 50 is provided as a flexible drive element. The cord drive is secured at one end 52 to the reduced diameter portion 26 at the right side of the upper roller 20 and the end portion is wound a number of turns 54 around the adjoining reduced diameter portion 26 from whence the cord extends along an intermediate path which leads down as indicated at 56 inside the adjacent side wall 14 to exit the lower side wall 16 through an apertured bush 32 (shown in cross-section) fitted in the side wall and below the reduced diameter portion at the right of the figure. The cord 50 then extends in a portion 58 exterior to the lower side wall 16 across to and through another apertured bush 34 (shown in cross-section). Having passed through the bush 34 the cord 50 passes the lower roller assembly and rises at 60 to pass round the reduced diameter portion 26 at the left of the upper roller assembly 20 —the portion 26 there acting as a guide pulley—and thence down at 62 to the reduced diameter portion 26 at the left of the lower roller assembly 30 . This end portion of the cord is treated in the same way as the other end portion 64 first described. It is wound several turns 64 around the reduced diameter portion 26 at the right of the lower roller 30 and the other end 54 of the cord 46 secured to this portion 26 . The wound portions of 54 and 64 of the cord 50 are wound in a direction enabling both rollers to rotate in the same direction, thereby winding the carrier 40 between them. The apertured bushes 32 and 34 are formed and are located below the reduced diameter portions 26 to assist a smooth longitudinal sliding motion of the cord 50 through the bushes.
[0017] It will be seen that the intermediate path traversed by the cord is designed to allow ease of longitudinal movement and free winding/unwinding of the turns on drive portions 26 . The intermediate path lies essentially in a single plane and for compactness of the unit this plane is the plane in which the rollers 20 and 30 are located. The cord drive 50 extending from bush 34 -could be taken directly to the drive portion 26 at the left of lower roller 30 but by taking it up over the drive portion 24 at the right of the upper roller 20 and back down to the lower roller variation in the angle which the cord makes to the drive portion 24 of the lower roller as it winds/unwinds is reduced aiding in ensuring free movement.
[0018] The section 58 of the cord outside the housing 10 provides the means by which it is manually-accessible for moving the cord lengthwise. The section 58 lies essentially in the plane of the rollers 20 and 30 and the housing 10 and is outside the spacing between the rollers within which the display area 22 is defined. A tension applied in the cord as indicated by arrow T will act to unwind the cord with respect to one roller, 30 in the case shown, and cause the carrier to be wound onto that roller. The resultant tension in the carrier 40 is communicated to the other roller and acts to wind the carrier off the other roller 20 . This in turn causes the winding up of the cord at 54 at the right of roller 20 .
[0019] A means 70 is provided on the cord in the external section 58 between apertures 32 and 34 to act as a manually grippable element to move the cord and/or to act as a cord tensioning element. In the embodiment shown, the means 70 does not pass through the apertures and acts as a stop member to limit the amount of longitudinal travel of the cord 50 . Preferably it performs all three functions. In the preferred embodiment the means 70 is a spring-loaded cord tensioning device described below with reference to FIG. 3.
[0020] This manual actuation requires no indexing of the blind as has been used in controlling motor-driven blind-winding systems. The person moving the cord watches the display and sets it to the required position. The system is particularly useful for displays which do not require continual change, for example menu displays which are changed at intervals during the day.
[0021] The length L of carrier moved in traversing the cord tensioning device between the apertures 32 and 34 over a distance D is related to distance D by the ratio R of the diameter of the larger diameter portion 24 of a roller assembly (about which the blind is wound) to the diameter of the adjoining smaller diameter portion 26 about which the cord is wound. Thus L=RD. L is sufficient to accommodate N displays lengthwise along the blind each of which occupies the height H (in the carrier travel direction) of the display window area 22 . Thus L is not less than NH.
[0022] [0022]FIG. 1 illustrates the mounting of the roller assemblies rather diagrammatically. A preferred roller support and rotational mounting will now be described, taking the right hand side of the upper roller assembly by way of example. Each roller end is supported and mounted in the same fashion. FIG. 2 also illustrates the winding of the drive cord onto the reduced diameter portion at the right hand side of the roller assembly 20 . The carrier blind 40 is not shown. In FIG. 2 parts like to those of FIG. 1 are denoted by like reference numerals.
[0023] [0023]FIG. 2 shows the section of right-hand side wall 14 adjacent the right hand end of the upper roller assembly 20 . The larger diameter portion of the roller comprises a cylindrical tube 80 of aluminium whose end portion is a snug slide fit on to an inwardly projecting cylindrical portion 82 of a member 84 which is inserted into the tube until the tube abuts an outwardly directed flange 86 . Portion 82 is shown as tubular: it could be solid. The tube 80 and insert 82 may be keyed together to ensure they rotate as a unit about axis A-A. The member 84 has the drive portion 26 extending axially outwardly from flange 86 . The outer end of portion 26 carries a flange 88 and projecting from this is a raised axial boss 90 . The outer end of portion 26 has an axial blind hole extending into it through boss 90 and flange 88 . A metal spigot 92 is received in the blind hole and projects outwardly to enter the plain bearing 18 .
[0024] The bearing 18 is formed in a bracket 94 fixed to and standing away from the inner surface of adjacent side wall 14 . The bracket 94 is apertured in alignment with axis A-A and an apertured bush 96 seats in the bracket aperture with an enlarged flange portion 98 axially inward to engage the facing surface of boss 90 for smooth rotational engagement therewith. The spigot 92 extends outwardly of boss 80 to enter the bearing bush 86 . The member 84 (parts 82 , 86 , 26 , 88 and 90 ) is formed as an integral moulding of plastics material, e.g. Teflon, and the bearing bush 96 is likewise formed of a plastics material such as Teflon.
[0025] The structure described above with reference to FIG. 2 is designed for ease of rotation bearing in mind that ease of manual actuation is required.
[0026] To complete the drive portion 26 shown in FIG. 2, there is also shown the rising cord portion 56 which engages the portion 26 at the rear (as seen in the figure) and is wound in a plurality of turns 54 of which only the first and last 54 a, 54 b are shown for clarity of illustration. The end of turn 54 b is then taken through an aperture in flange 88 and is suitably terminated for example in a knot 55 to retain the end in place and anchor the turns 54 to portion 26 . The flange 88 acts to prevent the wound cord from sliding off the drive portion 26 .
[0027] The flange 86 acts to locate the carrier and the display blind affixed thereto against any tendency for axial displacement. Preferably the aperture in the bracket 94 is provided with a releasable side portion so that the bush 96 and the spigot 92 within it are releasable from the bracket in order to remove the roller assembly as a unit. This provision is made on all four apertured brackets.
[0028] The construction of the combined handle/tensioning device 70 is illustrated in FIG. 3. It is considered to be novel in its own right. The device 70 comprises a tubular body 72 closed at one end. The closed end has a central aperture 73 allowing the cord 40 to enter the body from one side (FIG. 1). The other end of body 72 is interiorly threaded to receive a screw-in cap 74 which is also centrally apertured at 75 to allow the cord 40 to enter the handle from the other side. Within the body 72 are two helical springs 76 a, 76 b aligned in the body 72 , their outer ends bearing against the inner surfaces of the closed end of the body 72 and the cap 74 . The cord 40 is separated into two within the handle. One end portion 40 a of the cord passes through the helical spring 76 a and through the aperture of a washer 77 a engaging the inner end of the spring 76 a. The end of cord portion 40 a is tied into a knot 78 a interiorly of washer 77 a so that the cord end is retained by the washer. Similarly the other end portion 40 b of cord passes through the helical spring 76 b and through the aperture of a washer 77 b engaging the inner end of the spring 76 b. The end of cord portion 40 b is tied into a knot 78 b interiorly of washer 77 b so that the cord end is retained by the washer. The washers are axially movable in the body 72 to compress the respective springs. This construction has the advantage that by unscrewing the cap 74 , the interior assembly can be removed from body 72 . The handle effectively provides a continuous drive cord 40 in which a tension-maintaining resilience is incorporated.
[0029] In practice the handle can be set up to have the cord knots 78 a, 78 b a little separated to establish tension in the cord 40 and provide a degree of yielding enabling tension to be maintained in use of the apparatus. It is preferred to have the cord exit the lower side of the housing with the handle 70 accessible below the lower side, so that similar display units can be placed side by side in close proximity.
[0030] It will be appreciated that the rollers could be journalled to bearings provided directly in the side walls 14 . The apertures 32 and 34 could be substituted by curved cord guides extending out of the lower side wall. The embodiment described utilises a graphic carrier which is affixed to the roller assemblies 20 and 30 . With the aluminium roller tubes, e.g. 80 , described the carrier 40 can be affixed thereto by pop rivets. While it is preferred to have a graphics carrier by which the display blind is carried in a two layer composite, a single layer display blind could be used. A light box type of construction is not essential for the practice of the invention. | An advertising display unit has a blind wound between a pair of spaced rollers rotatably mounted for bringing a selected portion of the blind into a display window area. A mechanism for longitudinally moving the blind is provided which is easily accessed and actuated manually. Each roller comprises an assembly having a larger diameter portion onto which the blind is wound and a smaller diameter portion that rotates with it. A cord drive is secured to and wound a number of turns round the smaller diameter portion of one roller. The cord drive follows a path a section of which extends externally of a housing in which the rollers are mounted. The cord drive passes to the other roller where it is wound a number of turns about and secured to the small diameter portion of the other roller. The cord is wound about the small diameter portion so as to wind off one and onto the other with the rollers rotating in the same direction. The blind serves to transmit drive from the wind-up roller to the wind-off roller. The external section of the path includes a manually-graspable handle in which the cord is secured by a spring-loaded mechanism to maintain tension in the cord. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the recovery of gold from gold-bearing liquors, particularly such liquors obtainable in the known cyanidation process.
2. Description of the Prior Art
The cyanidation process is a well known process for extracting gold values from gold bearing ores. The process involves finely grinding the ore and then leaching the ore with a suitable cyanide solution. The cyanide leach solution is generally a sodium cyanide leach solution which contains calcium hydroxide or other suitable alkali to maintain the pH above about 10. The gold values are leached in the form of the aurocyanide (Au(CN) 2 ) ions. The following reaction occurs with sodium cyanide leach solution:
2Au+4NaCN+O.sub.2 +H.sub.2 O→2Na Au(CN).sub.2 +2Na OH.
the gold values may be recovered from the gold rich leach solution by any of a number of methods. The preferred method is to adsorb the gold values onto activated carbon and then desorb the gold values therefrom by treating the loaded carbon with water of low ionic strength such as softened or deionised water. Such methods are described in the specification of our South African Pat. No. 73/8939 and the specification of our co-pending South African patent application No. 76/4204.
SUMMARY OF THE INVENTION
According to the present invention, a process for recovering gold from a gold bearing liquor arising from a cyanidation process includes the steps of treating the liquor with ozonised air or ozonised oxygen, adsorbing the gold values from the treated liquor on activated carbon, and recovering the gold from the loaded activated carbon.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE shows a comparison of adsorption data obtained with a gold bearing liquid treated according to the process of the present invention with the adsorption data obtained with a similar solution which was not subjected to an ozone pretreatment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The gold bearing liquor may for example be a pregnant leach solution from a cyanidation process or effluent from a gold plant employing the cyanidation process.
Pretreatment with ozonised oxygen or ozonised air results in the precipitation of base metal, e.g. copper, cobalt or nickel, and silver cyanide complexes; in the oxidation of organic matter such as detergents, flocculating agents, flotation reagents and dispersants which are present in the liquor; and in a decrease in the concentration of free cyanide in the liquor. The duration of the pretreatment, which may for example be effected by bubbling the ozonised gas through the liquor, will depend on the nature of the liquor, but is preferably continued until the liquor is substantially free from base metals, organic matter, and free cyanide. This occurs typically when the pH of the liquor has decreased to below approximately 8.
The ozonised gas may be generated using known and commercially available ozone generators.
The pretreatment results in a significant increase in the equilibrium or saturation loading of gold on the activated carbon thereby improving significantly the recovery of gold from the gold rich liquor.
The gold may be recovered from the loaded carbon by treating the carbon with water of low ionic strength in the manner described above.
The following examples illustrate the process of the invention.
EXAMPLES 1-4
Gold bearing solutions originating from leaching a gold bearing ore with a sodium cyanide leach solution in a standard cyanidation process were treated by bubbling ozonised air at a rate of approximately 200 ml/min at ambient conditions of temperature and pressure through a 500 ml sample of the solution in a beaker equipped with a magnetic stirrer. The ozonised air was produced using a Gallenkamp ozone generator type GE-150. The treatment resulted in each case in the formation of a white precipitate and a decrease in the pH.
The results obtained are tabulated in Table I.
From the tabulated results it is seen that copper, nickel, silver and iron are precipitated by the ozone treatment, while gold remains unaffected.
A treatment lasting of the order of 1-2 hours was found sufficient to yield a liquor substantially free of base metals and having a pH value of 7,7.
EXAMPLE 5
A sample of clarified pregnant solution from a gold plant using the standard cyanidation process was subjected to a pretreatment according to the procedure of Examples 1 to 4 until the pH value was 7,7.
The resulting solution was pumped at ambient temperature at a rate of 14 bed volumes per hour through a carbon column (30 cm length×1 cm internal diameter) containing 10 g of a commercially available activated carbon. The resulting adsorption data is represented graphically by line (2) in the attached drawing.
In the same FIGURE is represented graphically by line (1) the adsorption data obtained with a similar solution which was not subjected to an ozone pretreatment, but merely had its pH value adjusted to 7,7 using concentrated sulphuric acid.
A comparison of the two sets of results indicates the marked benefits of the ozone pretreatment. A 3-4 fold increase of the equilibrium or saturation loading of gold, giving an approximate 17 weight percent loading following ozone pretreatment is observed.
It has been adequately demonstrated that the ozone treatment of gold plant pregnant solution has a most beneficial effect on the subsequent adsorption of the contained gold values onto activated carbon. A significant increase in the equilibrium or saturation gold loading from a value of about 3,7 weight percent gold (1 800 bedvolumes pregnant solution as influent) to a value of about 17 percent (9 000 bedvolumes ozonised pregnant solution as influent) indicates that both the decrease in influent pH together with the precipitation of silver and base metals, the oxidation of organic constituents and the destruction of free cyanide have a marked effect on increasing gold adsorption capacity. Furthermore, a decrease in influent pH shifting the carbonate equilibrium to the bicarbonate side overcomes the most troublesome build-up of calcium carbonate on the activated carbon. This precipitate would otherwise have to be removed periodically with dilute hydrochloric acid.
TABLE I______________________________________OZONE TREATMENT OFVARIOUS PREGNANT SOLUTIONSAir/O.sub.3 Mixture at approximate flow rate of 200 ml/min.bubbled through 500 ml of solution in an open beaker.After 1 hour solution filtered and analysed.Solution NumberEle- 1 2 3 4 5ment B: before Air/O.sub.3 treatment; A: after Air/O.sub.3 treatment(g/t)B A B A B A* B A B A______________________________________Au 7,9 7,5 495 485 4,25 4,25 8 8 85 83Ag 1,6 0,2 7,1 0,4 0,2 0,1 1 0,9 12 10Cu 6,3 0,6 5,0 0,2 9 3 7 2 -- --Fe 2,3 0,9 0,6 0,5 2 1 3 0,2 -- --Ni 2,0 1,7 32 0,2 3,5 0,8 2 1,5 1400 66Co -- -- -- -- 20 17 <0,5 <0,5 -- --pH 9,2 7,0 12,2 12,0 10,95 2,2 9,6 7,9 13,0 13,0______________________________________ Sol. No. 1 Clarified gold plant pregnant solution from Western Deep Level gold mine, batch from Nov. 1975 Sol. No. 2 Eluate from charcoal columns, composite sample Sol. No. 3 Pregnant calcine leach liquor Sol. No. 4 Clarified gold plant pregnant solution Sol. No. 5 Combined eluate from charcoal columns *After 16 hours treatment | A process for recovering gold from a gold bearing liquor arising from a cyanidation process including the steps of treating the liquor with ozonized air or ozonized oxygen, adsorbing the gold values from the treated liquor on activated carbon, and recovering the gold values from the loaded activated carbon. | 2 |
FIELD OF DISCLOSURE
This disclosure relates to positioning apparatuses, and in particular, to actuators for positioning apparatuses.
BACKGROUND
Positioning apparatuses are utilized in a variety of applications, such as scanning probe microscopy, micro-scale and nano-scale characterization and testing, and micro-scale and nano-scale fabrication or assembly. In general, a sample resting on a stage is moved approximately into position by a coarse positioning apparatus and then adjusted into a precise position by a precision positioning apparatus having finer resolution. In many cases, positioning apparatuses employ piezoelectric actuators.
Referring to FIG. 1 , one example of a positioning apparatus is a friction-driven actuator 100 used for positioning a sample 199 that rests on a driven element 190 . A piezoelectric (PZT) element 150 is attached to a base 110 . A friction element 170 coupled to the PZT element 150 frictionally engages a bottom surface of the driven element 190 . The PZT element 150 elongates or contracts in the X direction in response to an applied electrical signal, causing the friction element 170 to move along the X axis. This linear motion is transferred to the driven element 190 via the frictional engagement between the friction element 170 and the driven element 190 , thus causing the driven element 190 to slide relative to the base 110 and effecting Xmotion of the sample 199 in the X direction.
SUMMARY
In one aspect, the invention features an apparatus for actuating a positioning device. Such an apparatus includes a housing; a piezoelectric element connected to the housing; a driven element configured to move relative to the housing; and a flexible element connected to the piezoelectric element. The flexible element is configured to transfer a motion of the piezoelectric element to the driven element.
In some embodiments, the flexible element is configured to frictionally engage the driven element.
Other embodiments also include a preload element configured to impose a force normal to an interface between the flexible element and the driven element. Among these are those embodiments in which the pre-load element has a spring, and those in which it has a magnet. However, any other that applies a pre-loading force can be used.
Yet other embodiments include a friction element disposed between the flexible element and the driven element, the friction element being configured to frictionally engage the driven element. In some of these embodiments, the friction element includes a magnet. However, this is not always the case, as the friction element can be something other than a magnet.
Also included among the many alternate embodiments of the apparatus are those that further include a preload element configured to impose a force normal to an interface between the friction element and the driven element.
Other embodiments include structures for guiding motion of the drive element relative to the housing. Among these embodiments are those that include a slide guide configured to guide the motion of the driven element relative to the housing. In some of these embodiments, the slide guide is further configured to limit the extent of motion of the driven element.
In other embodiments, the driven element is separated from the piezoelectric element.
The apparatus also includes many embodiments that cause the driven element to move in a variety of directions relative to the housing. For instance, there are embodiments of the apparatus in which the driven element is configured to move linearly relative to the housing, and there are also embodiments of the apparatus in which the driven element is configured to rotate relative to the housing.
Also included are embodiments that vary the way in which the driven element is moved relative to the housing. Among these are those in which the driven element is configured to move relative to the housing via stick-slip motion.
In other embodiments, the apparatus also includes a position-sensing element coupled to the driven element; and a detection element configured to detect the position of the position-sensing element
A variety of signals can be used to control the motion caused by the apparatus. For example, embodiments of the apparatus include in which the piezoelectric element is controllable by a triangular wave signal, those in which the piezoelectric element is controllable by a saw-tooth electrical signal, those in which the piezoelectric element is controllable by a pulse-width modulated electrical signal, and those in which the piezoelectric element is controllable by any one of the foregoing, whether singly or in combination.
Many different kinds of piezoelectric elements can be used in the apparatus. For instance, in some embodiments, the piezoelectric element has a piezoelectric stack. In others, it has a shear mode piezoelectric element.
The driven element, in some embodiments of the apparatus, is configured to receive a specimen. For example, the driven element might be a stage of a microscope or coupled to a stage of a microscope to cause movement thereof.
In another aspect, the invention features an apparatus for actuating a positioning device. Such an apparatus includes a housing; a piezoelectric element; a flexible element connected to the piezoelectric element; and a driven element configured to move relative to the housing in response to a motion of the piezoelectric element.
Among the embodiments of the foregoing apparatus are those in which a friction element is disposed between the piezoelectric element and the driven element. Such a friction element is configured to transfer a motion of the piezoelectric element to the driven element. In some embodiments, the friction element includes a magnet.
Yet other embodiments include those having a preload element configured to impose a force normal to an interface between the friction element and the driven element.
Other embodiments include those in which the flexible element is also connected to the housing and those in which the piezoelectric element is connected to the driven element.
The friction-driven actuator described herein has a number of advantages. Piezoelectric elements are made of fragile ceramics that are generally sensitive to external impacts or shear stresses. Because the driven element does not directly contact the piezoelectric element, the piezoelectric element can be protected from damage that could otherwise result from, for instance, a sudden impact on the driven element or strain deformation of the driven element due to a heavy sample. The lifetime of the piezoelectric element can thus be extended.
The friction-driven actuator described herein can be utilized for centimeter-scale, millimeter-scale, nanometer-scale, and sub-nanometer-scale positioning, and thus is suitable for both long-range positioning and high-precision scanning in various scanning probe microscopy applications, such as atomic force microscopy (AFM).
Other features and advantages of the invention are apparent from the following description and from the claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective diagram of a prior art positioning apparatus.
FIG. 2 is a perspective diagram of a friction-driven actuator.
FIG. 3 is a block diagram of the friction-driven actuator of FIG. 2 .
FIGS. 4A and 4B are block diagrams of the friction-driven actuator of FIG. 2 with external forces applied.
FIGS. 5A and 5B are block diagrams of a friction-driven actuator employing a magnet.
FIG. 6 is a block diagram of a friction-driven actuator with a position sensor.
FIG. 7 is a triangular waveform.
FIG. 8 is a diagram illustrating elongation and contraction of a piezoelectric stack element.
FIG. 9 is a diagram illustrating shear deformation of a shear mode piezoelectric element.
FIG. 10 is a continuous saw-tooth waveform.
FIGS. 11A and 11B are block diagrams of the friction-driven actuator of FIG. 2 under the application of the saw-tooth waveform of FIG. 10 .
FIGS. 12A-12C are pulse width modulation waveforms.
FIGS. 13A and 13B are block diagrams of an alternative embodiment of a friction-driven actuator.
FIGS. 14A-14C are block diagrams of an alternative embodiment of a friction-driven actuator.
FIGS. 15A-15D are block diagrams of alternative embodiments of a friction-driven actuator.
FIGS. 16A and 16B are block diagrams of an alternative embodiment of a friction-driven actuator.
FIGS. 17A-17D are block diagrams of a friction-driven actuator that generates rotary motion in a driven element.
FIG. 18 is a block diagram of an alternative embodiment of a friction-driven actuator that generates X and Y motion in a driven element.
DETAILED DESCRIPTION
Friction-Driven Actuator
Referring to FIGS. 2 and 3 , a friction-driven actuator 10 includes a piezoelectric (PZT) element 13 , such as a PZT stack, connected at one end to a housing 11 . A second end of PZT element 13 is connected to a flexible element 14 , which frictionally engages a surface 121 of a driven element 12 . In some cases, the flexible element 14 directly contacts a surface 121 of the driven element 12 . In other cases, the flexible element 14 is coupled via a friction element 16 to the driven element 12 . The friction element 16 is anchored to the flexible element 14 and is frictionally coupled to the driven element 12 . The driven element 12 holds a specimen (not shown), such as a specimen for investigation in a scanning probe microscope, or a stage on which a specimen is placed.
Application of an electrical signal to the PZT element 13 induces an elongation or contraction of the PZT element in the X direction. As the PZT element 13 elongates and contracts, the flexible element 14 and the friction element 16 are moved in the X direction. Due to the frictional contact between the friction element 16 and the driven element 12 , the driven element 12 is also moved in the X direction relative to the housing 11 . The direction and extent of motion of the driven element 12 are restricted by a slide guide 18 .
The driven element 12 does not directly contact the PZT element 13 . Thus, any load, stress, or strain applied to the driven element 12 (e.g., by the weight of a specimen resting on driven element 12 ) or to another part of friction-driven actuator 10 is absorbed by the flexible element 14 rather than by the PZT element 13 . The presence of the flexible element 14 thus protects the PZT element 13 from damage, cracking, malfunction, and stresses that are often induced by the application of external forces to a PZT element. For instance, referring to FIG. 4A , an external impact torques the driven element 12 , thus tilting it relative to the slide guide 18 , and bending the flexible element 14 , thereby protecting the PZT element 13 from experiencing a torque. Similarly, referring to FIG. 4B , a downward force applied to the driven element 12 (e.g., by the weight of a specimen) also causes the flexible element 14 to bend, and thus avoids application of a torque to the PZT element 13 .
The flexible element 14 may be formed of, for instance, steel, aluminum, carbon fiber, plastic, wood, or another suitable material. The friction element 16 is formed of, for instance, ceramic, copper or copper alloy, sapphire, or another material suitable to establish a frictional contact with the driven element 12 . In some cases, the friction element 16 may be formed of a magnet, a magnetic material, or a conductive material, including a magnetic conductive material.
Referring again to FIGS. 2 and 3 , a preload element 151 is disposed between the flexible element 14 and the housing 11 . The preload element 151 is, for instance, a spiral spring or a spring plate formed of metal, carbon fiber, or plastic. The preload element 151 applies a mechanical force between the friction element 16 and the surface 121 of the driven element 12 , augmenting the frictional force between the friction element 16 and the surface 121 .
Referring to FIG. 5A , as an alternative to a mechanical preload force, a magnetic force can be applied between the friction element 16 and the driven element 12 by a magnetic preload element 152 . In this case, the driven element 12 is formed of a magnetic material or a magnetic conductive material and the magnetic preload element 152 is a magnet. The attractive magnetic force between the driven element 12 and the magnet 152 augments the frictional force between the friction element 16 and the surface 121 .
In an alternative embodiment illustrated in FIG. 5B , a magnetic force causes the friction force. In this embodiment, the driven element 12 is formed of a magnetic material, and a magnet 154 is disposed between the flexible element 14 and the driven element 12 . Motion is transferred from PZT 13 to the driven element 12 via a combination of a frictional coupling between the magnet 154 and the driven element 12 and a magnetic coupling between the magnet 154 and the driven element 12 .
Referring to FIG. 6 , a position sensor 15 is coupled to the driven element 12 . An encoder 17 , which may employ optical, magnetic, resistive, or other encoding mechanisms, is coupled to the housing 11 . The position sensor 15 communicates with the encoder 17 to allow long-range closed-loop positioning control of the friction-driven actuator 10 .
Control of the Piezoelectric Element
The PZT element used in the friction-driven actuator may include a piezoelectric stack element, a shear mode piezoelectric element, or another type of piezoelectric element. The PZT element may be driven by any of a number of electrical signal formats, such as a triangular signal, a saw-tooth signal, or a pulse width modulation signal. The frequency, amplitude, and shape of the electrical signal applied to the PZT element affect the transfer of motion from the PZT element to the driven element. Appropriate selection of the frequency, amplitude, and shape of the electrical signal can enable rapid long-range (centimeter or millimeter scale) positioning and scanning as well as slower, precision (nanometer or sub-nanometer scale) positioning and scanning.
Referring to FIGS. 7 and 8 , a PZT stack 41 is actuated via the application of the triangular electrical signal shown in FIG. 7 for sub-nanometer scale high resolution positioning and scanning in one direction. Prior to application of a signal, the PZT stack 41 is not deformed, as shown in FIG. 8A . Upon application of a first signal C 11 , the PZT stack 41 elongates by a distance ΔX along the X axis to a position +ΔX, as shown in FIG. 8B . Upon application of a second signal C 12 , the PZT stack 41 contracts along the X axis to a position −ΔX, as shown in FIG. 8C . In response to a third signal C 13 , the PZT stack 41 elongates to its original configuration, as shown again in FIG. 8A .
Referring to FIGS. 7 and 9 , a shear mode PZT element 42 is actuated via the application of the same triangular electrical signal. Prior to application of a signal, the PZT element 42 is not deformed (position A). Upon application of the first signal C 11 , the PZT element 42 deforms and a top surface of the PZT element 42 shifts along the X axis to a position +ΔX (position B). Upon application of the second signal C 12 , the PZT element 42 deforms in the opposite direction and the top surface of the PZT element 42 shifts along the X axis to a position −ΔX (position C). In response to the third signal C 13 , the PZT element 42 returns to its original configuration (position A).
Referring to FIGS. 10 and 11A , the PZT element 13 is actuated via the continuous saw-tooth waveform to drive the driven element via “stick-slip” motion (also known as “inertial drive”) for long-range motion. Prior to the application of an electrical signal, the PZT element 13 is not deformed, and a distal end 19 of the driven element 12 is at its initial position X 1 (shown in FIG. 3 ). When a voltage signal C 1 is applied to the PZT element 13 , the PZT element 13 elongates in the X direction, causing the flexible element 14 and the friction element 16 to move in the X direction. This motion is transferred to the driven element 12 via the frictional coupling between the friction element 16 and the driven element 12 , causing a distal end 19 of the driven element 12 to move a distance ΔX to position X 2 .
Referring now to FIGS. 10 and 11B , a second voltage signal C 2 is then applied to the PZT element 13 , causing the PZT element 13 to contract to its original configuration. This contraction causes the flexible element 14 and the friction element 16 to move back along the X axis to their respective original positions. However, if the dynamic acceleration of the flexible element 14 and the friction element 16 caused by the sudden contraction of the PZT element 13 is sufficiently large, relative motion may occur between the friction element 16 and the driven element 12 . For example, the friction element 16 may slide relative to the driven element 12 , causing the driven element 12 to stay in position X 2 (as shown) or to move back along the X axis by a distance less than ΔX.
When applying a continuous saw-tooth or inverted saw-tooth waveform to the PZT element 13 , the driven element 12 may be moved by this stick-slip mechanism in the range of a millimeter in the X direction relative to housing 11 . The frequency and/or amplitude of the saw-tooth waveform can be adjusted to achieve a desired response from the PZT element.
Referring to FIGS. 2 and 12 A- 12 C, the PZT element 13 may also be controlled by an electrical pulse width modulated (PWM) signal for high-speed, centimeter-scale long range movement via a stick-slip mechanism. No movement of the driven element 12 occurs when a selective frequency square wave with 50% duty cycle (i.e., t/T=0.5; FIG. 12A ) is applied to the PZT element 13 . When a square wave with less than 50% duty cycle (t/T<0.5; FIG. 12B ) is applied to the PZT element 13 , the driven element 12 moves in the +X direction. When a square wave with greater than 50% duty cycle (t/T>0.5; FIG. 12C ) is applied to the PZT element 13 , the driven element 12 moves in the −X direction. In general, stick-slip motion driven by a PWM signal is faster but less precise than motion driven by a triangular or saw-tooth electrical signal.
Alternative Configurations
Referring to FIG. 13A , in an alternative configuration, a friction-driven actuator 20 includes a housing 21 , and a PZT element 23 connected at a first end to a driven element 22 and at a second end to a flexible element 24 . A friction element 26 is anchored to flexible element 24 and slidably frictionally engages a top surface of a slide guide 28 . The elongation and contraction of the PZT element 23 causes driven element 22 to move in the ±X direction along slide guide 28 by a stick-slip mechanism. In this embodiment, the distance that driven element 22 can be moved is limited by the length of slide guide 28 rather than by the length of driven element 22 . This embodiment is well suited to millimeter- or centimeter-scale long range motion.
In an alternative embodiment shown in FIG. 13B , slide guide 28 is formed of a magnetic material, and a magnet 25 is disposed between flexible element 24 and slide guide 28 . Magnet 25 and slide guide 28 are engaged via both a frictional coupling and an attractive magnetic force.
Referring to FIGS. 14A-14C , in another alternative configuration, a friction-driven actuator 70 includes a flexible element 74 connected at a first end to a housing 71 and at a second end to a PZT element 73 . A driven element 72 is mounted on a slide guide 78 , which is connected to the housing 71 . As the PZT element elongates and contracts, this linear motion is transferred to the driven element 72 via a friction element 76 , which is slidably frictionally coupled to the driven element 72 . In some cases, a mechanical or magnetic preload force may be applied. In this configuration, the flexible element 74 protects the PZT element 73 from potentially damaging loads, stresses, and strains, such as a torque from the weight of a specimen, as shown in FIG. 14C .
Referring to FIGS. 15A-15D , in some embodiments, a slide guide is not present. Referring specifically to FIGS. 15A and 15C , in friction-driven actuators 60 a and 60 c , a PZT stack 63 a and a shear PZT element 63 c , respectively, are anchored to a housing 61 . Motion of the PZT stack 63 a and the PZT element 63 c is transferred to a driven element 62 via a flexible element 64 and a friction element 66 . A mechanical or magnetic preload force may also be applied.
Referring now to FIGS. 15B and 15D , in friction-driven actuators 60 b and 60 d , a flexible element 64 ′ is anchored to housing 61 . A PZT stack 63 b and a shear PZT element 63 d , respectively, are connected to the flexible element 64 ′. Motion of the PZT stack 63 b and the shear PZT element 63 d is transferred to a driven element 62 via a friction element 66 ′. A mechanical or magnetic preload force may also be applied.
Referring to FIG. 16A , in another alternative embodiment, a friction-driven actuator 50 includes two shear mode PZT elements 53 a , 53 b anchored at one end to a housing 51 . Application of an electrical signal to the PZT elements 53 a , 53 b induces shear deformation in the PZT elements 53 a , 53 b . Second ends of the PZT elements 53 a , 53 b are connected to flexible elements Ma, 54 b , which frictionally engage a driven element 52 via two friction elements 56 a , 56 b . In some instances, the flexible elements 54 a , 54 b directly frictionally engage the driven element 52 . Preload elements 551 a , 551 b , such as springs, apply forces between the friction elements 56 a , 56 b and the driven element 52 , increasing the strength of the coupling between the friction elements 56 a , 56 b and the driven element 52 . The shear deformations of the PZT elements 53 a , 53 b are transferred to the flexible elements 54 a , 54 b and the friction elements 56 a , 56 b as linear motion along the X axis, which in turn causes the driven element 52 to move in the X direction along a slide guide 58 .
Referring to FIG. 16B , in another example, a magnet 552 is added to a friction-driven actuator 50 between a flexible element 54 and a friction element 56 . The driven element 52 is formed of a magnetic material. The attractive magnetic force between a magnet 552 and the driven element 52 enhances the frictional coupling between the friction element 56 and the driven element 52 .
Referring to FIG. 17A , in another embodiment, a friction-driven actuator 30 induces rotary motion in a ring-shaped driven element 32 related to the ring shape rotary guide 38 . A PZT element 33 is connected at one end to a housing 31 (not shown). A second end of the PZT element 33 is connected to a flexible element 34 . The flexible element 34 is frictionally coupled to a side face 321 of the driven element 32 via a friction element 36 . A preload force P, generated by a spring, a magnet, or another mechanism, enhances the coupling between the friction element 36 and the driven element 32 . Application of an electrical signal to the PZT element 33 induces an elongation or contraction of the PZT element 33 , which in turn causes the flexible element 34 and the friction element 36 to move in the X direction. Through the frictional coupling between the friction element 36 and a side face 321 of the driven element 32 , the X direction motion of the friction element 36 induces rotation of the driven element 32 about its center.
Referring to FIG. 17B , in some cases, the driven element 32 is formed of a magnetic material, and a magnet 35 is employed in place of the friction element 36 . The attractive magnetic force between the driven element 32 and the magnet 35 enhances the frictional force between the driven element 32 and the magnet 35 .
Referring to FIG. 17C , in other instances, the driven element 32 is formed of a magnetic material, and a magnet 35 ′ is coupled to a side surface 321 of the driven element 32 . Elongation or contraction of the PZT element 33 causes a flexible element 34 and the magnet 35 ′ to move in the X direction, inducing rotation of the driven element 32 about its center.
Referring to FIG. 17D , a friction-driven actuator 30 ′ induces rotary motion in a driven element 32 ′. A first portion of the friction-driven actuator 30 ′ includes a piezoelectric element 33 a connected at one end to a housing 31 a . A second end of the piezoelectric element 33 a is connected to a flexible element 34 a . The flexible element 34 a directly engages a bottom edge of the driven element 32 ′. A preload force Pa enhances the frictional force between the flexible element 34 a and the driven the element 32 ′. A second portion of the friction-driven actuator 30 ′ includes a piezoelectric element 33 b connected at one end to a housing 31 b . A second end of piezoelectric element 33 b is connected to a flexible element 34 b . The flexible element 34 b directly engages a top edge of the driven element 32 ′. A preload force Pb enhances the frictional force between the flexible element 34 b and the driven element 32 ′. Rotation of the driven element 32 ′ is controlled by both piezoelectric elements 33 a and 33 b . In some cases, a friction element (not shown) is disposed between the flexible element 34 a and the driven element 32 ′ and/or between the flexible element 34 b and the driven element 32 ′.
Referring to FIG. 18 , a friction-driven actuator 80 induces X and Y linear motion in a driven element 82 . The friction-driven actuator 80 includes a first piezoelectric element 83 a connected at one end to an X, Y slide guide frame 88 . The other end of the piezoelectric element 83 a is connected to a flexible element 84 a . The flexible element 84 a is connected at the other end to a friction element 86 . The second piezoelectric element 83 b is connected at one end to the X, Y slide guide frame 88 and the other end of the piezoelectric element 83 b is connected to a flexible element 84 b . The flexible element 84 b is connected at the other end to the friction element 86 . The friction element 86 engages a bottom face of the driven element 82 . A preload force P enhances the frictional force between the friction element 86 and the driven element 82 . X axis movement of the driven element 82 is driven by the piezoelectric element 83 a . Y axis movement of the driven element 82 is driven by the piezoelectric element 83 b.
In general, a shear mode PZT can be used in place of a PZT stack in both the linear and rotational motion embodiments described above.
It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims. | An apparatus for actuating a positioning device includes a housing; a piezoelectric element connected to the housing; a driven element configured to move relative to the housing; and a flexible element connected to the piezoelectric element and configured to transfer a motion of the piezoelectric element to the driven element. | 7 |
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/973,971 filed on Apr. 2, 2014, the entire contents of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed generally to non-aqueous heat transfer fluids comprised primarily of ethylene glycol (EG), a glycol that exhibits supercooling. The fluids are further comprised of one or more other glycols that also exhibit supercooling. The heat transfer fluid may be used in internal combustion engines as an engine coolant. By combining certain glycols that also exhibit supercooling with the EG, the low temperature operating limit (LTOL) of the heat transfer fluid is lowered, thereby expanding the operating range of the fluid in cold environments, while avoiding the high viscosities from combinations using 1,2 propanediol (PG) for the same purpose.
BACKGROUND
[0003] A non-aqueous heat transfer fluid is a heat transfer fluid formulated and used without any added water. The heat transfer fluid may contain some small, incidental amount of water as a trace impurity, typically below one percent by weight. Corrosion inhibitors for non-aqueous heat transfer fluids do not require water in order for them to dissolve. By contrast, an aqueous, water-glycol heat transfer fluid typically comprises water, one or more polyhydric alcohol freezing point depressants, and may contain one or more corrosion inhibitors or buffers that require water for them to dissolve.
[0004] Water in its liquid state has excellent heat transfer characteristics. Even when the water is combined with a polyhydric alcohol freezing point depressant, such as EG, the heat capacity and thermal conductivity of the resulting aqueous heat transfer fluid remain preferable for heat transfer applications as long as the fluid is maintained in its liquid state. The challenge for a water-glycol heat transfer fluid is keeping it in its liquid state at all times, under the high heat density conditions of modern engines and their Exhaust Gas Recirculation (EGR) coolers. Water-glycol heat transfer fluids are operated close to their boiling points and water vapor from localized boiling is not always surrounded by liquid fluid cold enough to condense the water vapor. Water vapor does not transfer heat well. A coolant that is 50% water together with 50% ethylene glycol has a thermal conductivity of about 0.42 W/m·K in its liquid state, while water vapor, liberated by localized boiling, has a thermal conductivity of just 0.024 W/m·K, a 94% decrease. When water vapor displaces liquid coolant from hot engine metal, hot spots can develop that result in pre-ignition, detonation, and possible engine damage.
[0005] Non-aqueous heat transfer fluids have atmospheric boiling points that are far hotter than the temperatures at which they are typically controlled. Localized boiling can still produce vapor but the vapor condenses immediately into colder surrounding liquid coolant, avoiding the pocketing of vapor and displacement of liquid coolant. Use of a high boiling point non-aqueous coolant, by preventing the accumulation of vapor, keeps liquid in contact with hot metal at all times, giving improved heat transfer, as compared to coolants that contain water under conditions when water vapor is present.
[0006] Among the most common glycols that might comprise a non-aqueous coolant, EG stands out as having the highest thermal conductivity and lowest viscosity, both extremely important for a good non-aqueous heat transfer fluid. The downside of anhydrous EG is that it exhibits a supercooling range that initiates solidification at an easily-reached low temperature. Once solidified, it remains solidified until it is heated to a higher temperature, its published freezing point.
[0007] The freezing point of a glycol that exhibits supercooling is a temperature well above the temperature where solidification from low temperatures initiates. The supercooling temperature range of a glycol that exhibits supercooling is a freezing range; it begins to freeze at a lower temperature and remains frozen to a higher temperature. The freezing point of a glycol that exhibits supercooling is actually the melting point of the solidified mass after it freezes. The published freezing point for EG is −13° C., a temperature well above the temperature that is required to be reached in order to initiate freezing (−22° C.). The LTOL of an anhydrous glycol that exhibits supercooling is a temperature just above the onset of freezing symptoms. If the LTOL is never reached, operation within the supercooling range is stable, without nodules, crystals or solidification. The LTOL for EG at −21° C. (8° C. colder than its −13° C. freezing point) can be easily breached if the EG is exposed to common wintertime weather in many parts of the world.
[0008] U.S. Pat. No. 8,394,287 (the '287 patent) describes the use of propylene glycol (PG or 1,2 propanediol), as a means to reduce the toxicity of EG, but also as a means to lower the temperature at which the freezing of EG is initiated. PG, unique among glycols, does not exhibit a supercooling range, despite certain industry literature stating to the contrary. PG simply gets thicker and thicker to at least −65° C., where it is “rubbery”, rather than solid in a crystalline sense. Taken to the lower temperature of −86° C., PG is solid but still exhibits no nodules or crystals. As such, PG does not have an LTOL based upon a temperature at which freezing occurs, but is technically limited only by its low-temperature viscosity. (The temperature of −60° C. for PG is variously reported as the freezing point or the temperature below which it “sets to glass”. Another source reports −57° C. as PG's pour point.). The addition of PG to EG effectively lowers the LTOL of EG to temperatures far colder than the −21° C. LTOL for EG. The use of PG to lower the freezing point of EG as in the '287 patent, however, comes with the penalty of increased viscosity of the heat transfer fluid, as PG is extremely viscous at low temperatures.
[0009] At −40° C., EG, by itself, is of course frozen solid. PG at −40° C. is highly viscous, having a viscosity of 21,600 mPa·s. Mixtures of EG and PG are viscosity-tempered to a large extent because EG is the glycol that exhibits the lowest viscosity. A non-aqueous EG/PG coolant mixture, comprised of 13.5% PG and 86.5% EG can tolerate −40° C. without solidifying and the mixture has a viscosity of about 2,500 mPa·s. It would be advantageous to lower the viscosity of non-aqueous EG-based heat transfer fluids further.
[0010] It would be desirable to find one or more glycols that could be added to ethylene glycol that would have at least the same capacity as PG to lower the LTOL of a non-aqueous ethylene glycol-based heat transfer fluid, and that contributed a lower increase in viscosity at lower temperatures, than results from the addition of PG to a non-aqueous ethylene glycol based heat transfer fluid.
SUMMARY OF THE INVENTION
[0011] The current invention is directed to a non-aqueous heat transfer fluid comprising EG combined with 1,3 propanediol (“PDO”) and/or diethylene glycol (“DEG”). EG, PDO and DEG, all exhibit supercooling ranges. The published freezing points for EG, PDO, and DEG are −13° C., −24° C., and −9° C., respectively. These are the temperatures at which these glycols melt after they have undergone solidification at lower temperatures. The onset of freezing symptoms for EG, PDO, and DEG are −22° C., −45° C., and −36° C., respectively. Table 1 shows the LTOL and the supercooling range for each of these glycols.
[0000]
TABLE 1
EG
PDO
DEG
Published Freezing Point ° C.
−13
−24
−9
Onset of Freezing Symptoms ° C.
−22
−45
−36
Low Temperature Operating
−21
−44
−35
Limit (LTOL) ° C.
Supercooling Range ° C.
−22 to −13
−45 to −24
−36 to −9
[0012] EG has the lowest viscosity of all glycols and the greatest thermal conductivity of all glycols. It has a supercooling range that prevents it from being used as a non-aqueous heat transfer fluid in most climates because it solidifies at −22° C. This invention combines EG with minor amounts of PDO and/or DEG, both of which exhibit supercooling ranges, with the surprising result that the combination retains nearly all of EG's viscosity and thermal conductivity features, while giving the fluid a substantially improved LTOL, such as −40° C. The resulting viscosity by this technology, at any given LTOL, is significantly less than the viscosity from using an EG/PG mixture for the same purpose. The non-aqueous heat transfer fluid contains suitable hybrid additives for the inhibition of corrosion.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a chart that shows the general temperature profile of a glycol that exhibits supercooling.
[0014] FIG. 2 is a chart that shows the temperature profile of EG at temperatures below 0° C.
[0015] FIG. 3 is a chart showing the temperature profile of PG at temperatures below 0° C.
[0016] FIG. 4 is a chart showing the temperature profile of PDO at temperatures below 0° C.
[0017] FIG. 5 is a chart showing the temperature profile of DEG at temperatures below 0° C.
[0018] FIG. 6 is a chart showing the temperature profile of a heat transfer fluid comprising EG and PG with a PG to (EG+PG) mass ratio of 0.135 at temperatures below 0° C.
[0019] FIG. 7 is a chart showing the temperature profile of a heat transfer fluid comprising EG and PDO with a PDO to (EG+PDO) mass ratio of 0.14 at temperatures below 0° C.
[0020] FIG. 8 is a chart showing the temperature profile of a heat transfer fluid comprising EG and PDO with a PDO to (EG+PDO) mass ratio of 0.275 at temperatures below 0° C.
[0021] FIG. 9 is a chart showing the temperature profile of a heat transfer fluid comprising EG and PDO with a PDO to (EG+PDO) mass ratio of 0.40 at temperatures below 0° C.
[0022] FIG. 10 is a chart showing the temperature profile of a heat transfer fluid comprising EG and DEG with a DEG to (EG+DEG) mass ratio of 0.22 at temperatures below 0° C.
[0023] FIG. 11 is a chart showing the temperature profile of a heat transfer fluid comprising EG and DEG with a DEG to (EG+DEG) mass ratio of 0.30 at temperatures below 0° C.
[0024] FIG. 12 is a chart showing the temperature profile of a heat transfer fluid comprising EG and DEG with a DEG to (EG+PDO) mass ratio of 0.40 at temperatures below 0° C.
[0025] FIG. 13 is a chart showing the temperature profile of a heat transfer fluid comprising EG, PDO and DEG with a PDO to (EG+PDO+DEG) mass ratio of 0.06 and with a DEG to (EG+PDO+DEG) mass ratio of 0.10 at temperatures below 0° C.
[0026] FIG. 14 is a chart showing the temperature profile of a heat transfer fluid comprising EG, PDO and DEG with a PDO to (EG+PDO+DEG) mass ratio of 0.12 and with a DEG to (EG+PDO+DEG) mass ratio of 0.155 at temperatures below 0° C.
[0027] FIG. 15 is a chart showing the temperature profile of a heat transfer fluid comprising EG, PDO and DEG with a PDO to (EG+PDO+DEG) mass ratio of 0.20 and with a DEG to (EG+PDO+DEG) mass ratio of 0.20 at temperatures below 0° C.
DESCRIPTION OF THE INVENTION
[0028] The present invention is directed to a non-aqueous heat transfer fluid comprising EG combined with PDO and/or DEG. When a sufficient amount of PDO and/or DEG is combined with EG, the LTOL of the resulting heat transfer fluid can be reduced to any temperature desired below EG's LTOL, thereby extending the operating range of the non-aqueous heat transfer fluid.
[0029] The non-aqueous heat transfer fluid begins with anhydrous EG because EG (1) has the highest thermal conductivity of all the alkylene glycols and (2) has the lowest viscosity of all the alkylene glycols. A significant disadvantage of the use of EG in a non-aqueous heat transfer fluid is that it freezes at temperatures easily encountered in cold climates.
[0030] Most anhydrous glycols, including EG, DEG, and PDO, have a supercooling range that is shown generally in FIG. 1 . Glycols that have a supercooling range do not exhibit any of the physical characteristics of freezing, such as formation of solid crystals or nodules, until the fluid reaches a temperature well below the temperature where crystals or nodules will melt back into a liquid form. One could say that the supercooling temperature range of a glycol that exhibits supercooling, is a freezing range; it begins to freeze at a lower temperature and remains frozen to a higher temperature. The “freezing point” of a glycol that exhibits supercooling is actually the melting point of the solidified mass after it freezes. Indeed, the temperature often referred to as the “freezing point” is usually determined using an apparatus that measures the melting point of solid material. The LTOL of an anhydrous glycol that exhibits supercooling is the temperature just above the onset of freezing symptoms. If the LTOL is never violated, operation within the supercooling range is stable, without nodules or solidification.
[0031] As shown in FIG. 2 , EG has a freezing point of −13° C. and a supercooling range that extends from −22° C. to −13° C. The LTOL of EG is about −21° C., i.e. about one degree warmer than −22° C., the temperature at which freezing symptoms initiate.
[0032] FIG. 3 shows that PG does not exhibit a supercooling range and in fact does not form nodules or crystals that would indicate a freezing condition. In an actual test at −65° C., PG exhibited no symptoms of freezing, was a clear but very thick liquid, and would flow, albeit very slowly. Taking the temperature down to −86° C., the limit of the testing equipment, the PG was solid, but not crystalline. Reheating did not produce a melting but rather a viscosity reduction. In the prior art, PG added to EG produced a lower LTOL, depending upon the amount of PG added. The disadvantage of using PG for that purpose is the excessive viscosity of the resulting heat transfer fluid at low temperatures. The viscosity of neat PG, tested at −40° C., was found to be 21,600 mPa·s. The viscosity of neat PDO, tested at the same temperature, was just 3480 mPa·s. (The viscosity of neat DEG cannot be ascertained at −40° C. because it solidifies at −36° C.)
[0033] FIG. 4 for PDO shows a very different characteristic from that of PG ( FIG. 3 ). As shown in FIG. 4 , PDO has a freezing point of −24° C. and a supercooling range that extends from −45° C. to −24° C. The LTOL of PDO is −44° C., i.e. about one degree warmer than −45° C., the temperature at which freezing symptoms initiate.
[0034] FIG. 5 for DEG shows distinctive differences from both EG ( FIG. 2 ) and PDO ( FIG. 4 ), all of which exhibit supercooling ranges. As shown in FIG. 5 , DEG has a freezing point of −9° C. and a supercooling range that extends from −36° C. to −9° C. The LTOL of DEG is −35° C., i.e. about one degree warmer than −36° C., the temperature at which freezing symptoms initiate.
[0035] FIG. 6 shows the effect of combining EG, which exhibits supercooling, with PG, which does not, at a PG to (EG+PG) mass ratio of 0.135. The resulting heat transfer fluid exhibits supercooling and has an LTOL of −40° C. The viscosity of the heat transfer fluid is 2540 mPa·s at −40° C.
[0036] In a surprising discovery, the inventor found that the LTOL of EG can be extended to much colder temperatures by the addition of PDO, which itself exhibits supercooling. FIG. 7 shows the effect of combining EG and PDO at a PDO to (EG+PDO) mass ratio of 0.14. The resulting heat transfer fluid exhibits supercooling and has an LTOL of −40° C. The viscosity of the EG/PDO mixture at −40° C. tested at 1950 mPa·s compared to 2540 mPa·s using PG in a similar concentration, a 23% reduction in viscosity. The lower viscosity of the EG/PDO mixture is advantageous for using the fluid in heat transfer applications, particularly in cold climates.
[0037] Higher PDO to (EG+PDO) mass ratios (in the range toward about 0.50) produce progressively lower LTOL values. FIG. 8 shows an LTOL of −51.1° C. by increasing the PDO to (EG+PDO) mass ratio to 0.275. The LTOL of −51.1° C. (−60° F.) is an appropriate LTOL for a coolant blended for use in Arctic regions.
[0038] A further increase in the PDO to (EG+PDO) mass ratios to 0.40 and beyond produced another unexpected result: PDO/EG combinations in this range have no freezing symptoms and do not change from liquid to solid at temperatures as cold as −86° C. (the limit of the test apparatus). In other words, a mixture of EG and PDO, having a 0.40 mass ratio of PDO to (EG+PDO), does not supercool. FIG. 9 for a PDO to (EG+PDO) mass ratio of 0.40 looks like FIG. 3 for neat PG, except that the EG/PDO combination continued to pour, albeit very slowly, all the way down to −86° C. Useful PDO to (EG+PDO) mass ratios are in the range of about 0.05 and about 0.50.
[0039] In a surprising discovery, the inventor found that the LTOL of EG can also be extended to much colder temperatures by the addition of DEG, which itself exhibits supercooling. FIG. 10 shows the effect of combining EG and DEG at a DEG to (EG+DEG) mass ratio of 0.22. The resulting heat transfer fluid exhibits supercooling and has an LTOL of −40° C. The viscosity of an EG based heat transfer fluid with an LTOL capability of −40° C. tested at 2135 mPa·s using DEG compared to 2540 mPa·s using PG, a 15.9 percent reduction in viscosity. The lower viscosity of the EG/DEG mixture, while not as dramatic as in the EG/PDO case, is advantageous for using the fluid in heat transfer applications, particularly in cold climates.
[0040] Higher DEG to (EG+DEG) mass ratios produce progressively lower LTOL values. FIG. 11 shows an LTOL of −51.1° C. by increasing the DEG to (EG+DEG) mass ratio to 0.30. The LTOL of −51.1° C. (−60° F.) is an appropriate LTOL for a coolant blended for use in Arctic regions.
[0041] Higher DEG to (EG+DEG) mass ratios in the range of 0.30 to about 0.50 produce progressively lower LTOL values. A DEG to (EG+DEG) mass ratio of 0.40 produced another unexpected result: A DEG/EG combination of this mass ratio has no freezing symptoms and does not change from liquid to solid at temperatures as cold as −86° C., showing that it does not supercool. FIG. 12 for a DEG to (EG+DEG) mass ratio of 0.40 looks the same as FIG. 9 that shows a PDO to (EG+PDO) mass ratio of 0.40. Useful DEG to (EG+DEG) mass ratios are in the range of about 0.05 to about 0.50.
[0042] In a surprising discovery, the inventor found that the LTOL of EG can also be extended to much colder temperatures by the addition of both PDO and DEG, both of which exhibit supercooling. FIG. 13 shows the effect of combining EG, PDO and DEG at a PDO to (EG+PDO+DEG) mass ratio of 0.06 and a DEG to (EG+PDO+DEG) mass ratio of 0.10. The resulting heat transfer fluid exhibits supercooling and has an LTOL of −40° C.
[0043] Greater PDO to (EG+PDO+DEG) and DEG to (EG+PDO+DEG) mass ratios produce progressively lower LTOL values. FIG. 14 shows an LTOL of −51.1° C. achieved by increasing the PDO to (EG+PDO+DEG) mass ratio to 0.12 and increasing the DEG to (EG+PDO+DEG) mass ratio to 0.155.
[0044] Higher PDO to (EG+PDO+DEG) and DEG to (EG+PDO+DEG) mass ratios produce progressively lower LTOL values. A PDO to (EG+PDO+DEG) mass ratio of 0.20, together with a DEG to (EG+PDO+DEG) mass ratios of 0.20 produced yet another unexpected result: A PDO/DEG/EG combination of these mass ratios has no freezing symptoms and does not change from liquid to solid at temperatures as cold as −86° C. and shows that it does not supercool. FIG. 15 for these mass ratios looks the same as FIG. 9 , that has a PDO to (EG+PDO) mass ratio of 0.40, and the same as FIG. 12 , that has a DEG to (EG+DEG) mass ratio of 0.40.
[0045] When the non-aqueous EG-based heat transfer fluid comprises both PDO and DEG, the useful PDO to (EG+PDO+DEG) mass ratio range would be about 0.025 to about 0.40 and the useful DEG to (EG+PDO+DEG) mass ratio range would also be about 0.025 to about 0.40. The useful range for the mass ratio of (PDO+DEG) to (EG+PDO+DEG) is about 0.05 to about 0.50.
[0046] The heat transfer fluid may also contain one or more corrosion inhibiting additives. The non-aqueous heat transfer fluid contains only a trace of water when formulated, i.e. less than 1.0% by weight. It is possible that, in use, additional amounts water may become present as an impurity. In general, the water content of the non-aqueous heat transfer fluid during use should not exceed about three percent, and less preferably, five percent.
[0047] Because the non-aqueous heat transfer fluid contains almost no water, the corrosion inhibitor must be soluble in at least one of the glycols in the heat transfer fluid. Corrosion inhibitor additives that may be used in the heat transfer fluid includes nitrates, such as sodium nitrate, molybdates, such as sodium molybdate, azole compounds, such as tolyltriazole (TT), hydrogenated tolyltriazole (THT), butylbenzotriazole (BBT), or mixtures thereof, and one or more organic acid corrosion inhibiting agents, such as 2-ethylhexanoic acid. Combinations of these corrosion inhibitors may also be used. Additionally, potassium or sodium hydroxide may be suitably added to raise the pH of the heat transfer fluid to a desired level. The corrosion inhibitor additives may be present in concentrations of about 0.05% to about 3% by weight.
[0048] There are various benchmarks that are important for non-aqueous heat transfer fluids used as engine coolants. The most important is an LTOL of −40° C., as the temperatures at all times on most of the world's surface never reach temperatures that cold. In one embodiment of the heat transfer fluid with an LTOL of −40° C. is comprised of EG and PDO, with a PDO to (EG+PDO) mass ratio of about 0.14. The heat transfer fluid is further comprised of at least one corrosion inhibitor selected from a nitrate, such as sodium nitrate, a molybdate, such as sodium molybdate, an azole, such as tolyltriazole (TT), hydrogenated tolyltriazole (THT), butylbenzotriazole (BBT), or mixtures thereof, a carboxylic acid, such as 2-ethylhexanoic acid, and a hydroxide, such as potassium hydroxide. The one or more corrosion inhibitors may be present in the following concentrations: nitrate: about 0.05% to about 3%, molybdate: about 0.05% to about 3%, azole: about 0.1% to about 3%, carboxyl acid: about 0.1% to about 3%, and hydroxide: about 0.1% to about 3%. This preferred embodiment exhibits a viscosity of 1950 mPa·s at −40° C., compared to 2540 mPa·s for a comparable PG/EG fluid having a −40° C. LOTL.
[0049] In a second embodiment, a heat transfer fluid with an LTOL of −40° C. is comprised of EG and DEG, with a DEG to (EG+DEG) mass ratio of about 0.22. The heat transfer fluid is further comprised of at least one corrosion inhibitor selected from a nitrate, such as sodium nitrate, a molybdate, such as sodium molybdate, an azole, such as tolyltriazole (TT), hydrogenated tolyltriazole (THT), butylbenzotriazole (BBT), or mixtures thereof, a carboxylic acid, such as 2-ethylhexanoic acid, and a hydroxide, such as potassium hydroxide. The one or more corrosion inhibitors may be present in the following concentrations: nitrate: about 0.05% to 3%, molybdate: about 0.05% to 3%, azole: about 0.1% to 3%, carboxyl acid: about 0.1% to 3%, and hydroxide: about 0.1% to 3%. This second embodiment exhibits a viscosity of 2135 mPa·s at −40° C., as compared to 2540 mPa·s for a comparable PG/EG fluid having a −40° C. LOTL.
[0050] A third embodiment of the heat transfer fluid with an LTOL of −40° C. is comprised of EG, PDO, and DEG, with a mass PDO to (EG+PDO+DEG) ratio of about 0.06 and a mass DEG to (EG+PDO+DEG) ratio of about 0.10. The heat transfer fluid is further comprised of at least one corrosion inhibitor selected from a nitrate, such as sodium nitrate, a molybdate, such as sodium molybdate, an azole, such as tolyltriazole (TT), hydrogenated tolyltriazole (THT), butylbenzotriazole (BBT), or mixtures thereof, a carboxylic acid, such as 2-ethylhexanoic acid, and a hydroxide, such as potassium hydroxide. The one or more corrosion inhibitors may be present in the following concentrations: nitrate: about 0.05% to 3%, molybdate: about 0.05% to 3%, azole: about 0.1% to 3%, carboxyl acid: about 0.1% to 3%, and hydroxide: about 0.1% to 3%. This embodiment exhibits a viscosity of 2001 mPa·s at −40° C., as compared to 2540 mPa·s for a comparable PG/EG fluid having a −40° C. LOTL.
[0051] Another benchmark that is important for non-aqueous heat transfer fluids used as engine coolants is an LTOL of −51.1° C. (−60° F.), as that temperature is colder than most Arctic environments. Embodiments of the heat transfer fluid for an LTOL of −51.1° C. may be 1) comprised of EG and PDO, with a PDO to (EG+PDO) mass ratio of about 0.275, 2) comprised of EG and DEG, with a DEG to (EG+DEG) mass ratio of about 0.30, or 3) comprised of EG, PDO, and DEG with a PDO to (EG+PDO+DEG) mass ratio of about 0.12 and a DEG to (EG+PDO+DEG) mass ratio of about 0.155.
[0052] These embodiments for heat transfer fluids having an LTOL of −51.1° C. are further comprised of at least one corrosion inhibitor selected from a nitrate, such as sodium nitrate, a molybdate, such as sodium molybdate, an azole, such as tolyltriazole (TT), hydrogenated tolyltriazole (THT), butylbenzotriazole (BBT), or mixtures thereof, a carboxylic acid, such as 2-ethylhexanoic acid, and a hydroxide, such as potassium hydroxide. The one or more corrosion inhibitors may be present in the following concentrations: nitrate: about 0.05% to 3%, molybdate: about 0.05% to 3%, azole: about 0.1% to 3%, carboxyl acid: about 0.1% to 3%, and hydroxide: about 0.1% to 3%.
[0053] Small percentages of other polyhydric alcohols, such as glycerol, tetraethylene glycol, triethylene glycol, PG, tripropylene glycol, and dipropylene glycol could be added to the heat transfer fluids described herein without much effect except that they would add to the viscosity, a negative feature.
[0054] As will be recognized by those skilled in the art based on the teachings herein, numerous changes and modifications may be made to the above-described embodiments of the present invention without departing from its spirit or scope. Accordingly, the detailed description of specific embodiments of the invention is to be taken in an illustrative rather than a limiting sense. | Non-aqueous heat transfer fluids or engine coolants for internal combustion engines comprised primarily of ethylene glycol, a glycol that exhibits supercooling. The fluids are further comprised of 1,3 propanediol and/or diethylene glycol which also exhibit supercooling. The combinations expand the Low Temperature Operating Limit of the ethylene glycol, while avoiding the extent of the viscosity increase imposed by the use of 1,2 propanediol for the same purpose. | 2 |
FIELD OF THE INVENTION
[0001] Disclosed herein is an expression vector capable of expressing myrcene. Also disclosed herein are a strain transformed with the vector and having improved capability of producing myrcene and a method for producing myrcene and a method for recycling glycerol using the same.
CROSS-REFERENCE TO RELATED APPLICATION
[0002] This application claims priority to Korean Patent Application No. 10-2015-0097250, filed on Jul. 8, 2015, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference.
DESCRIPTION ABOUT NATIONAL SUPPORT RESEARCH AND DEVELOPMENT
[0003] This study is made by the support of Cooperative Study Business (Creative Allied Project, CAP) of Korea Ministry of Science, ICT and Future Planning under the supervision of Korea Institute of Science and Technology, and the subject name thereof is Development of technology for producing next generation fuel/material by integrative use of woody biomass (Subject Identification No. CAP-11-1).
BACKGROUND OF THE INVENTION
[0004] Monoterpenes are naturally occurring substances which are very important in cosmetic or pharmaceutical industry. Among them, myrcene is a substance that can be used as a starting material for various substances. In particular, it can be widely used as a precursor for menthol or other alcohol substances (e.g., linalool, geraniol). Until now, various myrcene-synthesizing genes have been found in different plants and have been characterized. Nevertheless, the currently available method of producing myrcene is limited only to extraction from plants or pyrolysis of β-pinene.
REFERENCES OF THE RELATED ART
Non-Patent Documents
[0005] (Non-patent document 1) Sarria S et al., (2014) Microbial Synthesis of Pinene”, ACS Synthetic Biology 3, pp. 466-475.
SUMMARY
[0006] In an aspect, the present disclosure is directed to providing an expression vector capable of expressing myrcene by transforming Escherichia coli.
[0007] In another aspect, the present disclosure is directed to providing an Escherichia coli strain having improved capability of producing myrcene.
[0008] In another aspect, the present disclosure is directed to production of myrcene on a large scale using a transformed Escherichia coli strain.
[0009] In another aspect, the present disclosure is directed to production and isolation/extraction of strongly volatile myrcene simultaneously.
[0010] In another aspect, the present disclosure is directed to production of high value-added myrcene using waste glycerol.
[0011] In an aspect, the present disclosure relates to a first vector containing, in sequence, a chloramphenicol resistance gene as a selection marker; a p15A replication origin as a replication origin; a lacUV5 promoter; a first domain containing a gene encoding an enzyme which produces mevalonate from acetyl-CoA; and a second domain containing a gene encoding an enzyme which produces dimethylallyl pyrophosphate (DMAPP) from mevalonate.
[0012] In another aspect, the present disclosure relates to a second vector containing, in sequence, an ampicillin resistance gene as a selection marker; a ColE1 replication origin as a replication origin; a trc promoter; and a gene encoding an enzyme which is capable of producing myrcene from geranyl pyrophosphate (GPP).
[0013] In another aspect, the present disclosure relates to an Escherichia coli strain transformed with the first vector and the second vector.
[0014] In another aspect, the present disclosure relates to an Escherichia coli strain producing 45 mg/L or more of myrcene in 70 hours under a condition of 37° C. and 1% (w/v) glycerol.
[0015] In another aspect, the present disclosure relates to a method for producing myrcene, including a step of cultuirng an Escherichia coli strain.
[0016] In another aspect, the present disclosure relates to a method for recycling glycerol, including a step of cultuirng an Escherichia coli strain.
[0017] In another aspect, the present disclosure relates to a kit for producing myrcene.
[0018] In an aspect, an Escherichia coli strain transformed with the vector of the present disclosure can produce myrcene with high purity on a large scale using glycerol or glucose as a carbon source. The Escherichia coli strain is economical because it can produce high value-added myrcene using waste glycerol as a carbon source. Also, it is environment-friendly because the microorganism can remove waste glycerol.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1A and 1B show depository receipts of transformed Escherichia coli strains of the present disclosure.
[0020] FIG. 2 shows a myrcene production pathway of a transformed Escherichia coli strain of the present disclosure.
[0021] FIG. 3 shows the structure of a first plasmid vector (plasmid 1 ) and a second plasmid vector (plasmid 2 ) of the present disclosure.
[0022] FIG. 4 shows six transformed strains of the present disclosure.
[0023] FIG. 5A and FIG. 5B show a result of measuring myrcene production by a transformed Escherichia coli strain of the present disclosure by gas chromatography-mass spectrophotometry (A: standard myrcene, B: myrcene produced by transformed Escherichia coli ).
[0024] FIG. 6A , FIG. 6B and FIG. 6C show a result of measuring myrcene production by transformed Escherichia coli strains of the present disclosure when incubated in a medium supplemented with 1% glucose (first bar: 24 hours later, second bar: 48 hours later, third bar: 72 hours later, A: LB medium, B: EZ-rich medium, C: M9-MOPS medium).
[0025] FIG. 7A and FIG. 7B show a result of measuring myrcene production by transformed Escherichia coli strains of the present disclosure when incubated in a medium supplemented with 1% glycerol (first bar: 24 hours later, second bar: 48 hours later, third bar: 72 hours later, A: EZ-rich medium, B: M9-MOPS medium).
[0026] FIG. 8 shows recovery of myrcene with (w) or without (w/o) dodecane overlay.
[0027] FIG. 9 shows the sequence of an atoB gene (SEQ ID No.: 1).
[0028] FIG. 10 shows the sequence of an HMGS gene (SEQ ID No.: 2).
[0029] FIG. 11 shows the sequence of an HMGR gene (SEQ ID No.: 3).
[0030] FIG. 12 shows the sequence of an MK gene (SEQ ID No.: 4).
[0031] FIG. 13 shows the sequence of a PMK gene (SEQ ID No.: 5).
[0032] FIG. 14 shows the sequence of a PMD gene (SEQ ID No.: 6).
[0033] FIG. 15 shows the sequence of an IDI gene (SEQ ID No.: 7).
[0034] FIG. 16 shows the sequence of a tGPPS gene (SEQ ID No.: 8).
[0035] FIG. 17 shows the sequence of a tMS-Qi gene (SEQ ID No.: 9).
[0036] FIG. 18A - FIG. 18E show the sequence of a pBbA5c-MevT(co)-MBI(co) plasmid vector(SEQ ID No.: 10), in sequence.
[0037] FIG. 19A - FIG. 19E show the sequence of a pBbA5c-MevT(co)-MBIG(co) plasmid vector(SEQ ID No.: 11), in sequence.
[0038] FIG. 20A - FIG. 20E show the sequence of a pBbA5c-MevT(co)-T1-MBI(co) plasmid vector(SEQ ID No.: 12), in sequence.
[0039] FIG. 21A - FIG. 21E show the sequence of a pBbA5c-MevT(co)-T1-MBIG(co) plasmid vector(SEQ ID No.: 13), in sequence.
[0040] FIG. 22A - FIG. 22B show the sequence of a pBbE1a-tMS(co.Qi) plasmid vector(SEQ ID No.: 14), in sequence.
[0041] FIGS. 23A - FIG. 23C show the sequence of a pBbE1a-tGPPS2(co)-tMS(co.Qi) plasmid vector(SEQ ID No.: 15), in sequence.
DETAILED DESCRIPTION
[0042] Hereinafter, the present disclosure is described in detail.
[0043] In an aspect, the present disclosure relates to a transformed Escherichia coli strain transformed with a first vector and a second vector, the first vector containing, in sequence, a chloramphenicol resistance gene as a selection marker; a p15A replication origin as a replication origin; a lacUV5 promoter; a first domain containing a gene encoding an enzyme which produces mevalonate from acetyl-CoA; and a second domain containing a gene encoding an enzyme which produces dimethylallyl pyrophosphate (DMAPP) from mevalonate, and the second vector containing, in sequence, an ampicillin resistance gene as a selection marker; a ColE1 replication origin as a replication origin; a trc promoter; and a gene encoding an enzyme which is capable of producing myrcene from geranyl pyrophosphate (GPP).
[0044] In the present disclosure, a pathway of synthesizing mevalonate from acetyl-CoA is denoted by the acronym MevT, and a pathway of synthesizing isopentenyl diphosphate (IPP) from mevalonate is denoted by the acronym MBI.
[0045] In the present disclosure, the first vector is also called a first plasmid or a first plasmid vector, and the second vector is also called a second plasmid or a second plasmid vector.
[0046] In this aspect, the first vector may further contain one or more selected from a trc promoter; and a gene encoding an enzyme which is capable of producing geranyl pyrophosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP). The trc promoter may be located between the first domain and the second domain, and the gene encoding an enzyme which is capable of producing geranyl pyrophosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP) may be located downstream of the second domain.
[0047] In the transformed Escherichia coli strain according to an aspect of the present disclosure, the first domain of the first vector may contain, in sequence, a gene encoding acetyl-CoA thiolase (ACAT); a gene encoding 3-hydroxyl-3-methyl-glutaryl-CoA synthase (HMGS); and a gene encoding 3-hydroxyl-3-methyl-glutaryl-CoA reductase (HMGR). In this aspect, the second domain of the first vector may contain, in sequence, a gene encoding mevalonate kinase (MK); a gene encoding phosphomevalonate kinase (PMK); a gene encoding mevalonate diphosphate decarboxylase (PMD); and a gene encoding isopentenyl diphosphate isomerase (IDI).
[0048] In this aspect, the enzyme which is capable of producing geranyl pyrophosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP) may be geranyl pyrophosphate synthase (GPPS).
[0049] In the transformed Escherichia coli strain according to an aspect of the present disclosure, the gene encoding acetyl-CoA thiolase (hereinafter, atoB gene) may contain a sequence of SEQ ID NO 1, the gene encoding 3-hydroxyl-3-methyl-glutaryl-CoA synthase (hereinafter, HMGS gene) may contain a sequence of SEQ ID NO 2, the gene encoding 3-hydroxyl-3-methyl-glutaryl-CoA reductase (hereinafter, HMGR gene) may contain a sequence of SEQ ID NO 3, the gene encoding mevalonate kinase (hereinafter, MK gene) may contain a sequence of SEQ ID NO 4, the gene encoding phosphomevalonate kinase (hereinafter, PMK gene) may contain a sequence of SEQ ID NO 5, the gene encoding mevalonate diphosphate decarboxylase (hereinafter, PMD gene) may contain a sequence of SEQ ID NO 6, and the gene encoding isopentenyl diphosphate isomerase (hereinafter, IDI gene) may contain a sequence of SEQ ID NO 7.
[0050] And, the gene encoding geranyl pyrophosphate synthase (hereinafter, GPPS or tGPPS gene) may contain a SEQ ID NO 8.
[0051] In the transformed Escherichia coli strain according to an aspect of the present disclosure, the first vector may contain a sequence of any of SEQ ID NOS 10-13.
[0052] In this aspect, the enzyme which is capable of producing myrcene from geranyl pyrophosphate (GPP) may be myrcene synthase (MS).
[0053] And, in the transformed Escherichia coli strain according to an aspect of the present disclosure, the second vector may further contain, between the trc promoter and the gene encoding an enzyme which is capable of producing myrcene from geranyl pyrophosphate (GPP), an enzyme which is capable of producing geranyl pyrophosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP).
[0054] The enzyme which is capable of producing geranyl pyrophosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP) may be geranyl pyrophosphate synthase (GPPS).
[0055] In this aspect, the gene encoding myrcene synthase (MS) (hereinafter, MS or tMS gene) may contain a sequence of SEQ ID NO 9, and the gene encoding geranyl pyrophosphate synthase (GPPS) (hereinafter, GPPS or tGPPS gene) may contain a sequence of SEQ ID NO 8.
[0056] In the transformed Escherichia coli strain according to an aspect of the present disclosure, the second vector may contain a sequence of SEQ ID NO 14 or 15. In the present disclosure, pM1 denotes a first vector containing a chloramphenicol resistance gene, a p15A replication origin, an atoB gene, an HMGS gene and an HMGR gene, and further containing an MK gene, a PMK gene, a PMD gene and an IDI gene, and is also expressed as pBbA5c-MevT(co)-MBI(co). And, in the present disclosure, pM2 denotes a first vector (pM1) further containing a tGPPS gene, and is also expressed as pBbA5c-MevT(co)-MBIG(co). And, in the present disclosure, pM3 denotes a first vector (pM1) further containing a promoter, e.g., a Trc promoter (P Trc ). The promoter may be located between the HMGR gene and the MK gene. pM3 is also expressed as pBbA5c-MevT(co)-T1-MBI(co). In the present disclosure, pM4 denotes a first vector (pM3) further containing a tGPPS gene, and is also expressed as pBbA5c-MevT(co)-T1-MBIG(co). And, in the present disclosure, pM(Qi) denotes a second vector containing a trc promoter and an MS gene, and is also expressed as pBbE1a-tMS(co.Qi). And, in the present disclosure, pGM(Qi) denotes a second vector (pM(Qi)) further containing a GPPS gene. The GPPS gene may be located between the tMS gene and the promoter. pGM(Qi) is also expressed as pBbE1a-tGPPS2(co)-tMS(co.Qi).
[0057] pM1 may contain a sequence of SEQ ID NO 10, pM2 may contain a sequence of SEQ ID NO 11, and pM3 may contain a sequence of SEQ ID NO 13. pM(Qi) may contain a sequence of SEQ ID NO 14, and pGM(Qi) may contain a sequence of SEQ ID NO 15.
[0058] The vectors according to an aspect of the present disclosure may be those described in Table 1.
[0000]
TABLE 1
Plasmid vectors
Characteristics
pBbA5c-MevT(co)-MBI(co)
Contains p15A, Cm R , PlacUV5 and
mevalonate pathway gene
pBbA5c-MevT(co)-MBIG(co)
Contains p15A, Cm R , PlacUV5,
mevalonate pathway gene and tGPPS
gene
pBbA5c-MevT(co)-T1-MBI(co)
Contains p15A, Cm R , PlacUV5, Ptrc
and mevalonate pathway gene
pBbA5c-MevT(co)-T1-MBIG(co)
Contains p15A, Cm R , PlacUV5, Ptrc,
mevalonate pathway gene and tGPPS
gene
pBbE1a-tMS(co.Qi)
Contains ColE1, Amp R , Ptrc and
myrcene synthase (MS) from
Q. ilex L.
pBbE1a-tGPPS2(co)-tMS(co.Qi)
Contains ColE1, Amp R , Ptrc, GPPS2
gene from A. grandis and myrcene
synthase (MS) from Q. ilex L.
[0059] In Table 1, Cm R denotes a chloramphenicol resistance gene and Amp R denotes an ampicillin resistance gene.
[0060] Also, the first vector and the second vector may be Escherichia coli expression vectors.
[0061] The transformed Escherichia coli strain according to an aspect of the present disclosure may be Escherichia coli DH1 transformed with the first vector and the second vector. Specifically, it may contain two vectors, i.e., the first vector containing a gene which encodes an enzyme capable of producing dimethylallyl pyrophosphate (DMAPP) or geranyl pyrophosphate (GPP) from a carbon source and the second vector containing a gene which encodes an enzyme capable of producing myrcene from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP) or from geranyl pyrophosphate (GPP).
[0062] In the present disclosure, the ‘first’ vector and the ‘second’ vector do not mean that the parent strain should be transformed with the vectors in that order.
[0063] In this aspect, the strain may be one described in Table 2.
[0000]
TABLE 2
Strains
Characteristics (introduced plasmid vectors)
Ec-pM1/pGM(Qi)
DH1, pBbA5c-MevT(co)-MBI(co) and
pBbE1a-tGPPS2(co)-tMS(co.Qi)
Ec-pM2/pM(Qi)
DH1, pBbA5c-MevT(co)-MBIG(co) and
pBbE1a-tMS(co.Qi)
Ec-pM2/pGM(Qi)
DH1, pBbA5c-MevT(co)-MBIG(co) and
pBbE1a-tGPPS2(co)-tMS(co.Qi)
Ec-pM3/pGM(Qi)
DH1, pBbA5c-MevT(co)-T1-MBI(co) and
pBbE1a-tGPPS2(co)-tMS(co.Qi)
Ec-pM4/pM(Qi)
DH1, pBbA5c-MevT(co)-T1-MBIG(co) and
pBbE1a-tMS(co.Qi)
Ec-pM4/pGM(Qi)
DH1, pBbA5c-MevT(co)-T1-MBIG(co) and
pBbE1a-tGPPS2(co)-tMS(co.Qi)
[0064] The transformed Escherichia coli strain according to an aspect of the present disclosure may produce 45 mg/L or more of myrcene in 70 hours under a condition of 37° C. and 1% (w/v) glycerol. It may produce 5 mg/L or more, 10 mg/L or more, 15 mg/L or more, 20 mg/L or more, 25 mg/L or more, 30 mg/L or more, 35 mg/L or more, 40 mg/L or more, 45 mg/L or more, 50 mg/L or more, 55 mg/L or more, 60 mg/L or more, 65 mg/L or more or 70 mg/L or more of myrcene, although not being limited thereto.
[0065] The transformed Escherichia coli strain according to an aspect of the present disclosure may use glucose or glycerol as a carbon source, although not being limited thereto.
[0066] In this aspect, when glycerol is used as a carbon source, the strain may produce 3 times or more, 1.5 times or more, 1.7 times or more, 1.9 times or more, 2 times or more, 2.1 times or more, 2.3 times or more, 2.5 times or more, 2.7 times or more, 2.9 times or more or 3.1 times or more of myrcene as compared to when glucose is used as a carbon source, although not being limited thereto. In this aspect, the amount of myrcene produced may vary depending on the components of a medium in which the Escherichia coli strain is cultured.
[0067] Also, the Escherichia coli strain may be a strain of an accession number KCTC12850BP or KCTC12851BP.
[0068] In another aspect, the present disclosure relates to a method for producing myrcene, including a step of culturing a transformed Escherichia coli strain.
[0069] In this aspect, the method for producing myrcene may further include a step of supplying a carbon source to the culture medium. The carbon source may be glucose or glycerol, although not being limited thereto.
[0070] Also, the method for producing myrcene according to an aspect of the present disclosure may further include a step of adding 10-30% (w/v) of dodecane based on the volume of the culture medium. The addition amount of dodecane may be 5-35%, 10-30%, 10-25%, 10-20%, 10-15%, 15-30%, 15-25% or 15-20%, although not being limited thereto. The dodecane may be added simultaneously with the culture medium or the carbon source, or may be added after the culture medium and/or the carbon source has been supplied. The dodecane may be located naturally above the culture medium without being mixed with the culture medium. Specifically, it may be added on top of the culture medium. When the dodecane is added, evaporation and loss of the strongly volatile myrcene into the atmosphere may be prevented.
[0071] In another aspect, the present disclosure relates to a method for recycling glycerol, including a step of culturing the Escherichia coli strain. In this aspect, the method may further include a step of supplying glycerol, specifically waste glycerol, to the Escherichia coli strain. The waste glycerol may be a byproduct from biodiesel production.
[0072] Hereinafter, the present disclosure will be described in detail through examples. However, the following examples are for illustrative purposes only and it will be apparent to those of ordinary skill in the art that the scope of the present disclosure is not limited by the examples.
EXAMPLE 1
Establishment of Strategy for Producing Myrcene
[0073] A myrcene metabolic pathway as shown in FIG. 1 was designed to prepare an Escherichia coli strain having superior capability of producing myrcene.
[0074] Also, literature search was conducted to select a gene encoding a myrcene synthase (MS) gene. Candidate genes were selected based on the literature search and synthesized after codon optimization for expression in Escherichia coli . The selected gene was myrcene synthase derived from pine tree ( Quercur liex L.) (Fischbach R et al., Eur. J. Biochem., 2001).
EXAMPLE 2
Preparation of Plasmid Vector and Strain
[0075] Two types of plasmids were constructed for production of myrcene. To a first plasmid, a gene necessary for producing IPP and DMAPP from acetyl-CoA was introduced. The first plasmid was cloned using a pBbA5c-RFP vector (Lee T S, Krupa R A, Zhang F, Hajimorad M, Holtz W J, Prasad N, Lee S K, Keasling J D (2011 b) BglBrick vectors and datasheets: a synthetic biology platform for gene expression. J Biol Eng 5:12). pBbA5c-RFP was treated with restriction enzymes EcoRI and BamHI and pBbA5c and RFP fragments were isolated by agarose gel electrophoresis. Only the purified pBbA5c vector was used for cloning. A DMAPP producing gene synthesized in the same manner was treated with the same restriction enzymes and then purified. The restriction enzyme-treated pBbA5c vector and DMAPP producing gene were transformed into E. coli by treating with ligase and then cloning was conducted. All the genes introduced into the plasmids were prepared by GenScriptR. Additionally, a strong pTrc promoter was introduced upstream of a mevalonate kinase (MK) gene. A total of four plasmids pM1, pM2, pM3 and pM4 were constructed.
[0076] A second plasmid was prepared as two types, one in which a myrcene synthase gene and a GPP synthase gene were introduced and the other in which only a myrcene synthase gene was introduced (Table 1). The second plasmid was cloned using a pBbE1a-RFP vector (Lee T S, Krupa R A, Zhang F, Hajimorad M, Holtz W J, Prasad N, Lee S K, Keasling J D (2011 b) BglBrick vectors and datasheets: a synthetic biology platform for gene expression. J Biol Eng 5:12). The second plasmid was constructed in the same manner as the first plasmid. The constructed plasmids are shown in Table 2 and FIG. 3 .
[0077] The constructed first plasmid and second plasmid were introduced into an Escherichia coli DH1 strain through transformation. The parent strain Escherichia coli DH1 was acquired from the Coli Genetic Stock Center (CGSC). A total of six myrcene-producing strains were prepared (Table 2).
EXAMPLE 3
Production of Myrcene Using Transformed Escherichia coli Strain
[0078] The transformed Escherichia coli strain was pre-cultured in a Luria-Bertani (LB) medium for 24 hours and then cultured again in three media: 1. LB, 2. EZ-rich (Teknova, Hollister, Calif.), 3. M9-Mops (M9 salt, 75 mM MOPS, 2 mM MgSO 4 , 0.01 mM CaCl 2 , 1 mg/L thiamine HCl, 2.78 mg/L FeSO 4 , micronutrients: 3 nM ammonium molybdate, 0.4 M boric acid, 30 nM cobalt chloride, 23 nM cupric sulfate, 80 nM manganese chloride, 10 nM zinc sulfate). 1% glucose or 1% glycerol was supplied as a carbon source. After inoculating the strain to the three media and incubating for 4 hours in a shaking incubator at 37° C. at 200 rpm, enzymatic expression was induced by adding 100 μM IPTG (isopropyl β-D-1-thiogalactopyranoside) within an OD 600 value range of 0.8-1. Then, myrcene was produced by covering the culture medium with 20% (w/v) of dodecane based on the volume of the culture medium. Myrcene production was measured 24 hours, 48 hours and 72 hours later. The amount of myrcene produced for each medium was measured for the cases when 1% glucose was used as a carbon source ( FIG. 5 ) and when 1% glycerol was used ( FIG. 6 ).
[0079] For quantitative analysis of the produced myrcene, comparative analysis was conducted with respect to standard myrcene by gas chromatography-mass spectrometry (GC-MS, Agilent 6890N series GC/TOF-MS (LECO)) ( FIG. 4 ): injector temperature: 250° C., flow rate: 1.2 mL/min, split ratio=2:1, oven temperature: 60° C. for initial 5 minutes, raised at 4° C./min (to 240° C.), He gas used, HP-Ultra2 column: 25 m, 0.2 mm diameter, film thickness: 0.11 μm. All the reagents used in the experiment were acquired from Sigma-Aldrich.
EXAMPLE 4
Confirmation of Dodecane Overlay Effect
[0080] The dodecane overlay method was used to increase recovery of the strongly volatile myrcene. Because dodecane is separated on top of the medium without being mixed with the medium, the myrcene which is evaporated as soon as it is produced can be extracted from the above dodecane layer. The dodecane overlay effect was compared using the strain (Ec-pM2/pM(Qi) and condition (1% glycerol, EZ-rich) that showed the highest productivity. As seen from FIG. 7 , when dodecane overlay was not used, all the produced myrcene was evaporated and nothing remained.
[0081] [Accession Numbers]
[0082] Depositor: Korea Research Institute of Bioscience & Biotechnology
[0083] Accession number: KCTC12850BP
[0084] Date of accession: 20150623
[0085] Depositor: Korea Research Institute of Bioscience & Biotechnology
[0086] Accession number: KCTC12851BP
[0087] Date of accession: 20150623 | Disclosed herein are an expression vector capable of expressing myrcene, an Escherichia coli strain transformed with the vector and having improved capability of producing myrcene and a method for producing myrcene and a method for recycling glycerol using the same. In an aspect, the transformed Escherichia coli strain of the present disclosure can produce myrcene with high purity on a large scale using glycerol or glucose as a carbon source. Also, the Escherichia coli strain of the present disclosure is economical and environment-friendly because it can produce high value-added myrcene using waste glycerol as a carbon source. In addition, the strongly volatile myrcene can be produced and isolated at the same time. | 2 |
RELATED APPLICATION
[0001] This application is related in subject matter to U.S. Application No.______ (Attorney Docket No. 054862-5001), filed concurrently herewith, and which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of fabricating a polymer resistor in an interconnection via, and more particularly, to a method of fabricating a polymer resistor in an interconnection via of a printed circuit board (PCB).
[0004] 2. Discussion of the Related Art
[0005] [0005]FIG. 1 provides a cross-section of a typical circuit board 1 used in an electronic device, such as a cell phone, MP3 player, or personal digital assistant. The circuit board includes a circuit substrate S and a plurality of discrete components mounted on the top surface of the substrate S. The circuit substrate may be a printed circuit board having conductive traces to interconnect the discrete components mounted on the board. The discrete components typically include passive components and active components. The discrete components may include a resistor R, a capacitor C, and an inductor L. The active components may include integrated circuits (ICs), such as processors, application specific integrated circuits (ASICs), or other logic.
[0006] Consumers are demanding electronic products that are small and light weight, have reduced power consumption, and increased functionality. To meet this demand, the basic circuit board must be redesigned to accommodate a larger number of electronic components in a reduced area. Moreover, the manufacturing process for such a redesigned circuit board must be inexpensive, fast, efficient, and yield high quality electrical performance.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention is directed to a method of fabricating a polymer resistor in an interconnection via of a printed circuit board that substantially obviates one or more problems due to limitations and disadvantages of the related art.
[0008] An object of the present invention is to provide an inexpensive and efficient method of fabricating a polymer resistor in an interconnection via of a printed circuit board, in which the geometry and thickness of the resistor can be precisely controlled.
[0009] Another object of the present invention is to provide a method of fabricating a polymer resistor in an interconnection via of a printed circuit board having reduced signal path and precise resistance value.
[0010] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0011] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method of fabricating a polymer resistor in an interconnection via in a printed circuit board includes forming a plurality of first conductive traces on a substrate, forming an interconnection via through one of the first conductive traces in the substrate and terminating at a second conductive trace, filling polymer resistor paste in the interconnection via so as to contact the second conductive trace, thermally treating the polymer resistor paste to produce a polymer resistor, and forming a conductive layer in contact with the resistor and the one first conductive trace.
[0012] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0014] [0014]FIG. 1 is a cross-sectional view of a PCB according to the related art;
[0015] [0015]FIGS. 2-3 are cross-sectional views of a PCB according to an exemplary embodiment of the present invention;
[0016] [0016]FIGS. 4-11 are cross-sectional views of a PCB according to another exemplary embodiment of the present invention;
[0017] [0017]FIG. 12 is a cross-sectional view of a PCB according to another exemplary embodiment of the present invention;
[0018] [0018]FIG. 13 is a flowchart of an exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention;
[0019] [0019]FIG. 14 is a flowchart of another exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention; and
[0020] [0020]FIG. 15 is a flowchart of another exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0022] [0022]FIGS. 2-3 illustrate cross-sectional views of a PCB according to an exemplary embodiment of the present invention. In FIG. 2, conductive traces 12 - 1 and 12 - 2 may be formed on opposing surfaces of a PCB substrate 10 . For example, the conductive traces 12 - 1 and 12 - 2 may be formed by a photolithographic patterning a conductive layer on the substrate 10 . In this regard, a photoresist material may be formed over the conductive layer, developed into a pattern, and used as an etch mask to remove selected portions of the conductive layer and thereby produce traces 12 - 1 and/or 12 - 2 . The remaining photoresist can then be removed. It should be appreciated that FIGS. 2 and 3 (as well as FIGS. 4-12) are illustrated in cross section and that conductive traces 12 - 1 and 12 - 2 extend over the top and bottom surfaces of the substrate 10 .
[0023] In addition, via holes 16 - 1 and 16 - 2 may be selectively formed in the substrate 10 . Via holes may be formed, for example, by laser drilling, mechanical drilling, or chemical etching. Internal surfaces of the via hole 16 - 1 may be coated with a conductive material to electrically connect a conductive trace 12 - 1 on a top surface of the substrate 10 and a conductive trace 12 - 2 on a bottom surface on the substrate 10 . Alternatively, a polymer resistor pattern 18 may be formed inside the via hole 16 - 2 . For example, instead of plating with a conductive material, polymer resistor paste may be printed inside or dispensed using a dispenser into the via hole 16 - 2 and on a conductive trace 12 - 2 to form the polymer resistor pattern 18 . The polymer resistor pattern 18 may then be cured, for example, by a baking process to produce a resistor R 1 . The polymer resistor pattern 18 may, but need not, undergo exposure to ultraviolet (UV) radiation to harden its surface and fix its shape.
[0024] The geometry of a resistor is a factor in determining its resistance value and, consequently, must be carefully controlled to ensure that the resistance value is within tolerance for the application. By dispensing the resistance paste in the via 16 - 2 , the area of the resistor will be fixed by the dimensions of the via 16 - 2 . Accordingly, the dimensions of the via 16 - 2 , particularly the cross-sectional area of the via, should be carefully controlled during its formation. In addition, the volume of polymer resistance paste dispensed into the via 16 - 2 should be carefully controlled to produce the selected resistance value within tolerance. While it is possible to adjust the volume of polymer resistor paste dispensed to the size of the via, it may be simpler in some applications to control both the size of the via and the volume of paste. A dispenser may be used to dispense the correct volume of resistor paste, preferably avoiding problems, such as trapped air within the via, that would reduce the yield rate of the resistors so produced. A polymer resistor paste without or with limited aromatic solvent may be used to avoid imprecise volume fluctuations when the solvent evaporates.
[0025] In FIG. 3, a conductive material may be applied or dispensed onto resistor R 1 to form a resistor contact to a trace 12 - 1 on the top surface of the substrate 10 . The conductive material may be the same material as the conductive traces 12 - 1 and 12 - 2 , a conductive paste, or another conductive material. For example, a material may be selected that has a similar conductivity as the conductive traces 12 - 1 and 12 - 2 . Accordingly, a resistor may be formed in a via of the substrate rather than on an uppermost surface thereof, thereby saving surface space for formation of other discrete components, such as IC chips, and/or a reduction in the size of the substrate. Forming the resistor in the via can also reduce signal path length, which permits an increase in operation speed, reduced power, and reduced electromagnetic interference.
[0026] [0026]FIGS. 4-11 illustrate cross-sectional views of a PCB according to another exemplary embodiment of the present invention. In FIG. 4, conductive layers 22 - 1 and 22 - 2 may be formed on opposing surfaces of a first substrate 20 . The conductive layers 22 - 1 and 22 - 2 may be made of a conductive material, such as copper foil or other metal, or a metal alloy. In FIG. 5, conductive traces 24 may be formed on the first substrate 20 , for example, by photolithographic patterning of the conductive layers 22 - 1 and 22 - 2 , as described above
[0027] In FIG. 6, a second substrate 30 may also be prepared. For example, conductive layers 32 - 1 and 32 - 2 may be formed on opposing sides of the second substrate 30 . The conductive layers 32 - 1 and 32 - 2 may be made of a conductive material, such as copper foil or other metal, or a metal alloy. In FIG. 7, conductive traces 34 - 1 and 34 - 2 may be formed on the second substrate 30 , for example, by a photolithographic patterning-process of the conductive layers 32 - 1 and 32 - 2 . Furthermore, in FIG. 8, via holes 38 may be selectively formed in the second substrate 30 and lined or filled with conductive material to electrically connect the conductive traces 34 - 1 and 34 - 2 . As described above, the via holes 38 may be formed, for example, by laser drilling, mechanical drilling, or etching.
[0028] Moreover, in FIG. 9, the first and second substrates 20 and 30 may be stacked onto one another. An adhesive layer 40 may be inserted between the first and second substrate 20 and 30 , such that the first and second substrates 20 and 30 may be affixed to each other with the adhesive layer 40 therebetween. The adhesive layer 40 may comprise, in whole or in part, an insulative material. In FIG. 10, an additional via hole 38 a may be subsequently formed in the bonded structure, e.g., by laser drilling, mechanical drilling, or etching. For example, the via hole 38 a may be formed to a conductive trace of the first substrate 20 .
[0029] In FIG. 11, a resistor R may be formed inside the via hole 38 a . For example, polymer resistor paste may be first dispensed in or printed onto the inside of the via holes 38 a to form a polymer resistor pattern. For example, the polymer resistor paste may be applied using a dispenser or a jet-type head. The polymer resistor pattern may then be cured by a baking process to produce the polymer resistor R. Then, a conductive layer may be formed on or in contact with the resistor R, thereby forming the resistor contact. The polymer resistor pattern may, but need not, be subjected to a UV radiation process before undergoing the thermal baking process. Accordingly, resistors may be formed in vias, such as 38 a , rather than on an uppermost surface of the bonded first and second substrates 20 and 30 , thereby saving surface spaces for formation of other components and/or reducing the size of the substrate, among other advantages described herein.
[0030] [0030]FIG. 12 is a cross-sectional view of a PCB according to another exemplary embodiment of the present invention. In FIG. 12, a resistor r may also be embedded within the first and second substrates 20 and 30 . For example, before bonding the first and second substrates 20 and 30 , polymer resistor pastes may be printed between two conductive traces 34 - 3 on the second substrate 30 , thereby forming a resistor pattern. The resistor pattern may then be hardened in a curing process to fix its shape and, therefore, its resistive value. The curing process may include exposure to UV radiation to harden the exposed surface of the resistive pattern, thereby fixing its shape. Following the UV radiation process, the hardened resistive pattern may be baked to activate the resistor.
[0031] [0031]FIG. 13 is a flowchart of an exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention. The process shown in FIG. 13 may be used to produce the PCB shown in FIG. 3. As illustrated in FIG. 13, conductive traces may be formed on a substrate in ST 1 . As above, the substrate may be an insulative material, such as FR 4 or other insulator, and conductive traces may be formed using a photolithographic process. In ST 2 , a through hole may be formed on one of the conductive traces in the substrate to a conductive trace on the opposite side of the substrate. The through hole may be formed by laser drilling, for example. The dimensions of the through hole are selected so that, when a resistor is formed therein, the resistor will exhibit a selected resistance value. In ST 3 , polymer resistor paste may be filled inside the through hole to form a polymer resistor pattern. The polymer resistor paste contacts the conductive trace on the opposite side of the substrate. In ST 4 , the polymer resistor pattern may be thermal baked to produce a resistor. The polymer resistor may, but need not, undergo an addition curing process, such as UV radiation process. Furthermore, in ST 5 , a conductive layer may be formed on or in contact with the resistor and with a trace on the surface of the substrate, thereby providing electrical connection to the resistor. Consequently, the polymer resistor inside the through hole. Accordingly, the polymer resistor inside the through hole may have precise resistance value based on the geometric shape of the polymer resistor pattern. It should be appreciated that ST 4 and ST 5 may be reversed so that the baking step is performed after the contact is formed.
[0032] [0032]FIG. 14 is a flowchart of another exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention. The process of FIG. 14 may be used to produce the PCB shown in FIG. 11. In FIG. 14, ST 11 , two substrates may be bonded together. For example, conductive traces may be formed on one or both surfaces of a first substrate. Conductive traces may be formed on one or both surfaces of a second substrate. The substrates may be made from an insulative material, such as FR 4 , and the conductive traces may be produced using a photolithographic process.
[0033] The second substrate may be stacked and affixed onto the first substrate to form a bonded structure. For example, an insulative adhesive layer may be interposed between the two substrates. In ST 12 , a through hole may be formed in one of the conductive traces of the bonded structure to another conductive layer either within or on the opposite side of the bonded structure. As above, the hole may be formed, for example, by laser drilling and may be sized to achieve a predetermined resistance value. In ST 13 , polymer resistor paste may be dispensed or printed inside the through hole to form a polymer resistor pattern in contact with the other conductive layer. The area of the resistor pattern in contact with the other conductive layer is determined by the sized of the through hole. In addition to the size of the through hole, the volume of polymer resistance paste dispensed in the through hole is selected to achieve a predetermined resistance value. In ST 14 , the polymer resistor pattern may then be baked to produce a resistor. Furthermore, in ST 15 , a conductive layer may be formed on or in contact with the polymer resistor and with the conductive trace on the surface of the substrate, thereby permitting electrical connection. Accordingly, the polymer resistor is formed inside the through hole and has a precise resistance value based on the geometric shape of the polymer resistor pattern. As discussed above in connection with FIG. 13, steps ST 14 and ST 15 may be reversed.
[0034] [0034]FIG. 15 is a flowchart of another exemplary method of fabricating a polymer resistor in an interconnection via of a PCB according to the present invention. The process of FIG. 15 may be used to form the PCB shown in FIG. 12. In FIG. 15, ST 21 , conductive traces are formed on a first substrate. ST 21 may be performed as described above. In ST 22 , polymer resistor patterns may be printed between the conductive traces on the first substrate. As described above, the printed polymer resistor pattern may be exposed to UV radiation process in ST 23 , and then may undergo a thermal baking process in ST 24 to form resistors on the first substrate. In ST 25 , the first substrate may be bonded to a second substrate, wherein the resistors on the first substrate are embedded therebetween.
[0035] Moreover, in ST 26 , a via hole may be formed in the bonded structure. For example, the via hole may be formed in one of the conductive traces on the first substrate and terminating at one of the conductive traces between the first and second substrates (e.g., on the opposite side of the first substrate or on the second substrate. Then, in ST 27 , polymer resistor paste may be printed inside the via hole to form a polymer resistor pattern. In ST 28 , the polymer resistor pattern may then be subjected to a baking process to form a polymer resistor inside the via hole. The polymer resistor may, but need not, undergo another curing process, such as a UV radiation process. It should be appreciated that step ST 24 may be omitted if step ST 28 is sufficient to activate the embedded resistors. As described above, the dimensions of the via and the volume of polymer resistor paste dispensed in the hole may be selected to produce a predetermined resistor value. In ST 29 , a conductive layer may be formed on or in contact with polymer resistor inside the via hole and with the conductive trace on the surface of the multi-layer structure. Steps ST 28 and ST 29 may be reversed. Accordingly, the polymer resistor inside the via hole may have precise resistance value based on the geometric shape of the polymer resistor pattern.
[0036] It will be apparent to those skilled in the art that various modifications and variations can be made in the method of fabricating a polymer resistor in an interconnection via of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method of fabricating a polymer resistor in an interconnection via in a printed circuit board includes forming a plurality of first conductive traces on a substrate, forming an interconnection via through one of the first conductive traces in the substrate and terminating at a second conductive trace, filling polymer resistor paste in the interconnection via so as to contact the second conductive trace, thermally treating the polymer resistor paste to produce a polymer resistor, and forming a conductive layer in contact with the resistor and the one first conductive trace. | 7 |
This application is a continuation, of application Ser. No. 938,921 filed Dec. 5, 1985, now abandoned.
This invention relates to rail fasteners as used in a rapid transit rail system wherein such fasteners are used to fasten the rails to an underlying structure such as wood ties, concrete ties or concrete slabs. The invention more specifically relates to an improved rail fastener to protect against electrical current leakage of the rail to the support system and to protect the metal components of the rail and/or rail fastener from corrosion.
BACKGROUND OF THE INVENTION
Rail fasteners of the general type described above have heretofore been proposed: see e.g., German Auslegeschrift No. 1204697 and U.S. Pat. Nos. 3,576,293 and 3,784,097. The assemblies of each of the foregoing references include a base plate, a rail plate for attachment to the rail and positioned between the rail and the base plate, and an elastomeric material such as neoprene interposed between the base plate and the rail plate. The elastomeric material supports the rail plate from the base plate, damps vibration of the rail plate and electrically insulates the base plate and the rail plate and/or rail.
Because rapid transit rails are used as electrical conductors for traction power current as well as for train speed command signals, it is necessary to provide and maintain electrical insulation between the rails and the rail support structure. The aforesaid rail fasteners presently in use do provide some electrical insulation between the rails and the rail support structure. However, heretofore, the surface creepage paths provided by the insulating elements of existing apparatus were found to be relatively short and easily contaminated with dirt and wheel and rail wear products. When these contaminated surfaces then became wet by fog, rain, or ground water, electrically conductive paths are formed over which electrical leakage currents flowed. Such leakage currents caused corrosion of the rail as well as of the metal parts of the rail fasteners and supports, resulting in further contamination of the surface creepage paths. This additional contamination of the creepage paths results in further reduction of the electrical resistance of the creepage paths and thence results in larger magnitudes of leakage currents.
Such excessive leakage currents from train operation over poorly insulated rails caused destructive corrosion of rail, rail fasteners, rail support structures, metal tunnel liners, concrete reinforcement bar and other metallic structures. An excessively low rail to rail support structure electrical resistance caused by such corrosion also tended to short out train speed command signals between the rails. In such a situation, the shorted section of track then appears to the train speed command system as though it were occupied by a train, and for safety reasons train operation is disrupted. Such an occurence is generally referred to in the art as a "ghost train".
To prevent loss of electrical train speed command signals and leakage of electrical traction currents over potential creepage paths, rail circuit insulation integrity must be maintained, and the rail fastener or support insulation must provide electrical insulation even when wet and contaminated with electrolyte. Therefore, the rail must be insulated from the supporting structure and/or portions of the rail fastener with electrical insulation means which provides relatively high electrical resistive surface creepage paths. Such high electrical resistive creepage paths will maximize the electrical leakage path resistance between rail and rail support even when the rail and the rail fastener or support apparatus are wet and/or contaminated with electrolyte.
In addition, the rail support insulating device must not interfere with the rail fastener's ability to securely fasten the rail relative to the support structure and to limit relative movement of the rail to within acceptable tolerances in the vertical, lateral, roll and longitudinal directions.
One form of rail support insulating device to prevent the above decribed current leakage is disclosed in U.S. Pat. No. 4,615,484 which included an electrically non-conductive skirt member surrounding and extending outward from the rail fastener and over it support structure and a pair of planar disc members of electrically nonconductive material adjacent the bolt heads. Such a device adds extra components to a rail fastener to overcome the problem of current leakage. It is desirous to have a rail fastener that overcomes the problem of current leakage by incorporating additional electrical protection into the rail fastener.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved rail fastener that overcomes the problem of current leakage by incorporating current leakage protection into the rail fastener.
It is another object of the present invention to provide an improved rail fastener having a rail plate coated with an elastomer material that acts as a barrier against current leakage from the rail to the supporting structure and/or portions of the rail fastener. Furthermore, the elastomeric material provides corrosion protection to the entire rail fastener and between the rail and rail fastener.
The rail fastener for fastening a rail to an underlying support structure of a rapid transit rail system comprises (1) a rigid rail support plate to which a rail is attached; (2) means to secure said rail to said rigid rail metal support plate such that said rail will overlie said support plate in a predetermined area of said plate; (3) a means for securing said rail support plate to said support structure; (4) a resilient elastomeric material interposed between said support plate and said support structure wherein said resilient elastomeric material allows for vertical and lateral movement of said upper plate relative to said lower plate and provides electrical insulation within said rail fastener; and (5) an electrically resistant elastomeric material covering said support plate to prevent leakage of current from said rail and said support structure.
DESCRIPTION OF THE DRAWINGS
Other features of the invention will be apparent from the following description of illustrative embodiments thereof, which should be read in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of a rail fastener assembly in accordance with the invention;
FIG. 2 is a vertical section taken approximately along the line 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the drawings, FIG. 1 and FIG. 2 show a typical rail fastener 10 as it appears when installed for directly affixing a rail 14 to a support structure 11. The rail fastener 10 has a rail support plate 16 and means to secure the rail to the support plate which in the present embodiment is a pair of clips 30 wherein the pair of clips 30 and support plate 16 are coated with electrically resistant elastomeric material 39, 35 according to the present invention. Although the electrically resistent elastomeric material coating the clips and support plate may be used on different rail fasteners, for purposes of illustration, it is shown as used on a rail fastener similar to that described in U S. Pat. No. 3,576,293.
The rail fastener 10 further includes a lower plate 18, which is also coated with electrically resistant elastomeric material 36, which is interconnected to the support plate 16 by resilient elastomeric material 20. The rail 14 is mounted in place on the rail support plate 16 and held in place by the clips 30.
The support plate 16 generally has a lateral width of approximately 14.5 inches and a longitudinal extent, parallel to the direction of the rail 14 of about 7.5 inches and a thickness of about 1/2 inch, having openings 26 at two of its diagonally opposite corner areas for reception of the anchor bolts 12. Located on the upper surface of the support plate 16 is a series of serrations 41 extending in a direction parallel to the direction of the rail 14. However, in some applications it is known that the directio of the serration may be at an angle to the direction of the rail.
The layer of resilient elastomeric material 20 is interposed between the support plate 16 and the lower plate 18 to provide vibrational damping for the support plate 16 and to electrically isolate the support plate 16 from the support structure 11. In a typical rail fastener, the resilient elastomeric material 20 has a thickness of about 0.75 inches.
A plurality of laterally directed elongated voids 25 are provided in the resilient elastomeric material 20 (see FIG. 1) in the central region generally underlying the rail 14. The voids 25 are spaced apart along the direction of the rail 14 by approximately 1 inch between center lines.
The rail support plate is adapted to be fixedly secured to a support structure 11, such as a wood tie, concrete tie or concrete slab, by means such as suitable anchor bolts 12. The bolts 12 pass through openings 26 in the plates 16 and 18 to threadably mate with a metallic insert 88 anchored in the support structure 11. A pair of plastic inserts 13 surround the anchor bolts 12. The inserts are disposed coaxially of the anchor bolts 12 through plate 16 in the opening 26.
The pair of clips 30 are each attached by a bolt 32a and a nut 32b to the support plate 16 and serve to secure the lower flanges 15 of the rail 14 to the support plate 16. The lower end of the bolt extends below the support plate 16 through a T slot 34 therein and into an aligned, enlarged cavity 37 formed within the resilient elastomeric layer 20. The T slot 34 allows the clip 30 to be moved and adjusted into engagement with the rail flange 15 before the bolt 32a and nut 32b are tightened. Located on each clip 30 is a set of teeth 42 which matches the serrations 41 of the upper plate 16 to facilitate locking of the clip in place as described above.
The rigid rail support plate 16 and the lower plate 18 of the rail fastener 10 are covered with a coating of electrically resistant elastomeric material 35 bonded by vulcanization to said support plate 16 and said lower plate 18 to cover any exposed metal part except for the set of serrations 41. The electrically resistant elastomeric material 35, 36 is a composition of natural rubber, or a mixture of natural rubber and styrene butadiene, or neoprene. The rail fastener assemby, excluding the clips, is assembled in an upside down fashion in a mold in the following steps:
(1) position a suitably calendered electrically resistant elastomeric material, which will cover the top upper plate, on the bottom of the mold;
(2) position the rail support plate 16 onto the calendered electrically resistant elastomeric material such that pins of the mold correspond to openings 26 of the support plate 16;
(3) position the plastic inserts 13 over the pins into the support plate 16;
(4) position the lower plate 18 such that the pins allign the lower plate 18 with the support plate 16; and
(5) position a suitable calendered electrically resistant elastomeric matrial which will cover the bottom of the lower plate, on top of the assembled components.
Thereafter, the mold is closed, and the resilient elastomeric material 20 is injected intermediate of said support plate 16 and said lower plate 18. The elastomeric material is then vulcanized at a temperature from 300° to about 340° F. at a pressure from about 2000 to about 3000 psi for a time from about 15 to about 20 minutes depending on the elatomeric material and desired properties.
The clips 30 are coated with the electrically resistant elastomeric material 39 by a dipping or coating process to cover exposed metal parts except for the teeth 42. The elastomer coating for the clip may or may not be the same composition as the elastomer used on the support plate 16. One suitable coating is CHEMGLAZE® M331 elastomeric polyurethane coating which is commercially available from Lord Corporation. The electrically resistant elastomeric material 35, 36 may be the same elastomeric material as the resilient elastomeric material 20. The thickness of the coating of elastomeric material on the clips 30 and support plate 16 is about 0.0625 inch.
When the clips and upper plate of the rail fastener have been coated with elastomeric material, the flow of leakage current through the fastener is greatly reduced or essentially entirely limited.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A rail fastener having a rail support plate coated with electrical resistant elastomeric material to protect against electrical current leakage from the rail through the rail support plate is described. The only part of the support plate not coated with the electrical resistant elastomeric material are the serrations of the support plate. The coating of the support plate protects against current leakage from the rail to the support system. | 4 |
TECHNICAL FIELD
[0001] This application relates to subsurface drilling, specifically, to gap assemblies useful for EM telemetry. Embodiments are applicable to drilling wells for recovering hydrocarbons.
BACKGROUND
[0002] Recovering hydrocarbons from subterranean zones typically involves drilling wellbores.
[0003] Wellbores are made using surface-located drilling equipment which drives a drill string that eventually extends from the surface equipment to the formation or subterranean zone of interest. The drill string can extend thousands of feet or meters below the surface. The terminal end of the drill string includes a drill bit for drilling (or extending) the wellbore. Drilling fluid, usually in the form of a drilling “mud”, is typically pumped through the drill string. The drilling fluid cools and lubricates the drill bit and also carries cuttings back to the surface. Drilling fluid may also be used to help control bottom hole pressure to inhibit hydrocarbon influx from the formation into the wellbore and potential blow out at surface.
[0004] Bottom hole assembly (BHA) is the name given to the equipment at the terminal end of a drill string. In addition to a drill bit, a BHA may comprise elements such as: apparatus for steering the direction of the drilling (e.g. a steerable downhole mud motor or rotary steerable system); sensors for measuring properties of the surrounding geological formations (e.g. sensors for use in well logging); sensors for measuring downhole conditions as drilling progresses; one or more systems for telemetry of data to the surface; stabilizers; heavy weight drill collars; pulsers; and the like. The BHA is typically advanced into the wellbore by a string of metallic tubulars (drill pipe).
[0005] Modern drilling systems may include any of a wide range of mechanical/electronic systems in the BHA or at other downhole locations. Such electronics systems may be packaged as part of a downhole probe. A downhole probe may comprise any active mechanical, electronic, and/or electromechanical system that operates downhole. A probe may provide any of a wide range of functions including, without limitation: data acquisition; measuring properties of the surrounding geological formations (e.g. well logging); measuring downhole conditions as drilling progresses; controlling downhole equipment; monitoring status of downhole equipment; directional drilling applications; measuring while drilling (MWD) applications; logging while drilling (LWD) applications; measuring properties of downhole fluids; and the like. A probe may comprise one or more systems for: telemetry of data to the surface; collecting data by way of sensors (e.g. sensors for use in well logging) that may include one or more of vibration sensors, magnetometers, inclinometers, accelerometers, nuclear particle detectors, electromagnetic detectors, acoustic detectors, and others; acquiring images; measuring fluid flow; determining directions; emitting signals, particles or fields for detection by other devices; interfacing to other downhole equipment; sampling downhole fluids; etc. A downhole probe is typically suspended in a bore of a drill string near the drill bit. Some downhole probes are highly specialized and expensive.
[0006] Downhole conditions can be harsh. A probe may experience high temperatures; vibrations (including axial, lateral, and torsional vibrations); shocks; immersion in drilling fluids; high pressures (20,000 p.s.i. or more in some cases); turbulence and pulsations in the flow of drilling fluid past the probe; fluid initiated harmonics; and torsional acceleration events from slip which can lead to side-to-side and/or torsional movement of the probe. These conditions can shorten the lifespan of downhole probes and can increase the probability that a downhole probe will fail in use. Replacing a downhole probe that fails while drilling can involve very great expense.
[0007] A downhole probe may communicate a wide range of information to the surface by telemetry. Telemetry information can be invaluable for efficient drilling operations. For example, telemetry information may be used by a drill rig crew to make decisions about controlling and steering the drill bit to optimize the drilling speed and trajectory based on numerous factors, including legal boundaries, locations of existing wells, formation properties, hydrocarbon size and location, etc. A crew may make intentional deviations from the planned path as necessary based on information gathered from downhole sensors and transmitted to the surface by telemetry during the drilling process. The ability to obtain and transmit reliable data from downhole locations allows for relatively more economical and more efficient drilling operations.
[0008] There are several known telemetry techniques. These include transmitting information by generating vibrations in fluid in the bore hole (e.g. acoustic telemetry or mud pulse (MP) telemetry) and transmitting information by way of electromagnetic signals that propagate at least in part through the earth (EM telemetry). Other telemetry techniques use hardwired drill pipe, fibre optic cable, or drill collar acoustic telemetry to carry data to the surface.
[0009] Advantages of EM telemetry, relative to MP telemetry, include generally faster baud rates, increased reliability due to no moving downhole parts, high resistance to lost circulating material (LCM) use, and suitability for air/underbalanced drilling. An EM system can transmit data without a continuous fluid column; hence it is useful when there is no drilling fluid flowing. This is advantageous when a drill crew is adding a new section of drill pipe as the EM signal can transmit information (e.g. directional information) while the drill crew is adding the new pipe. Disadvantages of EM telemetry include lower depth capability, incompatibility with some formations (for example, high salt formations and formations of high resistivity contrast), and some market resistance due to acceptance of older established methods. Also, as the EM transmission is strongly attenuated over long distances through the earth formations, it requires a relatively large amount of power so that the signals are detected at surface. The electrical power available to generate EM signals may be provided by batteries or another power source that has limited capacity.
[0010] A typical arrangement for electromagnetic telemetry uses parts of the drill string as an antenna. The drill string may be divided into two conductive sections by including an insulating joint or connector (a “gap sub”) in the drill string. The gap sub is typically placed at the top of a bottom hole assembly such that metallic drill pipe in the drill string above the BHA serves as one antenna element and metallic sections in the BHA serve as another antenna element. Electromagnetic telemetry signals can then be transmitted by applying electrical signals between the two antenna elements. The signals typically comprise very low frequency AC signals applied in a manner that codes information for transmission to the surface. (Higher frequency signals attenuate faster than low frequency signals.) The electromagnetic signals may be detected at the surface, for example by measuring electrical potential differences between the drill string or a metal casing that extends into the ground and one or more ground rods.
[0011] Design of the gap sub is an important factor in an EM telemetry system. The gap sub must provide electrical isolation between two parts of the drill string as well as withstand the extreme mechanical loading induced during drilling and the high differential pressures that occur between the center and exterior of the drill pipe. Drill string components are typically made from high strength, ductile metal alloys in order to handle the loading without failure. Most electrically-insulating materials suitable for electrically isolating different parts of a gap sub are weaker than metals (e.g. rubber, plastic, epoxy) or quite brittle (ceramics). This makes it difficult to design a gap sub that is both configured to provide efficient transmission of EM telemetry signals and has the mechanical properties required of a link in the drill string.
[0012] There remains a need for gap subs that are compact and robust.
SUMMARY OF INVENTION
[0013] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools, and methods which are meant to be exemplary and illustrate, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while some embodiments are directed to other improvements.
[0014] One aspect of the invention provides a gap assembly useful in subsurface drilling. The gap assembly includes a drill string section having a longitudinal channel extending through it and a threaded pin at one end thereof for coupling to an adjacent drill string section. The drill string section includes electrically-conductive female and male portions spaced apart from one another and electrically insulated from one another. The female portion has an outer surface which provides threads of the pin and an inner surface which defines a bore through the female portion. The male portion includes a projecting part that extends axially from a first end thereto. The projecting part extends into the bore through the female portion and projects longitudinally into the threads of the pin.
[0015] In some embodiments, the gap assembly includes rigid electrically-insulating spacers located between the male and female portions.
[0016] In some embodiments, the male portion includes a first flange face on the first end of the male portion surrounding the projecting part and the female portion includes a second flange face facing the first flange face. A first plurality of the electrically-insulating spacers are received between the first and second flange faces.
[0017] In some embodiments, the first and second flange faces each have a circumferentially-extending groove. The first plurality of the electrically-insulating spacers are received between the circumferentially-extending grooves of the first and second flange faces.
[0018] In some embodiments, a second plurality of the electrically-insulating spacers are received between the projecting part of the male portion and the inner surface of the female portion.
[0019] In some embodiments, the projecting part of the male portion and the inner surface of the female portion are each formed to provide axially-extending grooves. At least some electrically-insulating spacers of the second plurality of electrically-insulating spacers are received between the axially-extending grooves of the projecting part of the male portion and the inner surface of the female portion.
[0020] In some embodiments, the projecting part of the male portion and the inner surface of the female portion are each formed to provide one or more circumferentially-extending grooves. At least some electrically-insulating spacers of the second plurality of electrically-insulating spacers are received between the circumferentially-extending grooves of the projecting part of the male portion and the inner surface of the female portion.
[0021] In some embodiments, the gap assembly includes one or more fill ports located in a compartment contained within the gap assembly and respectively connected to the circumferentially-extending grooves.
[0022] In some embodiments, the compartment is sealed against downhole pressures.
[0023] In some embodiments, the one or more circumferentially extending grooves includes a plurality of circumferentially-extending grooves and the one or more fill ports includes a separate fill port for each one of the circumferentially-extending grooves.
[0024] In some embodiments, the one or more circumferentially-extending grooves includes a groove that extends in a spiral or helix along the male portion.
[0025] In some embodiments, the male portion includes a first portion having a flange face which faces a corresponding flange face of the female portion, a second portion having circumferential channels, and a third portion having axially-extending channels. At least some of the spacers are in contact with each one of the first, second and third portions.
[0026] In some embodiments, the spacers include ceramic balls.
[0027] In some embodiments, the projecting part of the male portion is tubular and the longitudinal channel of the drill string section extends through the projecting part of the male portion.
[0028] In some embodiments, the gap assembly includes a flow tube extending through the longitudinal channel. The flow tube is made of an electrically-insulating material at least in a vicinity of the end of the projecting part of the male portion.
[0029] In some embodiments, the flow tube includes a first part axially aligned with a second part and seals sealingly arranged between the first and second parts and the longitudinal channel.
[0030] In some embodiments, the first part of the flow tube is made of ceramic, the second part of the flow tube is made of metal and the end of the projecting part of the male portions lies within the first part of the flow tube.
[0031] In some embodiments, the gap assembly includes a sleeve of an electrically-insulating material provided on the outside of a body of the male portion. The sleeve covers a portion of the body of the male portion that is closest to the female portion.
[0032] In some embodiments, the electrically-insulating material is selected from the group consisting of a glass-reinforced plastic, PEEK and ceramic.
[0033] In some embodiments, the sleeve has a length in the range of 1 inch (about 2½ cm) to 20 inches (about 50 cm).
[0034] In some embodiments, the gap assembly includes an electronics package housed in a cavity located between the longitudinal passage and an outer surface of the male portion.
[0035] In some embodiments, the electronics package includes one or both of an EM telemetry transmitter and an EM telemetry receiver connected electrically to each of the male portion and the female portion.
[0036] In some embodiments, the gap assembly includes a bolt extending from the cavity through an electrically-insulating sleeve, the bolt threadedly engaged with the female portion.
[0037] In some embodiments, one or both of the EM telemetry transmitter and the EM telemetry receiver is connected electrically to the female portion by way of the bolt.
[0038] In some embodiments, the space between the male and female portions is filled with solid, electrically-insulating material.
[0039] In some embodiments, the female portion is removably coupled to the male portion.
[0040] In some embodiments, the female portion is one of first and second interchangeable female portions having different configurations of threads on their outer surfaces.
[0041] In some embodiments, the threads of the pin extend along the female portion for at least one half of the length of the female portion.
[0042] In some embodiments, the gap assembly includes a dielectric liquid or fluid sealed in the gap between the male and female portions.
[0043] Another aspect of the invention provides a drill string including a mud motor coupled to drive a drill bit and a gap assembly according to any embodiment described herein between the mud motor and the drill bit.
[0044] Another aspect of the invention provides a gap assembly useful in subsurface drilling. The gap assembly includes an electrically-conductive first portion having a pin and having one or more first portion receivers, an electrically-conductive second portion couplable to the pin end of the first portion and having a box end including one or more second portion receivers, one or more axial channels defined by the first portion, and one or more circumferential channels defined by the first portion. The first portion receivers and the second portion receivers are complementarily shaped to define one or more receiving areas to receive one or more spacers when the first and second portions are coupled at the pin end and the box end. The one or more axial channels extend in substantially an axial direction of the first portion and are sized to receive the one or more spacers. Each of the one or more circumferential channels is defined about a circumference of the first portion, extends in a direction substantially transverse to the axial direction, and is sized to receive one or more spacers. When the pin end of the first portion is coupled to the box of the second portion and the one or more spacers are received by the one or more axial channels, the one or more circumferential channels, and the one or more receiving areas, the first and second portions are spaced apart to define a gap between the first and second portions so that the first portion is electrically isolated from the second portion.
[0045] In some embodiments, the second portion includes one or more channels complementary to at least one of the one or more axial channels and the one or more circumferential channels.
[0046] In some embodiments, the first portion receivers are defined by a first portion flange face at the pin end and the second portion receivers are defined by a second portion flange face at the box end.
[0047] In some embodiments, the receiving areas comprise flange channels.
[0048] In some embodiments, the gap assembly includes one or more fill ports sized to receive the one or more spacers. The one or more fill ports are in communication with at least one of the one or more circumferential channels so that the spacers received by the one or more fill ports are received by the at least one of the one or circumferential channels.
[0049] In some embodiments, the one or more fill ports define apertures in communication with an interior chamber of the first portion and the interior chamber is sealed from downhole pressures.
[0050] In some embodiments, the gap assembly includes an inlet for receiving fluid insulating material and an outlet for expressing fluid insulating material. The inlet is defined by the first portion at a first end of the gap and the outlet is defined by the first portion at a second end of the gap, the second end distal to the first end. The outlet is in communication with the inlet so that, while the first and second portions are coupled, fluid insulating material received at the inlet under pressure flows radially towards the outlet through the gap.
[0051] In some embodiments, the outlet is proximate to and in communication with at least one of the one or more axial channels.
[0052] In some embodiments, the gap assembly includes an electrically-insulating sleeve for increasing a longitudinal distance at which the first and second portions are spaced while the first and second portions are coupled. The sleeve is couplable to the first portion so that, while the first and second portions are coupled and the first portion and sleeve are coupled, the electrically-insulating sleeve is proximate to the second portion.
[0053] In some embodiments, the gap assembly includes a seal between the sleeve and the first portion for reducing ingress of drilling fluid proximate to the sleeve.
[0054] In some embodiments, the seal is proximate to a first end of the sleeve, the first end of the sleeve is distal to a second end of the sleeve, the second end of the sleeve is proximate to the second portion while the first and second portions are joined.
[0055] In some embodiments, the gap assembly includes an electrically-conductive member in electrical communication with the second portion. The member extends through the gap from the first potion towards the second portion. The member is in electrical communication with an EM telemetry system housed by the first portion.
[0056] In some embodiments, the EM telemetry system is in electrical communication with the first portion.
[0057] In some embodiments, while the first and second portions are joined, the member is received by the second portion so that the channels of the first and second portions are in alignment.
[0058] In some embodiments, the gap assembly includes a bore defined by the first portion and a flow tube lining the bore. At least a portion of the flow tube is electrically-insulating.
[0059] In some embodiments, the at least a portion of the flow tube is proximate to the gap.
[0060] In some embodiments, the flow tube extends axially through the first portion from a first end of the first portion to a second end of the first portion. The flow tube is sealable at the first and second ends of the first portion.
[0061] In some embodiments, at least one of the spacers includes a sphere.
[0062] In some embodiments, at least one of the spacers for receipt by the axial channels includes a rod.
[0063] In some embodiments, at least one of the spacers for receipt by receiving areas includes a ring, a plate, a disc, an arc, or a block.
[0064] In some embodiments, at least one of the circumferential channels includes a helix.
[0065] In some embodiments, at least one of the circumferential channels includes a spiral.
[0066] Another aspect of the invention provides a method for insulating a gap sub assembly, the gap sub assembly including an electrically-conductive first portion and an electrically-conductive second portion. The method includes inserting spacers into one or more axial channels defined by the first portion so that the spacers extend in substantially an axial direction of the first portion, inserting spacers into one or more circumferential channels defined by the first portion so that the spacers are positioned about a circumference of the first portion, the spacers extending in a direction substantially transverse to the first direction, inserting spacers into one or more receiving spaces defined by one or more first portion receivers at a pin end of the first portion and by one or more second portion receivers at a box end of the second portion, and coupling the first and second portions so that the first and second portions are spaced apart by the spacers to define a gap between the first and second portions, the first portion being electrically isolated form the second portion.
[0067] In some embodiments, the method includes inserting spacers into one or more channels defined by the second portion. The one or more channels are complementary to at least one of the one or more axial channels and the one or more circumferential channels.
[0068] In some embodiments, the method includes inserting spacers into the gap proximate to a flange face defined by the first portion at the pin end so that, while the first and second portions are coupled, the flange face is spaced apart from the second portion in the axial direction.
[0069] In some embodiments, the one or more first portion receivers include flange channels.
[0070] In some embodiments, at least one of inserting spacers into the one or more axial channels and inserting spacers into the one or more circumferential channels includes inserting spacers into a fill port defined by a surface of the first portion.
[0071] In some embodiments, the method includes injecting fluid insulating material into the gap.
[0072] In some embodiments, injecting fluid insulating material into the gap includes injecting fluid insulating material under pressure at an inlet in communication with the gap and expressing fluid insulating material at an outlet in communication with the gap so that the fluid insulating material flows radially towards the outlet through the gap.
[0073] In some embodiments, expressing fluid insulating material includes passing fluid material through the one or more axial channels.
[0074] In some embodiments, the method includes inserting a mandrel into a bore of the first portion so that vent holes of the mandrel correspond generally with the outlet.
[0075] In some embodiments, injecting fluid insulating material includes injecting fluid insulating material at an outer circumference of the gap so that the fluid insulating material flows toward an axial center of the first portion.
[0076] In some embodiments, the method includes coupling an electrically-insulating sleeve to the first portion so that a longitudinal distance at which the first and second portions are spaced while the first and second portions are coupled is increased and the electrically-insulating sleeve is proximate to the second portion.
[0077] In some embodiments, the method includes forming a seal between the sleeve and the first portion for reducing ingress of drilling fluid proximate to the sleeve.
[0078] In some embodiments, the seal is proximate to a first end of the sleeve, the first end of the sleeve distal to a second end of the sleeve, the second end of the sleeve proximate to the second portion while the first and second portions are joined.
[0079] In some embodiments, the method includes placing the member in contact with the second portion so that the member and the second portion are in electrical communication.
[0080] In some embodiments, while the first and second portions are joined, receiving the member with the second portion so that the channels of the first and second portions are in alignment.
[0081] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0082] The accompanying drawings illustrate non-limiting example embodiments of the invention.
[0083] FIG. 1 is a schematic view of a drilling operation.
[0084] FIG. 2 is a cross-section of a gap assembly according to an example embodiment.
[0085] FIG. 3 is a cross-section of the gap assembly of FIG. 2 with male and female portions separated.
[0086] FIG. 3A is a perspective view of the male portion of the example gap assembly and insulating spacers.
[0087] FIG. 4 is a perspective view of the male portion of the gap assembly with the female portion and spacers removed.
[0088] FIG. 5 is a cross-section through a gap sub looking toward a gap assembly.
[0089] FIG. 6 is a longitudinal cross-section of a gap sub incorporating an example gap assembly.
[0090] FIG. 7 is a longitudinal cross section illustrating a mandrel in a bore of an example gap sub.
DESCRIPTION
[0091] Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. The following description of examples of the technology is not intended to be exhaustive or to limit the system to the precise forms of any example embodiment. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
[0092] FIG. 1 shows schematically an example drilling operation. A drill rig 10 drives a drill string 12 which includes sections of drill pipe that extend to a drill bit 14 . The illustrated drill rig 10 includes a derrick 10 A, a rig floor 10 B and draw works 10 C for supporting the drill string. Drill bit 14 is larger in diameter than the drill string above the drill bit. An annular region 15 surrounding the drill string is typically filled with drilling fluid. The drilling fluid is pumped through a bore in the drill string to the drill bit and returns to the surface through annular region 15 carrying cuttings from the drilling operation. As the well is drilled, a casing 16 may be made in the well bore. A blow out preventer 17 is supported at a top end of the casing. The drill rig illustrated in FIG. 1 is an example only. The methods and apparatus described herein are not specific to any particular type of drill rig.
[0093] One aspect of this invention provides a novel constructions for a gap assembly. In some embodiments the gap assembly is designed to permit disassembly for service and then reassembly to place back into service. The illustrated gap assembly is particularly well adapted for use in the portion of a drill string between a mud motor and a drill bit, although its use is not so limited.
[0094] FIG. 2 is a cross section of a gap assembly according to an example embodiment. As shown, the gap assembly 100 is provided at the pin end 20 A of a drill string section 20 . The gap assembly provides electrical isolation between the pin 21 of drill string section 20 and the body 22 of drill string section 20 . As shown, gap assembly 100 comprises a male portion 23 which is attached to, and is in electrical contact with, body 22 of drill string section 20 and a female portion 24 which includes pin 21 .
[0095] Electrical isolation between the male and female portions 23 , 24 is provided by electrically-insulating spacers 25 . In the illustrated embodiment, however, as described in more detail below, at least some of spacers 25 may comprise electrically-insulating pieces of other shapes.
[0096] FIG. 3 shows male portion 23 with female portion 24 removed. The contact surface of male portion 23 includes a flange face 23 A, a portion 23 B which includes circumferential channels 26 for receiving spacers 25 and a portion 23 C which includes axially-extending channels 28 for receiving other spacers 25 . Similar complementary channels are provided on inside surfaces of the female section.
[0097] The engagement between electrically-insulating spacers 25 and the axially-extending channels facilitates transfer of torque through gap sub assembly 100 . The engagement of electrically-insulating spacers 25 in the circumferentially-extending channels facilitates transmission of tension and compression through gap assembly 100 . The provision of electrically-insulating spacers 25 between the flange face 25 A and a corresponding face on the female portion facilitates transmission of compressive forces through the gap assembly 100 .
[0098] The insulating members that are located between flange face 23 A and female section 24 resist compressive loads and prevent the ceramic balls in circumferential channels 26 from experiencing significant shear forces when gap assembly 20 is under compression.
[0099] In the illustrated embodiment, the male and female portions 23 , 24 each have three circumferential channels 26 which receive electrically-insulating spacers such as ceramic balls. The number of circumferential channels may be varied. It is not mandatory that the circumferential channels be completely circular. The channels may be wavy to some degree while still permitting ceramic balls in the channels to withstand tension/compression axial forces. In other embodiments, channels 26 extend around male and female portions 23 , 24 in a spiral or helix.
[0100] Axially-extending channels 28 may open at the tip of pin 21 . These openings may be plugged with plugs at passages 29 after spacers have been inserted into channels 28 .
[0101] The ceramic balls in the axially-extending channels may be replaced with other forms of electrical insulator. For example, the ceramic balls could be replaced by rods which may optionally be configured to screw into threaded end portions of the axially extending channels. Similarly, the ceramic balls 25 illustrated in the channels on flange face portion 23 A could be replaced with insulating spacers of other shapes. For example, insulating spacers in the form of rings, plates, discs, arcs, block, or the like may be provided.
[0102] In some embodiments, channels 27 are provided to facilitate introduction of ceramic balls into circumferential channels 26 after the male and female portions 23 , 24 have been mated together. The ceramic balls introduced into circumferential channels 26 can then hold together the mated male and female portions. FIG. 4 shows an example embodiment in which passages 27 are provided through which ceramic balls or other similar insulating members may be introduced into circumferential channels 26 after the male and female portions have been mated together.
[0103] Providing a separate fill port 27 A for each circumferential channel 26 may facilitate easy assembly and disassembly of the gap assembly. The fill ports may be located in the interior of the drill string section. This protects the fill ports from possible damage by erosion. Fill ports 27 A are shown in FIG. 5 .
[0104] Furthermore, the fill ports through which ceramic balls may be introduced into the ceramic channels may be located in a portion of the assembly which is sealed from downhole pressures. This portion may, for example, house electronics or other downhole equipment. Providing the fill ports in this area prevents fluid ingress through the fill ports. In FIG. 5 , fill ports 27 A open into a chamber 35 into which electronics may be placed. The electronics may, for example, include an EM telemetry transmitter and/or an EM telemetry receiver. An EM telemetry transmitter may have outputs electrically coupled to the male and female portions of the gap assembly. An EM telemetry receiver may have inputs electrically coupled to the male and female portions of the gap assembly.
[0105] After assembly of the male and female portions and the hard electrical insulators (e.g. spacers 25 ) that keep them spaced apart, additional insulating material may be introduced into the gap between the male and female members. This additional electrically-insulating material may, for example, comprise settable material such as a suitable plastic, epoxy, cement, engineered resin, thermal plastic, or the like.
[0106] In other embodiments, the additional electrically-insulating material comprises a suitable electrically-insulating oil, or other dielectric liquid or fluid. In such other embodiments, suitable seals are provided to prevent ingress of drilling fluid between the male and female portions and to prevent the leakage of the electrically-insulating fluid or other dielectric material.
[0107] In some embodiments, the gap between the male and female portions is injected with a plastic material. It is advantageous in some cases to inject the plastic material from the outside diameter of gap assembly 100 so that the plastic flows radially inwardly past flange face 23 A. Injection may be continued until the plastic flows into the bore of pin 21 . For example the plastic material may flow through the gap and exit through passages 29 provided near to the ends of the axially-extending channels 28 , thereby sealing the male and female portions together and also preventing any relative motion between the male and female portions.
[0108] During plastic injection, a mandrel may optionally be inserted into the bore of the male portion 23 . Vent holes may be provided in the mandrel. The vent holes or another vent channel are arranged to correspond generally with passages 29 and/or axially-extending channels 28 . The mandrel may be removed after plastic has been injected to fill the gap.
[0109] FIG. 7 illustrates an example mandrel 40 inserted into a bore 42 of male portion 23 . Mandrel 40 may comprise a rod having a close running fit in bore 42 . Mandrel 40 comprises vents 44 which extend to the surface of mandrel 40 adjacent the end of male portion 23 . In the illustrated embodiments, vents 44 comprise passages that extend radially to join a passage 45 that extends axially to the end of mandrel 40 . In the embodiment illustrated in FIG. 7 , the gap assembly 100 may be placed into a plastic injection mould which injects plastic from the outside diameter of gap sub assembly 100 as indicated by arrow 47 . The plastic may flow through the gaps separating male portion 23 and female portion 21 past the end of male portion 23 into vents 44 located in bore 42 . The flowing plastic may force air out of the gap as it flows and fills the gap. In the illustrated embodiment, the outside diameter of male portion 23 is reduced in an area 48 near flange face 23 A. Area 48 provides a channel to receive plastic material, facilitates distribution of plastic material around the circumference of gap assembly 100 , and also makes alignment of gap assembly 100 with plastic injection ports of an injection mold less critical.
[0110] A layer of electrically-insulating material 30 (also referred to as ‘sleeve 30 ’) may be provided on the outside of section body 22 to increase the longitudinal separation on the outside of the drill string between electrically conducting parts on either side of the gap provided by the gap assembly described above. The electrically-insulating material may, for example, comprise a sleeve of a suitable glass-reinforced plastic, a ceramic material, or the like. This material may be coated on to the outside of the drill string segment 20 and/or heat shrunk in place and/or be a tight fit onto the outer surface of drill string segment 20 . In some embodiments, O-rings or other seals are provided to seal behind the sleeve 30 to prevent the ingress of drilling fluid behind sleeve 30 and/or into the gap.
[0111] Particularly when gap assembly 100 is used in the portion of a drill string between a mud motor and a drill bit, the plastic sleeve or other electrically-insulating material 30 is relatively well protected from erosion and damage from contact with the walls of the bore hole. This is because the gap assembly will typically remain centralized in the bore hole by the bit, which is nearby.
[0112] The gap length may be varied by altering the length of sleeve 30 . For example, in some embodiments, the gap may have a length in the range of 1 inch (about 2½ cm) to 20 inches (about 50 cm). Smaller or longer gaps may be provided. For example, gaps of ¼ inch (about 6 mm) or more may be provided. In some cases, such as where a short gap is acceptable, sleeve 30 may be omitted.
[0113] Sleeve 30 may be rated for downhole temperatures. Appropriate grades of PPS or PEEK plastic tend to be a good material to use for sleeve 30 because of such materials' anti-erosion characteristics and cost-effectiveness.
[0114] As best illustrated in FIG. 2 , in some embodiments, an electrical conductor is provided that extends across the gap and makes contact with female section 24 . The illustrated embodiment shows a bolt 32 which extends through an electrically-insulating sleeve 31 to make contact with female portion 24 . In the illustrated embodiment, bolt 32 threads into a threaded bore in female portion 24 . Electronics may then make electrical contact with pin 21 of segment 20 by way of bolt 32 or other electrically conducting member. In an example embodiment, one terminal of an EM telemetry transmitter, receiver, or transceiver is connected to pin 21 via bolt 32 . In some embodiments the head of bolt 32 projects into an electronics assembly.
[0115] Bolt 32 may optionally serve to aid assembly of gap assembly 100 by keying together members 23 , 24 in a position (e.g. a rotational orientation) in which corresponding channels are aligned to receive spacers.
[0116] In those embodiments where the gap assembly is not filled with a setting material which prevents disassembly of the gap assembly 100 , the gap assembly may be disassembled, for example by removing ceramic balls from the circumferentially extending channels 26 and then taking the gap assembly apart. Each component can then be serviced, as required.
[0117] FIG. 6 shows a gap sub 200 which includes a gap assembly 100 . Gap sub 200 includes a box 50 on an end opposed to pin 21 . A bore 52 extends between box 50 and pin 21 . Bore 52 is lined with a flow tube 53 . Flow tube 53 is sealed near its ends by O-rings or other seals 54 . At least the portion of flow tube 53 that extends across the gap between male portion 23 and female portion 24 is made of an electrically-insulating material such as a suitable ceramic. In the illustrated embodiment, a section 53 A of flow tube 53 is electrically-insulating. The remainder of flow tube 53 may be made of a suitable erosion-resistant and wear-resistant material.
[0118] Electronics, which may be housed in a cavity or chamber 35 , can make electrical contact with either side of the gap by contacting bolt 32 , which extends into as in electrical contact with female portion 24 , and body 20 .
[0119] In cases where the gap assembly is designed to permit the gap assembly to be disassembled and reassembled, one can appreciate that different female portions may be provided which include different couplings. For example, the different couplings may provide different thread profiles, thread pitches, thread tapers, or the like. This permits a single drill bit section to be readily adapted for being coupled to other drill string components that have different couplings.
[0120] An advantage of providing a connection by way of a bolt 32 or other similarly-located electrically-conductive member is that the electrically-conductive member which makes contact with female portion 24 is not exposed to drilling fluid.
[0121] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
INTERPRETATION OF TERMS
[0122] Unless the context clearly requires otherwise, throughout the description and the claims:
[0123] “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.
[0124] “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof.
[0125] “herein,” “above,” “below,” and words of similar import, when used to describe this specification shall refer to this specification as a whole and not to any particular portions of this specification.
[0126] “or,” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
[0127] the singular forms “a,” “an,” and “the” also include the meaning of any appropriate plural forms.
[0128] Words that indicate directions such as “vertical,” “transverse,” “horizontal,” “upward,” “downward,” “forward,” “backward,” “inward,” “outward,” “vertical,” “transverse,” “left,” “right,” “front,” “back”,” “top,” “bottom,” “below,” “above,” “under,” and the like, used in this description and any accompanying claims (where present) depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.
[0129] Where a component (e.g. a circuit, module, assembly, device, drill string component, drill rig system, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e., that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.
[0130] Specific examples of systems, methods and apparatus have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and/or acts with equivalent features, elements and/or acts; mixing and matching of features, elements and/or acts from different embodiments; combining features, elements and/or acts from embodiments as described herein with features, elements and/or acts of other technology; and/or omitting combining features, elements and/or acts from described embodiments.
[0131] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. | A gap sub has electrically-conductive parts held together by electrical insulators which engage in channels formed in the parts. The electrical insulators hold the parts in a spaced-apart electrically-insulated relationship. In some embodiments, the electrical insulators are removable to allow separation of the parts. An insulating oil or other fluid may fill the gap. | 4 |
FIELD OF THE INVENTION
This invention relates to methods of attaching ferrules to the outer circumferential surface of optical fibers to act as terminations and/or connectors for said fibers and more particularly to a method of ferrule attachment involving welding by laser irradiation.
BACKGROUND OF THE INVENTION
For industrial application purposes, optical fibers are commonly terminated with plastic ferrules. This is done, for example, so that small diameter optical fibers can be positioned with respect to optical couplers and the like.
It is known to bond optical fibers to plastic ferrules through the use of adhesives, such as with epoxies, by mechanical crimping and by welding using an irradiation source such as a laser. Epoxy bonding is an exacting process which requires high precision in formulating, applying and curing the epoxy. Crimping is also a mechanically exacting process which, if incorrectly done, can adversely impact the optical and/or structural characteristics of the fiber. Welding is typically carried out using a plastic ferrule which is transparent to the laser radiation and a jacket on the optical fiber which fits snugly within the ferrule and which is much more absorbent to the laser radiation. This approach, however, results in highly asymmetric heating and a weld pool which is composed substantially entirely of material from the fiber jacket. Such an asymmetric weld is often mechanically weak and will not stand up to either application temperature extremes or mechanical stress created by rough handling or environmental conditions.
SUMMARY OF THE INVENTION
The present invention, in one aspect, is an improved method of welding plastic ferrules to plastic jacketed optical fibers. According to this aspect of the invention, a plastic jacketed optical fiber is provided in combination with the plastic ferrule so that the outer circumferential surface of the plastic jacket is in juxtaposed relationship to an inner circumferential surface of the ferrule. A layer of material is placed between and in contact with the two juxtaposed surfaces, which material is substantially more absorptive to radiation at a predetermined wavelength than the materials of both of the jacket and ferrule. In the preferred embodiment, the plastic material of the ferrule is substantially transparent to the predetermined wavelength radiation, whereas the material of the intermediate layer is highly absorptive as a result of its optical content. Thereafter, the combination is irradiated substantially at said wavelength to create a weld pool which, according to the preferred aspects of the invention, is highly symmetrical and extends in substantially equal amounts to equal depths into the materials of both the jacket and the ferrule. The radiation is typically from a laser.
In accordance with the second aspect of the invention, a ready-to-weld plastic jacketed optical fiber is provided. In accordance with the invention, an exposed outer surface of a plastic jacket surrounding the optical fiber is coated either circumferentially continuously or discontinuously with a second transitory material whose absorptivity to radiation at a predetermined wavelength is much higher than that of the plastic material on which it is placed. This combination is ready to place within the confines of a plastic ferrule which itself is also transparent to the predetermined wavelength radiation and which is sized to fit over and in contact with the intermediate transitory material. That combination may then be irradiated and welded as described above.
The terms “plastic” and “polymer” are used interchangeably in this document.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The description herein makes reference to the accompanying drawing wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 is a sectional view of the juxtaposed combination of a jacketed optical fiber and a plastic ferrule with the transitory material in place prior to irradiation;
FIG. 2 is a cross-section through the components of FIG. 1; and
FIG. 3 shows the combination of FIG. 1 during and after radiation welding.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, there is shown an optical fiber 10 having a non-strippable exterior cladding 12 of mechanically stable material and a strippable polymer layer 14 disposed over the layer 12 . In this embodiment, a second strippable outer layer 16 is also provided over the layer 14 and a portion of the layer 16 has been stripped back to expose an axial length of the layer 14 . In addition, the layer 14 , to the extent that it once continued to the righthand terminal end of fiber 10 , has also been stripped back to expose a portion of the non-strippable cladding 12 .
In FIG. 1, a plastic ferrule 18 has been located over the stripped end of the optical fiber 10 such that the smallest diameter portion snugly engages the cladding 12 . A larger diameter surface 22 is in juxtaposed relationship to an outside circumferential surface 20 of the strippable polymer layer 14 and an even larger diameter portion overlies the strippable outer layer 16 as shown. The juxtaposed surfaces may be fully radially spaced apart or only partly spaced to allow for a thin spot or layer of intermediary material. In this combination, an intermediary layer 24 of material which is highly absorptive to radiation from one or more sources such as lasers emitting radiation in the near infrared range is placed. The layer 24 is of such thickness as to lie between but in contact with each of the surfaces 20 and 22 as shown. Layer 24 may be one spot, several spots or an entire circumferential band.
After providing the combination as essentially shown in FIGS. 1 and 2, one or more laser sources 26 are activated to irradiate the material 24 through the essentially transparent plastic material of the ferrule 18 as shown in FIG. 3 . The transitory absorbing layer 24 creates a weld pool 28 which extends both radially outward and radially inward to essentially equal extents and to essentially equal depths such that the weld pool 28 , when re-solidified, is symmetric and of maximum mechanical strength.
In a usable embodiment, the laser 26 may be a single source laser which is moved from point to point around a circumferential path or it may comprise a plurality of lasers which are activated at essentially the same time. Alternatively, it is possible to provide an arcuate or annular source of laser radiation using appropriate objects as will be apparent to those skilled in the art. The ferrule may be made of Nylon, LCP or any suitable polymer which is highly transmissive of, i.e., essentially transparent to, laser radiation in the near infrared range or transmissive to the light at whatever wavelength is used. The polymer layer 14 may be made of Tefzel, Nylon or any other suitable material. The absorptive layer 24 may be printed or applied in film form and typically comprises a material containing carbon black or other material which creates a high degree of optical absorptivity of radiation from the laser 26 . Suitable materials are available from Epolin Inc. and are referred to in the literature as infrared blocking silk screen inks capable of strongly absorbing near infrared light in the 81 nm to 1080 nm range as well as to transmit high percentage of light in the visible spectrum from about 400 nm to 750 nm. Epolin Inc. is located in Newark, N.J. 07105. A laser source having a curved or arcuate beam is described in the on-line article from Plastics Technology , February 2002, “Laser Welding Comes of Age,” by Robert Leaversuch, Executive Editor.
This invention may be used to apply a ferrule to the terminal end of an optical fiber which has been divided or severed from a longer length fiber using the process described in co-pending application, attorney docket YAZ-173-A, filed simultaneously herewith; the entire content of such application is incorporated herein by reference.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | A plastic ferrule is laser welded to the stripped end of an optical fiber using a highly radiation absorptive transitory material between the outer plastic surface of the fiber and the inner plastic surface of the ferrule. The use of an intermediary transitory material of high-radiation absorbing material creates a symmetrical weld pool which contributes to higher mechanical strength in the weld area. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application 61/438,838, entitled “Structures of and methods of making sports shafts suitable for graphic application”, filed Feb. 2, 2011 by the same inventors, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of sports equipment, and in particular, a sports shaft that supports a basket or a blade at its end to allow a ball or a ‘puck’ in play.
[0003] Sports shafts, such as lacrosse shafts, usually include color patterns or designs on the exterior surfaces to identify the manufacturers and provide aesthetic appeal. Existing cosmetic applications include a rubberize substance, paint, or decals that lay on the surface of the shaft. These rubberized materials are typically applied by molding, shaping, extruding or hydra forming, or deep drawing on the outer surface of a pre-formed stick. For the veneer/wood covered shafts, these rubberized materials can be applied during the molding process. Graphics on the wood shaft can be applied before or after molding depending on the appearance desired for the graphics.
[0004] A drawback of the conventional sports shafts is that the colors and graphic display are easily scraped off by bumping, collisions, and abrasion when the shafts are used in playing games.
[0005] Some sports shafts are applied with some forms of graphics media that tend to improve grip. Such coatings, including rubber coatings, are usually not durable. Players often apply tapes around the sports shaft to improve their grips. Tapes are also often applied to other “stencil” or “silk-screened” shafts to enhance grip, as the surfaces of these sports shafts can be slippery and lack tactile feel for the players. When covered by tapes, the graphics on the sports shaft is useless in providing product identification and brand recognition as it is originally designed.
SUMMARY OF THE INVENTION
[0006] In one aspect, the present invention relates to a method for making a sports shaft that includes forming a negative image, by a printing apparatus, on an image-receiving surface of a flexible cover sheet; obtaining a first tube with a sheet of composite material; covering the first tube with the flexible cover sheet that has the negative image facing an outer surface of the first tube; and applying heat and pressure to cure the flexible cover sheet and the first tube by one or more molds to form a sports shaft having a composite core made of the composite material and the flexible cover sheet wrapped around the core and showing to the outside a positive image based on the negative image.
[0007] Implementations of the system may include one or more of the following. The step of applying heat and pressure can include holding the flexible cover sheet and the first tube inside one or more molds; and applying pressure inside the first tube to press the first tube and the flexible cover sheet against the one or more molds. The method can further include inserting an elastic inflation tube into the first tube and inflating the elastic inflation tube by compressed air to press the first tube and the flexible cover sheet against the one or more molds. The step of applying heat and pressure can include heating the flexible cover sheet and the first tube to a temperature between about 180° F. to about 325° F. The negative image can be formed by a dye or an ink, wherein the method can further include before the step of forming a negative image, treating the image-receiving surface by heat, flame, the Corona process, sand blast, or a chemical to assist the adhesion of the dye or the ink to the image-receiving surface. The method can further include rolling the flexible cover sheet to form a second tube having the negative image facing inside, leaving the positive image visible from outside of the second tube, wherein the step of covering comprises inserting the first tube into the second tube. The flexible cover sheet can be formed by a material selected from the group consisting of a polymeric or a plastic material such as Nylon™, Polybutylene terephthalate (PBT), and co-extruded Nylon™ and PBT. The flexible cover sheet can be formed by a substantially transparent material. The flexible cover sheet can be formed by a translucent, a white, or substantially opaque material. The flexible cover sheet can have a thickness a range between about 0.01″ and about 0.04″. The flexible cover sheet can have a satin or matte finish on a cover surface opposing to the image-receiving surface. The negative image can be formed on the image-receiving surface of a flexible cover sheet using silk screen printing, ink jet printing or thermal dye sublimation printing.
[0008] In another aspect, the present invention relates to a method for making a sports shaft. The method includes forming a negative image on a transfer sheet by a printing apparatus, forming a first tube with a sheet of composite material, covering the first tube by a flexible cover sheet, placing the transfer sheet on the flexible cover sheet with the negative image facing an outer surface of the flexible cover sheet, applying heat and pressure to the flexible cover sheet and the first tube by one or more molds to cure the flexible cover sheet and the composite material in the first tube and to transfer the negative image to the outer surface of the flexible cover sheet; and removing the transfer sheet from the flexible cover sheet to form a sports shaft having a composite core made of the composite material and a flexible cover sheet wrapping around the core. The outer surface of the flexible cover sheet can be printed with a positive image based on the negative image.
[0009] Embodiments may include one or more of the following advantages. The present invention provides graphics to sports shafts with improved durability for the graphics and grips for the players, compared to the conventional sports shafts. The color printing is protected by a sheet of transparent material against abrasion and impact during the game play. The transparent material can be made of a material to improve grip and adhesion of feel of the shaft in players' hands, which eliminates the need for taping over the sports shaft and allows the branding and trademarks to be visible through the use lives of the sports shafts.
[0010] Another advantage of the disclosed sports shaft is that it can act as a cushion and can help dampen the feel of impact to the player's hands.
[0011] Additionally, the flexible cover sheet can also protect the players from sharp edges that ensue of shaft breakage as the plastic sheet tends to stretch over a breakage and prevents the shards from injuring the player or lessons the degree of injuries.
[0012] The present invention is applicable to a wide range of sports shafts such as lacrosse shafts, hockey sticks, and other shaft style tools, and various shaft cross-sectional shapes such as octagon, square, round, or oval cross sections.
[0013] Although the invention has been particularly shown and described with reference to multiple embodiments, it will be understood by persons skilled in the relevant art that various changes in form and details can be made therein without departing from the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The following drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the invention.
[0015] FIG. 1 illustrates the printing of a negative image on an image-receiving surface of a flexible cover sheet.
[0016] FIG. 2 illustrates the flexible cover sheet printed with a negative image on the image-receiving surface.
[0017] FIG. 3 illustrates the formation of a tube by the flexible cover sheet carrying the negative image on the image-receiving surface.
[0018] FIG. 4 shows that a tube-shaped of composite material is inserted inside the tube of the flexible cover sheet and the tube of the flexible cover sheet is fitted into a mold.
[0019] FIG. 5 shows the formation of a sport shaft having a core made of the composite material wrapped by the flexible cover sheet showing a positive image visible from the outside.
[0020] FIG. 6 shows a flowchart for forming a sports shaft in accordance with the present invention.
[0021] FIG. 7 shows a flowchart for forming a sports shaft in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention discloses a sport shaft that is covered by a flexible cover sheet that is printed with graphics such as identification, trademark, branding, and color text or images on its inner surface contacting the shaft surface. The flexible cover sheet can be molded to the shaft. The flexible cover sheet can be molded simultaneously during the molding of composite shafts, hydra-formed compressed air expansion, or other expanded molding process and forming techniques. The flexible cover sheet can also be molded to the sports shaft after the sports shaft is formed as in the case of extruded or formed alloy shafts.
[0023] As shown in FIG. 1 , a flexible cover sheet 100 includes an image-receiving surface 110 . In most cases, the flexible cover sheet 100 is formed by a substantially transparent material. In some cases, the flexible cover sheet 100 can be translucent, white, or substantially opaque. (In these cases, the colorant can diffuse deep into the flexible cover sheet 100 and still make the positive image visible from outside, as shown in FIGS. 2-5 below). Suitable materials for the flexible cover sheet 100 can include a polymeric or a plastic material such as Nylon™, Polybutylene terephthalate (PBT), co-extruded Nylon™ and PBT, etc. The flexible cover sheet 100 can have a thickness in a range between about 0.01″ and about 0.04″, or about 0.02″ provide strength to sustain abrasion and impact during usage of the sports shaft to be formed.
[0024] The image-receiving surface 110 can be treated by techniques such as heat, flame, the Corona process, sand blast, or chemicals. The treatments can alter the surface structure of the image-receiving surface 110 to make it more adhesive to the colorant to be printed, such as epoxy ink, and better adhesion to the composite material as describe below. The surface treatments can make the image-receiving surface 110 more easily adhere to the surface of the sports shafts (as shown in FIGS. 3 and 4 below) because the flexible cover sheet 100 normally does not easily adhere to the surface of the sports shaft, such as an alloy shaft.
[0025] A silk screen printing device 150 is prepared with a layer of epoxy ink in a negative image 160 , which corresponds to the intended graphics or image pattern to be displayed on the finished sports shaft. The screen printing device 150 is pressed against the image-receiving surface 110 of the flexible cover sheet 100 to print a negative image 170 of epoxy ink on the image-receiving surface 110 (step 610 , FIG. 6 ), as shown in FIG. 2 . The negative image 170 can include multiple color images sequentially printed with different silk screens to render a blended color image.
[0026] It should be noted that other forms of printing techniques, such as thermal sublimation printing and ink jet printing, can also be used to print the negative image 170 on the image-receiving surface 110 of the flexible cover sheet 100 .
[0027] In some embodiments, a positive image can be first printed on a transfer sheet, for example, by thermal dye sublimation printing, and then transferred to form the negative image 170 on the image-receiving surface 110 of the flexible cover sheet 100 under heat and pressure. The dye molecules diffuse into the structure of the plastic to sufficient depth to become cohesive.
[0028] After printing, the flexible cover sheet 100 is cut to a specified width and length which are compatible with the outer surface of the sports shaft while taking into account with the thermal expansion in the molding heat.
[0029] Next, as shown in FIG. 3 , the flexible cover sheet 100 is rolled up to form a tube 300 with the negative image 170 ( FIG. 2 ) facing inside leaving a positive image 310 visible from outside (step 620 , FIG. 6 ). The seam 320 of the tube 300 is held by a clear tape 330 which can be made of high-temperature resistant Mylar™.
[0030] Optionally, a protective sheet (not shown) can be applied to the outer surface of the tube 300 to protect the flexible cover sheet 100 from being contaminated by resins, epoxy, or glues used during molding or assembly of the sports shaft ( FIG. 4 below).
[0031] Next, referring to FIG. 4 , a sports shaft is formed in a sports shaft molding apparatus 400 . The sports shaft molding apparatus 400 includes a lower mold 410 and a top mold (not shown for clarity purpose) which respectively have recesses 415 that together can define the shape of the sports shaft ( FIG. 5 ) to be formed. The shapes of the recesses 415 can define a cavity having a cross section in octagonal, square, round, or oval shape. The top mold and the lower mold 410 can have substantially the symmetric shape and can be heated by an external heater or furnace. The sports shaft molding apparatus 400 also includes an elastic inflation tube 420 that can be inflated by compressed air pumped into an air inlet 430 in fluid connection with the elastic inflation tube 420 . The elastic inflation tube 420 can be made of Nylon™. The air inlet 430 can be held to the elastic inflation tube 420 by a tape 435 . The top mold and the lower mold 410 also include the tube clamp 417 which can form a hole to clamp the air inlet 430 when the top mold and the lower mold 410 are held again one another.
[0032] A sheet 450 of composite material is rolled up to form a tube 460 (step 630 , FIG. 6 ). The tube 460 is inserted inside the tube 300 formed by the flexible cover sheet 100 (step 640 , FIG. 6 ). The nested tubes 300 and 460 are fitted into the lower mold 410 . The elastic inflation tube 420 is inserted into the tube 460 formed by the sheet 450 of composite material. An upper mold (not shown) is then placed over the tube 300 of the flexible cover sheet 100 and clamped against the lower mold 410 , which holds the nested tubes 300 , 460 in the cavity formed by the recesses 415 in the lower mold 410 and the upper mold (not shown) (step 650 , FIG. 6 ). The air inlet 430 is fit in the tube clamp 417 . The elastic inflation tube 420 is inflated to press the tube 460 of composite material and the tube 300 formed by the flexible cover sheet 100 against the lower mold 410 and the upper mold (not shown), which causes the nested tubes 300 , 460 to expand and to conform to the shapes of the recesses 415 in the lower mold 410 and the upper mold (not shown). The lower mold 410 and the upper mold (not shown) are heated to a temperature in a range such as from about 180° F. to about 325° F. The flexible cover sheet 100 in the form of the tube 300 and the sheet 450 of composite sheet in the tube 460 are co-axially molded by heat and pressure to form a multi-layer tube assembly (step 660 , FIG. 6 ). After the applications of heat and pressure, the flexible cover sheet 100 and the sheet 450 of composite material are cured. The upper mold (not shown) is lifted. The ends of the nested tubes 300 and 460 are trimmed. The optional protective sheet (not shown) over the outer surface of the tube 300 is removed.
[0033] As shown in FIG. 5 , the resulting sport shaft 500 includes a hollow composite core 510 made of the composite material from the sheet 450 ( FIG. 4 ) wrapped by the flexible cover sheet 100 (step 670 , FIG. 6 ). The sport shaft 500 can formed in various shapes to have cross-section in octagon, square, round, oval shapes, etc. The positive image 310 is visible from outside. The flexible cover sheet 100 provides protection to the colorants (inks or dyes) that form the positive image 310 as well as the composite core 510 underneath. An advantage of the flexible cover sheet 100 is that it has sufficient thickness and strength to prevent from being abraded and scuffed from repetitive uses so the graphics and color patterns in the positive image 310 can be protected and continuously visible from outside. Another advantage of the flexible cover sheet 100 is that it can act as a cushion and can help dampen the feel of impact to the player's hands. Additionally, the flexible cover sheet can also protect the players from sharp edges that ensue of shaft breakage as the plastic sheet tends to stretch over a breakage and prevents the shards from injuring the player or lessons the degree of injuries.
[0034] The texture of the flexible cover sheet can be chosen to provide additional friction and better hand grip. A satin or matte finish on the surface opposing the image receiving surface 110 can soften the appearance of the underlying graphics and dim the brilliance of the colors in the positive image 310 , which can provide desirable cosmetic effect for some users.
[0035] As mentioned above, the flexible cover sheet 100 is not required to be transparent; the flexible cover sheet 100 can sometimes be formed by a translucent, a white, or substantially opaque material. In a thermal dye sublimation printing, the colorants in the negative image 170 ( FIG. 2 ) can diffuse deep into the flexible cover sheet 100 in the sublimation process such that the positive image 310 is visible from outside of the sports shaft 500 (shown in FIG. 5 ) while being protected from resistant to scuffing and abrasions by the flexible cover sheet 100 .
[0036] In some embodiments, the positive image 310 can be formed during the molding of the composite material in the composite core 510 and the flexible cover sheet 100 . A negative image is formed on a transfer sheet using, for example, thermal dye sublimation printing (step 710 , FIG. 7 ). A first tube is formed using a sheet of flexible cover sheet (step 720 , FIG. 7 ) similar to the description above in relation to FIG. 3 except that flexible cover sheet is not printed with a negative image. A second tube is formed with a sheet of composite material (step 730 , FIG. 7 ) as described above. The second tube is inserted into the first tube (step 740 , FIG. 7 ). The transfer sheet carrying the negative image is pressed against the outer surface of the flexible cover sheet 100 (step 750 , FIG. 7 ), which are held in the upper mold and the lower mold with the nested tubes 300 and 460 (step 760 , FIG. 7 ), and applied with heat and pressure (step 770 , FIG. 7 ). A positive image is formed on the outer surface of the flexible cover sheet when the flexible cover sheet and the composite material are cured by the heat and pressure to form a sports shaft (step 770 , FIG. 7 ). The transfer sheet is removed (step 780 , FIG. 7 ).
[0037] It should be understood that the above described methods are not limited to the specific examples used. Configurations can vary without deviating from the spirit of the invention. For example the flexible cover sheet can be formed by other types of materials than previously described. The negative or the positive images for the graphics and brand patterns can be printed with other printing techniques. The present invention is applicable to a wide range of sports shafts such as lacrosse shafts, hockey sticks, and other shaft style tools, and various shaft cross-sectional shapes such as octagon, square, round, or oval cross sections. The temperature for molding the sports shaft can vary according to the materials used. | A method for making a sports shaft include forming a negative image on an image-receiving surface of a flexible cover sheet, forming a first tube with a sheet of composite material, covering the first tube with the flexible cover sheet that has the negative image facing an outer surface of the first tube, and applying heat and pressure to cure the flexible cover sheet and the first tube by one or more molds to form a sports shaft having a composite core made of the composite material and the flexible cover sheet wrapped around the core and showing to the outside a positive image based on the negative image. | 8 |
This is a continuation of application Ser. No. 07/394,210, filed Aug. 15, 1989, now abandoned.
FIELD OF INVENTION
The present invention relates to photo-magnetic recording apparatus of the type in which a magnetic recording medium for example a magnetic disc is magnetized in a direction perpendicular to its surface. In particular the invention is directed to a system for generating a bias-magnetic field which is applied to the recording medium in an area where recording or erasing is to be effected.
SUMMARY OF THE INVENTION
In photo-magnetic (magneto-optical) recording apparatus a pickup head is disposed on one side of a magnetic recording medium which has magnetic characteristics in a direction perpendicular to its surface and is movable relative to the recording medium so as to scan a selected portion of the recording medium. On the opposite side of the recording medium there is provided means for generating a bias-magnetic field which is applied to the recording medium.
In accordance with the invention, the bias-magnetic field generating means comprises a plurality of small coils each of which, when energized, generates an individual bias-magnetic field. The coils are arranged in mutually overlaping relation to one another so that magnetic fields generated by the coils overlap one another.
Means is provided for coordinating the selective energizing of the coils with the movement of the pickup head relative to the recording medium so as to provide an effective bias-magnetic field in an area of the recording medium scanned by the pickup means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following description of a preferred embodiment shown by way of example in the accompanying drawings in which
FIG. 1 is a schematic illustration of a bias-magnetic-field generating system in accordance with the invention comprising a plurality of overlapping coils.
FIG. 2 is a schematic illustration of magnetic fields generated by the coils.
FIG. 3 is a block diagram to explain the operation of the bias-magnetic field generating system illustrated in FIG. 1.
FIG. 4 is a block diagram of a portion of the circuit shown in FIG. 3.
FIG. 5 is a block diagram of a further portion of the circuit shown in FIG. 3 and
FIG. 6 illustrates a coil structure applied to the bias-magnetic-field generating system of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
As illustrated schematically in FIG. 1, a photomagnetic recording apparatus comprises a magnetic disc 2 placed on a turntable 1. The disc 2 is made of, for example, MnBi, TbFe, or DyFe. A pickup 7 irradiates a light beam which is focused on a surface of the disc 2 as a spot. In order to record or erase data at that spot, a bias-magnetic-field should be generated at that place with the perpendicular direction to the surface of the disc 2. For this purpose there is provided an assembly of small coils shown as comprising coils 8 1 , 8 2 and 8 3 on the opposite side of the disc 2 to the pickup 7. The small coils 8 1 , 8 2 and 8 3 are spaced from the disc 2 and are mounted on a base 9 in overlapping relation to one another with the axis of the coil perpendicular to the disc 2.
The pickup 7 is movable radially of the disc 2 in order to scan selected areas of the disc. Movement of the pickup is controlled and position information is generated in known manner by an address system as disclosed by way of example in U.S. Pat. Nos. 4,106,058, 4,142,209, 4,375,091 and 4,506,355.
In order to provide an effective bias-magnetic-field in the area where the pickup 7 is located, one or another of the coils 8 1 , 8 2 and 8 3 is energized according to an address signal or a location signal from the pickup 7 corresponding to the location of the pickup. In FIG. 2 the magnetic fields generated by the respective coils are schematically illustrated. In FIG. 2 the horizontal axis represents radial distance from the center of the disc while the vertical axis represents strength of the magnetic field. The strength of the magnetic field necessary to effect recording or erasing on the disc is indicated by a horizontal broken line.
If the pickup 7 is located between positions A and B, coil 8 1 is energized. If the pickup is located between positions B and C coil 8 2 is energized. If the pickup is located between positions C and D coil 8 3 is energized. To the selected coil, electric current is applied and a predetermined perpendicular bias-magnetic-field is generated with desired polarity according to whether the operation is recording or erasing.
A block diagram to explain the operation of the device is shown in FIG. 3 in which reference numeral 10 represents an input of a reading signal, block 11 is a data separator which separates the reading signal into a data signal and a clock signal, block 12 is an address recognizing circuit which obtains an address signal from the data signal, block 13 is a control circuit which converts the address signal to a coil selecting signal, 14 represents a polarity selecting input to which a polarity selecting signal is inputted according to whether a recording or an erasing operation is being carried out, block 15 is a bias-magnetic-field sequential selecting circuit which selects coils in accordance with the polarity selecting signal and the coil selecting signal and 16 indicates coils.
The circuitry of the data separator 11, the address recognizing circuit 12 and the control circuit 13 is shown in FIG. 4. The data separator II comprises a phase comparator 70 having first and second inputs, a charge pump 71 connected to an output of the phase comparator and a VCO22 connected to an output of the charge pump and having first and second outputs. The second output of the VCO is fed back to the input of the phase comparator. The data separator 11 further comprises an MFM decoder 73 having first and second inputs for decoding MFM signals from the incoming encoded MFM data. The first input of the MFM decoder is connected to the output of the VCO. Encoded MFM data are supplied to the first input of the phase comparator and the second input of the MFM decoder. The VCO supplies VCO clock signals at the first output thereof and the MFM decoder supplies NRZ data at the output thereof. The address recognition circuit 12 comprises a serial/parallel converter circuit 74, a buffer 75 connected to the converter 74 through a bus connection, and AM (Address Mark) detection circuit 76 connected to the converter 74 and buffer 75 through a bus connection and a counter 77 connected to the AM detector 76 through an AND gate and having a first output connected to the buffer 75 and a second output. The VCO clock signals and the NRZ data signals derived from the data separator 11 are supplied to the serial/parallel converter circuit 74 converted into 8 bit parallel data therein and supplied to the buffer 75. Since the drive (energizing) of the coil is performed by switching or selection with the track number, the track number portion (two bites) must be derived from the ID portion and be supplied to the control circuit 13 of the bias coil drive 15. This is performed by the AM detection circuit 76 and the counter 77. The control circuit 13 of the coil drive or selection circuit 15 comprises a latch 78 connected to the CPU through a bus connection and connected to the counter 77, and a ROM 79 connected to the latch through a bus connection. Since the track number portion is placed after the AM portion with predetermined clocks, the track number can be obtained by counting predetermined clock pulses in the counter 27 after AM detection. The output of the counter drives the latch 28, thereby latching the data in the buffer 25. The ROM 29 generates the data which perform selection of coils by the latched track number. In the ROM 29, the data for selecting coils in accordance with the track number are previously written, so that coil selection or drive signals can be generated by supplying address signals to the ROM.
The bias-magnetic-sequential selecting circuit 15 as shown in FIG. 5 comprises a polarity selecting part I which selects the polarity of coil current according to whether a recording operating or an erasing operation is to be carried out and a coil selecting part II which selects a certain coil and gives it energizing current.
In the polarity selecting part I, the first polarity selecting input 17 is connected to bases of transistors 21 and 22 through an inverter 18 and base resistors 19 and 20. A collector of the transistor 21 is connected to a source V cc through base bias resistors 23 and 24 of a transistor 25. A transistor 26 is coupled with a transistor 25 with a Darlington conjunction. The second polarity selecting input 27 is connected to bases of transistors 31 and 32 through an invertor 28 and base resistors 29 and 30. A collector of the transistor 31 is connected to the source V cc through bias resistors 33 and 34 of a transistor 35. A transistor 36 is coupled to the transistor 35 with Darlington conjunction.
The coil selecting part II consists of inverters 37 and 38 which are connected to the polarity selecting inputs 17 and 27 respectively; NAND gates 42-47 which receive outputs of the inverters 37 and 38, and coil selecting signals from coil selecting inputs 39, 40, 41; photo-couplers 38-53 which are connected to the NAND gates 42-47 respectively. The photocouplers are connected to a common line 60 in the right side which is connected to an emitter of the transistor 36 and a collector of the transistor 22 in the polarity selecting part I.
Small coils 54-56, which generate bias-magnetic-field according to the invention, have a common connecting point at one end of the coiled wire. The common connecting point is connected to an emitter of the transistor 26 and a collector of the transistor 32 in the polarity selecting part I. The other wire end of each coil is connected to the photo-coupler 48 and 49, or 50 and 51, or 52 and 53, separately.
FIG. 7 shows a general structure of one of the coils of the bias-magnetic-field generating system according to the invention. Assuming that a recording or erasing area on a disc is rectangular and that the length of the long sides of the rectangle is 2a and that of the short sides is 2b, the following equation is obtained ##EQU1## In the equation, H is a perpendicular component of a magnetic field at the point P, which is located in a disc with a distance x from the center of the coil as shown in FIG. 6, and I is electric current flowing in the coil 57. When a recording area on a disc has a width of 40 mm in the radial direction of the disc the preferred values are 40 mm for 2a, 5 mm for 2 b and 5 mm for x as far as generating a magnetic field with one rectangular coil. In that case the perpendicular component H of a magnetic field at the point P is 26.3 A/m, assuming that the magnetizing current equals 1A and the turn number of the coil equals 1.
We will now explain the operation of the bias-magnetic-field generating system according to this invention, the structure of which has been described above. In this system, an address signal is taken out from a reading signal which is an output of the pickup 7. Then the address signal is converted to a coil selecting signal by the control circuit 13 which selects a coil corresponding to the location of the pickup 7. The bias-magnetic-field sequential selecting circuit 15 selects a coil 8 1 , 8 2 , or 8 3 , according to the coil selecting signals and supplies electric current to the selected coil with a certain polarity according to the polarity selecting signal which selects a current polarity corresponding to a recording operation or an erasing operation. Consequently, the desired bias-magnetic-field is generated in the area scanned by the pickup 7 with a desired polarity. There are other methods of selecting a coil. For example, a coil can be selected according to a location signal from a position detector such as a line encoder which is linked to the pickup 7 instead of the address signal as described above.
When the first polarity selecting input 17 is made low level by the bias-magnetic-field sequential selecting circuit, the output of the inverter 18 becomes high level. That makes the transistor 21 ON so that the transistors 25 and 26 which supply electric current for the coils become ON state. While the transistor 22, which draws electric current from coils 54, 55 and 56 through the coil selecting part II, becomes ON state with the high level output of the inverter 18. In this state, as making a coil selecting input 39 high level, the output of the NAND gate 43 becomes low level because of the high level output of the inverter 38, and then the photo-coupler 49 becomes ON state. Consequently, a coil current flows from the source V cc , through the transistor 26, the coil 54, the photo coupler 49, the draw-in transistor 22 and to ground.
In the same way, selecting the polarity selecting inputs 17, 27; and the coil selecting inputs 39, 40, 41; a desired magnetic field can be obtained in any one of the coils 8 1 , 8 2 or 8 3 , with a desired polarity.
The number of coils is not restricted although three coils are used in the preferred embodiment of the invention described above. Additionally, a photocoupler can be replaced by other devices such as, for example, a combination of a light emitting diode and a photo transistor, or FET etc. Moreover, the recording medium is not restricted to a disc. | A photo-magnetic (magneto-optic) recording device having recording medium in the form of a rotating magnetic disc having magnetic characteristics in a direction perpendicular to its surface has a pickup head (7) disposed on one side of the disc and movable radially of the disc to scan selected areas of the disc. On the side of the disc opposite to that on which the pickup head is located, there are provided a plurality of coils (8) generating a bias-magnetic field applied to the disc. The coils are disposed in overlapping arrangement with their centers disposed on a line extending radially of the disc. The coils are energized by electric circuitry which comprises means for sensing the position of the pickup head and energizing a respective coil located in position to apply a bias-magnetic to the area of the disc scanned by the pickup head. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation Application of application Ser. No. 10/847,280 entitled PISTON COMPRESSOR, PARTICULARLY A HERMETIC REFRIGERANT COMPRESSOR to Frank Holm Iversen, et al. filed on May 17, 2004 and claims the benefit of the filing date thereof under U.S.C. §120. This application is also entitled to the benefit of and incorporates by reference essential subject matter disclosed in German Patent Application No. 103 23 767.4 filed on May 22, 2003 and German Patent Application No. 103 30 760.5 filed on Jul. 7, 2003.
FIELD OF THE INVENTION
The invention concerns a piston compressor, particularly a hermetic refrigerant compressor, with a compression chamber, which is limited by a valve plate arrangement having a valve plate with a suction gas opening and a pressure gas opening, a suction valve plate with a suction valve element, and a pressure valve plate with a pressure valve element.
BACKGROUND OF THE INVENTION
Such a refrigerant compressor is known from, for example, DE 199 15 918 C2. A suction valve is fixed on the valve plate bottom side facing the compression chamber. A pressure valve is fixed on the opposite valve plate upper side, where it is located in a recess. A sealing is located between the cylinder adopting the compression chamber and the valve plate, and an additional sealing is located between the valve plate and the cylinder head cover. Together with a partition wall formed in the cover, this additional sealing ensures that the suction side and the pressure side are separated from each other. For this purpose, it is required that the complete cylinder head arrangement be assembled by means of screw bolts and fixed on the cylinder. In order to achieve a sufficient tightness, high tightening forces are required. Further, only narrow manufacturing tolerances are permitted. When the separation between the suction side and the pressure side is not realised satisfactorily, compressed, and thus hot, gas from the pressure side can reach the suction side, which reduces the efficiency of the compressor.
The tightening forces, which can be achieved with screws, are limited. Also, the forces, with which the parts forming the cylinder head are assembled, cannot in other ways be increased to a value exceeding a predetermined value, as this would cause a too high material strain.
SUMMARY OF THE INVENTION
The invention is based on the task of achieving a good efficiency, also with simple mounting.
With a piston compressor as mentioned in the introduction, this task is solved in that the pressure valve plate and the suction valve plate are located on the side of the valve plate facing the compression chamber.
Thus, the pressure valve plate and the suction valve plate are no longer located on different sides of the valve plate, on the contrary, they are located on the same side of the valve plate, namely on the side facing the compression chamber. In this connection, the fact is utilised that the suction valve plate and the pressure valve plate are usually substantially thinner than the valve plate. This means that the suction valve plate and the pressure valve plate are more flexible than the valve plate, that is, they can bear more closely on each other, when the forces used for tightening are smaller. Further, an additional advantage occurs. The fact that the compressed gas no longer has to pass through the valve plate before reaching the pressure valve causes that the dead space is reduced. This improves the efficiency of the compressor. A projection, often formed on the front side of a piston reducing the compression chamber, which projects into the pressure gas opening of the valve plate in the upper dead point position, thus reducing the damaging dead volume, is no longer required. Locating not only the suction valve plate but also the pressure valve plate on the side of the valve plate facing the compression chamber simplifies the manufacturing. Usually, it is no longer required to fit sealings between the valve plate, the suction valve plate and the pressure valve plate.
Preferably, the suction valve plate forms a pressure valve seat for the pressure valve element and the pressure valve plate forms a suction valve seat for the suction valve element. Thus, the working required for manufacturing the valve seat could be limited to the suction valve plate and the pressure valve plate. This working, if required at all, then takes place on the sides of the suction valve plate and the pressure valve plate, which bear on each other in the mounted state. This further improves the tightness.
It is particularly preferred that, with intermediate mounting of a reinforcement plate, the pressure valve plate and the suction valve plate are located on the side of the valve plate, which exists in the form of a stiffening element, facing the compression chamber. However, the valve plate, which exists in the form of a stiffening element, is not limited to a substantially plane embodiment. It can also perform other functions, for example be part of a muffling arrangement or other parts of the cylinder head. However, still the valve plate ensures that the limiting wall of the compression chamber adopting the valves is rigid and mechanically stable. However, it is an advantage that the suction valve plate and the pressure valve plate are usually substantially thinner than the traditional valve plate. Thus, the suction valve plate and the pressure valve plate are more flexible than the valve plate. The flexibility of the suction valve plate and the pressure valve plate makes it possible for both plates to bear more closely on bearing surfaces, also when the forces used for tightening are smaller. In principle, an improved tightness will thus occur. However, the flexible embodiment of the suction valve plate involves the risk that, during a suction stroke, when suction pressure rules in the compression volume, the suction valve plate sags in the area of the environment of the pressure valve. During a suction stroke, the previously generated pressure namely rules here. In many cases, a flexible suction valve plate is not stable enough to adopt the forces occurring through the pressure difference without significant bending. Under certain circumstances, a repeated deformation will cause a fatigue fracture of the suction valve plate. The deformation is now effectively prevented or at least substantially reduced by the reinforcement plate. The reinforcement plate does not have to be substantially more stable than the suction valve plate. Also with a relatively weakly dimensioned reinforcement plate, the sag of the suction valve plate can be reduced to a harmless extent.
Preferably, the suction valve plate, the reinforcement plate and the pressure valve plate have substantially the same thickness. However, their thicknesses do not have to be exactly the same. Deviations from 50% downward and 100% upwards are permissible. The thickness of the reinforcement plate will be chosen in dependence of the magnitude of the pressure ruling on the pressure side in such a manner that fatigue fractures of the suction valve plate are avoided. This means that the thickness of the reinforcement plate will be chosen so that it provides a sufficient support. On the other hand, the thickness of the reinforcement plate will be kept as small as possible to avoid an excessive increase of the harmful volume in the pressure opening.
Preferably, the reinforcement plate forms a pressure valve seat for the pressure valve element and a suction valve seat for the suction valve element. Thus, the workings, which are required for the manufacturing of the valve seats, can be limited to the reinforcement plate. If required at all, this working then occurs on the two sides of the reinforcement plate, which bear on the suction valve plate or the pressure valve plate, respectively, in the mounted state. This further improves the tightness.
Preferably, the suction valve plate, in relevant cases the reinforcement plate and the pressure valve plate are made of spring steel. In this case, spring steel has several advantages. Firstly, the suction valve element and the pressure valve element can be made in one piece with the suction valve plate and the pressure valve plate, respectively, for example as a flexible tongue. Secondly, spring steels can be formed relatively plane, so that a safe closing of the suction opening and the pressure opening in the suction valve plate and the pressure valve plate can be ensured in a simple manner.
Preferably, the valve plate, the pressure valve plate and the suction valve plate, or the valve plate, the pressure valve plate and the reinforcement plate and, in some cases, the suction valve plate are undetachably connected with each other. In this case, undetachably means that the three or four plates cannot be detached from each other by removing an auxiliary assembling part, for example a screw. Of course, if required, it is possible to use auxiliary assembling parts to connect the plates additionally to the undetachable connection.
In this connection, preferably a connection is provided, which connects the valve plate, the pressure valve plate and the suction valve plate, or the valve plate, the pressure valve plate and the reinforcement plate and, in relevant cases, the suction valve plate, at a common position. For example, the suction valve plate and the valve plate are connected through the pressure valve plate. When a reinforcement plate is available, it may be ensured that the suction valve plate and the valve plate in the form of a stiffening element are connected through the reinforcement plate and the pressure valve plate.
Advantageously, the connection is made in the form of a line, which surrounds an area around a pressure valve. Then, the connection is not used to provide a mechanical cohesion between the suction valve plate, in relevant cases the reinforcement plate, the pressure valve plate and the valve plate. At the same time, the connection forms a sealing line, which surrounds the area around the pressure valve, so that pressure gas, which passes the pressure valve, may reach this line, but cannot penetrate the connection along this line. In this connection, the term “line” must be understood functionally. Of course, the connection along this line may have a certain width.
Preferably, the connection is made as a welded connection. Such a welded connection is easily manufactured. A welded connection has the advantage that with the welding several elements can be fixed to each other at the same time, that is, the suction valve plate, in relevant cases the reinforcement plate, the pressure valve plate and the valve plate can be connected with each other. In some cases it can be avoided to weld the suction valve plate onto the other elements of the stack, when the tightness between the suction valve plate and the reinforcement plate can be ensured otherwise. Such a welding can preferably be made without adding electrode material, for example by means of a laser beam. After alignment of the valve plate, the suction valve plate, in relevant cases the reinforcement plate and the pressure valve plate in relation to each other, such a laser beam is directed onto the surface of the suction valve plate and then moved along the line. Thus, not only the suction valve plate, in relevant cases the reinforcement plate, the pressure valve plate and the valve plate are connected with each other, but at the same time, a sealing around the pressure valve is produced. Such a method is not only possible with a welding process, but can also be used with an electron beam process.
It is preferred that the suction valve plate has at least one slot-like opening, which follows the course of the line. Of course also more than one slot-like opening can be provided. Particularly, when the connection between the three or four plates is realised by means of a welding, the slot-like opening(s) has/have advantages. A possibly occurring welding bead will be adopted by the opening, that is, it does not project into the compression chamber. Thus, the dead volume of the compressor can be further minimised. In its upper dead point, the piston can namely be set to a smaller distance to the suction valve plate, as it would be possible, when a welding bead existed. These considerations also apply, when the connection is not made as a welded connection, but as a soldered or glued connection. Also in this case, the slot-like openings can adopt possibly occurring projecting. Also the reinforcement plate may have corresponding slot-like openings, so that also inside the plate package comprising the four plates interfering welding or gluing beads cannot occur.
Preferably, the side of the valve plate facing the compression chamber has a bearing surface for the pressure valve element located in the pressure gas opening. Thus, the bearing surface serves as retainer bridge. A separate retainer bridge for the pressure valve element is no longer required. In principle, the element called valve plate could also be regarded as “retainer bridge”, so that with the present embodiment the valve plate in its traditional form is practically omitted.
Preferably, the valve plate, the pressure valve plate, in relevant cases the reinforcement plate and the suction valve plate has corresponding recesses in the area of their circumferences, in which projections of a cylinder element surrounding the compression chamber engage. Together with the recesses, the projections serve the purpose of aligning the suction valve plate, in relevant cases the reinforcement plate, the pressure valve plate and the valve plate in relation to each other in the correct angular positions. This further simplifies the mounting.
Preferably, the valve plate arrangement bears with intermediate mounting of a sealing on a bearing surface of the cylinder element, which is formed by a diameter extension of the cylinder element. This sealing ensures that during a compression process, that is, during a reduction of the compression chamber, gas cannot leak from the compression chamber at an undesired spot. The discharge of the gas from the compression chamber is thus limited to its way through the pressure valve. The sealing can equalise possibly occurring unevennesses. It is, for example, made of an elastomer.
Preferably, the valve plate arrangement is connected with a flange surrounding the bearing surface, and compresses the sealing. Such a connection can, for example, be made by means of welding. However, the connection can also be made by bordering the flange. Before the welding or bordering, a pressure is exerted on the valve plate arrangement, which causes a compression of the sealing. In this compressed state, a welding is then made. Such a welding can, for example in the circumferential direction, lead to a closed welding seam, which further improves the tightness.
Preferably, the recesses in the valve plate only penetrate partly through the thickness of the valve plate. This involves the advantage that the “upper side” of the valve plate, that is, the side facing the compression chamber, is plane. Thus, the recesses do not have to be additionally closed or taken into consideration in other ways.
Preferably, a recess surrounds the suction gas opening and/or the pressure gas opening in the valve plate. A connector of a suction muffler or a pressure muffler, respectively, can be inserted in such a recess, so that also on the side of the valve plate facing away from the compression chamber an excellent separation of the suction side from the pressure side can be realised.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is described on the basis of preferred embodiments in connection with the drawings showing:
FIG. 1 is a schematic sectional view of a piston compressor
FIG. 2 a is an enlarged section from FIG. 1 of a valve plate arrangement with three plates
FIG. 2 b is an enlarged section from FIG. 1 of a valve plate arrangement with four plates
FIG. 3 is a view of a valve plate arrangement seen from the piston
FIG. 4 is a view of a cylinder element in the longitudinal section
FIG. 5 is a suction valve plate
FIG. 6 is a pressure valve plate
FIG. 7 is a modified embodiment of a suction valve plate
FIG. 8 is a valve plate from the side facing away from a compression chamber.
FIG. 9 is a sectional view IX-IX according to FIG. 8
FIG. 10 is a sectional view X-X according to FIG. 8
FIG. 11 is a view of the valve plate from the side of the compression chamber
FIG. 12 is a view of a reinforcement plate
FIG. 13 is a perspective exploded view of the valve plate arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A piston compressor 1 , shown schematically in FIG. 1 , has a cylinder element 2 , which surrounds a compression chamber 3 in the circumferential direction. On a front side, the compression chamber 3 is bordered by a merely schematically shown piston 4 , which is movable in the direction of a double arrow 5 . On the side facing the piston 4 , the compression chamber 3 is bordered by a valve plate arrangement 6 , which will be described in detail in the following. For reasons of clarity, other elements, like suction muffler, pressure muffler, cylinder head cover or the like are not shown, can, however, be fitted accordingly by the person skilled in the art according to needs.
The valve plate arrangement 6 with three plates in FIG. 2 a shows a valve plate 7 , which is penetrated by a suction gas opening 8 and a pressure gas opening 9 . The valve plate arrangement 6 with four plates in FIG. 2 b has a valve plate 7 in the form of a stiffening element, which is also penetrated by the suction gas opening 8 and the pressure gas opening 9 . The valve plate 7 in the form of a stiffening element is here made as a plate. However, with this valve plate 7 in the form of a stiffening element, the plane or plate-like shape is not absolutely required. As can also be seen from FIG. 10 , a recess 10 surrounds the suction gas opening 8 . A recess 11 surrounds the pressure gas opening 9 . In both recesses, connection pipes, not shown in detail, from suction mufflers or pressure mufflers, respectively, can be inserted. It is also possible to connect these connection pipes fixedly with the valve plate 7 , for example by means of gluing or welding. In this case, a cylinder head cover may, under certain circumstances, be avoided.
On the side of the valve plate 7 facing the compression chamber 3 , firstly a pressure valve plate 12 bears, which has ( FIG. 6 ) a pressure valve element 13 in the form of a flexible tongue. Further, the pressure valve plate has a suction opening 14 , which is merely formed by a hole in the pressure valve plate 12 .
On the side of the pressure valve plate 12 facing the compression chamber 3 bears, according to FIG. 2 a , a suction valve plate 15 . On the side of the pressure valve plate 12 facing the compression chamber 3 bears, according to FIG. 2 b , a reinforcement plate 40 ( FIG. 12 ), which also has a pressure gas opening 41 and a suction gas opening 42 , which are formed by holes in the reinforcement plate 40 .
On the side of the reinforcement plate 40 facing the compression chamber 3 bears a suction valve plate 15 . The suction valve plate has ( FIG. 5 ) a suction valve element 16 and a pressure opening 17 . The suction valve element 16 is also made as a flexible element. The pressure opening 17 is merely a circular hole.
Both the pressure valve plate 12 and the suction valve plate 15 are made of spring steel. Also the reinforcement plate 40 is made of spring steel. In the present embodiment, spring steel has the advantage that both the pressure valve element 13 and the suction valve element 16 can be made in one piece with the pressure valve plate 12 or the suction valve plate 15 , respectively. However, the valve elements 13 , 16 can be made separately from the valve plates 12 , 15 , and then be fitted together with the valve plates 12 , 15 . Further, spring steel is relatively thin and can be provided with a surface, which ensures that the pressure valve plate 12 , in relevant cases the reinforcement plate and the suction valve plate 15 bear sealingly on each other.
With a valve plate arrangement with three plates according to FIG. 2 a, the suction valve plate 15 forms, together with the pressure opening 17 , a valve seat 29 for the pressure valve element 13 . The pressure valve plate 12 forms, together with the suction opening 14 , a valve seat 30 for the suction valve element 16 . In the valve plate arrangement with four plates according to FIG. 2 b , the reinforcement plate 40 forms, together with the pressure opening 41 a valve seat 29 for the pressure valve element 13 . The reinforcement plate 40 forms, together with the suction opening 42 , a valve seat 30 for the suction valve element 16 ( FIG. 3 ). According to the views in FIGS. 5 and 6 , the pressure valve plate 12 is folded onto the suction valve plate 15 .
FIG. 12 shows a top view of the reinforcement plate 40 .
FIG. 13 shows a perspective exploded view of the valve package or the valve arrangement 6 , which is formed by the valve plate 7 , the pressure valve plate 12 , the reinforcement plate 40 and the suction valve plate 15 . From this figure, the relative allocations of the individual suction openings 8 , 14 , 42 and the individual pressure openings 9 , 41 , 17 can be seen.
As appears from FIG. 2 a , the pressure valve plate 12 , the suction valve plate 15 and the valve plate 7 are connected with each other by means of a welded seam 18 . In this connection, the welded seam penetrates the pressure valve plate 12 .
As appears from FIG. 2 b , the pressure valve plate 12 , the reinforcement plate 40 , the suction valve plate 15 and the plate 7 are connected with each other by means of a welded seam 18 . In this connection, the welded seam 18 penetrates the pressure valve plate 12 and the reinforcement plate 40 .
As appears particularly from FIG. 3 , the welded seam 18 surrounds an area around the pressure valve. Thus, it surrounds the pressure valve element 13 and the pressure opening 17 , according to FIG. 2 b also the pressure opening 41 at a certain distance. The welded seam 18 is made to be gas tight, that is, it surrounds a pressure gas area, from which the compressed gas cannot escape during the upward movement of the piston 4 .
For the welding, for example, a laser can be used, which is directed to the surface of the suction valve plate 15 , after aligning of the valve plate 7 , the pressure valve plate 12 , in relevant cases the reinforcement plate 40 and the suction valve plate 15 in relation to each other. The beam intensity of the laser is controlled so that the material of the parts mentioned is only molten in a relatively narrow area. This keeps the risk small that the valve plates mentioned, 7 , 12 , 15 and in relevant cases 40 , are distorted. This is not only possible with a laser welding process; also an electron beam process can be used.
With the welded seam 18 , an undetachable connection is made between the valve plate 7 , the pressure valve plate 12 , in relevant cases the reinforcement plate 40 and the suction valve plate 15 . On the one hand, this connection keeps the valve plates 7 , 12 , 15 , and in relevant cases the reinforcement plate 40 , firmly together, and on the other hand, it ensures that gas passing the pressure valve cannot leak to other areas.
Of course, also other connection methods can be used, for example, soldering or gluing processes. In certain cases, also auxiliary assembling parts, like rivets or the like, can be used, the auxiliary assembling parts, however, not taking over the only connection, when they cannot take over the additional task of sealing around the pressure gas area.
For adopting the valve plate arrangement 6 , the cylinder element 2 has a diameter extension 19 . This diameter extension 19 forms a support face 20 , that is, a sort of offset front side of the cylinder element 2 , on which the valve plate arrangement 6 is supported under insertion of a sealing 21 . The valve plate arrangement 6 is then loaded in the direction of the cylinder element 2 in such a way that the sealing 21 is compressed. Then the valve plate arrangement 6 , or rather the valve plate 7 , is connected, by means of a welded connection 22 , with a circumferential flange 23 of the cylinder element 2 , so that the sealing 21 remains compressed. The welded connection 22 can also be replaced by another connection kind, for example a bordering connection. In this connection, it is expedient, when the flange 23 projects over the valve plate arrangement 6 or the valve plate arrangement 6 has a circumferential groove, in which a corresponding bordering edge can engage.
The sealing 21 seals the compression chamber 3 in the area of the end facing the valve plate arrangement 6 , thus preventing that compressed refrigerant gas escapes to the outside here. The only way for the refrigerant gas to leave the compression chamber 3 remains the pressure opening 17 , when it is released by the pressure valve element 13 .
FIG. 7 shows an embodiment of a suction valve plate 15 , which is somewhat modified in relation to the embodiment shown in FIG. 5 . The same parts have the same reference numbers.
Slits 24 have been added, which extend along the welded seam 18 shown. The slits are meant for preventing that during welding of the valve plate 7 with the suction valve plate 15 , in relevant cases the reinforcement plate 40 , and the pressure valve plate 12 , molten metal leaves a welding bead to project from the surface of the suction valve plate 15 . This would require a larger safety distance to the piston and thus cause an increased dead volume. When the slits 24 are provided, the unavoidable welding bead is located in the slit. Accordingly, this also applies, when a soldering seam or a gluing seam replaces the welding seam 18 . Alternatively to the slit, stamps may be provided in the valve plate 7 , in relevant cases in the reinforcement plate 40 and in the suction and pressure valve plates 12 , 15 , said stamps pointing away from the compression chamber 3 .
The slits 24 have interruptions 25 . These interruptions are located where the sealing 21 is supported on the side of the suction valve plate 15 facing the compression chamber 3 . Here, a bead can still project from the surface of the suction valve plate 15 . However, this area is outside the cross-section of the compression chamber 3 and is adopted by the sealing ring 21 .
Both the pressure valve plate 12 and the suction valve plate 15 , and in relevant cases the reinforcement plate 40 , have several recesses 26 , 26 ′ distributed in the circumferential direction, which correspond to projections 26 a on the cylinder element 2 ( FIG. 4 ). Also the valve 7 has corresponding recesses 26 , 26 ′. As shown, the recesses 26 , 26 ′ can be distributed evenly in the circumferential direction. However, one of the recesses is broader than the others, so that it is ensured that the valve plates 7 , 12 , 15 , and in relevant cases 40 , can only be assembled in one predetermined angular orientation.
The valve plate 7 can be seen in the FIGS. 8 to 11 . From a comparison of the FIGS. 8 and 11 it appears that the recesses 26 , 26 ′ in the valve plate 7 do not penetrate through the whole thickness. Thus, the recesses 26 , 26 ′, do not interfere with the topside of the valve plate 7 shown in FIG. 8 , which is facing away from the compression chamber. The same applies for the upper area of the circumference of the valve plate 7 . This makes it easier to make the welded connection 22 tight.
FIG. 9 shows that a projection 27 projects laterally into the pressure gas opening 9 , which projection 27 forms a bearing surface 28 for the pressure valve element 13 . The bearing surface 28 limits the movement of the pressure valve element 13 , when compressed refrigerant gas is discharged from the compression chamber 3 . Thus, the bearing surface 28 replaces a separate retainer bridge, which is otherwise usually provided to protect the pressure valve element 13 from damages during opening.
FIG. 3 now shows the design of a valve plate arrangement 6 with the individual valve elements. The pressure valve element 13 bears on the pressure valve seat 29 , which, according to FIG. 2 a , is formed on the side of the suction valve plate 15 facing away from the compression chamber 3 , and according to FIG. 2 b on the side of the reinforcement plate 40 facing away from the compression chamber 3 . The suction valve element 16 bears on the suction valve seat 30 , which is formed on the side of the pressure valve plate 12 facing the compression chamber 3 . The fact that merely the suction valve plate 15 , and in relevant cases the reinforcement plate 40 , is located between the compression chamber and the pressure valve plate 12 , makes it possible to keep the undesired dead volume between the pressure valve element 13 and the compression chamber 3 relatively small. It is practically limited to the thickness of the suction valve plate 15 , when the valve plate arrangement comprises three plates, and to the sum of the thicknesses of the suction valve plate 15 and the reinforcement plate 40 , when the valve plate arrangement comprises four plates. This thickness is in the area of some tenths of a mm. Additional measures for keeping the dead volume small are not required. Also without additional measures an excellent efficiency of the compressor can be achieved.
The reinforcement plate 40 prevents that the area of the suction valve plate 15 , which is inside the welding seam 18 , and acted upon by a pressure difference during a suction stroke, said pressure difference resulting from the reduced pressure in the compression chamber and the increased pressure on the pressure side of the compressor, sags. Without the reinforcement plate 40 , a sagging in the magnitude of 150 μm could be observed. With the reinforcement plate 40 , this sagging was reduced to a harmless magnitude of about 10 μm. Such a reduction can also be achieved with a relatively thin reinforcement plate 40 . The thickness of the reinforcement plate 40 is, for example, in the magnitude of 0.2 mm, that is, approximately in the magnitude of the thickness of the suction valve plate 15 and the pressure valve plate 12 . | The invention concerns a piston compressor, particularly a hermetic refrigerant compressor, with a compression chamber, which is limited by a valve plate arrangement having a valve plate with a suction gas opening and a pressure gas opening, a suction valve plate with a suction valve element, and a pressure valve plate with a pressure valve element. It is endeavored to achieve a good efficiency combined with a simple assembly. For this purpose, it is ensured that the pressure valve plate and the suction valve plate are located on the side of the valve plate facing the compression chamber. | 5 |
This is a divisional of application Ser. No. 07/174,422 filed 03/28/88 now U.S. Pat. No. 4,885,995 with issue date of 12/12/89.
FIELD OF THE INVENTION
The present invention relates generally to solar induction monorails and more particularly, is concerned with a system and method for the construction of a solar induction monorail system having solar power conversion, distribution and power sharing capability.
DESCRIPTION OF THE PRIOR ART
It is known to provide monorail structures for elevated monorail trains. Most known monorail structures consist of fabricated cast concrete or rolled steel sections supported by columns and improvements thereon. There are no known monorails that are constructed having a photovoltaic skin or surface for collecting solar energy and converting the energy for utilization by the transportation means using the monorail. The prior art teaching the structure of monorails systems is described in the following U.S. patents.
U.S. Pat. No. 4,690,064 to W. E. Owen teaches a side-mounted monorail transportation system provided with a support beam from which vehicles are supported in a pendulum-like manner. The support beam is supported on columns both of which are constructed of steel rebar-reinforced concrete. The power source is dc electric power which is presumably supplied to the vehicle through conductors secured to the support beam. The means of propulsion discussed are rotating electric motors, linear induction motors, hydraulic motors, steam engines, internal combustion engines, jet engines, rocket engines, nuclear power engines or combinations thereof.
U.S. Pat. No. 4,313,38 to S. Parazadar teaches a guideway unit, which is an elevated structure on which rapid transit cars can run. The guideway unit teaches supporting a railway system of the type employing steel running rails, a central support for a linear induction motor assembly and a power collector rail mounted on removable side panels.
U.S. Pat. No. 2,923,254 to H. Barthelmess teaches a transition curve track section for connecting a mono-track railway system. The monobeam of the patent is preferably formed of poured concrete and reinforced in accordance with conventional practice.
U.S. Pat. No. 2,985,114 to B. M. Lindner teaches an improved low friction truck for mono beam supported and guided vehicles.
U.S. Pat. No. 4,274,336 to pater et al. teaches a monorail guideway structure wherein of interest is the teaching of selectively reinforcing the structure "on site". The guideway structure of this patent does not teach an extruded rail of the present invention.
U.S. Pat. No. 4,375,193 to D. P. Sullivan teaches an improved guideway assembly wherein of interest is the teaching of "on site" reinforcement of the structure. The guideway structure improvements go towards solving weather related problem which result in decreasing reliability.
The prior art assumes the availability of electric energy from a utility company and teaches the construction of a monorail structure designed in accordance with providing the appropriate interface between the electrical source and the monorail structure to the point of utilization by a vehicle on the monorail. In today's energy shortage prone environment, alternate energy sources must be considered in designing systems that have a high demand of utilization. Solar energy conversion technologies have not reaches their full utilization potential, especially in the field of monorail transportation systems. The prior art, as evident by the above prior art patents, does not teach a monorail structure and method for utilizing the surface of a monorail structure for collecting solar energy and converting the solar energy into electrical energy for utilization by a monorail vehicle. The monorail structures of the prior art are constructed according to methods which use machinery known in the fabrication of reinforced concrete structures. The fabrication machine for a solar collector monorail structure is not taught by the prior art. Thus, a need is felt to exist for continued emphasis on the utilization of solar energy as an alternative energy source, especially in the development of monorail transportation systems, which type of transportation systems are foreseen to be a primary means of public transportation in the near future. A need is also seen for a monorail structure that take advantage of the enormous amount of surface area of the monorail and uses the surface of the structure as a solar collector and converts the collected solar energy into electrical energy for use by a vehicle designed for propulsion using the converted electrical energy. A need is further seen to exist for a fabrication machine which will produce, on-site, a solar collecting monorail. Still a need is seen to exist for a solar collecting monorail system having an energy source switching means, which means contemplates the sun as a primary source for the electrical energy and a power utility as an alternate source. Thus, a primary object of the present invention is to provide a monorail structure which collects energy from the sun and within the structure converts and stores the collected energy into electrical energy for use by a mono-railed vehicle. A second object of the present invention is to provide a fabricating machine which can produce the solar collecting monorail structure on-site according to survey information, material specification and other pertinent structural data and building code requirements. A related object with the primary object is to provide a solar collecting monorail structure which can also be powered from a utility power source and which can also provide excess electrical power to the utility power source.
SUMMARY OF THE INVENTION
The present invention provides a system and method for the construction of a solar induction monorail system designed to satisfy the aforementioned needs. The system consists of a solar energy collecting means comprising a monorail structure formed with a photovoltaic surface layer having a solar energy converting means for converting the collected solar energy to electrical energy, an electrical energy storage means for storing the converted electrical energy, an electrical energy management interface means for controlling the input and output power demand on the system from the transit vehicle being propelled, the solar collecting monorail energy source or from a power utility source, a power distribution means for distributing stored energy to transit vehicles being propelled along the monorail structure and a magnetic induction means on the monorail structure for propelling a transit vehicle according to magnetic principals associated with transverse flux motors (tfm).
The system is further comprised of a computer controlled monorail structure extrusion means comprising a fabrication chamber which continuously fabricates, in an extruded manner, the monorail structure having a material receiving chamber section, a monorail core assembly chamber section, a monorail body assembly section, a solar collector skin application chamber section and monorail finishing and column mounting chamber section. The monorail structure extrusion means also having a computer controlled elevation compensating track means for following terrain in the right-of-way.
The method consists of providing a computer controlled monorail structure extrusion system, fabricating a solar induction monorail structure, interconnecting a power distribution network within the monorail structure, interconnecting the solar induction monorail structure to a back-up energy supplying source, such as electric power utility source, and propelling monorail vehicles on the monorail structure.
Therefore, to the accomplishments of the foregoing, the invention consists of the foregoing features hereinafter fully described and particularly pointed out in the claims, the accompanying drawings and following disclosure describing in detail the invention, such drawings and disclosure illustrating, however, but one of the various ways in which the invention may be practiced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective view of the system of the present invention showing generally a completed portion of a monorail structure collecting solar energy, a transit vehicle being propelled along the monorail, a ground support vehicle being charged from the system, a power utility source supplying supplemental power, a monorail structure fabrication means, and material being delivered into the fabrication means.
FIG. 2 is a partial longitudinal fragmented view of the monorail structure showing the support columns, a partial diagrammatic representation of the distribution network internal and external to the monorail structure.
FIG. 3 is a typical cross section of the monorail and a monorail vehicle taken along the line 3--3 in FIG. 2 showing the solar collector conversion interconnections, magnetic induction means and a transit vehicle having transverse flux motor levitation and propulsion components.
FIG. 3a shows an exploded fragmentary view taken along the line 3a--3a in FIG. 3 showing the details of the interface between the monorail and the magnetic induction means within the transit vehicle.
FIG. 3b shows an enlarged sectional view taken along the line 3b--3b in FIG. 3 showing the solar collector composition applied on the inner core portion of the monorail structure.
FIG. 4 is a longitudinal view of the mobile monorail structure fabricator means showing the fabrication chambers and elevation compensating track driven system.
FIG. 5 is a cross-sectional view of the mobile monorail structure fabricator means taken along the line 5--5 of FIG. 4 showing a partially completed monorail structure being extruded and ready for mounting on supporting column and further showing the elevation compensating capability of the track driven system.
FIG. 6 is a cross sectional view of the mobile monorail structure fabricator means taken along the line 6--6 of FIG. 4 showing the monorail core assembly chamber section.
FIG. 7 is a cross sectional view of the mobile monorail structure fabricator means taken along the line 7--7 of FIG. 4 showing the monorail body assembly section.
FIG. 8 is a cross sectional view of the mobile monorail structure fabricator means taken along the line 8--8 of FIG. 4 showing the solar collector material application chamber section.
FIG. 9 is a cross sectional view of the mobile monorail structure fabricator means taken along the line 9--9 of FIG. 4 showing the monorail finishing chamber section.
FIG. 10 is a perspective view of a typical monorail support column showing a footing, a post, mounting guides, electrical connections, and optical connections.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIG. 1, where is shown a solar energy dependent monorail system, generally designated 100. The monorail system 100 is comprised of a monorail structure 101 and a mobile structure fabricator means 105. In use, monorail transit vehicle 103 is bi-directionally propelled along monorail structure 101 in the directions of arrows a1 and a2. The preferred embodiment of the invention is directed at designing a monorail system that will enable propelling a transit vehicle using the principles of transverse flux motors (tfm). For further information regarding "transverse flux motors" see an article entitled: "Three-dimensional Engineering", in Transportation Without Wheels, edited by E. R. Laithwaite, Westview Press, Boulder, Co., 1977. The tfm principles enable a transit vehicle to incorporate means of suspension and guidance. The monorail system of the present invention will complete the magnetic interface required between the transit vehicle and the monorail structure by providing a magnetic energy source which is derived within the monorail structure using photovoltaic conversion of energy from the sun. Thus, in the preferred embodiment, monorail structure 101 is designed having a solar collector 104 receiving sunlight 99 from sun S and using photovoltaic energy conversion principles, electrical energy is produced within the entire structure of the monorail and is distributed to storage means 127, see FIG. 2, in a plurality of support columns 102 throughout the system 100 for use by transit vehicle 103 upon demand. As an added feature, the system as an alternative energy source such as an electric power utility, generally designated U, which feeds the system via support columns 102. The system 100 is also designed to feed any excess energy into the power utility U and also provides an electrical charging means for charging a ground support vehicle 103b.
Still referring to FIG. 1, monorail structure 101 is shown being extruded from mobile monorail structure fabricator means 105, at a monorail fabrication exit end 115. The mobile monorail structure fabricator means 105 includes a fabrication chamber 110, an elevation compensating track driven assembly 106, and a material entry end 107. The elevation compensating capability of the mobile fabricator melans is shown by directional arrows a4 while forward motion is depicted by directional arrows a3. The material used to fabricate the monorail structure may be delivered to fabricator means 105 in a liquid form and supplied using an entry supply hose 107a delivered by material carrier 108. Other material which is required for completing the monorail construction includes unassembled columns 102, electrical conduit material 109 and sheet material spool 109a, which is shown ready for use at entry end 107 or beneath fabricator means 105 as the mobile fabricator means 105 advances along the construction right-of-way.
Referring now to FIG. 2, where is shown a partial longitudinal fragmented view of the monorail structure 101 being supported on support columns 102 and solar collector 104 absorbing sunlight 99 from sun S. Shown also is a cutaway portion of monorail structure 101 and column 102 showing a partial diagrammatic representation of the energy distribution and communication network internal and external. In the assembly of column 102, post 102a is fixedly attached to post footing 102b at post-footing joint 102c. Post footing 102b is typically a poured concrete structure and is located above and below ground level g. Monorail structure 101 is preferably constructed in sequential segments joined to the top portion of posts 102a at a post-monorail joint 123, while sequential monorail structure segments are joined at a monorail-monorail expansion joint 122. A more detailed description of column 102 will follow in describing FIG. 10.
Also shown in FIG. 2 is transit vehicle 103 capable of being propelled by transverse flux motor (tfm) 118 in either direction, shown by arrows a1 and a2. In use, transit vehicle 103 communicates energy demand requests from storage means 127 via optical control means 120 which is optically coupled to energy controller 128 by a plurality of optical sensors 130 and fiber optics conductors 131.
Referring now to FIG. 3b, showing the composition of solar collector 104. In actual operation, solar collector 104 converts the incident sunlight 99 to electrical energy according to photovoltaic principles by penetrating the outer protective barrier 138 and is absorbed by layered, electrical energy producing, light sensitive, silicon materials comprised of vacuum deposited inner p-layer material 142a, typically, hydrogenated silicon doped with phosphorous, an intrinsic layer 142c, typically undoped hydrogenated silicon, and an outer n-layer 143a, typically hydrogenated silicon doped with boron. The solar energy thus converted to electrical energy is gathered by a metallic grid conductor material 144a, which is applied in an emulsion form. Referring now to FIG. 2, the electrical energy created is then distributed by input power conductors 125 from photovoltaic transfer point 139 via power lead 139a (see FIG. 3) to storage battery 127 via a battery charger 126 and input cable lead 127a. Upon demand, power is withdrawn from storage battery 127 through output cable 127b to monorail control unit and switch means 128 or to utility power U through output cable 128a, if there is an excess amount of power stored in battery 127. Monorail control unit 128 can not only receive power from storage battery 127 through cable 127b but also from power utility U through input cable 128b in the event that solar collector 104 is unable to produce electrical energy due to cloudy conditions or for other reasons making the sysltem non-functional. From monorail control unit 128, power is distributed to the transit vehicle 103 via power conductors 132a, 132 and brushes 119. Between segments of monorail structure 101 there is provided column-monorail electrical and optical connector means 102d and monorail-monorail electrical and optical connector means 122a for allowing independent operation of individual monorail segments. Similarly, electrical connectors 128c are provided between post 102a and post footing 102b. Also shown in FIG. 2 is a grounding means 129 provided for safety purposes. The system is also provided with an electrical outlet 127c for charging a ground support vehicle 103b.
Referring now to FIGS. 3 and 3a showing a typical cross section of monorail 101 and transit vehicle 103. Transit vehicle 103, having a floor 103a, is provided with a transverse flux linear induction motor 118 (hereinafter tfm 118) which is comprised of a primary 118c and secondary 118d and an air gap portion 133. The primary 118c receives power through primary wiring 118a from brushes 119 housed in enclosure 118b in contact with power conductor 132. The secondary 118d of tfm 118 is magnetically coupled through air gap 133 and includes aluminum reaction sheet 118e bonded to steel sheet 118f. Also shown is the optical control means 120 in transit vehicle 103 which is optically coupled to energy controller 128 by a plurality of optical sensors 120 and fiber optics conductors 131. Since transit vehicle 103 is magnetically levitated by tfm 118, incidental contact with monorail 101 is eased by low friction skid rollers 134. Also, due to the magnetic levitation, directional monorail guidance is maintained by the substantially omega-shaped bottom portion of floor 103a which is magnetically coupled to monorail 101.
Referring to FIGS. 3 and 3b, monorail 101 is shown comprised of solar collector 104 applied onto an inner core 101a. Inner core 101a is shown provided with longitudinal rail reinforcement 135 and longitudinal tensioning cable 137. Solar collector 104 is comprised of an outer protective barrier 138 and layered, electrical energy producing, light sensitive, silicon materials comprised of vacuum deposited inner p-layer material 142a, typically, hydrogenated silicon doped with phosphorous, an intrinsic layer 142c, typically undoped hydrogenated silicon, and an outer n-layer 143a, typically hydrogenated silicon doped with boron. Solar collector 104 is further comprised of a metallic grid conductor material 144a, which is applied in an emulsion form and used for gathering the converted electrical energy. The electrical energy gathered by grid conductor 144a is then distributed from photovoltaic transfer point 139 via power leads 139a and input power conductors 125 to storage battery 127.
Referring now to FIGS. 4 and 5 showing mobile monorail structure fabricatior means 105, having fabrication chamber 110, an elevation compensating track driven assembly 106, engine 112, and cabin 113. Cabin 113 contains a computer control operating panel used to maneuver fabricator means 105 and the monorail fabrication process. Fabrication chamber 110 includes material entry end 107, monorail core assembly section 105a, monorail body assembly section 105b, solar collector application section 105c, monorail finishing section 105d. Mobile monorail structure fabricator means 105 is designed for high maneuverability along the right-of-way, thus fabricator means 105 is provided with flexibility joints 105e and elevation compensating track driven assembly 106. The mobility of elevation compensating track driven assembly 106 is achieved by providing legs 106a which compensate, indicated by arrows a4, for ground g elevation variations using elevation adjustment motor 106b and forward motion of tracks 106d, indicated by arrows a3, by using track motor 106c. Material input accommodations, such as power conductors spool 109, aluminum or steel sheet material spool 109a and liquid material delivery hose 107a, needed to construct the monorail 101 is provided at end 107 of fabricator means 107. A pathway 111 allows access to monitor the assembly process. After providing the necessary material at end 107, the monorail construction can begin. As previously stated fabrication chamber 110 includes monorail core assembly section 105a, monorail body assembly section 105b, solar collector application section 105c, monorail finishing section 105d. Referring now to FIG. 6, showing a cross section of monorail core assembly section 105a, having outer wall 105g, wherein is shown various core elements being formed including a positioned power conductor 132, optical conductor 131, tfm secondary 118d, rail reinforcement 135, tensioning cable 137, photovoltaic conductor 125. Once the various core elements are positioned the embodiment process may begin. Referring now to FIG. 7, showing a cross section of monorail body assembly section 105b and showing positioned tfm secondary 118d, rail reinforcement 135, tensioning cable conduit 137 and interconnecting wiring 139a and 131. The core material 136 used to form the monorail core body 101a is in a liquid form and is contained in a reservoir 136a and is injected into a core body form 141 by material injector 136b. The core body is allowed to cure before applying the solar collector 104.
Once the monorail core body is cured the solar collector 104 is ready to be formed. Referring now to FIG. 8 showing a cross section of solar collector formation section 105c. The formation process consists of layering onto inner core 101a silicon materials comprised of inner p-layer material 142a, typically hydrogenated silicon doped with phosphorous, an intrinsic layer 142c, typically undoped hydrogenated silicon, and an outer n-layer 143a, typically hydrogenated silicon doped with boron. The process includes a vacuum deposition chamber means 145 having entry tubes 145a connected to reservoir 142 containing material 142a, reservoir 142d containing material 142c and reservoir 143 containing material 143a. The formation process of solar collector 104 further includes applying a metallic grid conductor material 144a from reservoir 144 via entry tube 145a. The grid conductor material, in emulsion form, is applied using moving applicator 144c, shown in motion by arrow a5. The applied solar collector 104 is allowed to cure before being exposed to the environment. Once cured, the monorail fabrication advances to the finishing section. Referring now to FIG. 9 showing a cross section of monorail finishing section 105d where finishing material 138 contained in reservoir 138a is sprayed onto the monorail using a plurality of spray nozzles 138c supplied from tube 138c.
FIG. 10 shows a typical support column assembly 102 including support post 102a having sides 102f and post footing 102b. Positioned between sides 102f are the electronic component access panels 102g and electrical outlet 127c. To enable external interface with power utility U, electrical connectors 128c are provided between post 102a and post footing 102b. The assembly of the post 102a to post footing 102b takes place during the finishing stages of the fabrication of monorail 101 at which time the post 102a is lifted using lifting means 102i and then the bottom end of post 102a is inserted into post receiver shoe 102h. Also provided for the mounting of monorail 101 to column 102 are post-monorail structural connectors 123a. The necessary wiring between monorail and post 102a is connected using electrical and optical connector means 102d.
Therefore, while the present invention has been shown and described herein in what is believed to be the most practical and preferred embodiment, it is recognized that departures can be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent apparatus. | A transportation system including a solar energy collecting monorail structure formed with a photovoltaic surface layer having a solar energy converting means for converting the collected solar energy to electrical energy. A power distribution means for distributing stored energy to transit vehicles being propelled along the monorail structure or distributing excess energy to a remote power utility source. The monorail structure includes means for propelling a transit vehicle according to magnetic principals associated with transverse flux motors. The system also includes a computer controlled, elevation compensating monorail structure extrusion machine comprising a fabrication chamber which continuously fabricates the monorail structure along a monorail construction right-of-way. | 4 |
ORIGIN OF INVENTION
The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government for Government purposes without the payment of any royalties thereon or therefore.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Non-Provisional patent application Ser. No. 12/431,456 filed Apr. 28, 2009, entitled “Offset Compound Gear Inline Two-Speed Drive”, which issued as U.S. Pat. No. 8,091,445 B1 on Jan. 10, 2012. The entirety of the above-noted application is incorporated by reference herein.
TECHNICAL FIELD
The invention relates to transmissions, and more particularly to a device(s) and configurations which provide a simple, lightweight two-speed drive which can be used either as an overall transmission or as a supplemental add-on input transmission (e.g., over-drive/under-drive) to extend the capability of an existing transmission.
BACKGROUND
In several recent studies and on-going developments for advanced rotorcraft, the need for variable or multi-speed capable rotors has been raised. A speed change of up to 50% has been proposed for future rotorcraft to improve overall vehicle performance. Accomplishing rotor speed changes during operation requires both a rotor that can perform effectively over the operational speed-load range, and a propulsion system that can enable these speed changes.
Rotorcraft propulsion is a critical element of the overall rotorcraft. Unlike fixed wing aircraft, the rotor propulsion system provides lift and control as well as forward thrust. As a result, the rotorcraft engine-gearbox system must be highly reliable and efficient. In addition, the gearbox system must be kept at minimum weight. Presently, the propulsion system accounts for up to 25% of empty vehicle weight. The drive system accounts for up to 72% of the total propulsion system weight. Future rotorcraft trends call for more versatile, efficient, and powerful aircraft, all of which challenge state-of-the-art propulsion system technologies. Variable speed rotors have been identified as having a large impact on many critical rotorcraft issues.
Currently, rotor speed can only be varied a small percentage by adjusting the speed of the engine. The variation in rotor speed is generally limited by engine efficiency and stall margin, permitting speed changes limited to approximately 15% when used in current tilt-rotor applications.
There is a need for a transmission with a high-range ratio (1:1) for hover mode operation and low-range reduction ratio, such as for example 50% (2:1), through a speed change mechanism, for cruise mode operation. A transmission of this type could be incorporated as an element within the overall propulsion system resulting in overall ratios of 50:1 to 100:1 in the aircraft.
It is commonly recognized that variable speed propulsion is required for the design of future advanced rotorcraft. Reductions in rotor speed are required to limit the advancing rotor tip speed and reduce rotor noise.
RELATED PATENTS
The following patents are incorporated by reference in their entirety herein.
U.S. Pat. No. 7,044,877 to Ai discloses for example a two speed transmission having an input shaft and an output shaft. The two-speed transmission is capable of changing the rotating speed of the output shaft from a first speed ratio to a second speed ratio. The shift between the first rotating speed ratio and the second rotating speed ratio is smoothly accomplished by the combination of two sets of planetary gear clusters and two electric motors. The electric motors being are to smooth the mechanical shift between the first speed ratio and the second speed ratio. However, Ai does not disclose a transmission with a high-range ratio (1:1) and low-range reduction ratio, such as for example 50% (2:1), which changes from one to the other through a speed change mechanism including gears, a clutch and a sprag.
U.S. Pat. No. 6,641,365 to Karem disclosed for example “A variable speed helicopter tilt rotor system and method for operating such a system are provided which allow the helicopter rotor to be operated at an optimal angular velocity in revolutions per minute (RPM) minimizing the power required to turn the rotor thereby resulting in helicopter performance efficiency improvements, reduction in noise, and improvements in rotor, helicopter transmission and engine life.”
US Patent Application No. 2007/0205321 to Waide discloses for example gearboxes providing first and second power-balanced paths in which a speed changer is configured to operate with only one path. Most preferably, the gearbox includes a friction clutch and a sprag clutch arranged such that, together with a lay-shaft and spur-gear differential, gear shifting can be done while transmitting power. The speed changing gearbox of the '321 application has first and second independently and concurrently operational drive paths for transmission of torque. However, Waide does not disclose a transmission with a high-range ratio (1:1) and low-range reduction ratio, such as for example 50% (2:1), which changes from one to the other and directs the torque through an output shaft which is in the same drive path as the input shaft.
SUMMARY OF THE INVENTION
With the present invention, a transmission, preferably for a rotorcraft is provided where the rotation of the rotor blades can be at 50% or less while maintaining engine speed at the optimal efficiency/performance speed. A portion of the overall 50% reduction can come from extending the engine speed operability range beyond present 15% decrease with the balance provided by the transmission of the present invention. At the present time, the reduction in rotor speed of about 15% is presently accomplished by changing the engine speed. However, with the transmission of the present invention, the entire 50% decrease in rotational speed can be realized without requiring any additional reduction in the speed of the engine. Future overall propulsion system (engine, driveline, and rotor) studies will determine what portion the transmission device should provide for overall optimal performance. This invention uniquely provides both a high-speed 1:1 range and a low-speed 2:1 range (50% speed reduction) with minimal robust parts. The low range ratio being dependent upon the gearing contained within can be varied, as required, to meet specific requirements.
According to the present invention, there is disclosed a transmission having a gear arrangement for transmitting torque from an input shaft to an output shaft. The input shaft rotates about a first rotational axis and has a first gear coupled thereto. An elongated, hollow, cylindrical shaft rotates about a second rotational axis that is offset from the first rotational axis. The hollow cylindrical shaft has a second gear at one end there of which meshes with the first gear and a third ring gear at an opposite end thereof. A fourth gear is mounted to one end of a hollow drive shaft. The fourth gear and the hollow drive shaft rotate about the first rotational axis. The fourth gear is meshed with the third gear of the hollow, cylindrical shaft. The hollow drive shaft has a cylindrical end portion at an opposite end thereof. The output shaft rotates about the first rotational axis and has a flange portion attached thereto. A sprag clutch has an input side mounted to the cylindrical end portion of the hollow drive shaft and an output side mounted to the flange portion of the output shaft. A multi-plate clutch is attached to an end portion of input shaft and to the output shaft. Coupling structure is provided for coupling the input shaft with the output shaft whereby the transmission operates in first and second modes.
Further according to the present invention, the first mode of operation results in a rotating speed ratio R 1 of 1 to 1 between the input shaft and the output shaft and the second mode of operation results in the rotating speed reduction ratio range of 4.00>R 2 >1.50 between the input shaft and the output shaft. Preferably, the second mode of operation results in the rotating speed reduction ratio range of 2 to 1 between the input shaft and the output shaft.
Still further according to the present invention, coupling structure for coupling the input shaft with the output shaft can cause the rotational speed of the output shaft to be the same as the rotational speed of the input shaft is the multi-plate clutch.
Yet further according to the present invention, the clutch is a multi-plate clutch having first spaced clutch plates driven by an end portion of the input shaft and second spaced clutch plates which drive the output shaft and interspersed between the first spaced clutch plates.
Moreover, according to the present invention, a clutch actuator means engages or disengages the first and second interspersed clutch plates whereby if the multi-plate clutch is engaged the rotational speed of the output shaft is at a first speed which is the same as that of the input shaft and if the clutch is disengaged the rotational speed of the output shaft is at a speed that is different from that of the input shaft.
Also, according to the present invention, the multi-plate clutch causes the rotational speed of the output shaft to be the same as the rotational speed of the input shaft whereby the transmission operates in first mode (high speed range, 1:1 ratio).
Also, according to the present invention, the sprag clutch causes the rotational speed of the output shaft to be less than the rotational speed of the input shaft whereby the transmission operates in second mode (low speed range, 2:1 ratio).
According to the present invention, the first gear has external teeth adapted to mesh with the internal teeth of the second gear and third gear has external teeth adapted to mesh with the internal teeth of fourth gear.
Further according to the present invention, the relationship between the output rotational speed and the input rotational speed for the second mode of operation is given by the equation
Output speed = Input speed × ( N 14 N 30 ) × ( N 34 N 18 )
where N 14 is equal to the number of teeth on first gear, N 30 is equal to the number of teeth on the second gear, N 34 is equal to the number of teeth on the third gear, and N 18 is equal to the number of teeth on the fourth gear.
Still further according to the present invention, the input shaft is driven by a device from which it receives rotational power such as an engine or an intermediate drive coupling if the present invention is added to an existing design engine-transmission driveline and used as a supplemental inline speed change device.
Yet further according to the present invention, the first input shaft of the transmission is connected to the output shaft of a second gear arrangement for transmitting torque from a second input shaft to the first input shaft. The second gear arrangement comprises a second input shaft rotating about the first rotational axis and having a first gear coupled thereto. An elongated, hollow, cylindrical shaft rotating about the second rotational axis is offset from the first rotational axis. The hollow cylindrical shaft having a second gear at one end thereof which engages the first gear and a third gear at an opposite end thereof. A fourth gear is supported by a bearing at the aft end of the input shaft of the transmission.
Still further according to the present invention, the relationship between the output speed and input for low speed operation of the second gear arrangement is given by the equation:
Output Speed=Input Speed×( N 414 /N 430 )×( N 434 /N 418 )
Where N 14 is equal to the number of teeth on first gear ( 414 ), N 30 is equal to the number of teeth on the second gear ( 430 ), N 34 is equal to the number on the third gear ( 434 ), and N 18 is equal to the number of teeth on the fourth gear ( 418 ).
Yet further according to the present invention, the transmission is a rotorcraft transmission of a light weight configuration with reduced parts.
According to the present invention, there is disclosed a method of transmitting torque from an input shaft to an output shaft of a transmission. The method includes the steps of rotating the input shaft having a first gear coupled thereto about a first rotational axis; rotating an elongated, hollow, cylindrical shaft about a second rotational axis that is offset from the first rotational axis, the hollow cylindrical shaft having a second gear at one end thereof which engages the first gear and a third gear at an opposite end thereof; rotating a fourth gear mounted to one end of a hollow drive shaft with a cylindrical end portion at an opposite end thereof about the first rotational axis whereby the fourth gear engages the third gear of the hollow, cylindrical shaft; rotating the output shaft with a flange portion attached thereto about the first rotational axis; mounting an input side of a sprag clutch to the cylindrical end portion of the hollow drive shaft and an output side of the sprag clutch to the flange portion of the output shaft; and coupling the input shaft with the output shaft whereby the transmission ( 10 ) operates in first or second modes.
Further according to the present invention, there is disclosed the steps of operating in the first mode of operation resulting in a rotating speed ratio R 1 of 1 to 1 between the input shaft and the output shaft; and operating in the second mode of operation resulting in the rotating speed ratio R 2 of and the second mode of operation results in the rotating speed reduction ratio range of 4.00>R 2 >1.50 between the input shaft and the output shaft.
Still further according to the present invention, means are provided for attaching first spaced clutch plates of a multi-plate clutch to an end portion of input shaft and attaching second spaced clutch plates to the output shaft whereby the second clutch plates are interspersed between the first spaced clutch plates; and engaging the first and second interspersed clutch plates whereby the rotational speed of the output shaft is the same as that of the input shaft or disengaging the first and second interspersed clutch plates whereby the rotational speed of the output shaft is less than that of the input shaft.
Also according to the present invention, there is disclosed a method of transferring torque from an input shaft to an output shaft of a transmission including the steps of operating in the first mode of operation resulting in a rotating speed ratio R 1 of 1 to 1 between the input shaft and the output shaft; and operating in the second mode of operation resulting in the rotating speed ratio R 2 of 2 to 1 between the input shaft and the output shaft.
Further according to the present invention, there is disclosed a method of transferring torque from an input shaft to an output shaft of a transmission including the step of engaging or disengaging the multi-plate clutch whereby when the multi-plate clutch is engaged the rotational speed of the output shaft is at a first speed which is the same as that of the input shaft and when the multi-plate clutch is disengaged the rotational speed of the output shaft is at a speed that is less than that of the input shaft.
Also according to the present invention, there is disclosed the steps of engaging or disengaging the clutch whereby when the clutch is engaged the rotational speed of the output shaft is at a first speed which is the same as that of the input shaft and when the clutch is disengaged the rotational speed of the output shaft is at a speed that is less than that of the input shaft.
Still further according to the present invention, there is disclosed the steps of coupling the input shaft with the output shaft to cause the transmission to operate in the first mode with the rotational speed of the output shaft the same as the rotational speed of the input shaft is with the multi-plate clutch.
Still further according to the present invention, there is disclosed the steps of coupling the input shaft with the output shaft to cause the transmission to operate in the second mode with the rotational speed of the output shaft less than the rotational speed of the input shaft is with the sprag clutch where the output speed is governed by the overall ratio of the gear set comprised of the first, second, third and fourth gears.
Yet further according to the present invention, there is disclosed the step of connecting the input shaft to a device that transmits rotational power.
Further according to the present invention, there is disclosed the step of serially connecting a plurality of gear arrangements and determining the overall output ratio of the two serially connected gear arrangements from the product of the two in-series ratios, R 1 , R 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made in detail to embodiments of the disclosure, examples of which may be illustrated in the accompanying drawing figures (FIGURES). The figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the invention to these particular embodiments.
Certain elements in selected ones of the figures may be illustrated not-to-scale, for illustrative clarity. The cross-sectional views, if any, presented herein may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines which would otherwise be visible in a true cross-sectional view, for illustrative clarity. In some cases, hidden lines may be drawn as dashed lines (this is conventional), but in other cases they may be drawn as solid lines.
If shading or cross-hatching is used, it is not intended to be of use in distinguishing one element from another (such as a cross-hatched element from a neighboring un-shaded element). It should be understood that it is not intended to limit the disclosure due to shading or cross-hatching in the drawing figures.
FIG. 1 is an oblique cross sectional view of a two-speed, mechanical-power-conveying transmission, according to the present invention.
FIG. 2A is an orthogonal cross sectional view of the two-speed, mechanical-power-conveying transmission, according to the present invention.
FIG. 2B is a schematic axial view of the gear relationships in the two-speed, mechanical-power-conveying transmission, in according to the present invention.
FIG. 3A is an orthogonal cross sectional view of the present invention showing the path of power flow during high-speed output operation of the two-speed, mechanical-power-conveying transmission, according to the present invention.
FIG. 3B is an orthogonal cross sectional view of the present invention showing the path of power flow during low-speed output operation of the two-speed, mechanical-power-conveying transmission, according to the present invention.
FIG. 4 is an orthogonal cross sectional view of multiple stages of the two-speed, mechanical-power-conveying transmission in series, according to the present invention. This configuration consists of a fixed-ratio first stage and a variable-ratio second stage with only the second stage clutch controlled.
FIG. 5 is an orthogonal cross sectional view of multiple stages of an alternate two-speed, mechanical-power-conveying transmission in series, according to the present invention. This configuration consists of two variable-ratio stages both simultaneously clutch controlled.
FIG. 6 is an orthogonal cross sectional view of the above ( FIG. 5 ) in a configuration in which the power input is transferred directly into the input gear in lieu of the input shaft end providing for up to three outputs at different speeds, both of fixed ratio and variable ratio relative to the motor input speed.
DETAILED DESCRIPTION OF THE INVENTION
Throughout the descriptions set forth herein, various features of the invention may be described in the context of a single embodiment. The features, however, may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment. Furthermore, it should be understood that the invention can be carried out or practiced in various ways, and that the invention can be implemented in embodiments other than the exemplary ones described hereinbelow. The descriptions, examples, methods and materials presented in the description, as well as the claims, should not be construed as limiting, but rather as illustrative.
If any dimensions are set forth herein, they should be construed in the context of providing some scale to the relationship between the elements. For example, a given element may have an equal, lesser or greater dimension (such as diameter) than another element. Any dimensions that are important or critical will generally be identified as such. The term “at least” includes equal to or greater than. The term “up to” includes less than. Also, an open-ended range or ratio as “at least 2:1” should be interpreted to include sub-ranges such as at least 2:1, at least 5:1, and at least 10:1.
The present two-speed transmission invention 10 is referred to herein as a “transmission,” “two-speed transmission,” “compound gear transmission,” or variations thereof, or as the inventors' preferred usage: “offset compound gear drive,” or OCG.
Referring to FIG. 1 there is shown in cross sectional view the novel two-speed, mechanical-power-conveying transmission 10 comprising an input shaft 12 having a first gear 14 attached thereto, an output shaft 26 , an elongated, hollow, cylindrical shaft 16 having a second gear 30 possessing internal teeth at one end 16 a of the cylindrical shaft, and a third gear 34 possessing external teeth at the other end 16 b of the cylindrical hollow shaft, a fourth gear 18 integral with or attached to wheel 65 and supported on bearing 62 maintaining concentricity with gear 14 by means of the aft end of shaft 12 , a multi-plate clutch 22 , and a sprag clutch 28 . The input shaft ( 12 ) is rotationally driven by a device ( 13 ), such as an engine, from which it receives rotational power. The elongated cylindrical shaft 16 has a rotational axis 19 that is offset from a shared main rotational axis 21 of the input shaft 12 and the output shaft 26 . Input shaft 12 is supported on bearings 60 and 62 . Output shaft 26 is supported on bearings 64 and 66 . Bearings 60 and 66 serve as drive system main bearings. Bearings 62 and 64 serve as intermediate bearings. Bearing 62 maintains concentricity and permits relative differential rotational speeds between gear 18 and shaft 12 . Bearing 64 serves as a pilot bearing between input shaft 12 and output shaft 26 to maintain concentricity and permit relative differential rotational motion between input shaft 12 and output shaft 26 (i.e., differential rotational speeds). Bearings 60 , 62 , 64 , and 66 share a common central axis 21 . Shaft 16 is supported on bearings 48 which are concentric with the axis 19 and are offset from the central axis 21 of bearings 60 , 62 , 64 , and 66 . The offset between the axis 19 and 21 is a direct function of the gear ratios. Bearings 60 , 62 , 64 , and 66 are represented as rolling element type bearings but may also be of the fluid film type or magnetic type as warranted by overall transmission speed and power requirements, and bearings 48 which are represented as fluid film type journals may also be of the rolling element type.
The first gear 14 having external teeth, is affixed to the input shaft 12 , and meshes with the second gear 30 having internal teeth, on the forward end 16 a of the elongated hollow shaft 16 . At the aft end 16 b of the elongated hollow shaft 16 is a third gear 34 , having external teeth, and which meshes with a fourth gear 18 , having internal teeth. The fourth gear 18 is attached to a hollow drive shaft 20 at a forward end 20 a , by means such as bolts 29 (see FIG. 2A ). The opposite or distal end 20 b of hollow drive shaft 20 has a cylindrical end portion 20 c onto which is mounted the input side 28 a of a sprag clutch 28 .
The output shaft 26 has an integral flange portion 43 that is located between opposite ends 26 a and 26 b of the output shaft 26 . Flange portion 43 has an upstanding rim 43 a with an inner surface 43 b that receives the output side 28 b of the sprag clutch 28 . The input shaft 12 has an end portion 12 b that is large in diameter as compared to the remainder of the input shaft 12 .
A hollow cylinder 24 , sized to accommodate the multi-plate clutch assembly 22 , is attached or contiguous with the input shaft distal end portion 12 b of input shaft 12 . The clutch assembly 22 has alternating stacked clutch plates 22 a , 22 b , 22 c , 22 d ( 22 a - 22 d ) (see FIG. 2 ) that are driven by, and rotate at the same speed as hollow cylinder 24 by means of a spline or tooth engagement at the outer perimeter. The spaced stacked plates 22 a - 22 d engage by means of friction a set of interspersed stacked clutch plates 23 a , 23 b , 23 c , 23 d ( 23 a - 23 d ) which drive and rotate at the same speed as the output shaft 26 by means of spline or tooth engagement at the inner perimeter. An annularly arranged clutch actuator 51 , which is mounted to and rotates with the end portion 12 b of input shaft 12 , compresses or releases the clutch 22 to cause it to engage or disengage during operation, as described herein below. The configuration of the clutch actuator 51 is a mechanical spring arrangement (e.g., helical coil, Belleville, diaphragm spring) activated and hydraulically released (e.g., by an annular piston). A mechanical fail safe feature is incorporated in the clutch release (disengagement) mechanism so that the clutch will be engaged if there is a failure of the clutch release mechanism. FIG. 2B provides an axial schematic view of the rotating components of the present transmission invention 10 . The elements shown are the input shaft 12 (which has the output shaft 26 behind it and out of view), having the first gear 14 attached thereto, a ball or roller type bearing 17 , the second gear 30 and the third gear 34 that are part of, and integral with, the offset hollow cylindrical shaft 16 , and the fourth gear 18 . The solid line 27 defines the foreshortened, end view of the cylindrical surface plane of bearings 48 , which provide support to offset hollow shaft 16 . The offset aspect of the hollow driveshaft 16 is evident in the location of its axis of rotation 19 in relation to the axis of rotation 21 that is shared by the input shaft 12 and the output shaft 26 . Axis of rotation 21 is the central, or primary, machine axis on which the drive system input and output are centered, whereas axis of rotation 19 is a secondary axis of rotation on which some of the internal components between the input and output rotate, primarily hollow shaft 16 , second gear 30 , and third gear 34 . The dashed oval 37 a encompasses a first mesh plane 37 where the first gear 14 meshes with the second gear 30 , and the second dotted oval 41 a encompasses the second mesh plane 41 where the third gear 34 meshes with the fourth gear 18 . FIG. 2B in an idealized view combining mesh plane 37 and mesh plane 41 into a single plane for presentation of the OCG Offset Compound Gear concept basis, whereas in the present invention the two mesh planes are separated axially.
A first bearing set 60 (see FIGS. 1 AND 2A ) supports the input end 12 a of the input shaft 12 . A first single bearing 62 supports the fourth gear 18 in relation to the input shaft 12 . A second single bearing 64 supports the output shaft 26 in relation to the input shaft 12 . A second bearing set 66 supports the output shaft 26 . The hollow, cylindrical offset shaft 16 is carried by bearings 48 , which are of the fluid film journal/thrust type or rolling element bearing type based upon specific transmission requirements.
Operational Dynamics
During operation, if the multi-plate clutch 22 is engaged, then the rotational speed of the output shaft 26 is the same as that of the input shaft 12 and the power flows directly from the input shaft 12 to the output shaft 26 through the multi-plate clutch 22 by means of torque transmitted via friction created by the clamping force provided by releasing clutch actuator 51 . If the clutch 22 is disengaged, then the rotational speed of the output shaft 26 is less than that of the input shaft 12 and the power flows from the fourth gear 18 to the flange portion 43 of the output shaft 26 by way of the sprag clutch 28 . The ratio of the input rotational speed and the output rotational speed when the clutch 22 is disengaged is on the order of 2:1 as described or some other ratio as required.
The input/output speed ratio is a function of the effective respective diameters of the first and second meshing gears 14 and 30 , respectively, and the respective diameters of the third and fourth meshing gears 34 and 18 , respectively, as should be readily evident to those who are skilled in the art of transmission of rotary mechanical power. The input/output ratio is discussed in more detail hereinbelow.
The two-speed operation of the present transmission invention 10 becomes more evident upon contemplation of cross sectional views of FIGS. 3A and 3B . FIG. 3A illustrates high-speed operation of the present transmission invention 10 , which takes place when the multi-plate clutch assembly 22 is engaged. The direction of flow of rotary mechanical power is shown by means of the line 77 with arrowheads 77 a . The direction of flow of mechanical rotary power is from input shaft 12 , hollow cylinder 24 , to clutch assembly 22 and through output shaft 26 , such that the output speed is the same as the input speed (the output ratio is 1:1.)
FIG. 3B illustrates low-speed operation of the present transmission invention 10 , which takes place when the multi-plate clutch assembly 22 is disengaged. Power enters at the input shaft 12 and is transferred by way of the first gear 14 to the second gear 30 , which is contiguous with the hollow driveshaft 16 . The hollow driveshaft 16 conveys rotary power to the contiguous third gear 34 , which transmits it to the fourth gear 18 , which conveys it onward to the hollow drive shaft 20 that is affixed, such as by means of bolts 29 , to a wheel portion 65 of the fourth gear 18 . The hollow driveshaft 20 conveys power to the sprag clutch 28 , which transmits it onward to the flange portion 43 of the output shaft 26 , such that the output speed is less than the input speed, such as for example the output ratio is 2:1.
Input/Output Speed Ratios
The cylindrical offset shaft 16 comprises second and third gears 30 and 34 , respectively, disposed respectively at opposing ends 16 a and 16 b of the offset hollow shaft assembly. The second gear 30 has internal gear teeth 30 ′ and the third gear 34 has external gear teeth 34 ′. The second gear 30 of the cylindrical offset shaft 16 receives mechanical rotary power from the first gear 14 at the first gear mesh 52 ( FIG. 2A ) and then conveys the rotary mechanical power by means of the third gear 34 that meshes with the fourth gear 18 at the second gear mesh 54 .
The internal gear teeth 30 ′ of second gear 30 of the cylindrical offset shaft 16 receive rotary force from the external gear teeth 14 ′ of the first gear 14 ; the external teeth 34 ′ of the third gear 34 conveys rotary force to the internal gear teeth 18 ′ of the fourth gear 18 which conveys rotary mechanical power to the hollow driveshaft 20 . Input/output speed ratios are determined by the respective numbers of gear teeth 30 ′, 34 ′, 14 ′, 18 ′ of the two meshing gear sets, first and second gears 14 , 30 , respectively and third and fourth gears 34 , 18 , respectively.
The respective gear teeth 30 ′, 34 ′, 14 ′, 18 ′ of first and second gears 14 , 30 , respectively and third and fourth gears 34 , 18 , respectively, can be of the straight cut spur varieties or of the helically cut or other gear teeth types such as herringbone as deemed necessary for required power rating operational reliability and quiet operation.
Note that all rotating parts described hereinabove rotate in the same direction. Reductions in rotary speed take place at two locations: (1) at the first gear mesh 52 between the first gear 14 and the second gear 30 of the cylindrical offset, double-gear assembly 16 and, (2) at the second gear mesh 54 between the third gear 34 of the second gear 18 .
The relationship between the output speed and input for the low speed operation is given by
Output speed = Input speed × ( N 14 N 30 ) × ( N 34 N 18 )
where N 14 is equal to the number of teeth on first gear 14 , N 30 is equal to the number of teeth on second gear 30 , N 34 is equal to the number of teeth on third gear 34 , and N 18 is equal to the number of teeth on fourth gear 18 .
The remainder of this section is a discussion on the ratio range potential of the OCG. The term “R” means the same as “ratio.”
The ratio-range potential for the speed reduction between the input and the output shafts 12 and 26 of the OCG transmission 10 in a single-stage configuration is 4.00>R>1.50 (speed reduction output) and, conversely, it is 0.25<R<0.75 for a back driven, or reverse (speed increasing output) configuration. Preferably, however, the speed reduction ratio from the input to the output is 2:1 or R=2.0.
OCGS in Series: Arrangement One (Multi-Stage Fixed/Variable Ratio)
Referring now to FIG. 4 , there is shown, in cross-sectional schematic view, two OCGs 310 , 410 coupled in such a way that the output of a first OCG 310 is directed into a second OCG 410 so as to provide a series arrangement 300 wherein the overall ratio of input/output speed reduction (or multiplication) can be greater than that of a single OCG. It is possible, as those skilled in the art would clearly appreciate, that an unlimited number of OCGs could be so serially arranged, though practical considerations would necessarily place limits.
The series arrangement 300 , portrayed in FIG. 4 , includes the first OCG 310 which is comprised of the gear portion only of the transmission 10 described hereinabove. The first OCG 310 has an input shaft 312 and three moving parts with gears such that the input shaft drives a fifth gear 314 , a hollow driveshaft 316 , and an eight gear 318 , which correspond respectively to the first gear 14 , the hollow driveshaft 16 and the fourth gear 18 in the above described OCG transmission 10 . The operational dynamics of the OCG gear train 310 need not be described again, as it is the same as that given hereinabove in relation to the basic OCG transmission 10 .
First OCG 310 , as shown in FIG. 4 , has an output shaft formed of a flange 313 which is secured to the eighth gear 318 by means such as screws 329 . The output shaft 413 is shown as being contiguous with, and/or is one in the same as, the input shaft 412 of the second OCG portion 410 . The other parts of the second OCG portion 410 , and their operational dynamics, are as described hereinabove in reference to the OCG transmission 10 . It should be noted that the method of bolting the output shaft 313 to eighth gear 318 is only one of many such coupling methods that could be used to greater or lesser advantage in the series coupling of the present OCG series arrangement 300 . Splined connections could be used, or other types of bolted couplings, including flexible or universal joints could also be used, as called for by competent engineering judgment.
The second OCG portion 410 consists of the input shaft 412 , a fifth gear 414 (compare first gear 14 ), a hollow driveshaft 416 , an eight gear 418 (compare fourth gear 14 ), a hollow driveshaft 420 housing a clutch 422 , a sprag clutch 428 , and an output shaft 426 , each of which, with the exception of the input shaft having the flange 413 has corresponding parts as described hereinabove in reference to the OCG transmission 10 . That is to say, the second OCG transmission portion 410 displayed in FIG. 4 is of the same physical and operational sort that is described hereinabove as the transmission invention 10 .
In operation, the overall series arrangement 300 provides an overall rotational speed reduction between the input shaft 312 and the output shaft 426 that is the multiplicative product of the speed reduction ratio of the first OCG portion 310 and the speed reduction ratio of the second OCG portion 410 . Thus the input/output speed reduction ratio exceeds that of a single OCG transmission 10 . Note also that said speed reduction property could, upon reverse driving, provide a speed multiplication, as should be obvious to those who are skilled in the art.
In the embodiment shown in FIG. 4 , ratios above 4.00 can be configured using multiple stages of the transmission 10 in series. As an example, the OCG ratio range potential for the OCG Drive 10 in a two-stage configuration can provide R=16.00 by employing two R=4.00 (as the single stage limit) in series (i.e., 16=4×4). Ratios between 4 and 16 can be created using a combination of twin ratios or dual ratios in series. A series arranged dual-ratio, two-stage configuration would employ configurations with two different OCG ratios to provide the desired overall output ratio. The overall ratio is defined as the product of the two in-series ratios, R 1 , R 2 (i.e., R out =R 1 ×R 2 ). The subject of two-stage configurations does not imply the use of two duplicate configurations, each with a clutch and sprag. More properly, it means that the OCG gearing would be employed in a two-stage configuration while maintaining the single clutch and sprag.
For a speed reduction of the sort the OCG was designed for, the upper and lower ratio limits are restricted by the geometrically possible input gear size. Above R=4.00, the input gear becomes impractically small because the bearing size and shaft become impossibly small. Below R=1.50, the input gear becomes too large creating gear tooth interference with the internal teeth of the second mesh.
OCGS in Series: Arrangement Two (Multi-Stage Variable/Variable Ratio)
Referring now to FIG. 5 , there is shown, in cross-sectional schematic view, two OCGs 310 A and 410 A, coupled in such a way that the output of a first OCG 310 A is directed into a second OCG 410 A so as to provide an alternate series arrangement 300 A, wherein the overall ratio of input/output speed reduction (or multiplication) can be also be greater than that of a single OCG. In contrast to the series arrangement described above, and shown in FIG. 4 , the coupling of the two OCGs, 310 A and 410 A, as shown in FIG. 5 , is configured to change the power flow through both OCGs 310 A and 410 A simultaneously, permitting a larger overall output speed ratio change though the OCG device than that of FIG. 4 . In FIG. 4 , the series arrangement only permits ratio change in the second OCG 410 . In FIG. 4 , OCG 310 is used as a fixed ratio device. In FIG. 5 , OCG 310 A and OCG 410 A are mechanically connected in a manner which permits both OCG to simultaneously shift between output ratio R=1:1 direct drive (clutch engaged), or the combined ratio of OCG 310 A and OCG 410 A (clutch disengaged). The selection of either the configuration described in FIG. 4 , or that described in FIG. 5 , is dependent upon design requirements of the intended end use application.
The series arrangement 300 A portrayed in FIG. 5 includes the first OCG 310 A which is comprised of the gear portion only of the transmission 10 described hereinabove. The first OCG 310 A has an input shaft 312 A and three moving parts with gears such that the input shaft drives a gear 314 , a hollow driveshaft 316 , and gear 318 , which correspond respectively to the gear 14 , the hollow driveshaft 16 and gear 18 in the above described OCG transmission 10 . The operational dynamics of the OCG gear train 310 A need not be described again, as it is the same as that given hereinabove in relation to the basic OCG transmission 10 .
Differences relative to OCG 300 shown in FIG. 4 , reflected in OCG 300 A shown in FIG. 5 , provide a different functionality, and consists of several changes. First, combining shaft 312 and shaft 412 (ref: FIG. 4 ) into an integral shaft 312 A, which is now common to both OCG 310 A and 410 A. Secondly, flange 313 (ref: FIG. 4 ) is eliminated and is replaced with drive hub 414 A (forward extension of gear 414 ). Thirdly, gear 414 is mechanically decoupled at 414 B from shaft 312 A, and is now supported by bearings located between hub 414 A at gear 414 and shaft 312 A, permitting relative rotational motion between gear 414 and shaft 312 A, with no transfer of power at 414 B. The effect of the above three reconfiguration changes redirects power from OCG 310 A (gear 318 ) directly to gear 414 via drive hub 414 A. Drive hub 414 A is depicted as integral to gear 414 . In certain instances, it may be advantageous for hub 414 A and gear 414 to be separate parts mechanically connected to provide power transmission capability in lieu of being a single integral part as shown in FIG. 5 . Whether hub 414 A and gear 414 are integral in configuration, or two separate parts mechanically connected, their function in FIG. 5 is to transfer power from ring gear 318 directly to input gear 414 of second stage OCG 410 A, which are mechanically connected via bolts 329 .
Relative to FIG. 5 , the second OCG portion 410 A consists of the alternate configuration input shaft 312 A (common to, and shared by both OCG 310 A and OCG 410 A), a gear 414 (compare gear 14 , except changes described above regarding decoupling of gear 414 from shaft 312 A at 414 B), a hollow driveshaft 416 , a gear 418 (compare gear 14 ), a hollow driveshaft 420 housing a clutch 422 , a sprag clutch 428 , and an output shaft 426 , each of which, with the exception of reconfigured input gear 414 and shaft 312 A, has corresponding parts as described hereinabove in reference to the OCG transmission 10 . That is to say, the second OCG transmission portion 410 A displayed in FIG. 5 is of the same physical and operational sort that is described hereinabove as the transmission invention 10 , except with power entry directly to gear 414 / 414 A in lieu of input shaft 12 .
In operation, the overall alternate series arrangement 300 A provides an overall rotational speed reduction between the input shaft 312 A and the output shaft 426 that is the multiplicative product of the speed reduction ratio of the first OCG portion 310 A and the speed reduction ratio of the second OCG portion 410 A. Thus the input/output speed reduction ratio exceeds that of a single OCG transmission 10 . In addition, this alternate arrangement permits the simultaneous shifting of both OCG 310 A and OCG 410 A resulting in an overall ratio change between 1:1 (clutch engaged) and the multiplicative product of the speed reduction ratio of the first OCG portion 310 A and the speed reduction ratio of the second OCG portion 410 A (clutch disengaged). This functionality is in contrast with that of OCG 300 series depicted in FIG. 4 where only OCG 410 is clutch controlled and OCG 310 is a fixed-ratio device.
In the embodiment shown in FIG. 5 , ratios above 4.00 can be configured using multiple stages of the transmission 10 in series. As an example, the OCG ratio range potential for the OCG Drive 10 in a two-stage configuration can provide R=16.00 by employing two R=4.00 (as the single stage limit) in series (i.e., 16=4×4). Ratios between 4 and 16 can be created using a combination of twin ratios or dual ratios in series. A series arranged dual-ratio, two-stage configuration would employ configurations with two different OCG ratios to provide the desired overall output ratio. The overall ratio is defined as the product of the two in-series ratios, R 1 , R 2 (i.e., R out =R 1 ×R 2 ). The subject of two-stage configurations does not imply the use of two duplicate configurations, each with a clutch and sprag. More properly, it means that the OCG gearing would be employed in a two-stage configuration while maintaining the single clutch and sprag. The embodiment shown in FIG. 5 , provides the output ratios 1:1 (direct drive), or R out , where R out =R 1 ×R 2 , whereas in the embodiment shown in FIG. 4 , the output ratios are R 1 , where R 1 is that of the first-stage OCG, or R out , where R out =R 1 ×R 2 . It should be obvious, that for an equally geared pair of OCG in series that the 300 A configuration as shown in FIG. 5 provides a greater overall ratio change than OCG 300 in FIG. 4 .
Multiple Output OCG Application
Referring now to FIG. 6 , there is shown, in cross-sectional schematic view, a configuration consisting of an OCG 300 A ( FIG. 5 ), or, optional series drive OCG 300 ( FIG. 4 ), or, optional basic OCG 10 ( FIGS. 1 and 2 ), coupled to a drive motor 500 such that the configuration provides for a possibility of three output speed capability.
It should be obvious that the introduction of gear 314 A, which is mechanical coupled to gear 314 , redirects the power entry in the OCG from shaft 312 A to gear 314 .
The primary output is located at output shaft 426 , with optional outputs at shaft 504 , and/or at output shaft 312 A, each at a unique speed(s) with respect to drive motor 500 . For the depicted figure, the speeds for the output shafts are as follows. Output shaft 426 rotational speeds are direct drive ratio 1:1, or the speed determined by OCG overall ratio (R1×R2), dependent upon clutch mode. Output shaft 312 A speed is the product ratio of gear 502 and gear 314 A, at a fixed speed relative to the motor 500 speed. Output shaft 504 is direct drive and equal to the speed of motor 500 . Motor 500 may be a fixed or variable speed device as required in the end application. The orientation of motor 500 and/or rotational axis is not limited to the example configuration, but may be placed to the left of gear 502 / 314 A mesh if advantageous, or even perpendicular to the central axis of the OCG using appropriate gear geometry as the end application design requirements dictate.
The fixed-ratio speeds available at shaft 312 A and shaft 426 are a function of the drive ratio determined by gear 502 and gear 314 A and the former combined with the overall reduction ratio of OCG 300 A, 300 , or 10 . These gears ( 502 and 314 A) may be speed-increasing as shown by gear 502 and gear 314 A, or speed-decreasing optional gear set comprised of gear 502 A and gear 314 B. The configuration depicted in FIG. 6 provides a wide range of flexibility in the number of possible output speeds, and their respective speed ratios relative to the speed of motor 500 . Outside the intended application for the OCG drive described in the background, an application for this configuration, utilizing a gear set such as example gear set 502 A/ 314 B, may be a high-reliability long-life low speed/power gear drive system for extraterrestrial applications requiring a clutch-controlled two speed drive and one/multiple power take-offs which may be independently clutch controlled (coupled/uncoupled) and driven by a common motor.
If no intermediate output speeds are required for a given application, the user should use configurations Alternate Series OCG Drive 300 A ( FIG. 5 ), or optional series drive OCG 300 ( FIG. 4 ), or basic OCG 10 ( FIGS. 1 and 2 ) coupled to a driving device.
Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, certain equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described components (assemblies, devices, etc.) the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several embodiments, such feature may be combined with one or more features of the other embodiments as may be desired and advantageous for any given or particular application. | A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation, under 35 U.S.C. §120, of copending International Application No. PCT/EP2006/007975, filed Aug. 11, 2006, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German Patent Application DE 10 2005 038 707.1, filed Aug. 15, 2005; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a process and an apparatus for treating an exhaust gas from an internal combustion engine. A particularly preferred application area for the present invention is its use for treating an exhaust gas from large-volume internal combustion engines, in particular diesel engines, especially in locomotives and water-borne vehicles.
The exhaust gases from internal combustion engines contain undesirable substances, the levels of which in the exhaust gas must be below statutory emission limits in many countries. That includes the concentration of particulates in the exhaust gas, which in many countries must not exceed specific levels. However, in particular in the case of large-volume internal combustion engines, in some cases it is difficult to comply with those emission limits, especially under idling conditions.
BRIEF SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a process and an apparatus for treating exhaust gas of an internal combustion engine and a vehicle having the apparatus, which overcome the hereinafore-mentioned disadvantages of the heretofore-known processes and apparatuses of this general type and with which the emission of undesirable substances can be reliably reduced even for large-volume internal combustion engines.
With the foregoing and other objects in view there is provided, in accordance with the invention, a process for treating an exhaust gas from an internal combustion engine. The process comprises providing at least two modules for exhaust-gas treatment, and at least partly diverting an exhaust-gas stream as a function of a loading state of the internal combustion engine to cause at least parts of the exhaust gas to flow through at least one of the modules.
In this context, the term exhaust-gas treatment is to be understood in particular as meaning a reduction in the concentration of at least one component in the exhaust gas. In the present context, exhaust-gas treatment is preferably also understood as meaning a reduction in the level of particulates in the exhaust gas. The loading state of the internal combustion engine has an effect, in particular, on the following exhaust-gas variables: temperature, exhaust-gas mass flow, pollutant concentration and/or mean exhaust-gas velocity. It is often the case that only a very small number of load points, for example an idling load point, a partial load point and a full load point, occur especially in large-capacity internal combustion engines, in particular corresponding diesel engines, which are used in railcars, for example locomotives, water-borne vehicles, for example ships and/or boats, and in stationary operation. By suitably configuring the modules and suitably adopting a procedure, it is possible in this way to effect an exhaust-gas treatment that is accurately matched to the above-mentioned load points. For example, all of the modules can be formed as an idling module which is adapted to the exhaust-gas situation in idling mode and is therefore suitable for treating the exhaust gas under idling conditions. By suitably controlling the connecting device, it is possible to divert the exhaust-gas stream in such a way that a total exhaust-gas stream is applied substantially equally to at least two modules. A total exhaust-gas stream is to be understood in particular as meaning an exhaust-gas stream, especially an exhaust-gas mass or volumetric flow, which is integrated and/or cumulative over the time for which it flows through the corresponding module. This leads to a substantially equal flow through the modules. In particular, if each module includes at least one particulate filter for reducing the particulate content in the exhaust gas, uniform loading and if appropriate also a uniformly changing pressure loss is advantageously achieved.
A first module may be formed in such a way that it alone or in combination with a further module is adapted to the exhaust-gas situation at the partial load point, while a second module may be formed in such a way that it, in conjunction with a further module and the first module, is adapted to the exhaust-gas situation at the full load point. In this way, a modular structure and a suitable diversion of the exhaust gas can lead in each case to optimum conversion of the exhaust gas at the various load points.
A module generally includes at least one honeycomb body which has cavities, for example passages, through which an exhaust gas can flow. A honeycomb body may, in particular, be a ceramic and/or a metallic honeycomb body. A ceramic honeycomb body can be produced as an extruded monolith, while a metallic honeycomb body may include at least one at least partially structured layer, which has in particular been deformed in such a way as to form cavities through which an exhaust gas can flow. This deformation is to be understood in particular as meaning winding or twisting of at least one stack composed of at least one metallic layer. In this case it is also possible to use substantially smooth layers which, together with the structures of the at least partially structured layer, form the cavities. The honeycomb body may also include walls which in part allow a fluid to flow through them. The honeycomb body may form or include a particulate filter.
The effectiveness of an exhaust-gas treatment is highly dependent on the flow conditions through the corresponding module. For example, it is advantageous in particular for there to be, as far as possible, no laminar flows within the module, but rather for the flows, as far as possible, to be turbulent. In this way it is possible to effectively avoid laminar boundary flows which result in only a small part of the exhaust gas coming into contact with the walls of the cavities in the honeycomb body, which generally have a catalytically active coating. This is particularly important if an open particulate filter is included in the module, since the effectiveness of such a filter is highly dependent on a corresponding turbulent flow. In particular, in the case of large-volume internal combustion engines, however, the generally large dimensions of the corresponding exhaust-gas systems as well as the low idling speed of such engines in idling mode means that the exhaust-gas mass flow is very low, resulting in low flow velocities. This leads to a relatively low Reynolds number of the flow as it flows through the modules and therefore to possibly too low a degree of turbulence. In this case, the process according to the invention can lead to an increase in the Reynolds number by, as it were, reducing the total available surface area of the modules for the exhaust gas to flow through in order to be treated, thereby increasing the flow velocity and Reynolds number.
By way of example, it is possible for a corresponding exhaust-gas system to include four modules for reducing the particulate concentration in the exhaust gas. In idling mode, the installation is operated in such a way, through suitable actuation of the connecting device, that in each case only one of four possible modules has the exhaust gas flowing through it. Although this also reduces the respective maximum available reaction and filtration surface area, it particularly advantageously leads to an increase in the flow velocity and therefore to an increase in the Reynolds number of the flow. However, there is no disadvantage in the lower reaction and/or filter surface area, since under idling conditions in particular, the level of particulates is so low that the corresponding filter or reaction surface area of the module is sufficient to achieve enough respective conversion and filtering. In this way, even in idling mode of large-volume internal combustion engines, the exhaust gas can be effectively treated. This is advantageous since in particular in large-volume internal combustion engines, there are prolonged idling or low-load phases, for example when switching locomotives are waiting for the next switch or for ship engines which, for example in port, are used only to supply power.
As the load rises, i.e. for example as the internal combustion engine speed increases, it is possible, for example, to gradually switch further modules to have exhaust gas flowing through them. At higher engine speeds, a higher mean exhaust-gas velocity and a higher exhaust-gas mass flow are generally present, and consequently it is then advantageous for the exhaust gas to flow through a plurality of modules in order to provide a sufficiently large respective reaction and filter surface area.
In accordance with another mode of the process of the invention, in each module at least a reduction in the particulate concentration of the exhaust gas flowing through the module takes place.
For this purpose, a particulate filter may, in particular, be provided in each of the modules. The provision of further components is possible and advantageous. For example, a suitable oxidation catalytic converter on a honeycomb body may be provided upstream of the particulate filter, leading in particular to oxidation of nitrogen monoxide (NO) to nitrogen dioxide (NO 2 ), which serves as an oxidizing agent for the carbon contained in the particulates. A particulate filter of this type is known as a continuously regenerating particulate filter (CRT or Continuous Regenerating Trap).
In accordance with a further mode of the process of the invention, the reduction in the particulate concentration takes place in an open particulate filter.
An open particulate filter is to be understood as meaning a particulate filter in which the exhaust gas flowing through the particulate filter does not have to flow through a wall of the particulate filter. The alternative is a closed particulate filter, in which a multiplicity of passages are formed, of which in each case some are open on the entry side and closed on the exit side, while others are closed on the entry side and open on the exit side. In this way, the exhaust-gas stream is forced to flow through the porous wall of the particulate filter, in order to pass from a passage that is open on the entry side into a passage that is open on the exit side. As the exhaust gas flows through the wall, the particulates which it contains are filtered out. Open filters are also understood as bypass flow filters in which there is no filtering of the main stream, for example by a diesel particulate filter with passages closed on alternate sides, but rather only filtering of a bypass flow.
An open particulate filter therefore cannot per se become blocked. Although it is theoretically possible for the porous walls used as filter surfaces to become laden with particulates to such an extent that particulates are no longer filtered, in this case the unfiltered exhaust gases can continue to flow through the particulate filter unimpeded. In contrast, a closed filter in which the filter surfaces become blocked forms a very high back-pressure which ultimately means that exhaust gas can no longer flow through the particulate filter. In this respect, an open particulate filter can also be understood as a barrier-free particulate filter.
In the case of an open particulate filter, it is particularly preferable for the filter to be composed of substantially smooth layers and at least partially corrugated layers. In particular, in this case the substantially smooth layer, at least in partial regions, may be composed of a material through which a fluid can flow and which is in particular porous, while the at least partially corrugated layer is composed for example of thin metal sheet or a thin sheet-metal foil or a thin metal foil. The corrugated layer may preferably have guide structures which are responsible for diverting the exhaust gas toward the filter regions. With regard to the configuration of these or similar guide structures, it is preferable for the structures to effect an increase in the velocity of the exhaust gas in the passage, so that in particular the proportion of the exhaust gas which remains in the open passage and flows past or along the filter surface is at a significantly increased velocity compared to the velocity of the exhaust gas when it enters the passage. Tests have shown that as the velocity of this bypass exhaust-gas stream increases, the separation rate of the filter surface(s) or the particulate trap can be increased.
The process according to the invention is advantageous, in particular, for an open particulate filter which is in each case included within the modules, since in this case it is ensured even at low idling speeds of, in particular, even large-volume internal combustion engines, that the flow in the modules has a Reynolds number which during flow through the particulate filter is sufficiently high to nevertheless bring about effective removal of the particulates or conversion of the component.
In accordance with an added mode of the process of the invention, a diversion of the exhaust gas takes place as a function of at least one of the following variables:
1) a regeneration capacity of the exhaust gas for a module, and
2) a need for regeneration of a module.
In this context, a diversion of the exhaust gas is to be understood as meaning a diversion by the connecting device. A regeneration of a particulate filter includes in particular an oxidation of the particulates held in the particulate filter. This can be effected firstly by providing an oxidizing agent, such as for example nitrogen dioxide, or as an alternative or indeed an addition, for example, by additional heating measures which increase the temperature of the particulate filter above a limit temperature above which the particulates are preferentially oxidized. If the exhaust gas is at a certain temperature that can lead to increased regeneration during flow through a module, it is possible to refer to a regeneration capacity of the exhaust gas as defined in 4.1) above. On the other hand, a need for reaction 4.2) of a module as referred to above, for example in the case of a particulate filter, means that the quantity of particulates that are present has exceeded a limit value above which it is advantageous to regenerate the module. In particular, in a particulate filter, this may also manifest itself in a rise in the pressure loss across the particulate filter.
In accordance with an additional mode of the process of the invention, in an idling load state, the exhaust-gas stream is diverted in such a way that on average a substantially identical total exhaust-gas stream flows through substantially all of the modules.
In this context, a total exhaust-gas stream is to be understood as meaning the sum and/or the integral over time of the exhaust-gas stream, preferably of the exhaust-gas mass flow or the exhaust-gas volumetric flow, over the time during which the exhaust gas flows through the module in question. The total exhaust-gas stream therefore preferably constitutes a mass, if it is the exhaust-gas mass flow that is under consideration, or a volume, if it is the exhaust-gas volumetric flow that is under consideration. In this context, in particular, through-flow times of up to 5 minutes, up to 10 minutes or even of an hour or more are possible and in accordance with the invention. In principle, it is preferable in this case to adopt a procedure in which the flow velocity in a module, preferably in a passage of a honeycomb body that is at least part of a module, lies in a range from 10 meters per second to 25 meters per second.
In accordance with yet another mode of the process of the invention, the number of modules through which the exhaust gas flows increases monotonically to at least one of the following variables:
1) exhaust-gas temperature, and
2) exhaust-gas mass flow.
It is particularly advantageous to be dependent on the exhaust-gas mass flow, since otherwise, for example if the exhaust gas is flowing through just one module, at higher loading states, in particular even at full load, flow through just one module may be disadvantageous for the effectiveness of exhaust-gas treatment. In particular, if each of the modules includes an open particulate filter, it is advantageous if the exhaust gas flows through all of the modules up to the full-load state of the internal combustion engine. Regeneration of the particulate filters in question can also take place, in particular, during the full-load state.
With the objects of the invention in view, there is also provided an apparatus for treating an exhaust gas from an internal combustion engine. The apparatus comprises an exhaust pipe to be connected to the internal combustion engine, at least two modules to be connected to the exhaust pipe for exhaust-gas treatment, and at least one connecting device, associated with at least one of the modules, for connecting the at least one module to the exhaust pipe to cause at least part of the exhaust gas to flow through the at least one module.
Each module includes, in particular, a honeycomb body, which preferably includes a corresponding catalytically active coating and/or is suitable for particulate filtering. A connecting device is to be understood, in particular, as meaning a component through the use of which a connection to the module through which a fluid can flow can be produced or disconnected. The connecting device is preferably a correspondingly constructed flap, which in the closed state can close a through-flow opening leading to the module and in the open state can open the opening. In particular, the various connecting devices can be provided in such a way that in each case only part of the exhaust gas can flow through the associated module or alternatively all of the exhaust gas can flow through the associated module. In particular, in the case of the latter option, various connecting devices can interact.
In accordance with another feature of the apparatus of the invention, the connecting device is provided in such a way that exhaust gas can flow through each module alone.
Thus, the apparatus according to the invention can be operated in such a way that, in particular in idling mode, exhaust gas flows to a uniform extent through the individual modules, so that the individual modules are utilized equally. In particular, if the modules include particulate filters, it is possible in this way to achieve a substantially uniform loading of the particulate filters in the modules. This leads to a substantially uniform pressure loss across the respective modules.
In accordance with a further feature of the apparatus of the invention, each module effects at least a reduction in the particulate concentration of the exhaust-gas stream flowing through the module.
In accordance with an added feature of the apparatus of the invention, it is preferable for each module to include at least one particulate filter, which is particularly preferably open. For a definition of an open particulate filter, reference is made to the statements made above and to International Publication No. WO 02/00326 A2, corresponding to U.S. Pat. No. 6,712,884, the content of the disclosure of which in connection with the structure of the particulate filter is hereby incorporated by reference into the instant application.
In accordance with an additional feature of the apparatus of the invention, the connecting device includes at least one flap.
A flap constitutes a connecting device that is, on one hand, simple to produce and is, on the other hand, able to effectively produce or stop a connection to a module. Furthermore, flaps are simple to actuate and have proven stable and durable when used in exhaust-gas systems.
In accordance with yet another feature of the apparatus of the invention, the connecting device is configured in such a way that when the exhaust gas can flow through the associated module, it excludes at least one further module from the exhaust-gas flow.
This can be realized, in particular, by a flap that has three possible positions:
1) a first position, in which the connection to the module is closed, 2) a second position, in which the connection to the module is open and the exhaust pipe is blocked, so that all of the exhaust gas that is present at the connection to the module flows through this module, and 3) a third position, in which exhaust gas can flow freely through both the module and the exhaust pipe.
Flaps of this type can be used, in particular, to realize an apparatus according to the invention in which exhaust gas can flow through all of the modules individually.
With the objects of the invention in view, there is furthermore provided a rail-borne vehicle, preferably a railway motor car, particularly preferably a locomotive, which includes an apparatus according to the invention or in which a process according to the invention takes place.
With the objects of the invention in view, there is concomitantly provided a water-borne vehicle which includes an apparatus according to the invention or in which a process according to the invention takes place.
The process and the apparatus according to the invention can particularly advantageously be deployed in exhaust-gas systems of diesel engines. It is preferable for the rail-borne vehicle and the water-borne vehicle to also have a diesel engine. Furthermore, it is possible for the apparatus and the process according to the invention to be used in stationary internal combustion engines, in particular diesel internal combustion engines.
The advantages and details which have been disclosed with respect to the process according to the invention can also be transferred to and exploited in the same way in the apparatus according to the invention. The same also applies to the details and advantages disclosed with respect to the apparatus according to the invention, which can equally be transferred to and exploited in the process according to the invention. The apparatus according to the invention is suitable, in particular, for carrying out the process according to the invention.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a process and an apparatus for treating exhaust gas of an internal combustion engine and a vehicle having the apparatus, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a fragmentary, diagrammatic, perspective view of a first exemplary embodiment of an apparatus according to the invention;
FIG. 2 is an enlarged, fragmentary, perspective view of a portion of a module of an apparatus according to the invention;
FIG. 3 is a cross-sectional view as seen from an end of a module of an apparatus according to the invention;
FIG. 4 is a first longitudinal-sectional view of a second exemplary embodiment of an apparatus according to the invention;
FIG. 5 is a second longitudinal-sectional view of the second exemplary embodiment of an apparatus according to the invention;
FIG. 6 is a fragmentary, longitudinal-sectional view of a portion of an apparatus according to the invention with a connecting device in a first position;
FIG. 7 is a fragmentary, longitudinal-sectional view of a portion of an apparatus according to the invention with a connecting device in a second position; and
FIG. 8 is a fragmentary, longitudinal-sectional view of a portion of an apparatus according to the invention with a connecting device in a third position.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic illustration of a first exemplary embodiment of an apparatus 1 according to the invention for treating an exhaust gas 6 . The apparatus includes an exhaust pipe 2 , a first module 3 and a second module 4 for exhaust-gas treatment. An idling module 5 is also provided. A non-illustrated internal combustion engine emits the exhaust gas 6 which flows through the exhaust pipe 2 in a through-flow direction 7 . The first module 3 for exhaust-gas treatment is assigned a first connecting device 8 . In the present, first exemplary embodiment, the connecting device 8 includes a pivotable flap, through the use of which the module 3 can be connected to the exhaust pipe 2 in such a way that at least part of the exhaust gas 6 can flow through the module 3 . A second connecting device 9 is provided in a corresponding way and is assigned to the second module 4 for exhaust-gas treatment.
The idling module 5 is not assigned a connecting device, since the exhaust gas 6 flows through this idling module 5 even when the first connecting device 8 and the second connecting device 9 are in a first position preventing flow through the first module 3 and the second module 4 . In particular, for large-volume internal combustion engines, for example of locomotives, of water-borne vehicles, such as ships or boats in particular, and of stationary installations, it is advantageous for the idling module 5 to be adapted to the exhaust-gas situation during idling phases. By way of example, in the case of a switching locomotive, the internal combustion engine is in idling mode for a very large part of its operating time, and it is therefore useful to adapt to idling conditions. Moreover, large-volume internal combustion engines have a very low idling speed and very low flow velocities and consequently low Reynolds numbers in idling mode. If the exhaust gas 6 were to also flow through both the idling module 5 as well as the first module 3 and the second module 4 for exhaust-gas treatment in idling mode, the result would be a very low Reynolds number of the exhaust-gas flow in all of the modules 3 , 4 , 5 . This would lead to more of a laminar flow, which is generally undesirable in modules for exhaust-gas treatment.
If, for example, open particulate filters are included within the modules 3 , 4 , 5 , however, laminar flow through these particulate filters is undesirable. FIG. 2 diagrammatically depicts a portion of an open particulate filter of this type. An open particulate filter of this type is formed, for example, from corrugated metallic layers 10 and substantially smooth layers 11 . The substantially smooth layers 11 are formed from a material which at least in part allows a fluid to flow through it, for example a sintered porous material or a porous fiber material.
In this case, the illustrated corrugated metallic layer 10 has apertures 12 which form guide vanes 13 . The substantially smooth layers 11 and the corrugated metallic layers 10 form passages 14 through which the exhaust gas 6 can flow. The exhaust gas 6 follows flow lines indicated by arrows. The apertures 12 and the guide vanes 13 cause the exhaust gas 6 to be guided through the substantially smooth layer 11 . Particulates 15 contained in the exhaust gas 6 accumulate in the substantially smooth layer 11 .
A module 3 , 4 , 5 may include at least one honeycomb body 16 , as is diagrammatically depicted in cross section in FIG. 3 . In this case, the honeycomb body 16 is formed from corrugated metallic layers 10 and substantially smooth layers 11 . These layers 10 , 11 have been stacked to form three stacks, and these stacks have then been intertwined so as to form passages 14 . In addition to a particulate filter, it is also possible to form other types of honeycomb bodies. By way of example, it is possible to form honeycomb bodies 16 which carry a catalytically active coating and/or are formed just from metal foils. In particular, this catalytically active coating may include a washcoat having catalytically active particulates. In particular, it is also advantageous if a module 3 , 4 , 5 includes an oxidation catalytic converter, the catalytically active centers of which catalyze at least the oxidation of nitrogen monoxide to nitrogen dioxide and include a corresponding open particulate filter downstream of this oxidation catalytic converter. The nitrogen dioxide formed in this way can then advantageously be used to regenerate the particulate filter, i.e. to oxidize the particulates 15 . Both the substantially smooth layers 11 and the corrugated layers 10 may be formed from thin metal foils. It is possible to do without the formation of guide vanes 13 and apertures, in particular if the honeycomb body 16 is used not as a particulate filter but rather exclusively as a carrier for a catalytically active coating.
FIG. 4 diagrammatically depicts a second exemplary embodiment of an apparatus 1 according to the invention for exhaust-gas treatment. This apparatus 1 includes an exhaust pipe 2 , a first module 3 , a second module 4 , a third module 17 and a fourth module 22 for exhaust-gas treatment. An idling module is not provided in this case. Furthermore, a first connecting device 8 , a second connecting device 9 and a third connecting device 18 are provided and assigned to the respective modules 3 , 4 , 17 . The connecting devices 8 , 9 , 17 therefore number one fewer than the modules 3 , 4 , 17 , 22 . The connecting devices 8 , 9 , 17 are formed in such a way that exhaust gas can flow through each module 3 , 4 , 17 , 22 alone. In this way, the exhaust gas emitted by an internal combustion engine 19 can be advantageously diverted through the use of the connecting devices 8 , 9 , 18 , as a function of a loading state of the internal combustion engine 19 , in such a way that at least parts of the exhaust gas flow through one or more modules 3 , 4 , 17 , 22 for exhaust-gas treatment.
In particular, according to the second exemplary embodiment of an apparatus 1 according to the invention, it is advantageously possible in the idling state to divert the exhaust-gas stream in such a way that on average a substantially identical total exhaust-gas stream flows through all of the modules 3 , 4 , 17 , 22 . Therefore, in idling mode, substantially all of the modules 3 , 4 , 17 , 22 are acted on substantially uniformly.
FIG. 5 diagrammatically illustrates a further longitudinal section through the second exemplary embodiment of an apparatus 1 according to the invention for treating an exhaust gas from an internal combustion engine 19 . Each of the modules 3 , 4 , 17 , 22 includes a plurality of honeycomb bodies 16 . Each of the honeycomb bodies 16 may include various zones. This will be explained in more detail below on the basis of the example of the honeycomb bodies 16 of the fourth module 22 . Each of the honeycomb bodies 16 of the fourth module 22 includes an oxidation catalytic converter zone 20 and a particulate filter zone 21 . These zones 20 , 21 are disposed in such a way that the exhaust gas flows firstly through the oxidation catalytic converter zone 20 and then through the particulate filter zone 21 . Further catalytic converter zones are also shown in the further modules 3 , 4 , 17 and are provided in such a way that they are adapted to the respective loading states at which these modules 3 , 4 , 5 , 17 are connected. They may, in particular, be further oxidation catalytic converter zones 20 , zones for conversion of nitrogen oxides and standard three-way catalytic converter zones. These are only examples and other catalytic converter zones are possible and covered by the scope of the invention. As an alternative to having a plurality of zones 20 , 21 per module 3 , 4 , 17 , 22 , it is also possible for a plurality of corresponding honeycomb bodies 16 to be provided in series.
In particular, the apparatus for treating an exhaust gas can be operated in such a way that the diversion of the exhaust gas effected by the connecting devices 8 , 9 , 18 takes place as a function of the regeneration capacity of the exhaust gas 6 and a need for regeneration of a module 5 , 3 , 4 , 17 , 22 . This means that when the exhaust gas satisfies certain parameters required for the regeneration of the particulate filter zones 21 , for example exceeds a certain limit temperature, this exhaust gas is passed in a targeted way to a module 3 , 4 , 17 , 22 that is in need of regeneration. This can be effected, in particular, by the connecting devices 8 , 9 , 18 , which are provided in such a way that, in addition to a connection of the respective modules 5 , 3 , 4 , 17 , 22 , it is also possible to prevent flow through other modules. The oxidation catalytic converter zone 20 and the particulate filter zone 21 may also be provided as individual honeycomb bodies 16 through which exhaust gas can flow in succession.
FIG. 6 diagrammatically illustrates a portion of an apparatus 1 according to the invention. In this case, a connecting device 8 assigned to a first module 3 for exhaust-gas treatment is in a first position, with the result that the exhaust gas 6 from the internal combustion engine 19 does not flow through the first module 3 , but rather bypasses it.
FIG. 7 diagrammatically illustrates the same portion of an apparatus according to the invention, in which the connecting device 8 has adopted a second position. This closes the exhaust pipe 2 so that the exhaust gas 6 from the internal combustion engine 19 flows through the module 3 . Depending on whether further modules are also provided upstream of the first module 3 , either all of the exhaust gas 6 from the internal combustion engine flows through the first module 3 or only a corresponding proportion of the exhaust gas 6 does so. The proportion in this case depends on the pressure losses in the parts of the exhaust-gas system through which the exhaust gas can flow.
FIG. 8 diagrammatically illustrates the connecting device 8 in a third position. In this case, access to the first module 3 is open, so that a part of the exhaust gas 6 can flow through the module 3 . However, a further part of the exhaust gas 6 can flow onward through the exhaust pipe 2 . The distribution of the partial-streams which flow through the exhaust pipe 2 and the module 3 is dependent on the pressure loss in the respective partial regions 2 , 3 through which the exhaust gas is to flow.
Providing the connecting devices 8 , 9 , 18 in a corresponding or similar way to that shown in FIGS. 6 to 8 advantageously makes it possible to implement a procedure in which exhaust gas can flow through each module individually. This, in particular, means that it is advantageously possible, in particular in idling mode, for each module 3 , 4 , 17 , 22 to be fed, in particular, with a substantially uniform total exhaust-gas stream.
The process according to the invention and the apparatus 1 according to the invention advantageously enable even the exhaust-gas systems of large-volume internal combustion engines 19 to be configured in such a way that, even in idling mode and in principle at very low exhaust-gas mass flow rates, the exhaust gas 6 is converted and treated in the individual modules 5 , 3 , 4 , 17 , 22 . The individual modules can be adapted to different load points of the internal combustion engine 19 . | A process and an apparatus for treating exhaust gas from an internal combustion engine include at least two exhaust-gas treatment modules. An exhaust gas stream can be at least partly deflected depending on a load state of the internal combustion engine in such a way that at least parts of the exhaust gas flow through one or more modules. This makes it possible to advantageously construct and operate even an exhaust gas system of large-volume internal combustion engines, in which conversion and treatment of the exhaust gas is carried out in individual modules, even in no-load operation, basically at very low exhaust gas mass flow rates. The individual modules can be adapted to various load levels of the internal combustion engine. A rail-borne vehicle and a water-borne vehicle having the apparatus are also provided. | 5 |
FIELD OF INVENTION
The invention concerns a machine for producing e.g. nails by providing oblong shanks with an enlarged head in one end thereof, wherein said machine is of the type comprising a rotatable tool ring bounding a substantially cylindrical space and having a plurality of holding tools for in one angle position during rotation of the tool ring receiving the shanks, and in another angle position securing the shanks so that they extend substantially radially of the tool ring with each shank having its said end protruding into said cylindrical space, and said machine also comprises a rotatable roll mounted in the cylindrical space of the tool ring at the securing position of this adapted for deforming said protruding end of the shanks successively to provide enlarged heads thereon.
BACKGROUND OF INVENTION
U.S. Pat. No.5,050,260 discloses such a machine. This known machine forms excellent enlarged heads on the protruding end of the shanks when the proportion between the length of said protruding end and the diameter of the shanks does not exceed a factor of about 2.5 and when the proportion between the diameter of the formed enlarged head and the diameter of the shanks does not exceed a factor of about 2.5. Concerning e.g. nails, for some applications, however, it is necessary with heads with such a large diameter that the proportion between the diameter of the head and the diameter of the shank will exceed the factor of 2.5. In these cases the protruding end must be so long that the proportion between its length and the diameter of the shanks also will exceed the factor of 2.5. This means that the protruding end of the shanks now will be so long that the end is liable to bend when engaging the rotating roll instead of being clenched properly to the wanted head.
SUMMARY OF THE INVENTION
The object of the invention is therefore to provide a machine of, the type mentioned in the opening paragraph, which is able to provide, on shanks, heads having larger diameter in proportion to the diameter of the shank than known before.
This object is obtained in the machine of the invention comprising a bending device mounted between the receiving position and the rotatable roll in said cylindrical space for bending the protruding end of the shanks. When the protruding end engage the roll, the end will be acted on by a force from the roll in a direction forming an angle with the axis of the shank. The end will therefore be somewhat bended, but if the protruding end in proportion to the diameter of the shank is not too long, as normally is the case, the end nevertheless can be clenched to the wanted head. If, on the other hand, the length of the protruding end is too big the end will instead be bended so much that a defect head is formed. To avoid this drawback the protruding end is, according to the invention, bended at an angle turning into the same direction as the rotary direction of the tool ring before engaging the roll. The angle between the protruding end and the direction of the acting force from the roll then is decreased with said bending angle. By choosing the size of the bending angle in dependence of the length of the protruding end and of the diameter of the shank, the protruding end will no more be liable to bend too much but can readily be formed to a perfect head having a big diameter.
Choosing bending angles between 5 and 45 degrees, and preferably between 5 and 15 degrees, has been found to give expedient conditions in forming on shanks heads having very big diameters.
The bending of the protruding end of the shanks may be performed by means of a punch situated close to the roll where the shanks safely are secured and therefore do not move when acted on by the punch.
In a simple embodiment the punch can be a radially extending projection on a shaft rotating synchronously with the conveying of the shanks so that the punch always will hit the protruding end to be bended in the same position.
In a preferred embodiment the punch can be mounted on a guiding device, e.g. a link motion to impart a mainly reciprocating movement to the punch synchronously with the conveying of the shanks. This guiding device then may be adapted to move the punch between a position where the punch act on the protruding end of a shank, and another position where the punch goes clear of the shanks coming from behind the punch.
To get the shanks to protrude sufficiently long into the cylindrical space of the tool ring, i.e. longer than normal, there can be mounted a pushing device outside the outer periphery of the tool ring for pushing on the rear end of the shanks. In this way the shanks can be pushed further into said cylindrical space than normally possible for the conventional feeding devices for inserting the shanks into the tool ring.
It is well known that spreading of the material of the protruding end of a shank to form a well-defined head requires the peripheral speed of the roll to be greater than the conveying speed of the heads or of the inner periphery of the tool ring. The reason is that the roll in this way will drag some of the material into the rotating direction while the clenching power from the roll will act somewhat in the opposite direction.
The difference of velocities is normally about 20%, but this is too much when the protruding end of the shank is pre-bent as the roll then will drag too much material in the rotating direction so that the head consistently will not achieve the desired form.
When using the machine of the invention for forming on shanks enlarged heads with greater diameters than normally possible for conventional rotary machines, the circumferential velocity of the roll should advantageously be between 0% and 12% more than the conveying velocity of the enlarged head of the shanks.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be explained more fully by the following description of preferred embodiments, which are given by way of example and form no limitation in the scope of protection of the invention, with reference to the drawing, in which
FIG. 1 is a sketch of the principle for forming on a shank an enlarged head having greater diameter than usually possible when using a conventional rotary machine,
FIG. 2 is a sketch of the same principle, but when using a machine according to the invention,
FIG. 3 is a partial, vertical view in greater scale of a tool ring with the protruding end of a nail to be bended by a punch,
FIG. 4 is a top view of the same,
FIG. 5 shows the machine according to the invention in a vertical, transverse sectional view,
FIG. 6 shows the same machine in a side view along the line VI--VI in FIG. 5,
FIG. 7 is a partial side view of a first embodiment of the machine according to the invention, showing a punching device in bended position,
FIG. 8 shows the same, but with the punching device in a retracted position. FIG. 9 is a partial side view of a second embodiment of the machine according to the invention,
DETAILED DESCRIPTION
The following description concerns the providing of heads on nails. This, however, only serves as an example, and the machine can as well be used for forming heads on e.g. screws or bolts.
The basis principle for forming such heads is known from U.S. Pat. No. 5,050,260 and is characterized in that the shanks are worked by so-called internal rolling.
This process is illustrated in FIG. 1 and 2 where FIG. 1 schematically shows the process when using a conventional rotary machine, e.g. the above named known machine, and FIG. 2 schematically shows the process when using a machine according to the invention.
In FIG. 1 a roll 1 revolves in the direction of the arrow with the peripheral velocity R1 when the machine is operating. A tool ring 2 rotates simultaneously in the direction of the arrow with the peripheral velocity T1. In the tool ring 2 there is secured with equal spacing a number of shanks 3, each having a protruding end 4 extending into the cylindrical space 5 inside the tool ring. The length of the protruding end 4 is 1, and the diameter of the shank 3 is d. The diameter of the head is D (FIG. 2).
When the protruding end 4 engages the roll 1 it will bend rearwardly as shown in FIG. 1 where a conventional rotary machine is used. In such machines the peripheral velocity R1 of the roll is greater than the peripheral velocity T1 of the tool ring. The difference between the two velocities is normally about 20%.
Even though the material in the protruding end 4 is asymmetrically distributed at the beginning where the end hits the roll and is bent rearwardly, there could be formed a symmetrical head or an offset head as the frictional forces acting between the protruding end and the roll will drag some material the opposite way of the bending since the peripheral velocity of the roll is greater than the peripheral velocity of the tool ring.
Thus the conventional rotary machine is able to produce nails with symmetrical heads or offset heads when there, however, have not too big a diameter, and consequently the protruding end of the shank is not too long.
Practically D/d and l/d must both not exceed a factor of about 2.5. If this limitation is not observed the protruding end will be too long. As seen in FIG. 1, the end now will be bent, so much when engaging the roll that the frictional forces acting between the protruding end and the roll no longer will be able to drag sufficient material the opposite directions of the bending to counterbalance the highly unequal distribution of the material in this bending. As result a defect head 6 is formed.
An important parameter in this forming process is the acute angle u of entry, defined as the angle between the tangent to the roll 1 at the point where it initially hits the protruding end 4 and the tangent to the tool ring 2 at the point where the shank is secured in the tool ring.
The angle u also is the angle under which the force from the roll 1 is acting on the protruding end 4 of the shank 3 and if this angle is too big, as is the case in FIG. 1 where the proportion l/d is more than 2.5, the protruding end will be bent so much that an efficient and well-defined spreading of the material is not possible and instead the material will be spread to a defect form like the head 6.
FIG. 2 corresponds to FIG. 1 and shows a roll 1, a tool ring 2 and shanks 3 secured in the tool ring 2. The length l of the protruding end 4 is the same as in FIG. 1.
In this case, however, the protruding end is pre-bent in the rotating direction by means of a reciprocating punch 7. The angle u now is reduced with the bending angle v so the force from the roll will act on the protruding end of the shank only under the angle u minus v. With this reduction of the acting angle it is possible to produce expedient enlarged heads 8 even if D/d>2.5 and l/d>2.5. This means that with the machine, according to the invention, it now is possible to produce e.g. nails with very big, flat heads. In FIG. 2 symmetrical heads of this kind are by way of example illustrated. The big heads mainly are flat but with a little conical part formed in a mold cavity 9.
When the protruding end is pre-bent, as in FIG. 2, the material is bendt the same way as the frictional forces between the protruding end and the roll are acting. Consistently the roll now will not have to drag so much of the material in the protruding end in the rotating direction as in the conventional rotary machines.
In the machine of the invention the peripheral velocity R2 of the roll 1 still must be greater than the peripheral velocity T2 of the tool ring 2. The difference between the two velocities, as normally is about 20%, should, however, in this case now be not more than between 0% and 12%.
FIG. 3 and 4 show, partially in section, in greater scale the construction of the punch 7. The punch has just engaged the protruding end 4 of the shank 3 secured in the tool ring 2 for bending said end. The nose of the punch is formed with a groove 10. This groove serves to retain the protruding end against bending in a direction transversely to the rotating direction. For safely catching of the end the groove is diverging in the rotating direction.
FIG. 5 and 6 schematically show the machine, according to the invention, in a vertical, transverse sectional view and in a side view, respectively.
The tool ring 2 includes, as seen in FIG. 5, two mutually inclined tool rings 2A and 2B secured to respective inner rings 14A and 14B that may be ball or roller bearings. The outer rings 15A and 15B, respectively, of said bearings are secured to associated supporting plates 16A and 16B, respectively.
The inner ring 14A of the tool ring 2A has an internal toothing 11 axially clearing the sides of the roll 1 and being engaged with a toothed drive 12 driven by a motor 13. The roll 1 may be driven separately or by rolling on the inside of the tool ring 2A,B.
The plate 16A is rigidly attached to a base plate 17 so that the plates 16A and 16B may be urged against each other by means of a bolt 18 and a hinge 19. The roll is secured to a shaft 20 rotatably mounted to the plates 16A and 16B, respectively, by means of bearings 21A and 21B, respectively
The shanks 3 are secured in the tool rings 2A,B by means of splitted tools or mould jaws 22A and 22B, respectively, and inserted radially in these jaws at a schematically shown station 23 where the straightening, cutting and pointing of the raw material in form of a wire also is performed. At the station 23 the jaws 22A,B are open so that they can receive the shank. When the tool ring 2A,B turns in the direction of the arrow the two jaws 22A,B will be brought nearer to each other owing to the inclination between the tool ring 2A and the tool ring 2B. When the shank 3 in the tool ring is turned to the area at the roll 1 the jaws 22A,B will clamp the shank tightly so that the shank cannot move in the jaws during forming of the head.
The finished nails are removed at another schematically shown station 24 from where they are taken to a location for packing and storing.
In FIG. 6 also is shown a punching device 25 for pre-bending the protruding end of the shanks and a pushing device 26 for pushing on the rear end of the shanks.
These devices are seen in a larger scale in FIG. 7 and 8. The punching device 25 has form of a link motion with a first lever 27 and a second lever 28. At the front end of the first lever 27 the punch 7 is mounted. At the rear end the first lever 27 can swing about a first pivot 29 mounted eccentric on a shaft 30 as can be driven separately or from the machines' driving mechanism. The second lever 28 can swing about a second pivot 31 at the rear end and at the front end about a third pivot 32 mounted on the first lever 27 between the punch 7 and the first pivot 29.
When operating the machine, the shaft 30 rotates synchronously with the conveying of the shanks clamped in the rotating tool ring and said link motion 25 then brings the punch to reciprocate between the bending position shown in FIG. 7 and the retracted position shown in FIG. 8. During the movement from the punching position to the retracted position the punch will be lifted over the succeeding shank by means of the second lever 28 and the eccentric mounted first pivot 29 of the first lever 27.
As above named, the shanks will be inserted into the open jaws 22A,B at the station 23. The conventional inserting stations, however, are normally adapted to insert shanks with a not too long protruding end. When making nails with very big heads the pushing device 26 therefore ensures that the shanks protrude with a sufficient length into the cylindrical space inside the tool ring by pushing on the rear end of the shanks.
The pushing device 26 also consists of a link motion with a first lever 33 and a second lever 34. At the rear end the first lever 33 can swing about a first pivot 35 mounted eccentric on a driven wheel 37 mounted again on a shaft 36. Said wheel 37 is via a transmission belt 38 driven by a driving wheel 39 which itself can be driven separately or from the machines driving mechanism. A belt adjuster 40 serves to keep the belt tight.
The second lever 34 can swing about a second pivot 41 at the rear end and at the front end about a third pivot 42 mounted on the first lever 33 between the first pivot 35 and a pushing shoe 47 at the front end.
When operating the machine, the driving chain wheel 39 will bring the link motion 26 to work in such a way that the first lever 33 will swing between the pushing position shown in FIG. 7 and the retracted position shown in FIG. 8 synchronously with the conveying of the shanks clamped in the rotating tool ring. In the pushing position the shoe 47 is pushing the shanks further into the tool ring following simultaneously the movement of the end of the shank in the rotary direction of the tool ring 2A,B.
For making it possible on each shank to form a head with exactly the desired wanted form and size it is necessary to insure that each shank protrudes the same length into the cylindrical space inside the tool ring. The pushing device therefore first will push the shanks a little too far into the tool ring. Later the shanks have to pass an adjusting roll 43 situated upstreams the roll 1. The adjusting roll 43 will then press the shanks back again into the jaws 22A,B so that all shanks will have protruding ends with the same height, namely the height up to the adjusting roll 43.
FIG. 9 shows another embodiment for a punching device 44 operating in the same machine as shown in FIG. 8 and 9. This embodiment is very cheap and simple as it consists only of a rotatable shaft 45 with three radially extending projections 46 acting as punches. When the shaft 45 is rotated synchronously with the conveying of the shanks clamped in the rotating tool ring the three punches 46 alternately will bend the protruding end 4 of the shanks 3. | A machine for producing e.g. nails by providing oblong shanks (3) with an enlarged heads in one end (4) thereof comprising a rotatably tool ring (2) having a plurality, of holding tools for in one angle position during rotation of the tool ring receiving the shanks, and in another angle position securing the shanks so that they extend radially of the tool ring with each shank having its said end protruding inside the tool ring. Said machine also comprising a rotatably roll (1) mounted inside the tool ring at the securing position of this and adapted for deforming said protruding end of the shanks successively to provide enlarged heads thereon. Said machine further comprising a bending device (25) mounted between the receiving position and the rotatably roll for bending the protruding end of the shanks. Thus the machine according to the invention is able to provide on shanks enlarged heads having larger diameter in proportion to the diameter of the shank than known before. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a non-provisional application and claims the benefit of Application No. 60/399,857, filed Jul. 31, 2002, entitled “FOOD KIT FOR COMPONENTS OF CHILLED AND FROZEN DESSERTS”, (Attorney Docket No. 020903-014700US) which disclosure is incorporated herein by reference for all purposes.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK.
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention pertains to the field of food kits, and more particularly, to the field of food kits for the components of chilled and frozen desserts.
[0006] 2. Description of the Prior Art
[0007] Food kits are commonly used to hold the ingredients of meat sandwiches as well as cheese and cracker snacks. They have also been used to contain the ingredients of pizzas. Still other kits have been designed to hold the components of a breakfast cereal including the milk. Kits for dessert items such as ice cream are less common and for the most part, only provide a limited number of companion ingredients and ways to assemble and eat them. For example, one kit contains ice cream, but the only associated components are solid, particulate fragments of other food stuffs such as nuts. Further, this kit only provides for the consumption of the ice cream and particulates using a spoon, essentially just a sundae kit. The consumer in this regard is greatly limited in the variety of dessert components and the manners in which they may be assembled and eaten.
[0008] With these and other drawbacks in mind, the present invention was developed. With the present invention, a food kit is provided having a plurality of components for a ready-to-make, chilled or frozen dessert. The kit includes compartments for dessert ingredients such as, for example, ice cream, yogurt and pudding, cookies and wafers, and toppings such as fudge, syrup, and bits of candy and dough. With the kit of the present invention, a wide variety of dessert combinations may be assembled and eaten by the consumer in any number of ways beyond simply using a spoon.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention provides a food kit for the components or ingredients of a chilled or frozen dessert. The kit preferably includes a plurality of compartments for the ingredients. In the preferred embodiments, one of the compartments is filled with a first or primary dessert component such as, for example, ice cream, yogurt or pudding. The second compartment is filled with a secondary dessert component such as cookies or wafers and the third with a topping component such as fudge, syrup, or bits of candy. In use, the consumer may create a dessert with any number of combinations of the ingredients. For example, the consumer may manually dip one of the cookies into the ice cream to scoop out a desired amount and then dip the ensemble into the fudge topping. The ensemble may then be eaten as is or a second cookie easily added to make an ice cream sandwich. A spoon is also conveniently provided with the kit for the consumer to use if desired to create still other combinations of the dessert components.
[0010] Two embodiments of the ready-to-make dessert kit are provided. In the first embodiment, the compartment for the ice cream or yogurt has scalloped or curved sides that substantially match the curved shape and size of the cookie or wafer. In this manner, the cookie or wafer may be used to scoop out virtually all of the ice cream from its compartment. The cookies in the first embodiment are stacked in their compartment with the spoon positioned atop them. Side or ear portions are then provided in the cookie compartment that receive the ends of the spoon to help hold it in place. Additionally, the ear portions slope downwardly and inwardly to provide opposing spaces into which the consumer may insert his or her fingers to easily grip and remove the individual cookies. In the second embodiment of the kit, the shapes of the compartments are somewhat simplified and the cookie compartment has a slanted side to hold the cookies in a shingled manner for easy pickup by the consumer.
[0011] Other features and advantages of the present invention will be apparent in view of the following detailed description of preferred exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view of a first embodiment of the food kit of the present invention.
[0013] [0013]FIG. 2 is a top plan view of the food kit of FIG. 1 filled with the components for a chilled or frozen dessert.
[0014] [0014]FIG. 3 is view similar to FIG. 2 showing details of the compartments for the ingredients of the dessert before they are filled.
[0015] FIGS. 4 - 6 sequentially show one manner in which a cookie in the food kit of FIG. 1 may be used to scoop out a desired amount of the ice cream from its compartment.
[0016] FIGS. 7 - 10 illustrate additional details of the manner in which the cookies of the food kit of FIG. 1 may be used to scoop out virtually all of the ice cream from its compartment.
[0017] FIGS. 11 - 12 show a further manner in which the cookies of the food kit of FIG. 1 may be used to laterally swipe across the sidewalls of the ice cream compartment.
[0018] [0018]FIG. 13 is a bottom view of the food kit of FIG. 1.
[0019] FIGS. 14 - 16 illustrate the manner in which the cookie compartment is shaped to hold a stack of cookies in its central, cylinder portion. FIG. 14 further shows how the side or ear portions of the cookie compartment may be used to firmly hold the ends of a spoon positioned atop the cookie stack. FIGS. 15 - 16 additionally illustrate the downwardly and inwardly sloping surfaces of the opposing ear portions, which surfaces provide spaces for the consumer to insert his or her fingers to easily grip and remove a cookie from the stack.
[0020] [0020]FIG. 17 is a perspective view of a second embodiment of the food kit of the present invention.
[0021] [0021]FIG. 18 is a top plan view thereof.
[0022] [0022]FIG. 19 is a cross-section view taken along line 19 - 19 of FIG. 18 showing the cookies positioned in a shingled manner for easy pickup by the consumer.
[0023] [0023]FIG. 20 is view similar to FIG. 18 showing details of the compartments for the ingredients of the dessert before they are filled.
[0024] [0024]FIG. 21 is a bottom view of the food kit of FIG. 17.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As best seen in FIGS. 1 - 3 , the food kit 1 of the present invention preferably has three compartments 3 , 5 , and 7 for the ingredients or components of a chilled or frozen dessert. The compartments 3 , 5 , and 7 may hold various dessert components and in the illustrated ones of FIGS. 1 and 2, compartment 3 is shown filled with ice cream 9 , compartment 5 filled with a fudge topping 11 , and compartment 7 filled with cookies 13 and an overlying spoon 15 . Those skilled in the art will understand that other foods or toppings may be used as desired.
[0026] Compartment 3 for the ice cream 9 preferably has scalloped or similarly shaped sidewalls 17 , 17 ′, 19 , and 19 ′ that substantially match the shape of the perimeter of the cookies 13 . For the rounded cookies 13 illustrated in FIGS. 1 - 2 , the sidewalls 17 , 17 ′, 19 , and 19 ′ of the ice cream compartment 9 are substantially spherical sections. In this manner and as illustrated in FIGS. 4 - 12 , the cookies 13 may be used to easily and effectively scoop virtually all of the ice cream 9 from the ice cream compartment 3 .
[0027] More specifically as best seen in FIGS. 4 - 6 , the round cookie 13 may be manually gripped by the consumer 2 and sequentially moved to scoop out a desired amount 9 ′ of ice cream 9 . In doing so, the consumer 2 may initially align the perimeter 13 ′ of the cookie 13 with the substantially mating, upper edge 21 of the sidewall 17 (see FIGS. 4 and 7). The cookie 13 may then be run down into the ice cream 9 (see FIGS. 5 and 8) and once the desired amount 9 ′ of ice cream 9 has been scooped out as in FIG. 6, the cookie 13 and scooped ice cream 9 ′ may be dipped into the fudge topping 11 in compartment 5 (see FIG. 2). The assembled dessert could be eaten as is or a second cookie 13 placed over it to make an ice cream sandwich. In subsequent passes, a cookie 13 may be run along the substantially mating surface 23 (see FIG. 9) of the sidewall 17 all the way down to the bottom 25 of the sidewall 17 to scoop out virtually all of the remaining ice cream 9 in the compartment.
[0028] As indicated above, the consumer 2 may assemble and eat the ingredients 9 , 11 , 13 of the dessert in any desired order or combination. For example, he or she could dip the cookie 13 into the fudge or other topping 11 and then scoop out the ice cream 9 . Alternatively, the topping 11 could be first spooned over the ice cream 9 in the compartment 3 before scooping the cookie 13 . The spoon 15 could also be used at any stage to dip out the fudge topping 11 or ice cream 9 .
[0029] The general matching of the shapes of the sidewalls 17 , 17 ′, 19 , and 19 ′ of the ice cream compartment 3 to the shape of the cookie 13 discussed above results in a very easy and efficient use of the food kit 1 . In the illustrated embodiment of FIGS. 4 - 8 , the cookie 13 has a round perimeter 13 ′ (see FIG. 7) and the sidewall 17 of the compartment 3 is a matching, substantially spherical section. The radii of the cookie 13 and sidewall 17 may actually be the same but the radius of the cookie 13 is preferably slightly less as best seen in FIG. 7. Nevertheless, the cookie 13 may be positioned as in FIG. 10 slightly off to the side to contact any portion of the edge 21 and sidewall 17 to remove any ice cream 9 not scooped on the prior passes. Further, the shapes and sizes of the cookie 13 and sidewall 17 as indicated above substantially match and mate. This is preferably the case both about the top edge or rim 21 of the sidewall 17 (see FIG. 7) as well as down the sidewall surface 23 to the bottom 25 thereof (see FIG. 9). Consequently and in addition to the downward scooping action of FIGS. 4 - 9 , the consumer may also swipe the cookie 13 laterally or horizontally across the sidewall 17 (see FIGS. 11 - 12 ). As in FIG. 10, the cookie 13 in FIG. 11 may be positioned anywhere along the sidewall 17 to reach all of the ice cream 9 therein.
[0030] It is noted that the opposing sidewalls 17 and 17 ′ are preferably mirror images of one another and may be slightly different in size from the opposing sidewalls 19 and 19 ′ (see FIGS. 2 - 3 ). As illustrated, sidewalls 19 and 19 ′ are slightly larger than sidewalls 17 and 17 ′ yet the cookie 13 may still be used to scoop out virtually all of the ice cream 9 adjacent sidewalls 19 and 19 ′ in the same manner as FIGS. 7 - 12 .
[0031] One advantage of the clover pattern (i.e., pairs of opposing sidewalls 17 - 17 ′ and 19 - 19 ′ 19 ′ in FIG. 2) is that it allows the consumer to scoop the ice cream 9 in any number of directions depending upon his or her preference. That is, the consumer may scoop the cookie 13 always down the sidewalls 17 , 17 ′, 19 , and 19 ′ toward the center of the ice cream compartment 3 if desired. He or she could also make passes completely across the ice cream compartment 3 in the same direction (e.g., from right-to-left down sidewall 19 in FIG. 2 and with the same or different cookie 13 up the opposing sidewall 19 ′). The consumer could also scoop in the opposite directions if preferred or toward/away from himself or herself (e.g., 17 to 17 ′ or 17 ′ to 17 in FIG. 2). The ice cream compartment 3 in this regard is illustrated with four, curved sidewalls 17 , 17 ′, 19 , and 19 ′ but could have more or fewer. The curved sidewalls are also shown in orthogonal relationship to each other (e.g., the spherical section of sidewall 17 faces that of sidewall 17 ′ and is perpendicular to the facing directions of the spherical sections 19 and 19 ′). However, the sidewalls could be oriented in any number of ways to each other. FIG. 13 is a bottom view of the food kit 1 further illustrating the overall shapes of the compartments 3 , 5 , and 9 . It is noted that the cookies 13 have been shown for illustrative purposes as having a round, circular perimeter but they could be virtually any shape (e.g., elongated with rounded ends or rectangular). In this regard, it is preferred that the shape of the sidewalls 17 , 17 ′, 19 , and 19 ′ then substantially match at least a portion of the perimeter of the cookie (e.g., the rounded ends or sides of the rectangle) so that essentially all of the ice cream may be scooped out of the ice cream compartment.
[0032] FIGS. 14 - 16 illustrate an advantage of the shape of the cookie compartment 7 in which side or ear portions 25 are provided with downwardly sloping surfaces 25 ′ (see FIGS. 15 - 16 ). When the central, cylindrical portion 27 of the compartment 7 is filled with cookies 13 , the ear portions 25 conveniently receive and firmly hold the ends 15 ′ of the spoon 15 in place atop the stack of cookies 13 (see FIG. 14). This not only creates a neat appearance but also with the film cover 29 sealed across the kit 1 to hold the spoon 15 in place, movement of the cookies 13 is kept to a minimum helping to limit breakage and rattling of the cookies 13 . In use with the film 29 and spoon 15 removed, the downwardly and inwardly sloping surfaces 25 ′ of the ear portions 25 (see FIG. 16) provide convenient spaces to permit the consumer 2 to easily place his or her fingers on each side of a cookie 13 to grip and remove the cookie 13 . It is noted that the film 29 is initially tightly sealed not only about the perimeter of the kit 1 but also between the compartments 3 , 5 , and 7 thereof.
[0033] The kit 1 of FIGS. 1 - 16 preferably has a full return of the sides 31 (see FIG. 1) for increased stability (i.e., the kit 1 will support itself on a flat surface much like a water bowl). Further, indents or spacers 33 are preferably provided in the sides 31 so the empty kits 1 may be stacked or nested on one another and then easily separated for filling without binding or sticking to each other.
[0034] In FIGS. 17 - 22 , a second embodiment 1 ′ of the food kit is illustrated. As shown, the compartments 3 ′, 5 ′, and 7 ′ for the ice cream 9 , topping 11 , and cookies 13 /spoon 15 have shapes that may be easily formed during manufacture. The topping 11 is illustrated as being bits or chips of chocolate but could be other candies, dough, or similar pieces. The topping 11 could also be fudge, syrup, or the like as in kit 1 and the cookies 13 could be wafers, crackers, or similar items if desired. The cookie compartment 7 ′ of food kit 1 ′ as best seen in FIGS. 17 - 19 is preferable provided with a ramp or slanted side 41 (see FIG. 19) to hold the cookies 13 in a shingled manner for easy pickup by the consumer. FIGS. 20 and 21 are top and bottom views of the food kit 1 ′ further illustrating the shapes of the compartments 3 ′, 5 ′, and 9 ′.
[0035] Both embodiments 1 and 1 ′ of the dessert kit of the present invention are designed to be chilled or frozen (e.g., chilled around 32° F. or frozen to −10° F. or −20° F.) depending upon the particular components (e.g., ice cream or yogurt) of the dessert. In all cases, the present invention offers a ready-to-make dessert kit whose components may be easily and quickly assembled by the consumer in any number of manners and combinations to fit his or her wishes.
[0036] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. 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 and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A food kit for the components or ingredients of a ready-to-make, chilled or frozen dessert. The kit preferably includes a plurality of compartments for the ingredients with one of the compartments being filled with a dessert component such as ice cream, yogurt or pudding. The second compartment is filled with a component such as cookies or wafers and the third with a topping component such as fudge, syrup, or bits of candy. In use, the consumer may create a dessert with any number of combinations of the components. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional application of copending U.S. patent application Ser. No. 08/903,838 filed Jul. 31, 1997.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for drying a paper web to be surface-treated, in particular fine paper, in an after-dryer in a paper machine. The paper web is first dried in a forward dryer section of the paper machine by passing through a number of successive groups with single-wire draw that are open downwards on support of a drying wire, after which the paper web is passing through a finishing section to be finished, e.g., surface-sized or coated.
[0003] Further, the present invention relates to an after-dryer of paper machine for drying a paper web to be surface-treated, in particular fine paper. In the paper machine, there is a forward dryer section including a number of successive groups with single-wire draw that are open downwards arranged before the after-dryer, and a finishing section arranged after the forward dryer section in which there are devices for surface-sizing or coating the paper web.
BACKGROUND OF THE INVENTION
[0004] As known in the prior art, in multi-cylinder dryers of paper machines, twin-wire draw and/or single-wire draw is/are employed. When employing twin-wire draw, a group of drying cylinders comprises two wires which press the web one from above and the other one from below against heated cylinder faces of drying cylinders arranged in rows. Between the rows of drying cylinders, which are usually horizontal rows, the web has free and unsupported draws which are susceptible to fluttering and may cause web breaks, in particular when the web is still relatively moist and, therefore has a low strength. For this reason, in recent years, ever increasing use has been made of the single-wire draw in which each group of drying cylinders includes only a single drying wire on whose support the web runs through the entire group so that the drying wire presses the web on the drying cylinders against the heated cylinder faces thereof, whereas on the reversing cylinders or rolls between the drying cylinders the web remains at the side of the outside curve. Thus, in single-wire draw, the drying cylinders are arranged outside the wire loop, and the reversing cylinders or rolls are arranged inside the wire loop.
[0005] In so-called normal groups with single-wire draw, known in the prior art, the heated drying cylinders are placed in an upper row and the reversing cylinders or rolls are placed in a lower row below the upper row of drying cylinders, which rows are typically horizontal and parallel to one another. In the following, when the terms “normal (dryer) group” and “inverted (dryer) group” are used, what is meant is expressly groups with single-wire draw in multi-cylinder dryers, of the type mentioned above. In an inverted dryer group, the heated drying cylinders are placed in a lower row and the reversing cylinders or rolls are placed in an upper row above the lower row of drying cylinders.
[0006] When paper is dried by means of normal groups with single-wire draw from the side of its bottom face, the drying is asymmetric and if such asymmetric drying is extended over the entire length of the forward dryer section, the drying takes place so that first the bottom-face side of the paper web is dried and, when the drying makes progress, the drying effect is also extended to the side of the top face of the paper web. Under these circumstances, the dried paper is usually curled and becomes concave, when viewed from above.
[0007] As known in the prior art, the tendency of curling of paper (or the tendency to curl) is already affected in connection with the web formation, in particular at the sheet formation stage by means of the selection of the difference in speed between the slice jet and the wire, and by means of other running parameters. For example, in the case of copying paper, by means of unequalsidedness of drying in the after-dryer, a suitable initial curl form is regulated for the sheet in order that the curling of the paper after one-sided or double-sided copying could be optimized. In the case of copying paper, the reactivity of curling, i.e., the extent to which curling occurs per unit of change in moisture content, is affected to a greater extent by means of a multi-layer structure of the paper, which is produced in connection with the web formation in the wet end.
[0008] The most recent technology related to the present invention in high-speed paper machines, in particular in fine-paper machines, is based on dryer sections in which there is single-wire draw over the major part of the length of the machine and, with a view toward controlling the tendency of curling of paper, in practice, an inverted group has also almost always been used in order that the drying may be made sufficiently symmetric in the z-direction.
[0009] In the prior art, constructions are known for an after-dryer for paper to be coated, in particular for fine paper or equivalent, in which there is first an upper cylinder and a lower cylinder and after this, one group that employs normal single-wire draw and thereafter, a necessary number of dryer groups that make use of twin-wire draw. In these applications, it is a problem that, in view of the tendency of curling of paper, the ratio of the upper and lower cylinders is inappropriate if the curling is to be regulated efficiently.
[0010] In prior art after-dryers, in particular for fine paper, in which the drying has been regulated so that the emphasis is on the lower cylinders, problems are often also encountered in relation to the moisture of air. The hood of the after-dryer, and in particular the pocket spaces of the draw(s) therein, are often excessively dry in order to control the curling. The problems described above cannot be controlled by means of an increased moisture level in the hood alone, but the moisture levels in the upper and lower pocket spaces in the draw should also be separately adjustable.
[0011] Groups of the type mentioned above for finishing of paper to be coated, in particular of fine paper, have been described, among other things, in the current assignee's Finnish Patent Application No. 950434, filed Feb. 1, 1995.
OBJECTS AND SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to further develop the paper machine constructions disclosed in Finnish Patent Application No. 950434 so that the tendency of curling of paper can be controlled more efficiently in an after-dryer of the paper machine.
[0013] It is a further object of the present invention to provide a construction for an after-dryer suitable for use in particular in dryer sections in which it has not been possible or desirable to control the curl of the paper web in a forward dryer section alone.
[0014] It is another object of the present invention to provide an arrangement in which, in an after-dryer of a paper machine, the ratio of moisture between the upper and lower pockets can be regulated so that the moisture levels in the pocket spaces can be used for controlling the curling of the paper web.
[0015] It is still another object of the present invention to provide an arrangement in a paper machine including an after-dryer in which the curling of paper is controlled so that the after-dryer does not become substantially longer in comparison with existing after-dryers.
[0016] In view of achieving the objects stated above and others, in one exemplifying embodiment of the method in accordance with the present invention, after the surface-sizing or coating of the paper web, the paper web is dried by means of an upwardly open, inverted group with single-wire draw, in which connection the tendency of curling formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for. In an alternative exemplifying embodiment, hot, moist air is fed into connection with the dryer groups in the after-dryer at certain locations therein in order to restrain the evaporation, or hot dry air is fed to promote the evaporation from the side of the web at certain locations therein desirable with a view toward the control of curling of the web. In this manner, a tendency of curling that is formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for.
[0017] In another exemplifying embodiment of the invention, after the surface sizing or coating of the paper web, the paper web is dried by means of an upwardly open, inverted group with single-wire draw, and in addition, hot moist or dry air is fed to the desired locations into connection with the dryer groups in the after-dryer, in which connection the tendency of curling formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for.
[0018] One exemplifying embodiment of the after-dryer of a paper machine in accordance with the present invention comprises, after the surface-sizing or coating devices, an upwardly open, inverted group with single-wire draw in which the tendency of curling that is formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for. In another exemplifying embodiment, air supply devices are arranged in connection with the dryer groups in the after-dryer to feed hot moist or dry air to the desired locations, in which connection the tendency of curling that is formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for.
[0019] In an embodiment of a dryer section in accordance with the invention, after the surface-sizing or coating devices, an after-dryer is placed which first includes an upwardly open, inverted group with single-wire draw and, in connection with the dryer groups, air supply devices arranged to feed hot moist or dry air to the desired locations, in which connection the tendency of curling that is formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for.
[0020] According to the present invention, the after-dryer is started with a dryer group that applies an inverted single-wire draw, in which case, in view of the tendency of curling of paper, the desired ratio of upper cylinders to lower cylinders is obtained. After the coating device, size press or equivalent, the drying is started by means of an inverted group with single-wire draw, and this group is followed by either normal or inverted groups with single-wire draw or by dryer groups based on twin wire draw. The paper web is brought from the coating device or equivalent onto an upper or lower cylinder, and after this cylinder, the inverted dryer group follows. Before the inverted group, there can be a spreader roll or spreader rolls, a reversing dryer, an airborne, infrared or combination dryer. One of the most important advantages of this arrangement in accordance with the present invention is the formation of a ratio of upper cylinders to lower cylinders that is appropriate and correct in view of the tendency of curling of paper, without resulting in any additional length to the dryer section. Owing to this, no additional arrangements are needed to supply additional heat to provide unequalsidedness.
[0021] In accordance with the present invention, in the after-dryer of the paper machine, moist air is introduced at appropriate locations inside the hood, in which case the moisture levels in the different pocket spaces formed by the cylinders, rolls and wires in the dryer groups can be controlled. For supplying moisture, it is possible to use air supply devices, ventilators, blow pipes, etc., arranged in the after-dryer. Through these devices, hot moist air is supplied into the desired upper/lower pockets, in which connection, the control of curling takes place so that evaporation taking place from the wrong side of the paper (i.e., that side of the web from which evaporation of water from the web is not desired) is restrained by means of the supply of hot moist air. The necessary moist air is obtained, for example, from the exhaust air from the hood or from suction rolls. According to preferred additional embodiments of the invention, in the devices that supply air to the after-dryer, appropriately selected moisture levels of air are employed in order to achieve the desired distribution of moisture in the web. The air moisture levels at all of the different moisture supply points can be regulated separately, and so also the exhaust quantities of all the air exhausts can be regulated separately, if necessary. Also, the supply of hot dry air onto the side or sides of the web from which evaporation is to be promoted is included in the scope of the present invention.
[0022] Thus, it is appreciated that the supply of hot, moist air to one side of the web will affect the moisture profile at that side and by regulating this supply, the tendency of curling of the web can be controlled. Similarly, the supply of hot, dry air to one side of the web will affect the moisture profile at that side and by regulating this supply, the tendency of curling of the web can also be controlled. It is contemplated that it would be possible to supply hot, dry air to one side of the web and hot, moist air to the other side of the web control curling of the web or even supply two flows of hot, moist air having a different moisture content to a respective side of the web (or two flows of hot, dry air having different moisture content to a respective side of the web) with a view toward compensating for or eliminating the tendency of curling of the web imbued therein the forward dryer section. Thus, in general, the moisture content of the hot air is controlled relative to the web in order to achieve the desired effect on the web, i.e., restrain or promote evaporation of water from the web or moisten the web.
[0023] In one embodiment of the method for drying a paper web after the web is initially dried in a forward dryer section of the paper machine by passing through at least one dryer group with single-wire draw and then surface-sized or coated in a finishing section of the paper machine, an inverted dryer group with single-wire draw is arranged after the finishing section and the web is passed through the inverted dryer group to dry the web such that the tendency of curling of the web formed in the paper web in the forward dryer section is substantially eliminated and/or compensated for. Both sides of the web may be coated and/or moistened in the finishing device by passing through a double-sided coating device in the finishing section, and the web may then be passed through an additional dryer group after the inverted dryer group with single-wire draw in which heat is applied directly at least to a side of the web opposite that side of the web dried by direct contact with the heated drying cylinders in the inverted dryer group. In one embodiment, the web may be passed from the finishing section onto a drying cylinder arranged between the finishing section and the inverted dryer group and from this drying cylinder into the inverted dryer group.
[0024] In one embodiment of the method in accordance with the invention, the web is passed from the finishing section into and through an after-dryer including at least one dryer group of drying cylinders, and curling of the web is controlled in the after-dryer by feeding hot air having a certain moisture content relative to the web into the vicinity of the web to restrain or promote evaporation of water from one or both sides of the web such that the tendency of curling formed in the paper web in the forward dryer section is substantially eliminated and/or compensated for. The curling of the web may be controlled by feeding hot, moist air into the vicinity of the web to restrain evaporation of water from one or both sides of the web or feeding hot, dry air into the vicinity of the web to promote evaporation of water from one or both sides of the web. The hot, moist air may be fed in a regulated quantity into the at least one dryer group through blow boxes and/or blow-suction boxes arranged in the at least one dryer group in proximity to the web or by means of air supply devices spaced at a distance from the web. Also, air may be removed air from the at least one dryer group by means of moisture removing devices spaced at a distance from the web. In some embodiments, curling of the web is controlled by feeding hot, moist air into pocket spaces defined between drying wires, drying cylinders and reversing rolls in the dryer group(s).
[0025] The invention will be described in detail with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawing. However, the invention is not confined to the illustrated embodiments alone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Additional objects of the invention will be apparent from the following description of the preferred embodiment thereof taken in conjunction with the accompanying non-limiting drawings, in which:
[0027] [0027]FIG. 1 is a schematic illustration of an embodiment of a construction of the dry end of a paper machine, showing the forward dryer section and the following finishing section;
[0028] [0028]FIG. 2 is a schematic illustration of an after-dryer in accordance with the present invention;
[0029] [0029]FIGS. 3A, 3B and 3 C are illustrations in part of different variations of the after-dryer as shown in FIG. 2, which variations are included in the scope of the invention;
[0030] [0030]FIGS. 4A and 4B are further illustrations of an embodiment of an after-dryer in accordance with the present invention;
[0031] [0031]FIGS. 5A and 5B are schematic illustrations of test results related to curling of the paper web in the after-dryer; and
[0032] [0032]FIG. 6 is a schematic illustration of a further embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Referring to FIGS. 1 - 6 wherein like reference numerals refer to the same or similar elements, as shown in FIG. 1, a paper web is passed from a press section (not shown) into a forward dryer section D 1 and more particularly, onto a drying wire of the first group R 1 with single-wire draw in the forward dryer section D 1 . The web is made to adhere to the wire by the effect of a vacuum in suction boxes. In the forward dryer section D 1 , there are normal groups R 1, . . . , N generally N−4-11, preferably N=6-9, and typically N=9. All of the single-wire groups R 1 , . . . , R N are so-called normal groups, in which steam heated smooth-faced drying cylinders 110 are arranged in an upper horizontal row and reversing suction cylinders 111 are arranged in a lower horizontal row. The web has closed draws over the gaps between the adjacent dryer groups.
[0034] Each normal group R 1 , . . . , R N has a drying wire 115 of its own, which is guided by respective guide rolls 118 . The drying wires 115 press the web W to be dried on the drying cylinders 110 against the smooth heated cylinder faces thereof whereby on the reversing cylinders 111 , the web W remains on the outer face of the wire 115 at the side of the outside curve, i.e., the wire 115 is interposed between the web and the surface of the reversing cylinders. On the reversing cylinders 111 , the web W is kept reliably on support of the wire 115 against the effect of centrifugal forces by the effect of a vacuum present on grooved faces of the reversing cylinders 111 , if present, or on a perforated mantle of an equivalent suction roll, by means of which effect cross-direction shrinkage of the web W is also prevented. As the reversing suction cylinders 111 , particularly favorably suction cylinders are used which are marketed by the current assignee with the trade mark “VAC-ROLL”™ and which have no inside suction box, and with respect to the details of the constructions of these cylinders reference is made to the current assignee's Finnish Patent No. 83,680 (corresponding to U.S. Pat. Nos. 5,022,163 and 5,172,491, entirely incorporated herein by reference).
[0035] In the forward dryer D 1 , the support contact between the web and the drying wire 115 is also kept adequate on the straight runs between the drying cylinders 110 and the reversing cylinders 111 by employing blow suction boxes at least on the runs from the drying cylinders 110 to the reversing cylinders 111 . By means of such blow suction boxes, the formation of pressures induced by the wire 115 in closing wedge-shaped nip spaces defined between the wire 115 and the mantles of cylinders 111 is prevented. Blow suction boxes are understood herein to designate blow boxes whose blowing of air produces a vacuum, and these boxes do not communicate with sources of vacuum.
[0036] Further, in the forward dryer section D 1 , in the groups R 1 , . . . , R N with single-wire draw, blow boxes are also used in the gaps between the reversing cylinders 111 . By means of these blow boxes, the intermediate spaces defined between the reversing cylinders 111 are air-conditioned and evaporation from the web is promoted. The faces of the drying cylinders 110 can be kept clean by means of doctors. In the forward dryer section D 1 , broke removal by means of gravity can be applied because the groups R 1 , . . . , R N with single-wire draw are open downwards so that, in the event of a web break, the removal of paper broke can be carried out below the dryer groups R 1 , . . . , R N that are open downwards, substantially by the effect of gravity, onto a broke conveyor placed underneath. FIG. 1 shows a conveyor belt 119 of the broke conveyor and its associated drive rolls 119 a , 119 b . The paper broke is carried on the belt 119 of the broke conveyor into a pulper 119 c placed at one end of the broke conveyor.
[0037] At the rear end of the forward dryer section D 1 , there is a finishing unit D 2 , which includes, among other things, a surface-treatment or surface-coating device, an after-dryer, a calender, and a machine reel-up, for example a Pope type reel-up. The machine reel that is being produced by means of the reel-up 150 is denoted by reference MRO, and one complete machine reel is denoted by reference MR.
[0038] After the forward dryer section D 1 , the paper web W, which has been dried to a dry solids content k 2 from about 96% to about 99%, is passed over paper guide rolls 125 and over a measurement beam 126 which measures the property profiles of the paper and is placed between the paper guide rolls 125 . The web W continues into the coating device, which is, for example, a coating device marketed by the current assignee under the name Sym-Sizer™. The coating device includes two opposite coating rolls 11 and 12 , in connection with each of which there are size feed devices so that the paper web is coated from both sides in the coating nip between the rolls 11 and 12 . After the coating device, the web W is passed into the after-dryer.
[0039] As shown in FIG. 2, after the coating rolls 11 , 12 , the web W is passed over a guide roll 13 onto a first drying cylinder 14 in the after-dryer and thereafter onto a second drying cylinder 15 . On the first drying cylinder 14 , the top side of the web W is placed against the cylinder face thereof, and on the second drying cylinder 15 , the bottom face of the web is placed against the cylinder face thereof. After this, the web is passed into an inverted dryer group Rk with single-wire draw, in which drying cylinders 20 are arranged in a lower row and reversing rolls or cylinders, preferably rolls 25 that are marketed by the current assignee under the trade mark VAC-ROLL and that have no inside suction box, are arranged in an upper row. A wire 24 that supports the paper web W to be dried enters from below the group Rk, guided by guide rolls 21 , 22 , onto a first one of the drying cylinders 20 , and after this, the wire runs meandering from the drying cylinders 20 onto a reversing roll 25 in the upper row so that on the drying cylinders 20 , the web W is placed between the heated cylinder face and the wire 24 . After the last reversing roll 25 in the group Rk, the web W is passed on the wire 24 of the inverted group onto a drying cylinder 31 in the lower row in the following dryer group R22, with twin-wire draw, in which group the web W runs from the drying cylinder 31 in the lower row onto a drying cylinder 32 in the upper row. Between the rows of cylinders, the web has a free draw W′, and both the drying cylinders 32 in the upper row and the drying cylinders 31 in the lower row have drying wires 36 , 35 , respectively, of their own as well as wire guide rolls 34 , 33 , respectively, of their own.
[0040] In the exemplifying embodiment shown in FIGS. 3A, 3B and 3 C, after the coating rolls 11 , 12 , there are two guide rolls 13 , by whose means the web W is passed onto the drying cylinder 15 placed in the upper row, after which the web is passed onto the first drying cylinder 20 in the inverted group Rk, which cylinder 20 is thus in the lower row in the group. In this respect, the inverted group is similar to the draw illustrated in FIG. 2, but after the inverted group Rk, the web W is passed from the last suction roll 25 in the inverted group Rk onto a suction cylinder 37 arranged in connection with the upper wire in the group R22 with twin-wire draw. Suction cylinder 37 is arranged substantially at the same level as the lower cylinders 31 in the group R 22 with twin-wire draw. In the embodiment shown in FIG. 3C, the web is passed from the last drying cylinder 20 in the inverted group Rk directly onto the first cylinder 32 in the upper row in the group with twin-wire draw.
[0041] In the embodiment shown in FIG. 4A, the web is passed over the guide roll 13 after the coating rolls 11 , 12 in a manner similar to the exemplifying embodiment shown in FIG. 2, but in this embodiment, the after-dryer is composed of only one inverted single-wire draw dryer group Rk. After the dryer group Rk, a drying cylinder 41 is arranged in an upper row and a calender nip is formed in connection with drying cylinder 41 by means of an additional roll 44 . Below the cylinder 41 , there may be a doctor 42 for doctoring the cylinder 41 .
[0042] In the embodiment shown in FIG. 4B, in the portion PV after the inverted group in the after-dryer, a holding wire 47 is arranged in connection with the drying cylinder 41 and has guide rolls 48 of its own.
[0043] The schematic test results illustrated in FIGS. 5A and 5B are related to a test in which the effects of modes of running of the forward dryer section and after-dryer on the tendencies of curling of paper were examined. The machine that was used in the test comprised a former, a press, a forward dryer section, in which there was, in the beginning, one single-wire group followed by three twin-wire groups, a coating device, and an after-dryer, which consisted of two twin-wire groups. The paper grade was copying paper, 76 grams per sq.m. The three points of comparison in the test were:
[0044] R23 normal running mode of the machine: all cylinders in the forward dryer are open; in the after-dryer slightly more heat is supplied to the top face of the paper than to the bottom face,
[0045] R20 the supply of steam to all lower cylinders in the forward dryer in the machine is closed; the after-drying was normal, i.e., as in R23,
[0046] R21 the supply of steam to all lower cylinders in the forward dryer in the machine was closed; the supply of heat in the after-dryer had been changed so that the emphasis was significantly on the bottom face of the paper.
[0047] During the test points R23, R20 and R21, no other changes affecting the curl of the paper were made except the regulations in the dryer sections.
[0048] The results of one method of curl measurement are illustrated in FIGS. 5A and 5B. In the method, from a sample taken in the cross direction of the web, a number (in this case 16 ) of small pieces of paper sample are cut off, and the curling of these pieces is examined and measured under conditions constructed for the purpose. Based on the results, among other things, graphs that illustrate the cross-directional curl profile, as shown in FIGS. 5A and 5B, can be drawn. When the profiles of the points R20 and R23 are compared with one another, it cannot be said that there is a significant difference between them. Between these points, the difference in the running mode is present in the forward dryer section: in R20 the steam supply into the lower cylinders is closed, in R23 open. The difference in the running mode between R20 and R21 is present both in the forward drying and in the after-drying. In the former test, it was, however, noticed that the difference in the running mode in the forward dryer section is insignificant from the point of view of curling, so that the profiles in FIG. 5B indicate the considerable effect of the after-dryer on the curling.
[0049] In the after-dryer shown in FIG. 6, whose frame constructions are denoted by reference numeral 100 , there is first one dryer group R 21 with normal single-wire draw, which group is followed by a group R 22 with twin-wire draw. The group R 21 with single-wire draw comprises heated drying cylinders 230 in an upper row and reversing rolls 231 in a lower row. The wire of the group with single-wire draw is denoted by reference numeral 235 . The wire guide rolls 238 guide the run of the wire 235 . The group R 22 with twin-wire draw comprises two horizontal rows of steam-heated drying cylinders 230 A and 230 B, and the web has free draws W O on the runs between these rows. The group R 22 includes an upper wire 235 A, which runs guided by guide rolls 238 and by guide rolls 239 arranged in the gaps between the upper cylinders 230 A. Similarly, the group R 22 includes a lower wire 235 B, which runs guided by respective guide rolls 238 and respective guide rolls 239 arranged in gaps between the lower cylinders 230 B.
[0050] As shown in FIG. 6, in the vicinity of the wire guide rolls 239 , at the inlet side of the web W and the drying wire 235 A and 235 B, air blow boxes 237 are employed. Out of the blow boxes 237 arranged in the gaps between the drying cylinders 230 A, 230 B, air jets of appropriate directions and blow velocities are applied into connection with the runs of the drying wire 235 A, 235 B and with the free sectors of the wire guide rolls 239 , placed in the vicinity of these blow boxes. By means of the air jets, the support contact between the drying wires 235 A, 235 B and the web W is promoted, the formation of detrimental differences in pressure is prevented, and fluttering of the web W on the free draws W O is prevented. The blowings can also be applied through the drying wires 235 A, 235 B, by means of which ventilation of the pocket spaces P formed in the gaps between the drying cylinders 230 A, 230 B can be promoted.
[0051] On the runs from the drying cylinders 230 onto the reversing cylinders 231 in the single-wire draw group R 21 , there are blow-suction boxes 217 , by whose means formation of pressures induced by the wire 235 is also prevented in the closing wedge-shaped nip spaces between the wire 235 and the mantles of the cylinders. The blow-suction boxes 217 are understood to designate blow boxes whose air blowing creates a vacuum, and these boxes 217 do not communicate with sources of vacuum. With respect to the details of the constructions of these blow-suction boxes 217 , which are marketed by the current assignee under the trade mark “UNO RUN BLOW BOX”™, reference is made to the current assignee's Finnish Patent Nos. 59,637, 65,460, and 80,491 (corresponding to U.S. Pat. Nos. 4,441,263, 4,516,330, and 4,905,380, respectively, incorporated herein by reference in their entirety). After the introduction of the “UNO RUN BLOW BOX”™ in the market by the current assignee, others have suggested some blow-box constructions, with respect to which reference is made to U.S. Pat. No. 4,502,231 (assigned to J. M. Voith GmbH) and U.S. Pat. No. 4,661,198 (assigned to Beloit Corp.), whose applications in positions of blow boxes are also included in the overall concept of the present invention.
[0052] In the gaps between the reversing cylinders 231 , there are blow boxes 216 , by whose means these intermediate spaces are air-conditioned and evaporation from the web W is promoted.
[0053] In connection with each of the dryer groups R 21 ,R 22 in the after-dryer, an additional supply of moisture has been arranged for the purpose of controlling the curling. Moist, hot air is blown into connection with the dryer groups, in particular into the pocket spaces P. The values of moisture and temperature to be selected depend to a very great extent on the conditions; for example, the moisture limits can be from about 80 to about 400 grams of H 2 O per kilogram of dry air, and the temperature from about 60° C. to about 95° C. The moisture can be introduced in connection with the dryer group by means of the above blow boxes 237 , blow-suction boxes 217 , blow boxes 216 and/or by means of separate air supply devices 222 , and in connection with each group, it is also possible to arrange a separate air removing device (devices) 221 . If necessary, the moisture content and the temperature of each air supply device 237 , 217 , 216 , 222 can be regulated separately, and so also the evacuation efficiency of the moisture removing points 221 can be regulated separately. In FIG. 6, the arrangement of control of the moisture state of the dryer groups in this after-dryer is illustrated quite schematically, but it can be accomplished by means of principles and devices in themselves known to a person skilled in the art.
[0054] Above, some preferred embodiments of the invention have been described, and it is obvious to a person skilled in the art that numerous modifications can be made to these embodiments within the scope of the inventive idea defined in the accompanying patent claims. As such, the examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims. | A method and arrangement for drying a paper to be surface-treated, in particular fine paper, in an after-dryer in a paper machine. The paper web is first dried in a forward dryer section of the paper machine by one or more groups with single-wire draw that are open downward on support of a drying wire, the paper web is then finished in a finishing section, e.g., surface-sized or coated, and thereafter, the paper web is dried by an upwardly open inverted group with single-wire draw. In the inverted group with single-wire draw, the tendency of curling formed in the paper web in the forward dryer section can be substantially eliminated and/or compensated for. In the alternative, to eliminate or compensate for the tendency of curling formed in the paper web in the forward dryer section, hot moist air may be fed into certain locations into connection with the dryer groups in an after-dryer in order to restrain the evaporation, or hot dry air may be fed in order to promote the evaporation from the side of the web that is desirable in view of the control of curling. | 3 |
FIELD OF THE INVENTION
The present invention relates to fluorescent lamps; and more particularly, it relates to a portable fluorescent lamp for use in special applications. As used herein, "special applications" is intended as a broad term which refers to use environments other than the normal domestic, commercial or industrial use.
BACKGROUND OF THE INVENTION
Special applications include use in damp, or even wet applications, as are found in food plants, for example, where a salt spray might be used and produce a constant mist, or in chemical plants, or in manufacturing environments where volatile or inflammable solvents are used in the manufacturing process. In the damp or wet environments, the problem of corrosion exists with attendant reduction in the life of the fixture. In hazardous environments, safety requirements dictate that the possibility of an electrical discharge or spark be accounted for and either eliminated or encapsulated so that it is isolated from the environment in which the fixture is used. Alternatively, operating circuits may be designed to operate at inherently safe power levels, as discussed further below.
For brevity, reference will be made more frequently herein to hazardous environment application than wet, damp or other special applications. Persons skilled in the art will readily appreciate the facility with which the present invention is accommodated to many-different applications. One application where the present invention might have particular utility, as an example, might be a manufacturing plant for aircraft or a petroleum refinery where the use of volatile solvents and other flammable liquids or fumes are present. In most of these applications, it is desirable that the lighting be portable. From the user's standpoint, it is also desirable that the fixture be capable of being re-lamped without the use of special tools or devices because unless substitute lighting is available, when a lamp burns out, production may have to be curtailed or shut down, and safety may be compromised if supplemental light is not available.
Lighting has been designed for hazardous duty applications using incandescent lamps. However, incandescent lamps, particularly those capable of generating larger outputs of light, operate at fairly high temperatures, and therefore may create another potential hazard, particularly in an environment of volatile materials. Fluorescent lamps have also been incorporated in lighting for hazardous applications. However, fluorescent lamps typically require one hundred volts or more to initiate discharge, as well as for continual operation. Thus, precautions have to be made to reduce the possibility of arcing.
Conventional fluorescent lamps have electrodes passing through the glass envelope for connecting to the power source. In order to be able to replace the lamp, the electrodes are mounted in sockets in such a manner that they normally are exposed to the environment, again, unless special precautions are taken.
In some designs employing conventional fluorescent lamps, where leads, terminals, circuit elements or electrodes are exposed to the environment, designers have designed circuitry to operate at "intrinsically safe" power levels. This term is known in the art and refers to predetermined operating levels of voltage and current for switching circuits to insure that arcing will not occur. Although circuit designs can incorporate requirements for inherently safe circuit operation, that is not the case for fluorescent lamps and it becomes next to impossible to achieve an inherently safe control or ballast circuit for a conventional fluorescent lamp wherein the entire control and power system operates at inherently safe levels and still permit the fixture to be conveniently re-lamped. Thus, whereas operating or control circuits may operated at inherently safe levels, the power portions of circuitry for conventional fluorescent lighting cannot, and some other provisions (such as air purging) must be made for operation of conventional fluorescent lamps in hazardous environments.
One attempt to overcome the problems associated with operating conventional fluorescent lamps in a hazardous environment is described in the co-pending application of Baggio and Granat entitled AIR PURGED PORTABLE ELECTRIC LAMP, Ser. No. 431,308, filed Apr. 28, 1995. In that application, the fluorescent lamps and the power source are housed in an enclosure which is purged with breathable air before power is applied to the fluorescent lamp. Although these devices have been useful and represent an advance in the art, they require a separate source of breathable air, conduit or tubing routing the air from the source to the location of use, and circuitry for controlling the purging cycle and sensing when the breathable air is not flowing through the enclosure to purge the interior of the enclosure. Moreover, because the lamps are housed in a sealed environment except for the entrance and discharge of the breathable air, it normally requires that the fixtures be taken out of use and lamps replaced at a remote location where tools and the like are required.
Electrodeless lamp technology has been developed in which electrodes do not pass through the glass envelope of a fluorescent lamp. However, electrodeless lamp technology to date has been directed primarily to domestic or commercial applications in which the RF source, coupling mechanism and lamp are all integrated into a screw-type base so that it might replace the conventional incandescent lamp, such as is shown, for example, in U.S. Pat. Nos. 4,171,378 and 5,220,236. Other examples of the application of electrodeless lamp technology have characteristics similar to these two applications which prevent their use in hazardous or wet locations, for example, because the attempt has been to integrate the power source integrally with the lamp, leaving some portion of the input power supply lines, power supply or coupler in contact with, or not sealed from the environment in which the fixture is intended to operate.
SUMMARY OF THE INVENTION
The present invention is directed to a modification of the electrodeless lamp technology which enables it to be useful in special applications such as the ones mentioned above. According to the present invention, a fluorescent lamp includes an electrodeless envelope of glass or other light-transmissive material carrying fluorescent material within the envelope. An RF energy source and coupler are embedded in epoxy as an integral power unit, isolated from the environment. The power supply line coupling a conventional energy source to the RF energy source has the connection to the RF energy source also embedded in epoxy.
The power unit and the envelope are shaped in complementary form such that the coupler and envelope are in energy-transfer relation to excite the lamp during use, but they are separated by the sealant. Thus, the envelope, though it may be mechanically mounted to the epoxy-covered power unit, may also be removed from the power unit to re-lamp the fixture.
One advantage of the present invention, then, is that all of the fixture which has any electrical voltage or current is completely embedded in epoxy. Epoxy is recognized as a substance which creates a seal or encapsulation which permits electrical circuitry to operate safely (i.e. without fear of spark) even in hazardous environments. Not only is the possibility of a spark eliminated, but corrosion normally associated with salt environments and other environments having corrosive chemicals or volatile materials, is eliminated.
Another advantage of the present invention is that re-lamping can be made simple and direct without the use of special locations, and the fixture can be re-lamped right in the hazardous environment so that any interruption in the manufacturing process is kept to a minimum.
Another advantage of the present invention is that it is much more flexible and adaptable to different use applications since it does not have the bulk of conventional fluorescent tubes with their awkward length.
Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment accompanied by the attached drawing wherein identical reference numerals will refer to like parts in the various views.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic view of a first electrodeless lamp including a electromagnetic coupler according to the present invention;
FIG. 2 is a diagrammatic view of a second embodiment of an electrodeless lamp incorporating a magnetic coupler constructed according to the present invention;
FIG. 3 is a diagrammatic view of a third embodiment of an electrodeless lamp incorporating a capacitive coupler constructed according to the present invention;
FIG. 4 is a cross section taken through the sight line B--B of FIG. 3; and
FIG. 5 is a side view of a portable hand lamp constructed according to the present invention and incorporating an electromagnetic radiation shield.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, reference numeral 10 generally designates a diagrammatic outline of a light-transmissive envelope of a globular fluorescent lamp of the type commonly referred to as electrodeless. The envelope 10, which preferably may be of glass or other light-transmissive material, is filled with an ionizable gas (for example, a mixture of a rare gas such as krypton and/or argon and mercury vapor and/or cadmium vapor). The interior surface of the envelope 10 are coated in a well-known fashion with a suitable phosphor which, when stimulated or excited by an electromagnetic field, emits visible radiation upon absorption of ultraviolet radiation, in a manner similar to that in which conventional fluorescent lamps operate.
In the illustrated embodiment, the envelope 10 has a portion formed into a cavity 12 for receiving a portion of an RF power unit generally designated 11. Power unit 11 includes an RF power source and a coupler. In the embodiment of FIG. 1, an electromagnetic coupling element is generally designated 13. The electromagnetic coupler 13 includes a core 14 in the form of a ring, and which may be formed in a toroidal shape having a generally round and uniform cross section. A winding 15 is wound around the core 14 and energized by a conventional source of RF current generally designated 17. The structure thus far described is disclosed in U.S. Pat. No. 4,117,378, which disclosure is incorporated herein by reference. In that patent, however, the glass envelope and RF power source are integrally mounted into a base which is provided with a conventional screw-type mounting for conventional sockets.
In the illustrated embodiment, on the other hand, a flexible power cord 20, which may be coupled to a conventional plug adapted to be received in a wall socket, for example (not shown for brevity) couples power to the RF source 17. The RF source and terminal end of the power cord 20 (i.e., the entire power unit), as well as the leads from the RF power source 17 to the winding 15 and the electromagnetic coupler itself, are all encased in epoxy. The envelope of the epoxy covering is diagrammatically illustrated by the solid line 22; and it encompasses, covers and seals all of the elements carrying an electrical voltage or circuit which could in any way be directly exposed to the environment in which the fixture shown in FIG. 1 may be used. Moreover, that portion of the epoxy covering 22 which covers the coupler 13 is molded to be received in and engage the surface of the cavity 12 of the envelope 10 so that the electromagnetic coupler 13 is properly positioned inside the lamp envelope 10 for use in accordance with the teachings of the prior art. That is, the coupler 13 generates a radio frequency magnetic field within the core 14 when excited by the RF power source 17. The resulting magnetic field induces a solenoidal electric field in the ionizable gas contained within the envelope 10. The RF magnetic field ionizes the gas within the envelope and stimulates the emission of ultraviolet radiation from the gas, and the ultraviolet radiation impinges on the phosphor deposited within the lamp 10 for generating visible light.
In the embodiment illustrated in FIG. 1, the envelope 10 seats firmly and snugly on the portion of the power unit 11 which encompasses the magnetic coupler, so that if the lamp 10 becomes non-functional, it may be replaced. However, additional structure can be provided so that the envelope 10 and the coupler 13 may be more securely, but removably coupled together. The provision of the epoxy covering 22 and the flexible power cord 20 to the RF power source 17 permit the fixture shown in FIG. 1 to be portable, and yet to be adaptable for either a hazardous location, a damp location, or even a wet location. In fact, it may be submersed in water without deleterious effect on the RF power source or the magnetic coupler 13, though the unit shown is not intended for continuous underwater use.
Turning now to the embodiment of FIG. 2, the glass envelope is again designated by reference numeral 10 and the power unit 11. The envelope is provided with a cavity 12A for receiving electromagnetic coupler 13A comprising coil formed from a winding 15A which surrounds a torroid (not shown) and excited by an RF power source 17a.
In the embodiment of FIG. 2, the winding 15A forms a coil 25 having spiral turns and defines a generally vertical axis parallel to the axis of the elongated socket 12a. Again, RF current flows through the winding 15A and establishes a radio frequency magnetic field about the coil 25 (in the form of a toroid having a mid-plane lying horizontally and perpendicular to the plane of the page of FIG. 2). The RF electromagnetic field induces an electric field within the envelope 10. The field ionizes and excites the gas within the envelope resulting in a discharge which generates ultraviolet radiation which is absorbed by and excites the phosphor coating on the interior surface of the envelope, thereby stimulating the emission of a visible radiation by the lamp envelope.
As in the embodiment of FIG. 1, the flexible power cord 20 coupling conventional alternating voltage to the RF power source 17A, the RF power source 17A itself, the lead 15A and the winding 25 are all encapsulated by and embedded within epoxy material 22A.
Turning now to the embodiment of FIG. 3, a fluorescent lamp is generally designated 28, and it is in the form of a cylindrical tube which is bent at its mid-section to form an inverted U. This configuration is conventional and is sometimes referred to as a "twin tube" or a biaxial lamp. The inclusion of phosphors deposited on the interior of the glass envelope and the ionizable gases is the same as other fluorescent lamps. However, there is no starter or filament. Rather, the coupler in this case, which is generally designated as numeral 30 is a capacitive coupler.
The capacitive coupler 30 includes an RF power source 31, and first and second ring electrodes 32, 33 which surround respectively the adjacent free ends 28A, 28B of the biaxial tube 28. On the interior of the adjacent free ends, at or near the distal ends thereof, there are deposited on the interior surface of the glass tube, interior ring electrodes 34, 35 respectively. Thus, the exterior ring electrode 32 and the associated interior ring electrode 34 form one capacitative coupling to one end of the biaxial tube 28, and the exterior ring electrode 33 and its associated interior ring electrode 35 form a second capacitive coupling. Both of the exterior ring electrodes 32, 33 are energized by the RF power source 31. A field is created inside the tube 28, between interior electrodes 34, 35 which ionizes the gas inside the tube. Other configurations of capacitive-coupled electrodeless lamps as well as combinations employing both capacitative and inductive couplers are described in U.S. Pat. No. 5,300,860, the disclosure of which is incorporated herein by reference.
The exterior ring electrodes 32, 33 as well as the RF power source 31 and its associated power leads 35, which may be flexible, as described above, are embedded in an epoxy material, the envelope of which is diagrammatically illustrated at 36 similar to the one described above.
Turning now to FIG. 4, there is shown a cross section of one of the free ends of the tube 28. The glass envelope is designated 28D for one of the tube sections for the biaxial tube 28; the interior ring electrode is designated 34, and the exterior ring electrode is shown at 32 in FIG. 4, the epoxy covering again being shown at 38. It will be observed that the epoxy is formed into two cup-shaped receptacles or sockets for the free ends 28A, 28B of the biaxial fluorescent tube 28 so that it may be assembled to the combination of power lead, RF power source and exciting capacitor coupling, but be removed in the event that re-lamping is necessary.
Turning now to FIG. 5, there is shown a structure for housing a portable handlamp employing the construction of the present invention shown in FIG. 3. The flexible power cord is again designated 35, and it is coupled into a metal base 38 which is sized to be conveniently held in one hand. Housed within the base 38 would be the epoxy-encompassed RF power source 31 and the exterior ring electrodes 32, 33. The biaxial tube 28 is received in the sockets formed by the epoxy compound, and an exterior protective screen or gridwork, of metal, surrounds the tube 28, and is designated 42. The upper portion of the protective grid 42 is covered with a coventional metal cap 43 which may be provided with a convenience hanger 44. The grid 42 is formed from interconnected axial elements 46 and circumferential elements 47 to form an EMI suppression grid. The spacing of the elements of the grid 42 is related to the wavelength of the operating frequency (or harmonics) of RF source to suppress electromagnetic interference as desired according to principles well known to those skilled in the art. In this case, the metal grid forms not only a protective function for the lamp 28, but it also provides an electromagnetic interference shield.
In addition to those embodiments which have been illustrated, there are other configurations of glass envelopes as well as other excitation devices or couplers to which the invention is readily adaptable. For example, it is known that the glass envelope 10 for an electrodeless lamp may be in the form of a toroid, and the coupler may be in the form of a coil surrounding a portion of the toroid in a circumferential manner.
In order to re-lamp this type of fixture, the coupler is made into a split coil so that it may be removed from the lamp. In this case, the coupler may be designed so that each portion of the winding is fixed on a ferrite material of semi-toroidal shape, and conforming to the shape of the glass envelope when the two halves of the coupler are assembled. The RF power source for exciting the coupler may be conventional. This type of structure is sometimes referred to as a "tokomac" design, and a person skilled in the art will readily appreciate that the present invention may be modified and accommodated to it.
Still another modification is to extend the application to high-intensity discharge (HID) lamps. Electrodeless HID lamps are now commercially available.
Having thus disclosed in detail preferred embodiments of the invention, persons skilled in the art will be able to modify certain of the structures which has been illustrated and to substitute equivalent elements for those disclosed while continuing to practice the principle of the invention; and it is, therefore, intended that all such modifications and substitutions be covered as they are embraced within the spirit and scope of the appended claims. | A fluorescent lamp for use in special applications includes an electrodeless envelope of glass or other light transmissive material carrying fluorescent material within the envelope. An RF energy source and coupler are embedded in epoxy as an integral power unit, thereby isolating the power unit from the hazardous environment. The power unit and the envelope are shaped in complementary form such that the coupler and envelope are in energy-transfer relation to excite the lamp, but the envelope may be removed from the power unit to re-lamp the fixture. | 5 |
FIELD OF THE INVENTION
This present invention relates generally to post caps, and more particularly to lighted post caps for residential use.
BACKGROUND OF THE INVENTION
For many landscaping and architectural purposes, lighted fixtures and structures are placed to help illuminate paths and to add aesthetic appeal. In particular, lights may generally include lanterns placed on posts, small candles, or small low voltage lighted stakes. Other accompaniments may be added to these lighted structures to increase their aesthetic appeal or the usefulness of the light structure.
Often, however, low voltage lighting systems are placed on stakes which are low to the ground and provide a low spread of illumination for a pathway or to light particular landscaping features. Taller or larger lamps are also known which are conventionally mounted in one location and provide a great amount of light that radiates generally spherically from the light source to cover a large area in the case of a flood light or a narrow directed beam in the case of a spotlight. Furthermore, such items as lawn torches provide a more temporary light source and also include an open flame or a hot light source.
Commonly known light sources especially for residential structures are particularly related to lighting an area or another structure. In addition, commonly known light sources require a separate, free standing mounting pole or post upon which to place the light source. Furthermore, the mounting pole or post is usually in addition to any other structures which may be placed around a residence or other landscape and may further obstruct the landscape for which the light source is needed. Additionally, the light source is visible at all times whether energized or not.
SUMMARY OF THE INVENTION
The present invention relates to the structure and construction of a post cap which includes an open area inside the post cap structure. The inner open area of the post cap structure is adapted to receive a light source which emits a curtain of light onto the post cap through openings created in the post cap. The post cap is provided with a removable shutter for selectively adapting the post cap for unlit or lit applications.
One advantage of the present invention is the ability to selectively use the post cap in an illuminated or unilluminated capacity.
A further advantage of the present invention is its adaptability to being placed on numerous types of posts. Therefore, this advantage removes the necessity of placing an additional post in a particular landscape or area for the inclusion of an illuminating source.
A further advantage includes the ability of the present invention to receive conventional low-voltage light sources, thus negating the need to rewire current light sources which may already be in a landscape.
Another advantage includes the fact that the selectability between a simple post cap cover and an illuminating source is selectable by the final consumer of the post cap.
Yet, a further advantage is that when the post cap of the present invention is not illuminated, the light source is not visible. However, upon illuminating the light source, the light curtain effect is created. Additionally, the light source is never visible, only the light emitted is visible.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is an isometric view of the post cap according to the present invention;
FIG. 2 is a top view of a post cap without a cover according to the present invention;
FIG. 3 is a cross section of a post cap with a cover taken along Line A—A in FIG. 2 according to the present invention;
FIG. 4 is a cross section of a post cap with a lid taken along Line B—B in FIG. 2 according to the present invention;
FIG. 5 is a cross section of a post cap with a lid taken along Line C—C of FIG. 2 installed on a post according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With references to FIGS. 1-4, the post cap of the present invention is illustrated. In particular, a post cap, shown generally at 2 , includes walls 4 having an interior 6 and an exterior 8 . The walls 4 extend generally vertically from a bottom portion 10 to a top portion 12 . With particular reference to FIGS. 3 and 4, it will be understood that the walls 4 are not necessarily planar. In particular, the walls 4 of the present invention may include ornamental or decorative features such as moldings which are understood to be independent of the utilitarian aspects of the present invention. As presently preferred, the four walls as illustrated in particular in FIG. 2 are formed in two halves. With particular references to FIGS. 3 and 4, a first section of walls may include a female or receiving member 14 while a second section of walls may include a male locking member 16 . In this way, sections of the post cap 2 may be affixed to one another post production. Furthermore, a singular die may produce two mirror images that may be locked together. However, one skilled in the art will recognize that the post cap 2 may be formed as a unitary piece or in a number of pieces greater than two.
The walls 4 terminate at the top portion 12 in an eave or horizontal flange 20 . The flange 20 extends generally perpendicular to the walls 4 over the exterior of the wall 8 . On the outside perimeter of the flange 20 is formed therewith a secondary wall 22 . The secondary wall 22 extends generally parallel to the walls 4 of the post cap 2 . A cap 24 is formed to be selectively placed over the top portion 18 of post cap 2 . The outer perimeter of the cap 24 includes edges 26 generally parallel to the secondary wall 22 . The edges 26 of the cap 24 are only minimally greater in dimension than the secondary wall 22 , therefore there is a snug or a snap fit over the secondary walls 22 . Although not shown, it is understood, that the secondary wall 22 and the edge 26 of the cap 24 may also include other releasable catch or locking mechanisms to further secure the cap 24 to the secondary walls 22 .
The flange 20 includes a shutter or removable portions 30 which may be selectively removed from the flange 20 . With particular reference to FIG. 2, weakened regions 32 at either end of the removable portion 30 allow the removable portion 30 to be broken away from the flange 20 . In this way, an aperture 34 is formed in the flange 20 . The aperture may have any appropriate aspect ratio, but generally has an aspect ratio equal to or greater than 0.5:1. Thus, even when the cap 24 is placed over the post cap 2 , the aperture 34 creates an open area between the interior and exterior of the post cap 2 . Furthermore, a lens 40 may be placed upon the flange 20 of the post cap 2 . This lens 40 acts as a barrier between the outside and the inside of the post cap 2 . As presently preferred, the lens 40 is made of a translucent material to allow light from the inside of the post cap 2 to emanate towards the outside of the post cap 2 .
Extending inwardly from the inside 6 of the walls 4 are locating members or ribs 50 . Such locating members 50 are to position me post cap 2 on top of a post (shown at 80 in FIG. 4 ). The locating members 50 act as stops to locate the post cap 2 onto the post at a designated position. In addition, the locating members 50 also provide a base upon which a mounting member 60 , described herein, may rest when inserted into the post cap 2 . Each of the ribs 50 include a top surface 52 and a bottom surface 54 . The top surface 52 provides a base to receive a platform or mounting member 60 for mounting a light source 70 . The bottom surfaces 54 provide an area upon which the post cap 2 may rest when placed on a post (shown at 80 in FIG. 4 ). Furthermore, the top side 52 defines the bottom of the top volume 62 of a post cap 2 while the bottom surface 54 defines the upper limit of a bottom volume 64 of the post cap 2 .
With particular reference to FIGS. 3 and 4, the top side 52 of the rib 50 receives a mounting member 60 which receives a light source 70 . The mounting member 60 may be variably designed to include mounting areas for several different types of lights. In the preferred embodiment of the present invention, the mounting member 60 includes a bayonet mount for commonly available bayonet light sources. In particular, low voltage lights 72 which are mounted on common landscaping bayonet mounts 74 may be placed through the mounting members 60 and affixed thereto allowing wires 76 to be routed through the bottom 10 of the post cap 2 . In this way, the light 74 is able to illuminate the top volume 62 of the post cap 2 . When the cap 24 is placed on the post cap 2 and the light source 70 is illuminating the top volume 62 of the post cap 2 and further when a removable section 30 has been removed from the flange 20 , light is allowed to emanate through the aperture 34 . If the lens 40 is placed upon the flange 20 , the lens 40 acts as a diffuser for the light source 70 from the interior of the post cap 2 . In this way, the light source from the interior of the post cap 2 illuminates the exterior 8 of the walls 4 of the post cap 2 . In particular, since the cap 24 of the post cap 2 includes vertically extending walls 26 and is reflective on its interior surface, the light from the light source 72 is reflected downwards over the exterior edge 8 of the walls 4 . This is preferably referred to as a “light curtain” being formed on the exterior 8 of the walls 4 .
With continuing reference to FIGS. 1-5, and a particular reference to FIG. 5, the mounting position of the post cap 2 is illustrated. In particular, the post cap 2 is adapted to be mounted to a post 80 . The post 80 is received through the bottom portion 10 of the post cap 2 and abuts against the bottom side 54 of the ribs 50 . Therefore, the bottom side 54 of the ribs 50 stop the advancement of the post 80 into the post cap 2 . Furthermore, the top volume 62 of the post cap 2 is then left open for the insertion of a light source 70 . A first preferred embodiment of the present invention will include a flange 90 extending generally parallel to the outside of the post 80 . This preferred embodiment is for particular use when the post 80 is formed of PVC or other polymeric material. The flange 90 receives an adhesive material for adhering the post cap 2 to the post 80 . A second preferred embodiment includes a bore 92 through the bottom 10 of the post cap 2 . The bore 92 would be placed on the post cap 2 when the post 80 is formed of a wood material. The bore 92 would receive a nail or other fastening means to affix the post cap 2 to the post 80 .
Once the post cap 2 is affixed to the top of a post 80 , a light source 70 may be inserted into the post cap 2 and mounted on the mounting member 60 . However, it is to be understood that this is a selection which may be made by a final consumer. In particular, a consumer may purchase or receive the post cap 2 with the intent that initially a light source 70 will not be used. However, the post cap 2 may then later be adapted to be used with a light source 70 . The cap 24 is selectively removable as are the removable portions 30 . In this way, the consumer is given a greater variety of choices as to whether have a lighted post cap or simply a decorative post cap to place on top of a post 80 .
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the invention are intended to be within the scope of the invention. For example, it is to be understood that the post cap 2 may have its dimensions varied greatly to receive different size posts while including all the features herein described. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A post cap assembly having a body including a generally vertical side defining an interior volume. A one locating member projecting into the interior volume and having a stop formed thereon for positioning the post cap on a support. Furthermore, the post cap having an upper portion to selectively receive a light source. The light source reflected down over and substantially illuminating only the sides of the post cap through apertures selectively formed in eaves on the tops of the sides. | 4 |
RELATED APPLICATIONS
[0001] The application is a continuation application of U.S. application Ser. No. 14/191,772, filed Feb. 27, 2014, which is a continuation of U.S. application Ser. No. 12/886,769, filed Sep. 21, 2010, and issued as U.S. Pat. No. 8,707,381, on Apr. 22, 2014, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/244,823, filed Sep. 22, 2009, which are herein incorporated by reference in their entirety.
[0002] This application also cross references U.S. nonprovisional application Ser. No. 12/429,808, entitled “METATAGGING OF CAPTIONS” and filed on Apr. 24, 2009, which is herein incorporated by reference in its entirety.
TECHNICAL FIELD
[0003] The technology described herein relates to a synchronization process between closed-captioning data and/or associated metadata and the video and/or audio with which the closed captioning and/or metadata is associated.
BACKGROUND
[0004] Closed-captioning of television and other media programs is often provided in order for people with hearing impairments to understand the dialogue in a program. Often live broadcasts, for example, news programs, award shows, and sporting events, are captioned in real time by transcriptionists watching a feed of the program and/or listening to an audio feed for the program (such as via a telephone or voice over Internet protocol connection) which may be a period of time (such as 4-6 seconds) ahead of the actual live broadcast time. Naturally, there is a delay in the presentation of the closed caption information to a hearing-impaired viewer because of the time it takes the transcriber to type the words spoken after hearing them and because the feed utilized by the transcriptions is typically a short period of time ahead of the actual live broadcast. Presently, when such programs are streamed real time or recorded, the closed captions remain in the vertical blanking interval of the original frames in an analog signal or in the same location within the bit stream or data packet of a digital signal. Thus, upon receipt of the streamed live program and/or replay of a recording of the original live program, the closed captioning is still delayed and is not simultaneous with the actual spoken words or sounds in the program.
[0005] Fundamentally, the Internet is about text. Internet search engines (e.g., Google®) parse the text of the pages in websites and index it. When an Internet search is performed, it is this index of the text that is analyzed. Local searches on desktop computers (e.g., “Find” commands, Apple® “Spotlight” software, or Microsoft Windows “Search”) are similarly basically text searches for words or phrases in a document, file names, and metadata about a file (e.g., author, file creation date, etc.). Digitally recorded video and audio have traditionally been fairly opaque with regard to search engines, either local or Internet-based. For example, the Google® search engine cannot process recorded video in any meaningful way—only the text that surrounds the video is indexed. This indexing is thus typically limited to the title of the video, a few keywords (assuming the site uses “tagging” of some sort), and possibly the date that the recording was made. There is currently no way to conduct a deeper search of the video to identify particular content, for example, occurrences of names, places, music, events, or occurrences.
[0006] The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the disclosure is to be bound.
SUMMARY
[0007] A synchronization process between closed-captioning data and/or corresponding metatags and the video or audio with which the closed captioning is associated parses the video and audio files, correlates the caption information and/or metatags with segments of the audio files, and provides a capability for textual search and selection of particular scenes or segments. A time-synchronized version of the closed captions delivered during the presentation of an event, for example, a television program, a lecture delivered in a classroom, or any number of other types of events, is created such that upon re-streaming of the event presentation and/or replay of a recording of the event presentation, the captions are automatically synchronized to the moment that the speech is uttered in the recorded media. Search functions may be conducted on locally stored media files or via the Internet to search a vast library of video and audio files that may be available for access and presentation.
[0008] The caption data, i.e., effectively the complete text of what is spoken throughout the media, is leveraged to enable search engines like Google® to index not merely the title of a video, but the entirety of what was said during the video as well as any associated metatags relating to contents of the video. Further, because the entire media file is indexed, a search can request a particular scene or occurrence within the event recorded by the media file, and the exact moment within the media relevant to the search can be accessed and played for the requester. The technology disclosed herein automates the correlation of the caption segments to audio segments in a media file of the event, thereby providing an association between time stamps in the media file and searchable text. The connection between the captions and video allows a consumer to jump directly to a pertinent or desired section of video.
[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. A more extensive presentation of features, details, utilities, and advantages of the present disclosure is provided in the following written description of various embodiments of the disclosure, illustrated in the accompanying drawings, and defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic diagram of a network system for synchronizing closed captioning in a broadcast event to provide a searchable media file.
[0011] FIG. 2 is a combined schematic and process flow diagram of primary process modules, including inputs and outputs, for synchronizing closed captioning in a recorded event to provide a searchable media file.
[0012] FIG. 3 is a schematic diagram comparing audio segments in a media file to caption segments corresponding to the media file.
[0013] FIG. 4 is a flow diagram of an example process for synchronizing caption segments with audio segments in a broadcast event to provide a searchable media file
[0014] FIG. 5 is a schematic diagram of an example computer system that may be configured as one or more of the computer systems for performing the closed captioning synchronization and media search processes.
DETAILED DESCRIPTION
[0015] In order to provide searchable media files to an end user, three basic steps or functions may be performed. First, an event is captured and transformed into a media file. Second, the event, and primarily the audio portion of the event, is captioned and further annotated with metadata. Third, the captioned audio and any metadata are synchronized with the corresponding content in the media file. In some implementations, the media files and the associated captioning and metadata creation occurs in real-time (i.e., as an event takes place or with a minimal delay, e.g., less than a minute) providing substantially immediate search capability for media files.
[0016] FIG. 1 is an example implementation of an audio/video search system 100 that processes and formats audio, video, or combined audio-video (individually and collectively “media files”) to be searchable by a user in order to pinpoint and play content occurring at a particular time within the media file. The media file may be a real-time or pre-recorded audio signal or file, video signal or file, or combined audio/video signal or file containing data corresponding to an event. An “event” is defined herein as any live or prerecorded programming including television shows, newscasts, movies, live performances, lectures, symposiums, teleconferences, courtroom proceedings, sporting events, or any other live or recorded proceeding, display, or activity that may be captioned or transcribed. Preferably the event is in the form of a media file that includes an audio component capable of transcription. However, an event could be a video only file that is annotated with metadata.
[0017] In FIG. 1 a media source 102 performs the event capture function. It should be noted that in the example implementation of FIG. 1 , a television station is depicted as the media source 102 . However, many other systems may function as an appropriate media source. Among these may be, for example, a radio station; output from public address equipment at a live concert, a speech, a lecture, a symposium, or other similar event; a teleconference system; a playback device (e.g., a CD player, DVD player, VCR, cassette player, turntable, etc.) for presenting a prerecorded film or television show or music or other audio recording stored on physical media; or any other event or programming that can be recorded or otherwise function as a media source 102 .
[0018] In the example of FIG. 1 , the TV station media source 102 generates content through its television camera 104 that records audio and video signals from live programming, for example, a newscast. Other live programming may originate at an event location outside of the television station, for example, at a sporting event, but the live audio/video signal is transmitted back to the TV station for processing before broadcast.
[0019] One type of processing of live programming is the closed captioning of audio/video programs for the hearing impaired. When a live event or other programming is selected for closed captioning, the audio portion of the recording may be sent to a media service client 106 to begin the captioning process. The media service client 106 may be a computer that, in part, processes and transmits the audio portion of the audio/video signal or other media file to a voice transcriptionist or captioner system 114 for preparation of captions of the media program.
[0020] The term “captioner” is used herein to refer to either a person or an entity and the hardware and software system used by the person or entity to create captions. The captioner 114 may receive an audio file in real-time as the event is taking place or may receive an audio file of a prerecorded event for captioning. Although possible, in practice the captioner 114 generally does not receive the video information associated with the media file. The captioner 114 may transcribe the audio file 110 and generate other caption content and/or data using a stenotype or other transcription device (e.g., a voice writer using a stenomask). The transcription device any be part of a larger computer controlled transcription system, e.g., the Bison Interactive Captioning Console (“BICC”) or other suitable captioning system. For live events, the captioner 114 may transcribe the audio portion of the event as it occurs substantially in real time. Additionally, non real-time resources such as recorded video, audio, lectures, court proceedings, audio books, and other media may be captioned for replay including caption presentation at any future time.
[0021] “Caption information” or “captions” may include transcription text as well as other verbal or nonverbal content or data that additionally describes the event, for example, identification of speakers; indication of laughing and/or music; formatting information so that the text may be displayed on video screens (which is generally not shown on a viewer display); chevrons, carets, or other indicators of pauses, changes between speakers, or other transitions.
[0022] The captioner system 114 may be located at the media source 102 , e.g., at the TV or radio station or at a particular event (e.g., at a lecture), or the captioner 114 may be located remotely from the media source 102 and receive the audio file from the media source 102 over a network (e.g., the Internet, a local-area network, a wide-area network, a wired network, a wireless network including infrared, radio frequency, and Bluetooth networks), via real-time audio transmission (e.g., voice over Internet protocol (VoIP)). In an alternative implementation, the captioner 114 may receive the audio portion of the programming via a standard telephony system. Regardless of the method of receiving the audio portion of the event, the captioner 114 prepares a written transcript of the audio portion of the event. The captioner 114 may use a stenotype or other standard transcription device to transcribe any spoken dialog within an event.
[0023] The captioner 120 may use pre-defined keystrokes or voice commands that correspond to words, phrases, names, or other terms when generating the caption file from the audio file 110 . Generally, words, phrases, names, and other terms may be programmed as specific keystrokes (including combinations of keystrokes) on the captioning device. Certain common groups of letters, words, and/or phrases, may be mapped to a single keystroke or a combination of keystrokes. Such shortcut keystrokes may be previously defined by the captioner 114 and stored in a dictionary. The dictionary may be a file stored in the captioning device or an associated computing device or storage medium. This allows the captioner 114 to use fewer keystrokes to spell commonly used, long and/or complex terms, and/or names during captioning of the event and thus allows the captioner 114 to caption faster and more accurately. For example, a football player's name may have a long and/or complex spelling. By assigning the football player's name to certain keystrokes on the captioning device, the captioner may prevent misspelling the football player's name and may be faster when transcribing the words spoken during the football game.
[0024] In addition to transcribing spoken words, the captioner 114 may additionally indicate a specific occurrence within the event. Keystrokes may be used to provide embedded metadata information in the text code of the caption file to provide additional information (e.g., biographical, geographical, statistical, temporal or other information) pertaining to the captioned event. Other types of metadata may include statistical information regarding individuals participating in the event, video portions of the event, phrases, places and/or people associated with the event, specific occurrences in the event itself, or any combination thereof. For example, during a live sporting event the captioner 114 may hit a specially designated key or keystrokes on the stenotype to indicate that the next segment of captioning corresponds to an occurrence within the event, rather than transcription of spoken words. Using the example of a football game, the captioner 114 may hit a preprogrammed series of keystrokes to indicate the occurrence of a touchdown, the beginning or end of a quarter, the present “down”, or even the moment when each particular play begins. By identifying this additional information outside of a straightforward transcription with special keystrokes, such information may be designated as metadata about the event and may be identifiable for use or storage separately from the captions.
[0025] As the captions are transcribed by the captioner 114 , they are transmitted back to the media service client 106 via the network. The captioner 114 may format the caption data into a file format appropriate for the media service client 106 or other receiver. For example, the caption data may be formatted into a data file (such as an XML file) compliant with a closed captioning standard such as EIA-608, generally referred to as “line 21 ” captioning, compatible for receipt and/or processing by various devices such as television receivers and computing devices. The media service client 106 then sends the received captions to a captioning encoder 108 for combination with the audio/visual signal received from the camera 104 . The captioning encoder 108 inserts the captions into the audio/video signal, for example, within the vertical blanking interval or, if within a digital transmission, in packets with appropriately coded headers indicating that the packets contain captioning information. The captioned audio/video signal is then transmitted by a broadcast transmitter 110 for reception by consumers. The broadcast transmitter 110 may be a terrestrial antenna transmitter, a cable television network head end, a satellite television service uplink, or even a network server that provides streaming audio/video output over the Internet.
[0026] In the embodiment shown in FIG. 1 , an audio/video encoder 112 at the media source 102 transforms the captioned audio/video signal from the captioning encoder 108 into a streaming media signal for transmission over a network. In an example form, the audio portion of the signal may be compressed into an MPEG-1, Audio Layer 3 (MP3) format while the video signal may be transformed into a Flash video file (.flv). Alternatively, an audio/video signal without the captioning information taken from the camera 104 or other recording device may be processed and streamed by the audio/video encoder 112 to transmit a media file without the captioning information.
[0027] The next significant component of the audio/video search system 100 involves the creation of metadata information, e.g., in the form of tags, that additionally describe the media event. As previously discussed, the captioner 114 may be charged with creating metadata about a particular event while simultaneously transcribing the speech or dialog. In addition to the captioner 114 , an editor or producer 116 may additionally prepare metadata information related to a particular event. Such information may include a unique numerical identifier for the event, the title of the event, a date the event was first aired, and other information regarding the event. For example, continuing with the football game event, such information may include the names of he teams playing, names of coaches, and names of star athletes on the teams. For alternate types of events, metadata provided by the producer 116 may include episode titles, and actor and director names, plot synopses, and other information. The producer 116 may alternatively be an automated editing system. The editing system may edit the caption file for grammar and spelling and may additionally insert metadata. Words, people, phrases, subject matter, concepts, related terms, references to other sources of similar terms, places, specific happenings in the captioned event, and other textual cues may be identified by the editing system as prompts for insertion of corresponding metadata.
[0028] In addition to captioner 114 and producer 116 generated metadata, other automated sources of metadata 118 may be accessed. For example, a “scoreboard” data feed may be accessed to provide real-time scores for multiple sporting events that may be processed within the audio/video search system 100 to correlate various scores with corresponding events or programs. Other automated data feeds may include financial information, or any other information from a real-time data source. In one implementation wherein the producer 116 is an automated editing system, the producer 116 may operate in conjunction with an automated data feed 118 to associate the data from the automated data feed 118 with textual cues identified in the captions.
[0029] The third primary component of the audio/video search system 100 is the synchronization system 120 . The synchronization system 120 is additionally composed of three major components: a caption server 122 , a caption synchronization processor 128 , and a streaming media server 132 . The caption server 122 is further composed of a captioner web service portal 124 , a caption and metadata database 126 , and a client web services portal 130 . The captioner web services portal 124 provides a link between the synchronization system 120 and the captioner device 114 , the producer device 116 , and the automated metadata feeds 118 . The transcribed captions generated by the captioner 114 are transmitted to the captioner web services portal 124 (in addition to the media service client 106 ) where they are processed and formatted for storage in the database 126 . Similarly, metadata generated by the captioner 114 , the producer 116 , and/or the automated metadata feeds 118 are received at the captioner web services portal 124 where they are similarly processed and formatted for storage within the database 126 .
[0030] While the closed caption transcription prepared by the captioner 114 is created and inserted into the audio/video signal as close to real time as possible (when accounting for the transcription and processing delays), other than the physical placement of the captions within the broadcast signal, there may be no further tie of the captions to the corresponding audio/video data. The purpose of the synchronization system 120 is thus to correlate the captions and, in some instances, the metadata with the specific time that the corresponding speech or occurrence occurs within the audio/video segments of the event. The streaming media server 132 receives the audio/video file from the audio/video encoder 112 at the media source 102 and provides the audio/video file to the caption synchronization processor 128 for synchronization with the captions and metadata.
[0031] The caption synchronization processor 128 accesses the captions and any metadata embedded with the captions by the captioner 114 from the database 126 for processing in conjunction with the audio/video file. Details of an example synchronization processing method are presented with respect to FIGS. 2-4 later herein. In general, the caption synchronization processor 128 analyzes the audio component of the media file, translates the audio using language recognition algorithms into likely sound phrases, and matches the captions with the sounds phrases to correlate them with the precise time sequence within the audio file. A time stamp is then associated with the caption segment corresponding to the audio segment and stored as another metadata field for the particular event within the database.
[0032] Depending upon the type of event, in some implementations video information may also be analyzed in order to identify additional metadata and associate a time stamp with such data. For example, video frames of a sporting event may be analyzed to search for images of a scoreboard. The images could then be processed and parsed to identify the period of play, the time remaining, the score, and other information (e.g., in a football game, the particular “down”). This metadata information could then be associated with a time stamp corresponding to the point in the video component of the media file in which the analyzed frame appeared. Again, this additional metadata and timing information may be stored in the database 126 as associated with the particular event.
[0033] As an additional function, the caption synchronization processor 128 may further implement copyright controls with respect to the media file. For example, the producer 116 may identify a particular event or program as subject to copyright restrictions and place such restriction information within the metadata associated with the media file. An example restriction may be understood in the context of a television news broadcast in which the right to use clips of professional sporting events may be contractually limited by the professional sports leagues. Thus, a producer may want to remove such content from the media file on the streaming media server 132 before it is provided for access and download by consumers. Once the caption synchronization processor 128 has correlated the audio portion of the media file to the caption information, it may be possible to identify that portion of the event that the producer 116 has flagged for copyright control restrictions and provide the appropriate timing information to the streaming media server 132 to ensure that such segments are blocked from transmission.
[0034] In a further aspect of this implementation, to the extent that metadata corresponding to automated data feeds 118 has associated real-time time stamps, the caption synchronization processor 128 may additionally access such metadata from automated feeds and correlate the real-time time stamps of those feeds with the relative time stamps within the media file. In this way metadata from automated data feeds may be associated with particular time periods of the recorded event within the media file.
[0035] Once the synchronization system 120 has correlated time stamps between the media file and the captions and metadata associated with the particular event or program, the media file is fully searchable, allowing a consumer to search for a media file of a particular event and to further search for specific scenes or occurrences within the event for pinpoint presentation of such scenes or occurrences to the user. As shown in the example implementation of FIG. 1 , a consumer may use a personal computer 140 with a web browser or similar client computer searching presentation software to conduct a network search, for example, over the Internet, for a media file of a particular event. The consumer may further specify as part of the search parameters a particular scene or occurrence within the event or program.
[0036] Returning to the football game example, the consumer may specify as part of the search parameters that he would like to see a particular fourth quarter touchdown by a particular team in a particular game. The consumer can transmit this specific query across the network 138 to a search service 136 (e.g., Google). The search service 136 may send a request to the synchronization system 120 to identify an event meeting the search criteria. The client web services portal 130 may query the database 126 to identify the corresponding event based upon the caption information and associated metadata stored within the database 126 . If a particular scene or occurrence within the event was requested within the search parameters, the timing information identifying the relative location within the media file will be returned to the search service 136 . The search service can then identify and retrieve the desired media file either directly from the streaming media server 132 or via a content distribution network 134 that provides a greater ability for multiple simultaneous access to media files.
[0037] The search service 136 can then pass the location of the particular media file within the content distribution network 134 to the consumer computer 140 and further provide the time stamp information indicating the relative time within the media file of the requested scene or occurrence. The consumer computer 140 can then request delivery of that portion of the media file meeting the search criteria.
[0038] FIG. 1 also shows an example auxiliary implementation of this process providing a consumer having appropriate hardware and software equipment with an augmented live television viewing experience. As shown in FIG. 1 , a consumer's television 142 may receive a broadcast transmission of a live event transmitted by the broadcast transmitter 110 of the media source 102 . Presuming that all the processing performed by the captioner 114 , the media source 102 , and the synchronization system 120 occurs in real time as well, the consumer may be able to request replays of specific scenes or occurrences in real time.
[0039] The consumer may also be able to request presentation of additional information regarding the program provided by the metadata associated with the programming during the captioning and synchronization processes. For example, if the consumer computer 140 is configured as a media center and is connected to a television 142 , the consumer may have access to additional content available for presentation on the television 142 via the media center 140 .
[0040] Returning to the example of the live broadcast of a football game, the consumer could pause the live presentation of the football game on the television (e.g., using digital video recorder functionality provided by the media center 140 or a separate special purpose DVR component). Through an interface provided by the media center 140 on the television 142 , the consumer could initiate a search for a specific prior scene or occurrence within the football game. Rather than searching through the entire program stored on the local DVR, the media center 140 may send a search request over the network 138 to the search service 136 with a request for the specific scene or occurrence. As previously described, the search service 136 may query the client web services portal 130 to provide a match for the requested content and then identify the content on the content distribution network 134 providing a specific time stamp for the media segment corresponding to the search request. The segment could then be transmitted from the content distribution network 134 to the media center 140 for presentation on the television 142 of the consumer.
[0041] Additionally or alternatively, the consumer may use the media center 140 to request additional information about the event being presented on the consumer's television 142 . Again, the media center 140 may generate a query to the search service 136 , which polls the client web services portal 130 and requests metadata information from the database 126 related to the programming presented on the television 142 . The search service 136 may return such metadata to the media center 140 which may then format the metadata information for appropriate presentation in conjunction with the program presentation on the consumer's television 142 .
[0042] Having discussed capturing events, transforming the captured events into media files, captioning the audio portions of events, and annotating the captioned audio with metadata, the discussion will now turn to the process of synchronizing the captioned audio and any metadata for captured events with the corresponding content in the media files. This synchronization will now be elaborated in detail.
[0043] In an example implementation as shown in FIG. 2 , the synchronization process 200 may be viewed as performed by three main engines: an acoustic model engine 210 , a language model engine 220 , and an indexing engine 230 .
[0044] The acoustic model is used to describe the nature of the audio signal to be processed. For example, a telephone signal is compressed in a very specific way, with certain frequencies being heavily emphasized and others left out almost entirely. The acoustic processing translates the audio signal into a sequence of logical word sounds (e.g., similar to phonemes). Acoustic models based on sample recordings may also be used to help the acoustic model engine better process the audio into the most likely word sounds.
[0045] The second part of the process is the language model. A language model engine may be used to construct and merge language models. Essentially, the language model is built up from hundreds or thousands of pieces of speech that have been transcribed to text. Its essentially a collection of statistics that describe sequences of logical word sounds and the odds that they represent a given word or group of words. An example language model engine is available from Sail Labs, Austria.
[0046] In one implementation, the language model engine may be used to combine a “base” language model and an “event specific” language model. The base language model may be composed of a large amount of text that is not specific to the event being processed. Statistics may be further derived from the actual transcript of the event that is being processed to create the event specific language model. A time stamp from the place in the recording where the word sound occurs is associated with each word sound.
[0047] Once the precise moment during the audio where each word sound comes from is known, the word sounds may be grouped back together as words and a precise time stamp can be related to the moment when each word in the recording begins and ends. Hence, the audio input is processed to produce a time-coded sequence of words that (based on the language model) are the most likely things said throughout the recording.
[0048] The language model is used to process the output of the acoustic model to put the word sounds taken from the audio into the most likely string of words that would have been built from those logical word sounds. An indexing engine processes the audio, using the output of the acoustic model engine and the language model in order to produce time-indexed text. A batch file or script may be used to automate the steps to create an event-specific language model and then to execute the indexing engine on the audio file.
[0049] The timing from the transcript created by the indexing engine is applied to the original captioner-built transcript text. The timing information output from the indexing engine is aligned with the original transcript. The indexing engine produces a transcript with timing information, but the transcript it produces is generally not exactly the same as the one originally produced by the captioner. Captioners make mistakes and often will paraphrase in order to keep up with fast-moving speech. As a result, there will be times when the transcript text is not a verbatim account of what was spoken. The indexing engine produces a “best-guess” word or phrase for everything said in the audio. Therefore, if the two transcripts are compared, there will be some sequences where both the words are identical and others where the words either do not match or line up at all.
[0050] Several outputs may be received from the process and delivered to a common output directory. First, a new copy of the original closed-caption transcript with the caption segments maintained per the original transcript is saved. Timing for each line of captions is updated to match the first line of the caption with the time at which that word is spoken in the media. A best approximation may be considered acceptable should the specific word from the transcript not be located by the voice recognition engine. In one embodiment, the file format may be in W3C Timed Text Interchange format. (See http://www.w3.org/AudioVideo/TT/.) File naming is not material, but it may be practical that the core of the file name matches the code name of the original transcript and media.
[0051] Second, a new copy of the original closed-caption transcript in which each word is individually annotated with the time at which it appears is saved. Again, a best approximation may be considered acceptable should the specific word from the transcript not be located by the voice recognition engine. In one embodiment, the file format may be in W3C Timed Text Interchange format. File naming is not material, but it may be practical that the core of the file name matches the code name of the original transcript and media.
[0052] FIG. 3 is a schematic diagram of an audio stream 302 of an event compared to a caption stream 306 of closed captions transcribed from the audio stream 302 . As depicted in FIG. 3 , the audio stream may be divided into multiple audio segments 304 . Similarly the caption stream 306 may be divided into a plurality of discrete caption segments 308 . The creation of caption segments 308 is a standard methodology in the closed captioning process. Note that the audio segments 304 of the audio stream are not discrete like the caption segments 308 , but instead overlap in order to maximize the chance of fluid and complete translation of the audio stream by the language model engine as described with respect to FIG. 2 . As shown in FIG. 3 , the audio segments 304 overlap with adjacent segments. For example, audio segment A 2 overlaps the last half of audio segment A 1 and the first half of audio segment A 3 . Similarly audio segment A 3 overlaps the last half of audio segment A 2 and the first half of audio segment A 4 , and so on.
[0053] The benefit of overlapping the audio segments 304 in FIG. 3 can be seen in the example process of synchronization for providing audio and/or video search functionality as shown in FIG. 4 . The synchronization process shown in FIG. 4 presents the processing of one audio segment at a time. However, it should be understood that the synchronization process 400 may be conducted to process several or many audio segments and related caption segments at the same time (in parallel) in order to reduce delay in providing searchable media files and provide as near a real-time experience for live presentations as possible.
[0054] An example synchronization process for a search 400 may begin with a setting operation 402 in which the minimum audio segment for the process is initially designated as the first audio segment (A 1 ) of the media file. A first caption segment is selected for processing in selection operation 404 . As the process 400 iterates, the selection operation 404 selects the next caption segment in the sequence of caption segments related to the media file for processing.
[0055] A processing loop for each caption segment now begins at loop limit indicator 406 . First, for each loop a counter of caption segments searched is set to 0 in operation 408 . Next, a language model of “quasi-phonemes” is developed for the selected caption segment in operation 410 . This language model may be built by the language model engine as previously described with respect to FIG. 2 . The minimum audio segment is selected as the next audio segment in selection operation 412 .
[0056] Once an audio segment is selected for processing, an internal loop for each audio segment, starting with a minimum audio segment, begins as indicated by loop limit 414 . The selected audio segment is then processed to build an acoustic model of the audio segment as indicated in operation 416 . This process may be performed by an acoustic model engine as previously described with respect to FIG. 2 . Next, the data structure of the language model for the selected caption segment is compared to the data structure of the acoustic model of the selected audio segment in order to determine whether there is a strong correlation between the two as indicated in operation 418 . A strong correlation would indicate that the audio segment corresponds to the audio transcription of the caption segment.
[0057] A decision is indicated in query operation 420 . If there is not a strong match between the caption segment and the audio segment, then the audio segment counter is incremented by 1 in operation 422 . An analysis of the counter is also conducted to determine whether more than three audio segments have been compared to the caption segment as indicated in query operation 424 . The searched audio segment counter cap of three segments is an arbitrary selection based upon what is likely to be a reasonable number of audio segments to compare with a caption segment to find a correlation between a caption segment and an audio segment.
[0058] If three audio segments have been searched and compared to a caption segment then the process 400 will jump to select a new caption segment as indicated by link 426 to the next caption segment selection operation 404 . The premise for selecting a new caption segment is that, although there was not a strong match to the prior caption segment, a correlation between the next caption segment and the audio segments previously searched may likely be found as the audio segments are typically longer than the caption segments. A caption segment may not match an audio segment at any given time for a number of reasons. First, the caption segment may have been mis-keyed by the captioner or poorly processed by the language model engine. Second, the audio segment could be garbled or difficult to parse due to background sound (e.g., music or explosions). Third, there may be a period of silence in the audio track before speech and therefore a delay before captioning occurs. In this case, all the captions will be checked against successive groups of audio segments until a match is made in order to ensure that the lack of a match is not due to the first and second issues with the caption or audio quality described above.
[0059] It should be understood that the described searching of three audio segments is an arbitrary selection of a reasonable number of audio segments to compare with a caption segment to find a correlation between a caption segment and an audio segment. In various implementations, the number of audio segments to compare with a caption segment may be a number other than three, may be configurable, and may vary as audio segments are compared with caption segments.
[0060] Further, as part of comparing audio segments with caption segments, in some implementations leading silence of the audio segments and/or the entire audio portion of the media file may be eliminated for purposes of comparison utilizing various audio processing techniques. For example, in some implementations, audio segments and/or the entire audio portion of the media file may be shortened by audio processing techniques to actually remove the leading silence from the audio segments and/or the entire audio portion of the media file. In other implementations, audio processing techniques may be utilized to determine offsets to effectively eliminate leading silence from the comparisons.
[0061] Returning to query operation 424 , if the searched audio segment count is still less than three, a further determination is made as to whether any audio segments still remain as indicated by query operation 428 . If all the audio segments have already been searched and there is no correlation between the audio segments and the caption segments searched, then the process terminates as indicated by loop terminator 430 . If, however, additional audio segments remain to be searched, then the process moves from query operation 428 to jump operator 432 to jump to selection operation 412 to select the next audio segment for comparison.
[0062] Returning to query operation 420 , if a strong match or correlation between a caption segment and an audio segment is found, then the process 400 moves to assign a time code to the captions in the caption segment that correlates to the time stamp of the audio segment within the media file as indicated by assignment operation 434 . Once a time stamp has been assigned to a caption segment, a query operation determines whether prior adjacent caption segments were skipped as a result of query operation 424 for failure to find a strong correlation between those prior caption segments and an audio segment. If it is found that prior adjacent caption segments were skipped, then those skipped caption segments will be assigned an approximate time stamp as indicated in operation 438 . In this case, the time stamp may be the same time stamp as allocated to the present caption segment or it may be a time stamp associated with one or more of the immediately prior audio segments that may have been skipped for a lack of correlation with the caption segment.
[0063] In either case, that is, whether prior adjacent caption segments were skipped or not, the process continues to operation 440 in which the minimum audio segment is reset to the last audio segment searched. Note that the minimum audio segment is not set to the next audio segment, but remains as the last audio segment searched because the audio segments are generally longer than the caption segments as indicated in FIG. 3 . Thus multiple caption segments may be associated with a single audio segment.
[0064] Once the minimum has been reset, the process 400 determines whether any caption segments remain to be correlated as indicated in query operation 442 . If additional caption segments do need to be correlated, then the process 400 jumps back to selection operation 404 to select the next caption segment for analysis as indicated by link operator 444 . If no caption segments remain to be correlated, then the process 400 terminates and is considered complete for the particular group of caption segments as indicated by operation 446 .
[0065] An example computer system 500 for implementing the closed-captioning synchronization processes above is depicted in FIG. 5 . For example, a number of computer systems 500 for implementing each of the caption synchronization engines, the closed captioning system, the media service client, the audio/video encoder, the streaming media server, the caption server, and/or the web services clients may be one or more of a personal computer (PC), a workstation, a notebook or portable computer, a tablet PC, a handheld media player (e.g., an MP3 player), a smart phone device, a video gaming device, or a set top box, with internal processing and memory components as well as interface components for connection with external input, output, storage, network, and other types of peripheral devices. Internal components of the computer system in FIG. 5 are shown within the dashed line and external components are shown outside of the dashed line. Components that may be internal or external are shown straddling the dashed line. Alternatively to a PC, the computer system 500 may be in the form of any of a server, a mainframe computer, a distributed computer, an Internet appliance, or other computer devices, or combinations thereof.
[0066] In any embodiment or component of the system described herein, the computer system 500 includes a processor 502 and a system memory 506 connected by a system bus 504 that also operatively couples various system components. There may be one or more processors 502 , e.g., a single central processing unit (CPU), or a plurality of processing units, commonly referred to as a parallel processing environment (for example, a dual-core, quad-core, or other multi-core processing device). The system bus 504 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, a switched-fabric, point-to-point connection, and a local bus using any of a variety of bus architectures. The system memory 506 includes read only memory (ROM) 508 and random access memory (RAM) 510 . A basic input/output system (BIOS) 512 , containing the basic routines that help to transfer information between elements within the computer system 500 , such as during start-up, is stored in ROM 508 . A cache 514 may be set aside in RAM 510 to provide a high speed memory store for frequently accessed data.
[0067] A hard disk drive interface 516 may be connected with the system bus 504 to provide read and write access to a data storage device, e.g., a hard disk drive 518 or other computer readable medium, for nonvolatile storage of applications, files, and data. A number of program modules and other data may be stored on the hard disk 518 , including an operating system 520 , one or more application programs 522 , and other program modules and related data files 524 . In an example implementation, the hard disk drive 518 may store the media recording and closed-caption transcript in a drop directory 526 , the acoustic model engine 564 , the language model engine 566 , and the indexing engine 568 for execution according to the example processes described herein above. Note that the hard disk drive 518 may be either an internal component or an external component of the computer system 500 as indicated by the hard disk drive 518 straddling the dashed line in FIG. 5 . In some configurations, there may be both an internal and an external hard disk drive 518 .
[0068] The computer system 500 may further include a magnetic disk drive 530 for reading from or writing to a removable magnetic disk 532 , tape, or other magnetic media. The magnetic disk drive 530 may be connected with the system bus 504 via a magnetic drive interface 528 to provide read and write access to the magnetic disk drive 530 initiated by other components or applications within the computer system 500 . The magnetic disk drive 530 and the associated computer-readable media may be used to provide nonvolatile storage of computer-readable instructions, data structures, program modules, and other data for the computer system 500 .
[0069] The computer system 500 may additionally include an optical disk drive 536 for reading from or writing to a removable optical disk 538 such as a CD ROM or other optical media. The optical disk drive 536 may be connected with the system bus 504 via an optical drive interface 534 to provide read and write access to the optical disk drive 536 initiated by other components or applications within the computer system 500 . The optical disk drive 530 and the associated computer-readable optical media may be used to provide nonvolatile storage of computer-readable instructions, data structures, program modules, and other data for the computer system 500 .
[0070] A display device 542 , e.g., a monitor, a television, or a projector, or other type of presentation device may also be connected to the system bus 504 via an interface, such as a video adapter 540 or video card. Similarly, audio devices, for example, external speakers or a microphone (not shown), may be connected to the system bus 504 through an audio card or other audio interface (not shown).
[0071] In addition to the monitor 542 , the computer system 500 may include other peripheral input and output devices, which are often connected to the processor 502 and memory 506 through the serial port interface 544 that is coupled to the system bus 506 . Input and output devices may also or alternately be connected with the system bus 504 by other interfaces, for example, a universal serial bus (USB), an IEEE 1394 interface (“Firewire”), a parallel port, or a game port. A user may enter commands and information into the computer system 500 through various input devices including, for example, a keyboard 546 and pointing device 548 , for example, a mouse. Other input devices (not shown) may include, for example, a joystick, a game pad, a tablet, a touch screen device, a satellite dish, a scanner, a facsimile machine, a microphone, a digital camera, and a digital video camera.
[0072] Output devices may include a printer 550 and one or more loudspeakers 570 for presenting the audio performance of the sender. Other output devices (not shown) may include, for example, a plotter, a photocopier, a photo printer, a facsimile machine, and a press. In some implementations, several of these input and output devices may be combined into single devices, for example, a printer/scanner/fax/photocopier. It should also be appreciated that other types of computer-readable media and associated drives for storing data, for example, magnetic cassettes or flash memory drives, may be accessed by the computer system 500 via the serial port interface 544 (e.g., USB) or similar port interface.
[0073] The computer system 500 may operate in a networked environment using logical connections through a network interface 552 coupled with the system bus 504 to communicate with one or more remote devices. The logical connections depicted in FIG. 5 include a local-area network (LAN) 554 and a wide-area network (WAN) 560 . Such networking environments are commonplace in home networks, office networks, enterprise-wide computer networks, and intranets. These logical connections may be achieved by a communication device coupled to or integral with the computer system 500 . As depicted in FIG. 5 , the LAN 554 may use a router 556 or hub, either wired or wireless, internal or external, to connect with remote devices, e.g., a remote computer 558 , similarly connected on the LAN 554 . The remote computer 558 may be another personal computer, a server, a client, a peer device, or other common network node, and typically includes many or all of the elements described above relative to the computer system 500 .
[0074] To connect with a WAN 560 , the computer system 500 typically includes a modem 562 for establishing communications over the WAN 560 . Typically the WAN 560 may be the Internet. However, in some instances the WAN 560 may be a large private network spread among multiple locations, or a virtual private network (VPN). The modem 562 may be a telephone modem, a high speed modem (e.g., a digital subscriber line (DSL) modem), a cable modem, or similar type of communications device. The modem 562 , which may be internal or external, is connected to the system bus 518 via the network interface 552 . In alternate embodiments the modem 562 may be connected via the serial port interface 544 . It should be appreciated that the network connections shown are merely examples and other means of and communications devices for establishing a network communications link between the computer system and other devices or networks may be used.
[0075] The technology described herein may be implemented as logical operations and/or modules in one or more systems. The logical operations may be implemented as a sequence of processor-implemented steps executing in one or more computer systems and as interconnected machine or circuit modules within one or more computer systems. Likewise, the descriptions of various component modules may be provided in terms of operations executed or effected by the modules. The resulting implementation is a matter of choice, dependent on the performance requirements of the underlying system implementing the described technology. Accordingly, the logical operations making up the embodiments of the technology described herein may be referred to variously as operations, steps, objects, engines, or modules. Furthermore, it should be understood that logical operations may be performed in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.
[0076] In some implementations, articles of manufacture are provided as computer program products that cause the instantiation of operations on a computer system to implement the disclosure. One implementation of a computer program product provides a computer program storage medium readable by a computer system and encoding a computer program.
[0077] The above specification, examples and data provide a complete description of the structure and use of example embodiments of the disclosure. Although various embodiments of the disclosure have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this disclosure. In particular, it should be understood that the described technology may be employed independent of a personal computer. Other embodiments are therefore contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the disclosure as defined in the following claims. | A synchronization process between captioning data and/or corresponding metatags and the associated media file parses the media file, correlates the caption information and/or metatags with segments of the media file, and provides a capability for textual search and selection of particular segments. A time-synchronized version of the captions is created that is synchronized to the moment that the speech is uttered in the recorded media. The caption data is leveraged to enable search engines to index not merely the title of a video, but the entirety of what was said during the video as well as any associated metatags relating to contents of the video. Further, because the entire media file is indexed, a search can request a particular scene or occurrence within the event recorded by the media file, and the exact moment within the media relevant to the search can be accessed and played for the requester. | 7 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a method and an apparatus for dispensing paint powders for powder coatings, and more particularly, the present invention relates to a corona charge spray gun for dispensing paint powders for powder coatings.
2. Description of the Related Art
Electrostatic powder coating is a method of surface finishing for metals or other materials in which a paint layer is applied in a dry powder form without the use of solvents. The powder, usually having powder particles with a mean size of about 30-60 microns and composed of a resin, pigments, flow agents and curing agents etc., is fluidized in a hopper and pneumatically transported to a spray gun through a plastic or rubber hose. The powder is then sprayed out the exit passageway of the gun whereupon it is positively or negatively charged and is attracted to a grounded work-piece, whereupon if forms a uniform powder layer. The work-piece covered with powder paint is then transferred to an oven where the powder layer melts and certain chemical reactions occur to form a smooth film of paint.
The spray gun can be a corona charge gun which is most widely used in the coating industry, or a tribo charge gun which occupies only a small fraction of the total market share. Conventional corona charge spray guns have a configuration similar to that shown in FIG. 1 a which includes a powder-air mixture conduit, a high-voltage needle-like electrode located at the gun tip and a powder diffuser. Another typical configuration includes a powder-air mixture conduit in the side of a central gun housing midway of the housing for injecting the powder-air mixture into a chamber, as shown in FIG. 1 b . A pointed needle or charge pin is connected to a high voltage generator which typically imparts a negative potential to the electrode. An electric field is established between the needle electrode and the grounded work-piece, with an intensified electric field located at the needle tip due to its small radius of curvature. When a combination of needle geometry and potential is sufficient to create a local electric field strength of 3 MV/m or higher, electrical breakdown of the air, or corona discharge, occurs in a region around the electrode tip. As a result of the local discharge, the air will be ionized, producing negatively charged ions. Powder particles carried by compressed air are transported along the conduit and pass through a discharge region, picking up negative ions on their way to the work-piece.
Corona charge guns, although are widely used in the coating industry, suffer from problems such as Faraday cage effect and back ionization. It would be desirable to provide an apparatus for dispensing powders while avoiding or minimizing the Faraday cage effect and back ionization. When workpieces with a convex geometry have to be coated by corona guns, the presence of an electric field between the gun tip and the work-piece generates a very serious problem, namely poor powder coverage in recessed areas coupled with excessive building up of powder in areas of boundaries or edges. This is a direct result of classical electrostatics, namely, less or no electric field lines can exist or penetrate areas which are surrounded by a grounded metal boundary. If air velocity is low, particles will follow a field line pattern that does not penetrate into an inside of a recessed or concave area of a work-piece. As a general rule, electrostatic forces will deposit material into an opening to a depth equal to or less than a smallest dimension of the opening. This is known as the Faraday cage effect. To a certain extent, a higher air velocity will help by “pushing” a powder into recessed or concave areas but this does not compensate for poor uniformity of coverage.
To eliminate or significantly reduce problems caused by the Faraday cage effect, alternative configurations of corona charge guns have been proposed and/or patented. Included in these are internal charging guns which charge the powder internally in the gun barrel before the powder is ejected from a gun outlet. Since there are no electrical lines built up between the gun nozzle and the grounded work-piece, the Faraday cage effect is eliminated. It is noted that given that the charged powder coming out of the gun tip also generates electrical potential, there may exist a weak electrical field between the gun tip and the work-piece, but such an effect is negligible. As referred to by Moyle, B. D. and Hughes, J. F. ( Electrostatics, 16, 277, 1985), an internal charging gun comprises a duct in which a corona discharge needle electrode is located, an grounded ring electrode surrounding the tip of the corona needle or located downstream of the needle, as indicated in FIG. 1 c . All powder emanating from the gun nozzle will pass through the corona discharge region surrounding the needle tip and charging is imparted to the powder in this region. Free ions not captured by the powder will be attracted to the surface of the grounded counter electrodes so that few of them are ejected from the nozzle. The result is a high specific charge with a fairly small voltage on a corona electrode, an electrical line free space between the gun nozzle and work-piece, and a large reduction of free ion emission towards the work-piece.
As stated by Moyle, B. D. and Hughes, J. F. ( Electrostatics, 16, 277, 1985), although remarkably good in terms of high-quality coatings, long-term tests with the prior art internal charging corona guns have shown deterioration in performance after long uninterrupted runs. This is considered to be associated with a growth of partially cured powder and back-ionization on a ground counter electrode inside the gun. The inventors have conducted tests showing that with this configuration of electrodes, the ground counter electrode is coated by powder and becomes back-ionized within a few seconds to a few minutes. Powder deposition results in a significant deterioration of the charging performance leading to a degradation and failure of the gun. Thus, frequent cleaning of the gun must be performed with utmost care. This is a time consuming operation which normally requires shutdown of a production line.
Considerable efforts have been made to improve long-term efficiency of internal charging guns. Two different approaches involving a piezo-electric ceramic ring electrode which undergoes an oscillatory deformation and a curtain electrode with a double helix configuration have been considered as a solution to the problem (Moyle, B. D. and Hughes, J. F., Electrostatics, 16, 277, 1985; Masuda, S. IEEE/IAS Conference Proceedings 35D, 1977, P. 887). However, as mentioned by Misev, T. A. (Powder Coatings Chemistry and Technology, John Wiley & Sons, 1990), despite the promising results, neither attempt resulted in a commercial gun system. Another alternative is to employ a porous metal ring electrode which is cleaned by air purge (Misev, T. A., Powder Coatings Chemistry and Technology, John Wiley & Sons, 1990) to remove powder coated on a ring surface. Again, this design found no wide application as the ring surface can not be thoroughly cleaned because of the nature of the porous surface.
A recent improvement to the internal charging gun has been made by Muhlhausen, B. G. and Heidelberg, H-G. N. etc., ABB Research Ltd., Zurich, Switzerland and is disclosed in U.S. Pat. No. 6,254,684B1 (continuation of PCT/EP96/05462, or WO98/245555). This design includes a chamber, several high-voltage electrodes annularly distributed in a region upstream of the outlet and a tubular ground electrode extending along the cylindrical axis of the chamber at the back of the gun housing. The tubular ground electrode has an end directed towards an interior of the chamber and is covered by an insulating material with a small hole through which the tubular ground electrode is exposed to the high-voltage electrodes. The purpose of this configuration is to prevent the charged powder from depositing on the ground counter electrode because the ground counter electrode is located upstream of the high-voltage electrodes and is also continuously flushed by clean air. However, this design suffers from two drawbacks. First, the area of the ground electrode exposed to the high-voltage electrodes is very small which can result in dangerous sparking during operation. Secondly, due to the small area of the exposed ground electrode, the intensity of electrical field at the high-voltage electrode may not reach sufficiently high strengths to generate enough free ions that charge the powder effectively.
German Patent No. 27 22 100 B1 also describes a spray gun having a blunt ground electrode in a section of the gun barrel having an enlarged diameter located upstream of the charging pin and centrally located in the flow passageway. The purpose of having the ground electrode with a blunt shape in the enlarged cross-sectional area is to cause powder flow to slow to allow time for powder charging. However, the inventors have conducted tests on such configurations which have shown that this structure results in a highly irregular passageway for the powder and causes a surface of the blunt ground electrode, especially the side facing the high voltage electrode, to be coated almost immediately, leading to performance failure of the gun.
It would be very advantageous to provide a powder spraying apparatus which overcomes the aforementioned disadvantages of the above designs that provides long-term efficient charging performance and with a relatively simple configuration.
SUMMARY OF INVENTION
In one aspect of the invention there is provided an apparatus for spraying powders which includes a housing having first and second opposed ends defining a chamber terminating in an outlet passageway at a first end of the housing. A high voltage electrode is positioned in the chamber spaced upstream of the outlet passageway. The high voltage electrode includes at least one charging pin connected to a conductor located in an electrically insulated tube disposed along an axis of the housing, the conductor being connectable to a power supply for applying high voltages to the at least one charging pin. A ground electrode is positioned in the chamber spaced upstream from the high voltage electrode and the ground electrode has a surface area sufficiently larger than a surface area of the high voltage electrode in order to allow high voltages to be applied to the high voltage electrode without arch discharging occurring in the chamber. Also an inlet opening into the chamber is provided at the second end of the housing for conducting a powder-gas mixture into the chamber. The high voltage electrode receives a gas for avoiding powder deposits on the high voltage electrode. The chamber defines an inner cylindrical surface and the ground surface electrode is a cylindrical electrode having an outer diameter such that the cylindrical electrode is substantially concentric with the inner cylindrical surface, the cylindrical electrode having an inner surface which has the second conducting surface area that is sufficiently larger than the first surface area of the high voltage pin electrode.
In another aspect of the invention, there is provided an apparatus for spraying powders including a housing having first and second opposed ends and a housing wall defining a chamber terminating in an outlet passageway at the first end of the housing. A high voltage electrode is mounted in the chamber spaced upstream of the outlet passageway. A ground electrode is mounted in the chamber spaced upstream from the high voltage electrode and has a surface area sufficiently larger than a surface area of the high voltage electrode in order to allow high voltages to be applied to the high voltage electrode without arch discharging occurring in the chamber. Also an inlet opening into the chamber is at a position in the housing wall located between the ground electrode and the high voltage electrode for conducting the mixture of gas and powder particles into the chamber where the powder particles acquire a charge as they move downstream between said inlet and said high voltage electrode to be ejected from the chamber through the outlet passageway. Further, the ground electrode and the high voltage electrode receive air for avoiding powder deposits on the ground electrode and the high voltage electrode.
BRIEF DESCRIPTION OF DRAWINGS
The following is a description, by way of example only, of embodiments of an apparatus for dispensing powder coatings constructed in accordance with the present invention, reference being had to the accompanying drawings, in which:
FIG. 1 a is a cross sectional view of a Prior Art corona charge gun for dispensing powders;
FIG. 1 b is a cross sectional view of another Prior Art corona charge gun for dispensing powders;
FIG. 1 c is a cross sectional view of another Prior Art internal charging gun for dispensing powders;
FIG. 2 is a cross sectional view of an apparatus for dispensing powders constructed in accordance with the present invention;
FIG. 2 a a cross sectional view of FIG. 2 showing the ground electrode sections being jointly grounded;
FIG. 2 b is a cross sectional view of FIG. 2 showing the ground electrode sections being separately grounded;
FIG. 3 is a cross sectional view of an alternative embodiment of an apparatus for dispensing powders having a cone-shape ground electrode;
FIG. 3 a is a cross sectional view of another embodiment of an apparatus for dispensing powders which combines features of the embodiments shown in FIGS. 2 and 3 ;
FIG. 4 is a cross sectional view of another embodiment of an apparatus for dispensing powders with a powder inlet located between a ground electrode and a high voltage electrode;
FIG. 4 a is a cross sectional view of an embodiment of an apparatus for dispensing powders similar to the embodiment shown in FIG. 4 ;
FIG. 5 is a cross sectional view of yet another alternative embodiment of an apparatus for dispensing powders having a cone-shape ground electrode coupled with the side powder-air inlet configuration of FIG. 4 ;
FIG. 6 is a cross sectional view of another alternative embodiment of an apparatus for dispensing powders having a planar ground electrode;
FIG. 7 is a cross sectional view of another alternative embodiment of an apparatus for dispensing powders having an internal barrel configuration for shielding a ground electrode from powder buildup;
FIG. 7 a is a cross sectional view showing details of an embodiment of an apparatus for dispensing powders similar to the embodiment shown in FIG. 7 ;
FIG. 8 shows yet another alternative embodiment of an apparatus for dispensing powders having an internal barrel configuration for shielding a ground electrode from powder buildup; and
FIG. 9 shows a portion of an apparatus for dispensing powders in which a high voltage electrode is located on a wall of the housing.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2 , an apparatus for dispensing powders is shown at 20 which comprises an elongate housing 12 made of an insulating material such as plastic. Housing 12 has a longitudinal axis 14 and defines a chamber 16 terminating in an outlet passageway 18 from which a mixture of gas and powder particles is expelled. A supply conduit opening or inlet 22 for introducing a powder-air mixture into the chamber 16 is located at an opposing end of housing 12 . A high voltage pin electrode 24 is spaced upstream of the outlet passageway 18 , a short distance, and a ground surface electrode 10 is located further upstream of high voltage pin electrode 24 . The high voltage pin electrode 24 includes one or more charging pins 28 with the electrode aligned along the longitudinal axis 14 of housing 12 .
The ground electrode 10 , which is spaced upstream from the high voltage electrode 24 , is preferably cylindrical. The chamber 16 defines an inner cylindrical surface and the ground electrode 10 has an outer diameter such that an outer surface of the cylindrical electrode 10 bears against the inner cylindrical surface of chamber 16 . The ground electrode 10 can also be several pieces forming sections of the cylindrical surface, each being separately ( FIG. 2 b ) or jointly ( FIG. 2 a ) grounded. The ground electrode 10 has an inner surface having a surface area that is much larger than a surface area of the high voltage electrode 24 . A cylindrical body 38 is located along the axis 14 in the section of the housing 12 containing the ground electrode 10 . The cylindrical body 38 is made of an electric insulating material and serves the purpose of accelerating the powder flow so as to keep the ground electrode 10 from being coated with powder. The body 38 reduces the effective open cross sectional area of the chamber 16 upstream of the high-voltage electrode 24 , thus creating an increased flow velocity from the inlet 22 toward the high-voltage electrode of the powder-air mixture. A power supply 32 is connected to electrode 24 by a wire 34 running through an insulated tube 36 which extends along axis 14 of the housing 12 . Section 26 of housing 12 containing the ground electrode 10 may optionally be made to have a larger or smaller diameter than the rest of the housing 12 to optimize flow of the powder-air mixture so as to provide an appropriate velocity and turbulence for best cleaning of the ground electrode 10 .
In operation, a high negative voltage is applied to high voltage electrode 24 by a power supply 32 . Cleaning air flows into tube 36 to keep powder from caking on electrode 24 . In this embodiment of spray gun 20 , the ground electrode 10 is placed up-stream of the high-voltage electrode 24 in the barrel or housing 12 . This differs from some conventional configurations where the ground electrode is placed either down-stream of the high voltage electrode, or in the same axial position as the high voltage electrode (see FIG. 1 c ). With the electrode embodiments disclosed herein, an electrical field will be established between the down-stream high-voltage charging electrode 24 and the ground electrode 10 and a charging zone, primarily surrounding the high voltage electrode 24 , will be formed because of the more concentrated electrical field lines in this region due to a much smaller surface area of the high voltage electrode compared to the ground electrode.
When powder passes through the cylindrical electrode 10 , it is in a neutral state because it has not passed the charging zone and thus the powder will not cling to the ground electrode 10 . On the other hand, free ions created at the high voltage charging electrode 24 flowing counter currently with the powder-air mixture towards the cylindrical electrode, lead to an enhanced mixing with powder, thus creating a much higher charge transfer efficiency to the powder and a reduced back ionization on the surface of ground electrode 10 , thereby mitigating deterioration in charging performance over long-term operation.
For a corona charge gun, a high efficiency of ionization of air at the high voltage charging electrode is preferred, so as to provide adequate charge to the powder. This requires an intense electrical field at the high voltage electrode created by a high enough voltage. In the present invention, a ground electrode with a large surface area is employed to make a pin-to-surface configuration. This ensures a localized high density electric field in a space adjacent to the pin tip and in turn an efficient ionization of air molecules. Equation 1 (Technical Handbook for Electrostatic Discharge Protection, Zhang, B. M. et al., Electronics Industry Press, Beijing 2000) can be used to estimate the breakdown voltage of air, V b (KV), for a negative pin to grounded flat surface configuration:
V b =100+8.6 d (1)
where d (cm) is the distance between the pin and the flat surface. When a negatively charged high voltage pin is, for example, 5 cm away from the ground electrode, it needs 143 KV of voltage to break through air between the pin and the ground electrode. In other words, the voltage of the pin can go as high as 143 KV without occurrence of sparking. A pin-to-pin arrangement, however, allows a much smaller voltage difference between the charging pin and the grounded pin, so that the ionization efficiency of air is highly limited by the low voltage. This is because the intensive field lines between two pin points will cause the air to break down and produce dangerous sparks as soon as a minimum breakdown intensity of electrical field, estimated by Equation 2 (Technical Handbook for Electrostatic Discharge Protection, Zhang, B. M. et al., Electronics Industry Press, Beijing 2000), is reached:
V b =5.2d (2)
where d (cm) is the distance between the charging pin and the grounded pin. If the two pins are set to 5 cm apart, for example, only 26 KV is needed for the breakdown of air, which is more than 5 times lower than that of a pin-to-surface arrangement.
Therefore, for the pin-to-surface configuration, as employed in this invention, a much higher voltage can be imparted to the charging pin without causing sparks, because the intensity of field lines upon the surface of the ground electrode is low enough to prevent arc discharging or air breakdown near the ground electrode and further prevent powder curing on the ground electrode. For this reason, this invention significantly enhances the powder charging efficiency compared with the pin-to-pin arrangement patented by Muhlhausen, B. G. and Heidelberg, H-G. N. et al., ABB Research Ltd., Zurrich, Switzerland (U.S. Pat. No. 6,254,684B1, 2001, continuation of PCT/EP96/05462, or WO98/245555). Tests conducted by the inventors have shown that with the pin-to-pin embodiments of the prior art, the sparking voltage is quickly reached, while with the pin-to-surface embodiment of the apparatus of the present invention shown at 20 in FIG. 2 , a sparking voltage was found to be several times higher. This invention also prevents powder curing compared with the pin-to-pin arrangement.
Referring to FIG. 3 , an embodiment of an alternative powder spray apparatus is shown at 30 in which a ground electrode 46 is a conductor located on a conical shaped surface located at the downstream end of cylindrical body 38 . This position is preferred over other places of cylindrical body 38 because the high turbulent powder-air flow at this region has a very significant cleaning effect on the ground electrode thereby preventing buildup of powders on the ground electrode surface. Based on the discussion above, special care should be taken to ensure there exist no sharp points on the surface or exposed sharp edges of electrode 46 in order to prevent points of concentration for the electric field lines resulting in arc discharging.
FIG. 3 a shows another embodiment of a powder spray gun apparatus at 35 which is similar to the embodiment shown in FIG. 3 but with an additional ground cylindrical electrode 10 located at the same position as the grounded electrode in FIG. 2 , at the inner surface of the section 26 .
An alternative embodiment of a powder spray apparatus is shown in FIG. 4 at 40 . In apparatus 40 , a conduit 44 defines a powder-air inlet 42 opening into chamber 16 for conducting the mixture of gas and powder particles into chamber 16 , located at a position in the wall of housing 12 between the ground electrode 10 and the high voltage electrode 24 . In this configuration the powder does not pass directly over ground electrode 10 and the powder particles acquire a charge as they move downstream between inlet 42 and the high voltage electrode 24 in chamber 16 . This arrangement further ensures that a clean ground electrode 10 is maintained. The cleaning air enters chamber 16 through the inlet 22 located at the back end of housing 12 with the direction of air flow indicated by the arrows. The air flowing through cylindrical ground electrode 10 helps prevent powder buildup on the ground electrode and mixes with the powder/gas mixture entering chamber 16 from inlet 42 downstream of electrode 10 . In addition, cleaning air flows into tube 36 from the back end thereof located at the back end of the housing 12 with the direction of air flow indicated by the arrows with the air flow acting to keep powder from caking on electrode 24 .
FIG. 4 a shows the details of an embodiment of a powder discharge apparatus similar to the embodiment shown in FIG. 4 . Housing or gun barrel 12 snaps onto a gun base 17 and is locked by a plastic screw 48 . An electrically conductive rod 47 is located inside an insulated tube 23 running along the longitudinal axis of housing 12 . The conductive rod 47 connects the high voltage from the gun base to the high voltage electrode 24 and the charging pins 28 through a metal spring 51 . Ground electrode 10 is grounded so that an electric field will be established between the charging pins and the ground electrode. Conduit 44 is a powder-air mixture conduit with an inlet at 42 . When powder particles enter chamber 16 through conduit 44 , the particles are charged and then sprayed out of the end 18 of the housing 12 and are dispersed by the diffuser 39 mounted at the end of housing 12 . Cleaning air entering chamber 16 through air inlet 11 and the insulated tube 23 cleans the charging pins 28 . The ground electrode 10 is kept clean by another stream of cleaning air coming in through inlet 15 at high air velocity through the section of the housing containing the ground electrode.
With the powder/gas inlet 42 being located between the high voltage electrode and the ground electrode 10 , as shown in FIG. 4 , the ground electrode 10 may be of any shape. For example, referring to FIG. 5 , another embodiment of a powder spray apparatus is shown at 50 having a ground electrode 46 with a conical shape symmetric about the axis 14 of housing 12 and located at the downstream end of the cylindrical body 38 .
In addition, referring to FIG. 6 , another embodiment of the spray apparatus shown generally at 60 is similar to apparatus 40 but instead of using a cylindrical ground electrode 10 as in apparatus 40 , a flat planar ground electrode 62 is used with special care taken to ensure there are no exposed sharp edges or sharp points on the surface of ground electrode 62 in order to prevent points of concentration for electric field lines, resulting in arc discharging.
In this embodiment of the invention, since the chamber 16 is a cylindrical chamber having a circular cross section, ground electrode 62 is a circular electrode having a planar surface and a radius equal to a radius of the circular cross section of the chamber 16 and is disposed in the chamber so that the planar surface is perpendicular to the cylindrical axis, and again, the ground electrode has a surface area that is sufficiently larger than the surface area of the high voltage electrode 24 to permit high voltages to be applied to electrode 24 . Housing 12 is sealed by a plate 64 at the back end 22 of housing 12 while the other end 18 of housing 12 is the outlet similar to the embodiments shown in FIGS. 2 and 4 . The cleaning air used to clean ground electrode 62 enters chamber 16 downstream of electrode 62 through one or more air inlet(s) 66 located in the wall of housing 12 and the flow of the air and powder-gas mixture is indicated by the arrows. Cleaning air for high voltage electrode 24 is also introduced into the entrance of tube 36 located at the back end of housing 12 .
Referring to FIG. 7 , another alternative embodiment of an apparatus for spraying powders is shown generally at 70 . Apparatus 70 is similar in structure to apparatus 20 shown in FIG. 2 but includes a tapered tube 72 made of insulating material aligned around the axis 14 of housing 12 and concentric on the inside of cylindrical ground electrode 10 defining a powder/gas passageway 74 located between the tube 36 and tapered tube 72 so that ground electrode 10 is shielded from the powder flow. The cleaning air flow is directed down tube 36 and through holes 76 which are located at the back end of housing 12 and in the annular region between tapered tube 72 and the outer section 26 of housing 12 (as indicated by the arrows in FIG. 7 ) whereupon the air or gas flow passes through cylindrical ground electrode 10 to help prevent powder buildup on the ground electrode 10 and mixes with the powder-air mixture downstream of tube 72 . The powder-air mixture enters inlet 22 and into passageway 74 .
FIG. 7 a shows a more detailed view of an embodiment similar to the embodiment 70 shown in FIG. 7 . Housing 12 is threaded onto a base 17 ′. Inside the housing 12 and extending along chamber 16 in the section containing the ground electrode is a tube 21 connected to the powder-air conduit which in turn has an inlet at 22 . Tube 21 guides the powder-air mixture through the section where the ground bushing 10 is and thus shields the bushing from being coated by powder. A metal spring 29 ′ connects the high voltage from the base 17 to the pin-type connector 19 ′ which carries the high voltage to the electrode 24 and charging pins 28 through a wire, an electrically conductive rod 47 and the metal spring 51 located inside the insulated tube 23 . Powder particles are charged between the downstream end of tube 21 and the charging pins 28 and are sprayed out of the end 18 of the gun barrel. Cleaning air entering through inlet 15 prevents powder from moving backwards upstream so as to ensue the ground electrode 10 is not coated with powder. Cleaning air entering tube 23 through air inlet 27 flushes the tube 23 and cleans the charging pins 28 .
Referring to FIG. 8 , an alternative embodiment of a powder spray gun is shown generally at 80 . Apparatus 80 is very similar to embodiment 70 shown in FIG. 7 , but in apparatus 80 the ground electrode 78 is located on the outer surface of the insulating tapered tube 72 , instead of the inner surface of the outer gun barrel as shown at 10 in FIG. 7 .
Alternatively, the internal barrel 72 may itself be used as the ground electrode if it is made from conducting material. In this alternative embodiment, it is noted that the fact that the ground electrode has two conducting surfaces will not significantly affect the functionality of the ground electrode because the outer surface of tapered tube 72 is the most effective surface for charging.
It will be understood by those skilled in the art that although the high voltage electrode 24 is shown to be located along the axis of the gun barrel in the devices shown in FIGS. 2-8 , it may also be placed at other places in the section of chamber 16 near the first end of the housing 12 , downstream of the ground electrode and the powder inlet and upstream of outlet passageway 18 . FIG. 9 shows a specific embodiment where the high voltage electrode 24 with multiple pins 28 are spaced along the inner surface of the housing 12 . These pins 28 are all connected to the same or separate high voltage source.
It should also be mentioned that although the ground electrode is shown as a complete cylindrical piece in FIGS. 2 , 4 , 7 and 8 , it can also be of sections of a metallic cylinder that are grounded either jointly or separately to act, in whole, as a cylindrical piece.
The internal corona-charging powder dispensing guns disclosed herein are useful for a large number of applications in the powder coating industry. The most significant advantage is that they largely eliminate the Faraday cage effect found in coating work-pieces with recessed areas. The present powder dispensing devices disclosed herein can also maintain long-term optimum performance without frequent manual cleaning, as required by the prior art of internal charging guns. This enhances coating quality, reduces powder consumption and labor costs, and increases the productivity of existing coating lines, especially for parts with recessed areas.
When flat surfaces are being coated using the devices of the present invention, the powder transfer efficiency is increased due to the fact that less free ions are ejected out of the outlet 18 resulting in less back ionization at the surface of the part being coated. Furthermore, fat edge effects will also be eliminated due to the absence of an external electrical field with the present invention.
This invention can also be applied to other areas where air needs to be ionized or powder form materials need to be corona-charged. For instance, the devices disclosed herein may be used in electrostatic dust collectors, air cleaners, ion generators and the like.
Differences between the present spray devices and that disclosed in German Patent No. 27 22 100 B1 include the fact that the role of the ground electrode disclosed in German Patent No. 27 22 100 B1 is to decrease the powder flow rate and to induce turbulent flow in the chamber while, in the present invention, the ground electrode is positioned to contribute to acceleration of the flow of the powder-air mixture. The German device uses an undulating geometry to provide greater turbulence and longer residence for the powder so as to increase probability of charging. However, the wakes produced behind the ground electrode(s) make it much easier for the powder to deposit on the surface(s) of the ground electrode(s), due to the low velocity of the powder/air mixture. Also, for the same reason, the ion wind driven by the electrical field between the high voltage electrode and the ground counter-electrode will push the powder particles to move backwards and impact on the surface of the ground electrode facing the charging pin which causes impact fusing and curing of paint. By contrast, in the present invention, the accelerated powder-air flow over the surface of the ground electrode prevents the powder particles from being pushed backwards so that impact fusing and curing are avoided.
Another advantage of the present invention is a reduction of curing at the counter or ground electrode due to the lower intensity electric fields surrounding the surface of the counter electrode. In pin-to-pin configurations, curing at the counter electrode may be problematic, which is avoided with the present invention.
It will be appreciated that while the cleaning gas and the gas used to produce the gas-powder mixture has been disclosed as air, other inert gases may be used, for example, nitrogen. In addition, while the different embodiments of the powder dispensing devices as disclosed herein have used cylindrical housings with circular cross sections, it will be understood that the principles disclosed herein are not in any way limited to housings with circular cross sections and housings with other cross-sectional shapes, including square and rectangular, may also be used.
As used herein, the terms “comprises”, “comprising”, “including” and “includes” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises”, “comprising”, “including” and “includes” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.
The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents. | A corona charge spray gun for dispensing powders for powder coatings. The spray gun includes a housing defining a chamber terminating in an outlet passageway. A high voltage electrode is mounted in the chamber spaced upstream of the outlet passageway and a ground electrode is mounted in the chamber spaced upstream from the high voltage electrode. The ground electrode is selected to have a surface area sufficiently larger than the surface area of the high voltage electrode in order to allow high voltages to be applied to the high voltage electrode without arch discharging occurring in the chamber. An inlet opens into the chamber for conducting a powder-gas mixture into the chamber and the electrodes receive cleaning gases for avoiding powder deposits on the electrodes. | 1 |
BACKGROUND
[0001] Valving systems such as tubular valving systems, for example, typically employ seals that are slidably sealingly engaged via radial compression in an annular space defined between movable nested tubulars. When closed ports in the two tubulars are positioned on opposing longitudinal sides of the seal and when open are positioned on a same longitudinal side of the seal. Actuation of such valves simply requires longitudinally sliding one tubular relative to the other such that the ports of one of the two tubulars pass by the seal. The seals can however, be damaged upon such movement since the radial compression of the seal is at least momentarily removed when the port is aligned with the seal. Once the end of the port reaches the seal the seal must be recompressed. This recompression sometimes results in the seal being cut. Additionally, flow by the seal while the seal is uncompressed can dislodge or extrude the seal from a recess designed to position the seal. This can result in leakage upon closure of the valve. Operators of tubular valves are always interested in new devices and methods that avoid the foregoing drawbacks.
BRIEF DESCRIPTION
[0002] Disclosed herein is a valve. The valve includes a first member having a first port therethrough, a second member in operable communication with the first member having a sealing surface thereon and a second port therethrough that is movable relative to the first member. The valve also has a seal sealingly engaged with the first member and slidably sealingly engagable with the second member, and a support member movably disposed relative to the first member and the second member. The support member has a support surface dimensioned similarly to the sealing surface, and is movable with the second member relative to the first member so that upon such movement the seal is continuously supported by at least one of the sealing surface and the support surface.
[0003] Further disclosed herein is a method of supporting a seal of a valve. The method includes moving a second member and a support member relative to a first member and a seal, altering engagement of the seal between sealing engagement with a sealing surface of the second member and supporting engagement with a support surface of the support member, and altering position of a second port of the second member between a side of the seal opposite that of a first port of the first member to a same side of the seal as the first port of the first member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
[0005] FIG. 1A depicts a partial cross sectional view of a valve disclosed herein shown in a closed position;
[0006] FIG. 1B depicts a magnified view of a portion of the valve of FIG. 1A taken at circle 1 B;
[0007] FIG. 2A depicts a partial cross sectional view of the valve disclosed herein shown in an alternate closed position;
[0008] FIG. 2B depicts a magnified view of a portion of the valve of FIG. 2A taken at circle 2 B;
[0009] FIG. 3A depicts a partial cross sectional view of the valve disclosed herein shown in an open position;
[0010] FIG. 3B depicts a magnified view of a portion of the valve of FIG. 3A taken at circle 3 B; and
[0011] FIG. 4A depicts a partial cross sectional view of an alternate embodiment of the valve disclosed herein shown in a closed position;
[0012] FIG. 4B depicts a magnified view of a portion of the valve of FIG. 4A taken at circle 4 B.
DETAILED DESCRIPTION
[0013] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
[0014] Referring to FIGS. 1A-3B , an embodiment of a valve disclosed herein as a tubular valve is illustrated at 10 . The valve 10 includes a first member 14 , a second member 18 movable relative to the first member 14 and a support member 22 movable relative to both the first member 14 and the second member 18 . The first member 14 and the second member 18 both being tubulars in this embodiment, and the support member 22 being a sleeve. A seal 26 is sealingly engaged with the first tubular 14 and slidably sealingly engaged with a sealing surface 30 of the second tubular 18 . The valve 10 is configured such that when moving from a closed position, as shown in FIG. 1A , to an open position, as shown in FIG. 3A , a support surface 34 of the sleeve 22 first moves into supporting engagement with the seal 26 , as shown in FIG. 2A , prior to the valve 10 opening. The foregoing structure assures that the seal 26 is always supported by either the sealing surface 30 or the support surface 34 at all possible positions of the tubulars 14 , 18 and the sleeve 22 . This differs from typical tubular valves that do not include the sleeve 22 and as such the seal 26 is unsupported during actuation of the valve thereby permitting fluid flow to possibly erode the seal 22 or to dislodge it from its seating position with the first tubular 14 . Additional damage can occur to the seal 26 of such valves while being actuated due to clipping a portion of the seal 26 between the tubulars 14 , 18 as the seal 22 reengages with sealing surface 30 after being unsupported. It should be noted that the support surface 34 is dimensioned substantially the same as the sealing surface 30 to minimize any changes in radial compression of the seal 26 as the sleeve 22 and the second tubular 18 move into and out of engagement with the seal 26 . In fact, the seal 26 may sealingly engage with the support surface 34 upon engagement therewith.
[0015] The open versus closed position of the instant valve 10 is determined by the relative longitudinal positions of a first port 38 in the first tubular 14 and a second port 42 in the second tubular 18 relative to the seal 26 . The closed position ( FIG. 1A ) is defined by the second port 42 being on an opposite side of the seal 26 than the first port 38 , while the open position ( FIG. 3A ) is defined by the second port 42 being on a same side of the seal 26 as the first port 38 . The open position allows fluidic communication between an inside and outside of the tubulars 14 , 18 .
[0016] The seal 26 may be constructed of various materials and have various shapes with the seal 26 illustrated in this illustrated embodiment being polymeric with a plurality of chevron elements 46 that are radially compressed between the first tubular 14 and either the sealing surface 30 or the support surface 34 depending on the instant position of the valve 10 . The chevron shaped elements 46 provide increasing sealing forces when pressure is greater on one side than the other. By having some of the chevron shaped elements 46 oriented in each of two opposing longitudinal directions the seal 26 supports greater pressure in both directions than if the chevron shaped elements 46 were oriented in only a single longitudinal direction.
[0017] The sleeve 22 is longitudinally biased between the first tubular 14 and the second tubular 18 by a biasing member 50 illustrated herein as a compression spring. This biasing assures that an end 54 of the sleeve 22 remains in contact with a shoulder 58 of the second tubular 18 whenever the sleeve 22 is moving relative to the seal 26 . This contact prevents a longitudinal gap from forming between the end 54 and the shoulder 58 that portions of the seal 26 could extend radially into if it were allowed to form.
[0018] A shoulder 68 on a second end 72 of the sleeve 22 is contactable with a shoulder 76 on the first tubular 14 to stop movement of the sleeve 22 relative to the first tubular 14 during opening of the valve 10 . This allows the second port 42 to become uncovered by the sleeve 22 as the second tubular 18 moves to position the second port 42 on a same side of the seal 26 as the first port 38 .
[0019] Two detents are formed between the first tubular 14 and the second tubular 18 by a snap ring 78 that move with the second tubular 18 into grooves 82 , 86 on the second tubular 18 . The grooves 82 , 86 are positioned to maintain the valve 10 in the closed position when the snap ring 78 is located in the first groove 82 and the open position when the snap ring 78 is located in the second groove 86 .
[0020] The valve 10 disclosed in this embodiments includes a second seal 90 that sealingly engages with both the first tubular 14 and the second tubular 18 throughout all movements thereof. The second seal 90 prevents leakage between the tubulars 14 , 18 in a longitudinal direction opposite the direction of the first port 38 where the seal 22 is located. Alternate embodiments could employ other means than the sliding second seal 90 shown, such as a flexible bellows member (not shown), for example, that would allow the tubulars 14 , 18 to move relative to one another while maintaining a seal therebetween.
[0021] The tubular valve 10 disclosed herein is employable in any tubular system. For example, the valve 10 could be employed downhole in a borehole of a carbon sequestration operation, in a wellbore of a hydrocarbon recovery operation and in a wellbore of a water well operation, to name a few. These examples often employ very high pressures and flow rates that can be detrimental to seals of typical valves that are unsupported for even short durations of time while such valves are actuated. By employing the disclosed valve 10 in these applications, even higher pressures and flow rates than those currently allowed will likely be achievable.
[0022] Referring to FIGS. 4A and 4B , an alternate embodiment of a valve disclosed herein is illustrated at 110 . The valve 110 employs many of the same components as the valve 10 and as such these components are depicted by the same reference characters. These components will not be described in detail again herein but instead the differences between the two valves 110 , 10 will be elaborated on. Instead of using the biasing member 50 to bias the sleeve 22 against the shoulder 58 the valve 110 employs an interfering member 150 illustrated in this embodiment as a collet that is formed as a portion of the second tubular 18 . The collet 150 includes fingers 156 that are biased radially outwardly such that the fingers 156 interferingly engage with the second end 72 of the sleeve 22 such that when the second tubular 18 is moved leftward in the Figures, the sleeve 22 also moves leftward. This arrangement assures that the sleeve 22 is positioned over the second ports 42 before the second ports 42 move longitudinally past the seal 26 . The sleeve 22 is stopped from moving further leftward when the shoulder 68 on the sleeve 22 contacts the shoulder 76 on the first tubular 14 . The fingers 156 of the collet 150 then flex radially inwardly as the second tubular 18 continues to move allowing the fingers 156 to slide along an inner surface 170 of the sleeve 22 until the second ports 42 longitudinally align with the first ports 38 resulting in an opening of the valve 110 .
[0023] During closing of the valve 110 the sleeve 22 remains in its previous position by frictional engagement with the first tubular 14 , for example, until the shoulder 58 of the second tubular 18 contacts the end 54 of the sleeve 22 thereby causing the sleeve 22 to move with the second tubular 18 from there on until the valve 110 is back to the fully closed position.
[0024] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. | Disclosed herein is a valve. The valve includes a first member having a first port therethrough, a second member in operable communication with the first member having a sealing surface thereon and a second port therethrough that is movable relative to the first member. The valve also has a seal sealingly engaged with the first member and slidably sealingly engagable with the second member, and a support member movably disposed relative to the first member and the second member. The support member has a support surface dimensioned similarly to the sealing surface, and is movable with the second member relative to the first member so that upon such movement the seal is continuously supported by at least one of the sealing surface and the support surface. | 5 |
[0001] The invention relates to an exhaust-gas turbocharger including a compressor and a turbine disposed in a housing with multiple exhaust gas supply passage of which some can be closed by adjustable shut-off flaps.
BACKGROUND OF THE INVENTION
[0002] The publication US 18 16 787 describes a multi-cylinder internal combustion engine, which is equipped with an exhaust-gas turbocharger, which comprises a compressor in the inlet duct of the internal combustion engine and an exhaust-gas turbine in the exhaust duct. The exhaust gas turbine is driven by the pressurized exhaust gases from the internal combustion engine, the rotation of the turbine being transmitted, by way of a common shaft, to the compressor, which draws in the combustion air and compresses it to an increased charge-air pressure, under which the combustion air is delivered to the cylinder inlets of the internal combustion engine. In order to be able to adjust the turbocharger output, the exhaust gas is delivered to the turbine rotor by way of three flow ducts, in each of which a valve is arranged, whose position can be adjusted by way of a common control rod as a function of the charge-air pressure, so as to compensate for pressure fluctuations. No provision is made here for any independent adjustment of the opening cross section of each flow duct, the valves in the flow ducts instead being opened or closed in a set order through the actuation by means of the control rod. In the exhaust-gas turbocharger according to US 18 16 787 no further adjustment facilities are provided other than the atmospheric pressure compensation.
[0003] Another problem is that the shut-off valves in the flow ducts are designed as pivoted flaps, the pivot axes of which extend approximately centrally through the respective flow duct, so that even in its open position the shut-off valve forms an obstacle to the flow of the exhaust gas.
[0004] Another exhaust-gas turbocharger is disclosed by the generic publication DE-AS 1 253 510. The exhaust-gas turbine of this exhaust-gas turbocharger comprises two parallel exhaust manifolds, which each open into a spiral section, which radially surrounds part of the turbine rotor. A pivotal shut-off flap, which can be pivoted between a shut-off position closing the flow inlet of the exhaust manifold and an open position exposing it is arranged in the area of the flow inlet of one of the two exhaust manifolds. In the open position, the shut-off flap is accommodated in a correspondingly shaped recess in the inside wall of the turbocharger housing, thereby avoiding any adverse effect on the flow of exhaust gas entering. No shut-off flap is provided in the area of the second exhaust manifold; the second exhaust manifold remains permanently opened.
[0005] For adjustment of the turbocharger output, the shutoff flap can be adjusted between its open position and its shut-off position, so that given an identical cross section in both exhaust manifolds the total unrestricted inlet cross section available to the exhaust gas inlet flow can be approximately doubled.
[0006] It is the main object of the invention to provide an exhaust-gas turbocharger that is variably adjustable.
SUMMARY OF THE INVENTION
[0007] In an exhaust-gas turbocharger having a compressor and an exhaust-gas turbine, which drives the compressor and comprises a multi-part exhaust gas supply duct manifold and a turbine rotor, to which pressurized exhaust gas can be delivered by way of the exhaust gas supply duct, the exhaust gas supply duct manifold includes at least three flow passages, which, except for one, are provided with shut-off flaps, which are adjustable independently of one another.
[0008] This arrangement allows a maximum number of adjustments for the admission of exhaust gas to the turbine rotor to be achieved using a minimum number of shut-off flaps. The independent adjustment of the shut-off flaps enables the existing flow ducts to be interconnected in any combination, in order to provide a greater or lesser overall cross section for the delivery of exhaust gas, at least the one flow duct having no flap being permanently open, so that a minimum of exhaust gas is delivered to the exhaust gas turbine in any operating condition of the internal combustion engine.
[0009] A further advantage lies in the simplicity of the design. In contrast to exhaust-gas turbines having a variable turbine geometry achieved, for example, by means of a guide baffle with adjustable guide vanes, so that a multiplicity of moveable components have to be adjusted, which increase the susceptibility to malfunction, in the simplest design of the exhaust-gas turbocharger according to the invention, having a total of three flow ducts, only two shutoff flaps are needed, which are arranged in two of the three flow ducts for adjustment of the unrestricted inlet cross section. This reduces the number of moving parts considerably. At the same time, however, the various possible combinations of opened and closed shut-off flaps, available even in the simplest version with three flow ducts, mean that up to four different-sized overall inlet cross sections can be set for the delivery of exhaust gas, which is usually sufficient for all operating conditions both during engine power operation and during engine braking of the vehicle.
[0010] Through an adept choice of inlet cross sections for the flow ducts—such as two flow ducts of equal cross section, one flow duct with a cross section twice as large, for example—four overall inlet cross sections, divided up in the size ratio 1:2:3:4, can be exposed for the various operating conditions of the internal combustion engine.
[0011] In an advantageous embodiment, at least two shut-off flaps are arranged in the two outer flow ducts, and supported so that they are capable of pivoting onto the inside wall of the turbine housing. In this design at least one flow duct, situated in the middle between the two outer ducts, is designed without a flap, the middle flow duct and the two outer flow ducts in each case sharing a common wall in the event of there being a total of just three flow ducts.
[0012] The shut-off flaps are advantageously designed to conform to the contour of the inside wall of the turbine housing and in the open position fit precisely against the inside wall, thereby presenting the least possible flow resistance to exhaust gas flowing in. The outside of the shut-off flap remote from the inside wall of the turbine housing and facing the flow duct may here have a flow-enhancing contour in order to further minimize the flow resistance and to obtain any desired flow effects, such as an acceleration of the flow through tapering of the unrestricted inlet cross section.
[0013] It may also be appropriate, however, to incorporate a recess, designed to conform to the shut-off flap, into the inside wall, in which recess the shut-off flap can be received in the open position. In this design the shut-off flap in the open position can be fully accommodated in the recess, thereby providing for a smooth inside wall surface.
[0014] In order to improve the flow ratios over the turbine rotor a fixed guide baffle may be provided in a duct upstream of the turbine rotor, the duct being connected to, or being part of, the exhaust manifold. In an alternative version, the guide baffle may also be variably adjustable, being axially insertable into the guide channel, for example, or equipped with adjustable guide vanes. A variable turbine geometry is thereby achieved, which permits a multiplicity of possible adjustments of the unrestricted inlet cross section.
[0015] The exhaust manifold—with or without guide baffle—is advantageously divided into a plurality of angular sections, which are hermetically separated from one another, precisely one angular section in the guide channel being assigned to each flow duct. The ratio of the angular sections advantageously corresponds to the ratio of the flow duct cross sections, so that a double angular section is also assigned to the flow duct having twice the cross section.
[0016] The invention will become more readily apparent from the following description thereof on the basis of the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 shows a longitudinal section through an exhaust-gas turbocharger,
[0018] [0018]FIG. 2 shows an exhaust-gas turbine of an exhaust-gas turbocharger in a sectional view taken along the line II-II in FIG. 1,
[0019] [0019]FIG. 3 shows an exhaust-gas turbine comparable to FIG. 2, but with a different division of the areas of the inlet cross sections in the exhaust manifold of the turbine.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] In the figures, identical components are provided with identical reference numbers.
[0021] The exhaust-gas turbocharger for an internal combustion engine represented in FIG. 1 comprises an exhaust-gas turbine 1 having a turbine rotor 3 , which is rotatably mounted in a turbine housing 2 , and whose rotation is transmitted, by way of a shaft 4 , to a compressor impeller of a compressor 22 for the compression of intake air. The exhaust-gas turbine 1 is suitably designed as an axial-flow impulse action turbine.
[0022] A fixed, immovable guide baffle 5 , which serves to optimize the flow ratios of the exhaust gas striking the turbine rotor, is arranged in an exhaust manifold 6 positioned axially upstream of the turbine rotor 3 , through which manifold the exhaust gas from the internal combustion engine is to be delivered axially to the turbine rotor and which is connected to a collecting chamber 13 in the turbine housing.
[0023] According to FIG. 2 the exhaust manifold 6 , positioned axially upstream of the turbine rotor 3 , is divided by means of wall plates 10 , 11 , 12 in the turbine housing 2 into a total of three flow ducts 7 , 8 , 9 . The exhaust manifold 6 is of approximately annular construction, a first flow duct 7 of the exhaust manifold 6 covering an angle range of approximately 180°, which is defined by the two wall plates 10 and 12 . A second, middle flow duct 8 , which is separated from the two outer flow ducts 7 and 9 by the wall plates 10 and 11 , extends over an angular section of approximately 90° of the exhaust manifold 6 in front of the turbine rotor. The third flow duct 9 , which, like the first flow duct 7 , is designed as an outer flow duct, is bounded by the wall plates 11 and 12 and likewise extends over an angular section of approximately 90° of the exhaust manifold. Each flow duct 7 to 9 shares one common wall plate with each of the other two flow ducts.
[0024] The collecting chamber 13 is arranged upstream of the exhaust manifold 6 . The collecting chamber 13 is likewise an integral part of the exhaust-gas turbine 1 ; the exhaust gases from the exhaust of the internal combustion engine are fed into this chamber. The collecting chamber 13 is connected to inlet cross sections 7 a , 8 a and 9 a of the flow ducts 7 , 8 and 9 , the inlet cross sections 7 a , 8 a , and 9 a lying in a common admission flow plane 20 , which separates the collecting chamber 13 from the exhaust manifold 6 . Two shut-off flaps 16 and 17 , by means of which the unrestricted inlet cross sections 7 a and 9 a of the two outer flow ducts 7 and 9 can be closed or opened, are pivotally mounted by way of articulations 18 and 19 on the inside walls 14 and 15 of the collecting chamber 13 . The inlet cross sections 8 a and 9 a of the middle flow duct 8 and of the second outer flow duct 9 are of approximately equal size and each occupy approximately one quarter of the overall flow cross section in the admission flow cross-section 20 . The inlet cross section 7 a of the first outer flow duct 7 occupies approximately half the overall inlet cross section and is therefore approximately twice as large as each of the other two inlet cross sections 8 a and 9 a.
[0025] The wall plates 10 , 11 and 12 extend essentially parallel to one another, the wall plates 10 and 11 between the middle flow duct 8 and each of the outer flow ducts 7 and 9 being situated at approximately the same height and the further wall plate 12 being arranged on that side of the turbine rotor 3 situated 180° opposite, between the two outer flow ducts 7 and 9 .
[0026] The shut-off flaps 16 and 17 can be actuated independently of one another and can each be adjusted between a shut-off position, closing the unrestricted inlet cross section 7 a or 9 a , and an open position, in which the respective inlet cross section is exposed. In the representation shown in the figure both shut-off flaps 16 and 17 are in their shut-off position, so that only the middle inlet cross section 8 a of the middle flow duct 8 is open and all exhaust gas is delivered to the turbine rotor 3 in the direction of the arrow 21 through the middle flow duct 8 . In the open position of the shut-off flap 17 of the second, outer flow duct 9 , the inlet cross section 9 a is also exposed in addition, so that the total unrestricted inlet cross section available for admission of the exhaust gas comprises the individual cross sections 8 a of the middle flow duct and 9 a of the second, outer flow duct, provided that the shut-off flap 16 of the first flow duct 7 remains in its shut-off position. If, on the other hand, the shutoff flap 16 of the first flow duct 7 is in the open position and the second shut-off flap 17 of the opposite outer flow duct 9 is in the shut-off position, the total unrestricted inlet cross section available comprises the individual cross sections 7 a and 8 a of the first, outer flow duct 7 and the middle flow duct 8 . If both shut-off flaps 16 and 17 are in their open position, a maximum inlet cross section is provided, which comprises the individual cross sections 7 a , 8 a , and 9 a of all three flow ducts 7 to 9 .
[0027] The wall plates 10 , 11 and 12 between the flow ducts 7 , 8 and 9 divide the exhaust manifold into different angular sections, hermetically separated from one another, in such a way that the ratio of the respective angular sections corresponds to the ratio of the unrestricted inlet cross sections 7 a , 8 a and 9 a of the relevant flow duct.
[0028] The shut-off flaps 16 and 17 are suitably designed to conform to the contour of the inside wall 14 and 15 of the collecting chamber 13 , so that, in their open positions, the shut-off flaps fit precisely against the inside wall 14 and 15 . If necessary, only that wall side of each shut-off valve 16 and 17 facing the inside wall is designed to conform to the contour of the inside wall, whereas the outside may assume a different form and may, in particular, be optimized with regard to the fluid mechanics. In the shutoff position the unexposed face of each shut-off flap 16 and 17 bears against the wall plate 10 and 11 respectively between the adjacent flow ducts 7 and 8 or 8 and 9 .
[0029] The design according to FIG. 3 differs from that according to FIG. 2 in the ratio of the inlet cross sections 7 a , 8 a and 9 a of the flow ducts 7 , 8 and 9 to one another. The inlet cross section 7 a of the left-hand, outer flow duct 7 occupies half of the total inlet cross section in the admission flow plane 20 . The inlet cross section 8 a of the middle flow duct 8 is approximately twice as large as the inlet cross section 9 a of the right-hand outer flow duct 8 , which taken together cover the remaining half of the total inlet cross section, so that the inlet cross sections 7 a , 8 a and 9 a of the flow ducts are in a ratio of 3:2:1 to one another. It is therefore possible, through corresponding flap positions, to open the total cross section by one third, by half, by five sixths or completely.
[0030] In the open position, the shut-off flaps 16 and 17 are accommodated in recesses in the respective inside walls 14 and 15 of the collecting chamber 13 , so that in the open position there is a smooth, unobstructed inside wall surface without increased flow resistance.
[0031] Use of the invention in a radial-flow turbine and/or a mixed-flow turbine may also be considered as an alternative to an axial-flow impulse action turbine. | In an exhaust-gas turbocharger having a compressor and an exhaust-gas turbine, which drives the compressor and comprises a multipart exhaust gas supply duct manifold and a turbine rotor, to which pressurized exhaust gas can be delivered by way of the exhaust gas supply duct, the exhaust gas supply duct manifold includes at least three flow passages, which, except for one, are provided with shut-off flaps, which are adjustable independently of one another. | 5 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to signal evaluating equipment and in particular to a new and useful arrangement for evaluating an optical beam which has passed through a Bragg-cell, in particular a Bragg-cell which has been exposed to radio frequency signals.
An arrangement to evaluate optical beams is known from the article "Bragg-Cell RF-Signal Processing" by Coppock et al, Microwave Journal, September 1978, pages 62-65. In such an arrangement, an RF signal to be analyzed produces sound waves in a Bragg-cell causing the deflection of a light beam passing through the Bragg-cell. Advantageously, a coherent light beam, for example a laser beam, is used. The diffraction patterns produced by the deflected light beam are to be considered as Fourier transforms of the RF signal into the frequency range (frequency range here corresponds to angular range) and are usually evaluated by means of photodetectors, to measure the spectral power density of the RF signal.
With Bragg-cells of high resolution, several hundred points must be evaluated. For this purpose, so-called "photodiode arrays" are usually employed which have a serial display (digital or analog) through connected shift registers. The signals of the photodetectors are available in time sequence (in phase with the shifting cycle of the shift register), i.e. always only a single signal of a photodetector (corresponding to a frequency window of the RF signal) is available. The intensity of the signal (photocurrent of one photodetector) corresponds to the integral ##EQU1## wherein T=integration interval of the photodetector, and P RF (t) a variation in time of the signal amplitude during the integration interval. The integration interval T of the photodetector may be taken as being about N.τ with N being the total number of photodetectors, and τ being the duration of the shifting cycle at the sequential readout. Thus, not the true spectral power of the RF signal, but the integral power within a frequency window is determined corresponding to the angular range covered by a single photodiode. If, as in an RF monitoring reception for example, a plurality of pulse modulated transmitters is concerned, having overlapping spectra and/or pulse repetition rates smaller than the integration interval T, neither the power nor the spectrum of the individual transmitters can be inferred from the photocurrent of a single photodiode associated with a definite frequency window.
Another disadvantage is that the limiting sensitivity (minimum detectable RF power or brightness in the angular interval) of photodiode arrays is poor. This is primarily due to the small photoactive areas of the photodiode arrays.
SUMMARY OF THE INVENTION
The present invention is directed to an improved arrangement of the above-mentioned kind, which increases the limiting sensitivity for RF signals and permits the determination of a true spectral power of an RF signal and the evaluation of any frequency windows in any way.
Accordingly an object of the present invention is to provide an arrangement for evaluating an optical beam which can be deflected by means of a Bragg-cell, which comprises a light wave guide having at lease one entrance gate and at least one exit gate, the entrance gate being disposed adjacent the Bragg-cell for receiving light deflected thereby, and the exit gate being optically coupled to at least one photodetector for generating an output, and at least one evaluating unit for receiving and evaluating the photodetector output.
Another object of the invention is to provide such an arrangement wherein the light wave guide includes a plurality of aligned entrance gates which are closely adjacent each other, and a plurality of spaced exit gates each associated with a separate photodetector.
A still further object of the invention is to provide such an arrangement wherein the evaluating unit is provided with at least one alarm device for determining the presence of at least one RF signal, by which the frequency range and/or channel number of at least one RF signal which has been applied to the Bragg-cell, is determined.
A still further object of the invention is to provide an arrangement for evaluating an optical beam which can be deflected by means of a Bragg-cell, which is simply in design, rugged in construction and econimical to manufacture.
A primary advantage of the invention is that the electrical output signals produced by the photodetectors can be evaluated in any way, for example through a data processing device. It is possible, for example, to simultaneously monitor a plurality of frequency windows, in a so-called "multiple reading mode", and/or to monitor any of the frequency windows, in a so-called "random addressing mode". The "random addressing mode" makes it possible, for example, to monitor only certain, particularly important frequency windows at a monitoring rate which is higher than that obtainable with a time-sequential, cyclic operation by means of a photodiode array.
Another advantage of the invention is that photodetectors may be employed which are best suitable electrically and/or optically, while their geometry and/or mechanical structure can almost be neglected.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a schematic representation of one embodiment of the invention;
FIG. 2 is a schematic representation of one embodiment of the electronic evaluating unit used in the invention; and
FIG. 3 is a schematic representation of another embodiment of the evaluating unit used in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the invention embodied therein comprises an arrangement for evaluating an optical beam which can be deflected by means of a Bragg-cell which includes a light wave guide for conveying the deflected light beam from the Bragg-cell to one of a plurality of photodetectors, and an evaluating unit 5 for evaluating signals from the photodetectors.
As shown in FIG. 1, an optical beam 10, preferably a coherent light beam, issuing from a light source 1, preferably a laser, falls on a Bragg-cell 2, for example a crystal, to which an electromechanical transducer 21 provided with electrical leads 22 is coupled. If now an electric signal, such as an RF signal to be monitored, is supplied through leads 22 to transducer 21, which is a piezoelectric ceramic element for example, acoustic oscillations are excited in the Bragg-cell by which the incident beam 10 is deflected (reflected). Since a modulated RF signal is assumed, an optical output beam 20 thus produced moves as indicated by the double arrow 24. The motion of output beam 20 may thus be considered a transformation of the frequency range into the geometric, multi-dimensional space. From the spatial position of output beam 20, for example, frequency variations in time of the exciting RF signal may be inferred.
In accordance with the invention, output beam 20 falls upon at least one of the entrance gates 31 of at least one lightwave guide 3, for example an optical glass fiber. With a proper spatial arrangement of entrance gates 31, for example, along a straight line, and an optically effective cross-section thereof, for example squares or other suitable polygons of as small an area as possible, the spacing between adjacent entrance gates 31 can be minimized to ensure an exact determination of the spatial position of the output beam. From this position and variation in time thereof, the exact frequency or frequency variation of the exciting RF signal can be determined. Further, it is advisable to isolate entrance gates 31 from each other optically, to prevent so-called optical coupling between adjacent lightwave guides 3. The just mentioned arrangement may be obtained, for example, by wrapping the optical fibers having a substantially square and/or rectangular cross-section, in substantially opaque envelopes and connecting them in juxtaposition by means of an adhesive to a so-called flat optical cable. If then, one end of such a flat cable is ground and polished, the desired entrance gates 31 are obtained which may be provided with a reflection-reducing coating for the wavelength of the light used.
The other end of the flat optical cable is fanned out to couple each of exit gates 32 of lightwave guides 3 to at least one photoconductor 4, as shown in the figure. Such an arrangement makes it possible to select photodetectors 4 which are best suitable for the specific application. In the shown example, photodetectors 4 comprise individual (discrete) photodiodes which are electrically connected, by their anodes, to at least one electric current or voltage source (not shown), and by their cathodes, through resistances, to ground. The optical properties (spectral sensitivity, aperture) and electrical parameters (response or follow-up time) of such a photodetector 4 can easily be brought into relation with the properties required for the specific analysis of RF signals. If, for example, rapid frequency variations are to be analyzed, a small time constant T=R·C of photodetector 4 is wanted, with R or C being the values of the electrical resistance or capacitance of photodetector 4.
The electrical outputs 41 of photodetectors 4 are connected to at least one evaluating unit 5 comprising, for example, preamplifiers 51 and pulse shapers (not shown) and an electronic data processor (microprocessor). Such an evaluating unit 5 is very versatile in analyzing electrical output signals of photodetectors 4 and of RF signals to be monitored, and makes it possible, for example, to simultaneously monitor a plurality of frequency windows (multiple reading mode), or to monitor in any way any frequency window (random address mode).
The invention is not limited to the described embodiment. For example, it is within the scope of the invention to couple exit gates 32 to an optical switch (demultiplexer) having a single photodetector 4 applied to its one output, and being switches by the evaluating unit. Further, incident beam 10 may be split into a plurality of light beams which are deflected at a Bragg-cell by means of a plurality of transducers 2. Then, with correspondingly distributed entrance gates 31, a plurality of RF signals can be monitored.
FIGS. 2 and 3 show an embodiment of an electronic evaluating unit according to the invention. For clarity, a unit for evaluating electrical output signals of only four photodetectors is shown as an example. It is possible to enlarge the system to any number of photodetectors. The diagrammatical connecting lines between individual schematically indicated electronic sections relate to the main signal flow only, which is indicated by arrows.
A unit described in the following is advantageously very inexpensive and makes different modes of monitoring the above mentioned RF signals possible at a high speed of evaluation.
In a first exemplary mode of operation, whether an RF signal is present in a given frequency band is to be determined. Then, an RF signal, which is assumed to be present, is to be analyzed, for example as to its frequency and/or variation in time and electric power.
Another exemplary mode of operation is to monitor known RF transmitters and/or RF frequency channels.
FIG. 3 is a schematic of the evaluating unit, the circuitry and operation of which is explained in the following with reference to FIG. 2. Identical reference numerals are used in both figures to represent identical or similar parts.
In FIG. 2 at least one electrical output signal (RF pulses) of a photodetector 4 passes through a preamplifier 51 to a coupling capacitor 52 by which a disturbing DC voltage (DC offset) which might occur is kept away from the following comparators 53. A reference voltage is applied to comparators 53, through an adjustable voltage source 54, which permits the cutting out of RF pulses that fall short of a certain minimum amplitude (sensitivity adjustment). Each RF pulse in any frequency channel, and thus any photodetector 4, produces a voltage pulse at the output of the respective comparator 53, having a selected amplitude such that a following digital signal processing is possible, for example in the so-called ECL technique.
The output signals of all the comparators 53 are supplied to an alarm device 55, for example an OR gate, where a so-called alarm signal is produced at the output, i.e. in an alarm line 551, at the instant when, during the involved period of time, at least one RF pulse has occurred in the frequency band B=N·Δf, wherein Δf is the equivalent bandwidth of an individual channel, and N is the number of individual channels, i.e. four in the present example. To test the frequency band B exactly, it is not sufficient to ascertain that at least one RF pulse occurred. The respective channel numbers must also be determined. This is done by applying the N outputs of comparators 53 to the N inputs of latches 56, for example flip-flops. An n-digit binary information is thus obtained at the N outputs of latches 56, indicating in which individual channel an RF signal occurred, for example "1" means at least one RF pulse in the considered individual channel, "0" means no pulse in this channel.
The binary information is read out through a readout device 57, for example N AND gates having their outputs interconnected through a common OR gate 58. At the output of OR gate 58, a store instruction appears for a high speed address storage 59. In a binary channel counter 60, an address is continually produced which also is supplied to address storage 59 and stored therein as soon as a store instruction arrives. The output of binary channel counter 60 is further applied to binary-to-decimal decoder 61 producing all numbers within the range of l to N in ascending order until, upon reaching a maximum number N, it is reset by a binary comparator 62. The N outputs of binary-to-decimal decoder 61 are applied to the AND gates of readout device 57 where an interconnection with latches 56 is affected. Upon an accomplished storage, binary comparator 62 produces in addition a reset pulse which is transmitted through a reset line 621 to channel counter 60 and latches 56, so that a new address can be stored. A clock 601 produces the timing pulses for channel counter 60. A connection line 620 serves the purpose of setting the maximum number Nmax in binary comparator 62. The contents of address storage 59 are displayed through a so-called interface 630 by an indicator 63, for example a cathode-ray tube (CRT). The output of (analog) preamplifiers 51 are further applied to an analog selector switch 64 which can be switched through a connecting line 641 (channel select address) to obtain at the output 642 of analog selector switch 64, the analog RF signal present in a certain individual channel, for further testing.
The arrangement described in the foregoing has the following advantages: In addition to a single-channel analog evaluation (output 642) of an RF signal to be tested, a general information (alarm line 551) and a channel-oriented detail information with an associated address (address storage 59), on a frequency band to be tested, are made possible, with the option of cutting out RF pulse amplitudes which might be desirable (sensitivity setting at the adjustable voltage source 54).
The section for working out the digital information described in the foregoing, including the operation of (analog) comparators 53 and address storage 59, operate very rapidly so that in the course of a signal seeking cycle taking some microseconds, the entire frequency band B to be tested can be analyzed generally as well as closely. This ensures a quick monitoring of the frequency band, with a 100% pickup chance. If the binary information in this storage 59 is used for addressing (through 641) the individual (analog) frequency channels of interest, the above described registering arrangement changes into an interactive arrangement. Such a further development is described in the following with reference to FIG. 3.
In addition to the circuitry of FIG. 2, FIG. 3 shows an address processor 65 permitting the selection in advance of certain (frequency) channel groups having channel numbers N2-N1, or individual frequency channels (N2=N1), through a programmable channel counter 60. The binary comparator 62 which is programmable through address processor 65, determines a channel group limit in channel counter 60, for example the channel number N2. Address processor 65 does not work up the active (channel) addresses in address storage 59 cyclically, but in accordance with an information file 601 of a main computer 66. In this information file 601, the properties, such as transmitter power, of known (frequency) channels are stored. Also, new data may be stored in information file 601 through main computer 66. In this way, (frequency) channels of particular interest can be handled preferentially. If, for example, a certain address (channel number) is selected in address processor 65, and if an RF pulse appears in this channel, a store instruction is produced which is based solely on the (frequency) channel selected by the selector switch 64 through connecting line 641 (channel select address). The store instruction is supplied through a connecting line 581 to a sample hold circuit 67 by which an analog sample is taken from the selected channel simultaneously with the store instruction, which is then converted, in a following analog-to-digital converter 68, into a binary word. This binary word corresponds to the analog value of the RF pulse power at the instant of the analog sample taking.
The occurrence in time of the store instruction is a measure of the so-called real-time occurrence of an RF pulse to be tested. If a plurality of RF pulses occur in a (frequency) channel in time sequence, the time interval between the stored instructions thereby produced is a measure of the RF pulse repetition intervals to be determined. All the data determined, for example repetition period and channel address, are initially processed in a signal processor 69, then stored in data storages 691, 692, 693, and displayed by a display 70 which also collects information from main computer 66. Advantageously, the described arrangement may be operated in a so-called stand-by mode and activated only if an alarm signal arrives at main comouter 66 through alarm device 551.
In another embodiment (not shown) an RF pulse signal to be tested is initially supplied to an RF mixer, to which also a frequency oscillator is connected in which the frequency is commutated continuously in time. This makes it possible to monitor a wide frequency band continuously in time. The output signal of the RF mixer, designated as baseband, is supplied to the transmitter 21 shown in FIG. 1. If an RF pulse appears in a frequency band monitored in this way, the frequency oscillator can be prevented through alarm 551 (FIG. 3) from switching over, and the RF signal can exactly be analyzed by means of the arrangement of FIG. 3.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A high-resolution Bragg-cell receiver for monitoring and/or analyzing the frequency of RF signals comprises a lightwave guide arrangement with discrete photodiodes coupled thereto which is substituted for a photodiode array. The guide has closely spaced inlets for light from the Bragg-cell and fanned-out outlets for coupling to the discrete photodiodes. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a system and implement for the surveying and mapping of land surfaces by recording unevennesses, and for serving as navigation aid especially in uneven terrain.
2. The Prior Art
The precise recording of surface features causing unevenness of the topography is of importance not only in map-making but, on a smaller scale, in such activities as agriculture and road and airfield construction. In agriculture, unevennesses must be discovered and evened out in order to prevent the undue collection or runoff of rain and irrigation water and to obviate the impairment of the accuracy of farm machinery working, which is unpredictably affected by topographical irregulaties which influence, among other things, the depth of penetration of such implements as cultivators, planting machines, and the like. In airfield runway and road construction, uneven surfaces--caused by uneven foundations--lead to excessive vibrations and rough rides, especially at high speeds, as well as to the accumulation of rain water in puddles.
A great number of implements, relying on a variety of principles, have been devised and are in more or less widespread use. The following are worth mentioning:
Israel Patent Number 38696 is based on the recording of the movements of a damped pendulum. The degree of damping is critical to this type of instrument, since too little will cause excessive swings owing to the influence of inertia, while too much damping will adversely affect the responsiveness of the device. These difficulties have militated against its general introduction.
Also based on a mechanical construction is the so-called inertial platform, which is carried on a vehicle and relies on gyroscopes to maintain a steady position against which deviations from the plane are measured and recorded. One drawback of this system is its extremely high price, another that it is prone to a number of errors that must be taken into account if acceptable results are to be obtained.
Optical principles and techniques are employed in the photogrammetric surveying of the ground, generally from high or low-flying aircraft depending on the quality of the details desired. An important disadvantage of this method is the fact that results are received only after a certain delay, because of the need for processing the photographs taken.
A more modern application of optical methods is a system using laser beams and known under the Trade Name of LASERPLANT. A revolving laser beam creates a stationary plane of monochromatic light against which deviations are measured and recorded by means of a pick-up device locked onto it and carried on an expandable mast mounted on a vehicle, the pick-up being raised and lowered by the mast in accordance with the irregularities encountered. Again, one of the drawbacks is its high price and limited range.
Finally, deviations from the plane can be measured by vehicle-borne ultrasonic sounding equipment. However, the applicability of this system is limited especially by the fact that no plane of reference can be resorted to.
All the methods enumerated, with the exception of the "Laserplan" type of device, have the one common drawback of their inability to refer their measurements to a common plane of reference and will thus give a little or no indication of the overall nature of the terrain surveyed; nor can any of them be used as navigational aids. The "Laserplan" type of device, for its part, is limited in its ranges, both horizontally (distance from the revolving laser beam) and vertically (the heights recordable being circumscribed by the properties of the mast carrying the pick-up device).
The present invention seeks to overcome these drawbacks by presenting a system that is both simple and rugged and produces results that are invariably referred back to a plane of reference, viz. the plane from which the survey initially started.
SUMMARY OF THE INVENTION
The implement of the invention consists of two carriages connected together by a centrally located universal joint, a first carriage--generally the leading one and thus referred to in this specification--having at least two wheels, one behind the other in the direction of travel, but preferably three or four for the sake of stability; the second carriage,, generally the trailing one, having one wheel only or preferably two co-axial wheels. For the sake of simplicity, the distance between the axis of the front and the rear wheels of the leading carriage--the latter wheel also being referred to as the centre wheel of the implement--equals the distance between the axis of the centre wheel and that of the trailing wheel, the latter also referred to as the rear wheel of the system.
The leading carriage is preferably self-propelled, such as an overland motor car, e.g. a Jeep. At least one of the wheels is equipped with a device for measuring the distance travelled. Two further measurement devices are fitted, one to measure the vertical angle between the two carriages, the other to measure the horizontal angle. The readings of the three measuring devices--all of a type delivering electrical signals--are fed into a computer carried on one of the carriage--generally the leading one--which is programmed to produce the horizontal distance travelled, the actual route traversed, and the profile of the route travelled.
At the beginning of the survey care should be taken that the implement stands on a horizontal plane in such a manner that the vertical and the horizontal angles between the two carriages are Zero and that the direction in which the implement points is known. All the measurements and surface recordings that follow will then automatically be referred back to the initial plane and direction.
By adding a video display screen (or x-y-z recorder of known design) on which a map of the area surveyed is projected as well as the route travelled by the implement of the invention, the position of the implement in the area can be shown at any desired moment; and when the point to be eventually reached is also projected--determined by beeline direction and azimuth angle--the implement serves as a navigational aid in difficult terrain.
Optionally, a third angle-measuring device producing an electrical signal may be added in order to measure the angle of twist between the axis of the implement's centre wheels and that of the rear wheels (when the latter are trailed) or that of the front wheels (when the latter are pushed). In that manner a transverse profile of the route travelled may be obtained. When a more precise transverse profile is desired, one of the carriages may be fitted with a transverse boom to which instruments measuring the distance between the boom and the ground--the height of the instrument above ground--are attached, such instruments being placed at intervals and in numbers according to the precision required. Instruments of this kind are known to the art and may be of the mechanical, optical, ultrasonic, or short or ultra-short wave (electro-magnetic) type. Obviously, both when the angle of twist and/or the transverse profile is to be measured, two wheels must be trailed or pushed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a schematic side view of the implement, showing the front carriage frame foreshortened because of its deflection as shown by FIG. 1b;
FIG. 1b is a schematic view from above of the implement of the invention, showing the front vehicle frame foreshortened because of the drop of the front wheels as shown in FIG. 1a;
FIG. 2 illustrates schematically two consecutive positions of the implement of the invention;
FIG. 3 describes the method of increasing the accuracy of profile drawings;
FIG. 4 schematically shows a boom and a height-measuring instrument for producing a transverse profile;
FIG. 5 is a side view of an implement showing a vertical section of a universal joint connecting the leading and the led carriage;
FIG. 6 is a plan view and section along line B--B of the implement illustrated in FIG. 5; and
FIG. 7 is a cross section along line C--C of FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENT
The functioning of the system will now be explained with the aid of the drawings. Referring to FIG. 1, the implement consists of two carriages, the frames of which are represented by a straight line each, (1) being the leading carriage, (2) denoting the led carriage. It will be understood that the led carriage could be either pulled or pushed by the leading carriage; in the following, however, reference will always be made to the arrangement wherein the led carriage is pulled, and a tractor-relationship will be used in order to avoid confusion.
The leading carriage has two wheels shown, one behind the other--(3) and (4) respectively being the front and centre wheels of the system--the trailing carriage (so called whether pulled as illustrated or pushed) has one wheel, the rear wheel of the implement as illustrated. FIG. 1a being a schematic side view, any other wheels on the same axis will be hidden; but for the explanation of the principle only one wheel of each type is needed. The leading carriage is preferably a self-propelled vehicle of the cross-country type; the trailing carriage, which essentially consists of a shaft or thill and a traverse for attachment of the wheels, or a fork if only one wheel is fitted, may have two wheels on the same axis, the space between them, conveniently but not necessarily, being of the same order as that between the centre wheels, or it may have one wide-rimmed wheel, both alternatives ensuring upright stability.
The two carriages are connected together by means of a universal joint as illustrated in FIGS. 4, 6 and 7. In the initial position, at the outset of the survey, the implement should stand on a level plane so that the two frames, represented by lines (1) and (2) linking the hubs of the wheels--are in one straight line. The distance between the axes of the front and center wheels of the implement is "A" as is that between the axes of the center and rear wheels. This equality greatly simplifies the mathematics and consequently the programming of the associated computer; but unequal lengths are not excluded provided programming is adjusted accordingly. Such inequality may occur if, for example, self-propelled vehicles of different wheel-bases are used with one and the same trailer. In that case either provision must be made for this contingency in the computer program or the shaft of the trailing carriage must be made expandable and contractable and be adjusted to the appropriate length.
The position shown in FIG. 1 is one in which the implement's front wheels have entered a depression, so that the two frames form an angle a as shown. At the same time the tractor has turned from the straight line pointed by the shaft (2) of the trailer through an angle b which is illustrated in FIG. 1b and indicated in FIG. 1a by the foreshortened length of the frame, given by A cos b. The front wheel has dropped through a height h to its new position H after travelling a distance equal to the distance between the axes of the front and center wheels of the implement. The distance so tavelled is measured by an odometer device 9, shown positioned on the center wheel (FIGS. 6 and 7), although it may be connected to any of the other wheels. The height h through which the front wheel has dropped is given by the formula h=A sin a, and the relative height of point H 1 , if the altitude of the initial position, H o , is known, by the formula H 1 =H o -h=H o -A sin a. Obviously, since sin(-a)=-sin a, the sign of the sine will be negative when the front wheel drops relative to the center wheel and positive when it rises.
FIG. 2 assists in arriving at a general formula. Here the front wheel of the implement has risen to a point H 1 and has then continued to rise, to arrive at a further point H 2 . The center wheel is now at H 1 , and the rear wheel has reached the position initially occupied by the center wheel. The height of the point attained by the front wheels relative to the initial point, viz. H o , is given by H 2 =H 1 +A sin (a 1 +a 2 ), where a 2 is the vertical angle between the two carriage frames upon their reaching point H 2 , while a 1 is the vertical angle between the two frames that existed when the front wheel was at H 1 . Similarly, if the ascent continues and a point H 3 is reached, the height relative to the initial position H o will be H 3 =H 2 +A sin (a 1 +a 2 +a 3 ), where a 3 is the vertical angle between the vehicle frames at point H 3 . At any point, H i , the height relative to the initial position is: ##EQU1##
For the use of the system of the invention as an aid to navigation the horizontal distance travelled is of special importance. That distance can be determined by similar reasoning; thus, with the symbols used in FIG. 2: ##EQU2## Measurements will be taken, and calculations made, whenever the center wheel has reached the position occupied by the front wheel at the preceding measurement-taking, as indicated by the odometer signal. If greater accuracy is desired, the individual distances between measurements will be shorter than a, as illustratted by FIG. 3, in which the distance referred to is assumed to be A/5. In that case: ##EQU3## and so on; and generally: ##EQU4## where k is an integer being the quotient of i/n, and the distance between measurements is a/n.
Similarly, the distance travelled along the path taken by the system is given by the formula: ##EQU5## The computer carried by the system will be programmed accordingly.
Turning now to the universal joint--6 in FIG. 1b--linking the two parts of the system of the invention, in engineering practice a universal joint consists of two forks, one each at the ends of two abutting shafts, the two forks being positioned so that the lines linking the ends of their two prongs are at right angles to each other. Each of the two forks, and with them the shafts to which they are attached, is free to swing round an axle situated between the two prongs, the two axles being fixedly joined together. With the aid of this device the two shafts can assume a wide range of angles with respect to each other, yet they may revolve together in the same direction.
For the present invention this concept has been modified to satisfy the particular requirements of the link between the leading vehicle and the trailer and to accommodate the angle-measuring devices.
A preferred embodiment of the idea will now be explained with the aid of FIGS. 5, 6 and 7.
A U-shaped vertical frame 17, rigidly connected to the chassis or frame 1 of the leading carriage, bears the two center wheels 4, as well as the measuring instruments serving the present invention, namely the device measuring the vertical angle a, (10), the device measuring the horizontal angle b, (11), and the odometer (9), which measures the distance travelled by the implement as evidenced by the revolutions of the center wheel, to which it is attached. The rear wheel or wheels is (are) attached to the leading vehicle by means of a thill 20 via a bearing 15, which permits the thill to turn axially (to "twist") when either the leading carriage or the trailer, or both, twist owing to the unevenness of the terrain. The thill ends inside the U-shaped frame in a vertical fork 14. It can turn through a horizontal angle, being pivoted on a vertical axis 13, itself rigidly fixed at right angles to a stub 12, which is concentric with the centre wheels and which, in turn, is pivoted on the measuring device 10, measuring the vertical angle between the leading vehicle and the trailer, transmitted to the instrument by the thill 20. The readings of all the instruments--the odometer 9, the device 10 recording the vertical angle 10, and the device 11 recording the horizontal angle--are transmitted to the computing device 16, which is programmed to display, on a screen, the route travelled and to calculate the profile with reference to the point of departure. The universal joint is represented by the fork 14, the bearing 15, and the T-shaped combination of pivots 12 and 13. When it is desired to include in the display the angle of twist, a suitable probe is attached to the bearing 15, on the trailer thill, and the signals generated by the probe are transmitted to the computer 16.
The first carriage is provided with a single front wheel 3 which is swivellingly attached to the front portion of the frame 1 by means of a vertical fork 18 and a vertical pin 21 which is rotatingly fitted in the front end of the frame 1. A drawbar 22 serves to attach the implement to a traction vehicle.
As an alternative the implement may be self-propelled by an I:C-engine mounted on the first carriage.
Owing to the presence of the measuring instruments and the universal joint associated with them it is advisable, in the case of the thill 20, and the trailer connected with it being trailed rather than pushed, that the leading carriage be of the front-wheel-drive type. When the "trailer" is pushed, a rear-wheel-drive carriage will be found preferable, but in this case the steering action of the front wheels and the mechanism associated with it are likely to complicate the construction.
When the entire system--leading carriage and trailer--is trailed or pushed, the stub 12, can easily be mounted concentrically with the center wheels; and the vertical angle, a, will then automatically be the "true" angle as shown in FIGS. 1 and 2. When the U-shaped frame 17, containing the universal joint and the measuring and other apparatus is designed as a separate, detachable unit, to be mounted on self-propelled vehicles drawing or pushing the trailer, provision must be made in the computer program for the different vertical angles measured, since the pivot 12 is offset against the axis of, respectively, the rear or the front wheel of the selfpropelled carriage. Alternatively the lead carriage's thill 20 which is expandable and contractable, must be adjusted so that the distance between the axis of the rear wheel and the axis of the pivot 12, equals the distance between the axis of the pivot 12, and the axis of the rear wheels--if the system of the invention is trailed, or that of the front wheels--if the system is pushed. The level of the pivot 12 should be that of the center of the rear or front wheels.
The U-shaped box should conveniently, and for reasons of mechanical strength, have at least three sides, viz. two substantially parallel lateral sides to which the center wheels can be attached--in the case of the selfpropelled carriage, or the pivot 12, with its angle-measuring instrument--if the U-shaped box is made detachable; and a third side connecting the two lateral ones. The remaining three sides may be partially closed to protect the devices inside it; but free play must be afforded the thill 2. Strictly speaking, only one, preferably upright, side is required, since all the devices are attached to one lateral side of the box; but for reasons of security, cleanliness in field conditions, etc., a U-shaped box or partially enclosed box will be preferred. | A surveying and mapping implement indicates the level differences of the ground over which it travels, in relation to the distance travelled. It comprises a carriage consisting of a swivelling front wheel, two center wheels attached to the outside of a U-shaped vertical frame, and two rear wheels connected to the U-shaped frame by means of a thill and a universal joint positioned co-extensive with the axis of the center wheels. The universal joint permits the rear wheels to move up and down and sideways, as well as to twist in relation to the center wheels. The wheel base between the center wheels and the front wheel is identical with that between the center wheels and the rear wheels, in order to facilitate calculations. Recording instruments are provided on the carriage adapted to measure the distance travelled, the different angles of inclination and of angular twist of the rear wheels in relation to the center wheels, and to transmit their output to computer means adapted to record the surface features of the ground. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to vertical display panel units and particularly to a portable folding display unit having improved frame construction, hinges, and fastening devices for interconnecting adjacent panel units.
Vertical display panels are used by educators, for displaying course materials and the like, and by manufacturers and other businessmen to display their materials at trade shows, sales meetings and the like, and are generally useful in many similar or related situations. Particularly in the case of displays to be used by manufacturers, educators, and salesmen to disclose and display the same materials at several successive exhibitions it is desirable for display panel units to be quickly and easily erected or disassembled and packed for shipping. Displays which are difficult to set up require longer lead time. Added costs are incurred when displays must be shipped ahead to be erected in advance of the scheduled opening of an exhibition, instead of merely being carried as baggage accompanied by the personnel who will be making presentations illustrated by the displays.
Preferably, such display devices are sturdy enough to support not only printed material but small samples or models. Nevertheless the display devices should be as light in weight as possible consistent with the required strength, so that the costs of shipping displays by air carrier are minimized, and so that the displays may be carried and set up easily by people of ordinary size and strength.
It is highly desirable that a display unit have no loose connecting parts or pieces which might be lost during travel or the process of erection or disassembly of a display. Nevertheless, a display unit should be capable of being packed in containers small enough to be carried in passenger vehicles, when possible, in order to minimize transportation difficulties.
Ideally, the above-described desirable features could be provided in an inexpensive display unit. Additionally, it is desirable to provide a display device which permits exchange of panels including permanently affixed display material, and which permits internal illumination of a display unit.
In the past, sturdy, lightweight panel display units have been constructed with wooden frames surrounding lightweight synthetic plastic foam core material. Protective metal frame members are attached to the wooden frame by wood screws and similar fasteners, because no better or more economical construction has been generally known to the industry, although use of such fasteners is undesirably time-consuming and expensive. For displays of significant height, upper panel sections have been connected to lower panel sections by pin-and-socket arrangements which are only marginally satisfactory, as they are difficult to align for assembly and may be difficult to disassemble because of the tendency of the pin-and-socket arrangements to become jammed because of misalignment.
Laterally adjacent individual panel members have previously been interconnected by hinges which must be pinned together during erection of the display unit assembly. Separation of the hinged members upon disassembly of a display has presented the risk of loss of hinge pins and related fasteners. As a result, the previously known display units for portable displays have been less than satisfactory in their cost, their weight, and their convenience for assembly and disassembly.
What is desired, then, is an improved vertical panel display device which is sturdy, yet light in weight, inexpensive to manufacture, and easy to assemble during manufacture, and which permits repeated interconnection and separation of upper and lower panel units without difficulty, and which permits displays to be folded and packed for transportation without disassembly and potential loss of parts of hinges or other interconnecting devices.
SUMMARY OF THE INVENTION
The present invention provides a display unit which overcomes the aforementioned shortcomings and disadvantages of the previously available display units. The display unit of the present invention is inexpensive to construct, in comparison with previously available display units of this type, is light in weight, and is easier to erect or to disassemble and pack for transportation than the previously available display units of this type.
The present invention provides a multi-panel display unit, in which each panel, in a preferred embodiment of the invention, includes a core of lightweight synthetic foam covered by a stiff, relatively hard sheet material, which, in turn, may be covered with a suitable fabric layer. All of these layers are assembled to provide a predetermined total thickness which corresponds to the size of a standard frame assembly. The frame assembly is of a uniform size, regardless of whether the panel faces are of hard material or are cover by fabric.
The frame assembly includes a connector member, and the peripheral surfaces of the panel core are machined specially, providing a groove to accept the connector member in a lockingly mating relationship. The connector member provides a reinforcement of the margins of the panel units, making the previously used wooden frame unnecessary, and connects a protective and supporting metal channel outer frame to the panel units. A bead on one edge of the connector fits in the groove in the core, while edges of face portions of the connector lockingly fit in grooves defined within the channel members of the frame.
In a preferred embodiment of the invention, a latching plunger mechanism is provided to connect a removable portion of the channel frame to the connector members in a releasable manner permitting disassembly and exchange of individual display panels as desired or required in preparation of a particular exhibit. Additionally, in a preferred embodiment of the invention, fabric hinges connect the frames of adjacent panel units and facilitate pivoting movement of each panel unit in either direction relative to the adjacent panel, permitting the several panels of a display unit to be folded compactly for transportation without limiting the ability of the display unit to be erected with the panels in a desired angular relationship to one another.
The invention also provides a fastening device for fastening the frames of upper and lower panel units securely to one another. The fastening device is easily fastened or separated and is self-aligning.
It is therefore a principal object of the present invention to provide an improved folding portable display panel assembly which is economical to produce, and which is sturdy, yet light in weight.
It is another important object of the present invention to provide an improved display panel frame permitting convenient exchangability of individual panel faces of a display unit.
It is yet a further object of the present invention to provide a portable display unit which can be folded into a conveniently portable configuration without removal and potential loss of hinge parts, and which includes a fastener for removably interlocking upper and lower display panel sections with one another.
An important feature of the present invention is a frame assembly including a connector member, which may be a plastic extrusion, and which serves to strengthen the panels of the display unit by being matingly connecting with them, and which also matingly connects an outer frame of metal channel configuration to the panels.
Another important feature of the present invention is the provision of a panel constructed of light, yet strong synthetic plastic foam material covered by a backing layer of strong durable sheet material attached to the core by a pressure sensitive adhesive.
A further important feature of the present invention is the provision of a fabric hinge assembly which permits a panel section to be pivoted through an angle of 360° with respect to an adjacent panel and to lie flat against such adjacent panel regardless of which direction it is pivoted.
Yet another feature of the present invention is the provision of a self-aligning, locking, yet easily releasable, fastener for interconnecting adjacent panel sections, particularly upper and lower sections of a display unit.
It is an important advantage of the present invention that it may be produced at a lower expense than previously available comparable display units.
It is another important advantage of the present invention that it provides a display unit which may be set up or disassembled and packed for shipment without use or removal of any small loose parts.
It is another important advantage of the present invention that it provides a display unit which is more versatile than previously available display units for this purpose.
The foregoing and other objectives, features and advantages of the present 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 partially cutaway perspective view of a display unit embodying the present invention.
FIG. 2 is a sectional view of a portion of a panel unit shown in FIG. 1, with the frame channel in place.
FIG. 3 is a section view of a portion of a partially assembled one of the panels of the display unit shown in FIG. 2, showing the relationship of the connector member to the core of the panel.
FIG. 4 is a sectional view of the portion of a panel shown in FIG. 3, with the connector member in place and the outer channel member of the frame being put in place.
FIG. 5 is a perspective view of an upper corner portion of one panel unit of the display unit shown in FIG. 1, showing attachment of the upper portion of the frame to the remainder of the frame of the panel unit.
FIG. 6 is a sectional view, taken along line 6--6 of FIG. 5, showing the retainer used to keep the upper portion of the frame channel attached to the vertical side portions of the frame channel members.
FIG. 7 is a view of a pair of panel units side by side, showing one of the fabric hinges interconnecting the panels.
FIG. 8a is a sectional view, taken on an enlarged scale along line 8a--8a of FIG. 1, showing the construction of the fabric hinges of the display unit of the present invention.
FIG. 8b is a sectional view, taken on an enlarged scale along line 8b--8b of FIG. 1 showing another portion of the hinge construction of the display unit.
FIG. 9 is a perspective view of a fastener for interconnecting upper and lower panels of a two-tier display unit according to the present invention.
FIG. 10 is a sectional view of the fastener shown in FIG. 9, taken along line 10--10 of FIG. 9.
FIG. 11 is a top plan view of the fastener shown in FIG. 9, at an enlarged scale.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, in FIG. 1, an exemplary display unit 10, shown partially cut away, includes an upper display unit portion 12 and a lower display unit portion 14. A lamp 16 is mounted on the upper display unit 12, which is removably attached to the lower display unit 14 by a plurality of fasteners 18, one of the fasteners 18 being located atop each of the panel units 20 of the lower display unit 14, and fitting matingly into the bottom of each panel unit of the upper display unit 12. The panel units 20 each include a frame assembly 22, and hinges 24 interconnect the panel units 20 of each of the upper and lower display units 12 and 14, permitting the display panel units 20 to be rotated about the hingedly interconnected edges of adjacent ones of the panel units, through an angle of up to 360°. Each of the upper and lower display units 12, 14 can be folded to a transport configuration (not shown) in which the panel units 20 lie closely side by side, in a zig-zag configuration. Although only three panel units 20 are shown interconnected side by side in FIG. 1, a typical display unit would include five such panel units 20 in each of the upper and lower portions 12, 14.
Referring now to FIG. 2, a marginal portion of one of the display panel units 20 is shown in section view. The frame assembly 22 may be seen to include a U-shaped channel member 26 including a pair of opposite, generally parallel side portions 28, extending generally perpendicularly inwardly of the frame 22, and a peripheral face portion 30. A pair of inwardly-facing base grooves 32 are defined within the interior angles formed between the side portions 28 and the peripheral face portion 30 of the channel member 26.
Each of the parallel sides 28 has what will herein be called beveled edges 34. These beveled edges 34 preferably are actually arcuate as seen in end view as in FlG. 2.
The panel within the frame assembly 22 includes a light, stiff core 36 of material such as a polystyrene foam plastic, which may be as light as two pounds per cubic foot density. The material of the core 36 is cut precisely to the required thickness 38 so that the core 36 plus a pair of backing sheets 40, 42 and an optional layer of fabric 44 supported on one or each of the backing sheets 40, 42 have a total thickness 46 equal to the interior distance between the opposite parallel sides 28 of the U-shaped channel member 26.
Preferably, the backing sheets 40, 42 are of a strong, rigid plastics material such as melamine, available in sheet form from Pioneer Plastics of Auburn, Me. The backing sheets 40, 42 of such material are 0.020 inch thick, for example, and are attached to the core 36 by a pressure-sensitive hot melt adhesive which is sprayed on the backing sheets 40, 42, after which they are pressed against the core 36.
The fabric covering 44 is preferably a nylon fabric having a loop pile face, and may include a thin resilient foam layer (not shown). The fabric 44 is provided so that resilient plastic hook fastening material, such as that manufactured under the trademark Velcro, may be used to attach display materials to the faces of the panel unit 20. The layer of fabric 44 is, however, optional, and the thickness 38 of the core 36 is adjusted so that the display panel fits within the channel 26 members of the frame assembly 22, depending upon whether either or both of the backing sheets 40, 42 are covered by a layer of such fabric 44. Where the layer of fabric 44 is used, it may also be attached to the backing sheet 40, 42 by a hot melt pressure-sensitive adhesive sprayed on the backing sheet. Although the adhesives are not shown as separate layers in the figures of the drawings, it will be understood that an adhesive is present between the core 36 and other layers of the display panel unit 20.
The channel member 26 is attached to the marginal portions of the display panel by a connector 50, which is preferably an extruded elongate resilient plastic member having a spacer body portion 52 which has a pair of laterally apart-spaced faces 54 and a pair of coplanar inner faces 56. A web 58 extends generally inwardly of the frame assembly 22, perpendicular to the inner faces 56, and a bead 60 extends along an inner edge of the web 58. A pair of outer face members 62, 64 are aligned in a single plane perpendicular to the web 58. Each outer face member 62, 64 includes a beveled outer edge 66 or 68, which, as in the case of the beveled edges 34, is preferably of an arcuate configuration.
The dimensions of the outer face members 62, 64 are such that the beveled edges 66, 68 fit snugly within the base grooves 32. The beveled edges 66, 68 thus normally protrude slightly beyond the thickness 46 of the panel unit 20.
As may be seen in FIG. 3, the margins of the core 36, and the edges of the backing sheets 40, 42 coincide, defining generally a peripheral surface 69 along each margin of the panel. A groove 70 defined by a pair of parallel, marginal ribs 71 is formed extending along each of the peripheral surfaces 69 of the panel core 36 and includes a slot 72 and a tubular cavity 74 extending parallel with the peripheral surface 69 of the core 36. The sides of the slot 72 are moved apart slightly when the connector 50 is inserted and then resiliently resume their shape to receive the web 58 and bead 60 of the connector 50 and retain it with the spacer body portion 52 located within the groove 70. The material of the core 36 resiliently grips the bead 60 and web 58, although, for the sake of clarity, this resiliently gripping close contact is not shown in FIGS. 2-4.
With the connector 50 extending along the marginal portions of a panel unit 20, the beveled edges 66, 68 protrude slightly beyond the faces of the panel unit, as shown most clearly in FIG. 4, but the outer face members 62, 64 are separated by a space 76. The hollow construction of the spacer body portion 52 permits the face members 62, 64 to be moved resiliently toward one another, as indicated by the arrows 78 in FIG. 4, as the respective beveled edqes 34 of the opposite parallel sides 28 of the channel 26 interact with the beveled edges 66 and 68 of the outer face members 62 and 64. This permits the U-shaped channel member 26 to be pushed onto the marginal portion of the display unit panel 20 as indicated in FIG. 4. When the U-shaped channel member 26 is fully in place the margins of the outer face members 62 and 64 are resiliently mated within the base grooves 32, retaining the U-shaped channel members 26 of the frame assembly 22, respectively, in place about the margins of the panel unit 20 as shown in FIG. 1. Preferably, respective connector members 50 extend along each of the vertical edges and along the bottom of each of the panel units 20, with the connectors 50 either being cut off at a bevel or ending far enough from each corner of the frame assembly 22 to avoid interference. A bottom frame member 79 of U-shaped channel 26 has corner sections of its side walls cut away and has the peripheral face 30 bent upwardly at 90° angles to define end portions 81 which fit over the lower ends of the vertical sections of connectors 50 installed along the vertical margins of the panel units 20.
As shown in FIG. 2, a locking pin 80, which may be a countersunk resilient plastic hollow rivet with a conical core plug which expands an inner end of the locking pin during installation, prevents the outer face members 62 and 64 from moving toward each other as indicated by the arrows 78 in FIG. 4, thus locking the U-shaped channel members 26 in place, mated with the connector members 50 along each margin of the panel unit 20. This fastening also helps maintain alignment of the end portions 81 with the channel members 26 situated along the vertical margins of the panel units 20.
Referring now also to FIGS. 5 and 6, the display panel units 20 may be made as are those of the upper display unit 12, shown in FIG. 1, in which an upper frame member 82 which is of U-shaped channel like that of the channel members 26 extends along an upper marginal portion of each of the panel units 20 of the display unit 10. A short downwardly-extending portion 84 is formed at each end of the upper frame member 82 by removing portions of the opposite sides 28 and bending the peripheral face portion 30 downwardly at a 90° angle. A locking plunger detent 86 extends outwardly through a plunger hole 88, holding the upper frame member 82 in place atop the panel unit 20 yet facilitating its removal and replacement. The connector 50 of each vertical side of the panel unit 20 extends upwardly within the downwardly-extending leg 84. The margins of the outer face members 62 and 64 of the connectors 50 extend upwardly within the base grooves 32 of the downwardly-extending leg portions 84, holding the upper frame member 82 properly aligned with the two U-shaped channels 26 extending along the vertical margins of the panel unit 20.
The plunger detent 86 is formed of wire, as an extension of a spring coiled about a transversely extending pin 90 mounted within the spacer body portion 52 of the connector 50, and is biased outwardly thereby to extend through the hole 88.
The display panel unit 20 shown in FIG. 6 is similar to the panel units 20 shown in FIG. 2, except that instead of having a foam core 36 it has a pair of removable opposite display panels 92 and 94, whose margin portions 93, 95 fit in the space between a respective side portion 28 of a channel member 26 and the spacer body portion 52 of the connector 50. The display panel 92, for example, is of a transparent or translucent material, while the display panel 94 includes a hard plastic backing sheet 96, and a fabric cover layer 98, and a core 100 which may be of a lightweight foam material such as that of the core 36. An interior space 102 between the panels 92 and 94 may be illuminated electrically as back lighting for the display panel 92. By releasing the detents 86 and removing the upper frame member 82 the display panels 92 and 94 are released to be exchanged as desired, with the connectors 50 and channel members 26 being kept together by the bottom frame channel member 79.
Referring now to FIGS. 7 and 8, horizontally adjacent ones of the panel units 20 are interconnected with one another by the hinges 24. The hinges 24 include flexible ribbons 110 and 112 which extend crossingly between opposite faces of the adjacent panel units 20, with slack being kept out of the ribbons as well as possible during assembly. At least three of the flexible ribbons, including at least one of each of the ribbons 110 and 112, are necessary to provide a stable hinged connection between adjacent display panel units 20, as will be appreciated presently. Preferably, at least two hinges 24, each having one of the ribbons 110 and one of the ribbons 112, are provided along each hingedly connected side of a display panel unit 20.
Referring to the U-shaped channel members of a hinge 24 as channel 26a and channel 26b, shown in FIGS. 7, 8a, and 8b, a first ribbon retaining plate 114 is engaged in the base grooves 32 of channel member 26a, and a pair of ribbon retaining plates 116 (FIG. 8a) and 118 (FIG. 8b) are similarly engaged in the base grooves 32 of the channel member 26b, holding the ribbons 110 and 112 securely attached to the channel members 26a and 26b. Preferably, the hinge retaining plates 112, 116, 118, are made of a resilient synthetic plastic material, while the flexible ribbons 110 and 112 are of a sturdy woven cloth, such as a heavy satin weave nylon cloth approximately 2 inches wide. As may be seen in FIG. 8a, with the panel units 20 in the position shown in FIG. 1, the flexible ribbon member 110 extends around the one of the side portions 28 of the channel 26a which is farther from the channel member 26b, thence along and in contact with the peripheral face 30 of the channel member 26a, and thence along and in contact with the adjacent side portion 28 of the channel member 26b. When the panels 20 are rotated with respect to one another from one side to the other of a coplanar alignment, to the position in which the frame member 26b is shown in broken line in FIG. 8a, the ribbon member 110 is displaced away from the peripheral face portion 30 of the channel member 26a and extends instead along the peripheral face 30 of the channel member 26b.
Referring now to FIG. 8b, the ribbon member 112 is wrapped similarly about the retaining plate 114 within the channel member 26a, but extends along the side portion 28 of the channel member 26a which is immediately adjacent the channel member 26b, extending thence between the channel member 26a and the channel member 26b, thence along the peripheral face 30 of the channel 26b around the distant side portion 28 of the channel member 26b. The ribbon member 112 is retained within the channel member 26b by a retaining plate member 118.
The connector 50 is interrupted along the portions of the margins of the panel units 20 where the hinges 24 are located, but it is unnecessary to machine the U-shaped channel member 26 of the frame assembly 22 to receive metal hinges, as is necessary when mounting metal hinges as has been done in the past, and it is unnecessary to disconnect the hinges 24 to fold the display units 20 for storage or shipment.
To interconnect the upper and lower panel units 20 of a panel display device 10 according to the present invention, the horizontal U-shaped channel member 26 at the top of each of the lower display units 14 is provided with an oval aperture 130, and the horizontal U-shaped channel member 26 at the bottom of each of the upper panel units 20 is a socket comprising an essentially identical oval aperture 132, located to be opposite the oval aperture 130 when the upper and lower display units are mated together. The connector member 50 is interrupted within the U-shaped channel member 26 in the vicinity of the oval apertures 130 and 132 on both of the frame assemblies 22 to be connected by the fastener 18.
The fastener 18 includes a base plate portion 134 whose width corresponds to the distance between the base grooves 32 of the U-shaped channel member 26. Centrally located on the base plate 134 and extending from the base plate outwardly through the oval aperture 130 is a bubble-like hollow body 138 of the fastener 18. The entire fastener 18, including the base plate portion 134, is made of a plastic material which is flexible enough for the base plate 134 to snap into place with its lateral edges 136 engaqed in the base grooves 32, when the body 138 of the fastener 18 is pushed through the aperture 130 from within the channel member. The body 138 can be formed within an appropriate die by well known methods, and preferably has a greater wall thickness along a central ridge portion 140 than along the convex lateral faces 142. The hollow body 138, seen in end view along the U-shaped channel members 26 (FIG. 10) resembles slightly more than half of an ellipse. When the body 138 is in a relaxed shape, it has its greatest width 144 at a location shaped a distance above the base plate 134, so that when the body 138 extends through the oval aperture 130 and into the oval aperture 132 the side walls 142 exert an outward pressure against the interior of the oval aperture 132 and extend to a width greater than that of the oval aperture 132 at a location beyond the U-shaped channel member 26 of the upper frame assembly 22, providing a wedgelike grip against removal of the frame assembly 22 of the upper display unit panels 20 from engagement with the corresponding lower panel units 20.
Nevertheless, the shape of the fastener 18 is such that it is self-aligning, since the profile of the hollow body 138, as seen when directly facing the panel 20 is approximately semi-elliptical, while the plan shape is generally elliptical, as may be seen in FIG. 11, where the elliptical base line 145 coincides closely with the shape of the oval aperture 130 and is narrower than the maximum width 144. An exemplary fastener 18 has a body 138 whose length 146 is 1-7/16 inch, with a height 148 of 1/2 inch, and a width 144 of 3/8 inch.
The two U-shaped channel members 26, respectively, of the top of a lower panel unit and bottom of an upper panel unit 20, are mated together, pushing the hollow body 138 of the fastener 18 upwardly into the oval aperture 132. The walls 142 thereupon resiliently return, as closely as the shape of the oval aperture 132 permits, to their relaxed state, exerting outward pressure against the interior of the oval aperture 132. The part of the body 138 located within the channel 26 of the upper panel unit 20 is free to bulge outwardly somewhat beyond the confines of the oval aperture 132, to lock the two frame assemblies together securely enough to maintain the integrity of the display unit 10 until it is desired to disassemble the display unit 10. The hollow body 138 is preferably of an ABS plastic, with wall and base thicknesses of, for example, about 1/16 inch.
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. | A portable display unit including a plurality of panels hingedly connected along adjacent vertical sides with an upper set of panels connected by a single resiliently compressible fastener extending from frame to frame of vertically adjacent panels. A frame assembly for each panel provides sufficient structural support for panels having lightweight foam cores and adhesively attached outer sheets. Fabric hinges permit a set of panels to be stacked closely, without disassembly, for storage and shipment. Individual panel faces are replaceable and the interior of a panel unit may be illuminated in one embodiment of the invention. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a clamping device for keyless mounting of a hub to a shaft. More specifically, the invention is a device comprising a pair of wedge-shaped clamping rings positioned in the annular space between the shaft and the hub and is an improvement to the device disclosed in U.S. Pat. No. 3,501,183 to Andrew Stratienko.
2. Description of the Prior Art
A number of hub-to-shaft connecting devices exist which employ some form of clamping rings placed in the annular space between the hub and the shaft. Such devices are useful for connecting the hub to the shaft without the use of keys in either the hub or shaft. A particularly satisfactory device of this type, disclosed in the above-mentioned patent, employs a pair of nesting wedge rings. The inner wedge ring has a cylindrical inner surface for gripping the shaft, and the outer wedge ring has a cylindrical outer surface for gripping the inner surface of the hub bore. The interacting surfaces of the wedge rings are provided with matching shallow-angle annular tapers, and at least one of them is provided with a stable, dry anti-friction material, such as Teflon, preventing metal-to-metal contact between the rings.
The device includes axial force means for forcing one wedge ring into engagement with the other wedge ring, thereby contracting the inner ring tightly about the shaft and expanding the outer ring into tight engagement with the hub bore.
The wedge angle and magnitude of coefficient of friction on the ring surfaces has such interrelation as to provide a self-locking action in the rings. Self-locking results when the axial component of force exerted on one of the wedge rings by the other wedge ring when forced into engagement is less than the frictional force between the cylindrical surfaces of the wedge rings and the shaft or hub, whichever it engages, so that by increase of axial force further engagement occurs rather than the rings sliding on the smooth surfaces of the shaft or hub.
The preferred embodiment of the locking device is also self-releasing, which means that the wedge rings automatically disengage from each other when the axial force is relaxed. Self-releasing results when the radial force exerted by the contracted inner ring and the expanded outer ring on each other has an axial component of force which is large enough to disengage the wedge rings when the axial engaging force is relaxed. By proper selection of the taper angle, the anti-friction material, and the straight cylindrical surface frictional characteristics of the wedge rings, the clamping device can be designed to be both self-locking and self-releasing. Such design considerations are described in detail in the above-mentioned U.S. Pat. No. 3,501,183, which is herein incorporated by reference.
Although the axial clamping device embodiments of U.S. Pat. No. 3,501,183 are capable of producing extremely large locking forces between the hub and shaft in the axial direction, the unmodified form does not provide good rotational locking. A modified embodiment of this axial device employs a key placed in matching slots of the inner and outer wedge rings to increase the rotational locking force between the two wedge rings. But this embodiment permits only partial use of the rotational gripping capacity of the clamping device designed within practical limits of size.
The rotational gripping capacity between the inner ring and the shaft and between the outer ring and the hub are much higher than the rotational gripping capacity on the slippery surfaces between the wedge rings, even with a key placed between the rings. Since very little rotational gripping action results between the slippery tapered surfaces of the wedge rings, the key must take most of the rotational force transmitted. However, the rotational force transmitted by the key stresses the contact surfaces and body of the rings over their entire annular circumference, and since the rings are thin and have large circimferential lengths, their capacity is small and circumferential deflection is big. Their capacity can be increased by increasing the ring thickness, but it is undesireable to increase the size of the annular space between the hub bore and the shaft for a number of obvious reasons, one of which is that increasing the hub bore results in a weaker hub and limited use of the device to only the large diameter hubs.
Additional problems exist in the use of a key for a rotational stop between a pair of wedge rings. In particular, the expansion and contraction of the wedge rings results in the key slots either becoming wider than the key or closing up to grip the key so tightly that it restricts free engagement of the rings. When the key slots open up, backlash develops which prevents reversal loading or accurate "timing" applications.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a clamping device for securing a hub to a shaft which is improved to provide increased torsional capacity of the clamping device without increasing (and preferably decreasing) the required annular space between the hub shaft.
It is a further object of the invention to provide an improved clamping device with elimination of excessive backlash between the wedge rings due to clearance between the rotational stop member and the rotational stop slots in the rings.
It is a further object of the invention to provide an improved clamping device in which the axial force means also perform the function of the rotational stop means and eliminate the need for drilling and tapping either the hub or shaft.
These and other objects are provided by the invention, which in its broadest form is an improvement to a clamping device for keyless mounting of a hub on a shaft, which comprises a nesting pair of radially flexible wedge rings for placement within the annular space between the hub bore and the shaft and axial force means for forcing the wedge rings into nesting engagement to thereby radially expand one of the wedge rings and radially contract the other wedge ring. The pair of wedge rings is provided by an inner wedge ring having a cylindrical inner surface for gripping the shaft when contracted and an outer wedge ring having a cylindrical outer surface for gripping the bore surface of the hub when expanded. The inner wedge ring has an outer annular surface and the outer wedge has an inner annular surface with matching, shallow-angle axial tapers for nesting the inner wedge ring within the outer wedge ring, and at least one of the matching tapered surfaces has coated thereon a stable, dry anti-friction material preventing metal-to-metal contact. The angle of the matching tapered surfaces and the interrelation of coefficients of friction on the cylindrical and tapered surfaces of the wedge rings provides self-locking, and preferably self-releasing of the wedge rings.
The improvement comprises each of the inner and outer wedge rings being provided by an equal number of a plurality of connected circumferential sectors with each sector of the inner wedge ring aligning circumferentially with a sector of the outer wedge ring, and each pair of aligned sectors are separated from the adjacent pair of aligned sectors by a common rotational stop member. Each circumferential sector transmits only part of the rotational force between the wedge rings to thereby provide maximum rotational securement of the hub to the shaft and substantially reduced circumferential deflection of the wedge rings under load.
To illustrate the advantages of the invention, the rotational forces and ring deflections will be considered for an embodiment having each wedge ring provided by two circumferential sectors of equal size. The total rotational force between the wedge rings is divided equally between the two sectors, providing a stress of only one-half that which would occur with use of the prior art rings. Moreover, the circumferential length of each sector, being one-half as long, is subjected to only one-half the rate of deflection for any given stress. Therefore, the actual deflection of the wedge ring is reduced to one-fourth by dividing the ring into two sectors. An even more dramatic reduction in circumferential deflection can be realized by dividing the ring into more sectors. For example, four sectors will reduce the deflection to one-sixteenth.
In a preferred embodiment of the invention, the improvement employs axial force means which also perform the function of the rotational stop means for preventing rotation of one wedge ring with repect to the other wedge ring under load. In this embodiment, the axial force means are provided by a plurality of bolts, threaded means associated with the bolts, and an opening for each bolt formed by a pair of aligned axial grooves in the matching tapered surfaces of the rings. Each bolt passes through one of the openings to force the wedge rings into engagement in response to tightening of the bolt in the threaded means, and it also prevents relative rotation between the wedge rings by acting as a rotational stop.
In a more preferred form of the invention, only a single pair of inner and outer wedge rings is employed, and the axial force means fits entirely within the annular space between the hub bore and the shaft. The single pair of wedge rings are self-centering and are capable of providing the advantages of the present invention, in contrast to the prior art forms which employ two pairs of wedge rings with attendant complexity for centering them and do not employ bolts for rotational stop means.
More preferred embodiments of the invention provide modifications to the rotational stop slots which separate adjacent circumferential sectors of each ring to provide a tight fit against the rotational stop member after the wedge rings are pressed into complete engagement in the annular space between the hub bore and the shaft. The embodiments are more fully described in the detailed description of the invention and in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of one embodiment of the clamping device of the invention shown installed in the bore of a hub mounted on a shaft through use of hub attachment means.
FIG. 2 is an exploded sectional view of one embodiment of the wedge rings shown in FIG. 1.
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.
FIG. 4 is a sectional view similar to FIG. 3, but illustrating an alternative embodiment of wedge rings.
FIG. 5 is a sectional view of an embodiment of the clamping device of the invention like that illustrated in FIG. 1, but installed through use of shaft attachment means.
FIG. 6 is a sectional view of an alternative embodiment of an outer wedge ring useful in the hub attachment arrangement of FIG. 1.
FIG. 7 is a sectional view of an alternative embodiment of an inner wedge ring useful in the shaft attachment arrangement of FIG. 5.
FIG. 8 is a preferred embodiment of the clamping device of the invention shown installed in the hub bore mounted on a shaft, which embodiment employs a plurality of bolts to provide both the axial force means necessary to secure the clamping device to the hub and shaft and the rotational stop members.
FIG. 9 is an exploded sectional view of an alternative embodiment of wedge rings useful in the clamping device illustrated in FIG. 8.
FIG. 10 is an end view of the outer wedge ring illustrated in FIG. 9, taken along line 10--10.
FIG. 11 is an end view of the inner wedge ring illustrated in FIG. 9, taken along line 11--11.
FIG. 12 is a sectional view taken along line 12--12 of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The clamping device of the invention is illustrated in FIG. 1, where the hub 1 of a gear, cam, bearing, pulley or the like, is mounted on a shaft 2 and secured by the inner wedge ring 3 and outer wedge ring 4. The wedge rings 3 and 4 are desired to be self-locking and preferably self-releasing and have coated on at least one of their interacting wedge surfaces a stably dry anti-friction material which prevents metal-to-metal contact.
When installed, the inner wedge ring 3 is contracted tightly against the shaft 2, and the outer wedge ring 4 is expanded tightly against the bore surface of the hub 1. The wedge rings 3 and 4 have slots in which rotational stop members 5 and 6 are installed to resist rotational movement between the wedge rings 3 and 4. The wedge angle of the rings 3 and 4 is very shallow, for example from 2° to 10°, and each wedge ring 3 or 4 provides a very high gripping capacity between itself and it respective member, the shaft 2 or the hub 1. Through use of the special design considerations discussed above and further discussed below, the rotational stop members 5 and 6 provide rotational locking strength between the rings 3 and 4 sufficiently high to utilize the maximum gripping strength developed between the rings 3 and 4 and the shaft 2 and hub 1. Furthermore, rotational backlash on tapered surfaces is sufficiently minimized in reversal loading applications and provides for accurate "timing" application.
The wedge rings 3 and 4 are installed by forcing one wedge ring into engagement with the other by the axial force means provided by annular flange 7 and the plurality of screws 8. Flange 7 fits over shaft 2 and engages the end of inner wedge ring 3, which extends beyond the corresponding end of outer wedge ring 4 and the hub 1 before the rings are pressed into engagement. Spaced around the flange 7 in a balanced arrangement are a plurality of openings through which screws 8 pass. Screws 8 engage corresponding tapped and threaded holes in the end of hub 1. When screws 8 are screwed into the hub 1, they force hub 1 with ring 4 toward flange 7 and thereby force outer ring 4 into engagement with inner ring 3. Further tightening of screws 8 causes further expansion of outer ring 4 and further contraction of inner ring 3, and thus, greater securing of the hub 1 to the shaft 2.
The special design considerations of the wedge rings can best be understood by referring to FIG. 2, which illustrates one embodiment of the wedge rings useful in the device of FIG. 1. Inner wedge ring 9 and outer wedge ring 10 are each shown with slots 11 and 12 extending part way through the length of the ring and leaving a web beyond the end of the slot to hold the ring sectors together and provide sufficient strength to transmit the force between adjacent sectors. Within the slots 11 and 12 are placed the rotational stop members like the members 5 and 6 illustrated in FIG. 1.
In addition to the rotational stop slots 11, inner wedge ring 9 has resiliency slots 13 and 14 positioned around the circumference of the ring 9 in a balanced arrangement and extending partially through the length of the ring. By balanced arrangement, it is meant that the resiliency slots are positioned so that the ring expands and contracts radially without circumferential displacement. The length of resiliency slots 13 and 14 is preferably such that the slots 14 from one end overlap with the slots 13 from the other end to provide a large degree of radial flexibility over the entire length of the ring 9. On the other hand, it is necessary that the resiliency slots 13 and 14 do not extend entirely through the length of the ring 9 in order to provide sufficient web to withstand the circumferential forces transmitted between adjacent segments. The web at this point is the remainder of the ring body left where the resiliency slot stops.
Outer ring 10 has resiliency slots 15 and 16 positioned around the circumference of the ring 10 in a balanced arrangement like those of inner wedge ring 9. The wedge rings 9 and 10 could be designed without the resiliency slots 13, 14, 15, and 16, since the thin walls of the rings permit some radial flexibility by mere expansion and contraction of the ring walls under the very high forces exerted when the rings are forced into engagement. However, the resiliency slots provide a valuable function in utilizing the rotational stop means and liberalization of clearances between cylindrical surfaces of rings and shaft and hub.
The value of the resiliency slots to the rotational stop means can best be described by referring to FIG. 3, where an alternative embodiment of the wedge rings of FIG. 2 is shown. In the embodiment of FIG. 3, the inner wedge ring 17 having no resiliency slots is substituted for the inner wedge ring 9 of FIG. 2. All other parts illustrated are the same as in FIGS. 1 and 2.
When the clamping device of FIG. 3 is first placed in the annular space between hub 1 and shaft 2, the rings are in a relaxed position. Upon pressing the wedge rings together, to complete the installation, the inner wedge ring 17 is contracted and the outer wedge ring 10 is expanded. This action can result in two occurrences. First, the inner ring 17 squeezes the rotational stop members 5 and 6 sufficiently tight to prevent backlash under reversal loading applications. However, if it becomes tight before complete contraction of the inner wedge ring 17, it becomes much more difficult to further contract the inner ring 17. Second, the outer ring 10 expands and can open up the rotational stop slots 12, thus providing a loose fit between the rotational stop members 5 and 6 and the outer wedge ring 10. The loose fit results in backlash in reversal load applications and is unacceptable for applications requiring accurate timing.
By special design, the advantage provided by the closing of the rotational stop slots in the inner wedge ring 17 when it is contracted can be utilized and the disadvantage can be eliminated. The clearance between the inner wedge ring 17 and the shaft diameter is determined and multiplied by pi. This gives the amount of closing of the rotational stop slots which will occur when the inner wedge ring 17 is contracted. The width of the rotational stop slots is then designed to be larger than the width of each rotational stop member by this amount divided by the total number of rotational stop slots. In determining the clearance, the minimum value within the tolerances of shaft and ring is used.
The above described design is particularly for use with solid inner wedge rings, where very little contraction will occur. By the use of resiliency slots, such as shown in FIG. 2, the radial flexibility of the inner ring can be greatly increased and it is not necessary to provide any additional width in the rotational stop slots.
The design of the outer wedge ring 10 presents a different problem. The rotational stop slots 12 tend to spread when the rings 10 and 17 are brought into engagement, which cannot be permitted if backlash is to be eliminated. Therefore, the outer wedge ring 10 should be designed to be in contraction when placed in the bore of the hub 1 but before engagement of the wedge rings. The amount of pre-engagement contraction is at least equal to the expansion which will occur when the rings are engaged. Thus, the width of the rotational stop slots 12 will remain constant, and the rotational stop members 5 and 6 will remain firmly within the slots 12.
The pre-engagement contraction of the outer wedge ring 10 is provided by pressing the outer wedge ring 10 into an interference fit with the bore of the hub. This means that the outer diameter of the outer wedge ring 10 with the rotational stop members 5 and 6 in place will be larger than the bore diameter of the hub 1. The added flexibility of the resiliency slots 15 and 16 in outer wedge ring 10 is particularly beneficial in facilitating a large amount of pre-engagement contraction.
FIG. 4 illustrates an alternative embodiment of wedge rings. In FIG. 4, inner wedge ring 19 has a single resiliency slot 21, and outer wedge ring 18 also has a single resiliency slot 20. In this case, the slots 20 and 21 can extend the entire length of the wedge rings. The same special design considerations discussed with respect to FIG. 3 apply to FIG. 4 also. However, an additional consideration applies to the embodiment of FIG. 4. Ring expansion and contraction upon engagement will result in resiliency slot 20 becoming wider and resiliency slot 21 becoming narrower. In this case, only one resiliency slot exists for each ring, and therefore, there can be no balanced arrangement. Therefore, expansion and contraction of the rings is not purely radial, but the rings are subjected to circumferential displacement. That is, both of the rotational stop slots in the inner ring 19 tend to move circumferentially towards the resiliency slot 21 as that ring contracts. Both of the rotational stop slots in the outer ring 18 tend to move away from the resiliency slot 20 as that ring expands.
If the resiliency slots 21 and 20 were aligned with each other, as they are conventionally, the rotational stop slots in the inner ring 19 would move in a direction opposite that of the rotational stop slots in the outer ring 18. This results in opposite movement to each rotational stop member 5 and 6, which will jam the rotational stop member by one ring pushing the stop member one way and the other member pushing the stop member in the opposite direction. Jamming of the stop member prevents further circumferential displacement. If the rotational stop slots are wider than the stop members 5 and 6 when the rings are completely engaged, each rotational stop member 5 or 6 is functional in only one direction, the direction in which it is jammed. However, the jammed direction for one stop member happens to be opposite to that of the other stop member. The same would be true if, say four stop members were used, the two on one side of the resiliency slot would be jammed in a direction opposite to the two on the other side of the resiliency slot. This arrangement provides tight locking in both directions, preventing backlash at reversal load applications.
It is particularly advantageous to take up slop in the stop slots when they are larger than the stop members, and thus does not require the use of fitted stop members, which are those made closely to match the width of the slots.
In manner similar to that described for FIG. 3, the widths of the rotational stop slots in the embodiment of FIG. 4 can be modified to be larger or smaller to compensate for the expansion or contraction in the wedge rings. The positioning of the rotational stop slots can also be modified so that mating slots in the inner and outer rings do not align with each other when the rings are relaxed, but are designed to align when the rings are engaged. This arrangement is beneficial when stop members fit tightly in the stop slots before engagement.
A further modification is illustrated in FIG. 4. The resiliency slot 20 of outer ring 18 is positioned opposite from the resiliency slot 21 of the inner ring 19. Thus, expansion of outer ring 18 moves the rotational stop slots of the outer ring 18 in the same direction as contraction of inner ring 19 moves the rotational stop slots of the inner ring. With this arrangement, the need for the modifications described above can be minimized, and by proper selection of clearances between the inner wedge ring 19 and the shaft 2 and between the outer wedge ring 18 and the hub 1 to provide equal expansion and contraction, the modifications described above can be left out. However, where expansion of the outer ring is not equal to contraction of the inner ring, due to unequal clearances, there will be a tendency to jam the stop members in the same manner described above, although to a lesser extent. Again, this tendency can be advantageously used to eliminate backlash. It should be noted that the foregoing considerations also apply to embodiments where each ring has more than one resiliency slot, but where they are positioned in an unbalanced arrangement.
The preceding embodiments can be modified to include more than two ring sectors and corresponding rotational stops. All of the preceeding considerations would also apply to wedge rings with more than two sectors. However, the rotational stop slot width expansion and contraction considerations discussed with respect to FIGS. 3 and 4 would be adjusted to be divided over the total number of rotational stops, rather than just two.
An alternative axial force engagement means is illustrated in FIG. 5. Flange 26 fits into the bore of hub 22 and engages the end of outer wedge ring 25 to force it into engagement with inner ring 24. A plurality of screws 27 pass through holes in flange 26 and into corresponding tapped and threaded holes in the end of shaft 23. Stop means 5 and 6 like those in FIG. 1 are placed in rotational stop slots in both inner ring 24 and outer ring 25. The actual design of the wedge rings for the embodiment of FIG. 5 can be like any of those disclosed and described with respect to FIGS. 2, 3, and 4. However, if the wedge rings of FIG. 2 are to be used in FIG. 5, the webs at the end of the rotational stop slots 11 and 12 should be on the other end of each, as shown in FIG. 5, to hold the stop members 5 and 6 in place until engagement is made. In other words, this arrangement has reverse direction of wedge inclination in respect to the location of the loading flanges and the outer wedge is pushed for engagement rather than pulled, as in FIG. 1.
FIG. 6 illustrates an alternative outer wedge ring 28 for use in the arrangement of FIG. 1. The ring 28 has rotational stop slots 29 like other embodiments and a resiliency slot 31 in between each rotational stop slot 29. It differs from the earlier described outer wedge rings by having a lip 30 which engages the end of the hub just outside of the bore. Lip 30 helps hold the outer ring 28 in place in the hub when beginning engagement of the wedge rings and until outer ring 28 is sufficiently expanded against the bore of hub 1 to permit self-locking to occur. Use of lip 30 permits a clearance between the outer wedge ring and the hub bore and eliminates the necessity of a snug (springing) fit in the hub bore needed for initiation of self-locking.
FIG. 7 illustrates an alternative inner wedge ring 32 for use in the arrangement illustrated in FIG. 5. It has a lip 35 extending inwardly for placement against the end of the shaft 23 to hold the inner ring 32 in place on the shaft until sufficient engagement of the wedge rings occurs to provide self-locking. The advantages of the embodiment of FIG. 7 are similar to those of the embodiment of FIG. 6.
FIG. 8 illustrates the preferred embodiment of the invention in which the axial force engagement means also performs the function of the rotational stop means. A hub 36 is mounted on a shaft 37 through use of the clamping device of the invention. The clamping device includes inner wedge ring 38 and outer wedge ring 39 forced together into engagement by the plurality of bolts 40 which when tightened pull flanges 41 and 42 towards each other. The bolts 40 are positioned in a balanced arrangement around the flange 41 so that the wedge rings will be engaged uniformly around their circumference. Each bolt 40 passes through a circular hole in the flange 41, through a pair of mating semi-circular grooves in the wedge rings 38 and 39, and into a threaded hole in the other flange 42. One flange engages the thicker end of one wedge ring, and the other flange engages the thicker end of the other wedge ring so that pulling the two flanges towards each other results in pushing the wedge rings into engagement with each other. The bolts are preferably provided by rods with threads generally only at the end to provide a solid, smooth surface in the grooves. The grooves are parallel to the cylindrical surfaces of the rings, and are therefore, slanted with respect to the tapered surfaces of the rings.
FIG. 12 illustrates how the mating semi-circular grooves in the wedge rings 38 and 39 form circular holes 43 for forming the equivalent of rotational stop slots. The bolts 40 passing through the holes 43 provide the rotational stop members. The embodiment illustrated in FIG. 12 shows an arrangement with only one resiliency slot in each ring, similar to the arrangement in FIG. 4.
With the unbalanced arrangement for the resiliency slots 44 and 45 in FIG. 12, the wedge rings 38 and 39 are subjected to circumferential displacement when expanded and contracted. As in the embodiment of FIG. 4, the circumferential displacement tends to cause jamming of the bolts 40 in the holes 43. Such jamming provides the advantage of eliminating backlash, but it can interfere with further tightening of the bolts if jamming occurs before engagement of the rings is substantially complete. Therefore, it is desirable to provide holes 43 which are larger than the bolts by the amount of circumferential displacement to be expected between mating grooves forming a hole 43. The amount of circumferential displacement to be expected is determined in the same manner described for the embodiment of FIG. 4. However, the displacement will vary from hole 43 to hole 43, depending upon how far the hole is from the resiliency slot 44 or 45.
FIGS. 9, 10, and 11 illustrate the preferred embodiment of wedge rings to be used in the clamping arrangement of FIG. 8. Outer wedge ring 46 and inner wedge ring 47 each have semi-circular grooves forming holes 48 and 49, respectively, which provide rotational stop slots. Outer ring 46 has an integral inwardly extending flange extension 50. Inner wedge ring 47 has an integral outwardly extending flange extension 51. The semi-circular grooves 48 and 49 extend through the extensions 50 and 51 in the form of circular holes through which bolts 40 pass. The holes in one of the extensions can be threaded to engage the bolts, or additional nuts can be employed. Resiliency slots 52 and 53 are cut most of the length of the wedge rings 46 and 47 in positions between the bolt holes and grooves 48 and 49 in a balanced arrangement. This arrangement of the resiliency slots permits pure radial contraction and expansion of the wedge rings without circumferential displacement of the rings.
Having resiliency slots in a balanced arrangement avoids the jamming which occurs in the embodiment of FIG. 12. Therefore, it is permissible and preferable to use fitted bolts in the embodiment which expands and contracts purely radially. Fitted bolts are sized to fit snugly into the holes 48 before engagement, so that backlash is eliminated. Pure radial expansion and contraction also occurs with solid rings (those having no resiliency slots), and it is preferable to employ fitted bolts in that design also.
The clamping device of the invention is preferably made from strong materials, such as metals, which are easily machined or formed by other methods. The tapered wedge surfaces of the wedge rings are coated, preferably on both of them, with a stable dry anti-friction material, preferably Teflon composition. The bolts employed in the embodiment of FIGS. 8-12 are small enough to fit into the annular space between a hub and shaft, and therefore, are preferably made of high tensile strength materials, such as heat treated steel and alloys, having a tensile strength of at least 50,000 p.s.i. | Disclosed is an improved clamping device for keyless mounting of a hub on a shaft of the type comprising an inner wedge ring having a cylindrical inner surface for gripping the shaft when contracted and an outer wedge ring having a cylindrical outer surface for gripping the bore surface of the hub when expanded. The pair of wedge rings have interracting annular surfaces with matching shallow-angle tapers and at least one has a stable dry anti-friction material coated thereon. The pair of wedge rings placed in the annular space between the hub and shaft are engaged with axial force means to cause the outer wedge ring to expand and the inner wedge ring to contract and thereby lock the hub to the shaft. The improvement is each of the wedge rings being provided by an equal number of a plurality of circumferential sectors separated from each other by a rotational stop member to provide maximum rotational securement of the hub to the shaft and substantially reduced circumferential deflection of the wedge rings under load. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The purpose of the disclosed serial data bus is to allow multiple microprocessors to easily communicate with each other over a common pair of wires using a scheme similar to a telephone party line. The invention relates to data communications links between members of a distributed processing multiplex system in a vehicle such as an automobile. The serial data bus and interface integrated circuit developed and disclosed herein is capable of supporting many types of communication protocols.
2. Description of the Prior Art
Data communications between microprocessors or microcomputers need to communicate with each other in many applications.
Local area networks (LAN) link such microprocessor or microcomputers, allowing one of the microcomputers to seize control of a serial data channel commonly linked to all other microprocessors on the LAN and transmit data to any other unit. The protocols, controllers and software needed in a LAN are very complex, especially in large systems.
An automotive environment is a smaller application and, thus, does not require the complex performance capabilities available in a LAN.
Digital data buses have been designed to handle the above-described data communications link in a small area. Such a system is described in SAE Paper No. 840317, by Ronald L. Mitchell entitled "A Small Area Network For Cars." This document is hereby expressly incorporated by reference. Also descriptive of such a digital data bus is U.S. Pat. No. 4,429,384 to Kaplinsky entitled "Communication System Having An Information Bus And Circuits Therefor."
Also descriptive of developments in this field is SAE Paper No. 860390 by Frederick H. Phail and David J. Arnett entitled "In Vehicle Networking--Serial Communications Requirements And Directions." This document is also hereby expressly incorporated by reference.
The subject invention differs from the art noted above by use of a constant speed, the lack of use of an acknowledgement bit and the lack of a requirements for a tight link between the transmitting station and the receiving stations. Also important in the subject invention is the communication link between the message transmitter and receiver.
Generally, the following U.S. patents discuss collision detection in data communications systems: U.S. Pat. No. 4,281,380 of DeMeas III et al. entitled "Bus Collision Avoidance System For Distributed Network Data Processing Communications System" dated July 28, 1981; U.S. Pat. No. 4,409,592 of V. Bruce Hunt entitled "Multipoint Packet Data Communication System Using Random Access And Collision Detection Techniques" dated Oct. 11, 1983; U.S. Pat. No. 4,434,421 of Baker et al. entitled "Method For Digital Data Transmission With Bit-Echoed Arbitration" dated Feb. 28, 1984; U.S. Pat. No. 4,470,110 of Chiarottino et al. entitled "System For Distributed Priority Arbitration Among Several Processing Units Competing For Access To A Common Data Channel" dated Sept. 4, 1984; and U.S. Pat. No. 4,472,712 of Ault et al. entitled "Multipoint Data Communication System With Local Arbitration" dated Sept. 18, 1984.
The U.S. Pat. No. 4,434,421 patent to Baker et al. deals with a method to reduce the number of collisions. This is done by reducing the number of slave stations attempting bus access until there is one master and one slave station in communication. This differs from the subject invention in that a broadcast method is employed whereby several users can receive the same message.
The U.S. Pat. No. 4,470,110 to Chiarottino et al. discloses a system to exchange messages including an interface. In addition, the '110 patent assigns a priority to an address bit of a particular logical level.
Also of interest is an article in an IEEE publication "Automotive Applications of Microprocessors,"1984; Paper No. CH2072-7/84/0000-0083 entitled "A Data Link For Agricultural And Off Highway Communications" by Boyd Nichols, Vijay Dharia and Kanaparty Rao.
Of paramount importance in the subject invention is the inclusion of the capability to communicate with a serial communication interface (SCI) port, a serial peripheral interface (SPI) port and a buffered serial peripheral interface (BSPI) port.
SUMMARY OF THE INVENTION
The purpose of the serial data bus system disclosed herein, also known as Chrysler Collision Detection (C 2 D) bus, is to allow multiple microprocessors to easily communicate with each other over a common pair of wires or bus using a scheme similar to a telephone party line. All microprocessors connectred to the bus are able to receive all messages transmitted on the bus. Any microprocessor with a message to transmit on the bus waits until any current user is finished before attempting to use it.
Whenever the bus is available, its use is allocated on a first-come first-serve basis. That is, whichever microprocessor begins transmitting its message on the bus, after any previous message finishes, gets the use of the bus. If, however, multiple microprocessors attempt to begin transmitting their messages on the bus at exactly the same time, then the message priority values and each message is transmitted by only one microprocessor.
The invention disclosed herein is further summarized in two co-pending patent applications on related material. Both applications were filed in the U.S. Patent & Trademark Office on Feb. 24, 1986, and are commonly owned with the subject patent application. They are: "Serial Data Bus For Intermodule Data Communications," U.S. Ser. No. 832,908; and "Method Of Data Arbitration and Collision Detection On A Data Bus," U.S. Ser. No. 832,909. Both of these applications are hereby expressly incorporated by reference.
Also hereby expressly incorporated by reference is SAE Information Report entitled "J1567 Collision Detection Serial Data Communications Multiplex Bus" to be presented to the SAE Multiplexing Committee by Frederick O. R. Miesterfeld on May 23, 1986.
Attention is invited to the above-described applications for further explanation of the summaries of some of the basics of the invention described in the subject application.
It is an object of the subject invention to provide an SCI port, an SPI port and a buffered SPI port as part of the serial data interface integrated circuit described herein. This allows communication with any device configured with any one of these three ports all on the same bus. The inclusion of the ports augments the simplification of the serial data communication described in the previously filed patent applications on the related subject matter.
DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and in the accompanying drawings in which:
FIG. 1 is a block diagram showing a serial data bus network;
FIG. 2 illustrates the hardware for the serial data bus described herein;
FIG. 3 is a continuation of the hardware drawing for the serial data bus;
FIG. 4 is a block diagram of the bus interface integrated circuit (IC);
FIG. 5 is a timing diagram showing an example of the collision detection on the bus interface IC during arbitration;
FIG. 6 is a gate diagram of the arbitration detector 42;
FIG. 7 is a gate diagram of the collision detector 44;
FIG. 8 is a gate diagram of the start bit detector 200;
FIG. 9 is a gate diagram of a clock divider 201;
FIG. 10 is a gate diagram of a word counter 202;
FIG. 11 is a gate diagram of a flip-flop 203;
FIG. 12 is a gate diagram of framing error detector 204;
FIG. 13 is a gate diagram of idle counter 206;
FIG. 14 is a gate diagram of idle flip-flop 207;
FIG. 15 is a gate diagram of digital filter 210;
FIG. 16 is a gate diagram of mode selector 301;
FIG. 17 is a gate diagram of SCK selector 302;
FIG. 18 is a gate diagram of SCK counter 303;
FIG. 19 is a gate diagram of a 16-bit buffer and bit reverser 304;
FIG. 20 is a gate diagram of a 2 or 1 byte receive 305;
FIG. 21 is a gate diagram of a 2 byte counter 306;
FIG. 22 is a gate diagram of a start/stop bit generator and SPI data path 307;
FIG. 23 is a gate diagram of SPI clock generator 308;
FIG. 24 is a gate diagram of SPI transmit scheduler and controller 309;
FIG. 25 is a gate diagram of test mode detector 401;
FIG. 26 is a gate diagram of reset circuit 402;
FIG. 27 is a gate diagram of break generator 403; and
FIG. 28 is a gate diagram of an over range latch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This application is one of three filed on the same day and having related specifications and drawings. The other cases are commonly owned with the same inventors are Ser. Nos. 866621 and 866628 and are entitled "Method For Serial Peripheral Interface In A Serial Data Bus" and "Method For A Buffered Serial Peripheral Interface In A Serial Data Bus." Both of these cases are hereby expressly incorporated by reference.
Further documents hereby expressly incorporated by reference include U.S. Pat. No. 4,429,384 issued to Kaplinsky and entitled "Communication System Having An Information Bus And Circuits Therefor"; SAE Technical Paper No. 830536 entitled "Serial Bus Structures For Automotive Applications" by Anthony J. Bozzini and Alex Goldberger dated Feb. 28, 1983; SAE Paper No. 840317 by Ronald L. Mitchell entitled "A Small Area Network For Cars"; SAE Paper No. 860390 by Frederick H. Phail and David J. Arnett entitled "In-Vehicle Networking--Serial Data Communication Requirements And Directions"; and SAE Paper No. 860389 by Frederick O. R. Miesterfeld entitled "Chrysler Collision Detection (C 2 D) A Revolutionary Vehicle Network."
Attention is invited to the previously filed patent applications on related subject matter for a partial description of some of the hardware disclosed in FIG. 1, FIG. 2, FIG. 3 and FIG. 4.
The interaction between the arbitration detector 42, collision detector 44, word counter 202, word flip-flop 203, start bit detector 200, framing error detector 204, idle counter 206, idle flip-flop 207, clock divider 201, digital filter 210, bus driver made up of OR gate 62 and NAN gate 63, along with bus receiver 30 in conjunction with current source 34 and current sink 36 as connected to the bus 26.
An understanding of the above-listed blocks is necessary for understanding the improvements outlined in the subject application. Attention is, therefore, invited to patent applications U.S. Ser. Nos. 832,908 and 832,909 and the explanations included therein and the drawings which all have been incorporated by reference.
Referring now to FIG. 1, FIG. 2, FIG. 3 and FIG. 4, the hardware for the serial data bus is shown.
SCI MODE OF OPERATIONS
The circuit shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, used to obtain SCI operation are used for the other modes of operation and are basic to the entire interface IC.
When the start bit detector 200 senses a valid start bit, it causes the word counter 202 to synchronize itself to the timing of the received data word. The word counter 202 is used to generate pulses, one for the collision detector 44 and another for the word flip-flop 203. At 1/4 bit time, the word flip-flop 203 clocks the arbitration detector 42. The word counter 202 triggers the framing error detector 204 at the stop bit time. If the stop bit is not detected, the idle counter 206 is extended by the framing error detector 204 until 10 idle periods in a string are received.
The collision detector 44 samples the transmitted input and received output. It is the function of the collision detector 44 to block transmission that could interrupt bus 26 operations. If two or more user microprocessors 22 want to transmit at about the same time, the arbitration detector 42 will allow transmission on a first-come first-serve basis. If the user microprocessors 22 both try to transmit in synchronism, that is within an arbitration window of time, the collision detector 44 will permit only the one with the highest priority to continue transmitting.
When a user microprocessor 22 is connected to the bus 26 and is ready for transmission, it shall use the following procedure. First, the user microprocessor looks at the IDLE line and waits until it goes to a logical zero, indicating that the bus 26 is idle. Then the user microprocessor 22 tries to transmit an 8-bit ID word associated with the data to be transmitted. If the user microprocessor 22 started transmitting first or has the highest priority ID, the collision detector 44 and arbitration detector 42 will permit transmission. The user microprocessor 22 confirms transmission by reading the received ID word by comparing it with the ID it wanted to transmit. If there is a confirmation that the same ID was transmitted, then the data can be transmitted. If not, then the user microprocessor needs to check to see if the received ID and data is needed for its own use.
It is important to realize that data collision may result due to outside interference or a request for arbitration when long data strings are transmitted. The user microprocessor 22 that is transmitting data can compare the transmitted data with the received data for this type of collision. Appropriate action should then be taken by the user microprocessor 22.
The function of the idle counter 206 and idle flip-flop 207 is to detect when the bus 26 is in the idle condition. This is accomplished by sensing a received stop bit. A delay is then imposed for a short idle period of ten bit times. The IDLE output is then set to a logical zero. The IDLE line is set to a logical one by receiving a start bit. This signal is also used to terminate transmission not allowing transmission during a received signal message. The idle counter 206 and idle flip-flop 207 also supply a reset signal to the collision detector 44 at the beginning of an idle period.
A request for arbitration can be generated by a module that needs to interrupt transmission of a long data string. The way this can be accomplished is by forcing the IDLE input to a logical zero; this forces a data collision after transmitting the start bit of the fifth byte, and the transmitting user microprocessor 22 is required to detect this and stop transmitting. It is, however, allowed to again arbitrate for the bus 26, but the interrupting module may not cause a second data collision if it loses arbitration.
In the SCI mode, the bus interface 24 supports a typical full duplex asynchronous serial communications interface for transfer of data bytes to and from a user microprocessor 22.
In addition to the asynchronous data interfaces, the user microprocessor must also have an interface to the bus interface IC 24 for the IDLE line and for control purposes.
In the SCI mode, when a user microprocessor 22 wants to send a message on the bus 26, it sends and receives each byte one at a time and monitors its progress. As the bits of a byte are sent from the transmit line of the SCI port of the user microprocessor 22, they are passed through the bus interface IC 24 and onto the bus 26.
Simultaneously, the bits on the bus 26 are detected by the bus interface IC 24 and passed to the receive line of the user microprocessors 22 SCI port. The user microprocessor 22 compares the received/reflected byte to the last transmitted byte and, if they are equal, the user microprocessor 22 knows that the last byte was transmitted successfully and can go on to process the remaining bytes. When the messages are transmitted on the bus 26 by other user microprocessors 22, the bus interface IC 24 receives then one byte at a time through the receive line of its SCI port.
The user microprocessor 22 must monitor the IDLE line in order to determine when the last byte of a message has been received, when the next received byte will be the first message and when it is arbitration time.
SPI MODE OF OPERATION
In this mode, the word counter 202 generates the timing signals to drive the SCK counter 303 in conjunction with the SCK selector 302 and the start bit detector 200. The user microprocessor 22 becomes a slave to the bus interface IC 24. When the user microprocessor 22 needs to transmit a word, it loads that word into its buffer register and watches for the IDLE pin of the bus interface 24 to go to a logical zero signifying that the bus 26 is idle.
The user microprocessor then pulses the CONTROL pin of the bus interface IC 24. This sets an XMIT ENABLE register within the scheduler and controller 309 to transmit. The bus interface IC 24 will then generate a start pulse and supply the user microprocessor 22 with 8 SCK shift pulses in synchronization with the start pulse. If a collision is detected on the message ID byte by the user microprocessor 22, the user microprocessor 22 stops transmitting immediately and starts receiving. If no collision is detected, this means that the user microprocessor 22 has won arbitration and it, therefore, completes data transmission.
Synchronizer logic works with the SPI clock generator 308 and produces synchronized shift clock pulses for both receiving and transmitting of data. However, it does not output shift pulses for start and stop bits. A very accurate clock is required here to synchronize an established data transmission/reception rate.
In the SPI mode, the bus interface IC 24 supports the SPI type of interface facilities available on some model microprocessors.
With the generally available SPI support, two microprocessor family devices, one a master and the other a slave, interchange at high speed, two bytes of data, one bit at a time, with data synchronization controlled by a clock signal supplied by the master device.
With the bus interface IC 24 in the transmit mode, one byte of data is, one bit at a time, simultaneously transferred to the bus interface IC 24, transmitted onto the bus 26, while a received reflected bit is received from the bus 26 and transferred back to the user microprocessor 22. At the end of a one-byte transmit cycle, the user microprocessor 22 has, in its SPI data register, the byte that reflects the transmission of the byte that was in its SPI data register when the user microprocessor 22 pulled the CONTROL line low to request the beginning of the transmission cycle.
When the bus interface IC 24 begins to receive a byte of data from the bus 26 before the user microprocessor 22 pulls the CONTROL line low, the bus interface IC 24 pulls the CONTROL line low and starts generating the SCK clock signal. As each data bit is received, it is clocked out of the bus interface IC 24 into the user microprocessor 22. Any data in the user microprocessor's SPI data register before the SCK signal starts is transferred out of the data register to nowhere as the received data is transferred into the SPI data register.
In some cases, it may be useful to connect the CONTROL line of the bus interface IC 24 to the SS line of the user microprocessor SPI port as an alternative to other ways of setting the SS low.
There is a slight time delay between the transfer of the bit from the user microprocessor 22 to the bus interface IC 24 on the rising edge of an SCK cycle and the transfer of the bit from the bus interface IC to the user microprocessor on the falling edge of the same SCK cycle.
Data transfers between the user microprocessor 22 and the bus interface IC 24 occur at the bus transfer speed, 7,812.5 bits per second.
SPI mode differs from the SCI mode mainly because of the differences between SPI types of interfaces and SCI types of interfaces. In the SPI mode, the user microprocessor 22 does not have access to the start and stop bits transmitted on the bus 26. In the SPI mode, the user microprocessor must reverse the bit order of transmitted and received bytes.
SPI mode is similar to the SCI mode in that the user microprocessor 22 sends or receives data to and from the bus interface IC 24 one byte at a time. When transmitting a message, each bit of a transmitted byte is simultaneously transmitted onto the bus while the reflected bit is received from the bus 26.
In SPI terms, the user microprocessor 22 operates in the slave mode and the bus interface IC 24 operates as the master.
In functional terms, the user microprocessor 22 in the bus interface IC 24 are on somewhat equal terms with the bus interface IC 24 being more equal than the user microprocessor 22 as both can initiate a data transfer. The user microprocessor 22 can request the transmission of a byte by the bus interface IC 24 by pulling the CONTROL line low, but it has to do so before the bus interface IC 24 begins receiving data from the bus.
As a slave to the bus interface 24, the user microprocessor 22 must be able to handle the use of the SPI port at any time by the bus interface IC 24.
Data is transmitted on the bus 26 in an asynchronous fashion with a start bit, eight data bits and a stop bit. The order of data bits is the least significant bit (LSB), bits 1, 2, 3, 4, 5, 6 and MSB. In an SPI transfer, a user microprocessor 22 normally transfers the MSB first and the LSB last, just the opposite of the bus transmission.
In order to use SPI mode, the user microprocessor 22 must reverse the bit order of all transmitted and received bytes. (This problem does not occur in the buffered SPI mode explained below.)
BUFFERED SPI MODE OF OPERATION
The buffered SPI mode required additional circuits to that used in the SCI and SPI modes. A 16-bit buffer and bit reverser 304 is provided for both receiving and transmitting data. A control flip-flop is used to determine whether the buffer 304 is connected to the user microprocessor 22 or to the bus transmit circuitry.
When powered up, the control flip-flop is connected to the user microprocessor 22. The user microprocessor 22 is the master and the bus interface IC 24 is a slave peripheral. The user microprocessor 22 can be connected to other peripheral ICs and the bus interface IC 24 will be selected by the CS pin (chip select not pin). When the user microprocessor 22 wants to transmit, it selects the bus interface IC 24 by outputting a "zero" to the CS pin and then watches the CONTROL pin. When the control pin goes to a logical one, signifying that the buffer register 304 is full of received data and can be read by the user microprocessor 22, the user microprocessor 22 then supplies the 16 shift pulses and reads the data at the same time it loads the SPI buffer in block 304 with the ID and data it wants to transmit.
The user microprocessor 22 then pulses the CONTROL pin and the data will be transmitted at the proper time. If the microcomputer just wants to read, it just reads by supplying the shift clocks and does not pulse the CONTROL pin. The bus interface IC 24 contains the circuitry to hold the received data in the buffer register and ignore receiving new data until after the old data has been read. This ensures that the transmitted data can be tested to be sure that it won arbitration; if not, it will need to be re-transmitted.
In the buffered SPI mode, the bus interface IC 24 uses an internal 16-bit shift register called a 16-bit buffer and bit reverser 304, to buffer two bytes of data between the user microprocessor 22 and the bus 26 while supporting the use of the typical SPI type of interface for the transfer of data between the user microprocessor 22 and the bus interface IC 24.
The two byte buffer separates the user microprocessor 22 from the operation of the bus 26. This allows the user microprocessor 22 to concentrate on other higher priority tasks and to have multiple devices on its SPI bus.
The user microprocessor 22 loads the two-byte buffer in the bus interface IC 24 at high speed using an SPI interface and signals the bus interface IC 24 to transmit the data in the buffer.
The bus interface IC 24 at bus speed, attempts to transmit the buffered data to the bus 26. During this attempt to transmit, the bus interface IC 24 receives two bytes of reflected data back from the bus 26, stores them in the buffer and locks the buffer from receiving further data from the bus 26 until the received data is unloaded by the user microprocessor.
Later, the user microprocessor 22, again using the high speed SPI transfer technique, unloads the received bytes and simultaneously loads the next bytes to be transmitted.
While it is transmitting and receiving two bytes of data to and from the bus, the bus interface IC 24 is not transferring data to and from the microprocessor 22 and, in fact, does not need to be chip selected by the user microprocessor 22 during this time.
The user microprocessor uses the IDLE and CONTROL line to sense the status the bus interface IC 24 and to control its operation.
The principle differences between the buffered SPI and the unbuffered SPI mode are the use of a two-byte internal buffer, that the user microprocessor 22 operates in master mode instead of slave mode and, the separate rather than combined steps of transferring data between the bus interface IC 24 buffer and the user microprocessor 22, and transmitting/receiving data to/from the bus 26.
Referring now to FIG. 2 and FIG. 3, the hardware of the bus interface IC will be described.
The mode select block 301 is composed mostly of data multiplexers and gates well known to those who design ICs. The function of the mode select block 301 is to control data and the shift clock (SCK) signal flow into and out of the bus interface IC 24. The MODE and CS(active low) inputs determine which one of the three modes the bus interface IC is in.
If the MODE and CS inputs are a logical one value, the bus interface IC 24 is in the SCI mode. Here data flows from the XMIT (transmit) pin and is gated directly to an output of mode select block 301 to the arbitration detector 42. In addition, the data to be sent to the received data (REC) pin comes into the block 301 from the digital filter 210.
If the MODE input is at a logical one state and the CS input is at a logical zero, then the bus interface IC 24 is in the SPI mode. In the SPI mode, data is input to the bus interface IC 24 in a synchronous fashion in which the bus interface IC 24 is the master. When the user microprocessor 22 is transmitting, the SCK output produces rising and falling edges which will induce the user microprocessor 22 to output data on the rising edge and will latch data into its on the falling edge.
The SCK pulses for the SCK pin come into the block 301 from the SPI clock generator 308. Data that comes in from the XMIT pin is sent out to the start/stop bit generator and SPI data path 307 for start and stop bit generation. Data from the start/stop bit generator 307 comes back into the mode select block 301 and is then sent out on an output line to arbitration detector 42. Data for the REC pin from the mode select block 301, while in the SPI mode, comes from the digital filter 210.
If the MODE pin is at a logical zero state, the bus interface IC 24 is in the buffered SPI mode. In this mode, the CS input acts as a true chip select.
If the CS is a logical zero, the REC pin will be in the active or driving state. If the CS input is at a logical one, the REC pin will be in a high impedance state, and any SCK pulses entering the bus interface IC 24 will be blocked.
While in the buffered SPI mode, the user microprocessor 22 is the master, which means that the user microprocessor 22 must supply the SCK pulses. The use microprocessor 22 selects the chip or bus interface IC 24 via the CS input and produces 16 SCK pulses, the data associated with these pulses will be put into a 16 bit buffer and bit reverser 304 via mode select 301. The 16-bit buffer and bit reverser 304 is clocked from SCK selector 302.
Data from the XMIT pin flows from that pin out of the mode select block 301 and into the 16-bit buffer and bit reverser 304. While the buffer is being clocked, data intended for the receive pin REC is sent from the buffer via the 2 or 1 byte receive block 305.
The mode select block 301 also supports a test mode facility. This is signal to the block 301 from the test mode detector 401 in combination with the reset circuit 402. The signal will pass the data from the over range latch 61 to the REC pin. REC pin on the mode select block 301. The test mode detector 401 comprises essentially two D flip-flops and two NOR gates.
The test mode detector 401 has a purpose to signal the mode select block 301 to pass data from the over range latch 61 to the REC pin located off the mode select block 301. The test mode detector 301 also allows the user microprocessor 22 to perform a reset.
The test mode condition is entered when the A input to the test mode detector 401 is given two pulses. At the point the two pulses are given, the test mode is in effect and the data from the over range latch 61 is sent to the REC pin directly bypassing the digital filter 210.
The test mode is exited by pulsing the A pin two more times. The test mode detector 401 is also reset on power up.
While in the test mode and when the B pin is put to a logical one, the bus interface IC 24 will enter a reset state. If the B input pin is at a logical zero level, the bus interface IC 24 will not be in reset. This reset circuit 402 also produces a reset upon the power up condition. The 402 reset circuit comprises essentially two NOR gates with an internal reset capability.
The clock divider 201 allows the user microprocessor 22 the capability of having a divide by 10, 8, 4 or 1. The four states of the counter included in the clock divider are determined by the inputs on pin A and pin B. The clock divider 201 is also reset by the reset circuit 402. The clock divider 201 is composed of five D flip-flops, six gates and three data multiplexers.
The arbitration detector 42 comprises essentially the following gates: one D flip-flop and two nand gates. The arbitration detector operates as follows. When a user microprocessor 22 accesses the bus 26, the IDLE line of the bus interface IC 24 goes high and the user microprocessor 22 sees this condition and determines that access to the bus 26 is still possible. If the user microprocessor accesses the bus within 1/4 bit times, then the arbitration window is not set and the user microprocessor attempting access has a chance to go through the collision detector phase. If the user microprocessor does not get the start bit on the bus 26 within 1/4 bit times, then the user microprocessor 22 attempting to access the bus 26 is locked out from the bus 26 until the bus idle condition occurs. This decision is made at the 1/4 bit time and is reset by the bus idle line.
Turning now to the collison detector 44, this block is comprised essentially of the following logical elements: one D flip-flop and a nand gate.
The collision detector 44 is clocked at the mid bit time. When the collision detector 44 is clocked, it determines if the user microprocessor 22 was transmitting a one while the bus 26 carried a logical zero state; if so, a latch is set in the collision detector 44 and the bus interface IC 24 is blocked from transmitting onto the bus 26. A logical one at the bus 26 or on the input to the collision detector 44 will not affect the latch and the user microprocessor 22 will continue to have access to the bus 26. The collision detector 44 is reset at the bus idle condition.
The digital filter 210 comprises three flip-flops and two gates to filter for noise. It has two D-type flip-flops connected in a shift register fashion, clocked by the system clock, the Q outputs of the flip-flops go into an AND gate. Also, the Q outputs go into a NAND gate. The first NAND gate goes into the set of an RS flip-flop, and the second flip-flop goes into the reset of the RS flip-flop. The result of this is to give a two out of three vote detector. The digital filter 210 takes its input from the over range latch 61, and outputs its data. The digital filter 210 is also held in reset during a reset condition.
The word counter 202 comprises basically twelve D-type flip-flops configured as a ripple counter. The purpose of the word counter 202 is to start counting when a start bit enters from the start bit detector 200. The word counter 202 then provides the timing for the collision detector 44, arbitration detector 42, framing error detector 204 and other SPI timing functions.
The word counter 202 provides the 1/4 bit time clock for the word counter 202, the output of which is taken off of the sixth flip-flop in the counter chain.
The collision detector 44 gets its 1/2 bit time signal from the seventh flip-flop in the counter chain. Also, a signal is decoded from the counter chain to give a signal at the center of the tenth bit (stop bit). This signal, from word counter 202, is used to clock the framing detector circuit 204. A clock cycle delay signal from word counter 202 is used in setting block 203 the word flip-flop. The SPI control outputs from the word counter in block 202 will be covered completely in the respective portions of the bus interface IC 24 in the rest of FIG. 2 and FIG. 3.
The function of the word flip-flop in block 203 is to, after the middle of the tenth bit, or after a reset condition, lock onto a start bit from the start bit detector 200 if the start bit has been in existence for 1/4 bit time.
If the start bit, after the middle of the tenth bit, or after reset is less than 1/4 bit time, then the word flip-flop 203 will not lock onto a start bit and the word counter 202 is allowed to reset via the start bit detector 200, but if the start bit has been in existence for more than 1/4 bit time, the word flip-flop 203 is latched and will not be reset until the middle of the tenth bit (a stop bit). Resetting to the word flip-flop in block 203 is done via an output signal from the word counter 202.
The start bit detector is block 200 is basically a NOR gate and it works in conjunction with the word flip-flop 203.
These two blocks work together after the passing of the middle of the tenth bit or just after a reset. The blocks look for a start bit from the framing error detector 204 and when this start bit appears, the word counter 202 is turned on via the start bit detector 200.
If the start bit remains, the word counter 202 is kept on and, if the start bit has been there for 1/4 bit time, then the word flip-flop 203 will be latched and, hence, the word counter 202 will also be latched on via the start bit detector 200.
The start bit detector 200 is a NOR gate with its inputs from the framing error detector 204 and the word flip-flop 203. The output of the start bit detector 200 goes to the reset of the word counter 202 so that either of these two circuits can turn the word counter 202 on. If the start bit is less than 1/4 bit time, then the start bit detector 200 turns off the word counter 202. When the start bit detector 200 sees a start bit, idle flip-flop 207 output is activated, thus forcing IDLE to a high level. The framing error detector 204 accepts data from the digital filter 210 and passes its data along to the start bit detector 200. The framing error detector 204 is clocked at the middle of the tenth bit, or the stop bit. If the stop bit bit is a logical one in value, then the stop bit is valid and the data can continue to pass freely through the circuit. But, if the tenth bit is a logical zero, then this is a framing error condition and the framing error detector 204 will lock out any more start bits from entering the start bit detector 200. The effect of this is to keep the word counter 202 in an off or reset condition and leave the idle counter 206 running until the bus 26 has been idle for at least 10 bit times. The framing error detector 204 will be reset at the bus idle time.
The idle counter 206 is similar in construction to the word counter in block 202 and is an 11-bit ripple counter. The idle counter 206 turns on whenever the word flip-flop in block 203 is in a set condition. This occurs after reset or after the middle of the tenth data bit.
The purpose of the idle counter 206 is to count the bit times after a word has been completed. The counter will count up to ten bit times and will reset the idle flip-flop 207 and the framing error detector 204. If, while counting out the idle times, a zero on the bus 26 of less than 1/4 bit time appears, the upper four bits of the idle counter 206 will be reset, and the ten bit times will be extended. The bus data, from the digital filter 210 is sampled at 1/2 bit time durations to give some noise immunity to the upper four bits in the idle counter 206. Therefore, the less than 1/4 bit time zero value on the bus 26 would have to appear during the 1/2 bit time window in order to reset the upper four bits in the idle counter 206, thus extending the idle time.
The idle flip-flop 207 is comprised of a flip-flop, an AND/NAND gate and a transistor with an active pull up. Its purpose is to signal the bus 26 as busy whenever there is an activity on the bus 26. The idle flip-flop 207 comes up in a set condition after a power on reset. This is then passed through an AND gate. The output of the AND gate drives a transistor. So, when the AND gate is high, the IDLE pin is low and vice-versa. The other input of the AND gate comes from the start bit detector 200.
Assuming that conditions in the bus interface IC 24 are just after a power on reset or a long idle period, greater than 10 bit times, the IDLE pin will be low. As soon as a logical zero is detected on the bus 26, the output of the start bit detector 200 goes low and signals the AND gate to drive the IDLE pin high. Then, if the start bit is deformed by noise or generated by noise and is less than 1/4 bit time, the output of the start bit detector 200 will go high and the IDLE output will return low. But when the start bit is more than 1/4 bit times in duration, it is probably a valid start bit, and the word flip-flop 203 will latch. This will reset the idle flip-flop 207 and when the output of the idle flip-flop 207 is applied to the AND gate, this will guarantee the output of the AND gate to be a logical zero, thus forcing the IDLE pin high. The bus 26 will signal a busy condition until a signal from the idle counter 206 sets the idle flip-flop, thus forcing the IDLE pin back to a low condition and signaling a bus idle condition. The break generator 403 is intended to allow a user microprocessor 22 to force a zero state on the bus 26. This zero state on the bus 26 is only allowed to be forced on the bus 26 after a user microprocessor has transmitted at least four bytes. At the first data bit of the fifth byte, the break will be enabled. So, if the user microprocessor 22 then pulls down on the idle line, a zero state will be put out onto the bus 26. If the idle is then released, the break generator 403 no longer has an effect on the bus 26. The break generator 403 comprises essentially three D flip-flops and four gates.
The SPI transmit scheduler and controller in block 309 is made up of approximately three D flip-flops, nine gates, a data multiplexer and a transistor with an active pull up. The transmit scheduler and controller in block 309 is used in the SPI and the buffered SPI modes. Its primary function is to control when data from a user microprocessor 22 is put onto the bus 26. When the user microprocessor 22 wants to transmit data, it pulls down on the CONTROL line. In the unbuffered SPI mode, after pulling down on the CONTROL line, the SPI transmit scheduler and controller in block 309 is latched low by the bus interface IC 24. If the CONTROL line which is connected to the block 309 had been pulled low immediately after the IDLE line had gone low, there is a 2-bit time delay inserted before a start bit can go out onto the bus 26. A signal from the idle counter 206 determines 1.5 bit times of the 2-bit time delay. When the 1.5 bit time after idle has been reached, the signal from the idle counter 206 will set a flip-flop in the scheduler and controller 309. This flip-flop is reset at the idle time by a signal from the idle flip-flop in block 207.
Therefore, once this signal is set, and the control pin is low, this action will enable another flip-flop in the scheduler and controller 309 to be set 1/2 bit time later. This flip-flop is clocked by another signal from the idle counter 206. Once this flip-flop is set in block 309, its output signal is sent to the start/stop generator and SPI data path block in 307 where a start bit is generated. The output of the flip-flop is reset via a signal from the word counter 202 at the end of the start bit time.
If a start bit does come onto the bus 26 and the user microprocessor 22 did not pull the CONTROL line to a low state, then another signal from the word counter 202 clocks the control latch in block 309 and makes the CONTROL line go to a low condition. This happens at the end of a start bit.
Two inputs, one from the arbitration detector 42 and another from the collision detector 44, tell the scheduler and controller in block 309 if there have been any collisions or lost arbitrations and, thus, that no more start bits may be produced by the bus interface IC 24 until the bus idle condition reappears.
The scheduler and controller in block 309 in a buffered SPI mode works essentially the same as in the unbuffered SPI mode described above, but with a few minor exceptions. When the buffered SPI user microprocessor wishes to transmit, it must first load its 16-bit buffer in block 304 with data. Then, it must pull down on the control line and the CONTROL line will be latched low by the bus interface IC 24.
The input to the scheduler and controller 309 from the SCK counter 303 signals the scheduler and controller 309 that if 16 bits have been read and a byte comes in from the data bus 26, then the CONTROL line will be pulled low, when the input signal from the word counter 202 clocks the control latch. This will happen at the end of the start bit time. The determination of whether the 16 bits have been read or not is determined by another signal from the SCK counter 303 as presented to the scheduler and controller 309. If the 16 bits have not been read, the control line will not be pulled to a low condition.
Given that the 16 bits have been read and the user microprocessor pulls on the control line, then the bus interface IC 24 will respond just as in the unbuffered SPI mode, by generating a start bit, clocking 8 data bits onto the bus, followed by a stop bit, a start bit, then 8 more data bits, followed by the stop bit. In the buffered SPI mode, the control line will return high at the end of the ninth bit of the second byte. This is accomplished via a signal from the SPI clock generator 308 as presented to the scheduler controller 309 which clocks the control latch in the scheduler and controller 309.
In the buffered SPI mode, the control line is brought back to a high condition at the end of the ninth bit time. This is accomplished by clocking the control latch via a signal from the start/stop bit generator in the SPI data path block 307 as presented to the scheduler and controller block 309.
The SPI clock generator found in block 308 is made up of a gate and an RS flip-flop and it is used to generate the SCK pulses to the user microprocessor 22 and to the 16-bit buffer bit reverser in block 304.
These pulses are such that a rising edge is given at the beginning of the second bit, which is the first data bit and a falling edge at the middle of the second bit. This continues for eight bit times. That will now be at the middle of the ninth bit.
The main time base for the SCK signal is from the word counter 202 as presented to the SPI clock generator 308. This is a 1/2 bit time clock.
The SCK output from this block is derived from the 1/2 bit time clock signal, but the SPI clock generator 308 must block any clock pulses before the end of the start bit. The SCK output from the SPI clock generator 308 is presented both to the mode select block in 301 and to the SCK selector in block 302.
A signal from the word counter 202 and presented to the SPI clock generator 308 is activated at the end of a start bit. This signal, in turn, clears an internal flip-flop in SPI clock generator 308 whose output is the reset for the control latch. Once this signal is clear, the SCK generator signal output from the SPI clock generator 308 begins to clock in the fashion described earlier. The signal is then blocked at the middle of the ninth bit. This is done with another signal from the word counter 202 which blocks the SCK. This signal sets the internal flip-flop of the SPI clock generator 308. As before, this output is the reset control latch signal as presented to the scheduler and controller 309, and is also set at a power on reset.
Turning now to the SPI start/stop bit generator and data path block in 307, this is the block used as a data path for the buffered and unbuffered SPI modes. It comprises essentially one RS flip-flop and two gates.
Usually, data flows freely from the input to block 307 from the mode select block 301 to the output of the block 307 back into the mode select block 301. However, the data is interfered with when a start bit or a stop bit is generated. When the bus interface IC 24 comes up from a power on reset, the signal from the arbitration detector 42 is blocking data from the bus 26. That is, it forces a stop it level onto the bus 26. When a user microprocessor 22 is in the SPI mode and is ready to transmit, the signal from the scheduler and controller 309 to the data path block in 307 induces a start bit onto the bus 26. At the end of the start bit, the input signal from the word counter 202 to the data path block 307 resets an internal flip-flop in block 307, the output of which is sent to the SPI clock generator 308 and to the brake generator 403, thus allowing valid SPI data to enter the bus 26. Data can then pass freely until the input signal from the word counter 202 sets the output signal of the block 307 as presented to the SPI clock generator 308 and the scheduler and controller 309. This, then, will induce a stop bit onto the bus 26 and block any more SPI data. This signal, as presented from the word counter 202, is also labeled "set at stop bit time."
The SCK selector in block 302 is used only during the buffered SPI mode. It comprises a flip-flop, a data multiplexer and a gate. The SCK selector 302 has a function to describe what source is to clock the 16-bit buffer and bit reverser 304. The clocking is done via the output from SCK selector 302 into the 16-bit buffer and bit reverser 304. The clocking can come from one of two sources, either the internally generated SCK signal from the SPI clock generator 308 or the user microprocessor 22, which enters the SCK selector 302 from the mode select block 301.
When the bus interface IC 24 comes off of a power on reset, as signaled from reset circuit 402, or after a two-byte receive signal, as signaled by the 2-byte counter 306, or after a bus idle, as signaled by the idle flip-flop 207, the 16-bit buffer and bit-reverser 304 can be clocked by the user microprocessor 22. When the user microprocessor clocks the 16-bit buffer and bit reverser 304, 16 times via the SCK pin, this enables the user microprocessor to transmit or to receive new data from the bus 26. When the 16 bits have been input, this enables the output from the SCK counter 303 which will go high at the end of the first start bit, because of the signal from the word counter 202 which is a reset at the first bit time.
When the output from the SCK counter 303 is presented to the SCK selector 302, this will determine what clocks the 16-bit buffer and bit reverser 304, via signal MUXCNTRL. When the MUXCNTRL signal from 302 is reset, the 16-bit buffer and bit reverser 304 will be clocked by the bus interface IC 24. When it is set, the user microprocessor 22 will clock the block 304. The MODE input to this block 304 will make the signal shared between one of the outputs of the SCK counter 303 and one of the inputs to the 16-bit buffer and bit reverser 304, always to be in a logical zero condition, so the 16-bit buffer and bit reverser 304 will always be clocked by the user microprocessor 22.
The 16-bit buffer and bit reverser in block 304 is made up of a shift register utilizing 16 flip-flops and 16 data multiplexers. It is connected as a shift register. Two to one multiplexer gates are used to change the feedback path. When a signal from the multiplex control (MUXCNTRL) line of the SCK selector 302 is a logical zero, data in the 16-bit buffer and bit reverser 304 is shifted from the right to the left. Data from the user microprocessor 22 is input to the first flip-flop in the chain in the signal line labeled "data for BSPI."
Data will then flow out of the last flip-flop intended for the REC pin.
When the MUXCNTRL signal from block 302 is a logic one, the data enters the eighth flip-flop from the digital filter 210. Data is then shifted from the eighth bit towards the first bit. The first bit will then pass data to the 16th bit, and the data from the 16th bit is shifted down towards the 9th bit. Data is sent out to the data bus 26 from the 9th flip-flop.
The SCK counter consists of five D flip-flops hooked up as a ripple counter and flip-flops and gates to control the counter. The purpose of the SCK counter is to count the SCK pulses that come in from the user microprocessors 22. This counts the pulses from the signal fed from the mode select block 301.
Upon power up, the SCK counter 303 is reset. When the user microprocessor 22 counts, a five-stage ripple counter counts the number of SCK Pulses that enter. When the number hits 16, the last counter in the stage is latched and its outputs goes to a logical one and is presented to the scheduler and controller in block 309.
When the user microprocessor 22 begins to transmit and the input signal NQSFF8 goes from a logic zero to a logic one, this, too, will reset the SCK counter. An output from the SCK counter 303 resets the signal NQSFF8; it also drops the control pin to a low state during the buffered SPI mode if a start bit comes in from the bus 26, if the user microprocessor has read 16 bits from the bus 26.
The two or one byte receive block in 305 is basically an RS flip-flop and a data multiplexer. Its function is to distinguish between a two byte receive signal and a one byte receive signal. This is done because typically most messages are at least two bytes. If so, the user microprocessor 22 will go out and receive the two bytes, and the bus interface IC 24 will have its 16 bits buffer and bit reverser 24 full, and the first byte is clocked out first and the second byte second. If, however, the bus interface IC 24 receives only a one byte message, then there is only one good byte sitting in the block 304. What will happen is that the first byte to be clocked out of the 16-bit buffer and bit reverser 304 will be the bad byte and the next byte will be the received byte. To correct this, we added a circuit to detect a one byte or two byte receive. When the transmission begins, the block 305 is reset by an output signal from the SCK counter 303 which produces a default one byte receive. If, after transmission, two bytes were received, the block will be set by the two byte counter in block 306.
If there was a one byte receive, then data will be sent to the receive pin from the middle of the 16-bit buffer and reverser 304. If there was a two byte receive, data will be sent to the receive pin from the end of the buffer in block 304.
The two byte counter 306 is essentially made up of two flip-flops and a NOR gate to count bytes. The function of the block is to count up to two receive bytes. The two byte counter is clocked via the output from the arbitration detector 42. The clocking takes place at the middle of the ninth bit, which is the the eighth data bit.
This counter serves two purposes, when it counts up to two, it will switch the SCK selector 302 from being clocked by the bus interface IC 24 to being clocked by the user microprocessor 22. This is done via the output directly connecting the two byte counter 306 with the two or one byte receive block in 305. This same signal also sets the flip-flop internal to block 305 after a one byte receive. The over range detector found in block 60 is used to detect when the bus 26 goes above 3.13 volts or below 1.8 volts. This is known as an over range condition and the output signal from this block goes high. When the inputs to the block are both below 3.13 volts, and above 1.8 volts, then there is no over range condition and the output of the block is low. The block is essentially a detector that is internal to the I/O cell.
The over range latch (ORL) found in block 61 is essentially a D latch. When an over range latch condition is detected in block 60, the over range detector 60 will signal the over range latch in block 61 which will latch on the last valid piece of data before the over range condition. When there is no over range condition, data has passed freely from the block 60 through block 61 and out to the digital filter 210.
The three input OR gate, shown as block 62, is used in conjunction with the collision detector 44 and arbitration detector 42 and multiplexed output from mode select block 301, which is the transmitted data. If either of the detectors is set, the output of the gate is a constant one value. Thus, when passed through block 63, this will force a zero. This will not turn on the current sources in block 34 and 36 and, thusly, the bus interface IC 24 will not transmit onto the bus 26. If the detectors 44 and 42 are not set on the data from the multiplexed output of the mode select 301, will pass freely into the NAND gate in block 63 and will be transmitted onto the bus 26.
The two input NAND gate shown as block 63 will transmit data from either the block 62 or from the break generator in block 403. When either input is a logical zero, the output of the NAND will be a logical one, thus turning on the current sources in blocks 34 and 36.
The bus plus current source shown in block 34 is turned off and has no effect on the bus plus line when the input to the block is a logical zero. When input to the block is a logical one, the current source 34 is turned on. When the source is on, current is passed from V CC to the bus plus line.
The bus minus current source in block 36 is turned off and has no effect on the bus minus line when the input to the block is a logical zero. When the input to this block is a logical one, the current source is turned on and the current is passed from the bus minus line to ground.
FIG. 5 illustrates an example of the collision detection on the bus interface IC including the CONTROL signal.
FIG. 6 through FIG. 28 are gate diagrams of the blocks shown in the block diagrams.
While the present invention has been disclosed in connection with the preferred embodiment thereof, it should be understood that there may be other embodiments which fall within the spirit and scope of the invention and that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the following claims. | The aim of the Chrysler Collision Detector (CCD) Bus System is to allow multiple microprocessors to easily communicate with each other over a common pair of wires (called a bus) using a scheme similar to a telephone party line. All microprocessors connected to the bus are able to receive all messages transmitted on the bus. Any microprocessor with a message to transmit on the bus waits until any current user is finished before attempting to use it. Whenever the bus is available, its use is allocated on a first-come, first serve basis (i.e., whichever microprocessor first begins transmitting its message on the bus after any previous message finishes gets the use of the bus). If, however, multiple microprocessors attempt to begin transmitting their messages on the bus at exactly the same time, then the message with the highest priority wins the use of the bus. All messages have unique message priority values and each message is transmitted by only one microprocessor. The subject invention provides the ability to communicate with a SCI port, a SPI port or a buffered SPI port. This allows communication with any device configured with any one of these ports, all on the same bus. | 6 |
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
The U.S. Government has rights in this invention pursuant to contract No. W-7405-ENG-26 awarded by the U.S. Department of Energy.
BACKGROUND OF THE INVENTION
This invention relates to an absorption machine and, more particularly, to an improved coupled dual loop absorption heat pump/refrigeration machine utilizing two separate complete single effect loops.
In a typical single effect absorption system, water may be the refrigerant and lithium bromide may be the absorbent, and together they are called a solution pair. Some systems employ high temperature solution pairs that are capable of operating at higher generator temperatures to increase efficiency but are precluded from operating at lower evaporator temperatures due to the possibility of freezing and crystallization of the solution pairs, while other chemical systems capable of operating at lower evaporator temperatures could not operate at the higher generator temperatures without chemical stability problems. Consequently, a single effect system is generally a compromise between higher and lower operating temperature conditions in the generator and evaporator.
Well known absorption cycles are mainly of a single effect type comprising a generator for heating a weak or relatively dilute absorbent solution to generate vapor of refrigerant, a condenser for condensing the vapor of refrigerant, an evaporator for evaporating the condensed refrigerant to provide cooling, and an absorber for absorbing the refrigerant vapor of the evaporator into a strong or relatively concentrated absorbent solution. However, the thermal efficiency (coefficient of performance or COP) of a single effect type absorption system is relatively low and ordinarily about 0.6-0.7. With a view toward increasing the thermal efficiency of absorption cycles, double effect type absorption units have been developed in which a second generator is additionally provided in the single effect type absorption unit such that the high temperature vapor of refrigerant generated in a first generator is utilized to heat a second generator.
In general, the double effect type absorption unit comprises a high temperature generator and a low temperature generator whereby the external heat supplied is utilized twice in the high and low temperature generators and so the thermal efficiency increases in comparison with the single effect type system.
An improvement of the double effect type absorption unit has been the dual loop system. The absorption system in U.S. Pat. No. 3,483,710 is a prior art version of a two loop system that combines a higher temperature loop with a lower temperature loop. Although this prior art discloses a high temperature condenser in heat exchange relation with a low temperature generator, it fails to teach the relationship between the other components in both loops.
SUMMARY OF THE INVENTION
The present invention is directed to an improved coupled dual loop absorption heat pump/refrigeration cycle which utilizes two separate complete loops. Each individual loop operates at three temperatures within a temperature range and two pressures within a pressure range. The pressures of either loop can be greater than the pressures of the other loop depending upon the fluids employed.
When the generator/condenser pressures are higher than the absorber/evaporator pressures, the cycles are the conventional ones found in heat pumps and air conditioners, and heat is input at the two temperature extremes of each loop and is rejected at the middle temperatures. When the pressures are reversed, the heat input and rejection is also reversed, and the cycles form a heat transformer or temperature booster.
In a preferred embodiment, the evaporator of the first loop is fired by part of the heat rejected by the condenser and absorber of the second loop, while the generator of the second loop is fired by the total heat rejected by the condenser and absorber of the first loop. Further, since the coupling between the two individual loops is across heat exchanger surfaces only, the present invention allows the use of separate refrigerant/absorbent combinations in each loop. The use of separate combinations in each loop permits the use of a working fluid in each loop that is best suited to the temperature/pressure levels in that loop.
Accordingly, it is an object of the present invention to provide an absorption heat pump/refrigeration system with both heating and cooling efficiencies advanced beyond current commercial offerings.
It is another object of the present invention to provide an absorption system that extends the operaitng temperature region higher and lower than current cummercial offerings.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, forming a part of this specification, and in which reference numerals shown in the drawings designate like or corresponding parts throughout the same,
FIG. 1 is a schematic representation of a dual loop system of the present invention in the cooling mode; and
FIG. 2 is a diagrammatic view of a dual loop system of the present invention in the heating mode.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a schematic representation of a dual loop absorption machine 10. The machine 10 generally comprises two single effect loops thermally coupled to transfer heat therebetween. The present machine comprises a high temperature loop 12 or upper loop or stage, and a lower temperature loop 14 or lower loop or stage. This schematic representation is shown within a coordinate system having increasing temperature form left to right along the abscissa and increasing pressure from bottom to top along the ordinate. Accordingly, the upper limit of the high temperature loop 12 is at a higher relative temperature than the upper limit of the lower temperature loop 14. It is noted, however, that the upper loop pressures are not necessarily higher than the lower loop pressures. The typical high temperature loop 12 comprises a high temperature generator 15, a high temperature condenser 16, a high temperature evaporator 17, and a high temperature absorber 18, while the low temperature loop 14 comprises a low temperature generator 25, a low temperature condenser 26, a low temperature evaporator 27, and a low temperature absorber 28. The high temperature and low temperature loops are coupled so that the low temperature condenser 26 and low temperature absorber 28 are thermally coupled with the high temperature evaporator 17. The algebraic sum of these three heat quantities is equal to the heat delivered to the load. The second thermal coupling point between the high temperature and low temperature loops is through the use of rejected heat from the high temperature absorber and high temperature condenser as input heat for the low temperature generator. The operating conditions are chosen so that the algebraic sum of these heats is zero. Thus the heat to the low temperature generator 25 will be generally twice that to the high temperature generator 15 giving an enhanced thermal efficiency.
Referring now to FIG. 2, high temperature generator 15 is contained within a shell 22 and is heated by combustion gases from burner 20 which flow through conduit 19. Heat is transferred from the combustion gases in conduit 19 to a weak absorbent solution being discharged from conduit 24. The heat concentrates the weak solution by removing refrigerant therefrom. The released refrigerant vapor flows from the high temperature generator 15 through conduit 29 into low temperature generator 25 which is within shell 31. The vaporized refrigerant is condensed within conduit means 32 through a portion of low temperature generator 25 and discharged to low temperature solution and condensate heat exchanger 30 by way of conduit means 33. The refrigerant flows from low temperature solution and condensate heat exchanger 30 through conduit 82 and is discharged through spray header 34 into high temperature evaporator 17. The condensed refrigerant within shell 36 is recirculated through conduit 37 by high temperature refrigerant pump 38 by way of conduit 39 through spray header 41 back to the high temperature evaporator 17.
Vaporized refrigerant within shell 36 flows through opening 42 in partition 43 which separates the high temperature evaporator 17 from the high temperature absorber 18, where it weakens the strong solution supplied to the high temperature absorber 18 from high tempersture generator 15 by way of conduit means 84, high temperature solution heat exchanger 50 and conduit 44 through spray header 46.
In the high temperature loop 12 the weak absorbent solution in high temperature absorber 18 is pumped therefrom by high temperature solution pump 48 by way of conduit means 47, 49, and 24, through high temperature solution heat exchanger 50 to high temperature generator 15, thus completing the fluid flow through high temperature loop 12.
In operation, the low temperature generator 25 is in heat transfer relationship with conduit 32 of high temperature condenser 16 and heat pipe 40 of high temperature absorber 18. The heat pipe 40 is a closed loop heat exchanger well known in the art and serves to provide heat exchange between high temperature absorber 18 and low temperature generator 25.
In the low temperature loop 14 (as shown in FIG. 1) the low temperature absorber 28 is connected to low temperature generator 25 through low temperature solution and condensate heat exchanger 30 by weak solution conduit means 51 and 52, and strong solution conduit means 58 and 59. The low temperature generator 25 is connected to low temperature partial condenser 26 within shells 31 through demister 86, and to low temperature partial condenser 88 within shell 36 by conduit 73. The low temperature condenser outlets are connected through liquid vapor interchanger 54 by conduits 53, 55, 73 and 77 to expansion valve 56 and to the low temperature evaporator 27 by conduit means 57.
In the lower loop 14 (shown in FIG. 1) strong absorbent solution flows from low temperature generator 25 through low temperature solution and condensate heat exchanger 30 by conduit means to spray header 61 into low temperature absorber 28 where it absorbs refrigerant and the resulting weak solution is pumped through low temperature solution and condensate heat exchanger 30 and spray header 62 by low temperature solution pump 60. Heat is removed from the vaporized refrigerant flowing from the low temperature evaporator 27 to the low temperature absorber 28 by liquid vapor interchanger 54.
In the heating mode (as shown by the solid arrows) indoor coil 66 transfers heat from absorption cycle 40 to the conditioned space while outdoor coil 68 transfers heat from the outdoor ambient to the absorption cycle. A secondary fluid is circulated through the indoor and outdoor coils to accomplish this by loop pumps 67 and 69 respectively which are connected through a dual four-way heat/cool valve 70. In the cooling mode (as shown by the dashed arrows) the heat/cool valve 70 is reversed and the functions of the indoor and outdoor coil are also reversed.
An exemplary recuperator 75 is also shown, which supplements heat to the load with recovered heat from the flue gas leaving conduit 19 in the heating mode. Bypass valve 87 is provided so that the recuperator 75 is not operational in the cooling mode. | A coupled dual loop absorption system which utilizes two separate complete loops. Each individual loop operates at three temperatures and two pressures. This low temperature loop absorber and condenser are thermally coupled to the high temperature loop evaporator, and the high temperature loop condenser and absorber are thermally coupled to the low temperature generator. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to apparatus for the production of fine powders from a liquid melt by gas atomization and solidification, and more particularly to a melt tube assembly for delivering a stream of high temperature melt to the atomization zone of such apparatus.
It is known to pass a stream of molten material, for example molten metal, through a nozzle or melt delivery tube, and to direct one or more high velocity fluid jets at the emerging stream to break up the stream into small globules, which are then solidified into particulates of varying sizes. Typical atomizing apparatus suitable for atomizing metals includes a heated crucible for melting or maintaining the melt temperature of the metal, a melt delivery tube for directing a stream of the melt to an atomizing zone below the crucible, and a gas nozzle to direct one or more streams or sheets of atomizing gas to impinge on the melt stream at the atomizing zone.
However, melt tube arrangements for atomizing molten metals for use in making powdered products have left much to be desired, particularly in the atomization of higher melting metals, i.e. those having melting points above 1000° C., and especially of alloys having melting temperatures above 1200° C. The major problems affecting known atomization apparatus and processes are: freeze-up (solidification of the melt) at the melt tube outlet, erosion of the melt tube, and melt tube breakage. In confined gas atomization systems, i.e. systems in which the gas nozzle closely surrounds the melt delivery tube, the outer surface of the tube is subject to severe cooling due to the proximity or actual impingement thereon of the atomizing gas, the temperature of which is greatly lowered by expansion as it exits the gas nozzle. In contrast, the inner surface of the tube is exposed to high temperature metal melts, some in excess of 1200°-1500° C. Thus, the melt delivery tube experiences severe thermal stress due to this drastic temperature differential between its inner and outer surfaces. Further, the inner surface of the melt delivery tube is subject to substantial erosive forces due to the flow of the melt aspirated therethrough, while the entire tube experiences severe mechanical shock or spring forces during the start-up of the high pressure gas flow.
The superimposition of these mechanical and thermal stresses generally leads to catastrophic failure of the system due to fracture of the melt delivery tube. The change in melt tube geometry and melt outlet position due to the fracture leads to backpressure conditions on the melt causing a cessation of melt flow and even the bubbling of atomization gas upward through the melt in the crucible. These problems have greatly increased the cost of operating such a confined system in a production environment where component reliability over an extended time is a necessity. This in turn has led to the underutilization of confined gas atomization in production processes and has led to increases in the cost of the metal powders produced thereby.
SUMMARY OF THE INVENTION
The melt tube assembly according to the present invention reduces or eliminates problems of catastrophic failure of the melt delivery tube by the provision of a structure which is mechanically stronger and provides thermal and mechanical insulation for the element(s) in contact with the high temperature melt, i.e. an insulating support shield surrounding the tip of the melt tube. The preferred assembly presents a further advantage, in that the melt tube tip is separate from the portion of the melt tube seated against or within the crucible, and may be easily and quickly removed and replaced. In a most preferred embodiment, the support shield encloses the joint between the melt tube and melt tube tip, and holds the tip in place against the melt tube.
The melt delivery tube assembly according to the present invention is intended for use with a melt reservoir having a downwardly opening outlet. The assembly includes a refractory melt delivery tube having a longitudinal bore therethrough. The tube has an upper portion, and a lower portion having a tip. The upper portion is seatable at the reservoir outlet for melt flow from the reservoir generally vertically downward through the reservoir outlet and melt tube bore. A thermally insulating support shield having a longitudinal bore therethrough is coaxially and removeably mounted surrounding the longitudinal outer surfaces of at least the lower portion of the melt tube. The support shield bore is shaped complementarily to the surrounded outer surfaces of the melt tube for close and slideable fit thereover.
A preferred melt delivery tube assembly according to the invention includes a refractory melt delivery tube having an upper portion, a lower portion, and a longitudinal bore therethrough. The upper portion of the tube is seatable at the reservoir outlet for melt flow from the reservoir generally vertically downward through the reservoir outlet and melt tube bore. A refractory melt tube tip has an upper portion, a lower portion and a longitudinal bore therethrough. The upper portion is coaxially and removeably positionable at the melt tube lower portion for melt flow from the melt tube bore through the melt tube tip bore. A supporting and thermally insulating shield having a longitudinal bore therethrough is coaxially and removeably mountable surrounding the longitudinal outer surfaces of the melt tube tip and at least the lower portion of the melt tube. The shield bore is shaped complementarily to the surrounded outer surfaces of the melt tube tip and the melt tube for close and slideable fit thereover. The support shield includes means for reversibly retaining the melt tube tip in position within the assembly. The support shield and melt tube tip are easily disassemblable from and reassemblable with each other and with the melt tube without removing the melt tube from the reservoir outlet.
In another preferred assembly, the melt tube has upper surfaces of a configuration for seating of the melt tube at the reservoir outlet, and a downwardly facing countered socket coaxial with the melt tube bore. The melt tube tip upper portion is coaxially and removeably positionable within the melt tube socket. The support shield bore is shaped complementarily to the portion of the melt tube tip which protrudes from the socket for close and slideable fit thereover.
In yet another preferred assembly, the tip bore provides a metering orifice for the melt flow through the assembly. Thus, the melt tube tip may be one of a set of interchangeable tips of differing metering orifice diameters, so that the tip may be selected to provide the desired metering orifice diameter.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, together with other and further advantages, objects, and capabilities thereof, reference is made to the following disclosure and appended claims together with the drawings, in which:,
FIG. 1 is an exploded perspective view of one embodiment of the melt tube assembly according to the invention;
FIG. 2 is a sectional elevation view, schematically representing a portion of a typical gas atomization apparatus including the melt nozzle assembly according to the invention; and
FIG. 3 is an exploded sectional elevation view, schematically representing another embodiment of the melt tube assembly according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An illustrative melt tube assembly 10 according to the invention, as shown in FIG. 1, includes three parts: melt delivery tube 12, melt tube tip 14, and thermally insulating support shield 16. Melt tube 12 includes upper portion 18, lower portion 20, and bore 22 passing longitudinally through melt tube 12. Melt tube tip 14 includes bore 24 passing longitudinally through the tip. Melt tube tip 14 also includes upper portion 26 and lower portion 28. Alternatively, tip 14 may be unitary with melt tube 12. Support shield 16 includes bore 30 passing therethrough. The diameter of bore 30 is selected to provide close sliding fit of support shield 16 over outer surface 32 of melt tube lower portion 20 and outer surface 34 of tip 14. Upper portion 18 includes annular top surface 36, annular cylindrical surface 38, and annular beveled surface 40 interconnecting surfaces 36 and 38. The melt tube and melt tube tip are formed of refractory materials compatable with the molten metal to be atomized. A preferred material for the melt tube and tip is graphite. The support shield is formed of a material having sufficient mechanical and thermal stress and shock resistance to withstand the atomizing process, and should be inert to the molten metal. Suitable materials include high temperature molybdenum, titanium, or niobium based alloys, carbon-carbon composites, or advanced ceramics such as Si 3 N 4 , boron nitride, or Al 2 O 3 monolithic or composite materials.
FIG. 2 illustrates a portion of a typical gas atomization system including melt tube assembly 10. Melt crucible 42 includes bore 44 of a diameter selected for close fit of melt tube cylindrical surface 38 therein. Bore 44 includes annular beveled shoulder 46 to act as a stop for melt tube 12 within bore 44. Shoulder 46 is shaped complementarily to beveled surface 40 of melt tube 12 for sealing of beveled surface 40 against beveled shoulder 46. The seal between surface 40 and shoulder 46 is maintained by the close fit between surfaces 38 and 44. Normally, refractory cement is also used to ensure that melt tube 12 remains fixed in sealing relationship with melt crucible 42. Preferably upper surface 36 of melt tube 12 is contiguous with inner surface 48 of crucible 42. Melt tube bore 22 may include conical portion 50, shaped complimentarily to conical portion 52 of stopper rod 54 to provide a melt flow valve. Stopper rod 54 may be moved in known manner vertically upward or downward as shown by arrow 56, to seat conical portion 52 within conical portion 50 to prevent flow of melt through bore 22, or to raise the conical portion to permit melt flow. A closing force is maintained on stopper rod 54 prior to atomization.
As shown in the embodiment illustrated in FIG. 2, annular flange 58 of support shield 16, bears against lower annular surface 60 of melt tube upper portion 18. Flange 58 is supported by upper surface 62 of annular gas atomization nozzle 64. Melt tube 12 is supported independently of shield 16, as described above, so that the shield may be removed without unseating melt tube upper portion 18 from its position within bore 44 of crucible 42. Such independent support may also be augmented in known manner, for example by resting annular shoulder 66 of tube upper portion 18, and optionally crucible 42 on support means 68, as shown in FIG. 2. Shield 16 may then be supported as shown in FIG. 2 or, for example, by releaseably securing shield 16 to tube 12 in known manner.
Lower portion 20 of melt tube 12 includes cylindrical stem 70 of smaller diameter than outer surface 32 of lower portion 20, forming shoulder 72 joining stem 70 and outer surface 32. Similarly, upper portion 26 of melt tube tip 14 includes counterbored socket 74, the inside diameter of which is larger than the diameter of bore 24 passing through tip 14, socket 74 forming with bore 24 upper shoulder 76. The inner diameter of socket 74 and the outer diameter of stem 70 are selected for close slideable fit of melt tube 12 and tip 14.
The diameters of bores 22 and 24 may be the same or different. In the preferred melt tube assembly, at least a portion of bore 24 is of a diameter equal to or smaller than that of bore 22, providing a metering orifice for control of the melt mass flow rate. Outer surface 34 of melt tube tip 14 may be the same or smaller diameter than outer surface 32 of tube lower portion 20. Bore 30 of shield 16 is of a configuration selected for close sliding fit over outer surfaces 34 and 32 of melt tube tip 14 and melt delivery tube 12 respectively. Melt tube 12 as shown in FIG. 2 includes an annular 45° fillet at the intersection of outer surface 32 and lower surface 60, providing a structural reinforcing support against shear stresses encountered during atomization. Shield bore 30 is shaped complementarily to all enclosed surfaces of melt tube 12 and tip 14, providing further structural support to the assembly, particularly at the joint between melt tube 12 and tip 14, where stem 70 and socket 74 are each of reduced thickness and structural strength. Preferably, lower portion 28 of melt tube tip 14 includes stem 78 of smaller outer diameter than that of outside surface 34 of melt tube tip 14, forming with outside surface 34 lower shoulder 80. Shield bore 30 is shaped complementarily to lower portion 28, stem 78, and shoulder 80 of melt tube tip 14, so that shoulder 80 of tip 14 rests on and is supported by shoulder 84 of shield bore 30 and stem 78 fits closely within shield lower portion 82. Thus, tip 14 is retained in place within the assembly by shield 16. The thermal barrier provided by support shield 16 is enhanced by the small insulating air space provided by the slideable fit of the shield over the melt tube and tip.
Shield 16 as shown in FIG. 2 includes beveled surface 86 providing annular sharp edge 88 at the bottom of shield 16. Alternatively, shield lower portion 82 may be provided with an annular, planar lower surface or a combination of an outer beveled surface and an inner planar surface. Preferably, sharp edge 88 (or the corresponding planar surface) and bottom surface 90 of melt tube tip 14 are coplanar, so that all longitudinal surfaces of tip 14 are entirely covered by support shield 16. The longitudinal dimensions of melt delivery tube 12, melt tube tip 14 and shield 16 preferably are selected to provide gaps 92 and 94 between tip 14 and melt tube lower portion 20, allowing for thermal expansion of the tip in use. Outer surface 96 of shield 16 is conveniently of a diameter permitting close slideable fit within central bore 98 of gas atomization nozzle 64.
Gas nozzle 64 further includes annular gas plenum 100, and an annular array of bores 102 and 104 to deliver pressurized atomizing gas to atomizing zone 106. Preferably, bores 104 are inclined at the same angle from the vertical as beveled surface 86 of shield 16, so that high pressure gas jets flowing from bores 104 toward atomization zone 106 trace a conical configuration complementary to beveled surface 86. The close fit of support shield 16 within bore 98 of nozzle 64 provides precise centering of the melt flow to coincide with the apex of the cone traced by the gas jets. Most preferably some of the gas impinges on beveled surface 86 and is deflected downward to create aspiration conditions, as described in commonly assigned, copending U.S. patent application Ser. No. 926,482. Alternatively, where shield lower portion 82 has no beveled surface, as described above, all of the atomizing gas may impinge outer surface 96 of shield 16, resulting in different atomizing conditions than those described in application No. 926,482. Optionally, annular heat transfer chamber 108 may be provided for flow through gas nozzle 64 of a heat transfer fluid, for example a cooling gas.
Prior to operation of the atomization system, elements 12, 14 and 16 of melt tube assembly 10, as shown in FIGS. 1 and 2, are assembled. Melt tube upper portion 18 is inserted into crucible bore 44 and secured as described above. Melt tube assembly 10 then may be quickly and easily assembled by sliding melt tube tip 14 into shield bore 30 so that tip stem 78 fits within shield lower portion 82 and tip lower shoulder 80 rests upon shield shoulder 84. Shield 16 is then slid into place surrounding outer surface 32 of melt tube 12 so that elements 12, 14 and 16 are arranged in close sliding relationship as shown in FIG. 2.
Crucible 42 is lowered into position, fitting gas nozzle bore 98 around outside surface 96 of support shield 16. Stopper rod 54 is seated in the closed position with conical surface 52 resting within conical surface 50 of melt delivery tube 12, during the filling of the crucible and, if necessary, the melting of the material to be atomized.
At the start of the atomization process, stopper rod 54 is vertically raised out of its seated position to initiate melt flow through bores 22 and 24 of melt tube 12 and melt tube tip 14 respectively, toward atomization zone 106. Pressurized atomizing gas flows from a source (not shown) into annular gas plenum 100 of gas nozzle 64, flowing through bores 102 and 104 to exit nozzle 64 as an array of gas streams, preferably sweeping shield conical surface 86, and impinging the stream of molten material flowing from tip bore 24 at atomization zone 106. The impinging gas streams break the melt stream into small globules of melt, which are rapidly solidified into fine particles to form a powder of the atomized material.
Gas nozzle 64 is cooled by a cooling gas flowing from a source (not shown) through annular heat transfer chamber 108. However, melt delivery tube 12 and melt tube tip 14 are not in direct contact with the cooled surfaces 62 and 98 of gas nozzle 64, but are insulated therefrom by support shield 16. Thus melt tube 12 and melt tube tip 14 are protected from the cracking due to thermal shock caused by the drastic temperature differential which would otherwise occur between the inner surfaces in contact with the hot melt flowing through bores 22 and 24 and outer surfaces 32 and 34.
Further, the high pressure gas flowing through gas nozzle 64 is chilled by expansion as it exits bores 104. The impingement of this chilled gas against tip lower portion 28 could cause severe differential expansion resulting in cracking or shattering and catastrophic failure of the tip lower portion. However, support shield 16 covers and protects tip lower portion 28 from direct impingement of the chilled gas.
Support shield 16 also presents a further advantage, in that melt tube tip 14 and the melt flowing therethrough are not instantaneously cooled by the impinging chilled gas because of the thermal barrier presented by the shield and by the insulating air gap between shield 16 and tip 14. Thus, premature solidification of melt within bore 24 due to such conductive cooling is minimized. Also, if minor cracking of melt tube tip 14 should occur, the tip is protected from shattering by the support provided by the walls of bore 30 closely surrounding tip 14. Further, in the event of cracking of tip 14, catastrophic failure of the system due to melt "splash-up" is prevented. In prior art systems, changes in the geometry of the melt tube tip resulted in development of severe backpressure, causing the melt to splatter upward and damage the components of the system. With the shield in place, the geometry of the melt tube assembly is unchanged by such tip failure.
An even further advantage is provided by the embodiment of the melt tube assembly illustrated in FIGS. 1 and 2, in that in the event of severe damage to melt tube tip 14, the tip may be quickly and easily removed and replaced without the removal of the melt tube from the crucible. For example, in the event of catastrophic failure of tip 14, stopper rod 54 is lowered into the closed position to stop the flow of melt through melt tube assembly 10. Crucible 42 is then raised away from gas atomization nozzle 64 carrying with it melt tube 12, shield 16 and melt tube tip 14. When support shield 16 is sufficiently clear of nozzle 64, the shield is removed from melt tube 12, shattered tip 14 is removed from the shield, and a new tip 14 is inserted therein. The system is then rapidly reassembled by fitting shield 16 and tip 14 around lower portion 20 of melt tube 12 and lowering crucible 42 into position. The flows of melt and high pressure gas may then be resumed to start up operation.
The above-described procedure may also be used to provide another unique advantage of the melt tube assembly of the present invention. A series of melt tube tips 14 having identical upper and outer configurations may be provided. However, metering orifices of different diameters may be provided by bore 24 of each tip and/or different materials or coatings may be used for each tip. Thus, the melt tube assembly of the present invention may be adapted to the atomization of different materials, or the flow rate of a single molten material may be adjusted to control the size of the particles produced, as described in above-referenced application No. 926,482.
An alternate embodiment of the melt tube assembly according to the invention is shown in FIG. 3. Melt tube assembly 200 includes melt tube 202, melt tube tip 204 and insulating support shield 206. All features of assembly 200 are similar to those described above for assembly 10, except the manner in which the melt tube and melt tube tip are mated for operation. Melt tube 202 includes socket 208 (replacing lower portion 20 of melt tube 12). Melt tube tip 204 includes upper portion 210. The diameters of socket 208 and tip upper portion 210 are selected for close slideable fit of tip upper portion 210 within socket 208 during pre-operation assembly. The diameter of shield bore 212 is selected for close slideable fit over tip outer surface 214 and tip stem 216, in the same manner described above for shield 16. This arrangement of elements further reduces the stress placed on melt tube 12, particularly that imposed on lower portion 20 and stem 70 of melt tube 12, and increases the surface area of contact between the melt tube and melt tube tip.
While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined by the appended claims. | A melt tube assembly comprising a melt delivery tube and a supporting and insulating shield providing mechanical protection to the melt tube tip and a thermal barrier between the flowing melt and the gas atomization nozzle and the gas jets issuing therefrom during confined gas atomization. In a preferred embodiment, the melt tube tip is a separate element, easily replaceable or interchangeable without removing the melt delivery tube from the crucible. | 1 |
[0001] This patent application claims priority from provisional patent application serial No. 60/621,972 filed Oct. 25, 2004.
FIELD OF THE INVENTION
[0002] The present invention generally relates to an improved process for the economical production of dialkylphosphinic acid compounds, preferably branched dialkylphosphinic acid compounds. The process enables a single phase separation which realizes a high purity dialkylphosphinic acid product.
BACKGROUND OF THE INVENTION
[0003] Numerous derivatives of organic phosphinic acids are known to exist and to have considerable commercial value as well as a great variety of useful applications. For example, organic phosphinates as well as their acids are effective wetting agents and detergents; plasticizers for many plastics and resins; bonding agents for asphalt and similar compositions; color stabilizers and oxidation inhibitors for greases and lubricants (U.S. Pat. No. 3,001,938); corrosion inhibitors; flame proofing agents; flotation auxiliaries; metal extractants; setting retarders for gypsum; and textile auxiliaries such as filament stabilizers (U.S. Pat. No. 3,374,288).
[0004] Highly purified, highly branched dialkylphosphinic acids have been especially recognized as being very important and much desired precursors, intermediate products, and end products in numerous specialized fields. For example, branched dialkylphosphinic acids act as complex-forming agents; pharmaceutically active materials, especially those suitable for the treatment of inflammations, and degenerative diseases of the joints, such as rheumatoid arthritis (U.S. Pat. No. 4,524,211); general agricultural and household chemicals including plant growth regulators, insecticides, and herbicides; and antistatic agents. In many, if not all of these applications, the presence of monoalkylphosphinic acid by-product can be detrimental due to the reactivity of the phosphorus—hydrogen moiety and the thermal instability of such compounds.
[0005] As a result of the above listed numerous possibilities of practical application, a demand has been created for a simple industrial synthesis for the production of these dialkylphosphinic acids in a highly purified state. Because of the aforedescribed great commercial value, many methods of preparing organic phosphinic acids and their phosphinates have been advanced. Although the methods vary widely in their individual steps, a great many employ the reactions of phosphorous-halogen compounds to attain carbon-to-phosphorous bonds. While it has long been known to be possible to form such bonds by reacting alkyl halides with phosphine, or by the use of Grignard reagents, such methods are not practical in commercial scale operations.
[0006] Stiles et al. (U.S. Pat. No. 2,724,718) discloses a process for the production of phosphinates employing the reaction between a compound containing olefinic double bonds and, preferably, a class of compounds consisting of compounds of the formula (I):
wherein Z represents a monovalent hydrocarbon radical free of aliphatic multiple bonds, or a monovalent inorganic cation, and Y represents a hydrogen atom, a monovalent hydrocarbon radical free of aliphatic multiple bonds, or the group—OZ in which Z is defined as above. Among the phosphorous classes and compounds that Stiles et al. suggest as reactants are the salts of hypophosphorous acid, hydrocarbyl esters of hypophosphorous acid, hydrocarbyl esters of organic phosphinic acids and mono- and di-hydrocarbyl esters of phosphorous acid. A particularly preferred subclass comprises the alkali metal salts of hypophosphorous acid such as sodium hypophosphite which Stiles et al. found to be able to be directly added to olefins containing up to 14 carbon atoms “to produce in a single, operational step a water soluble detergent in substantially quantitative yields.”
[0007] Stiles et al. also noted that 1-olefins exhibit a somewhat higher rate of reaction in these processes than do other olefins. The Stiles et al. addition reaction is initiated by the presence of free radicals in intimate contact with the reactants. Neither the reaction temperature nor the reaction pressure is taught to be critical by Stiles et al.
[0008] Stiles et al. teach that where a mole to mole addition is desired, it is generally preferable to employ the reactants in about equimolar proportions or with the phosphorous compound in excess; and, where it is desirable to cause more than one mole of the olefinic compound to be incorporated in the product, for example to produce a di-alkylphosphinic acid, it is preferable to employ about a 2 to 3 to 1 molar excess of the olefinic compound.
[0009] A. J. Robertson (U.S. Pat. No. 4,374,780) discloses the production of a highly branched, dialkyl phosphinic acid namely di-2,4,4′-trimethylpentyl phosphinic acid by the free radical addition of two moles of an alkene, specifically 2,4,4′-trimethylpentene-1, to phosphine gas followed by an oxidation of the phosphine reaction product to the phosphinic acid using two moles of hydrogen peroxide. It is disclosed, however, that high phosphine pressures, i.e., up to about 1000 psig may be necessary to achieve high phosphine to olefin ratios and thus reduce unwanted tri-2,4,4′-trimethylpentylphosphine by-product; for any such by-product formed is a total yield loss. Also, the exothermic oxidation stage is said to be temperature critical for if the temperature exceeds about 120° C., an alkyl group is removed and additional monoalkylphosphinic acid is formed; temperatures below about 50° C., result in excessive reaction times. A straight forward distillation was said to be able to achieve good dialkylphosphinic acid yields.
[0010] Of course, monoalkyl- and dialkylphosphinic acids could also be formed by hydrolytic cleavage of the respective alkyl esters, whose phosphorous-carbon bonds had been formed in the first place by other means, at temperatures of from about 160° C. to 300° C. using at least a quantity of water which is required by stoichiometry for the hydrolysis. The alkanol formed as one of the hydrolysis products is usually removed from the reaction mixture by distillation. (U.S. Pat. No. 4,069,247)
[0011] Alkyl phosphinic acids have also been used to extract rare earth elements (U.S. Pat. No. 5,639,433). In the general procedure employed for the separation of rare earth elements from solutions thereof, especially acidic solutions, the feed solution generally results from the treatment of ores containing rare earth elements such as monazite, bastnaesite, xenotime, bauxite, and similar crude ores. The extract containing the extracted rare earth element(s) is usually sent to a scrubber wherein it is scrubbed with dilute acid and then sent to a stopper where it is stripped with more concentrated acid to separate the rare earth elements. Hydrochloric acid is the preferred acid of the prior art to scrub and strip the extract. Bis-(2,4,4-trimethylpentyl)phosphinic acid is said to be a preferred extractant; especially for the separation of cobalt from nickel.
[0012] Further, with respect to end uses of the dialkylphosphinic acids and their esters, U.S. Pat. No. 6,165,427 discloses the use of a composition comprising sodium di-(n-octyl)phosphinate and sodium di-(n-dodecyl)phosphinate to precipitate and recover soluble heavy metals such as lead, cadmium, zinc species and mixtures thereof from wastewater streams. It is taught that advantageously, the organophosphorus salts may be regenerated from the precipitate by treating the precipitate with concentrated aqueous hydroxide to dissolve it and then contacting the resulting solution with diethyl ether in, for example, a separation funnel. After agitation and subsequent phase disengagement, two phases are present. One phase is an aqueous phase containing the metal with a concentration higher than that of the feed. The other phase is the ether solution of the precipitating agent. The ether is evaporated and the sodium di-(alkyl)phosphinate is regenerated.
[0013] Purifications of the alkyl phosphinic acids and their esters are often accomplished via additions of an organic material such as diisopropyl ether or petroleum ether (U.S. Pat. No. 4,434,108); followed by repeated evaporations, crystallizations, and filtrations (U.S. Pat. No. 4,524,211).
[0014] The major problem inherent in the aforedescribed processes of the prior art, is that it is extremely difficult to separate the di-alkylphosphinic acids from co-formed mono-alkyl reaction products since they have very similar aqueous solubilities. This art-recognized problem of producing high purity dialkyl phosphinic acids by a practical reaction process which is applicable to the production of compounds having a variety of structures, especially highly branched dialkyl structures, has heretofore remained unsolved.
[0015] Accordingly, it is an object of this invention to provide a practical and efficient process for addressing this technical problem by providing conditions whereby, in a straightforward alpha olefin-hypophosphorous acid or a salt thereof free radical reaction, any monoalkylphosphinic acid and other water soluble impurities present are removed from the di-alkylphosphinic acid product by a simple neutralization/phase separation without the need for a third component organic solvent addition.
[0016] Other objects will be evident from the ensuing description and appended claims.
SUMMARY OF THE INVENTION
[0017] The present invention relates to a process wherein a straightforward synthesis of dialkylphosphinic acids, especially branched dialkylphosphinic acids and their phosphinates can be produced with high purity using standard reaction processing and apparatus, i.e., in the absence of high pressures and temperatures; and straightforward aqueous phase extraction / separation processing without the need for an additional organic solvent addition step and the attendant recovery procedures and equipment for the necessary additional solvent recovery.
[0018] The improved process permits the production of dialkyl phosphinic acids in high purity by the free radical reaction of an alpha olefin with certain phosphorus compounds wherein the olefin is used in excess in order to provide the solvent medium for the reaction product and subsequently isolating the dialkylphosphinic acid by preferentially neutralizing any monoalkylphosphinic acid by-product; extracting same with an aqueous wash; and isolating and purifying the desired dialkyl phosphinic acid from the excess olefin reactant solvent by art recognized techniques such as acidification, filtration, and distillation.
[0019] This is accomplished firstly by the use of excess alpha olefin which subsequently functions as the preferential solubility medium phase for the dialkylphosphinic acid; and secondly, by the recognition that by creating a basic pH environment, the alkali or alkali earth ester of the monoalkylphosphinic acid is significantly more soluble in the aqueous phase than in the organic phase, i.e., the excess olefin reactant phase, than the dialkylphosphinic acid ester product.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The subject of the present invention is an improved process for the preparation of purified dialkylphosphinic acids, preferably dialkylphosphinic acids of the formula (I):
wherein R 1 and R 2 are each independently, i.e., either identical or different, an alkyl radical having from 2 to 22 carbon atoms, these radicals optionally substituted, preferably di- or higher substituted by chloro, bromo, alkyl or alkoxy groups or mixtures thereof, each alkyl or alkoxy group individually having from 1 to 4 carbon atoms; by the free radical enhanced reaction of hypophosphorous acid or its salts with a stoichiometric excess of an alpha olefin and isolating and purifying the dialkylphosphinic acid reaction product by adding an aqueous base solution which has been found to preferentially neutralize any monoalkylphosphinic acid by-product formed by the reaction. The monoalkyl phosphinic acid, being more soluble in the aqueous phase than in the organic phase where the dialkylphosphinic acid is preferentially solubilized, is easily separated from the dialkylphosphinic acid product. Optionally, for higher purification of the dialkylphosphinic acid, additional purification steps well known by those skilled in the art may be used, such as a subsequent acidification and distillation.
[0021] In this manner, unwanted impurities, such as unreacted alkenes, water, or other volatiles can be easily removed from the dialkyl product.
[0022] Preferably R 1 and R 2 are identical.
[0023] The alpha olefins used in the process of the invention contain from 2 to 22 carbon atoms, preferably from 2 to 12 carbon atoms and most preferably from 2 to 9 carbon atoms. In the process of the invention, although straight-chain alpha mono-olefins can be used, preferably the alpha mono olefins are branched, most preferably highly branched. Examples of such olefins are: ethylene, propene, butene-(1), hexane-(1), octane-(1), dodecene-(1), tetradecene-(1), hexadecene-(1), octadecene-(1), heneicosene-(1), docosene-(1), 2-methylpentene-(1), 2-ethylhexene-(1), and diisobutylene-(1). Also mixtures of such olefins may be used.
[0024] The alpha-olefins which are used as starting compounds in the instant process are obtained by processes well known in the art including the cracking of petroleum distillates or waxes, by splitting off hydrochloric acid from paraffins with terminal chlorine atoms, or by dehydration of alcohols with a terminal hydroxyl group.
[0025] The reaction initiator/generator compound may be any compound that readily dissociates either under the influence of temperature, preferably between about 24° C. and 200° C. and/or actinic light. As free radical forming agents in the process of the invention, all known radical forming substances may be used, for example: positive halogen compounds such as calcium hypochlorite, sodium N-chloro-p-toluenesulfonamide, and sodium N-chlorobenzenesulfonamide; metallo-alkyl compounds such as lead tetraethyl and lead tetraphenyl; carbonyl compounds such as acetone, methyl ethyl ketone, and benzaldehyde; and the organic peroxides such as di-tertiary-butyl peroxide, tertiary-butyl hydroperoxide, di-cumylperoxide, benzoylperoxide; tertiary-butyl perbenzoate, 2,5-dimethyl-bis-2,5-(peroxybenzoate), 2,2-bis(tertiary-butylperoxy)butane and benzoyl peroxide. Advantageously, di-tert-butylperoxide is used.
[0026] The radical forming agent(s) is used in catalytically effective amounts and may be varied over wide limits depending on the character of the particular initiator. In general, usually from about 0.5 mole percent to about 10 mole percent of reaction initiator, based on the phosphorus reactant, is suitable.
[0027] In order to solubilize the free radical generator in the reaction mixture, it may be necessary to add an inert solvent as a dissolving agent. It is preferable, however, that the free radical generator be selected so that it is able to be dissolved in at least one of the reactants; i.e., the alpha olefin or the hypophosphorous acid or a salt thereof. All of the free radical generator-reactant composition can be added at the beginning of the reaction or added subsequently in portions into the reaction vessel.
[0028] In the situation wherein the reaction is started by ultraviolet radiation, the reaction solution has to be exposed to direct radiation by an ultraviolet lamp.
[0029] It may be advantageous to add any suitable transition metal catalyst to further improve the reaction rate. Suitable transition metal catalyst include, but are not limited too, salts of nickel, cobalt, iron and chromium.
[0030] The reaction according to the invention is advantageously carried out as follows: The alpha olefin, optionally mixed with catalytic amounts of a radical forming agent, is slowly introduced into hypophosphorous acid or a salt thereof.
[0031] The reaction of the instant invention should occur in the presence of an excess of the alpha olefin, i.e., the ratio of the olefin to the hypophosphorous acid or its salt should be greater than 2 to 1; preferably greater than 2.5 to 1.
[0032] The presence of acid has been found to have a positive effect on the yield of the dialkylphosphinic acids in olefin phosphination reactions. It has been theorized that the acid catalyzes the breakdown of the organic peroxide initiator favoring the formation of the dialkylphosphinic acid and also that the acid converts the phosphorous salt to its acid form. Therefore, preferably the reaction takes place in the presence of a yield enhancingly effective amount of an acid(s). Suitable acids are inorganic as well as organic acids insofar as they do not decompose or cause negative side reactions under the primary reaction conditions. Suitable examples are hydrochloric acid, sulfuric acid, and/or, most preferably, acetic acid.
[0033] The reaction may also be carried out in the presence of inert solvents, for example alcohols, esters, or hydrocarbons, such as benzene. However, it is much preferred to conduct the reaction in the absence of an additional solvent component.
[0034] When the initial reaction is completed, water may be added to adjust the viscosity of the product composition for ease in subsequent processing.
[0035] To enhance separation and purification of the dialkylphosphinic acid from the monoalkylphosphinic acid by-product and other undesirable impurities, the organic phase is intimately washed with a basic solution, preferably caustic, which preferentially neutralizes the monoalkylphosphinic acid. The resulting aqueous layer, in which the monoalkylphosphinic acid is highly soluble, is removed. The dialkylphosphinic acid product can be isolated from the reaction mixture and purified by well-known, art recognized techniques such as fractional distillation, the wipe film evaporation, and/or conventional washing techniques. Preferably, to further purify the desired dialkylphosphinic acid product, which is solubilized in the organic medium phase, primarily the alpha olefin reactant which was originally added to the reaction vessel in excess, the organic phase is acid washed, preferably with an inorganic acid such as sulfuric acid. The aqueous phase is again removed and the organic phase filtered and distilled to remove any final impurities and volatile materials.
[0036] Examples of specific compounds that may be prepared include: di-(2,4,4-trimethylpentyl)phosphinic acid, and di-(2-ethylhexyl)phosphinic acid.
[0037] The temperature employed in the process of this invention can be varied depending on factors known to those skilled in the art. Reaction will generally be carried out at temperatures within the range of from about 24° C. to about 200° C. and reaction temperatures of from about 100° C. to about 150° C. are particularly preferred. In the most preferred embodiments of the invention, the reaction is conducted at a temperature of from about 110° C. to about 140° C.
[0038] The reaction may be carried out at atmospheric pressure or above atmospheric pressure in a sealed vessel.
[0039] The process of this invention is conducted for a period of time sufficient to produce the desired compound in adequate yield. Reaction times are influenced to a significant degree by the reaction temperature; the concentration and choice of reactants; and other factors known to those skilled in the art. In general, reaction times can vary from 8 hours to several days or longer.
[0040] If the alpha olefin is initially used in its pure form, the excess alpha olefin can be recycled.
[0041] The process of this invention is preferably conducted in a batch or semi-continuous fashion. The reaction can be conducted in a single reaction zone or in a plurality of reaction zones or it may be conducted intermittently 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 equipment should be fabricated such that it is able to withstand the reaction temperatures and pressures.
[0042] The invention will now be described with reference to a specific example which is to be regarded solely as illustrative of the methods and compositions of this invention and not as restrictive of the scope thereof.
EXAMPLE I
Synthesis
[0043] To synthesize bis(2,4,4-trimethylpentyl)phosphinic acid, a 1.5 liter autoclave was charged with 40 g (0.377 moles) of sodium hypophosphite; 40 g of acetic acid; 132.3 g (0.943 moles) of diisobutylene (80%); and 2.8 g (0.019 moles) of tert-butyl peroxide initiator. The mixture was then heated to about 135° C. during an 8 hour day for about four days, i.e., a total of 30 hours and 1.4 g of the initiator was added at the beginning of each day. The reaction mixture was monitored by 31 P NMR and resulted in the composition identified in Table I below. The original mixture contained 75.3% of the desired dialkylphosphinic acid product and 12.1% of the undesired monoalkylphosphinic acid by-product.
Purification
[0044] The completed reaction mixture (220 g) was transferred to an Erlenmeyer flask and heated in the range of from about 70° C. to about 80° C. to reduce the viscosity. 38 g of water was slowly added until two phases were observed. The aqueous phase was removed and its pH was measured to be about 5. The organic phase was then washed with 75 g of a 4% caustic solution and the resulting aqueous layer (89.2 g) was removed. The organic layer was acidified and washed with 50 g of a 10% sulfuric acid solution and the resulting aqueous phase removed.
[0045] The acidified and washed organic phase was filtered through PS paper and volatile materials were removed by vacuum distillation. 95 g of dialkylphosphinic acid product were recovered with a purity of 93.7% based on phosphorous NMR; thus a yield of 86.9%. The composition of the final product is identified in Table I below.
TABLE I Initial Reaction Reaction Product Product Mixture Mixture After Components (%) Purification (%) Unreacted Hypophosphorus Acid 1.6 0 Monoalkylphosphinic Acid 12.1 0 Dialkylphosphinic Acid 75.3 93.7 Other Impurities 11.0 6.3
[0046] From the above Example and the detailed descriptions of the process in the body of this specification, it can be readily seen that the process of this invention permits the preparation of dialkylphosphinic acids, especially branched dialkylphosphinic acids of high purity in a simple manner with very good yields and therefore represents a significant advance in the industrial art.
[0047] Although this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of this invention as described hereinabove and as defined in the appended claims. | In a process for the production of dialkylphosphinic acids, especially branched, dialkylphosphinic acids in high purity via the reaction of an alpha olefin with a hypophosphorous acid or a salt thereof, the improvement comprising conducting the reaction in the presence of a stoichiometric excess of the olefin and isolating and purifying the desired dialkylphosphinic acid product by neutralizing the monoalkylphosphinic acid by-product with an aqueous base; removing the aqueous phase in which the neutralized monoalkylphosphinic acid is preferentially solubilized; acidifying the dialkyl product in the organic phase; and isolating the purified product. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing heat-sensitive recording materials which provide developed images by the reaction between a color former and a color developer upon heating.
Conventional heat-sensitive recording materials, widely used in facsimiles, various printers, or electrocardiographs, for example, exhibit an undesirable lack of stability in high humidity conditions. If these recording materials are subjected to high humidity conditions after recording, the density of recorded images decreases and finally fades to such an extent that the images can no longer be read. Further, if the recorded images are rubbed with fingers or with a cloth after contact with moisture, they readily disappear.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the above defects, i.e., poor resistance to water or moisture, of conventional heat-sensitive recording materials.
To achieve the above object and in accordance with the purpose of the invention, as embodied and broadly described herein, the process of this invention comprises the steps of (1) applying to a support a coating composition comprising a color former, a color developer, and at least one of a water-soluble binder and a water-dispersible binder, to form a layer, and (2) irradiating the layer with electron beams.
In another embodiment, the claimed invention comprises drying the layer formed as above, applying to this first layer a resin coating composition comprising at least one of a water-soluble binder and a water-dispersible binder to form a second layer, and irradiating both layers with electron beams.
Either the coating composition applied to the support to form the first layer or the resin coating composition applied to the first layer to form the second layer, or both, may further comprise a water-soluble or water-dispersible electron beam-curable monomer or a water-soluble or water-dispersible electron beam-curable prepolymer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Color former/color developer combinations useful in the present invention are typically combinations of colorless or pale-colored basic dyes and inorganic or organic acidic substances; combinations of higher fatty acid metal salts, such as ferric stearate, and phenols, such as gallic acid; and combinations of diazo compounds and couplers.
Examples of colorless or pale-colored basic dyes which can be used in the coating composition of the heat-sensitive recording material of the present invention include triarylmethane-based dyes such as 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-(1,2-dimethylindole-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-methylindole-3-yl)phthalide, 3,3-bis(1,2-dimethylindole-3-yl)-5-dimethylaminophthalide, 3,3-bis(1,2-dimethylindole-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazole-3-yl)-6-dimethylaminophthalide, 3,3-bis(2-phenylindole-3-yl)-6-dimethylaminophthalide, and 3-p-dimethylaminophenyl-3-(1-methylpyrrole-3-yl)-6-dimethylaminophthalide; diphenylmethane-based dyes such as 4,4'-bis-dimethylaminobenzhydrylbenzylether, N-halophenyl-leucoauramine, and N-2,4,5-trichlorophenyl-leucoauramine; thiazine-based dyes such as benzoyl-leucomethyleneblue, and p-nitrobenzoyl-leucomethyleneblue; spiro-based dyes such as 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methylnaphtho(6'-methoxybenzo)spiropyran, and 3-propyl-spiro-dibenzopyran; lactam-based dyes such as rhodamine-B-anilinolactam, rhodamine(p-nitroanilino)lactam, and rhodamine(o-chloroanilino)-lactam; and fluoran-based dyes such as 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-6,7-dimethylfluoran, 3-(N-ethyl-p-toluidino)-7-methylfluoran, 3-diethylamino-7-(N-acetyl-N-methylamino)fluoran, 3-diethylamino-7-methylaminofluoran, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-(N-methyl-N-benzylamino)fluoran, 3-diethylamino-7-(N-chloroethyl-N-methylamino)fluoran, 3-diethylamino-7-diethylaminofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-phenylaminofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-(p-toluidino)fluoran, 3-diethylamino-6-methyl-7-phenylaminofluoran, 3-dibutylamino-6-methyl-7-phenylaminofluoran, 3-(N-ethyl-N-cyclopentyl)amino-6-methyl-7-phenylaminofluoran, 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-phenylaminofluoran, 3-pyrrolidino-6-methyl-7-phenylaminofluoran, 3-piperidino-6-methyl-7-phenylaminofluoran, 3-diethylamino-6-methyl-7-xylidinofluoran, 3-(N-methyl-N-n-amyl)amino-6-methyl-7-phenylaminofluoran, 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluoran, 3-(N-methyl-N-n-hexyl)amino-6-methyl-7-phenylaminofluoran, 3-(N-ethyl-N-n-hexyl)amino-6-methyl-7-phenylaminofluoran, 3-(N-ethyl-N-tetrahydrofurfuryl)amino-6-methyl-7-phenylaminofluoran, 3-diethylamino-7-(2-carbomethyloxy-phenylamino)fluoran, 3-diethylamino-7-(o-chlorophenylamino)fluoran, 3-dibutylamino-7-(o-chlorophenylamino)fluoran, and 3-dibutylamino-7-(l-fluorophenylamino)fluoran. The present invention is not limited to these exemplified basic dyes. Rather, these basic dyes can be used either alone or in admixture with each other or with other dyes shown to be useful in heat-sensitive recording materials.
Color developers which are used in combination with the color formers as described above are not critical in the present invention. Various substances known to be capable of forming a color upon coming into contact with the color formers can be used. Representative examples of such color developers include inorganic acidic substances such as activated clay, acidic clay, attapulgite, bentonite, colloidal silica, and aluminum silicate; and organic acidic substances including phenolic compounds such as 4-tert-octylphenol, 4,4'-sec-butylidenediphenol, 4-phenylphenol, 4,4'-isopropylidenediphenol, 4,4'-cyclohexylidenediphenol, 4,4'-dihydroxydiphenyl sulfide, 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-dihydroxydiphenylsulfone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, sec-butyl 4-hydroxybenzoate, pentyl 4-hydroxybenzoate, phenyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, tolyl 4-hydroxybenzoate, chlorophenyl 4-hydroxybenzoate, phenylpropyl 4-hydroxybenzoate, phenetyl 4-hydroxybenzoate, p-chlorobenzyl 4-hydroxybenzoate, p-methoxybenzyl 4-hydroxybenzoate, novolak phenol resins, and phenol polymers; aromatic carboxylic acids such as benzoic acid, p-tert-butylbenzoic acid, trichlorobenzoic acid, terephthalic acid, 3-sec-butyl-4-hydroxybenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3,5-dimethyl-4-hydroxybenzoic acid, salicyclic acid, 3-isopropylsalicylic acid, 3-tert-butylsalicylic acid, 3-benzylsalicylic acid, 3-(α-methylbenzyl)salicylic acid, 3-chloro-5-(α-methylbenzyl)salicylic acid, 3,5-di-tert-butylsalicylic acid, 3-phenyl-5-(α,α-dimethylbenzyl)salicylic acid, and 3,5-di-α-methylbenzylsalicylic acid; and salts of such phenolic compounds or aromatic carboxylic acids with polyvalent metals such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin, and nickel.
In connection with the ratio of the color former to the color developer, the amount of the color developer used is generally from 100 to 700 parts by weight, preferably from 150 to 400 parts by weight, per 100 parts by weight of the color former. If desired, the color developer may be used as a mixture comprising two or more thereof.
The coating composition, containing the above-described color former and color developer, is generally prepared in the form of an aqueous dispersion using, for example, a ball mill, an attritor, or a sand mill. To the aqueous dispersion is added a water-soluble binder and/or a water-dispersible binder. Various binders which may be used for this purpose include entirely or partially saponified polyvinyl alcohol; acetoacetylated polyvinyl alcohol in which an acetoacetyl group is introduced by reacting polyvinyl alcohol and diketene; carboxy-modified polyvinyl alcohol such as the reaction products of polyvinyl alcohol and polyvalent carboxylic acids, such as fumaric acid, phthalic anhydride, trimellitic anhydride, and itaconic anhydride, esterified products of such reaction products, and compounds resulting from saponification of copolymers of vinyl acetate and ethylenically unsaturated carboxylic acids, such as maleic acid, fumaric acid, itaconic acid, crotonic acid, acrylic acid, and methacrylic acid; sulfonic acid-modified polyvinyl alcohol resulting from saponification of copolymers of vinyl acetate and olefinsulfonic acids such as ethylenesulfonic acid and allylsulfonic acid, or their salts; olefin-modified polyvinyl alcohols resulting from saponification of copolymers of vinyl acetate and olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadodecene; nitrile-modified polyvinyl alcohol resulting from saponification of copolymers of vinyl acetate and nitriles such as acrylonitrile and methacrylonitrile; amide-modified polyvinyl alcohol resulting from saponification of copolymers of vinyl acetate and amides such as acrylamide and methacrylamide; pyrrolidone-modified polyvinyl alcohol resulting from saponification of a copolymer of vinyl acetate and N-vinylpyrrolidone; modified polyvinyl alcohol containing silicon in the molecule thereof; cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose; casein; gum arabic; starches such as oxidized starch, etherified starch, and esterified starch; and emulsions of copolymers such as a styrene/butadiene copolymer, a vinyl acetate/ethylene copolymer, a vinyl acetate/vinyl chloride/ethylene copolymer, and a methacrylate/butadiene copolymer.
Of these binders, various modified polyvinyl alcohols, cellulose derivatives, and casein are preferred. Particularly preferred are acetoacetylated polyvinyl alcohol and carboxy-modified polyvinyl alcohol.
The amount of the water-soluble binder and/or water-dispersible binder added is not critical, but usually varies from 10 to 40% by weight, preferably from 15 to 30% by weight, based on the total weight of solids of the coating composition.
To the binder may be added a water-proof agent such as glyoxal, methylolmelamine, potassium persulfate, ammonium persulfate, sodium persulfate, ferric chloride, magnesium chloride, boric acid, and ammonium chloride. In addition, hydroxides such as LiOH, NaOH, KOH, Mg(OH) 2 , Ca(OH) 2 , Ba(OH) 2 , and NH 4 OH, amine-based basic substances such as dimethylaminoethanol, diethylamine, morpholine, ethylenediamine, and pyridine, and salts of the above basic substances and weak acids, such as ammonium borate, sodium borate, ammonium carbonate, ammonium hydrogencarbonate, sodium carbonate, sodium hydrogencarbonate, ammonium phosphate, sodium phosphate, sodium tartarate, ammonium tartarate, sodium citrate, and ammonium citrate may be added to obtain the effects of the present invention more efficiently.
The coating composition may further contaain auxiliary agents. Examples of such auxiliary agents are dispersants such as sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and fatty acid metal salts; ultraviolet light absorbers such as triazole-based compounds; defoaming agents; fluorescent dyes, and coloring dyes. In order that the heat-sensitive recording material does not stick upon coming into contact with a recording device or a recording head, lubricants such as dispersions or emulsions of stearic acid, polyethylene, carnauba wax, paraffin wax, zinc stearate, calcium stearate, and ester wax may be added to the coating composition. In addition, in order to reduce the attachment of tailings to the recording head, inorganic pigments such as kaolin, clay, talc, calcium carbonate, calcined clay, titanium oxide, diatomaceous earth, fine granular anhydrous silica, and activated clay can be added to the coating composition. Still further, if desired, fatty acid amides such as stearic acid amide, stearic acid methylenebisamide, oleic acid amide, parmitic acid amide, sperm oleic acid amide, and coconut fatty acid amides; hindered phenols such as 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), and 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane; ethers such as 1,2-bis(phenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, and 2-naphthol benzyl ether; esters such as dibenzyl terephthalate, and phenyl 1-hydroxy-2-naphthoate; and various other known heat-fusible substances may be added as sensitizers.
The coating composition is applied to a support such as paper, a synthetic paper, or a film by techniques such as air knife coating or blade coating to form a layer. The amount of the coating composition applied to form the layer is not critical but usually varies from 2 to 12 g/m 2 , preferably from 3 to 10 g/m 2 , on a dry weight basis.
The coating composition applied to the support to form a layer is then irradiated with electron beams. The irradiation may be performed immediately after applying the coating composition or after applying and drying the coating composition. Preferably, the irradiation is performed immediately after applying the coating composition and before drying.
Although it is not completely clear why the resistance to water and moisture of the heat-sensitive recording material is improved when irradiation with electron beams is performed either after applying the coating composition or after applying and drying the coating composition, it is believed that the binder contained in the coating composition undergoes a cross-linking reaction upon irradiation.
Further, the present inventors have found that, if a part of the binder used in the coating composition of the heat-sensitive recording material (together with the color former and color developer) is substituted with an electron beam-curable prepolymer or an electron beam-curable monomer, a heat-sensitive recording material having excellent moisture resistance and water resistance can be obtained. Any water-soluble or water-dispersible prepolymer or monomer containing an ethylenically unsaturated double bond which is curable by irradiation with electron beams can be used in the present invention.
Examples of useful electron beam-curable prepolymers include:
(a) Poly(meth)acrylates of aliphatic, alicyclic, or araliphatic polyhydric (having from 2 to 6 alcoholic hydroxy groups) alcohols or polyalkylene glycols, such as esterified compounds of polyhydric alcohols (e.g., ethylene glycol and propylene glycol) or polyalkylene glycols (e.g., polyethylene glycol) and (meth)acrylic acid;
(b) Poly(meth)acrylates of polyhydric alcohols resulting from addition of alkylene oxides to aliphatic, alicyclic or araliphatic polyhydric (having from 2 to 6 alcoholic hydroxy groups) alcohols, such as esterified compounds of polyhydric alcohols resulting from addition of alkylene oxides (e.g., ethylene oxide) to polyhydric alcohols (e.g., pentaerythritol) and (meth)acrylic acid;
(c) Poly(meth)acryloyloxyalkyl phosphates resulting from reaction of hydroxy group-containing (meth)acrylates and phosphorus pentoxide, e.g., poly(meth)acryloyloxyethyl phosphate;
(d) Polyester poly(meth)acrylates resulting from esterification of (meth)acrylic acid, polyhydric alcohols, and polycarboxylic acids, e.g., di(meth)acrylate of polyester diol between maleic acid and ethylene glycol, di(meth)acrylate or polyester diol between phthalic acid and diethylene glycol, and poly(meth)acrylate of polyester diol between adipic acid and triethylene glycol;
(e) Epoxy poly(meth)acrylates which are a reaction product of (meth)acrylic acid and epoxy resin resulting from reaction of polyhydric phenols and epichlorohydrin, e.g., a reaction product of bisphenol A-diglycidyl ether-based epoxy resin and (meth)acrylic acid;
(f) Polyurethane poly(meth)acrylates such as reaction products of hydroxy group-containing (meth)acrylates (e.g., 2-hydroxyethyl (meth)acrylate) and diisocyanate;
(g) Polyamide poly(meth)acrylates such as reaction products of polyamide-based polycarboxylic acids (e.g., that resulting from reaction of ethylenediamine and phthalic acid) and hydroxy group-containing (meth)acrylates (e.g., 2-hydroxyethyl (meth)acrylate);
(h) Polysiloxane poly(meth)acrylates such as reaction products of polysiloxane bond unit-containing polyhydric alcohols and (meth)acrylic acid or hydroxy group-containing (meth)acrylates;
(i) Low molecular weight vinyl or diene polymers containing (meth)acryloyloxy group in the side chain and/or terminal thereof, such as reaction products of copolymers of (meth)acrylic acid and other vinyl monomer and glycidyl (meth)acrylate; and
(j) Modified products of the oligoester (meth)acrylates of (a) to (i) above, such as modified products obtained by modifying a part of the hydroxy or carboxyl groups remained in the oligoester with an acid chloride, an acid anhydride, or an isocyanate.
Examples of useful electron beam-curable monomers include:
I. Monofunctional Unsaturated Monomers
(1) Carboxyl group-containing monomers exemplified by ethylenically unsaturated mono- or poly-carboxylic acids (e.g., maleic acid, fumaric acid, and itaconic acid), and carboxylic acid salt group-containing monomers such as alkali metal salts, ammonium salts, and amine salts of the foregoing monomers;
(2) Amide group-containing monomers exemplified by ethylenically unsaturated (meth)acrylamides or alkyl-substituted (meth)acrylamides (e.g., N,N-dimethyl (meth)acrylamide), and vinyl lactams (e.g., N-vinylpyrrolidone);
(3) Sulfonic acid group-containing monomers exemplified by aliphatic or aromatic vinylsulfonic acids, and sulfonic acid salt group-containing monomers such as the alkali metal, ammonium and amine salts of the foregoing vinylsulfonic acids, e.g., 2-acrylamido-2-methylpropanesulfonic acid;
(4) Hydroxyl group-containing monomers exemplified by ethylenically unsaturated esters, such as tripropylene glycol mono(meth)acrylate;
(5) Amino group-containing monomers such as dimethylaminoethyl (meth)acrylate and 2-vinylpyridine;
(6) Quaternary ammonium salts group-containing monomers such as N,N,N-trimethyl-N-(meth)acryloyloxyethylammonium chloride;
(7) Alkyl esters of ethylenically unsaturated carboxylic acids, such as methyl (meth)acrylate and ethyl (meth)acrylate;
(8) Nitrile group-containing monomers such as (meth)acrylonitrile;
(9) Styrene;
(10) Ethylenically unsaturated alcohol esters such as vinyl acetate and (meth)allyl acetate; and
(11) Mono(meth)acrylates of alkylene oxide adducts of compounds containing active hydrogen (e.g., monohydric alcohols, phenols, carboxylic acids, amines, and amides).
II. Difunctional Unsaturated Monomers
(1) Ester group-containing difunctional monomers exemplified by diesters of polyols and ethylenically unsaturated carboxylic acids, such as trimethylolpropane di(meth)acrylate, and diesters of polybasic acids and unsaturated alcohols, such as diallyl phthalate;
(2) Difunctional diesters of (meth)acrylic acid and alkylene oxide adducts of compounds containing active hydrogen (e.g., polyhydric alcohols, phenols, carboxylic acids, amines, and amides) such as pentanediol propylene oxide adduct;
(3) Bisacrylamides such as N,N-methylenebisacrylamide; and
(4) Difunctional compounds such as divinylbenzene, divinylethylene glycol, divinylsulfone, divinyl ether, and divinyl ketone.
III. Polyfunctional Unsaturated Monomers
(1) Ester group-containing polyfunctional monomers exemplified by polyesters of polyols and ethylenically unsaturated carboxylic acids, such as trimethylolpropane (meth)acrylate and dipentaerythritol hexa(meth)acrylate, and polyesters of polycarboxylic acids and unsaturated alcohols, such as triallyl trimellitate;
(2) Polyfunctional monomers exemplified by polyesters of alkylene oxide adducts of compounds containing active hydrogen (e.g., polyhydric alcohols, polyhydric phenols, polycarboxylic acids, polyamines, and polyamides) and (meth)acrylic acid; and
(3) Polyfunctional unsaturated monomers such as trivinylbenzene.
Of the above-described electron beam-curable prepolymers or monomers, those which are soluble in water can be added directly to the coating composition for heat-sensitive recording material. Water-dispersible prepolymers or monomers are generally stirred with water in the presence of a surfactant to form an oil-in-water type emulsion, which is then added to the coating composition of the heat-sensitive recording material. Further, electron beam-curable prepolymers and monomers may be used in a mixture in which both prepolymers and monomers are present.
Examples of surfactants which may be used include anionic surfactants such as fatty acid salts, higher alcohol sulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, a naphthalenesulfonic acid/formalin condensate, dialkylsulfosuccinic acid salts, alkyl phosphate salts, and polyoxyethylene sulfate salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene acyl esters; cationic surfactants such as alkylamine salts, quaternary ammonium salts, and polyoxyethylenealkylamines; and water-soluble polymers such as polyvinyl alcohol. These surfactants may be used singly or in combination with each other. Of these compounds, nonionic surfactants having an HLB of at least 10 are preferable to obtain emulsions having greatly increased stability.
The amount of the surfactant used is usually from 0.01 to 20% by weight, preferably from 0.05 to 10% by weight, based on the weight of the monomer or prepolymer.
It is desirable to add an amount of the electron beam-curable monomer or prepolymer, according to the present invention, which will substitute for about 1 to 80% by weight, preferably 3 to 60% by weight, of the binder component in the coating composition. If the amount is less than 1% by weight, satisfactory results are not obtained. Further, if the amount of the water-dispersible compound, in the form of an oil-in-water type emulsion, exceeds 80% by weight, the surfactant present adversely affects the stability of the coating composition and background fog is generated in the layer formed by the coating composition.
Although the reason why the moisture and water resistance is improved when an electron beam-curable monomer or prepolymer is substituted for a portion of the binder is not completely clear, it is believed that the presence of the monomer or prepolymer, having many active sites, accelerates the crosslinking reaction when irradiated with electron beams.
Furthermore, the present inventors have found that heat-sensitive recording materials having extremely excellent moisture and water resistance can be produced by applying to the support the above-described coating composition to form a first layer, drying the first layer, forming a second layer by applying to the first layer either (A) a resin coating composition comprising at least one of a water-soluble binder and a water-dispersible binder or (B) a resin coating composition comprising a mixture of (a) at least one of a water-soluble binder and a water-dispersible binder and (b) at least one of a water-soluble electron beam-curable monomer, a water-soluble electron beam-curable prepolymer, a water-dispersible electron beam-curable monomer, and a water-dispersible electron beam-curable prepolymer, and irradiating the first and second layers with electron beams.
The thus produced heat-sensitive recording material not only exhibits excellent moisture and water resistance but also exhibits improved plasticizer resistance. By plasticizer resistance is meant that the color density of images recorded on a heat-sensitive recording material which has been stored in contact with a plastic film is not greatly reduced, as would be normally expected, by the plasticizer contained in the plastic film.
In accordance with the present invention, the resin coating composition used to form the second layer can comprise any of the water-soluble binders, water-dispersible binders, and the water-soluble or water-dispersible electron beam-curable monomers or prepolymers, listed above for use in the coating composition used to form the first layer of the heat-sensitive recording layer. However, it is preferred to use a resin coating composition containing at least one member selected from the group consisting of various modified polyvinyl alcohols, cellulose derivatives, and casein, or a mixture of at least one member selected from the foregoing group and at least one member selected from the group consisting of water-soluble or water-dispersible electron beam-curable monomers and water-soluble or water-dispersible electron beam-curable prepolymers. In particular, a heat-sensitive recording material produced by the use of a resin coating composition containing at least one member selected from the group consisting of acetoacetylated polyvinyl alcohol and carboxy-modified polyvinyl alcohol, or a mixture of at least one member selected from the foregoing group and at least one member selected from the group consisting of water-soluble or water-dispersible electron beam-curable monomers and water-soluble or water-dispersible electron beam-curable prepolymers exhibits especially excellent moisture resistance, water resistance, and plasticizer resistance.
In accordance with the present invention, when the resin coating composition comprises a mixture of a water-soluble binder and/or water-dispersible binder and a water-soluble or water-dispersible electron beam-curable monomer or prepolymer, the amount of the electron beam-curable monomer or prepolymer is desirably adjusted to fall in the range of from 1 to 80% by weight, preferably from 3 to 60% by weight, of the whole resin component.
Any water-dispersible binder or water-dispersible electron beam-curable monomer or prepolymer used is employed as an oil-in-water type emulsion as described above.
If desired, in order to improve printability and sticking, pigments may be added to the resin coating composition. Examples of the pigment which may be used include inorganic pigments such as calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, silicon dioxide, aluminum hydroxide, barium sulfate, zinc sulfate, talc, kaolin, clay, calcined clay, and colloidal silica; and organic pigments such as styrene microball, nylon powder, polyethylene powder, urea/formalin resin filler, and raw starch particles. The pigment is usually used in an amount of from 5 to 500 parts by weight, preferably from 80 to 350 parts by weight, based on 100 parts by weight of the resin component.
Furthermore, if desired, the resin coating composition used to form a second layer may further contain the waterproof agents, hydroxides, amine-based basic substances, salts of these basic substances and weak acids, as well as the lubricants, dispersants, defoaming agents, ultraviolet light absorbers, fluorescent dyes, and coloring dyes exemplified above for the coating composition used to form the first layer of the heat-sensitive recording material.
In accordance with the present invention, the resin coating composition is prepared as an aqueous composition and, if appropriate, is thoroughly mixed and dispersed by means of, for example, a mixer, an attritor, a ball mill, or a roll mill, and then applied to the first layer by means of conventional coating apparatus to form a second layer. The amount of the resin coating composition applied is not particularly critical. However, it is desirable to adjust it within the range of from 0.1 to 20 g/m 2 , preferably from 0.5 to 10 g/m 2 , on a dry weight basis, since there is a possibility that the recording sensitivity of the heat-sensitive recording material will be decreased if the amount exceeds 20 g/m 2 .
After applying the resin coating composition to the first layer to form a second layer, the first and second layer are irradiated with electron beams. The irradiation can be performed either immediately after applying the resin coating composition or after applying and drying the resin coating composition. However, heat-sensitive recording materials having a more excellent quality are obtained when the irradiation with electron beams is performed immediately after applying the resin coating composition. Although the first layer, to which the resin coating composition is applied to form a second layer, must be dried, the effects of the invention are increased by irradiating the first layer per se with electron beams either before or after drying it.
Either after applying the coating composition to the support to form the first layer of the heat-sensitive recording material, or after applying and drying it, or after applying the resin coating composition to the first layer of the heat-sensitive recording layer, or after applying and drying it, the layer(s) present are irradiated with electron beams, the dose of which is preferably from 0.1 to 15 Mrad. Less than desirable results are obtained if the dose of electron beams used for irradiating is less than 0.1 Mrad. On the other hand, if the dose is in excess of 15 Mrad, color contamination of the coated surface occurs, resulting in a reduction of whiteness and of product quality.
Irradiation with electron beams can be performed in any suitable manner such as the scanning method, the curtain beam method, or the broad beam method. A suitable acceleration voltage employed in the irradiation with electron beams is from about 100 to 300 KV.
In the thus-produced heat-sensitive recording material of the present invention, the cross-linking reaction of the binder component of the first layer, and the second layer if present, is accelerated by irradiation with electron beams. The resulting recording material exhibits excellent moisture resistance, water resistance, and plasticizer resistance.
If desired, the desirable effects of the invention may be increased even more by providing the support side of the heat-sensitive recording material with a resin layer, too. Also, if desired, various techniques known in the art of producing heat-sensitive recording materials, such as providing a subbing layer on the support, treating the support side of the recording material with a tackifier, and/or processing into a tacky label, may be employed in the present invention.
The present invention is described in greater detail with reference to the following examples. All parts and percents are by weight unless otherwise indicated.
EXAMPLE 1
______________________________________Dispersion A3,3-Bis(p-dimethylaminophenyl)-6- 10 partsdimethylaminophthalide5% Aqueous solution of polyvinyl alcohol 10 parts(PVA-110 produced by Kuraray Co., Ltd.;degree of saponification: 98 mol %, degreeof polymerization: 1,100)Water 15 partsDispersion B4,4'-Isopropylidenediphenol 20 parts5% Aqueous solution of polyvinyl alcohol 10 parts(PVA-110)Water 40 parts______________________________________
Dispersions A and B were pulverized separately by means of a sand mill to an average particle diameter of about 3 μm. 35 Parts of Dispersion A, 70 parts of Dispersion B, 25 parts of calcium carbonate, 25 parts of fine granular anhydrous silica, and 270 parts of a 15% aqueous solution of polyvinyl alcohol (PVA-110) were mixed to prepare a coating composition for heat-sensitive recording material. This coating composition was applied to a paper support (basis weight: 50 g/m 2 ) at a dry weight of 5.0 g/m 2 , irradiated with 2 Mrad of electron beams at an acceleration voltage of 170 KV, and then dried to produce a heat-sensitive recording paper.
The resulting recording paper was evaluated for moisture resistance and water resistance by the following methods.
Moisture Resistance
The recording paper was recorded with a commercially available heat-sensitive facsimile apparatus (MELFAS-550 manufactured by Mitsubishi Denki K.K.) and the color density (initial color density (d 1 )) of the recorded image was measured with a Macbeth reflection densitometer (Model RD-100R of Macbeth Corp.). Thereafter, the recording paper was allowed to stand at 40° C. and 90% RH (relative humidity) for 50 hours, and the color density (d 2 ) was again measured. The respective color densities and retention [(d 2 /d 1 )×100(%)] are shown in Table 1.
Water Resistance
One drop of water was placed on the surface of the recording paper recorded in the same manner as above. After 30 seconds, the moistened recording paper was rubbed once back and forth with a finger, and the appearance of the recorded images was visually evaluated. The results are shown in Table 1.
EXAMPLES 2 TO 9
Eight heat-sensitive recording papers were produced in the same manner as in Example 1 except that 270 parts of each of an aqueous solution of acetoacetylated polyvinyl alcohol (Gohsefimer Z-200 produced by The Nippon Synthetic Chemical Industry Co., Ltd.) (Example 2), an aqueous solution of carboxy-modified polyvinyl alcohol (T-330 produced by The Nippon Synthetic Chemical Industry Co., Ltd.) (Example 3), an aqueous solution of sulfonic acid-modified polyvinyl alcohol (Example 4), an aqueous solution of methyl cellulose (Example 5), an aqueous solution of oxidized starch (Example 6), an aqueous solution of casein (Example 7), a styrene-butadiene copolymer emulsion (JSR-0696 produced by Japan Synthetic Rubber Co., Ltd.) (Example 8), and an aqueous solution of acetoacetylated polyvinyl alcohol (Gohsefimer Z-200) containing boric acid in an amount of 1% based on the solids content of polyvinyl alcohol (Example 9), each having a concentration of 15%, was used in place of 270 parts of the 15% aqueous solution of polyvinyl alcohol (PVA-110) used in the coating composition for the heat-sensitive recording material of Example 1. These recording papers were evaluated in the same manner as in Example 1. The results are shown in Table 1.
EXAMPLE 10
A heat-sensitive recording paper was produced in the same manner as in Example 1 except that the irradiation with electron beams was not performed until after drying the coating composition. This recording paper was evaluated in the same manner as in Example 1. The results are shown in Table 1.
COMPARATIVE EXAMPLES 1 TO 9
Heat-sensitive recording papers were produced in the same manner as in Examples 1 to 9, respectively except that the coating composition was not irradiated with electron beams. These recording papers were evaluated in the same manner as in Example 1. The results are shown in Table 1.
TABLE 1______________________________________ Moisture Resistance Color Density after Initial Allowing to Color Stand at 40° C. Den- and 90% RH Retention Water.sup.(1) sity for 50 Hours (d.sub.2 /d.sub.1 × 100) Resis- (d.sub.1) (d.sub.2) (%) tance______________________________________Example1 1.30 1.07 82 C2 1.30 1.08 83 A3 1.29 1.06 82 A4 1.31 1.06 81 B5 1.29 1.04 81 B6 1.28 1.02 80 C7 1.29 1.04 81 B8 1.28 1.05 82 C9 1.31 1.15 88 A10 1.32 1.06 80 CComparativeExample1 1.30 0.61 47 D2 1.30 0.72 55 D3 1.30 0.78 60 D4 1.28 0.77 60 D5 1.29 0.71 55 D6 1.28 0.60 47 D7 1.29 0.83 64 D8 1.28 0.82 64 D9 1.31 0.85 65 D______________________________________ .sup.(1) Water resistance A: The recorded images did not fade at all. B: The recorded images faded slightly, but images remained clear. C: The recorded images faded considerably, but images remained readable. D: The recorded images completely disappeared, and reading was impossible
EXAMPLE 11
______________________________________Dispersion A3,3-Bis(p-dimethylaminophenyl)-6- 10 partsdimethylaminophthalide5% Aqueous solution of polyvinyl 10 partsalcohol (PVA-110)Water 15 partsDispersion B4,4'-Isopropylidenediphenol 20 parts5% Aqueous solution of polyvinyl 10 partsalcohol (PVA-110)Water 40 parts______________________________________
Dispersions A and B were pulverized separately by means of a sand mill to an average particle diameter of about 3 μm.
Separately, 50 g of the prepolymer of polyester polyacrylate (Aronix M-8060 produced by Toagosei Chemical Industry Co., Ltd.) was placed into a beaker, and 35 g of a 10% aqueous solution of polyoxyethylene nonylphenyl ether surfactant (Emulgen 935 (HLB: 17.5) produced by Kao Atlas Co., Ltd.) was added thereto with stirring. 50 g of water was further added to obtain a 40% oil-in-water type emulsion of the polyester polyacrylate.
35 parts of Dispersion A, 70 parts of Dispersion B, 25 parts of calcium carbonate, 25 parts of fine granular anhydrous silica, 260 parts of a 5% aqueous solution of acetoacetylated polyvinyl alcohol (Gohsefimer Z-200), and 30 parts of the 40% emulsion of polyester polyacrylate were mixed to prepare a coating composition for heat-sensitive recording material. This coating composition was applied to a paper support (basis weight: 40 g/m 2 ) at a dry weight of 4 g/m 2 , irradiated with 2 Mrad of electron beams, and then dried to produce a heat-sensitive recording paper. The resulting recording paper was evaluated for moisture resistance and water resistance by the following methods. The results are shown in Table 2.
Moisture Resistance
The evaluation was performed in the same manner as in Example 1.
Water Resistance
One drop of water was placed on the surface of the recording paper recorded by the heat-sensitive facsimile apparatus of Example 1. After one minute, the resulting recording paper was rubbed with a finger five times back and forth, and the appearance of the recorded images was visually evaluated.
EXAMPLES 12 TO 15
Four heat-sensitive recording papers were produced in the same manner as in Example 11 except that 260 parts of each of a 5% aqueous solution of carboxy-modified polyvinyl alcohol (T-330) (Example 12), a 5% aqueous solution of methyl cellulose (Example 13), a 5% aqueous solution of casein (Example 14), and a 5% aqueous solution of acetoacetylated polyvinyl alcohol (Gohsefimer Z-200) to which boric acid had been added in an amount of 2% based on the solids content of polyvinyl alcohol (Example 15), was used in place of 260 parts of the 5% aqueous solution of acetoacetylated polyvinyl alcohol used in the coating composition. These recording papers were evaluated in the same manner as in Example 11. The results are shown in Table 2.
EXAMPLE 16
A heat-sensitive recording paper was produced in the same manner as in Example 11 except that 30 parts of a 40% emulsion of trimethylolpropane triacrylate prepared in the manner described below was used in place of 30 parts of the 40% emulsion of polyester polyacrylate used in the coating composition. The recording paper was evaluated in the same manner as in Example 11. The results are shown in Table 2.
Preparation of Trimethylolpropane Triacrylate Emulsion
4 g of polyoxyethylene nonylphenyl ether (Emulgen 935) was dissolved in 100 g of trimethylolpropane triacrylate (M-309 produced by Toagosei Chemical Industry Co., Ltd.), and 156 g of water was gradually added thereto by means of a homomixer with stirring (rate of revolution: 3000 to 4000 rpm) to obtain a 40% oil-in-water type emulsion of trimethylolpropane triacrylate.
EXAMPLE 17
A heat-sensitive recording paper was produced in the same manner as in Example 11 except that 260 parts of a 5% aqueous solution of carboxy-modified polyvinyl alcohol (T-330) and 30 parts of the 40% emulsion of trimethylolpropane triacrylate prepared in Example 16 were used in place of the acetoacetylated polyvinyl alcohol aqueous solution and the polyester polyacrylate emulsion used in the coating composition, respectively. The recording paper was evaluated in the same manner as in Example 11. The results are shown in Table 2.
EXAMPLES 18 AND 19
Two heat-sensitive recording papers were produced in the same manner as in Example 11 except that 30 parts of each of a 35% mixed emulsion of polyurethane polyacrylate/tri(propyloxy) diacrylate (Example 18) and a 40% emulsion of epoxy polyacrylate (Example 19), each having been prepared in the manner described below, was used in place of the polyester polyacrylate used in the coating composition. These recording papers were evaluated in the same manner as in Example 11. The results are shown in Table 2.
Preparation of Mixed Emulsion of Polyurethane Polyacrylate/Tri(propyloxy)Diacrylate
40 g of a prepolymer of polyurethane polyacrylate (M-1100 produced by Toagosei Chemical Industry Co., Ltd.) was mixed with 60 g of tri(propyloxy)diacrylate (M-220 produced by Toagosei Chemical Industry Co., Ltd.), and 35 g of a 10% aqueous solution of a polyoxyethylene nonylphenyl ether-based nonionic surfactant (Emulgen 950 (HLB: 18.2) produced by Kao Atlas Co., Ltd.) was added to the mixture for dissolution. Thereafter, 160 g of water was gradually added thereto by means of a homomixer with stirring (rate of revolution: 2500 to 3000 rpm) to obtain an oil-in-water type mixed emulsion of polyurethane polyacrylate/tri(propyloxy)diacrylate (solids content: 35%).
Preparation of Epoxy Polyacrylate Emulsion
4 g of lauryl alcohol sulfuric acid ester ammonium salt (Emal A produced by Kao Atlas Co., Ltd.), as a surfactant, was dissolved in 100 g of a prepolymer of epoxy polyacrylate (Unidick V-5502 produced by Dainippon Ink & Chemicals, Inc.), and 156 g of water was gradually added to the solution by means of a homomixer with stirring (rate of revolution: 4000 to 4500 rpm) to obtain a 40% oil-in-water type emulsion of epoxy polyacrylate.
COMPARATIVE EXAMPLES 10 TO 18
Nine heat-sensitive recording papers were produced by the same methods as in Examples 11 to 19, respectively except that the irradiation with electron beams was not performed. These heat-sensitive recording papers were evaluated in the same manner as in Example 11. The results are shown in Table 2.
TABLE 2______________________________________ Moisture Resistance Color Density after Initial Allowing to Color Stand at 40° C. Den- and 90% RH Retention Water.sup.(1) sity for 50 Hours (d.sub.2 /d.sub.1 × 100) Resis- (d.sub.1) (d.sub.2) (%) tance______________________________________Example11 1.30 1.17 90 A12 1.28 1.15 90 A13 1.28 1.09 85 B14 1.29 1.11 86 B15 1.31 1.21 92 A16 1.26 1.13 90 B17 1.27 1.13 89 B18 1.27 1.17 92 A19 1.31 1.19 91 AComparativeExample10 1.10 0.60 55 D11 1.15 0.60 52 D12 1.18 0.60 51 D13 1.18 0.63 53 D14 1.24 0.72 58 D15 1.20 0.63 53 D16 1.20 0.62 52 D17 1.13 0.62 55 D18 1.00 0.50 50 D______________________________________ .sup.(1) Water resistance A: The recorded images did not fade at all. B: The recorded images faded slightly, but images remained clear. D: The recorded images completely disappeared, and reading was impossible
EXAMPLE 20
A coating composition for a heat-sensitive recording material obtained in the same manner as in Example 1 was applied to a paper support (basis weight: 50 g/m 2 ) at a dry weight of 5.0 g/m 2 and then dried without irradiating with electron beams to produce a first layer. To this first layer, a resin coating composition having the formulation described below was applied at a dry weight of 5 g/m 2 to form a second layer. The resulting recording paper was irradiated with 5 Mrad of electron beams and then dried to produce a heat-sensitive recording paper having two layers.
______________________________________Formulation of Resin Coating Composition______________________________________10% Aqueous solution of acetoacetylated 1,000 partspolyvinyl alcohol (Gohsefimer Z-200)Calcium carbonate (Softon 1200 produced 100 partsby Bihoku Funka K.K.)______________________________________
EXAMPLES 21 TO 27
Seven heat-sensitive recording papers having two layers were produced in the same manner as in Example 20 except that each of the resin coating compositions having the formulations described below was used in place of the resin coating composition of Example 20.
______________________________________Formulation of Resin Coating Composition______________________________________In Example 21:10% Aqueous solution of acetoacetylated 1,000 partspolyvinyl alcohol (Gohsefimer Z-200)Calcium carbonate (Softon 1200) 100 parts3% Aqueous solution of potassium hydroxide 65 partsIn Example 22:10% Aqueous solution of carboxy-modified 1,000 partspolyvinyl alcohol (T-330)Kaolin (UW-90 produced by Engelhard 100 partsMinerals & Chemicals Corp.)In Example 23:10% Aqueous solution of casein 1,000 partsKaolin (UW-90) 100 partsIn Example 24:10% Aqueous solution of methyl cellulose 1,000 partsCalcium carbonate (Softon 1500 produced 100 partsby Bihoku Funka K.K.)In Example 25:10% Aqueous solution of polyvinyl alcohol 700 parts(PVA-110)40% Emulsion of polyester polyacrylate 75 partsprepared in Example 11Kaolin (UW-90) 100 partsIn Example 26:10% Aqueous solution of polyvinyl alcohol 500 parts(PVA-110)40% Emulsion of polyester polyacrylate 125 partsprepared in Example 11Kaolin (UW-90) 100 partsIn Example 27:10% Aqueous solution of carboxy-modified 500 partspolyvinyl alcohol (KL-318 produced byKuraray Co., Ltd.)40% Emulsion of polyester polyacrylate 125 partsprepared in Example 11Kaolin (UW-90) 100 parts______________________________________
COMPARATIVE EXAMPLES 19 TO 26
Eight heat-sensitive recording papers having two layers were produced in the same manner as in Examples 20 to 27 except that, after the formation of the second layer, irradiation with electron beams was omitted.
The sixteen heat-sensitive recording papers having two layers produced in Examples 20 to 27 and Comparative Examples 19 to 26 were evaluated by the following methods. The results are shown in Table 3.
Background Color Density
The respective recording papers were processed in a checked pattern by means of a heat-sensitive facsimile apparatus (MELFAS-550), and the density of the non-colored area was measured with a Macbeth reflection densitometer (Model RD-100R). The lower the value, the less the fog.
Initial Color Density
The initial color density (d 1 ) of the colored area of the recording paper processed in the same manner as above, was measured with a Macbeth reflection densitometer.
Moisture Resistance
The colored recording paper was allowed to stand at 40° C. and 90% RH for 50 hours, the color density (d 2 ) was again measured with the Macbeth reflection densitometer, and retention [(d 2 /d 1 )×100 (%)] was calculated.
Water Resistance
The colored recording paper was immersed in water for 15 hours and air dried. The color density (d 3 ) was then measured with the Macbeth reflection densitometer and retention [(d 3 /d 1 )×100 (%)] was calculated.
Plasticizer Resistance
The colored recording paper was disposed between two polyvinyl chloride wrapping films (produced by Mitsui Toatsu Chemicals Inc.) and allowed to stand at room temperature for 14 days. Thereafter, the color density (d 4 ) was measured with the Macbeth reflection densitometer, and retention [(d 4 /d 1 )×100 (%)] was calculated.
TABLE 3__________________________________________________________________________ Initial Moisture Resistance Water Resistance Plasticizer Resistance Background Color Color Retention Color Retention Color Retention Color Density Density (d.sub.2 /d.sub.1 × 100) Density (d.sub.3 /d.sub.1 × 100) Density (d.sub.4 /d.sub.1 × 100) Density (d.sub.1) (d.sub.2) (%) (d.sub.3) (%) (d.sub.4) (%)__________________________________________________________________________Example20 0.08 1.40 1.11 79 1.35 96 1.10 7921 0.07 1.38 1.14 83 1.36 99 1.13 8222 0.08 1.41 1.10 78 1.34 95 1.08 7723 0.08 1.42 1.04 73 1.27 89 0.91 6424 0.08 1.37 1.02 74 1.21 88 0.93 6825 0.08 1.39 1.01 73 1.23 88 0.89 6426 0.09 1.39 1.04 75 1.28 92 0.85 6127 0.08 1.41 1.13 80 1.37 97 0.90 64ComparativeExample19 0.09 1.41 0.78 55 0.71 50 0.61 4320 0.08 1.43 0.82 57 0.75 52 0.63 4421 0.08 1.41 0.73 52 0.78 55 0.60 4322 0.08 1.38 0.69 50 0.71 51 0.56 4123 0.08 1.37 0.66 48 0.70 51 0.53 3924 0.09 1.38 0.65 47 0.66 48 0.49 3625 0.09 1.39 0.60 43 0.63 45 0.41 2926 0.08 1.40 0.63 45 0.70 50 0.48 34__________________________________________________________________________
The results show that, not only can heat-sensitive recording materials having excellent moisture resistance and water resistance in accordance with the present invention be obtained, but also those embodiments of the invention further comprising a second layer comprising a resin coating composition applied to the first layer exhibit excellent plasticizer resistance.
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. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A process for the production of heat-sensitive recording materials is described, comprising the steps of (1) applying to a support a coating composition comprising a color former, a color developer, and at least one of a water-soluble binder and a water-dispersible binder, to form a layer, and (2) irradiating the layer with electron beams. Images recorded on the heat-sensitive recording material exhibit superior stability. The color density of the recorded images remains stable even when the recording material is moistened with water or placed in a high humidity atmosphere. Further, even moistened recorded images do not disappear when rubbed with a finger. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to a process and a device for separating off one component from a gas mixture and to a process for recycling a gas mixture such as an anesthetic gas. The invention finds application, in particular, in connection with instruments for and techniques of xenon anesthesia.
The anesthetic effects of xenon have been known since the 1940s. A mixture of about 80% xenon and 20% oxygen is regarded as a virtually ideal anesthetic gas, with numerous advantages over the anesthetic gases predominantly in use today which are based on laughing gas. Owing to the high costs of xenon, xenon anesthesia is practiced hardly at all in the clinical field. In order to reduce these costs proposals have therefore been made, for example in DE 44 11 533 C1, for anesthetic machines having a xenon recovery system. In the case of the recovery system proposed in DE 44 11 533 C1, the exhaled respiratory gas is first cleaned and then compressed and passed into a pressure vessel which is taken into a cooling device. By means of the cooling device the pressure vessel is cooled to such an extent that the xenon that is to be recovered is liquefied. The gaseous constituents in the pressure vessel are let off through an outflow valve. When there is a sufficient amount of liquid xenon in the pressure vessel, it is pumped into a further vessel.
This device has the disadvantage of a highly complex apparatus for compressing the gas and for the cooling of an entire vessel. Moreover, the degree of transfer in xenon recovery is not satisfactory.
DE 35 18 283 A1 discloses a process for removing volatile purities from gases which are produced in the semiconductor industry, where the gas to be cleaned is guided, in a vacuum system, onto a cold surface of a condensor, on which condenser the gas to be purified is deposited while the more volatile impurities are drawn off continuously in gas form from the vacuum system. In this process too, the vacuum system used means that the apparatus for recovery is highly complex.
SUMMARY OF INVENTION
It is the object of the invention to provide a simple and economic process for separating off one component of an anesthetic gas from the expirational respiratory gas of an anesthetized patient, and an associated device. Another object of the invention is to provide an economic recycling process for an anesthetic gas, especially for a xenon-based anesthetic gas.
It has surprisingly been found that it is also still possible to separate off xenon with an acceptable purity with condensation under a pressure in the range from 0.6 bar to 150 bar. When the novel recycling process is used for an anesthetic gas, it is even possible to reduce the purity requirements for the xenon still further, since residual fractions of oxygen in the recovered xenon can be compensated for by an appropriately lower proportion of oxygen when the anesthetic gas is remixed.
Advantageously, through the use of a heat exchanger consisting of a tube or a tube bundle, the energy required to condense out the xenon is reduced, since it is now necessary to cool no longer the entire vessel but instead a comparatively small condensation surface to the temperature which is required for the condensation of the xenon in solid form. At the same time this opens up a possibility of controlling the layer thickness. Since the solid xenon deposited on the heat exchanger has an insulating effect, the degree of cooling of the interior of the vessel by the heat exchanger drops as the thickness of the solid xenon layer grows, so that the thickness of the xenon layer on the heat exchanger can be deduced from the temperature in the vessel.
The pressure produced when the deposited xenon is evaporated can be used, in accordance with the invention, to transfer the recovered xenon to another vessel. Pumps for conveying the recovered xenon for further processing, therefore, can be omitted or made smaller.
The novel process can be designed as a continuous process at low pressure, with the respiratory gas, after first being cleaned, flowing along a tube bundle heat exchanger. The tube bundles of this heat exchanger are advantageously configured such that the flow path along the cooled tubes is as long as possible. The pressure of the gas flowing through the deposition apparatus is in this case typically in the range from 0.6 bar to 5 bar, preferably close to atmospheric pressure.
In accordance with the invention the respiratory gas can also be stored in a pressure vessel in which, after a sufficient amount of gas has flowed in, the xenon is condensed out in solid form on a heat exchanger and the uncondensed gases are let off as overhead gas. In the course of the subsequent evaporation of the xenon deposited in solid form in the sealed vessel, a pressure is brought about which on the one hand enables the separated xenon to be passed into a further vessel, without an additional pump, and on the other hand is also in a range corresponding to the pressure of commercial xenon gas bottles. If, for example, the deposition vessel is designed to a pressure of 150 bar, the pressure which results for the deposited xenon after evaporation is 65 bar. The deposition vessel can therefore be used directly as a store of xenon for further processing.
In accordance with an advantageous embodiment of the invention, two deposition apparatuses are used in tandem. This makes it possible to collect the expirational respiratory gas and to condense out xenon in one of the two deposition apparatuses, while in the other deposition apparatus the xenon already condensed out is evaporated.
The novel process and its modifications are also suitable in principle for separating off a component from a general gas mixture.
Further features and advantages of the invention will become clear from the following detailed description of two exemplary embodiments of the invention in reference to the attached drawings.
THE DRAWINGS
FIG. 1 shows, diagrammatically, a device for recovering xenon from anesthetic gas by a low-pressure process;
FIG. 2 shows, diagrammatically, a device for recovering xenon by a high-pressure process.
DETAILED DESCRIPTION
FIG. 1 shows a first embodiment of the novel xenon recovery system, in which the xenon is separated off with a low-pressure process. The center of the system is a deposition apparatus 1, which has a heat exchanger 3, which is cooled by liquid nitrogen, and a heater 5, which in the drawing are indicated merely in the form of functional symbols. The deposition apparatus 1 has an inlet 7 for expiration of respiratory gas from an anesthetic machine (not shown) and also two outlets 8 and 9. The heat exchanger 3 consists of a tube bundle through which liquid nitrogen is formed. However, it could also be passed through a surface having good thermal conductivity of a reservoir for liquid nitrogen. The heat exchanger 3 is located in the flow path from the inlet 7 to the outlet 8 and is customarily configured such that as large as possible an area of heat exchanger comes into contact with the gas flow. The heater 5 is an electrical heater which heats the vessel of the deposition apparatus 1.
Interposed between the anesthetic machine and the inlet 7 is an initial cleaning apparatus 10 having four cleaning stages 10a to 10d. The purpose of the four cleaning stages is to remove various impurities present in the expirational respiratory gas from the anesthetic machine. For instance, the cleaning stage 10a can contain soda lime for removing carbon dioxide, the cleaning stage 10b can contain a molecular sieve for removing moisture in the respiratory gas, the cleaning stage 10c can contain an active carbon filter for removing hydrocarbons present as metabolic products in the respiratory gas, and the cleaning stage 10d can contain a particle filter, for example a HEPA filter, for removing suspended particles, microbes and the like. The initial cleaning apparatus 10 is connected to the inlet 7 by way of an intermediate store 12 and a shutoff valve 14.
The first outlet 8 of the deposition apparatus 1 is connected to a membrane pump 16, which passes the gas it sucks in either into the free atmosphere or into a waste-gas collection vessel (not shown). The second outlet is connected by way of a nonreturn valve 18 and a shutoff valve 20 to a collecting vessel 22 for the recovered xenon.
The unit illustrated in FIG. 1 operates as follows: the respiratory gas coming from the anesthetic machine is passed first of all through the initial cleaning apparatus 10, in which impurities such as hydrocarbons and microbes and substances having a higher freezing point than xenon (H 2 O, CO 2 ) are removed from the gas. The initially cleaned gas is then stored in the intermediate store 12. When the deposition apparatus 1 is ready to receive respiratory gas and/or a sufficient amount of gas has been stored in the intermediate vessel 12, the shutoff valve 14 is opened and the gas flows through the inlet 7 into the deposition apparatus 1. In this arrangement, the pump 16 produces a flow over the heat exchangers 3 whose surface, as a result of cooling by liquid nitrogen, has a temperature of approximately -196° C. On the heat exchange surface of the heat exchanger 3 the xenon (freezing point: -112° C.) is deposited in solid form while the principal impurities, namely oxygen (freezing point --219° C.) and nitrogen (freezing point: -210° C.), remain in gas form and are taken off by suction as overhead gas by the pump 16. Since the components having a higher freezing point than that of xenon have been separated off in the initial cleaning apparatus 10, the xenon deposited on the heat exchanger now contains only very small fractions of impurities.
The deposition process described above is continued there is a sufficient layer thickness of the xenon on the heat exchanger 3. The presence of a sufficient layer thickness can be ascertained, for example, by means of a flow meter in the line to the inlet 7, since a certain amount flowing through corresponds to a certain layer thickness of xenon on the heat exchanger. Another possibility is to detect, by means of a temperature sensor in the vessel of the deposition apparatus, by how much the temperature in the vessel has risen in relation to the start of the deposition process. Since the deposited xenon insulates the heat exchanger 3, a certain layer thickness corresponds to a certain rise in temperature in the vessel of the deposition apparatus 1. When the desired layer thickness is reached, the supply of respiratory gas from the intermediate store 12 is interrupted by means of the valve 14, and the outlet 8 of the deposition apparatus is closed. The vessel of the deposition apparatus 1 is subsequently heated by means of the heater 5 so that the xenon deposited on the heat exchanger 3 is evaporated. As a result there is a buildup of pressure in the vessel of the deposition apparatus 1. Following the evaporation of the xenon, the outlet 9 and the valve 20 are opened, so that the gaseous xenon in the deposition apparatus 1 flows as a result of the built-up pressure into the xenon vessel 22 via the nonreturn valve 18 and the valve 20.
The embodiment described above can be modified in various respects. For instance, the connection between the anesthetic machine and the intermediate store 12 can be designed such that when the valve 14 is closed a moderate pressure, for instance in the range from 3 to 5 bar, is established in the intermediate store. In this case the pump 16 can be omitted and the outlet 8 can be connected directly to the atmosphere. The gas present in the intermediate store 12 then flows, after the valve 14 has been opened, and as a result of the pressure gradient relative to the atmosphere, via the inlet 7 and the outlet 8 through the deposition apparatus 1 and the heat exchanger 3.
Furthermore, the heater can be operated such that after the inlet 7 has been closed the xenon is initially only liquefied, so that impurities included in the solid xenon are released and are removed under suction as overhead gas by the pump 16.
It is also possible to pass the recovered xenon in liquid form to the xenon store 22. In this case, the deposited xenon is only liquefied and a liquid pump is provided in the connection between the outlet 9 and the vessel 22.
Finally, the vessel of the deposition apparatus can also be fitted only with an outlet 8, through which it is possible to lead off both the gas containing impurities, in the course of the deposition process, and, later, the recovered xenon, with a multiway valve passing the emerging gas either into the atmosphere or to the xenon store 22.
FIG. 2 shows a system for recovering xenon from anesthetic gas in a high-pressure process, where gas lines are shown by solid lines and measurement and control lines (temperature, pressure, pneumatics, flow) are shown by dashed lines. This system again has an initial cleaning apparatus 10 with cleaning stages 10a to 10c for cleaning the expirational respiratory gas coming from the anesthetic machine. The cleaning stages in the initial cleaning apparatus 10 are indicated only by way of example. It is of course also possible here to employ a HEPA filter and/or further cleaning stages. The initial cleaning apparatus 10 is connected by way of a pressureless pump control 112 or buffer with a pump 114 which passes the precleaned respiratory gas via a branch changeover unit 116 to either of two deposition vessels 120, 220, which are identical in construction. The description given below of their construction relates to the first deposition apparatus, with the reference numerals for the second deposition apparatus being indicated in brackets. Each of the two deposition apparatuses consists of a pressure-resistant vessel which is designed for a pressure of 150 bar and has an inlet valve 122 (222) and an outlet valve 124 (224). A pressure sensor 126 (226) detects the pressure in the vessel. In the vessel there is a heat exchanger in the form of a stainless steel cooling tube 128 (228) through which liquid nitrogen can flow. A temperature sensor 130 (230) detects the temperature in the interior of the vessel, while a temperature sensor 132 (232) detects the temperature on the outer wall of the vessel. The vessel itself is surrounded by an insulating jacket 134 (234). The inlet valve 122 (222) is connected via the branch changeover unit 116 to the pump 114, while the outlet valve 124 (224) is connected to a multiway valve 140 (240) which is likewise directed by the branch changeover unit 116. Depending on these directions, the multiway valve 140 (240) leads the gas coming from the outlet valve 124 either off, as waste gas, or via a product line 141 to a pump 142. The cooling tube 128 (228) is connected to a supply of liquid nitrogen 150, and a temperature control 152 uses the measurements from the temperature sensors 130 (230) and 132 (232) to determine the amount of liquid nitrogen flowing through the cooling tube. The liquid nitrogen evaporated in this process is led off as waste gas via the line 154 (254).
The system illustrated in FIG. 2 operates as follows. The expirational respiratory gas from the anesthetic machine, first cleaned in the initial cleaning apparatus 10, is passed first of all via the pump controller and the pump 114 solely to one of the two deposition apparatuses, for example apparatus 120, with the outlet valve 124 of this apparatus remaining closed. On reaching the final pressure of 150 bar in the vessel of the deposition apparatus 120, the branch changeover unit 116 closes the inlet valve 122 and passes all further respiratory gas coming from the pump 114 to the other deposition apparatus 220. In the interim, the temperature controller 152 passes liquid nitrogen from the nitrogen reservoir 150 into the cooling tube 128, so that solid xenon is deposited on the cooling tube 128. When the xenon in the gas mixture has been substantially deposited, which can be ascertained, for example, by measuring when a characteristic time period has elapsed or by measuring the temperature pattern in the vessel of the deposition apparatus 120, the associated multiway valve 140 is set such that the gas coming from the outlet valve 124 is led off as waste gas, and the outlet valve 124 is opened. The overhead gas in the vessel, which contains the uncondensed components of the gas mixture introduced, is let off and led off as waste gas. The outlet valve 124 is subsequently closed and the vessel is heated by a heater (not shown) so that the xenon deposited on the cooling tube 128 is evaporated. In the course of this procedure a pressure of 65 bar is typically established within the vessel, corresponding to the pressure of customary commercial xenon bottles. After changeover of the multiway valve 140, the gaseous xenon thus obtained is then passed via the outlet valve 124 and the product line 141 to the pump 142, which passes the xenon to a downstream analysis stage or processing stage. After this, the deposition apparatus 120 is again ready to receive expirational respiratory gas from the pump 114. As soon as the maximum pressure of 150 bar is reached in the second deposition apparatus 220, into which all of the expirational respiratory gas produced in the interim has been pumped, the associated inlet valve 222 is closed and the pump 114 is reconnected, by means of the branch changeover unit 116, to the first deposition apparatus 120. The two deposition apparatuses 120 and 220 therefore operate in tandem, so that there is continuous processing of the expirational respiratory gas produced.
In this second embodiment of the novel recovery system, too, it is possible to provide modifications as in the case of the first embodiment described above. For example, here too the cooling tube 128 can be configured as a tube bundle. The product pump 142 may, depending on the nature of further processing, be omitted. Since the pressure of the vaporized xenon (typically 65 bar) corresponds to the pressure of customary commercial xenon bottles, the vessels of the deposition apparatuses 120 and 220 can also be used directly as compressed gas bottles. In this case provision can be made for the vessels to be changed after each recovery operation. It is of course also possible to employ more than two vessels, which are then successively filled or used for a recovery operation under direction by the branch changeover unit 116. Finally, it is also possible to couple two low-pressure systems as shown in FIG. 1, with the aid of a branch changeover unit, or to couple a low-pressure system with a high-pressure system, by way of a branch changeover unit, so that depending on requirements and circumstances it is possible to operate by the low-pressure process or the high-pressure process. Alternatively, it is also possible to use a single high-pressure deposition apparatus, for example the deposition apparatus designated as 120 in FIG. 2, and to provide--in a manner similar to the embodiment of FIG. 1--an intermediate store which accommodates the respiratory gas produced during the evaporation of the condensed xenon.
Since the recovered xenon is reused as anesthetic gas, the recovered xenon need not be of high purity. In accordance with the invention the recovered xenon is analyzed before the anesthetic gas is remixed and, if there are residual concentrations of oxygen and nitrogen, the corresponding proportion of oxygen or nitrogen which is added to the xenon when the anesthetic gas is remixed is reduced accordingly. Any other residual concentrations of impurities, for example CO 2 , are physiologically unobjectionable and can, moreover, be taken into account accordingly, following an analysis of the recovered xenon, in the anesthesia supply. | A process is disclosed for separating a component from a gaseous mixture, in particular for separating xenon from the breathing gas exhaled by an anaesthetized patient. The disclosed process has the following steps: the gaseous mixture is brought into contact with a cooling surface at a temperature below the melting point of the components to be separated, the proportion of the gaseous mixture which is not condensed on the cooling surface in a solid state is carried away, and the component condensed on the cooling surface is heated above the melting point of the component to be separated. Also disclosed are a device for carrying out this process, a corresponding process for recovering anaesthetic gas and an associated anaesthetic equipment. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to heat pumps and more particularly concerns transfering heat energy between two different temperatures by means of the cyclical disassociation and reassociation of chemical species. The traditional need for a compressor is eliminated, resulting in significant cost reduction in both capital and operating expenses.
2. Prior Art
Conventional rankine cycle heat pumps use a compressor to change the phase of a secondary fluid, such as Freon. The compressor represents the major energy consuming portion of a heat pump system. Chemical heat pumps use phase changing chemicals. Both systems are rather inefficient compared to the present invention.
OBJECT OF THE INVENTION
The principal object of the present invention is to provide the transfer of heat via a closed loop system without the need for a compressor.
A further object is to provide a heat pump system which enables the elimination of moving parts.
A still further object is to provide a heat pump with substantially lowered operating costs due to the greatly decreased consumption of electrical power.
A still further object is to provide a heat pump which requires a smaller working area than that required by those utilizing compressor systems.
A still further object is to provide a heat pump which eliminates the traditional maintenance necessary with present heat pumps of compressor design.
SUMMARY OF THE INVENTION
In accordance with the invention, the primary fluid of the heat pump system is a chemical (or combination of chemicals) which is capable of being cyclically disassociated and reassociated by radiative or electrical means, as exemplified by the class of chemicals referred to as polymers, some of which are capable of being depolymerized by radiation and spontaneously repolymerized when removed from the radiation environment.
In one form of the invention ultraviolet light causes the disassociation of a chemical into a species which spontaneously changes from liquid to a gaseous state, through the absorption of heat from its surroundings. Upon the spontaneous reassociation of the gaseous species, heat is evolved.
The original chemical species returns to the liquid state simultaneously with the removal of the heat evolved to a heat sink. This may be summarized by the following equations where the boiling point of A is less than the boiling point of A 2 . ##STR1##
The pressure of the high pressure liquid may be reduced by an expansion valve or device. The reassociated liquid is then returned to the ultraviolet light source for disassociation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of the heat pump system of the present invention in a cooling mode.
FIG. 2 is a diagrammatic representation of the heat pump system in a heating mode.
FIG. 3 is a diagrammatic representation of the heat pump system of the present invention is adapted to a conventional heat pump system in the cooling mode.
FIG. 4 is a diagrammatic representation of the heat pump system as adapted to a conventional heat pump system in the heating mode.
DETAILED DESCRIPTION OF THE INVENTION
The first law of thermodynamics states a relationship between E(Internal Energy), O(Heat) and W(Work). If one considers work of expansion only, ##EQU1## thus in a constant volume process the work integral equals zero. That is, no net mechanical work is obtained.
In most situations of interest, if a chemical reaction is carried out at constant volume, no work of any kind is obtained and
ΔE.sub.v =O.sub.v
thus, at constant volume, the heat quantity accompanying the process depends only on the initial and final states. In other words, the internal energy, E, is a thermodynamic property and if a process is used in which only PdV work is done, and the volume is held constant, the heat absorbed or evolved is independent of the path and depends only on the nature and state of the initial and final reactants. Thus, one is afforded the opportunity of minimizing the amount of energy necessary to achieve this change, although the amount of energy transferred (in this case as heat) is constant. Thus, one can choose a set of "different paths" in going from state A to state B. At present the conventional heat pump utilizes a gas which is compressed mechanically to a liquid form and then allowed to expand to its original gaseous state, absorbing heat from its surroundings in the process.
A basic heat pump system of the present invention is shown in FIG. 1 in the cooling mode. The disassociation unit 10 is located within a space 12 which is to be cooled and the heat exchange unit or condenser 14 is located in a space 16 outside of the space to be cooled. Typically, the space 12 is the inside of a building and the space 16 is outside adjacent to the building.
The system includes a liquid chemical species 18 such as a polymer which disassociates or depolymerizes upon exposure to radiation, such as ultraviolet light, forming a gas and reassociates or repolymerizes upon being condensed. Examples of chemicals which will disassociate on exposure to radiation and reassociate include conjugated carbonyl compounds such as aromatic keytones, dicarbonyls, enones, and quinones. Carbonyl compounds on excitation produce triplet excited species in high yields through intersystem crossing. This excitation energy is subsequently lost by non-radiative decay, with minor contributions of fluorescence and phosphorescense. For example quinones 1,2 dicarbonyl compounds are typical. Other excellent examples are photodimerizations, cyclo-hexadienones and related compounds.
The chemical 18 is exposed to radiation from radiation source 20 within the disassociation unit 10. Upon exposure to the radiation, the chemical disassociates into lower molecular weight species. These disassociated products will be referred to collectively as "disassociated chemical".
The disassociated chemical changes from liquid to gaseous phase within the disassociation unit 10 absorbing heat and forming a high pressure gas. To improve the cooling efficiency of the disassociation unit, a fan 22 directs the indoor air across the disassociation unit.
The high pressure gaseous disassociated chemical is directed by conduit 24 to condenser 14 where it is condensed and reassociated. The reassociation is accellerated within the condenser because the number of physical interactions between the molecules is increased due to the increased density. The reassociation reactions give off heat which is transferred to the outdoor air. The fan 26 directs the outdoor air across the condenser to improve the heat transfer. The condensed and reassociated chemical is returned to the disassociation unit by conduit 28.
Because of the difference of density between the high pressure gaseous disassociated chemical and the high pressure liquid reassociated chemical, and because of the condensation of the gaseous chemical, the disassociated and reassociated chemical heat exchange fluid will circulate through the system without a pump. If the condenser 14 is located at an elevation higher than the disassociation unit 10, the condensing chemical liquid will flow toward the disassociation unit to replace the liquid evaporated in the disassociation unit and maintain the liquid levels in the condenser or conduit and the disassociation unit equal. Also the reassociation and condensing of the gaseous disassociated chemical will create a region of lower pressure which will cause the gaseous disassociated chemical to flow toward the condenser. Therefore, the system will operate without any moving mechanical devices or the associated energy losses. However, a pump may be included in one of the conduits to assist flow of the fluid.
In the cooling mode shown in FIG. 1, the indoor air within the building space 12 is the source of heat which is pumped to the outdoor air in space 16 which acts as the heat sink. As shown in FIG. 2, to operate in heating mode the location of the components are interchanged. The disassociation unit 10 and fan 22 are located in the outdoor space 16 and fan 26 directs indoor air across the heat exchange unit 14 located in the indoor space 12. Therefore, heat is transferred from the outdoor air to the indoor air to warm the building.
As shown in FIGS. 3 and 4, the system may be retrofitted into an existing conventional heat pump system. FIG. 3 shows the system operating in the cooling mode. The high pressure gaseous disassociated chemical formed in the disassociation unit 10 flows through the four way valve 30 to an outdoor heat exchanger or condenser 32.
Heat is transferred from the high pressure gaseous disassociated chemical within the heat exchanger 32 to the outdoor air which is directed by fan 34 over the heat exchanger 32. Upon condensing, the disassociated chemical reassociates giving off additional heat.
The high pressure reassociated liquid chemical flows through check valve 36 and expansion valve 38. The low pressure liquid from the expansion valve is directed to the indoor heat exchanger or evaporator 40 where heat is transferred from the indoor air which is directed by fan 42 across the heat exchanger 40 to the reassociated chemical. The reassociated chemical vaporizes within the heat exchanger 40 to form a low pressure vapor which flows through the four way valve 30 back to the disassociation unit 10.
To operate the system in the heating mode, the four way valve 30 is repositioned as shown in FIG. 4 so that the high pressure gaseous disassociated chemical is directed from the disassociation unit 10 through the four way valve 30 to the indoor heat exchanger 40. Heat is transferred from the disassociated chemical within the indoor heat exchanger to the indoor air, condensing and reassociating the chemical.
The high pressurre reassociated liquid chemical is directed through check valve 44 to expansion valve 46. The low pressure liquid from the expansion valve is directed to the outdoor heat exchanger 32 where the reassociated chemical is vaporized. The low pressure vapor chemical is then redirected to the disassociation unit 10 through the four way valve 30 to the indoor heat exchanger 40. Heat is transferred from the disassociated chemical within the indoor heat exchanger to the indoor air, condensing and reassociating the chemical.
The high pressure reassociated liquid chemical is directed through check valve 44 to expansion valve 46. The low pressure liquid from the expansion valve is directed to the outdoor heat exchanger 32 where the reassociated chemical is vaporized. The low pressure vapor chemical is then redirected to the disassociation unit 10 by four way valve 30.
Laboratory tests have been conducted using an ultraviolet laser to prove that the system can be used as a heat pump. Conjugated carbonyl compounds such as aromatic keytones, dicarbonyls, enones and quinones are disassociated by the ultraviolet laser to form a gaseous disassociated chemical. Upon cooling of the disassociated chemical, it condenses and reassociates to form the original chemical.
As in the conventional heat pump system, the change of phase between liquid and gas is accompanied by the absorption and release of the latent heat of vaporization. The rate of disassociation within the disassociation unit can be varied by changing the intensity or wave length of the radiation emitted by the radiation source. Since the flowrate of fluid is influenced by the rate of disassociation, the flowrate of fluid can be varied by controlling the rate of disassociation.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. | A heat pump system includes a chemical which is disassociated into lower molecular weight species in the liquid state upon exposure to radiation such as ultraviolet light. The disassociated species then spontaneously change to the gaseous phase with a simultaneous absorption of heat. Heat is removed from either the disassociated gaseous species or the reassociated gaseous species to a heat sink thereby causing their return to the liquid phase. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to surface paving, and more particularly to a surface paving apparatus which can be easily assembled into an immovable, durable, surface and which can be subsequently disassembled and moved.
2. Description of the Background Art
When civilization arose, so arose the necessity for paved surfaces to facilitate the movement of people and the goods of commerce. In general, the utilitarian requirements of a reliable paved surface have been that it remain immovable in the face of heavy traffic, that it be durable in the face of the elements, that it be adaptable to varying terrain and soil conditions, that it provide for adequate drainage and that it be simple to maintain. To achieve the requirement of immovability, most prior art paving surfaces have employed borders of rock or cement, to hold the paving material in place, or else in addition to borders, have used packed sand, or some other suitable material placed in between the sections of paving material, to achieve the requirement of immovability.
For example, British Pat. No. 244,504 applied for by Cardell, on Aug. 19, 1924, discloses a paving surface comprised of grooved paving blocks, wherein the grooves are designed to accommodate the bars of a structural "rebar" lattice, laid upon a roadbed. Wet cement or mortar is poured into the rebar lattice and the paving blocks are set upon the wet cement, such that the grooves settle upon the bars of the lattice, thereby bonding the blocks, rebar lattice and cement, together.
Belgian Pat. No. 540850 applied for by Desmedt et. al. on Aug. 27, 1955, discloses a tile laying apparatus wherein the tile have wide channels on their undersides. A series of rods are placed in the channels for purposes of aligning adjacent pieces of tile. Once the tile is laid and aligned, the rods are removed.
U.S. Pat. No. 123,219 issued to Beidler on Jan. 30, 1872, discloses a wooden paving surface comprised of wedge-shaped wooden blocks, cut away at the outer edges, to form a tenon and shoulder, which allows the blocks to rest upon strips laid parallel with the street. The spaces between the blocks are then filled with gravel, sand, tar, or pitch, to create an immovable surface.
U.S. Pat. No. 112,239 issued to Grant on Feb. 28, 1871, discloses a wood pavement comprised of a set of grooved upper and lower blocks; the lower blocks being set upon the road bed and the upper blocks serving as the road surface. The blocks are joined by the nature of their interlocking grooves, as well as by a system of hooks which wrap around the grooves, to form a sturdy paving surface. Any spaces between the blocks are then filled with sand or gravel to create an immovable surface.
British Pat. No. 373,715 applied for by Russell on Apr. 1, 1931, discloses a wooden pavement surface comprised of a series of wooden blocks with grooved bottoms. The grooves in the bottoms of the blocks match the configuration of a series of ribs laid upon the surface to be paved, such that when the ribs are matched to the grooves, they become interlocked, thereby holding the blocks in position.
U.S. Pat. No. 3,148,482 issued to Neale on Sep. 15, 1964, discloses a composite floor structure comprised of bricks laid upon a metal grid. At intervals, the grid has projections which are spaced according to the width of the bricks used. When the bricks are placed between the projections on the grid, the projections abut against the edges of tile bricks, such that the bricks are held fast between the projections.
U.S. Pat. No. 4,047,825 issued to Lundahl on Sep. 13, 1977, discloses a pavement apparatus comprised of a wire grid, possessing brick-size grid spaces, which may be transported, or stored on a roll and when unrolled onto a flat path, the bricks can subsequently be individually mounted in each of the grid spaces. Sand or mortar can then be driven into the spaces between the bricks, to create an immovable surface.
U.S. Pat. No. 4,813,811 issued to Adams on Mar. 21, 1989, discloses a prefabricated pavement device which has a support layer consisting of wire or plastic mesh.
U.S. Pat. No. 3,905,172 issued to Blackburn on Sep. 16, 1975, discloses a method for laying wooden floors, wherein slices of wood material are placed on an asphalt or bitumen foundation and then adhesives are poured between the slices of wood material to fill in any gaps.
The foregoing paving surfaces achieve a degree of permanence which make it difficult for them to be moved once they are in place. Should a need arise for these paving surfaces to be moved, movement can only be achieved through a significant expenditure of energy and by incurring damage to the paving surface itself, thereby necessitating replacement of whole or part of the surface with an entirely new paving surface. Attempts to create a surface which is durable and immovable in place, yet which can be easily disassembled and moved, have met with marginal success.
U.S. Pat. No. 321,403 issued to Underwood on Jun. 30, 1885, describes a system of grooved paving blocks adapted to be assembled upon a series of ribbed base plates. The ribbed plates serve as a base material and have perforations to allow for drainage. The grooves in the paving blocks accommodate the ribs on the baseplate, allowing for the assembly of a paving surface, by placing numerous blocks over the ribs on the base plates. The outermost ribs on the base plates are half as wide as the center ribs, specifically so that two base plates can be joined by fitting a grooved paving block over the outermost ribs of the two adjoining base plates, effectively locking them together. This design was created so that whole sections of pavement could be removed by merely lifting the blocks off the ribs and subsequently removing the baseplates, should a section of road bed or sewer beneath the pavement require repair. While Underwood allows for the disassembly and removal of small sections of pavement, the cumbersome and rigid nature of the base plates, make it difficult to disassemble and move the entire pavement in a quick and efficient manner.
U.S. Pat. No. 658,868 issued to Rosenbaum on Oct. 2, 1900 discloses an improvement in securing vitreous slabs to walls, floors or ceilings. In Rosenbaum, the wall, floor, or ceiling to be covered, possess parallel, hollow, dovetailed ridges, the parallel nature of the ridges thereby creating channels. The vitreous slabs are pressed into the channels and are held secure by the spring-like characteristics of the hollow dovetailed ridges. While it may be inferred that the spring-like nature of the dovetailed ridges allow for simple disassembly of the invention, it is not specifically stated as such. Also, in Rosenbaum, no mention is made of the utility of this invention for use as a pavement surface.
A need therefore still exists for a paving surface which is durable and immovable when in place, yet which can be easily disassembled, moved, and reassembled in another location without incurring any damage to the paving surface. Additionally, it is also important that a movable paving surface be free from weeds and plants, which can protrude through the joints of the paving surface and degrade it. The surface paving apparatus disclosed herein, satisfies these requirements.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.
SUMMARY OF THE INVENTION
The present invention pertains to a surface paving apparatus and a method for using the same. By way of example and not of limitation, the surface paving apparatus is comprised of a mesh material for covering a surface to be paved, a plurality of ribs fastened to the mesh material, and a grooved paving material which frictionally engages the ribs of the mesh material, thereby holding the paving material in an immobile position. The mesh material preferably is a mesh fabric of a type commonly selected for landscaping, which has the favorable characteristics of providing excellent drainage and preventing the growth of plants which can degrade the paving surface. The ribs, being preferably substantially elongate and substantially parallel, may be fastened to the mesh material by any variety of fastening means. The paving material has grooves placed upon its surface either by cutting or extruding. The ribs and grooves are designed to engage each other in a tight frictional fit. This frictional engagement is of such a nature that, when the paving material is pressed down upon the ribs, a tight fit is achieved between the grooves and vinyl strips on the ribs. The paving material may be a series of paving blocks comprised of materials commonly used in the paving arts. One other notable feature of the surface paving apparatus, is that the paving material is detachably coupled to the mesh material and can be uncoupled at will.
The method of using the present invention involves placing the mesh material upon a surface to be paved. The ribs may be attached to the mesh material either prior to, or after, placing the mesh material upon the surface to be paved. The grooves in the paving material may be placed there either prior to practicing the invention, or else may be placed there as part of an invention step, by extruding or cutting. Once the ribs and grooves are in place, the person practicing this method places the grooves of the paving material upon the ribs on the mesh material and, using adequate pressure, pushes down upon the paving material until a tight frictional engagement is achieved between the ribs and the grooves.
An object of the invention is to provide a paving surface which is durable and which can be easily disassembled, moved and reassembled at will.
Another object of the invention is to provide a paving surface which is impervious to weeds or other plants which can degrade a paving surface.
Another object of the invention is to provide a paving surface wherein the paving material is held to the remainder of the surface paving apparatus by an immovable, frictional engagement.
Another object of the invention is to provide a paving surface which is adaptable to sloped surfaces and remains immobile thereon.
Still another object of the invention is to provide a paving surface where the paving material is readily detachable from the remainder of the surface paving apparatus.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 is a perspective view of the apparatus embodying the present invention.
FIG. 2 is a detailed perspective view showing a section of the apparatus of FIG. 1.
FIG. 3 is a perspective view of the mesh material and rib components of the apparatus of FIG. 1.
FIG. 4 is a detailed plan view of a section of the mesh material component of the apparatus of FIG. 1.
FIG. 5 is an end view of one of the rib components of the apparatus of FIG. 1.
FIG. 6 is a side elevation view of the apparatus of FIG. 1, prior to engaging the paving material with the remainder of the present invention.
FIG. 7 is a cross-sectional view of the apparatus of FIG. 1 taken through line 7--7 and showing the frictional engagement of the rib and groove components.
FIG. 8 is a detailed view showing a section of the assembly of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts and that the method may vary as to the details and sequence of steps without departing from the basic concepts as disclosed herein.
As can be seen in FIG. 1 and FIG. 2, the surface paving apparatus 10 of the present invention includes a mesh underlayment material 12 to which a plurality of ribs 14 extending upward from the surface of the mesh material 12 are attached. The ribs 14 are preferably elongate and preferably laid in a substantially parallel configuration, and a paving material 16 is then pressed upon the ribs 14 until a tight frictional engagement is achieved. The ribs 14 are positioned on the mesh material 12 so as to permit a plurality of paving material sections to be used to establish a paved surface. The edges of adjacent sections of paving material 16 overlap the ribs 14. This overlap 18 allows the edges of adjacent sections of paving material 16 to abut against each other, thus reducing the size of gaps 20 between adjacent sections of paving material 16. The tight abutment of the sections of paving material against each other along with the immovable nature of the finished paving surface, reduces or eliminates the necessity to place mortar or sand in the gaps to achieve an immovable surface. The sections of paving material 16 may be selected from a number of types and compositions but, in the preferred embodiment, are composed of materials commonly used in the landscaping art.
Referring now to FIG. 3, the apparatus is shown laying upon a surface to be paved, without the paving material 16 attached. The ribs 14 are shown as laying in a substantially parallel configuration upon the mesh material 12. The ribs 14 may be attached to the mesh material 12 either prior to practicing the invention, or else as part of an invention step. The mesh material 12 is porous in the preferred embodiment, but may be replaced with a non-porous, non-mesh material, as well. The mesh material 12 is illustrated in more detail in FIG. 4, where the preferably porous nature of the mesh material 12 is shown. The porous nature of the mesh material 12 allows for the drainage of water or other liquids away from the surface paving apparatus 10. It also provides for evaporation of moisture beneath the surface paving apparatus 10. An additional feature of the mesh material 12 is that it prevents the growth of weeds or other plants which can degrade the surface paving apparatus 10. The mesh material 12 may be selected from any number of suitably porous materials, but is preferably selected from any one of a number of woven landscape fabrics commonly used in the landscaping arts for erosion control, weed control, paving underliners and the like.
Referring to FIG. 5, the structure of the ribs 14 may be more closely examined. The ribs 14 may be fashioned in a variety of sizes or shapes. However, with regards to shape, those shapes which closely approximate a rectangular configuration are preferred. Ribs 14 may be fastened to the mesh material 12 by any number of means including molding or laminating but, in the preferred embodiment, the ribs are fastened to the surface of the mesh material 12 by adhesive means. FIG. 5 shows the preferred embodiment of the ribs 14 being composed of a rigid center 26 and strips 22 running longitudinally along the upper edges of the rigid center 26. The strips 22 are made of a suitable frictional material. In the preferred embodiment, vinyl is the frictional material of choice for the strips 22. The strips 22 serve as a frictional gripping surface, and are fastened to the rigid center 26 of ribs 14 by any number of fastening means including adhesive means, in the preferred embodiment. Alternatively, ribs 14 could be molded as a one-piece structure having this configuration. The rigid centers 26 may be composed of a plurality of materials, flexible plastics being preferred. It is also within the contemplation of this invention, that the ribs 14 be composed of a rigid center 26 where the strips 22 are replaced by a frictional material which completely surrounds the rigid center 26. In an alternative embodiment, it is also contemplated that the ribs 14 be molded or laminated to the mesh material 12. In another embodiment, it is contemplated that the ribs 14 be of a compressible nature. Additionally, it is contemplated that the frictional strips 22 have a "feathered" surface which allows the frictional surface to have a larger surface area, and thereby provide more area to engage the paving material 16. Finally, as an alternative to the two-material plastic center/vinyl strip preferred embodiment of the ribs 14, it is contemplated the ribs be composed of a single material which has the requisite rigidity, flexibility, and frictional capacity required by this invention. The functioning of the strips 22 is more clearly illustrated in FIG. 6, FIG. 7, and FIG. 8.
Referring to FIG. 6, the relationship of the paving material 16 is shown prior to engagement upon the ribs 14. FIG. 7 and FIG. 8 illustrate the invention after achieving a tight frictional engagement between the strips 22 and grooves 24 in paving material 16. The rigid centers 26 of ribs 14 impart the necessary structural integrity to the ribs 14 such that the grooves 24 can easily engage upon the ribs. The frictional engagement between the strips 22 and the grooves 24 is such that, when a plurality of paving material sections 16 are placed upon the mesh material 12, the entire pavement surface apparatus is immovable laterally, from any direction. Preferably, each groove 24 in paving material 16 will be engaged to a corresponding rib 14 for maximum prevention against lateral movement. The grooves 24 may be of a plurality of shapes, rectangular being the preferred shape. The grooves 24 may be placed into the paving material 16 as part of an invention step, or the grooves 24 may be a previously existing feature of the paving material 16. The grooves 24 may be placed into the paving material 16 by any number of methods including cutting and extruding.
The method of practicing this invention involves the user placing the mesh material 12 with ribs 14 attached upon a surface to be paved. The ribs 14 may be previously attached to the mesh material 12 or, in the alternative, the user may place the ribs 14 upon the mesh material as part of an invention step. Next, the user must lay down the sections of paving material 16 to create a paving surface. The grooves 24 may be placed in the paving material 16 prior to practicing the invention or the grooves 24 may be placed in the paving material 16 as part of an invention step. Next, the user must couple the paving material 16 to the ribs 14 by pressing the ribs 14 into the grooves 24 of the paving material 16. When enough pressure is applied, the strips 22 on the ribs 14 will contact the inner walls of the grooves 24, creating a tight frictional engagement. A preferred method for coupling the paving material 16 to the ribs 14 is to position the paving material 16 into place by hand or by lightly tapping an edge, and then lightly tapping the top of the paving material 14 with a striking implement until a tight frictional engagement is achieved between the paving material and the ribs. Subsequently, this method may be repeated for numerous sections of paving material 16, as well as with numerous sections of mesh material 12 until a substantial paving surface is achieved. Once the apparatus is assembled, the flexible nature of the ribs 14 along with the mesh material 12, allows the apparatus to flex and accommodate large roots or other surface anomalies which may develop beneath the apparatus. Additionally, this surface paving apparatus can be disassembled by breaking the frictional engagement between the ribs 14 and the sections of paving material 16. Upon detaching the sections of paving material 16, the entire surface paving apparatus 10 may be moved and reassembled in another location.
Accordingly, it will be seen that this invention provides a surface paving apparatus and a method of paving a surface, which allows the user to readily apply an immovable paving surface to a variety of surfaces, including sloped surfaces and surfaces having minor elevational changes. The user will find that the frictional engagement of the pavement surface to the underlying mesh material is so immovable, that the necessity to use cement borders and/or packing the gaps between the sections of paving material with sand or other filler material, to create immovability, is obviated.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents. | A surface paving apparatus (10) and a method for using the apparatus is disclosed herein. The apparatus is comprised of a mesh material (12) having parallel ribs (14) attached, laid upon a surface to be paved. A paving material (16) with grooves (24) cut into its underside is then placed upon the mesh material (12) such that the ribs (14) on the mesh material (12) frictionally engage the grooves (24) on the paving material (16). The frictional engagement between the grooves (24) and ribs (14) is stable enough to render the paving surface laterally immovable from any direction. The surface paving apparatus (10) can also be disassembled and moved, should this be desired. | 4 |
FIELD OF THE INVENTION
The present invention relates to a device and a method for controlling an impulse-generating device for drilling in rock.
BACKGROUND OF THE INVENTION
In rock drilling, a drilling tool is used that is connected to a rock-drilling device via one or more drill string components. The drilling can be carried out in several ways, a common method being percussive drilling where an impulse-generating device, a striking tool, is used to generate impacts by means of an impact piston that moves forward and backward. The impact piston strikes the drill string, usually via a drill shank, in order to transfer impact pulses to the drilling tool via the drill string, and then on to the rock to deliver the energy of the shock wave. The impact piston is typically driven hydraulically or pneumatically, but can also be driven by other means, such as by electricity or some form of combustion.
In another kind of impulse-generating devices the shock wave energy is generated as pressure impulses which are transferred to the drill string from an energy storage by means of an impact element that performs only a very small motion instead of, as described above, being generated as released kinetic energy by a piston moving backwards and forwards.
An example of such a device is a device where an impact element is pre-loaded using a counter-pressure chamber, and where the energy is transferred to the drill string by means of the impact element by a sudden reduction of the pressure in the counter-pressure chamber.
Another example of such a device is a device where a working chamber is arranged in front of the impact element instead of using a counter-pressure chamber, and wherein the shock waves are generated by supplying pressure medium of high pressure in form of pressure pulses to the working chamber from an energy storage.
According to the currently known technology, such solutions generate shock waves with lower energy, and, in order to maintain the efficiency of the drilling, the lower energy in each shock wave is compensated for by the shock waves being generated at a higher frequency.
A problem with all the abovementioned impact-generating devices is that available impact energy is not fully made use of.
OBJECTS OF THE INVENTION AND MOST IMPORTANT CHARACTERISTICS
An object of the present invention is to provide a method for controlling a rock drilling process that solves the abovementioned problem.
Another object of the present invention is to provide a regulation device at an impulse-generating device that solves the abovementioned problem.
These and other objects are achieved according to the present invention by means of a method as defined in claim 1 and by a control device as claimed in claim 13 .
According to the present invention there is provided a method for controlling a rock drilling process, with an impulse-generating device comprising an impact element transmits a shock wave to a tool connected to the impact-generating device, where a portion of the energy of said shock wave is transmitted to the rock by means of the tool and a portion of the shock wave energy is reflected and returned to the impulse-generating device as reflected energy. The method comprises the steps of generating at least one parameter value that represents the reflected energy, and to control the interaction of the impact element with the tool at least partially based on said value or values to control the rise time of said shock wave and/or the length of said shock wave. This has the advantage that the form of the shock wave at all times can be controlled based on current conditions to thereby keep harmful reflection energies at an minimum, below a predetermined value, or at a value that has been determined in relation to other demands on the drilling process.
The amplitude of the shock wave can also be controlled. This has the advantage that even larger possibilities of optimum control of the rock drilling device is provided.
At least one damping pressure in at least one damping chamber may constitute a representative quantity of the reflected energy. Alternatively, the quantity may constitute the strain of one or more strain gauges. This has the advantage that the reflection can be read in a simple manner.
The value or values representing the reflected energy may be generated continuously, acyclic, with predetermined intervals and/or when generating each or certain shock waves. This has the advantage that current input parameters for the regulation may always be available.
The present invention also relates to an impulse-generating device and a drilling rig.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a schematically shows a control and regulating device for an impact-generating device according to the preferred embodiment of the present invention.
FIG. 1 b shows an example of a device with which the present invention advantageously may be utilized.
FIGS. 2 a - 2 e shows examples of wave forms of shock waves and reflection waves.
FIGS. 3 a - b shows an example of another control and regulating device according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 a shows an impulse-generating device 10 for a rock-drilling device that can advantageously be used with the present invention. During operation, the device 10 is connected to a drill tool such as a drill bit 11 via a drill string 12 consisting of one or more drill string components 12 a , 12 b . During drilling, energy in the form of shock waves is transferred to the drill string 12 , and then from the drill string component 12 a , 12 b to drill string component 12 a , 12 b and finally to the rock 14 via the drill bit 11 , for breaking the rock 14 .
In the device 10 illustrated, a piston that moves forward and backward is not used to generate the shock waves, but instead a loaded impact element in the form of an impact piston 15 is used, which is urged towards the end of a housing 17 that is opposite to the drill string 12 by the effect of a pressure medium acting against a pressure area 16 . During operation, a chamber 18 is pressurized via a control device 20 so that the pressure in the chamber 18 acts on the pressure area 16 and thereby urges the impact piston 15 towards the rear end 19 of the housing 17 . The chamber 18 thus acts as a counter-pressure chamber.
In known technology, a control valve in the control device 20 is then opened suddenly to create an immediate reduction of pressure in the counter-pressure chamber 18 , whereupon the impact piston 15 expands to its original length and transmits potential energy to the drill string 12 in the form of a shock wave. This sudden reduction of pressure generates a shock wave of essentially the same form as a shock wave generated by a normal impact piston, that is a principally rectangular form, see FIG. 2 a , which propagates through the drill string to the drill bit 11 for transmission to the rock 14 . On account of the characteristics of the rock 14 , however, all the energy of the shockwave cannot be taken up by the rock on account of the short rise time of the shock wave (see τ in FIG. 2 a ; in the figure, τ is exaggerated for the sake of clarity; τ can be considerably shorter, that is the edge can be considerably steeper), but instead a part of the provided energy is reflected and returned to the impulse-generating device 10 through the drill string 12 . The reflections from the drill steel rock impact is dampened using a damping chamber 22 and a damping piston 23 . The function of these is well known to a person skilled in the art. The damping pressure in the damping chamber may also be used to ensure that the drill bit 11 is in contact with the rock when the impact piston 15 hits the drill string 12 . Even if the reflections is dampened, these reflections still have an adverse effect on the rock-drilling device and drill string and can cause wear of various components and serious damage as a result.
By means of the regulation device 30 according to the invention that is shown in FIG. 1 a , these harmful reflections can, however, be reduced considerably. Instead of the reduction of pressure taking place suddenly, the opening of the control device 20 of the shown device 10 can be controlled, that is, the control device 20 can control the reduction of pressure in the counter-pressure chamber 18 . By controlling the opening of the counter-pressure chamber using the control valve 20 , the rise time of the shock wave induced in the drill string, and hence in the drill bit, can be controlled. This is very advantageous, since the force that the drill bit can transmit to the rock varies with the depth of penetration of the drill bit.
FIG. 2 b shows an example of the penetrating force as a function of the penetration depth for an exemplary type of rock. As can be seen in the figure, the penetrating force that the drill bit can transmit to the rock is essentially zero at the moment of impact (d=0) and then increases exponentially with the penetration depth until the shock wave reaches its end and the penetration reaches its maximum (d=d max ) and there is accordingly no longer any energy for further penetration, after which the penetration force rapidly drops to zero and, as can be seen in the figure, the drill bit is moved backward slightly by the elasticity of the rock and/or by reflection.
FIG. 2 c shows the appearance of the reflection wave for the device according to known technology. As the penetration force of the drill bit is zero or essentially zero at the moment of impact, the amplitude of the reflection wave at this moment will, in principle, correspond to the amplitude of the incident shock wave, however as a tension wave. If the edge of the shock wave is very steep, as in FIG. 2 a , this thus means that the reflection wave will have very high and hence harmful initial amplitude.
During the regulation, information regarding the size of the resulting reflection when the shock wave hits the rock is needed. The reflection may be read from the pressure change that occurs in the damping chamber 22 when the reflected wave reaches the drilling machine. In particular, the maximum pressure change appearing in the damping chamber is directly related to the amplitude of the reflection wave. In operation, the regulation device 30 continuously or at certain intervals receives measurements representing the damping pressure in the damping chamber 22 . If needed, the measurement values may be converted to an appropriate quantity in the regulation device 30 or in a measurement value converter (not shown) connected to the regulation device 30 . The damping pressure may be read in a suitable way, e.g., during measurement, sensing or monitoring. The exact way of appropriately reading the damping pressure constitutes knowledge known to a person skilled in the art. The obtained measurement value is then compared to the value of the damping pressure that was obtained at the previous measurement, e.g., the reflection of the previous shock wave, whereupon the rise time and/or length and/or amplitude of the shock wave is regulated based on the comparison in coming impacts using the control device 20 .
The damping pressure is preferably measured continuously or using such frequent intervals that the regulation of the form of the shock wave, i.e. rise time and/or length and/or amplitude, based on the reflection of a certain shock wave can be performed already at the generation of the very next shock wave. When shock waves are generated using a very high frequency it may, however, be possible that the calculation of new regulation parameters is not finished in time for the generation of the next shock wave but perhaps not until the shock wave following thereafter or an even later shock wave.
In order to obtain an accurate value of the reflection the damping pressure may, in stead of only reading the size of the pressure change, be very frequently read so that a reproduction of the reflection wave form may be obtained. In this way, an accurate value of the size of the reflected energy may be obtained by performing a numerical algorithm of the obtained wave form.
As an alternative to measuring the reflection using damping pressure this may also be performed, e.g., by use of a strain gauge. The strain gauge is then mounted on a suitable part of the rock drilling device, said part being exerted to tensile stress/compressive stress by the reflection wave. The optimum position is on the drill string. This however may be hard to perform since the drill string often is rotated during drilling in a conventional manner and with regular intervals is provided with extension components. The positioning may thus vary from machine to machine and exactly how and which positioning that is used is within the scope of knowledge of a person skilled in the art. The essential for the invention is that a signal representing the appearance of the reflection is obtained. When using strain gauge it is also possible to, as above, obtain a wave form description of the appearance of the reflection wave.
The regulating device may further be arranged to try to minimize the reflected energy at all times. In this kind of regulation, the drilling may be started using an unregulated shock wave, i.e., in this embodiment with the reduction of the pressure totally unregulated (alternatively, the minimizing regulation is started at a predetermined rise time and/or shock wave length and/or shock wave amplitude, wherein various predetermined initial values for various types of rock may be stored in a memory in the regulation device 30 ), whereafter, when the drilling has started, the regulation device continuously or at certain times obtains measurement values representing the reflected energy, and then sends control signals to the control device 20 to regulate the form of the shock wave based on these measurement values. For example, the regulation may be arranged such that the inclination of the edge of the shock wave is gradually increased, i.e., that the duration of the reduction of pressure of the counter-pressure chamber continuously increases by a certain value Δt, so that the time of reduction of pressure is t=t f Δt, wherein t f is the time of reduction of pressure at the previous regulation, e.g., at the previous impact, for as long as the value representing the reflection energy (i.e., the reflected energy calculated by a numerical algorithm or the measured damping pressure change) is influenced in a desired direction. When the reflection reaches a minimum, i.e., an increase in the duration of the reduction of pressure does not result in any further reduction (a larger inclination of the edge) the regulation can be kept about the desired value. When minimizing the reflected energy, there is a risk that the edge of the shock wave is built up under such a long time that the penetration rate substantially is reduced. For this reason, the regulation may instead be aimed at a predetermined highest value of the reflection energy and/or highest allowable reflection amplitude. The predetermined value may, e.g., be inputted by an operator. When regulating about the predetermined value the edge time may of course also be allowed to be reduced, i.e., the above mentioned time of reduction of pressure is being reduced. By regulating the edge inclination forwards and backwards it may at all time be ensured that the reflection energy is kept at or below a desired value. In an exemplary embodiment, the control device 20 may act as a throttle valve where opening of the throttle valve is controlled by a controlled throttling. In FIG. 2 d - e is shown a regulated shock wave form and reflection of such a shock wave.
As an alternative to regulating the inclination of the edge, the length of the shock wave may be regulated instead. This is performed by lowering the pressure in the counter-pressure chamber to a certain remaining pressure and then closing the valve and/or keeping the pressure at desired level using the valve. The reduction of pressure to a desired pressure may be abrupt. The pressure in the chamber may, for example, be kept at a constant level. By successively increasing or decreasing the pressure to which the reduction of pressure is performed, the reflection energy may be regulated as above.
The above regulation, however, may advantageously be combined with a regulation that is also based on penetration rate. In this case, the regulation device is also provided with means for receiving a measurement value that represents the penetration rate. How to measure the penetration rate is well known to a person skilled in the art, and may, e.g., be obtained by a measuring the flow to the feed motor or by having a sensor on the impulse-generating device to detect how fast it moves along the feed beam along which it normally moves during the drilling process. By measuring the penetration rate in addition to measurement of the reflection, the regulation method may be used to, by controlling the form of the shock wave, balance the relationship between reflected energy and penetration rate so that in some way an optimum operation of the drilling device is obtained. If only the reflected energy is measured and used during the regulation, there is a risk that the edge of the shock wave is built-up under such a long time that the penetration rate is substantially reduced.
By also reading the penetration rate concurrently or in connection to the reading of the reflecting energy, the penetration rate may be compared with the previous value, and if it is shown that the penetration rate decreases substantially while at the same time the reflection only is reduced to a small extent, the regulation may be arranged to, e.g., keep the reflected energy below a set threshold value, while varying the time of reduction of pressure with the reflection energy maintained below this threshold value in order to achieve a maximum penetration rate at the same time as the reflection energy is kept under a pre-determined value. Although penetration rate per impulse may be measured according to the above, the penetration rate may be arranged to be read more seldom that the reflection, e.g., every fifth shock wave, every tenth shock wave or even more seldom, in order to obtain a reliable measurement of the penetration rate, i.e., the penetration rate per an arbitrary number of impulses may be measured.
When the regulation is then oscillating about an “optimum” point, the length and amplitude of the shock wave may be regulated as well in order to further try to improve the penetration rate. This may, in the above example, be achieved by lowering the pressure in the chamber using the control device 20 , and then maintain the pressure at a certain remaining pressure. Alternatively, the pressure level in the control device may be adjusted. By controlling the control device 20 , the extent in time and amplitude and build-up and stress-relieve of the shock wave be freely adjusted. Alternatively, the regulation may, of course, be performed in a reverse manner, i.e., that the length and amplitude of the shock wave is first regulated and thereafter the rise time of the edge.
It is also possible to have a regulation algorithm wherein the rise time, amplitude and length of the shock wave is concurrently regulated according to some pre-determined algorithm in order to obtain a maximum penetration rate with low reflection. When an optimum point is encountered, the regulation may be kept about this point. The regulation may further be arranged to try to obtain a new, even better point of operation at regular intervals. During adjustment of the form of the shock wave according to some algorithm, other performance than penetration rate may be included, such as straightness of the drilled hole and tightening torque of the drill string.
The above regulation may also be arranged to optimize a weighted relation between reflection energy and, for example, penetration rate, i.e., the quantities may be given various weights wherein the weighted result is regulated to a minimum level. For example, the operator may chose arbitrary weights for different performance in dependence of current priorities (for example regarding reflected energy, straightness of the hole, productivity, working life). Rock parameters or suitable values of the shock wave form may also be inputted.
In the above description the regulation has been performed by regulating the time of reduction of pressure of a counter-pressure chamber. Apart from the impulse-generating device in FIG. 1 a , there is a number of other impulse generating devices having counter-pressure chambers wherein the present invention advantageously may be utilized, as well as there are various ways of performing the reduction of pressure in said counter-pressure chamber. For example, in the parallel Swedish patent application 0501149-9, having the English title “Control device”, and having the same filing date as the present invention, is shown numerous examples of devices having counter-pressure chambers and how the reduction of pressure of these may be regulated. Also, in the parallel Swedish patent application 0501153-1, having the English title “Impulse generator and a method for generating impulses”, which application also has the same filing date as the present invention, is shown an example of another device having a counter-pressures chamber. All of these devices and methods may by used in the regulation according to the present invention.
The device in the latter of the above mentioned application is shown in FIG. 1 b and includes, apart from a counter-pressure chamber 2 , a second chamber 4 acting against the impact element 3 . The device further includes a main chamber 5 , which preferably is constantly pressurized, said pressure being obtained by, for example, having a pressure source such as a pump which is regulated such that a constant pressure is maintained. The chamber 4 constitutes a pressure-building chamber. By pressurizing the counter-pressure chamber 2 and pressure-building chamber 4 , sequentially or in parallel, and then, with a pressurized counter-pressure chamber 2 , pressure-relieve the pressure-building chamber 4 the pressure in the pressurized counter-pressure chamber 2 will increase when the pressure-building chamber 4 is relieved. As to the rest this device it operates as the device described in FIG. 1 b , however with the advantage that an even higher pressure may be obtained in the counter-pressure chamber 2 , which in turn results in even larger regulation possibilities.
It has been shown above how the form of the shock wave may be regulated by controlling the reduction of pressure in a counter-pressure chamber. Apart from controlling the form of the shock wave in this way, the present invention may of course be used with an arbitrary impulse-generating device at which the form of the shock wave may be regulated. In FIG. 3 a is shown an example of such a device 40 . In this device no counter-pressure chamber is used, but a working chamber 42 is localized in front of the impulse piston 41 and shock waves are generated by supplying pressure medium having a high pressure in form of pressure pulses to the working chamber 42 from an energy storage 43 , which may be localized in or outside the impulse-generating device 40 , via three channels 44 - 46 , which preferably have different cross-sectional dimensions.
By opening one or both connections between working chambers 42 and energy storage 43 a pressure pulse is obtained by the pressure increase in the working chamber, which causes a compressive stress in the impulse piston which is transferred to the drill string as a shock wave. The energy storage 43 may by of such dimension that the transfer of pressure medium to the working chamber does not result in too large a reduction of pressure in said energy storage.
When the shock wave has been generated, the connections between working chamber 42 and energy storage are closed and the pressure in the working chamber is lowered by opening a connection 46 between working chamber 42 and a pressure reservoir 48 . The pressure reservoir is substantially pressure relieved. Thereafter the connection between working chamber 42 and reservoir 48 is closed and a new stroke may by performed (the working chamber is thus pressure relieved or substantially pressure relieved at the beginning of the next pulse generation). When a connection between energy storage 43 and working chamber 42 is opened, a part of this wave will, when the pressure medium wave reaches the working chamber 42 , reflect back to the energy storage 43 as a negative pressure wave, which in the energy storage is re-reflected whereat a new positive wave directed towards the working chamber arises. This process will continue until the difference in pressure between energy storage and working chamber has levelled out. By varying the distances, i.e., the length of the channels 44 - 46 , and the time difference between the opening of the various channels 44 - 46 , these pressure waves and pressure reflections may be utilized to form the pressure build-up and thereby the form of the shock wave.
According to the present invention the regulation is, as before, performed by a regulation device 49 , but instead of regulating the reduction of pressure in a counter-pressure chamber, the way in which the respective channels 44 - 46 are opened is now regulated, i.e., which channel is opened first and with which time difference the channels are opened. Further the lengths of the channels 44 - 46 may be regulated, which, i.e., may be achieved by having channels 44 - 46 provided with displaceable sleeves 44 a , 45 a , 46 a , which are allowed to stretch a longer or shorter way into the energy storage 43 . The displaceability is indicated in the figure by two-way arrows, and the sleeves 44 a , 45 a , 46 a are shown in different positions. The regions within the dashed circles are also shown enlarged in the figure for the sake of clarity. The sleeve displacement mechanism is not shown since it is considered that a person skilled in the art is capable implementing such a mechanism in a suitable manner. By controlling the pressure increase in the working chamber in this manner a desired shock wave appearance may be obtained. The required input parameters may be obtained as above, i.e., for example, by measuring the pressure in a damping chamber (not shown) or by using a strain gauge. There may be arranged a table of different channel lengths and time difference settings and resulting rise time of the shock wave edge for each of these settings in the regulation device 49 . Using the table the inclination of the edge may be controlled in a desired direction (i.e., more flattened or steeper) based on the reflection of the shock wave.
In an alternative embodiment the pressure increase in the working chamber in FIG. 3 a may be regulated in a similar manner as the reduction of pressure of the counter-pressure chamber in FIG. 1 a - b , i.e., by, for example, using a throttle valve to controllably increase the pressure in the working chamber through the throttling.
In another alternative embodiment the essentially pressure relieved reservoir 48 may be pressurized to a certain pressure, which compared to the pressure of the energy storage 43 is lower. This has as a result that the working chamber 42 thus will always be permanently pressurized and thereby be able to act as damping chamber, which means that the pressure/pressure change in the working chamber after a stroke may be used to obtain the input parameters for the regulation according to what has been described above.
As is obvious to a person skilled in the art the number of channels between energy storage and working chamber may, of course, be arbitrary, the more channels, preferably having various cross-sectional dimensions, the more regulation possibilities obtained.
In FIG. 3 b is shown a variant of the device in FIG. 3 a wherein three energy storages 53 a - c are used and which have different working pressures instead of using only one energy storage 43 having a single pressure. By connecting the energy storages 53 a - c sequentially, e.g., the storage having the lowest pressure first, another possibility of regulating the structure of the shock wave is achieved, e.g., stepped. Naturally, each energy storage 53 a - c may be connected to the working chamber 52 by means of a channel 54 - 56 having adjustable length, or by means of two or more channels according to the above. This embodiment thus allows a very free regulation of the form of the shock wave. Naturally, an arbitrary number of energy storages having different pressures may be utilized. The regulation of the form of the shock wave using the regulation device 59 is preferably based on values stored in a table here as well.
A plurality of examples of suitable impulse-generating devices for which the present invention is applicable have been described in the above description, but, as will be recognized by an expert in the field, the present invention can, of course, be used with any impulse-generating device where a reduction of pressure in one (or more) counter-pressure chambers is used to generate a shock wave. The impulse drilling mentioned in the above description can of course be combined with a rotation of the drill strings in the usual way for the purpose of achieving drilling where the drill elements of the drill bit encounters new rock at each stroke (that is, does not make contact in a hole that has been made by the previous impact). This increases the penetration rate.
Further, in the above description nothing has been mentioned about impulse frequency. Normally, as high as possible an impulse frequency is desired in order to utilize the drilling rig resources to a maximum. The above regulation, however may of course be combined with regulation of impulse frequency, this may be particularly interesting during collaring and when there are high demands on straightness on the whole. | The present invention relates to a method for controlling a rock drilling process, in which an impulse-generating device comprising an impact element transmits a shock wave to a tool connected to the impulse-generating device, whereby a portion of the energy of the shock wave is transmitted to the rock by means of the tool and a portion of the energy of the shock wave is reflected and brought back to the impulse-generating device as reflected energy. The method comprises steps of generating at least one parameter value representing the reflected energy, and regulating the interaction of said impact element with said tool at least partially based on said value or values to control the rise time and/or length of said shock wave. The invention also relates to a regulation device, an impulse-generating device and a drilling rig. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national entry of PCT/CA2008/000900 filed May 14, 2008, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/929,389 filed Jun. 25, 2007, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to biotechnology, in particular to gene expression systems in Escherichia coli.
BACKGROUND OF THE INVENTION
New hosts and expression vectors for the production of industrially important recombinant protein are continuously being developed for the purpose of increasing production yields and simplifying down stream processes such as single-step purification using affinity tag systems. Though many expression hosts are available, Escherichia coli continues to remain one of the most frequently employed host for the mass production of various useful recombinant proteins or peptides, and many promoters such as P lac , P trp , P tac , λP L , P T7 and P BAD are commonly utilized for the construction of expression vectors (Baneyx, 1999). Among these, lacUV5, tac and combined system of P T7 with lacUV5 are widely used, because the expression can easily be regulated by varying the concentration of the inducer isopropyl-beta-D-thiogalactopyranoside (IPTG, Schein and Noteborn, 1988). However, the use of IPTG precludes the use of these expression systems in pilot scale production of recombinant proteins, mainly due to the high cost and potential toxicity of IPTG (Figge et al., 1988, Kosinski et al., 1992, Bhandari and Gowrishankar, 1997, Leigh et al., 1998, Yogender et al., 2001, Wang et al., 2004). Other promoters called λPL and λPR are generally induced by a temperature shift, which can have an adverse effect on the protein folding and reduce the final yield of the product (Remaut et al., 1981).
It is known that the expression of a homologous or heterologous gene may be enhanced by replacing a promoter sequence naturally associated with that gene with a strong promoter sequence, which results in an enhanced expression of the gene at the transcriptional level (Studier and Moffatt, 1986, Gupta et al., 1999). However, ideal expression system should provide high-level expression under induced conditions and no basal expression under repressed conditions, yet should show adjustability to intermediate levels over a wide range of inducer concentrations (Rossi and Blau, 1998, Keyes and Mills, 2003). To date, only a limited number of expression system have been explored for the industrial recombinant protein production. The field of modern biotechnology is competitive and is attracting considerable interest from industrial partners outside the traditional fermentation industry, interested in the industrial applications of enzymes and other proteins. Therefore, it is not surprising that several of these partners have started to explore the possibility of using new expression systems as alternatives to those covered by patents and patent application (Staub, et al., 2002). It is in the interest of the biotechnological industry to seek new expression systems, which are easily accessible, cheap and simple to regulate. Especially, systems that are independent of the host strain, medium, and growth rate are needed. Therefore, the aim of our work was to develop a next generation of a novel expression system which fulfills most of factors to be an ideal expression system of E. coli.
The ability to produce high biomass densities of E. coli in fermentors (Lee, 1996, Thiry and Cingolani, 2002), combined with the newly adopted regulatory genetic elements obtained from Pseudomonas putida F1 (Choi et al., 2006), renders this novel expression system extremely interesting as a potential tool for the production of recombinant proteins and of industrially important bulk chemicals. The applications of such an expression system is equally comprehensive encompassing the: (1) production of research reagents to support R&D in biotechnology and in various biological fields including proteomics; (2) production of commercial recombinant proteins (enzymes and bio-active peptides); (3) production of various biomaterials including proteinaceous and non-proteinaceous bio intermediates; (4) as a tool for metabolic engineering work.
International Patent Publication WO 2007/022623 published Mar. 1, 2007 discloses the use of regulating elements from Pseudomonas putida to enable inducible regulation of gene expression in Methylobacterium extorquens . International Patent Publication WO 2006/037215 published Apr. 13, 2006 discloses the use of cumate inducible regulating elements to enable inducible regulation of gene expression in Chinese Hamster Ovary (CHO) cells. In both of these cases, the repressor and its weak promoter are incorporated into the genome of the host cell separately from the plasmid containing the gene of interest, operator and promoter for the operator.
There is a need for a tightly regulated, inducible gene expression system in Escherichia coli.
SUMMARY OF THE INVENTION
A novel inducible expression system, designated pNEW, is disclosed carrying a synthetic operator of Pseudomonas putida and expression profiles of nucleic acid molecules of interest. The expression system comprises an operator and repressor complex that is activated by cumate and like inducers, leading to regulated gene expression over several orders of magnitude.
Thus, there is provided an expression system for transforming E. coli with a nucleic acid molecule of interest, the vector comprising: an operator sequence of a cmt operon operatively linked to a promoter for the operator; and, a repressor sequence from a cym operon operatively linked to a promoter for the repressor.
The expression system may further comprise the nucleic acid molecule of interest, which may be, for example, an antisense inhibitor of gene expression, a nucleic acid coding for a protein, or any other nucleic acid molecule for which expression is desired in E. coli . Preferably, the nucleic acid molecule encodes a protein.
There is further provided an E. coli host cell transformed with an expression system of the present invention.
There is further provided a method of producing a protein comprising transforming an E. coli host cell with an expression system of the present, the nucleic acid molecule of the expression system coding for a protein; and, culturing the host cell in a culture medium under conditions in which the nucleic acid molecule will express the protein.
Expression of the nucleic acid molecule of interest in E. coli is activated by addition of an inducer. The inducer may comprise, for example, p-cumate, butyrate, dimethyl-p-aminobenzoic acid (DM PABA), trimethyl cumate, ethylbenzoate, a salt thereof or a combination thereof. p-Cumate is preferred.
A tightly regulated gene expression system in Escherichia coli of the present invention may include regulatory elements of the Pseudomonas putida F1 cym and cmt operons to control target gene expression at the transcriptional level by using p-cumate as an inducer in any type of E. coli strains. This expression system includes a specific expression vector, pNEW, that may contain a partial T5 phage promoter combined with the P1 synthetic operator and the cymR repressor protein encoding gene designed to express constitutively in the host strain. The induction of transcription relies on the addition of the exogenous inducer, e.g. p-cumate, which is non-toxic, inexpensive and easy to use. High concentrations of recombinant protein accumulation are observed (generally, 40-85% of total cellular protein), which is a more than 10,000-fold induction in stably transformed cells on average. Both high induction of transcription and extremely low basal expression allowed extremely high induction levels, with a degree of control that is far superior to other currently available E. coli expression systems, for example the T7 system with IPTG inducer. The results indicated that the present pNEW expression system is a highly efficient system for the potential production of recombinant proteins in any type of E. coli strains, especially when cloned proteins have growth inhibitory or toxic effects to host cell metabolism.
Further features of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of the mechanism of action of the cumate-switchable expression system;
FIG. 2 is a physical map of plasmid pNEW-gfp designed for regulated expression of heterologous gene in E. coli;
FIGS. 3A and 3B depict culture plate assays (A) and liquid culture assays (B) showing regulated expression of GFP in various E. coli strains as lost;
FIG. 4 depicts a comparison between T7 system and cumate system for green fluorescent protein (GFP) expression in plates containing IPTG (1 mM) and cumate (0.12 mM) as inducer, respectively;
FIG. 5 is a physical map of pNEW-PhaC1, 2 and microscopic observation of the recombinant strains upon cumate induction (0.12 mM);
FIG. 6 depicts culture plates showing heterologous gene expression of esterase in E. coli Top10 using cumate expression system of the present invention without and with cumate as inducer;
FIG. 7 depicts an expression profile of recombinant β-galactosidase on SDS-PAGE;
FIG. 8 depicts SDS-PAGE profile of soluble and insoluble fractions in the production of synthetic thrombin inhibitor peptide using carrier protein (SFC120) to form fusion peptide in E. coli;
FIGS. 9A-9F depict fermenters at various stages of cell culture for recombinant E. coli cultures induced with IPTG or cumate; and,
FIGS. 10A and 10B are graphs depicting time course green fluorescent protein (GFP) yield comparisons between T7 system and cumate system at concentrations of 100 μm inducer (A) and 1000 μm inducer (B).
DESCRIPTION OF PREFERRED EMBODIMENTS
Materials and Methods
Bacterial strains and growth conditions. The bacterial strains and plasmids used in this study are listed in Table 1. E. coli strains DH5α, S17-1 λ/pir, K12, Top10, and BL21(DE3), were used for the heterologous gene expression host. Especially, E. coli strain Top10 was used for cloning and propagation of recombinant DNA and some target protein expression host. E. coli was cultured in Luria Bertani broth (LB) at 37° C. and media were solidified by 1.8% agar (Difco) when appropriate. Antibiotics were used at the following concentrations (in μg/ml): ampicillin, 100; kanamycin (Km), 50; tetracyclin (Tc), 35.
Benchtop Fermentations. Batch fermentation experiments were carried out in a 14-I bioreactor (BioFlo 110, New Brunswick Scientific, Edison, N.J. USA) to compare GFP production yield between T7 expression system and cumate system. For the batch culture, pre-cultures were used to inoculate the bioreactor filled with 5 l of medium A (Yoon et al, 2003) and initial O.D. was adjusted to 0.1 for both expression systems. The cultures induced with IPTG for T7 system and cumate for cumate system when O.D. reached at 38 to 42. For cultures carried out in bioreactors, pH and dissolved oxygen were controlled at 7 and 25%, respectively.
Construction of expression vector. The operator sequence of cmt operon from P. putida F1 was introduced downstream of the phage T5 promoter (Bujard, et al. 1987) by polymerase chain reaction (PCR). The pNEW regulative expression vector was obtained in several steps: first, the P T5 synthetic operator sequence (OP)-GFP was PCR-amplified from pCUM-gfp (Choi, et al. 2006) using primers T5-OP-F-SAC (5′-C GA GCT C AA ATC ATA AAA AAT TTA TTT GCT TTG TGA GCG GAT AAC AAT TAT AAT AGA TTC AAC AAA CAG ACA ATC TGG TCT GTT TGT ATT AT-3′) (SEQ ID NO: 1) (the SacI site is underlined, partial T5 promoter is boxed and operator site is in bold) and GFP-SPH-R (5′-C GC ATG C TC AGT TGT ACA GTT CAT CCA TGC C-3′) (SEQ ID NO: 2) (the SphI site is underlined). The 954 bp PCR fragment containing P T5 -operator-gfp was cloned into pCR2.1 to create pCR-T5OP. Next, a 954 bp SacI-SphI fragment from pCR-T5OP was then ligated between the SacI-SphI sites of pET36 (Novagen) to form pNEW-pre.
Subsequently, the P km -cymR was amplified by PCR from pBRI-cymR1 (Choi et al. 2006) using primers PKM-CYM-MLU-F (5′-C AC GCG T CC GGA ATT GCC AGC TGG GGC GCC CTC TGG TAA GGT TGG GAA GCC CTG CAA AGT AAA CTG GAT GGC TTT CTT GCC GCC AAG GAT CTG ATG GCG CAG GGG ATC AAG ATC TGA TCA AGA GAC AGG ATG AGG ATC GTT TCG CAA GAT GGT GAT CAT GAG TCC AAA GAG AAG AAC ACA G-3′) (SEQ ID NO: 3) (the MluI site is underlined) and CYM-PCI-R (5′-C AC ATG T CT AGC GCT TGA ATT TCG CGT ACC GCT CTC-3′) (SEQ ID NO: 4) (the PciI site is underlined). The PCR product containing P km -cymR was then cloned into pCR2.1 to create pCR-Pkm-cymR, and MluI-PciI fragment from pCR-P km -cymR was ligated to the pNEW-pre digested by the same enzymes to generate pNEW-gfp.
Other reporter gene cloning. In order to validate heterologous protein production using newly developed cumate switch system (pNEW system), we have tested GFP, polyhydroxyalkanoic acids synthetase (PhaC1 and PhaC2), lactase, esterase and synthetic thrombin inhibitory peptides. To clone PhaC1 and PhaC2 genes from Pseudomonas fluorescens GK13, the genomic DNA was isolated, and the chromosome was subjected to PCR using the primers PhaC1FNhe (5′-C GC TAG C AT GAG CAA CAA GAA CAA TGA AGA CCT GCA GCG C-3′) (SEQ ID NO: 5) (the NheI site is underlined), PhaC1RMFE (5′-G CA ATT G TC AAC GTT CGT GGA CAT AGG TCC CTG G-3′) (SEQ ID NO: 6) (the MfeI site is underlined), for PhaC1 and PhaC2FNhe (5′-C GC TAG C AT GCG AGA GM ACA GGT GTC GGG AGC CTT G-3′) (SEQ ID NO: 7) (the NheI site is underlined), PhaC2RCla (5′-G CA ATT G TC AGC GCA CGT GCA CGT AGG TGC CGG G-3′) (SEQ ID NO: 8) (the ClaI site is underlined) for PhaC2 to obtain 1680-bp and 1683-bp PCR products, respectively. The PCR products were digested with NheI and MfeI (PhaC1) and with NheI and ClaI (PhaC2), and cloned into pNEW-gfp digested with same restriction enzymes to generate pNEW-phaC1 and pNEW-phaC2, respectively. The 2,100 bp fragment carrying the lactase gene (bgl) from Bifidobacterium infantis was amplified from pEBIG4 (Hung et al. 2001) using primers BGL-F-Nhe (5′-C GC TAG C AT GGA ACA TAG AGC GTT CAA GTG G-3′) (SEQ ID NO: 9) (the NheI site is underlined) and BGL-R-Sac (5′-C GA GCT C TT ACA GCT TGA CGA CGA GTA CGC CG-3′) (SEQ ID NO: 10) (the SacI site is underlined). For the amplification of esterase gene (1,800 bp, estI) from Lactobacillus casei , pCESTa (Choi, et al. 2004) was used as a template with primers EST-F-Nhe (5′-C GC TAG C AT GGA TCA ATC TAA AAC AAA TCA AAA C-3′) (SEQ ID NO: 11) (the NheI site is underlined) and EST-R-Sac (5′-C GA GCT C TT ATT TAT TTG TAA TAC CGT CTG C-3′) (SEQ ID NO: 12) (the SacI site is underlined). These NheI-SacI fragments of bgl and est were then replaced with a gfp gene in the pNEW-gfp to form pNEW-bgl and pNEW-est, respectively. To amplify synthetic thrombin inhibitor peptide encoding gene with carrier protein (SFC120), pTSN-6A (Osborne et al., 2003) was used as a template with primers MFH-FNhe (5′-C GC TAG C AT GGC AAC TTC AAC TAA AAA ATT AC-3′) (SEQ ID NO: 13) (the NheI site is underlined) and MFH-RMfe (5′-G CA ATT G TT ATT GTA AAT ACT CTT CTG GAA TCG G-3′) (SEQ ID NO: 14) (the MfeI site is underlined). The PCR product was digested with NheI and MfeI and the 456 bp fragment encoding carrier protein with synthetic thrombin inhibitor peptide was cloned into pNEW-gfp digested with same restriction enzymes to generate pNEW-mfh.
Host cell transformation and gene expression. pNEW vectors harbouring different genes of interest were transformed into various E. coli cells by chemical or electroporation methods (Sambrook and Russell, 2000). The transformed cells were grown at 37° C. in LB medium, and expression of genes under developed system was induced with 20 μg/ml cumate or as indicated.
Detection of gene expression. Detection of GFP was carried out by fluorescence microscopy, and quantified by using a SPECTRAFluor Plus (TECAN Austria Gmbh, Grodïg, Austria) under excitation and emission wavelengths of 485 and 508 nm, respectively. Concentration of GFP was calculated based on a linear relationship between concentration and fluorescence units determined using solutions of purified GFP (Qbiogene). The biomass (X) was determined by cell dry weight measurement of the samples (Moisture Analyzer MA 30, Sartorius).
Esterase activity was determined by a spectrophotometric method using paranitrophenyl caprylate (pNP-caprylate) as substrate. The rate of hydrolysis of pNP-caprylate at 37° C. was measured in 50 mM sodium phosphate buffer (pH 7.0) according to the method described previously (Kademi et al., 1999). One unit of activity was defined as the amount of enzyme that liberated 1 μmol of p-nitrophenol per min under the given assay conditions. The β-galactosidase activity was measured with o-nitrophenol-β-D-galactoside (ONPG) as a substrate and one unit of activity was defined as the amount of enzyme that liberated 1 μmol of o-nitrophenol per min (Sambrook and Russel, 2000). The protein concentration was estimated by the method of Bradford (Bradford, 1976) using the Bio-Rad protein assay kit with bovine serum albumin as a standard.
Western blotting. Integrative expression of repressor protein (cymR) was determined by western blotting using standard protocol. cymR was detected with rabbit anti-bCymR #422 antibody (0.1 g ml −1 ) and a goat anti-rabbit IgG (H+L) HRP conjugate (0.1 μg ml −1 ; Pierce cat #31460, West Grove, Pa.). Cells were lysed in SDS-PAGE sample buffer.
TABLE 1 Strains and Plasmids Strain or plasmid Description Reference or Source Pseudomonas strains fluorescens GK13 Source of PhaC1 and C2 genes Jaeger, et al., 1995 putida F1 Origin of cymR gene and operator Eaton, 1997 sequence in the cmt operon, respectively. E. coli strains S-17Iλ pir Tp r Sm r , recA thi pro hsdR M + RP4: 2- De Lorenzo et al., 1993 Tc:Mu:Km Tn7 λpir Top10 F− mcrA Δ(mrr-hsdRMS-mcrBC) Grant et al., 1990 φ80lacZΔM15 ΔlacX74 recA1 araD139 Δ(araleu) 7697 ga/U ga/K rpsL (StrR) endA1 nupG BL21(DE3)PLyS F − ompT gal dcm Ion hsdS B (r B − m B − ) Novagen λ(DE3) pLysS(cm R ) DH5α endA1 recA1 hsdR17(r K − m K + ) Hanahan, 1985 supE44 thi-1 gyrA96 φ80dlaCZΔM15 Δ(lacZYA-argF)U169 λ − K-12 F − λ − rph-1 INV(rrnD, rrnE) Jer sen, 1993 Plasmids pBRI-cymR1 pBRI80 plasmid containing one copy Choi, et al., 2006 of cymR expression cassette pNEW-pre pET36 plasmid containing P km -cymR This study expression cassettes, lack of T7 promoter and lac operator pCR2.1-TOPO PCR cloning vector Invitrogen Inc. pCR-P km -cymR pCR2.1-TOPO plasmid containing This study P km -cymR PCR-T5OP pCR2.1-TOPO plasmid containing This study P T5 -operator pCR-bgl pCR2.1-TOPO plasmid containing bgl This study pCR-est pCR2.1-TOPO plasmid containing estl This study pCR-PhaC1 or C2 pCR2.1-TOPO plasmid containing This study phaC1 or C2 pNEW Newly constructed regulative This study expression vector pNEW-mfh pNEW vector containing mfh fusion This study peptide expression cassette pNEW-phaC1 or 2 pNEW vector containing PhaC1 or C2 This study expression cassette pNEW-bgl pNEW vector containing lactase This study expression cassette pNEW-est pNEW vector containing esterase This study expression cassette pNEW-gfp pNEW vector containing gfp This study expression cassette pET36(b) T7 based expression vector Novagen pCESTa Esterase gene source Choi et al., 2004 pEBIG4 Lactase gene source Hung et al., 2001 pTSN-6A Source of fusion peptide mfh Csborne et al., 2003
Results:
The basic mechanism of the cumate regulated gene expression in E. coli is depicted in FIG. 1 . FIG. 1 shows a schematic diagram of the mechanism of action of the cumate-switchable expression system. (a) In the absence of a cumate, inducer, the repressor protein (cymR) is bound to the operator site upstream of the reporter gene or gene of interest, and block the transcription. (b) The presence of the cumate is necessary for transcription of gene of interest. The addition of cumate rapidly alters the inactive conformation (operator-cymR), facilitating the formation of the cymR-cumate complex and detached the cymR from the operator, and activating transcription of the downstream reporter gene. The cymR-cumate complex is unable to bind to operator site.
Development of regulated expression vector pNEW-gfp. To develop a new generation of tightly regulated E. coli expression vectors, we applied T5 promoter-cumate operator carrying vector in cooperation with cymR repressor encoding gene in the same plasmid ( FIG. 2 ).
Validation of the developed expression system in E. coli hosts. Since T5 promoter is recognized by E. coli RNA polymerase, developed expression vectors can be applied to any type of E. coli strain, as shown in FIG. 3 . FIG. 3A depicts plate assays, while FIG. 3B depicts liquid culture assays in culture tubes. In FIG. 3 , the regulated expression of GFP (green fluorescent protein) in various E. coli strains as host is depicted. In FIG. 3B , tube #1 contains E. coli DH5α, tube #2 contains E. coli S17-1 λ/pir, tube #3 contains E. coli K12, tube #4 contains E. coli Top10, and tube #5 contains E. coli BL21(DE3).
Heterologous gene expression. The performance or the cumate-regulated expression system was examined with various proteins as reporter.
Example 1
Green Fluorescent Protein (GFP) Expression
FIG. 4 depicts a comparison between T7 system and cumate system for GFP expression in plates containing IPTG (1 mM) and cumate (0.12 mM) as inducer, respectively. It is evident from FIG. 4 that the cumate systems dramatically outperforms the IPTG system for expressing GFP in host cells.
Example 2
Expression of Polyhydroxyalkanoic Acids Synthetase (PhaC1 and PhaC2) Genes in E. coli Top10
Genes encoding PhaC1 and C2 were amplified from Pseudomonas fluorescens GK13 and cloned into E. coli Top10 using cumate expression system. Amplified genes were successfully expressed in E. coli Top 10, and recombinant E. coli Top 10 produced PHB-like granules as shown in FIG. 5 . FIG. 5 depicts a physical map of pNEW-PhaC1, 2 and microscopic observation of the recombinant strains upon cumate induction (0.12 mM).
Example 3
Production of Esterase Using Cumate Expression System in E. coli
FIG. 6 depicts heterologous gene expression of esterase in E. coli Top10 using the cumate expression system of the present invention. Recombinant strain was streaked on the plate containing 1% (v/v) tributyrin as a substrate of esterase without and with cumate (0.12 mM) as an inducer, respectively. It is evident from FIG. 6 that the cumate expression system was successful at heterologous gene expression of esterase.
Example 4
Production of Beta-Galactosidase Using Cumate Expression System in E. coli Top 10
FIG. 7 depicts the expression profile of recombinant β-galactosidase on SDS-PAGE. Lane M is protein standard marker. Lane 1 is the first eluted sample as purified β-galactosidase using Ni-NTA mini affinity column. Lane 2 is the second eluted sample from the same column as Lane 1. Lanes 3 and 4 are crude protein samples 1 and 3 hr after induction, respectively. It is evident from FIG. 7 that β-galactosidase has been successfully expressed in E. coli Top 10 by the cumate expression system of the present invention.
Example 5
Production of Synthetic Thrombin Inhibitor Peptide Using Carrier Protein (SFC120) to Form Fusion Peptide in E. coli
FIG. 8 depicts the SDS-PAGE profile of soluble and insoluble fractions. Fusion peptide was produced in the form of inclusion body as expected, and the yield of fusion peptide reached about 85% of total cellular protein.
Example 6
Bench Top Fermentation
FIG. 9A is a photograph of a fermenter with sterilized E. coli cultivation medium to show the original color of the cultivation medium. The original color is a gray/brown.
FIG. 9B is a photograph of two fermenters side-by-side, each fermenter containing cultivation medium and E. coli cells transformed with GFP. The fermenter on the left has the T7 expression system with no IPTG added yet. The fermenter in the right has the cumate expression system of the present invention with no cumate added yet. These photographs depict the cultures prior to induction by IPTG or cumate. The color of the cultures in each fermenter is the same, a light yellow/brown.
FIG. 9C is a photograph of the fermenters depicted in FIG. 9B at a time 45 minutes post induction with 100 μm IPTG (T7 system) and 100 μm cumate (cumate system). GFP yields are similar at this stage. The GFP yield for the IPTG induced system is 27 mg/g. The GFP yield for the cumate induced system is 30 mg/g. The color is a brighter yellow/green than in FIG. 9B .
FIG. 9D is a photograph of the fermenters depicted in FIG. 9B at a time 1 hour post induction with 100 μm IPTG (T7 system) and 100 μm cumate (cumate system). GFP yields remain similar. The GFP yield for the IPTG induced system is 37 mg/g. The GFP yield for the cumate induced system is 38 mg/g. The color is a brighter yellow/green than in FIG. 9C .
FIG. 9E is a photograph of the fermenters depicted in FIG. 9B at a time 2 hours post induction with 100 μm IPTG (T7 system) and 100 μm cumate (cumate system). At this point, GFP yields begin to differ that the cumate induced culture showing better yield. The GFP yield for the IPTG induced system is 74 mg/g. The GFP yield for the cumate induced system is 84 mg/g. The color is green and brighter than the colors in FIG. 9C . The medium in the fermenter with the cumate system is brighter green than the medium in the T7 system.
FIG. 9F is a photograph of the fermenters depicted in FIG. 9B at a time 3 hours post induction with 100 μm IPTG (T7 system) and 100 μm cumate (cumate system). GFP yield of the cumate induced culture is markedly greater than the IPTG induced culture. The GFP yield for the IPTG induced system is 90 mg/g. The GFP yield for the cumate induced system is 123 mg/g. The color is even brighter green than in FIG. 9E and the cumate induced system is brighter green than the IPTG induced system.
FIGS. 10A and 10B are graphs depicting the time course of GFP yield comparing the T7 system to the cumate system at different concentrations of inducers. For FIG. 10A , the concentration of inducer was 100 μm, while for FIG. 10B the concentration of inducer was 1000 μm. After 4 hours post induction, the IPTG induced GFP expression reached its maximum, whereas the cumate induced GFP expression continues even after 8 hours post induction (see also Tables 2 & 3). A similar phenomenon occurs when the cultures are induced with 1000 μM IPTG or cumate. The cumate induced GFP yield is more than double that of the IPTG induced culture. Furthermore, in cultures induced with 100 or 1000 μM cumate, expression of the GFP continues even though the culture has reached the stationary phase of growth. In other words, it is a form of resting cell GFP expression. The cumate induced culture remains healthy, no lysis occurred and no foaming was observed in contrast to the IPTG induced culture which after 8 hours post induction quickly began to lyse and GFP was released onto the culture medium.
TABLE 2
Inducer
conc.
Induction Time (h)
(μM)
Inducer
1
2
4
5
6
7
8
9
100
Cumate
38
84
123
164
176
165
193
222
IPTG
37
74
90
96
85
58
68
67
1000
Cumate
36
71
110
141
149
155
249
289
IPTG
37
60
83
103
118
135
145
—
Table 2 shows results for the specific yield of GFP (mg/g x) up to 8 hours of induction for T7 and cumate expression systems in E. coli BL21(DE3)pLysS for two inducer concentrations. All results obtained were in defined medium A. The value ‘x’ is dry weight in g/L.
TABLE 3
Inducer conc.
Induction Time (h)
(μM)
Inducer
1
2
4
5
6
7
8
9
100
Cumate
602
644
3002
4719
5443
6194
6977
7838
IPTG
554
1300
1778
2486
2035
1567
1948
2090
1000
Cumate
486
1459
2851
4593
4885
5989
9666
11150
IPTG
606
1191
1966
2464
3340
4238
4079
—
Table 3 shows results for the total yield of GFP (mg/L) up to 8 hours of induction for T7 and cumate expression systems in E. coli BL21(DE3)pLysS for two inducer concentrations. All results obtained were in defined medium A.
REFERENCES
The contents of the entirety of each reference listed herein are incorporated by this reference.
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Jessee, F. R. Bloom, and D. Hanahan. 1990. Differential Plasmid Rescue From Transgenic Mouse DNAs Into Escherichia coli Methylation-Restriction Mutants. Proc. Natl. Acad. Sci. USA 87:4645-4649. Gupta, J. C., M. Jaisani, G. Pandey, and K. J. Mukherjee. 1999. Enhancing recombinant protein yields in Escherichia coli using the T7 system under the control of heat inducible λP L promoter. J. Biotechnol. 68:125-134. Hanahan, D. 1985. in DNA Cloning: A Practical Approach (Glover, D. M., ed.), Vol. 1, p. 109, IRL Press, McLean, Va. Hung, M. N., Z. Xia, N. T. Hu, and B. H. Lee. 2001. Molecular and biochemical analysis of two β-galactosidases from Bifidobacterium infantis HL96. Appl. Environ. Microbiol. 67: 4256-4263. Jaeger, K. E., A. Steinbüchel, and D. Jendrossek. 1995. Substrate specificities of bacterial polyhydroxyalkanoate depolymerases and lipases: bacterial lipases hydrolyze poly(omega-hydroxyalkanoates). Appl. Environ. Microbiol. 61:3113-3118. Jensen, K. F. 1993. 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Miguez, Carlos B., et al., International Patent Publication WO 2007/022623 published Mar. 1, 2007. Yu, Yan, et al., International Patent Publication WO 2006/037215 published Apr. 13, 2006.
Other advantages that are inherent to the structure are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims. | An expression system for transforming E coll with a nucleic acid molecule of interest has an operator sequence of a cmt operon operatively linked to a promoter for the operator, and, a repressor sequence from a cym operon operatively linked to a promoter for the repressor. The expression system may have a nucleic acid molecule of interest, for example, a nucleic acid molecule that encodes a protein. Any type of E coll host cells may be transformed with the expression system. A method of producing a protein involves transforming an E coll host cell with the expression system having a nucleic acid molecule that codes for a protein, and, culturing the host cell in a culture medium under conditions in which the nucleic acid molecule will express the protein. | 2 |
REFERENCE TO PRIOR APPLICATION
This application is a continuation-in-part of prior application Ser. No. 10/750,073, filed Dec. 31, 2003.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for fabricating an array pH sensor and a readout circuit of such array pH sensor, and more particularly to a method for fabricating an array pH sensor and a readout circuit of such array pH sensor by utilizing an extended gate ion sensitive field effect transistor (EGFET). The structure of this EGFET in combination with fabrication of biosensors and its readout circuit are produced as an integrated biosensor system. Therefore, the present invention can be applied to some applications such as medical detection, circuit design, semiconductor component fabrication, etc.
2. Description of the Prior Art
Conventional glass electrodes have many advantages such as high linearity, excellent ion selectivity and good stability. However, due to the relatively large volume, high cost and long reaction time, the technologies for fabricating these ion selective glass electrodes have been developed toward the technologies of established silicon semiconductor integrated circuits so as to fabricate field effect sensors. Thus, the conventional glass electrodes are replaced.
In 1970, Piet Bergveld P. in “Development of an ion-sensitive solid-state device for neurophysiological measurements”, IEEE Transaction Biomedical Engineering, BME-17, pp. 70-71, 1970, has firstly removed the metal portion from the gate electrode of a general metal oxide semiconductor field effect transistor (MOSFET). Then, the device is dipped into an aqueous solution. With the oxide layer of the sensor's gate electrode serving as an insulating ion sensing membrane, when the transistor is in contact with solutions with different pH values, different potential changes will occur at an interface between the transistor and the solution, such that the current passing through its channel is changed accordingly. In such manner, the pH values or concentrations of other ions can be measured. Thus, this device is referred by Piet Bergveld as a field effect ion sensor.
In 1970's, the studies and the applications of the field effect ion sensors were still under exploration. D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 1, pp. 57-62, 1990. However, in 1980's, the studies of the field effect ion sensors were promoted to a new level. The studies about those basic principle researches, crucial technologies or practical applications have been greatly progressed. For example, based on the structure of the ion sensitive field effect transistor, the types of field effect transistor fabricated for measuring a variety of ions and chemical substances had more than 20 or 30. In the aspects of miniaturization, module or multifunction, the component has been greatly developed. See also D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 6, pp. 52-60, 1991; D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 1, pp. 49-56, 1992; and D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 2, pp. 51-55, 1992.
The ion sensitive field effect transistor have been dominated all over the world with several decades of development, because they have the following special features, when compared with the conventional ion selective electrodes. They can be miniaturized to perform microanalysis of solutions. They have high input impedance but low output resistivity. D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 1, pp. 57-62, 1990.
Due to the above advantages, many research institutes have been interested in researching the ion sensitive field effect transistor since the past twenty years. Some important researches associated such sensors can be depicted as follows:
(1) miniaturization of reference electrodes (D. Yu, G. H. Wang, and S. X. Wu, Chemical Sensors, J. Sensor & Transducer Tech., No. 3, pp. 53-57, 1991);
(2) differential field effect ion sensor (Gui-Hua Wang, Dun Yu and Yao-Lin Wang, “ISFET temperature characteristics”, Sensors and Actuators, 11, pp. 221-237, 1987);
(3) field effect ion sensors having immobile enzyme for detecting function information of organisms, for example glucose concentration, oxygen content in blood, etc. (A. Saito, S. Miyamoto, J. Kimura, T. Kuriyama, “ISFET glucose sensor for undiluted serum sample measurement”, Sensors and Actuators B, 5, pp. 237-239, 1992);
(4) exploration of theories, for example adsorptive bonding models;
(5) researches on packaging materials (R. E. G. van Hal, “Characterization and testing of polymer-oxide adhesion to improve the packaging reliability of ISFETs”, Sensors and Actuators B, 23, pp. 17-26, 1995);
(6) integration of measurement systems and sensors (B. H. Van Der Schoot, H. H. Van Den Vlekkert, N. F. De Rooij, A Van Den Berg and A. Grisel, “A flow injection analysis system with glass-bonded ISFETs for the simultaneous detection of calcium and potassium ion and pH”, Sensors and Actuators B, 4, pp. 239-241, 1991); and
(7) researches on simulation of field effect ion sensors (M. Grattarola, “Modeling H+-sensitive FETs with spice”, IEEE Transactions on Electron Devices, Vol. 39, NO. 4, pp. 813-819, April 1992).
The extended gate ion sensitive field effect transistor (EGFET) is one of an ion sensitive field effect transistor and firstly introduced by J. Spiegel (J. Van Der Spiegel, I. Lauks, P. Chan, and D. Babic, “The extended gate chemical sensitive field effect transistor as multi-species microprobe”, Sensors and Actuators, 4, pp. 291-298, 1983). In contrast to the traditional ion sensitive field effect transistor, the extended gate field effect transistor retains the original metal gate of the metal-insulation layer-semiconductor transistor and the sensitive membrane is deposited on the other end extended from the metal gate. Comparing with the traditional ion sensitive field effect transistor, the extended gate ion sensitive field effect transistor has a lot of advantages, for example (1) the conducting line provides electrostatic protection for the sensor; (2) the transistor of the sensor can prevent direct contact with the aqueous solution; and (3) the influence of light on the sensor is reduced.
The first publication associated to the EGFET is disclosed in 1983 (J. Van Der Spiegel, I. Lauks, P. Chan, and D. Babic, “The extended gate chemical sensitive field effect transistor as multi-species microprobe”, Sensors and Actuators, 4, pp. 291-298, 1983). However, the papers published on the international journals are insufficient. After 1986, few researchers published the papers associated to EGFET. Until 1988, our research group proposed an improved EGFET structure, which is divided into two portions, i.e. a sensing portion of SnO 2 /Al/SiO 2 and a readout circuit portion. L. L. Chi, J. C. Chou, W. Y. Chung, T. P. Sun and S. K. Hsiung, “Study on extended gate field effect transistor with tin oxide sensing membrane”, Material Chemistry and Physics, 63 (2000) 19-23.
[14] L. L. Chi, L. T. Yin, J. C. Chou, W. Y. Chung, T. P. Sun, K. P. Hsiung and S. K. Hsiung, “Study on separative structure of EnFET to detect acetylcholine”, Sensors and Actuators B, 71, pp. 68-72, 2000.
The patents related to the ISFET are listed hereinafter.
U.S. Patent Publication No. 5,833,824, inventor: Barry W. Benton, date of patent: Nov. 10, 1998, entitled “Dorsal substrate guarded ISFET sensor” disclosed an ion sensitive field effect transistor (ISFET) sensor for sensing ion activity of a solution, wherein the sensor includes a substrate and an ion sensitive field effect transistor. The substrate has a front surface exposed to the solution, a back surface opposite to the front surface and an aperture extending between the front and back surfaces. This patent connects the back surface of the substrate to the front-end sensor through the aperture surface such that only the back surface region is exposed to the solution.
In this study, the word “extended ISFET” and “extended-gate field effect transistor (EGFET)” indicates the same thing. The chemical sensors referenced in this paper were based on the ion sensitive field effect transistors (ISFETs), which were first reported by P. Bergveld [1]. However, the structure of the sensor in the present invention were based on the extended-gate field effect transistor (EGFET), which was first introduced by Van Der Spiegel et al. [2]. The extended-gate filed effect transistor differs from the ISFET in that it was separated into two parts; one was a sensing structure containing a sensitive membrane; the other was a MOSFET structure. The configuration of the extended-gate field effect transistor has several advantages: firstly, it has a lower cost than traditional ion-sensitive field effect transistor; secondly, the transistor could be tested and characterized without the need to contact solutions; thirdly, the device could avoid the influences of temperature and light. The conditions of the disposable biosensor were mass-production and low-cost. Therefore, the extended-gate configuration is useful to develop disposable biosensors for clinical applications.
U.S. Patent Publication No. 6,353,323, inventor: Fuggle; Graham Anthony, Date of patent: Mar. 5, 2002, entitled “Ion concentration and pH measurement” discloses an apparatus and a measuring method for processing the front-end sensor. The front-end ion sensor comprises an ion selective electrode, a reference electrode and an ion sensitive field effect transistor, all of which are immersed in the solution. The sensor is connected to the pre-amplifier, and the reference electrode is connected to the readout circuit so as to separate the sensor from the reference electrode. Accordingly, plural sensor can use a common reference electrode.
U.S. Patent Publication No. 5,350,701, inventor: Jaffrezic-Renault; Nicole; Chovelon; Jean-Marc; Perrot; Hubert; Le Perchec; Pierre; Chevalier; Yves, Date of patent: Sep. 27, 1999, entitled “Process for producing a surface gate of an integrated electrochemical sensor, consisting of a field-effect transistor sensitive to alkaline-earth species and sensor obtained” discloses an improved production process for treating a surface gate comprising a selective membrane as an integrated chemical sensor. A layer of chemically synthesized phosphonate-based is deposited on the gate region of the field-effect ion sensor, and thus the sensing membrane is reactive to alkaline-earth species. This sensor is effective as a detector for measuring concentration of alkaline-earth species, in particular the calcium ion.
U.S. Patent Publication No. 5,319,226, inventor: Sohn; Byung K.; Kwon; Dae H., Date of patent: Jun. 7, 1994, entitled “Method of fabricating an ion sensitive field effect transistor with a Ta 2 O 5 hydrogen ion sensing membrane” discloses a radio frequency sputtering method for depositing a tantalum oxide film onto a non-conducting silicon nitride film, i.e. onto the gate region of the ion sensor, thereby forming a field-effect ion sensor having the tantalum oxide/silicon nitride/silicon dioxide. The Ta 2 O 5 film has a thickness of from 40×10 −9 to 50×10 −9 m. Then, the resultant film is annealed at an elevated temperature of 375° C. to 450° C. in oxygen gas ambience for about one hour.
U.S. Patent Publication No. 4,657,658, inventor: Sibbald; Alastair, Date of patent: Apr. 14, 1987, entitled “Semiconductor devices” uses a semiconductor integrated circuit for sensing a physico-chemical property of an ambient. The circuit includes a pair of semiconductor devices having a similar geometric and physical structure. Its readout circuits are connected to the same circuit, and the overall structure thereof comprises a metal oxide semiconductor field effect transistor and a field-effect ion sensor so as to construct a differential module system.
U.S. Patent Publication No. 5,922,183, inventor: Rauh; R. David, Date of patent: Jul. 13, 1999, entitled “Metal oxide matrix biosensors” uses a metal oxide-based film as substrate of biological molecules. Such configuration is suitable for developing electrochemical biosensors. The most common metal oxide-based film is a hydrous metal oxide, which can be conductive or semiconductor and have excellent stability against dissolution or irreversible reaction in aqueous and non-aqueous solutions. The metal oxide can be used for both amperometric and potentiometric sensing of enzymes, antibodies, antigens, DNA strands, etc. Iridium oxide is the preferred embodiment of metal oxide film due to the best sensing feature. Furthermore, some other metals, for example Ru, Ti, Pd, Pt, Zr, etc., have similar features and their oxides are very stable against oxidation damage.
The hydrogen ion sensing membrane commonly used on the gate oxide of the field-effect ion sensitive transistor can be selected from silicon dioxide, silicon nitride, tantalum oxide, aluminum oxide, etc., for example. A field-effect ion sensitive transistor with having a hydrogen ion sensing membrane made of tin dioxide is first fabricated in the laboratory. H. K. Liao, J. C. Chou, W. Y. Chung, T. P. Sun and S. K. Hsiung, “Study on the interface trap density of the SiN 4 /SiO 2 gate ISFET”, Proceedings of the 3rd East Asian Conference on Chemical Sensors, Seoul, Korea, November 5-6, pp. 340-400, 1997. The characteristics of this field-effect ion sensitive transistor has an approximate Nernst response in a range of from 56 to 58 mV/pH, a high linear sensitivity, a long-termed stability with low drift, and a low response time of <0.1 second. In addition, the temperature of this sensor can be reduced to zero at an appropriate working current.
Since the ion sensitive field-effect transistor can be used to fabricate array ion sensor array pH sensor by means of the semiconductor fabrication process, the sampling number for detection of the sensor will be increased. The error resulting from one single sensing device can be decreased due to the larger sampling number signals. Thus, when the array sensor is used to measure hydrogen concentration in a human body, the result has a high accuracy and a low error so as to enhance its measuring performance. Furthermore, since the ion sensitive field-effect transistor can be miniaturized, the amount of body fluid to be draw out will be minimized for microanalysis. Due to the rapid reaction time of the ion sensitive field-effect transistor, the array sensor can instantaneously monitor the solution to be measured, thereby reducing measuring time of the tested sample.
Accordingly, the above-described prior art product is not a perfect design and has still many disadvantages to be solved.
In views of the above-described disadvantages resulted from the prior art, the applicant keeps on carving unflaggingly to develop method for fabricating an array pH sensor and a readout circuit device of such array pH sensor according to the present invention through wholehearted experience and research.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method for fabricating an array pH sensor and a readout circuit of such array pH sensor, wherein this fabrication method has a lot of advantages such as simple fabrication equipment, cost effectiveness, mass production, etc. so as to be suitable for fabricating disposable sensors. Therefore, in the field of the array pH sensor, the present invention is highly feasible and applicable.
The method for fabricating an array pH sensor and a readout circuit device of such array pH sensor that can accomplish the above-mentioned objects are implemented by utilizing an extended gate ion sensitive field effect transistor to construct the array pH sensor and related readout circuit. Thus, the present invention is intended to provide an array sensor structure, i.e. a tin dioxide/metal/silicon dioxide multi-layer structure sensor and a tin dioxide/indium tin oxide/glass multi-layer structure sensor, by utilizing such method and device.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings disclose an illustrative embodiment of the present invention which serves to exemplify the various advantages and objects hereof, and are as follows:
FIG. 1 is the cross-sectional view showing a sensing configuration of SnO 2 /Al/SiO 2 /Si;
FIG. 2 is the cross-sectional view showing the sensing configuration of SnO 2 /ITO/glass;
FIG. 3 is a flowchart for fabricating the array pH sensor of the present invention;
FIG. 4 is a schematic view showing the Al layer mask;
FIG. 5 is a schematic view showing the sensing membrane SnO 2 layer mask;
FIG. 6 is the configuration of the array pH sensor of the present invention;
FIG. 7 is the circuit configuration of the pre-amplifier for the array pH sensor;
FIG. 8 shows the output/input ratio of the pre-amplifier;
FIG. 9 shows the circuit configuration of the switch of the control portion;
FIG. 10 shows the circuit configuration of a 2 to 4 decoder of the control portion;
FIG. 11 is a schematic diagram showing the output/input ratio of the circuit combined the pre-amplifier and the control circuit;
FIG. 12 is a schematic diagram showing the output/input ratio of the circuit of the array pH sensor;
FIG. 13 is a schematic diagram showing the readout signal of the array pH sensor;
FIG. 14 is a schematic correction curve of the readout signal of the array pH sensor; and
FIG. 15 is a cross-section view showing the related processes for fabricating a chip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The method for fabricating an array pH sensor and its readout circuit of the present invention are implemented by depositing a non-conductive pH sensing film onto a non-insulated substrate, thereby fabricating a separate array pH sensor and detecting the pH value of the solution by using such array pH sensor. In addition, the readout circuit of this array pH sensor, which includes pre-readout circuit, a multiplexer, a rear end buffer circuit and an amplifier circuit, is fabricated according to the typical processes for making semiconductors. The array pH sensor and the readout circuit can be combined to be a hybrid array pH sensor. The array sensor is advantageous over the single sensing element, because larger sampling signals can decrease error resulting from the sensing element and accuracy thereof is increased. When it is commercialized, the sensor would have high stability and accuracy.
The metal oxide thin-films were prepared by the radio frequency sputtering system (SnO 2 target: 99.9%) at a substrate temperature of 150° C. The sensing part of the sensor was based on the SnO 2 thin film and the SnO 2 thin film was deposited onto the ITO glass by the radio frequency sputtering method. Before depositing the SnO 2 thin film, the ITO glasses were washed by methyl alcohol and deionized (D.I.) water. Finally, the device was bounded and packaged to form the SnO 2 pH electrode by epoxy.
The extended ISFET can be fabricated when the sensing devices and readout circuits are separated. Additionally, based on the previous reports, several types of sensors were fabricated based on a separated structure, including the pH sensor [ 3 , 4 ], the acetyicholine sensor [ 5 ], the glucose sensor [ 6 ] and the pH-sensitive electrode-based urea sensor [ 7 ].
As mentioned above, the extended-gate field effect transistor was separated into two parts; one was a sensing structure containing the sensitive membrane and another was a MOSFET structure. Therefore, the circuit part (MOSFET structure) of the sensing structure could be reused and the sensitive membrane part is served as a deposable device. That is to say, the cost of the extended-gate field effect transistor is lower than the ion sensitive field effect transistors.
The process for fabricating the array sensor of the present invention comprises the following steps:
Step 1: providing a p-type silicon substrate with resistivity of 4˜7 Ohm-cm and silicon dioxide of 1000 angstrom;
Step 2: growing an Al film by using a metallic mask and a vacuum evaporation machine;
Step 3: growing a SnO 2 film by using a metallic mask and a sputter machine; and
Step 4: encapsulating the resulting product with epoxy resin.
The readout circuit portion is fabricated according to a 0.5 micrometer 2P2M n-well process provided by United Microelectronics Corp. (Hsinchu, TW), wherein the related processing conditions are shown in FIG. 14 . The features for each layer of the sensor can be illustrated as follows:
1. The thickness of Cpoly is 0.2 micrometer (μm);
2. The thickness of Gpoly is 0.3 micrometer (μm);
3. The thickness of Metal 1 is 0.6 micrometer (μm);
4. The thickness of Metal 2 is 1.1 micrometer (μm);
5. The thickness of Passivation layer is 0.7 micrometer (μm);
6. The thickness of gate oxide layer is 135 angstrom (Å); and
7. The total area of the chip is 1.8 mm 2 .
FIG. 1 is the cross-sectional view showing a sensing configuration of SnO 2 /Al/SiO 2 /Si. As can be seen in FIG. 1 , such structure is easily fabricated according to the standard CMOS fabrication process, and can be a tin dioxide/aluminum metal/silicon dioxide structure 1 , which is constructed by depositing an aluminum layer 12 and a tin dioxide layer 13 onto a substrate 11 , and encapsulating the resulting structure with epoxy resin 14 to form a opening channel. Via the aluminum layer 12 , a conducting line 4 is led out.
FIG. 2 is the cross-sectional view showing the sensing configuration of SnO 2 /ITO/glass. Since the glass substrate is cost effective, the sensor with this structure can be applied to fabricate disposable sensors. This structure is a tin dioxide/indium tin oxide/glass structure 2 , which is constructed by depositing an indium tin oxide layer 22 and a tin dioxide layer 23 onto a glass substrate 21 , and partially encapsulating the resulting structure with epoxy resin 24 to form a opening channel. Via the indium tin oxide layer 22 , a conducting line 4 is led out.
Please refer to FIG. 3 . The flowchart for fabricating the array pH sensor of the present invention comprises the following steps:
Step 1: providing a silicon substrate 31 , for example a p-type silicon substrate with resistivity of 4˜7 Ohm-cm and silicon dioxide layer of 1000 angstrom, wherein the silicon substrate can be replaced by glass substrates, ceramic substrates or polymeric substrates in order to broaden the applications of the sensor;
Step 2: growing an Al film 32 by using a metallic mask and a vacuum evaporation machine;
Step 3: growing a SnO 2 film 33 by using a metallic mask and a sputter machine; and
Step 4: encapsulating the resulting product with epoxy resin 34 .
The process for fabricating such sensor is easy because the procedures of coating photoresist solutions and etching films are omitted.
FIG. 4 is a schematic view showing the Al layer mask, which is a metallic mask. The portions of the aluminum film to be deposited are indicated with the black portions. After the metallic mask is etched away, the Al film is deposited onto the metallic portions where the mask has been removed.
FIG. 5 is a schematic view showing the sensing membrane SnO 2 layer mask, which is a metallic SnO 2 mask. The portions of the tin dioxide film to be deposited are indicated with the black portions. After the metallic mask is etched away, the tin dioxide film is deposited onto the metallic portions where the mask has been removed.
FIG. 6 is the configuration of the array pH sensor of the present invention. This array pH sensor comprises four sensing elements and four pre-amplifiers at the front end thereof. The respective sensing element is read by control circuits, and the pre-amplifier and the control circuits are compensated by the rear end amplifiers, thereby obtaining an output/input ratio of 1. The rear end readout circuit of this array sensor can be used to receive different signals and amplifying these signals for determination. Thus, when the multiplexer is modified, a variety of array sensors can be fabricated for many applications such as fabrication of potentiometric sensor.
FIG. 7 is the circuit configuration of the pre-amplifier for the array pH sensor. The pre-amplifier is consisted of four CMOS devices so as to reduce the layout space.
FIG. 8 shows the input/output ratio of the pre-amplifier. The output/input ratio is 0.7184 and an offset voltage is −1.097V. Accordingly, the signal would be decreased, when the sensing element is connected to the pre-amplifier.
FIG. 9 shows the circuit configuration of the switch of the control portion, which is consisted of an inverter and a CMOS switch.
FIG. 10 shows the circuit configuration of a 2 to 4 decoder of the control portion, which is consisted of six inverters and four NAND circuits.
FIG. 11 is a schematic diagram showing the output/input ratio of the circuit combined the pre-amplifier and the control circuit. The output/input ratio is 0.675 and the offset voltage is −1.095V. Accordingly, the signal would be further decreased, when the sensing element was connected to the pre-amplifier and multiplexer.
FIG. 12 is a schematic diagram showing the output/input ratio of the circuit of the array pH sensor. As can be seen in FIG. 12 , due to the amplification of the rear end readout circuit, the signals of the sensing membrane can be compensated to the initial values and the ratio of the output voltage to the input voltage is 1.04.
It was in order to compensate the decreasing of pre-circuit. So, The input output ratio is 1.04 of the array pH sensor system, when the circuit included the pre-amplifier, multiplexer, buffer and post amplifier.
FIG. 13 is a schematic diagram showing the readout signal of the array pH sensor. As can be seen in FIG. 13 , four sets of signals are stable, indicating a stable fabrication process of this array sensor.
FIG. 14 is a schematic correction curve of the readout signal of the array pH sensor. The correction curve shows a linear pH sensitivity of 0.99969, which indicates an excellent performance of the array ion sensor.
FIG. 15 is a cross-section view showing the related processes for fabricating a chip. In FIG. 15 , the relative positions of the layer structures of a 0.5 micrometer n-well double polysilicon double-metal process are shown.
Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims. | A method for fabricating an array pH sensor and a readout circuit device of such array pH sensor are implemented by utilizing an extended ion sensitive field effect transistor to construct the array pH sensor and related readout circuit. The structure of the array sensor having this extended ion sensitive field effect transistor comprises a tin dioxide/metal/silicon dioxide multi-layer structure sensor and a tin dioxide/indium tin oxide/glass multi-layer structure sensor and has excellent properties. Furthermore, the readout circuit and the sensor utilize two signal generators for controlling and reading signals. In particular, the sensor can be effective for increasing the accuracy of measurement and reducing the interference of noise. | 6 |
This is a continuation of co-pending application Ser. No. 06/432,598 filed on Oct. 4, 1982 now abandoned.
FIELD OF THE INVENTION
The present invention relates to movable arms on which equipment is mounted and supported while being easily moved.
BACKGROUND OF THE INVENTION
Movable arms on which equipment may be mounted are known in the art such as seen in U.S. Pat. No. 3,030,128 issued Apr. 17, 1962 to K. Versen. The movable arm shown in this patent utilizes three rotating and swivel joints in conjunction with friction couplings and a torsion spring to counterbalance the weight of a lamp at the end of the arm. The interaction of all these joints and elements permits the lamp at the end of the movable arm to be easily positioned in a large number of positions within the reach of the arm, and the lamp will stay in the position in which it is placed.
There are, however, problems with such prior art movable arms. Each movable joint has only two degrees of freedom, and when it is desired to orient the lamp or other equipment in a specific position, there is often difficulty in that the three movable joints do not cooperatively move as easily as desired when the lamp or other equipment at the end of the arm is moved.
In addition, in some applications it is sometimes desired to change the type of equipment mounted on the end of the movable arm. In the prior art, the weight of the new equipment must be the same as the weight of the original equipment being replaced. If heavier or lighter equipment is placed on the end of the arm, the counterbalancing forces within the arm are not optimum for the new weight and the equipment sometimes will not stay in a position in which it is placed. For example, with the heavier piece of equipment the arm will sag when the equipment is manually positioned and then released. To compensate for this type of problem in the prior art, the pressure on friction coupling elements in one or more of the movable joints is increased or decreased. However, when the pressure is increased it is correpondingly harder to position the heavier equipment on the end of the arm due to jerky arm movement, with the result being difficulty in positioning the equipment in a precise position. This is caused by greater forces being required to overcome the increased friction and therefore increasing the tendency to overshoot. Thus, changing pressure on friction couplings to accommodate differing weight loads on the end of a movable arm is impractical. Accordingly, in the prior art a movable arm is usually designed only for a given weight load on the end of the arm. This has been acceptable in the prior art as there has not been much demand for movable arms that can accommodate differing weight loads.
There is a need in the art for a movable arm that can be used with differing weight loads at the end of the arm without any change in the force required to move the load and without requiring different parts.
There is also a need in the art for a movable arm that can be moved more easily than in the prior art.
SUMMARY OF THE INVENTION
The above described problems with prior art movable arms are solved by our novel movable arm. Our novel arm utilizes three movable joints, two of which are pivoting joints each having two degrees of freedom, and the third joint is a unique friction ball joint having more than two degrees of freedom, which thereby allows the arm to be moved more easily. In addition, we provide means for quickly and easily adjusting the tension of a torsion spring within one of the joints of our arm to properly counterbalance differing weights on the end of the arm. This permits different weights on the end of the movable arm to all be moved with equal ease. Furthermore, we provide a clamp means on the end of our movable arm opposite the end on which the equipment is fastened which permits our movable arm to be mounted on other than a dedicated support base table. This permits greater flexibility and portability. For example, with a small computer system or word processor terminal, the video display can be mounted on the edge of an existing desk or table.
DESCRIPTION OF THE DRAWING
Our invention will be better understood on reading the following detailed description in conjunction with the drawings in which:
FIG. 1 shows the assembly attached to the top of a table and flexibly supporting a television type monitor;
FIG. 2 is an exploded assembly drawing showing the individual elements making up our novel arm;
FIG. 3 is a bottom view of the base of our arm to show the manner in which it controls the maximum swing of the arm;
FIG. 4 is a side view of the base of our arm showing the torsion spring adjustment; and
FIG. 5 is a cross sectional view of the assembled friction ball joint at the end of our arm supporting a piece of equipment such as a video display.
FIG. 6 is a prespective view showing the arm with a computer video monitor installed.
DETAILED DESCRIPTION
In FIG. 1 is shown an assembled arm in accordance with the teaching of our invention. Our novel arm is quickly and easily mounted to table 10, which is shown in phantom view by means of a clamp 12. The other end of our arm is fastened to a piece of equipment 11, also shown in phantom view and, which for the present application is a video display. Our arm is made up of clamp 12 which is used to fasten our arm to the edge of a desk or table 10 or to any other mounting surface having an edge to which the clamp can be fastened. A base 13 is connected to clamp 12 such that base 13 can rotate in a plane parallel to the surface of table 10. Base 13 is connected to an arm member 14 via an adjustable torsion spring [not shown] and a friction coupling [not shown], and arm member 14 can rotate in a plane perpendicular to the plane of the top of table 10. At the outer end of arm member 14 is connected a friction ball joint assembly 15, which is in turn fastened to the base of video display 11. Friction ball joint assembly 15 enables video display 11 to be tilted forward and backward and from side to side. With friction ball joint assembly 15, video display 11 may be moved to any position, and it will remain in that position without tilting further due to its own weight. Thus, the combination of the different joints in our movable arm coupled with an adjustable torsion spring and friction coupling provides for multiple degrees of freedom of movement of our novel movable arm and video display 11.
In FIG. 2 is shown an exploded view of our novel movable arm showing the individual components making up the arm. Clamp 12 is partially C shaped as shown to go around the edge of a desk, table or any other mounting surface, whether that mounting surface be horizontal or other than horizontal. Screw means 20 is used to move plate 21 in a vertical direction to securely fasten clamp 12 onto the edge of a table in a manner well known in the art. The top of plate 21 and its opposing surface on clamp 12 may have a piece of plastic or other material fastened thereto to provide friction in contact with the mounting surface and to prevent marring the mounting surface. Plate 21 has two conical protuberations 50 and 51 which may be created with conical set screws in threaded holes. These protuberations 50 and 51 embed in the underside of table 10 so the clamp will not slip. The top surface of clamp 12 has a circular recess 22 having a diameter only slightly larger than circular bottom 26 of base 13. Within recess 22 are located three holes 24, in one of which is placed a peg 25. The particular one of holes 24 in which peg 25 is placed determines the rotational travel of base 13 on the top of clamp 12 as will be better understood in the description for FIG. 3 further in this specification. Holes 24 may also be threaded and a set screw turned partially therein to accomplish the same result as peg 25.
Recess 22 in clamp 12 also has a pivot member 23 mounted thereon which has a groove 19 around its periphery as shown. Groove 19 is used to fasten base 13 to clamp 12 as is described hereinafter. Base 13 has a hole 18 vertically therethrough having substantially the same diameter as pivot member 23. Hole 18 may also be oversized with a brass bushing press fit therein with the inside diameter of the bushing being substantially the same diameter as pivot member 23. Base 13 is mounted down on clamp 12 with its bottom portion 26 sitting within recess 22 of clamp 12 and with pivot member 23 coming up through hole 18 of base 13. When in this position, a recessed screw [not shown] is turned inward in threaded hole 30 through base 13 until the tip of the screw extends into groove 19 around pivot member 23. There is not an interference fit between the screw and pivot member 23. A drop of thread lock sealant may be added to the thread of a screw to retain it in hole 30 without loosening. With the screw mounted in hole 30 as just described, base 13 cannot be removed from clamp 12 but can rotate about pivot member 23. A nylon piece [not shown] may be placed in recess 22 before base 13 is assembled to clamp 12 to aid in movement of base 13.
Base 13 also has a pivot member 27 which is coaxial with and mounts within hole 36 through arm member 14 when arm member 14 is assembled to base 13. The diameter of hole 36 and pivot member 27 are substantially the same. Again, a brass bushing may be used in hole 36. In assembly, torsion spring 28, partially wound to provide tension, is mounted over the outside of pivot member 27, and arm member 14 is then mounted up against base 13 on pivot member 27. When arm member 14 is mounted up against base 13, wound torsion spring 28 is captivated between these two members. Hook end 49 of torsion spring 28 is captivated by a boss [not shown] within the back side of arm member 14. Hook end 48 of torsion spring 28 crosses the axis of threaded hole 29 through base 13 and is captivated by a boss 53 [not shown in FIG. 2, but shown in FIG. 4] on base 13 to prevent torsion spring 28 from unwinding. A recessed screw 54 [not shown in FIG. 2, but shown in FIG. 4] within threaded hole 29 has the tip of the screw hitting hook end 48 of torsion spring 28. As the screw [not shown] is screwed further within hole 29, it pushes against hook end 48 of spring 28 to increase the torsion loading of spring 28 and thereby provides an effective means to adjust the torsion loading of spring 28 to compensate for different weight loads attached to the outer end of arm member 14 via friction ball joint assembly 15. Initially, screw 54 in hole 29 is set to push hook end 48 away from lip 53 [shown in FIG. 4], and thereafter the torsion of spring 28 may be increased or decreased by turning screw 54.
Arm member 14 is held assembled to base 13 in the following manner. A friction screw 17 has a broad head 32 and a threaded shaft 34 which passes through friction washer 31, wave washer 16, cork washer 50 and then through hole 36 at the bottom end of arm member 14. Threaded shaft 34 then passes through torsion spring 28 and into threaded hole 35 in the end of pivot member 27 on base 13. Head 32 of friction screw 17 has a diameter only slightly smaller than the diameter of a recess 37 in the bottom end of arm member 14. On assembly, the screw captivates washers 16, 50 and 31 within recess 37 and fastens arm member 14 onto base 13. Head 32 of friction screw 17 has two edge recesses 33, and a spanner wrench is utilized to tighten screw 17. As screw 17 is tightened against washers 16, 50 and 31, friction is created against the movement of arm member 14 about pivot member 27 due to the function of the washers. The outer end of arm member 14 has a hole 47 therethrough and a plurality of mounting holes 41 as shown. On assembly, screws coming up through threaded holes 41 from the bottom of arm member 14 will be turned into respective ones of threaded holes 40 through the flange of middle friction member 39 of our novel friction ball joint 15. This is shown in greater detail in FIG. 5. In this manner, middle friction member 39 is attached to the outer end of arm member 14. The rest of our novel friction ball joint 15 comprises an upper friction member 38, a fastening screw 45, a lower friction member 42, a spring 43, a flat washer 44, and a nut 46. The diameter of hole 47 through the outer end of arm member 14 is greater than the diameter of lower friction member 42, spring 43, flat washer 44, and nut 46. The holes through upper friction member 38 and lower friction member 42 each have a diameter only slightly larger than the diameter of the shaft of screw 45. However, the hole 50 through middle friction member 39 is significantly larger than the diameter of the threaded shaft of screw 45. The concave bottom of upper friction member 38 is spherical and has the same radius and center point of curvature as the convex spherical top of middle friction member 39. The concave bottom side of middle friction member 39 is also spherical, has a radius of curvature equal to that of the convex spherical top of lower friction member 42, and has a common center point of radius as all the spherical surfaces. On final assembly, the spherical top of lower friction member 42 is mounted up inside the spherical surface in the bottom of middle friction member 39, and the spherical top surface of member 39 is mounted up inside the spherical surface in the bottom of upper friction member 38, such that all spherical surfaces are free to move about the common center point. On assembly, nut 46 is screwed onto the threaded end of screw 45 and is screwed down to apply pressure via washer 44 and spring 43 to hold members 38, 39 and 42 against each other as is shown in greater detail in FIG. 5. Depending upon how tightly bolt 46 is screwed onto the shaft of screw 45, the degree of friction created between the spherical mating surfaces of elements 38, 39 and 42 may be varied to create our novel double surface friction ball joint 15. Upper friction member 39 is attached to video display 11 or may be an integral part of the base of video display 11. As video display 11 is tilted forward, backward or to either side, elements 38, 45, 42, 43, 44, and 46 pivot while member 39 remains in a fixed position attached to outer end of arm member 14. The friction between the assembled elements 38, 39 and 42 permit the video display 11 to be moved into a position and remain in that position.
Turning now to FIG. 3, there is shown a bottom view of base 13. In the bottom of base 13 are located three grooves 50, 51, and 52 which lie along the periphery of circles having different radii. When base 13 is assembled to clamp 12, each of grooves 50, 51 and 52 sit directly over one of the three holes 24 in recess 22. As previously mentioned, peg 25 is inserted into one of holes 24 and extends upward out of the hole as shown in FIG. 2. The portion of peg 25 protruding up from a hole 24 extends into one of grooves 50, 51 and 52. In particular, when peg 25 is located in the one of holes 24 closest to pivot member 23 of clamp 12, the top of peg 25 protrudes into groove 52. Rotation of base 13 is thereby limited to ninety degrees in one quadrant. When peg 25 is mounted in the middle one of holes 24 of base 12, its protruding end extends into groove 51 to restrict rotation to 90 degrees in a different quadrant. With peg 25 being located in the outer one of the three holes 24, it extends into groove 50 which allows for 180 degrees rotation of base 13 about pivot member 23 of clamp 12. It would be obvious to one skilled in the art that the position and length of these grooves may be varied to suit particular applications or may be eliminated allowing a full 360 degrees rotation.
FIG. 4 is a side view of base 13 showing the aforementioned lip or boss 53 against which hook end 48 of partially wound torsion spring 28 sits when spring 28 is assembled between base 13 and arm 14 on assembly of the arm. Hook end 48 extends downward and is in line with the axis of hole 29 through base 13 and screw 54 therein, the tip of which contacts hook end 48. The tension of torsion spring 28 is increased by turning screw 54 into threaded hole 29 through base 13. Screw 54 is screwed into push hook end 48 of spring 28 away from lip 53 to set an initial tension in torsion spring 28. As different weight loads are attached to the outer end of our novel arm, screw 54 is screwed in or out to change the tension of torsion spring 28, to compensate for the different weight loads. For lighter weight loads on the end of our novel arm, screw 54 is unscrewed to decrease the tension of torsion spring 28. For heavier weights on the end of our arm, screw 54 is screwed into hole 29 to further wind tension spring 28 and thereby increase the torsion to compensate for the increased weight load.
FIG. 5 shows the above described details of our novel friction ball joint 15 with the ball joint being in an assembled state. The outer end of arm member 14, having hole 47 therethrough, is only partially shown, with its mounting holes 41 being aligned with the holes 40 through the flange of middle friction member 39, and which is fastened to arm 14 via screws through each pair of holes 40 and 41. Thus, member 39 is affixed to arm member 14. Upper friction member 38 is an integral part of or is attached to video display 11 [not shown]. It can be seen how the spherical inner surface of upper friction member 38 matches the convex spherical surface of middle friction member 39. It can also be seen how the concave spherical surface of member 39 mates with the convex spherical surface of lower friction member 42 and all spherical surfaces have a common center point of radii. In assembly, nut 46 is fastened to bolt 45 as shown and applies pressure via washer 44 and spring 43 against lower friction member 42. This spring action forces members 38, 39 and 42 together so that there is a friction coupling as well as a ball joint function being accomplished between members 38, 39 and 42 as shown in FIG. 5. As video display 11 [not shown in FIG. 5] is tilted forward, backward or from side to side, the ball joint friction members 38, 39 and 42 rotate against each other with a friction coupling. This friction coupling permits the video display 11 to be tilted to a certain position and then to stay in that position. The degree of friction coupling in our novel friction ball joint depends upon the nature of the materials and the amount of force transmitted through spring 43 to elements 38, 39 and 42 when turning nut 46 onto bolt 45.
While what has been described above is the preferred embodiment of our invention, it would be obvious to those skilled in the art that numerous variations may be made therein without departing from the spirit and scope of our invention. For instance hole 51 through middle friction member 39 may be oval or any other shape and limit the degree to which video display 11 [not shown in FIG. 5] may be tilted. In addition, spring 43 in our friction ball joint 15 may be eliminated and pressure applied directly by nut 46. Further, it should be realized that friction ball joint 15 may be modified to eliminate one of the spherical friction surfaces. | A mounting arm is disclosed on one end of which a piece of electronic or other equipment is mounted and the other end of which is detachably fastened to the edge of a supporting surface. The arm has three moving joints that permit the equipment fastened thereto to be moved with multiple degrees of freedom for desired positioning of the equipment. One joint utilizes a friction washer assembly and a preloaded torsion spring counterbalancing the weight of the equipment. The torsion spring tension is adjustable to compensate for differing weights of equipment on the one end of the arm. Another joint utilizes a friction ball joint arrangement having double concentric friction ball surfaces in an assembly that permits multiple degrees of freedom of motion and is easily removed from the remainder of the arm without disassembling the ball joint. | 5 |
INTRODUCTION
The present invention relates to a recreational device and more particularly to a floating device for use when engaged in water sports to enhance the maximum enjoyment while minimizing the solar hazards associated therewith.
BACKGROUND
Popular contemporary recreational activities involving water include such individual or group endeavors as swimming, fishing, boating, or "tubing" (that sport which involves entering a river upstream and riding the current downstream sitting on or laying across a tire inner tube as a floation device). Inner tubes are also useful in swimming and fishing when a floating platform is desired.
In most climes, the described water activities usually occur in bright sunlight on warm summer days and frequently result in heat discomfort. Further, when costumes are brief, the user risks possible blistering of body parts from the accumulation of rays and heat directly from the sun or reflected from the surface of the water. It can be readily understood that the minimal clothing often used while participating in water sports or "tubing" could exacerbate discomfort and/or physiological damage.
SUMMARY OF INVENTION
The present invention comprises a device which provides greater user comfort while providing conventional flotation. More particular, the device comrises a hydrophobic waterproof elastomeric body capable of holding compressed gas for floatation purposes having a special corrosion resistant heat reflective surface integrally formed on or with the upper portion thereof.
The present invention is in part predicated upon the discovery that a unique interaction is obtained between conventional inner tube materials and a coating material containing a chlorosulfonated polyethylene dissolved/suspended in dimethylbenzene. With chlorosulfonated, polyethylene containing 20-45% chlorine and 1-2.5% sulfur, the action creates a long wearing, corrosion resistant, heat dissipating surface capable of providing the needed creature comforts hereinbefore described.
Accordingly, a prime object of the present invention is to provide a new and improved recreational device capable of resisting the deleterious effects of adverse environmental factors while providing protection for the occupant from the searing effects of solar heat and radiation.
Another object of the present invention is to provide a new and improved recreational device which is especially suited to enhance the enjoyment while minimizing the discomfort associated with the sport of tubing and the like.
A still further object of the present invention is to provide a recreational device especially useful in water sports which is easily manufactured, handy to transport, ready to assemble and requires no special training to enable the operator to enjoy the full benefit thereof.
Still another object of the present invention is to provide compositions and methods of producing an improved recreational floatation device which provides a pleasureful experience for the user while reducing the user's fatigue and heat discomfort.
These and still further objects as shall hereinafter appear are readily fulfilled by the present invention in a remarkably unexpected manner as will be readily discerned from the following detailed description of an exemplary embodiment thereof especially when read in conjunction with the accompanying drawing in which like parts bear like numerals throughout the several views.
DRAWINGS
FIG. 1 is an isometric showing of a device embodying the present invention;
FIG. 2 is a partially broken cross section taken on line 2--2 of FIG. 1;
FIG. 3 is a fragmented cross section of the device shown in FIG. 1;
FIG. 4 is an enlarged fragment of area 4 as marked on FIG. 1; and
FIG. 5 is an enlarged fragment of an alternative embodiment of the present invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Referring to FIG. 1, a device 10 embodying the present invention comprises a rubber-like or latex or neoprene or other elastomeric body capable of containing compressed gas such as inner tube 11 upon the outer surface 12 of which has been integrally formed a white film surface 13 on the uppermost half 14 of tube 11. Surface 13 can be formed as shown in FIGS. 2, 3 and 4, or, it can be applied over the entire exterior surface of tube 11 as shown in FIG. 5. In usual use, approximately the lower half of the body 11 will be submerged into the water so that for pragmatic reasons the coating on the top surface thereof is all that is essential to provide the benefits of this invention for most applications. The full coating however does eliminate the need to orient the device 10 at the time it is placed into the water.
An alternative embodiment of the invention comprises an enlarged body 11 capable of providing a floatation platform for stationary or multiple person use. This embodiment still comprises an elastomeric enclosure 11 capable of holding compressed gas therewithin.
In the preferred practice of the present invention, a chlorosulfonated polyethylene elastomer (commercially available under the trade name HYPALON® from DuPont) is dissolved and/or suspended in dimethylbenzene. This material is then applied to the upper surface of the elastomeric floatation device or tube using coventional coating techniques such as spraying, brushing and the like. The coated device is then allowed to cure at room temperature. When cured, the resulting film integrally adheres to and coacts with the material of the floatation device to provide a heat-reflective, corrosion-resistant substantive film throughout the coated portion of the base unit.
While the application of coatings to elastomeric substances has heretofore resulted in unsightly and ineffectual surfaces which readily cracked or peeled within a very short period of time, especially when those surfaces were subjected to the hostile environment found in use, e.g., domestic swimming pools treated with chlorine and algacide compounds to control algae and bacteria, a device embodying the present invention has been subjected to the swimming pool environment for more than three weeks without any noticable change in the appearance or substantiuity of the applied film.
In additional testing, devices embodying the present invention were exposed to direct sunlight in a pool. One device was positioned with its coated side exposed to the sun and another device was positioned with its black (uncoated) side exposed to the sun. After one hour, the exposed dark side of the one tube had a surface temperature of 156° F. while the coated side on the other tube had a surface temperature of 123° F. This unexpected large differential in surface temperature (33° ) and the ability of the coated side to maintain temperatures below 140° F. clearly demonstrates the utility of the device in preventing pain, skin damage or burns when used as a floatation platform in water sports.
As used herein "chlorosulfonated polyethylene" describes polyethylene chlorinated in the presence of sulfur dioxide which permits various amounts of sulfonyl chloride groups to be introduced into the polymer structure. The addition of a polybasic metal oxide or a polybasic metal salt of a weak acid, an organic acid, and an organic accelerator provide the basis for effective curing. The principal crosslinking reaction is believed to occur between the metal oxide and sulfonic acid. Normally the reaction will be conducted in an anhydrous solvent such as carbon tetrachloride. Suitable catalyzers include organic peroxides or azobisisobutyronitrile.
In a preferred practice, the polymer will be placed in solution and the reaction carried out at a temperature sufficient to dissolve the polyethylene polymer in the solvent. Superatmospheric pressure may be employed to achieve the desired result. The reaction will be allowed to proceed until the chlorine content of the polymer reaches the range of 20-45% and the sulfur content of the polymer is in the range of 1-2.5%.
Uncured chlorosulfonated polyethylene is readily soluble in aromatic and chlorinated hydrocarbons and soluble to some extent in ketones, esters, alicyclic hydrocarbons, alcohols and glycols.
Optimum properties are realized with chlorosulfonated polyethylene containing 30-35% (by weight) chlorine and 0.8-1.5% (by weight) sulfonyl sulfur. Magnesia or titanium dioxide or other whiting materials provide suitable pigmentation to the coating surface.
In general, chlorosulfonated polyethylenes may be processed using ordinary procedures on standard processing equipment and they may be mixed satisfactorily in internal mixers or on open mills.
To further aid in the understanding of the present invention and not by way of limitation, the following examples are presented.
EXAMPLE 1
A coating formulation is prepared by admixing 90 parts of chlorosulfonated polyethylene with 3 parts of hydrogenated rosin and 135 parts toluene. This mixture is transferred to a pebble mill where 40 parts of tribasic lead maleate, 1.5 parts of 2-mercaptobenzothiazyl disulfide, 0.5 parts of tetramethylthiuram disulfide, 2 parts of isophthalic acid, 70 parts of titanium dioxide, 120 parts of toluene, 10 parts of mineral spirits and 20 parts of butyl alcohol are added and mixed to obtain fineness. Thereafter, 10 parts of chlorosulfonated polyethylene and 40 parts of toluene are introduced and the milling is continued until the polymer solution is effected.
EXAMPLE 2
An inner tube of conventional manufacture is coated with a composition prepared according to Example 1. After curing, the device was inspected and found to have an integral resilient coating formed thereupon which resisted bending and reflected solar heat.
From the foregoing, it is apparent that a device has been herein described and illustrated which fulfills all of the aforestated objectives in a remarkably unexpected fashion. It is of course understood that such modifications, alterations and adaptations as may readily occur to the artisan confronted with this disclosure are intended within the spirit of this disclosure which is limited only by the scope of the claims appended hereto. | A recreational device comprising an elastomeric body portion capable of holding compressed gas and having a surface temperature reducing coating integrally formed therewith on the outer surface thereof. The device is used in water sports where flotation is desired to reduce creature discomfort and physiological damage. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to and claims the benefit of priority to U.S. Provisional Application Ser. No. 61/065,294, entitled “SYSTEM, APPARATUS, AND METHODS FOR SOURCE CODE COMPILATION”, filed Feb. 8, 2008, the entirety of which is hereby incorporated by reference.
GOVERNMENT INTEREST
[0002] Portions of this invention were made with U.S. Government support under contract/instrument DARPA F03602-03-C-0033 with the U.S. Air Force Research Laboratory and DARPA. The U.S. Government has certain rights.
FIELD OF THE INVENTION
[0003] The present invention generally concerns computer programming. More particularly, the invention concerns a system, methods, and apparatus for source code compilation.
BACKGROUND OF THE INVENTION
[0004] The progression of the computer industry in recent years has illustrated the need for more complex processor architectures capable of processing large volumes of data and executing increasingly complex software. A number of systems resort to multiple processing cores on a single processor. Other systems include multiple processors in a single computing device. Additionally, many of these systems utilize multiple threads per processing core. One limitation that these architectures experience is that the current commercially available compilers can not efficiently take advantage of the increase of computational resources.
[0005] In the software design and implementation process, compilers are responsible for translating the abstract operational semantics of the source program into a form that makes efficient use of a highly complex heterogeneous machine. Multiple architectural phenomena occur and interact simultaneously; this requires the optimizer to combine multiple program transformations. For instance, there is often a trade-off between exploiting parallelism and exploiting locality to reduce the “memory wall”, i.e., the ever widening disparity between memory bandwidth and the frequency of processors. Indeed, the speed and bandwidth of the memory subsystems are a performance bottleneck for the vast majority of computers, including single-core computers. Since traditional program optimization problems are associated with huge and unstructured search spaces, this combinational task is poorly achieved by current compilers, resulting in poor scalability of the compilation process and disappointing sustained performance of the supposedly optimized program.
[0006] Even when programming models are explicitly parallel (threads, data parallelism, vectors), they usually rely on advanced compiler technology to relieve the programmer from scheduling and mapping the application to computational cores, and from understanding the memory model and communication details. Even provided with enough static information and code annotations (OpenMP directives, pointer aliasing, separate compilation assumptions), traditional compilers have a hard time exploring the huge and unstructured search space associated with the mapping and optimization challenges. Indeed, the task of the compiler can hardly be called “optimization” anymore, in the traditional meaning of reducing the performance penalty entailed by the level of abstraction of a higher-level language. Together with the run-time system (whether implemented in software or hardware), the compiler is responsible for most of the combinatorial code generation decisions to map the simplified and ideal operational semantics of the source program to a highly complex and heterogeneous target machine.
[0007] Generating efficient code for deep parallelism and deep memory hierarchies with complex and dynamic hardware components is a difficult task. The compiler (along with the run-time system) now has to take the burden of much smarter tasks, that only expert programmers would be able to carry. In order to exploit parallelism, the first necessary step is to compute a representation which models the producer/consumer relationships of a program as closely as possible. The power of an automatic optimizer or parallelizer greatly depends on its capacity to decide whether two portions of the program execution may be run one after another on the same processing element or on different processing elements, or at the same time (“in parallel”). Such knowledge is related to the task of dependence analysis which aims at precisely disambiguating memory references. One issue is to statically form a compact description of the dynamic properties of a program. This process is generally undecidable and approximations have to be made.
[0008] Once dependence analysis has been computed, a compiler performs program transformations to the code with respect to different, sometimes conflicting, performance criteria. Any program transformation must ultimately respect the dependence relations in order to guarantee the correct execution of the program. A class of transformations targeting the loop nests of a program (such as “DO” loops in the FORTRAN language, and “for” and “while” loops in languages derived from the C language) are known to account for the most compute intensive parts of many programs.
[0009] Traditional optimizing compilers perform syntactic transformations (transformations based on a representation that reflects the way the program source code text was written, such as the Abstract Syntax Tree), making the optimizations brittle since they are highly dependent on the way that the input program is written, as opposed to the more abstract representation of the program's execution offered by the polyhedral model. Moreover, syntactic transformations are not amenable to global optimizations, since the problem of optimally ordering elementary syntactic transformations is yet unsolved. Many interesting optimizations are also not available, such as fusion of loops with different bounds or imperfectly nested loop tiling.
[0010] In some situations, such as in high performance signal and image processing, the applications may primarily operate on “dense” matrices and arrays. This class of applications primarily consists of do-loops with loop bounds which are affine functions of outer indices and parameters, and array indexing functions which are affine functions of loop indices and parameters. Other classes of programs can be approximated to that class of programs.
[0011] One significant area of concern in these large scale systems is memory management. For example, in a program, a large multi-dimensional array may be allocated and used to store data. This large block of data is typically stored in memory in contiguous memory cells. Certain operations on the array may not access all portions of the data. For example, in nested loops an outer loop may be indexed by the column of the array and an inner loop may be indexed by the rows of the array. In a situation where the loop operation only accesses a portion of the elements of the array, it would be inefficient to transfer the entire array to a processing element that is assigned the access task. Further, since portions of the array are not accessed, the loop indices may be rewritten for local access on a processing element.
[0012] There have been a number of approaches used to implement these program transformations. Typical goals of these approaches include reducing the memory size requirements to increase the amount of useful data in local memory and to reduce communication volumes. One such algorithm is described in U.S. Pat. No. 6,952,821 issued to Schreiber. Schreiber's method is applicable to non-parametric rectangular iteration spaces and employs the Lenstra-Lenstra-Lovasz (LLL) lattice basis reduction algorithm. Schreiber's methods are additionally incapable of addressing data with non-convex sets of accessed data.
[0013] Therefore a need exists for more efficient compiler architectures that optimize the compilation of source code.
SUMMARY OF THE INVENTION
[0014] The present invention provides a system, apparatus and methods for overcoming some of the difficulties presented above. Various embodiments of the present invention provide a method, apparatus, and computer software product for a class of automatic program transformations that reduce the memory size requirements by relocating and compressing the memory accesses of a program that includes loop nests with arbitrary affine indices. Exemplary methods extract a lattice of points within the iteration domain to handle iteration domains with strides, for which the values of loop counters differ by more than a unit for loop iterations executed consecutively. Other provided methods operate on programs that contain arbitrary affine array index functions; and in some instances where the program transformation handles arbitrarily complex data footprints.
[0015] An exemplary method includes receiving program source code containing loop nests with arbitrary parametric affine iteration domain containing at least one array. The method identifies inefficiencies in memory usage where the inefficiencies are related to access and the memory footprint of the arrays. The method further allocates at least one local array and maps a portion of the received arrays to one or more of the local arrays. The mapping reduces the memory size requirements and the memory footprint of the arrays.
[0016] A further embodiment provides a local memory compaction module that assists a processor in the optimization of source code. Other embodiments provide computing apparatus and computer software products that implement the described methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Various embodiments of the present invention taught herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which:
[0018] FIG. 1 is an overview of an exemplary compiler architecture consistent with provided embodiments;
[0019] FIG. 2 illustrates the operational flow of one embodiment of a provided local memory compaction module;
[0020] FIG. 3 illustrates the operational flow of another provided local memory compaction module, in which array references are partitioned into groups and algebraic and geometric data re-indexing functions are computed;
[0021] FIG. 4 illustrates the operational flow of an additional local memory compaction module in which inefficiencies in memory usage are determined using lattices of integer points;
[0022] FIG. 5 illustrates the operational flow of an additional local memory compaction module for reducing the inefficiencies in local memory usage by extracting representative array references and producing re-indexing functions using Hermite factorizations;
[0023] FIG. 6 illustrates the operational flow of an additional local memory compaction module for computing data re-indexing functions by producing linear constraints and solving a series of linear programming problems.
[0024] FIG. 7 illustrates the operational flow of an additional local memory compaction module for computing data re-indexing functions by finding a prism of triangular base that encloses the accessed data set and reducing the memory requirements of the enclosed data region by transforming the data elements that lie within a subset of the prism of triangular base.
[0025] FIG. 8 illustrates the operational flow of an additional local memory compaction module using data re-indexing information to produce abstract communication commands and schedule computations and communications for the program in such a way that their executions overlap; and
[0026] FIG. 9 illustrates a computing apparatus and computer software product consistent with provided embodiments.
[0027] It will be recognized that some or all of the figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The Figures are provided for the purpose of illustrating one or more embodiments of the invention with the explicit understanding that they will not be used to limit the scope or the meaning of the claims.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. While this invention is capable of embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. That is, throughout this description, the embodiments and examples shown should be considered as exemplars, rather than as limitations on the present invention. Descriptions of well known components, methods and/or processing techniques are omitted s 0 as to not unnecessarily obscure the invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s).
[0029] The trend of increasing the frequency at which processors perform computations seems to have come to an end. Power consumption and control complexity have reached such high levels that manufacturers are backing out of this design path. Current machines have evolved to multiprocessor architectures on a chip with increasingly many cores per chip and multiple threads per core. This trend is expected to dramatically increase, reaching thousands of cores per chip in the next few years. Thus, modern computers increasingly need to exploit parallelism at different levels to provide sustained performance. On the other hand, parallel programming techniques have not evolved at the same speed and the gap between theoretical machine speed and actual utilization continues to increase.
[0030] Compilers are responsible for translating the abstract operational semantics of the source program, i.e., a text description of what the program's execution is supposed to perform, into an executable form that makes efficient use of a highly complex heterogeneous machine. Multiple architectural phenomena occur and interact simultaneously within the targeted computer during the execution of the program; this requires the optimizing compiler to combine multiple program transformations in order to define a program execution that takes advantage of those architectural phenomena. For instance, when targeting computers that have multiple processing elements (multi-core computers), there is often a trade-off between exploiting more processing elements simultaneously (parallelism) and exploiting data access locality to reduce memory traffic. Indeed, the speed and bandwidth of the memory subsystems are almost always a bottleneck. The problem is typically worse for multi-core computers. Since, in traditional compilers, optimization problems are associated with huge and unstructured search spaces, this combinational task is poorly achieved in general, resulting in poor scalability and disappointing sustained performance of the supposedly optimized program.
[0031] Generating efficient code for deep parallelism and deep memory hierarchies with complex and dynamic hardware components is a difficult task: the compiler (and run-time system) has to take the burden of tasks that only expert programmers would be able to carry. In order to exploit parallelism the first necessary step is to compute a representation which models the producer/consumer relationships of a program as closely as possible. The power of an automatic optimizer or parallelizer greatly depends on its capacity to decide whether two portions of the program execution may be interchanged or run in parallel. Such knowledge is related to the task of dependence analysis which aims at precisely disambiguating memory references. The issue is to statically form a compact description of the dynamic properties of a program. Forming a precise description is generally undecidable and approximations have to be made.
[0032] Once dependence analysis has been computed, a compiler performs program transformations to the code with respect to different, sometimes conflicting, performance criteria. Any program transformation must ultimately respect the dependence relations in order to guarantee the correct execution of the program. A class of transformations targeting the loop nests of a program (such as “DO” loops in the FORTRAN language, and “for” and “while” loops in languages derived from the C language) are known to account for the most compute intensive parts of many programs. The polyhedral model is a representation of a program's structure particularly suited for expressing complex sequences of loop nests, complex sequences of loop nest transformations, and other relevant information such as for instance dependences, communications, and array layouts.
[0033] A polyhedron is defined as a set of points verifying a set of affine inequalities and equalities on a number of variables. There exist alternate but equivalent definitions for polyhedrons, such as the one based on a combination of vertices, rays and lines proposed by Minkowski. There are also alternate representations, often based on the alternate definitions. While the present disclosure teaches using one of those definitions and representations to illustrate the various embodiments, various embodiments are in no way restricted to a particular definition or representation.
[0034] A polyhedral domain is defined as a finite union of polyhedrons. One of the main interests in using polyhedral domains is that they provide a precise representation of sets and relations among sets, on which many optimization problems can be phrased and solved using a rich set of algorithms, which are mostly available in the literature. Some embodiments of the sets in question represent loop iterations, mono- and multi-dimensional data sets, sets of processing elements, data transfers, synchronizations, and dependences. Thus, essential characteristics of the execution of a program can be summarized into compact mathematical objects, polyhedrons, which can be manipulated and transcribed into an executable program that has desired execution properties.
[0035] By considering a subset of the variables of a polyhedron as symbolic constants, also called “parameters”, it is possible to perform program optimizations and parallelization as a function of the symbolic constants. Hence, programs involving loops that depend on a constant value that is not known at the time when compilation is performed, but only when the program is executed, can be modeled using polyhedrons that are defined as a function of those constant values. A polyhedron involving parameters is called a parametric polyhedron. Similarly, a parametric polyhedral domain is defined by a finite union of parametric polyhedrons. For instance, the set of values that the counters of a loop nest reach during the execution of the loop nest is represented by the loop nest's “iteration domain”. The iteration domain of the following loop nest (using the C language's syntax, where F is a C function call) can be written as the parametric domain P(n): {(i, j)εZ 2 |5≦i≦n; 0≦j≦10; j≦i}:
[0000] for (i=5; i<=n; i++) { for (j=0; j<=i && j<=10; j++) { F(i,j); } }
The set of iterations of such a loop nest depends directly upon the value of the parameters. The parametric domain that represents the set of iterations is called a “parametric iteration domain”. It has to be noted that the values of the loop counters are integer. Hence, the set of values of i and j also lie on a regular lattice of integer points (the standard lattice Z 2 in the current example). However, it is possible to represent the fact that a set belongs to a polyhedral domain as well as the fact that it also belongs to a regular lattice of points using polyhedral domains exclusively. While alternate, equivalent representations exist (for instance those based on “Z-polyhedrons”, which are an explicit intersection of a polyhedral domain and a lattice of integer points), various embodiments of the present invention are in no way restricted to exclusively using polyhedral domains. The use parametric polyhedral domains as a means to illustrate various provided embodiments. In some embodiments, either or both polyhedrons and Z-polyhedrons can be used as a representation, and there exist conversion methods between both representations.
[0036] While most of the transformations applied to the polyhedral representation of a program are defined for any element of the polyhedral domain to transform, a class of more complex and precise transformations is obtained by partitioning the vector space in which the polyhedral domain is defined into sub-polyhedrons, and by defining a different transformation for each polyhedron of the partition. The resulting transformation is called a “piecewise” transformation. For example, consider the transformation that takes two numbers i and j and computes three numbers x, y, and z as: {x=2i+1; y=(i+j)/2; z=−3j+4} when i is greater than j and {x=i; y=i−j+3; z=2j} when i is less than or equal to j. It is a piecewise affine function since it has different definitions for each set of values, {i>j} and {N}, which define a partition of the (i,j) vector space.
[0037] The context of various embodiments, the use of polyhedral representations to perform complex optimizations on programs, either independently or within a system of optimizing components. An exemplary embodiment of such a system is illustrated in FIG. 1 , where it is described as being part of a compiler. Flow of the exemplary embodiment starts in block 1 , where the compiler is processing a program. Flow continues in block 14 , where the compiler analyzes the program to decide if there are portions of the program that should be optimized and mapped using a polyhedral system. If it is the case, the flow goes to block 2 , where the compiler provides the system of optimizing components with a polyhedral representation of a portion of the program to be optimized. If not, the compiler continues to process the program without using the system of optimizing components and completes. The components of the system are in charge of a part of the global optimization of the input program. In the flow of the embodiment illustrated in FIG. 1 , the polyhedral representation of the input code is analyzed in block 2 to produce dependence information. Flow continues in block 3 where such information is used in a local memory compaction component or module that modifies array layouts in a way that removes some dependencies, schedules loop iterations in a way that exposes loops that scan independent iterations, and schedules the execution of operations using a same data to be executed within a close time interval. Flow continues in block 4 , where the modified polyhedral representation of the program is processed by another optimizing component, which partitions the represented loop operations into entities called tasks, which have good data locality properties (they access a data set that involves an optimized use of the memory subsystem of the target computer), and assigns a processing element of the target machine to each task. In this exemplary embodiment, the flow continues to decision block 5 , which decides which block is next in the flow as a function of the target machine. If the target machine requires the execution of explicit communication commands to transfer data to and from its processing elements, flow goes to block 6 , where the representation of the program thus modified is then processed by a series of optimizing modules which define a new layout for data that is transferred to a processing element's local memory. Otherwise, the flow goes to block 9 . From block 6 , flow continues to block 7 , where a representation of the explicit communications is produced, based on polyhedrons, and then to block 8 , where the execution of the communications are scheduled for parallel execution with the tasks, using multi-buffering. Whether the target machine requires explicit communications or not, the flow continues to block 9 , where an optimizing component processes the polyhedral representation of the program obtained from the previous components by inserting a polyhedral representation of synchronization operations, which ensure that the execution of the modified program produces the same results or similar results as the original input program. The flow of the exemplary embodiment then goes to block 11 , where an optimizing component partitions the tasks into subtasks whose execution reduces traffic between the processing elements' memories and their registers. Then, in block 12 , a polyhedral representation of commands that trigger the execution of a series of tasks on the different processing elements of the target machine and that wait for the completion of those, is generated by the next optimizing component. Finally, in block 13 , the polyhedral representation of the optimized program is transformed by polyhedral code generation component into a representation (Abstract Syntax Tree, high-level language code, or a compiler's internal representation) that can be either processed by a compiler or processed further by the user. In the exemplary embodiment, the flow continues back to block 1 , where it may cycle again through the whole flow if there is more code to be optimized using the system of optimizing components.
[0038] In contrast to compilers based on polyhedral domains, traditional loop-oriented optimizing compilers typically perform syntactic transformations. As a result, many interesting optimizations are often not available, such as fusion of loops with different bounds or imperfectly nested loop tiling.
[0039] In some embodiments, the optimizing components or modules comprise processor executable code that when executed by a processor, convert source code into other forms of source code, or in some instances machine code. In other embodiments, various modules may be implemented in hardware such as monolithic circuits, Application Specific Integrated Circuits (ASIC), or Field Programmable Gate Arrays (FPGA). These modules may comprise software, hardware, firmware, or a combination of these implementations. It is important to note that various embodiments are illustrated in specific programming languages, these illustrations are mere examples and the scope is not therefore limited to any particular programming language.
[0040] Embodiments of a provided optimization module, described above as local memory compaction are illustrated in FIGS. 2-8 . FIG. 2 illustrates the flow of a provided method for local memory compaction. Flow begins in block 10 where source code is received into memory. In this embodiment, the source code represents loops with arbitrary parametric affine iteration domain and contains at least one array reference. An array reference is an operation that represents an access, typically a read or a write, to an array. Such a reference represents, either explicitly or implicitly, for instance by using programming language conventions, a function to retrieve the memory address of an element of the array. In loop programs, that function is typically a direct or indirect function of the loop indices and of some loop-constant values. For instance, in C, arrays are typically referenced through mono- and multi-dimensional affine functions of some input values. In the C language, the declaration of an array includes parameters called “array size”, which implicitly define the address of an array element as a function of the input values to references to this array. declaring “char A[100][200]” allocates an array of 20000 elements (100×200), named A, and defines that for any two integer values x and y, the memory address of the element of A referenced through A[x][y] is b+200x+y, where b is a value called the “base address” of array A. b is constant for each array and is determined at some point in the compilation process. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. In one embodiment, the inefficiencies are related to access and memory footprint of the array. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. The mapping portion of the module outputs code that is more efficient than the original code in terms of the memory size requirements of the local array versus the original array. In some embodiments the accessed data is arbitrarily complex. In further embodiments, the mapping produces a piecewise affine index function for the local arrays. Other embodiments include the rendering of a visualization of the optimized code on a monitor.
[0041] Arrays are typically allocated sets of contiguous memory blocks. Some loop operations may access only portions of the allocated memory. When reorganizing the data layout for a specific processor, there is an opportunity to take advantage of the inefficiencies in memory access requirements versus the actual utilization of the array. For example, given the following code fragment, 900,000 contiguous memory blocks are allocated, but only 100 are accessed in this operation. Furthermore, access to the array is not contiguous, but contains gaps, and thus will have less than optimal locality. Thus keeping the original data layout (and array size) in a remote processor is extremely inefficient. Moreover, if there are less than 900,000 blocks available in the local memory, the local memory cannot hold the entirety of the array and the program cannot be executed properly. In the provided code fragments, we are using “ . . . ” to elude other operations which do not have any specific illustrative purpose.
[0000]
double A[300][300];
for (i=0; i<100; i++) {
. . . = . . . A[2*i+100][3*1]; }
[0042] One embodiment of a provided method, illustrated in FIG. 2 , would map this code fragment into a local array with 100 elements. An exemplary mapping would produce the following pseudo-code fragment, in which the storage requirement of a local array is reduced from 300×300 elements to the optimal 100 elements.
[0000]
double A_local[100]; //local memory
transfer A[2*i+100][3*1] to A_local[i], i=0, 1, ... 99;
for (i=0; i<100; i++) {
. . . = . . . A_local[i]; }
[0043] One feature of this embodiment is that it provides a method of compacting local memory in a computing apparatus. This method provides a more efficient memory structure in terms of both access to the elements and the amount of memory occupied by the data that is actually accessed. The memory requirements are reduced from the initial allocation to an allocation that is large enough to contain the data that is actually used in the operations. In contrast to other methods, the provided method handles loops whose iteration domains are non-rectangular, and loops that have a parametric iteration domain. In this document we refer to polyhedral iteration domains that are either non-rectangular or parametric or both as “arbitrary parametric iteration domains”. In addition, the provided methods handle non-convex accessed data sets. The provided embodiments are very useful in image and video processing. Imaging applications typically utilize significant multi-dimensional arrays where data representations of physical objects and systems are stored. Many image processing steps, such as discrete wavelet transforms for example, only utilize discrete portions of the stored data. In these situations, various embodiments provide significant optimizations to local data storage.
[0044] Another embodiment of a provided method is illustrated in FIG. 3 . In this embodiment, flow begins in block 10 where source code is received in memory. Similar to the above embodiment, the source code contains loops with arbitrary parametric iteration domain and contains at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. In this embodiment, mapping block 40 includes partitioning references to form compatible references in block 50 ; determining a relation within compatible references in block 60 ; grouping compatible references based on the relation in block 70 ; performing algebraic simplification in block 80 ; and performing geometric arrangement through re-indexing the elements of the local array in block 90 . In some embodiments the set of references partitioned are references that access a portion of the array. The following pseudo-code example illustrates this embodiment.
[0000]
float A[256] [256] ;
doa11 (1=128*j+16*P; 1 <= min(−i+254,128*j+16*P+15); 1++)
doa11 (m = 16*k; m <= min(−i+254, 16*k+15); m++)
A[1+i+m] [1+i+1] −= A[1−i+m] [i] * A[i] [1+i+1];
[0045] In this case, all three references to array A are disjoint in that they access disjoint portions of the array. In this case, they are transformed into three local arrays A — 2, A — 3 and A — 4 in the following manner.
[0000]
float A_2[16] [16]; // a triangular subregion of A
float A_3[16]; // a column of A
float A_3 [16]; // a row of A
doa11 (1 = 0; 1 <= min(15, −i−128*j−16*P+254); 1++)
doa11 (m = 0; m <= min(−i−16*k+254, 15); m++)
A_2[m] [1] −= A_3[m] * A_4[1];
[0046] Performing transformations of the way data are allocated in memory, i.e., transforming the data layouts, has a combinational aspect, since the data sets accessed through each array reference may overlap with one or more data sets accessed by other array references. Since each one of those overlaps entail constraints in the way that data layouts can be transformed, analyzing all the combinations of overlaps for all the references is a source of high computational complexity. Hence, references are grouped into sets in such a way that data accessed through one set of references does not overlap data accessed through another set of references. In this embodiment, references of the same set are called “compatible references”. Since there is no overlap among sets of compatible references, the following parts of the memory layout transformation, which consider the overlaps, can be applied independently to each set of compatible references. In particular, they will decide if the overlapping data sets accessed by a set of compatible references should be partitioned further and how.
[0047] In some embodiments, compatible references are identified by overlapping memory footprints during the execution of a particular subset of loop iterations. In an exemplary embodiment, the provided method identifies array references having overlapping memory footprints; duplicates a portion of the identified references; and associates each of the duplicates with disjoint subsets of the memory footprint. An example pseudo-code illustrates this embodiment.
[0000]
double A[100] [100];
for (j = 0; j < 100; j++) {
... = A[i] [j] * A[j] [i];
}
[0048] The two references A[i][j] and A[j][i] overlap when H. However, if the references are allocated together, it is impossible to reduce the local memory usage using only affine transformations. This is because the data footprint of the two references is a 2-dimensional set (a cross), while the data footprints of the individual references are both 1-dimensional. In order to compute better allocations in situations like this, one embodiment first estimates how much overlapping is in the references. If the references are read-only, and if the overlapping data set is a small percentage of the overall data set, the embodiment splits the references into two distinct references to one-dimensional data sets. In the above example, the embodiment will generate the following local memory allocation. Note that the center element of the data foot print, A[i][i], has been replicated and put into the locations A_I[i] and A — 2 [i].
[0000]
double A_1[100];
double A_2[100];
Transfer A[i] [j] to A_1[i], i = 0 . . . 99
Transfer A[j] [i] to A_2[i], i = 0 . . . 99
for (j 0; j < 100; j++)
... A_1[j] * A_2[j];
[0049] The geometric re-arrangements provided by a further exemplary embodiment are defined by a piecewise affine transformation. In other words, the transformation applied to the references is defined as a set of functions, each element of the set being valid within a polyhedral domain of the loop values, the parameters and the coordinates of the data accessed through the set of compatible references. In an exemplary embodiment, when some of the data accessed by a set of compatible references are written by some of the references, the written data subset and a subset of the data set that is only read define a partition for the piecewise affine transformation. Consider the program represented by the following pseudo-code:
[0000]
double A[100][100];
for (j = 0; j < 99; j++) {
A[i] [j+1] = ... A[j] [i];
}
[0050] In this example, the data set accessed by the both references to array A form a two-dimensional set, while the data sets accessed through each reference are one-dimensional. The data accessed through both references overlap in A[i][i]. In the exemplary embodiment, a piecewise transformation of A is applied, which separates A into two subsets, one for each one-dimensional data set, and marks one of them as receiving the updates (let us call it the “writing reference”) to the duplicated data. In the example, the duplicated data is A[i][i] and the iteration domain is partitioned into three polyhedral domains, {0≦j<i}, {j=i} and {i<j<99}, in order to take into account the fact that only one of the data subsets is updated. Such a partition of the iteration domain is obtained by defining the iterations accessing duplicate data through “non-writing” references and replacing those accesses with an access through the writing reference. The resulting piecewise affine transformation is {(A[i][j−1]=A — 1[j], A[j][i]=A — 2[j]) for 0≦i<100, 0≦j<i or i<j<100; and (A[i][j−1]=A — 1[j], A[j][i]=A — 1[j]) for 0≦i<100, i=j}. The result of the piecewise affine transformation can be represented by the following pseudo-code, which uses only two arrays as a replacement for the original array A, has quasi-optimal memory requirements (198 memory cells, while the optimal would be 197):
[0000]
double A_1[99], A_2[99]
for (int j=0; j<i; j++) {
A_1[j] = ... A_2[j];
}
A_1[i] = ... A_1[i−1]; // the updated value of A[j][i] is
in A_1[j] when j=i
for (int j=i+1; j< 99; j++) {
A_1[j] = ... A_2[j];
}
[0051] In other exemplary embodiments, the geometric rearrangement is a piecewise affine transformation that defines a partition of the iteration domain and of the data sets in such a way that the number of references to a local array varies from one element of the partition to another. In the following example, in which the possible values of variable i are {0≦i≦99900}, the data sets accessed through reference A[j] and A[i+j] overlap when i is less than 100. Otherwise, they do not overlap.
[0000]
double A[10000];
for (j =0; j< 100; j++) {
A[i] = ... * A[i+j]
}
[0052] Since those data sets overlap for some values of i, both references are put in the same group of compatible references. If the accessed data sets are allocated as a single local array, the amount of memory necessary to contain the array is 10000 memory cells. On the other hand, if they are allocated as two separate arrays, some of the data would have to be duplicated and the iteration domain (the j loop here) would have to be partitioned as in the previous exemplary embodiment. The amount of overlap when i is less than 100 may not be small enough and it may not be profitable to perform the duplication. The geometric rearrangement provided by the embodiment is a piecewise affine transformation that defines a partition of the set of parameters (in the current example, i): {(A — 1[j]=A[j]) for 0≦i<100, and (A — 1[j]=A[j], A — 2[j]=A[i+j]) for i≧100}. The maximum amount of memory that has to be allocated for any value of i is 200 memory cells (as compared to 10000), and it is 100+i when i is less than 100. The resulting transformation can be represented as pseudo-code as follows:
[0000]
if (i <100) {
double A_1[100+i];
for (j=0; j< 100; j++) {
A_1[j] = ... * A_1[i+j]
}
else {
double A_1[100];
double A_2[100];
for (j=0; j<100; j++) {
A_1[j] = ... *A_2[j];
}
}
[0053] One advantage of the geometric rearrangement that is performed by this exemplary embodiment is that the j loops are not partitioned. Partitioning the loops into smaller loops is often a factor of performance degradation, which is avoided in this exemplary embodiment. The partition of i is obtained by computing the domain in which both data sets intersect, by projecting the intersection onto the vector space of the parameters (in the current example, the parameter is i and the projected domain is {i<100}.
[0054] The operation flow of a further provided embodiment of a local memory compaction module is illustrated in FIG. 4 . In this embodiment, flow begins at block 10 where source code is received in memory. Similar to the above embodiment, the source code represents loops with arbitrary parametric affine iteration domains and contain at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. In this embodiment, the identification of inefficiencies includes block 100 where strides in the polyhedral domain that defines the accessed dataset are identified, and block 110 where a lattice of integer points within the domain is extracted from the domain. These integer points indicate that only a regular subset of the accessed data region is accessed. In this manner, more efficient allocation of local arrays is accomplished because portions of the array that are not accessed are identified and excluded from the mapping from the array to the local array.
[0055] An additional provided embodiment is illustrated in FIG. 5 . In this embodiment, like earlier embodiments flow begins at block 10 where source code is received in memory. Similar to the above embodiment, the source code represents loops with arbitrary parametric affine iteration domain and contains at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. In this embodiment, like in the embodiment illustrated by FIG. 3 , mapping block 40 includes partitioning references to form compatible references in block 50 ; determining a relation within compatible references in block 60 ; grouping compatible references based on the relation in block 70 ; performing algebraic simplification in block 80 ; and performing geometric arrangement in block 90 . The algebraic simplification block 80 includes block 130 where a representative array reference is extracted from a set of references accessing a portion of the array. In some embodiments, the representative array reference represents a set of references which access polyhedral datasets whose accessed points all lie on a lattice of integer points that is not the standard lattice, on which any integer point lies. These embodiments take advantage of the fact that array references represent affine functions, which can be represented as matrices called “access matrices”. In the exemplary embodiment, the flow within block 40 goes from block 130 to block 140 where a Hermite factorization is performed for the access matrix representing the representative array reference. The Hermite factorization produces a piecewise affine index function.
[0056] One purpose of Hermite factorization is to reduce the dimension of the reference to the actual geometric dimension of the data footprint. In addition, if the access pattern contains strides, i.e., regular intervals between accessed data, using the non-unimodular matrix that results from the Hermite factorization in the transformation removes these strides in the resulting local references. For example, given an affine access function f(x, y) on loop indices x and parameters y, we first decompose it into the sum of g(x)+h(y), where g(x) is a linear function on x and h(y) is an affine function on y. This decomposition is an algebraic simplification that makes it possible to perform further computations on the part of f(x,y) that involves variables only. Function g(x) can be decomposed into g(x)=HU, where H=[H′ 0] is the Hermite Normal Form of g(x) and U is unimodular matrix. Let
[0000]
U
=
[
U
1
U
2
]
[0000] where HU=H′U 1 . The following mapping from global to local indices is then performed f(x, y)f→U 1 x.
[0057] Hermite factorizations have many uses is lattice computations. The Hermite factorization of a matrix G, written G=HU, writes matrix G as the product of two matrices, H and U. H, called the “Hermite normal form”, is a canonical representation of the lattice (also) represented by G. U is a unimodular matrix, which entails that U, when used as a transformation, always transforms any point that has integer coordinates into another point that has integer coordinates. Also, any point that has integer coordinates can be obtained by transforming a point with integer coordinates using a unimodular transformation. This is important since most programming language conventions enforce that data elements, and particularly array elements, must have integer coordinates.
[0058] The flow of a still further provided embodiment is illustrated in FIG. 6 . In this embodiment, like previous embodiments, flow begins at block 10 where source code is received in memory. Similar to the above embodiment, the source code represents loops with arbitrary parametric affine iteration domain and contain at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. In this embodiment, mapping block 40 includes partitioning references to form compatible references in block 50 ; determining a relation within compatible references in block 60 ; grouping compatible references based on the relation in block 70 ; performing algebraic simplification in block 80 ; and performing geometric arrangement in block 90 . Geometric rearrangement 90 contains blocks 150 where linear constraints are formed, block 160 where sets of linear programming problems are formed from the linear constraints and solved, and block 170 where a data reindexing is computed. In some embodiments, the flow goes back to block 150 . In such embodiments, geometric rearrangements are applied iteratively until no reindexing function is found that reduces memory requirements.
[0059] Most modern programming languages abide by the convention that multi-dimensional arrays are allocated in memory as if they were canonical rectangular parallelotopes. In a space of d dimensions, a parallelotope is a finite polyhedron defined by 2d faces, and whose faces are pair-wise parallel. A canonical rectangular parallelotope is a parallelotope for which the normal vectors to its faces are either a canonical vector or the negation of a canonical vector. Examples of rectangular parallelotopes are a cube (in a 3-dimensional space) and a rectangle (in a 2-dimensional space). In an exemplary embodiment, the transformation is a unimodular reindexing of the accessed data that minimizes the size of the smallest canonical rectangular parallelotope that encloses the accessed dataset. The smaller the enclosing rectangular parallelotope, the smaller the amount of memory that has to be allocated for the dataset.
[0060] In some embodiments, this is accomplished by formulating a first set of linear constraints through the use of Farkas Lemma. This first set of linear programming constraints is decomposed dimension by dimension to form a set of integer linear programming problems. This set of problems is then solved to provide the data reindexing function which can then be applied to the at least one local array. Unimodular reindexings transform integer points into integer points. Hence, the convention that data elements have integer coordinates is preserved by such a reindexing. In the case of affine transformations, the linear part of the transformation can be represented by a unimodular matrix.
[0061] Farkas lemma is a basic linear algebra theorem which is often used to obtain, from a set of affine constraints (i.e., inequalities and equalities) on variables with unknown coefficients, constraints that apply to the unknown coefficient themselves. In this embodiment, it is used to obtain a set of constraints involving the coefficients of the unimodular data reindexing function (which is represented as a matrix) and the width of the enclosing rectangular parallelotope along each dimension. From those obtained constraints, the method embodiment finds values of the coefficients of the unimodular data reindexing function for which the width is minimal, using integer linear programming. For example, the data set accessed through reference B[i+j][j] in the following pseudo-code can be reindexed so as to occupy only 100 memory cells:
[0000]
Double A[n+10][n+10];
Double B[[2n+20][n+10];
For (i=n; i<n+10; i++) {
For (j=n; j<n+10; j++) {
A[i]j] = ... B[i+j][i];
}
}
[0062] The coordinates (x 1 ,x 2 ) of the elements of array B accessed by that loop node are defined by the constraints D:{n≦x 2 <n+10; n≦x 1 ≦n+10}. The embodiment finds values of the coefficient of a matrix U such that U is unimodular and the coordinates x′ 1 and x′ 2 of the reindexed data are defined by:
[0000]
[
x
1
′
x
2
′
]
=
U
[
x
1
x
2
]
+
[
t
1
t
2
]
n
+
[
t
01
t
02
]
[0000] The set of possible values of the coefficients of U, as well as the possible values of t 1 , t 2 , t 01 and t 02 are defined from the set of constraints D and the constraints that the data (x′ 1 ,x′ 2 ) are enclosed in a rectangular parallelotope of size (s 1 , s 2 ) using Farkas lemma. Then, a value for those coefficients is computed for which the size of the smallest enclosing rectangular parallelotope (s 1 , s 2 in our example) is minimal. Those values are computed by solving, dimension by dimension of the data set, an integer linear programming problem.
[0063] An integer linear programming problem defines a linear function of a set of variables, called the “objective function” and whose minimal (or, alternatively, maximal) value over a polyhedral domain called the “feasible set”, is looked for. Solvers for such problems typically return a polyhedral domain, within the feasible set, for which the value of the objective function is minimal. In the running example, the embodiment finds:
[0000]
[
x
1
′
x
2
′
]
=
[
1
-
1
0
1
]
[
x
1
x
2
]
+
[
-
1
-
1
]
n
+
[
0
0
]
[0000] The following pseudo-code represents the program resulting from the data reindexing of array B in our running example:
[0000] Double A[10][10]; Double B[[2n+20][n+10]; For (i=n; i<n+10; i++) { For (j=n; j<n+10; j++) { A[i]j] = ... B[j−n][i−n]; } }
The data footprint of the re-indexed array B is now reduced to 100 memory cells, instead of n 2 +20n+100 initially.
[0064] In one of the exemplary embodiments, the unimodular nature of the reindexing matrix U is obtained by forcing U to be triangular and forcing the absolute value of the diagonal elements to be one. In another embodiment, the unimodular nature of the reindexing matrix is obtained by composition of an upper triangular unimodular and a lower triangular unimodular matrix. The advantage of that other embodiment is that the class of unimodular reindexing functions produced is not limited to the reindexing functions represented by a triangular matrix. Finding those two matrices is equivalent to reindexing data twice, first by finding an upper triangular reindexing matrix as described above and applying the reindexing, and then by finding a lower triangular reindexing matrix for the reindexed set and by applying that second reindexing. Yet another embodiment produces, in the same way, a unimodular reindexing by composition of an upper triangular unimodular matrix, a permutation matrix and a lower triangular unimodular matrix. The advantage of the embodiment is that the class of reindexing function that can be produced is the whole class of integer unimodular matrices.
[0065] Turning to FIG. 7 which illustrates another embodiment of a provided method, like the previous embodiments, flow begins in block 10 where source code is received in memory. Similar to the above embodiment, the source code represents loops with arbitrary parametric affine iteration domain and contains at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. In this illustration, block 40 contains block 180 where a parallelotope of minimal volume is derived this parallelotope enclosing the domain of the data set accessed by the local arrays. Block 40 additionally contains block 190 where a finite prism of triangular base is derived.
[0066] As used herein, a finite prism is a polyhedron defined by a set of translations of a “base” polyhedron, which lies in a subspace of the considered space, by a finite convex set of linear combinations of vectors of the complementary subspace. Since they are finite, it is possible to characterize the maximum extent of a finite prism along the directions of the complementary subspace. In this document, those extents are called “height” of the prism (there is one height along every direction of the complementary subspace). A triangular prism is a prism whose base polyhedron is a triangle. In two dimensions, it is just a triangle. In one embodiment, this finite prism has a minimum volume that encloses the data footprint domain. In block 200 the prism is compared to the parallelotope. In block 210 the prism is partitioned into two prisms. One of the two is then transformed using a central symmetry such that the union of the transformed prism and the non-transformed prism has a smaller memory footprint than the enclosing parallelotope. One advantage of that embodiment is that it provides data layouts that have smaller memory requirements, for a class of accessed datasets for which methods based on parallelotopes are not optimal.
[0067] For instance, the dataset accessed by the program represented by the following pseudo-code through reference B is triangular:
[0000]
For (i=0; i< 10; i++) {
For (j=0; j< i; j++) {
... = ... B[i][j];
}
}
[0068] The embodiment finds three constraints that enclose the accessed data set, in a similar way as in the embodiment depicted in FIG. 6 , using the Farkas lemma. The minimal volume for a parallelotope that encloses the dataset would be about twice the volume of the triangle. Hence, using such a parallelotope to determine the memory allocation of the dataset is bound to be sub-optimal. Instead, the current embodiment, depicted in FIG. 7 , defines a tighter enclosing polyhedron using three inequalities (it is then a prism of triangular base). Using the enclosing prism, the data set is partitioned in two subsets, say A and B, and subset A is re-indexed in such a way that both the array elements in B and the re-indexed elements are enclosed in a smaller parallelotope than the original parallelotope. The volume of the new parallelotope is about the volume of the prism of triangular base. Since there is a parallelotope of smaller volume enclosing the reindexed data set, its memory requirements are smaller. The result is a piecewise affine array reindexing, which typically partitions the loop iterations into the iterations that access A, and the ones that access B.
[0069] In the current embodiment, the three inequalities {(a): aI+a 0 ≧0; (b):bI+b 0 ≧0; (c): cI+c0≧0} that define the triangular prism P, where I is the vector of data coordinates are used to devise the partitioning. Let x w a point in the intersection of (b) and (c) and let w=ax w I+a 0 . The prism is partitioned into A and B as follows:
[0000]
A
=
P
⋂
{
aI
+
a
0
-
w
+
1
2
≥
0
}
[0000] and B=P−A. A point, x 0 , is defined that is in the domain {aI+a 0 −w+1<0; bI+b 0 <0} whose coordinates are a multiple of ½ and whose “height” in the prism is about half of the height of the prism. Array elements that are defined by A are transformed using a central symmetry of center x 0 . In the program represented by the following pseudo-code, the tightest enclosing parallelotope, defined by {0≦x1≦9; 0≦x2≦9}, where x1 represents the first dimension of array C and x2 its second dimension, includes 100 array elements.
[0000]
Double C[10][10];
For (i=0; i< 10; i++) {
For j=0; j< i; j++) {
...C[i,j]...;
}
}
[0070] The tightest enclosing triangle, defined by {0≦x1; 0≦x2; x1+x2≦9}, by comparison, includes 55 elements, which is about half the number of elements required for the enclosing parallelotope. Since the number of array elements in the enclosing triangle is less than the number of array elements in the enclosing parallelotope, the embodiment considers the tightest enclosing triangle and partitions the enclosed data into data subsets A: {0≦x 1 ; 5x 2 ; x 1 +x 2 ≦9} and B: {0≦x 1 ; 0≦x 2 ≦4; x 1 +x 2 ≦9}. Point x 0 =(5, 9/2) is selected as center of symmetry and the elements of A are then transformed into a new array subset A′ as follows:
[0000]
{
x
1
′
=
(
2
⋆
5
)
-
x
1
;
x
2
′
=
(
2
⋆
9
2
)
-
x
2
}
,
[0000] where (x′ 1 ,x′ 2 ) are the new array element coordinates. The resulting program can be represented by the following code:
[0000] Double C[11][5]; For (i=0; i< 10; i++) { For (j=0; j<=4 && j<i; j++) { ...C[i][j]...; } For (j=5; j<i; j++) { ...C[10−i][9−*j]...; } }
The accessed data set is included in the parallelotope {0≦x1<11, 0≦x2<5}, whose memory requirements are of 55 memory cells, i.e., about half of the parallelotope before the transformation. Other data layout optimizations, which are optimal when there is a tight parallelotope enclosing the accessed dataset, will then be more optimal than if applied straightforwardly to the original dataset that can be enclosed more tightly with a triangular prism.
[0071] FIG. 8 illustrates a further embodiment of a provided method. In this embodiment, flow begins in block 10 where source code is received in memory. Similar to the above embodiment, the source code contains loops with arbitrary parametric affine iteration domain and contain at least one array reference. Flow continues to block 20 where inefficiencies in memory usage in the at least one array are identified. Flow then continues to block 30 where at least one local array is allocated, and in block 40 a portion of the array with inefficient memory usage is mapped into the local array. Flow then continues to block 220 where asynchronous communications and wait operations are generated. The exemplary embodiment uses the mapping between local memory elements and the elements of the original arrays, in conjunction with a description of the data that are needed as input and produced as output of the tasks to be executed, to produce an abstract representation of the transfers between the original arrays and the local memory elements. In an exemplary embodiment, the generation of these communications and wait operations includes the use of multi-buffering for overlapping communication and computation operations.
[0072] Many computers that contain processors that have an explicitly managed local memory also have the ability to transfer data at the same time as they are performing other computations. Such transfers are called “asynchronous”. The main reason for using that feature is that the typical time necessary for such transfers is often comparable to the time taken to perform computations between two consecutive transfers of input data. Since doing both transfer and computation at the same time takes less time than doing one after another, the effect of overlapping them is to improve the overall program execution time. The use of several memory zones, specialized to either execution, reception or sending of data, makes the overlap possible. Such a use is called “multi-buffering”. The specialization of the buffers is also modified at certain times. Such a modification is called a “rotation of the buffers”, since a buffer is cyclically assigned the same specialization.
[0073] One embodiment computes a local memory mapping, adds a polyhedral representation of the communications and schedules communications and computations in a multi-buffering scheme for the program represented by the following pseudo-code. In this pseudo-code, every iteration of the k loop works on a distinct instance of local memory:
[0000]
for (k = 0; k <= 7; k++) {
for (l = 0; l <= 15; l++) {
for (m = 0; m <= 15; m++) {
for (n = 16 * k; n <= 16 * k + 15; n++) {
C[l][m] = C[l][m] + A[l][n] * B[n][m];
}
}
}
}
[0074] This results in a program that can be represented by the following pseudo-code:
[0000] for (k = −1; k <= 8; k++) { if (k <= 7 && k >= 0) { wait(tag=0); rotate(vars=[C_l, A_l, B_l]); } if (k <= 6) { for (l = 0; l <= 15; l++) { for (m = 0; m <= 15; m++) { get(src=&B[l][16 + 16 * k + m], dst=&B_l<1>[l][m], tag=0); } } for (l = 0; l <= 15; l++) { for (m = 0; m <= 15; m++) { get(source=&A[l][m], destination=&A_l<1>[l][m], tag=0); } } for (l = 0; l <= 15; l++) { for (m = 0; m <= 15; m++) { get(src=&C[l][16 + 16 * k + m, tag=0); } } } if (k >= 1) wait(tag=1); if (k <= 7 && k >= 0) { for (l = 0; l <= 15; l++) { for (m = 16 * k; m <= 16 * k + 15; m++) { for (n = 0; n <= 15; n++) { C_l[l][−16 * k + m] = C_l[l][−16 * k +m] + B_l[n][−16 * k + m] * A_l[l][n]; } } } for (l = 0; l <= 15; l++) { for (m = 0; m <= 15; m++) { put(src=&C_l[l][m], dst=&C[l][16 * k + m], tag=1); } } } }
In the code example, “Get” operations are transfers from an original array to a re-indexed array in local memory. “Put” operations are transfers from local memory to original array. While the values of k in the original program were going from 0 to 7, in the multi-buffered version produced by the embodiment they are going from −1 to 8. At iteration k=−1, the first “get” transfers are issued. At iteration k=8, the last “put” transfers are issued. “Wait” operations, which wait for the completion of a series of transfers, were also inserted to ensure that a transferred data set is completed at that point of the program's execution. In the embodiment, a tag system is used to identify the transfers whose completion is to be waited upon. The “rotate” operations operate the buffer rotation.
[0075] Illustrated in FIG. 9 are computing apparatus and computer software products consistent with provided embodiments. Computing apparatus 720 includes processor 660 , memory 670 , storage medium 680 , and in some embodiments input port 690 and network interface 710 . In many provided embodiments, storage medium 680 contains a set of processor executable instructions that when executed by processor 660 configure computing apparatus 720 to implement the modules and methods described herein. In one embodiment, storage medium 680 , containing the set of processor executable instructions resides in another computing apparatus 720 across network 730 . In an embodiment of a computer software product, computer software product 700 is a computer readable storage medium containing processor executable instructions sufficient that when executed by processor 660 configure computing apparatus 720 to implement the above described modules and methods. Further, computer software product, in some embodiments consists of a physical medium configured to interface with input port 690 to allow its contents to be copied to storage medium 680 . In other embodiments, computer software product 700 is an internal storage medium, such as 680 . An additional embodiment of computing apparatus 720 includes a plurality of processors 680 ( a - n ), a plurality of memories 670 ( a - n ), a storage medium 680 and in some embodiments input port 690 and network connection 710 . In some embodiments, one or more processors 680 ( a - n ) is a host, while others are modeled in the form of a grid.
[0076] Thus, it is seen that methods apparatus and computer software products for allocating arrays in memories with constrained memory requirements according to the way those arrays are accessed is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. The specification and drawings are not intended to limit the exclusionary scope of this patent document. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well. That is, while the present invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those of ordinary skill in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims. The fact that a product, process or method exhibits differences from one or more of the above-described exemplary embodiments does not mean that the product or process is outside the scope (literal scope and/or other legally-recognized scope) of the following claims. | Methods, apparatus and computer software product for local memory compaction are provided. In an exemplary embodiment, a processor in connection with a memory compaction module identifies inefficiencies in array references contained within in received source code, allocates a local array and maps the data from the inefficient array reference to the local array in a manner which improves the memory size requirements for storing and accessing the data. In another embodiment, a computer software product implementing a local memory compaction module is provided. In a further embodiment a computing apparatus is provided. The computing apparatus is configured to improve the efficiency of data storage in array references. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims. | 6 |
CROSS REFERENCE TO RELATED APPLICATION AND INCORPORATION BY REFERENCE
This application claims the benefit, pursuant to 35 U.S.C. §119(e), of U.S. Provisional Application No. 60/492,124, filed Aug. 1, 2003. The entire specification of U.S. Provisional Application No. 60/492,124, filed Aug. 1, 2003, including all text and drawing figures is hereby incorporated herein by this reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally pertains to the optical imaging arts. Further, the present invention pertains to an improved system for reading optical indicia.
2. Description of Related Art
Devices have been developed that can read optical indicia without coming into physical contact with the particular optical indicia being read. Such reading or imaging devices are said to read in an “non-contact” fashion. Portable and non-portable such devices are known.
The reading devices capture an image of the indicia by sensing light-energy reflected from the indicia to the reading device. Such optical indicia readers illuminate the optical indicia by directing or scanning a light-energy source, such as a laser-generated or other type of light, across the surface of the indicia. Other types of reading devices are sometimes referred to as “instantaneous” readers. These readers generally illuminate the entire optical indicia at once and sense the reflected light energy with an area-type sensor.
All types of optical indicia readers, however, often capture an image of an optical indicia that turns out to be unreadable. The unreadability can be the result of several factors. Sometimes, for example, the reader is not accurately aimed and a sufficient portion of the optical indicia is not within the captured field of view. Sometimes the light-energy reflected back to the reader is not sufficient to permit a quality imaging. Other factors can also cause a captured field of view to be unreadable. As a final example, if the optical indicia is not located within the indicia reader's depth of field, if the indicia is too far from the reader for example, the captured image will be too out of focus to be readable.
Past indicia readers have incorporated some features calculated to increase reading performance. For example, some readers employ filtering technology in the time or spatial domain to remove some problems. Some readers have used a Fourier transformation to aid the reading process. If, however, a filtered or Fourier transformed image is not readable, the reading process must start over and a new image must be acquired.
What is needed is an improved indicia reading system that can read images that would have been unreadable with previous systems. Such a capability would improve efficiency since fewer optical indicia would have to be reread.
SUMMARY OF THE INVENTION
The present invention provides an improvement in optical indicia reading systems. The system achieves its objective by using multiple images of the same field of view. Two or more symmetrical transforms are then applied to the images. Characteristic features are identified in the frequency domain. An inverse transform is then applied to create modified representations of the optical indicia being read. The various modified representations are then compared and they are combined to create an improved representation of the optical indicia.
Other embodiments, aspects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more fully understood by reading the following detailed description of the embodiments of the invention, in conjunction with the appended drawings, wherein:
FIG. 1 depicts a flowchart outlining steps that can be carried out in practicing the invention.
FIG. 2 depicts an optical indicia located within the field of view of an optical indicia reader.
FIG. 3 depicts an image of an optical indicia that has been captured by an optical indicia reader.
DETAILED DESCRIPTION
The present invention can be practiced with a wide variety of optical indicia readers. It will be appreciated that the present invention can be used with hand-held, portable, and stationary (non-handheld) optical readers. It can be used with scanning-style (laser and non-laser) readers as well as instantaneous or area-type optical readers. It is envisioned that many later-developed indicia readers will also be able to use this invention. The main requirements of the reading system being that it have sufficient processing capability and memory resources to perform the disclosed algorithms.
FIG. 1 depicts a flowchart outlining steps that can be carried out in practicing the invention. First, multiple images of the same field of view, a field of view containing an optical indicia for example, are captured 100 . The optical indicia can be any of a wide variety of such indicia. For example, the optical indicia can be a 1D or a 2D code or some other type of optical indicia. Optical indicia are well known in the art and will not be discussed here further.
FIG. 2 depicts a field of view 200 including an optical indicia 202 . In FIG. 2 , the optical indicia is depicted as a 1D bar code. The choice of a 1D bar code for FIG. 2 is for demonstration purposes only and should not be construed to limit the invention to the scanning of 1D codes. As explained, a wide-variety of codes can be read with the present invention. The field of view 200 can be captured, for example, by a scanning or an instantaneous type reader.
When an optical indicia, the indicia indicated in FIG. 2 for example, is captured but is not within the reader's depth of field, the captured image may be significantly distorted. FIG. 3 depicts one example of an image 300 captured when the field of view 302 is located outside of the reader's depth of field at the time of image capture. In this figure, the captured optical indicia 300 appears diffuse and out-of-focus. The image lacks the sharp black-to-white transitions of the actual indicia (see 202 , FIG. 2 ). The present invention, however, can convert a captured image that would otherwise be unreadable into a readable image representation. Thus, the need for a second or further imagings is eliminated.
Referring again to FIG. 1 , multiple images of the optical indicia should be captured or created 100 . The multiple images can be captured in quick succession due to the quick reading rates of many scanning and instantaneous readers. The number of images to be captured 100 will be a function of the resources of the reader and the expected reading conditions and parameters. The chances of obtaining a readable representation of an indicia increase when a greater number of images of the indicia are captured and processed.
The multiple images of the indicia are stored in memory in some suitable manner so as to permit them to be readily accessed and processed. In one embodiment, the multiple indicia images are sequentially connected together to form a single, integrated image of extended length. Other structures or relationships can alternatively be employed.
Next, a symmetrical transform is applied 102 to each indicia image to be processed. More than one transform is used. For example, if two images of an indicia are to be processed, each is subjected to a different symmetrical transform. If three indicia images are to be processed, three different transforms are applied: one transform for each indicia image to be processed. When more indicia images are to be processed, an equivalent number of transforms is used.
The symmetrical transform is applied to transform the indicia image from the time or spatial domain to the frequency domain. Several different symmetrical transforms are available for this purpose. For example, the transform can be a Fourier transform, a Karhunen-Loeve transform, or any of a multitude of Wavelet transforms.
The two-dimensional discrete Fourier transform pair for an N×N array of pixels f(x, y), x, y=0, 2, . . . , N−1 is given by the following equations:
f ( x , y ) = ∑ u = 0 N - 1 ∑ v = 0 N - 1 F ( u , v ) exp [ j 2 π ( ux + vy ) N ] and F ( u , v ) = 1 N ∑ x = 0 N - 1 ∑ y = 0 N - 1 f ( x , y ) exp [ - j 2 π ( ux + vy ) N ]
where u, v=0, 2, . . . , N−1.
The Wavelet transform decomposes signals over dilated and translated wavelets. A wavelet is a finite energy function ψ,
∫|ψ( t )| 2 dt<∞
with a zero average:
∫ - ∞ ∞ ψ ( t ) ⅆ t = 0.
It is normalized
∥ψ( t )∥=1
and centered in the neighborhood of t=0.
The ψ function can be any of a variety of different functions. Much work in this area has been done by Daubechies. Several functions that can be used for the ψ function are disclosed in I. Daubechies, Orthonormal Bases of Compactly Supported Wavelets, Comm. Pure & Appl. Math. 41, pp. 909-996 (1988), and I. Daubechies, The Wavelet Transform, Time - Frequency Localization and Signal Analysis, IEEE Trans. Inf. Theory 36, pp. 961-1005 (1990). The entire content of I. Daubechies, Orthonormal Bases of Compactly Supported Wavelets, Comm. Pure & Appl. Math. 41, pp. 909-996 (1988), and I. Daubechies, The Wavelet Transform, Time - Frequency Localization and Signal Analysis, IEEE Trans. Inf. Theory 36, pp. 961-1005 (1990), including all text, drawings and appendices, is hereby incorporated herein by this reference.
Thus, when applying the symmetrical transforms 102 , two or more Wavelet transforms, each having a different ψ function, can be used. Each different Wavelet transform being applied 102 to a different indicia image 100 . Further, one or both of the Fourier and Karhunen-Loeve transforms can be used in conjunction with one or more different Wavelet functions in the step of applying the symmetrical transforms 102 .
A family of time-frequency atoms is obtained by scaling ψ by s and translating by u;
ψ
u
,
s
(
t
)
=
1
s
ψ
(
t
-
u
s
)
A formal definition of the Wavelet transform of the signal f at time u and scale s is as follows:
Wf
(
u
,
s
)
=
〈
f
,
ψ
u
,
s
〉
=
∫
-
∞
∞
f
(
t
)
1
s
ψ
*
(
t
-
u
s
)
ⅆ
t
and
f
=
∑
u
=
-
∞
∞
∑
s
=
-
∞
∞
〈
f
,
ψ
u
,
s
〉
ψ
u
,
s
Since ψ(t) has a zero average, each partial sum
g s = ∑ u = - ∞ ∞ 〈 f , ψ u , s 〉 ψ u , s
can be interpreted as detail variation at the scale s. These detail variations are added at all scales to progressively improve the approximation of the signal f, and at the limit to fully reconstruct f.
After being transformed from the time or spatial domain to the frequency domain by application of the symmetrical transforms 102 , the transformed image is analyzed 104 . In this step, each transformed indicia image is analyzed to identify the special features therein and to “clean up” the image so that it achieves a specific and sufficient prominence. For example, the image can be analyzed so as to identify those characteristic features that correspond to repetitive features present in the time or spatial domain representation of the indicia image.
Next, the appropriate inverse (or reverse) transform is applied to each frequency domain representation 106 . Application of the inverse transforms 106 will result in the creation of modified, improved forms of the originally captured indicia images. The plurality of modified image representations can then be used to create a further improved representation of the imaged optical indicia.
The modified representations are next compared 108 . One or more of the modified representations of the optical indicia may still contain portions that are not readable. For example, one or more portions of a modified image representation may be absent, obscured or otherwise unreadable. The better quality portions of each modified image representation can be identified. Those portions can then be used to construct the further improved representation of the imaged optical indicia 110 . An image processing algorithm can be applied 112 to the improved image representation to initiate the recognition and decoding stages of the reading process.
In a related embodiment of the invention, instead of applying the image processing algorithm to a single improved image representation, an image processing algorithm is applied to each of the modified image representations created by the application of the inverse transformations 106 . The appropriate portions of the results obtained by that processing are then selected for decoding and further use.
Thus, even an optical indicia that is not within the depth of field of the reader imaging it, can be processed, improved, reconstructed and read. In effect, the depth of field of the indicia reader has been increased and operational efficiency has been improved.
It will be understood that the instructions for performing the steps disclosed herein can be written in a variety of computer languages. It will be further understood that the instructions can be stored and executed in a variety of ways. If desired, an ASIC can also be used to perform the invention disclosed herein. Also, the computerized processing required to carry out the invention can be performed in same device that is used to capture the optical indicia image. Alternatively, some or all of the required processing can be performed in a different, even remotely located, apparatus.
In addition, the instructions can be supplied to the optical indicia reader via hardware or by media designed to store software. For example, the instructions can be supplied to the system via an internet or network-type connection. Alternatively, the instructions can be delivered via a removable card such as a Compact Flash, SD or other such removable or non-removable card, module or component. Further still, the instructions can be supplied via some magnetic, optical or other type of storage media, removable or non-removable, such as a hard drive, a floppy disk, a CD, a DVD, or other such storage media.
The scope of the present invention is intended to cover all variations, omissions, substitutions and combinations which are and which may become apparent from the disclosed embodiments. The scope of the invention should be extended to the claimed invention and all of its equivalents. | A method for reading optical indicia involving the application of different symmetrical transforms to each of a plurality of images of an optical indicia. Characteristic features are identified in the transformed frequency domain representation of each transformed image, the characteristic features corresponding to repetitive features found in the original non-transformed representation of each image. Modified images are created by subjecting the frequency-domain representation of each image to an inverse transformation. The modified images can be combined to create an improved representation of the optical indicia being read. Thus, the depth of field and efficiency of an optical indicia reader can be enhanced. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. Non-Provisional patent applications Ser. No. P-109,352, filed Aug. 23, 2004; Ser. No. 10/787,788, filed Feb. 26, 2004; and Ser. No. 09/835,672, filed Apr. 16, 2001 and claims priority on U.S. Provisional Patent Applications Ser. No. 60/450,812, filed Feb. 27, 2003 and Ser. No. 60/501,988, filed Sep. 11, 2003.
FIELD OF THE INVENTION
[0002] This invention generally relates mechanisms to control exercise equipment and in particular to programs for controlling stride adjustment of elliptical exercise equipment.
BACKGROUND OF THE INVENTION
[0003] There are a number of different types of exercise apparatus that exercise a user's lower body by providing a generally elliptical stepping motion. These elliptical stepping apparatus provide advantages over other types of exercise apparatuses. For example, the elliptical stepping motion generally reduces shock on the user's knees as can occur when a treadmill is used. In addition, elliptical stepping apparatuses tend to exercise the user's lower body to a greater extent than, for example, cycling-type exercise apparatuses. Examples of elliptical stepping apparatuses are shown in U.S. Pat. Nos. 3,316,898; 5,242,343; 5,383,829; 5,499,956; 5,529,555, 5,685,804; 5,743,834, 5,759,136; 5,762,588; 5,779,599; 5,577,985, 5,792,026; 5,895,339, 5,899,833, 6,027,431, 6,099,439, 6,146,313, and German Patent No. DE 2 919 494.
[0004] A feature of some elliptical stepping apparatus is the ability to adjust stride length. Naturally, different people have different stride lengths and the exercise apparatus and it is desirable to accommodate each user so that they have a more comfortable and efficient workout. Existing elliptical stepping machines can compensate for people who have different stride lengths to a limited extent. However, such machines are not able to change the stride length during the operation of the device which can be a disadvantage. For example, existing elliptical stepping machines are not able to cope with the effect of increasing foot speed to result longer stride lengths. As a result, a problem with elliptical exercise machines is that they are not able to adjust horizontal stride length to compensate for various machine operating parameters or user exercise programs.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the invention to provide a mechanism for adjusting stride length in an elliptical type machine in order to compensate or respond to various machine operating parameters or exercise.
[0006] A further object of the invention is to use an adjustable stride mechanism and a control system to compensate for machine operating parameters such as pedal speed or direction.
[0007] An additional object of the invention is to use an adjustable stride mechanism and program logic in the control system of an elliptical stepper machine to implement various exercise programs that utilize varying stride lengths. Such programs can include a hill program, a random program, an interval program and a cross training program that includes changing direction of the stepping motion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side perspective view of an elliptical stepping exercise apparatus;
[0009] FIG. 2 is a schematic and block diagram of representative mechanical and electrical components of an example of an elliptical stepping exercise apparatus in which the method of the invention can be implemented;
[0010] FIG. 3 is a plan layout of a display console for use with the elliptical exercise apparatus shown in FIG. 2 ;
[0011] FIGS. 4 and 5 are views of a mechanism for use in adjusting stride length in an elliptical stepping apparatus of the type shown in FIG. 1 ;
[0012] FIGS. 6A, 6B , 6 C and 6 D are schematic diagrams illustrating the operation of the mechanism of FIGS. 4 and 5 for a 180 degree phase angle;
[0013] FIGS. 7A, 7B , 7 C and 7 D are schematic diagrams illustrating the operation of the mechanism of FIGS. 4 and 5 for a 60 degree phase angle;
[0014] FIGS. 8A, 8B , 8 C and 8 D are schematic diagrams illustrating the operation of the mechanism of FIGS. 4 and 5 for a zero degree phase angle;
[0015] FIGS. 9A, 9B and 9 C are a set of schematic diagrams illustrating angle measurements that can be used to determine stride length in an elliptical stepping apparatus of the type shown in FIG. 1 ;
[0016] FIG. 10 is a flow diagram illustrating the operation of exercise program operations in an apparatus of the type shown in FIG. 1 ; and
[0017] FIG. 11 is a flow diagram illustrating the operation of exercise program operations incorporating variable stride lengths in an apparatus of the type shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 depicts a representive example of an elliptical step exercise apparatus 10 of the type that can be modified to have the capability of adjusting the stride or the path of the foot pedal 12 . The exercise apparatus 10 includes a frame, shown generally at 14 . The frame 14 includes vertical support members 16 , 18 A and 18 B which are secured to a longitudinal support member 20 . The frame 14 further includes cross members 22 and 24 which are also secured to and bisect the longitudinal support member 20 . The cross members 22 and 24 are configured for placement on a floor 26 . A pair of levelers, 28 A and 28 B are secured to cross member 24 so that if the floor 26 is uneven, the cross member 24 can be raised or lowered such that the cross member 24 , and the longitudinal support member 20 are substantially level. Additionally, a pair of wheels 30 are secured to the longitudinal support member 20 of the frame 14 at the rear of the exercise apparatus 10 so that the exercise apparatus 10 is easily moveable.
[0019] The exercise apparatus 10 further includes the rocker 32 , an attachment assembly 34 and a resistance or motion controlling assembly 36 . The motion controlling assembly 36 includes the pulley 38 supported by vertical support members 18 A and 18 B around the pivot axle 40 . The motion controlling assembly 36 also includes resistive force and control components, including the alternator 42 and the speed increasing transmission 44 that includes the pulley 38 . The alternator 42 provides a resistive torque that is transmitted to the pedal 12 and to the rocker 32 through the speed increasing transmission 44 . The alternator 42 thus acts as a brake to apply a controllable resistive force to the movement of the pedal 12 and the movement of the rocker 32 . Alternatively, a resistive force can be provided by any suitable component, for example, by an eddy current brake, a friction brake, a band brake or a hydraulic braking system. Specifically, the speed increasing transmission 44 includes the pulley 38 which is coupled by the first belt 46 to the second double pulley 48 . The second double pulley 48 is then connected to the alternator 42 by a second belt 47 . The speed increasing transmission 44 thereby transmits the resistive force provided by the alternator 42 to the pedal 12 and the rocker 32 via the pulley 38 . The pedal lever 50 includes a first portion 52 , a second portion 54 and a third portion 56 . The first portion 52 of the pedal lever 50 has a forward end 58 . The pedal 12 is secured to the top surface 60 of the second portion 54 of the pedal lever 50 by any suitable securing means. In this apparatus 10 , the pedal 12 is secured such that the pedal 12 is substantially parallel to the second portion of the pedal lever 54 . A bracket 62 is located at the rearward end 64 of the second portion 54 . The third portion 56 of the pedal lever 50 has a rearward end 66 .
[0020] In this particular example of an elliptical step apparatus, the crank 68 is connected to and rotates about the pivot axle 40 and a roller axle 69 is secured to the other end of the crank 68 to rotatably mount the roller 70 so that it can rotate about the roller axle 69 . The extension arm 72 is secured to the roller axle 69 making it an extension of the crank 68 . The extension arm 72 is fixed with respect to the crank 68 and together they both rotate about the pivot axle 40 . The rearward end of the attachment assembly 34 is pivotally connected to the end of the extension arm 72 . The forward end of the attachment assembly 34 is pivotally connected to the bracket 62 .
[0021] The pedal 12 of the exercise apparatus 10 includes a toe portion 74 and a heel portion 76 so that the heel portion 76 is intermediate the toe portion 74 and the pivot axle 40 . The pedal 12 of the exercise apparatus 10 also includes a top surface 78 . The pedal 12 is secured to the top surface 60 of the pedal lever 50 in a manner so that the desired foot weight distribution and flexure are achieved when the pedal 12 travels in the substantially elliptical pathway as the rearward end 66 of the third portion 56 of the pedal lever 50 rolls on top of the roller 70 , traveling in a rotationally arcuate pathway with respect to the pivot axle 40 and moves in an elliptical pathway around the pivot axle 40 . Since the rearward end 66 of the pedal lever 50 is not maintained at a predetermined distance from the pivot axis 40 but instead follows the elliptical pathway, a more refined foot motion is achieved. It should be understood however that the invention can be implemented on other configurations of elliptical step apparatus having a variety of mechanisms for providing elliptical foot motion including the devices described in the patents referenced above as well as such machines shown in U.S. Pat. No. 6,176,814.
[0022] FIG. 2 is a combination schematic and block diagram that provides an environment for describing the invention and for simplicity shows in schematic form only one of two pedal mechanisms typically used in an elliptical stepping exercise apparatus such as the apparatus 10 . In particular, the exercise apparatus 10 described herein includes motion controlling components which operate in conjunction with an attachment assembly to provide an elliptical stepping exercise experience for the user. Included in this example of an elliptical stepping exercise apparatus 10 are the rocker 32 , the pedal 12 secured to the pedal lever 50 , the pulley 38 supported by the vertical support members 18 A and 18 B and which is rotatable on the pivot axle 40 . This embodiment also includes an arm handle 80 that is connected to the rocker 32 at a pivot point 82 on the frame of the apparatus 10 . The crank 68 is generally connected to one end of the pedal lever 50 by an attachment assembly represented by the box 34 and rotates with the pulley 38 while the other end of the pedal lever 50 is pivotally attached to the rocker 32 at the pivot point 84 .
[0023] The apparatus 10 as represented in FIG. 2 also includes resistive force and control components, including the alternator 42 and the speed increasing transmission 44 that includes the pulley 38 . The alternator 42 provides a resistive torque that is transmitted to the pedal 12 and to the rocker 32 through the speed increasing transmission 44 . The alternator 42 thus acts as a brake to apply a controllable resistive force to the movement of the pedal 12 and the movement of the rocker 32 . Alternatively, a resistive force can be provided by any suitable component, for example, by an eddy current brake, a friction brake, a band brake or a hydraulic braking system. Specifically, the speed increasing transmission 44 includes the pulley 38 which is coupled by a first belt 46 to a second double pulley 48 . A second belt 47 connects the second double pulley 48 to a flywheel 86 of the alternator 42 . The speed increasing transmission 44 thereby transmits the resistive force provided by the alternator 42 to the pedal 12 and the rocker 32 via the pulley 38 . Since the speed increasing transmission 44 causes the alternator 42 to rotate at a greater rate than the pivot axle 40 , the alternator 42 can provide a more controlled resistance force. Preferably the speed increasing transmission 44 should increase the rate of rotation of the alternator 42 by a factor of 20 to 60 times the rate of rotation of the pivot axle 40 and in this embodiment the pulleys 38 and 48 are sized to provide a multiplication in speed by a factor of 40. Also, size of the transmission 44 is reduced by providing a two stage transmission using pulleys 38 and 48 .
[0024] FIG. 2 additionally provides an illustration of a control system 88 and a user input and display console 90 that can be used with elliptical exercise apparatus 10 or other similar elliptical exercise apparatus to implement the invention. In this particular embodiment of the control system 88 , a microprocessor 92 is housed within the console 90 and is operatively connected to the alternator 42 via a power control board 94 . The alternator 42 is also operatively connected to a ground through load resistors 96 . A pulse width modulated output signal on a line 98 from the power control board 94 is controlled by the microprocessor 92 and varies the current applied to the field of the alternator 42 by a predetermined field control signal on a line 100 , in order to provide a resistive force which is transmitted to the pedal 12 and to the arm 80 . When the user steps on the pedal 12 , the motion of the pedal 12 is detected as a change in an RPM signal which represents pedal speed on a line 102 . It should be noted that other types of speed sensors such as optical sensors can be used in machines of the type 10 to provide pedal speed signals. Thereafter, as explained in more detail below, the resistive force of the alternator 42 is varied by the microprocessor 92 in accordance with the specific exercise program selected by the user so that the user can operate the pedal 12 as previously described.
[0025] The alternator 42 and the microprocessor 92 also interact to stop the motion of the pedal 12 when, for example, the user wants to terminate his exercise session on the apparatus 10 . A data input center 104 , which is operatively connected to the microprocessor 92 over a line 106 , includes a brake key 108 , as shown in FIG. 3 , that can be employed by the user to stop the rotation of the pulley 38 and hence the motion of the pedal 12 . When the user depresses the brake key 108 , a stop signal is transmitted to the microprocessor 92 via an output signal on the line 106 of the data input center 104 . Thereafter, the field control signal 100 of the microprocessor 92 is varied to increase the resistive load applied to the alternator 42 . The output signal 98 of the alternator provides a measurement of the speed at which the pedal 12 is moving as a function of the revolutions per minute (RPM) of the alternator 42 . A second output signal on the line 102 of the power control board 94 transmits the RPM signal to the microprocessor 92 . The microprocessor 92 continues to apply a resistive load to the alternator 42 via the power control board 94 until the RPM equals a predetermined minimum which, in the preferred embodiment, is equal to or less than 5 RPM.
[0026] In this embodiment, the microprocessor 92 can also vary the resistive force of the alternator 42 in response to the user's input to provide different exercise levels. A message center 110 includes an alpha-numeric display screen 112 , shown in FIG. 3 , that displays messages to prompt the user in selecting one of several pre-programmed exercise levels. In the illustrated embodiment, there are twenty-four pre-programmed exercise levels, with level one being the least difficult and level 24 the most difficult. The data input center 104 includes a numeric key pad 114 and a pair of selection arrows 116 , shown in FIG. 3 , either of which can be employed by the user to choose one of the pre-programmed exercise levels. For example, the user can select an exercise level by entering the number, corresponding to the exercise level, on the numeric keypad 114 and thereafter depressing a start/enter key 118 . Alternatively, the user can select the desired exercise level by using the selection arrows 116 to change the level displayed on the alpha-numeric display screen 112 and thereafter depressing the start/enter key 118 when the desired exercise level is displayed. The data input center 104 also includes a clear/pause key 120 , show in FIG. 3 , which can be pressed by the user to clear or erase the data input before the start/enter key 118 is pressed. In addition, the exercise apparatus 10 includes a user-feedback apparatus that informs the user if the data entered are appropriate. In this embodiment, the user feed-back apparatus is a speaker 122 , that is operatively connected to the microprocessor 92 . The speaker 122 generates two sounds, one of which signals an improper selection and the second of which signals a proper selection. For example, if the user enters a number between 1 and 24 in response to the exercise level prompt displayed on the alpha-numeric screen 112 , the speaker 122 generates the correct-input sound. On the other hand, if the user enters an incorrect datum, such as the number 100 for an exercise level, the speaker 122 generates the incorrect-input sound thereby informing the user that the data input was improper. The alpha-numeric display screen 112 also displays a message that informs the user that the data input was improper. Once the user selects the desired appropriate exercise level, the microprocessor 92 transmits a field control signal on the line 100 that sets the resistive load applied to the alternator 42 to a level corresponding with the pre-programmed exercise level chosen by the user.
[0027] The message center 110 displays various types of information while the user is exercising on the apparatus 10 . As shown in FIG. 3 , the alpha-numeric display panel 124 , shown on FIG. 3 , is divided into four sub-panels 126 A-D, each of which is associated with specific types of information. Labels 128 A-K and LED indicators 130 A-K located above the sub-panels 126 A-D indicate the type of information displayed in the sub-panels 126 A-D. The first sub-panel 126 A displays the time elapsed since the user began exercising on the exercise apparatus 10 or the current stride length of the apparatus 10 . One of the LED indicators 130 A or 130 K is illuminated depending if time or stride length is being displayed. The second sub-panel 126 B displays the pace at which the user is exercising. In the preferred embodiment, the pace can be displayed in miles per hour, minutes per mile or equivalent metric units as well as RPM. One of the LED indicators 130 B- 130 D is illuminated to indicate in which of these units the pace is being displayed. The third sub-panel 126 C displays either the exercise level chosen by the user or, as explained below, the heart rate of the user. The LED indicator 130 F associated with the exercise level label 128 E is illuminated when the level is displayed in the sub-panel 126 C and the LED indicator 130 E associated with the heart rate label 128 F is illuminated when the sub-panel 126 C displays the user's heart rate. The fourth sub-panel 126 D displays four types of information: the calories per hour at which the user is currently exercising; the total calories that the user has actually expended during exercise; the distance, in miles or kilometers, that the user has “traveled” while exercising; and the power, in watts, that the user is currently generating. In the default mode of operation, the fourth sub-panel 126 D scrolls among the four types of information. As each of the four types of information is displayed, the associated LED indicators 130 G-J are individually illuminated, thereby identifying the information currently being displayed by the sub-panel 126 D. A display lock key 132 , located within the data input center 104 , shown in FIG. 2 , can be employed by the user to halt the scrolling display so that the sub-panel 126 D continuously displays only one of the four information types. In addition, the user can lock the units of the power display in watts or in metabolic units (“mets”), or the user can change the units of the power display, to watts or mets or both, by depressing a watts/mets key 134 located within the data input center 104 .
[0028] It should be appreciated, that the control and display mechanisms shown in FIG. 2 only provide a representative example of such mechanisms and that there are a large number of such control and display systems that can be used to implement the invention.
[heading-0029] Stride Length Adjustment Mechanisms
[0030] The ability to adjust the stride length in an elliptical step exercise apparatus is desirable for a number of reasons. First, people, especially people with different physical characteristics such as height, tend to have different stride lengths when walking or running. Secondly, the length of an individuals stride generally increases as the individual increases his walking or running speed. As indicated in U.S. Pat. Nos. 5,743,834 and 6,027,43 as well as the patent applications identified in the cross reference to related applications above, there are a number of mechanisms for changing the geometry of an elliptical step mechanism in order to vary the path the foot follows in this type of apparatus.
[0031] FIGS. 4-5 , 6 A-D, 7 A-D and 8 A-D depict a stride adjustment mechanism 166 which can be used to remotely vary the stride length without the need to adjust the length crank 68 and thus is particularly useful in implementing the invention. Essentially, the stride adjustment mechanism 166 ′ replace the stroke link used to move the pedal lever 50 in earlier machines of the type shown in FIG. 1 . This approach permits adjustment of stride length independent of the motion of the machine 10 regardless as to whether the machine 10 is stationary, the user is pedaling forward, or pedaling in reverse. One of the significant features of the stride adjustment mechanism 166 is a dynamic link, that is, a linkage system that changes its length, or the distance between its two attachment points, cyclically during the motion of the apparatus 10 . The stride adjustment mechanism 166 is pivotally attached to the pedal lever 50 by a link crank mechanism 168 at one end and pivotally attached to the crank extension 72 at the other end. The maximum pedal lever's 50 excursion, for a particular setting, is called a stroke or stride. The stride adjustment mechanism 166 and the main crank 68 with the crank extension 72 together drive the maximum displacement/stroke of the pedal lever 50 . The extreme points in each pedal lever stroke correspond to extreme points between the Main Crank Axis 40 and a Link Crank—Pedal Lever Axis 169 . By changing the dynamic phase angle relationship between the link crank 168 and the crank extension 72 , it is possible to add to or subtract from the maximum displacement/stroke of the pedal lever 50 . Therefore by varying the dynamic phase angle relationship between the link crank 168 and the crank extension 72 , the stroke or stride of the pedal lever 50 varies the length of the major axis of the ellipse that the foot pedal 12 travels.
[0032] The preferred embodiment of the stride adjustment mechanism 166 shown in FIGS. 4 and 5 takes full advantage of the relative rotation between the crank extension 72 and a control link assembly 170 of the stride adjustment mechanism 166 as the user moves the pedals 12 . In this embodiment, attachment adjustment mechanism 166 includes the control link assembly 170 and two secondary crank arms, the link crank assembly 168 and the crank extension 72 . The control link assembly 170 includes a pair of driven timing-pulley shafts 172 and 174 , a pair of toothed timing-pulleys 176 and 178 and a toothed timing-belt 180 engaged with the timing pulleys 176 and 178 . For clarity, the timing belt is not shown in FIG. 4 but is shown in FIG. 5 . Also included in the link crank assembly 168 is a link crank actuator 182 . One end of the crank-extension 72 is rigidly attached to the main crank 68 . The other end of the crank-extension 72 is rigidly attached to the rear driven timing-pulley shaft 174 and the pulley 178 . Also, the rear driven timing-pulley shaft 174 is rotationally attached to the rearward end of the control link assembly 170 . The forward end of the control link assembly 170 is rotationally attached to the forward driven timing-pulley shaft 172 and pulley 176 . The two timing-pulleys 176 and 178 are connected to each other via the timing-belt 180 . The forward driven timing-pulley shaft 172 is pivotally attached to the link crank 168 , but held in a fixed position by the link crank actuator 182 when the actuator 182 is stationary; the link crank 168 operates as if it were rigidly attached to the forward driven timing-pulley shaft 172 . The other end of the link crank 168 is pivotally attached to the pedal lever 50 at the pivot axle 169 . In this particular embodiment of the elliptical step apparatus 10 shown in FIGS. 4 and 5 , the main crank 68 via a revolute joint on a linear slot supports the rearward end of the pedal lever 50 . Here, this is in the form of a roller & track interface indicated generally at 184 . When the apparatus 10 is put in motion, there is relative rotation between the crank extension/rearward timing-pulley 178 and the control link 170 . This timing-pulley rotation drives the forward driven timing-pulley 176 via the timing-belt 180 . Since the forward driven timing-pulley 176 is rigidly attached to one end of the link crank 168 , the link crank 168 rotates relative to the pedal lever 50 . Because the control link 170 is a rigid body, the rotation of the link crank 168 moves the pedal lever 50 in a prescribed motion on its support system 184 . In order to facilitate installation, removal and tension adjustment of the belt 180 on the pulleys 176 and 178 , the control link 170 includes an adjustment device such as a turnbuckle 186 that can be used to selectively shorten or lengthen the distance between the pulleys 176 and 178 .
[0033] In this mechanism 166 , there exists a relative angle indicated by an arrow 188 shown in FIG. 4 between the link crank 202 and the crank extension 70 . This relative angle 188 is referred to as the LC-CE phase angle. When the link crank actuator 182 is stationary, the LC-CE phase angle 188 remains constant, even if the machine 10 is in motion. When the actuator 182 is activated, the LC-CE phase angle 188 changes independent of the motion of the machine 10 . Varying the LC-CE phase angle 188 effects a change in the motion of the pedals 10 , in this case, changing the stride length.
[0034] In the embodiment, shown in FIG. 5 , the link crank actuator 182 includes a gear-motor, preferably an integrated motor and gearbox 190 , a worm shaft 192 , and a worm gear 194 . Because the link crank actuator 190 rotates about an axis relative to the pedal lever 50 , a conventional slip-ring type device 196 is preferably used to supply electrical power, from for example the power control board 94 shown in FIG. 2 , across this rotary interface to the DC motor of the gear-motor 190 . When power is applied to the gear-motor 190 , the worm shaft 192 and the worm gear 194 rotate. The rotating worm shaft 192 rotates the worm gear 194 , which is rigidly connected to the driven timing pulley 176 . In addition, the worm gear 194 and the forward pulley 176 rotate relative to the link crank 168 to effect the LC-CE Phase Angle 188 change between the crank extension 72 and the link crank 168 . A reverse phase angle change occurs when the motor 190 is reversed causing a reverse stride change, that is, a decrease in stride length. In this embodiment, less than half of the 360 degrees of the possible phase angle relationship between the link crank 168 and the crank extension 72 is used. In some mechanisms using more or the full range of possible phase angles can provide different and desirable ellipse shapes.
[0035] The schematics of FIGS. 6 A-D, 7 A-D and 8 A-D illustrate the effect of the phase angle change between the crank extension 72 and the link crank 168 for a 180 degree, a 60 degree and a 0 degree phase relationship respectively. Also, FIGS. 6A, 7A , and 8 A display the crank at 180 degree position; FIGS. 6B, 7B , and 8 B show the crank at 225 degree position; FIGS. 8C, 9C , and 10 C show the crank at a 0 degree position; and FIGS. 8D, 9D , and 10 D show the crank at a 90 degree position. In FIGS. 6 A-D the elliptical path 218 represents the path of the pedal 12 for the longest stride; in FIGS. 7 A-D the elliptical path 218 ′ represents the path of the pedal 12 for an intermediate stride; and in FIGS. 8 A-D the elliptical path 218 ″ represents the path of the pedal 12 for the shortest stride.
[0036] In certain circumstances, characteristics of stride adjustment mechanism of the type 166 can result in some undesirable effects. Therefore, it might be desirable to implement various modifications to reduce the effects of these phenomena. For example, when the stride adjustment mechanism 166 is adjusted to the maximum stroke/stride setting, the LC-CE Phase Angle is 180 degrees. At this 180-degree LC-CE Phase Angle setting, the components of the stride adjustment mechanism 166 will pass through a collinear or toggle condition. This collinear condition occurs at or near the maximum forward excursion of the pedal lever 50 , which is at or near a maximum acceleration magnitude of the pedal lever 50 . At slow pedal speeds, the horizontal acceleration forces are relatively low. As pedal lever speeds increase, effects of the condition increase in magnitude proportional to the change in speed. Eventually, this condition can produces soft jerk instead of a smooth transition from forward motion to rearward motion. To overcome this potential problem several approaches can be taken including: limit the maximum LC-CE phase angle 188 to less than 180 degrees, for example, restrict stride range to 95% of mechanical maximum; change the prescribed path shape 218 of the foot pedal 12 ; or reduce the mass of the moving components in the stride adjustment mechanism 166 and the pedal levers 50 to reduce the acceleration forces.
[0037] Another problem can occur when the stride adjustment mechanism 166 is in motion and where the tension side of the timing-belt 180 alternates between the top portion and the lower portion. This can be described as the tension in the belt 180 changing cyclically during the motion of the mechanism 166 . At slow speeds, the effect of the cyclic belt tension magnitude is relatively low. At higher speeds, this condition can produce a soft bump perception in the motion of the machine 10 as the belt 180 quickly tenses and quickly relaxes cyclically. Approaches to dealing with this belt tension problem can include: increase the timing-belt tension using for example the turnbuckle 186 until the bump perception is dampened; increase the stiffness of the belt 180 ; increase the bending stiffness of the control link assembly 170 ; and install an active tensioner device for the belt 180 .
[0038] A further problem can occur when the stride adjustment mechanism 166 is in motion where a vertical force acts on the pedal lever 50 . The magnitude of this force changes cyclically during the motion of the mechanism 10 . At long strides and relatively high pedal speeds, this force can be sufficient to cause the pedal lever 50 to momentarily lift off its rearward support roller 70 . This potential problem can be addressed in a number of ways including: the roller-trammel system 184 , as shown in FIG. 4 ; limit the maximum LC-CE phase angle 188 to less than 180 degrees; restrict stride range to 95% of mechanical maximum; and reduce the mass of the moving components in the stride adjustment mechanism and the pedal levers.
[heading-0039] Elliptical Step Programs
[0040] As shown in FIG. 10 , the exercise apparatus 10 can provide several pre-programmed exercise programs that can be used with a static or an adjustable stride length. In this embodiment of the invention a set of exercise programs 300 are stored within and implemented by the microprocessor 92 . The exercise programs 300 provide for a variable exercise and can enhance exercise efficiency. In this embodiment, the alpha-numeric display screen 112 of the message center 110 , together with a display panel 136 , guide the user through the various exercise programs. Specifically, the alpha-numeric display screen 112 prompts the user to select among the various pre-programmed exercise programs 300 and prompts the user to supply the data as indicated at a box 302 that can be useful in implementing the exercise program selected at a box 304 . The display panel 136 displays a graphical image that represents the current exercise program. One of the most basic exercise programs is a manual exercise program indicated at 306 . In the manual exercise program 306 the user, after entering a time, calorie or distance goal as indicated the first of a set of boxes indicated by 308 , selects one of the twenty-four previously described exercise levels at 310 . In this case, the graphic image displayed by the display panel 136 is essentially flat and the different exercise levels are distinguished as vertically spaced-apart flat displays. A second exercise program 312 , a hill profile program, varies the effort required by the user in a pre-determined fashion which is designed to simulate movement along a series of hills. In implementing this program 312 , the microprocessor 92 increases and decreases the resistive force of the alternator 42 thereby varying the amount of effort required by the user. The display panel 136 displays a series of vertical bars of varying heights that correspond to climbing up or down a series of hills. A portion 138 of the display panel 136 displays a single vertical bar whose height represents the user's current position on the displayed series of hills. A third exercise program 314 , termed the random hill profile program, also varies the effort required by the user in a fashion which is designed to simulate movement along a series of hills. However, unlike the regular hill profile program 312 , the random hill profile program 314 provides a randomized sequence of hills so that the sequence varies from one exercise session to another. A detailed description of a random hill profile program and of the regular hill profile program can be found in U.S. Pat. No. 5,358,105, the entire disclosure of which is hereby incorporated by reference.
[0041] A fourth exercise program 316 , termed a cross training program, instructs the user to move the pedal 12 in both the forward-stepping mode and the backward-stepping mode. When this program 316 is selected by the user, the user begins moving the pedal 12 in one direction, for example, in the forward direction. After a predetermined period of time, the alpha-numeric display panel 136 prompts the user to prepare to reverse directions. Thereafter, the field control signal 100 from the microprocessor 92 is varied to effectively brake the motion of the pedal 12 and the arm 80 . After the pedal 12 and the arm 80 stop, the alpha-numeric display screen 112 prompts the user to resume his workout. Thereafter, the user reverses directions and resumes his workout in the opposite direction.
[0042] A pair of exercise programs, a cardio program 318 and a fat burning program 320 , vary the resistive load of the alternator 42 as a function of the user's heart rate. When the cardio program 318 is selected, the microprocessor 92 varies the resistive load as shown at 322 so that the user's heart rate is maintained at a value equivalent to 80% of a quantity equal to 220 minus the user's age. In the fat burning program 320 , the resistive load is varied as shown at 324 so that the user's heart rate is maintained at a value equivalent to 65% of a quantity equal to 220 minus the user's heart age. Consequently, when either of these programs 318 or 320 is selected by the user at 304 , the alpha-numeric display screen 112 prompts the user to enter his age as one of the program parameters. Alternatively, the user can enter a desired heart rate. In addition, the exercise apparatus 10 includes a heart rate sensing device that measures the users heart rate as he exercises. In the apparatus shown in FIG. 2 , the heart rate sensing device consists a pair of heart rate sensors 140 and 140 ′ that can be mounted either on the moving arms 80 or a fixed handrail 142 , as shown in FIG. 1 . In the preferred embodiment, the sensors 140 and 140 ′ are mounted on the moving arms 80 . A set of output signals on the lines 144 and 144 ′ corresponding to the user's heart rate is transmitted from the sensors 140 and 140 ′ to a heart rate digital signal processing board 146 . The processing board 146 then transmits a heart rate signal over a line 148 to the microprocessor 92 . A detailed description of the sensors 140 and 140 ′ and the heart rate digital signal processing board 146 can be found in U.S. Pat. Nos. 5,135,447 and 5,243,993, the entire disclosures of which are hereby incorporated by reference. In addition, the exercise apparatus 10 includes a telemetry receiver 150 , shown in FIG. 2 , that operates in an analogous fashion and transmits a telemetric heart rate signal over a line 152 to the microprocessor 92 . The telemetry receiver 150 works in conjunction with a telemetry transmitter that is worn by the user. In the preferred embodiment, the telemetry transmitter is a telemetry strap worn by the user around the user's chest, although other types of transmitters are possible. Consequently, the exercise apparatus 10 can measure the user's heart rate through the telemetry receiver 150 if the user is not grasping the arm 80 . Once the heart rate signal 148 or 152 is transmitted to the microprocessor 92 , the resistive load 96 of the alternator 42 is varied to maintain the user's heart rate at the calculated value.
[0043] In each of these exercise programs, the user provides data at 308 that determine the duration of the exercise program. The user can select between a number of exercise goal types including a time or a calories goal or, in the preferred embodiment of the invention, a distance goal. If the time goal type is chosen, the alpha-numeric display screen 112 prompts the user to enter the total time that he wants to exercise or, if the calories goal type is selected, the user enters the total number of calories that he wants to expend. Alternatively, the user can enter the total distance either in miles or kilometers. The microprocessor 92 then implements the selected exercise program for a period corresponding to the user's goal. If the user wants to stop exercising temporarily after the microprocessor 92 begins implementing the selected exercise program, depressing the clear/pause key 120 effectively brakes the pedal 12 and the arm 80 without erasing or changing any of the current program parameters. The user can then resume the selected exercise program by depressing the start/enter key 118 . Alternatively, if the user wants to stop exercising altogether before the exercise program has been completed, the user simply depresses the brake key 108 to brake the pedal 12 and the arm 80 . Thereafter, the user can resume exercising by depressing the start/enter key 118 . In addition, the user can stop exercising by ceasing to move the pedal 12 . The user then can resume exercising by again moving the pedal 12 .
[0044] The exercise apparatus 10 also includes a pace option as depicted by a set of boxes indicated at 326 . In all but the cardio program 318 and the fat burning program 320 , the default mode is defined such that the pace option is on and the microprocessor 92 varies the resistive load of the alternator 42 as a function of the user's pace. When the pace option is on, the magnitude of the RPM signal 102 received by the microprocessor 92 determines the percentage of time during which the field control signal 100 is enabled and thereby the resistive force of the alternator 42 . In general, the instantaneous velocity as represented by the RPM signal 102 is compared to a predetermined value to determine if the resistive force of the alternator 42 should be increased or decreased. In the presently preferred embodiment, the predetermined value is a constant of 30 RPM. Alternatively, the predetermined value could vary as a function of the exercise level chosen by the user. Thus, in this embodiment, if the RPM signal 102 indicates that the instantaneous velocity of the pulley 38 is greater than 30 RPM, the percentage of time that the field control signal 100 is enabled is increased according to Equation 1.
Equation 1
[0045] field control duty cycle = field control duty cycle + ( ( ❘ instantaneous RPM - 30 / ) / 2 ) 2 * field control duty cycle ) 256 Equation 1
where field duty cycle is a variable that represents the percentage of time that the field control signal 100 is enabled and where the instantaneous RPM represents the instantaneous value of the RPM signal 98 .
[0047] On the other hand, in this embodiment, if the RPM signal 102 indicates that the instantaneous velocity of the pulley 38 is less than 30 RPM, the percentage of time that the field control signal 100 is enabled is decreased according to Equation 2.
Equation 2
[0048] field control duty cycle = field control duty cycle - ( ( ❘ instantaneous RPM - 30 / ) / 2 ) 2 * field control duty cycle ) 256 Equation 2
where field duty cycle is a variable that represents the percentage of time that the field control signal 100 is enabled and where the instantaneous RPM represents the instantaneous value of the RPM signal 102 .
[0050] Moreover, once the user selects an exercise level, the initial percentage of time that the field control signal 100 is enabled is pre-programmed as a function of the chosen exercise level as described in U.S. Pat. No. 6,099,439.
[heading-0051] Manual and Automatic Stride Length Adjustment
[0052] In these embodiments of the invention, stride length can be varied automatically as a function of exercise or apparatus parameters. Specifically, the control system 88 and the console 90 of FIG. 2 can be used to control stride length in the elliptical step exercise apparatus 10 either manually or as a function of a user or operating parameter. In the examples of FIGS. 1 and 2 the attachment assembly 34 generally represented within the dashed lines can be implemented by a number of mechanisms that provide for stride adjustment such as the stride length adjustment mechanism depicted in FIGS. 4 and 5 . As shown in FIG. 2 , a line 154 connects the microprocessor 92 to the electronically controlled actuator elements of the adjustment mechanisms in the attachment assembly 34 . Stride length can then be varied by the user via a manual stride length key 156 , shown in FIG. 3 , which is connected to the microprocessor 92 via the data input center 104 . Alternatively, the user can have stride length automatically varied by using a stride length auto key 158 that is also connected to the microprocessor 92 via the data input center 104 . In one embodiment, the microprocessor 92 is programed to respond to the speed signal on line 102 to increase the stride length as the speed of the pedal 12 increases. Pedal direction, as indicated by the speed signal can also be used to vary stride length. For example, if the microprocessor 92 determines that the user is stepping backward on the pedal 12 , the stride length can be reduced since an individuals stride is usually shorter when stepping backward. Additionally, the microprocessor 92 can be programmed to vary stride length as function of other parameters such as resistive force generated by the alternator 42 ; heart rate measured by the sensors 140 and 140 ′; and user data such as weight and height entered into the console 90 .
[heading-0053] Adjustable Stride Programs
[0054] As illustrated in FIG. 11 , adjustable stride mechanisms make it possible to provide enhanced pre-programmed exercise programs of the type described above that are stored within and implemented by the microprocessor 92 . As with the previously described exercise programs, the alpha-numeric display screen 112 of the message center 110 , together with a display panel 136 , can be used to guide the user through the various exercise programs. Again, the alpha-numeric display screen 112 prompts the user to select at 304 among the various preprogrammed exercise programs and prompts the user to supply the data needed to implement the selected exercise program. In this embodiment, one of a group of adjustable stride length exercise programs 328 can be selected by the user utilizing a stride program key 160 , as shown in FIG. 3 , which is connected to the microprocessor 92 via the data input center 104 . As indicated above, it should be appreciated, that the control and display mechanisms shown in FIG. 2 only provide a representative example of such mechanisms and that there are a large number of such control and display systems that can be used to implement the invention. Representative examples of such stride length exercise programs are provided below.
[0055] A first program 330 can be used to simulate hiking on a hill or mountain similarly to the hill program 312 of FIG. 10 . For example, the program can begin with short strides and a high resistance to simulate climbing a hill then as shown in a box 332 after a predetermined time change to long strides at low resistance as indicated at a box 334 to simulate walking down the hill. The current hill and upcoming hills can be displayed on the display panel 136 where the length of the stride and the resistance change at each peak and valley. In one implementation, the initial or up hill stride would be 16 inches and the down hill stride would be 24 inches, where the program automatically adjusts the initial stride length to 16 inches at the beginning of the program. Also, the program can return the stride length to a home position, for instance 20 inches, during a cool down portion of the program.
[0056] A second program 336 can be used to change both the stride length and the resistance levels on a random basis. Preferably, the changes in stride length and resistance levels are independent of each other as indicated at a box 338 . Also in one embodiment, the changes in stride length occur at different time intervals than the changes in resistance levels. For example, a random stride length change might occur every even minute and a random resistance level change might occur at every odd minute of the program. Preferably, the changes in increments will be plus or minus 2 inches or more. Again, the program can return the stride length to a home position, for instance 20 inches, during a cool down portion of the program.
[0057] A third program 340 can be used to simulate interval training for runners. In one embodiment, by using stride length changes in the longer strides and having the processor 92 generates motivating message prompts on the display 136 , interval training and the gentle slopes and intervals one would experience when training as a runner outdoors are mimicked. In one example, as indicated in a box 342 , the program spans the stride range of 22″-26″ with an initial warm-up beginning at 22″ then moving to 24″. Here the program then alternates between the 24″ and 26″ strides thus mimicking intervals at the longer strides such as those experienced by a runner in training. In addition as indicated in a box 344 , the display 136 can be used to alert the user to “Go faster” and “Go slower” at certain intervals. Thus the prompts can be used to encourage faster and slower pedal speeds. A representative example of such a program is provided below:
Warm-up: Prompt “Warm Up” message Minute 00:00=22″ stride (If machine is not at 22″ at program start-up, then it will adjust to the 22″ stride length at program start.) Minute 03:00=24″ stride Minute 03:30=prompt “Go faster” message Intervals: Minute 04:00=26″ stride Minute 08:30=prompt “Go slower” message Minute 09:00=24″ stride Minute 10:30=prompt “Go faster” message Minute 11:00=26″ stride Minute 15:30=prompt “Go slower” message
where the first change is initiated at the 03:00 minute mark, during the warm-up phase. Other aspects of this particular interval program include: stride adjustment increments of 2″; minimum duration of 10 minutes; and repeating the interval phase for the selected duration of the program.
[0071] A fourth program 346 can be used to simulate a cross training exercise. Here, as shown in a box 348 , stride length is shortened when the user is pedaling in a backward direction and increased when the user is pedaling in a forward direction. As with the interval training program 340 , the display 136 can be used in the cross training program 346 to generate indications to the user at a predetermined time, such as 30 seconds, before the direction of pedal motion is to change. | In an elliptical step exercise apparatus where stride length can be varied the various user programs can take advantage of this feature to provide for an enhanced workout. A control system can be used to implement a preprogrammed exercise routine such as a hill program where stride is shortened as the user goes up a simulated hill and lengthened as the user goes down the hill. In an interval training program, stride length can be increased and decreased at periodic intervals. In a cross training program, stride length can be decreased when the user is pedaling backwards and increased when the user is pedaling forwards. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to a semiconductor device having a Darlington circuit comprising a semiconductor body having two transistors comprising emitter and collector regions of the first conductivity type and an intermediate base region of the second conductivity type, the emitter region of one of the transistors, hereinafter termed "first transistor", being connected to the base of the second transistor, a diode being provided between the base and the emitter of the first transistor, a surface region of the first conductivity type which forms a first zone of the diode and is connected to the base region of the first transistor being present in said base region, a second region of the diode which forms a rectifying contact with the first zone being connected to the emitter region of the first transistor.
The object of the diode is to provide a drain for charge stored in the base of the second transistor, so that a short switching-off time is obtained. Such circuits are used, for example, in switching supply units, as well as in circuits for line deflection in television receivers.
A semiconductor device as described above is disclosed in U.S. Pat. No. 3,913,213. In this case the diode is provided by disposing a second n-type region in the p-type base of the first transistor beside the n-type emitter and forming a p-type region in said n-type region. The n-type region is connected to the base of the first transistor by means of a metal layer, while the p-type region is connected to the emitter of this transistor and to the base of the second transistor.
Experiments with such Darlington circuits have demonstrated that said circuits often do not operate satisfactorily; notably during switching off very high currents may occur, with sufficient power to cause permanent damage to the device.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a Darlington circuit having an integrated diode which can be operated at high powers and which does not exhibit parasitic current upon switching off.
The invention is based inter alia on the recognition that a cause of the high-current phenomena can be found in a parasitic four-layer structure effect. The invention is furthermore based on the recognition that said high-current effect can surprisingly be removed by giving the surface area of the first conductivity type a suitable geometry.
The p-n junction between the diode zones together with the p-n junction between the p-type region and the base of the first transistor and with the base collector junction of the first transistor constitutes a parasitic p-n-p-n structure (p-zone diode, n-zone diode, p-base zone, n-collector zone). When, as a result of the switching off of the Darlington circuit, the diode starts passing current, holes are injected from the p-type region into the n-type region which in principle are drained via the base contact which short-circuits the cathode of the diode and the base zone of the transistor. However, some of the charge carriers cross the n-type region towards the base region of the transistor below the anode of the diode and must be drained to the base contact, in this case the base-cathode short-circuit, through said base region below the n-type region (cathode). Dependent on the length of the current path below the n-type region, the value of the current and the resistivity of the base region, a potential across said current path is built up at which the voltage in the base region below the anode of the diode is higher than at the area of the base contact. As a result of said voltage drop, the potential between the p-type base and the n-type region may locally obtain such a forward voltage that a parasitic current starts travelling in the p-n-p-n structure and the parasitic transistor formed by the n-p-n part starts passing current. In practice it has been found that parasitic currents in the order of 1 ampere may occur.
A possible solution to this problem may result from the fact that the emitter efficiency of the parasitic p-n-p transistor formed by the diode and the base is strongly reduced, for example, by giving the n-type region a thickness which is many times larger than the diffusion length of the minority charge carriers. However, such a solution is usually not compatible with the requirements which are imposed upon the transistors of the Darlington circuit.
A Darlington circuit according to the invention is characterized in that the first zone comprises a number of juxtaposed sub-zones which each form a rectifying junction with parts of the second region of the diode and are separated from each other at least along a part of their circumference by parts of the base and along a substantial part of their circumference are connected to said parts of the base by a contact layer extending across the p-n junction between said sub-zones and the parts of the base.
By choosing the geometry of the sub-zones, notably those dimensions which determine the current path across which the potential is built up, in such manner that, given the maximum current through the sub-zone and the resistivity of the base zone said potential drop remains sufficiently small, the above-mentioned p-n-p-n effect can be avoided at higher powers, and also in the case of rapid switching of a Darlington circuit.
Since on the one hand the sub-zones of the first zone can be made so narrow that the resistance of the underlying parts of the base remains sufficiently low and on the other hand a sufficiently large number of zones can be chosen to sufficiently restrict the current through each of the sub-zones, the p-n junction between the base and a sub-zone is not biased in the forward direction.
A preferred embodiment of the invention is characterized in that said parts of the second region of the diode are formed by zones of the second conductivity type which are provided in the sub-zones of the first conductivity type and which form p-n junctions with the sub-zones of the first conductivity type.
The doping concentrations of the zones of the second conductivity type is preferably at most ten times higher than that of the surface region of the first conductivity type. The advantage of this is that the emitter efficiency of the parasitic transistor formed by the zones of the diode and the base of the transistor is restricted and hence also fewer charge carrier are injected in the base region of the parasitic transistor. This in turn reduces the number of charge carriers which can cross towards the base region of the transistor and thus the above-mentioned voltage drop.
The doping concentration of the sub-zones of the first conductivity type is preferably chosen to be comparatively high. For that purpose a preferred embodiment is characterized in that the doping concentration of said zones is at least equal to the doping concentration of the emitter regions of the transistors. An important preferred embodiment which has for its advantage that said zones of the diode can be provided entirely simultaneously with the emitter regions of the transistors and hence do not require extra process steps is characterized in that the thickness and the impurity concentration of the sub-zones of the first conductivity type are at least substantially equal to those of the emitters of the two transistors. It has been found that a favourable doping concentration is at most 7.10 19 atoms/cm 3 . A preferred embodiment is characterized in that said doping concentration is between approximately 5.10 19 and approximately 7.10 19 atoms/cm 3 .
A further preferred embodiment of the semiconductor device is characterized in that the sub-zones are formed by a number of mutually substantially parallel and elongate strip-shaped zones which are juxtaposed and are connected to the base zone of the first transistor by a contact layer extending along substantially the whole length of said strip-shaped zones above the p-n junction between said zones and the base zone of the first transistor. The sub-zones may be united to form one assembly so that the surface region of the first conductivity type shows, for example, a comb structure or meandering structure, but other configurations are also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail with reference to various embodiments and the drawing, in which:
FIG. 1 is a diagrammatic plan view of a semiconductor device according to the invention,
FIG. 2 is a diagrammatic cross-sectional view of the semiconductor device shown in FIG. 1 taken on the line II--II,
FIG. 3 shows the electric circuit diagram of the Darlington circuit as realized in FIG. 1,
FIG. 4 is a diagrammatic plan view of the embodiment of a part of another semiconductor device in accordance with the invention,
FIG. 5 is a diagrammatic plan view of a modified embodiment of the construction shown in FIG. 4,
FIG. 6 is a diagrammatic plan view of yet another modified embodiment of the construction shown in FIG. 4, and
FIG. 7 is a diagrammatic plan view of yet another construction of a part of another semiconductor device in accordance with the invention.
DETAILED DESCRIPTION
The figures are diagrammatic and not drawn to scale in which, for clarity, particularly the dimensions in the direction of thickness are exaggerated in the cross-sectional views. Semiconductor zones of the same conductivity type are generally shaded in the same direction; corresponding parts in the Figures are generally referred to by the same reference numerals.
The semiconductor device shown in FIGS. 1 and 2 comprises a so-called Darlington circuit of which FIG. 3 shows the electric equivalent circuit diagram. The device comprises a semiconductor body of a suitable semiconductor material, usually silicon, although other semiconductor materials may also be used advantageously. The circuit consists mainly of two transistors, namely a first transistor 10, a control transistor, with which the circuit can be switched, and a second transistor 20, the main transistor, of which the base is connected to the emitter of the first transistor 10 for supplying the base current.
The transistors 10, 20 comprise a common collector region 2, 3 of a first conductivity type, in this example the n-type, and consisting of a low-ohmic substrate part 2 and a part 3 which is formed thereon and has a lower doping concentration than the substrate 2. The part 3 may be formed, for example, by epitaxial growth. The region 2 has an electric contact layer 30 on its lower side.
The first transistor, the control transistor 10, comprises an n-type emitter region 11 and a p-type base region 12 situated between emitter and collector. The emitter is constructed as a closed path, approximately according to a rectangle as is shown in the plan view of FIG. 1.
The second transistor, the main transistor 20, comprises an n-type emitter region 21 and a p-type base region 22. The base regions 12 and 22 are separated for the greater part by a groove 9 extending from the surface of the semiconductor body through the base regions down to the collector region, except on the left-hand edge of FIG. 1, where the resistor R 1 is formed, which will be referred to hereinafter. The base region may also be formed by epitaxial growth on the high-ohmic collector part 3.
The emitter region 11 of the control transistor 10 and the base 22 are connected together by the conductive pattern 4, for example, of aluminium, shown shaded in FIG. 1, which is formed on the insulating layer 5, for example of silicon oxide, covering the surface and is connected, via contact windows 13 and 25, to the emitter region 11 and to a highly doped contact zone 24 provided in the base 22, respectively. It is to be noted that all contact windows in the plan view shown in FIG. 1 are shown in broken lines.
A diode is provided between the base and the emitter of the first transistor 10. As is known, such a diode serves to drain charge stored in the base of the main transistor during switching off, so that the switching-off time of the Darlington circuit is reduced. Said diode comprises an n-type surface region 16 which is provided in the base region 12 of the control transistor 10 and which forms a first zone of the diode, in this example the cathode, and is conductively connected to the base region 12. A second region of the diode, the anode, which forms a rectifying junction with the cathode 16 is conductively connected to the emitter region 11 of the control transistor and to the base region 22 of the main transistor. In the present example the anode is formed by a p-type zone 17, provided in the n-type region 16.
It has been found that in known devices of the kind described very large currents can occur during switching off, which may even cause fatal damage to the device. In order to prevent this disadvantage, according to the invention the first zone 16 comprises a number of juxtaposed sub-zones which for mutual distinction are provided with reference numerals 16a, 16b and 16c. Said sub-zones of the n-type conductivity each form a rectifying junction with parts of the second region of the diode, formed by p-type zones provided in each of the zones 16a, 16b and 16c and referred to by reference numerals 17a, 17b and 17c, respectively. The sub-zones 16a, 16b and 16c are separated from each other at least along a part of their circumference by parts 12a of the base 12 and are connected to said parts of the base along a substantial part of their circumference by a contact layer 8 which extends in the contact windows 7 above the p-n junction between said sub-zones and the parts of the base.
The effect of the invention will be described with reference to FIGS. 2 and 3. During switching off of the Darlington circuit, a low, preferably negative, potential is applied to the base of the control transistor 10. The transistor T 1 (10) extinguishes so that the main transistor 20 (T 2 ) no longer obtains base current. The charge stored in the base 22 of the main transistor 20 causes the transistor T 2 to remain temporarily conductive. This charge can be drained by R 1 and by the base-emitter junction of the control transistor 10 which is now cut off. The most important drain path is formed by the diode D 1 which becomes forward biased when the Darlington circuit is switched off. Holes are injected into the cathode 16 by the anode 17 of the diode. These holes will be drained for the greater part via the cathode. However, the diode forms a parasitic p-n-p transistor T 3 with the p-type base region 12, the collector of which transistor is connected to the base. A part of the injected holes reaches the collector of the p-n-p transistor and flows below the cathode of the diode to the short-circuit contact 8. As a result of this, a voltage can be built up below the cathode of the diode which in the known devices is sufficiently large to bias the p-n junction between the cathode of the diode and the base of the control transistor T 1 (10) in the forward direction. As a result of this the emitter-base junction of the parasitic transistor T 4 , formed by the cathode of the diode, the base of the control transistor and the collector of the Darlington circuit is also biased in the forward direction. As a result of this, said transistor T 4 will pass current; experiments have demonstrated that in the known devices this current may become so high (approximately 1 Ampere) that the device is damaged permanently.
In a device according to the invention, the switching of the transistor T 4 is prevented by choosing the geometry of the n-region to be so that the voltage which is built up below the cathode remains sufficiently low to prevent switching of said transistor. The shape of the n-regions 16a, 16b and 16c has been chosen to be so that the resistance in the p-type base region 12 of the current paths 32 is sufficiently low to prevent the p-n junction between the cathode 16 of the diode and the p-type base 12 from being biased in the forward direction. The width of the zones 16 depends on a large number of parameters, inter alia the resistance of the base region 12 and current to be passed. In a practical case said width can simply be chosen by those skilled in the art in such manner as is desired in connection with the optimum operation of the device.
In this example the doping concentration of the p-regions 17 are at most ten times higher than those of the n-type regions 16. This comparatively small doping difference has for its result that the emitter efficiency of transistor T 3 is low so that the number of injected holes remains low. This holds the current in the p-type base 12 below the regions 16 to a very small value and hence reduces the possibility of switching of transistor T 4 .
In this example the short-circuit 8 which extends across the p-n junction between the n-regions 16 and the parts of the base 12, also forms the base contact of transistor T 1 .
In order to effect a good contact, the surface concentration of the base of transistor T 1 is increased at the area of said contact layer.
In this example the contact layer has such a shape that an external contact can be provided on it directly (base connection 28 in FIGS. 1, 3). This contact face is preferably situated as symmetrically as possible with respect to the emitter zone of transistor T 1 .
The sub-zones 16a, 16b and 16c constitute a number of substantially parallel and elongate juxtaposed strip-shaped zones; this is a practical configuration both as regards the operation of the device and as regards the contact layer necessary for the various zones and regions. This contact layer has a comb shape, the projecting parts of which are parallel to said zones, and it connects said zones to the base zone 12. The p-type zones 17a, 17b and 17c which are situated in the strip-shaped zones 16a, 16b and 16c are also provided with a comb-like contact layer. Said comb shape is such that the projecting parts interdigitate with those of the first comb shape.
The Darlington circuit comprises two resistors R 1 and R 2 , as is usual. The resistor R 1 which connects the base of T 1 to the base of T 2 is formed by a pinch resistor formed by a part of the p-type layer 12 which is bounded in the vertical direction by a part of the emitter 11 and the collector region 5 and in the horizontal direction by the groove 9. The resistor R 2 is also formed in the same manner by a pinch resistor consisting of a part of the p-type region 22 bounded in the vertical direction by the n-type region 27 and the collector region 3 and bounded in the horizontal direction by the groove 9. This resistor R 2 connects the intrinsic emitter-zone adjoining part of the base 22 to the highly doped p-type region 33.
The p-type region 22 in which the highly doped p-zone is situated constitutes a p-n junction with the n-type collector region 3 which junction may be used as a protecting diode denoted in FIG. 3 by D 2 . As shown in the Figure, the emitter contact layer 29 has a number of fingers and a widened part which is suitable for providing an external connection.
The device can be manufactured entirely in a manner generally known to those skilled in the art.
In a specific embodiment the thickness of the p-type base regions 12, 22 is approximately 30 micrometers and the surface concentration is 5×10 18 atoms/cm 3 .
The thickness and the doping concentration of the cathode 16 which was provided simultaneously with the emitter of the transistors 10, 20 are 10 micrometers and 6×10 19 atoms/cm 3 , respectively.
The doping concentration of the anode 17 is 10 20 at/cm 3 , while the thickness of the anode is 2 micrometers.
It has been found that with these values good results can be obtained with a width for each n-type region 16 of 200 micrometers and a width for each p-type region 17 of 100 micrometers with a current through the diode of 2A.
FIG. 4 is a plan view of the diode 16, 17 according to a second embodiment of a Darlington circuit in accordance with the invention. The transistors 10 and 20 and the resistors R 1 and R 2 may be identical to the corresponding transistors and resistors according to the first embodiment and they are therefore not shown in FIG. 4. The sub-zones 16a, 16b and 16c in this embodiment are connected together by the part 16d to form a comb structure. The zones 17 are also connected to form a comb structure by the part 17d. The contact layer 8 short-circuits the region 16 along substantially its whole circumference with the base region 12 of transistor T 1 .
FIG. 5 shows a further modified embodiment in which the regions 16a, 16b, 16c and 16e are connected to form a meandering structure which is short-circuited along a substantial part of its circumference with the base of transistor T 1 via a comb-shaped contact 8. The p-regions 17a, 17b and 17c, 17e, respectively, are united to form two U-shaped zones which are contacted via the comb-shaped contact layer 4.
FIG. 6 is a plan view of a further modified embodiment of the diode 16, 17 in which the regions 16a, 16b form closed strip-shaped zones. The p-type zones 17a, 17b in this example are again more or less U-shaped.
FIG. 7 finally shows an embodiment in which the sub-zones of the cathode 16 are obtained from one coherent n-type region which has apertures in which the said intermediate parts of the base 12 adjoin the surface of the semiconductor body.
The zones 12a, which for purposes of making a good contact have an increased doping concentration, are provided so that the cathode 16 in plan view shows a grid-shaped pattern. The zones 17 are provided in the cathode 16 according to a second grid and are contacted by the contact layer 4 consisting of vertical strips having horizontal transverse parts. The short-circuit between the sub-zones of the cathode 16 and the sub-regions 12a is obtained by choosing the contact holes to be larger than the area of the sub-regions 12a. The contact 8 which is more or less comb-shaped short-circuits, as is shown in FIG. 7, the p-n junctions between the sub-zones and the adjoining parts of the cathode 16 along their whole circumference so that parasitic p-n-p-n action can again be prevented effectively, as described above.
It will be obvious that the invention is not restricted to the examples described but that many variations are possible to those skilled in the art without departing from the scope of this invention.
For example, the conductivity of all semiconductor zones and regions in the embodiments may (simultaneously) be replaced by their opposite types.
The contact layer 8 which effects the short-circuit between the regions 16 and the parts 12a of the base region need not necessarily be situated in a contact hole in which the p-n junction between said regions merges at the surface. This p-n junction may alternatively be covered, for example, by an insulating layer across which a metal track ensures the short-circuit via contact holes to said regions.
On the other hand, in FIG. 2, the insulating layer 5 between the regions 16a and 16b at the area of the connection contact 28 (B 1 in FIG. 3) may be omitted.
In the device shown in FIGS. 1 and 2 the groove 9 may be filled with silicon oxide or another insulating material, if so desired.
In addition, numerous other shapes possible in the design of the sub-regions of the cathode 16; the closed strip-shaped zones in FIG. 6, for example, may also be constructed as concentric circular zones; alternatively, the sub-zones may extend, for example, in the form of a star from a central part.
Finally, a circuit of the above-mentioned kind can be controlled again by a third transistor the emitter of which is connected to the base of the control transistor and the collector may be connected, if desired, to the common collector region of the Darlington circuit, in which this third transistor is provided with a similar diode as described above between the emitter and the base. | In a Darlington circuit with integrated speed-up diode the parasitic four-layer effect (p-n-p-n), which is detrimental to the circuit, is removed by giving the diode a divided configuration. The width of the sub-regions is chosen to be so small that the short-circuited p-n junction between the cathode of the diode and the base of the control transistor cannot or substantially can not be biased in the forward direction in the inner part of the semiconductor device. | 7 |
FIELD
[0001] The present invention relates to a pharmaceutical composition and a method for treating a disease caused by cholesterol accumulation such as lysosomal diseases and the like. More particularly, the present invention relates to a pharmaceutical composition for treating a disease caused by cholesterol accumulation, comprising hydroxypropyl-γ-cyclodextrin as an active ingredient. The present invention also relates to a method for screening a therapeutic agent for a disease caused by cholesterol accumulation such as lysosomal diseases and the like.
BACKGROUND
[0002] When an enzyme associated with a lysosome which is one of intracellular organelles is genetically defective or mutated, substances to be degraded or transported are accumulated as a foreign substance inside or outside cells. A disease of inborn error in metabolism caused by such a phenomenon is known as a lysosomal disease. Examples of the lysosomal disease include Niemann-Pick disease and GM1 gangliosidosis.
[0003] Niemann-Pick disease type C (NPC) is one of diseases of congenital lysosomal diseases caused by abnormality of a membrane protein NPC1 molecule which governs transportation of lipids mainly including cholesterol in cells or a secretory protein NPC2 molecule co-existing with NPC1 in endosomes. In patient's cells, free cholesterol and lipids are accumulated in lysosomes. NPC is characterized by hepatomegaly, splenomegaly, and a nervous symptom. NPC is a rare intractable disease which is developed at an infant stage, causes splenohepatomegaly or a progressive nerve disorder, and leads patients to death at around 10 years old. Effective therapy for the present disease has not been established.
[0004] A cyclic oligosaccharide, cyclodextrin (CyDs), is a monomolecular host molecule having hydrophobic hollow cavities in the molecule. When a guest molecule is taken into the hollow cavities of CyDs, to form inclusion complexes, a physicochemical nature of the guest molecule varies variously. The supramolecular inclusion phenomenon of CyDs called a molecular capsule is effectively utilized in many fields. Particularly, in drug development, the phenomenon is widely applied to improvement in preparation properties and construction of the drug delivery system.
[0005] Recently, Liu et al. have reported that when 2-hydroxypropyl-β-cyclodextrin (HPBCD) is intravenously administered to Npc1 gene-defective (Npc1-/-) mice, this is effective in improving the medical state or prolonging survival, and when HPBCD is directly administered into the brain, the improving effect thereof is increased a few hundreds times, compared with systemic administration (Non-Patent Document 1). Based on the outcome of these fundamental researches, US FDA specially approved humanistic use of HPBCD to NPC child patients (intravenous administration and intrathecal administration). Under such background, also in Japan, in Hospital Affiliated to Medical Department of Sage University, HPBCD injectables were prepared in the hospital, and treatment of NPC child patients was initiated. As a result of continuation for more than 1 year of intravenous instillation of HPBCD (2500 mg/kg per time, 1 to 3 times per week) to NPC child patients, the certain effect of reduction of splenohepatomegaly and improvement in a brain wave in child patients was obtained, but a nervous symptom has not been improved yet. Then, in addition to HPBCD, a glycolipid synthesis inhibitor, Miglustat (50 or 100 mg per time, two times per day), was used concurrently. Furthermore, in order to directly deliver HPBCD into the brain not through the blood brain barrier, intrathecal administration and intraventricular administration via the Ommaya reservoir (30 mg/kg, once per week) are performed, concurrently with intravenous administration of HPBCD. Since treatment with HPBCD is first in Japan and there is no precedent of high dose administration and long term administration, the treatment is continued while the effectiveness and the harmful events of the treatment are closely examined. However, there is also a of the side effect, and HPBCD has not been generalized in Japan yet.
[0006] Meanwhile, HPBCD is approved as an additive (solubilizer) of medicaments, but a renal disorder is apprehended. In addition, events such as a pulmonary disorder have also been reported, and in the case of high dose administration or long term administration, safety thereof has become a problem. Accordingly, safer therapeutic agents for NPC in place of HPBCD are desired.
[0007] GM1 gangliosidosis is one of Gaucher diseases caused by a mutation of lysosomal-β-glucosidase which is a glycohydrolase, and a mutation of lysosomal-β-galactosidase is the etiology. This is a disease in which by deficiency of beta galactosidase, a glycolipid such as GM1-ganglioside and asialo-GM1-ganglioside, which is a substrate thereof, is accumulated in the brain or internal organs (liver, spleen) and the like, or a mucopolysaccharide such as keratan sulfate or the like is accumulated in the bone. There are three types including the baby type (type 1) which is developed at an early babyhood stage and associated with wide central nervous system disorders including spastic paraplegia, and a cherry red spot of the eyeground, splenohepatomegaly and bone abnormality, the juvenile type (type 2) which is developed from an infant stage and in which a central nervous system disorder progresses, and further, the adult type (type 3) in which a symptom such as dysarthria is manifested from a school age stage and an extrapyramidal symptom is a main symptom.
[0008] For these diseases, enzyme replenishment therapy has been main therapy until now, and examples of the problem include a problem that an enzyme preparation hardly reaches a central nerve, and the therapeutic effect on a nervous system including the brain is not seen, and a problem that dripping treatment with an enzyme preparation at the high cost must be continued through life. Accordingly, new therapeutic agents for these lysosomal diseases are desired.
[0009] Induced pluripotent stem cells (iPS cells), which are artificially produced from human somatic cells, can be induced to undergo sustained, unlimited growth and exhibit multipotency (i.e., the ability to give rise to various cell types in vitro). Because of these features, iPS cells have potential applications as a source of cell therapy in clinical medicine. The process of iPS cell generation, known as reprogramming, is triggered by the expression of four transcription factors, Oct3/4, Klf4,and c-Myc, which are the same core factors underlying pluripotency in other pluripotent stem cells such as embryonic stem (ES) cells. Overexpression of the four factors was initially mediated by lentivirus and retrovirus vectors in human skin-derived fibroblasts. Although these gene expression systems are stable, they have two potential problems in that the genes encoding the four factors are integrated into the host genome and remain in the resultant iPS cells, and there is a risk of insertional mutagenesis, can facilitate tumorigenesis in vivo
[0010] The development of efficient and safe reprograming methods based on the Cre/loxP recombination system, adenovirus vector, piggyback transposons, microRNA, and protein has suffered from a low frequency of iPS cell colony generation, a need for repetitive induction, and retention of a short length of foreign DNA in the host genome. A recent study showed that episomal plasmid vectors, which rarely integrate into the host genome, can be used to generate iPS cells from blood cells; however, the efficiency was low (˜0.1%) and factors such as p53 knock-down and the transient expression of EBNA were required in addition to the four reprogramming factors.
[0011] Sendai virus (SeV) vector technology is analternative strategy developed to overcome the obstacles described above. SeV vectors are minus-strand RNA viruses that express a gene of interest without integration into the host genome and have been used to efficiently generate iPS cells from human skin-derived fibroblasts and blood cells (Non-patent documents 2 and 3). The frequency of iPS cell colony generation with SeV vectors is higher than that achieved with conventional methods using retrovirus and lentivirus vectors (0.1% versus 0.01%). However, the SeV remains inside the cells for more than one month, and thus the establishment of transgene-free iPS cells requires a long time. Recently, the temperature-sensitive SeV (Ts-SeV) system was developed to prevent uncontrolled iPS cell generation due to the sustained cytoplasmic replication of SeV (Non-patent document 4). Ts-SeVs are easily and immediately eliminated from iPS cells derived from cord blood cells and fibroblasts by a temperature upshift, but the efficiency of iPS cell generation with current Ts-SeV vectors is low than that with SeV.
[0012] Further, method using the SeV has been reported for producing iPS cells from peripheral blood monocytes. In the method, a SeV vector continuously expressing reprogramming genes Oct4, Sox2, Klf4, and c-Myc is used and the removal of reprogramming gene mounted viral vector from cells is performed by using siRNA (Patent Document 1).
[0013] Although skin fibroblasts are the most common cell type used for generating iPS cells, skin biopsies are invasive and are not ideal for children or patients with skin diseases or coagulopathy. Peripheral blood cells is a preferable source cell; however, Ts-SeV vectors have not been reported for generating iPS cells from peripheral blood cells, and prolonged retention of SeV in iPS cells remains a problem when non-temperature sensitive SeV vectors are used.
[0014] Numerous iPS cell lines derived from the somatic cells of patients harboring pathogenic mutations, using methods including SeV, were shown to phenocopy the disease. Therefore these cell lines represent a powerful tool not only for cell therapy, but also for biomedical research and drug development. Biomaterial samples obtained from patients with intractable diseases are indispensable for studying the molecular mechanism of diseases and developing new therapeutic agents. However, because the number of samples from such patients is usually limited, disease-derived iPS cells are expected to be useful as a replacement or supplemental source of biomaterials for cell therapy. As just described, iPS cells have been used as a cell source or a cell model of disease. However, its use is limited by inefficient production and the presence of the transgene in cells. Therefore, a method for more efficiently producing iPS cells without introducing genes therein and safe is desired.
CITATION LIST
[0015] Patent Literature 1: International Publication WO2012/063817
Non-Patent Literature
[0016] Non-Patent Literature 1: Liu et al. Proc Natl Acad Sci USA, 106, 2377(2009)
[0017] Non-Patent Literature 2: Fusaki et al., Proc. Jpn. Acad. Ser. B, Phys. Biol. Sci. 85, 348-362, 2009
[0018] Non-Patent Literature 3: Seki et al. Cell Stem Cell 7, 11-14, 2010
[0019] Non-Patent Literature 4: Banet al., Proc. Natl. Acad. Sci. USA 108, 14234-14239, 2011
[0020] Non-Patent Literature 5: Irie et al., J. Phar. Sci., vol 86, No. 2, pp. 147-162, 1997
SUMMARY OF THE INVENTION
Technical Problem
[0021] An object of the present invention is to provide pharmaceutical compositions for treating a disease caused by cholesterol accumulation such as lysosomal diseases and the like, for example, Niemann-Pick disease or GM1 gangli osidosis.
[0022] Another object of the present invention is to provide a method for screening those pharmaceutical compositions, more particularly, the object is to provide a method for screening pharmaceutical compositions for treating the disease caused by cholesterol accumulation such as lysosomal diseases and the like, using an iPS cell strain mirroring the phenotype of the disease.
[0023] The present invention also relates to a method for effectively preparing an iPS cell strain used in the above-described screening method, more particularly, it relates to a method for effectively preparing an iPS cell strain used in the above-described screening method, using a temperature-sensitive Sendai virus having only specified reprogramming factors.
[0024] Another object of the present invention is to provide a transgene-free iPS cell strain, which is an effective cell model of intractable diseases.
Solution to Problem
[0025] The present inventors have developed a new Sendai virus vector, TS12KOS, which improves the efficiency of preparing iPS cells, and can be easily removed from cells without being integrated into intracellular DNAs. The present inventors have also prepared an iPS cell strain exhibiting the phenotype of intractable diseases, from patients with the diseases, using the TS12KOS vector, and developed a method for screening therapeutic agent candidates for the diseases using the cell strain. The present inventors have, further, used such a method to find out a pharmaceutical composition for treating a disease caused by cholesterol accumulation such as lysosomal diseases and the like, for example, Niemann-Pick disease and GM1 gangliosidosis.
[0026] The present invention includes the following:
[0027] (1) A pharmaceutical composition for treating or preventing a lysosomal disease, comprising hydroxypropyl-y-cyclodextrin as an active ingredient.
[0028] (2) The pharmaceutical composition according to (1), wherein the lysosomal disease is Niemann-Pick disease.
[0029] (3) The pharmaceutical composition according to (1), wherein the lysosomal disease is GM1 gangliosidosis.
[0030] (4) The pharmaceutical composition according to any one of (1) to (3), wherein the pharmaceutical composition is an injectable and is administered for a long term.
[0031] (5) A method for screening a drug candidate for an intractable disease, comprising differentiating iPS cells into an arbitrary lineage, said iPS cells prepared by a step of preparing iPS cells comprising the following steps:
[0032] (i) a step of infecting cells derived from an intractable disease patient with a temperature-sensitive Sendai virus vector to reprogram the cells, wherein the vector comprises each gene of an NP gene, a P gene comprising three mutations generating alanine residues (D433A, R434A, and K437A), an M gene, an HN gene and an L gene, and carries sequences encoding three reprogramming genes, KLF4, OCT3/4 and SOX2 in this order direction between the P gene and the M gene, and (ii) a step of culturing the cells infected with the vector at a temperature exceeding 37° C., thereby removing the vector carrying the reprogramming genes from the cells to prepare transgene-free iPS cells,
[0033] then, culturing the cells together with a target substance,
[0034] and then, detecting an influence of the target substance on the cells.
[0035] (6) The screening method according to (5), wherein culturing at the step (ii) is at 38° C.±0.5° C.
[0036] (7) The screening method according to (5) or (6), wherein the cells derived from an intractable disease patient are skin fibroblasts.
[0037] (8) The screening method according to (5) or (6), wherein the cells derived from an intractable disease patient are cells derived from peripheral blood.
[0038] (9) The screening method according to any one of (5) to (8), wherein the intractable disease is a lysosomal disease.
[0039] (10) The screening method according to (9), wherein the lysosomal disease is Niemann-Pick disease or GM1 gangliosidosis.
[0040] (11) iPS cells derived from a lysosomal disease patient prepared by steps comprising:
[0041] (i) a step of infecting cells derived from a lysosomal disease patient with a temperature-sensitive Sendai virus vector to reprogram the cells, wherein the vector comprises each gene of an NP gene, a P gene comprising three mutations generating alanine residues (D433A, R434A and K437A), an M gene, an HN gene and an L gene, and carries sequences encoding three reprogramming genes, KLF4, OCT3/4 and SOX2 in this order direction between the P gene and the M gene, and
[0042] (ii) a step of culturing the cells infected with the vector at a temperature exceeding 37° C., thereby removing the vector carrying the reprogramming genes from the cells to prepare transgene-free iPS cells.
[0043] (12) The iPS cells according to (11), wherein the cells derived from a lysosomal disease patient are skin fibroblasts.
[0044] (13) The iPS cells according to (11), wherein the cells derived from a lysosomal disease patient are cells derived from peripheral blood.
[0045] (14) The iPS cells according to any one of (11) to (13), wherein the lysosomal disease is Niemann-Pick disease or GM1 gangliosidosis.
[0046] (15) The iPS cells according to (14), wherein the lysosomal disease is Niemann-Pick disease, and an NPC1 gene and an NPC2 gene have a mutation.
[0047] (16) The iPS cells according to (15), wherein the lysosomal disease is Niemann-Pick disease, and when differentiated into hepatocyte-like cells, the iPS cells exhibit the following phenotypes:
[0048] (a) intracellular cholesterol accumulation is increased,
[0049] (b) the autophagy function of the cells is impaired, and
[0050] (c) ATP production in the cells is reduced.
Advantageous Effect of Invention
[0051] The composition containing hydroxypropyl-y-cyclodextrin as an active ingredient of the present invention is effective for iPS cells mirroring the phenotype of the lysosomal disease, particularly Niemann-Pick disease or GM-1 gangliosidosis, and is also effective as a therapeutic agent for those diseases.
[0052] In addition, by the method of the present invention using the temperature-sensitive Sendai virus vector, iPS cells can be effectively prepared from cells from an intractable disease patient, and the prepared iPS cells mirror the phenotype of the disease, and at the same time, are transgene-free. When these iPS cells are used, drug candidates for the disease can be easily screened. Furthermore, the prepared iPS cells themselves do not undergo canceration, and are safe.
BRIEF DESCRIPTION OF DRAWINGS
[0053] FIG. 1 It shows comparison of schematic structures of the temperature sensitive Sendai virus (TS-SeV) vector and TS12KOS of the present invention with a conventional vector. The TS12KOS vector contains three point mutations in the RNA polymerase-related gene (P) and carries the coding sequences of KLF4(K), OCT3/4(O), and SOX2(S) in the KOS direction. In comparison, the HNL/TS15 c-Myc vector carries two additional mutations, L1361C and L15581, in the large polymerase (L) gene and an exogenous c-MYC cDNA sequence inserted between the hemagglutinin-neuraminidase (HN) and L genes. The conventional vector individually carries three reprogramming factors.
[0054] FIG. 2 It shows iPS cell generation from human skin-derived fibroblasts. N1, N2, and N3 indicate individual healthy volunteers. Experiments were conducted in triplicate (mean±SD). *P<0.01, TS12KOS vector versus conventional vector, Student's t-test.
[0055] FIG. 3 It shows temperature shift from 37° C. to 36° C. for the indicated periods in iPS cell generation. Data are means±SD of three independent experiments. **P<0.02, #P<0.05, Student's t-test.
[0056] FIG. 4 It shows nested RT-PCR analysis of the elimination of SeV vectors after the temperature shift from 37° C. to 38° C. in human fibroblast-derived iPS cells. It shows number of clones in which vectors are eliminated after passages (one or two) passages.
[0057] FIG. 5 It shows iPS cell generation from human peripheral blood cells. Experiments were conducted in triplicate (mean±SD). (A) N1, N2, and N3 indicate individual healthy volunteers. *P<0.01, TS12KOS vector versus conventional vector, Student's t-test. (B) Nested RT-PCR analysis of the elimination of SeV vector after the temperature shift from 37° C. to 38° C. It shows number of clones in which vectors are eliminated after passages (one or two) passages.
[0058] FIG. 6 It shows tissue morphology of a representative teratoma derived from an iPS cell (“iPSC”) line generated with TS12KOS vector after hematoxylin and eosin-staining. The descendants of all three germ layers were observed in the teratoma. The iPSC line is derived from human fibroblasts, BJ. CE, cuboidal epithelium (ectoderm); G, glandular structure (endoderm); M, muscle tissue (mesoderm); C, cartilage (mesoderm). Scale bars, 100 μm.
[0059] FIG. 7 It shows phase contrast images of iPSC lines derived from the NPC patients as immunofluorescence and alkaline phosphatase (AP) staining. The iPSC lines NPC5-1 and -2, and NPC6-1 and -2, were derived from the NPC patients, NPC5and NPC6, respectively. Scale bars, 200 μm.
[0060] FIG. 8 It shows RT-PCR analysis of Sendai virus and human ES-cell markers of iPSC lines derived from the NPC patients. NPC5 and NPC6 were derived from the NPC patients, NPC5and NPC6, respectively. 201B7, control human iPSC line; SeV(+), Day 7 SeV-infected human fibroblasts; SeV, first RT-PCR for SeV; Nested, nested RT-PCR for SeV.
[0061] FIG. 9 It shows Histological analysis of NPC-iPSC-derived teratomas after hematoxylin and eosin staining. CE, cuboidal epithelium (ectoderm); G, glandular structure (endoderm); M, muscle tissue (mesoderm); C, cartilage (mesoderm); MP, melanin pigment (ectoderm). Scale bars, 100 μm.
[0062] FIG. 10 It shows mutations in the NPC1 gene of NPC-derived iPSC lines. The mutations 2000C>T (S667L) and 3482G>A (C1161L) were observed in iPSC lines derived from patient NPC5 (leftpanel), whereas iPSC lines derived from patient NPC6 carried both 3263A>G (Y1088C) and a short deletion mutation in which the nucleotide region from 581 to 592 was replaced by a G residue, resulting in a frame shift (rightpanel). Mutations are indicated by arrows.
[0063] FIG. 11 It shows a pathway of iPS cell differentiation into hepatocyte-like cells. The pathway is divided into three periods: endoderm differentiation from day 0 to day 4, hepatic differentiation from day 4 to day 11 and hepatic maturation from day 11 to day 18. The culture conditions are described below each period. The cells were harvested on both day 4 and day 11 and reseeded under the next conditions.
[0064] FIG. 12 It shows cell size of HLCs derived from NPC-iPSC lines.
[0065] FIG. 13 It shows cholesterol accumulation in HLCs derived from NPC-iPSC lines. Free cholesterol was examined by filipin staining (upper panel), and the relative intensity was calculated relative to the normal iPSC line, N1-12 (lower graph). Data are means±SD of three independent experiments. *P<0.01, the indicated NPC-iPSC line versus the normal iPSC lines, Student's t-test. Scale bars, 100 μm.
[0066] FIG. 14 It shows ATP levels in HLCs derived from iPSC lines. Experiments were conducted in triplicate (mean±SD). *P<0.01, #P<0.05, the indicated NPC-iPSC line versus the normal iPSC lines, Student's t-test.
[0067] FIG. 15 It shows expression level of microtubule-associated protein 1 light chain 3 (LC3). *P<0.01, #P<0.05, the indicated NPC-iPSC lines versus the normal iPSC lines, N1-12 and N3-2, Student's t-test. The expression level was normalized to the expression of a-tubulin in each iPSC line.
[0068] FIG. 16 It shows expression level of insoluble form of p62.
[0069] FIG. 17 It shows immunofluorescence staining for p62. Abnormal aggregation of p62 was strongly present in NPC-derived HLCs (upper panel). The aggregated granules were counted and the results summarized in the lower graph. The proportion of cells carrying more than 40 granules was increased in NPC-derived HLCs comparing to normal HLCs. Nuclear staining, Hoechst 33258; Scale bars, 25 μm.
[0070] FIG. 18 It shows effect of a series of hydroxypropyl-cyclodextrins on the reduction of free cholesterol accumulation in NPC-derived HLCs. The upper panel shows the results of filipin stained, and the lower panel shows a result analyzed with an IN CELL ANALYZER. Data are mean±SD of three independent experiments. *P<0.01, #P<0.05, non-treatment versus treatment of each NPC-derived HLC, Student's t-test. Scale bars, 50 μm.
[0071] FIG. 19 It shows dose effect of HPBCD and HPGCD on the reduction of free cholesterol accumulation in NPC-derived HLCs. *P<0.01, non-treatment versus treatment of each NPC-derived HLC, Student's t-test.
[0072] FIG. 20 It shows effect of HPBCD on the reduction of free cholesterol accumulation in NPC-derived iPS cell differentiation. The upper panel shows experimental design and the lower graph shows filipin staining. Experiments were conducted in triplicate(mean±SD). *P<0.01, #P<0.05, non-treatment versus treatment, Student's t-test.
[0073] FIG. 21 It shows effects of hydroxypropyl-cyclodextrin (HPCD) treatments on ATP levels of HLCs derived from NPC-iPSC lines. Data are mean±SD of three independent experiments. #P<0.05, non-treatment versus treatment, Student's t-test.
[0074] FIG. 22 It shows effects of HPCD treatments on expression level of LC3 in NPC-derived HLCs. β: Treatment with 1 mM HPBCD for four days; γ: 1 mM HPGCD treatment for four days. The expression level was normalized to α-tubulin expression in each iPS cell line.
[0075] FIG. 23 It shows effects of HPCD treatments on p62 expression level in NPC-derived HLCs
[0076] FIG. 24 It shows the proportion of NPC-derived HLCs carrying insoluble p62 aggregation with HPCD treatments. β: Treatment with 1 mM HPBCD for four days; γ: 1 mM HPGCD treatment for four days.
[0077] FIG. 25 It shows hierarchical clustering of genes of NPC-iPSC derived HLCs with HPCD treatments.
[0078] FIG. 26 It shows principal component analysis (PCA) of NPC-iPSC derived HLCs with HPCD treatments.
[0079] FIG. 27 It shows microarray analysis/molecular signatures in healthy donor-derived HLCs and NPC-derived HLCs. The molecular signatures enclosed in squares shows signatures significantly (P<0.05) changed in NPC-derived HLCs, compared to healthy donor-derived HLCs. Upper panel: downregulated signatures in NPC, lower panel: upregulated signatures in NPC.
[0080] FIG. 28 It shows microarray analysis/molecular signatures with HPCBD and HPGCD treatments. Upper panel: HPBCD treatment, lower panel: HPGCD treatment. The molecular signatures enclosed in squares shows signatures significantly (P <0.05) changed in HPCBD and HPGCD treatments.
[0081] FIG. 29 It shows hierarchical clustering of genes significantly altered with HPBCD and HPGCD treatments. Left panel: genes included in the molecular signature altered with HPBCD treatment, right panel: genes included in the molecular signature altered with HPGCD treatment.
[0082] FIG. 30 It shows levels of markers (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) in the serum.
[0083] FIG. 31 It represents histological sections of liver from the NPC model mice with HPGCD treatment. Arrow heads indicate lipid-laden parts. Upper images: low magnification (×200), Lower images: high magnification (×400). Scale bars, 50 μm.
[0084] FIG. 32 It represents histological sections of cerebellar vermis from the NPC model mice with HPGCD treatment. The Purkinje cell defect (arrow head) was restored with HPGCD treatment. The sections were stained with H&E (upper panel) or for calbindin immunoreactivity (lower panel).
[0085] FIG. 33 It shows survival curve for NPC model mice with HPGCD treatment.
[0086] FIG. 34 It shows acute toxicity test of normal mice given HPBCD and HPGCD injections.
DESCRIPTION OF EMBODIMENTS
[0087] The present invention will be illustrated in detail below, but the present invention is not limited to aspects described below.
[0088] The vector carrying reprogramming genes used for preparing iPS cells in the present invention is a temperature-sensitive Sendai virus (TS-SeV) vector which has an NP gene, a P gene and an L gene derived from a Sendai virus (SeV), and is defective in an F gene. The vector comprises three mutations generating alanine residues (D433A, R434A and K437A) in the L gene. The Sendai virus vector (SeV) having these three mutations has a characteristic that it exhibits moderate expression of GFP at 37° C., and exhibits weak expression at a temperature exceeding 38° C. The vector used in the present invention is characterized in that it further carries sequences encoding three reprogramming genes, KLF4 (K), OCT3/4 (O) and SOX2 (S) in a KOS direction, between the P gene and the M gene. Thereby, even cells derived from an intractable disease patient can be effectively reprogrammed, and at the same time, the virus vector can be easily removed from the cells.
[0089] The Sendai virus vector is a gene introduction and expression vector which can express an arbitrary gene by inserting the gene into a genome of the Sendai virus, or substituting a gene of the Sendai virus with the gene. The Sendai virus has respective genes of NP, P, M, HN, F and L, and the NP, P and L genes of the same virus are genes involved in transcription and replication of the Sendai virus, while the M, F and NH genes are genes involved in formation of virions. Accordingly, the Sendai virus vector defective in the F gene cannot form novel virions by itself alone after infection of cells therewith, and becomes non-propagating.
[0090] In addition, for the TS-Sev vector used in the present invention, the Sendai virus to which other mutation or alteration is added can also be used, as far as it has three mutations in the L gene contributing to temperature sensitivity, and three reprogramming genes, KLF4 (K), OCT3/4 (O) and SOX2 (S) carried between the P gene and the M gene in a KOS direction, and has a nature that the virion forming ability is deleted.
[0091] The reprogramming gene to be inserted into SeV used in the present invention is characterized in that it comprises each gene of Oct3/4, Sox2 and Klf4 of a human, a mouse or an arbitrary mammal in a specified sequence order. In addition, it may comprise a reprogramming gene involved in tumor formation, other than it, for example, a c-Myc gene or an L-Myc gene, preferably comprises only Oct3/4, Sox2 and Klf4 as the reprogramming gene, and do not comprise a gene having the tumor forming activity other than it.
[0092] The TS-SeV vector having the above characteristics can be prepared using the known method.
[0093] In reprogramming of cells, differentiated cells to be a subject of reprogramming are infected with the TS-SeV vector carrying reprogramming genes in a form of the virion. The cells to be a subject of reprogramming are cells derived from a patient with an intractable disease, preferably, skin fibroblasts or cells derived from peripheral blood. The cells derived from peripheral blood may be any of T lymphocyte cells and monocyte cells. Peripheral blood is lower in invasiveness, compared with the skin fibroblasts, and is also suitable for infant patients and patients having a skin disease or a coagulation disorder. Using the TS-SeV vector in the present invention, iPS cells can be prepared at the high efficiency of “˜4%” in the skin fibroblasts, and “˜2%” in the peripheral blood cells.
[0094] An operation such as infection of cells with the TS-SeV vector in the present invention, and culturing, treatment, selection etc. of the infected reprogrammed cells can be performed according to the conventional method.
[0095] In addition, when cells are reprogrammed using the TS-SeV vector in the present invention, an introduced gene or a part thereof is not inserted into unspecified sites of chromosomes. Further, one aspect of the TS-SeV vector in the present invention does not use a c-Myc gene or an L-Myc gene having the tumor forming activity. For this reason, the resulting iPS cells have no possibility that they cause canceration, and are extremely safe.
[0096] Removal of the vector carrying the reprogramming genes can be performed by shifting (elevating) a temperature for culturing cells. For example, the vector can be completely removed, for example, by elevating a temperature of cells which are being cultured and passaged at 37° C. to a temperature exceeding 37° C., preferably a temperature exceeding 37° C. and not higher than 39° C., more preferably 38° C±0.5° C., and further preferably 38° C. A culturing term at a temperature exceeding 37° C. is not particularly limited as far as the vector can be removed, and when the term is expressed by the number of days, it is for example 2 to 20 days, preferably 2 to 15 days, and further preferably 3 to 5 days, and on the other hand, when the term is expressed by the passaging number, it is preferably 1 to 3 passages, and further preferably 1 to 2 passages. By separating single clones after the reprogrammed cells are treated at a temperature exceeding 37° C., clones from which the vector has been completely removed can be obtained. Confirmation of vector removal can be performed by the conventional method, for example, by detecting an arbitrary gene in the vector by RT-PCR. Like this, when the TS-SeV vector in the present invention is used, transgene-free iPS cells can be prepared in a short term of within one week from isolation of iPS cell colonies. In addition, unlike the previous technique not using the SeV vector, this system does not require a plurality of infection cycles, and further, the efficiency of preparing iPS cells is 20 to 100 times of the case where iPS cells are obtained using the technique such as a retrovirus, a lentivirus, or a plasmid vector.
[0097] iPS cells prepared from cells of an intractable disease patient, using TS-SeV in the present invention, can exhibit the characteristic of the disease (phenotype). The phenotype can be confirmed by differentiation-inducing the prepared iPS cells into desired cell lineages. Differentiation inducement of iPS cells can be performed according to the conventional method. For example, differentiation inducement into a liver lineage can be performed by culturing the prepared iPS cells in a hepatocyte differentiation-inducing medium. Thus differentiation-induced cells exhibit the characteristic of a disease (phenotype) from which the cells are derived. For example, hepatocyte-like cells which were induced from iPS cells derived from a Niemann-Pick disease type C patient accumulate cholesterol, and as a result, exhibit a functional disorder. Examples of the functional disorder include a functional disorder of autophagy and ATP production. As other example, liver-like cells which were induced from iPS cells derived from a GM-1 gangliosidosis patient exhibit the characteristic of abnormality of autophagy (phenotype).
[0098] Since cells which were differentiation-induced from iPS cells derived from an intractable disease patient become a cell model of the disease, they become a powerful tool for research and screening of drug candidates.
[0099] For example, as will be described in the following Examples in detail, both 2-hydroxy-γ-cyclodextrin (HPGCD) and 2-hydroxypropyl-β-cyclodextrin (HPBCD) removed cholesterol accumulated in hepatocyte-like cells derived from NPC, and recovered the function of the hepatocyte-like cells. This shows that HPGCD is a promising new candidate for treatment of NPC.
[0100] The pharmaceutical composition of the present invention contains hydroxypropyl-γ-cyclodextrin as an active ingredient, and can be used as a therapeutic agent for a lysosomal disease. Examples of the lysosomal disease include Niemann-Pick disease, Tay-sachs disease, sialidosis or GM-1 gangliosidosis.
[0101] As shown below, HPGCD exhibited the activity equal to or more than that of HPBCD, on hepatocyte-like cells which had been differentiation-induced from NPC patient-derived iPS cells, which exhibit the phenotype of Niemann-Pick disease. Meanwhile, 2-hydroxy-α-cyclodextrin (HPACD) exhibited no activity at all. This result is surprising in view of the result that the effect of HPGCD is a several tenth part or less, compared with that of HPBCD, in a report (Non-Patent Document 5) confirming the cholesterol dissolution activities of HPBCD and HPGCD using cultured cells.
[0102] One of the most important requirements for drug candidates is no or acceptable low levels of intrinsic cytotoxicity. Interaction between cyclodextrin and a cell membrane is an initial stage of such cell damage. The in vitro dissolution activity of isolated erythrocyte is an index of toxicity of each cyclodextrin, and the hemolytic activity of hydroxypropylcyclodextrin is in the order of HPBCD>HPACD>HPGCD (Non-Patent Document 5). The previous research showed that γ-cyclodextrin is safer than α- or β-cyclodextrin in acute intravenous administration to rats, and it has been reported that an intravenous dose showing lethality to 50% of population (LD50 value) is 1000, 788, and >3750 mg/kg, respectively, for α-, β-, and γ-cyclodextrins. Accordingly, HPGCD is more excellent as a therapeutic agent for Niemann-Pick disease, as compared with HPBCD.
[0103] The composition of the present invention preferably takes a form of a preparation for injection, but is not limited to this. The preparation for injection of the present invention can be intravenously, intramuscularly or subcutaneously administered. In addition, the pharmaceutical composition of the present invention can take a form of any of a water-soluble preparation or a lyophilized preparation, and preferably, examples thereof include aqueous injectables, and lyophilized injectables soluble at use.
[0104] The composition of the present invention may comprise saccharides, antiseptics, stabilizers, and antistatic agents which are usually used in injectables. The composition of the present invention can also contain pharmacologically acceptable pH adjusting agents. The pH adjusting agents used in the present invention are not particularly limited as far as they are substances which can be used in utility of medicines, and are pharmacologically acceptable, and are preferably sodium hydroxide, a carbonate buffer, a phosphate buffer, a citrate buffer, an acetate buffer and hydrochloric acid. These pH adjusting agents may be used alone, or may be used by mixing two or more kinds. The composition of the present invention can also contain osmotic pressure adjusting agents or isotonizing agents, and can contain, for example, at least one kind of sodium chloride, dextrose and the like.
[0105] The effective dose of the pharmaceutical composition of the present invention can be appropriately selected depending on a kind of a disease, an degree of a sickness, a treatment plan, a weight, an age, a sex, and the (hereditary) racial background of a patient, and a pharmaceutical effective dose is generally determined based on factors such as a clinically observed symptom, a degree of progression of a disease etc. A dose per day is, for example, 0.1 g/kg to 10 g/kg (3 g to 600 g in an adult having a weight of 60 kg), preferably 0.2 g/kg to 10 g/kg, more preferably 0.2 g/kg to 5 g/kg, and further preferably 0.2 g/kg to 2 g/kg. A dose may be administered once, or may be administered by dividing into plural times, or may be continuously administered by dripping etc. over time, and preferably may be administered by dripping over a period of a few hours or longer, for example, over a period of a few hours to about 10 hours. In addition, administration may be daily or intermittent administration, and can be appropriately selected depending on the state of an administration subject, and is preferably intermittent administration. For example, it is also possible to administer 0.5 g/kg to 10 g/kg per one time, 1 to 3 times per week.
[0106] In addition, since the pharmaceutical composition of the present invention is excellent in safety, it can be administered for a long term. That is, the lysosomal disease targeted by the pharmaceutical composition of the present invention is a hereditary disease, and administration is required in many cases as far as patients are alive. Since the pharmaceutical composition of the present invention is excellent in safety, it is particularly excellent in such use. A term during which the medicament of the present invention can be administered is not particularly limited, but the medicament of the present invention can be administered over a long term, such as at least over a few weeks or longer, preferably a few months or longer, and more preferably a plurality of years or longer.
EXAMPLES
[0107] Hereinafter, the present invention will be described in further detail with reference to the Examples. However, the present invention is not limited thereto.
1. Material and Method
[0108] (1) Generation of Sendai Virus (SeV) Vectors
[0109] Generation and production of temperature-sensitive Sendai virus vectors were performed as described in the report by Ban et al (non-patent literature 4). The conventional type of SeV vectors carrying Oct3/4, Sox2, Klf4 and c-Myc were also generated as described in the report by Fusaki et al. (non-patent literature 2). To generate TS12 vector, three mutations including D433A, R434A and K437A were introduced into the polymerase-related gene P. For TS15 vector generation, other mutations, L1361C, and L15581, were inserted into polymerase-related genes L of TS12. For “three-in-one” vector, human KLF4, OCT3/4 and SOX2 genes were inserted between P and M gene-encoding region in order as described in FIG. 1A . Each gene was sandwiched by E (End), I (Intervening) and S (Start) sequences.
[0110] (2) Maintenance of Human iPS Cells
[0111] Human iPS cells were maintained on MMC-treated MEF feeder cells in human iPS medium containing DMEM/F12 (SIGMA) supplemented with 20% KNOCKOUT™ serum replacement (KSR, Invitrogen), 2 mM L-glutamine (Life technologies), 0.1 mM nonessential amino acids (NEAA, SIGMA), 0.1 mM 2-mercaptoethanol (SIGMA), 0.5% penicillin and streptomycin (Nacalai Tesque, Japan) and 5 ng/ml basic fibroblast growth factor (bFGF, WAKO, Japan).
[0112] (3) Differentiation into Hepatocyte-Like Cells
[0113] For hepatocyte-like cell (HLC) induction, the culture medium of semi-confluent human iPS cells were switched from the iPS medium to the definitive endoderm differentiation medium containing RPMI1640 supplemented with 2% B27 (Life technologies), 100 ng/m1 Activin A and 1mM Sodium butyrate (NaB, SIGMA). The NaB concentration is changed in 0.5 mM on day 2. On day4, the cells were harvested and re-seeded onto Matrigel-coated dishes in hepatic differentiation medium containing DMEM supplemented with 20% KSR, 1mM glutamine, 1mM NEAA, 0.1 mM 2-mercaptoethanol (SIGMA), 1% Dimethyl sulfoxide (DMSO, SIGMA). CXCR4 expressions were examined by FACS on day 4. On day 11, the cells were harvested and re-cultured in the hepatic maturation medium containing L15 medium (SIGMA) supplemented with 8.3% FBS, 8.3% tryptose phosphate broth (SIGMA), 10 mM hydrocortisone 21-hemisuccinate (SIGMA), 1 mM insulin (SIGMA), 2 mM glutamine, lOng/ml Hepatocyte growth factor (HGF, R & D) and 20 ng/ml Oncostatin M (OSM, R & D). On day 18, the cells were used for various experiments. For the hydroxypropyl cyclodextrin treatments, HLCs were cultured with 0.1 mM or 1 mM of the hydroxypropyl cyclodextrins for four days. For Annexin and TUNEL stainings, HLCs are cultured for four days and a week from day 18, respectively.
[0114] (4) Karyotype Analysis
[0115] G band analyses of chromosome were performed by Nihon Gene Research Laboratories. Inc. (Sendai, Japan), according to the manufacturer's protocol.
[0116] (5) Teratoma Formation
[0117] Healthy volunteer and patient-derived iPSC lines grown on MEF feeder layers were collected by collagenase IV treatment and injected into the testis of NOD-SCID immunodeficient mice. Palpable tumors were observed about 8-12 weeks after injection. Tumor samples were collected, fixed in 10% formalin, and processed for paraffin-embedding and hematoxylin-eosin staining following standard procedures.
[0118] (6) RNA Isolation and PCR
[0119] Total RNA was purified with Sepasol® Super G reagent (Nacalai Tesque, Japan). Total RNA was transcribed to DNA with Superscript III (Invitrogen) and randam primers (Invitrogen). RT-PCR was performed with QuickTaq™ (TOYOBO, Japan) as described in the report of Hamasaki et al. (Stem Cells, 30, 2437-2449, 2012). Primers used for Oct3/4, Sox2, Klf4 and c-Myc were designed to detect the expressions of endogenous genes, but not of transgenes. To detect SeV genome, nested RT-PCR was performed. The sequences of primers and amplification conditions are listed in Table 1 (The sequences are numbered as Sequence Nos. 1 to 48 in order from the top).
[0000]
TABLE 1
The sequences of primer sets for
RT-PCR, nested PCR, and qPCR
Sequences
Annealing
Product
Genes
(Forward; F, Reverse; R)
(° C.)
Cycle
size (bp)
SeV
F: GGATCACTAGGTGATATCGAGC
58
30
181
R: ACCAGACAAGAGTTTAAGAGATATGTATC
Nested
F: TCGAGCCATATGACAGCTCG
58
30
148
R: GAGATATGTATCCTTTTAAATTTTCTTGTCTTCTTG
OCT3/4
F: GACAGGGGGAGGGGAGGAGCTAGG
55
33
144
R: CTTCCCTCCAACCAGTTGCCCCAAAC
SOX2
F: GGGAAATGGGAGGGGTGCAAAAGAGG
55
33
151
R: TTGCGTGAGTGTGGATGGGATTGGTG
KLF4
F: GATTACGCGGGCTGCGGCAAAACCTACACA
56
35
357
R: TGATTGTAGTGCTTTCTGGCTGGGCTCC
c-MYC
F: GCGTCCTGGGAAGGGAGATCCGGAGC
56
33
328
R: TTGAGGGGCATCGTCGCGGGAGGCTG
NANOG
F: CAGCCCCGATTCTTCCACCAGTCCC
60
30
391
R: CGGAAGATTCCCAGTCGGGTTCACC
GDF3
F: CTTATGCTACGTAAAGGAGCTGGG
56
35
631
R: GTGCCAACCCAGGTCCCGGAAGTT
REX1
F: CAGATCCTAAACAGCTCGCAGAAT
55
30
306
R: GCGTACGCAAATTAAAGTCCAGA
SALL4
F: AAACCCCAGCACATCAACTC
58
30
138
R: GTCATTCCCTGGGTGGTTC
DNMT3b
F: TGCTGCTCACAGGGCCCGATACTTC
55
33
242
R: TCCTTTCGAGCTCAGTGCACCACAAAAC
SOX17
F: CGCTTTCATGGTGTGGGCTAAGGACG
50
40
186
R: TAGTTGGGGTGGTCCTGCATGTGCTG
CXCR4
F: CACCGCATCTGGAGAACCA
55
30
272
R: CTGACAGGTGCAGCCTGTA
HNF4a
F: CTGCTCGGAGCCACCAAGAGATCCATG
62
30
370
R: ATCATCTGCCACGTGATGCTCTGCA
HNF6
F: CGCTCCGCTTAGCAGCAT
55
40
504
R: CCCTGCTGAAGTGTGTGTCT
AFP
F: AGAACCTGTCACAAGCTGTG
55
25
675
R: GACAGCAAGCTGAGGATGTC
ALB
F: CCTTTGGCACAATGAAGTGGGTAACC
62
35
354
R: CAGCAGTCAGCCATTTCACCATAGG
β-ACTIN
F: CAACCGCGAGAAGATGAC
60
25
455
R: AGGAAGGCTGGAAGAGTG
PAX6
F: GTCCATCTTTGCTTGGGAAA
50
40
110
R: TAGCCAGGTTGCGAAGAACT
ZIC1
F: CTGGCTGTGGCAAGGTCTTC
57
40
97
R: CAGCCCTCAAACTCGCACT
ZNF 521
F: ACCTCCGTGTCCAGTACGAC
50
40
125
R: ATGTCAGGGGTTTGTTGAGC
OTX2
F: GCCAATCCTTGGTTGAATCTTAGG
45
40
120
R: CAATCAGTCACACAATTCACACAGC
NEUROGENIN1
F: AGCCTGCCCAAAGACTTGCTCC
44
40
201
R: CCTAACAAGCGGCTCAGGTATCCC
HES5
F: CTCAGCCCCAAAGAGAAAAA
45
40
168
R: GACAGCCATCTCCAGGATGT
[0120] (7) Genomic Sequencing
[0121] The mutations of NPC1 gene in NPC-derived iPSC lines were confirmed by direct sequencing. The genomic DNAs extracted were amplified by PCR and the resultant PCR products sequenced by ABI PRISM™ 310 Genetic Analyzer (Applied Biosystems). Sequencing primers and amplification conditions are listed in Table 2 (The sequences are numbered as Sequence Nos. 49 to 56 in order from the top.).
[0000]
TABLE 2
The sequences of primer sets
for genomic sequencing
Sequences
Product
(Forward; F,
Annealing
size
Genes
Reverse; R)
(° C.)
Cycle
(bp)
exon5
F: TGCCTCGTG
52
30
315
sequence
AATTACAGCAA
R: CAAGCACTG
GTGAGCCACT
exon13
F: GCCCGAGCA
56
35
382
sequence
GACCTAGAAAT
R: ATGCTGAGC
CCTGTGAGAAT
exon22
F: GGTGAGTCT
58
30
297
sequence
TGTAGACAGCC
R: ATGGCGATG
GTGGCACACAT
exon23
F: CAGGCTTTT
55
30
375
sequence
GGCTGTGTGTA
R: GGATTACTT
TGTGGTGCGACT
[0122] (8) Cell Staining and Immunocytochemistry
[0123] Alkaline phosphatase staining was performed using the Leukocyte Alkaline Phosphatase kit (SIGMA). For immunocytochemistry, cells were fixed with PBS containing 4% paraformaldehyde for 30 min at 4° C. For the molecules localized in nucleus, samples were treated with 0.2% Triton X-100 for 15 min at room temperature (RT). The cells were washed three times with PBS containing 2% FBS and then incubated overnight at 4° C. in PBS containing 2% FBS with primary antibodies. Nucleuses were stained with Propidium Iodide (PI, WAKO, Japan) and 1 mg/ml Hoechst 33258 (Invitrogen). The list of the primary and secondary antibodies is described in Table 3. For Filipin staining, samples were washed with PBS three times after the fixing and incubated with PBS containing 1.5 mg/ml glycine for 10 min at RT. The samples were then treated with PBS containing 10% FBS and 50 mg/ml Filipin (SIGMA). The data was calculated by UV absorption (360/460) and analyzed with Developer Toolbox software of IN CELL ANALYZER 6000 (GE Healthcare). The number of insoluble p62 granules were counted by IN CELL ANALYZER 6000 (GE Healthcare). To investigate glycogen accumulation, Periodic acid Schiff (PAS) staining of hepatocyte-like cells were performed by PAS staining solution (Muto Pure chemicals, Tokyo, Japan), according to the manufacturer's protocol.
[0000]
TABLE 3
List for antibodies applied.
Antibody
Species
Dilution
Vendor
Anti-SSEA4
Mouse
1:500
MILLIPORE
Anti-TRA-1-60
Mouse
1:500
MILLIPORE
Anti-Nanog
Goat
1:1000
R&D systems
Anti-Oct3/4
Mouse
1:500
Santa Cruz
Anti-CXCR4
Mouse
1:300
R&D systems
Anti-Albumin
Mouse
1:500
SIGMA
Anti-Alpha
Mouse
1:500
SIGMA
fetoprotein
Anti-LC3
Rabbit
1:500
Cell Signaling
Technology
Anti-p62
Mouse
1:500
MBL
Anti-Parkin
Mouse
1:500
Abcam
Anti-Calbindin
Mouse
1:200
Leica
Anti-mouse HRP
Goat
WB 1:3000
Bio rad
IC 1:300
Anti-Rabbit HRP
Goat
1:3000
Bio rad
Alexa 488-conjugated
Goat
1:1000
Invitrogen
goat anti-mouse IgG
Alexa 488-conjugated
donkey
1:1000
Invitrogen
donkey anti-rabbit IgG
Alexa 594-conjugated
Goat
1:1000
Invitrogen
goat anti-mouse IgG
[0124] (9) Immunoblot Analysis
[0125] Protein lysates were separated by SDS-PAGE and transferred to PVDF membrane. LC3-I and LCS3-II were detected by anti-LC3 antibody (Cell Signaling). The data are normalized to α-tubulin expression. The HLCs were solved in RIPA buffer and then insoluble p62 was collected as a pellet after the centrifuge of the samples.
[0126] (10) Albumin Production Analysis
[0127] Albumin production of hepatocyte-like cells were measured by Human Albumin ELISA Quantitation kit (Bethyl E80-129), according to the manufacturer's protocol. The data was normalized to Albumin-positive percentages in the samples.
[0128] (11) Cell Size Analysis
[0129] The cell sizes of albumin-positive cells was calculated by Developer Toolbox software of IN CELL ANALYZER 6000 (GE Healthcare).
[0130] (12) Indocyanine Green (ICG) Analysis
[0131] The culture cells on day 18 of differentiation were treated with 1 mg/ml ICG for 30 min at 37 ° C. The cells were washed three times with PBS and the positive cells were analyzed. The cells were then incubated with the medium for 5 min and were re-analyzed again.
[0132] (13) Measurement of ATP
[0133] Hepatocyte-like cells derived from the iPSC lines were cultured in DMEM medium in the absence of glucose for 24 hours and were then cultured in the DMEM medium containing 10% FBS and high glucose for 6 hours. ATP was measured by ATP measurement Kit (TOYO INK), according to the manufacturer's protocol.
[0134] (14) Mitochondria Staining by MitoTrackers
[0135] Hepatocyte-like cells derived from the iPSC lines were cultured in the presence of 100 nM MitoTracker red CMXRos (Molecular Probe) for 20 min and were analyzed by FACS. The HLCs were stained with JC-1, according to the manufacturer's protocol (Molecular Probe). The red and green fluorescence intensities of JC-1 stainings were measured by Developer Toolbox software of IN CELL ANALYZER 6000 (GE Healthcare).
[0136] (15) TUNEL Staining
[0137] TUNEL staining was performed by APO-BrdU TUNEL assay kit (Invitrogen), according to the manufactual protocol.
[0138] (16) Ammonia Removal and Urea Secretion Activities
[0139] HLCs were cultured in the medium with 1 mM ammonium chloride for two days. The supernatant was collected and then, according to the manufactual protocols, ammonia and urea concentrations were measured by ammonia assay kit (SIGMA) and urea colorimetric assay kit (BioVision), respectively.
[0140] (17) Cyclodextrins
[0141] 2-Hydroxypropyl-α-cyclodextrin with an average degree of substitution of 5.0 (HPACD), 2-hydroxypropyl-β-cyclodextrin with an average degree of substitution of 4.7 (HPBCD), and 2-hydroxypropyl-γ-cyclodextrin with an average degree of substitution of 6.4 (HPGCD) were obtained from Nihon Shokuhin Kako (Tokyo, Japan).
[0142] (18) Antibody Staining and FACS Analysis
[0143] Differentiated iPS cells were harvested on day 4 and stained with biotin-conjugated mouse anti-human CXCR4 antibody (R & D Systems) and Streptoavidin-allophycocyanin (SA-APC, eBioscience). The proportion of apoptotic and dead cells was measured by flowcytometer using Annexin (Beckman Coulter) and 7-amino-actinomycin D (7-AAD, Beckman Coulter).
2. Results
Example 1: Vector Generation
[0144] By using temperature-sensitive Sendai virus (SeV) vectors, iPS cells containing the sequences for four reprogramming factors (OCT3/4, SOX2, KLF4and c-MYC) were generated.
[0145] To increase the efficiency of iPS cell generation and reduce the length of time the vector remains inside the cells, the inventors generated a new Ts-SeVvector, TS12KOS, carrying coding sequences for three of the above factors, KLF4(K), OCT3/4(O), and SOX2(S) tandemly linked in the KOS direction ( FIG. 1 ). The TS12KOS vector contains three mutations that produce alanine residues (D433A, R434A, and K437A) in the large protein(L)-binding domain of the phosphoprotein, a component of SeV RNA polymerase. SeV carrying these three mutations showed moderate expression of GFP at 37° C., but weak expression at temperatures above 38° C.
Example 2: iPS Cell Generation with SeV Vector
[0146] Fibroblasts from healthy volunteers and patients were generated and isolated from explants of skin biopsy following informed consent under protocols approved by the ethics committee assigning inventors. Skin samples were minced and cultured in Dulbecco's modified essential medium (DMEM, Life technologies) supplemented with 10% Fetal Bovine Serum (FBS). After the fibroblast appeared, it was expanded for iPS cell induction.
[0147] To generate iPS cells from peripheral blood cells, mononuclear cells (MNCs) were isolated by Ficall gradient. To stimulate T lymphocytes, MNCs were cultured on anti-CD3 antibody-coated dishes with IL-2 for five days.
[0148] iPS cells were generated from human skin-derived fibroblasts and stimulated T lymphocytes as described in the report by Seki (2010, non-patent document 3). Briefly, 1×10 5 of human MNCs per well of 48-well plate and 5×10 5 cells of human fibroblast cells per well of 6-well plate were seeded one day before infection and then were infected with Sendai virus (SeV) vectors at various multiplicity of infection (MOI) including three, ten and thirty. After two-day culturing for blood cells and seven-day culturing for fibroblasts, the cells infected were harvested by trypsin and re-plated at 5×10 4 cells per 60 mm dish on the mitomycin C (MMC)-treated mouse embryonic fibroblast (MEF) feeder cells. Next day, the medium was replaced in human iPS cell medium. The cultures with new Sendai virus infection were incubated at 36° C. for one week. From 18 to 25 days after infection, colonies were picked up and re-cultured again in human iPS cell medium. To remove Sendai virus, the temperature of culture shifts from 37° C. to 38° C. at passage 1 or 2 of iPS cells.
[0149] First, the TS12KOS and conventional SeV vectors in terms of the efficiency of iPS cell generation from human skin fibroblasts of healthy volunteers was compared ( FIG. 2 ). On day 28 after induction, the number of colonies with alkaline phosphatase (AP)-positive staining and human embryonic stem (ES) cell-like morphology were counted. The efficiency of iPS cell generation was significantly higher using the TS12KOS vector than with the conventional vector.
[0150] Next, the effect of temperature shift on iPS cell generation from human fibroblasts was examined. When the culture temperature was shifted from 37° C. to 36° C. for the initial two weeks after infection, the efficiency of colony formation remained high, and however, when the temperature downshift continued for three weeks or more after infection, the efficiency decreased significantly ( FIG. 3 ). Temperature shift for the initial one week and two week is more effective than for later period. Therefore, a temperature downshift for the initial one week only was used in the following experiments.
Example 3: Analysis of Established iPS Cells
[0151] Nested RT-PCR analysis of viral RNA was conducted to determine whether the TS12KOS vector was eliminated from the iPS cells earlier than the conventional SeV vector. The individual colonies were expanded and the temperature was shifted from 37 ° C. to 38° C. for 3 days at various passages. In conventional SeV infection, temperature upshifts at passage 1 or 2 induced no virus removal. In contrast, in the case of the TS12KOS vector, when the temperature was upshifted at passage 1 and 2, 84% and 65%, respectively, of iPS cell-like clones were negative for the viral genome ( FIG. 4 ). These results indicate that the TS12KOS vector was superior to the conventional SeV vector in terms of both the efficiency of iPS cell generation and the removal of virus from iPS cells.
Example 4: iPS Cell Generation from Human Peripheral Blood Cells
[0152] One goal is to develop safe and efficient vectors to generate iPS cells from human peripheral blood cells. Peripheral T lymphocytes were stimulated with both anti-CD3 antibody and interleukin 2, and then were infected with SeV vectors to generate iPS cells. The generation of iPS cells was significantly more efficient using the TS12KOS vector than with the conventional SeV vector ( FIG. 5A ). In conventional SeV infection, temperature shifts from 37° C. to 38° C. at passage 1 and 2 induced no elimination from the iPSC clones. In contrast, when TS12KOS vector was used under the same conditions, 65% and 47%, respectively, of the clones were negative for the viral genome ( FIG. 5B ). Therefore, similar to the results obtained with fibroblasts, the elimination of TS12KOS vector from iPS-like cells derived from peripheral T lymphoctyes was faster than that observed for conventional SeV vector.
[0153] The colonies formed from skin fibroblasts and peripheral blood cells induced by TS12KOS vector exhibited a typically ES cell-like morphology and expressed a set of typical markers for pluripotency (data not shown). These iPS cell lines had a normal 46 XY karyotype even after the temperature upshift and culturing for more than 10 passages (data not shown). To confirm the pluripotency of the clonal lines, a single cell line was transplanted into the testis of immunodeficient mice. Twelve weeks after injection, the iPS cell line tested formed a teratoma that contained derivatives of all three germ layers ( FIG. 6 ). That is, the iPS cell lines generated with the TS12KOS vector meet the criteria of iPS cells.
Example 5: Establishment of iPS Cells Expressing Disease Phenotype
[0154] To explore the use of disease-derived iPS cells as cellular models, inventors focused on Niemann-Pick disease type C (NPC), which is a lysosomal storage disease associated with mutations in the NPC1 and NPC2 genes. Npc1 acts as a transporter between endosomes and lysosomes, and Npc2 works cooperatively with Npc1 to transport molecules in the cell. Mutations in the NPC1 and NPC2 genes disrupt this transporting system, resulting in the accumulation of free cholesterol and glycolipids in lysosomes. By using the TS12KOS vector, iPS cell lines were established from skin fibroblasts of two patients carrying different NPC1 mutations. The efficiency of iPS cell generation from these patients was similar to that from healthy volunteers. The NPC-derived iPS cell lines exhibited ES cell-like morphology ( FIG. 7 ) and expressed a set of pluripotent markers ( FIG. 8 ). Nested RT-PCR analysis determined that the iPS cell lines were negative for SeV ( FIG. 8 ).
[0155] Next, the differentiation potential of the NPC-derived iPS cell lines was investigated by evaluating teratoma formation. Histological analysis revealed that the teratomas analyzed consisted of the descendants of all three germ cell layers such as cuboidal epithelia, melanin pigment, cartilage, muscle, and various glandular structures ( FIG. 9 ). The established iPS cell lines had a normal karyotype, 46XY and 46XX (data not shown). Mutations in the NPC1 gene were confirmed by DNA sequencing ( FIG. 10 ). Thus the NPC-derived iPSC lines fulfilled the criteria for iPS cells.
Example 6: Analyses of NPC-Derived iPSClines
[0156] Enlargement of the liver is one of major symptoms of NPC patients, and those with severe forms of the disease suffer from liver dysfunction and failure. To investigate the effect of Npcl deficiency on the hepatocytic lineage, NPC-derived iPSC lines were differentiated into hepatocyte-like cells expressing albumin. In a previous study, treatment with Activin A selectively induces the differentiation of mouse ES cells into definitive endoderm cells and hepatocyte-like cells (HLCs), and an endodermal surface marker, Cxcr4, could be used to detect endodermal differentiation. Here, based on these results, culture conditions were modified, in which modified conditions HLCs were easily generated from human iPS cells ( FIG. 11 ). On day 18 of differentiation, the HLCs expressed α-fetoprotein (˜65% of total cells) and albumin (˜80% of total cells) and other hepatic makers (data not shown), and they absorbed indocyanine green (ICG) and stored glycogen (data not shown). The generation rate of definitive endoderm-like cells, calculated as the percentage of Cxcr4-positive cells, and the efficiency of hepatic differentiation, calculated from the percentage of albumin-positive cells and the marker expressions, were similar between the normal iPS cell and the NPC-derived iPS cell lines. In contrast, the cell size of NPC-derived HLCs was larger than that of control HLCs ( FIG. 12 ). In NPC patients, defective transportation of lipids from endosomes to lysosomes results in the accumulation of free cholesterol in lysosomes. Therefore, to detect free cholesterol in the cells and thus assess the level of cholesterol accumulation, filipin staining was performed. Negligible numbers of positively stained cells were observed in the control HLCs derived from healthy volunteers. In contrast, extreme levels of cholesterol accumulation were detected in the NPC-derived HLCs ( FIG. 13 ), which suggests that these cells mirror the cellular phenotype of NPC.
[0157] Next, the various functions of HLCs derived from normal iPS cell and NPC-iPS cell lines were investigated. There was not detection in any differences in terms of ICG uptake or release, glycogen storage, albumin production, urea secretion, or ammonia removal, all of which are indicative of hepatocyte function (data not shown). The ATP levels in NPC-HLCs were significantly lower than those in control HLCs ( FIG. 14 ). Despite this, apoptosis in the NPC-HLCs was not exacerbated compared to that in the controls (date not shown). To investigate the membrane potential of mitochondria, the specific MitoTracker staining reagents, JC-1 and CMXRos were used. JC-1 concentrates in the mitochondria and aggregates at normal mitochondrial membrane potentials, resulting in a high red/green fluorescence intensity ratio. A reduction in the mitochondrial membrane potential affects the aggregation of JC-1, resulting in a decreased red/green fluorescence intensity ratio. In addition, CMXRos accumulates in mitochondria at normal membrane potential. There was no detection in any difference in staining patterns for JC-1 or CMXRos between normal and NPC-derived HLCs (data not
[0158] Cellular autophagy is impaired in lysosomal storage diseases. The autophagy pathway in control and NPC-derived HLCs were monitored by using two methods. First expression of microtubule-associated protein 1 light chain 3 (LC3), which is a marker protein for autophagy, was examined. C-terminal processing of LC3 produces LC-I, which is modified to LC-II with the initiation of autophagosome formation. Then, p62/SQSTM1 (p62) expression was measured to assess autophagic flux. Because p62 binds to LC3 and is degraded upon fusion with the lysosome, impairment of autophagy flux results in the accumulation and aggregation of insoluble p62. The expression levels of LC3-II and insoluble p62 proteins were higher in NPC-HLCs than in normal HLCs ( FIGS. 15 and 16 ). In addition, excessive p62 aggregation was observed in NPC-derived HLCs compared with normal HLCs ( FIG. 17 ). These results suggest that autophagy was upregulated in the NPC-derived HLCs and autophagic flux was impaired in the NPC-derived HLCs.
Example 7: Effect of Various Cyclodextrin Treatments on Cholesterol Accumulation and Restoration of Cellular Functions
[0159] Because NPC-derived iPS cell lines expresses phenotype of NPC, as described above, the present invention provides an in vitro system for screening drug candidates for NPC treatment. Since extreme cholesterol accumulation in NPC iPS cell-derived HLCs was observed, it enables to examine the effect of various drug treatments on this process.
[0160] It has been reported that 2-Hydroxypropyl-β-cyclodextrin (HPBCD) is effective for reducing of cholesterol accumulation in NPC1-defective cells. The inventors therefore treated the HLCs derived from normal and NPC-iPS cell lines with a series of 2-hydroxypropyl-cyclodextrins with different cavity sizes, and observed effect of a series of hydroxypropyl-cyclodextrins. HLCs were cultured with 1 mM of the indicated hydroxypropyl-cyclodextrin for 4 days, stained with filipin and analyzed with an IN CELL ANALYSER (GE Healthcare) ( FIG. 18 ). In the experiment using NPC-HLCs of the present invention, the observed cholesterol accumulation was significantly decreased with HPBCD treatment. Interestingly, 2-Hydroxypropyl-α-cyclodextrin (HPACD) did not show any effect on cholesterol accumulation, whereas 2-Hydroxypropyl-γ-cyclodextrin (HPGCD) reduced the cholesterol accumulation in NPC-HLCs to the same extent as that observed for HPBCD.
[0161] The size of HLCs is decreased by the treatments with HPBCD and HPGCD (data not shown). Effects of various concentration of HPBCD and HPGCD in NPC-derived HLCs was observes. HLCs were cultured with HPBCD or HPGCD for 4 days, stained with filipin and analyzed with an IN CELL ANALYSER (GE Healthcare). Low concentrations (100 μM) of HPBCD and HPGCD were ineffective for reducing cholesterol accumulation ( FIG. 19 ). We next treated the cells during HLC differentiation with HPBCD, which was effective at the intermediate stages in hepatic differentiation ( FIG. 20 ).
[0162] Because the NPC-derived HLCs exhibited abnormally low ATP levels and abnormal autophagy, the inventors examined whether cyclodextrin treatment could restore these abnormalities. HLCs were culture with 1 mM 2-hydroxypropylcyclodextrins (HPCDs) for 4 days, and ATP level, expression levels of LC3 and p62, and insoluble p62 granules were measured. The results showed that treatments with HPBCD and HPGCD recovered both the ATP level ( FIG. 21 ) and the autophagy function ( FIGS. 22-24 ). As shown in FIG. 22 , the expression level of LC3 was recovered to normal levels by treatments with HPBCD and HPGCD, which suggest that the treatments restored the abnormal induction of autophagy. As shown in FIG. 23 , HPBCD and HPGCD treatments reduced the amount of insoluble p62. Also, as shown in FIG. 24 , the proportion of HLCs carrying more than 40 granules of insoluble p62 aggregation was greatly reduced by HPBCD and HPGCD treatments. These suggest that the treatment restored the impairment of autophagic flux. These suggest that NPC-iPS derived HLCs are useful for evaluating a drug candidate. These also suggest that HPGCD, in addition to HPBCD, is a promising drug candidate for NPC treatment.
Example 8: Effects of HPBCD and HPGCD on NPC-Derived HLCs
[0163] Microarray analysis for HLCs treated with HPBCD or HPGCD, cluster analysis and principal component analysis (PCA) were conducted to evaluate whether the effect, which are ATP level restoration and autophagy function restoration, of HPBCD on HPLCs is the same mechanism of action as that of HPGCD. The HLCs induced by the procedure described in Example 11 were cultured in a medium supplemented with HPBCD or HPGCD for 4 days. The control HLCs were cultured in the absence of HPCDs. RNA was extracted from HLCs for exhaustive gene expression analysis using microarray analysis. The procedures are described below.
[0164] Two hundred fifty ng of total RNA from the iPSC-derived HLCs cultured in each condition were labeled with biotin and fragmented according to the manufacturer's protocol (3′ IVT Express kit, Affymetrix). Then, samples were hybridized to a GeneChip® Human Genome U133 Plus 2.0 (Affymetrix). Arrays were scanned with a GeneChip® Scanner 3000(Affymetrix). Data were analyzed using GeneSpring GX 12.5 software (Agilent technologies). Each chip is normalized to the median of the measurements. The genes with fold change >1.5 were considered to be differentially expressed genes between NPC and normal HLCs. Comparing the profiles of differentially expressing genes each other revealed commonly up-regulated and down-regulated genes of NPC-derived HLCs. In the commonly up- or down-regulated genes, Gene set enrichment analysis (GSEA, BROADINSTITUTE) enriched the biological processes of gene ontology, which significantly contain the commonly up-regulated or down-regulated genes in NPC-derived HLCs. In the commonly up- or down-regulated genes, GSEA also enriched the biological processes of gene ontology, which contain differentially expressing genes between HPBCD and HPGCD treatments. The number of permutation was conducted one thousand times for the statistics analysis and the algorism used enriched the biological processes of gene ontology, which contain the genes that appeared in more than five times. The biological processes of gene ontology were selected and described solely based on p-value ranking. The biological processes with p value <0.05 or <0.1 were considered to be significantly altered in NPC or HPGCD treatment, comparing to normal or HPBCD treatment, respectively. Then with the hierarchical clustering analysis the genes which were significantly in the biological processes were identified.
[0165] Each cells, including fibroblast cells (fibro) and iPS cells derived from normal volunteer (N1), patient NPC-5 (A114) and patient NPC-6 (A225) and HLCs derived those iPS cells, in the absence of HPCDs or the presence of HPBCD or HPGCD were analyzed by cluster analysis and PCA analysis. The results of cluster analysis and PCA analysis are shown in FIG. 25 or 26 , respectively. It concluded that HPGCD acts with the mechanism different from HPBCD.
[0166] Molecular signatures identified by the above analysis are shown in FIG. 27 . The molecular signatures significantly down-regulated in NPC are shown in the upper panel and those significantly up-regulated in NPC are shown in the lower panel.
[0167] Expressions of the molecular signatures identified above were measured with HPBCD or HPGCD treatments. The results are shown in FIG. 28 . The effect of HPBCD treatment is shown in the upper panel, and that of HPGCD is shown in the lower panel.
[0168] Hierarchical clustering of genes significantly altered with HPBCD and HPGCD treatments were measured. The results are shown in FIG. 29 . The data sets of the genes included in the molecular signatures, as shown in the red squares of FIG. 28 , were clustered according to Euclidean distance metrics. The gene expression patterns of the molecular signature altered with HPGCD treatment were closer to that of normal HLCs than those with HPBCD treatments.
Example 9: Effects of HPGCD Treatment Using NPC-Model Mouse
[0169] Effects of HPGCD treatment on cholesterol accumulation in NPC-derived HLCs were evaluated using NPC-model mice. NPC model mice bear a spontaneous mutation of the Npc1 gene that causes a defect in lysosome to ER trafficking of cholesterol. These mice also exhibit a similar phenotype to the human disease including cholesterol accumulation in the liver and brain. The model mice show liver injury and neural functional impairment and die before 12 weeks old without proper treatment.
[0170] 4-week-old NPC mice were treated with HPGCD (4000 mg/kg) once a week until 8.5 weeks of age (5 injections in total), followed by sample collection. Control was treated with saline. The experiments were conducted twice (first; n=6; second: n=4).
[0171] Following treatment, AST (aspartate aminotransferase) and ALT (alanine aminotransferase), serum markers for liver injury, were markedly and significantly reduced by HPGCD treatment. The results are shown in FIG. 30 . Histological analysis revealed a marked morphological improvement in the livers of mice treated with HPGCD ( FIG. 31 ). Deletion of Purkinje cells in the cerebellum was also rescued by the treatment with HPGCD ( FIG. 32 ).
[0172] In NPC mice treated with HPGCD abnormal autophagy was restored, and in addition, expression levels of LC3 and insoluble p62 were restored to the normal level in the livers and brains of HPGCD-treated NPC mice (data not shown).
[0173] To evaluate the effect of HPGCD treatment on NPC mice survival, 4-week-old model mice were injected with HPGCD one a week (HPGCD injection group: n=6, control (saline injection) group: n=6). HPGCD treatment significantly prolonged the NPC mouse survival, as shown in FIG. 33 .
Example 10: Toxic Effects of HPBCD and HPGCD
[0174] To confirm the excellent safety of HPGCD, acute toxicity was tested using normal mice. 14.4 mM HPBCD or HPGCD were injected in the amount of 19.18 ml/g into subcutaneous tissues of 8-week-old mice (n=10), and then survival rates were calculated. Almost all mice injected with HPBCD dies up to 72 hours after injection, but no mice dies with the HPGCD injection.
[0175] The above results indicate that iPS cells without introduced genes are useful cell model for intractable diseases.
[0176] To date the inventors have used SeV vectors including the TS12KOS vector to establish more than 1000 iPS cell lines from more than 100 patients with intractable diseases, examples of which are shown in Table 4. In the table, Miyoshi Myopasy used conventional vectors, not TS12KOS vector of the present invention. All iPS cell lines established from the patients exhibited ES cell-like colony morphology and expressed a set of pluripotent markers (data not shown). The SeV-negative status of all iPS cell lines established was confirmed by nested RT-PCR (data not shown), indicating that the lines do not carry the transgenes used for reprogramming.
[0000]
TABLE 4
Name of disease
Number of cases
Neurologic disease
Alexander's disease
3
Allan-Herndon-Dudley syndrome
1
Amyotrophic lateral sclerosis
8
Bardet-Biedl syndrome
1
Charcot-Marie-Tooth disease
1
Familial amyloid polyneuropathy
6
Huntington's disease
1
Kii-amyotrophic lateral sclerosis
2
Kugelberg-Welander disease
1
Moyamoya disease
2
Nasu-Hakola disease
1
Parkinson disease
1
Pelizaeus-Merzbacher disease
1
Spinal muscular atrophy
1
Spinobulbar muscular atrophy
1
Wolfram syndrome
1
X-linked α-thalassemia/Mental retardation syndrome
2
Metabolic disease
Adrenal hyperplasia
1
Adult-onset type II citrullinemia
1
Cystinuria
1
Fabry's disease
1
Galactosialidosis
1
Glycogen storage disease type Ia
2
Glycogen storage disease type II
1
GM1 gangliosidosis
1
Hyperlacticacidemia
1
Krabbe disease
4
Metachromatic leukodystrophy
1
Methylmalonic acidemia
2
Niemann-Pick disease type C
2
Ornithine transcarbamylase deficiency
1
Propionic acidemia
1
Pyruvate dehydrogenase complex deficiency
1
Tay-Sachs disease
1
Triglyceride deposit cardiomyovasculopathy
1
Skin disease
Dermatomyositis
2
Dyschromatosis universalis hereditaria
1
Scleroderma
2
Muscular disease
Central core disease
1
Congenital fiber type disproportion
1
Inclusion body myositis
1
Mitochondrial disease
2
Miyoshi myopathy*
1
Muscular dystrophy type becker
1
Muscular dystrophy type ducehenne
3
Muscular dystrophy type limb-girdle
2
Myotonic dystrophy
1
Kidney disease
Alport's syndrome
1
Congenital nephrotic syndrome
1
Galloway-Mowat syndrome
1
Wolf- Hirschhorn syndrome
1
Bone and connective tissue disease
Ehlers- Danlos syndrome
1
Fibrodysplasia ossificans progressiva #
4
Loeys-Dietz syndrome
3
Marfan syndrome
1
Primary osteogenesis imperfecta
1
Winchester syndrome
1
Others
Chronic inflammatory neurological cutaneous
1
articular syndrome
Cockayne's syndrome
1
Daimond-Blackfan Anemia
3
Prader-Willi syndrome
1
Pulmonary hypertension
3
X-linked agammaglobulinemia
2
Werner syndrome
1
Wiskott-Aldrich syndrome
1
*, #: Published in Tanaka A. et. al, 2013; Hamasaki M. et. al, 2012, respectively.
[0177] The foregoing merely illustrates objects and subjects of the present invention, and does not limit the accompanying Claims. Without departing from the accompanying Claims, various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein.
INDUSTRIAL APPLICABILITY
[0178] The pharmaceutical composition containing hydroxypropyl-γ-cyclodextrin as an active ingredient of the present invention is useful as a therapeutic agent for the lysosomal disease, particularly, Niemann-Pick disease or GM-1 gangliosidosis.
[0179] In addition, the iPS cells and the screening method of the present invention can be used for screening therapeutic agents for intractable diseases. | Provided is a pharmaceutical composition for the treatment of disorders such as Niemann-Pick disease and GM1 gangliosidosis which are caused by the storage of cholesterol, such as lysosomal storage disease. Also provided is a method for screening for said pharmaceutical compositions that uses iPS cell strains that phenocopy phentotypes of these disorders. Provided is a pharmaceutical composition for the treatment and/or prevention of lysosomal storage disease, characterized by containing hydroxypropyl-γ-cyclodextrin as an active ingredient. Also provided are an iPS cell strain derived from patients suffering from intractable disorders and prepared using a new temperature-sensitive Sendai virus vector, and a screening method for pharmaceuticals using said iPS cell strain. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection nozzle which injects fuel from an injection hole formed in a nozzle body by the pressure of fuel forcedly fed.
A previous fuel injection nozzle of this type comprises, as shown in FIG. 5, a nozzle needle 105 for opening and closing an injection hole 103 formed in the tip of a nozzle body 121, and a spring 107 for urging the nozzle needle 105 in the direction of closing the injection hole 103. The nozzle body 121 is mounted on a main body 101. In a fuel passage formed in the main body are contained shims 111, 113, a piston 115, a spring seat 117, and a spacer 129, besides the above spring 107. The nozzle body 121 is secured to the main body 101 by a retaining nut 123. On the other hand, in the main body 101 and the nozzle body 121, a fuel passage 125 is formed, and fuel is forcedly fed to the injection hole 103. By the pressure of fuel in the fuel passage 125, the needle nozzle 105 is withdrawn to open the injection hole 103 and to inject fuel from the injection hole 103.
Generally, in this type of fuel injection nozzle, it is effective to restrain the initial injection rate when injecting fuel into a cylinder, for example, in order to decrease NOx and combustion noise of a diesel engine. Therefore, as shown by E in FIG. 5, a clearance for a prelift L1 is defined between the tip portion 127 of the piston 115 receiving a part of pressure (back pressure) in the fuel passage 125 and the spring seat 117. On the other hand, between the nozzle needle 105 and the spacer is established 129, a needle lift L2 (larger than the prelift L1). Because of such arrangements, by the pressure of fuel supplied into the fuel passage 125, the nozzle needle 105 and the spring seat 117 travel through the prelift L1 against the urging force of the spring 107 and a back pressure P applied to the piston 115 in the direction shown by the arrow D1, so that the nozzle needle 105 opens the injection hole 103 (pressure at this time is called the first valve opening pressure) to perform an initial fuel injection at a low injection rate. Thereafter, the nozzle needle 105 and the spring seat 117 further travel through a distance of the needle lift against the urging force of the spring 107 and the back pressure P applied to the piston 115 in the direction of the arrow D1, so that the nozzle needle 105 further opens the injection hole 103 (pressure at this time is called the second valve opening pressure) to perform a stationary fuel injection (main injection) at a high injection rate.
However, the above mentioned previous fuel injection nozzle has the following problems:
(1) When the nozzle needle 105 and the spring seat 117 further travel through the needle lift against the back pressure applied to the piston 115 in the direction of the arrow D1 shown in FIG. 5 by the large pressure of fuel passing through the fuel injection passage 125, the piston 115 releases the shim 111 at the second valve opening pressure and afterward, so that the shim 111 is released from the fixed state and the wear of the shim 111 is liable to occur because of the own vibration of the shim 111. Therefore, when the shim 111 is worn, the tip portion 127 of the piston 115 comes in contact with the spring seat 117 to produce a state where the prelift L1 cannot be ensured. That is, the first valve opening pressure or the initial low injection pressure is lost and a pressure substantially higher than the usual second valve opening pressure comes to be a first valve opening pressure.
Consequently, delay of fuel injection timing and lowering of the fuel injection quantity in a diesel engine occur. In other words, the characteristics of the fuel injection are changed. Such changing in the characteristics of the fuel injection gives a large load to the diesel engine.
(2) Since the state of the shim 111 is unstable, and further, since the piston 115 is supported only on one side by the shim 113, the piston 115 is liable to be inclined from the moving axis for the piston 115, and a cyclic fluctuation in fuel injection performance is liable to occur, and stability thereof is lacking. Consequently, a problem occurs that control of characteristics of fuel injection is difficult.
(3) In a case where the shim 111 is worn and it is necessary to change the shim 111 in adjusting or changing the prelift L1, it is required to remove the nozzle 121, the retaining nut 123, the spacer 129, the spring seat 117, the spring 107, the shim 113, the piston 115, and the shim 111. Consequently, such adjusting operation is very troublesome.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a fuel injection nozzle by which changes in characteristics of fuel injection thereof can be avoided and adjustment of the characteristic of fuel injection is easy.
In order to achieve this object, the present invention provides a fuel injection nozzle for injecting fuel from an injection hole by pressure of fuel forcedly fed through a fuel passage, the fuel passage communicating with a back pressure chamber to be received pressure of the fuel in the fuel passage. The nozzle includes a nozzle body having an injection hole formed at a tip thereof; a nozzle needle slidably mounted in the nozzle body, the nozzle needle having a tip portion for opening and closing the injection hole by sliding thereof; a spring arranged on a base end portion side of the nozzle needle, the spring urging the nozzle needle in a direction of closing the injection hole; a spring seat arranged on the base end portion side of the nozzle needle, the spring seat receiving one end portion of the spring and urged toward the nozzle needle; a lift piece located between the spring seat and a base end portion of the nozzle needle; and a push rod having a proximal end portion receiving the pressure of fuel in the back pressure chamber and a distal end portion capable of coming in to contact with a spring-side end portion of the lift piece, a prelift clearance being provided between the spring-side end portion of the lift piece and the distal end portion of the push rod to obtain a prelift of the nozzle needle for initial fuel injection.
According to the fuel injection nozzle described above, as the spring-side end portion of the lift piece located between the spring seat and the base end portion of the nozzle needle, and the distal end portion the push rod define therebetween the prelit clearance for the prelift of the nozzle needle, the prelift clearance is defined on the nozzle needle side, and the influence directly given to the prelift by wear of the lift piece is small. Accordingly, a low initial fuel injection rate can be ensured, and delay of injection timing and lowering of the fuel injection quantity do not occur. Furthermore, although disassembly of the injection nozzle is necessary when adjusting the prelift, the adjustment can be performed merely by removing the component parts on the nozzle needle side which are easy to remove, and therefore, the adjustment operation is simple.
It is desirable that the spring seat includes a guide member for guiding the movement of the push rod. The reason is that the movement of the push rod pushing the lift piece can be guided by the guide member, so that inclination of the axis of the push rod can be prevented, cyclic fluctuation in fuel injection performance can be eliminated, and fuel injection is made stable.
It is desirable that the guide member has a cylindrical hole, and the distal end portion of the push rod is inserted in the cylindrical hole so that the movement of the distal end portion is guided. The reason is that the distal end portion of the push rod can surely be guided by a simple structure.
It is desirable that the lift piece comprises a main body, and a protrusion projecting from the main body as the spring-side end portion thereof, and the protrusion is located in the cylindrical hole of the guide member so that the distal end portion of the push rod and the protrusion of the lift piece face each other in the guide member. The reason is that assembly is easy by inserting the lift piece into the guide member.
It is desirable that the guide member is formed integrally with the spring seat. Since the spring seat guides the distal end of the push rod, the aligning performance of the push rod can be increased and cyclic fluctuation in fuel injection performance can be restrained, so that stable fuel injection characteristics can be obtained. Furthermore, the guide portion formed integrally with the spring seat makes the structure more simple.
It is desirable that the push rod comprises a piston receiving the back pressure of fuel, and a rod, as a separate part from the piston, coming into contact with the piston. The distal end portion of the rod can push the spring-side end portion of the lift piece. Since the rod and the piston are separated, the length of each thereof can be made short, so that inclination of each of the piston and the rod can be decreased and cyclic fluctuation in fuel injection performance is restrained. Consequently, stable fuel injection characteristics can be obtained. Furthermore, since the component parts of the push rod or the piston and the rod are separate members, dimensional adjusting of each part is easy and there is a great deal of flexibility.
It is desirable that the nozzle needle includes a restriction member for restricting travel (needle lift) of the nozzle needle from the closing position of the injection hole to the spring side, and the movement of the nozzle needle determines a main injection quantity of fuel. The reason is that control of the main injection quantity of fuel can easily be performed by adjusting the restriction member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view showing a fuel injection device with a fuel injection nozzle according to an example of the present invention.
FIG. 2 is a cross sectional view of the fuel injection nozzle shown in FIG. 1.
FIG. 3A to FIG. 3D one similar views showing the operation of the fuel injection nozzle shown in FIG. 2.
FIG. 4 is a graph showing the relationship between the fuel injection rate and the time during operation of the fuel injection nozzle.
FIG. 5 is a cross sectional view of a previous fuel injection nozzle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the accompanying figures, FIG. 1 to FIG. 4, the embodiments of the present invention will be described below in detail.
As shown in FIG. 1, a fuel injection device 1 according to an embodiment of the present invention is used for a diesel engine. The fuel injection device 1 generally comprises a plunger barrel 2 and a fuel injection nozzle 3, and light oil is supplied from a fuel supply force feed portion (feed pump) 60 to the plunger barrel 2. An insertion hole 2a is formed in the plunger barrel 2. A plunger 25 for feeding fuel is inserted into the insertion hole 2a such that reciprocating motion of the plunger 25 is freely possible in the vertical direction in FIG. 1. The plunger 25 is urged in the upward direction (non-feed direction D1) in FIG. 1 by a plunger spring 26. The spring 26 is arranged between a tappet 27 located on the top of the plunger 25 and a spring receiving step portion 29 formed at the lower part of a cylindrical portion 28 of the barrel 2. At the lower part of the cylindrical portion 28, a preventing member 30 for preventing an excessive movement of the tappet 27 in the non- feed direction D1 is provided. When the tappet 27 travels through not less than a predetermined distance in the upward direction, the tappet 27 comes into contact with the preventing member 30.
A cam face of a rotating cam (not shown) contacts with the upper surface of the tappet 27. The rotating cam is rotated together with an output shaft of the diesel engine and the plunger 25 is reciprocated by the rotation of the rotating cam in the non-feed direction D1 and the feed direction D2.
A fuel supply opening 31 of the fuel supply force feed portion 60 is connected to the insertion hole (inner pressurizing chamber) 2a of the plunger barrel 2 through supply passages 33 and 36 of the cylindrical portion 28. The insertion hole 2a is connected through a discharge passage 34 to a fuel tank, and an electromagnetic valve (not shown) is inserted in the discharge passage 34 and opens and closes the discharge passage 34. Furthermore, the supply passages 33, 36 are connected to a leak passage 37 of the fuel injection nozzle 3.
Next, the structure of the fuel injection nozzle 3 will be described by referring to FIGS. 2-3D. In FIG. 2, the internal structure of the fuel injection nozzle 3 is shown on an enlarged scale, and in FIG. 3A to FIG. 3D the operation of the fuel injection nozzle 3 is shown.
The fuel injection nozzle 3 comprises a nozzle body 4, a retaining nut 45 and a main body 5. The nozzle body 4 is axially connected to the main body 5 by means of the retaining nut 45. In the nozzle body 4, a nozzle needle 9 is arranged such that it reciprocates in the direction D1 (in the direction of opening the injection hole 8) and the direction D2 (in the direction of closing the injection hole 8).
A thin base end portion 15 of the nozzle needle 9 is connected to a lift piece 40, and the lift piece 40 also moves together with the movement of the nozzle needle 9. The lift piece 40 integrally comprises a large diameter portion 41 and a small diameter portion as a protrusion 42, and has a nearly T-shaped cross section. In the large diameter portion 41, the base end portion 15 of the nozzle needle 9 is inserted, and the protrusion 42 is inserted into a guide hole 59 of a spring seat 51 (to be described later) in a spring chamber 20.
In the spring chamber 20, a spring 10, spring seats 50 and 51 located at opposite ends of the spring 10, and a push rod 57 are arranged. The push rod 57 comprises a piston 24 receiving back pressure of fuel in a back pressure chamber 72, and a rod 58 extending from one end of the piston 24 toward the lift piece 40. The rod 58 is formed coaxially with the piston 24, but is a separate member from the piston 24. By separating the push rod 57 into the rod 58 and the piston 24, each length can be made short, and inclination of the axes thereof can be decreased so as to restrain cyclic fluctuations of the fuel injection performance. Furthermore, dimensional adjusting of each part is easy and flexibility is increased.
The spring 10 is located between the two spring seats 50 and 51 and urges the two spring seats 50, 51 in the directions away from each other. One spring seat 50 is located on the side of the piston 24 of the push rod 57 and the other spring seat 51 is located on the side of the lift piece 40.
The two spring seats 50 and 51 have the same shape. Each of the spring seats 50 and 51 comprises a flange portion 55, a cylinder portion 56 and a guide hole 59 axially formed in the nearly central portion of the flange portion 55 and the cylinder portion 56. That is, since the cylinder portion 56 is arranged to guide the rod 58 inserted in the guide hole 59 thereof in the axial direction, the inclination of the axis of the rod 58 can be prevented. Furthermore, since the cylinder portion 56 as the guide portion is formed integrally with the corresponding spring seat, the structure is simple. The flange portion 55 of the spring seat 51 moves in the axial direction in the spring chamber 20.
The piston 24 comprises a shaft portion 61, a large diameter portion 63, and a pushing portion 65 that are integral with one another. The rod 58 is located between the pushing portion 65 of the piston 24 and the protrusion 42 of the lift piece 40. As shown at F and G, one end portion 67 of the rod 58 is inserted in the guide hole 59 of the spring seat 50 so that the movement thereof is guided, and the other end portion (distal end portion) 69 of the rod 58 is inserted in the guide hole 59 of the spring seat 51 so that the movement thereof is guided. The proximal end portion 67 and the distal portion 69 of the push rod 57 are supported by the holes 59 of the two spring seats 50 and 51. Furthermore, the pressure of fuel in the leak passage 37 acts as back pressure on the piston 24 through the back pressure chamber 72 formed on the side of shaft portion 61 of the piston 24.
In a rest state of the fuel injection nozzle, a clearance L1 for a prelift is secured between the distal end portion 69 of the rod 58 and the protrusion 42 of the lift piece 40, as shown in FIG. 3A. The clearance L1 is a gap for the movement or the prelift of the nozzle needle 9 in the direction D1. The prelift L1 is determined by previously adjusting the length of the protrusion 42 of the lift piece 40. Furthermore, on the base end side of the nozzle needle 9, the clearance for a needle lift L2 of the nozzle needle 9 is secured between the base end 9a of the nozzle needle 9 and the restricting member 71. As shown by A-B in FIG. 4, the prelift L1 indicates an initial injection in which fuel is injected at a low injection rate. The needle lift L2 indicates, as shown by D in FIG. 4, a stationary fuel injection (main injection) in which fuel is injected at a high injection rate.
Next, the operation of the fuel injection nozzle 3 according to the present embodiment will be described. When a cyclic operating force is given to the tappet 27 of FIG. 1 by the rotating cam rotated together with the output shaft of the diesel engine, the plunger 25 for feeding fuel reciprocates in the vertical direction of FIG. 1 in the insertion hole 2a with aid of the urging force of the plunger spring 26.
When the plunger 25 rises in the direction D1, fuel is introduced from a fuel supply opening 31 (FIG. 1) of the fuel supply force feed portion 60 through the supply passages 33, 36 into a pressurizing chamber. After that, when plunger 25 falls in the feed direction D2, the supply passage 36 is closed by the peripheral surface of the plunger 25 and the electromagnetic valve of the discharge passage 34 is shut, so that the introduced fuel is pressurized by the plunger 25 to be at a high pressure and is delivered to an oil chamber 11 (refer to FIG. 3A) through the fuel passage 37 of the fuel injection nozzle 3.
At the valve closing time in the rest state, as shown in FIG. 3A, the clearance for the prelift L1 is secured between the distal end portion 69 of the rod 58 and the protrusion 42 of the lift piece 40, and the clearance for the needle lift L2 is secured between the restraining member 71 and the base end 9a of the nozzle needle 9. In the rest state, the piston 24 receives the back pressure P from the pressurizing chamber 72 shown in FIG. 1, and the piston 24 pushed by the back pressure comes into contact with the spring seat 50. In the rest state, the clearance for the prelift L1 is held between the distal end portion 69 of the push rod 57 and the protrusion portion 42 of the lift piece 40. The termination of the rest state (valve closing time) is indicated by the reference mark A in the graph of the relationship between the fuel injection rate and time shown in FIG. 4.
When the pressure in the oil chamber 11 further rises, the nozzle needle 9 overcomes the urging force of the spring 10, and travels through a distance of the prelift L1 in the direction D1 (in the direction of opening the injection hole 8), as shown in FIG. 3B, and the nozzle needle 9 opens the injection hole 8. The change of the injection rate during the movement of the nozzle needle 9 from the state of FIG. 3A to the state of FIG. 3B, that is during the travel of the nozzle needle 9 through a distance of the prelift L1, is shown by A-B in FIG. 4. After the nozzle needle 9 has traveled through the prelift L1, fuel is injected from the injection hole 8 in a state of a low injection rate shown by B-C of FIG. 4.
Next, after the initial injection terminates as the second valve opening time C or a second valve opening time as shown in FIG. 4, the nozzle needle 9 further travels in the D1 direction and moves the lift piece 40 and the spring seat 51 toward the piston 24, as shown in FIG. 3C. Thus, piston 24 is moved to the back pressure side, and comes in contact with the body 5, so that further movement is restricted. The nozzle needle 9 further continues withdrawal from the injection hole 8.
Furthermore, during the term D shown in FIG. 4, the nozzle needle 9 further moves from the state in FIG. 3C to the state in FIG. 3D. The nozzle needle 9 overcomes the sum of the urging force of the spring 10 and the back pressure P, and moves through a distance of the needle lift L2 in the direction D1. During the term D shown in FIG. 4, the main fuel injection from the injection hole 8, that is, the stationary fuel injection at a high injection rate, is performed.
In the above mentioned series of operations, by performing the prelift L1, the initial fuel injection rate can be restricted for reducing NOx and combustion noise of the diesel engine.
In the fuel injection nozzle 3, the prelift L1 is obtained by the clearance between the distal end portion 69 of the rod 58 and the protrusion 42 of the lift piece 40 which is constantly sandwiched between the nozzle needle 9 and the spring seat 51. Therefore, even if wear of the protrusion 42 of the lift piece 40 progresses, the prelift L1 is not decreased contrary to the prior art. Since the prelift L1 can be increased due to the wear, delay of fuel injection timing and lowering of the fuel injection quantity in the diesel engine caused by the reduction or the elimination of the prelift, can be restricted, and it is possible to avoid applying a large load to the diesel engine. Furthermore, a state of fuel injection in a case where there is no prelift L1, is also shown by a broken line in FIG. 4, as a comparative example.
By the way, when adjusting or changing the prelift L1, the adjustment can be performed only by removing the nozzle body 4, the retaining nut 45, the spring 10, the spring seat 51, and the lift piece 40 of FIG. 2, in the above described order, so that the adjusting work can easily be performed.
Since both ends 57 and 59 of the rod 58 are supported by the two spring seats 50 and 51, accuracy of alignment of the push rod 57 can be increased by such two point support. Furthermore, since the piston 24 and the rod 58 are separate members, the lengths of the piston 24 and the rod 58 can be short, and accordingly, the inclination of the axes thereof can be decreased, and variations in the cycle of fuel injection can be restricted, so that stable injection characteristics can be obtained.
The present invention is not limited to the above mentioned embodiment, and various changes can be made without departing from the spirit and the scope of the present invention. For example, the above mentioned fuel injection nozzle is mounted on the fuel injection device of a diesel engine, but it can be applied to other types of internal combustion engines, or appliances of other fields.
Furthermore, in the above mentioned embodiment, the prelift L1 is obtained by the clearance between the distal end portion 69 of the rod 58 and the protrusion 42 of the lift piece 40 on the side of the nozzle needle 9, but it is also possible, without being limited thereto, that a clearance is also defined between pushing portion 65 of the piston 24 and one end portion 67 of the rod 58, and the sum of the clearances is set as the prelift L1. | A fuel injection nozzle includes a lift piece located on the side of a nozzle needle. A protrusion of the lift piece and the distal end of a push rod are held by a spring seat with a specified clearance therebetween as a prelift. The adjustment of the prelift can be performed only by taking out the lift piece to be adjusted, so that the adjusting work of the prelift, accompanied with disassembly of the fuel injection nozzle becomes easy and fuel injection characteristics are improved. | 5 |
The present patent application is a continuation of a previously filed patent application, U.S. patent application Ser. No. 13/709,208, filed Dec. 10, 2012, the entirety of which is hereby incorporated by reference.
TECHNICAL FIELD
The present disclosure relates in general to information handling systems, and more particularly to generating a one-time password for an information handling resource of an information handling system.
BACKGROUND
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
A key component of almost every information handling system is the basic input/output system (BIOS). A BIOS may be a system, device, or apparatus configured to identify, test, and/or initialize one or more information handling resources of an information handling system, typically during boot up or power on of an information handling system. A BIOS may include boot firmware configured to be the first code executed by a processor of an information handling system when then information handling system is booted and/or powered on. As part of its initialization functionality, BIOS code may be configured to set components of the information handling system into a known state, so that one or more applications (e.g., an operating system or other application programs) stored on compatible media may be executed by a processor and given control of the information handling system and its various components.
Oftentimes, various settings and parameters associated with a BIOS may be user-configurable, such that a user of an information handling system can configure or customize behavior of the BIOS and/or information handling resources of the information handling system. Because of its important role in the initialization of an information handling system, users often prefer to password protect the BIOS to prevent unauthorized access to the various settings and parameters associated with a BIOS. Similarly, other information handling resources of an information handling system (e.g., storage media such as a hard disk drive) may also be password-protected in order to provide security to prevent unauthorized access to the information handling system, its various components, and/or data stored thereon.
However, because a person may forget a password established for a BIOS or other information handling resource, a password unlock mechanism may exist in order to allow a user to gain access to the information handling resource when authentication credentials are forgotten.
Presently, one approach to unlocking a password for an information handling resource is based upon a master password that is generated from a unique identifier “challenge” associated with the information handling resource (e.g., a serial number or service tag number of the information handling resource or the information handling system in which the information handling resource is disposed). In such approach, a user may communicate the unique identifier to a vendor of the information handling resource (e.g., via telephone, e-mail, World Wide Web form submission, and/or other electronic method) along with information verifying the user's ownership of or authorization to use the information handling system and unlock the password (e.g., social security number, passphrase, birthdate, answer to challenge question, credit card number, or other personal data). Once user ownership or authorization is verified, the vendor may accept the unique identifier, apply a password-generation tool to the unique identifier to generate the master password for the information handling resource, and then communicate such master password to the user, who may input the master password in order to access the information handling resource.
The master password generation implementation may be based on an algorithm based on a shared secret shared between the information handling resource and the vendor's master password generation tool. Such algorithm may be used throughout many generations of information handling resources until it becomes compromised. Such implementation suffers from at least two disadvantages.
First, the input into the algorithm of the master password generation tool is always the same. For example, a particular information handling system with a particular unique identifier (e.g., service tag) will always have the same BIOS master password. Once a user has requested and received the master password from a vendor, that same master password will always unlock the specific information handling resource. This deficiency allows attackers to create lists of master passwords based on unique identifiers (e.g., “rainbow tables”) in order to initiate attacks on information handling systems.
Second, the security of the master password hinges on the obscurity of the shared secret algorithm in the information handling resource. For example, because the BIOS exists on the motherboard and the algorithm must run at boot time to compute the master password for verification purposes, an attacker with access to an in-circuit emulator may snoop the processor and determine the algorithm. This deficiency allows a sufficiently skilled attacker to identify the algorithm and publish his or her findings publicly.
SUMMARY
In accordance with the teachings of the present disclosure, the disadvantages and problems associated with unlocking an information handling resource have been reduced or eliminated.
In accordance with embodiments of the present disclosure, an information handling system may include a processor, an information handling resource, and a one-time password tool associated with the information handling system. The one-time password tool may comprise a program of instructions embodied in computer-readable media, and may be configured to cause the processor to generate a random number, generate a challenge string based at least on the random number, and encrypt the challenge string using a first shared secret. The one time-password controller may also be configured to receive a one-time password generated by a vendor associated with the information handling resource, the one-time password generated by decrypting the challenge string using the first shared secret, parsing the random number from the decrypted challenge string, and digitally signing the decrypted challenge string with a digital signature using a second shared secret. The one-time password tool may also be configured to grant user access to the information handling resource in response to verifying, using the second shared secret, that the digital signature matches the random number.
In accordance with these and other embodiments of the present disclosure, a method may include generating a random number to be associated with an information handling resource. The method may also include generating a challenge string based at least on the random number. The method may additionally include encrypting the challenge string using a first shared secret. The method may further include receiving a one-time password generated by a vendor associated with the information handling resource, the one-time password generated by decrypting the challenge string using the first shared secret, parsing the random number from the decrypted challenge string, and digitally signing the decrypted challenge string with a digital signature using a second shared secret. The method may also include granting user access to the information handling resource in response to verifying, using the second shared secret, that the digital signature matches the random number.
In accordance with these and other embodiments of the present disclosure, an information handling system may include a processor and a one-time password tool associated with the information handling system. The one-time password tool may comprise a program of instructions embodied in computer-readable media, and configured to cause the processor to receive an encrypted challenge string associated with an information handling resource, the encrypted challenge string generated by a second information handling system in which the information handling resource is disposed, the encrypted challenge string generated by encrypting, using a first shared secret, a challenge string based at least on a random number generated by the second information handling system. The one-time password tool may also be configured to decrypt the encrypted challenge message using the first shared secret and parse the random number from the decrypted challenge string. The one-time password tool may further be configured to digitally sign the decrypted challenge string with a digital signature using a second shared secret to generate a one-time password, such that the one-time password may be used to grant access to the information handling resource by a user of the second information handling system in response to verifying, using the second shared secret, that the digital signature matches the random number.
In accordance with these and other embodiments of the present disclosure, a method may include receiving an encrypted challenge string associated with an information handling resource, the encrypted challenge string generated by a second information handling system in which the information handling resource is disposed, the encrypted challenge string generated by encrypting, using a first shared secret, a challenge string based at least on a random number generated by the second information handling system. The method may also include decrypting the encrypted challenge message using the first shared secret. The method may additionally include parsing the random number from the decrypted challenge string. The method may further include digitally signing the decrypted challenge string with a digital signature using a second shared secret to generate a one-time password, such that the one-time password may be used to grant access to the information handling resource by a user of the second information handling system in response to verifying, using the second shared secret, that the digital signature matches the random number.
Technical advantages of the present disclosure will be apparent to those of ordinary skill in the art in view of the following specification, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
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 reference numbers indicate like features, and wherein:
FIG. 1 illustrates a block diagram of an example system for generating a one-time password for an information handling resource, in accordance with certain embodiments of the present disclosure; and
FIG. 2 illustrates a flow chart of an example method for generating a one-time password for an information handling resource, in accordance with certain embodiments of the present disclosure.
DETAILED DESCRIPTION
Preferred embodiments and their advantages are best understood by reference to FIGS. 1 and 2 , wherein like numbers are used to indicate like and corresponding parts.
For the purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an information handling system may be a personal computer, a personal digital assistant (PDA), a consumer electronic device, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include memory, one or more processing resources such as a central processing unit (“CPU”) or hardware or software control logic. Additional components of the information handling system may include one or more storage devices, one or more communications ports for communicating with external devices as well as various input/output (“I/O”) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more busses operable to transmit communication between the various hardware components.
For the purposes of this disclosure, computer-readable media may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Computer-readable media may include, without limitation, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such as wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing.
For the purposes of this disclosure, information handling resources may broadly refer to any component system, device or apparatus of an information handling system, including without limitation processors, service processors, BIOSs, busses, memories, I/O devices and/or interfaces, storage resources, network interfaces, motherboards, and/or any other components and/or elements of an information handling system.
FIG. 1 illustrates a block diagram of an example system 100 for generating a one-time password for an information handling resource, in accordance with certain embodiments of the present disclosure. As shown in FIG. 1 , system 100 may include a user information handling system 102 and a vendor information handling system 122 . In some embodiments, user information handling system 102 and vendor information handling system 122 may be communicatively coupled via a network 120 .
In some embodiments, user information handling system 102 may be a server. In others embodiment, user information handling system 102 may be a personal computer (e.g., a desktop computer or a portable computer). As depicted in FIG. 1 , user information handling system 102 may include a processor 103 , a memory 104 communicatively coupled to processor 103 , a storage resource 106 communicatively coupled to processor 103 , a network interface 108 communicatively coupled to processor 103 , BIOS 110 communicatively coupled to processor 103 , and a user interface 116 coupled to processor 103 .
Processor 103 may include any system, device, or apparatus configured to interpret and/or execute program instructions and/or process data, and may include, without limitation a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, processor 103 may interpret and/or execute program instructions and/or process data stored in memory 104 , storage resource 106 , BIOS 110 and/or another component of user information handling system 102 .
Memory 104 may be communicatively coupled to processor 103 and may include any system, device, or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). Memory 104 may include RAM, EEPROM, a PCMCIA card, flash memory, magnetic storage, opto-magnetic storage, or any suitable selection and/or array of volatile or non-volatile memory that retains data after power to user information handling system 102 is turned off.
Storage resource 106 may be communicatively coupled to processor 103 and may include any system, device, or apparatus configured to retain program instructions or data for a period of time (e.g., a computer-readable medium). In some embodiments, storage resource 106 may include a hard disk drive, a magnetic tape library, an optical disk drive, a magneto-optical disk drive, a compact disc drive, a solid state storage drive, a FLASH drive and/or any other suitable computer-readable medium.
In some embodiments, storage resource 106 may be password protected such that a user of user information handling system 102 must enter a password prior to accessing applications and/or data stored on storage resource 106 . For example, firmware associated with storage resource 106 may execute (e.g., on processor 103 ) upon boot and/or powering-on of user information handling system 102 to request a password (e.g., via user interface 116 ) prior to processor 103 accessing any applications and/or data of storage resource 106 . In embodiments in which storage resource 106 is password protected, storage resource 106 may comprise one-time password tool 114 and shared secrets 115 .
One-time password tool 114 may include any system, device, or apparatus configured to, in concert with a one-time password tool 134 of vendor information handling system 122 , facilitate the generation and receipt of a one-time password for accessing storage resource 106 (e.g., to provide access when a user password for storage resource 106 is lost or forgotten), as is described in greater detail elsewhere in this disclosure. In some embodiments, one-time password tool 114 may be implemented as a program of instructions that may be read by and executed on processor 103 to carry out the functionality of one-time password tool 114 .
Shared secrets 115 may comprise one or more random numbers, symmetric keys, asymmetric private/private key pairs, and/or other suitable secrets that may be used by one-time password tool 114 to facilitate the generation and receipt of a one-time password for accessing storage resource 106 , as is described in greater detail elsewhere in this disclosure.
Network interface 108 may comprise any suitable system, apparatus, or device operable to serve as an interface between user information handling system 102 and network 120 . Network interface 108 may enable user information handling system 102 to communicate over network 120 using any suitable transmission protocol and/or standard, including without limitation all transmission protocols and/or standards enumerated below with respect to the discussion of network 120 . In certain embodiments, network interface 108 may comprise a network interface card, or “NIC.” BIOS 110 may be communicatively coupled to processor 103 and may include any system, device, or apparatus configured to identify, test, and/or initialize information handling resources of user information handling system 102 . “BIOS” may broadly refer to any system, device, or apparatus configured to perform such functionality, including without limitation, a Unified Extensible Firmware Interface (UEFI). In some embodiments, BIOS 110 may be implemented as a program of instructions that may be read by and executed on processor 103 to carry out the functionality of BIOS 110 . In these and other embodiments, BIOS 110 may comprise boot firmware configured to be the first code executed by processor 103 when user information handling system 102 is booted and/or powered on. As part of its initialization functionality, BIOS code may be configured to set components of user information handling system 102 into a known state, so that one or more applications (e.g., an operating system or other application programs) stored on compatible media (e.g., memory 104 ) may be executed by processor 103 and given control of user information handling system 102 .
In some embodiments, BIOS 110 may be password protected such that a user of user information handling system 102 must enter a password prior to accessing user-configurable settings and/or parameters of BIOS 110 . For example, a portion of BIOS 110 may execute (e.g., on processor 103 ) when a user gives an indication (e.g., pressing of a “hot key”) of a desire to configure BIOS 110 settings and/or parameters of user information handling system 102 , and such portion of BIOS 110 may request (e.g., via user interface 116 ) a password prior to processor 103 accessing any additional portions. In embodiments in which storage resource 106 is password protected, storage resource 106 may comprise one-time password tool 112 and shared secrets 113 .
One-time password tool 112 may include any system, device, or apparatus configured to, in concert with a one-time password tool 134 of vendor information handling system 122 , facilitate the generation and receipt of a one-time password for accessing user-configurable settings and/or parameters of BIOS 110 (e.g., to provide access when a user password for BIOS 110 is lost or forgotten), as is described in greater detail elsewhere in this disclosure. In some embodiments, one-time password tool 112 may be implemented as a program of instructions that may be read by and executed on processor 103 to carry out the functionality of one-time password tool 112 .
Shared secrets 113 may comprise one or more random numbers, symmetric keys, asymmetric private/private key pairs, and/or other suitable secrets that may be used by one-time password tool 112 to facilitate the generation and receipt of a one-time password for accessing BIOS 110 , as is described in greater detail elsewhere in this disclosure.
User interface 116 may comprise any instrumentality or aggregation of instrumentalities by which a user 118 may interact with user information handling system 102 . For example, user interface 116 may permit user 118 to input data and/or instructions into user information handling system 102 (e.g., via a keyboard, pointing device, and/or other suitable component), and/or otherwise manipulate user information handling system 102 and its associated components. User interface 116 may also permit user information handling system 102 to communicate data to user 118 , e.g., by way of a display device.
Network 120 may be a network and/or fabric configured to couple user information handling system 102 and vendor information handling system 122 to each other and/or one or more other information handling systems. In some embodiments, network 120 may include a communication infrastructure, which provides physical connections, and a management layer, which organizes the physical connections and information handling systems communicatively coupled to network 120 . Network 120 may be implemented as, or may be a part of, a storage area network (SAN), personal area network (PAN), local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a wireless local area network (WLAN), a virtual private network (VPN), an intranet, the Internet or any other appropriate architecture or system that facilitates the communication of signals, data and/or messages (generally referred to as data). Network 120 may transmit data using any storage and/or communication protocol, including without limitation, Fibre Channel, Frame Relay, Asynchronous Transfer Mode (ATM), Internet protocol (IP), other packet-based protocol, small computer system interface (SCSI), Internet SCSI (iSCSI), Serial Attached SCSI (SAS) or any other transport that operates with the SCSI protocol, advanced technology attachment (ATA), serial ATA (SATA), advanced technology attachment packet interface (ATAPI), serial storage architecture (SSA), integrated drive electronics (IDE), and/or any combination thereof. Network 120 and its various components may be implemented using hardware, software, or any combination thereof.
In some embodiments, vendor information handling system 122 may be a server. In other embodiments, vendor information handling system 122 may be a personal computer (e.g., a desktop computer or a portable computer). As depicted in FIG. 1 , vendor information handling system 122 may include a processor 123 , a memory 124 communicatively coupled to processor 123 , and a network interface 128 communicatively coupled to processor 123 .
Processor 123 may include any system, device, or apparatus configured to interpret and/or execute program instructions and/or process data, and may include, without limitation a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, processor 123 may interpret and/or execute program instructions and/or process data stored in memory 124 and/or another component of user information handling system 122 .
Memory 124 may be communicatively coupled to processor 123 and may include any system, device, or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). Memory 124 may include RAM, EEPROM, a PCMCIA card, flash memory, magnetic storage, opto-magnetic storage, or any suitable selection and/or array of volatile or non-volatile memory that retains data after power to vendor information handling system 122 is turned off.
As shown in FIG. 1 , memory 124 may have stored thereon one-time password tool 134 and shared secrets 115 . One-time password tool 134 may include any system, device, or apparatus configured to, in concert with one-time password tool 112 and/or one-time password tool 114 of user information handling system 102 , facilitate the generation of a one-time password for accessing user-configurable settings and/or parameters of BIOS 110 (e.g., to provide access when a user password for BIOS 110 is lost or forgotten) or accessing storage resource 106 (e.g., to provide access when a user password for storage resource 106 is lost or forgotten) as is described in greater detail elsewhere in this disclosure. In some embodiments, one-time password tool 134 may be implemented as a program of instructions that may be read by and executed on processor 123 to carry out the functionality of one-time password tool 134 .
Shared secrets 135 may comprise one or more random numbers, symmetric keys, asymmetric private/private key pairs, and/or other suitable secrets that may be used by one-time password tool 134 to facilitate the generation and receipt of a one-time password for accessing BIOS 110 , storage resource 106 , and/or another information handling resource of information handling system 102 , as is described in greater detail elsewhere in this disclosure. A shared secret 135 may correspond to an associated shared secret 113 or shared secret 115 of user information handling system 102 . For example, where shared secret 135 is a first key of a key pair, shared secret 113 or shared secret 115 may be the second key of a key pair.
Although element 122 of FIG. 1 is referred to as a “vendor information handling system,” it is noted that the term “vendor” as used herein is intended to encompass any entity in the supply chain of a relevant information handling resource of information handling system 102 , whether such entity includes a seller, manufacturer, wholesaler, factory, and/or other provider of the relevant information handling resource.
FIG. 2 illustrates a flow chart of an example method 200 for generating a one-time password for an information handling resource, in accordance with certain embodiments of the present disclosure. According to one embodiment, method 200 may begin at step 202 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of system 100 . As such, the preferred initialization point for method 200 and the order of the steps comprising method 200 may depend on the implementation chosen.
At step 202 , a user (e.g., user 118 ) may make a request for a one-time password. Such request may be made via a user interface (e.g., user interface 116 ), for example, at a password-entry screen presented by a BIOS or other program of instructions associated with an information handling resource.
At step 204 , a one-time password tool (e.g., one-time password tool 112 or one-time password tool 114 ) of a user information handling system (e.g., user information handling system 102 ) may generate a random number. Such random number may be generated by any suitable manner known in the art.
At step 206 , the one-time password tool may concatenate the random number, a unique identifier associated with the information handling resource (e.g., service tag, serial number, etc.), and/or other information (e.g., key revision number) into a challenge string.
At step 208 , the one-time password tool may encrypt the challenge string using a first shared secret (e.g., a shared secret 113 or shared secret 115 ). In some embodiments, the one-time password tool may encrypt the challenge string with a public key of a first public/private key pair.
At step 210 , the one-time password tool may save the random number to a computer-readable medium associated with the information handling resource.
At step 212 , the encrypted challenge string may be communicated to a vendor information handling system (e.g., vendor information handling system 122 ). In some embodiments, the encrypted challenge string may be communicated via a network (e.g., the Internet). In other embodiments, the encrypted challenge string may be communicated by a user of the user information handling system (e.g., via telephone) to a technician who may enter the encrypted challenge string into the one-time password tool of the vendor information handling system.
At step 214 , a one-time password tool (e.g., one-time password tool 134 ) of the vendor information handling system may decrypt the encrypted challenge string using the first shared secret (e.g., shared secret 135 ) used to encrypt the challenge string at step 208 . In embodiments in which the challenge string is encrypted at the user information handling system using a public key of a first public/private key pair, the one-time password tool of the vendor information handling system may decrypt the challenge string using the corresponding private key of the first public/private key pair.
At step 216 , the one-time password tool may parse the random number, the unique identifier (e.g., a service tag or serial number), and/or other information (e.g., key revision).
At step 218 , the one-time password tool may sign the random number with a digital signature based on the unique identifier and/or the other information in order to create a one-time password. The one-time password tool may use a second shared secret to create the digital signature. In some embodiments, the second shared secret may comprise a private key of a second public/private key pair.
At step 220 , the one-time password may be communicated to the user information handling system. In some embodiments the one-time password may be communicated via a network (e.g., the Internet). In other embodiments, the encrypted challenge string may be communicated by a technician (e.g., via telephone) to the user information handling system who may enter the one-time password into the one-time password tool of the user information handling system.
At step 222 , the one-time password tool may verify the digital signature matches the random number based on the second shared secret. For example, the one-time password tool may perform the digital signature verification using the random number as the message, the one-time password as the message signature, and the second shared secret as the key. In embodiments in which the digital signature is created using a private key of the second public/private key pair, digital signature verification may be performed using the corresponding public key of the second public/private key pair. In these and other embodiments, the public key may be associated with a particular key revision value.
At step 224 , in response to digital signature verification, access to the information handling resource may be granted. In some embodiments, the one-time password tool associated with the information handling resource may query the user for a new password to be used for future accesses.
Although FIG. 2 discloses a particular number of steps to be taken with respect to method 200 , method 200 may be executed with greater or lesser steps than those depicted in FIG. 2 . In addition, although FIG. 2 discloses a certain order of steps to be taken with respect to method 200 , the steps comprising method 200 may be completed in any suitable order.
Method 200 may be implemented using system 100 or any other system operable to implement method 200 . In certain embodiments, method 200 may be implemented partially or fully in software and/or firmware embodied in computer-readable media.
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 disclosure as defined by the appended claims. | In accordance with embodiments of the present disclosure, a method may include generating a random number to be associated with an information handling resource. The method may also include generating a challenge string based at least on the random number. The method may additionally include encrypting the challenge string using a first shared secret. The method may further include receiving a one-time password generated by a vendor associated with the information handling resource, the one-time password generated by decrypting the challenge string using the first shared secret, parsing the random number from the decrypted challenge string, and digitally signing the decrypted challenge string with a digital signature using a second shared secret. The method may also include granting user access to the information handling resource in response to verifying, using the second shared secret, that the digital signature matches the random number. | 6 |
FIELD OF THE INVENTION
The present invention is directed at a game of chance and a device for playing the game.
BACKGROUND OF THE INVENTION
Keno is a game in which a player selects numbers from a grid of eighty squares, with each square numbered from one to eighty in sequence. An example of a keno grid is shown in FIG. 1a. The player first determines how many numbers (or "spots") to select. The number of spots selected determines the payout odds. For example, for a five-spot keno game (as shown in FIG. 1b), the player selects any five of the eighty numbers and marks them. Then, the machine selects at random, twenty of the eighty numbers (the shaded squares as shown in FIG. 1c) . When the machine selects a number that the player also selected, this is known as a "hit". If the player received enough hits to have a winning ticket, the machine then pays off according to an established payoff schedule. For example, the payout odds may be as follows: For $1 wagered, if the player catches three out of five, the player wins $1; if the player catches four out of five as shown in FIG. 1c) the player wins $20; and if the player catches all five out of five, the player wins $600.
The above example demonstrates keno as played on a video machine. Keno can also be played using paper tickets (similar to Bingo) and a common board used by multiple players but each with their own paper tickets. In this version of the game, a player marks his ticket with a crayon to indicate his number selections and then registers the ticket with an employee at the keno desk of the casino. This ticket is then played against the next game displayed on the common board, with each player playing independent tickets. The common board merely lights up the twenty random numbers which are selected using numbered ping pong balls (similar to the lottery). The player then reviews his ticket and circles the numbers that both he selected and the ones that were selected at random as displayed on the common keno board. If he received enough hits, as determined by the payout schedule, he would take his winning ticket to the employee at the keno desk for his payoff.
Keno played with paper tickets and a common board differs from video keno in that video keno is played by a single player using his own machine and own number selection process while the former is played by multiple independent players. Also, video keno indicates on a single medium (the eighty number grid) both the spots selected by the player and the spots subsequently selected by the machine, which easily shows the hits and whether or not the ticket is a winner. Video keno is also much faster, with the capability of playing each game in a matter of seconds as opposed to several minutes for a game using paper tickets and a common board.
Another form of keno is way-keno. In way-keno, the player plays multiple games of keno on a single ticket. In playing way-keno, groups of numbers are separated by lines or circles. The groups are then combined together to make individual tickets for all the ways that a player wishes to play (see FIG. 2). The player, in the example shown in FIG. 2, selected four separate groups of numbers and encircled each group. One group contains four numbers, one group contains three numbers and the other two groups contain two numbers each. In this example, the groups are then combined in every possible way to establish each of the games that are played. For instance, the group of four numbers is combined with the group of three numbers to establish a seven-spot game. In FIG. 2, there are fifteen different ways that the groups can be combined to form fifteen different games (or "ways"). Four of the ways played are the individual groups themselves. All of the combinations (games or "ways") being played are listed below in Table I.
In this example, there are a total of fifteen games of keno that are being played on one ticket. If the player decides to play $1 per way ($1 per game), the total price for this way ticket would be $15.
In the example shown, there is one way all four groups can be combined (4+3+2+2) to yield one eleven-spot game; there are four additional ways that three of the four groups can be combined; there are six additional games that two of the four groups can be combined; and finally, each of the groups can be played solo for four additional games to give fifteen games played altogether. Of the fifteen games, there is one eleven-spot, two nine-spots, one eight-spot, two seven-spots, two six-spots, two five-spots, two four-spots, one three-spot and two two-spots.
TABLE I______________________________________ SpotsGame No. Groups Used Played______________________________________1 4 3 2 2 11 All 4 groups used2 4 3 2 9 3 of 4 groups used3 4 3 2 9 3 of 4 groups used4 4 2 2 8 3 of 4 groups used5 3 2 2 7 2 of 4 groups used6 4 3 7 2 of 4 groups used7 4 2 6 2 of 4 groups used8 4 2 6 2 of 4 groups used9 3 2 5 2 of 4 groups used10 3 2 5 2 of 4 groups used11 2 2 4 2 of 4 groups used12 4 4 1 of 4 groups used13 3 3 1 of 4 groups used14 2 2 1 of 4 groups used15 2 2 1 of 4 groups used______________________________________
The player uses the payout schedules for each game independently and adds the winnings for each game independently. Way-keno tickets can have more than one winning game.
Way-keno often involves complicated math just to calculate how many games are being played and how much money is being wagered. In fact, because of its complexity, casinos often offer "suggested" or "fixed" way-keno games with the cost of the game and the payout schedule pre-printed so that the player may just play the games published by the casino and doesn't need to make any calculations. For the same reasons, it is often difficult for the player to figure out if any money is won and how much. Because way-keno is so complex, most players avoid it and simply play regular keno.
It is desirable to provide a game of chance which provides more excitement than keno and way-keno, but which is simple enough to be played by the average gambler.
SUMMARY OF THE INVENTION
The present invention is directed at a method and device for playing a game similar to keno. The device comprising a video screen for displaying a playing board wherein the playing board comprises an array of squares, access for accepting a bet from a player, a selector for a player to select a pattern of squares on the playing board, a template generator, a random number generator for selecting, at random, squares within the playing board, a scanner to calculate the number of randomly selected squares which are included within the template for each different position in which the template is included within the playing board, a calculator for determining the payout for a winning position and for tallying the winnings and crediting the winnings to the player.
The method comprises preparing a template from the pattern of squares selected by the player, generating a random selection of squares on the playing board by the game, overlaying the template over the playing board in each possible position where the template will be included, counting the number of randomly selected squares contained within the template, determining the payout for each position, totaling the payouts derived from each of the winning positions and crediting the payouts to the player.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described with reference to the accompanying drawings, wherein like reference numerals identify corresponding like components.
In the drawings:
FIG. 1a is a schematic of a keno grid;
FIG. 1b is a schematic of a keno grid in which five spots have been selected;
FIG. 1c is a schematic of a keno grid in which five spots have been selected and in which the keno device has randomly selected twenty numbers;
FIG. 2 is a schematic of a keno grid on which way-keno is being played;
FIG. 3 is a schematic of a Pattern Keno video device;
FIG. 4a is a schematic of a Pattern Keno grid on which the player has selected the pattern to be played;
FIG. 4b is a schematic of a Pattern Keno grid on which the game has made a template of the player's pattern and placed the template to the side of the playing board;
FIG. 4c is a schematic of a Pattern Keno grid on which the game has selected twenty random squares;
FIG. 4d is a schematic of a Pattern Keno grid on which the game has placed the template onto the first position on the grid to determine if a win has been achieved;
FIG. 4e is a schematic of a Pattern Keno grid on which the game has placed the template onto the second position on the grid to determine if a win has been achieved;
FIG. 4f is a schematic of a Pattern Keno grid on which the game has placed the template onto the thirty-sixth position on the grid to determine if a win has been achieved. At this position, there is a seven out of nine match, which is a winner for this pattern;
FIG. 4g is a schematic of a Pattern Keno grid on which the game has placed the template onto the thirty-seventh position on the grid to determine if a win has been achieved. At this position, there is another seven out of nine match, which is another winner;
FIG. 4h is a schematic of a Pattern Keno grid on which the game has placed the template onto the forty-forth position on the grid to determine if a win has been achieved. At this position, there is a six out of nine match, which is also a winner for this pattern, which is the third winner for this game;
FIG. 5a is a schematic of a Pattern Keno grid on which the player has selected the pattern to be played;
FIG. 5b is a schematic of a Pattern Keno grid on which the game has made a template of the player's pattern and placed the template to the side of the playing board;
FIG. 5c is a schematic of a Pattern Keno grid on which the game has selected twenty random squares;
FIG. 5d is a schematic of a Pattern Keno grid on which the game is shown with the template scanning the squares and finding a win of six out of eight at position twenty-six for this game;
FIG. 5e is a schematic of a Pattern Keno grid on which the template has continued scanning the squares and has found another winner of six out of eight at position twenty-seven for this game;
FIG. 5f is a schematic of a Pattern Keno grid on which the template has continued scanning the squares and has found another winner of six out of eight at position twenty-eight for this game;
FIG. 5g is a schematic of a Pattern Keno grid on which the template has continued scanning the squares and has found another winner of six out of eight at position thirty-two for this game; and
FIG. 5h is a schematic of a Pattern Keno grid on which the template has continued scanning the squares and has found another winner of six out of eight at position thirty-four for this game, which is the fifth winner for this game.
DETAILED DESCRIPTION
The present invention is a game of chance which is similar to keno which is called, for convenience, "Pattern Keno." Pattern Keno involves the use of a playing board grid 26 (see FIG. 4) of, for example, eighty squares. However, unlike keno, the squares may be unnumbered since the numbers have no relevance in this game. Instead of playing specific numbers as shown in keno and way-keno, "patterns" of squares are used. Like way-keno, Pattern Keno involves playing multiple games simultaneously on a single playing board grid.
The payout schedule for Pattern Keno is based on the number of spots the player picks and the number of games to be played. The number of games to be played is based on how many ways the selected pattern will be included in the playing board grid.
Pattern Keno is preferably played on a video device to automate the calculations required to determine the number of wins received by the player. FIG. 3 shows the components of a video Pattern Keno device of the present invention. These components and their programming are well known to those skilled in the art.
The Pattern Keno device comprises a video display screen 10 for displaying the progress of the game and a means, such as a light pen, a mouse, touch screen or other similar device 12 for selecting the desired pattern 28 (see FIG. 4) of the player on the video display screen. The Pattern Keno device includes a coin slot and coin counter 14 for inserting coins. There may also be a similar device which accepts paper money for credits. Once the player is satisfied with the pattern chosen, start button 16 is pressed to initiate the game. At the end of the game, if the player has won, coins are returned to the player through coin return 18 or, alternatively, credited to the player. The components of the device, the video display screen, the means for selecting the player's desired pattern on the video display screen, the coin slot, the start button and the coin return are connected to a central processing unit (cpu) 20. The cpu is connected to a random number generator 22 for generating numbers to select squares within a playing board displayed on the video display screen. The playing board, in the embodiment of the invention shown in FIG. 4, comprises a ten-by-eight grid of squares, although other configurations of grid arrays are possible.
To play a game, the player deposits coins into the video gaming device or plays credits which have already been established by the player. The player may play any number of coins or credits (to a determined maximum). The payout odds for the game are multiplied by the number of coins or credits played. In the example of a ten-by-eight grid, a player can play a single credit and play up to sixty-three possible games (when a two-by-two square pattern is played, as an example) on that one credit, depending on the pattern played and the number of ways that pattern is included into the playing grid. If a player plays multiple coins or credits, the payout odds are enhanced. In one embodiment of the present invention, the player may use multiple coins to play multiple patterns simultaneously, with independent wagers on each pattern. In this version, the player picks multiple patterns and after the machine selects the squares at random, the machine scans each pattern across the grid, one after the next and adds winnings for each pattern independently.
The player selects squares to form a pattern from the playing board grid of eighty squares. When the player selects a square, it changes color so as to be distinguished from the unselected squares. If the player selects a square in error, the player may "unselect" the square, changing the square back to its original color. The player may select any squares from a minimum of four to a maximum of ten (the minimum and maximum limits are arbitrarily set for the purposes of explanation). In one embodiment of the present invention, the payout odds are displayed below the playing board grid. The payout odds are updated as each square is selected (or "unselected") by the player in sequence, until the player has determined enough squares have been selected for the game. In addition, the number of games the player is playing is also updated with each square selected (or "unselected"). The number of games played is the number of different positions in which the selected pattern will be included onto the playing board grid without overlapping the edges of the grid (the pattern must be fully contained within the grid). In one embodiment of the present invention, the pattern may overlap the edges of the playing grid to accommodate more positions for the selected pattern. In another embodiment of the present invention, the template "wraps" around the edges of the playing grid such that the template emerges on the opposite edge of the playing grid to accommodate a greater chance of winning. In one embodiment of the present invention, patterns are selected from a menu of pattern choices which are displayed on the video display screen.
The player may modify the pattern until the player is content with the pattern created. The pattern chosen does not need to be contiguous and a non-contiguous pattern is played with its separate parts always having the same relative spacial arrangement (see FIG. 5).
When the player is content with the pattern created, the player selects the start button. The pattern is then stored in the memory of the device and a template 30 (see FIG. 4) of the pattern is created and displayed. The video device then selects, for example, twenty squares in the playing board grid at random and displays the results by "coloring" or "lighting" the selected squares 32.
After the twenty squares are selected by the video device, the template of the selected pattern scans the playing board grid, covering each of the positions in which the template is included onto the playing board grid, searching for winning games. The template is an outline of the pattern selected and is used to show the player if the pattern selected matches any of the twenty randomly selected squares closely enough to be a winner as established by the payout odds that correspond to that game.
Once the template has "scanned" the entire playing board grid, the credits reflecting the winnings from the game are paid to the player and the player may go on to play additional games. The player may retain the pattern from the prior game played and play it again or may start afresh with a different pattern.
EXAMPLE 1
A pattern of squares is chosen by the player on the playing board as shown in FIG. 4. In this example, nine contiguous squares are chosen. The video would then display the parameters of the game as follows:
______________________________________Games = 48 9 out of 9 pays 10,000Spots = 9 8 out of 9 pays 119Credits = 9 7 out of 9 pays 5Wins = 0 6 out of 9 pays 1______________________________________
In this example, "Games=48" indicates that there are fourty-eight ways (or positions) in which the selected pattern will be included within the playing grid and so the player is playing 48 games simultaneously by selecting this pattern. "Spots=9" refers to the nine squares selected by the player which form the pattern. The player had ten credits but deposited one in order to play the game. The number of credits remaining after depositing the one credit is nine. The player then designs or selects a pattern to be played. When the player is content with the selected pattern (FIG. 4a), the player selects the start button. A template is made from the pattern selected by the player and placed to the side of the playing grid (FIG. 4b). Twenty squares are then selected at random from among the array of eighty squares displayed on the video device. The selected squares are "colored" to distinguish them from the non-selected squares (FIG. 4c) . After all twenty squares are selected, the template is placed on the first position of the playing board grid (in the upper-left corner in this example), including nine of the squares of the playing grid (FIG. 4d) and then scans the entire playing grid, covering every possible grouping of nine squares in the form of the template on the grid, so long as the template is always entirely within the playing grid with no portion of the template overlapping or extending over any of the edges of the playing grid. While scanning, the template searches for winning positions in which there are enough selected squares within the template to be a winning combination (in this example, at least six of the nine squares within the template must have been selected to be a winning combination). In this example, the template scans the playing grid starting in the upper-left corner, scans to the right until it can go no farther, then moves down one position, then scans to the left until it can go no farther, then moves down one position again and repeats this motion until it has scanned the entire playing grid. This is just an arbitrary example of the path that the template makes across the playing grid. The scanning may be done in any manner so long as it covers all possible playing positions. An illustration of the template scanning for a winner is shown in FIGS. 4d-h.
In this example game, there are three winners (FIGS. 4f-h). The template scans the grid back and forth until it comes across the first winner. The template then pauses, and in one embodiment of the invention, changes the color of the randomly selected squares that are enclosed within the template, tallies the winnings, returns the squares to their original color and then continues to scan for additional winners. The first winner is shown in FIG. 4f. The video displays the winning for this match as follows:
______________________________________Games = 48 9 out of 9 pays 10,000Spots = 9 8 out of 9 pays 119Credits = 14 7 out of 9 pays 5Wins = 5 6 out of 9 pays 1______________________________________
The "7 out of 9 pays 5" line is highlighted to indicate the winning status that the template has discovered in this position. Seven out of nine of the squares in the pattern chosen by the player are among the squares selected at random when the pattern is in this position on the playing grid. The wins increases from zero to five because the player has won five credits with this win. "Wins=" indicates the aggregate winnings for all wins that the template finds in all positions of the playing grid. Similarly, the player's credits are increased from nine to fourteen because the player has won five credits with this win.
The template then continues to scan the grid until it comes across the second winner as shown in FIG. 4g. The video displays the winning for this match as follows:
______________________________________Games = 48 9 out of 9 pays 10,000Spots = 9 8 out of 9 pays 119Credits = 19 7 out of 9 pays 5Wins = 10 6 out of 9 pays 1______________________________________
The second winner is also seven out of nine and so the player has won another five credits. The winnings are added to both the total wins and player's credits. The wins increase from five to ten and the player's credits increase from fourteen to nineteen.
Finally, the template continues to scan until the third winner is found and tabulated (FIG. 4h). The video displays the winning for this match as follows:
______________________________________Games = 48 9 out of 9 pays 10,000Spots = 9 8 out of 9 pays 119Credits = 20 7 out of 9 pays 5Wins = 11 6 out of 9 pays 1______________________________________
The third winner is six out of nine and so, according to the pay schedule, the player has won one additional credit. The winnings are again added to both the total wins and player's credits. The wins increase from ten to eleven and the player's credits increase from nineteen to twenty.
The template continues scanning the rest of the grid but finds no additional winners for this game. This game is then over. The player has won a total of eleven credits from three winning positions (games).
EXAMPLE 2
A pattern of squares is chosen by the player on the playing grid as shown in FIG. 5a. In this example, eight non-contiguous squares (two groups of four) are chosen. The video would then display the parameters of the game as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 9 6 out of 8 pays 2Wins = 0______________________________________
In this example, "Games=36" indicates that there are thirty-six ways (or positions) in which the selected pattern will be included within the playing grid and so the player is playing thirty-six games simultaneously by selecting this pattern. "Spots=8" refers to the eight squares selected by the player which form the pattern. The player had ten credits but deposited one in order to play the game. The number of credits remaining after depositing the one credit is nine. The player then designs or selects a pattern to be played. When the player is content with the selected pattern (FIG. 5a), the player selects the start button. A template is made from the pattern selected by the player and placed to the side of the playing grid (FIG. 5b). Twenty squares are then selected at random from among the array of eighty squares displayed on the video device. The selected squares are "colored" to distinguish them from the non-selected squares (FIG. 5c). After all twenty squares are selected, the template scans the entire playing grid, covering every possible grouping of eight squares in the form of the template on the grid, so long as the template is always entirely within the playing grid with no portion of the template overlapping or extending over any of the edges of the playing grid. In a non-contiguous pattern, such as in this example, the separate pieces of the pattern retain their same relative spacing with respect to each other while scanning. While scanning, the template searches for winning positions in which there are enough selected squares within the template to be a winning combination (in this example, at least six of the eight squares within the template must have been selected to be a winning combination). In this example, the template scans the playing grid starting in the upper-left corner, scans to the right until it can go no farther, then moves down one position, then scans to the left until it can go no farther, then moves down one position again and repeats this motion until it has scanned the entire playing grid. This is just an arbitrary example of the path that the template makes across the playing grid. The scanning may be done in any manner so long as it covers all possible playing positions. An illustration of the template scanning for a winner is shown in FIGS. 5d-h. The first winner is shown in FIG. 5d. The video displays the winning for this match as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 11 6 out of 8 pays 2Wins = 2______________________________________
The wins increase from zero to two because the player has won two credits with this win and the player's credits likewise increase from nine to eleven.
The template then continues to scan the grid until it hits the second winner as shown in FIG. 5e. The video displays the winning for this match as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 13 6 out of 8 pays 2Wins = 4______________________________________
The second winner is also six out of eight and so the player has won another two credits. The wins now increase from two to four and the player's credits increase from eleven to thirteen.
The template continues to scan and finds the third winner (FIG. 5f). The video displays the winning for this match as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 15 6 out of 8 pays 2Wins = 6______________________________________
The third winner is again six out of eight and so the player has won another two credits and the wins and credits each increase by another two.
The template continues to scan and finds the fourth winner (FIG. 5g). The video displays the winning for this match as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 17 6 out of 8 pays 2Wins = 8______________________________________
The fourth winner is again six out of eight and so the player has won another two credits and the wins and credits each increase by another two.
Finally, the template continues to scan until the fifth winner is found and tabulated (FIG. 5h). The video displays the winning for this match as follows:
______________________________________Games = 36 8 out of 8 pays 1,800Spots = 8 7 out of 8 pays 86Credits = 19 6 out of 8 pays 2Wins = 10______________________________________
The fifth winner is once again six out of eight, the player has won another two credits and the wins and credits once again increase by two each.
The template continues scanning the rest of the grid but finds no additional winners for this game. This game is then over. The player has won a total of ten credits from five winning positions (games).
Pattern Keno offers many advantages to keno and way-keno. Pattern Keno is much simpler to play than way-keno. Pattern Keno involves simple pattern recognition. Simply play a coin, select any pattern, press go. If enough of the pattern is found anywhere on the playing grid, the player wins. Way-keno often involves complicated math just to calculate how many games are being played and how much money is being played. In fact, because of its complexity, the casinos often offer "suggested" or "fixed" way-keno games with the cost of the game and the payout schedule pre-printed so that the player just plays the games published by the casino and doesn't need any calculations. For the same reasons, it is often difficult for the player to calculate if any money is won and how much. Due to its complexity, most players avoid way-keno and simply play regular keno. Pattern Keno is exciting because the player can see a winner forming as the squares are selected at random on the playing grid. It also adds an extra element of excitement as the template scans the playing grid, searching for a winner.
Other advantages of the Pattern Keno game, over other keno games, are as follows:
The Pattern Keno game is dynamic with the template scanning the playing grid, searching for winners. In both keno and way-keno the player is playing specific numbers and after the numbers are chosen, the game is "static."
The payout odds are also flexible in Pattern Keno with payout odds being adjusted according to the number of ways the selected pattern can be included in the playing grid. For example, one 5-spot game may have different payout odds than another 5-spot game, depending on the pattern chosen. In effect, the player can manipulate the payout odds by selecting different patterns. In keno and way-keno, the payout odds remain the same between games that have the same number of spots chosen.
Pattern Keno is unlimited. The player can pick any pattern where the number of spots selected falls between the determined minimum and maximum. In way-keno, combinations of grouped numbers are used. If too many groups are selected, the number of combinations of games being played becomes confusing.
The present invention is not to be limited to the specific embodiments shown which are merely illustrative. Various and numerous other embodiments may be devised by one skilled in the art without departing from the spirit and scope of this invention. For example, "squares" are used for illustrating the game although other shaped playing areas within the grid could also be used. Also, a template can be included within the playing board by "wrapping" around the edges of the playing grid such that the template emerges on the opposite edge of the playing grid to increase the chances of winning or the template can be included by not "wrapping" around the edge of the board to reduce the chances of winning. Also, if desired, the positions in which the template is included may be designated by the operator of the game to reduce or increase the chances of winning and may not include all possible positions, as desired. The scope of this invention is defined in the following claims. | A method and device for playing a game. The device comprising a video screen for displaying a playing board wherein the playing board comprises an array of squares, access for accepting a bet from a player, a selector for a player to select a pattern of squares on the playing board, a template generator, a random number generator for selecting, at random, squares within the playing board, a scanner to calculate the number of randomly selected squares which are contained within the template for each different position in which the template is included within the playing board, a calculator for determining the payout for a winning position and for tallying the winnings and crediting the winnings to the player. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 09/509,360, filed Mar. 24, 2000, now allowed, which, in turn was a U.S. national phase filing under 35 USC §371 of International PCT Application No. PCT/US98/24983, filed Nov. 19, 1998, which claimed priority filing benefit from U.S. Provisional Application Serial No. 60/066,185 filed Nov. 19, 1997.
FIELD OF THE INVENTION
[0002] The present invention relates to methods for making sputter targets for magnetron sputtering, sputter targets made by the methods, and methods of sputtering using such targets. More particularly, the invention relates to the manufacture of sputter targets using nickel-silicon alloys and to targets manufactured thereby.
BACKGROUND OF THE INVENTION
[0003] Cathodic sputtering is widely used for depositing thin layers or films of materials from sputter targets onto desired substrates such as semiconductor wafers. Basically, a cathode assembly including a sputter target is placed together with an anode in a chamber filled with an inert gas, preferably argon. The desired substrate is positioned in the chamber near the anode with a receiving surface oriented normally to a path between the cathode assembly and the anode. A high voltage electric field is applied across the cathode assembly and the anode.
[0004] Electrons ejected from the cathode assembly ionize the inert gas. The electrical field then propels positively charged ions of the inert gas against a sputtering surface of the sputter target. Material dislodged from the sputter target by the ion bombardment traverses the chamber and deposits on the receiving surface of the substrate to form the thin layer or film.
[0005] In so-called magnetron sputtering, one or more magnets are positioned behind the cathode assembly to generate a magnetic field. Magnetic fields generally can be represented as a series of flux lines, with the density of such flux lines passing through a given area, referred to as the “magnetic flux density,” corresponding to the strength of the field. In a magnetron sputtering apparatus, the magnets form arch-shaped flux lines which penetrate the target and serve to trap electrons in annular regions adjacent the sputtering surface. The increased concentrations of electrons in the annular regions adjacent the sputtering surface promote the ionization of the inert gas in those regions and increase the frequency with which the gas ions strike the sputtering surface beneath those regions.
[0006] Nickel is commonly used in physical vapor deposition (“PVD”) processes for forming nickel silicide films by means of the reaction of deposited nickel with a silicon substrate. Yet, while magnetron sputtering methods have improved the efficiency of sputtering many target materials, such methods are less effective in sputtering “ferromagnetic” metals such as nickel. It has proven difficult to generate a sufficiently strong magnetic field to penetrate a nickel sputter target to efficiently trap electrons in the annular regions adjacent the sputtering surface of the target.
[0007] In order to provide a background for the present invention, certain aspects of the magnetic behavior of metals will be briefly described.
[0008] The magnetic flux density vector within a metal body generally differs from the magnetic flux density external to the body. Typically, the component “B” of the magnetic flux density along a given direction in space within a metal body may be expressed in accordance with the relationship B =μ 0 (H+M), where “μ 0 ” is a constant referred to as the magnetic permeability of empty space; “H” is the corresponding component of the so-called “magnetic field intensity” vector; and “M” is the corresponding component of the so-called “magnetization” vector. (Note that positive and negative values of the components of the magnetic flux density, the magnetic field intensity and the magnetization represent opposite directions in space, respectively.)
[0009] The magnetic field intensity may be thought of as the contribution to the internal magnetic flux density due to the penetration of the external magnetic field into the metallic body. The magnetization may be thought of as the contribution to the internal magnetic flux density due to the alignment of magnetic fields generated primarily by the electrons within the metal.
[0010] In “paramagnetic” materials, the magnetic fields generated within the metal tend to align so as to increase the magnetic flux density within the metal. Furthermore, the magnetic fields generated within a paramagnetic metal do not strongly interact and cannot stabilize the alignment of the magnetic fields generated within the metal, so that the paramagnetic metal is incapable of sustaining any residual magnetic field once the external magnetic field is removed. Thus, for many paramagnetic metals and at a constant temperature, the “magnetization curve,” which relates the magnetic flux density to the magnetic field strength within the metal, is linear and independent of the manner in which the external magnetic field is applied.
[0011] In a “ferromagnetic” metal such as nickel, the magnetic fields generated within the metal do interact sufficiently for the metal to retain a residual magnetic field when the external field is removed. Below a “Curie temperature” characteristic of a ferromagnetic metal, the metal must be placed in an external magnetic field directed oppositely to the residual field in the metal in order to dissipate the residual field.
[0012] At any constant temperature below the Curie temperature, the relationship between the magnetic flux density and the magnetic field intensity in the metal differs depending on how the external magnetic field has varied over time. For example, if a ferromagnetic metal is magnetized to its maximum, or “saturation,” flux density in one direction in space and then the external magnetic field is slowly reversed to the opposite direction, the magnetic flux density within the metal will decrease as a function of the magnetic field intensity along a first path until the magnetic flux within the metal reaches the negative of the saturation value. If the external field is again reversed so as to remagnetize the metal in the original direction, the magnetic flux density within the metal will increase as a function of the magnetic field intensity along a second path which differs from the first path in relation to the reversal of the residual magnetic field. The shape of the resulting dual-path magnetization curve, which is referred to as a “hysteresis loop,” is characteristic of ferromagnetic behavior.
[0013] When a ferromagnetic metal is surrounded by a gas in the presence of a magnetic field, the ferromagnetic metal tends to “attract” the flux lines of the magnetic field away from the surrounding gas into itself. This prevents the flux lines from penetrating the ferromagnetic metal and extending through to the surrounding gas. While paramagnetic metals may “attract” some flux lines of an external magnetic field, they do so to a far lesser degree than do ferromagnetic materials.
[0014] Above their Curie temperatures, nominally ferromagnetic metals behave in a manner similar to paramagnetic materials. In particular, nominally ferromagnetic metals tend to “attract” far less of the flux of an external magnetic field into themselves above their Curie temperatures than below.
[0015] Thus, without wishing to be bound by any theory of operation, it is believed that a nickel sputter target placed in the magnetic field of a magnetron sputtering device tends to “attract” the flux of the magnetic field into itself. This prevents the magnetic flux from penetrating through the target, thereby reducing the efficiency of the magnetron sputtering process.
[0016] Typically, only thin nickel targets of about 0.12 inch (3 mm) or less could be used in magnetron sputtering processes due to the ferromagnetic character of nickel. This increases the difficulty and cost of sputtering nickel, since it is necessary to replace the sputter targets at frequent intervals.
[0017] Meckel U.S. Pat. No. 4,229,678 sought to overcome this problem by heating the target material to its Curie temperature and magnetron sputtering the material while in such a state of reduced magnetization. Meckel further proposed a magnetic target plate structured to facilitate heating of the plate to its Curie temperature by the thermal energy inherent in the sputtering process. One drawback to this proposed method was the increased cost inherent in providing for the heating of the target as well as providing for the stability of the cathode assembly at increased temperatures.
[0018] The problem of magnetron sputtering nickel has been addressed in the specialty media industry by alloying the nickel with another transition metal such as vanadium. At about 12 at. % vanadium, the alloy ceases to behave ferromagnetically. Alloys of nickel with other transition metals such as chromium, molybdenum and titanium have shown a loss of ferromagnetic behavior at compositions under 15 at. %. Adopting a similar approach, Wilson U.S. Pat. No. 4,094,761 proposed alloying nickel with copper, platinum or aluminum to produce an alloy having a Curie temperature below the sputtering temperature. Unfortunately, all of these methods share the drawback that the metals alloyed with the nickel constitute impurities when the sputter target is used in a nickel silicidation process.
[0019] Therefore, there remains need in the art for a method for making a nickel sputter target which is compatible with magnetron sputtering processes.
SUMMARY OF THE INVENTION
[0020] These and other objects of the invention are met by a method for making a nickel/silicon sputter target including the step of blending molten nickel with sufficient molten silicon so that the blend may be cast to form an alloy containing no less than 4.5 wt % silicon, preferably about 4.5-50 wt % Si. The cast ingot is then shaped by rolling it to form a plate having a desired thickness and then the rolled plate is machined to form the desired target shape. The sputter target so formed is capable of use in a conventional magnetron sputter process; that is, it can be positioned near a cathode in cathodic sputtering operations, in the presence of an electric potential difference and a magnetic field so as to induce sputtering of nickel ion from the sputter target onto the substrate. However, these targets can be made thicker than conventional Ni targets so that they may be used for longer sputtering times without replacement.
[0021] Nickel-silicon alloy sputter targets in accordance with the invention have been found to exhibit sufficiently low Curie temperatures that their behavior at conventional sputtering temperatures is thought paramagnetic rather than ferromagnetic. Thus, the magnetizations of targets having thicknesses as large as 0.5 inch (1.3 cm) are sufficiently low that the targets may be used in conventional magnetron sputtering processes. Furthermore, the nickel/silicon alloy does not introduce any impurities when the target is used for nickel silicidation.
[0022] In addition, it has been found that rolling the ingot formed from casting the nickel-silicon alloy before machining the target promotes the deposition of a uniform layer of nickel silicide during the sputtering process.
[0023] Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a chart showing the magnetization curves for cast nickel, nickel-2.9 wt % silicon and nickel-4.5 wt % silicon ingots;
[0025] [0025]FIG. 2 is a chart showing the penetration of magnetic flux through nickel and nickel-4.39 wt % silicon plates of various thicknesses; and
[0026] [0026]FIG. 3 is a schematic diagram illustrating the face-centered cubic structure of pure nickel metal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] In accordance with an especially preferred method for making a sputter target, nickel and silicon are blended as powders or small blocks in a crucible and melted in an induction or resistance furnace. Preferably, the blend is then cast to form an ingot containing at least about 4.5 wt % silicon. The ingot is rolled to form a plate having a desired thickness (i.e., greater than 0.12 inch (3 mm)). Finally, the plate is machined to form the target.
[0028] The nickel and silicon may be blended either in the form of powders or of small blocks. Preferably, the blending occurs in a crucible, which may be inserted into an induction or resistance furnace to melt the nickel and silicon. For example, the nickel may be introduced in the form of 1 cubic inch blocks which are melted in a crucible before blending with the silicon.
[0029] The casting, rolling and machining of the metal may be carried out by conventional means well known to those of ordinary skill in the art.
[0030] The alloy should contain sufficient nickel to form an effective nickel silicide film when sputtered. Thus, it is preferred that the alloy not exceed an upper limit, perhaps on the order of 50 wt %.
[0031] The invention will be further described by means of the following examples, which are illustrative only and not limitative of the invention as claimed.
EXAMPLE 1
[0032] Three 10 g blends of nickel and silicon powders were prepared, melted in crucibles and cast to form pure nickel, nickel-2.9 wt % silicon and nickel-4.5 wt % silicon alloy ingots. Differential thermal analyses were performed to verify these compositions. After the compositions were verified, a VSM was used to obtain the magnetization curves for each of the three compositions.
[0033] The results are shown in FIG. 1. In the chart shown in FIG. 1, the horizontal axis 10 represents the magnetic field intensity (“H”) within the ingot while the vertical axis 12 represents the magnetic flux density (“B”) within the ingot. The magnetization curve 20 corresponds to the pure nickel ingot and the magnetization curve 22 corresponds to the nickel-2.9 wt % silicon alloy. While the saturation magnetic flux density of the nickel-2.9 wt % silicon alloy is about half the saturation level of the pure nickel, both of the magnetization curves 20 , 22 feature significant hystersis indicative of ferromagnetic behavior.
[0034] On the other hand, the magnetization curve 24 , which corresponds to the nickel-4.5 wt % silicon alloy, exhibits no significant hysteresis and appears approximately linear with a gentle slope. Thus, the magnetization curve 24 shows that the behavior of the nickel-4.5 wt % silicon alloy was paramagnetic rather than ferromagnetic. This result, along with the gentle slope of the magnetization curve 24 , implies that the nickel-4.5 wt % silicon alloy is a suitable target material for a magnetron sputtering process.
EXAMPLE 2
[0035] In order to illustrate this further, a nickel-silicon alloy ingot was formed by melting and casting a blend of nickel and silicon powders. The composition of the alloy was shown by atomic absorption to be nickel-4.39 wt % silicon. Under variable source magnetometry, this alloy was found to exhibit slight hysteresis, as shown in FIG. 1 by its magnetization curve 26 .
[0036] Plates of various thicknesses were prepared from pure cast nickel and from the nickel-4.39 wt % silicon alloy. The percentage of the magnetic flux which penetrated through these plates was then measured as a function of the plate thickness.
[0037] The results are shown in FIG. 2. The horizontal axis 30 in FIG. 2 represents plate thickness in inches while the vertical axis 32 represents the measured percentage of the original flux density which penetrated the plate. The line 40 represents the penetration of the magnetic flux through the nickel plates while the line 42 represents the penetration through the nickel-4.39 wt % silicon plates. At approximately 0.14 inch (3.5 mm) thickness, the magnetic penetration of the nickel was approximately 71%. By way of comparison, the magnetic penetration of the nickel-4.39 wt % silicon alloy at a thickness of 0.125 inch (3.2 mm) was greater than 96%.
[0038] Even at a thickness of 0.5625 inch (1.53 cm), approximately 90% of the magnetic flux penetrated through the nickel-4.39 wt % silicon alloy. While the magnetic flux penetration through the nickel-4.39 wt % silicon alloy decreased approximately linearly with increasing thickness, these results imply the suitability of sputter targets, made in accordance with the invention and having thicknesses as great as 0.5 inch (1.5 cm), for use in magnetron sputtering processes.
EXAMPLE 3
[0039] A nickel-4.5 wt % silicon ingot was cast and rolled to a thickness of 3.5 inch (8.9 cm). Slices were cut before and after the rolling process for scanning electron microscopy/optical microstructure analysis (“SEM”). An X-ray diffraction (“XRD”) study also was made of the rolled sample. In addition, sputter targets having a 3 inch (7.6 cm) diameters were machined from the alloy before and after rolling.
[0040] By way of background, a metallic sputter target typically comprises a plurality of “grains” of a size visible under an optical microscope. Within each grain, the metal atoms align in a crystalline matrix.
[0041] Pure nickel typically crystallizes in a “face-centered cubic” matrix. Each nickel atom in the face-centered cubic matrix is typically surrounded by twelve other equally spaced nickel atoms. As shown in FIG. 3, the crystalline structure of pure nickel can be illustrated by means of a so-called “unit cell” 50 which includes a first set of nickel atoms 52 at each of the comers of an imaginary cube 54 and a second set of nickel atoms 56 centered on the faces of the imaginary cube 54 .
[0042] An indication of the true size of the unit cell 50 is given by the “lattice parameter,” which is the length of one of the sides of the imaginary cube 54 . The lattice parameter for a unit cell of pure nickel is approximately 3.524 Å.
[0043] Two sets of planes relative to the crystalline matrix are specifically indicated on the unit cell 50 of FIG. 1: so-called “(200) planes” parallel to the sides of the imaginary cube 54 and so-called “(111) planes” which form diagonals relative to the sides of the cube 54 . Examples of (200) planes are shown at 60 and examples of (111) planes are shown in phantom at 62 . Since the unit cell 50 is symmetric with respect to a center point (not shown) of the imaginary cube 54 , each of the (200) planes 60 is physically equivalent to each of the other (200) planes. Likewise, each of the (111) planes 62 is physically equivalent to each of the other (111) planes.
[0044] Note that the atoms 52 , 56 in the unit cell 54 are more closely packed along the (111) planes 62 than along the (200) planes. The distance between these close-packed ( 111 ) planes 62 coincides with the so-called “d-spacing” of the lattice, which in the case of pure nickel is approximately 2.034 Å.
[0045] The SEM studies of the slices taken from the nickel-4.5 wt % silicon alloy before and after rolling showed that the grain sizes in the as-rolled slice were more uniform than those in the slice taken prior to rolling. It has been found that more uniform grain sizes tend to promote the deposition of more uniform film during sputtering processes.
[0046] The XRD study of the as-rolled material revealed that the material showed a preferred (200) orientation as opposed to a (111) orientation. The d-spacing of the as-rolled alloy was found to be 2.0354 Å, which corresponds closely to the d-spacing of pure nickel. This latter observation suggests a minimum of matrix deformation which might interfere with the deposition of a uniform film during sputtering.
EXAMPLE 4
[0047] The nickel-4.5 wt % silicon sputter targets prepared in Example 3 were mounted on magnetron-type cathodes for use in a DC sputtering system. A base pressure of 5.7×10 −7 Torr was achieved using a cryopump. Silicon substrates were placed below the targets and sputtered at ambient heat. The targets were sputtered in a 6 m Torr argon atmosphere at 150 W DC sputtering power. The flow of argon and the total gas pressure were manually adjusted by mass flow controllers and monitored with a capacitive manometer. After the sputtering was completed, portions of the as-deposited films were annealed under a positive field of argon gas at 400° C. for 30 min. The process was found to produce satisfactory nickel silicide films on the silicon substrates.
[0048] The foregoing examples demonstrate that the magnetizations of nickel-silicon alloy sputter targets in accordance with the invention having thicknesses as large as 0.5 inch (1.3 cm) are sufficiently low that the targets may be used in conventional magnetron sputtering processes. In addition, it has been found that rolling the ingots formed from casting the nickel-silicon alloys before machining the target promotes the formation of uniform grain sizes in the alloys, which, in turn, promotes the deposition of uniform layers of nickel silicide during the sputtering processes. Since no transition metals are alloyed with the nickel to lower its Curie temperature, no impurities are introduced when such targets are used in nickel silicidation processes.
[0049] While the method described herein and the sputter targets produced in accordance with the method constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise methods and sputter targets, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims. | A method for making a nickel/silicon sputter target, targets made thereby and sputtering processes using such targets. The method includes the step of blending molten nickel with sufficient molten silicon so that the blend may be cast to form an alloy containing no less than 4.5 wt % silicon. Preferably, the cast ingot is then shaped by rolling it to form a plate having a desired thickness. Sputter targets so formed are capable of use in a conventional magnetron sputter process; that is, one can be positioned near a cathode in the presence of an electric potential difference and a magnetic field so as to induce sputtering of nickel ion from the sputter target onto the substrate. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 USC §119 of the filing date of PCT Application No. PCT/USoo/14750, filed May 26, 2000, the disclosure of which is incorporated herein by this reference.
BACKGROUND
[0002] The present invention relates generally to operations performed and equipment utilized in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides well instrumentation, logging, monitoring and control using webservers.
[0003] In many situations it is advantageous to be able to remotely monitor and control aspects of a subterranean well. For example, well tools positioned in the well might be operated without requiring intervention into the well and without requiring the use of certain equipment, such as pumps, to apply pressure to the tools, etc. Well conditions might be monitored at a remote location, so that personnel do not have to physically travel to the well, and so that well data is available when needed at any location. Complex and/or hazardous operations, such as drill stem tests, might be monitored and controlled by a person or persons having special expertise in these operations at a remote location. These are but a few of the advantages of remotely monitoring and controlling a well.
[0004] Past attempts to provide such remote monitoring and control have only gone so far. That is, these attempts have fallen short of the goal of providing world-wide access to well data and to the tools needed to actually control equipment at the well. For example, some attempts to provide remote well monitoring and control have required that an operator utilize a specially configured control terminal which communicates via a proprietary system, etc.
[0005] What is needed is a well monitoring and control system which enables an operator anywhere in the world to monitor well data and/or to control equipment at the well using readily available facilities, such as a standard computer or terminal and a connection to the Internet or other network. A similar system might also be used to perform well tool diagnostics or other operations.
SUMMARY
[0006] In carrying out the principles of the present invention, in accordance with an embodiment thereof, a well monitoring and control system is provided which utilizes the Internet or other network to permit remote monitoring and control of aspects of the well. A webserver included in a well tool supports a website accessible by an operator having a connection to the Internet or other network.
[0007] In one aspect of the present invention, a well tool is provided that includes a sensor and/or an actuator. The sensor and/or actuator is connected to a webserver of the tool. The webserver is connected to a network. If a sensor is used, signals generated by the sensor are accessible at a remote location via the network. If an actuator is used, the actuator is controllable from the remote location via the network.
[0008] Multiple well tools may be used in a well, in which case each well tool may include a webserver and a sensor and/or actuator. The well tools may be independently monitored and/or controlled via a network connected to the webserver.
[0009] In another aspect of the present invention, surface equipment associated with a well may be monitored and/or controlled from a remote location using a system provided herein. An item of surface equipment may include a webserver connected to a sensor and/or actuator. The webserver is connected to a network. If a sensor is used, signals generated by the sensor are accessible at a remote location via the network. If an actuator is used, the actuator is controllable from the remote location via the network.
[0010] In yet another aspect of the present invention, logging tools may be monitored and/or controlled from a remote location using a system provided herein. A logging tool may include a webserver connected to a sensor and/or actuator. The webserver is connected to a network. If a sensor is used, signals generated by the sensor are accessible at a remote location via the network. If an actuator is used, the actuator is controllable from the remote location via the network.
[0011] In still another aspect of the present invention, a well tool may be tested from a remote location using a system and method provided herein. A webserver of the tool is connected to a network. One or more sensors may sense fluid properties proximate the tool and/or sense the position of one or more structures of the tool, etc. The webserver and sensors are connected to a test control module, which is also connected to one or more items of test equipment. The item of test equipment maybe operated remotely, for example, to apply pressure to the tool, via the network.
[0012] In a further aspect of the present invention, various methods may be utilized for communicating between the webserver and the network. A fiber optic line, a wireline, acoustic telemetry or a satellite uplink may serve as a part of a communication path between the webserver and the network. If a fiber optic line is used, the present invention provides a cable uniquely suited for use in a subterranean well.
[0013] These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic view of a well tool embodying principles of the present invention;
[0015] [0015]FIG. 2 is a schematic block diagram of a method of communicating between the well tool and a network, the method embodying principles of the present invention;
[0016] [0016]FIG. 3 is a partial side elevational view of a first cable for use with the well tool of FIG. 1, the first cable embodying principles of the present invention;
[0017] [0017]FIG. 4 is a cross-sectional view of the first cable, taken along line 4 - 4 of FIG. 3;
[0018] [0018]FIG. 5 is a cross-sectional view of a second cable embodying principles of the present invention;
[0019] [0019]FIG. 6 is a cross-sectional view of a third cable embodying principles of the present invention;
[0020] [0020]FIG. 7 is a cross-sectional view of a fourth cable embodying principles of the present invention;
[0021] [0021]FIG. 8 is a schematic partially cross-sectional view of a well tool monitoring and control system embodying principles of the present invention;
[0022] [0022]FIG. 9 is a schematic partially cross-sectional view of a surface equipment monitoring and control system embodying principles of the present invention;
[0023] [0023]FIG. 10 is a schematic partially cross-sectional view of a well monitoring and control system embodying principles of the present invention;
[0024] [0024]FIG. 11 is a schematic partially cross-sectional view of a well monitoring system embodying principles of the present invention.
[0025] [0025]FIG. 12 is a schematic partially cross-sectional view of a well logging system embodying principles of the present invention;
[0026] [0026]FIG. 13 is a schematic view of an alternate communication method that may be used in conjunction with any of the described systems; and
[0027] [0027]FIG. 14 is a schematic partially cross-sectional view of a method of remotely testing a well tool.
DETAILED DESCRIPTION
[0028] Representatively illustrated in FIG. 1 is a well tool 10 which embodies principles of the present invention. In the following description of the well tool 10 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
[0029] As depicted in FIG. 1, the well tool lo facilitates monitoring of well conditions from a remote location. However, it is to be clearly understood that other types of well tools may embody principles of the present invention. The well tool 10 may be appropriately configured for interconnection in a tubular string in a well by, for example, providing threaded connections at each end of the tool.
[0030] The well tool 10 includes two pressure and temperature sensors 12 , 14 . Preferably, the sensors 12 , 14 are conventional quartz pressure and temperature gauges, although other types of sensors may be used in the well tool 10 . The sensor 12 is connected to an internal flow passage 16 of the well tool 10 via a fluid passage 18 , so that properties of fluid in the flow passage 16 may be sensed by the sensor. The sensor 14 is connected to the exterior of the well tool 10 via a fluid passage 20 , so that properties of fluid external to the well tool may be sensed by the sensor. Thus, the pressure and temperature of fluids internal and external to the well tool 10 may be sensed by the sensors 12 , 14 . Of course, additional or alternate sensors may be provided in the well tool 10 to sense other properties, such as resistivity, water cut, density, etc.
[0031] The sensors 12 , 14 are connected to a webserver 22 . Preferably, the webserver 22 is an integrated circuit or “chip”, such as an Agilent model 11501, which is capable of supporting a web page on the Internet or other network. The Agilent model 11501 webserver is a network capable application processor which conforms to the IEEE 1451.2 industry standard. In this manner, signals generated by the sensors 12 , 14 are accessible on the web page, so that a person at a remote location may conveniently monitor the signals by merely going to the web page on the network.
[0032] A cable 24 provides a communication path between the well tool 10 and a remote location when the tool is positioned in a well. In the embodiment representatively illustrated in FIG. 1, the cable 24 includes one or more fiber optic lines for communication between the webserver 22 and the remote location. Accordingly, the well tool 10 includes a converter 26 for converting electrical signals generated by the webserver 22 into optical signals for transmission via the fiber optic line(s) of the cable 24 . Preferably, the converter 26 is a Versitron model M7235(10 base T) or M7245(10 base T), which utilize the conventional ethernet communication standard. However, it is to be clearly understood that the webserver 22 could communicate directly with the remote location via an electrical conductor, another converter could be used and another communication standard could be used, without departing from the principles of the present invention.
[0033] Referring additionally now to FIG. 2, a schematic block diagram of a method 28 of communicating between the well tool 10 and a network 30 is representatively illustrated, the method embodying principles of the present invention. In FIG. 2, it may be seen that the cable 24 extends to another converter 32 , which is in communication with the network 30 via a further communication path 34 . The converter 32 may be the same type as the converter 26 , but the converter 32 preferably converts optical signals on the cable 24 to electrical signals for transmission on the communication path 34 , which preferably includes one or more electrical conductors.
[0034] The communication path 34 from the converter 32 to the network 30 may be located, for example, at the earth's surface. The network 30 may be accessed via a computer terminal or other device, etc. (not shown), in which case the communication path 34 would be connected to the device, and the device would be connected to the network. Thus, signals generated by the sensors 12 , 14 are communicated to the webserver 22 , the webserver incorporates the signals (or a translated form thereof) into a web page supported by the webserver, and the webserver communicates with the network 30 using the converters 26 , 32 and communication paths 24 , 34 . Of course, if it is not desired to use optical signals, then the converters 26 , 32 may not be used.
[0035] Referring additionally now to FIGS. 3 - 7 , various configurations of cables that may be used for the cable 24 in the well tool 10 and method 28 described above are representatively illustrated. Of course, other types of cables may be used, without departing from the principles of the present invention. Each of the illustrated cables utilizes a fiber optic package 36 commercially available from ArmorTech. In this package 36 , multiple fiber optic lines 38 are hermetically sealed within a tubular material 40 . Preferably, the material 40 is metallic for strength and durability, for example, the material maybe steel or inconel.
[0036] A first cable 42 is depicted in FIGS. 3 & 4, with FIG. 4 illustrating a crosssection of the cable taken along line 4 - 4 of FIG. 3. In FIG. 3 it may be seen that the cable 42 includes a helically wrapped outer protective material 44 . The material 44 may be steel or another suitably strong and abrasion resistant material.
[0037] In FIG. 4 it may be seen that the cable 42 further includes two electrical conductors 46 , which may be used for communication, for supplying power to the well tool 10 for operation of the converter 26 and sensors 12 , 14 , or for other purposes. Each conductor 46 is supplied with insulation 48 . A filler material 50 occupies the spaces between the outer protective material 44 and the fiber optic package 36 and the conductors 46 and insulation 48 . The filler material 50 may be any suitable material, such as rubber, fluorocarbon, etc., and may be a dielectric material.
[0038] A cross-section of another cable 52 is depicted in FIG. 5. The cable 52 includes the fiber optic package 36 and a tubular conductor 54 disposed about the fiber optic package. The conductor 54 is, in turn, enveloped by a filler material 56 , which may be similar to the filler material 50 described above. A tubular outer protective material 58 outwardly surrounds the remainder of the cable 52 . The protective material 58 may be made of steel or another suitably strong and durable material, and the protective material may be in a solid tubular form, or may be helically wrapped as described above for the protective material 44 .
[0039] A cross-section of yet another cable 60 is depicted in FIG. 6. The cable 60 is similar in many respects to the cable 42 described above, and the same reference numbers are used in FIG. 6 to indicate similar elements. However, the cable 60 differs from the cable 42 at least in part in that the cable 60 does not include the filler material 50 , and an outer tubular protective material 62 of the cable 60 is depicted as being in a solid tubular form, rather than being helically wrapped as described above for the protective material 44 . Of course, the protective material 62 could be helically wrapped, without departing from the principles of the present invention.
[0040] A cross-section of still another cable 64 is depicted in FIG. 7. The cable 64 is similar in many respects to the cable 42 described above, and the same reference numbers are used in FIG. 7 to indicate similar elements. However, the cable 64 differs from the cable 42 at least in part in that the conductors 46 do not have the insulation 48 disposed thereabout, and an outer tubular protective material 66 of the cable 64 is depicted as being in a solid tubular form, rather than being helically wrapped as described above for the protective material 44 . Of course, the protective material 66 could be helically wrapped, without departing from the principles of the present invention.
[0041] Referring additionally now to FIG. 8, a well monitoring and control system 68 embodying principles of the present invention is schematically and representatively illustrated. In the system 68 , multiple well tools 70 , 72 , 74 are interconnected in a tubular string 76 positioned in a wellbore 78 . Each of the well tools 70 , 72 , 74 includes a flow control device, with the well tool 70 including a flow control device 80 operative to control the flow of fluid through the tubular string 76 , and each of the well tools 72 , 74 including a flow control device 82 operative to control the flow of fluid between the wellbore 78 and respective earthen formations or zones 84 , 86 intersected by the wellbore.
[0042] Each of the well tools 70 , 72 , 74 further includes a respective actuator 88 , 90 , 92 for operating the corresponding flow control device 80 or 82 . The actuators 88 , 90 , 92 maybe electrically, hydraulically or otherwise operated.
[0043] Each of the well tools 70 , 72 , 74 also includes a respective webserver 94 , 96 , 98 . In FIG. 8, each of the webservers 94 , 96 , 98 is shown schematically alongside the respective actuator 88 , 90 , 92 and flow control device 80 or 82 , in order to conveniently illustrate connections between the webservers, actuators and devices, but it should be understood that in actual practice the webservers would be positioned internally, rather than externally, in the well tools 70 , 72 , 74 .
[0044] The webserver 94 is connected to a sensor (not shown) of the flow control device 80 . For example, the device 80 may include a pressure and temperature sensor, such as the sensors 12 , 14 described above. Alternatively, the device 80 may include a position sensor for sensing the position of a closure structure of the device to indicate whether the device is open or closed to fluid flow therethrough. Examples of the use of such sensors are depicted in FIG. 14 and described more fully below.
[0045] The webserver 94 is further connected to the actuator 88 for controlling operation of the actuator. For example, if the actuator 88 is electrically operated, the webserver 94 may be connected to a switch (not shown) or other electrical component of the actuator. As another example, if the actuator 88 is hydraulically operated, the webserver 94 may be connected to an electrically operated pilot valve (not shown) or other component of the actuator.
[0046] In a similar manner, each of the webservers 96 , 98 is connected to one or more sensors of the corresponding flow control device 82 and to the associated actuator 90 , 92 . Thus, the webserver 96 is used to monitor the sensor(s) of the corresponding device 82 and to control operation of the actuator go, and the webserver 98 is used to monitor the sensor(s) of the corresponding device 82 and to control operation of the actuator 92 .
[0047] Each of the webservers 94 , 96 , 98 is connected via a communication path, such as a cable 100 , to the Internet 102 or another network. Of course, other types of communication paths may be used, such as acoustic telemetry, electromagnetic telemetry, etc., for connecting the webservers 94 , 96 , 98 to the Internet 102 .
[0048] Each of the webservers 94 , 96 , 98 supports a web page on the Internet 102 . Thus, a person at a remote location can go to a web page supported by one of the webservers 94 , 96 , 98 and monitor signals generated by the sensor(s) of the corresponding well tool 70 , 72 , 74 . In addition, a corresponding one of the actuators 88 , 90 , 92 may be controlled via the respective web page to operate the associated device 80 or 82 . Thus, in the system 68 , a person with a connection to the Internet 102 at a remote location may, for example, monitor a pressure drop across or a flow rate through the device 80 and, based on this information, operate the actuator 88 to adjust the pressure drop or flow rate, or to close the device, as desired.
[0049] Referring additionally now to FIG. 9, a surface equipment monitoring and control system 104 embodying principles of the present invention is schematically and representatively illustrated. In the system 104 , multiple items of surface equipment 106 , 108 , 110 , 112 are positioned at the earth's surface. The surface equipment 106 , 108 , 110 , 112 may be any type of surface equipment used in conjunction with operations performed at a wellsite. For example, the surface equipment 106 , 108 , 110 , 112 may include separators, burners, pumps, chokes, blowout preventers, valves, etc., for use in operations such as drill stem tests.
[0050] Each of the items of surface equipment 106 , 108 , 112 includes at least one respective sensor 114 , 116 , 118 , 120 and at least one respective actuator 122 , 124 , 126 , 128 . However, it is to be clearly understood that it is not necessary in keeping with the principles of the present invention for every item of surface equipment in a system to include both an actuator and a sensor. For example, an item of surface equipment could include only a sensor or only an actuator, or another element which may be monitored or controlled.
[0051] Each of the items of surface equipment 106 , 108 , 110 , 112 also includes a respective webserver 130 , 132 , 134 , 136 . Each of the webservers 130 , 132 , 134 , 136 is connected to the respective sensor 114 , 116 , 118 , 120 and actuator 122 , 124 , 126 , 128 of the associated item of surface equipment 106 , 108 , 110 , 112 . Each of the webservers 130 , 132 , 134 , 136 is further connected via a communication path 138 to a conventional intranet webserver 140 and thence via another communication path 141 to the Internet 142 or another network. The intranet webserver 140 serves as an interface between a local area network (not shown) and the Internet 142 in a manner well known to those skilled in the art. The intranet webserver 140 is also known to those skilled in the art as a “gateway webserver”.
[0052] Each of the webservers 130 , 132 , 134 , 136 supports a web page on the Internet 142 . Thus, a person at a remote location can go to a web page supported by one of the webservers 130 , 132 , 134 , 136 and monitor signals generated by the sensor 114 , 116 , 118 or 120 of the corresponding item of surface equipment 106 , 108 , 110 or 112 . In addition, a corresponding one of the actuators 122 , 124 , 126 , 128 may be controlled via the respective web page to operate the associated item of surface equipment 106 , 108 , 110 , 112 . Thus, in the system 104 , a person with a connection to the Internet 142 at a remote location may, for example, monitor one of the sensors 114 , 116 , 118 , 120 and, based on this information, operate the corresponding actuator 122 , 124 , 126 , 128 to adjust an operating parameter of the associated item of surface equipment 106 , 108 , 110 , 112 , as desired.
[0053] Note that the system 104 may also include a webserver 144 , sensor 146 and actuator 148 included in a well tool 150 positioned in the well. For example, if the system 104 is utilized in a drill stem test operation, the well tool 150 may be a tester valve which is selectively opened or closed to permit or prevent fluid flow therethrough in pressure buildup and drawdown phases of the drill stem test. The webserver 144 is also connected to the Internet 142 , so that signals generated by the sensor 146 may be monitored, and the actuator 148 maybe controlled, by a person connected to the Internet 142 at a remote location and accessing a web page supported by the webserver.
[0054] Referring additionally now to FIG. 10, a well monitoring and control system 152 embodying principles of the present invention is schematically and representatively illustrated. The system 152 incorporates some of the features of the systems 68 , 104 described above. Specifically, in the system 152 , items of surface equipment including sensors and/or actuators connected to webservers are represented in FIG. 10 by the block 154 . The webservers of the surface equipment 154 are connected to an intranet webserver 156 which is, in turn, connected to the Internet 158 or other network. A computer terminal 160 is shown connected to the Internet 158 for accessing any of the web pages supported by any of the webservers of the system 152 .
[0055] The system 152 also includes multiple well tools 162 , 164 , 166 positioned in a wellbore 168 . Each of the well tools 162 , 164 , 166 includes a webserver 170 connected to sensors 172 , 174 , 176 and actuators 178 of the well tools. The sensors 172 sense pressure and temperature of fluid internal to a tubular string 180 in which the well tools 162 , 164 , 166 are interconnected, and the sensors 174 sense pressure and temperature of fluid external to the tubular string. Note that a pair of the sensors 172 and a pair of the sensors 174 are positioned at upper and lower ends of each of the well tools 162 , 164 , 166 . The sensors 176 are position sensors used for monitoring the position of a structure 182 , such as a sleeve, which is displaced by the actuator 178 when the corresponding well tool 162 , 164 , 166 is operated. The webservers 170 are connected via a communication path 184 to the intranet server 156 and thence to the Internet 158 .
[0056] The well tools 162 , 164 , 166 are representatively depicted in FIG. 10 as variable chokes. The actuator 178 of each well tool 162 , 164 , 166 displaces the sleeve 182 to produce a desired flow rate of fluid produced from a respective one of formations or zones 186 , 188 , 190 intersected by the wellbore 168 . The position of the sleeve 182 , and the pressure and temperature of fluid above, below, internal and external to each of the well tools 162 , 164 , 166 are readily accessible to a person at a remote location via the computer 160 connected to the Internet 158 . The person at the remote location may also operate the actuator 178 of a well tool 162 , 164 , 166 to, for example, adjust the position of the sleeve 182 of a selected one of the well tools 162 , 164 , 166 to thereby adjust the rate of fluid flow therethrough.
[0057] Referring additionally now to FIG. 11, a well monitoring system 192 embodying principles of the present invention is schematically and representatively illustrated. In the system 192 , a sensor 194 , such as a pressure and temperature sensor, is connected to a webserver 196 included in a well tool 198 positioned in a wellbore 200 . The well tool 198 communicates with another tool 202 at a remote location.
[0058] The tools 198 , 202 communicate with each other using acoustic telemetry, for example, by transmitting acoustic waves through a tubular string 204 and/or fluid internal or external to the tubular string. Such acoustic telemetry is well known to those skilled in the art and may be similar to that used in the ATS (Acoustic Telemetry System) commercially available from Halliburton Energy Services, Inc. The acoustic telemetry between the tools 198 , 202 serves as a part of a communication path connecting the webserver 196 to the Internet 206 or other network. Note that acoustic telemetry may serve as a part of any of the communication paths between webservers and the Internet in any of the systems and methods described herein.
[0059] Converters, such as the converters 26 , 32 described above, may be used in respective ones of the tools 198 , 202 so that the ethernet communication standard is used for communication between the tools. In addition, an intranet webserver, such as the intranet webservers 140 , 156 described above, may be interconnected between the tool 202 and the Internet 206 .
[0060] Referring additionally now to FIG. 12, a well logging system 208 embodying principles of the present invention is schematically and representatively illustrated. In the system 208 , a string of logging tools 210 is conveyed into a wellbore 212 via a wireline 214 . The wireline 214 also serves as a communication path between a webserver 216 of each logging tool and the Internet 218 or other network.
[0061] The logging tools 210 may be any type of logging tools, such as resistivity tools, gamma ray tools, magnetic field sensing tools, etc., or other types of tools, such as samplers, formation testers, video cameras, etc. The webservers 216 may be connected to sensor(s) and/or actuator(s) (not shown) of the tools 210 , so that a person at a remote location with a connection to the Internet 218 may conveniently monitor signals generated by the sensors and/or operate the actuators.
[0062] Referring additionally now to FIG. 13, an alternate communication method 220 that may be used in conjunction with any of the systems described herein is schematically and representatively illustrated. The method 220 is depicted as being used with the system 208 of FIG. 12, wherein a wireline 214 serves as a part of a communication path between the webservers 216 and the Internet 218 . In FIG. 13, the wireline 214 is shown extending to a wireline truck or other type of wireline rig 222 .
[0063] The truck 222 is provided with a satellite uplink 224 for communication via satellite with the Internet 218 or other network. It will be readily appreciated by one skilled in the art that such a satellite uplink 224 may be used as a part of a communication path between any of the webservers described herein and the Internet or other network in any of the systems described herein.
[0064] Referring additionally now to FIG. 14, a well tool diagnostic system 226 embodying principles of the present invention is schematically and representatively illustrated. In FIG. 14, the system 226 is depicted as being utilized in conjunction with testing a well tool 228 which includes a ball valve 230 for selectively permitting and preventing fluid flow through an inner flow passage 232 of the tool. However, it is to be clearly understood that other types of well tools may be tested using the system 226 , without departing from the principles of the present invention.
[0065] The well tool 228 further includes a webserver 234 and sensors 236 , 238 , 240 . The sensors 236 , 238 are pressure sensors for sensing the pressure of fluid in the flow passage 232 . One of the sensors 236 is connected to the passage 232 above the ball valve 230 , and the other sensor 238 is connected to the passage below the ball valve. In this manner, a pressure differential, if any, across the ball valve 230 may be detected. The sensor 240 is a position sensor used to detect the position of the ball valve 230 . Of course, other types of sensors, such as a camera, flowmeter, etc., may be used in place of, or in addition to, the sensors 236 , 238 , 240 depicted in FIG. 14.
[0066] The sensors 236 , 238 , 240 and the webserver 234 are connected to a test control module 242 . The control module 242 is also connected to an item of test equipment 244 , such as a pump for applying pressure to the passage 232 . The control module 242 acts as an interface between the sensors 236 , 238 , 240 , the test equipment 244 and the webserver 234 . Alternatively, the webserver 234 could be connected directly to the sensors 236 , 238 , 240 and the test equipment 244 .
[0067] The webserver 234 is connected to the Internet 246 or other network. The webserver 234 supports a web page on the Internet 246 , which may be accessed by a person at a remote location with a connection to the Internet. In this manner, the person at the remote location may monitor the signals generated by the sensors 236 , 238 , 240 and may operate the test equipment 244 to thereby test the functionality of the well tool 228 and/or diagnose a problem encountered in testing the tool.
[0068] Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims. | Apparatus and methods for webserver-based well instrumentation, logging, monitoring and control provide convenience and economy in well site and off-site operations. In a described embodiment, a well tool includes a webserver connected to a sensor and an actuator of the tool. In response to a condition sensed by the sensor, a person utilizing a network to access a web page supported by the webserver at a remote location may operate the actuator to control operation of the well tool. | 6 |
[0001] This application claims priority of U.S. provisional patent application No. 60/265,180, filed Jan. 30, 2001 and entitled “System Architecture and Methods of Building Low-Power, Dynamically Reconfigurable, And Reliable Online Archival System,” which is hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates generally to data storage, and more specifically, to an online archival disk-based data storage system with algorithms for reducing power consumption, improving disk longevity and reliability, and maintaining data integrity.
BACKGROUND OF THE INVENTION
[0003] With the increasing popularity of Internet commerce and network centric computing, businesses and other entities are becoming more and more reliant on information. Protecting critical data from loss due to human errors, software errors, system crashes, virus attack and the like is therefore of primary importance. Data archival systems are typically used in information systems to restore information in the event of a failure or error. Tape drives and/or write-able CD drives have historically been the storage medium of choice for data archival systems. Magnetic disk based archival storage systems have generally not been considered for long term storage because the lifetime of disks is relatively short and their power consumption is high compared to magnetic tape or write-able CDs.
[0004] Magnetic disks are typically used as primary storage for information infrastructures and as storage drives in personal computers, laptop computers, servers, and the like. A number of power saving techniques have been proposed for laptop computers. Software controlled power saving modes have been used to control power consumption during periods of inactivity. Adaptive algorithms which analyze access patterns to adaptively determine when to spin disks up or down to reduce power consumption. Such algorithms, however, usually focus on reducing the power consumption of laptop computers whose disks are specifically designed to spin up and spin down more times than required during the typical life expectancy of a laptop computer. Disks for desktops or servers are usually engineered to handle a limited number of starts and stops. Applying the same power conservation methods used with laptop computers to disk-based archival systems would shorten disk lifetime. Furthermore, these power saving techniques do not address the problem of checking or maintaining the integrity of data stored on disks for extended periods of time.
[0005] An archival disk-based data storage system that reduces power consumption, improves disk longevity and reliability, and maintains data integrity for extended periods of time is therefore needed.
SUMMARY OF THE INVENTION
[0006] To achieve the foregoing, and in accordance with the purpose of the present invention, a disk-based archival storage system is disclosed. The system according to one embodiment includes a storage unit configured to store archival data, the storage unit including at least one spindle of disks configured to magnetically store archival data, an interconnect, and a control unit configured to process requests over the interconnect to either archive or retrieve data from the storage unit. In one embodiment, the system includes a plurality of the storage units, each including at least one spindle of disks. The control unit controls the storage unit(s) in a master-slave relationship. Specifically the control unit is capable of issuing commands to selectively cause the storage unit(s) to shut down or power up, enter a running mode or a standby mode, cause the spindle of disk(s) to either spin up or spin down, and to perform a data integrity check of all the archival data stored in the storage system. In various other embodiments, the control unit runs algorithms that expand the lifetime and longevity of the disk spindles, optimize power consumption, and perform data migration in the event a data integrity check identifies correctable errors. Hence for the first time, the present invention provides a disk-based storage system that practically can be used for data archival purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
[0008] [0008]FIG. 1 is a diagram of an exemplary information infrastructure in which the archival disk-based data storage system (hereafter storage system) of the present invention may be used.
[0009] [0009]FIG. 2 is a system diagram of the storage system of the present invention.
[0010] [0010]FIG. 3 is a system diagram of a storage unit provided in the storage system of the present invention.
[0011] [0011]FIG. 4 is a system diagram of a power controller provided in the storage system of the present invention.
[0012] [0012]FIG. 5 a is a flow diagram illustrating how the control unit of the archival disk-based data storage system manages the storage units with a competitive algorithm to process requests according to the present invention.
[0013] [0013]FIG. 5 b is a flow diagram illustrating how the control unit of the storage system manages the storage units with a competitive algorithm to optimize disk lifetime and power consumption according to the present invention.
[0014] [0014]FIG. 6 a is a flow diagram illustrating how the control unit of the storage system manages the storage units with an adaptive competitive algorithm to process requests according to the present invention.
[0015] [0015]FIG. 6 b is a flow diagram illustrating how the control unit of the storage system manages the storage units with an adaptive competitive algorithm to optimize disk lifetime and power consumption according to the present invention.
[0016] [0016]FIG. 7 is a flow diagram illustrating how the control unit of the storage system of the present invention performs data integrity checking and migration.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIG. 1, a diagram of an exemplary information infrastructure in which the archival disk-based data storage system of the present invention may be used is shown. The information infrastructure 10 includes a plurality of clients 12 and a server cluster 14 including one or more servers coupled together by a network 16 , a primary storage location 18 , the archival disk-based data storage system (hereafter “storage system”) 20 , and a network connection 19 coupling the primary storage location 18 and the storage system 20 . The clients 12 can be any type of client such as but not limited to a personal computer, a “thin” client, a personal digital assistant, a web enabled appliance, or a web enabled cell phone. The server(s) of server cluster 14 may include any type of server(s) configured as either a file server, a database server, or a combination thereof. Likewise, the network 16 can be any type of network. The primary storage location may be configured in any number of different arrangements, such as a storage array network, network attached storage, or a combination thereof. The primary storage location 18 may be either separate or part of the server cluster 14 . The network connection 19 can be any type of network connection, such as fiber channel, Ethernet, or SCSI.
[0018] Referring to FIG. 2, a system diagram of the storage system 20 is shown. The storage system 20 includes a control unit 22 , an interconnect 24 , a plurality of storage units (SUs) 26 , and a power controller 28 . The control unit 22 is a standard computer such as a personal computer that interfaces with primary storage location 18 over network 19 . The control unit 22 also operates as a master with respect to the storage units 26 and sends tasks to the storage units 26 , receives results from the storage units 26 , and controls the working modes of storage units 26 . The interconnect 24 can be either a custom-designed interconnect or a standard local area network capable of transmitting special commands or packets to the storage units 26 .
[0019] Referring to FIG. 3, a system diagram of a storage unit 26 is shown. Each storage unit 26 includes a controller 30 and one or more spindles of magnetic disks 32 . The storage unit 26 are slaves with respect to the control unit 22 . By responding to the commands of the control unit 22 over the, the controller 30 executes software that directs the storage unit 26 to shutdown or power up, change its modes between running and standby (sleep mode), and either spin up or down some or all of the magnetic disks 32 . The control unit 22 also commands the controller 30 to periodically perform data integrity checks of the data stored on its disks 32 . According to various embodiments of the invention, the magnetic disks 32 may assume a number of different configurations such as a Redundant Array of Independent Disks (RAID) or as individual disks in either a logical or physical arrangement.
[0020] Referring to FIG. 4, a system diagram of the power controller 28 is shown. The power controller includes a power input 40 for receiving power, a command input 42 for receiving an on/off command from the control unit 22 , an Input ID 44 for receiving an identity number input corresponding to one of the storage units 26 , and a number of power outputs 46 coupled to the storage units 26 respectively. In response to an on/off command and an identity number received from the control unit 22 at inputs 42 and 44 , the power controller 28 can selectively provide power from input 40 to the storage units 26 through power outputs 46 respectively.
[0021] The control unit 22 is responsible for moving archived and retrieved data between the primary storage location 18 and the storage units 26 . The control unit 22 maintains a directory of all the archived data stored in the storage system 20 . The directory includes a map of the data blocks for each of the storage units 26 in the system 20 . Each time data is either archived or retrieved, the accessed data block(s) and storage unit(s) 26 are updated in the directory. The control unit 22 also includes management software that controls the physical operation of the storage units 26 and the power controller 28 . For example, the control unit 22 under the direction of the management software issues commands to determine which storage units 26 should be used, how long each storage unit 26 should run, and when a storage unit 26 should do a data integrity check. Power on/off commands along with an identify number are sent to the inputs 42 and 44 of power controller 28 . Commands and/or packets are sent over the interconnect 24 by the control unit 22 to instruct an individual storage unit 26 to perform the requested task. In response, the controller 30 of the individual storage unit 26 executes software to perform the task.
[0022] An objective of the management software in control unit 22 is to maximize the lifetime of the storage units 26 and minimize their power consumption while providing a desirable response time. Keeping the storage units 26 running all the time provides the best response time, but will consume the maximum amount of power and shorten the lifetime of disks 32 . Simply turning off the storage units 26 immediately after each request and turning them on for each request is also a poor solution in terms of response time, lifetime of disks 32 , and power consumption. This scenario provides the worst response time because the storage units 26 will be turned off as soon as the current archival or retrieval job is complete. The lifetime of the disks 32 will be shortened because most disks other than those used for laptops are engineered to handle only a limited number of starts and stops (typically less than 50,000). Power consumption is not necessarily reduced because it takes much more power to spin up a disk than to perform normal operations. Therefore a strategy that optimizes disk lifetime, minimizes power consumption and provides desirable response times requires the advanced knowledge of request arrival times. Since it is impossible to know when future requests are going to occur, the best one can do is to derive an optimal off line strategy after the fact.
[0023] The present invention is a competitive algorithm implemented in the management software on the control unit 22 . The results of using this algorithm guarantees performance to be within a factor of two of the optimal offline case. H is the amount of time a storage unit 26 runs while waiting for another request before powering-off or entering standby. In other words, H is set to the duration of time where the life cost and power cost of an idle spinning disk approximately equals the life cost and power cost of a disk spin up and spin down cycle. The following equation (1) can therefore be used to define the value of H:
H = ( C SU N + C W × W Up × T Up ) / ( C SU L + C W × W RW ) ( 1 )
[0024] where:
[0025] C SU : the cost of the storage unit
[0026] C W : the cost per watt
[0027] L: the spin lifetime
[0028] N: the total number of start-and-stops
[0029] T Up : the time taken to spin up
[0030] W RW : the number of watts consumed for read or write operations, and
[0031] W Up : the number of watts consumed for a spin up.
[0032] Among these parameters, L and N are variable parameters that are initialized to the spin lifetime and start-and-stop limit as defined by the disk manufacturer. These values will decrease over time as the disks consume their spin lifetime and start-and-stop limits.
[0033] As noted an objective of the disk-based archival storage system 20 is to extend the lifetime of its disks. Each disk typically has a practical spin lifetime of three to five years. The error rate of a disk typically starts to increase significantly when the actual run time exceeds the spin lifetime of the disk. An important consideration therefore is to keep track of the remaining spin lifetime of a disk or a set of disks and to use this information to determine when to spin a disk down to extend its lifetime. A simple algorithm to extend disk lifetime is to spin down the disk as soon as a request is complete. Such an algorithm will preserve the remaining spin lifetime, but will typically provide an unacceptable response time following the next request. An improved algorithm that would generally provide better response times is to spin the disk for a small amount of time after each request. Since requests often have temporal locality, this algorithm seeks to improve response times at the expense of spin lifetime. Furthermore when a disk exceeds the start-and-stop limit, its error rate will typically increase significantly. Disks for desktops or servers usually have a limit of less than 50,000 start-and-stop times. To extend this lifetime, the start-and-stop limit of a disk should also be considered.
[0034] As is described in detail below, the present invention provides an algorithm that provides both excellent response times as well as helps extend the run time and the start and stop limit of the disks. With the algorithm of the present invention, a disk is kept spinning after each request for the amount of time equal to the lifetime of a start and stop. Since the remaining spin lifetime and the remaining start-and-stop limit change over time, the spin time needs to be recalculated after the completion of each request. In addition to lifetime, the algorithms of the present invention have the added benefit of reducing power consumption within an archival storage system 20 .
[0035] Referring to FIG. 5 a , a flow diagram 100 illustrating how the control unit 22 manages the storage units 26 with a competitive algorithm to process requests according to one embodiment of the invention is shown. For each storage unit (SU) 26 , the control unit 22 maintains several parameters including the current threshold value of H, the remaining-spin-lifetime L, remaining number of start-and-stops N, and the time-stamp of the last-request T (step 102 ). When the control unit 22 receives either an archival or retrieval request (step 104 ), it first allocates a storage unit 26 for an archival request or finds the appropriate storage unit 26 for a retrieval request using the directory of all the archived data stored in the storage system 20 (step 106 ). Thereafter the control unit 22 determines if the storage unit 26 is on (diamond 108 ). If the storage unit 26 is off or in standby mode (diamond 110 ), the control unit 22 issues commands to either power on or wake up the storage unit 26 (step 110 ). When the storage unit 26 is ready, the request will be sent (step 112 ) to that storage unit 26 . If the storage unit 26 is already on (diamond 108 ), the request is sent immediately to that storage unit 26 (step 112 ). After the request is processes by the storage unit 26 , it is reset and the values of SU.L and SU.T are all updated. SU.L or the remaining spin lifetime is calculated from the equation SU.L=SU.L−Time ( )+SU.T where SU.L is the previous spin lifetime value, and Time ( )+SU.T is the elapsed time since the previous request. SU.T is the time stamp of the current request. When another request occurs, control is returned back to step 104 .
[0036] Referring to FIG. 5 b , a flow diagram 200 illustrating how the control unit 22 manages the storage units 26 with a constant competitive algorithm to optimize disk lifetime and power consumption according to one embodiment of the invention is shown. The control unit 22 checks the status of all the running storage units 26 every k seconds (step 202 ). During this check, the control unit 22 sequences through storage units 26 , one at a time, and identifies which are running (step 204 ). For each running storage unit 26 , the control unit 22 computes an individual threshold SU.H using equation (1) as defined above (step 206 ). The control unit 22 then checks to determine if the threshold SU. H for each running storage unit 26 is greater than the elapsed time since the previous request Time( )−SU.T (step 208 ). If yes, control is returned to step 204 . If the running time SU.T has exceeded the threshold SU.H, the control unit 22 will turn off that storage unit 26 or issue a command to place it in standby mode. The values for SU.L and SU.N are also updated (step 210 ). The remaining spin lifetime SU.L is calculated as described above. The number of remaining start-and-stops SU.N is calculated by decrementing the previous value of SU.N by one. Finally, in decision diamond 212 , it is determined if the remaining lifetime SU.L and the remaining number of start and stops SU.N are too small as determined by the manufacturer of the disks 32 . If no, control is returned to step 204 . If yes with either parameter, a warning is generated (step 214 ) indicating that the storage unit 26 or at least the disks 32 should be replaced. After all the storage units have been checked, control is returned to box 202 and K seconds elapses before the above steps are repeated.
[0037] Referring to FIG. 6 a , a flow diagram 300 illustrating how the control unit 22 may manage the storage units 26 with an adaptive competitive algorithm to process requests according to another embodiment of the present invention is shown. With this embodiment, an adaptive algorithm is used that dynamically adjusts the value of H for each storage unit 26 based on the frequency and timing of requests. The adaptive algorithm is based on the assumption that there is a high probability that the wait time for the next request will exceed the time equivalent of a spin up and down cycle if the previous wait time for a request also exceeded the spin up and down cycle time. In situations where request arrivals tend to have temporal locality, this algorithm will achieve better results than the previous competitive algorithm.
[0038] The flow chart 300 is similar to flow chart 100 of FIG. 5 a . Steps 302 - 308 are identical to those of steps 102 - 108 of FIG. 5 a respectively and therefore are not described in detail herein. The main difference between the two flow charts 100 and 300 involves the use of a threshold Hmin and threshold Hmax to store the low and high thresholds for each storage unit 26 . These values are initialized in step 302 so that Hmax=SU.H and Hmin=Mmax/10. At decision diamond 308 , if the storage unit 26 to be access (in response to an archival or retrieval request) is off, then the current value of SU.H for that storage unit 26 is compared to Hmin (step 310 ). If the current value of SU.H is greater than Hmin, then the current value is decremented (step 312 ) before the storage unit 26 is turned on or woken up (step 314 ). If the current value of SU.H is less than Hmin, then the current value is not decremented and the storage unit 26 is turned on or woken up (step 314 ). Thereafter the request is sent to the storage unit 26 (step 316 ). On the other hand, if the storage unit 26 is on, then the current value of SU.H is compared to Hmax (step 318 ). If the current value is less than Hmax, the current value is incremented (step 320 ) and then the request is sent to the storage unit 26 . Otherwise the request is sent directly to the storage unit 26 (step 316 ). After the request is received by the storage unit 26 , the values of SU.L and SU.T are updated in a similar manner as described above (step 316 ). SU.H is adjusted between Hmax and Hmin in order to guarantee that the performance is within a factor of two of the optimal offline case.
[0039] [0039]FIG. 6 b is a flow diagram 300 illustrating how a control unit of the archival disk-based data storage system manages the storage units with an adaptive competitive algorithm to optimize disk lifetime and power consumption according to the present invention. FIG. 6B is identical to 5 B except in step 406 , Hmax and Hmin are recomputed. Thus the value of SU.H remains within the limits of these two thresholds. Otherwise the remainder of the flow chart for 408 - 414 are identical to 208 - 214 of FIG. 5B.
[0040] The present invention thus describes several approaches to extend the lifetime of disk storage in a storage unit 26 . The first approach keeps track of and uses the remaining spin life of a storage unit 26 to determine when to spin up and down to extend the lifetime of the disk(s) in the storage unit 26 . The second approach is to use the remaining spin life and the remaining start-and-stop limit of a storage unit 26 to determine when to spin up and down to extend the lifetime of the disk(s) in the storage unit 26 . The third is to use the life cost and power cost as a measure to combine spin life, start-and-stop limit, and power consumption, in order to determine when to spin up and down the storage unit 26 in order to improve both the lifetime and the power consumption of a storage unit 26 . This application described two algorithms using the third approach: a competitive algorithm and an adaptive competitive algorithm. Both algorithms have the property that their results are within a factor of two of the optimal offline case.
[0041] The storage system 20 ideally needs to maintain the integrity of its data for a long period of time. This is challenging for two reasons. Disks 32 often have undetectable errors. The error rate of current disk drive technology is typically 1 in 10 13 or 10 14 . For example with RAID, only detectable errors can be corrected. Second, detectable errors can be detected only when accessing data. Thus, there may be intervening catastrophic disk failures that can not be corrected even if they are detectable.
[0042] To detect hardware undetectable errors, the controller 30 of each storage unit 26 uses an algorithm to compute and store an error correction code (ECC) for each data block stored on its disks 32 . When the data block is later accessed, the storage unit re-computes the ECC and compares it with the code stored with the data. If they are identical, it is assumed there are no errors. On the other hand if they are not identical, the controller will re-compute the ECC value yet again. If the ECC values are still different, the storage unit 26 invokes correction code to correct the error and the data is stored in a new location. Whenever data is migrated (or scrubbed) to a new location, the directory of all the archived data stored in the storage system 20 maintained by the control unit 22 is updated.
[0043] Referring to FIG. 7, a flow diagram 500 illustrating how the control unit 22 performs data integrity checking and migration according to the present invention is shown. The data integrity check processes one object at a time (step 502 ). To check data integrity efficiently, the algorithm sorts the object's data blocks by location (step 504 ) and then checks one data block at a time (step 506 ). For each block, integrity errors are identified by calculating the ECC code (step 508 ). If there is no error, the data block is rewritten to the same location (step 520 ). If there are errors, then the algorithm checks to see whether the errors are correctable (step 510 ). If errors are not correctable, it will log the errors and go to check the next block ( 522 ). For correctable errors, it tries to find a new location for data scrubbing (step 512 ). If a new location is available on the same storage unit 26 , the data be scrubbed and the directory is updated. On the other hand if it a new location can not be found, the storage unit 26 informs the control unit 22 that this object needs to be migrate to another storage unit 26 (step 524 ). If a new location is found, the data is migrated to the new storage unit 26 and the directory in the control unit 22 is updated before the next block is checked (step 514 ). When the data integrity check process completes, the control unit 22 is notified of the completion (step 516 ) and then shuts down the storage unit 26 or puts the unit into standby mode (step 518 ).
[0044] According to one embodiment, the control unit 22 schedules the storage units 26 to perform data integrity checks of its data once every time period P. Since data integrity checks will consume the spin lifetime and power of disks 32 , P should be chosen based on a desired percentage p of the total spin lifetime and the number of start and stops. Accordingly, P may be set based on the following equation:
P = 1 p max { S BW , L N } ( 2 )
[0045] where S is the size of the storage unit and BW is the bandwidth of checking data integrity.
[0046] Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. For instance, the storage system 20 can be designed without a power controller 28 . In such embodiments, the control unit 22 would not be capable powering off the storage units 26 . Power would be conserved only by placing the storage units into standby mode. Typically the decision to either power off or place a disk into standby mode is a trade off between lower power consumption versus response time. If power consumption is more important than response time, the disks 32 should be powered off. If response time is more important, then the disks should be placed into a standby mode. The controller 30 can be a computer used to control the storage unit 26 . Therefore, the described embodiments should be taken as illustrative and not restrictive, and the invention should not be limited to the details given herein but should be defined by the following claims and their full scope of equivalents. | A disk-based archival storage system including a storage unit configured to store archival data, the storage unit including at least one spindle of disks configured to magnetically store archival data, an interconnect; and a control unit configured to process requests over the interconnect to either archive to or retrieve data from the storage unit. In one embodiment, the system includes a plurality of the storage units, each including at least one spindle of disks. The control unit controls the storage unit(s) in a master-slave relationship. Specifically the control unit is capable of issuing commands to selectively cause the storage unit(s) to shut down or power up, enter a running mode or a standby mode, cause the spindle of disk(s) to either spin up or spin down, and to perform a data integrity check of all the archival data stored in the storage system. In various other embodiments, the control unit runs algorithms that expand the lifetime and longevity of the disk spindles, optimizes power consumption, and performs data migration in the event a data integrity check identifies correctable errors. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to drilling of oil and gas wells. More particularly, the present invention relates to an apparatus positioned above the drill bit for reducing the hydro-static pressure of the column of mud at the bit for producing a more effective drilling by the bit into the rock formation.
2. General Background
In the drilling process of an oil or gas well, as the drill bit cuts through the formation which is often times rock or other hard substances, drilling muds of various weights are normally pumped through the bore in the drill string, through a number of drill collars, which serve to put additional weight onto the bit as it cuts through the formation, and through the drill bit to both lubricate the bore as the drill bit is drilling therethrough, hold back the formation, and to return up the annulus between the drill string and the wall of the bore to remove the cutting or the like which are cut from the rock formation. As the bore is increased in depth, the mud which must be pumped down the bore becomes quite heavy; that is, weighing literally hundreds of thousands of pounds and the back pressure of the mud to the bore increases because of the weight of the column. As this back pressure of the mud increases, or "hydro-static pressure" increases, it requires a higher pressure in the drill string in order to overcome the hydro-static head of the column of mud standing in the annulus. Therefore, this high back pressure in the annulus produces a force which is detremental to the jetting action of the mud flow, and in turn slows the effectivness of the cutting action of the bit. Therefore, this is undesirable in that the washing away of the cuttings near the vicinity of the bit is reduced, and therefore the effectivness of the bit is likewise reduced.
Therefore, it would be desirable to somehow reduce the weight column of mud near the drill bit during the drilling process, so that the drill bit is able to cut more effectively into the formation due to the decrease in pressure on the formation. This reduction of pressure or weight on the formation would drastically increase the effectiveness of the bit during the dirlling process.
There have been several patents addressing this particular activity, the most pertinent being as follows:
U.S. Pat. No. 4,049,066 issued to V. T. Richey and entitled "Apparatus For Reducing Annular Back Pressure Near The Drill Bit", discloses a device which is placed in the drill string immediately above a drill bit and below the drill collars. It incorporates an elongated tube which is threaded into the drill string and there is located an interior shaft having several sets of blades for rotating in response to the mud flow around the shaft. A rotatable exterior sleeve is mounted within a multi-turn helical screw. The mud is picked up by the bottom most flight of the helical thread on the exterior rotatable sleeve and is pulled rapidly away from the bottom of the well thus attempting to reduce the pressure just above the drill bit.
U.S. Pat. No. 4,312,415, issued to R. L. Franks, Jr. and entitled "Reverse Circulating Tool", discloses a tool which, although does not contain the fan or helical screw in order to remove mud away from the bit, it does provide for reverse circulating of drilling fluid, and apparently while the drilling fluid is able to escape from below the apparatus, it attempts to relieve the pressure which would enable less weight on the drill bit. The object of this invention is to help relieve the pressure on the bit.
U.S. Pat. No. 4,368,787, issued to J. U. Messenger and entitled "Arrangement For Removing Borehole Cuttings By Reverse Circulation With A Downhole Bit-Powered Pump", does teach the use of a pumping apparatus which is a reversible pump in order to pull the cuttings and such away from the drill bit so that there is no chance of pressure - differential sticking of the drill string.
U.S. Pat. No. 4,436,166, issued to A. Hayatdavoudi et al, and entitled "Downhole Vortex Generator And Method", discloses an apparatus which is designed to create an upward swirling flow in an annulus above the drill bit for removing cuttings and the like. In the summary of the invention the aim of the invention is to divert a portion of the downward flowing drilling fluid from the drill string and inject it into the annulus so that it imparts a swirling vortex motion. Although it does not address the question of reducing the hydro-static pressure on the bit, it does disclose a means for moving the drilling fluid and cuttings away from the bit.
U.S. Pat. No. 4,479,558, issued to E. R. Gill, et al, entitled "Drilling Sub", like the previous patent, also addresses the question of creating a vortex in the annulus for removal of drilling fluid and the like from around the bit.
U.S. Pat. Nos. 2,894,585; 2,234,454; and 2,990,894 likewise are patents which show drill string devices that are designated to create a vortex to draw up the fluid and cuttings from the drill bit.
SUMMARY OF THE PRESENT INVENTION
The apparatus of the present invention solves the problems of the art in a straightforward manner. What is provided is a downhole tool positioned intermediate the mud motor and the drill bit, for reducing the hydro-static head near or around the bit. What is provided is an upper body portion threadable attachable to the mud motor and having an internal shaft with a bore therethrough for allowing mud to flow down the shaft to the bit, rotatable during the the operation of the tool. The upper body portion further includes a gear member around the outer wall of the shaft for rotatably engaging the pair of upper gear members which imparts rotation to a pair of lower gear members for further imparting rotation to a fan member located in the lower portion of the tool. The lower portion of the wall of the tool member is flared to substantially engage the inner wall of the bore, and to distribute the weight of the tool on bearings more evenly, with the interior of the lower flared portion housing the multi-vane fan so that upon rotation of the fan, the mud below the fan member is "sucked" into the fan through ports in the bottom of the tool, and out of lateral ports in the wall of the lower section; this movement of mud effectively being "pulled" off of the bit to decrease the weight of the column of mud at the bit for more effective cutting. A second embodiment would include in the gearing section of the tool, a bell gear member for imparting increased rotation to the fan member for more effective movement of the mud away from the bit and lowering of the weight of the mud at the bit.
Therefore it is an object of the present invention to provide an apparatus for reducing the hydro-static pressure at the bit which is situated between the mud motor and the bit and operates in conjunction with the mud motor;
It is a further object of the present invention to provide an apparatus for lifting mud away from the bit by pulling the mud up from the bit for reducing the weight mud on the bit;
It is still a further object of the present invention to provide an apparatus for reducing the hydro-static pressure of the bit by incorporating a multi-vane fan member within the body of the apparatus above the bit for rotatable pulling the mud from the bit during the operation of the apparatus;
It is still a further object of the present invention to provide an apparatus for reducing the hydro-static pressure at the bit which is capable of moving a greater quantity of mud away from the bit that is being pumped down into the bit so as to create a "vacuum" or reduced pressure area and thus reducing the weight of the mud column on the bit.
It is still a further object of the present invention to provide an apparatus for creating the drilling weight and eliminating troublesome drill collars.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall cross-sectional view of the preferred embodiment of the apparatus of the present invention;
FIG. 2 is a top cross-sectional view along lines 2--2 in FIG. 1 illustrating the upper gearing mechanism of the apparatus of the present invention;
FIG. 3 is a cross-sectional view along lines 3--3 of FIG. 1 illustrating the lower gearing mechanism of the apparatus of the present invention;
FIG. 4 is a cross-sectional view of along lines 4--4 of FIG. 1 illustrating the fan mechanism of the apparatus of the present invention;
FIG. 5 is a partial cross-sectional view of an additional embodiment of the apparatus of the present invention;
FIG. 6 is a cross-sectional view along lines 6--6 in FIG. 5 of the upper gearing mechanism of the apparatus of the present invention;
FIG. 6-A is a cross-sectional view of an additional set of gears within the apparatus for gearing up in the apparatus of the present invention;
FIG. 7 is a cross-sectional view along lines 7--7 in FIG. 5 of the lower gearing mechanism of the apparatus of the present invention; and
FIG. 8 is a side view of the fan mechanism in the preferred embodiment and in the additional embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-4 and FIG. 8 illustrate the preferred embodiment of the apparatus of the present invention as illustrated by the numeral 10. As seen in the FIGURES, particularly in FIG. 1, apparatus 10 includes an outer annular closed housing 12 which is attachable at its upper end 13 (not illustrated), to a standard mud motor which is a standard motor utilized in drilling for pumping mud down into bit 14 as seen in the FIGURE. Housing 12 at its lower portion would threadably engage a second intermediate exterior closed housing 16 to form a continuous annular closed housing in the upper portion of the tool, which will be discussed at this time. Contained within the upper portion of the tool housings 12 and 16 are included an internal shaft 18 having a bore 19 therethrough wherein mud 19 is moved from the mud motors through interior space 20, through ports 22 in shaft 18 down into the internal bore 19 in the direction of arrows 25 to the bit 14 in order to lubricate the bit and to wash the cuttings away from the bit during the cutting process. Shaft member 18 is provided with an upper rotating shaft member 23 which is powered by the mud motor, and a lower portion of the shaft member 21 which is threadably engaged to connector 42 at point 41 rotating with the drill string. The upper shaft portion 23 and lower shaft portion 21 are rotatably mounted at bearings 27. Upper portion 23 of shaft member 18, rotating during the drilling process, is supported by internal annular shoulder plate 26 which is supportingly engaged at the juncture of annular wall 12 and 16 and supports shaft 18 at shoulder portion 28 and allows rotation of shaft 18 with bearing members 30. Directly below shoulder plate 26 there is provided an interior housing means 32 which, as seen in the top view in FIG. 2 is a solid metal housing which fills the entire inner space of annular housing 16 providing only space for the gearing mechanisms as will be discussed further. Solid internal housing 32 adds further support to shoulder plate 26 in supporting shaft 18, and itself is supported on its lower face 34 at the juncture of housing 16 and the lower housing 36 of the tool as that lower house threadably engages housing 16 at point 38 having an upper face member 40 for supporting the internal housing 32 thereupon. Face member 40 and housing 32 are rotatably engaged for preventing housing 32 from rotating within outer housing 16.
Therefore, in general the entire tool 10 is comprised of basic exterior housings 12, 16 and lower housing 36 to make up the total exterior housing of the tool.
Turning now to the internal gearing mechanism within intermediate housing 16 and solid housing 32, reference is made to shaft 18, as it is directed down through the tool and threadably engages a lower connector joint 42, located between the tool 10 and the bit 14. Shaft 18 at its upper portion further includes an exterior gear member 44 around its exterior wall as seen in the top view in FIGS. 2 and 3, with the teeth 45 of the gear member 44 meshing with the teeth of auxiliary gear members 46 and 48 as the shaft is rotated during the operation of the mud motor. Therefore, as shaft 18 is rotated the rotation of shaft 18 and gear 44 in the clockwise direction imparts rotation of auxiliary gears 46 and 48 in the counter-clockwise direction. The reason for that to be discussed further.
As further seen in FIG. 1, gears 46 and 48 include a lower elongated body portion 49 and 51 respectively, which are likewise housed within internal housing 32 and interconnect to a lower pair of gears 54 and 56 so that rotation of gears 46 and 48 by gear 44 likewise imparts rotation to gears 54 and 56. This gearing to the outside from the internal gear 44 to gears 54 and 56 is crucial in the overall operation of the tool. Two gear members in this portion of the tool is preferably to both balance the rotation of the internal rotation of the tool and to add additional strength to the tool.
This is so because the lower portion 35 of the tool includes the means for moving the mud away from the bit. This is accomplished through the following manner. Along lower shaft portion 21 of shaft 18 within the lower housing 36 of the tool there is included an exterior fan shaft 58 which has in its upper end an internal gear member 50, which is illustrated in FIG. 3 top view, which meshes with gears 54 and 56, so that the rotation of gears 54 and 56 likewise impart rotation to fan shaft 58. Fan shaft 58 is coaxially aligned around lower shaft 21 and rotates on bearings 57 as seen in FIG. 3. Further, fan shaft 58 follows along the internal shaft 21 and fans outwardly at point 59 to a frustro-conical body portion 60 wherein fan blades 62 are set thereupon. It should be noted that body portion 60 as it flares away from shaft 18 is supported by an annular wedge member 64 having a plurality of bearings 66 located intermediate the wedge member 64 and the body of fan shaft 60 to provide ease of rotation of the fan during the operation of the tool.
Further, the lower body portion 36 of the apparatus directly below the juncture of the housing 16 and body 36 at threads 38, includes a plurality of enlarged flow ports 70 which allow flow of mud through the apparatus and out through the flows port 70 as seen by arrow 72. Likewise, body portion 36, as is seen particularly in FIG. 1, shows a flaring of the body portion from that portion of body portion 36 at the top point 74 of ports 70 and the lower point 76 of ports 70. This flaring is necessary in order to accommodate the width of the fan blades 62 within housing 36 since the width of fan blades 62 provide a confined space 78, which may be as small as a few thousandths of an inch, between the outer most face of fan blade 62 and the inner wall of housing 36. Further, housing 36 is of the particular exterior diameter to be basically positioned within the width of the bore so that no mud flowing upward from the bit can bypass between the tool and the borehole. This is accommodated with a flexible and annular ring member 80 which is housed within the exterior body portion 36 and extrudes therefrom so as to make contact with the wall of the bore as the tool is in position and is capable of flexing to adapt to out of guage hole. The lower most face of the tool includes a lower plate 82 which is threadably engaged to the lower portion of housing 36, lower plate 82 having a plurality of ports 84 to which the mud from the bit flowing upward in the direction of arrows 86 flows through the ports to flow into the tool.
In the operation of the tool it is crucial to fully appreciate the positioning of fan blades 62 within body portion 36. As seen in FIG. 8, fan blades 62 include a plurality of helically situated blades forming a space 63 there between through which mud travels upward. This spacing between the plurality of blades 62 is crucial to effectively draw the mud through the blades and be expelled upward out ports 70 and to therefore have the tool work in an effective manner. In the operation of the tool, upon the tool being placed in position and the drilling begins with rotation of the drill string imparting rotation to the bit 14, mud likewise is pumped from the mud motor down interior port 19 into the bit. When the mud motor is in operation, upper shaft portion of shaft 18 is rotated at a high rate which likewise imparts rotation to gears 46 and 48, lower gears 54 and 56, which likewise would impart further rotation to fan shaft 58 and fan blades 62 of fan means 67. As the mud and cuttings are returned from the bit in the direction of arrow 86 through ports 84, fan blades 62 create a reduced pressure which draws the mud upward through the blades and out through ports 70 to be directed along the annular space 71 between the wall of the bore and wall 16 and wall 12 of the tool up to the floor of the rig to be returned again. It is this drawings of the mud by the fan means which would enable the weight of the mud to be reduced at the bit in a more effective cutting occurs.
It is important to note that the fan must have the ability to pump a greater quantity of mud that is being pumped down the tool by the rig pumps by gearing up the fan. A hypothetical example would be for example if the rig pumps are pumping 350 gallons per minute down to the center shaft through bit 14 of annulus 86, this much pumping ability is provided by the rig pumps for the 350 gallons. The horse power from the mud motor is geared out of the fan and geared up to provide a boost to pump 450 gallons per minute by the fan in the tool. Therefore, in effect, the rig is pumping the first 350 gallons per minute and the fan would increase that pumping rate 100 gallons or to 450 gallons per minute. Since it is impossible to pump 450 gallons per minute when there are only 350 gallons of mud available to pump, the fan would therefore in effect have geared up as such as it will create this lifting effect of the mud column away from the bit. Thus the hydro-static head at the bit is reduced providing the drilling weight and increasing the drill rate through lower hydro-static head of the bit.
Reference is now made to the additional embodiment of apparatus 10, as seen in FIGS. 5-7. Basically, the overall operation of the fan blade and the rotation of shaft member 18 is identical in nature. The differences in the structure would include that section of the tool which incorporates the internal gearing mechanisms of the tool. As seen in FIG. 5, as with the previous embodiment, there is also included a shoulder plate 26 which supports shaft 18 and a plurality of bearings 28 which allow rotation of shaft 18 vis-a-via plate member 26. Directly below plate member 26 there is situated a support block 90 in this additional embodiment, which likewise adds support to shaft 18 during operation of the tool.
It is this portion of the apparatus wherein the additional embodiment modifications are included. As seen in FIG. 5, shaft 18 further includes internal gear 44 on its wall portion. However, rather than meshing with gears 46 and 48 as with the principal embodiment, gear 44 meshing with the upper throat portion 92 of a bell gear 94. As seen in the FIGURE, bell gear 94 includes a flared shoulder portion 93 leading down to a bell portion 95 which includes a gear 96 on its interior wall so that rotation of gear 44 imparts rotation to bell gear 94.
It is at this juncture that the gear system which was included into the principal embodiment is differentiated. The gear system would further include upper gears 46 and 48 having lower body portions 49 and 51 respectively and a pair of lower gear members 54 and 56 as with the principal embodiment. However, gear members 46 and 48 would mesh with teeth 97 of bell gear 96 for imparting rotation to gear members 46 and 48 gearing up to a greater speed. Likewise, this rotation would impart rotation to gear members 54 and 56, with gear members 54 and 56 meshing with the gear 50 on fan housing 58 as with the principal embodiment, for imparting rotation to fan means 67.
In this additional embodiment, the utilization of the bell gear for gearing out to the exterior wall of the apparatus as opposed to the internal gear member 44 in the preferred embodiment, accomplishes two basic results. The most pertinent result is that the rotation of expanded bell gears 94 imparts a "gearing up", of gear members 46 and 48 to be rotated at a much higher speed than in the preferred embodiment. This may be necessary in the ultimate configuration of the tool. Likewise, whereas in the principal embodiment as the mud motor is rotated clockwise the gear members 46 and 48 are rotated in the counter-clockwise direction which likewise imparts counter-clockwise rotation to the lower gear members 54 and 56 identical or clockwise direction of rotation to fan 61. However, in the utilization of the bell gear, as seen in FIGS. 5-7, as the shaft member 18 is rotated in the clockwise direction, the bell gear is likewise rotated in the clockwise direction with gear members 46 and 48 being rotated likewise in the clockwise direction and fan member 61 being rotated in the counter-clockwise direction. If this occurs, then vanes 62 on fan means 67 must be directed in the opposite direction as seen in FIG. 8 i.e., the slope of the blades 62 must be from up to down going left to right so that since the fan is being rotated in the counter-clock wise direction mud must still be pulled away from the bit.
Therefore, in order to assure that the fan motor is rotating in the proper direction, and to further increase the speed of the fan blade, it may be necessary that below first bell gear 94 at the position of gear members 54 and 56 rather than gears members 54 and 56 meshing with the gear in fan housing 58, that a second bell housing, for example 100 as seen in FIG. 6A, be incorporated into the apparatus, and a second series of lower gear members 102 and 104 be incorporated in order to turn the rotation of the fan members 61 in the proper direction. This type of rotation and inclusion of a second bell gear is yet to be experimented upon, but is forseen as a possibility in the ultimate configuration of the operation of the tool.
For purposes of clarification as to the effectivness of such a tool, reference should be had to the following set of equations which will basically outline the weight differential when the weight of the mud pulled away from the drill bit reducing the hydro-static pressure at the bit, equivalent to a 10 pound mud at the unit and 11 pound mud above the fan. This formula is as follows:
______________________________________The formula for measuring Hydro-Static pressure (PSI):______________________________________HP = Depth (TVD feet) × mud weight × .052Wherein TVD = True vertical depth.052 = standard coefficientmudweight = pounds per gallonWherein the area of a circle is:A = π r2Example: The hydro-static pressure at 11000feet with 11 pound mudHP1 = 11000 × 11 × .052HP1 = 6292 pounds per square inch (above the fan in the apparatus)Example: The hydrostatic pressure at 11000square feet with 10 pound mudHP2 = 11000 × 10 × .052HP2 = 5720 pounds per square inch (below the fan in the apparatus)Amount of HP difference, PSI = Delta HP(change in HP),Delta HP = HP1 - HP2Delta HP = 6292 - 5720 PSIDelta HP = 572 PSI (Wherein the total weight created by the string is equal to the Delta HP × the area). Area of a 10 inch hole:A = π r2A = 3.14 × (5)2A = 3.14 × 25A = 78.5 square inchesTotal Weight (TW) created for dill weight:TW = Delta HP × A (area in square inches)TW = 572 × 78.5TW = 44,902 pounds.______________________________________
Therefore, if the fan in the apparatus is able to pull an equivalent of 1 pound of mud weight away from the drill bit by use of the apparatus, one has effectively decreased the weight of the mud column on the drill bit by 44,902 pounds. That is 44,902 pounds less pressure on the formation which would more readily allow the formation to be cut into and broken away during the drilling of the well. As the weight, therefore, on the bit is created without the use of drill collars as is done in the present state of the art.
Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. | A downhole tool positioned intermediate the mud motor and the drill bit, for reducing the hydro-static head near or around the bit. What is provided is an upper body portion threadably attachable to the mud motor and having an internal shaft with a bore therethrough for allowing mud to flow down the shaft rotatable during the the operation of the tool. The upper body portion further includes a gear member on the outer wall of the shaft for rotatably engaging the pair of upper gear members which imparts rotation to a pair of lower gear members for further imparting rotation to a fan member located in the lower portion of the tool. The lower portion of the tool member is flared to substantially engage the inner wall of the bore, with the interior of the lower flared portion housing the multi-vane fan so that upon rotation of the fan, the mud below the fan member is sucked into the fan through ports in the bottom of the tool, and out of lateral ports in the wall of the lower section, this movement of mud is effectively being "pulled" off of the bit to decrease the weight of the column of mud at the bit for more effective cutting. A second embodiment would include in the gearing section of the tool a bell gear member for imparting increased rotation to the fan member for more effective lowering of the weight of the mud at the bit. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a mobile communication system in which a radio speech channel is switched between radio zone areas while keeping the communication of a mobile station.
The mobile communication system comprises, as is well known, a plurality of base stations each having an independent radio zone area, a plurality of mobile switching centers which accommodate the base stations through wire speech path, and a mobile station connectable through a radio speech channel to any one of the base stations. With this mobile communication system the mobile station can move across the radio zone areas during communication to communicate with a telephone subscriber.
In such a mobile communication system, where the mobile station moves to a new radio zone area accommodated by a different mobile switching centers during a conversation, and a situation happens in which the conversation cannot be continued through the radio speech channel used up to now, it is needed to change the radio speech channel in use to a new radio speech channel for the new base station while continuing the conversation.
With reference to FIG. 1, an explanation is made of a handover used in mobile switching centers used in a conventional mobile communication system. This is described in a paper entitled "Nation-wide automobile telephone service using new tracking exchange technology," by T. Goto and T. Eto, which was published in International Switching Symposium '84, Session 32B-4, Florence, 1984.
When a mobile station 1 moves from a radio zone area 12 to a radio zone area 13 during communication with a stationary telephone 6 in a public switched telephone network through radio speech channel 7, an idle radio speech channel 9 in radio zone area 13, and wire speech path 10 and 11 are determined. Specifically, wire speech path 11 is set up in mobile switching center 4, while wire speech path 10 is set up in mobile switching center 5. Mobile switching center 4 instructs mobile station 1 through base station 2 used up to now to switch its radio speech channel (frequency) 7 to a radio speech channel (frequency) 9 assigned to base station 3. After the channel switching the instructed mobile station 1 relays that the radio speech channel has been switched to mobile switching center 4 via base station 3, wire speech path 10, mobile switching center 5, and wire speech path 11. Consequently mobile switching center 4 switches the connection path for a subscriber's wire speech path 14 of stationary telephone 6 from wire speech path 8 to wire speech path 11 which is connected to the new base station 3, wire speech path 10, and mobile switching center 5. And then, mobile switching center 4 releases wire speech path 8 connected between it and the old base station 2.
It is to be noted that, in the above described system, mobile station 1 may be applied to, for example, an automobile, ship, and airplane, if they have a telephone installed.
In the case of the system for effecting handover as described above, however, at a time when the switching is accomplished from the old radio speech channel 7 to the new radio speech channel 9, wire speech path 14 connected to telephone 6 remains connected in mobile switching center 4 to base station 2 via wire speech path 8. This means that the communication path between mobile station 1 and stationary telephone 6 is cut off. Thus, the conversation will be cut off until the connection procedure of subscriber's wire speech path 14 from wire speech path 8 to wire speech path 11 is completed in mobile switching center 4.
Further, the conversation cut-off time, which lasts from the time mobile station 1 switches its channel up to the time the wire speech path is switched in mobile switching center 4, involves a signal transmission delay time between the mobile switching centers. Thus, where a common control signaling system is used between the mobile switching centers the conversation cut-off time will depend on the traffic on control signal lines. In the worst case it is inevitable that the cut-off time becomes extremely long.
SUMMARY OF THE INVENTION
It is accordingly a primary object of this invention to provide a mobile communication system capable of channel switching while keeping a mobile station in a communication condition after the switching of the radio speech channel by a mobile station and thus reducing a communication cut-off time occurring when the handover is effected.
According to the present invention a mobile communication system is provided which comprises at least one mobile switching center for accommodating through respective networks a plurality of base stations each having an independent radio zone area, said mobile switching center being connected to a telephone through a wire speech path; a mobile station connectable to each of said base stations through a radio speech channel; and multi-connecting means included in said mobile switching center for multi-connecting, during a communication of the mobile station, a network between the mobile switching center and an old base station left by the mobile station during communication, a network between the mobile switching center and a new or destination base station entered by the mobile station, and a wire speech path between the mobile switching center and the telephone; the process of a handover comprising the steps of: detecting by said mobile switching center, when said mobile station moves across adjacent radio zone areas of two base stations during communication, a radio speech channel in the destination radio zone area; multi-connecting by said multi-connecting means a network between said mobile switching center and the old base station and a network between said mobile switching center and the new base station and a wire speech path between the mobile switching center and the telephone after the detection of the radio channel as a channel change; and switching the radio speech channel to be used by said mobile station from the radio speech channel in the old zone area to the radio speech channel in the new zone area while keeping the communication condition of said mobile station.
According to the mobile communication system of this invention, the channel switching can be effected from the radio speech channel in the old radio zone area to the radio speech channel in the destination radio zone area while keeping the communication condition of the mobile station after the switching of the radio speech channel by a mobile station, so that the communication is not interrupted. For example, qualitative comparisons revealed that for the common-line signaling system of 4.8 Kb/s the communication cut-off time is reduced to about one third that of the conventional system, while in the case of 48 Kb/s the cut-off time is reduced to about one half.
Further, the mobile communication system of this invention has an advantage that the common channel signal link capability between mobile switching centers does not affect the communication cut-off time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram for explaining a conventional system for handover;
FIG. 2 is a block diagram for explaining an embodiment of a mobile communication system of this invention;
FIG. 3 shows a control sequence for handover in connection with a first operational case in the mobile communication system of FIG. 2;
FIG. 4 shows a control sequence for handover in connection with a second operational case in the mobile communication system of FIG. 2;
FIG. 5 shows a control sequence for handover in connection with a third operational case in the mobile communication system of FIG. 2;
FIG. 6 is a block diagram for explaining another embodiment of the mobile communication system of this invention;
FIG. 7 shows a control sequence for explaining an operational case in the mobile communication system shown in FIG. 6; and
FIG. 8 shows a practical arrangement of a multi-connecting device of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, 1 designates a mobile station, 2 and 3 base stations, 4 and 5 mobile switching center, 6 a stationary telephone, 7 a radio speech channel, 8 a wire speech path, 9 a radio speech channel, 10 and 11 wire speech path, 12 and 13 radio zone areas, 14 a wire speech path, 15 a communication path switch, 16 a multi-connecting device, 17 a wire speech path, 18 a mobile switching center, 19 a wire speech path, 20 a base station, 21 a radio speech channel, and 22 a radio zone area. It is to be noted that base station 3 and wire speech path 10 and mobile switching center 5 and wire speech path 11, taken together, can be referred to as a network. Likewise, base station 20, line 19, mobile switching center 18 and wire speech path 17, taken together, can be referred to as a network. The telephone may be of a fixed or movable type. Mobile switching center 4, 5 and 18 are connected to local switch 25 via respective wire speech path 14, 23 and 24.
The operations of the handover channel switching system arranged as described above will be described below with respect to first through fourth operational cases.
(The first case)
This is the case where mobile station 1 moves from radio zone area 12 to radio zone area 13 while holding a conversation with stationary telephone 6.
That is, in this first case, while communicating with stationary telephone 6 via radio speech channel 7, base station 2, wire speech path 8, mobile switching center 4, and wire speech path 14, when mobile station 1 moves from radio zone area 12 to radio zone area 13, radio zone area 13, base station 3, and mobile switching center 5 are determined by means of an existing technique. Mobile switching center 4 determines and acknowledges wire speech path 11 to mobile switching center 5 to instruct mobile communication exchange 5 to connect with base station 3. Mobile switching center 5 determines and sets up wire speech path 10 to base station 3. Base station 3 determines an idle radio speech channel 9 in radio zone area 13, and then relays information on the idle radio speech channel 9 to the mobile switching center 4 via mobile switching center 5 after the new radio speech channel 9 is ready for transmission and reception of signals from mobile station 1. Upon reception of the information on the idle radio speech channel 9 mobile switching center 4 controls communication path switch 15 in order to release the connection between wire speech paths 8 and 14 and to connect wire speech paths 8, 11 and 14 to multi-connecting device 16. By the connection to multiconnecting device 16 signals transmitted from telephone 6 are distributed to wire speech paths 8 and 11, and signals to be transmitted through wire speech paths 8 and 10 to telephone 6 are added for subsequent transmission to wire speech path 14.
Mobile switching center 4 informs base station 2 of the new radio speech channel 9 which is in turn relayed to mobile station 1 via the old radio speech channel 7. As a result mobile station 1 changes its radio speech channel from the old radio speech channel 7 to the new radio speech channel 9. At this time, mobile station 1 is connected to telephone 6 via radio speech channel 9, wire speech paths 10 and 11, multi-connecting device 16, and wire speech path 14 so that a conversation is held between mobile station 1 and stationary telephone 6.
When mobile station 1 changes its radio speech channel to radio speech channel 9, base station 3 detects the radio speech channel switching completion, which is in turn relayed to mobile switching center 4 via mobile switching center 5. Consequently, mobile switching center 4 controls communication path switch 15 to release multi-connecting device 16, connect wire speech path 14 to wire speech 11, and interrupt wire speech path 8. Base station 2 releases the old radio speech channel 7. The control sequence of the first case is shown in FIG. 3.
As is evident from the first case described above, the handover system of this invention has an advantage that the communication is not interrupted after the radio speech channel is switched because the radio speech channel is switched while maintaining the condition capable of communicating with a telephone subscriber through either the present radio speech channel or the new radio speech channel.
Further, this invention provides another advantage that a signal transmission delay time between the mobile switching center and a signal efficiency of the common control signaling system have no effect on the communication cut-off time.
(The second case)
This is the case where mobile station 1 returns from radio zone area 13 to radio zone area 12.
That is, while communicating with stationary telephone 6 via radio speech channel 9, base station 3, wire speech path 10, mobile switching center 5, wire speech paths 11 and 14, when mobile station 1 moves from radio zone area 13 to radio zone area 12, radio zone area 12, base station 3, and mobile switching center 4 are determined by means of the existing technique. Mobile switching center 5 informs mobile switching center 4 of effecting the handover again. Consequently, mobile switching center 4 sets up wire speech path 8 to base station 2. Base station 2 determines the idle radio speech channel 7 in radio zone area 12 and then relays information on the idle radio speech channel 7 to mobile switching center 4 after mobile station 1 is ready for transmission and reception of signals through the new radio speech channel 7. Mobile switching center 4 controls communication path switch 15 in order to release the connection between wire speech paths 11 and 14, and to connect wire speech paths 8, 11 and 14 to multi-connecting device 16. By this connection to multi-connecting device 16 signals transmitted from telephone 6 are distributed to wire speech paths 8 and 11, and signals to be transmitted through wire speech paths 8 and 10 to telephone 6 are added together and then fed to wire speech path 14.
Next, mobile switching center 4 informs base station 3 of the new radio speech channel 7 which is in turn relayed to mobile station 1 via the old radio speech channel 9. As a result mobile station 1 changes its radio speech channel from the old radio speech channel 9 to the new radio speech channel 7. At this time, mobile station 1 is connected to telephone 6 via radio speech channel 7, wire speech path 8, multi-connecting device 16, and wire speech path 14 so that a conversation is held between mobile station 1 and stationary telephone 6.
When mobile station 1 changes its radio speech channel to radio speech channel 7, base station 2 detects the radio speech channel switching completion, which is in turn relayed to mobile switching center 4. Consequently, mobile switching center 4 controls communication path switch 15 to release multi-connecting device 16, wire speech path 14 to communication line 8, and interrupt wire speech path 11. Base station 3 releases the old radio speech channel 9 when mobile switching center 5 interrupts the wire speech path 10.
To summarize the handover system in the second case, the mobile station moves again to the radio zone area accommodated by the old (destination) mobile switching center in the above-described first case after the handover of the first case has been completed with the result that the handover is effected again. This is noticed by the former mobile switching center to the destination mobile switching center. Subsequently, the destination mobile switching center multi-connects the wire speech path between the destination mobile switching center and the destination base station and the wire speech path between the former mobile switching center and the destination mobile switching center. And the mobile station changes its radio speech channel from the radio speech channel in the former radio zone area to the radio speech channel in the destination radio zone area without interrupting its communication. The control sequence for the second case is shown in FIG. 4.
For the second case as described above the multi-connection is carried out in the new or destination mobile switching center, thus reducing the communication cut-off as in the first case so that the handover is realized without the use of a separate wire speech path between mobile switching centers.
(The third case)
This is the case where the mobile station 1 moves from radio zone area 12 to radio zone area 13, and then to radio zone area 22. The operations performed when the mobile station moves from radio zone area 12 to radio zone area 13 are the same as those described previously. Thus, only the operations carried out when the mobile station moves from radio zone area 13 to radio zone area 22 will be described below.
Radio zone area 22, base station 20 and mobile switching center 18 are determined by means of the existing techniques when mobile station 1 moves from radio zone area 13 to radio zone area 22 during communication with stationary telephone 6 via radio speech channel 9, base station 3, wire speech path 10, mobile switching center 5, and wire speech paths 11 and 14. Mobile switching center 5 notifies mobile switching center 4 of effecting switching to the new mobile switching center 18. As a result mobile switching center 4 determines and sets up wire speech path 17 for mobile switching center 18, and then instructs mobile switching center 18 to connect with base station 20. Mobile switching center 18 determines and sets up wire speech path 19 for base station 20. Radio zone area 20 determines an idle radio speech channel 21 in radio zone area 22, and notifies mobile switching center 4 of it via mobile switching center 18 after the new radio speech channel 21 is ready for transmission and reception of signals from mobile station 1. Upon receiving the information as to idle radio speech channel channel 21 mobile switching center 4 controls communication path switch 15 so as to release the connection between wire speech paths 11 and 14, and connect wire speech paths 11, 17 and 14 with multi-connecting device 16. By the connection with multi-connecting device 16 signals transmitted from telephone 6 are distributed to wire speech paths 17 and 11, and signals to be transmitted through wire speech paths 19 and 10 to telephone 6 are added for subsequent transmission to wire speech path 14.
Next, mobile switching center 4 informs base station 3 of the new radio speech channel 21 which is in turn relayed to mobile station 1 via the old radio speech channel 9. As a result mobile station 1 changes its radio speech channel from the old radio speech channel 9 to the new radio speech channel 21. At this time, mobile station 1 is connected to telephone 6 via speech radio channel 21, wire speech paths 19 and 17, multi-connecting device 16, and wire speech path 14 so that a conversation is held between mobile station 1 and stationary telephone 6.
After mobile station 1 is changed to radio speech channel 21, base station 20 detects the radio speech channel switching completion, which is in turn relayed to mobile switching center 4 via mobile switching center 18. Consequently, mobile switching center 4 controls communication path switch 15 to release multi-connecting device 16, connect wire speech path 14 to wire speech path 17, and interrupt wire speech path 11. Base station 3 releases the old radio speech channel 9 when mobile speech channel exchange 5 releases wire speech path 10.
To summarize the handover system in the third case, the mobile station further moves to a new radio zone area accommodated by a separate mobile switching center after the handover as in the first case has been completed with the result that the handover is effected again. This is noticed by the former mobile switching center to the first mobile switching center shown in the first case. Subsequently, the first mobile switching center multi-connects the wire speech path between the destination mobile switching center and the first mobile switching center and the wire speech path between the former mobile switching center and the first mobile switching center. And the mobile station changes its radio speech channel from the radio speech channel in the former radio zone area to the radio channel in the destination radio zone area without interrupting its communication. The control sequence for the third case is shown in FIG. 5.
In the third case as described above the multi-connection is achieved in the first mobile switching center, thus reducing the communication cut-off time. The third case provides an advantage that the wire speech path between the first mobile switching center and the destination mobile switching center alone suffices for a wire speech path which is used after the channel switching over the three mobile switching centers.
(The fourth case)
This is the case where, as shown in FIG. 6, mobile station 1 moves from radio zone area 12 to radio zone area 13 while maintaining communication, and both the radio zone areas are accommodated by mobile switching center 4.
That is, in this fourth case, radio zone area 13 and base station 3 are determined by means of existing techniques when mobile station 1 moves from radio zone area 12 to radio zone area 13 while communicating with stationary telephone 6 via radio speech channel 7, base station 2, wire speech path 8, mobile switching center 4, and wire speech path 14. Mobile switching center 4 determines and sets up wire speech path 10 to base station 3. Base station 3 determines an idle radio speech channel 9 in radio zone area 13, and then relays information on the idle radio speech channel 9 to mobile switching center 4 after the new radio speech channel 9 is ready for transmission and reception of signals from mobile station 1. Upon reception of the information on the idle radio speech channel 9 mobile switching center 4 controls communication path switch 15 in order to release the connection between wire speech paths 8 and 14, and to connect wire speech paths 8 and 11 and 14 to multi-connecting device 16.
Mobile switching center 4 informs base station 2 of the new radio speech channel 9 which is in turn relayed to mobile station 1 via the old radio speech channel 7. As a result mobile station 1 changes its radio speech channel from the old radio speech channel 7 to the new radio speech channel 9. At this time, mobile station 1 is connected to telephone 6 via radio speech channel 9, wire speech path 10, multi-connecting device 16, and wire speech path 14 so that a conversation is held between mobile station 1 and stationary telephone 6.
When mobile station 1 changes its radio speech channel to radio speech channel 9, base station 3 detects the handover completion, which is in turn noticed to mobile switching center 4 via mobile switching center 5. Consequently, mobile switching center 4 controls communication path switch 15 to release multi-connecting device 16, connect wire speech path 14 to wire speech path 10, and interrupt wire speech path 8. Base station 2 releases the old radio speech channel 7. The control sequence of the fourth case is shown in FIG. 7.
As will be evident from the fourth case as described above, according to the handover system of this invention, the radio speech channel is switched while maintaining the condition capable of communicating with a telephone subscriber by the use of either the present radio speech channel or the new radio speech channel. Thus, this invention provides an advantage that the communication is not interrupted after the radio speech channel has been switched.
With the above described four operational cases the channel switching control is achieved by the multi-connecting device included in the mobile switching center that is connected to the base station having the channel which is on communication before the mobile station moves. Alternatively, the switching control may be carried out by the multi-connecting device in the mobile switching center connected to the base station of the destination of the mobile station.
Referring now to FIG. 8, a practical arrangement of the multi-connecting device shown in FIGS. 2 and 6 will be described.
In FIG. 8, a up-link 100 of base station 2 and a up-link 120 of base station 3 are connected to multi-connecting device 16 via communication path switch 30 in the mobile exchange. In multi-connecting device 16 signals on up-links 100 and 120 are selectively applied by a selector circuit 40 to a PCM decoder 50. Consequently, PCM signals on links 100 and 120 are decoded to linear codes which are in turn applied to an adder 70. Adder 70 adds the linear codes together and the resultant output is in turn applied to a PCM coder 60 to be converted to a PCM signal. This PCM signal is transferred to a down-link 150 of telephone 6 via communication path switch 30. It will be understood that speech signals transmitted from base stations 2 and 3 are added together and then fed to telephone 6 by multi-connecting device 16.
On the other hand, a up-link 140 of telephone 6 is connected to multi-connecting device 16 via path switch 30. A speech PCM signal on up-link 140 is applied to a distributor 80 via selector 40. Distributor 80 distributes the PCM signal to two output lines. The distributed PCM signals are fed via selector 40 and path switch 30 to down-link 110 of base station 2 and down-link 130 of base station 3, respectively. Thus, it will been seen that the signals from telephone 6 are distributed to base stations 2 and 3.
The above example shows an arrangement of the multi-connecting device that can be applied to a digital exchange. However, a three-party communication equipment used in an analog exchange or a multiconnecting device having the same function as the above example may be used instead. | A mobile communication system comprises at least one mobile switching center for accommodating through respective networks a plurality of radio base stations each having an independent radio zone area, the mobile switching center being connected to a telephone through a wire speech path, a mobile station connectable to each of the radio base stations through a radio speech channel; and a multi-connecting device contained in the mobile switching center and having a network between the switching center and an old base station left by the mobile station during communication, a network between the mobile switching center and a new base station entered by the mobile station, and a wire speech path between the mobile switching center and the telephone. When the mobile station moves across adjacent radio zone areas of base stations during communication, the mobile switching center detects the movement of the mobile station to cause the multi-connecting device to multi-connect the aforementioned networks and wire speech path so that a channel is changed while maintaining the communication of the mobile station. | 7 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to holey fibres and to a method of fabricating holey fibres and holey fibre preforms.
[0002] A holey fibre is an optical fibre whose optical confinement mechanism and properties are affected by an array of air holes defined by cavities that run lengthwise down the fibre. Light can be guided within holey fibres by two distinct mechanisms. First, with periodic arrangements of air holes, guidance can be obtained through photonic band gap effects [1]. Second, guidance can be obtained from volume average refractive index effects. This second guidance mechanism does not rely on periodicity of the air holes [2].
[0003] Generally, a holey fibre has a solid core (FIG. 1A of the accompanying drawings) or a hollow core (FIG. 1B of the accompanying drawings) surrounded by a holey cladding region. The holey fibres illustrated have a hole structure characterised by a hole diameter, d, and an interhole spacing, i.e. pitch, Λ.
[0004] A holey fibre structure is fabricated by stacking tubular capillaries in a hexagonal close packed array within a larger tube that forms an outer jacket or casing containing the capillaries. To form a solid core holey fibre as in FIG. 1A, one of the tubular capillaries is removed from the stack and replaced with a solid rod of the same outer dimensions. To form a hollow core holey fibre as in FIG. 1B, a number of capillaries in the centre of the stack are removed. The fibre stack is then drawn into a preform by a caning procedure and then placed in a fibre drawing tower and drawn into fibre. The finished holey fibre structure is then characterised by an inner core (solid or hollow) surrounded by a holey cladding. Fabrication of holey fibres is discussed further in the literature [3][4].
[0005] To realise holey fibres for many applications, it is desirable to fabricate a holey fibre with relatively small feature sizes, such as interhole spacing, i.e. pitch, Λ˜1-2 microns. Fibres with such small hole feature sizes have a number of interesting and unique properties such as anomalous dispersion at short wavelength, high optical nonlinearity and the possibility for large evanescent fields in air.
[0006] To satisfy the desire for small pitch, it is necessary to construct a preform structure with relatively small capillaries. Because of the small size of the capillaries, several hundred capillary elements are needed to provide a structure which is large enough to handle conveniently during the fabrication stages of preform caning and fibre drawing. Moreover, to be practical, the fabricated fibre needs to have an outer diameter of about 80 microns or more. However, the large number of small capillaries required to fulfil these requirements presents difficulties in the fabrication and also results in a weak fibre.
[0007] An improvement is to stack the capillaries within an outer jacket which has a relatively thick wall, as shown by FIG. 2 of the accompanying drawings which shows a thick wall silica outer jacket 1 defining an inner cylindrical space in which is placed two rings of silica cladding capillaries 2 which are arranged concentrically about a centrally placed solid silica core 4 . In the illustrated example, the inner space of the outer jacket 1 is additionally sleeved by a vycore tube 3 . The dimensions included on the top of the figure are exemplary preform dimensions in millimetres, whereas the dimensions at the bottom of the figure are target fibre dimensions in microns. Use of a thick wall outer jacket has the advantage of allowing the number of capillaries required to be greatly reduced.
[0008] The thick wall outer jacket approach has been demonstrated by other groups. However, in the experience of the present inventors at least, it has proved difficult to reliably and controllably retain small hole features during the fibre pulling stage of the fabrication process when using such thick walled outer jacket structures. It is believed that this problem is attributable to the relatively small ratio of air to glass in the thickwalled structure, and to the relatively large thermal mass of the glass of the outer jacket as the preform is melted in the drawing tower furnace during the fibre drawing process.
[0009] It is therefore an aim of the invention to provide an improved method for fabricating holey fibres with relatively small feature sizes.
SUMMARY OF THE INVENTION
[0010] According to a first aspect of the invention there is provided an optical fibre structure comprising a holey fibre arranged in a holey outer support structure.
[0011] The holey outer support structure preferably has a lateral feature size at least five or ten times greater than that of the holey fibre.
[0012] The holey fibre may have a solid or hollow core surrounded by a holey cladding which may comprise cavities arranged in a plurality of rings concentrically about the core, e.g. 2-6 or more rings.
[0013] The holey outer support structure is conveniently made of an arrangement of tubular structures, each of roughly the same lateral dimensions as the holey fibre. The lateral dimensions are preferably between one fifth and five times that of the holey fibre, preferably between one half and twice that of the holey fibre. The holey outer support structure may conveniently further comprise an outer jacket surrounding the tubular structures.
[0014] An optical fibre structure embodying the invention possesses a microstructured transverse cross section in which the microstructuring in the holey fibre itself is on the scale of the wavelength of the light guided by the holey fibre, but is on a considerably coarser scale within an outer holey structure supporting the holey fibre (e.g. five times, ten times or a greater multiple of the wavelength).
[0015] With the invention it is possible to produce robust, coated and jacketed fibres with microstructured core features relatively easily using existing fibre fabrication technology.
[0016] According to a second aspect of the invention there is provided an optical fibre preform comprising: (a) a core rod; (b) a plurality of cladding capillaries arranged around the core rod; (c) an inner jacket containing the cladding capillaries; and (d) a plurality of support capillaries arranged around the inner jacket. The preform may further comprise an outer jacket containing the support capillaries.
[0017] According to a third aspect of the invention there is provided a method of making a holey fibre preform comprising: (a) arranging a core rod and a plurality of cladding capillaries within a first jacket; (b) arranging the first jacket and a plurality of support capillaries in a second jacket to form a tube assembly; and (c) reducing the tube assembly to a preform. The support capillaries may be arranged within an outer jacket.
[0018] According to a fourth aspect of the invention there is provided a method of making a holey fibre comprising: (a) making a holey fibre preform according to the method of the third aspect; and (b) drawing a holey fibre from the preform. The support capillaries may be arranged within an outer jacket.
[0019] According to a fifth aspect of the invention there is provided a method of guiding light along a holey fibre structure comprising a holey fibre arranged in a holey outer support structure, the light having a mode field extending in a cross-sectional plane through the holey fibre, wherein the mode field is mainly confined in the holey fibre. In other words, the structure is designed so that the holey outer support structure does not contribute in any significant way to the optical guiding properties of the holey fibre contained within it. Preferably, the mode field has less than one of 10%, 5%, 2%, 1%, 0.5% and 0.01% of its power extending beyond the holey fibre into the holey outer support structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings in which:
[0021] [0021]FIG. 1A is a schematic section of a solid core holey fibre;
[0022] [0022]FIG. 1B is a schematic section of a hollow core holey fibre;
[0023] [0023]FIG. 2 is a schematic diagram of a holey fibre preform according to a prior art approach;
[0024] [0024]FIG. 3 is an end view of a holey fibre preform according to an embodiment of the invention;
[0025] [0025]FIG. 4 is a cross-section of a holey fibre structure according to an example of the invention;
[0026] [0026]FIG. 5 is an expanded view of the holey fibre region of the holey fibre structure of FIG. 4; and
[0027] [0027]FIG. 6 is a cross-section of the holey fibre region of a holey fibre structure according to another example of the invention.
DETAILED DESCRIPTION
[0028] In order to get around the problem of applying a relatively thick-walled jacket, of large thermal mass, to a relatively fine microstructured inner cane, an approach has been adopted in the embodiments described below that may be viewed as replacing the thick wall outer jacket of the prior art approach of FIG. 2 with a combination of an outer thin wall jacket and an inner stack of relatively large capillaries. A microstructured inner cane containing the core and holey cladding is then supported by the larger scale capillaries.
[0029] [0029]FIG. 3 is an end view of a holey fibre preform according to this approach. The preform comprises an inner cane 14 containing the elements that will form the holey fibre after fibre drawing. Although not clearly evident from this figure, the central region comprises a solid core rod surrounded by a plurality of small capillaries arranged around the core rod, which ultimately form the holey cladding of the fibre. The rod and capillaries are retained in an inner jacket which forms the outer surface of the inner cane. The small cladding capillaries are arranged in one or more rings concentrically about the core rod. Generally at least two rings of cladding capillaries will be needed for most holey fibre applications. In fact, two is a preferred number, since it represents the smallest number of rings for providing the optical properties desired in many applications. The number of rings may be greater, e.g. three, four, five, six or more, but it should be borne in mind that very large numbers of capillaries will present fabrication difficulties, as described further above in relation to the prior art.
[0030] The inner cane 14 is supported by a plurality of relatively large-scale support capillaries 12 arranged around the inner cane. The support capillaries are retained in a relatively thin outer jacket 10 . In an alternative embodiment, the outer jacket could be dispensed with and the support capillaries fused together at the top and bottom prior to pulling to hold them together. As can be seen from the figure, the support capillaries have an outside diameter approximately the same as the outside diameter of the inner cane 14 , so that the inner cane can be arranged with the support capillaries in a hexagonal close packed array. More generally, it is convenient for the support capillaries to be of the same order of magnitude of lateral dimension as the inner cane. Preferably the support capillaries have lateral dimensions of between one fifth and five times that of the inner cane, more especially between one half and twice that of the inner jacket.
[0031] The capillaries can be made in a variety of ways. Typically, the starting point for the capillaries is a large-scale tube. The large-scale tubes can be produced by: extrusion, milling and drilling, polishing, piercing, spin/rotational casting, other casting methods (e.g. built-in casting), compression moulding, direct bonding etc. The tubes are then caned down using a fibre draw tower to the dimensions required for the preform assembly.
[0032] With this preform design, the thermal mass of the supporting structure used to bulk out the central region of the holey fibre is significantly reduced in comparison to a thick-wall outer jacket used in the prior art. It is thus easier to pull the preform and to retain the desired form of microstructure within the vicinity of the central holey fibre region.
[0033] The completed preform is then ready for the next main stage of fibre drawing. For drawing, the preform is placed in a fibre drawing tower. Fibre drawing is performed by the controlled heating and/or cooling of the silica or other glass through a viscosity range of around 10 6 poise. It is useful to monitor the diameter and tension of the fibre as it is being drawn and use the data thus acquired in an automatic feedback loop to control the preform feed speed, the fibre draw speed and/or other parameters related to the furnace in order to yield a uniform fibre diameter.
[0034] A principal component of the drawing tower used to pull the preform into fibre form is a heat source, which may be a graphite resistance heater or a radio-frequency (RF) furnace.
[0035] It is critical to control the fibre drawing temperature, and hence the glass viscosity, so that two criteria are met. First, the fibre drawing temperature must soften the glass to provide a viscosity for which the glass can deform and stretch into a fibre without crystallisation. Second, the softening of the glass must not be so great that the crucial internal structure, i.e. the holes, collapse and flow together. Cooling is provided above and below the furnace's hot zone. The cooling keeps the glass outside the hot zone cooled to below its crystallisation temperature.
[0036] [0036]FIG. 4 is a cross-section of a holey fibre structure according to an example of the invention which has been drawn from a preform generally of the kind illustrated in FIG. 3.
[0037] It is evident that the basic structure of the preform has been retained in the drawn holey fibre structure. Namely, the drawn holey fibre structure comprises a holey fibre 20 arranged in a holey outer support structure. The holey outer support structure comprises an arrangement of tubular structures 22 laterally bounded by a relatively thin wall outer jacket 24 of outer diameter approximately equal to 250 microns. The outer dimensions is preferably at least 80 microns. A preferred range of outer dimensions is 80 microns to between 1-5 mm. The internal structure of the holey fibre at the centre of the structure is just visible in FIG. 4, but is better seen in the enlarged view of FIG. 5.
[0038] [0038]FIG. 5 is a magnified view of the centre region of the holey fibre structure shown in FIG. 4. The holey fibre comprises a solid core 32 surrounded by a cladding 30 comprising hole rings generally concentrically arranged about the core. It will be understood that the holes will not form perfect circles around the core owing to the realities of the drawing process. The term concentric is thus not to be construed with any geometric rigour in this document. The cladding is in turn surrounded by the remnant 28 of the outer jacket of the preform. In other embodiments of the invention, the core could be hollow instead of solid, for example for photonic crystal fibre.
[0039] As well as the holey fibre of FIG. 5, a range of other similarly capillary-supported holey fibres of various dimensions have been pulled. By contrast, the inventors attempts to produce fibres with a thick outer jacket, according to the prior art approach described above with reference to FIG. 2, have been tended to result in loss of structural integrity of the core.
[0040] The large change in lateral feature size between the holey fibre on the one hand and the support tubes on the other hand is apparent. The support capillaries preferably have an outside diameter at least five or ten times greater than that of the holey fibre 20 .
[0041] In FIG. 4 it can be seen that the holey fibre 20 has an outside diameter somewhat smaller than that of the support capillaries 22 . Generally, these two lateral dimensions will be comparable. Specifically, it is preferred that the tubular support structures 22 have lateral dimensions of between one fifth and five times that of the holey fibre, more especially between one half and twice that of the holey fibre.
[0042] [0042]FIG. 6 is a cross-section of the central region of another holey fibre structure according to the invention. In this example, a larger number of cladding capillaries were used in the preform to form a larger number of generally concentric hole rings in the cladding. Otherwise the example of FIG. 6 will be understood from the previous description.
[0043] Although the above examples uses tubes as a basis for the holey fibre preform, it will be understood that other shapes -could be used either in the holey support structure or for the holey cladding part of the structure. It is sufficient that the holey outer support structure and holey cladding have a sufficient number of gaps or cavities to provide the desired properties. It will also be understood that the hole arrangement in the support structure will generally have no bearing on the optical properties of the fibre, since the fibre waveguide modes will usually have no significant power outside the holey cladding. Periodic or aperiodic arrangements may be used. It will also be understood that the holes in the cladding need not be periodic, unless the fibre is intended to have photonic crystal effects.
[0044] Holey fibre structures according to the invention may find application in many of the areas previously proposed to be of interest for holey fibres.
[0045] One application is sensing. It has been proposed that a fluid, i.e. gas or liquid, is present in the fibre cavities. A property of the fluid is then sensed by its effect on that part of the optical mode, generally an evanescent wave part, which propagates in the holey cladding region.
[0046] Another application suggested for holey fibres is for low-loss telecommunication fibre. Propagation losses may be reduced in a holey fibre, by virtue of the lower losses associated with the holes relative to the glass regions of the fibre. More fundamentally, a holey fibre with a photonic band gap could reduce losses through photonic crystal effects.
[0047] Some specific applications of interest are:
[0048] 1) transport of high power optical beams (low optical non-linearity fibre);
[0049] 2) low-loss optical fibre for transmission systems;
[0050] 3) optical sensors (gas detection, liquid composition, medical);
[0051] 4) atom optics;
[0052] 5) optical manipulation of microscopic particles;
[0053] 6) particle separation (by mass, induced polarisability, electric dipole moment);
[0054] 7) Raman lasers;
[0055] 8) non-linear optical devices;
[0056] 9) referencing of a laser to specific gas absorption lines:
[0057] 10) metrology; and
[0058] 11) dispersion compensation in transmission systems (holey fibre structures embodying the invention can be made to exhibit high dispersion).
REFERENCES
[0059] 1. T A Birks et al: Electronic Letters, vol. 31, pages 1941-1943 (1995)
[0060] 2. U.S. Pat. No. 5,802,236: DiGiovanni et al: Lucent Technologies Inc.
[0061] 3. P J Bennett et al: Optics Letters, vol. 24, pages 1203-1205 (1999)
[0062] 4. P J Bennett et al: CLEO '99, CWF64, page 293 | An optical fiber structure having a holey fiber arranged in a holey outer support structure made up of holey tubes encased in a thin walled outer jacket. The holey fiber may have a solid core surrounded by a holey cladding having a plurality of rings of holes. With the invention it is possible to produce robust, coated and jacketed fibers with microstructured core features of micrometer size relatively easily using existing fiber fabrication technology. This improvement is a result of the outer holey structure which reduces the thermal mass of the supporting structure and makes it possible to reliably and controllably retain small hole features during the fiber fabrication process. | 6 |
RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/179,892 filed May 20, 2009.
BACKGROUND
A typical scintillator crystal package 100 is assembled from the individual parts shown in FIG. 1 . A scintillator crystal 102 is wrapped or otherwise surrounded by one or more layers of a preferably diffuse reflective sheet that is preferably formed from a fluorocarbon polymer. The wrapped crystal 102 can be inserted in a hermetically sealed housing 104 which may already have the optical window 106 attached. The window 106 may be sapphire or glass, as noted in U.S. Pat. No. 4,360,733. The housing 104 may then be filled with a silicone (RTV) that fills the space 114 between the crystal 102 and the inside diameter of the housing 104 . Optical contact between the scintillator crystal 102 and the window 106 of the housing 104 is established using an internal optical coupling pad 108 comprising a transparent silicone rubber disk.
Alternatively, the scintillator may be surrounded by a reflecting powder that is chemically and mechanically compatible with the scintillator material. Such powders could be Al 2 O 3 , TiO 2 , BaSO 4 or similar materials. The powders can be packaged directly around the scintillator crystal 102 or be supported in a reflecting or transparent elastomer. With proper surface preparation, metallic reflectors such as Ag can be used as well, if they are chemically inert in the presence of the scintillator material.
An end cap is sealed over the open end to complete the scintillator package 100 and prevent exposure of the scintillator crystal 102 to air that would degrade performance. An internal spring 110 pushing against the scintillator 102 through a pressure plate 116 may be included to provide axial force on the scintillator crystal 102 to insure that optical contact is maintained. These general processes are known to those familiar with the art, as described in U.S. Pat. No. 4,764,677.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a hermetically packaged scintillator.
FIG. 2 is a graph showing 137 Cs spectra of a scintillator crystal before and after heating.
FIG. 3 is a graph showing initial 137 Cs spectrum of a scintillator crystal package of the invention.
FIG. 4 is a graph showing 137 Cs spectrum of a new package tested at 175° C. with transplanted subassembly.
FIG. 5 is a graph showing 137 Cs Spectrum from new package with pressure treated internal assembly after successive heating to 175° C. and 200° C.
FIG. 6 is a diagram of a scintillator package with ribs to avoid pressure over a large fraction of the reflector.
FIG. 7 is a diagram of a scintillator package with ribs touching the surface of the scintillator directly, where the space between the ribs is filled with a reflecting material.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
We have identified a flaw in sealed packages (as described above with respect to FIG. 1 ): heating the sealed package to high temperature results in degraded performance that can be substantial and unpredictable. The typical degradation can be quantified by measuring a gamma ray spectrum using a standard photomultiplier connected to a multichannel analyzer. The package can be measured at room temperature after exposure to specific time and temperature heating cycles. The 137 Cs spectra resulting from multiple such cycles are shown in FIG. 2 . Each cycle results in a reduction in light output which represents diminished performance.
The thermally induced degradation identified above could be attributed to outgassing from the reflective and elastic materials that surround the crystal. The vapor phase compounds released may interact with the air sensitive scintillator or condense to form a layer with reduced reflectivity on or in the reflecting material to cause this degradation. We disclose here methods to minimize the effects of outgassing by carefully selecting the materials used inside the package and individually pretreating the materials with a high temperature bake in vacuum or inert gas prior to applying them to the scintillator crystal. Silicone elastomers may be vacuum baked at about 200° C. for at least 12 hours or alternately baked at least to 200° C. in vacuum, N 2 or inert gas. The pure dry N 2 supply is preferably from the boil off of a liquid N 2 supply. The inert gas may consist of any noble gas such as He, Ne, Ar, Xe or other nonreactive gas including CO 2 . The purpose of the vacuum or gas atmosphere is to remove the low molecular weight impurities. The temperature used for baking the part should be at least as high if not slightly higher than the maximum expected operating temperature of the packaged scintillator assembly. For a 200° C. scintillator, the preferred baking temperature could be at or about 225° C., if such temperature is compatible with the material being heated.
The following describes the presently disclosed methods applied to the packaging of NaI(Tl), which is the preferred embodiment. However, the present disclosure applies to any scintillator crystal packaging that is hermetically packaged and ultimately to reflectorizing and packaging of any scintillators, including those that are not air-sensitive.
The scintillator crystal itself (in the present disclosure, NaI(Tl)) is also stabilized before packaging by annealing at high temperature in an inert gas or a controlled reactive atmosphere. The scintillator crystal can be heated in an ultra high purity inert gas to at least 200° C. A vacuum atmosphere can also be used in which air has essentially been excluded. Best results may be obtained by taking care to avoid heating or cooling rates that exceed 5° C./min depending on the material and crystal size.
Alternately, the scintillator crystal can be heated in a flowing stream of a reactive gas. For best results, the reactive gas should be free of oxygen and water vapor. The reactive gas may contain some amount of HI, I 2 or a halogenated organic compound like CH3I, CH 2 I 2 , CHI 3 , Cl 4 or other appropriate halocarbon that may be carried over the crystal surface by an inert medium. This process can be carried out at room temperature but a higher temperature of at least 200° C. is preferred.
Degradation may still take place even if the components are pre-treated separately as described herein, including independent heating of the scintillator, reflective wrapping, optical coupling and shock mounting materials. The degradation is easily observed by making direct pulse height measurements using a packaged NaI/Tl scintillator. A 137 Cs spectrum can be collected using a standard laboratory PMT connected to a multichannel analyzer. This standard laboratory system can also be calibrated using a packaged reference scintillator that is not heated so that it remains stable over time. The prototype package can then be exposed to temperature excursions and returned to room temperature to measure the effect of the temperature induced performance change. In such testing, the same prototype package was initially heated to 150° C. for 50 hours then to 175° C. for an additional 50 hours. The results are shown in FIG. 2 , revealing that moderate thermal testing resulted in a total decrease in relative light output of 23% even though the internal parts had been heated prior to the assembly of the sealed package. The horizontal axis in the graph 130 represents the light output from the scintillator package 100 . The curve 132 represents the initial performance at room temperature. After heating to 150° C. for 50 hours the spectrum 134 is obtained with the scintillator back at room temperature. Further heating to 175° C. for an additional 50 hours results in the spectrum 136 . The reference spectrum 138 was taken before and after the measurements with a reference crystal that was not heated to test the stability of the system.
If, however, the parts are assembled and then baked in a confined space that simulates the tubular housing, additional degradation can be limited after the housing is sealed. The confined bake need not include the scintillator crystal. It is possible to bake the materials assembled around a cylindrical part having the same dimensions as the scintillator crystal. The cylindrical crystal form may be manufactured from a metal such as aluminum alloy, a high temperature polymer like TEFLON™, or even glass. It is likely that this confined bake stabilizes the material by allowing the internal packaging materials to equilibrate with not only the applied temperature but also with the pressure developed from thermal expansion of the materials around the scintillator crystal material while constrained by the outer housing. The effects of temperature and pressure will likely result in material changes in the package materials, in a complex way, which cannot be duplicated outside the package environment.
Possible explanations for the material changes might include the cold flow of the fluoropolymers diffuse reflective wrapping. Cold flow takes place in many fluoropolymers at room temperature when pressure is applied. Cold flow can be mitigated to some extent by using inorganic fillers, but the most common filler would result in degraded optical properties. It is possible that the use of unconventional fillers could actually boost reflective performance. These unconventional fillers may include MgO, Al 2 O 3 , TiO 2 , BN, and BaSO 4 fillers, but generally fluoropolymers with these fillers are not commercially available.
Cold flow can be accelerated if the temperature is raised. Polymer properties are also a function of their crystalline content, which can be modified by both heat and pressure. Formation of an ordered phase in polymers can have dramatic effect on both optical and mechanical properties. A stable crystalline content can be achieved by aging under the actual conditions in which the polymer will be used.
Another possible effect that could be at work in the confines of a package is compression set. When a polymer with elastic properties is compressed for a period of time, it will tend to recover only a fraction of its original shape when the compression force is released. This is true for all plastics, and the amount of relaxation is a function of the amount of compression and the temperature. The preferred way to duplicate the conditions is to expose the elastomer parts to the package environment prior to sealing.
The experimental method on which these observations are based will be described here. A scintillator package was assembled using carefully prepared materials. The housing materials were carefully cleaned and the internal materials along with the housing were baked in dry N 2 at 200° C. The scintillator crystal was also annealed and a thin surface layer was removed by light abrasion to provide a clean surface free of superficial contamination. The scintillator crystal was then baked at 200° C. in a UHP Ar-gas. The individual parts were assembled into the housing and the housing was hermetically sealed by means of fusion welding.
The assembled scintillator package was placed in optical contact with a photomultiplier (PMT) maintained at room temperature. The scintillator package was thermally isolated from the PMT so that the scintillator package could be heated while maintaining the PMT at ambient temperature. A low activity 137 Cs source was used to excite scintillation pulses that can be used to reconstruct a nuclear spectrum showing the number of counts per unit energy. This nuclear spectrum can be directly applied to calculate the effective light output of the scintillator package as a function of time at temperature. This is shown in the graph 150 in FIG. 3 in the Relative Light Output 154 curve (circles). The light output is calculated by measuring the position of the 137 Cs photoelectric peak at 662 keV.
Initial heating shows a drop in light output as indicated by the change in relative peak position from the initial reference value at 100% to a value of about 85%. Much of this initial decrease is a result of the intrinsic temperature dependent properties of the Thallium doped Sodium Iodide scintillator crystal. This temperature dependent change is reversible. On cooling, the light output increases as the crystal package slowly returns to room temperature. The curve 154 (squares) shows the time evolution of the photopeak resolution over the same time period. The plot shows that there is a permanent loss in light yield of about 6% after heating for only a few hours. This can be put in perspective by considering that the prior methods/designs allowed for a change of 3% after a 50 hour bake at 200° C.
During testing of the initial package, damage resulted to the window assembly. The package was disassembled in an effort to understand what had caused the damage and also to recover the undamaged components. It was found possible to extract the entire crystal subassembly, which was then loaded into a new housing. The new housing was sealed and tested as before. The results are shown in graph 170 in FIG. 4 .
The initial expected drop in light yield 154 is about the same as before but stabilizes after only about 4 hours after reaching 175° C. Upon cooling recovery is 98% of the initial value and resolution 152 is essentially identical. The same package was successively heated to 175° C. and 200° C. for a soak time of 50 hours at each temperature. No change in light yield was detected as shown in graph 190 in FIG. 5 , which shows the initial spectrum ( 192 ), the virtually indistinguishable spectrum 194 after 50 h at 175° C. and the possibly slightly shifted spectrum 196 after an additional 50 h at 200° C.
According to our disclosure, proper heat and pressure treating of the materials used in the construction of a sealed scintillator are effective steps in assuring stable performance at elevated temperatures. The pressure treatment may result in a loss of performance of the reflecting material, which is at least in part due to cold flow of the material. This leads to a smoother surface and reduced diffuse reflectivity. Diffuse reflectivity can be enhanced by wrapping or otherwise mounting the reflecting material around a mechanical core with the same dimensions as the crystal. The surface of the mechanical core can be made rough, so that the reflecting material retains or develops a surface roughness conducive to good diffuse reflectivity as it cold flows on the core.
Since the cold flow of the material and its better conformance to the scintillator surface reduces the reflectivity, it is possible to reduce this effect by not applying pressure equally over the entire surface of the crystal. Ribs can be used separated by spaces over which there is no compressive force on the reflecting material. An example is shown in FIG. 6 . The scintillator 102 is surrounded by the reflector 202 and the assembly is held in place inside the housing 104 by the ribs 204 .
Alternatively, the scintillator may be held by a protrusion, such as the ribs shown in FIG. 7 . The (reflecting) ribs 204 or protrusions touch the scintillator directly and space between them is filled with a reflecting powder 223 . The ribs are held in place by an outer sleeve 224 , which may be made of the same material as the ribs. The ribs contain the powder and reduce the possibility that the powder moves and compacts under shock and vibration. The considerations described here also apply to scintillator packages that are mounted directly on to the PMT window without the intermediary of a package window. The package can be integrated with the PMT or other suitable photodetection device in the same sealed envelope and still be subject to the considerations discussed here.
The scintillator packages described above are suitable for use at high temperatures and in an environment with large mechanical stresses. Scintillator packages can be combined with a suitable photodetection device to form a radiation detector. The photodetection devices can be a photomultiplier, position sensitive photomultipliers, photodiodes, avalanche photodiodes, photomultipliers based on microchannel plates (MCPs) for multiplication and a photocathode for the conversion of the photon pulse into an electron pulse.
A typical scintillation detector comprises a PMT (photomultiplier) and a scintillation crystal. The scintillation detector is coupled to the entrance window of the photomultiplier by an optical coupling layer to optimize the transmission of the light from the scintillator package to the PMT. It should be noted that it is also possible to mount a scintillator directly to the PMT with only a single optical coupling and making the combination of PMT and scintillator into a single hermetically sealed package.
Given their properties, such detectors are well suited for use in downhole applications for the detection of gamma-rays in many of the instruments known in the art. The tools in which the detectors are used can be conveyed by any means of conveyance in the borehole.
While oilfield applications are of particular interest, scintillator packages and scintillation detectors of the invention may be used in any field or industry where usage of such types of crystals and devices are known, including but not limited to chemistry, physics, space exploration, nuclear medicine, energy industry use, including oilfield use, devices determination of weights and measurements in any industry, and the like, without limitation.
The invention has been disclosed with respect to a use with hygroscopic scintillators, in particular NaI(Tl). However the methods described, apply also to the construction of high temperature stable packaging for non-hygroscopic scintillators such as LuAP:Ce, LuYAP:Ce, LuAG:Pr, GSO:Ce and LPS.
Additionally, while the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention. | Methods for pre-treating packaging materials of particular composition for use in conjunction with a scintillation crystal are disclosed. The packaging materials may comprise a reflecting material, an elastomer, a reflecting fluorocarbon polymer, a polymer or elastomer loaded with a reflecting inorganic powder (including a reflecting inorganic powder comprising a high reflectance material selected from the group comprising Al 2 O 3 , TiO 2 , BN, MgO, BaSO 4 and mixtures thereof), or a highly reflective metal foil selected from the group comprising Ag and Al that is chemically compatible with the scintillator crystal. The scintillator crystal may comprise a crystal selected from the group comprising NaI(Tl), LaBr 3 :Ce, La—Cl 3 :Ce, La-halides, and La-mixed halides. The method includes subjecting a scintillator packaging material to a pre-treatment while in package form, said treatment selected from the group consisting of heating to a temperature exceeding a proposed operating temperature of the scintillator package, and placing the packaging material under pressure in a confined space until the packaging material is in final form. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a holder for arranging a specimen in a microscope for measuring a biological tissue or the like with a high spatial resolution, a probe microscope using the holder, and a specimen measurement method using the microscope.
BACKGROUND ART
[0002] In the case of measuring, evaluating and controlling a biological reaction such as adhesion of a cell to a biological base material in a culture solution, or subsequent extension and differentiation, hydration of biological molecules, biological tissues, biological base material or the like is important. In this case, the hydration structure shows a three-dimensional structure formed by an interaction between a specimen surface and water molecules and interactions including hydrogen bonding between water molecules, on a specimen-culture solution interface in a culture solution containing water as its principal component (NPL 1). So-called biocompatibility represented by adhesion between the inner wall of a blood vessel prosthesis and red blood cells or the like is considered to be closely related to this hydration structure. Moreover, ruggedness, potential distribution, composition distribution and sequence structure or the like of molecules and proteins or the like, on a specimen surface in a culture solution are particularly important characteristics for biological reactions of biological molecules, biological tissues, biological base material and the like in the culture solution.
[0003] As techniques for observing and measuring a specimen-culture solution interface of a biological molecule, biological tissue, biological base material or the like in a culture solution, optical microscopes and nonlinear optical microscopes based on the Raman spectroscopy, the second harmonic method, the sum frequency spectroscopy or the like are conventionally used. Particularly, the sum frequency spectroscopy can measure the sequence structure of water molecules that is related to the hydration structure on a specimen-culture solution interface. As a nonlinear optical microscope, for example, PTL 1 discloses a surface-selective nonlinear optical method using second harmonic light or sum frequency light based on water molecules, solvent molecules, or a marker substance near the interface with respect to an interaction between a probe and a target.
[0004] Meanwhile, a scanning probe microscope is based on atomic force microscopy (AFM). A scanning Kelvin probe microscope, which is an example of a scanning probe microscope, is a technique in which while an electrostatic field force acting between a cantilever with a conductive probe and a specimen is detected as a flexure of the cantilever, the probe is made to scan the surface of the specimen, thereby mapping electrostatic field force distribution. Since an atomic force or the like, other than the electrostatic field force, is applied to the probe, the electrostatic field force needs to be separated from other interactions. To do this, first, the cantilever is made to oscillate to adjust the probe-specimen distance in such a way that the oscillation amplitude reduced by the atomic force acting when the probe and the specimen contact each other is kept constant. Thus, the position in the direction of height of the specimen surface is decided, and in the state where the probe is moved away from the specimen surface by a predetermined distance from there, the electrostatic field force as a long-distance force is detected from phase change in the oscillation of the cantilever (for example, PTL 2).
CITATION LIST
Patent Literature
[0000]
PTL 1: U.S. Pat. No. 7,139,843
PTL 2: JP-A-2011-27582
Non Patent Literature
[0000]
NPL 1: Second Harmonic and Sum Frequency Generation Imaging of Fibrous Astroglial Filaments in Ex Vivo Spinal Tissues, Yan Fu, Haifeng Wang, Riyi Shi, and Ji-Xin Cheng, Biophysical Journal, Apr. 30, 2007.
SUMMARY OF INVENTION
Technical Problem
[0008] A sum frequency microscope using a laser, which is a typical nonlinear optical microscope, is used to investigate the distribution and order of electron state, bond orientation and molecular orientation on a photocatalyst interface, surface adsorption system, semiconductor interface, and superconductor surface. However, since its spatial resolution is approximately 1 μm, the sum frequency microscope cannot observe micro structures.
[0009] Meanwhile, a scanning probe microscope can operate in a culture solution and can achieve a high resolution of approximately 10 nm by a relatively simple operation. However, since the probe and the specimen surface must contact each other in order to detect the position of the specimen surface, there is a problem that a detected signal becomes unstable if the probe tip gets broken or the specimen surface adheres thereto during measurement.
[0010] Also, in the case where measurement is to be carried out while maintaining survival conditions for a cell as a measurement object, if the temperature of about 37 degrees, which is one of the survival conditions for the cell, is maintained, the water (liquid, for example, culture solution) surrounding the cell evaporates and consequently there is a possibility that the survival conditions cannot be maintained because of the drying of the cell itself. As a result, it is impossible to acquire physical information from the cell or cell surface while maintaining the survival conditions for the cell.
[0011] However, the above conventional examples do not consider this point and do not describe a holder for holding a measurement object.
Solution to Problem
[0012] Thus, the invention is provided in the form of a measurement holder including: a container in which a measurement object such as a cell is housed; a first cover section which covers at least a part of the measurement object and has an aperture for inserting a measurement probe; and a second cover section which is connected to the first cover section, covers the container, and has an aperture for inserting the measurement probe.
[0013] Also, using this holder, a cell or the like is measured with a probe microscope.
Advantageous Effect of Invention
[0014] According to the invention, since a good condition of a specimen can be maintained without evaporation of a culture solution or the like, the degree of orientation of water molecules on the interface between biological molecules, biological tissues, biological base material or the like and water can be measured in a culture solution with a high spatial resolution while maintaining survival conditions for a cell, and the aggregation position and function of a specific element in a cell or cell cluster can be specified.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 shows a holder structure ( 1 ) disclosed in the invention.
[0016] FIG. 2 is an example of a configuration view of a probe microscope.
[0017] FIG. 3 shows a holder structure ( 2 ) disclosed in the invention.
[0018] FIG. 4 shows a holder structure ( 3 ) disclosed in the invention.
[0019] FIG. 5 shows a holder structure ( 4 ) disclosed in the invention.
[0020] FIG. 6 is a view of change with time in heart rate of a cultured cardiac muscle cell.
[0021] FIG. 7 shows a holder structure ( 5 ) disclosed in the invention.
[0022] FIG. 8 shows a holder structure ( 6 ) disclosed in the invention.
[0023] FIG. 9 shows a holder structure ( 7 ) disclosed in the invention.
[0024] FIG. 10 shows a holder structure ( 8 ) disclosed in the invention.
[0025] FIG. 11 shows a holder structure ( 9 ) disclosed in the invention.
[0026] FIG. 12 shows a holder structure ( 10 ) disclosed in the invention.
DESCRIPTION OF EMBODIMENTS
[0027] The invention discloses the structure of a specimen holder in the case of measuring a biological specimen and water specimen represented by a cell and water in a probe microscope. Prior to this disclosure, the structure of a scanning probe microscope (scanning Kelvin probe microscope) for measuring the distribution of an electrostatic field force acting between the probe and the specimen is disclosed in FIG. 2 .
[0028] In this example ( FIG. 2 ), a probe-enhanced scanning sum frequency microscope as a form of scanning probe microscope is disclosed. A probe 1 is installed on an oscillator 2 and its relative position to a specimen 3 is controlled by the oscillator 2 . For the probe 1 , a material such that the intensity of near-field light is amplified and concentrated near its tip when placed in incident light is selected. Meanwhile, if Raman scattering is used as in Raman spectroscopy, sum frequency spectroscopy or the like, a metal such as gold, silver, copper or aluminum, or a compound of these is used, in which surface enhanced Raman scattering can be used effectively. A probe formed by vapor-depositing a thin gold film with a thickness of 1 to 20 nm on a silicon probe is used as an effective probe candidate. Also, in this example, the oscillator 2 oscillates mainly in a perpendicular direction to the specimen 3 . The distance between the probe 1 and the specimen 3 is controlled to 300 nm or below. Also, 200 kHz to 2 MHz is used as the specific frequency of the oscillator 2 . While a crystal oscillator which expands and contracts in a longitudinal direction is used as the oscillator 2 in this example, a tuning fork-type crystal oscillator generally used in a scanning probe microscope such as atomic force microscopy, a piezoelectric element-based oscillator, an oscillator having a piezoelectric element arranged on a cantilever, or the like can be used.
[0029] By the oscillator 2 , the probe 1 is made to oscillate in a perpendicular direction to the surface of the specimen 3 at a frequency close to the specific frequency of the oscillator 2 (within approximately ±1% of the specific frequency). An interaction (force) between the probe 1 and the specimen 3 generates a phase difference between the voltage applied to the oscillator 2 and the actual oscillation amplitude of the oscillator 2 . With respect to the phase difference, in this example, based on the phase difference between the AC voltage applied to the oscillator 2 and the current flowing in the oscillator 2 , the interaction (force) between the probe and the specimen is found and the distance between the probe and the specimen is found. Also, by scanning the relative position between the specimen 3 and the probe 1 in a perpendicular direction to the specimen and in a planar direction of the specimen by a scanning mechanism 4 while keeping this phase difference constant, it is possible to configure atomic force microscopy (AFM), which is a method of the scanning probe microscope, and to measure ruggedness on the specimen surface. The distance between the probe 1 and the specimen 3 is generally as close as 0 nm (contact) to 100 nm when in the closest position. However, the probe 1 can be sunk into the specimen 3 . Also, by scanning the relative position between the specimen 3 and the probe 1 in a perpendicular direction to the specimen and in a planar direction of the specimen by the scanning mechanism while reducing the oscillation amplitude of the oscillator 2 by a predetermined amount, it is possible to achieve the distance of 0 nm between the probe 1 and the specimen 3 when in the closest position (tapping mode AFM).
[0030] A specimen holder 5 can hold and replace a culture solution 6 . Also, water or a solvent can be used instead of the culture solution 6 .
[0031] A pulse laser beam or a plurality of synchronously inputted pulse laser beams is inputted near an area of the specimen 3 to which the probe 1 comes close, and the intensity of output light 8 is measured by a detector with filter 7 . In this example, a first pulse laser beam 9 which is a green pulse laser beam with a wavelength of 532 nm, and a second pulse laser beam 10 which is an infrared pulse laser beam with variable wavelengths of 2.3 to 10 microns, are inputted synchronously. The output light 8 is inputted to the detector with filer 7 , and the intensity of the frequency as the sum of the frequency of the first pulse laser beam 9 and the frequency of the second pulse laser beam 10 is measured. By recording the intensity of the output light 8 of the sum frequency, which is dependent on the frequency of the second pulse laser beam 10 , sum frequency spectroscopy is feasible. In this example, by comparing a peak with a wave number of 3200 kayser and a peak with a wave number of 3400 kayser, the rate of orientation of water molecules that are bonded asymmetrically with tetrahedrally coordinated water molecules on the interface between polycarbonate and the culture solution 14 can be specified.
[0032] While an example using pulse laser beams is described above, the pulse lasers and the detector are not essential in the case of measuring only the specimen surface.
Example 1
[0033] At the time of performing measurement, a specimen needs to be heated. At this time, evaporation of water, a culture solution or the like needs to be restrained and measurement needs to be realized while a cell is still alive. The structure of a specimen holder that is necessary to realize this is shown in FIG. 1 . To realize a structure that facilitates insertion of the probe 1 into the holder, the structure is characterized in that a cylindrical hole is provided inside the holder. 11 is a cover and has a cylindrical hole 12 at its center. Also, 13 is a culture solution intake port and is provided to perform resupply to make up for the evaporated culture solution and water in order to maintain the temperature of the holder during the measurement (approximately 37° C. is considered desirable, but this temperature is not limiting). The culture solution intake port can also be used to discharge a liquid (culture solution) when the liquid has deteriorated.
[0034] 14 is a holder main body (container) and is fixed by the cylindrical hole 12 and the spacer 15 . To supplement the structure shown in this FIG. 1 , explanation is given using FIG. 3 . This FIG. 3 is a side view of FIG. 1 . The holder cover 11 , the cylindrical hole 12 and the culture solution intake port 13 are provided concentrically. The spacer indicated by 15 is provided at a bottom part of the cylindrical hole. In this manner, a first cover section which covers apart of a specimen 18 , a second cover section (holder cover) 11 which covers the holder main body 14 , and a connecting section which connects the first cover section and the second cover section are provided. The first cover section is provided with a hole 26 through which the probe 1 passes. The second cover section (holder cover) 11 , too, is provided with a hole 12 through which the probe 1 passes. The connecting section is a cavity.
[0035] These first cover section, connecting section and second cover section are connected to the holder main body 14 .
[0036] Here, the spacer 15 is provided as a pad corresponding to the height of the specimen 18 . However, if the specimen is flat or the like, the spacer is not necessarily essential since the hole 26 is provided. Also, while the shape of the spacer 15 is illustrated in FIGS. 1 and 3 , an arbitrary shape can be employed since it is for padding.
[0037] Also, while the holder cover 11 , the cylindrical hole 12 and the culture solution intake port 13 are described here as concentric, the hole 12 may have other shapes as long as the probe can pass through the hole. Of course, the shape of the culture solution intake port 13 need not be circular and may be in any shape. Also, though the holder cover is shown as having a columnar shape since the holder main body 14 is columnar, the holder main body is not limited to columnar and may be in an arbitrary shape as long as the holder main body can hold the specimen 18 . Accordingly, the holder cover 11 may be connected in an arbitrary shape to the holder 14 .
[0038] Also, to maintain the survival conditions for the specimen 18 for a long time, it is preferable to warm the specimen 18 . If measurement ends in a short time, a heater for warming is not essential. In the case of warming, a heater 16 is connected to the holder main body 14 , as shown in FIG. 3 , and the temperature of the specimen holder is maintained. Also, for the purpose of measuring the temperature of the specimen holder, a temperature sensor 17 formed with a Peltier element or the like is connected. The specimen 18 represented by a cell or water can be arranged on this holder main body. Here, the configuration in which the holder main body 14 and the heater structure 16 are connected together has an advantageous effect in terms of costs, because the heater structure 16 can be used repeatedly even if the holder main body is discarded as a disposable item.
[0039] FIG. 4 is a view of actual mounting of the holder. The holder cover 11 and the holder main body 14 are in tight contact with each other and the spacer 15 is held in the state of light contact on the specimen 18 . The probe 1 passing through the cylindrical hole 12 can approach the top of the specimen, in the form of penetrating the holder and the spacer.
[0040] The actual method for using the holder shown in the drawings up to FIG. 4 is shown in FIG. 5. 19 is a control device for the probe microscope and is configured to carry out processing of the position of the probe 1 and the amount of light reaching the detector with filter 7 . 20 is a control device for the heater. 21 is a detection device for the temperature sensor. The control device for the heater indicated by 20 and the detection device for the temperature sensor indicated by 21 are connected to each other and can set a predetermined desired temperature by controlling the temperature via a feedback system. The information of these set temperature and detected temperature, and the control device 9 for the probe microscope are connected to each other, and it is an electronic computer 22 that serves as a hub for transmission of such information.
[0041] Using the holder disclosed in this example, image measurement of the heart rate of a cultured cardiac muscle of a rat (cardiac muscle cell culture kit by Primary Cell Co, Ltd.) is carried out. First, the heater 16 is warmed as an advance preparation. Meanwhile, the specimen kit 18 is arranged on the holder 14 and impregnated with a culture solution. Afterwards, the holder cover 11 is set via the spacer 15 . Then, while the temperature of the holder is kept substantially constant using the heater 16 and the sensor 17 , the surface shape and the state of the cell are observed for slightly less than an hour, using the oscillator 2 , the probe 1 and pulse irradiation light. The culture solution is replenished through the hole 13 from time to time. The result of this is shown in FIG. 6 . Although the preset temperature is 39° C., the temperature on the holder surface is 37° C. It is difficult to keep the heart rate perfectly constant due to the environment of the culture container. However, a heart rate of approximately 100 per minute is successfully maintained.
Example 2
[0042] In this example, a modification of the holder is described. In the holder shown in FIG. 1 , water and the culture solution are to be inputted from above the holder cover. However, in practice, there is a possibility that the culture solution may deteriorate, and a structure to avoid interference with the probe of the probe microscope needs to be provided. To solve these problems, a method for realizing injection and collection of water and the culture solution more easily is disclosed in FIGS. 7 and 8 .
[0043] FIG. 7 discloses a holder characterized by having a culture solution discharge port 23 in addition to the culture solution intake port 13 . This discharge port 23 is characterized by being provided on the lateral side of the holder. This is because it can easily realize discharge of the liquid that has deteriorated inside the holder, without obstructing the approach of the probe approaching from above, as described above.
[0044] Moreover, FIG. 8 discloses a structure in which the culture solution intake port 13 , too, is provided on the lateral side of the holder. This enables realization of both injection and discharge of the culture solution in the form of avoiding the influence of interference with the probe. Meanwhile, in practice, it is possible to control the amount of injection and the amount of discharge by using a micro-syringe or the like, along with the injection and discharge. It is possible not only to carry out injection and discharge artificially but also to perform these controls using the electronic computer shown in FIG. 5 .
[0045] Replenishing and collecting the culture solution as in this example has an effect that measurement can be carried out while the survival conditions are maintained, even if the measurement takes a longer time.
Example 3
[0046] In this example, a modification of the method for carrying out temperature measurement with respect to the holder is described. In the holder structures described in Examples 1 and 2, the heater is installed in the bottom part of the specimen holder, and the heater and the temperature sensor are integrated. However, in this disclosed method, there is a possibility that the temperature may be different from the temperature with the actual specimen, due to the thermal conductivity of the holder. Thus, in this example, an invention relating the arrangement position of the sensor is disclosed.
[0047] In FIG. 9 , a structure in which the temperature sensor 17 is inserted inside the holder main body is provided. This enables measurement of the temperature of the specimen 3 in the form of correctly reflecting the thermal conductivity of the holder formed with a plastic material or the like.
[0048] Meanwhile, FIG. 10 discloses a specimen holder characterized in that the temperature on the surface of the specimen 3 is measured using an optical fiber sensor 24 . With this method, the installation of the temperature sensor 17 on the specimen holder 5 is no longer necessary and a simpler specimen holder can be realized.
[0049] Moreover, FIG. 11 discloses a structure of the specimen holder 5 characterized in that the specimen holder 5 is heated by irradiation with electromagnetic waves represented by a laser or light using an optical fiber 25 instead of the heater 16 . It is desirable that the wavelength of the laser used for actual irradiation is in an infrared range or an adsorption wavelength band of the material of the specimen holder, considering that the specimen is a biological substance. By thus casting electromagnetic waves (light) from outside, the influence of electromagnetic noise at the time of measurement can be reduced better than in the case where the holder is directly heated by the heater.
Example 4
[0050] In this example, an attachment/removal structure of the holder is shown in FIG. 12 . By thus enabling the holder cover 11 to be attached to and removed from the holder main body 14 and the spacer 15 , it is possible to replace the cell within the holder main body (container) 14 and re-measure the cell. The top and bottom in FIG. 12 can each be cleaned and used repeatedly. Also, even during measurement, opening to the atmosphere from time to time enables the cell to breathe and further enables long-time measurement while maintaining survival conditions at high levels.
REFERENCE SIGNS LIST
[0000]
1 probe
2 oscillator
3 specimen
4 scanning mechanism
5 specimen holder
6 culture solution
7 detector with filter
8 output light
9 first pulse laser beam
10 second pulse laser beam
11 holder cover
12 cylindrical hole
13 culture solution intake port
14 holder main body
15 spacer
16 heater
17 temperature sensor
18 specimen
19 control device for probe microscope
20 control device for heater
21 detection device for temperature sensor
22 electronic computer
23 culture solution discharge port
24 optical fiber sensor
25 optical fiber for electromagnetic wave irradiation
26 hole | At the time of carrying out measurement of a biological tissue with a probe microscope, measurement is to be realized while maintain survival conditions for a cell.
As a holder for the probe microscope, a measurement holder including: a container in which a measurement object is housed; a first cover section which covers at least a part of the measurement object and has an aperture for inserting a measurement probe; and a second cover section which is connected to the first cover section, covers the container, and has an aperture for inserting the measurement probe, is used. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to automatic small flow control valves which can be used in place of needle valves for the fine control of liquid or gaseous fluid in a process system.
Quite often chemical processes require the control of corrosive or poisonous fluids. Conventional needle valves have stuffing boxes which are prone to leakage, which in turn can create a substantial health hazard to operating personnel.
Flow control valves using a diaphragm seal (see my U.S. Pat. No. 4,549,719) eliminate the need for packing. However, the travel is severely limited as it must stay within the elastic deflection range of the selected diaphragm material. This then excludes finely tapered, splined or grooved needle valve plugs, since these devices require a relatively large valve travel. Simple valve orifices shown in U.S. Pat. No. 4,549,719, again, are limited by the inability to drill small enough holes into a sometimes hard metal alloy. It is for this reason that the application of diaphragm sealed valves has been limited generally to a Cv number of 0.03 where the Cv coefficient defines the number of US gallons per minute of water passing an orifice or valve at a pressure loss of one pound per surface inch.
My present invention overcomes this limitation by providing for the insertion of a flexible valve member whereby the grooved portion which is normally located parallel to the cylindrical axis of a needle plug, is now located approximately parallel to the surface of the sealing diaphragm and therefore can be covered or uncovered by a relatively short motion of the sealing diaphragm.
Furthermore, by placing an opening through the conical portion of the valve member, a two stage throttling phenomena can be achieved which greatly limits the fluid velocity and associated erosion in such a valve.
Thirdly, the valve insert, as described later in more detail, can be easily exchanged with one of a different opening to suit the users preference for flowing quantities without the need to make time consuming adjustments, calibration or lapping.
All of these advantages are more clearly explained in the following detailed description.
DESCRIPTION OF DRAWINGS
FIG. 1 is a vertical, central, cross-sectional view showing a manually operated species of my invention with the valve element in the open position.
FIG. 2 shows the central portion of the valve depicted in FIG. 1, wherein the valve element is in the closed position.
FIG. 3 is an external isometric view of the valve member of my invention, when removed from the housing structure, showing a radially grooved flow passage.
FIG. 4 is an external isometric view of the valve member of my invention, when removed from the housing structure, showing a spiraled grooved as flow passage.
DESCRIPTION OF THE INVENTION
The subject invention comprises a housing 5 having two threaded ports 6 and 7 serving as either inlet or outlet passages.
The top portion of housing 5 terminates into an upper surface 8 which sealingly engages a flat diaphragm 9 typically made from a high tensil stainless steel or other alloy material. A threaded bonnet 10 compresses said diaphragm and in addition retains a threaded spindle 11 of a hand wheel 12 which by means of an anvil 13 is able to push diaphragm 9 downwards.
Housing 5 has a second, central, flat surface 14 being part of a raised portion within a cavity 15. A central port 16 connects between inlet and outlet passages 6 and 7. Slidingly engaged therein is a valve member 17 comprising a lower tubular extension 18 and an upper conical portion 19. The tubular extension 18, furthermore, retains an O-ring seal 20 capable of sealing the gap between the exterior of extension 18 and the wall surface of port 16.
In the configuration shown in FIG. 1, the upper portion of the outer conical wall portion 19 is in tight contact with the lower surface of sealing diaphragm 9 at rim 21 while the lower inner surface of the conical wall portion 19 is supported by the intersection 22 between the surface 14 and port 16. An orifice 23 is drilled into the conical wall portion 19 and is capable of conducting fluid between passage 6, via cavity 15, the hollow portion 24 of the tubular extension 18 and body passage 7. Any fluid passing through orifice 23 has to enter from a relatively narrow entrance portion (see flow arrow). There are therefore two successive throttling stages each having sharp 90° turns for the fluid to be controlled. This leads to a 40% reduction of fluid velocity necessary to achieve a desired pressure reduction. This in turn will reduce the possibility of erosion, cavitation or other undesirable throttling phenomena.
When hand wheel 12 is turned and anvil 13 presses diaphragm 9 downward, the distance "h" between conical wall portion 19 and flat surface 14 is gradually reduced leading to a linear decrease in the exposed flow area passages 23 until, as shown in FIG. 2, "h" is reduced to zero and the flow passage is closed completely.
Where it is impractical to drill a small enough hole for passage 23, my invention provides for alternative configurations of valve member 17. In FIG. 3, the flow passage used to conduct fluid from cavity 15 to opening 24 can be a groove 25 extending radially inward from rim 21. Typically, this groove has a triangular cross-section which diminishes in depth when approaching opening 24.
In an alternative arrangement, a groove is machined in a spiral geometry 26, commencing with its largest cross-sectional profile where it penetrates rim 21 and ending its depth in close vicinity to opening 24 (see FIG. 4). The latter configuration has some production merits since the spiralled groove can be cut on an engine lathe and does not require a separate milling operation. Furthermore, the fluid is forced to travel through an extended length of passageway expending considerable dynamic energy through wall friction, leading again to desired reduction in fluid velocity for a desired pressure loss.
In the foregoing example, my invention is illustrated as being operated by a hand wheel, however, in an automated process, hand wheel 12 would be replaced by a suitable pneumatic or electrical operating device as typically shown in my U.S. Pat. No. 4,684,103.
Finally, it is possible to omit the tubular extension 18 of valve member 17 and invert the conical portion 19 so that rim 23 is supported by surface 14 while sealing dipahragm 9 compresses the central periphery around hole 24.
These and numerous other changes such as using differently shaped flow passages in valve member 17 from those illustrated are possible without violating the scope of the following claims: | Flow Control Valve, capable of precisely regulating fluid flow, utilizing a part conical valve member having an integral flow passage which can be flattened by a sealing diaphragm motivated by a suitable actuating mechanism, whereby the flow passage within the valve member is closed. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The invention relates generally to the fields of toys and sporting equipment and in particular to stuffed animals with or without interactive electronic components, and to football kicking tees.
[0005] Stuffed animals and other soft plush toys are well known in the prior art and are common in the toy collections of children and adults alike. Also well-known in the prior art are electronic stuffed toys that produce light or sound upon the activation of one or more controls or sensors; such toys range from the relatively unsophisticated (e.g. toy speaks when a single button is pressed) to the sophisticated (e.g. toy responds to user's verbal input).
[0006] Similarly, football tees, or devices designed to hold an American football so that it may be kicked are well known in the art, and are available in many designs and constructions for children and adults.
[0007] Unknown in the art, however, are devices that place the football tee inside the arms of a stuffed toy. Also unknown are devices in which the stuffed toy that holds the football tee is capable of electronically sensing the placement and kicking of a football, and of presenting feedback to the sensed activity.
SUMMARY OF THE INVENTION
[0008] Accordingly, the invention is a stuffed toy that holds a tee, optionally equipped with an electronic feedback system that senses activity on the tee and responds with feedback for the user.
[0009] An object of the invention is to provide the kicker of a football, whether adult or child, with additional pleasure from looking at a stuffed toy and perceiving it to be holding the football for the kicker to kick.
[0010] Another object of the invention, when the invention employs electronic feedback to the user, is to help the user improve his or her kicking skills through pointers that the device provides based on what it senses of the action.
[0011] Additional features and advantages of the invention will be set forth in the description which follows, and will be apparent from the description, or may be learned by practice of the invention. The objectives and advantages of the invention will be realized and attained by the structure, particularly pointed out in the written description as well as the provided drawing.
[0012] The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawing is included to provide a further understanding of the invention and is incorporated into and constitutes a part of the specification. It illustrates one embodiment of the invention and, together with the description, serves to explain the principles of one embodiment of the invention. In the drawings:
[0014] FIG. 1 shows a front view of the first exemplary embodiment of the invention showing the kicking tee 1 , stuffed toy 2 , football 3 and stuffed toy arms 4 .
[0015] FIG. 2 shows a logical diagram of the electronic components of embodiments employing an electronic feedback system, showing a microprocessor, computer memory, data storage medium, power source, sensors, visual feedback devices, and auditory feedback devices.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to the invention in more detail, FIG. 1 illustrates the first exemplary embodiment of the invention. The invention comprises the combination of a tee ( 1 ) connected and a stuffed toy ( 2 ), connected by any means suitable for withstanding a hard kick. Many suitable stitches, adhesives, and other fasteners are known in the art, and may be of varying effectiveness depending on the materials used in the stuffed toy ( 2 ) and tee ( 1 ).
[0017] The stuffed toy ( 2 ) may be of any material or construction, of which many are known in the art, and its shape may be any animal (as with the stuffed bear shown in the drawing), character, or object. Where the appearance of the stuffed toy ( 2 ) resembles that of a human, non-human animal, or other real or fantastic creature or object having arms or arm-like appendages, the stuffed toy arms ( 4 ) may be positioned to appear as though they are holding the ball ( 3 ) or tee ( 1 ) for the user. The stuffed toy ( 4 ) need not be two in number; embodiment having stuffed toy arms ( 4 ) may have only one arm ( 4 ) or more than two arms ( 4 ). Alternatively, the shape of the stuffed toy ( 2 ) may be abstract, with or without appendages that fulfill the role of the stuffed toy arms ( 4 ). The choice of the shape, size, color, and tone of the stuffed toy ( 2 ) will determine each particular embodiment's target market.
[0018] The tee ( 1 ) contemplated in preferred embodiments of the invention is one designed to hold an American football ( 3 ), however the tee ( 1 ) may be shaped to hold any type of ball or object that the user might wish to kick or strike so as to send the American football ( 3 ) or other ball or object flying away from the user. Many designs and constructions of tees are known in the art, and any may be employed in the invention.
[0019] Optionally, the invention may include an electronic feedback component, sewn or otherwise internally incorporated into the stuffed toy ( 2 ), comprising a microprocessor, computer memory, digital storage medium, one or more sensors, one or more visual or auditory feedback devices, and a battery or other power source. These components may be either directly or indirectly connected, for example via a main bus, and may be in communication through any of many well-known methods, such as mounting on a printed circuit board or connection by wires.
[0020] The microprocessor, computer memory, and digital storage medium are all well-known in the prior art, and may be of any type suitable for use with each other and with the attached battery in the environment of a stuffed animal.
[0021] The battery or other power may be of any design, and many are known in the prior art. The battery may be replaceable, in which case it must be placed in a housing sewn accessibly into the stuffed toy. Alternatively, the battery may be rechargeable, in which case it must be connected to a power jack sewn accessibly into the outside of the stuffed toy ( 2 ), and suitable for connection to wall power using a common AC/DC converter of appropriate input and output voltage. In yet another alternative, the electronic feedback component may be configured so as to operate exclusively from wall power provided through an AC/DC converter of appropriate input and output voltage.
[0022] The employed sensors are of any type suitable for measuring and producing an electronic signal from whichever aspect of the ball ( 3 )'s motion through the tee ( 1 ) that the designer practicing the invention wishes to measure. Many electronic sensors that measure various relevant quantities are well-known in the prior art. Examples include a pressure switch to detect the presence or absence of a ball ( 3 ) in the tee ( 2 ), a force gauge to detect the force of the user's kick, and a RADAR or LIDAR sensor to measure the speed of the ball ( 3 ) leaving the tee ( 1 ). Additional sensed quantities are contemplated.
[0023] The employed visual or auditory feedback devices may be of any design suitable for providing the feedback that the designer practicing the invention wishes to provide. In preferred embodiments, visual feedback is provided by LEDs of various sizes, colors, and brightnesses (many LED designs are known in the prior art). In preferred embodiments, auditory feedback is provided by one or more speakers (many speaker designs are known in the prior art).
[0024] Finally, stored on the digital storage medium is a software program, which automatically loads into the computer memory for execution on the microprocessor. The software program comprises the combination of the following functional components, all of which are well-known in the prior art: (I) the ability to receive input based on the signal produced by the sensor or sensors; (II) the ability to send signals to the feedback devices to provide desired feedback; and (III) the ability to retrieve and play back sound recordings and visual sequences from the data storage medium (said sound recordings and visual sequences may be placed on the storage medium at the time of manufacture, or the invention may include functionality to store the user's own sounds and visual sequences); and (IV) logic (readily programmed by one of ordinary skill in the art) that relates particular sensor input signals to particular output signals, which may represent sounds or visual sequences to be played back, said logic may be calibrated to measurements for good kicking technique or may simply be arbitrary or humorous (for example, a sound clip may be played to poke fun at the user's performance, regardless of the performance quality), depending on the particular embodiment's target market.
[0025] While the foregoing written description of the invention enables one of ordinary skill to make and use what is presently considered to be the best mode thereof, those of ordinary skill in the art will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should, therefore, not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. | A stuffed toy resembling an animal figure holds a kicking tee. The toy is optionally equipped with an electronic feedback system that senses activity on the tee and responds with feedback for the user. | 0 |
FIELD OF THE INVENTION
This invention relates to a method of sewing large area sewing material which consists of plural layers and of two layers at least, of which at least one layer is formed of an elastical material, for instance foamed material. A further subject of the invention is a multiple-needle sewing machine for sewing large area sewing material which consists of plural layers and of two layers at least, wherein at least one layer is formed of an elastical material, said sewing machine comprising a sewing unit, storage mechanism for the layers to be stitched, and storage means for withdrawing and receiving stitched layers from the sewing unit.
BACKGROUND OF THE INVENTION
Large area material is understood to be for instance mattress fabric that is to be stretched around mattress cores. The sewing material concerned is of the type including at least one layer of a non-elastical material and one layer of an elastical material, for example foamed material, to be stitched together, wherein the stitched seams are arranged according to a predetermined pattern and particularly do not run exclusively in one direction which means that arbitrary sewing patterns are produced such as bias check or check patterns, circular saw or circular patterns and quite arbitrary contours. With sewing material of that kind the problem arises that due to the common drive for all the layers up to the sewing unit the elastical layer is subject to an expansion in the longitudinal or feeding direction. This elastical expansion is caused particularly by the fact that the sewing material, i.e. at least the two layers mentioned above, is drawn towards the pressure foot and into the sewing unit via a support. On this occasion, the tractive forces are transmitted to the sewing material which is stitched after it has passed through the sewing unit and is rolled onto a storage means. Doing this, the layer of elastical material rests either directly or indirectly on the support in front of the pressure foot and needle plate. Due to the friction existing in this area between said support and said layer of elastical material the latter is expanded and is stitched together with the layer of non-elastical material in this expanded condition. When the now stitched material leaves the multiple-needle sewing machine and is either rolled onto the storage means or cut to individual segments, the elastical material will tend to assume its original expansion, i.e. it will shrink again. Due to the shrinking of the elastical material said non-elastical material will form folds that disturb particularly the aesthetic appearance of the article produced from that material, for example a mattress.
Basing on this prior art, it is a problem of the present invention to provide a method and a multiple-needle sewing machine of the type concerned, wherein the formation of folds in the stitched product is prevented in a simple and inexpensive way.
SUMMARY OF THE INVENTION
The solution of this problem provides for a method comprising the features of claim 1. Furthermore, the problem of the invention is solved by a multiple-needle sewing machine of the type concerned, wherein the sewing unit is topped with a device by means of which the layer of elastical material is, in an unexpanded and within the area of the device preferably bulged condition, fed to the sewing unit under maintaining said bulging, together with said at least one additional layer or additional layers.
Accordingly, an advantage of the method according to the invention resides in that the property of the layer of elastical material to expand due to friction is compensated by the fact that the elastical material is fed to the sewing unit in the unexpanded and preferably bulged condition. To this end, the layer of elastical material may be fed at a higher speed than the layer of non-elastical material so that for the sewing process a volume of elastical material which is higher than in prior art is stitched together with said layer of non-elastical material so that the formation of folds in the finished material is avoided by the fact that the elastical material cannot shrink at all or only to a small extent after the sewing process.
A further development of the method according to the invention provides for the layers to be conveyed through the sewing unit by means of a tractive force transmitted to the stitched material, particularly to the layer of non-elastical material. Accordingly, two forces are transmitted to the layer of elastical material, namely the tractive force by which the stitched material is withdrawn from the sewing unit, on one hand, and the force which is applied to the layer of elastical material due to the increased speed and by which said layer of elastical material is pushed towards said sewing unit, on the other hand.
A further feature of the invention provides for the unstitched layers to be guided under different angles via a deflection device before the layers enter said sewing unit between a pressure foot and a needle plate corresponding to a needle row or shuttle row. In this respect is has to be pointed out to the fact that the layer of elastical material, for example foamed material, has a greater material thickness than said layer of non-elastical material, for example mattress drill, and that guiding these two superposed layers over a deflection device leads to that the layer formed of elastical material is guided past said deflection device at a higher speed than the layer of non-elastical material, e.g. mattress drill, guided directly over said deflection device.
According to another feature of the invention it is provided that the layer formed of non-elastical material is fed to said deflection device under a larger angle relative to a plane of the deflection device preferably defined by the needle plate than said layer formed of elastical material. Here it is important that both layers are fed under an angle relative to the plane of the deflection device, wherein said layer of elastical material is fed preferably under an angle of at least 5 ° relative to said plane.
Alternatively it may be provided that the layer formed of elastical material is conveyed over a predetermined distance directly into the zone of the sewing unit by means of a driven conveying device, whereby the speed of the layer of elastical material is increased as compared to the speed of the layer of non-elastical material.
A particular advantage is that the layer formed of elastical material is bulged in the conveying direction at least in the zone in front of the sewing unit and that the layer formed of elastical material is fed to the sewing unit in said bulged condition and is stitched together with said layer of non-elastical material. Here it has shown to be an advantage that by the bulging of the elastical material and by the stitching of the bulged elastical material together with the non-elastical material the tendency of the elastical material to shrink after stitching does not exist, so that the formation of folds in the stitched non-elastical material is prevented. According to another feature of the invention it may be provided that the layer formed of elastical material is bulged corresponding to its possible expansion, so that the layer formed of elastical material expands to its original dimension after the stitching process. Accordingly, a compensation takes place of the tendency of the elastical material to expand due to the friction between said elastical material and the supporting surface over which the elastical material is drawn.
However, it is also conceivable that the layer formed of elastical material is bulged in front of the sewing unit to an extent which is greater than that of the possible and/or average expansion of the layer of elastical material along the conveying distance. In this way, the tendency of the elastical material to expand is overcompensated, so that the elastical material does not expand prior to its entry into the sewing unit but only after withdrawal of the stitched material and thus causes biasing of the layer of non-elastical material to a certain extent, by which biasing the formation of folds is prevented.
Finally, according to another feature of the invention it is provided that a further layer, preferably a fleece of chemical pulp and/or synthetic fibers, is additionally simultaneously fed with said layer of elastical material, wherein said layer of elastical material is arranged between said two layers.
Concerning the multiple-needle sewing machine according to the invention another feature provides that the device is configured as an at least circular arc segment-shaped deflection member that is arranged substantially directly in front of the pressure foot of the sewing unit. Said circular arc segment-shaped configuration has to extend over at least the portion which is necessary in order to guide said at least two layers over said circular arc segment corresponding to the predetermined angles, so that different relative speeds of said two layers will be produced. Preferably, said deflection member is in the form of a roller having a circular cross-section, onto which roller said layers ascend under different angles relative to the plane of the needle plate. It is further provided that the deflection member is arranged vis a vis a support, with a gap being maintained therebetween. Here it is an advantage that the layer of elastical material meets the layer of non-elastical material only shortly before the deflection point or at the deflection point of said circular arc segment-shaped device.
Preferably, the gap formed between the deflection member and the support is adjustable, so that material layers of different thickness may be processed, without adversely affecting the advantageous effect of the method or the multiple-needle sewing machine according to the invention. In this case, either the deflection member may be adjustable relative to said support or said support relative to said deflection member.
A further improvement of the multiple-needle sewing machine according the invention provides for the roller to be driven, so that through the drive of said roller an additional component force is transmitted to the layer of non-elastical material.
According to another feature of the invention it is provided that the deflection member is topped with a roller for guiding said layer of elastical material in such a fashion that this layer ascends the deflection member under an angle of at least 5 ° relative to the plane and that the layer of non-elastical material ascending between the layer of elastical material and the deflection member ascends said deflection member under an angle which is larger than the angle under which the layer of elastical material ascends. Preferably, said two layers to be superposed pass over two rollers which are arranged substantially horizontally one above the other, so that different ascending angles are produced in the zone of the deflection member.
An alternative form of construction of the multiple-needle sewing machine provides for the device to be formed as an endless conveyor including at least one conveyor belt onto which the layer of elastical material ascends. By means of this endless conveyor said layer of elastical material is moved at a higher speed than the layer of non-elastical material, so that bulging of this material takes place in front of the sewing unit. Particularly, it is provided that plural synchronized conveyor belts are arranged one beside the other, so that uniform movement of the layer consisting of elastical material is obtained throughout its width.
In order to maintain the bulging of the elastical material until a point immediately in front of the sewing unit, i.e. to avoid relaxing of the bulged material, another feature of this form of construction provides for the conveyor belt or belts to reach as far as up and into a zone directly in front of the pressure foot, so that the pressure foot clamps the layer of non-elastical material together with the layer of elastical material during the sewing operation.
In this respect it has shown to be an advantage that the conveyor belt or belts are surrounded by supporting surfaces at least in part-portions thereof, so that the layer of elastical material rests on said support or conveyor over its entire surface. Preferably, said supporting surface and the surface of said conveyor belts form an approximately flush surface. In this respect it is merely important that the conveyor belt or the conveyor belts protrude beyond said supporting surface to an extent which guarantees safe conveying of said layer of elastical material. Preferably, said supporting surfaces are arranged in the zone directly in front of the pressure foot and extend in the conveying direction of the sewing material.
Finally, another feature of the invention provides for the supporting surface to be formed as a dovetail sheet metal plate, of which the dovetails extend in the conveying direction and have arranged therebetween said conveyor belts.
Further features and advantages of the method according to the present invention and of the multiple-needle sewing machine according to the present invention will become apparent from the following description and the attached drawings representing a preferred embodiment of a multiple-needle sewing machine. In the drawings it is shown by:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a schematical side view of a multiple-needle sewing machine;
FIG. 2 a first embodiment of a device for increasing the relative speed of a layer, in a schematical lateral representation;
FIG. 3 a second embodiment of a device according to FIG. 2, in a partial lateral representation;
FIG. 4 the device according to FIG. 3 in a partial sectional side view along line IV--IV in FIG. 3, and
FIG. 5 the multiple-needle sewing machine according to FIG. 1 in a perspective view.
DETAILED DESCRIPTION
A multiple-needle sewing machine comprises a machine frame 1 having a needle row 2 in its upper part, wherein the individually driven needles are juxtaposed substantially vertically to the picture plane. Reference number 3 designates a conventional pressure foot and reference number 4 a shuttle row corresponding to the needle row 2. Below the sewing material layers brought together in the sewing area is arranged a needle plate 13 or sewing table.
The sewing material is comprised of a top layer 6, e.g. an upper cloth, mattress drill or the like, and is withdrawn from a supply roller 5 and guided into the sewing area, i.e. into the area between the pressure foot and the supporting plate 13, underneath an operator pedestal 7 via deflection rollers 8, 9, 10, 11 and 12. Said sewing material layer 6 consists of a non-elastical material. In addition, the sewing material comprises a further layer 15 of elastical material, for instance foamed material, which is stored on a supply roller 14. For this elastical layer 15, too guide or deflection rollers 16, 17, 18 and 19 are provided.
Said layer 15 of elastical material is stitched together with said top layer 6 of non-elastical material as well as with another layer 21 in the sewing unit and is withdrawn from the sewing unit as a completely stitched product in the direction of arrow 29, wherein the feeding of the layers 6, 15 and 21 is effected through the force acting on the completely stitched product 28. Past the sewing unit, said completely stitched product 28 passes a distance including deflection or guide rollers 25, 26 and 27, which distance provides for the sewing material 28 to be tightly stretched in the outlet area of the sewing unit.
The bottom layer 21, which is withdrawn from the supply roller 20, is fed to the sewing unit via deflection or guide rollers 22, 23 and 24, wherein the bottom layer 21 corresponding to FIG. 2 may also be fed together with the top layer 6 and the layer 15 of the deflection roller 12 which are described in detail in the following.
Vis a vis said deflection roller 12 a support 30 is provided, wherein the distance between the outer circumference of said deflection roller 12 and said support 30 is adjustable, which means that either the deflection roller 12 is movable relative to the support 30 or that the support 30 is movable relative to the deflection roller 12. Alternatively, it may be provided that both said support 30 and deflection roller 12 are adjustable in the vertical direction. This embodiment serves for adapting said multiple-needle sewing machine to layers 6 and 15 of different thickness, wherein said layer 15 of elastical material is much thicker than said layer 6 of non-elastical material. It is necessary that the deflection roller 12 acts on said material layers 6, 15 at a predetermined pressure in order to provide the required friction forces.
The deflection roller 12 represents a device topping said sewing unit, by means of which device the layer 15 of elastical material is fed to the sewing unit at a speed which is relatively higher than the speed of the layer of non-elastical material, wherein the layer 15 of elastical material is bulged within the area of the deflection roller 12 and is, under maintaining said bulged condition, fed to the sewing unit together with the top layer 6 and the bottom layer 21. To this end, the deflection roller for the top layer 6 is arranged above the deflection roller 19 for the layer 15, so that the top layer 6 ascends the deflection roller 12 under a larger angle relative to the surface of the support 30 or needle plate 13 than the layer 15 of elastical material which is guided over the deflection roller 19. In this respect it is necessary that both the top layer 6 and the layer 15 of elastical material ascend the deflection roller 12 under an angle which is larger than 5 ° relative to the upper surface of the support 30 or needle plate 13. Due to this construction the circumferential distance of the top layer 6 on the deflection roller 12 is smaller than the circumferential distance of the layer 15 of elastical material, since the radius of the deflection roller 12 is smaller than the radius of the deflection roller 12 plus approximately half the material thickness of the layer 15 of elastical material in which the neutral line is arranged, i.e. the line at which the elastical material during its wrapping around said deflection roller 12 is neither stretched nor bulged. By this construction the layer 15 of elastical material is given a slightly higher conveying speed than the layer 6 of non-elastical material, so that bulging of the elastical material is produced in the zone between the deflection roller 12 and the pressure foot 3, which bulged condition is maintained up and into the area of said one needle row 2 or plural needle rows 2 so that the top layer 6 in the stretched condition is stitched together with the bulged layer 15 of the elastical material. Thereby stretching of the elastical material due to the frictional resistance on the upper surface of the support 30 or on the bottom layer 21 is compensated with the consequence that shrinking of the previously stretched elastical material does not take place after the sewing process.
Depending on the configuration of the above-described device, the expansion of the elastical material can be compensated by a corresponding bulging, or bulging of the elastical material may be effected which overcompensates the expansion of the elastical material, so that after the sewing process the elastical material expands and stretches the top layer 6.
An alternative embodiment is shown in FIGS. 3 and 4.
In this embodiment the support 30 is formed as a dovetail sheet metal plate comprising a plurality of dovetails 31, wherein between said dovetails 31 a rectangular incision 32 is respectively provided in which a conveyor belt 33 is arranged. The incisions 32 extend to a point directly in front of the pressure foot 3, so that the conveyor belts 33 are also guided up and into this area. Each conveyor belt is arranged so that its upper surface fed to the pressure foot 3 slightly protrudes beyond the upper surface of the support 30 or dovetails 31 in order to ensure safe transfer of the layer 15 of elastical material, which layer is conveyed in the bulged condition between the pressure foot and the needle plate 13. FIG. 4 shows that besides the layer 15 of elastical material also the layer of non-elastical material is conveyed after passing the deflection roller in the area between the pressure foot 3 and the needle plate 13. For guiding the conveyor belts 33 each conveyor belt has one or plural deflection rollers 34 and 35, of which deflection roller 34 is arranged in the area directly in front of the pressure foot in such a fashion that the conveyor belt 33 is, at the end of the incision 32, guided into the portion below the support 30.
With this embodiment, the layer 15 of elastical material is conveyed by means of the conveyor belts 33 in the direction of the pressure foot 3 at a speed which is higher than the speed of the top layer 6, so that the elastical material of the layer 15 is bulged in front of the pressure foot 3 and is fed in this bulged condition to the portion between the pressure foot 3 and the needle plate 13 together with the top layer 6, wherein the two layers 6 and 15 are stitched together. In this way the same successful effect is obtained as in the above-described device according to FIGS. 1 and 2.
It can be seen in FIG. 5 that the pressure foot 3 and the needle plate 13 are not movable in the direction of the machine frame 1, whereas the support 30 is arranged to be movable relative to the pressure foot 3 and the needle plate 13 in the longitudinal direction of the machine frame 1, so that the sewing material of which only the top layer 6 of non-elastical material is represented in FIG. 5 is movable relative to the needle row 2 in such a way that any sewing patterns can be transmitted to the sewing material. For moving the support 30 an electric motor 35 is provided in the machine frame 1, said motor comprising a pinion 37 on its driving shaft 36 which pinion 37 meshes with the teeth of a toothed rack 38 rigidly connected to said support 30.
As an alternative to the deflection roller 11 for the layer of elastical material shown in FIGS. 1 and 2 a stationary rod may be provided which offers the advantage that the friction of the non-elastical material drawn over said rod stretches the layer 6 of elastical material between the rod and the roller 12. In this case, the friction in the area of the rod should be as high as possible, while the friction in the area of the deflection roller 19 should be as small as possible so that the layer 15 of elastical material is stretched as little as possible between the deflection roller 19 and the sewing unit.
The invention is not limited to the examples described. In The invention it is essential that during stitching the two layers 6 and 16 together the elastical layer 15, against its property to be expanded due to friction on the support 30, is in place for being stitched at an excessive amount of material so that shrinking of the previously expanded elastical material does not take place after the sewing process. | This invention relates to a method of sewing large area sewing material consisting of plural and at least two layers, of which at least one layer is formed of an elastical material, for instance foamed material, wherein said layers are fed to the sewing unit in a superposed relationship and wherein the layer of elastical material is fed to the sewing unit in an unexpanded and preferably bulged condition and is stitched together with the layer formed of non-elastical material. Such a method offers the advantage that the formation of folds in the stitched product is prevented in a simple and inexpensive manner. | 3 |
[0001] This is a Continuation-in-Part of U.S. patent application Ser. No. 11/163,223, filed Oct. 11, 2005, which application claims priority from Provisional U.S. patent application Ser. No. 60/618,488 filed Oct. 13, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of systems for cleaning the interiors of tanks by removing scale build-up using a fluid at high pressure and, more particularly, to a system and method for altering the axis of rotation and diameter of spray nozzles in such a cleaning system to maximize the efficiency of the cleaning process.
BACKGROUND OF THE INVENTION
[0003] Most tanks in chemical plants, refineries, and similar factories are custom designed vessels that have to be cleaned periodically. Since the tanks are custom designed and thus may have different interior geometries, no one cleaning system will work adequately for all tanks. Furthermore, vessels are typically divided with dividing plates which include centered through-holes or partially removable dividing plates. Also, many processes in these types of plants or factories leave a hard, tenacious scale on interior surfaces of tanks, which presents an especially difficult cleaning problem.
[0004] Commonly, such a tank has an entry point or access way which is small relative to the interior diameter and height of the tank. On the other hand, a typical tank has relatively large inner surface areas which require periodic cleaning to remove the buildup of materials left by the material kept in the tank, such as calcium and magnesium carbonates and similar residues. Thus, a single manufacturing facility may have a wide variety of tanks of varying sizes, each requiring this sort of periodic maintenance and at least some of the tanks presenting a different aspect of interior geometry versus the size of the entry point or access way.
[0005] That restriction presents the engineering dilemma of having to insert the tool through a small opening (so the tool has to be small), but requiring a substantial distance for a water jet from the tool, in order to reach the farthest surfaces of the interior of the tank. To remove hard scale from the interior surfaces of a tank, the water jet must be operated at a high pressure, for example at least 9,000 psi, and the jet must be positioned in close proximity to the tank wall surface, for example at six inches or closer, in order to be effective.
[0006] With all of these factors in mind, one can see that it is difficult to find a single cleaning tool that fits all tank sizes and applications while doing a good job of cleaning the interiors of all of the tanks. One current proposed solution available on the market uses a small volume, high pressure water cleaning tool that is positioned inside the vessel and moved along the center axis of the tank while several water jets rotate around one or two axes simultaneously. Since the water jets are directed more or less radially from one point inside the tank, the distances from the water jet exit ports to the vessel walls are substantial and change continuously. For portions of the interior tank wall that are more than six inches from the water jet, hard scale is not removed and remains on the wall
[0007] For this type of water jet cleaning system, surface coverage cannot be exactly controlled since the water jet tracks contact the interior surface of the tank at more or less random locations. For proper surface coverage, each track of the water jet should overlap the previous track by a small amount. If the track does not overlap a previous track, then a portion of the interior surface of the tank will not be cleaned. If there is too great an overlap, then the track will be directed too much to a portion of the interior surface which has already been cleaned and the process is therefore inefficient.
[0008] However, in many known systems, the tracks of the jets are directed more or less randomly. That means that in order to insure that the entire interior surface of the tank is cleaned, the cleaning process must be continued for a much longer period of time than would be required if the direction of the spray of the jets could be more closely controlled. Such systems are also inefficient since the majority of time the spray from the jets is not effective directed to the wall of the vessel, but either up or down away from the surface to be cleaned.
[0009] Furthermore, since the distance from the center axis of the tank, where the jets are typically located, to the interior surface of the tank may be several feet, hard deposits cannot be adequately removed and thus the cleaning process is more a flushing process.
[0010] Systems for cleaning the interior surfaces of a tank encounter another serious problem in that the inside of the tank typically includes structural support plates extending laterally inwardly toward the axis of the tank. These plates represent surfaces which must be cleaned, and also present obstacles for the movement of the cleaning tool within the tank or vessel. As the cleaning tool is lowered into a tank from an access point at or near the top of the tank, the interior obstacles within the tank must be considered when directing a high velocity jet from a point off the axis of the tank.
[0011] Another proposed solution to the problem of the variations in interior geometries of tanks to be cleaned takes advantage of automation technology. The interior geometry of the tank, including inside diameter, height, and interior obstacles, are set into a programmable controller and the tool is then run into the tank. Unfortunately, such systems are highly complex, require a long setup time, and are very heavy and expensive. Further, the time and expense required to program and debug the programmable controller is often longer and greater than the total cost of a satisfactory cleaning job without such a controller. Since the system must be re-programmed for each tank geometry, such systems are currently not cost effective.
[0012] Thus, there remains a need for a system for cleaning the interior surfaces of tanks which is flexible, effective, and efficient. The present invention is directed to filling this long felt need in the art.
SUMMARY OF THE INVENTION
[0013] The present invention addresses these and other drawbacks in the art to improve high pressure water cleaning of inner surfaces of tanks or vessels. This improvement is achieved by the tool's ability to unfold and fold so that the tool easily fits through small access openings and at the same time allowing the water jets to be positioned at optimal distances relative to the vessel wall for superior cleaning results, i.e. six inches or less from the water jets to the vessel wall, preferably between one and six inches. The folding and unfolding process is powered only by the water jet force and water pressure supplied to the jets. The folding and unfolding process is speed controlled using dampening devices. In the present invention, no electric or electronic components are used.
[0014] This invention synchronizes the transversal and rotational movements of water jets. While the jets are directed at a pre-adjusted distance to the vessel wall, they are moved in three dimensions. This movement results in a controlled spiral or helical cleaning track along the vessel walls. The travel speed of the water jets and the distance between adjacent cleaning tracks can be adjusted to match the cleaning needs so that there is a predetermined overlap from one cleaning track to the next. In this way, the entire inner surface of the vessel can be covered precisely. Once the cleaning tool has been moved from one end of the vessel to the other with the travel of the water jets controlled in that manner the vessel wall will have been thoroughly cleaned. The exact positioning of the water jets allows the removal of very hard deposits.
[0015] The rotational movement is powered either by water or air flow. A pneumatic-hydraulic device is used to convert the rotational movement into the additional transversal movement.
[0016] Thus, the present invention provides a vessel cleaning system for cleaning storage tanks, reactors, etc. in all industries. The system of this invention is directed to cleaning many different types of deposits, especially very hard deposits from vessel walls using high pressure water jets. A spray sub-system comprises a tool carrier with water jet nozzles attached thereto which unfolds by rotating and telescoping inside the vessel at the start of a cleaning cycle and folds up at the end of the cleaning cycle. The unfolding and folding procedure is required to get the tool carrier in and out of the tank through a relatively small access so that the cleaning system is still able to position water jets at a required distance to a vessel wall and therefore deposits to be removed from the vessel wall. The unfolding and folding procedure is speed controlled and simultaneously used to clean certain areas inside the vessel.
[0017] The unfolding and folding operation is strictly a mechanic and/or hydraulic process initiated with the starting and stopping of and powered by the high pressure water flow only. A combined rotational and transverse movement of the tool carrier and the unfolding and folding movement is controlled in a way that results in a spiral movement of the water jets when cleaning two dimensional flat surfaces and in a helical movement of the water jets when cleaning cylinder walls. All movements are speed controlled: the travel speed of jets and the pitch of the spiral and the helix are adjusted depending on the cleaning requirements for the deposit to be removed from the vessel wall. Impact properties of water jets on deposited materials can be maintained constant throughout the cleaning operation.
[0018] These and other features and advantages of this invention will be readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to embodiments thereof which are illustrated in the appended drawings.
[0020] FIG. 1 is a side section view of a tank cleaning system of the present invention in use within a tank having horizontally disposed dividing plates with vertical channels through the plates.
[0021] FIG. 2 is a side section view of the tank cleaning system within a tank with no internal dividing plates.
[0022] FIG. 3A is a side view of a tank cleaning sub-system.
[0023] FIG. 3B is a front view of the tank cleaning sub-system of FIG. 3A .
[0024] FIG. 3C is a detail view of an alternative spray nozzle for use on the tank cleaning sub-system.
[0025] FIG. 4 is a section view of a damping device for controlling the rate of rotation of a spray sub-system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] FIG. 1 illustrates a presently preferred embodiment of the tank cleaning system 10 of this invention in a tank 12 with dividing plates 14 and a center hole 16 in each dividing plate. The tank is circular in cross section and oriented vertically along an axis 13 . It should be understood that only a portion of the tank 12 is illustrated, and it may extend a substantial distance above and/or below the portion illustrated in FIG. 1 .
[0027] The system 10 comprises a feed sub-system 20 , a support 22 , and a nozzle jet sub-system 24 . The feed sub-system 20 includes a prime mover 26 which imparts lateral movement to a feed tube 28 as shown by an arrow 30 . The prime mover 26 also imparts rotational movement to the feed tube 28 , as shown by an arrow 32 . The feed tube carries fluid, typically water, under high pressure for cleaning the interior of the tank 12 as described in greater detail below. The high pressure fluid is provided by a high pressure source, typically a compressor (not shown) at at least 9,000 psi., and preferably at least 10,000 psi. in order to cut hard scale from the interior surface of the tank 12 .
[0028] The prime mover thus controls the lateral and rotational movement of the feed tube. The lateral movement of the tube is controlled at such a rate as to create a controlled helical movement of the spray from the nozzle jet sub-system 24 for complete and efficient cleaning, as described further below.
[0029] The feed tube 28 passes through and is supported by a feed pedestal 34 which also serves to support a feed tube sheath 36 . The feed tube sheath is a flexible, non-rotating conduit through which the rotating feed tube passes. The other end of the feed tube sheath 36 is coupled to the support 22 , which is typically mounted to a structural member 38 in the vicinity of the tank 12 . The feed tube sheath 36 has an opening 40 through which the feed tube 28 passes. The feed tube 28 is then directed downwardly into the tank 12 , where it continues to rotate as shown by an arrow 42 . Also, movement back and forth of the prime mover 26 as shown by the arrow 30 results in lateral movement of the feed tube 28 as shown by an arrow 44 . Thus, the jet sub-system 24 is supported by the feed tube and pulls down on the feed tube by force of gravity. Further, the jet sub-system 24 travels within the tank 12 coincident with the axis 13 of the tank.
[0030] The nozzle jet sub-system 24 is illustrated in FIG. 1 already deployed within the tank 12 . While FIG. 1 is not necessarily to scale, it should be recognized that the horizontal diameter of the tank is large compared to the horizontal diameter of the center hole 16 , so that the nozzle jet sub-system must be small enough in its own horizontal diameter to pass through the center hole 16 . Once through the center hole 16 , however, the nozzle jet sub-system must then direct high pressure fluid against the interior surfaces of the tank in order to adequately clean these surfaces. The present invention accomplishes this difficult task by providing two motions to the nozzle jet sub-system, to be described below in greater detail.
[0031] The nozzle jet sub-system 24 comprises a centrally disposed swivel 50 with at least two arms 52 extending therefrom. It should be noted that each such arm 52 must have a corresponding arm extending in the opposite direction (i.e. 180° therefrom) in order to counteract the thrust created by the jets. While the nozzle jet sub-system is being deployed within the tank 12 , the arms 52 extend substantially vertically, i.e. parallel with the direction of travel of the system and coincident with the axis 13 of the tank. Once the nozzle jet sub-system is properly positioned about midway between dividing plates 16 , the arms are rotated to a horizontal positioned, as shown in phantom in FIG. 1 . Then, nozzle extensions 54 telescope out to a deployed position, carrying a nozzle jet 56 on the end of each nozzle extension 54 to a position six inches or less from an interior surface 58 of the tank 12 . It should be noted that the arms 54 may also be flexible to assist in drawing them through small access holes or center holes in dividing plates.
[0032] To clean vessel walls 58 , the sub-system 24 must be properly positioned within the tank between divider plates. Once a portion of the tank is cleaned, the sub-system 24 is collapsed, repositioned through center hole 16 , and redeployed to clean the next portion of the tank. Thus, the distance between dividing plates within the tank must be greater than the length between nozzle jets before the extension arms are extended so that the sub-system 24 can freely rotate into position between divider plates. Further, once the sub-system 24 is horizontally deployed with the jets near the interior surface of the tank, the sub-system is then lifted until the extension arms, which are now parallel to the dividing plates, are as close as possible to the dividing plate immediately above the sub-system 24 so that the portion of the inside surface of the tank immediately beneath the divider plate will be properly cleaned.
[0033] Once the sub-system 24 is properly positioned within the tank, the feed tube 28 is pressurized with fluid, typically water at 9,000 psi or more, preferably at least 10,000 psi. The nozzle jets 56 are then activated and the telescopic extension arms 54 extend, thereby positioning the nozzle jets 56 to within 6″ of the vessel wall 58 . No dampening of extension arm movement is applied. With the activation of the nozzle jets, the sub-system 24 is then rotated about the vertical axis of the tank to direct the jet spray around the interior surface of the tank, as controlled by the feed system 20 .
[0034] With the start of the rotation of the sub-system 24 , the sub-system 24 is then lowered by feeding the high pressure feed hose 28 at a controlled feed rate. The feed rate is determined by a predetermined length of feed for each rotation of the sub-system 24 to provide some overlap for each track of the spray against the interior surface of the tank. Since there are two opposing jets, the track of one jet is interleaved with the track of the opposing jet. Each jet thus forms a spiral track that overlaps the next adjacent track formed by the other jet, and the spiral centers on the axis 13 . As used herein, the term “track” refers to the area contacted by one jet spray.
[0035] Once the sub-system 24 has been lowered as much as possible, thereby cleaning the portion of the tank between the dividing plates, the nozzle jets are stopped and the telescopic arms are retracted. The sub-system 24 is then centered between the dividing plates and the extension arms are rotated into a vertical position. The tank cleaner can now be lowered in the next tank section between the next set of dividing plates.
[0036] Note that the preceding detailed description was directed to cleaning the interior surfaces of the tank in between dividing plates. However, the dividing plates themselves must also be cleaned. To clean dividing plate surfaces, two jets per extension arm are installed with the jet direction vertically up and down parallel to the vessel center axis 13 when in operation. The sub-system 24 is positioned along the axis of the tank and then lowered into the individual tank sections with the extension arms in a vertical position as previously described. When the sub-system 24 is positioned in the center between two dividing plates, the extension arms are rotated into a horizontal position. The sub-system is then lifted until the extension arms, which are now parallel to the dividing plate, are as close as necessary to the upper dividing plate for proper cleaning results.
[0037] The nozzle jets are then activated and the telescopic extension arms extend at a preset speed, determined by a dampening system. The system then operates as previously described, this time to spray a high pressure fluid against the bottom surface of the dividing plate above the sub-system 24 and the top surface of the dividing plate below the sub-system 24 . The rotational speed of the sub-system 24 is coordinated with the extension speed of the telescopic arms 54 so that the resulting movement of the water nozzle jets is a spiral pattern with some overlap from one spray track to the next.
[0038] We have found that the jets which face in a downward direction have less of a cleaning effect on the lower dividing plate than the upwardly directed jets. However, the downwardly direction jets must be active as a counter force to the jets facing up to provide a balanced force acting upon the ends of the extension arms.
[0039] Once the extension arms have extended all the way to their full extent, water pressure through the feed tube 28 is stopped and the extension arms retract. The sub-system 24 is then lowered until the extension arms are as close as necessary to the lower dividing plate. The process is then repeated with the cleaning of the top surface of the lower dividing plate in a manner just described in respect of the dividing plate above the sub-system 24 . After cleaning both dividing plate surfaces, the system is centered between the dividing plates and the extension arms are rotated into a vertical position. The sub-system 24 is then lowered into the next tank section.
[0040] FIG. 2 illustrates the application of the tank cleaning system 10 in an open tank 60 without dividing plates or internally installed moving parts. As previously described, the system 10 comprises the feed sub-system 20 , the support 22 , and the nozzle jet sub-system 24 . The feed sub-system 20 includes the prime mover 26 which imparts lateral movement to the feed tube 28 as shown by the arrow 30 . The prime mover 26 also imparts rotational movement to the feed tube 28 , as shown by the arrow 32 .
[0041] The feed tube 28 is flexible and passes through and is supported by the feed pedestal 34 which also serves to support the feed tube sheath 36 . The other end of the feed tube sheath 36 is coupled to the support 22 , which in the embodiment illustrated in FIG. 2 is adapted to mate with an upper access port 62 of the tank 60 . The feed tube 28 is then directed downwardly into the tank 60 , where it continues to rotate as shown by the arrow 42 . Also, movement back and forth of the prime mover 26 as shown by the arrow 30 results in up and down movement of the feed tube 28 as shown by the arrow 44 .
[0042] In the embodiment of FIG. 2 , the cleaning apparatus is positioned along the center axis of the tank 60 near the top of the tank, with the distance of sub-system 24 to the top of the tank equal to the radius of the vertical part of vessel. The length from the center of the sub-system 24 to the water jet outlet nozzles equals the horizontal radius of the vessel minus the distance for an individual jet outlet to the vessel wall for best cleaning results, from one to six inches. If the nozzle is too close to the vessel wall, the jet is too narrow, resulting in a pencil beam of water against the vessel wall and inadequate overlap from one track to the next. If the nozzle is too far from the vessel wall, the water spray has too little force to clean certain tenacious depots on the vessel wall.
[0043] With the initial positioning of the sub-system 24 , the extension arms are vertical, one jet facing the top of the vessel and one jet facing the bottom. When activated, the lower jet will typically be too far from the bottom of the tank to have much of a cleaning effect. Once the water jets are activated, the extension arms will rotate to a horizontal position. Also, simultaneously with the activation of the jets, the sub-system 24 will begin to rotate about the vertical axis, beginning a cleaning action along the inside top surface of the tank. This additional rotation is provided by the prime mover 26 through rotation of the feed tube 28 . The rotational speed around the vertical axis is coordinated with extension arm rotational speed around the sub-system 24 , so that the resulting spiral pattern track of water jets on the vessel wall provides an overlap of one jet track to the next. The distance between tracks and traveling speed of the water jets may require some adjustment, depending on type of material that has to be removed from the tank walls.
[0044] Once the extension arms have reached a horizontal position, the sub-system 24 is lowered into the tank with its rotation around the tank vertical axis maintained, thus creating a spiral cleaning track down the wall of the vessel. The cleaning apparatus is lowered by feeding the high pressure water feed tube at a controlled feed rate in relation to the rotational speed of the sub-system 24 . The prime mover 26 coordinates the rotation of the cleaning apparatus around the vertical tank axis and the downward movement of apparatus.
[0045] The downward movement of the apparatus is stopped once the apparatus reaches a position in the center of the vessel with a distance of the sub-system 24 to the bottom of the vessel equal to the radius of the vertical part of the vessel, thus the distance of the jet outlet to the vessel wall required for best cleaning results will be reached. Now the extension arms will be rotated back into vertical position at the same rotational speed as they were rotated into horizontal position at the beginning of the cleaning process with the high pressure water pump continuing to run. With the tank cleaner rotation along the tank vertical axis maintained the jet moving towards the lower center of the tank will clean the bottom in a spiral pattern. Alternatively, the supply of pressurized water through the feed tube may be stopped, and the extension arms rotated into a vertical position and the same procedure as in the very beginning is repeated to clean the bottom of the tank by starting at a vertical position and moving in a controlled fashion to a horizontal position. However, at the end of the cleaning process, the arms are returned to a vertical position in order to pull the tank cleaner out of the tank.
[0046] FIGS. 3A and 3B depict a presently preferred embodiment of the sub-system 24 , which may be referred to herein as the “tank cleaner”. FIG. 3C depicts an alternative spray nozzle for use on the sub-system 24 for cleaning dividing plates within a tank as described above, in which spray outlets from the nozzle are directed in diametrically opposed directions.
[0047] The sub-system 24 includes a frame 70 suspended by the rotating high pressure water hose or feed tube 72 in the center of the tank. A center plate 74 is held by the suspended frame and supported by a bearing 76 that allows the plate to rotate around an axis perpendicular to the vessel center axis 13 . The two extension arms 54 are coupled to the center plate, with one water jet insert 76 each at the end of each extension arm. The extension arms may vary in length, depending on the specific cleaning job or application. The jet directions and extension arm length axes are in the same geometrical plane perpendicular to the rotational axis of the center plate, and jet forces of the two jets match each other and are directed in opposite directions with one jet presenting the counter force to the other jet.
[0048] The jet and extension arm length axes are offset, thus, the jet reaction forces generate a torque with a direction perpendicular to the vertical tank center axis. This torque rotates the center plate with the extension arms. The rotational movement is dampened by a hydraulic cylinder 78 and restricted to 90° between vertical and horizontal extension arm positions. The damping can be adjusted with an adjustable orifice 80 in order to control the rotational speed of extension arms.
[0049] FIG. 4 depicts a schematic view illustrating the damping feature of the spray sub-system 24 . As previously described, the sub-system 24 is fed with high pressure fluid from a tube 28 , which is coupled into the swivel 50 . Fluid pressure is directed through the arms 52 and the extensions 54 , creating a moment to rotate the swivel as shown by the arrows in FIG. 4 . Rotation of the swivel 50 rotates a pinion gear 92 which meshes with a rack 94 . The rack 94 is joined to a piston 96 within a cylinder 98 . Moving the rack to the right pushes hydraulic fluid from the cylinder to the right out through the adjustable orifice 80 to the other side of the piston 96 . Thus, the rate of rotation of the swivel is controlled by the setting on the orifice 80 .
[0050] Preferably, the orifice 80 is an adjustable throttle check valve. The spray sub-system 24 is shown in FIG. 4 at the full horizontal position. Once the spray process with the spray sub-system in the horizontal position is complete, the arm extensions retract and the swivel rotates to place the arms in a vertical position. A weight 90 provides a biasing means to pull the arms to a vertical position. To aid in this movement, the orifice includes a check valve which permits unrestricted flow from left to right as seen in FIG. 4 to more quickly move the arms to a vertical position. The arm extensions 54 also include a biasing means to assist in retracting the arm extensions when the high pressure fluid is no longer being supplied to the spray nozzles 56 .
[0051] The principles, preferred embodiment, and mode of operation of the present invention have been described in the foregoing specification. This invention is not to be construed as limited to the particular forms disclosed, since these are regarded as illustrative rather than restrictive. Moreover, variations and changes may be made by those skilled in the art without departing from the spirit of the invention. | A rotating and telescoping cleaning system improves high pressure water cleaning of the inner surfaces of vessels or tanks. Vessels can be vertically divided with dividing plates with centered through-holes. Synchronized and controlled transverse and rotary movements of water jets result in a controlled spiral or helical cleaning track along the vessel walls. The water jets are directed at a pre-adjusted distance from the vessel wall and the travel speed of the water nozzle jets is exactly controlled allowing the removal of very hard deposits. One pass with the tool carrier with operating water jets along the length axis of the vessel results in a thoroughly cleaned vessel wall. The tool unfolds and folds inside of the vessel powered by the flow of the high pressure cleaning water. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cosmetic brush in which a stem is vertically formed at a cap screw-engaged with a cosmetic container, and more particular, to a cosmetic brush in which a tuft of bristles automatically gets in and out of the inside of a supporting tube by rotating the cap so as to be screw-engaged or screw-disengaged with/from the container, so that problems such as bending or spreading of the tuft of bristles and the like generated due to its twist can be prevented when rotating the tuft of bristles in a liquid cosmetics having high-viscosity.
2. Background of the Related Art
In general, in case of make-up with liquid cosmetic products such as lip gross, mascara, eye liner, and nail varnish by using a cosmetic brush, as a cap mounted at an upper portion of the stem where a tuft of bristles is implanted is screw-engaged with a cosmetic container, a user can conveniently carry the liquid cosmetic product in a state where the stem and the tuft of bristles is kept in the cosmetic container. If necessary, the user can apply make-up with the cosmetic brush stained with liquid cosmetics after removing the cap from the cosmetic container.
In the prior art, however, when the tuft of bristles is rotated in the liquid cosmetics having a high-viscosity upon screw-coupling the cap and the cosmetic container with each other, the tuft of bristles is twisted and tangled due to the resistance against the liquid cosmetics.
Consequently, since a user cannot properly apply make-up to where the liquid cosmetic is needed with the tangled bristles, it causes a waste of the liquid cosmetic due to the tangled bristles, and also a refined make-up is not operated.
The tendency of development of various liquid cosmetics having a high-viscosity is, especially in the present day, increased and also the liquid cosmetic gains increasing viscosity in proportion to its usage due to the volatilization of the solvent, and hence there is a great need for a cosmetic brush which can minimize the tangle of the bristles thereof.
Further, an inlet of the cosmetic container is coupled to an inner cap thereof having an inlet/outlet hole formed thereon, which is inclined so as to be gradually narrowed in its diameter toward its lower end, and by which the liquid cosmetic stained on the stem is wiped when the stem gets in and out of the inlet/outlet hole.
Thus, since the stem gets in and out of the inlet/outlet hole in such a manner as to be in close contact with the inner circumferential surface thereof, compressed air is produced inside of the container when the stem is inserted into the inlet/outlet hole of the inner cap, such as where a piston is inserted into a cylinder.
Since the pumping effect by which the liquid cosmetic is pushed up is induced by such compressed air, there occurs a problem in that the cap is stained by the liquid cosmetic which flows into the inside of the cap through a gap between the inlet/outlet hole of the inner cap and the stem.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above problems occurring in the prior art, and it is an object of the present invention to provide a cosmetic brush which can prevent problems such as the tangle of the turf of bristles and the like generated due to its twist in a liquid cosmetics having a high-viscosity by automatically being inserted to or removed from the inside of a supporting tube when a cap is screw-engaged and screw-disengaged with/from a cosmetic container, and can increase its convenience in use.
To achieve the above object, according to the present invention, there is provided
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view showing a state where a cosmetic brush according to the present invention is coupled to a cosmetic container;
FIG. 2 is an exploded perspective view of a cosmetic brush according to the present invention;
FIGS. 3 a through 3 c are cross-sectional views sequentially showing processes for coupling the cosmetic brush to the cosmetic container;
FIG. 4 is an exploded perspective view of another embodiment of the cosmetic brush according to the present invention;
FIG. 5 is an assembly cross-sectional view of FIG. 4 ;
FIG. 6 is an exploded perspective view of another embodiment of the cosmetic brush according to the present invention; and
FIG. 7 is an assembly cross-sectional view of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
As shown in FIGS. 1 and 2 , a cosmetic brush 1 according to the present invention includes a cylindrical cap 10 , and a stem 11 implanted with a tuft of bristles 11 a.
That is, the stem 11 is vertically erected at the inner center of the cylindrical cap 10 , and the tuft of bristles 11 a is fixed on a lower end of the stem 11 .
When a screw portion 10 a formed on an inner peripheral surface of the cap 10 is screw-engaged with a screw portion 20 a formed on an outer peripheral surface of an inlet of a cosmetic container 20 , the stem 11 is inserted through an inlet/outlet hole 21 a having a narrow width formed on an inner cap 21 of the cosmetic container 20 .
Thus, the cosmetic brush 1 is constructed in order to be easily carried in a state where the cap 10 of the cosmetic brush 1 is screw-engaged with the cosmetic container 20 and then the stem 11 and the tuft of bristles 11 a are received inside of the cosmetic container 20 .
Of course, the cosmetic brush 1 as constructed above belongs to a technical spirit, which has been already well known. Nevertheless, the most important feature in configuration of the present invention resides in that the cap 10 is screw-engaged and screw-disengaged with/from the cosmetic container 20 by rotating the cap 10 , the tuft of bristles 11 a automatically gets in and out of the inside of a supporting tube 14 , to thereby effectively prevent the tangle of the tuft of the bristles 11 a.
In other words, the supporting tube 14 is vertically mounted on the center of the inside of the cap 10 , and the stem 11 is inserted into the inside of the supporting tube 14 .
The stem 11 is elastically supported by a compressed spring 15 of a coil-type mounted to the upper portion of the supporting tube 14 , and receives a downward elastic force of the spring 15 .
Further, the stem 11 has a latching protrusion 12 formed on both sides of the upper portion thereof, however, of course the latching protrusion 12 may be protrusively formed on a side of the upper portion of the stem 11 .
The supporting tube 14 has a guide slit 14 a formed on the upper portion thereof in such a manner as to be formed long in a lengthwise direction thereof. The guide slit 14 a is constructed such that the latching protrusion 12 formed on the upper portion of the stem 11 is inserted into the guide slit 14 a and then the stem 11 together with the latching protrusion 12 is moved within the length of the guide slit 14 a.
At this time, the latching protrusion 12 together with the stem 11 descends by the elastic force of the spring 15 so as to be latched by a lower end of the guide slit 14 a , the tuft of bristles 11 a of the stem 11 is protruded out of the lower portion of the supporting tube 14 , to thereby allow a user to apply make-up using the tuft of the bristles 11 a , and the cap 10 is in a state of being removed from the cosmetic container 20 , as shown in FIG. 3 a.
In these state, when the cap 10 is screw-engaged with the inlet of the cosmetic container 20 so as to allow the supporting tube 14 to be inserted through the inlet/outlet hole 21 a formed on the inner cap 21 of the cosmetic container 20 , only the supporting tube 14 is downwardly moved in a state where the latching protrusion 12 of the stem 11 outwardly protruded from the supporting tube 14 is latched by the inner cap 21 , to thereby allow the tuft of bristles 11 a implanted in the lower end of the stem 11 to be partially inserted into the inside of the supporting tube 14 , as shown in FIG. 3 b.
So far, since the supporting tube 14 is merely inserted into the inlet/outlet hole 21 a of the inner cap 21 to thereby be downwardly moved so that the rotation of the stem 11 is not operated, the twist or tangle of the tuft of bristles 11 a is not generated at all.
In these state, when the cap 10 is rotated to thereby be screw-engaged with the inlet of the cosmetic container 20 , the supporting tube 14 is rotated to thereby be downwardly moved in a state where the stem 11 together with the latching protrusion 12 is latched by the inner cap 21 , so that the tuft of bristles 11 a can be completely inserted and received into the inside of the supporting tube 14 .
As a result, since the stem 11 together with the supporting tube 14 are rotated and also the tuft of bristles 11 a is completely inserted into the inside of the supporting tube 14 , the tuft of bristles 11 a is exposed to the liquid cosmetic for a comparatively short period of time, so that the tangle of the tuft of bristles 11 a generated due to its twist is effectively prevented to thereby allow a user to precisely apply make-up using the tuft of bristles 11 a stained with the liquid cosmetic, the cosmetic brush 1 has an advantage in that competitiveness of the cosmetic brush 1 is considerably enhanced.
Further, the tuft of bristles 11 a is rotated together with the cap 10 in a state where it is received into the inside of the supporting tube 14 when the cap is reversely rotated, so that the tuft of bristles 11 a is rotated with less resistance against the liquid cosmetic. Thereafter, when the cap 10 is removed from the inlet of the cosmetic container 20 , the latching protrusion 12 is removed from the top peripheral edge part of the inner cap 21 to thereby release the latched state, and also the stem 11 is downwardly moved so that the tuft of bristles is protruded out of the lower portion of the supporting tube 14 by a restoration force of the spring 15 , to thereby allow the cosmetic brush 1 to be used. Consequently, when the cap 10 is rotated so as to be removed from the cosmetic container 20 , the tuft of bristles 11 a is in contact with the liquid cosmetic for a comparatively short period of time to thereby be hardly affected by the resistance.
Meanwhile, as shown in FIGS. 4 and 5 , the latching protrusion 12 is outwardly protruded from an elastic piece 13 formed on the upper portion of the stem 11 , and has an inclined surface 12 a formed thereon.
At this time, when the spring 15 is inserted into the inside of the supporting tube 14 and then the elastic piece 13 formed on the upper portion of the stem 11 is inserted into the inside of the supporting tube 14 , the inclined surface 12 a of the latching protrusion 12 is advanced into the inside of the supporting tube 14 while being pressed together with the elastic piece 13 . Thereafter, when the latching protrusion 12 is positioned in a guide slit 14 a , it is outwardly protruded via the guide slit 14 a by means of an elastic force of the elastic piece 13 so as to be latched by the guide slit 14 a , so that the stem 11 can be easily assembled into the inside of the supporting tube 14 .
In addition, as shown in FIGS. 6 and 7 , a packing member 30 of a ring type having an elastic force is coupled around the upper portion of the stem 11 . In this state, when the stem 11 is inserted through the inlet/outlet hole 21 a of the inner cap 21 , the packing member 30 comes in close contact with the lower portion of the inlet/outlet hole 21 a , so that an inner compressed air inside of the cosmetic container 20 is prevented from being discharged.
At this time, although the stem 11 is inserted through the inner cap 21 to thereby generate an inner compressed air inside of the cosmetic container 20 , the packing member 30 of a ring type is in close contact with the inner circumferential surface of the inner cap 21 to thereby prevent the compressed air from being discharged, so that the pumping effect in which liquid cosmetic is reverse flowed into the upper portion of the cosmetic container 20 together with the compressed air can be effectively prevented, to thereby considerably enhance the competitiveness of the cosmetic container.
As describe above, according to the present invention, when the cap is rotated so as to allow the cap 10 to be screw-engaged or screw-disengaged with/from the cosmetic container 20 , only a short length of the tuft of bristles 11 a is exposed to the liquid cosmetic for a comparatively short period of time so as to be hardly affected by the resistance force against the liquid cosmetic while the tuft of bristles 11 a is rotated in a state where it is received into the inside of the supporting tube 14 , so that the tangle or twist of the tuft of bristles 11 a can be effectively prevented, to thereby allow a user to precisely apply make-up using the tuft of bristles 11 a stained with the liquid cosmetic, resulting in considerably increasing the competitiveness of the cosmetic brush 1 .
Accordingly, the cosmetic brush 1 according to the present invention has advantages such as where the twist of the tuft of bristles 11 a is prevented until the liquid cosmetic is completely consumed by considerably improving the tangle or twist of the tuft of bristles 11 a , to thereby provide a cosmetic brush having high quality to consumers.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. | A cosmetic brush which includes a cylindrical cap, a supporting tube mounted inside, of the cap, an upright-standing stem movably received in the tube, and a cosmetic container. A tuft of bristles is fixed on a lower end of the stem. A spring is disposed inside of the cap such that the stem is biased downwardly inside of the tube. The stem has a latching protrusion and the tube has a guide slit to receive the latching protrusion. The downward movement of the stem is stopped by the guide slit when the tuft of bristles is exposed outside of the tube. When the supporting tube is inserted into the container, the latching protrusion is latched and pushed upwards by the top opening of the container, thereby allowing the stem and the tuft of bristles to be raised so as to be received inside of the tube. | 0 |
CROSS-REFERENCE TO CO-PENDING APPLICATIONS
[0001] This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/329,717, filed on Dec. 26, 2002, the contents of which are incorporated herein in its entirety, which claims the benefit of the priority filing date of U.S. Provisional Patent Application Serial No. 60/426,589, filed Nov. 15, 2002, and is a continuation of U.S. patent application Ser. No. 10/302,038, filed Nov. 22, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 10/143,396 filed May 10, 2002.
BACKGROUND
[0002] The present invention relates to a lint roller assembly.
[0003] There are many previously known lint roller assemblies. These previously known lint roller assemblies typically comprise a handle secured to a cylindrical lint roller support. A tubular cylindrical adhesive lint roller is then removably mounted to the support such that the adhesive roller is rotatively relative to the handle. In use, the adhesive lint roller is rolled along a surface to remove unsightly particles, lint, pet hair, etc.
[0004] The previously known lint roller assemblies have used a number of different options to rotatively secure the lint roller support to the handle. For example, in U.S. Pat. No. 4,361,923, the lint roller support and handle are separately constructed and then rotatively secured together. One disadvantage of this type of previously known lint roller assembly, however, is that the rotatively connection between the handle and lint roller support is subject to mechanical failure.
[0005] A further disadvantage to this type of assembly is that both the lint roller support and the handle are separately molded from plastic and then assembled together requiring two separate molds, one for each part.
[0006] Still other types of lint roller assemblies, such as that disclosed in U.S. Pat. No. 6,055,695, the lint roller handle includes a pair of elongated housing parts, which are substantially identical to each other. A disadvantage to this type of assembly is that each housing part must be snapped exactly into the other perfectly registering using pins and sockets. A further disadvantage is that the handle section being integral to the support section is manufactured with rigid plastic material and uncomfortable to grip and does not provide for a customized plastic decorative top or hanger.
[0007] Still other types of previously known lint roller assemblies, such as that disclosed in U.S. Pat. No. 4,5577,0111, utilize a unitary lint roller handle and lint roller support. These previously known lint roller assemblies, however, require a complex and, therefore, expensive mold design in order to mold the lint roller handle and support. Furthermore, a relatively large frictional engagement between the lint roller and the lint roller support often times interferes with the desired free rotation of the lint roller about the lint roller support. Further, it does not provide for mounting a directional lint brush fabric under the rotatable tape roll.
SUMMARY
[0008] The present invention is a lint roller assembly which overcomes all of the deficiencies of the previously known lint roller art.
[0009] In one aspect, the lint roller apparatus or assembly of the present invention includes a handle and a lint roll support. The support is in the form of a cross-member extending transversely from the handle. First and second lint roll support members including legs extend from the cross-member and are adapted for receiving and supporting a lint roll therebetween. The lint roll supports or bearing surfaces are fixedly or moveably mounted to the legs.
[0010] In one aspect, lint roll supports or bearing surfaces are fixedly or moveably mounted to the legs.
[0011] In one aspect, the legs are moveably disposed relative to the cross-member and are coupled by a biasing member which normally biases the legs to a first dimension spacing for supporting a lint roll therebetween. At least one of the legs at a time may be expanded laterally outward from the opposite leg to allow insertion or removal of a lint roll between the legs.
[0012] In another aspect, a tubular lint roll support is formed of first and second telescopingly expandable and retractable end portions. A biasing member is carried within the first and second end portions and normally biases the first and second end portions outward to a first dimensional length. The first and second ends may be retracted or compressed toward each other to allow insertion or removal of a lint roll between the legs.
[0013] The apparatus of the present invention provides added functionality in lint and other debris removal operations by providing multiple cleaning surfaces or elements in a single tool. Each cleaning element is usable separately so as to enable most types of dirt, lint, debris, etc., to be effectively removed from various surfaces, fabric, clothes, furniture, animals, etc.
[0014] In another aspect, a liquid storage chamber is formed in the body. A dispenser means is disposed in fluid communication with the liquid storage chamber for dispensing liquid from the body to assist in cleaning operations.
BRIEF DESCRIPTION OF THE DRAWING
[0015] The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:
[0016] [0016]FIG. 1 is a side elevational view of one aspect of the present apparatus;
[0017] [0017]FIG. 2 is a front elevational view of the apparatus shown in FIG. 1;
[0018] [0018]FIG. 3 is a perspective view of another aspect of a cleaning apparatus according to the present invention;
[0019] [0019]FIG. 4 is a front elevational view of the cleaning apparatus shown in FIG. 3;
[0020] [0020]FIG. 5 is a partial, perspective view of a portion of the cleaning apparatus shown in FIGS. 3 and 4;
[0021] [0021]FIG. 6 is a partial, enlarged, exploded view of the cap mountable on the end of the handle of the cleaning apparatus shown in FIGS. 3 - 5 ;
[0022] [0022]FIG. 7 is an enlarged, partial, exploded view showing an alternate extension handle mountable in the handle of the cleaning apparatus shown in FIGS. 3 - 5 ;
[0023] [0023]FIG. 8 is a partial, exploded view showing the mounting of a depressable dispenser cap on the handle of the cleaning apparatus shown in FIGS. 3 - 5 ;
[0024] [0024]FIG. 9 is a perspective view of another aspect of the cleaning apparatus according to the present invention;
[0025] [0025]FIG. 10 is a front elevational view of the cleaning apparatus shown in FIG. 9; and
[0026] [0026]FIG. 11 is an exploded, perspective view of another aspect of the cleaning apparatus according to the present invention.
DETAILED DESCRIPTION
[0027] In the various lint rollers described hereafter, a tape roll 30 , is any commercially available tape roll having outwardly facing adhesive sheets or strips, generally arranged in a plurality of sheets wound in a roll wherein the outermost sheets are peelable from the roll, one at a time, along perforated edges of each sheet. When the roll 30 is mounted on a support, the roll 30 may freely rotate under applied force to remove lint, pet hair, and other debris from surfaces, such as clothes, furniture, or other fabrics.
[0028] Referring now to FIGS. 1 and 2, there is depicted yet one aspect of the present lint roller/brush apparatus denoted generally by reference number 400 . The apparatus 400 includes a body which may be integrally formed, such as from a blow molded plastic, or assembled of individual components fixedly joined together into unitary structure by heat or sonic welding, fasteners, etc.
[0029] The apparatus 400 includes an elongated handle 402 which has an ergonomic shape for easy hand gripping. Alternately, the handle 402 may be formed with a hollow interior chamber suitable for receiving a cleaning liquid. A dispenser, such as a push top or trigger type may be mounted on the end of the handle 402 to dispense cleaning liquid from the handle 402 .
[0030] A further optional adaptation is the provision of snap or screw together, threaded connections on the end of the handle 402 for connection to an elongated handle or handle extension, not shown, to enable the apparatus 400 to be conveniently used to clean floors, walls, ceilings, or other hard to reach surfaces.
[0031] The handle 402 transitions into a cross-member formed of two cross arms 404 and 406 which extend laterally in opposite directions from the end of the handle 402 . The arms 404 and 406 terminate in angularly disposed legs 408 and 410 , respectively. A pair of generally circular supports 412 and 414 extend axially inward from the legs 408 and 410 , respectively, and rotatably fit within the inner diameter of the lint roll 30 which can be snapped over the supports 412 and 414 for insertion or removal from the apparatus 400 .
[0032] In this aspect, an additional cleaning element in the form of a squeegee 420 is fixedly mounted in the arms 404 and 408 and projects angularly therefrom as shown in FIG. 26. The squeegee 420 has a blade-like shape formed of a resilient, flexible material terminating in one or more pointed edges 322 which, when dragged across the surface, is and are capable of pulling embedded hairs from fabric.
[0033] One aspect of a cleaning apparatus 440 according to the present invention is shown in FIGS. 3 - 6 . In this aspect, the cleaning apparatus 440 includes a body which may be integrally formed, such as from a blow-molded plastic or assembled of individual components fixedly jointed together into a unitary structure by heat or sonic welding, fasteners, adhesive, etc. The body is preferably formed of one monolithic piece utilizing materials, such as polyethylene, PET, polyvinyl chloride or similar thermoplastic materials.
[0034] The apparatus 440 includes an elongated handle 442 which has an ergonomic shape for easy hand gripping. Resilient inserts 444 may be mounted on the exterior of the handle 442 for a comfortable and secure hand grip.
[0035] An end cap 446 is applied to one end 448 of the handle 442 . Although a conical shaped end cap 446 is shown in FIGS. 3 and 6, it will be understood that the end cap 446 may take any other shape, including a cylindrical shape or an aesthetic, decorative shape.
[0036] The end cap 446 has an externally threaded shank 450 extending from an enlarged end portion 452 . The external threads 454 on the shank 450 threadingly engage internal threads 456 in a bore 458 extending inward from the second end 448 of handle 442 . The threads 454 and 456 enable the cap 446 to be removably attachable to the handle 442 , for reasons which will become apparent hereafter.
[0037] Although the cap 446 has been described as being removably attachable to the handle 442 , it will be understood that the cap 446 may be non-removably attached by means of a press-fit, adhesive or integral molding with the handle 442 .
[0038] As also shown in FIG. 6, the handle 446 is provided with an aperture 460 which can have a closed periphery or a discontinuous periphery to provide a hanger feature for the end cap 446 and the remainder of the attached cleaning apparatus 440 .
[0039] Referring briefly to FIG. 7, there is depicted an extension handle 470 having an externally threaded end 472 which is removably engagable with the threads 456 in the bore 458 on the second end 448 of the handle 442 after the end cap 446 has been removed from the handle 442 . The extension handle 470 enables the cleaning apparatus 440 to function as a cleaning device to remove debris from a floor or other surface beyond the normal arm reach of the user.
[0040] It will be understood that the extension rod 470 can also be attached to the handle 442 by press-fit, interlocking projections and grooves, or by other releaseable attachment means.
[0041] Referring briefly to FIG. 8, there is depicted another aspect of the cleaning apparatus 440 which provides a cleaning liquid dispersion function for the cleaning apparatus 440 . In this aspect of the invention, a modified handle 442 ′ has a reduced diameter portion adjacent the second end 448 . The periphery of the reduced diameter portion of the handle 442 ′ is externally threaded as shown by threads 474 . A hollow bore 476 extends through the handle 442 to an internal chamber within the handle 442 which is capable of storing cleaning liquid.
[0042] A conventional fluid dispenser in the form of an interiorly threaded cap 480 having a displaceable button 482 biased away from the end of the cap 480 by an internally mounted biasing means or coil spring 484 is provided for attachment to the handle 442 ′. A hollow stem 486 extends through and out of the cap 480 and supports a fluid conduit 488 which extends into the chamber in the handle 442 ′. The other end of the fluid conduit 488 is fluidically coupled to a fluid outlet or nozzle 490 mounted in the depressable button 482 . Depression of the button 482 will cause fluid to be drawn through the conduit 488 and dispensed through the outlet or nozzle 490 .
[0043] Referring back to FIGS. 3 and 4, the handle 442 transitions into a lint roll support, including a cross-member 492 . The cross-member 492 , although generally formed of one piece, has two arms 494 and 496 which project laterally and oppositely outward from one end of the handle 442 . A pair of roll support assemblies 500 and 502 are mounted on the arms 494 and 496 , preferably with at least one and preferably both of the support arm assemblies 500 and 502 being moveably mounted in the arm portions 494 and 496 of the cross-member 492 .
[0044] Since the support assemblies 500 and 502 are substantially identically constructed, the following description of the support assembly 500 will be understood to apply equally to the construction and operation of the support assembly 502 .
[0045] As shown in FIGS. 4 and 5, the support assembly 500 includes a leg 504 which depends from a tubular slider or channel member 506 . The leg 504 and the channel member 506 may be integrally constructed as a one piece plastic member or formed of two members fixedly joined together by fasteners, adhesive, sonic or heat welding, etc. The channel member 506 is moveably disposed within the hollow interior of the arm 494 of the cross-member 492 , as shown in FIG. 4.
[0046] As shown in FIGS. 3 and 4, the support assembly 502 includes a similarly constructed leg 508 which is fixedly joined to a slider or channel member 510 . The channel member 510 is moveably disposed within the arm 496 of the cross-member 492 .
[0047] A pin 512 projects from one end of the channel members 506 and 510 . A biasing means, such as a coil spring 514 , is connected between the pins 512 on the channel members 506 and 508 and functions to bias the support assemblies 500 and 502 inward toward each other. In this position, which is shown in solid in FIGS. 3 and 4, the legs 504 and 508 are disposed immediately adjacent the ends of the arm portions 494 and 496 of the cross-member 492 . Open ended slots may be formed in the ends of the arms 494 and 496 to enable the legs 504 and 508 to fit within the ends of the arms 494 and 496 as shown in solid in FIGS. 3 and 4.
[0048] The biasing force exerted by the spring 514 holding the support assemblies 500 and 502 together at a first spacing sized to support a lint roll 516 between the legs 504 and 508 can be overcome by lateral outward force exerted on at least one of the legs 504 and 508 in a direction pulling the one or both legs 504 and 508 outward from the end of the associated arm 494 and 496 to a position shown in phantom in FIG. 4. Although it is only necessary to pull one of the support assemblies 500 and 502 laterally outward to a second spacing with respect to the opposed support assembly 500 and 502 to enable removal and/or mounting of a lint roll 516 to the support assemblies 500 and 502 , as described hereafter, both of the support assemblies 500 and 502 can be laterally urged outward to the expanded position shown in phantom in FIG. 4.
[0049] Release of the laterally outward directed force on the support assemblies 500 and/or 502 will enable the biasing spring 524 to pull the one or both support assemblies 500 and 502 back toward the close together, inward position shown in FIGS. 3 and 4.
[0050] Referring to FIGS. 3, 4, and 5 , bearing surfaces in the form of generally circular members 524 and 526 are fixed or rotatably mounted on one end of the legs 504 and 508 , respectively. Each member 524 and 526 has a first outer diameter circular rim 528 which extends from one surface of a larger diameter end wall 530 . The end wall 530 abuts the end of the lint roll 516 as shown in FIG. 4, with the end portions of the lint roll 516 resting on the outer diameter of the circular runs 528 . An annular disk 532 is centrally carried on each end wall 530 within the circular wall 528 . An aperture is formed in the disk 532 and receives resilient latch members 534 which are spaced apart on one end of a stem 536 integrally joined to and extending from one end of the leg 504 or the leg 508 . The ends of the latch members 534 extend outward from the stem 536 to form an end projection which snaps over the inner wall of the annular disk 532 to latch the circular supports 524 and 526 to the legs 504 and 506 , respectively.
[0051] The above-described connection defines a rotatable connection allowing the circular members 524 and 526 to rotate along with the lint roll 516 mounted thereon as the lint roll 516 is forcibly urged across a surface to be cleaned.
[0052] Finally, as shown in FIGS. 3 and 4, cleaning apparatus 40 includes an additional cleaning element 540 which is mounted in the cross-member 492 and projects outward therefrom. The additional cleaning element 540 can be one of a number of different cleaning elements used to provide an added cleaning capability to the cleaning apparatus 440 . Thus, although the cleaning element 540 is depicted as being in the form of a resilient squeegee having one or more blades formed of a resilient, flexible material, each terminating in a pointed edge which, when dragged across a surface, is capable of pulling embedded hairs from fabric the cleaning element 540 can take other forms, such as a premoistened wipe strip(s), rotatable crumb pickers, etc. The cleaning element 540 is removably mountable in the cross-member 492 such as by a slide-in fit as shown in FIG. 3. Other types of releasable connections, including fasteners, or more permanent connections, such as through the use of adhesive or mechanical fasteners, may also be employed to mount the cleaning element 540 in the cross-member 492 . The cleaning element can also be fixed in the cross-member 492 .
[0053] Referring now to FIGS. 9 and 10, there is depicted another aspect of a cleaning apparatus 550 which is substantially similar to the cleaning apparatus 440 except for the mounting of the circular lint roll supports 552 and 554 to the ends of the legs 556 and 558 , respectively, of a cross-member 560 mounted transversely at one end of a handle 562 . An additional cleaning element, such a squeegee 564 , by example only, can also be mounted in the cross-member 560 .
[0054] In this aspect, each leg 556 and 558 terminates in a generally circular base 561 . A slot 563 is formed in each base 561 and can be closed by a snap-in cover 565 . The slots 563 provide access to at least one and preferably a pair of fasteners, such as screws 566 which fixedly engage the circular bases 561 to fix the bases 561 to the legs 556 and 558 .
[0055] The fasteners 566 extend into inward extending projections 568 which project inwardly from an inner wall of each circular support 552 and 554 . An outer peripheral surface 570 of each circular support 552 and 554 acts as a bearing surface for a lint roller 572 which can be rotatably mounted thereover.
[0056] Finally, another aspect of a cleaning apparatus 600 according to the present invention is shown in FIG. 11. The cleaning apparatus 600 shares many of the same features as the cleaning apparatus 440 and 550 in that it includes a handle 602 which has an end cap 604 mounted at one end and a laterally extending cross-member 606 at an opposite end. A cleaning element 608 , such as a squeegee, may optionally be mounted in the cross-member 606 .
[0057] A pair of legs 610 and 612 extend from opposite ends of the cross-member 606 and terminate in enlarged bases 614 and 616 . A recess 618 extends axially inwardly partially through each circular base 614 and 616 . An inner circumferential surface of each recess 618 acts as a bearing surface for an outwardly extending projection 620 of a cylindrical shaped member 621 telescopingly disposed over a second cylindrical member 624 . A similar bearing surface 620 is formed on the outer end of the second member 624 . The members 621 and 624 form a lint roll support tube 622 on which a lint roll 630 is placed.
[0058] An internally disposed biasing means, such as a coil spring 626 , is disposed between the ends of the members 621 and 624 and biases the ends of the members 621 and 624 outward, but enables the overall length of the support tube 622 to be shortened to allow the tube 622 to be inserted between the bases 614 and 616 of the cleaning apparatus 600 to remove or install a lint roll 630 between the leg 610 and 612 of the cleaning apparatus 600 .
[0059] In summary, there has been disclosed numerous aspects of a combination lint roll/brush apparatus which is useful in efficiently removing dirt, debris, embedded hair, from fabrics and other surfaces. The apparatus combines several cleaning elements into a single apparatus thereby affording many different cleaning uses with a single apparatus. This enables different types of debris to be successfully removed from fabrics, furniture, clothing, and other surfaces by choosing one or more of the different cleaning elements in a single cleaning operation. | A lint/pet hair roller assembly includes a body supporting a tubular adhesive lint remover roll. The assembly includes a handle and a roll support. The roller support includes a cross-member transversely mounted on the handle and carrying a pair of outwardly extending legs. Roll support members are fixed or rotatably carried on the legs for supporting a lint roll. The legs, in one aspect, are moveably mounted in the cross-member and biased to a normal first spacing to support a lint roll, but extendable outward for movement of the lint roll relative to the legs. In another aspect, a telescoping lint roll support is normally biased to an extended position to support the lint roll, but is collapsible for movement of the support relative to the legs. Alternately, a dispenser is carried on the handle for dispensing fluid from a storage chamber. Alternately, an additional cleaning element is carried on the support. | 1 |
BACKGROUND OF THE INVENTION
[0001] The invention pertains to a rotatable cutting tool that is useful for the impingement of earth strata such as, for example, asphaltic roadway material, coal deposits, mineral formations and the like. More specifically, the present invention pertains to a rotatable cutting tool that is useful for the impingement of earth strata wherein the cutting tool body possesses improved design so as to provide for improved performance characteristics for the rotatable cutting tool.
[0002] Rotatable cutting tools have been used to impinge earth strata such as, for example, asphaltic roadway material or ore bearing or coal bearing earth formations or the like. Generally speaking, these kinds of rotatable cutting tools have an elongate cutting tool body typically made from steel and a hard tip (or insert) affixed to the cutting tool body at the axial forward end thereof. The hard tip is typically made from a hard material such as, for example, cemented (cobalt) tungsten carbide. The rotatable cutting tool is rotatably retained or held in the bore of a tool holder or, in the alternative, in the bore of a sleeve that is in turn held in the bore of a holder.
[0003] The holder is affixed to a driven member such as, for example, a driven drum of a road planing machine. In some designs, the driven member (e.g., drum) carries hundreds of holders wherein each holder carries a rotatable cutting tool. Hence, the driven member may carry hundreds of rotatable cutting tools. The driven member is driven (e.g., rotated) in such a fashion so that the hard tip of each one of the rotatable cutting tools impinges or impacts the earth strata (e.g., asphaltic roadway material) thereby fracturing and breaking up the material into debris.
[0004] As can be appreciated, during operation the rotatable cutting tool and the cutting insert are typically subjected to a variety of extreme cutting forces and stresses in an abrasive and erosive environment. In addition, during a machining operation the cutting insert becomes heated. The heat spreads quickly through the cutting insert. The cutting insert reaches, in a very short time, a range of temperatures within which the resistance to plastic deformation of the cutting insert material decreases. When large cutting forces act on the cutting insert, this phenomenon entails a risk that the cutting insert will be subject to plastic deformation, in particular, in the proximity of the cutting edge, where insert breakage can result. In order to diminish the risk of plastic deformation, an efficient system for cooling the cutting insert would be desirable, whereby the working temperature of the insert can be regulated within desired limits.
[0005] As is also known during use of the rotatable cutting tool, a substantial amount of dust may be generated, e.g. coal dust during a mining operation. When the dust becomes air borne, it becomes a risk for humans and equipment in the immediate area. For example, the dust can be inhaled by humans (health risk) or the dust can be ignited by mining activities causing an explosion (safety risk). In order to reduce or minimize health and/or safety risks, an efficient system that reduces or minimizes the amount of dust that is generated would be desirable.
[0006] The present invention has been developed in view of the foregoing.
SUMMARY OF THE INVENTION
[0007] The present invention provides a rotatable cutting tool for use in impinging earth strata such as, for example, asphaltic roadway material, coal deposits, mineral formations and the like. The rotatable cutting tool includes a cutting tool body having a through coolant channel and a two-piece head portion, e.g., the head portion of the cutting tool body includes a base portion and a nose portion with a hard tip cutting insert affixed to the nose portion. The through coolant provides for cooling the hard tip cutting insert during operation of the cutting tool. In addition, the through coolant also provides for suppressing dust created by the rotatable cutting tool during operation.
[0008] An aspect of the present invention is to provide a rotatable cutting tool for use in impinging earth strata wherein the rotatable cutting tool comprises a cutting tool body and a hard tip affixed to the cutting tool body. The cutting tool body includes an axial forward end for receiving the hard tip and an axial rearward end, a head portion axially rearward of the axial forward end, a collar portion axially rearward of the head portion and a shank portion axially rearward of the collar portion and axially forward of the axial rearward end. The head portion includes a base portion affixed to the collar portion and a nose portion movably connected to the base portion. The cutting tool body defines an internal coolant channel extending axially from the axial rearward end through the shank portion, the collar portion and through at least part of the base portion of the head portion. The nose portion of the head portion is positioned adjacent to the internal coolant channel that extends through the base portion of the head portion. In one aspect of the invention, the base portion defines a pocket for receiving at least a part of the nose portion. In another aspect of the invention, the pocket is in fluid communication with the internal coolant channel. In yet another aspect of the invention, the nose portion includes at least one flute formed on a surface thereof.
[0009] Another aspect of the present invention is to provide a rotatable cutting tool for use in impinging earth strata wherein the rotatable cutting tool comprises a cutting tool body and a hard tip affixed to the cutting tool body. The cutting tool body includes an axial forward end for receiving the hard tip and an axial rearward end, a head portion axially rearward of the axial forward end, a collar portion axially rearward of the head portion and a shank portion axially rearward of the collar portion and axially forward of the axial rearward end. The head portion includes a base portion that defines a pocket, wherein the head portion further includes a nose portion that is at least partially received in the pocket of the base portion and is rotatably connected to the base portion. The cutting tool body defines a coolant channel that is in fluid communication with the pocket of the base portion. In one aspect, the nose portion defines at least one rotational flute.
[0010] A further aspect of the present invention is to provide a rotatable cutting tool body with a central longitudinal axis, the rotatable cutting tool body comprising a head portion, a shank portion, and a collar portion mediate of and contiguous with the head portion and the shank portion. The head portion includes a base portion and a nose portion. The cutting tool body further comprises an axial forward end adjacent to the nose portion of the head portion and an axial rearward end adjacent to the shank portion. Means for rotatably connecting the nose portion to the base portion are provided. The cutting tool body also comprises an internal coolant channel extending axially from the axial rearward end through the shank portion, the collar portion, and through at least a portion of the head portion. In one aspect of the invention, the nose portion of the head portion is positioned adjacent an axial forward end of the internal coolant channel that extends through at least a part of the head portion. In another aspect, the base portion defines a pocket for receiving at least a part of the nose portion. In yet another aspect of the invention, the pocket is in fluid communication with the internal coolant channel. In another aspect of the invention, the nose portion includes at least one rotational flute formed on a surface thereof.
[0011] These and other aspects of the present invention will be more fully understood following a review of this specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an exploded, perspective view of a rotatable cutting tool, in accordance with an aspect of the invention.
[0013] FIG. 2 is a side elevational view of the rotatable cutting tool, shown in FIG. 1 , as assembled, in accordance with an aspect of the invention.
[0014] FIG. 3 is an end elevational view of the rotatable cutting tool shown in FIGS. 1 and 2 , in accordance with an aspect of the invention.
[0015] FIG. 4 is a nose portion of a rotatable cutting tool, in accordance with an aspect of the invention.
DETAILED DESCRIPTION
[0016] As used herein, the term “coolant” generally refers to any liquid, gas, or other material that is suitable for use with the present invention as described herein. In one aspect, the coolant may be a liquid such as, for example, water. In another aspect, the coolant may be, for example, an air-water mixture, oil, or carbon dioxide.
[0017] Referring to FIGS. 1 and 2 , there is illustrated a rotatable cutting tool, generally designated as 20 , in accordance with an aspect of the invention. Rotatable cutting tool 20 comprises an elongate cutting tool body, generally designated as 22 . The cutting tool body 22 is typically made of steel such as those grades disclosed, for example, in U.S. Pat. No. 4,886,710 to Greenfield, which is hereby incorporated by reference.
[0018] Still referring to FIGS. 1 and 2 , the cutting tool body 22 has an axial forward end 24 and an axial rearward end 26 . A hard tip or insert 30 is affixed (such as by brazing or the like) in a socket 31 in the axial forward end 24 of the cutting tool body 22 . Hard insert 30 is typically made from cemented carbide such as, for example, cemented (cobalt) tungsten carbide wherein U.S. Pat. No. 6,375,272 to Ojanen, which is hereby incorporated by reference, discloses examples of acceptable grades of cemented (cobalt) tungsten carbide. The geometry of the hard insert 30 can vary depending upon the specific application. U.S. Pat. No. 6,375,272 to Ojanen discloses an exemplary geometry for the hard insert. It should be appreciated that as an alternative to the socket, the axial forward end of the cutting tool body may present a projection that is received within a socket in the bottom of the hard tip. This alternate structure can be along the lines of that disclosed, for example, in U.S. Pat. No. 5,141,289 to Stiffler, which is hereby incorporated by reference.
[0019] The cutting tool body 22 is divided into three principal portions; namely, a head portion 32 , a collar portion 38 and a shank portion 44 . These portions will now be described.
[0020] The most axial forward portion is the head portion 32 . The head portion 32 begins at the axial forward end 24 and extends along longitudinal axis X-X in the axial rearward direction.
[0021] The mediate portion is the collar portion 38 . Beginning at the juncture with the head portion 32 and extending along the longitudinal axis X-X in the axial rearward direction, the collar portion 38 comprises a tapered neck section 40 followed by a cylindrical collar section 42 .
[0022] The most axial rearward portion is the shank portion 44 . Beginning at the juncture with the collar portion 38 and extending along the longitudinal axis X-X in the axial rearward direction, the shank portion 44 comprises a forward cylindrical tail section 46 , followed by a mid-section 48 , followed by a retainer groove 50 , followed by a rearward cylindrical tail section 52 and terminating in a beveled section 54 . As is known by those skilled in the art, the shank portion 44 is the portion of the cutting tool body 22 that carries the retainer (not illustrated). The retainer rotatably retains the rotatable cutting tool in the bore of a tool holder (not illustrated) or the bore of the sleeve carried by a holder. While the retainer can take on any one of many geometries, a retainer suitable for use with this cutting tool body is shown and described, for example, in U.S. Pat. No. 4,850,649 to Beach et al., which is hereby incorporated by reference.
[0023] Still referring to FIGS. 1 and 2 , the head portion 32 includes a two-piece construction, in accordance with an aspect of the invention. Specifically, the head portion 32 includes a base portion 54 that is affixed to the collar portion 38 . The head portion 32 also includes a nose portion 56 that is movably connected to the base portion 54 . In one aspect of the invention, the hard tip 30 is affixed to the nose portion 56 .
[0024] As illustrated in FIGS. 1 and 2 , the base portion 54 of the head portion 32 defines a pocket, generally designated by reference no. 58 . In one aspect, the pocket 58 can have a substantially circular cross-section and extend axially along axis X-X from an axial forward end 60 of the base portion 54 rearwardly toward the collar portion 38 . A groove 62 (see FIG. 2 ) is formed in the base portion 54 circumferentially about the pocket 58 .
[0025] At least a part of the nose portion 56 is received in the pocket 58 . The nose portion 56 is movably connected to the base portion 54 . In one aspect of the invention, the movable connection is provided by a mounting clip 64 , e.g., a spring clip that is attached to the nose portion 56 and includes a plurality of dimples 66 that are received in the groove 62 . The mounting clip 64 is retained on the nose portion 56 by positioning the mounting clip 64 in an elongated notch 68 formed circumferentially about the nose portion 56 . In one aspect of the invention, the described configuration of the mounting clip 64 with dimples 66 that cooperate with groove 62 provides for the nose portion 56 to be rotatably connected to the base portion 54 . Thus, it will be appreciated that the nose portion 56 is allowed to move independently with respect to the base portion 54 . In addition, it will be appreciated that other means for movably connecting the nose portion 56 to the base portion 54 may be provided in accordance with the scope of the invention.
[0026] Referring to FIGS. 2 and 3 , the cutting tool body 22 defines a coolant channel 70 that extends axially along axis X-X from the axial rearward end 26 through the shank portion 44 , through the collar portion 38 , and through at least part of the base portion 54 of the head portion 32 . In one aspect of the invention, the coolant channel 70 has a substantially circular cross-section. In another aspect of the invention, the coolant channel 70 is formed on an internal portion of the cutting tool body 22 and an axial forward end 71 of the coolant channel 70 is in fluid communication with the pocket 58 of the base portion 54 . This configuration provides for the nose portion 56 of the head portion 32 to be positioned adjacent to the internal coolant channel 70 that extends through at least a part of the base portion 54 of the head portion 32 .
[0027] In operation of the rotatable cutting tool 20 of the invention, a coolant is passed through the internal coolant channel 70 in the direction indicated by arrows 72 . The coolant passes from the coolant channel 70 to the pocket 58 of the base portion 54 . Once the coolant reaches the pocket 58 , the coolant is able to contact the nose portion 56 which, as described, is movably mounted within the base portion 54 . It will be appreciated, therefore, that due to the nose portion 56 being movably connected relative to the base portion 54 , that the nose portion 56 does not have a snug or interference fit that would prevent the coolant from passing over the nose portion 56 and moving toward the axial forward end 60 of the base portion 54 . Once the coolant passes the axial forward end 60 of the base portion 54 , it continues to flow toward the axial forward end 24 of the nose portion 56 and toward the hard tip cutting insert 30 . Advantageously, the coolant provides for cooling the hard tip 30 during a cutting operation of the rotatable cutting tool 20 . This provides for the working temperature of the hard tip 30 to be regulated within desired limits during a cutting operation in order to increase the useful life of the hard tip 30 .
[0028] In addition, it will be appreciated that providing for the coolant to pass through the cutting tool body 22 and reach an axial forward end 24 thereof, provides for the coolant to act as a dust suppressant for dust that may be generated during a particular cutting operation using the rotatable cutting tool 20 .
[0029] As shown in FIGS. 1 and 2 , the nose portion 56 may have one or more flutes 74 formed on a surface of the nose portion 56 , in accordance with an aspect of the invention. Advantageously, the flutes 74 provide for the coolant that contacts the nose portion 56 to engage the flutes 74 and to rotate the nose portion 56 with respect to the base portion 54 . The increased rotation of the nose portion 56 due to the flutes 74 interacting with the coolant provides for increased life for the hard tip 30 by providing for more uniform wear of the hard tip 30 .
[0030] FIG. 4 illustrates an alternate embodiment of a nose portion 156 , in accordance with an aspect of the invention. Nose portion 156 includes a hard tip 130 affixed thereto, similar to the arrangement set forth and described herein in FIGS. 1 and 2 . However, the nose portion 156 includes a substantially smooth outer surface 176 , i.e., the outer surface 176 does not include flutes formed thereon. The nose portion 156 is still rotatably mounted with respect to a base portion (not shown in FIG. 4 ) to provide for relative movement between the nose portion 156 and the corresponding base portion.
[0031] Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims. | A rotatable cutting tool for use in impinging earth strata such as, for example, asphaltic roadway material, coal deposits, mineral formations and the like. The rotatable cutting tool includes a cutting tool body having a through coolant channel and a two-piece head portion, e.g., the head portion of the cutting tool body having a base portion and a nose portion with a hard tip cutting insert affixed to the nose portion. The through coolant provides for cooling the hard tip cutting insert during operation of the cutting tool. In addition, the through coolant also provides for suppressing dust created by the rotatable cutting tool during operation. | 4 |
This application claims benefit of Provisional Appl. 60/044,374, filed Apr. 28, 1997.
BACKGROUND OF THE INVENTION
Unauthorized distribution of software is a major commercial problem causing losses of billions of dollars each year to software developers.
Typically, consumer software products are sold with licenses which restrict the use of the product to operate on only a single CPU at any given time, i.e., a single-user license.
Additionally, multi-user licenses may authorize installation of a software product and use of the software product on a fixed number of CPUs at a given time.
Although many users voluntarily comply with license restrictions, a significant amount of unauthorized installation and use of licensed software exists. This unauthorized activity deprives software developers of revenue.
Accordingly, many techniques have been developed to prevent unauthorized installation and use of software products. Many solutions employ specialized hardware to prevent unauthorized activity. Current security measures offered by software developers require the inputting of passwords and/or product serial numbers in order to activate installation and/or execution of the main program. These measures have been proven ineffective. Accordingly, efforts continue to improve protection for software developers against illegal distribution of software.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a software solution of enforcing licensing restrictions generates a device-specific hardware key for encrypting program data transferred to an installation medium. If the installation medium is transferred to another unauthorized device a different hardware specific key is generated which prevents decryption of the program data stored on the installation medium to prevent unauthorized installation.
According to another aspect of the invention, a run file, which is executed to access and use a software product, is stored on the data processor in an encrypted format. When the run file is invoked by a user, a shell program decrypts the file, using the hardware specific key, and loads the decrypted run file in main memory. The decrypted run file is then executed. When use of the software product is terminated the decrypted run file is erased from memory. Thus, the run file cannon be copied from the hard drive of an authorized CPU for use on an unauthorized CPU.
According to another aspect of the invention, when a given number of multiple users is authorized, an installation counter is checked each time the software product is installed. If, for a given installation, the value of the installation counter exceeds the given number, installation is prevented.
According to another aspect of the invention, if the software product is previously installed it is encrypted utilizing the device-specific hardware key of the previous installation. This device-specific hardware key can not be generated on a different machine so installation is blocked.
According to another feature of the invention, a program image loaded into memory includes an unencrypted shell part and an encrypted part. The shell decrypts the encrypted part in main memory and then program control is transferred to the newly decrypted part.
Other features and advantages of the invention will be apparent in view of the following detailed description and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a standard data processing system;
FIG. 2 is a schematic diagram of a dynamic encryption/decryption process;
FIG. 3 is a flow chart depicting the steps of installing a software product utilizing the preferred embodiment;
FIG. 4 is a flow chart depicting the steps of running a software product utilizing the preferred embodiment;
FIG. 5 is a schematic diagram of data structures in main memory during the dynamic encryption/decryption process.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a typical prior art data processing system, including a CPU 100 and main memory 110 (RAM) which holds programs and data to be executed by the CPU 100. Typically long term storage of data is done on a hard disk drive 120 (HDD). Input can be via an input media 120, e.g., floppy disk, CD, or DVD devices, or via other I/O interfaces 124.
According to one embodiment, a Licensing Enforcement Product (LEP) offers protection against the illegal distribution of software products for developers of the DOS and Windows platforms. The LEP ensures that the regulations imposed by software licensing agreements for the mass-market are followed strictly, so that a licensed software product operates on only one single CPU at any given time. This is referred to this as single-mode usage. Single-mode users are permitted to transfer a licensed software product between different CPUs in so far as there are not two copies of a single licensed product installed concurrently. Therefore, the LEP insures that single-mode usage licenses are upheld by using CPU specific data to encrypt the installed software product and then to write this CPU specific encryption data to a floppy diskette which is required for installation. Therefore, the LEP is present on this installation diskette, hereafter referred to as the Installation Diskette (ID), which is required for each installation.
In single-mode usage, this diskette cannot be transferred to a different PC since the data written on that diskette is specific to the current installation on the initial PC. Once the software product has been properly uninstalled, the CPU specific information is no longer operative on the installation diskette and the software product can be legally transferred to a different PC. Therefore, it is necessary for the LEP to be active in both the installation procedures and the main program execution of any software product which utilizes this protection scheme. In cases where the software product is delivered to end-users in a CD-R, CD-RW, or a DVD format the ID is not necessary. All necessary information is transferred directly to the CD.
It is assumed that majority of users will be operating in single-mode usage. The LEP does support software products which offer multiple licenses per single software product purchases.
The ID is the only indication to the end-user that any security measures might be employed. Thus, the LED is not an alteration of the "normal installation procedure" and the LEP is absolutely unobtrusive and transparent to the legal end-user. Security measures are only activated by illegal usage, and require no input from a legal end-user.
In the present embodiment, illegal end-users will be confronted with a series of obstacles designed to deter the intrusion of illegal users into the code of the LEP as well as the code of a customer's software product. As such, the LED product does become obtrusive when illegal actions are performed such as the attempt to load a software product with a single-mode usage license on multiple CPUs concurrently, the attempt to "crack" the software product so as to overcome protection routines, and the attempt to alter a software developer's product to any unauthorized degree.
The LEP is delivered as a "shell" which is fused around the original code of a software product protected by the LEP. Therefore the LEP is not technically a separate program from a protected software product nor does it interfere with the original code. In fact, developers intending on using the LEP protection scheme do not need to alter their program to any degree in order for the protection shell to be operative. Also, the LEP does not alter or interfere with the normal operation of a software developer's product to any significant degree. Therefore, this program is unobtrusive and transparent to software developers as well.
The LEP shell can be seen as a set of two types of processes, proactive and reactionary. The LEP shell is operative during both the installation of a licensed software product as well as during each running of the main program executable. Hereafter the following terminology is used to refer to the generic installation and main execution programs: Install.exe and Run.exe respectively. Install.exe is defined as any program which is responsible for the transfer and configuration of program and data files from the product as delivered by a software developer (Floppy Diskette and/or CD-ROM) to the end-user's hard drive. Install.exe then refers to the union of the LEP and the native installation routine, referred to the install main routine, provided by a software developer. Therefore the native installation routine refers to the install main program designed by the software developer which moves the program files from the distribution medium to the end-user's hard disk and creates the necessary file structure for proper execution. Run.exe is defined as the main executable which end-users utilize in order to access the desired application and is also comprised of the LEP. The LED shell comprised header and middle parts encrypted with different keys.
The LEP is active in both the installation (Install.exe) and main execution (Run.exe) processes. These operations can be defined as proactive and reactionary. As proactive, the LEP provides protection schemes which attempt to deter any illegal usage and/or actively monitor that only legal input is being received from the end-user. As reactionary, the LEP provides routines which are not activated until illegal input from an end-user is received and provides a set of measures which punish illegal users, while leaving legal users unaffected.
The following outline will distinguish the process of the LEP as divided between proactive and reactionary:
3. Proactive
A. Encrypting/Decrypting Agent
1. Standard Key Encryption/Decryption
2. Hardware Specific Encryption/Decryption
3. Dynamic Decryption in Memory
B. Installation Counter
C. Memory Checksum
D. Anti-Debugging Tricks
1. Timer
2. Debugger Detection
4. Reactionary
A. Punishment Routines
1. Termination of Program
2. Loss of Installation
3. Loss of Program
The operation of each of these processes is described below as distinct units (Process Description) and then a description follows as to how each unit functions in relation to the whole of the LEP (Operational Outline). The Operational Outline is divided between the processes of the LEP as it relates to Install.exe and as it relates to Run.exe. Each process is considered unique as it is developed.
Process Description
1. Proactive
These processes are active during the execution of both Install.exe and Run.exe. As proactive they attempt to ensure single-mode usage and to monitor for illegal usage.
A. Encrypting/Decrypting Agent
The processes described in this section refer to the encryption and decryption of the files of a software developer's product, especially Install.exe and Run.exe insofar as the LEP shell has been fused around these programs.
1. Standard Key Encryption/Decryption
The standard key is a 64-bit key used to encrypt/decrypt data. The key is used by a encryption algorithm when encrypting the data, or by a decryption algorithm, when decrypting the encrypted data. These algorithms support the use of a 64-bit key. The key name has a string format (e.g. "ThekeyXX"). The files Install.exe and Run.exe will be encrypted using this key prior to the initial installation of a software product. The process of encryption and decryption is performed by the LEP shell.
2. Hardware Specific Encryption/Decryption
The hardware key is a 64-bit key and is hardware specific, a hard key. A hardware specific key is fabricated from hardware parameters. The purpose of having a hardware key is to encrypt or decrypt the data specific to the hardware used. The hardware specific key is fabricated by obtaining relevant parts of the BIOS information from the hardware which might vary from computer to computer. The start of the relevant BIOS information resides in the memory address FFFFH:OOOOH (where FFFFH is the segment, and OOOOH is the offset). The following contains a listing of BIOS information parameters that might vary from computer to computer:
A) BIOS revision date
B) BIOS version number
C) BIOS manufacturer's name
D) Other characters within the BIOS information
The hardware specific key is used to encrypt the contents of the ID and the installed main executable, Run.exe, of the software product, thereby replacing the standard key described above.
3. Dynamic Decryption in Memory
Dynamic decryption in memory will now be described with reference to FIG. 2. The LEP shell exists as an unencrypted portion 200 of Install.exe and Run.exe which acts as a decrypting/encrypting agent. During the execution of Install.exe or Run.exe, this decrypting/encrypting agent loads the program image into main memory 200, and decrypts the encrypted portions 220 of the executable with the appropriate key. After decryption, the program passes control to the newly decrypted part 230. At which point the main portion of the program executes normally, either installing the software product or running the application.
B. Installation Counter
In order to provide a limited number of installations, an installation counter is used. This installation counter keeps track of the condition of part of the executable file and encrypts part of it by the number of times it is installed. Thus, an executable file which has been installed twice part of it would be doubly encrypted, had it been installed three times it part of it would be triply encrypted, and so on. The installation counter keeps track of the number of encryption layers within the executable file. When the program is run, after having been installed a specific number of times (but still less than the maximum number), the partly encrypted files are decrypted in memory by the number of times it was encrypted.
Decryption is performed several times with the use of the proper key until the format of a part of the file is recognized. When the maximum number of installations is reached, the installation counter refuses to encrypt the file any further, and the decryption process for the file is fully disabled.
C. Memory Checksum
Performs a memory checksum of the whole code. So if any portions of the code are modified by a debugger or another program (e.g. TSR). The memory checksum value will not match the one expected, this will start a punishment routine.
The technical idea behind the memory checksum is to read the whole code segment in memory, character by character. As a character is read it is multiplied by a certain value and summed to the next character which is also multiplied by a value and so on. By doing this we make the ordering of the data in memory important to the process. Please refer to checksum.cpp.
D. Anti-Debugging Tricks
These are a set of operations which occur during the execution of Install.exe and Run.exe in order to insure that the program is executing normally. End-user initiated interference with the normal operation of the program is a violation of the licensing agreements provided by mass-market software products.
1. Timer
The technique is simple: a clock tick measurement is taken before and after a process runs. The first clock tick measurement represents the starting clock tick, after the process is done, the ending clock tick measurement is taken, which represents the finished clock tick. These values are subtracted from each other. This gives the duration value in clock ticks. If this duration value is greater than a specified tolerance than we know a debugger is being used. During normal execution, the duration value will be less than the specified tolerance.
2. Debugger Detection
The basic notion is to detect that a specific debugger program has been used to run the program. The LEP will target debugging software available in the mass market. The detection process of a specified debugger is done in the following manner. When a debugger program is loaded to memory, usually conventional memory (but could be also loaded to extended memory), the LEP detects it by performing an unique string search over the whole memory region. The detected string will be crucial code, specific to a debugger program, when loaded and run in memory. Once the detection is performed, we overwrite the crucial area of the debuggers' code with garbage. So when the debugger starts executing it crashes. The user will typically load the program unto the debugger and attempt to debug it. The string detection code will be deeply encrypted within the file, but when execution of the program begins, the string detection code decrypts itself and performs all the necessary actions.
II. Reactionary
These processes are activated only by the violation of the licensing agreement. End-users performing illegal operations will be detected by the proactive processes described above and will be punished as describe below. These punishments are not set parameters within the LEP and will be determined by software developers choosing to use the protection scheme.
A. Punishment Routines
1. Termination of program
Program will terminate once an illegal operation occurs. If this operation occurs as the result of an external program which is in use by the end-user for the illegal alteration of a software product under the LEP protection, the external product will be adversely affect but not permanently damaged.
2. Loss of Installation
If illegal operation by an end-user is detected it is possible for the LEP to terminate the licensed software product and to assign new values to the installation counter so that the counter reads one installation less than actual installations. For, example if a user has installed the product legally three times, and then performs an illegal operation the installation counter will read as if there had been four installations. Also, the installation counter can be set so that after an illegal operation is detected all further installations are invalid, hence the counter would read as having reached the maximum number of installs. The removal of an installation is accomplished by decrypting the multiply encrypted program by one time.
3. Loss of Program
If illegal operation by an end-user is detected it is possible for the LEP to remove itself from the hard drive of the end-user. This type of punishment can be used in conjunction with the loss of installation so that the user is required to utilize one of his/her limited number of installations to restored the application. This type of punishment generates a flag which is written to the end-user's hard drive. This flag would be a signal to the LEP resident around Install.exe to terminate installation procedures and then to disable the ID from further usage. Removing the files from the diskette can be achieved by first encrypting the file and using the remove () function in the C-library <stdio.h>, which deletes files specified by path.
Operational Outline
Preferred Embodiment
This applies to scenarios in which the LEP provides management of the transferring of files from the delivery medium to the hard drive.
Installation Process
As depicted in the flow chart of FIG. 3, the installation can be modeled into the following steps:
1. InstalL exe is loaded into memory by the operating system from the ID.
2. The LEP performs a check for active debuggers, and if it is a punishment routine will start. Through the following process the anti-debugging tricks are present and active (cf. Process Description I.E.1 and 2) and if a violation is detected a punishment routine will begin.
3. The LEP performs dynamic decryption in memory (cf. Process Description I.A.3) of the native installation routine and starts executing.
4. The LEP retrieves information from the computer's ROM BIOS and fabricates a hard key out of it. This hard key is used to re-encrypt the code in memory and the Install.exe file (cf Process Description I.A.2).
5. The number of the installations counter is updated by one (cf. Process Description I.C). Thus, the installation is tied down to that specific computer.
6. During execution of the Install.exe file. The standard encrypted files (cf Process Description I.A.1) of the protected software are copied to memory, decrypted, and copied to the hard disk in a specified directory. This is done by using regular copying routines provided in C-libraries. The transferring of files from the delivery medium to the hard drive can be performed by the native installation routine provided that the software developer has incorporated the above-described decryption routine.
7. During the physical installation of the main executable file, Run.exe, of the software product, this file is copied to memory, decrypted, and encrypted with the hard key, before being copied to the hard disk.
Execution Process
As depicted in FIG. 4, the execution of the main program can be modeled into the following steps:
1. Run.exe is loaded into memory by the operating system.
2. A check is performed for active debuggers, and if it is a punishment routine will start. Throughout the following process the anti-debugging tricks are present and active (cf. Process Description I.E.1 and 2) and if a violation is detected a punishment routine will begin.
3. The LEP performs a verification that the proper hard key encryption is present, if not a punishment routine begins.
4. The LEP performs dynamic decryption in memory (cf Process Description I.A.3).
5. The LEP performs a memory checksum of the LEP shell (cf. Process Description I.D.)
6. The LEP hands off of execution to the main program.
The format of run.exe in the main memory and on the hard drive is depicted in FIG. 5.
Secondary Embodiment
The secondary embodiment of the LEP is necessary only if a software developer desires that its code not be modified in any way by the LEP. The necessary changes occur only in the Install.exe and are as follows:
Installation Process
The installation can be modeled into the following steps:
1. Install.exe is loaded into memory by the operating system from the ID.
2. The LEP performs a check for active debuggers, and if it is a punishment routine will start. Through the following process the anti-debugging tricks are present and active (cf. Process Description I.E.1 and 2) and if a violation is detected a punishment routine will begin.
3. The LEP performs dynamic decryption in memory (cf. Process Description I.A.3) of the native installation program and starts executing.
4. The LEP retrieves information from the computer's ROM BIOS and fabricates a hard key out of it. This hard key is used to re-encrypt the code in memory and the Install. exe file (cf. Process Description I.A.2).
5. The number of the installation counter is updated by one (cf. Process Description I.C). Thus, the installation is tied down to that specific computer.
6. The execution is turned over to the native installation routine. After this process is complete, control is returned to the LEP.
7. The standard encrypted files (cf. cf. Process Description I.A.1) of the protected software are copied to memory from the hard disk, decrypted, and copied back to the hard disk in the proper directory.
8. The main executable file, Run.exe, of the software product is copied to memory, decrypted using the standard key, encrypted with the hard key, and copied back to the proper directory on the hard disk.
Execution Process
The execution of the main program can be modeled into the following steps:
1. Run.exe is loaded into memory by the operating system.
2. A check is performed for active debuggers, and if it is a punishment routine will start. Throughout the following process the anti-debugging tricks are present and active (cf. Process Description I.E.1 and 2) and if a violation is detected a punishment routine will begin.
3. The LEP performs a verification that the proper hard key encryption is present, if not a punishment routine begins.
4. The LEP performs dynamic decryption in memory (cf. Process Description I.A.3).
5. The LEP performs a memory checksum of the LEP shell (cf. Process Description I.D).
6. The LEP hands off of execution to the main program. | A software licensing enforcement product includes a shell utilizing a device specific hardware product to encrypt the install program and the run program to prevent non-authorized devices form installing or using a software product. The shell decrypts the run program to allow the authorized device to access the software product. | 6 |
This is a national stage of PCT/EP06/008324 filed Aug. 24, 2006 and published in German.
FIELD OF THE INVENTION
The invention concerns a wooden structural component for manufacturing flat structures, in particular for the construction of upright walls of buildings
with rectangular base plates of roughly equal area, arranged roughly parallel to each other, which are held, overlapping and projected normal to their main surfaces, by intermediate members at a distance from each other, and between which cover a cavity, with rectangular wall panels of roughly equal area, arranged roughly parallel to each other, which are fastened, overlapping and projected normal to their main surfaces, on the outside of the base plates, and are roughly the same size as, or slightly smaller than, the base plates, such that both the base plates and the wall panels on the finished structure are arranged horizontally, longitudinal edges roughly parallel to each other, and arranged roughly vertical on the finished structure, featuring top edges roughly parallel to each other, such that the wall panels are arranged offset to the base plates as regards their longitudinal edges and regards their top edges, such that—through longitudinal edges and top edges on the one hand, and through longitudinal edges and top edges of the wall panels removed from them on the other—bounded, exposed longitudinal frames and top frames of the base plates form the sides of two male part or tongue joints arranged roughly at right angles to each other, and that longitudinal frames of the wall panels lying opposite to each other and protruding over longitudinal edges of the base plates, and wall panel top frames lying opposite to each other and protruding over top edges of the base plates form the sides of two female part or groove joints arranged roughly at right angles to each other, roughly as the opposites of the male part or tongue joints, of which intermediate members feature rod-like, longitudinally-stretched supports which are arranged roughly parallel to each other and to top edges of the base plates on a side, and are arranged roughly perpendicular to the longitudinal edges of the base plates, and which are distributed at roughly the same distance from each other in the cavity between the base plates, and whose length is roughly the same as the length of the top edges of the base plates or wall panels on the side, such that the supports arranged between the same two base plates and joined directly to these, aligned roughly parallel to each other and to the top edges of the base plates, are arranged at the same distances as a specific grid dimension from each other, and such that a distance of a first support from the nearest top edge of the base plates directly joined to this first support, and a second distance of a last support to the nearest top edge of the base plate directly joined to this last support, complement each other to the full grid dimension, such that the supports feature a rectilinear mid-profile with an essentially right-angled cross section, and form retaining walls between the base plates roughly at right angles to it, which subdivide the cavity between the base plates into chambers of roughly equal length and breadth and such that the supports feature tongue joints, preferably dovetail joints, along their edge sides, which fit into roughly equal and opposite grooves, preferably corresponding dovetail grooves on the inner surface of the base plates, and so form a form-fitting tongue-groove connection or a twofold form-fitting dovetail connection between supports and base plates.
BACKGROUND OF THE INVENTION
A wooden structural component of the type named has been made known by DE 102 24 903 A1, by WO 2003 102 325 A3 and by EP 1 511 906.
The subject of the invention is also a corner structural component for insertion in a construction set and a structure in connection with wooden structural components of the type named. The structure according to the invention features corner structural components and wooden structural components in a particular insert with insulating material.
Wooden structural components of the type named are originally specified for structures with particularly advantageous thermodynamic properties as regards the heat and moisture permeability of their building walls. They can be manufactured with little economic outlay in the form of materials and labor, and have proved themselves optimally in the construction of building in areas with moderate hazards. Particular influences of earthquakes (tectonics), atmospheric conditions, industry and traffic or tremors as a result of warfare, for example hazards caused by seismic shocks, water penetration, whirlwinds or tornados and arbitrarily effected operations in the surrounding area require particular properties which, until now, structures of the type named initially could only achieve provisionally and only with substantial economic outlay. The general task now underlying the invention is to create structures which can be erected at little economic cost, which satisfy high structural-physical requirements and which in particular withstand the hazards named.
As was expected, what has been established about known wooden structural components of the type named, both in research areas and in industrial usage, is that the join between neighboring wooden structural components in walls of buildings, compared to mechanical influences in the direction normal to the walls of the buildings, is very robust, and satisfies even the strictest requirements of the greatest hazards. Nevertheless, it also turned out that particularly large mechanical forces can emerge in buildings in the hazardous surrounding area, too, which act in the direction along the walls of the buildings and put a high strain on the join between the wooden structural components neighboring each other. Thus a particular task of the invention consists in further developing the known wooden structural component without loss to its advantageous properties so that—without particular economic cost in terms of materials and labor—it can be joined to wooden structural components of the same type in walls of buildings which withstand the effect of large forces in all directions, in particular also the effect of large shear forces in the direction along the walls of the buildings.
SUMMARY OF THE INVENTION
The solution to the particular technical task, according to the invention, is given in the essential inventive characteristics of the wooden structural component of the type initially named include
the supports which are aligned roughly parallel to the top edges of the base plates and are of roughly equal length being arranged consistently in relation to the longitudinal edges of the base plates, with their tongue joints along their edge side and engaging partially into the equal and opposite grooves on the base plates, and so the base plates located opposite each other joining partially together, the supports featuring free end pieces of roughly the same length with free tongue joints of the same length which protrude over a first of two longitudinal front sides of the base plates located opposite each other, longitudinal front sides which are each bordered by the two longitudinal edges of the base plates nearest each other, and the grooves which are roughly equal and opposite to the tongue joints on the edge sides of the supports preferably featuring dovetail grooves in the free end pieces of the base plates, which are accessible by a second of the two longitudinal front sides of the base plates located opposite each other, and which are set up in each case to incorporate the free tongue joint on the finished structure, preferably the dovetail joint of one of the free end pieces of supports of a neighboring wooden structural component of the same type.
According to the invention, the tongue joints of the supports of a wooden structural component only grip partially into the otherwise equal and opposite grooves of the base plates of the same wooden structural component. The base plates of a single wooden structural component according to the invention are therefore no longer just as firmly joined together as the base plates of the known wooden structural component inserted up until now, that is, before the further development according to the invention. The required firmness between the base plates of a wooden structural component according to the invention nevertheless arises, however, in connection with neighboring equal wooden structural components in finished walls of buildings by the free end pieces of the supports of a neighboring wooden structural component protruding into the cavity of the one wooden structural component, and the free tongue joints on the free end pieces of the supports of the neighboring wooden structural component gripping into the free end piece of the equal and opposite grooves on the base plates of the one wooden structural component. If tongue and groove make up a dovetail joint on supports or base plates, then there is a firm connection between base plates located next to each other without the use of glue.
Shear forces will in any case be transmitted effectively by one wooden structural component to the neighboring wooden structural component in a direction along the building walls over the free end pieces of the grooves in the base plates of the one wooden structural component, and over the free tongue joints of the free end pieces of the supports of the neighboring wooden structural component engaging therein. For the transmission of forces, for example wind pressure in the direction normal to walls of buildings, according to wooden structural components as further developed by the invention, longitudinal edges and top edges of the base plates of the one wooden structural component are located between the sides of the longitudinal edges and top edges of wall panels of neighboring wooden structural components, as hitherto. In the further development of the known wooden structural components according to the invention, their technical and economic advantages remain completely retained and are supplemented by further technical advantages. The transmission of shear forces in the direction along a building wall of a wooden structural component onto a neighboring wooden structural component is certainly a known technical task and was already a goal being aspired towards by known technologies. For example, according to EP 0744507 B1 and in WO 97/39204, such shear forces in the longitudinal direction are transmitted by protrusions or points on the end of so-called module cores of a wooden structural component in connection with grooves or holes on the other ends of the same module cores of neighboring wooden structural components. These module cores are admittedly composed of several pieces and in any case can only be manufactured at great economic cost in terms of material, profiling and labor. On the other hand, according to the invention, the transmission of shear forces in the longitudinal direction takes place by supports of a wooden structural component which are very easy to manufacture and introduce, directly onto equally easily manufacturable base plates of neighboring wooden structural components. In contrast to the stated prior art, the supports and base plates and wall panels according to the invention form a surprisingly economically manufacturable combination and display particularly advantageous functional interactions of structural engineering.
In the cavities between the base plates of the wooden structural components according to the invention, without particular fixtures, individual installation channels for electricity, gas, drinking and effluent water, telecommunications or similar can certainly be built in during the construction of structures, and finally embedded in insulating materials if such installation channels are planned in due time before the erection of the structure. All the same, most installations are only planned after the erection of the structure, and must then be fixed to the outer sides of the wall panels covering the base plates, and must be covered by a further plaster wall.
In the interests of economic efficiency, the function of the wooden structural component according to the invention is also to be considered as a bearer of the conventional installations. From this there results the particular task for the further development of the invention: demarcating, in any order and without particular pre-planning, usable installations spaces in the cavity between the base plates, in such a way that structurally conventional installations are aligned without additional covering plaster walls, and can later be investigated and replaced without further ado.
In general, the solution to the task regarding lasting installation spaces consists in aligned partition walls being introducible between the supports, roughly parallel to the base plates, which, in the finished structure, feature roughly horizontally-aligned longitudinal edges and vertically-aligned top edges, and are held on both sides along their vertical top edges by the retaining walls of the supports which are turned towards each other. These partition walls should separate installation spaces turned towards inner base plates, and wall panels with little depth, from installation spaces turned towards outer base plates and wall panels which feature a large depth. The partition walls are preferably constructed with top frames running along their top edges, which are made to engage in notches on the retaining walls of the supports. The notches on the retaining walls should have an opening width in the range from 3 to 8 millimeters, in order to incorporate the top edges of partition walls made of wood fiberboard. Moreover, they should advantageously feature a gap of 20 to 30 millimeters, preferably from 20 to 25 millimeters, from an inner base plate, and a gap of 150 to 250 millimeters, preferably roughly 200 millimeters, from an outer base plate.
Co-ordinated to the particular requirements of the wooden structural components, the essentially rectangular-constructed partition walls feature lateral top edges with a length equal to the length of the supports, and are inserted between the supports in such a way that their longitudinal edges are arranged flush with the ends of the supports. The partition walls so arranged do not thereby disrupt the construction of a building wall by assembly of the wooden structural components. Hence a complete delimiting of installation spaces from insulation spaces only arises through the joining together of the wooden structural components to a finished building wall.
Wooden structural components according to the invention can be particularly advantageously utilized in connection with particularly adapted corner structural components.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail using the examples of particular embodiment types with the help of attached drawings. Schematically shown in the drawings are:
FIG. 1 : a section of a perspective view of a wooden structural component according to the invention;
FIG. 2 : the front view of a wooden structural component of the type shown in FIG. 1 , in a direction normal to the main surfaces of wall panels and base plates;
FIG. 3 : the side view of a first type of embodiment of the wooden structural component in a direction normal to the retaining walls of supports;
FIG. 4 : the side view of a second type of embodiment of the wooden structural component according to the invention, in a direction normal to the retaining walls of supports;
FIG. 5 : the top view of a wooden structural component of the type according to FIG. 1 to 4 with inserted partition walls for dividing installation spaces from insulation spaces;
FIG. 6 : the view of a cross-section through a corner structural component for insertion in a construction set according to the invention and a structure according to the invention together with wooden structural components of the type according to the FIGS. 1 to 5 ; and
FIG. 7 : a section from the front view of a corner structural component according to FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The same and similar constituents of the wooden structural component according to the invention and of the corner structural component are provided with the same labels in all the figures of the drawings, and are described together in the following description for all the embodiment types schematically represented in the drawings.
The wooden structural elements depicted in FIGS. 1 to 5 feature two base plates 1 and 2 , which are constructed rectangular with roughly the same area, aligned roughly parallel to each other, and arranged with a distance between them and in a projection normal to their main surfaces, overlapping each other. Rectangular wall panels 3 and 4 , of equal area, overlapping each other and in a projection normal to their main surfaces, are each fixed to one of the outer main surfaces of the base plates. The wall panels feature main surfaces which are either the same size as or slightly smaller than the main surfaces of the base plates. On the finished structure, both the base plates and the wall panels feature top edges which are aligned roughly horizontal and are roughly parallel to each other, and, laterally on the finished structure, top edges which are aligned roughly vertical and are roughly parallel to each other. The wall panels are arranged opposite the base plates offset in such a way that longitudinal edges of the base plates and wall panels, roughly parallel to each other, delimit a free longitudinal edge 5 on the outer surfaces of the base plates on the one hand, and a free longitudinal edge 6 on the inner surface of the wall panels on the other hand. Moreover, the wall panels are also arranged opposite the base plates in such a way that top edges of the base plates and wall panels roughly parallel to each other delimit a free top edge 7 on the outer surfaces of the base plates on the one hand, and a free top edge 8 on the inner surfaces of the wall panels on the other hand.
The base plates 1 and 2 of the wooden structural components depicted in the FIGS. 1 to 5 are held by four rod-like, elongated supports 9 at a distance from one another. The supports are aligned roughly parallel to each other and to lateral top edges of the base plates, and roughly perpendicular to the longitudinal edges of the base plates, and in a row at equal distances from each other. These distances are determined by a grid dimension which is manufactured again by the sum of the distances of the two outer supports in the row to the top edges of the base plates nearest to them.
The supports 9 feature a rectilinear mid-profile with an essentially rectangular cross-section and form retaining walls 10 between the base plates and roughly perpendicular to them, which subdivide the cavity between the base plates into chambers of roughly the same length and breadth. Dovetail grooves 11 aligned roughly parallel to the base plates can be designated to the retaining walls, into which bolts (not shown) for joining neighboring wooden structural components are to be inserted.
The supports 9 feature dovetail joints 12 along their edge sides which engage into roughly equal and opposite dovetail grooves 13 on the inner surfaces of the base plates 1 and 2 , and so form a twofold form-fit connection between supports and base plates.
It can be seen from FIGS. 1 to 3 of the drawings that the roughly equally long supports 9 aligned roughly parallel to the top edges of the base plates 1 and 2 are consistently arranged offset upwards in relation to the longitudinal edges of the base plates 1 and 2 , with their dovetail joints 12 along their edge sides only partially engaging into the equal and opposite dovetail grooves 13 of the same length on the base plates, and so the base plates located opposite each other only join partially together. The supports feature roughly equally long free end pieces with equally long free dovetail joints, which protrude consistently over an upper longitudinal front side 14 delimited by the upper longitudinal edges of the base plates. Through the displacement of the supports in relation to the longitudinal edges, equally long end pieces of the dovetail grooves 13 remain free on the inner surfaces of the base plates. These end pieces are accessible by a lower longitudinal front side 15 which is delimited by the lower longitudinal edges of the base plates, and is dedicated to incorporating the free dovetail profiles of the free end pieces of supports of neighboring wooden structural elements in combination with a finished building wall.
Emerging from FIG. 4 of the drawings is a modified embodiment type of the wooden structural component according to the invention. Similar to the embodiment type as per FIGS. 1 and 3 of the drawings, the roughly equally long supports 9 aligned parallel to the top edges of base plates 1 and 2 are arranged consistently offset in relation to the longitudinal edges of base plates 1 and 2 . With their dovetail joints 12 along their edge sides, they engage only partially into the equally long, equal and opposite dovetail grooves 13 on the base plates, and so only partially join the base plates located opposite each other. The supports also feature roughly equally long free end pieces with equally long free dovetail joints and release equally long end pieces of the dovetail grooves 13 on the inner surfaces of the base plates. Finally, in the modified embodiment type according to FIG. 4 , the free end pieces of the grooves are dedicated to incorporating the free dovetail profiles of the free end pieces of supports of neighboring wooden structural components in the composite of a finished building wall.
The embodiment type according to FIG. 4 differentiates itself from those according to FIGS. 1 to 3 by the fact that the supports 9 are arranged offset not upwards but downwards in relation to the longitudinal edges of the base plates 1 and 2 . Their free end pieces with the free dovetail joints accordingly protrude not over the upper longitudinal front side 14 but rather over the lower longitudinal front side 15 , and the free end pieces of the dovetail grooves 13 are accessible from the upper longitudinal front side 14 . This modified embodiment type has the advantage that the free end pieces of the supports and their free dovetail joints are located protected between the free longitudinal frames 6 of the wall panels which protrude over the lower longitudinal edges of the base plates.
The wooden structural component depicted in FIG. 5 features roughly rectangular-built partition walls 16 which are inserted between the supports 9 and aligned roughly parallel to the base plates 1 and 2 , and features roughly horizontally aligned longitudinal edges and vertically-aligned top edges on the finished structure. The longitudinal edges of the partition walls are longer than the free distance between two supports by the width of two top edges. These top frames along the top edges of the partition walls project into equal and opposite grooves 17 which are located in the retaining walls 10 of the supports. By the combination between the edges and grooves, the partition walls on the supports between the base plates are established and separate installation spaces 18 of small depth from insulation spaces 19 of large depth.
The partition walls 16 of the wooden structural component according to FIG. 5 are preferably manufactured out of wood fibreboards. The grooves 17 on the retaining walls 10 preferably feature an opening width in the range from 3 to 8 millimeters. The depth of the installation spaces comes to 20 to 30 millimeters, preferably 20 to 25 millimeters, corresponding to the distance of the grooves from the one base plate. Corresponding to the distance of the grooves from the other base plate, the insulation spaces feature a depth of 150 to 250 millimeters, preferably around 200 millimeters. If the longitudinal edges of the partition walls are arranged between the supports according to the invention flush to the ends of the supports, then the partition walls do not take part in a form-fitting connection between neighboring wooden structural components, and so require neither precision in their measurements on the top edges and grooves 17 , nor particular attentiveness during the erection of structures.
The manufacture of static and thermodynamically consistent structures with installation spaces in their walls, which are later freely available, only requires a small economic outlay. The wooden structural components inserted for that do not have to be constructed with particularly large dimensions, because the installation spaces together with the partition walls which separate the installation spaces from isolation spaces according to the invention already considerably reduce the heat and mass transfer to the structures and so complement the insulation of the insulation spaces. The expenditure for construction, material, manufacture and transport of the wooden structural components to the building site, and the assignment of labor on the building site for the erection of a structure, are not considerably influenced by the manufacture according to the invention of the insulation spaces in the walls later freely available.
The corner structural component depicted in FIGS. 6 and 7 of the drawings consists in its featuring a column 20 , square in its cross-section, which is essentially composed of two front panels 21 and 22 arranged opposite each other, and two side panels 23 and 24 arranged opposite each other, preferably made of wooden material, and contains an insulation space 25 for the incorporation of insulating material between the panels. The front panels have a width roughly equal to the distance of the base plates of a wooden structural component joined together by supports, measured between the outer surfaces of the base plates. The side panels are wider than the front panels and protrude with exposed top edges 26 on at least one side over the outer surface of the one front panel 21 . The width of the exposed top edges 26 of the side panels is roughly the same as the width of the exposed top edges 7 , 8 on the outer surfaces of the base plates 1 , 2 .
A first connecting post 27 is fixed on the first front panel 21 , in the middle between the exposed top edges 26 of the side panels. This post has a roughly rectangular cross-section with a cross-sectional length roughly equal to the gap between the base plates of a wooden structural component, which are joined to each other, measured between the inner surfaces of the base plates. Fixed to the one side panel 23 , in the middle between top edges of the column aligned roughly vertical on the finished structure, is a second connecting post 28 with measurements roughly equal to the measurements of the first connecting post. In a finished structure, the connecting posts stretch along the top edges of the base plates of neighboring wooden structural components. They protrude into the cavity between the base plates and so join with a positive fit the neighboring wooden structural components to the corner structural component.
The lower ends of the connecting posts 27 and 28 have a distance from the lower end of the column 20 roughly equal to the width of the free longitudinal edges 5 and 6 on the outsides of the base plates 1 and 2 , or on the insides of the wall panels 3 and 4 . Depicted in FIG. 7 are a ground sill 29 in cross-section and a ground sill 30 in side view, aligned roughly at a right angle to it, schematically raised off the corner structural component. These ground sills have a width roughly the same as the gap between a wooden structural element's wall panels ( 3 , 4 ) joined together by supports, measured between the inner surfaces of the wall panels. Their height is roughly the same as the width of the free longitudinal edges 5 and 6 on the outer surfaces of the base plates ( 1 , 2 ), or on the inner surfaces of the wall panels ( 3 , 4 ) of a wooden structural component. In a finished structure these ground sills should be laid out and fixed roughly at right angles to each other on a foundation base. Their ends which are directed towards a corner of the structure can be located under the lower ends of the connecting posts 27 or 28 of a corner structural component, and reinforce these posts. They are also dedicated, for example in wooden structural components of the embodiment type according to FIGS. 1 to 3 and 5 , to sill up the space between the wall panels and the lower longitudinal front sides 15 of the base plates, to reinforce the base plates and so to join the lowest wooden structural components with the foundation base in a form-fit and force-fit manner. With a cross-sectional profile (not shown) in the form of levels, ground sills can also stretch between the base plates ( 1 , 2 ) up to the lower ends of the supports 9 raised up by the longitudinal front sides 15 , according to the invention, and can transfer vertical forces from these supports to the foundation base.
Wooden structural components of the embodiment type according to FIG. 4 require the insertion of ground sills with particular cross-section profiles on finished structures. Such ground sills are not in fact depicted here, but will be in the thoughts of those skilled in the art as a result of the descriptions of ground sills 29 and 30 .
Wooden structural components and corner structural components are used inventively in the manufacture of structures in that, into the insulation spaces of the corner structural components and of the wooden structural components, first insulating materials with volumes which vary under the influence of atmospheric conditions and tremors are inserted or poured or blown or stuffed after grinding down the material, and that at least one permanently elastic second insulating material with an elasticity which remains as constant as possible and with volumes which change under pressure is arranged under and/or between and/or over the first insulating material. The second insulating material has equal shrinkage to the insulating material on other positions and so prevents the build-up of thermal bridges through insulation spaces or filling with insulating material. Particularly ecological requirements can thereby be advantageously met in that organic natural raw materials, preferably rock flour or granulates like clays, sands and/or pebbles, are inserted. Upon insertion of one of the first insulating materials of the type of particularly dense and heavy bulk goods which form heaps which keep their own shape, alongside the insertion of further first insulating materials with particularly advantageous thermodynamic properties regarding the heat and steam permeability, there emerge structures according to the invention, which withstand nearly every known hazard. | A wooden building element for producing planar constructions, especially for constructing the upright walls of a building. Also, a corner building element adapted to the wooden building element and to a building constructed using the elements. The wooden building elements have two approximately rectangular support bases and two wall panels that are approximately equal in area. The support bases are maintained at a distance from each other by a plurality of supports that are aligned vertically in relation to the finished building and that delimit an interior compartment for the insertion of insulating material and building installations. The wall panels are fastened to the outer surfaces of the support bases and are set off therefrom in relation to longitudinal edges that are aligned approximately horizontally to the finished building and high edges that are aligned approximately vertically. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to an airborne mobile platform laminate window that reduces vibration and sound transmissions to the airborne mobile platform fuselage interior.
BACKGROUND OF THE INVENTION
[0002] The reduction of sound transmissions to the fuselage interior of an airborne mobile platform (e.g. a modern jet aircraft) is becoming more of a concern for commercial aircraft manufacturers and their customers in an increasingly-competitive international marketplace. Commercial aircraft manufacturers and their customers are interested in reducing the level of noise inside their aircraft. More specifically, they are interested in reducing the amount of noise that is transferred from the aircraft exterior to the aircraft interior. Noise is typically created by the turbulent flow along the fuselage and radiated from the engine exhaust plume. An area of the aircraft through which noise is typically transferred is the fuselage sidewall, including the aircraft windows and its surrounding window belt area. Although interior noise is considered undesirable in commercial aircraft, aircraft manufacturers and their customers are simultaneously demanding aircraft that are lighter in order to reduce costs, and aircraft that have larger windows in order to increase outside visibility and permit larger amounts of light to enter the aircraft cabin.
[0003] While current aircraft windows are generally satisfactory for their applications, each is associated with its share of limitations. Historically, aircraft manufacturers used relatively dense materials to reduce the amount of noise that entered the cabin through the windows and window beltline. This meant using thick, transparent window materials or multiple pieces of a transparent material to reduce noise transmission. The problem with the prior art solutions to interior noise is that noise levels inside the cabin remained at undesirable levels, the aircraft weight was not being reduced, and the window size, and thus the amount of natural interior light, remained relatively small.
[0004] A need remains in the art for an airborne mobile platform window that overcomes the limitations associated with the prior art, including, but not limited to those limitations discussed above. This in turn, will result in an aircraft window that reduces interior noise relative to existing aircraft windows, remains relatively lightweight, and that is larger in size compared to traditional aircraft windows to permit higher quantities of light to enter the aircraft cabin.
SUMMARY OF THE INVENTION
[0005] A window for an airborne mobile platform is disclosed. More specifically, combinations of various window layers for use in an airborne mobile platform are disclosed. A window for an airborne mobile platform has an interior layer of transparent material and an exterior layer of transparent materials that together with the interior layer, define a space. The space may be a layer of air or a vacuum layer. The exterior layer may further be a multi-layer of transparent materials, such as an acrylic layer, a viscous noise-absorbing layer of transparent material, and a glass layer. A rubber seal, that is, a visco-elastic rubber, around the perimeter of the layers of the window provides a vibration and noise-absorbing frame that is further surrounded by a c-channel that peripherally bounds the rubber seal on three of its sides. The c-channel provides additional structural integrity to the window and acts as a structural member to provide support to the fuselage.
[0006] The features, functions, and advantages can be achieved independently in various embodiments of the present inventions or may be combined in yet other embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0008] FIG. 1 is a side view of an airborne mobile platform depicting a passenger window beltline;
[0009] FIG. 2A is a perspective view of an aircraft window having a c-ring frame;
[0010] FIG. 2B is a cross-sectional view of the c-ring frame of the aircraft window of FIG. 2A ;
[0011] FIG. 3A is cross-sectional view of an aircraft window configuration of the prior art;
[0012] FIG. 3B is a cross-sectional view of an aircraft window configuration according to a first embodiment of the present invention;
[0013] FIG. 3C is a cross-sectional view of an aircraft window configuration according to a second embodiment of the present invention;
[0014] FIG. 3D is a cross-sectional view of an aircraft window configuration according to a third embodiment of the present invention;
[0015] FIG. 3E is a cross-sectional view of an aircraft window configuration according to a fourth embodiment of the present invention;
[0016] FIG. 4 is a graph of the average velocity power spectral density (PSD) over a broadband frequency for the window configurations according to the teachings of the present invention;
[0017] FIG. 5 is a graph of the reduction of vibration (db) over a broadband frequency range for the window configuration employing a layer of visco-elastic material, relative to the prior art configuration;
[0018] FIG. 6 is a graph of the average velocity power spectral density (PSD) over a frequency broadband for various window configurations; and
[0019] FIG. 7 is a graph of the average velocity power spectral density (PSD) over a frequency broadband for various window configurations employing a stiffer c-ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Turning now to FIG. 1 , an airborne mobile platform 10 (e.g. an aircraft) is depicted. The aircraft has a fuselage 12 , a wing 14 attached to the fuselage 12 , an engine 16 attached to the wing 14 , an engine exhaust area 18 , and a window beltline 20 , located just above the wing 14 , having a multitude of passenger windows 22 . In an aircraft 10 having the window configuration depicted, noise from a variety of sources is able to penetrate through the passenger windows 22 and their surrounding window frames 23 .
[0021] One such source is the exhaust plume that originates in the engine exhaust area 18 , wherefrom noise radiates outwardly from the plume for a number of engine diameters aft of the engine 16 . Engine noise is a key concern in the aft cabin of the aircraft during take-off, climb, and at cruising altitudes. In addition, noise is generated at the fluid boundary layer of the aircraft as it moves through the air during flight. This noise source is apparent throughout the aircraft at cruising altitudes. The boundary layer is that layer of fluid in the immediate vicinity of a bounding surface. For an aircraft wing, the boundary layer is the part of the flow immediately adjacent to the wing, and for the fuselage, the part of the flow immediately adjacent to the fuselage. The boundary layer effect occurs at the region in which all changes occur in the flow pattern, for example, where the boundary layer causes distortion in the surrounding nonviscous flow.
[0022] To compound noise generation, the boundary layer also adds to the effective thickness of the aircraft, through the displacement thickness, which increases the pressure drag of the aircraft. Also, the shear forces at the surface of the aircraft wing create skin friction drag. Larger wings generally create a larger amount of drag. Since the engines are used to overcome the accumulated drag in order to move the aircraft through the air, as the drag increases, the engines must work harder to overcome the drag, which increases noise. Also, as the size of the aircraft increases, the engine size usually increases, which increases the noise generated. This highlights the strong dependence of acoustic design of an aircraft on aerodynamics and propulsion. Ultimately, the presence of noise within aircraft interiors is undesirable, and the present invention may be used to reduce an undesirable level of noise, such as a level that is created by a large aircraft, to a level that is desirable or at least acceptable.
[0023] To reduce the level of noise detectable in a fuselage interior for a given aircraft, various window material panel configurations, according to the present invention, have been developed. Window panel material configurations are also known as window or laminate buildups, window or laminate layups, or simply as layups. Turning now to FIGS. 2A and 2B , window parts that make up a portion of an aircraft window 22 will be explained. FIG. 2A depicts a window frame 23 of a window 22 of the window beltline 20 , and FIG. 2B depicts a structural c-ring 24 , or c-channel, of the window perimeter that forms the window frame 23 . The window frame 23 is defined by a c-ring 24 that is generally formed by an outside flange 30 and a web 32 . The c-ring 24 has a mounting flange 26 , which traverses the perimeter of the window 22 , and has a mounting flange inside surface 48 and a mounting flange outside surface 46 that are used for window alignment and mounting purposes. Continuing with the c-ring 24 , the outside flange 30 is referred to as the outside flange because it generally faces the fuselage exterior when the window 22 is installed. The outside flange 30 has an outside flange inside surface 38 and an outside flange outside surface 40 .
[0024] The web 32 not only blends, or joins, the mounting flange 26 and the outside flange 30 , but it provides rigidity, support and strength for the resulting c-ring 24 . The web 32 and outside flange 30 provide a partial enclosure for a visco-elastic rubber seal, to be discussed later, that abuts against the web inside surface 34 and the outside flange inside surface 38 . The web 32 has a web inside surface 34 and a web outside surface 36 . The rigidity or stiffness of the c-ring 24 is cumulatively provided by the outside flange 30 , web 32 , and mounting flange 26 . The c-ring 24 may be manufactured from a rigid, lightweight material such as aluminum or titanium, or other metal or non-metal material. With respect to weights, the specific material will be less dense than most metals or non-metals in its respective category. As will be discussed later, making the c-ring 24 stiffer may provide benefits in terms of noise reduction. To make the c-ring 24 relatively stiffer, a different aircraft aluminum or non-aluminum material could be used. Alternatively, a thicker cross-section of a given material could be used for stiffening purposes.
[0025] Before turning to the structure and operative workings of the window layer configurations of the present invention, a review of the construction of a prior art aircraft window will be briefly examined. FIG. 3A depicts an aircraft window 50 of the prior art having transparent layers as laminate pieces that make-up the transparent area 52 . The window 50 is bounded about its perimeter by the c-channel frame 24 . Against the c-channel 24 is a first rubber seal 58 , and a second rubber seal 60 . The rubber seals 58 , 60 are similarly situated in that the seals 58 , 60 together make up a single continuous seal that traverses the interior portion of the window 50 and bounds the window's laminate pieces, which will now be described.
[0026] The transparent area 52 of the prior art window 50 is comprised of a mid acrylic layer 62 , a center airspace 64 , and an outer acrylic layer 66 . The layers of material are held in place by a retainer clip. The outer acrylic layer 66 is generally the layer that may be exposed to the elements on the aircraft exterior, while the mid acrylic layer 62 is the layer that lies adjacent to a transparent dust pane (not shown). A passenger may touch the transparent dust pane when a non-transparent, retractable dust cover (not shown) is in its retracted position adjacent a passenger. The acrylic layers 62 , 66 are bounded about their peripheries by the rubber seals 58 , 60 , which define the air space 64 in conjunction with the acrylic layers 62 , 66 . The rubber seals 58 , 60 , to some degree, seal out noise that may propagate into the window layup and act as a dampener to dampen noise that is able to initially propagate to and into the seal.
[0027] In the prior art of FIG. 3A , the outer acrylic layer of 0.35″, the air layer of 0.27″, and the mid acrylic layer of 0.22″ were the respective measurements taken on a test window, the results of such testing to be discussed later. A limitation of the prior art window of FIG. 3A is the level of noise transmitted through its panes. The embodiments of the present invention will be compared to the prior art FIG. 3A , also known as the baseline window or layup.
[0028] Turning now to the operative workings of the present invention, FIGS. 3B-3E depict various window layer configurations. Before detailed discussion of FIGS. 3B-3E , it should be noted that the cross-sectional views depict a c-ring 24 and a rubber seal 102 on each side of the window. Although depicted as such, each c-ring 24 and rubber seal 102 is actually a single continuous piece of material that traverses the entire periphery of the laminate-formed window 22 . Additionally, while the rubber seal 102 is shown abutting the c-ring 24 in places, a gap of about 0.03″ to more than 0.1″ between the rubber seal and c-ring 24 may exist in some applications. An oval-shaped window and a rectangular-shaped window with rounded corners are examples of windows according to embodiments of the present invention; however, the invention is not limited to such shapes and other window shapes may be utilized.
[0029] FIG. 3B depicts a cross-sectional view of an aircraft window 100 according to a first embodiment of the present invention. The aircraft window 100 has multiple transparent layers sandwiched between a c-ring 24 that forms a frame that is lined with a rubber seal 102 . The layers of material are held in place by a retainer clip 25 , and not necessarily any force provided by the c-ring 24 . Throughout the embodiments of the invention, acrylic is used as an example of a transparent material used as panes in the window; however, the acrylic could be any suitable transparent plastic, for example, polycarbonate. The arrangement of transparent layers from the aircraft fuselage exterior 104 to the aircraft fuselage interior 106 is: a first, outer acrylic layer 112 , an air space or layer 110 , and a second, inner acrylic layer 108 . In the aircraft industry, the inner layer is sometimes referred to as a mid-layer. For the purposes of testing with regard to the present invention according to FIG. 3B , the outer acrylic layer 112 is 0.51″, the air layer 110 is 0.27″, and the inner acrylic layer 108 is 0.22″. The layers 108 , 110 , 112 are secured within the c-ring 24 and against the rubber seal 102 . The layers 108 , 110 , 112 are designed such that noise waves traveling in the path indicated by arrow 114 , may either be attenuated to some degree or completely stopped before reaching the inside area 106 . More specific advantages of the first embodiment, in terms of the broadband frequency response, will be discussed later.
[0030] The rubber seal 102 provides damping of vibration in both the outer pane 112 and middle pane 108 . This reduces the noise transmitted through the transparent area 110 . It also minimizes vibration, which originates as noise outside of the fuselage 12 , from passing from the transparent layers of material into the c-ring 24 and subsequently into the fuselage interior 106 . When a layer of window material protrudes into the rubber seal 102 , the advantage is that the more rubber that is able to protrude around and contact the individual layers of material 108 , 112 , the more noise and vibration dampening the rubber is able to provide to the respective layer of material. That is, for vibrations that propagate to the edge of the material, the rubber seal 102 may dampen such vibrations since the rubber seal 102 contacts the edge of the material. Such a path through the c-ring 24 , into the rubber seal 102 , into the outer acrylic 112 and into the rubber seal 102 is noted by arrow 111 . Because the rubber seal 102 is arranged in such a fashion, dampening of noise and vibration may occur.
[0031] Another path of noise propagation, from the aircraft exterior 104 to the rubber seal 102 is noted by arrow 116 . The rubber seal 102 lies within the c-ring 24 . The flange 30 and web 32 provide support to the rubber seal 102 , which helps secure the window layers 108 , 110 , 112 . The advantage of the window 100 of the first embodiment over the baseline window of FIG. 3A , is that increased sound dampening is achieved, at least because of its thicker outer layer 112 and its greater edge amount that abuts against the rubber seal 102 . By dampening or eliminating noise, passenger comfort inside the aircraft is increased. In the case of noise path 116 the noise may propagate through the outer layer 112 , but will then be partially or completely dampened by the rubber seal 102 .
[0032] Turning now to FIG. 3C , a second embodiment of the present invention will be explained. The window 120 of the second embodiment has an increased number of layers, from three to four, over the second embodiment window 100 . The layers and as-tested thicknesses of the second embodiment, FIG. 3C , from the fuselage exterior 104 to the fuselage interior 106 are: an acrylic layer 122 that is 0.35″ thick, a glass layer 124 that is 0.025″ thick, an air layer 126 that is 0.27″ thick, and a second acrylic layer 128 that is 0.22″ thick. An advantage of the second embodiment window 120 over the first embodiment window 100 is a decrease in broadband frequency response over some frequencies and very similar responses over the balance of frequencies, which will be discussed later. In short, there is increased sound dampening with the second embodiment.
[0033] Further comparing the first and second embodiments, one can see that the window 100 has a 0.51″ thick outer acrylic pane, while the window 120 has an outer acrylic pane 122 that is 0.35″ thick and a glass pane 124 that is 0.025″ thick. The advantage is that the combination of these latter two panes, for a total thickness of 0.375″, provides the same amount of structural stiffness as the first embodiment acrylic pane that is 0.51″ thick. The overall difference in window thickness is 0.135″, so the window 120 is thinner and provides comparable noise reduction as the first embodiment, as will be discussed later. Furthermore, because the window 120 of the second embodiment maintains the same level of structural stiffness and integrity as the first embodiment 100 , the decreased thickness is an advantage.
[0034] FIG. 3D depicts a window 140 of a third embodiment of the present invention. The third embodiment window 140 has five transparent layers situated adjacent to one another to form the see-through area of the window. From the fuselage exterior 104 to the fuselage interior 106 , specific thickness of the transparent layers were tested for their sound dampening and structural advantages. The layers tested consisted of an acrylic layer 142 that is 0.22″ thick, a urethane layer 144 that is 0.05″ thick, a glass layer 146 that is 0.12″ thick, an air layer 148 that is 0.27″ thick, and a second acrylic layer 150 that is 0.22″ thick. As in the prior embodiments, these layers were placed between a rubber seal 102 , which surrounded the layers and abutted against the inside perimeter of the c-ring 24 . The rubber seal 102 fits within the outside flange 30 and the web 32 . At specific frequencies, this window 140 provides sound dampening advantages over the prior embodiments, as will be discussed later. Urethane, such as the urethane used in this embodiment, is generally a material whose properties are dependent upon time, temperature, and frequency. Additionally, as an interlayer material, instead of urethane, a vinyl or silicon material could be used to bond its adjacent materials and provide sound dampening advantages. Furthermore, for the present embodiment, urethane typically possesses a loss factor around 0.06, but with a constant modulus of say, 1000 psi, and a constant overall damping ratio. As previously stated, and applicable to each embodiment, the rubber seal may actually form a slight gap with the c-ring 24 , as opposed to the rubber seal firmly abutting the c-ring 25 , since the retainer clip 25 secures the window layers.
[0035] FIG. 3E depicts a cross-sectional view of a window 160 according to a fourth embodiment of the present invention. Like the third embodiment, the fourth embodiment window 160 also has five layers of transparent material that entail the layup structure. From the fuselage exterior 104 to the fuselage interior 106 , the layers are: an acrylic layer 162 that is 0.22″ thick, a viscous layer 164 that is 0.05″ thick, a glass layer 166 that is 0.12″ thick, an air layer 168 that is 0.27″ thick, and a second, inner acrylic layer 170 that is 0.22″ thick. Like the other embodiments, the transparent layers are situated between a rubber seal 102 , which surrounds and abuts against the layers. The rubber seal 102 is then mounted against the inside perimeter of the c-ring 24 within an area bounded by the web 32 and the outside flange 30 . As each of the prior embodiments, the fifth embodiment window also provides advantages related to its sound dampening characteristics.
[0036] Concerning the visco-elastic material used in the present invention, it is a material that exhibits a high damping loss factor, generally greater than one (“1.0”)—and generally possesses a low modulus when compared to metal. When used in the embodiments of the present invention, a visco-elastic material is one in which shear strains due to deflections (e.g. vibrations) are converted to heat, which serves as a loss or damping mechanism.
[0037] Before turning to the advantages of the above structures, an explanation of the evaluation parameters applied to the embodiments of the present invention will be provided. Power Spectral Density (PSD) was the means used to measure and evaluate the sound dampening characteristics of the various structures. PSD is the amount of power per unit (density) of frequency (spectral) as a function of the frequency and describes how the power (or variance) of a time series is distributed with frequency, that is PSD dictates which frequencies contain a signal's power. Mathematically, it is defined as the Fourier Transform of the autocorrelation sequence of the time series. An equivalent definition of PSD is the squared modulus of the Fourier transform of the time series, scaled by a proper constant term. Being power per unit of frequency, the dimensions are those of a power divided by Herz.
[0038] Now, FIGS. 4 through 7 will be used to explain the operative workings, performances and advantages of the various embodiments. FIG. 4 is a graph of the average velocity power spectral density (PSD) over a broadband frequency for the window configurations according to the teachings of the present invention. The results of FIG. 4 are based upon testing of an isolated window, that is, one window in isolation, using the finite element method (FEM). FIG. 4 reveals that the baseline model of FIG. 3A of the prior art has the highest velocity PSD for most of the frequency band, and the window with a visco-layer in it has the lowest velocity PSD response. The comparative results with respect to the baseline window reveals that the average velocity PSD reduction of the window with the visco-material layer is significant (about 11.3 dB at 160 Hz), see FIG. 5 . This is due to the improvement of modal damping and the higher stiffness of the window layup, provided by the c-ring 24 .
[0039] As can be seen from FIG. 4 , the fourth embodiment window 160 of FIG. 3E having in part, a 0.22″ acrylic layer 162 , a 0.05″ viscous material layer 164 , and a 0.12″ glass layer 166 , all adjacent the fuselage exterior, dampens the vibration levels across the broadest frequency range most effectively. Also depicted in FIG. 4 is that the third embodiment window 140 also achieves a high level of dampening the vibration levels across a broad frequency range. The third embodiment window 140 , depicted in FIG. 3D , has in part, adjacent the fuselage exterior, a 0.22″ acrylic layer 142 , a 0.05″ urethane material layer 144 , and a 0.12″ glass layer 146 . According to the graphical results of FIG. 4 , while the fourth embodiment window 140 and fifth embodiment window 160 of FIGS. 3D and 3E , respectively, display excellent vibration reduction across a broad range of frequencies, relative to the other embodiments, the first embodiment window 100 of FIG. 3B displays excellent vibration reduction for a narrow frequency range, approximately 300-390 herz. The first embodiment window 100 employs a 0.51″ thick piece of acrylic adjacent the fuselage exterior 104 . As FIG. 4 depicts, for almost every frequency in the isolated window tests involving different compositions of the outer glass, the embodiments of the present invention performed better than that of the existing baseline window. For the purpose of the present invention, the term “outer glass” is known as those layers of material that lie between the 0.27″ airspace of the window and the fuselage exterior 104 . Therefore, the “outer glass” may have more than one layer of material.
[0040] FIG. 5 is a comparison graph that depicts the vibration reduction, in decibels (dB), achieved with the fourth embodiment window 160 having an outer pane of 0.22″ acrylic, 0.05″ visco-material, and 0.12″ glass. This particular window, known as the “visco-elastic window”, is depicted in FIG. 3E . The vibration reduction is calculated using the following formula:
Reduction (dB)=20 log( X 2 /X 1 )
where X 1 is the velocity PSD of the prior art window of FIG. 3A and X 2 is the velocity PSD of the fourth embodiment window 160 . Although the calculation was performed in terms of structural velocity, it is assumed that the normal velocity of the window is directly proportional to the radiated acoustic pressure. Therefore, the noise reduction associated with the fourth embodiment window is also represented by FIG. 5 .
[0041] The results depicted in FIG. 5 are relative to the baseline window of FIG. 3A . As an example, the fourth embodiment visco-elastic window dampens 6 decibels more at 200 Hz than the known window of FIG. 3A . As depicted, for most of the broadband range from approximately 20 Hz to 1,400 Hz, the visco-elastic window 160 of the fourth embodiment responds much more favorably, in terms of dampening vibration, and reducing noise transmission, than the baseline window. In fact, the visco-elastic window analysis of FIG. 5 depicts the most advantageous vibration reduction below 250 Hz and above 700 Hz.
[0042] In order to improve the benefit above 250 Hz, the present invention introduces a vacuum layer between the outer and middle panes. The effect of evacuating the air from between the two panes effectively decouples the panes over a broad frequency range. The vacuum layer, if utilized, in all embodiments may be either a full or partial evacuation of gas from between the middle and outer panes. Without the vacuum, when the outer pane deflects or vibrates during aircraft flight, it causes the air between the middle and the outer pane to act as a spring and is a medium to transmit vibration noise energy by compressing and expanding accordingly. This exerts a force on the middle pane and causes it to vibrate and transmit noise into the passenger cabin. When the panes are decoupled by a vacuum layer, the transmission of noise energy is effectively decoupled and lessened. There is, however, vibration energy transmitted through the boundary of the window layer panes in the area of the rubber seal.
[0043] Turning to FIG. 6 , results of testing using the finite element method on an isolated window having a vacuum layer between the outer acrylic and mid-acrylic layers reveals that a window with a vacuum between physical panes has a great advantage over other windows with respect to sound dampening. The advantage is attributed to the result of sound not transmitting through a vacuum. Referring to the window layup of FIG. 3E , the air layer was made into a vacuum layer. By examining the dashed curves of FIG. 6 , which are analysis performed on a 787 model aircraft window, a dramatic reduction in noise response is depicted. The dashed plots of FIG. 6 are the results of analysis performed on an isolated window model, while the solid plots are the resulting responses of a full window belt model, that is, a non-isolated window. In actuality, the full window belt model consisted of a three-bay group of windows.
[0044] It was expected that the 787 window with a vacuum layer between the panes would provide an advantage over other windows. This is evident looking at the dashed plots of FIG. 6 , where the 787 isolated model with vacuum depicts a response that is more desirable than its non-vacuum counterpart. However, when the vacuum layer was incorporated into a full window belt model, the results depicted by the solid plots were obtained. The benefit due to the vacuum was reduced, particularly at low frequencies. In an attempt to reproduce the performance of the 787 isolated model with vacuum in the window belt model, a stiffer c-ring was investigated. The effects of a stiffer c-ring is depicted in FIG. 7 .
[0045] Further investigation and testing of an isolated window model reveals that the primary path of vibration from the outer pane to the middle pane is through the rubber seal. Further, the majority of the vibration is absorbed by the outer pane boundary, but vibration propagates more efficiently to the middle pane through the c-ring. FIG. 7 depicts the results of a stiffer c-ring, such that the stiffer c-ring is effective in further decoupling the middle and outer panes, as desired. These results indicate that although a vacuum between window panes is effective for reducing vibration on the middle pane, stiffening the window frame c-ring provides additional vibration and sound reduction benefits.
[0046] FIG. 7 depicts results for a 787 full model, a 787 full model with a vacuum layer between the outer and middle panes, and a 787 model with a vacuum layer and a stiffened c-ring. From FIG. 7 , the solid plots are examples of full beltline models, again three bay models, whereas the dashed plot indicates testing on what is essentially an isolated window. Although it is a full model, since the c-ring is stiffened in the finite element analysis, each window in the model is further isolated, which results in a more favorable, that is, increased dampening, response.
[0047] While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art. | An aircraft window configuration utilizes a laminate build-up of the primary pane to increase damping and reduce the structural response to the turbulent boundary layer outside the aircraft. The laminate may consist of several acrylic layers or a combination of acrylic and glass layers. Noise dampening results from the introduction of a transparent visco-elastic material or a urethane. A vacuum layer may be introduced between the primary pane and a middle, or fail-safe pane. The vacuum layer decouples the panes over a broad frequency range resulting in a lower response of the inner pane that radiates noise into the passenger cabin. Such a window configuration reduces weight and improves noise performance. A damped laminate also reduces pane deflections into the air stream and improves aerodynamic performance of the aircraft. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a veneer lathe having a knife for cutting a log into a veneer sheet and at least one second knife which is located on rake face side of the veneer cutting knife and adapted to form a cut or slit in the periphery of the log while embedding a cord in the slit.
Various veneer lathes of the type described have heretofore been proposed in connection with Japanese Patent Publication No. 35-4246 entitled "Improvement in Method of Preventing Damage to Veneer Sheet in Plywood Production", Japanese Patent Publication No. 39-14994 entitled "Apparatus for Reinforcement of Veneer Sheet", Japanese Patent Publication No. 49-6642 entitled "Apparatus Associated with Rotary Veneer Lathe for Burying Cord in Trimmed Edge of Log", Japanese Patent Publication No. 49-35052 entitled "Veneer Sheet Processing Method", etc. All of these known types of veneer lathes with cord embedding knives have failed, however, to achieve a systematic combination of the cord embedding knife and the veneer lathe alloted with different functions: the cord embedding knife serving to embed a cord in a log and the veneer lathe serving to cut a veneer sheet from a log.
A typical example of a prior art veneer lathe having a cord embedding knife is illustrated in FIG. 1. The cord embedding knife denoted by the reference numeral 4 is so constructed and arranged to form a cut or slit in the periphery of a turning log 2 while embedding a string or cord 3 in the slit. The log 2 reinforced by the cord 3 is cut into a veneer sheet 1 by a usual veneer cutting knife 6 which is rigidly mounted on a tool rest 7 of the veneer lathe. FIG. 2 is an enlarged sectional side view of the veneer sheet 1 turned from the cord embedded log 2. It will be observed in FIG. 2 that the cord 3 in the slit 5 of the veneer sheet 1 has locally lifted itself away from the bottom of the slit.
This undesirable phenomenon is attributable to a tension which will be discussed with reference also to FIG. 3. When the veneer sheet 1 is cut from the log 2 by the knife 6, it moves outward away from the log at a high speed and at an angle to the log which corresponds to the angle of the cutting edge of the knife 6. This results in an abrupt and intense force which pulls the cord 3 so that the cord 3 is displaced from its normal position A to an abnormal position B rising from the bottom of the slit 5. Such a displacement of the cord 3 will also be invited by any other condition which would exert a pulling force on the veneer sheet 1 during travel of the veneer sheet out of the veneer lathe. Particularly, the pulling force or tension acts in a concentrated manner on the cord 3 every time a defective portion of the veneer sheet is moved past the veneer cutting knife 6. For this reason, the cord 3 rises away from the bottom of the slit at those portions of the veneer sheet which define the rear edges of the defects with respect to the moving direction of the veneer sheet as illustrated in FIG. 2, in which the defects are represented by a lost portion 8 caused by a crack and a lost portion 9 caused by a peripheral recessed part of the log. Naturally, a loose portion of the veneer sheet, if not completely lost, brings about a similar tension exerted in a concentrated manner on part of the cord bridging the defect 8 or 9 mentioned. In this way, the conventional veneer lathe with a cord embedding knife prevents the cord from reinforcing those portions of a veneer sheet which need reinforcement most acutely, due to its very characteristics. This constitutes a critical problem in the practical use of the veneer lathe. To solve this problem, the invention disclosed in Japanese Patent Application Post-Examination Publication No. 51-31559 introduced a veneer lathe in which a similar cord embedding knife works on a veneer sheet immediately after being cut from the log to ensure that the cord buried in a cut formed in the veneer sheet will not be subjected to any external force as observed at the moment of separation from the log. However, this prior art creates another problem; that is, since the veneer sheet cut off from the log is limp and has a lot of cracks formed at the time of cutting operation, it easily buckles when worked on by the cord embedding knife and the cracks in the sheet prevent the continuous forming of an elongated cut therein.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a veneer lathe in which a cord embedding knife is disposed such that the veneer sheet cut off from the log will not buckle while the cord embedded in the elongated cut will not be dislocated at the time of veneer separation from the log.
In order to realize the above object, there is essentially provided a veneer lathe for turning a log to cut into veneer comprising means for supporting a log to permit a rotation about its axis in a predetermined direction; a veneer cutting knife having a straight edge tangentially oriented relative to a log periphery and adapted to counteract the log rotation to cut off a veneer sheet from the log; a cord embedding knife having an edge extending in a plane intersecting said straight edge of the veneer cutting knife, said cord embedding knife being provided on a rake face side of the veneer cutting knife to cut into the log to form an elongated cut in the veneer sheet cut off from said log and to place a length of cord in said elongated cut; and means for restraining said length of cord firmly in the elongated cut, the edge of said cord embedding knife extending upstream of the edge of the veneer cutting knife thereby to cut into the log periphery whereas said cord restraining means is adapted to release the cord downstream of said edge of the veneer cutting knife.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a prior art veneer lathe;
FIG. 2 is a section of a veneer sheet formed by the veneer lathe of FIG. 1;
FIG. 3 is explanatory of operation of the same veneer lathe;
FIG. 4 shows in side elevation a veneer lathe according to the present invention;
FIG. 5 shows in side elevation a prior art veneer lathe; FIG. 6 is a perspective view of a cord embedding knife;
FIGS. 7-9 are perspective views of some examples of veneer sheets embedded with cords; and
FIGS. 10 and 11 illustrate another embodiment of the present invention in a side elevational view and a front view, respectively.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will be further explained again in comparison with prior art referring to FIGS. 4 and 5.
Both of the arrangements shown in FIGS. 4 and 5 include a cord embedding knife 4 indicated in a perspective view in FIG. 6 and which the present applicant's copending Japanese patent application entitled "Cord Embedding Apparatus", filed on Mar. 27, 1980, discloses.
Although not shown in the drawings, a log 2 is supported by suitable means to ensure that the log 2 is permitted to rotate about its axis in a predetermined direction. Further, there is provided a veneer cutting knife 6 having a straight edge tangentially oriented relative to a log periphery and adapted to counteract the log rotation to cut off a veneer sheet from the log. The knife 4 is provided on a rake face side of the veneer cutting knife and is formed with a cutting edge 10. Further, the knife 4 is perforated to thread a length of cord and has a cord outlet opening 12 for the cord and protuberance 11 downstream of the opening so located as to permit a blade portion of the knife 4 downstream of the opening 12 to contact the cord 3 suitably. The knife 4 is fixedly retained by a holder 14. Said edge of the cord embedding knife 4 has an edge 10 extending in a plane perpendicular to and upstream of the straight edge of the veneer cutting knife 6. The cord embedding knife cuts into the log to form an elongated cut or slit in the log upstream of the edge of the knife 6 and place a length of cord in said elongated cut. The knife design in FIG. 6 is not limitative but only illustrative, however. FIGS. 7-9 show in perspective some examples of veneer sheets formed with cuts 5a-5c of different cross-sections and embedded with cords 3 in the cuts individually by other designs of the knife 4 applicable to the present invention. A knife which processes a veneer sheet as indicated in FIG. 8 is disclosed in the present applicant's copending Japanese Patent Application No. 53-137098. Regardless of the design choice, the cord embedding knife must be provided with means for restraining the cord 3 within the slit 5 in one mode or another thereby to locate the cord securely therein and release the cord downstream of the edge of the veneer cutting knife 6. Indeed, cord embedding knives hitherto proposed are furnished with such means without exception. For instance, the knife 4 in FIG. 4 or 5 restrains the cord 3 within the slit 5 not only with its opening 12 but with its blade formed with the protuberance 11. The knife 4 frees the cord 3 from the restraint substantially at a position indicated by a reference character C in FIG. 4 or 5. A matter of the utmost concern in the present invention is this position C where the cord 3 becomes substantially released, more specifically the relationship between the cord releasing position C and the position of a veneer cutting knife 6 which constitutes a major part of the veneer lathe. In FIG. 5, the conventional cord releasing position C of the knife 4 is located far upstream of the cutting edge of the veneer cutting knife 6 with respect to the direction of rotation of the log 2. In contrast, the cord releasing position C according to the present invention is located downstream of a position contained in a plane which extends perpendicular to the rake face of the knife 6 and contains the cutting edge of the knife 6 as shown in FIG. 4. When a tension is imparted to the cord 3 in FIG. 4 from the veneer sheet 1 cut from the log 2, the cord 3 is essentially prevented from lifting itself clear of the bottom 13 of the slit 5 toward the open end of the slit since, at a position adjacent to the log cutting knife 6, the cord 3 is restrained by the cord embedding knife 4 while maintaining its substantially straight position. With the prior art arrangement of FIG. 5 on the other hand, the cord 3 in the position adjacent to the log cutting knife 6 is not restrained by the cord embedding knife 4 and, moreover, it is bent within the slit 5. The result is the tendency of the cord 3 to rise as discussed with reference to FIG. 3. The bent position of the cord 3 enhances the lifting tendency because it increases or doubles even a small magnitude of pulling force to a significant magnitude of force. Such conditions of the cord 3 last throughout the reinforcing operation to render the cord embedment of the veneer lathe unstable.
As will now be appreciated, the gist of the present invention resides in that the cord embedding knife 4 cuts into the log upstream of the plane X while the restraint on the cord 3 is released at a position C downstream of a plane X shown in FIG. 3. This plane X is perpendicular to a rake face of the knife 6 and contains the tip of the knife edge therein. Denoted by the reference character Y in FIG. 3 is a plane normal to a plane which bisects the cutting angle of the veneer lathe defined by the log cutting knife 6. It is most desirable in principle that the cord releasing position C of the knife 4 be located downstream of the plane Y.
The principle of the present invention is applicable to a veneer lathe shown in FIGS. 10 and 11 which the present applicant developed and disclosed in copending Japanese Patent Application No. 53-122199 laid open to public inspection. In FIGS. 10 and 11, the veneer lathe includes a roller 16 having annular disc members mounted to the roller 16 and a plurality of piercing elements each of which is formed with a number of radially outwardly extending spaced piercing members 17 supported by the circumference of the disc members. The roller 16 is so located that the piercing members 17 cut into a part of the log 2 located immediately ahead of the veneer cutting knife 6 and a veneer sheet 1 freshly cut from the log 2 at the same time. Journalled to the machine frame, the roller 16 may be connected with a suitable drive source to supply the power necessary for log cutting or it may be an idle roller driven by the rotating log. The veneer sheet 1 cut off from the log 2 moves along a predetermined path guided by a lower guide member 18 which is cooperative with the piercing roller 16. A lever 19 is positioned downstream of the roller 16 and the guide 18 to separate the veneer sheet 1 from the piercing members 17 on each piercing element. Until the separating lever 19 removes the veneer sheet from the piercing members 17, the veneer sheet is prevented from imparting a concentrated pulling force or tension to the cord 3. More specifically, even when a hole or rotten spot of the lod reaches the log cutting knife 6, the piercing members 17 cutting into the resultant veneer sheet 1 prevents the pulling force due to the veneer sheet from being centered on the cord 3 in the slit, as long as the length of such defect is less than the distance between the cutting edge of the log cutting knife 6 and the separating position defined by the lever 19. Providing a veneer sheet with this kind of countermeasure against the phenomenon discussed will achieve a certain reasonable degree of success, but the effect is not free from a fundamental problem. For example, a defect in the log longer than the distance between the cutting edge of the knife 6 and the separating position 19 will still permit a pulling force to concentrate in the cord 3. It is preferable in this respect to incorporate the idea according to the present invention into the arrangement depicted in FIGS. 10 and 11. Thus, the cord embedding knife 4 in FIGS. 10 and 11 is so located as to release the cord 3 at a position downstream of the cutting edge of the veneer cutting knife 6 while maintaining the position of the edge of the knife 4 upstream of the edge of the knife 6. The veneer lathe shown in FIGS. 10 and 11 include at least one cord embedding knife 4 positioned on one side of the row of piercing members and mounted on respective holders 14 which are in turn mounted on a support 22 through brackets 20. A cord 3 is guided by a pulley 21 into a groove formed in each bracket 20 wherefrom it is passed through the cord supply opening 12 from the back of the cord embedding knife 4 to bury itself in a slit in the log 2. With this improved design, the cord 3 is not only embedded progressively in each slit 5 from the opening 12 upstream of the edge of the knife 6 but restrained by the protuberance 11 until it is freed from the restraint at the aforementioned position downstream of the cutting edge of the knife 6. The reference numeral 15 in FIG. 11 designates pressure bars.
Additionally, the piercing roller 16 forming part of the veneer lathe has a noteworthy relationship with the cord embedding knives 4. At opposite sides of each cord embedding knife 4, the rotatable roller 16 causes its piercing members 17 to pierce the log deeper than the knife 4. Hence, the piercing members 17 on the roller 16 positively and continuously support even an internal structural part of the log adjacent to the outer periphery in the vicinity of the knife 4 so that the knife 4 and its immediate neighborhood is safeguarded against clogging due to wood chips which may be separated from the log.
In summary, for a veneer lathe wherein a veneer sheet 1 cut from a log exerts a pulling force which tends to impart a tension to a cord 3, the present invention has been elaborated paying particular attention to a position C where the cord 3 is to become free from the restraint of the knife 4. In the embodiments shown and described, the cord embedding knife 4 is formed with a protuberance 11 downstream of a cord supply opening 12 which defines the cord releasing position C at a location downstream of a plane X substantially perpendicular to the rake face of a veneer cutting knife 6. Alternatively, a cord supply opening 12 may be relocated on the same face of the knife 4 such that the cord 3 becomes unrestrained at the relocated opening 12.
Conventional cord burying operations have been least stable at portions of a log which are in the greatest need of reinforcement. The present invention promotes stable embedment of a cord even in such portions while facilitating desired reinforcement when an adhesive is used in combination with a cord. Moreover, the construction according to the invention is very fundamental and simple so that an effect which is a key to the practical usability is afforded with an economical improvement. | A veneer lathe provided with a cord embedding knife. The cord embedding knife has an edge perpendicular to the veneer cutting knife of the veneer lathe. The cord embedding knife cuts into a log and forms an elongated cut therein to place a length of cord therein. At the same time, the lathe is provided with means for restraining the said length of cord firmly in the elongated cut until it releases the cord downstream of the edge of the veneer cutting knife. This structure ensures that the elongated cut is formed without causing a buckling of the veneer sheet or the like while the cord embedded in the elongated cut in the veneer sheet cut off from the log is firmly retained in the cut and prevented from slipping out of the cut. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to can openers. More particularly the invention concerns a hand operated, mechanical can opener.
[0003] 2. Description of the Invention
[0004] A number of different designs of mechanically operated can openers have been suggested in the past. As a general rule, the prior art can openers comprise a traction wheel and a cooperating cutting wheel. The traction wheel is typically adapted to frictionally engage an annular abutment formed about the top periphery of the can and functions to drive the can opener around the top of the can while the sharpened cutting wheel cuts through the top wall of the can.
[0005] A major problem of prior art can openers of the aforementioned character resides in the fact that if the cutting wheel does not operate properly it can form small shavings that can undesirably contaminate the contents of the can.
[0006] Additionally, in the operation of certain prior art can openers, the cutting wheel fails to cleanly and effectively penetrate the top of the can as the traction wheel is moved into engagement with the annular abutment thereby making opening of the can unduly difficult. Another problem found in some prior art, manually operated can openers is a difficulty in keeping the opener in proper position on the can during the can opening process. Still another drawback of certain of the prior art manually operated can openers resides in the fact that in many cases a high degree of dexterity on the part of the user is required to properly use the can opener.
[0007] A quite popular type of prior art can opener is a hand operated can opener that includes a lever handle integrating a cutter at the end thereof to make a circumferential cut on a sealed cover of a can adjacent to a projecting edge joint formed between the sealed cover and a cylindrical wall of the can. A disadvantage of this type of can opener is that a substantial force is required to first pierce the sealed cover of the can and to then sever the cover from the body of the can. A can opener construction that somewhat alleviates the disadvantages of this latter type of can opener is disclosed in U.S. Pat. No. 2,354,467 issued to Lubetsky. The Lubetsky can opener includes a spindle, a crank for turning the spindle and a drive member fixed on the spindle for rotation therewith. The drive member is adapted to rotate around upon a peripheral margin formed proximate the upper end of the can. A blade that is also carried by the spindle is adapted to pierce the can end and cut the latter as the drive member travels around the margin of the can. A movable guide depends from the spindle and is adapted to engage an annular abutment on the can. A novel feature of the Lubetsky device resides in the provision of camming means that are adapted to move the movable guide into engagement with the abutment. The device also includes means provided on a crank for actuating the camming means.
SUMMARY OF THE INVENTION
[0008] An object of the invention is to provide an improved can opener of a simplified design which is easily operated and effectively overcomes the disadvantages of the prior art can openers.
[0009] Another object of the invention is to provide a can opener of the aforementioned character that is readily adjustable so that it can be used to open generally cylindrically shaped cans of various sizes.
[0010] Another object of the invention is to provide a can opener of the type described in the preceding paragraphs in which the operating handle, when rotated in a first direction to a first position, functions to bring the sharpened cutting wheel of the apparatus into piercing engagement with the top of the can. Continued rotation of the handle will cause rotation of the can and will cause the cutter wheel to cleanly cut the top of the can so that it can be easily removed.
[0011] Another object of the invention is to provide a can opener of the type described in the preceding paragraphs in which the operating handle, when rotated in a second, opposite direction, functions to move the sharpened cutting wheel of the apparatus out of piercing engagement with the top of the can so that the opened can may be expeditiously removed from the can opener.
[0012] Another object of the invention is to provide a can opener of the character described which includes a novel clutch arrangement comprising a wrap spring that circumscribes the cutter wheel spindle for controlling the movement of the cutter wheel into and out of cutting engagement with the can.
[0013] In summary, the present invention comprises a novel can opener for cutting the lid of a can having a generally cylindrically shaped body portion, a top wall connected to the body portion and a peripheral, outwardly projecting edge joint between the body portion and the top wall that includes a support assembly, a housing connected to the support, the housing having a longitudinal bore therethrough, a spindle housing rotatably carried within the longitudinal bore of the housing for rotation between first and second positions, the spindle housing having an axial centerline and a longitudinally extending bore having an axial centerline radially offset from the axial centerline of the spindle housing, a spindle disposed within the longitudinally extending bore of the spindle housing and operating means connected to the spindle for rotating the spindle between first and second positions to move the cutter wheel, which is connected to the spindle, into and out of engagement with the top of the can. For this purpose, a novel wrap spring circumscribes the spindle and is so constructed and arranged so that rotation of the spindle in a first direction to a first position will causes the wrap spring to drivably grip the spindle so that continued rotation of the spindle will cause rotation of spindle housing to the second position wherein the cutter wheel is moved into cutting engagement with the top of the can. Continued rotation of the spindle in the first direction to a second position will cause the wrap spring to release the spindle and enable rotation of the spindle and the cutter wheel independently of the spindle housing. As the spindle housing moves into the second position, a traction wheel connected to the housing will drivably engage the peripheral, outwardly projecting edge joint of the can to cause smooth rotation of the can. After the top of the can has been cut, rotation of the spindle in a second, opposite direction will causes the wrap spring to once again drivably grip the spindle and rotate the spindle housing to its starting position wherein the cutting wheel is withdrawn from cutting engagement with the top of the can.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 side elevational view of one form of the can opener apparatus of the invention.
[0015] [0015]FIG. 2 is a view taken along lines 2 - 2 of FIG. 1.
[0016] [0016]FIG. 3 is a view taken along lines 3 - 3 of FIG. 1.
[0017] [0017]FIG. 4 is an enlarged cross-sectional view taken along lines 4 - 4 of FIG. 2.
[0018] [0018]FIG. 5 is a cross-sectional view taken along lines 5 - 5 of FIG. 4
[0019] [0019]FIG. 6 is a cross-sectional view taken along lines 6 - 6 of FIG. 4.
[0020] [0020]FIG. 7 is an enlarged, generally perspective view of one form of the wrap spring and spindle of the apparatus of the invention shown in a first starting position.
[0021] [0021]FIG. 8 is a cross-sectional positioned view similar to FIG. 6, but showing the crank handle of the apparatus moved from a first to a second intermediate position and showing the travel of the front tang of the wrap spring.
[0022] [0022]FIG. 9 is a cross-sectional position view similar to FIG. 8, but illustrating the travel of the rear tang of the wrap spring.
[0023] [0023]FIG. 10 is a side-elevational view similar to FIG. 1, but showing the crank handle of the apparatus moved from a first to a second position.
[0024] [0024]FIG. 11 is an enlarged, cross-sectional view taken along lines 11 - 11 of FIG. 10.
[0025] [0025]FIG. 12 is an enlarged, cross-sectional view taken along lines 12 - 12 of FIG. 10.
[0026] [0026]FIG. 13 is a cross-sectional view taken along lines 13 - 13 of FIG. 11.
[0027] [0027]FIG. 14 is a cross-sectional view taken along lines 14 - 14 of FIG. 13.
[0028] [0028]FIG. 15 is a cross-sectional view taken along lines 15 - 15 of FIG. 13.
[0029] [0029]FIG. 16 is an enlarged, generally perspective view of the wrap spring and spindle of the apparatus of the invention shown in a second position different from that shown in FIG. 7.
[0030] [0030]FIG. 17 is an enlarged fragmentary cross-sectional view of the cutting wheel of the apparatus of the invention shown in a can cutting configuration.
[0031] [0031]FIG. 18 is a view taken along lines 18 - 18 of FIG. 17.
[0032] [0032]FIG. 19 is a plan view of one form of the traction wheel and spindle of the apparatus of the invention.
[0033] [0033]FIG. 20 is an enlarged, generally perspective, exploded view of the various cooperating components of the apparatus of the invention.
DESCRIPTION OF THE INVENTION
[0034] Referring to the drawings and particularly to FIGS. 1 through 7, one form of the can opener of the present invention is there shown. The can opener of the invention is specially designed for cutting a can having a body portion “B”, a top wall “W” connected to the body portion and a peripheral, outwardly projecting edge joint “J” formed between the body portion “B” and the top wall “T” (FIGS. 1 and 11).
[0035] In the form of the invention shown in the drawings, the can opener comprises a support assembly 14 that includes an elongated, vertically extending rigid support member 14 a and clamping means for adjustably affixing the support member to a supporting panel “SP” such as a counter or tabletop or the like. The clamping means here comprises a mounting assembly 16 that includes a body portion 18 having an opening 20 for telescopically receiving support member 14 a. Mounting assembly 16 also includes a panel engaging, generally yoke shaped arm 22 that extends from body portion 18 for engagement with the upper surface of supporting panel “SP”. Yoke shaped arm 22 also functions to center the can body relative to support member 14 and a manner depicted in FIGS. 1 and 8. Spaced apart from arm 22 and extending outwardly from body portion 18 is a second arm 24 that is provided with a threaded bore 26 . Threadably received within threaded bore 26 is a threaded shaft 28 having at one end a clamping head 30 and having at the other end a transversally extending, finger engaging rod 32 for rotating threaded shaft 28 .
[0036] Connected to the upper portion of support assembly 14 is a housing assembly 36 that includes a housing 36 a having a longitudinal bore 38 therethrough (FIGS. 4 and 18). As best seen in FIG. 4, a spindle housing assembly 40 is mounted within longitudinal bore 38 . Spindle housing assembly 40 , which includes a first end portion 40 a and a second portion 40 b that are interconnected by a threaded connector 40 c, is rotatable within bore 38 between a first position shown in FIG. 4 and a second position shown in FIG. 11. Spindle housing assembly 40 has an axial centerline “C” (FIG. 5) and a longitudinally extending bore 42 having an axial centerline “C- 1 ” that is radially offset from the centerline “C” of spindle housing assembly 40 (see FIGS. 5 and 12). Rotatably carried within bore 42 is a spindle 44 that has first and second ends 44 a and 44 b respectively. First end 44 a of spindle 44 extends outwardly from body 36 and, as best seen in FIG. 3, is generally square and cross-section. Connected to first end 44 a for rotation therewith and is a cutter wheel 46 having a sharpened cutting edge 46 a for cutting the top wall “W” of the can. Also connected to first end 44 a of spindle 44 for rotation therewith is a traction wheel 48 that is adapted to engage the peripheral, outwardly projecting edge joint “J” of the can after cutter wheel 44 is moved into cutting engagement with the top wall of the can in a manner presently to be described. As shown in FIG. 17, traction wheel 48 is provided with a plurality of circumferentially spaced apart engaging teeth 48 a to provide positive traction between the traction wheel and edge joint “J”.
[0037] Operating means is connected to end 44 b of spindle 44 for controllably rotating spindle 44 and also for controllably rotating spindle housing 40 between the first and second positions. In the present form of the invention, the operating means comprises an elongated handle or crank like assembly 50 that is connected to spindle 44 in the manner shown in the drawings.
[0038] In starting the can opening process, the housing assemblage 36 along with the crank assembly is first lifted so that the can can be positioned on the supporting panel “SP”. This done, the assemblage is lowered to the position shown in FIGS. 1 and 2 where the can rim is disposed between the cutter wheel and the idler wheel 55 a of idler wheel assembly 55 . Idler wheel 55 a, is of the general configuration shown in FIGS. 4 and 5 and is rotatably mounted on a shaft 55 b that is carried by a threaded member 55 c that is threadably connected to housing 36 a in the manner shown in FIG. 4 of the drawings.
[0039] To begin the can opening process, the handle 50 a of the operating means is rotated in a clockwise direction causing concomitant rotation of spindle 44 in a clockwise direction.
[0040] Forming an important aspect of the apparatus of the present invention is clutch means for controlling the rotation of the spindle housing assembly 40 within bore 38 of housing 36 a. This novel clutch means is here provided in the form of a conventional wrap spring 58 that circumscribes a portion of spindle 44 . As best seen in FIG. 7 wrap spring 58 includes first and second tangs 60 and 62 , the purpose of which will presently be described. FIG. 7 illustrates the position of the wrap spring and spindle when the handle 50 a has been rotated in a counter-clockwise direction and into the can opening starting position shown in FIGS. 4 and 5. In this position, second tang 62 is in engagement with the inboard end 64 a of a transversely extending stop pin 64 that is threadably connected to housing 36 a (FIG. 7). Second tang 62 is also in engagement with the end wall 66 a of a groove 66 formed in spindle housing portion 40 b (see also FIG. 20). Groove 66 comprises a part of the guide means of the invention for guiding travel of the first and second tangs. Rotation of handle 50 a and spindle 44 in a counter-clockwise direction will cause tang 62 of the wrap spring 58 to engage stop pin 64 and will cause it to tend to unwind or disengage spindle 44 allowing it to freely rotate within the wrap spring. However, rotation of handle 50 a and spindle 44 in the opposite, clockwise direction will permit the wrap spring to return to its normal at rest position and to drivably engage the spindle causing the spindle and wrap spring to rotate as a unit. This clockwise rotation of the handle will also cause tang 62 to exert a force on channel end portion 66 a and to thereby impart rotation to spindle housing assembly 40 in a manner to rotate the assembly to the intermediate position shown in FIGS. 8 and 9.
[0041] Continued rotation of the handle assembly past the intermediate position shown in FIGS. 8 and 9 will cause the cooperating components to next move into the position shown in FIGS. 10, 11, 13 and 14 . More particularly, since the spindle and wrap spring are mounted eccentrically within spindle housing assembly 40 , rotation of the spindle housing assembly from the starting position shown in FIGS. 4 and 5 to the position shown in FIGS. 13 and 14 will cause the spindle and the cutter wheel that is attached thereto to move into the can cutting position shown in FIGS. 11, 13 and 14 . At the same time, the supporting assembly 14 will move upwardly in the direction of the arrow 15 of FIG. 10 bringing the idler wheel 55 a into engagement with the edge join “J” in the manner shown in FIG. 10.
[0042] When the assemblage made up of spindle 44 and wrap spring 58 reaches the can cutting position shown in FIGS. 11, 13 and 14 , tang 60 will move into engagement with the inboard end 68 a of a second transversely extending stop pin 68 (see FIGS. 14 and 16). Continued rotation of the spindle in a clockwise direction will cause the wrap spring to “unwind” and disengage the spindle thereby permitting the spindle to freely rotate within the wrap spring and within spindle housing assembly 40 .
[0043] As best seen by referring to FIG. 20, assembly portion 40 b, spindle housing is also provided with a second guide channel or groove 70 which receives and guides the travel of tang 60 as spindle 44 is rotated between the starting and can cutting positions. Guide channel 70 , which also forms a part of the guide means of the invention, has an end portion 70 a that engages tang 60 in the manner shown in FIG. 7. With the wrap spring of the clutch means disengaged from the spindle, further rotation of the handle assembly in a clockwise direction, will cause rotation only of spindle 44 which, in turn, will cause the traction wheel 48 to engage the peripheral joint “J” of the can in a manner to controllably rotate the can and cause the cutter wheel to cleanly cut the top of the can at a location proximate the peripheral joint.
[0044] After the top of the can has been cut, the handle assembly 50 is rotated in a counter-clockwise position causing tang 60 to move away from stop pin 68 and causing the wrap spring to once again return to its normal at rest position and to drivably engage the spindle. Continued rotation of the spindle in the counter-clockwise direction will cause the spindle and the spindle housing assembly 40 , which is now driven as a result of tang 62 engaging shoulder 70 a (FIG. 16) to move into the position shown in FIGS. 4 and 5. As indicated in FIG. 12, the axis “X” of the housing assembly is skewed at an angle so as to make the can lid or top rise at the end of the cut. In the position shown in FIGS. 4 and 5, tang 62 will once again engage stop pin 64 in the manner shown in FIG. 7 “unwinding” the wrap spring and permitting the spindle to rotate freely within the wrap spring. With the spindle housing assembly 40 in this starting position, another can can be opened in the same manner as described in the preceding paragraphs.
[0045] Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this are will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. | A can opener for opening cans of various sizes having an operating handle, which when rotated in a first direction functions to bring a sharpened cutting wheel of the can opener from an elevated position into piercing engagement with the top of the can with the butting wheel n piercing engagement with the top of the can, continued rotation of the handle will cause rotation of the can and will cause the cutter wheel to cleanly cut the top of the can so that the top can be easily removed. Reverse rotation of the handle will cause the cutting wheel to disengage from the top of the can and to return to its elevated, starting position. | 1 |
BACKGROUND OF THE INVENTION
The technical scope of the invention is that of priming devices for an explosive charge, and notably for a shaped charge.
Known priming devices generally comprise at least one pyrotechnic igniter and at least one igniting relay placed between the igniter and an explosive load.
One of the problems encountered with known priming devices is the difficulty of ensuring the accurate centering of the pyrotechnic igniter with respect to the charge body.
More particularly, in the case of shaped charges, the detonation wave that is propagated in the charge must be perfectly symmetrical with respect to the charge axis.
Such a symmetry enables the optimal displacing or deformation of the shaped charge liner (slug or hollow charge). Even slight asymmetry (for example of around a few tenths of a millimeter) risks causing a reduction in effectiveness of the shaped charge.
Moreover, in the field of self-destruct charges for ballistic missiles, it is customary to include back-up priming means so as to reduce this risk of failure of the self-destruct system.
The multiplication of priming means thus raises the problem of producing a priming wave that is symmetrical and this whatever the position of the igniter being activated.
SUMMARY OF THE INVENTION
The aim of the invention is to propose a priming device that overcomes such problems and does not suffer from the drawbacks of known devices.
Thus, the priming device according to the invention ensures the ignition of an explosive charge along the charge axis whatever the position of the igniter or igniters with respect to said axis.
The invention thus makes it possible to obtain priming symmetry, using simple means.
Thus, the invention relates to a safety priming device for an explosive charge, notably a shaped charge, comprising a pyrotechnic igniter and at least one igniting relay placed between the igniter and an explosive load of the charge, wherein the igniting relay comprises means enabling the detonation wave produced by the igniter or igniters to be re-centered along the charge axis, said means comprising a confinement block having a bore converging between an external face positioned on the said having the igniter or igniters and an inner face positioned beside the explosive load, said bore filled with a relay explosive, the confinement block comprising means to prevent the propagation of a shock wave axially through the confinement block between the igniter or igniters and the explosive load.
According to a first embodiment of the invention, the confinement block may be made of an organic material having acoustic impedance that is less than 15.10 6 kg/m 2 s, this material constituting means to prevent the propagation of a shock wave through the confinement block.
According to a second embodiment of the invention, the confinement block may incorporate at least one collar that will be placed in the vicinity of the igniter or igniters and which will be followed by a free space surrounding the block, said free space constituting means to prevent the propagation of a shock wave axially through the confinement block.
This free space may be formed by a cylindrical groove delimited by two collars.
The bore in the confinement block may incorporate at least one conical part having a half-angle at the apex of between 10 and 25°, the small diameter of the cone being of between 2 and 5 mm and the large diameter of the cone being of between 13 and 30 mm.
The igniting relay may comprise a first layer of relay explosive applied to the confinement block and placed between the igniter or igniters and the confinement block.
The confinement block will be generally cylindrically shaped and arranged in a body.
The first relay layer may be of a thickness of at least 2 mm.
The first layer of relay explosive may be ring-shaped or else may be in the shape of a substantially rectangular tongue.
Advantageously, the device may comprise at least two pyrotechnic igniters placed at a distance from the charge axis.
A further subject of the invention is a shaped charge incorporating a safety priming device having at least two igniters and having the same performances whichever igniter is activated.
Such a charge may be used notably to ensure the destruction function during the trajectory for ballistic projectiles or for their payload.
In this case, this charge may advantageously be an explosively-formed charge.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more apparent after reading the following description of the different embodiments, such description being made with reference to the appended drawings, in which:
FIG. 1 is a longitudinal section view of a shaped charge fitted with a priming device according to a first embodiment of the invention,
FIG. 2 is a longitudinal section view of a shaped charge fitted with a priming device according to a second embodiment of the invention,
FIG. 3 is a transversal section view of a shaped charge according to a third embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, a shaped charge 1 (in this case an explosively-formed charge) comprises an explosive load 2 placed in a cylindrical casing 3 screwed to a body 9 having fastening lugs 19 a , 19 b.
A cup-shaped liner 4 is applied to the explosive load 2 . A priming device 5 allows the explosive load 2 to be ignited.
In accordance with the invention, the priming device 5 comprises a confinement block 6 placed in a cylindrical cavity 10 in a body 9 .
According to this first embodiment, the block 6 is made of an organic material having acoustic impedance less than 15.10 6 kg/m 2 s. The block 6 may, for example, be made of polyacetal.
The block 6 has a bore 7 that comprises a conical part 7 a extended by two cylindrical parts 7 b and 7 c.
The bore 7 is filled with a relay explosive 8 .
The priming device 5 also comprises a first layer 11 and a second layer 12 of relay explosive.
These two relay layers 11 and 12 are arranged on the upper and lower faces of the confinement block 6 .
The second relay layer 12 is, in this case, housed in a cavity made in the explosive load 2 . It might also be simply applied to an upper surface of the explosive load 2 . It would also be possible for no second relay layer to be provided and for the block 6 to be applied directly onto the load 2 .
The first relay layer 11 is arranged at the bottom of the cavity 10 in the body 9 . It communicates with two pyrotechnic igniters 13 a , 13 b placed symmetrically on either side of the charge axis 14 .
Here these igniters are electrically-ignited primers and are controlled by an ignition device 20 placed at a distance and connected to the igniters 13 a , 13 b by conductors 15 a , 15 b . The igniters may also be formed by pyrotechnic transmission lines, for example detonating lines.
The conical part 7 a of the bore 7 converges between an outer face of the block 6 positioned beside the igniters 13 a , 13 b and an inner face of the bock positioned beside the explosive load 2 . This conical part 7 has a half-angle at the apex that is of between 10 and 25°, the small diameter of the cone being of between 2 and 5 mm and the large diameter of the cone being of between 13 and 30 mm.
Relay layers 11 and 12 may be made of composite explosive cut out of plates.
The relay composition 8 filling the bore 7 will be cyclonite, for example. This composition 8 will be put in place by compression.
This priming device operates as follows.
When the charge 1 is required to be fired, the ignition device 20 sends a firing order to both igniters 13 a , 13 b simultaneously. These ignite the first relay layer 11 which in turn ignites the relay composition 8 placed in the bore 7 of the bore 6 .
Because of the convergence of the conical part 7 a of this bore, the shock wave that is propagating in the composition 8 also converges towards the second relay layer 12 which is ignited practically along the axis 14 of the charge 1 .
The second relay layer in turn ignites the explosive load 2 , causing the projectile to be formed by the liner 4 .
If only one of the igniters 13 a , 13 b functions, the other presenting a failure, the first layer 11 is ignited out-of-line with the axis. It nevertheless ignites the relay composition 8 and the convergence of the conical bore 7 a ensures the re-centering of the shock wave and thus the faultless ignition of the second relay layer 12 , and thus of the explosive load 2 .
So as to avoid the inadvertent ignition of the second relay layer 12 or of the load 2 directly by the shock wave through the material of the confinement block 6 , means must be provided to prevent such a propagation.
According to this first embodiment, the block 6 is made of a material enabling such a propagation to be absorbed. The block 6 will thus be made of an organic material having an acoustic impedance of less than 15.10 6 kg/m 2 s.
Other means can be used to prevent the direct ignition of the relay layer 12 or the explosive 2 by the propagation of the shock wave through the material of the confinement block 6 .
FIG. 2 thus shows a second embodiment of the invention that differs from the first one in that the confinement block 6 incorporates a collar 16 placed at the upper face of the block and onto which the first relay layer 11 is applied. This collar 16 is followed by a free space 17 surrounding the block 6 .
A second collar 18 allows the block 6 to be positioned in the bore 10 . Thus, the free space 17 is formed by a cylindrical groove arranged in the block 6 and delimited by the two collars 16 and 18 .
The free space 17 constitutes means to prevent the propagation of a shock wave axially through the confinement block 6 . Indeed, the shock received by the collar 16 further to the ignition of the first relay layer 11 is not able to propagate directly to the second collar 18 .
The relay composition 8 is ignited as in the previous embodiment and the convergent profile of the bore 7 a ensures the centering of the shock wave and the axial ignition of the second relay layer 12 and thus of the explosive load.
Once again, this axial ignition is ensured even if only one of the igniters 13 a , 13 b functions.
Thanks to the presence of the free space 17 , it is possible for the confinement block 6 to be made of metal, for example an aluminum alloy.
The first layer 11 of relay explosive shown in FIGS. 1 and 2 has revolving symmetry.
It is possible for a first relay layer of a different shape to be implemented.
FIG. 3 thus shows a top view and section view of a priming device according to a variant embodiment in which the first layer 11 is in the shape of a substantially rectangular tongue passing through the axis 14 of the charge.
This view is a section made along a plane referenced AA in FIG. 1 . The latter Figure has been described previously with reference to an embodiment in which the first relay layer 11 is ring-shaped. This Figure may also be associated with this third embodiment where the first layer is a tongue.
The igniters 13 a , 13 b (the position of only one of which is shown) are arranged on either side of axis 14 , each at one end of the relay layer 11 .
The relay composition 8 arranged in the confinement block 6 is ignited by means of the relay layer 11 whichever igniter is primed.
As in the previous example, the convergent profile of the bore 7 a ensures the centering of the shock wave and the axial ignition of the second relay layer 12 and of the explosive load.
The block 6 can be either structured according to FIG. 1 (organic material) or to FIG. 2 (peripheral groove) regardless.
Other variants are possible without departing from the scope of the invention.
Thus, the device according to the invention may implement only one igniter that is out-of-line with respect to axis 14 of the charge. Such a configuration makes it easier to integrate a charge in a given projectile. Indeed, thanks to the invention, it is no longer necessary for the igniter to be positioned axially with respect to the charge.
It is also possible for a first relay layer 11 and the relay explosive placed in the confinement block to be made in the form of a single mass of explosive, implemented for example by compression. The explosive mass will comprise a conical lower part and a disk or tongue-shaped upper part. In this case, the confinement block will be given a suitably shaped upper face enabling it to receive the disk or tongue-shaped relay explosive part.
It is naturally possible for the priming device according to the invention to be implemented with other types of explosive charges: hollow charges, splinter-generating charges, etc.
The shaped charge proposed by the invention is fitted with at least two igniters. Greater reliability is thereby ensured in the event of using the charge for the function of destroying a ballistic projectile such as a rocket or missile during its trajectory or else for the destruction of the charge carried on-board this projectile. This improved reliability is due to the backed-up igniters, of which there may be more than two. This is coupled thanks to the invention to an effectiveness that is the same whatever the number and position of the igniters primed, the priming device ensuring in any case the ignition of the explosive load along the axis of symmetry 14 of the charge. The igniters are shown in the Figures having orientations substantially parallel to one another and to the charge axis. These igniters may also be placed at a different orientation making an angle with the charge axis. | The invention relates to safety priming device for an explosive charge, notably a shaped charge, comprising a pyrotechnic igniter and at least one igniting relay placed between the igniter and an explosive load.
This priming device is characterized in that the igniting relay comprises means enabling the detonation wave produced by the igniter or igniters to be re-centered along the charge axis, said means comprising a confinement block having a bore converging between an external face positioned beside the igniter or igniters and an inner face positioned beside the explosive load, said bore filled with a relay explosive, the confinement block comprising means to prevent the propagation of a shock wave axially through the confinement block between the igniter or igniters and the explosive load. | 5 |
FIELD OF THE INVENTION
The present invention relates to lubricating oil compositions and concentrates therefor containing metal core compounds, specifically polynuclear molybdenum core compounds.
BACKGROUND OF THE INVENTION
Certain oil-soluble or oil-dispersible metal core compounds, ie compounds having a metal core bonded to one or more ligands, are known as additives (or additive components) for lubricating oil compositions (or lubricants) for improving the composition's properties and performance. The ligand or ligands confer oil-solubility on the compound. For example, certain oil-soluble molybdenum- and sulfur-containing compounds have been proposed and investigated as lubricant additives. U.S. Pat. Nos. 2,951,040; 3,419,589; 3,840,463; 4,966,719; 4,995,996; and 4,978,464 are representative of patent specifications describing molybdenum- and sulfur- containing compounds.
Molybdenum compounds for use as lubricant additives described in the art are principally dinuclear molybdenum compounds, characterised by the oxidation state Mo(V). See, for example, U.S. Pat. No. 5,627,146. Also, EP-A-0 960 178, based on International Patent Application No. PCT IB97/01656, describes use of trinuclear molybdenum compounds as lubricant additives, i.e. characterised by a different oxidation state (Mo(IV)).
Such dinuclear molybdenum compounds may be exemplified by the formula Mo 2 O x S y L 2 , and such trinuclear molybdenum compounds may be exemplified by the formula MO 3 S k L 4 , where x+y=4, k is at least 4, and L represents a monoanionic ligand for conferring oil-solubility or oil-dispersability on the compound, a typical example being a dithiocarbamate, frequently referred to as “dtc”.
The above-exemplified compounds have Mo: ligand (L) molar ratios of 1:1 and 3:4 respectively, ie the number of moles of Mo never exceeds the number of moles of ligand L. Since the Mo is an active part of the compound, it would be desirable to increase its proportion, relative to ligand L, in order to reduce the raw material cost of making the compounds. The art does not describe any such accomplishment, even though it would be beneficial to do so.
The present invention solves the above problem and provides oil-soluble or -dispersible compounds with polynuclear Mo cores whose Mo content exceeds its solubility or dispersibility conferring ligand content.
SUMMARY OF THE INVENTION
In a first aspect, the invention is a lubricating oil composition comprising, or made by mixing, a major amount of an oil of lubricating viscosity and a minor amount of, as an additive, at least one compound comprising a polynuclear, such as a di- or trinuclear, molybdenum core and bonded thereto one or more monoanionic ligands capable of rendering the compound oil-soluble or oil-dispersible, wherein the ratio of the number of molybdenum atoms in the core to the number of said ligands is greater than 1:1, such as 3:2 or greater. The compound may provide at least 1, for example 1 to 2000, such as 5 to 1000, preferably 20 to 1000, ppm by mass of the Mo, expressed as Mo atoms, based on the mass of the composition.
Preferably, the molybdenum core, as a Mo cluster core comprising more than one Mo atom, is dinuclear or trinuclear. It may contain non-metallic atoms consisting wholly or partly of sulphur. Preferably it consists of trinuclear molybdenum and sulphur. The ligands or ligands may, for example, be bidentate ligands, e.g. bonding to the core through two sulphur atoms.
The lubricating oil composition according to the first aspect of the invention has excellent antiwear, antioxidant, and friction-reducing properties; also it may be compatible with other additives used in formulating commercial lubricating oil compositions and can be made from readily available starting materials.
In a second aspect, the invention is an additive concentrate for blending with an oil of lubricating viscosity comprising, or made by mixing, an oleaginous carrier and from 1 to 200,000, for example 50 to 150,00, such as 50 to 100,000, ppm by mass of the Mo, expressed as Mo atoms, of an additive defined in the first aspect of the invention, based on the mass of the concentrate.
In a third aspect, the invention is a method of lubricating an internal combustion engine comprising operating the engine and lubricating the engine with a lubricating oil composition of the first aspect of the invention.
In a fourth aspect, the invention is use of an additive as defined in the first aspect of the invention for enhancing one or more lubricating oil properties of a lubricating oil composition.
In a fifth aspect, the invention is a method of making a lubricating oil composition or an additive concentrate comprising mixing an additive defined in the first aspect of the invention with an oil of lubricating viscosity or an oleaginous carrier.
In this specification:
“comprising” or any cognate word is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof;
“major amount” means in excess of 50 mass % of the composition;
“minor amount” means less than 50 mass % of the composition, both in respect of the stated additive and in respect of the total mass % of all of the additives present in the composition, reckoned as active ingredient of the additive or additives;
the invention also provides the product obtained or obtainable as a result of any reaction between the various additive components of the composition or concentrates, essential as well as customary and optimal, under the conditions of formulation, storage or use;
“oil-soluble” or “dispersible” used herein do not necessarily indicate that the compounds or additives are soluble, dissolvable, miscible, or capable of being suspended in the oil in all proportions. These do mean, however, that they are, for instance, soluble or stably dispersible in oil to an extent sufficient to exert their intended effect in the environment in which the oil is employed. Moreover, the additional incorporation of other additives may also permit incorporation of higher levels of a particular additive, if desired.
DETAILED DESCRIPTION OF THE INVENTION
OIL OF LUBRICATING COMPOSITION
This oil may be selected from vegetable, animal, mineral, or synthetic oils. The oils may range in viscosity from light distillate mineral oils to heavy lubricating oils such as gas engine oil, mineral lubricating oil, motor vehicle oil, and heavy duty diesel oil. The oils may be unrefined, refined, and re-refined. The oil may be used oil.
The ligands, including ligands L, may be independently selected from the group of:
and mixtures thereof, and perthio derivatives thereof wherein X, X 1 , X 2 and Y are independently selected from the group of oxygen and sulfur, and wherein R 1 , R 2 , and R are independently selected from the group consisting of H and organo groups that may be the same or different. Preferably the organo groups are hydrocarbyl groups such as alkyl (e.g., in which the carbon atom attached to the remainder of the ligand is primary, secondary or tertiary), aryl, substituted aryl and ether groups. More preferably, all ligands are the same.
Importantly, the organo groups of the ligands have a sufficient number of carbon atoms to render the compounds soluble or dispersible in the oil. The compounds' oil solubility or dispersibility may be influenced by the number of carbon atoms in the ligands. Preferably the ligand source chosen has a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil. In the compounds in the present invention, the total number of carbon atoms present among all of the organo groups of the compounds' ligands typically will be at least 21, e.g. 21 to 800, such as at least 25, at least 30 or at least 35. For example, the number of carbon atoms in each alkyl group will generally range between 1 to 100, preferably 1 to 40 and more preferably between 3 and 20. Preferred ligands include dialkyldithiophosphate (“ddp”), xanthates, thioxanthates, dialkylphosphate, dialkyldithiocarbamate (“dtc”), and carboxylate and of these the dtc is more preferred.
The term “hydrocarbyl” denotes a substituent having carbon atoms directly attached to the remainder of the ligand and which is predominantly hydrocarbyl in character within the context of this invention. Such substituents include the following: (1) hydrocarbon substituents, that is, aliphatic (for example alkyl or alkenyl), alicyclic (for example cycloalkyl or cycloalkenyl) substituents, aromatic-, aliphatic- and alicyclic-substituted aromatic nuclei, as well as cyclic substituents wherein the ring is completed through another portion of the ligand (that is, any two indicated substituents may together form an alicyclic group); (2) substituted hydrocarbon substituents, that is, those containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbyl character of the substituent. Those skilled in the art will be aware of suitable groups (e.g., halo, (especially chloro and fluoro), amino, alkoxyl, mercapto, alkylmercapto, nitro, nitroso, sulfoxy, etc.); (3) hetero substituents, that is, substituents which, while predominantly hydrocarbon in character within the context of this invention, contain atoms other than carbon present in a chain or ring otherwise composed of carbon atoms.
The compounds may, for example have the general formula (I) below:
Mo a E k L n X b (1)
wherein E represents O, S or Se, or a combination thereof
L represents monoanionic ligands that confers oil-solublility or -dispersibility on the compound;
X represents an anion bonded to the core above, to confer electrical neutrality to the compound;
a is 2, 3 or 4:
k is at least 4, for example in the range from 4 to 10, such as 4 to 7, preferably 4 or 7;
n is an integer that is less than a; and
b is an integer to confer, in combination with n, electrical neutrality to the compound.
Preferred embodiments of compounds of formula (I) are those where E represents O or S or a combination thereof; and/or a is 2 or 3.
A more preferred embodiment is a compound of the general formula (II) below:
Mo 3 S k L 2 X
where k is 4 or 7 and X (II) represents a divalent anion such as the disulfide ion.
The subject compounds may be made by reacting, in a polar medium, a reactant molybdenum compound that contains a polynuclear molybdenum core, such as a trinuclear molybdenum core, and the ligand, L, such as a dithiocarbamate, in a stoichiometric ratio, corresponding to that of the subject compound, wherein neither the reactant molybdenum compound nor the ligand is derivatised.
The polar medium may, for example, comprise a liquid alkanol such as methanol, tetrahydrofuran, dimethylformamide, toluene or water; the reactant molybdenum compound may, for example, contain the [Mo 3 S 13 ] 2− ion; and L may, for example, be a dihydrocarbyl-, preferably dialkyl-, substituted dithiocarbamate. Appropriately, the above-described reaction is conducted at elevated temperature.
By “stoichiometric ratio” above is not intended to mean or require exact stoiochiometry according to a chemical equation that can be written to represent the reaction, but rather close enough to the stoiochiometry of such equation to ensure that there is more Mo than ligand, L, in the product (mole: mole).
As an example, the synthesis of MO 3 S 7 (dtc) 2 (S 2 ), being a subject compound, may proceed with stoichiometric quantities of dtc according to the equation shown below:
(NH 4 ) 2 Mo 3 S 13 +2Hdtc→Mo 3 S 7 (dtc) 2 (S 2 )+2H 2 S 2 +2NH 3
COMPOSITION AND CONCENTRATE
The lubricating oil compositions of the present invention may be prepared by adding to an oil of lubricating viscosity a mixture of an effective minor amount of at least one compound, and, if necessary, one or more co-additives such as described hereinafter. This preparation may be accomplished by adding the compound directly to the oil or by first mixing the compound in a suitable carrier fluid to achieve oil solubility or dispersibility, and adding the mixture to the lubricating oil. Co-additives may be added to the oil by any method known to those skilled in the art, either prior to, contemporaneously with, or subsequent to addition of the compound.
Concentrates of the compounds and co-additives, if required, in a suitable oleagenous, typically hydrocarbon, carrier fluid provide a convenient means of handling them before their use. Oils of lubricating viscosity, such as those described above as well as aliphatic, naphthenic, and aromatic hydrocarbons, are examples of suitable carriers for concentrates. These concentrates may contain 1 to 90 mass % of the additives based on the weight of the concentrate; preferred is 1 to 50, more preferably 20 to 70, mass %.
The lubricating oil compositions made by mixing (or blending) an oil of lubricating viscosity containing at least one compound of the types and in the amounts described herein and optional co-additives may be used to lubricate mechanical engine components, particularly of an internal combustion engine such as a spark-ignited or compression-ignition engine, by adding the lubricating oil thereto in the crankcase thereof.
CO-ADDITIVES
Other lubricant additives may be used for blending in the compositions of this invention. These include dispersants, detergents, e.g., single or mixed metal detergent systems, pour point depressants, viscosity improvers, antioxidants, surfactants, antiwear agents, and friction reducing agents. These can be combined in proportions known in the art. For example, additives containing phosphorus and/or sulfur compounds such as a zinc dialkyl dithiophosphate(ZDDP) can be prepared and used with the compounds of the present invention. However, the compounds of the present invention may be effective or may even possess improved properties when used in lubricating oil compositions that are free or substantially free of added phosphorus and/or sulfur. i.e., phosphorus and/or sulfur in addition to (i.e., except for) any phosphorus or sulfur contained in the compounds themselves. A lubricating oil composition that is substantially free of phosphorus and/or sulfur is one in which the amount of phosphorus and/or sulfur is not more than is inherently present in base oils of lubricating viscosity.
Particularly noteworthy is the use of anti-oxidants in combination with the compounds.
Examples of suitable antioxidants are selected from copper-containing antioxidants, sulfur-containing antioxidants, aromatic amine-containing antioxidants and phenolic antioxidants.
Examples of suitable copper-containing antioxidants include oil-soluble copper compounds described in EP-B-24 146, EP-A-280 579 and EP-A-280 580. Thus, for example, the copper may be blended into the oil as an oil-soluble copper salt of a synthetic or natural carboxylic acid. Examples of carboxylic acids from which suitable copper salts may be derived include C 2 to C 18 carboxylic acids (e.g., acetic acid, and fatty acids such as stearic acid and palmitic acid), unsaturated acids (e.g., oleic acid), branched carboxylic acids (e.g., naphthenic acids of molecular weight of from 200 to 500, neodecanoic acid and 2-ethylhexanoic acid), and alkyl- or alkenyl-substituted dicarboxylic acids (e.g., polyalkenyl-substituted succinic acids such as octadecenyl succinic acids, dodecenyl succinic acids and polyisobutenyl succinic acids). In some cases, suitable compounds may be derived from an acid anhydride, for example, from a substituted succinic anhydride. The copper antioxidant may be, for example, a copper dithiocarbamate or copper dithiophosphate. Other copper- and sulfur-containing antioxidant compounds, for example, copper mercaptides, xanthates, and thioxanthates, are also suitable for use in accordance with the invention, as are copper sulfonates, phenates (optionally sulfurized) and acetylacetonates. Other copper compounds which may be used in accordance with the invention are overbased copper compounds. Examples of such compounds, and of processes for their preparation, are described in U.S. Pat. No. 4,664,822 and EP-A-0 425 367. The copper compound may be in cuprous or cupric form.
Examples of suitable aromatic amine-containing antioxidants are aromatic amines which have at least one aromatic group directly attached to at least one amine nitrogen atom. Secondary aromatic amines, especially those having two aromatic groups attached to the same amine nitrogen atom, are preferred, but the use of other aromatic amines is not excluded. The amines may contain one or more aromatic groups, for example at least two aromatic groups. Where there are two aromatic groups, both are preferably bonded directly to the same amine nitrogen. Compounds in which two aromatic groups are linked by a covalent bond or by an atom or group (e.g., an oxygen or sulfur atom, or a —CO—, —SO 2 — or alkylene group) may be used. Aromatic rings, which are preferably aromatic hydrocarbon rings, may be unsubstituted or substituted by one or more substituents selected from alkyl, cycloalkyl, alkoxy, aryloxy, acyl, acylamino, hydroxy, and nitro groups. Amines containing alkyl-substituted aromatic hydrocarbon rings are preferred, especially those containing two alkylsubstituted phenyl groups. Preferred N-aryl amines for use in accordance with the invention are naphthylamines and, especially, diphenylamines, including alkyl substituted diphenylamines, wherein the alkyl group may be the same or different, having 1 to 28 carbon atoms. Other nitrogen- containing antioxidants, for example, phenothiazine type compounds, may also be used in this invention.
Examples of phenolic antioxidants include (a) sterically hindered tertiary-alkylated monohydric phenols such as those described in more detail in U.S. Pat. Nos. 2,944,086; 3,043,775; and -3,211,652; and (b) methylene-bridged tertiary alkyl polyphenols, such as 4,4′-methylene bis (2,6-di-tertbutylphenol) and 2,2′-methylene bis (4,6-di-(1,1,2-trimethylpropyl)phenol), and mixtures of (a) and (b) such as those described in more detail in EP-B-0456925.
Examples of sulfur-containing antioxidants (compounds) are alkaline earth metal salts of alkylphenoithioesters having preferably C5 to C12 alkyl side chains, calcium nonylphenol sulfide, ashless oil-soluble phenates and sulfurized phenates, phosphosulfurized or sulfurized hydrocarbons, phosphorus esters and other sulfur-containing molybdenum-containing compounds. Other examples of sulfur-containing antioxidants are metal salts of dihydrocarbyl dithiophosphate or dihydrocarbyl dithiocarbamate compounds, wherein the metal is selected from Zn, Mn, Ni, Al, Group 1 metals and Group 2 metals. Other sulfur-containing compounds include those described in EP-A-699 759, for example, sulfides of oils, fats or polyolefins, in which a sulfur group having two or more sulfur atoms is adjoined and bonded together in a molecular structure. Examples include sulfurized sperm oil, sulfurized pinene oil, sulfurized soybean oil, sulfurized polyolefin, sulfurized esters, dialkyl disulfide, dialkyl polysulfide, dibenzyl disulfide, ditertiary butyl disulfide, polyolefin polysulfide, a thiadiazole type compound such as bis-alkyl polysulfide thiadiazole, and sulfurized phenol.
Preferable antioxidants are copper-containing antioxidants, aromatic amine-containing compounds including diphenylamines and derivatives thereof that have an effect herein comparable to diphenylamines), and mixtures thereof. Examples of copper-containing antioxidants include copper polyisobutylene succinic anhydride (“copper PIBSA”) and copper oleate, and diphenylamines include all effective derivatives of diphenylamines.
Thus, the lubricating oil compositions of the present invention may include a minor amount of at least one antioxidant and at least one oil-soluble or oil-dispersible compound. The composition may include a mixture of the compounds and antioxidants of the types disclosed herein, the lubricating oil and/or other additives disclosed herein per se, and/or of any intermediates and reaction products occurring as a result of the mixture. In combination, the antioxidants and compounds are present in a minor effective amount to produce the enhanced lubricating performance, particularly friction reduction, friction reduction retention, antioxidancy and/or antiwear properties in the oil.
EXAMPLES
The invention will be more fully understood by reference to the following examples.
Example 1
Preparation of Mo 3 S 7 (octyl 2 dtc) 2 (S 2 )
Methanol (50 mL), dioctylamine (0.66 mL, 2.2 mmol), and carbon disulfide (0.13 mL, 2.2 mmol) were combined in a 250 mL round bottomed flask under a nitrogen atmosphere and allowed to stir for 2 hours. (NH 4 ) 2 Mo 3 S 13 (750 mg, 1 mmol) was added and the mixture heated and refluxed overnight. The mixture, containing a red solid, was removed from the heat and the methanol decanted from the red solid. The solid was washed with methanol, dried, dissolved in toluene and filtered. The toluene was removed by vacuum distillation to yield a dark-red glassy solid product, whose elemental analysis corresponded to that of Mo 3 S 7 (octyl 2 dtc) 2 (S 2 ).
Example 2
Preparation ofMo 3 S 7 (coco 2 dtc) 2 (S 2 ):
Methanol (50 mL), dicocoamine (1.00 g, 2.2 mmol), and carbon disulfide (0.13 mL, 2.2 mmol) were combined in a 250 mL round bottom flask under nitrogen and allowed to stir for 2 h. (NH 4 ) 2 Mo 3 S 13 (750 mg, 1 mmol) was added to the solution. The mixture was heated and refluxed overnight. The solution was removed from heat and the methanol decanted from the red solid. The solid was washed with methanol and then dried. The product was dissolved in toluene and filtered. The toluene was removed via vacuum distillation to yield a dark-red glassy solid.
Test
The product of Example 2 was subjected to the Cameron-Plint test as follows.
It was added, as an additive, to a commercial 10W30 lubricating oil to provide 500 ppm by weight of elemental Mo. The mixture was heated at 80° C. for 30 minutes with vigorous stirring to disperse the additive. The untreated oil and the additive-containing oil were then subject to the Cameron-Plint ball-on-plate test, which provides a measure of friction modification. The conditions of the test were:
Load
120N
Stroke
2.42 cm
Temperature
120° C.
Rate
8.3 Hz
The length of the test was 30 minutes: the final friction coefficient was measured at the end of the test and the average friction coefficient recorded as the mean of the values between 10 and 30 minutes. The results obtained were as follows:
Final Friction Coefficient
Average Friction Coefficient
Untreated Oil
0.10
0.11
Treated Oil
0.04
0.04
It is thus seen that treatment with the product of Example 2 reduced friction by more than half. | A lubricating oil composition is provided comprising a major amount of an oil of lubricating viscosity and a minor amount of, as an additive, at least one compound comprising a polynuclear molybdenum core and bonded thereto one or more anionic ligands capable of rendering the compound oil-soluble or oil-dispersible, wherein the ratio of the number of molybdenum atoms in the core to the number of said ligands is 1:1, such as 3:2 or greater. | 2 |
FIELD OF THE INVENTION
[0001] This invention relates generally to methods for human or veterinary medical treatment and more particularly to a) the endovascular application of hypothermia to beating heart donors prior to harvesting of organ(s) and/or tissue(s) for transplantation to avoid hypoxic damage to the organ(s) and/or tissue(s) and b) the endovascular (e.g., intravascular) application of hypothermia to transplant recipients during and/or after transplantation of organ(s) and/or tissue(s) to reduce acute inflammatory response and help avoid acute transplant rejection and/or other complications.
BACKGROUND OF THE INVENTION
[0002] In the early days of organ transplantation, all cadaveric (non-living) organ donors were pronounced dead by loss of heart function or “cardiac death” criteria. However, in the late 1960's and early 1970's “brain death” criteria were developed that allowed organs to be harvested from donors who's hearts were still beating but who had been pronounced dead based on the irreversible cessation of all brain activity. Additionally, it was learned that organ transplantation was more successful in cases where the donor's respiration and circulation were supported by artificial means (e.g., the use of mechanical ventilation and the administration of pharmacologic or mechanical support of cardiac activity) after brain death had occurred until the organs could be removed for transplantation. This “beating heart donor” technique enables oxygenated blood to continue to flow through the organs until immediately before they are harvested from the donor, thereby enhancing the organs' viability.
[0003] Every day, approximately ten people die in the United States while awaiting an organ transplant, simply because suitable donor organs are not available for them in time. Various approaches have been proposed for making transplantable organs more readily available to patients in need of transplants. For example, research is underway to develop genetically or immunologically modified animals who's organs may be suitable for xenotransplantation (i.e., transplantation of an organ or tissue from one species of animal into another species of animal) in humans. However, it remains uncertain as to whether xenotransplantation research will ultimately give rise to universally useable organs of all needed types and even if the current research is successful, the potential clinical implementation of xenotransplantation techniques remains many years away. Another approach has been to obtain some types of organs from human cadaveric donors who have been declared dead by traditional cardiac death criteria as opposed to brain death criteria. However, a number of important transplantable organs (e.g., hearts) can not typically be harvested from cadaveric donors more than just a few minutes after the cardiac death has occurred because the viability of the organ is lost.
[0004] On Jan. 6, 2001 The United Network for Organ Sharing (UNOS) national patient waiting list for organ transplant included the following:
Patients Waiting Type of Transplant for Transplant kidney transplant 47,689 liver transplant 16,815 pancreas transplant 1,033 pancreas islet cell transplant 178 kidney-pancreas transplant 2,457 intestine transplant 147 heart transplant 4,152 heart-lung transplant 206 lung transplant 3,676 *Total Patients Total *73,989
[0005] However, because of the shortage of suitable donor organs, the number of organ transplants that will actually be performed during the year 2001 is likely to be substantially lower than the number of patients on the waiting list. During the year 2000, the number of transplants actually performed in the United States were as follows:
Type of Transplant Number kidney alone transplants 13,290 (5,227 were living donors) liver transplants 4,934 pancreas alone transplants 436 kidney-pancreas transplants 914 intestine transplants 79 heart transplants 2,197 heart-lung transplants 48 lung transplants 956 Total 22,854
[0006] Apart from the fact that the pool of potential organ donors is relatively small compared to the demand for transplantable organs, the shortage of organs is further exacerbated by the fact that sometimes, even after a potential donors family has agreed to organ donation, that donor's organs are lost because the donors cardiac activity can not be maintained for sufficient time to allow the necessary testing to establish and certify brain-death and to arrange for the arrival of the team of surgeons who are trained to remove the desired organ(s) from the donor's body. In view of these facts, there remains a need in the art for the development of new techniques to facilitate the harvesting of viable organs for transplantation so that more organs may be made available.
SUMMARY OF THE INVENTION
[0007] The present invention provides methods for decreasing the potential for hypoxic damage to transplantable organs in brain dead “beating heart” organ donors. The present invention also provides methods for preventing or treating episodes of acute transplant rejection in patients who have received organ or tissue transplants.
[0008] In accordance with one embodiment of the present invention, a heat exchange apparatus is inserted into the vasculature of a potential organ donor who is believed to be brain dead, but who has not yet been declared brain dead. The heat exchange apparatus is then used to cool the blood flowing through the potential donor's vasculature, thus cooling all of a portion of the donor's body to a desired temperature below normothermia (e.g., from about 37° C. to about 35° C. or less, often as low as 30°), thereby decreasing the oxygen demand of the tissues or organs to be transplanted and thus decreasing the likelihood that such tissues or organs will suffer hypoxic damage as a result of a hypoxic event while the patient is undergoing the necessary evaluation of his/her suitability as an organ donor, during the performance of testing necessary to confirm brain death (i.e., the “brain death work-up”) and until such time as brain death has been certified and any organs deemed suitable for transplantation have been harvested from the donor's body. The types of hypoxic events that may occur during this period of time include periods of cardiac arrest where the donor's heart ceases to beat for a period of time, periods of extreme hypotension or periods where the mechanical ventilation is inadvertently or purposely interrupted.
[0009] Further in accordance with the present invention, a heat exchange apparatus is may be inserted into the vasculature of a potential organ donor who has already been declared brain dead but from whose body the organs or tissues desired for transplantation have not yet been harvested. The heat exchange apparatus is then used to cool the blood flowing through the potential donor's vasculature, thus cooling all of a portion of the donor's body to a desired temperature below normothermia (e.g., from about 37° C. to about 35° C. or less), thereby decreasing the oxygen demand of the tissues or organs to be transplanted and thus decreasing the likelihood that such tissues or organs will suffer hypoxic damage as a result of a hypoxic event while the patient is undergoing the necessary evaluation of his/her suitability as an organ donor and until such time as brain death has been certified and any organs deemed suitable for transplantation have been harvested from the donor's body. The types of hypoxic events that may occur during this period of time include periods of cardiac arrest where the donor's heart ceases to beat for a period of time, periods of extreme hypotension or periods where the mechanical ventilation is inadvertently or purposely interrupted.
[0010] Still further in accordance with the present invention, the heat exchange apparatus may be a pliable or flexible structure that is formed or mounted and configured to expand when filled with thermal exchange fluid. One or more lumens may extend through the catheter to permit infusion or circulation of thermal exchange fluid through the heat exchange apparatus in situ. The catheter may be initially inserted into the vasculature of the donor or recipient patient using well known percutaneous catheter insertion techniques and the catheter may then be advanced through the vasculature to a position where the heat exchange apparatus is situated at a desired location. The heat exchange apparatus may comprise a balloon or inflatable structure that is attached to one or more lumens of the catheter such that cooled thermal exchange fluid may be infused into or circulated through the heat exchange apparatus in situ. Blood flowing in heat exchanging proximity to the heat exchange apparatus will thereby become cooled. The subsequent circulation of the cooled blood will then cool all or a selected portion of the donor's or patient's body to the desired temperature below normothermia. The core body temperature or the temperature of a particular body part or organ of the donor or patient may be monitored and the temperature of the heat exchange apparatus may be modified periodically or continuously in response to the monitored temperature to prevent significant overshoot beyond the desired temperature and to thereafter maintain the temperature of the body or portion thereof at the desired temperature or within a range of desired temperatures, such as about 33° C. to about 30° C. An automated controller may be connected to temperature sensor(s) used to monitor the core body temperature or the temperature of the desired organ or portion of the donor's or patient's body. Also, such controller may be operatively connected to an apparatus that changes the temperature of the thermal exchange fluid being circulated through the heat exchange apparatus and/or the rate at which such thermal exchange fluid is circulated through the heat exchange apparatus. Based on the signal(s) received from the temperature sensor(s), the controller will then modify the temperature and/or rate of the thermal exchange fluid to optimize the cooling and maintenance of the temperature of the donor's or patient's body or portion thereof.
[0011] Further aspects and advantages of the present invention will become apparent to those of skill in the art upon reading and understanding the detailed descriptions of certain embodiments of the invention set forth herebelow and in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective drawing of an embodiment of the catheter of the invention.
[0013] FIG. 1A is a perspective drawing of an alternative tie-down at the proximal end of the catheter shown in FIG. 1 .
[0014] FIG. 2 is a cross-sectional drawing of the shaft of the catheter taken along the line 2 - 2 in FIG. 1 .
[0015] FIG. 3 is a cross-sectional drawing of the heat exchange region of the catheter taken along the line 3 - 3 in FIG. 1 .
[0016] FIG. 3A is a cross-sectional view through line 3 A- 3 A of FIG. 1 .
[0017] FIG. 4 is a perspective drawing of a segment of the heat exchange region of the catheter within the circle 4 - 4 in FIG. 1 .
[0018] FIG. 5 is a cross-sectional drawing of the heat exchange region of the catheter taken along the line 5 - 5 in FIG. 1 .
[0019] FIG. 6 is a perspective drawing of a segment of the heat exchange region of the catheter within the circle 6 - 6 in FIG. 1 .
[0020] FIG. 7 is a perspective drawing of the multi-lobed balloon of one embodiment of the invention.
[0021] FIG. 8 is a perspective drawing of the distal portion of the shaft of one embodiment of the invention.
[0022] FIG. 9 is a perspective drawing of the heat exchange region formed by the shaft and multi-lobed balloon of FIGS. 7 and 8 .
[0023] FIG. 10 is an expanded view of the attachment of the central lumen of the balloon to the shaft of the catheter of FIG. 9 showing the region within the circle 10 - 10 in FIG. 9 .
[0024] FIG. 10 A is an expanded view of the plug between the shaft and the central lumen of the balloon of the catheter of FIG. 9 showing the region within the circle 10 A- 10 A in FIG. 9 .
[0025] FIG. 11 is a perspective view of a portion of a multi-lobed, curvilinear heat exchange balloon that forms a portion of one embodiment of the invention.
[0026] FIG. 11 A is a cross sectional view of the heat exchange region taken along the line 11 A-!!A in FIG. 11 .
[0027] FIG. 12 is a sectional view of the proximal portion of the heat exchange region of one embodiment of the invention.
[0028] FIG. 12A is a cross-sectional view of a portion of the heat exchange region taken along the line 12 A- 12 A of FIG. 12 .
[0029] FIG. 12B is a cross-sectional view of a portion of the heat exchange region taken along the line 12 B- 12 B of FIG. 12 .
[0030] FIG. 12C is a cross-sectional view of a portion of the heat exchange region taken along the line 12 C- 12 C of FIG. 12 .
[0031] FIG. 13 is a sectional view of the distal portion of the heat exchange region of one embodiment of the invention.
[0032] FIG. 13A is a cross-sectional view of a portion of the heat exchange region taken through line 13 A- 13 A of FIG. 13 .
[0033] FIG. 13B is a cross-sectional view of a portion of the heat exchange region taken through line 13 B- 13 B FIG. 13 .
[0034] FIG. 14 is a general flow diagram of a method of the present invention wherein endovascular hypothermia is used in a beating heart organ dead donor to minimize the likelihood of hypoxic damage to the donor's organs between the time the donor is pronounced brain dead and the time the organs are actually harvested from the donor's body.
[0035] FIG. 15 is a general flow diagram of a method of the present invention wherein endovascular hypothermia is used in a beating heart but brain dead organ donor to minimize the likelihood of hypoxic damage to the donor's organs from the time brain death is suspected to have occurred, during the time the brain death work-up is performed and until the organs are actually harvested from the donor's body.
[0036] FIG. 16 is a general flow diagram of the present invention wherein endovascular hypothermia is used in a beating heart but brain dead organ donor to cool potentially transplantable organs or tissue while simultaneously maintaining other tissue at a higher temperature.
DETAILED DESCRIPTION OF EMBODIMENTS
[0037] The following detailed description is provided for the purpose of describing only certain embodiments or examples of the invention and is not intended to describe all possible embodiments and examples of the invention.
A. A Preferred Intravascular Heat Exchange Catheter System Useable to Perform the Methods of this Invention
[0038] Referring to FIGS. 1 through 10 A, in one embodiment, the catheter is comprised of a shaft 50 with a heat exchange region 100 thereon. The shaft has two roughly parallel lumens running through the proximal shaft, an inflow lumen 52 and an outflow lumen 54 . The shaft generally also comprises a working lumen 56 running therethrough for the insertion of a guide wire, or the application of drugs, radiographic dye, or the like to the distal end of the catheter. The heat exchange region comprises a four-lumen balloon, with three outer lumens 58 , 60 , 62 disposed around an inner lumen 64 in a helical pattern. In the particular embodiment shown, the balloon preferably makes one full rotation about the inner lumen 64 for each 2 to 4 inches of length. All four lumens 58 , 60 , 62 and 64 are thin walled balloons and each outer lumen 58 , 60 , 62 shares a common thin wall segment 66 , 68 , 70 with the inner lumen. The balloon is approximately twenty-five centimeters long, and when inflated has an outer circumference 72 of approximately 0.328 in. When deflated, the profile is generally about 9 French (3 French is 1 mm in diameter). When the balloon portion is installed on the shaft, both the proximal end 74 of the balloon and the distal end 76 of the balloon are sealed around the shaft in fluid tight seals, as described more fully herebelow. Heat exchange fluid may be directed in through the inflow lumen, return through the outer lobes of the balloon in heat exchange proximity with blood flowing over the outside of the balloon, and then out through the outflow lumens, as will be described in greater detail below.
[0039] The catheter is attached at its proximal end to a hub 78 . At the hub, the guide wire lumen 56 communicates with a guide wire port 80 , the inflow lumen 52 is in fluid communication with an inflow port 82 , and the outflow lumen 54 is in communication with an outflow port 84 . Attached at the hub and surrounding the proximal shaft is a length of strain relief tubing 86 which may be, for example, a length of heat shrink tubing. The strain relief tubing may be provided with suture tie-downs 88 , 90 . Alternatively, a butterfly tie-down 92 may be provided. (See FIG. 1A ).
[0040] Between the strain relief tubing 86 and the proximal end of the balloon 74 , the shaft 50 is extruded with an outer diameter of about 0.118 inches. The internal configuration is as shown in cross-section in FIG. 2 . Immediately proximal of the balloon attachment 74 , the shaft is necked down 94 . The outer diameter of the shaft is reduced to about 0.100 to 0.110 inches, but the internal configuration with the three lumens is maintained. Compare, for example, the shaft cross-section of FIG. 2 with the cross-section of the shaft shown in FIG. 3 . This length of reduced diameter shaft remains at approximately constant diameter of about 0.100 to 0.110 inches between the necked down location at 94 and a distal location 96 where the outflow lumen is sealed and the guide wire extension tube 98 is attached as will be described.
[0041] At the necked down location 94 , a proximal balloon marker band 102 is attached around the shaft. The marker band is a radiopaque material such as a platinum or gold band or radiopaque paint, and is useful for locating the proximal end of the balloon by means of fluoroscopy while the catheter is within the body of the patient.
[0042] At the location marked by the marker band, all four lobes of the balloon are reduced down and fastened around the inner member 67 in a fluid-tight seal. This may be accomplished by folding the outer lobes of the balloon 58 , 60 , 62 down around the inner lumen 64 , placing a sleeve, for example a short length of tubing, snugly over the folded-down outer lumens of the balloon and inserting adhesive, for example by wicking the adhesive, around the entire inner circumference of the sleeve. The inner lumen is then fastened to the shaft using a second short length of tubing. The second short length for example 1 mm, of intermediate tubing 104 is heat welded to the inside of the inner lumen. The intermediate tube has an outer diameter approximately the same as the inner diameter of the inner lumen. The intermediate tube is then slid over the shaft at about the location of the neck-down region near the proximal marker 102 , and adhesive 106 is wicked into the space between the inside of the intermediate tubing and the outer surface of the shaft 50 . A similar process may be used to attach the distal end of the balloon, as will be described, except that the distal end of the balloon is attached down around the guide wire extension tube 98 rather than the shaft.
[0043] Just distal of the proximal balloon seal, under the balloon within the inner lumen, an elongated window 108 is cut through the wall of the outflow lumen in the shaft. Along the proximal portion of the balloon above this window, five slits, e.g. 110 , are cut into the common wall between each of the outer lumens 58 , 60 , 62 and the inner lumen 64 . Because the outer lumens are twined about the inner lumen in a helical fashion, each of the outer tubes passes over the outflow lumen of the inner shaft member at a slightly different location along the length of the inner shaft and, therefore, an elongated window 108 is cut into the outflow lumen of the shaft so that each outer lumen has at least one slit e.g. 110 that is located over the window in the shaft. Additionally, there is sufficient clearance between the outer surface of the shaft and the wall of the inner lumen to allow relatively unrestricted flow of heat exchange fluid through all 5 slits in each outer lumen, around the shaft, and through the elongate window 108 into the outflow lumen 54 in the shaft 50 .
[0044] Distal of the elongated window in the outflow lumen, the inner lumen 64 of the four-lumen balloon is sealed around the shaft in a fluid tight plug. Referring to FIG. 10 a , the plug is formed by, for example shrinking a relatively thick length of PET tubing to form a length of plug tubing 112 where the inner diameter of the length of plug tubing is approximately the same as the outer diameter of the shaft at the location where the plug is to be formed. The plug tubing is slid over the shaft and fits snugly against the shaft. The shaft is generally formed of a material that is not heat shrinkable. As may be seen in FIGS. 10A and FIG. 3 , some clearance exists between the outer wall of the shaft and the inner wall of the inner lumen 64 . The walls of the inner lumen are composed of thin heat shrinkable material, for example PET. A probe with a resistance heater on the distal end of the probe is inserted into the guide wire lumen of the shaft and located with the heater under the plug tubing. The probe is heated, causing the heat shrink wall of the inner lumen to shrink down against the plug tubing, and the plug tubing to shrink slightly down against the shaft. The resultant mechanical fit is sufficiently fluid tight to prevent the outflow lumen and the space between the shaft and the wall of the inner lumen from being in fluid communication directly with the inner member or the inflow lumen distal of the plug except through the outer lumens as will be detailed below.
[0045] Just distal of the plug, the outflow lumen is closed by means of a heat seal 99 , and the inflow lumen is skived to form an opening 101 to the inner member. This may be accomplished by necking down the shaft at 96 , attaching a guide wire extension tube 98 to the guide wire lumen, and simultaneously opening the inflow lumen 101 to the interior of the inner lumen and heat sealing the outflow lumen shut 101 . The guide wire extension tube continues through the inner lumen, beyond the distal seal of the balloon (described below) to the distal end of the catheter 114 and thereby creates communication between the guide wire port 80 and the vessel distal of the catheter for using a guide wire to place the catheter or for infusing drugs, radiographic dye, or the like beyond the distal end of the catheter.
[0046] The distal end of the balloon 76 is sealed around the guide wire extension tube in essentially the same manner as the proximal end 74 is sealed down around the shaft. Just proximal of the distal seal, five slits 116 are cut into the common wall between each of the three outer lumens 58 , 60 62 of the balloon and the inner lumen 64 so that each of the outer lumens is in fluid communication with the inner lumen.
[0047] Just distal of the balloon, near the distal seal, a distal marker band 118 is placed around the guide wire extension tube. A flexible length of tube 120 may be joined onto the distal end of the guide wire tube to provide a soft tip to the catheter as a whole.
[0048] In use, the catheter is inserted into the body of a patient so that the balloon is within a blood vessel, for example in the inferior vena cava (IVC). Heat exchange fluid is circulated into the inflow port 82 , travels down the inflow lumen 52 and into the inner lumen 64 distal of the plug tube 112 . The heat exchange fluid fills the inner lumen and travels down the inner lumen, thence through slits 116 between the inner lumen 64 and the three outer lumens 58 , 60 , 62 .
[0049] The heat exchange fluid then travels back through the three outer lumens of the balloon to the proximal end of the balloon. Since outer lumens are wound in a helical pattern around the inner lumen, at some point along the length of the balloon near the proximal end and proximal of the plug, each outer lumen is located over the portion of the shaft having the window to the outflow lumen 108 . There is also sufficient clearance between the wall of the inner lumen and the shaft, as illustrated in FIG. 3 , that even the slits that are not directly over the window 108 allow fluid to flow into the space between the wall of the inner lumen and the outer wall of the shaft 50 and then through the window 108 and into the outflow lumen. The heat exchange fluid then flows down the outflow lumen and out the outflow port 84 . At a fluid pressure of 41 pounds per square inch, flow of as much as 500 milliliters per minute may be achieved with this design.
[0050] Counter-current circulation between the blood and the heat exchange fluid is highly desirable for efficient heat exchange between the blood and the heat exchange fluid. Thus if the balloon is positioned in a vessel where the blood flow is in the direction from proximal toward the distal end of the catheter, for example if it were placed from the femoral vein into the Inferior Vena Cava (IVC) cava, it is desirable to have the heat exchange fluid in the outer balloon lumens flowing in the direction from the distal end toward the proximal end of the catheter. This is the arrangement described above. It is to be readily appreciated, however, that if the balloon were placed so that the blood was flowing along the catheter in the direction from distal to proximal, for example if the catheter was placed into the IVC from a jugular insertion, it would be desirable to have the heat exchange fluid circulate in the outer balloon lumens from the proximal end to the distal end. Although in the construction shown this is not optimal and would result is somewhat less effective circulation; this could be accomplished by reversing which port is used for inflow direction and which for outflow.
[0051] Where heat exchange fluid is circulated through the balloon that is colder than the blood in the vessel into which the balloon is located, heat will be exchanged between the blood and the heat exchange fluid through the outer walls of the outer lumens, so that heat is absorbed from the blood. If the temperature difference between the blood and the heat exchange fluid (sometimes called “ΔT”), for example if the blood of the patient is about 37° C. and the temperature of the heat exchange fluid is about 0° C., and if the walls of the outer lumens conduct sufficient heat, for example if they are of very thin (0.002 inches or less) plastic material such as polyethylene terephthalate (PET), enough heat may be exchanged (for example about 200 watts) to lower the blood temperature sufficiently to effect hypothermic anti-platelet activity, and to cool the temperature downstream of the catheter, for example of the heart, sufficiently for therapeutic inhibition of platelet activation, aggregation and/or adhesion. If the cooling catheter is left in place long enough for example for over half an hour, the entire body temperature of the patient may be cooled sufficiently for hypothermic anti-platelet activity. In this way, for example, blood to the brain and even the brain tissue itself may be cooled sufficiently for therapeutic hypothermic anti-platelet effect.
[0052] The helical structure of the outer lumens has the advantage over straight lumens of providing greater length of heat exchange fluid path for each length of the heat exchange region. This creates additional heat exchange surface between the blood and the heat exchange fluid for a given length of balloon. It may also provide for enhanced flow patterns for heat exchange between flowing liquids. The fact that the heat exchange region is in the form of an inflatable balloon also allows for a minimal insertion profile, for example 9 French or less, while the heat exchange region may be inflated once inside the vessel for maximum diameter of the heat exchange region in operation.
[0053] Automated control of the process is optional. Examples of apparatus and techniques that may be used for automated control of the process are described in U.S. Pat. Nos. 6,149,673 and 6,149,676 and co-pending United States Patent Application SN 09 / 138 , 830 , the entireties of which are expressly incorporated herein by reference.
[0054] Referring now to FIGS. 11 through 13 B, in another example of a preferred embodiment, the heat exchange region is in the form of a series of five lumens arranged side-by-side in a configuration that may be loosely described as a twisted ribbon. The heat transfer fluid circulates to and from the heat exchange region 202 via channels formed in the shaft 206 in much the same manner as previously described for shaft 50 . Indeed, although not depicted, the shaft has a similar internal configuration as the shaft previously described with an inflow lumen, an outflow lumen, and a working lumen. Although also not depicted, a hub is attached at the proximal end of the shaft which is maintained outside the body; the hub has a guide wire port communicating with the working lumen, an inflow port communicating with the inflow lumen, and an outflow port communicating with the outflow lumen. Heat exchange fluid is directed into the catheter through the inflow port and removed from the catheter through the outflow port. A guide wire, or alternatively medicaments, radiographic fluid or the like are introduced through the guide wire port and may thus be directed to the distal end of the catheter.
[0055] FIGS. 11 and 11 A illustrate this embodiment of a heat exchange region 202 comprising a plurality of tubular members that are stacked in a helical plane. More specifically, a central tube 220 defines a central lumen 222 therewithin. A pair of smaller intermediate tubes 224 a , 224 b attaches to the exterior of the central tube 220 at diametrically opposed locations. Each of the smaller tubes 224 a , 224 b defines a fluid lumen 226 a , 226 b therewithin. A pair of outer tubes 228 a , 228 b attaches to the exterior of the intermediate tubes 224 a , 224 b in alignment with the aligned axes of the central tube 220 and intermediate tubes 224 a , 224 b . Each of the outer tubes 228 a , 228 b defines a fluid lumen 230 a , 230 b within. By twisting the intermediate and outer tubes 224 a , 224 b , 228 a , 228 b around the central tube 220 , the helical ribbon-like configuration of FIG. 11 is formed.
[0056] Now with reference to FIGS. 12 and 12 A- 12 C, a proximal manifold of the heat exchange region 202 will be described. The shaft 206 extends a short distance, desirably about 3 cm, within the central tube 220 and is thermally or adhesively sealed to the interior wall of the central tube as seen at 250 . As seen in FIG. 12A , the shaft 206 includes a planar bulkhead or web 252 that generally evenly divides the interior space of the shaft 206 into an inflow lumen 254 and an outflow lumen 256 . A working or guide wire lumen 260 is defined within a guide wire tube 262 that is located on one side of the shaft 206 in line with the bulkhead 252 . Desirably, the shaft 206 is formed by extrusion. The outflow lumen 256 is sealed by a plug 264 or other seal at the terminal end of the shaft 206 . The inflow lumen 254 remains open to the central lumen 222 of heat exchange region 202 . The guide wire tube 262 continues a short distance and is heat bonded at 270 to a guide wire extension tube 272 generally centered within the central tube 220 .
[0057] A fluid circulation path is illustrated by arrows in FIG. 12 and generally comprises fluid passing distally through the inflow lumen 254 and then through the entirety of the central lumen 222 . The heat exchange fluid is directed from the central lumen 222 to the intermediate and outer tubes as will be described below, and returns through the lumens 226 a , 226 b , and 230 a , 230 b of the intermediate and outer tubes 224 a , 224 b , and 228 a , 228 b , respectively, and enters reservoirs 274 and 275 . Alternatively, two windows may be formed 276 and a counterpart not shown in FIG. 12 one helical twist farther down the shaft, between each side of the twisted ribbon (i.e., lumens 224 a and 224 b on one side, and 228 a and 228 b on the other side). In this way, one reservoir from each side of the twisted ribbon is formed in fluid communication with the outflow lumen 256 (configuration not shown). Fluid then enters the outflow lumen 256 through apertures, e.g., 276 , provided in the central tube 220 and a longitudinal port 278 formed in the wall of the shaft.
[0058] A distal manifold of the heat exchange region 202 is shown and described with respect to FIGS. 13 and 13 A- 13 B. The outer tubes 228 a , 228 b taper down to meet and seal against the central tube 220 which, in turn, tapers down and seals against the guide wire extension tube 272 . Fluid flowing distally through the central lumen 222 passes radially outward through a plurality of apertures 280 provided in the central tube 220 . The apertures 280 open to a distal reservoir 282 in fluid communication with lumens 226 a , 226 b , and a distal reservoir 281 in fluid communication with lumens 230 a , 230 b of the intermediate and outer tubes 224 a , 224 b , and 228 a , 228 b.
[0059] With this construction, heat exchange fluid introduced into the input port 240 will circulates through the inflow lumen 254 , into the central lumen 222 , out through the apertures 280 , and into the distal reservoir 282 . From there, the heat exchange fluid will travel proximally through both intermediate lumens 226 a , 226 b and outer lumens 230 a , 230 b to the proximal reservoirs 274 and 275 . Fluid then passes radially inwardly through the apertures 276 and port 278 into the outflow lumen 256 . Then the fluid circulates back down the shaft 206 and out the outlet port 242 .
[0060] The ribbon configuration of FIGS. 11-13B is advantageous for several reasons. First, the relatively flat ribbon does not take up a significant cross-sectional area of a vessel into which it is inserted. The twisted configuration further prevents blockage of flow through the vessel when the heat exchange region 202 is in place. The helical configuration of the tubes 224 a , 224 b , 228 a , 228 b also aids to center the heat exchange region 202 within a vessel by preventing the heat exchange region from lying flat against the wall of the vessel along any significant length of the vessel. This maximizes heat exchange between the lumens and the blood flowing next to the tubes. Because of these features, the twisted ribbon configuration is ideal for maximum heat exchange and blood flow in a relatively small vessel such as the carotid artery. As seen in FIG. 11A , an exemplary cross-section has a maximum diameter of about 5 mm, permitting treatment of relatively small vessels. The helical pattern of the balloon in the fluid flow may act to induce a gentle mixing action of the flowing blood to enhance heat exchange between the heat exchange surface and the blood without inducing hemolytic damage that would result from more violent churning action.
[0061] The deflated profile of the heat exchange region is small enough to make an advantageous insertion profile, as small as 7 French for some applications. Even with this low insertion profile, the heat exchange region is efficient enough to adequately exchange heat with blood flowing past the heat exchange region to alter the temperature of the blood sufficient for anti-platelet action and affect the temperature of tissue downstream of the heat exchange region. Because of its smaller profile, it is possible to affect the temperature of blood in smaller vessels and thereby provide treatment to more localized body areas.
[0062] This configuration has a further advantage when the heat exchange region is placed in a tubular conduit such as a blood vessel, especially where the diameter of the vessel is approximately that of the major axis (width) of the cross section of the heat exchange region. The configuration tends to cause the heat exchange region to center itself in the middle of the vessel. This creates two roughly semicircular flow channels within the vessel, with the blood flow channels divided by the relatively flat ribbon configuration of the heat exchange region. It has been found that the means for providing maximum surface for heat exchange while creating minimum restriction to flow is this configuration, a relatively flat heat exchange surface that retains two approximately equal semi-circular cross-sections. This can be seen in reference to FIG. 1 1 A if the functional diameter of the dashed circle 300 is essentially the same as the luminal diameter of a vessel into which the twisted ribbon is placed. Two roughly semi-circular flow paths 302 , 304 are defined by the relatively flat ribbon configuration of the heat exchange region, i.e. the width or major axis (from the outer edge of 228 a to the outer edge of 228 b ) is at least two times longer than the height, or minor axis (in this example, the diameter of the inner tube 222 ) of the overall configuration of the heat exchange region. It has been found that if the heat exchange region occupies no more than about 50% of the overall cross-sectional area of the circular conduit, a highly advantageous arrangement of heat exchange to flow is created. The semi-circular configuration of the cross-section of the flow channels is advantageous in that, relative to a round cross-sectioned heat exchange region (as would result from, for example, a sausage shaped heat exchange region) the flow channels created minimize the surface to fluid interface in a way that minimizes the creation of laminar flow and maximizes mixing. Maximum blood flow is important for two reasons. The first is that flow downstream to the tissue is important, especially if there is obstruction in the blood flow to the tissue. The second reason is that heat exchange is highly dependent on the rate of blood flow past the heat exchange region, with the maximum heat exchange occurring with maximum blood flow, so maximum blood flow is important to maximizing heat transfer.
B. Examples of Methods for Preventing Hypoxic Damage to Organs and Tissues in a Beating Heart Organ Donor
[0063] FIGS. 14, 15 and 16 are flow diagrams that illustrate examples of methods wherein endovascular hypothermia is used in beating heart organ donors, prior to the harvesting of organs and/or tissues for transplantation, in order to decrease the potential for hypoxic damage to the transplantable organs and tissues in the event of an hypoxic episode. The types of hypoxic episodes that may occur in beating heart organ donors include; cardiac arrest, ventricular arrhythmia, periods of hypotension, disruption of ventilation due to inadvertent disconnection of ventilator tubing, hypoxia secondary to pulmonary embolus, etc.
[0064] In the example of FIG. 14 , the endovascular hypothermia is initiated in an organ donor after the organ donor has been formally declared or pronounced brain dead. In the example of FIG. 15 , the endovascular hypothermia is initiated in an organ donor who is suspected to be brain dead but who has not yet been declared or pronounced brain dead, and such hypothermia is maintained while the potential donor is subjected to the tests and evaluations necessary to make a clinical determination of brain death.
[0065] Additionally, even after the declaration or pronouncement of brain death has been made, there may be substantial further delays before the organs or tissues can be harvested from the donor's body. This is especially true in cases where a time-critical organ such as the heart has been matched to a recipient who is located far away from the donor and it is necessary to wait until a surgical team has been flown in from the recipient's location to perform the organ harvest and to then transport the critical organ to the location where the transplant surgery is to be conducted. Accordingly, in such cases, the provision of endovascular hypothermia even after the brain death declaration or pronouncement has been made may be beneficial in avoiding hypoxic damage to donor's the organs or tissues.
[0066] Moreover, a substantial period of time may be required before the brain death declaration or pronouncement may be made, as it is often necessary for heath care workers to locate and obtain written consent from the donor's family and to perform extensive tests and evaluations to confirm that the donor is in fact brain dead. The exact criteria by which brain death may be declared or pronounced may differ from state to state, country to country, or even institution to institution. In many jurisdictions, a declaration or pronouncement of brain death can only be made after numerous tests and evaluations have been completed (collectively referred to herein as the “brain death work-up”). These required tests and evaluations may include a clinical assessment to establish the lack of neurological responses and reflexes, hypoxia test(s) to confirm that the spontaneous respiratory drive is absent, and multiple electroencephalograms (EEGs) taken at time points separated by a prescribed waiting period (e.g., 24 hours). In at least some institutions, the declaration or pronouncement of brain death must be made by no fewer than two (2) physicians. Thus, the time period required to obtain the requisite consent and complete the entire brain death work up may span 48 hours or even longer. The provision of endovascular hypothermia during the brain death work up period in accordance with the method of FIG. 15 may be extremely beneficial in such cases to, for example, protect potential donor organs and tissue.
[0067] Specifically referring to the method of FIG. 14 , in a case where the potential organ donor has already been declared or pronounced brain dead in accordance with the applicable criteria, an endovascular heat exchange apparatus is inserted into the patient's vasculature and used to cool blood flowing though the vasculature such that all or a portion of the donor's body is cooled to a temperature below 37° C. (i.e., below normothermia). In many cases, the desired temperature will be in the range of about 34° C. through about 28° C. and preferably about 30° C. Generally the lower the temperature, the more protective it is of the donor organs or tissue, but below a temperature of about 25° C. the heart function may be adversely affected. In order to accomplish endovascular hypothermia, the heart must generally be pumping effectively, so a body temperature of about 30° C. will effectively protect the organ or tissue for preservation and at the same time, will not adversely affect cardiac function. The endovascular heat exchange device may comprise a catheter of the type shown in FIGS. 1-13C and described hereabove. The endovascular heat exchange device may further be used in conjunction with a controller and/or related equipment useable to monitor and control the temperature of the catheter and/or the patient. Examples of heat exchange catheters and related devices & controllers that might be useable in this step of the method are described in PCT International Application No. PCT/US 99/18939 and U.S. Pat. No. 5,486,208 (Ginsburg), U.S. Pat. No. 6,149,676 (Ginsburg), U.S. Pat. No. 6,149,673 (Ginsburg), U.S. Pat. No. 5,957,963 (Dobak III), U.S. Pat. No. 6,096,608 (Dobak III, et al.), U.S. Pat. No. 6,110,168 (Ginsburg), U.S. Pat. No. 6,126,684 (Gobin, et al.) and U.S. Pat. No. 6,264,679 (Keller, et al.), the entire disclosures of which expressly incorporated herein by reference. In particular, one presently preferred intravascular heat exchange catheter system for use in the present invention is described in U.S. application Ser. No. 09/777,612 the entirety of which is expressly incorporated herein by reference and portions of which are set forth in the paragraphs herebelow. In cases where it is desired to cool the donor's entire body such that the donor's core body temperature is in the desired range, the endovascular temperature exchange device may be positioned in the inferior vena cava near the right atrium of the donor's heart such that venous blood that is cooled by the heat exchange apparatus will subsequently be pumped throughout the donor's body by the donor's the heart, cooling the entire body in the process. In other cases where it is desired to selectively cool only a specific body portion (e.g., a limb, organ or group of organs) to a temperature within the desired target range, the heat exchange apparatus may be positioned within a blood vessel through which blood flows into the specific body portion (e.g., a limb, organ or group of organs) and that heat exchange apparatus may then be used to cool blood flowing into the specific organ or specific portion of the body, thereby also cooling the parenchyma of that specific organ or specific portion of the body to the desired target temperature. A temperature monitoring probe or thermocouple may be placed within the specific body portion (e.g., a limb, organ or group of organs) to facilitate the controlled cooling of that specific body portion (e.g., a limb, organ or group of organs) to the desired target temperature without significant overshoot and to thereafter maintain the specific body portion (e.g., a limb, organ or group of organs) at the target temperature for the desired period of time. Some incidental cooling of other portions of the body may or may not occur concurrently with the selective cooling of the specific body portion (e.g., a limb, organ or group of organs) to the desired target temperature and subsequent maintenance of that target temperature.
[0068] In cases where it is desired to minimize or prevent cooling of portions of the body other than the selected body portion (e.g., a limb, organ or group of organs), a second heat exchange apparatus may be placed in one or more other blood vessels from which blood flows out of or away from the selected body portion (e.g., a limb, organ or group of organs) and the second heat exchange apparatus may be used to rewarm blood that flows out of or away from the selected body portion (e.g., a limb, organ or group of organs or blood flowing from the heart), thereby preventing the remainder of the body or at least the heart from becoming as hypothermic as the tissue or organ desired for transplantation. In this manner it is possible to cool the organ or tissue for transplantation well below the 25° C. temperature at which the heart begins to experience fibrillation or other adverse events, and yet keep the heart above that temperature to maintain effective cardiac function. For example, a first, cooling catheter might be placed in the renal artery to cool a kidney and a second warming catheter be placed in the renal vein or the IVC to warm blood returning from the kidneys to the heart. In fact, several additional catheters might be used, for example a cooling catheter might be placed in the artery for each kidney, and a warming catheter in each of the veins coming from the kidneys, and a warming catheter in IVC all to keep the heart warm enough to function effectively as a pump, and yet cool the target organ or tissue. This method of persevering organs or tissue is illustrated in the flow chart of FIG. 16 .
[0069] Although several illustrative examples of means for practicing the invention are described above, these examples are by no means exhaustive of all possible means for practicing the invention. The scope of the invention should therefore be determined with reference to the appended claims, along with the full range of equivalents to which those clams are entitled. | Methods for (a) preventing hypoxic damage to a potentially transplantable organ or tissue prior to explanation of that organ or tissue from the body of a mammalian transplant donor and (b) preventing rejection of a transplanted organ or tissue in a human or veterinary transplant recipient. The methods comprise placing a heat exchange apparatus in the vasculature of the donor or recipient and using that heat exchange apparatus to cool at least a portion of the body of the donor or recipient to a temperature below normothermia (e.g. below normothermia and sometimes between about 30° C. and about 36° C.). | 0 |
BACKGROUND
[0001] The present invention relates to an image forming apparatus and a registration inspection method of the image forming apparatus, and more particularly to a technology, in an image forming apparatus for performing plus-one-color printing, to perform inspection of registration displacement and to correct the registration displacement if the registration displacement is detected.
SUMMARY
[0002] An aspect of the present invention provides an image forming apparatus for forming a print image, which is composed of a first color image and a second color image, on a print medium, including: a test pattern printing portion that prints a test pattern including the first color and the second color; an image pickup portion that pictures an image of the test pattern printed by the test pattern printing portion; and a registration failure discrimination portion that discriminates a registration failure between the first color and the second color according to the pictured image of the test pattern pictured by the image pickup portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Embodiments of the present invention will be described in detail based on the following figures, wherein:
[0004] FIG. 1 is a block diagram showing control configuration related to registration inspection and registration correction of an image forming apparatus of the invention;
[0005] FIG. 2 is an image diagram showing an example of a test pattern;
[0006] FIG. 3 is a diagram showing an example of test pattern definition information;
[0007] FIG. 4A and FIG. 4B are diagrams showing examples of scanned images of test patterns in a case where registration displacement has occurred in a main scanning direction of a plus-one-color image forming section;
[0008] FIG. 5A and FIG. 5B are diagrams showing examples of scanned images of test patterns in a case where registration displacement has occurred in a sub-scanning direction of a plus-one-color image forming section;
[0009] FIG. 6 is a diagram showing an example of a scanned image of a test pattern in a case where registration displacement has occurred in both a main scanning direction and a sub-scanning direction of a plus-one-color image forming section;
[0010] FIG. 7 is a flow chart showing operations for registration displacement detection and correction processing; and
[0011] FIG. 8 is a diagram showing a modified example of test pattern images.
DETAILED DESCRIPTION
[0012] Embodiments of the image forming apparatus of the invention will be described with reference to the accompanying drawings.
(Control Configuration of Printer for Printing Plus-One-Color Image)
[0013] A control configuration of the image forming apparatus of the invention is shown in FIG. 1 .
[0014] A printer 1 is comprised of a main control section 2 for controlling the printer 1 as a whole, a storage section 3 , a CCD camera 4 , and an image forming section 6 , and the main control section 2 has as functional structures an image processing section 21 , a color-by-color pixel calculation portion 22 , a displacement amount measuring section 23 , a plus one color output timing control section 24 , and a test pattern print control portion 25 .
[0015] The image processing section 21 performs color space conversion processing of a scanned image, which is based on the read signal of a test pattern 51 read at a prescribed resolution by the CCD camera 4 , by a R. G. B-YMCK conversion portion 213 to develop to test pattern read data 33 .
[0016] A plus-one-color pixel extraction portion 211 extracts pixel data, which agrees with color information of plus one color recorded in the test pattern definition information, from the test pattern read data 33 .
[0017] A black color pixel extraction portion 212 extracts black pixels from the test pattern read data 33 . The color-by-color pixel calculation portion 22 calculates a SUM value indicating a total of black pixels and a SUM value indicating a total of plus-one-color pixels on the basis of the pixel data extracted by the black color pixel extraction portion 212 and the plus-one-color pixel extraction portion 211 .
[0018] The displacement amount measuring section 23 has a main scanning direction displacement detecting portion 231 which detects in units of pixels of read data a registration displacement amount in the main scanning direction of the plus-one-color registration with black registration determined as reference in the test pattern read data 33 , and a sub-scanning direction displacement detecting portion 232 which detects a width of the registration displacement in the sub-scanning direction.
[0019] A main scanning direction displacement correction portion 241 calculates, for example, a registration correction amount based on the number of clocks from the displacement width of the plus-one-color registration indicated by the number of pixels of the test pattern read data 33 and detected by the main scanning direction displacement detecting portion 231 , and controls the registration correction based on the calculated correction amount for the plus-one-color output timing control section 24 .
[0020] A sub-scanning direction displacement correction portion 242 calculates the registration correction amount based on the number of clocks from the displacement width of the plus one color registration, which is detected by the sub-scanning direction displacement detection portion 232 , indicated by the number of pixels of the test pattern read data 33 , and performs registration correction based on the calculated correction amount for the plus-one-color output timing control section 24 .
[0021] The plus one color output timing control section 24 controls in prescribed units of clocks the time of starting to record the image on a record medium in the main scanning direction and the sub-scanning direction for a black image forming portion 62 and a plus-one-color image forming portion 61 .
[0022] The test pattern print control portion 25 rasterizes the black image and the plus-one-color image based in the test pattern definition information 32 recorded in the storage section 3 , and performs print control for transferring the image of the test pattern 51 onto a print sheet 5 by the image forming section 6 .
[0023] The image forming section 6 performs print processing by transferring to the print sheet 5 a rasterize image having a test image and a print image transferred to a developing device for a black color image and a plus-one-color image by control performed by the main control section 2 and the test pattern print control portion 25 .
[0024] The plus-one-color image forming portion 61 rasterizes a plus-one-color image to be formed with color toner among images to be printed to form on the print sheet 5 .
[0025] The black color image forming portion 62 rasterizes the image formable with the black color toner in the print image to form on the print sheet 5 .
[0026] The CCD camera 4 performs the image read processing of the test pattern 51 printed on the print sheet 5 and outputs the read signal to the main control section 2 .
[0027] As information related to the black color image, a buffer region for development of raster data of the plus one color, the registration inspection and the correction processing, the storage section 3 stores the test pattern read data 33 , the definition information (e.g., definition information about the color used as the plus one color, a pattern size, and information related to the arrangement as shown in FIG. 3 ) required for rasterizing the image of the test pattern 51 , namely the test pattern definition information 32 , and a registration displacement detecting standard value list 31 for recording and managing information including the control parameter required for registration displacement inspection processing, the individual criteria values, and the unit conversion values when the number of pixels and the registration displacement correction amount required for correction of the registration displacement are calculated.
[0028] In FIG. 3 , the color information on the plus one color is color identification information for specifying a print region of the plus one color based on the read image data about the test pattern 51 read by the CCD camera 4 , and totaling distinctly the number of pixels in the specified region for the black image and the plus one color.
[0029] The area size is information recording the sizes of the individual areas in the main scanning direction and the sub-scanning direction determined by dividing the test pattern 51 into quarters.
[0030] The area-by-area color information is information used to measure a displacement amount and a displacement direction (either positive or negative in the main scanning direction and the sub-scanning direction) from the read data of the test pattern 51 .
(Description of Test Pattern 51 )
[0031] The test pattern 51 is an image of a lattice-shaped pattern including four squares having the same area obtained by dividing a square having its sides in the main scanning direction and the sub-scanning direction into quarters and alternately filling the divided squares in black and plus one color.
[0032] It is an image configured so that if there is no registration displacement in the main scanning direction and the sub-scanning direction, the SUM value of the number of pixels in the print regions of the individual colors becomes 50% as shown in FIG. 2 , and the lines of the individual leading edges in the main scanning direction and the sub-scanning direction are disposed on a straight line orthogonal to the individual scanning directions.
(Registration Displacement in Main Scanning Direction)
[0033] As an example that registration displacement has occurred in the main scanning direction, an area 2 and an area 4 are overlapped partially if the displacement occurs in the positive direction of the main scanning direction, and an area 1 and an area 3 are overlapped partially if the displacement occurs in the negative direction of the main scanning direction, when the leading edge portion of a black image is determined as reference as shown in FIG. 4A and FIG. 4B .
[0034] Thus, the plus-one-color image becomes a scanned image which is filled to form a black image for the overlapped portion due to the registration displacement, and the total value of the pixels of the plus one color in the scanned image data becomes low in comparison with that without the registration displacement.
[0035] Thus, the detection of a change in the total value is used to judge the presence or not of the registration displacement.
[0036] In a case where the occurrence of the registration displacement has been detected, the method for detection of the displacement width (displacement amount) based on the read data of the test pattern 51 calculates the registration displacement in the main scanning direction according to the value obtained by counting from the read data of the number of pixels present between the leading edge portion of the plus-one-color image and the leading edge portion of the black image which is used as reference.
(Registration Displacement in Sub-Scanning Direction)
[0037] As an example that the registration displacement has occurred in the sub-scanning direction, the area 1 and the area 2 are partially overlapped if the plus-one-color registration is displaced in the positive direction with respect to the black image, and the area 3 and the area 4 are partially overlapped if the registration displacement occurs in the negative direction of the main scanning direction as shown in FIG. 5A and FIG. 5B .
(Registration Displacement in Main Scanning Direction and Sub-Scanning Direction)
[0038] If the registration displacement occurs in both the main scanning direction and the sub-scanning direction, the example shown in FIG. 6 is, for example, a scanned image where the registration displacement has occurred in the positive direction of the main scanning direction and in the negative direction of the sub-scanning direction.
[0039] The size of the area which becomes the constituent unit of the test pattern 51 shown in FIG. 4 , FIG. 5 and FIG. 6 is sufficiently longer than the maximum width of the registration displacement and defined by the length sufficiently satisfying the maximum displacement width in all the positive and negative directions of the main scanning direction and the sub-scanning direction.
(Inspection of Registration, and Correction Processing of the Registration in Case of Detection of Registration Displacement)
[0040] Then, the registration inspection processing in the printer shown in FIG. 1 and the operation of correction processing in case of detection of registration displacement in the registration inspection processing will be described with reference to the flow chart of FIG. 7 .
[0041] In FIG. 7 , the printer 1 produces a raster image of the test pattern 51 in response to the test image print control (S 101 ).
[0042] When the test pattern 51 has been printed, read processing of the test pattern 51 by a CCD is started, the read data is converted for color information by a R. G. B-YMCK conversion portion 213 , and the pixels of the individual images formed by the plus-one-color image forming portion 61 and the black image forming portion 62 are extracted by the plus-one-color pixel extraction portion 211 and the black color pixel extraction portion 212 of the image processing section 21 and temporarily stored in a development region of the test pattern read data 33 of the storage section 3 (S 102 ).
[0043] SUM values of the number of pixels of the individual colors are totaled by the color-by-color pixel totaling portion from the test pattern read data 33 which is temporarily stored in the storage section 3 by the test pattern read portion (S 103 ).
[0044] The presence or not of registration displacement is judged according to the totaled SUM value (S 104 ), and if there is no registration displacement (NO in S 104 ), the inspection processing is terminated.
[0045] Meanwhile, if there is registration displacement (YES in S 104 ), it is notified to, for example, an operation panel disposed on the printer 1 that the registration displacement has been detected as an inspection result, and a screen is displayed to let the operator select whether or not the registration correction processing is continued (S 105 ).
[0046] Where it is operated to instruct the registration correction processing (S 106 ), a displacement amount in the main scanning direction is measured by the main scanning direction displacement amount measuring portion (S 107 ).
[0047] Where registration displacement in the main scanning direction is detected (YES in S 108 ), the displacement amount in the main scanning direction is measured by the main scanning direction displacement amount measuring portion (S 109 ), and a displacement correction amount in the main scanning direction is calculated based on the displacement amount measured by the main scanning direction displacement correction portion 241 , and registration correction control is performed to the plus-one-color image forming portion 61 (S 111 ).
[0048] Meanwhile, if registration displacement in the main scanning direction is not detected (NO in S 108 ), or if the displacement amount correction processing in the main scanning direction is completed, the displacement amount in the sub-scanning direction is measured by the sub-scanning direction displacement detecting portion 232 (S 110 ).
[0049] If the registration displacement in the sub-scanning direction is detected (YES in S 112 ), the displacement correction amount in the sub-scanning direction is calculated by the sub-scanning direction displacement correction portion (S 113 ), and the registration correction control is performed to the plus-one-color image forming portion 61 (S 114 ).
[0050] After the first correction processing is completed (NO in S 112 , and the processing in S 114 is completed), re-inspection for the success or not of the correction processing may be performed back in step S 101 .
[0051] If the registration displacement is detected by the processing in step S 104 (YES in S 104 ), the registration correction processing in step S 107 and later may be performed without condition.
(Modified Example of Test Pattern 51 )
[0052] The test pattern 51 in the embodiment described above is an example of a square having its sides in the main scanning direction and the sub-scanning direction and divided into quarters. But, it is not limited to the test pattern 51 shown in the above embodiment. In another case having a leading edge portion in both the main scanning direction and the sub-scanning direction and not having registration displacement, if a ratio of SUM values of pixels of the individual colors becomes 1:1, and an overlapped region is produced and registration displacement occurs in either the main scanning direction or the sub-scanning direction or in both the directions, it is appropriate when the SUM value of the read number of pixels, and more particularly the SUM value of pixels of the highlight color changes smaller than the SUM value in a case where there is no registration displacement, and the displacement width of the registration displacement can be detected by a difference in position of the leading edge portion in the scanning direction that the registration displacement has occurred.
[0053] For example, it is naturally possible to have the test pattern 51 such as a rectangular divided into quarters as indicated by 81 in FIG. 8 or into 16 equal parts as indicated by 82 in FIG. 8 .
(Structure of Modified Example Other Than Embodiment 1)
[0054] An example of the image forming apparatus for printing the plus one color was described above. But, in a case of having a plural-color image forming unit for forming two or more images in an overlaid state on a recording medium, the inspection of registration and the correction processing of the registration with respect to the image forming unit for each color shown in the above embodiment may be performed separately.
[0055] It was determined in the above embodiment that the registration displacement amount detection criteria were used for the black image forming unit, but if there is a plus-one-color or plural-color image forming unit, it may be configured to calculate the displacement amount and the correction amount with a prescribed color determined as reference.
[0056] In a case where there is a plural color image forming units, for example, the test pattern 51 shown in FIG. 2 of the above embodiment may be configured to print enumerated test patterns 51 of individual image forming units and to read collectively the enumerated plural test patterns 51 by a single reading processing so as to perform the registration inspection processing of the individual test patterns 51 and the registration displacement correction processing.
[0057] The above embodiment is an example of a laser printer using the color toner for forming the plus-one-color image. In addition, it can also be applied to an ink jet printer having a unit of reading the test pattern 51 printed in color inks by a CCD and a unit of performing the registration correction.
[0058] The image forming apparatus and the registration inspection method of the image forming apparatus of the invention can be used for an image forming apparatus which detects registration displacement by reading the test pattern and corrects it.
[0059] The foregoing description of the embodiments of the present invention has been provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling other skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents. | An image forming apparatus for forming a print image, which is composed of a first color image and a second color image, on a print medium, including: a test pattern printing portion that prints a test pattern including the first color and the second color; an image pickup portion that pictures an image of the test pattern printed by the test pattern printing portion; and a registration failure discrimination portion that discriminates a registration failure between the first color and the second color according to the pictured image of the test pattern pictured by the image pickup portion. | 7 |
BACKGROUND
[0001] The present invention relates generally to sealing means for downhole tools and, in an embodiment described herein, more particularly provides a seal structure for a downhole tool.
[0002] It is well known that significant problems are typically encountered when an attempt is made to sealingly engage a seal bore in a downhole tool in an abrasive environment. Such an abrasive environment may exist, for example, in a fracturing or gravel packing job. These problems are multiplied when such sealing engagement must be performed multiple times downhole.
[0003] [0003]FIGS. 1A & B illustrate a representative example of such a situation. A prior art seal structure 10 is disposed externally on a mandrel 12 of a downhole tool. The seal structure 10 includes a seal support ring 14 and two seals 16 disposed in open-sided grooves 18 formed externally on the ring. The seals 16 are bonded to the ring 14 in the grooves 18 .
[0004] It is desired to have the seal structure lo enter a seal bore 20 and effect a pressure bearing seal between the mandrel 12 and the seal bore. Unfortunately, sand 22 , or another abrasive material, such as synthetic proppant, etc., has accumulated between the mandrel 12 and the seal bore 20 . When the seal structure 10 enters the seal bore 20 , the sand 22 is compressed between the seals 16 and the seal bore, as may be seen in FIG. 1B.
[0005] Compression of the sand 22 between the seals 16 and the seal bore 20 may not cause immediate failure of the seals. However, with repeated cycles of the seal structure 10 entering and withdrawing from the seal bore 20 , the seals will eventually deteriorate.
[0006] This problem appears to be exacerbated where a relatively large degree of compression is experienced in the seals 16 when they enter the seal bore 20 . Note that the seals 16 fill the grooves 18 and so, when the seals enter the smaller diameter seal bore 20 , they are compressed inwardly against walls of the grooves, as well as being significantly compressed against the seal bore and the sand 22 between the seals and the seal bore. An improved seal structure should provide space for the seals to deflect inwardly when a seal bore is entered, so that compression of the seals against the seal bore is reduced.
[0007] Another problem experienced in these situations is high “stabbing” force. That is, the force which must be exerted against the seal structure 10 to urge it into the seal bore 20 . In general, high stabbing forces are to be avoided, since they are known to cause seal damage, they may cause operational problems, etc. An improved seal structure should reduce the stabbing force needed for the seal structure to enter a seal bore.
SUMMARY
[0008] In carrying out the principles of the present invention, in accordance with an embodiment thereof, a seal structure is provided which solves the above problems in the art.
[0009] In one aspect of the invention, a seal structure for a downhole tool is provided which includes a seal support ring and a seal. The seal support ring has at least one annular groove formed thereon. The seal is disposed at least partially in the groove, the seal is bonded to the ring, and the seal has an annular recess formed thereon.
[0010] The recess may have a variety of cross-sectional shapes. In addition, the recess may be positioned in various portions of the seal body. Furthermore, there may be multiple seals disposed in multiple respective grooves on the ring.
[0011] In another aspect of the invention, another seal structure for a downhole tool is provided. The seal structure includes a seal support ring having at least one annular groove formed thereon and a longitudinal axis. A seal is disposed at least partially in the groove, and the seal is bonded to the ring. An annular recess is positioned longitudinally between opposing side walls of the groove.
[0012] Again, the recess may have a variety of cross-sectional shapes, the recess may be positioned in various portions of the seal body, and there may be multiple seals disposed in multiple respective grooves on the ring. In addition, the recess may be formed in a body of the seal.
[0013] In yet another aspect of the invention, another seal structure for a downhole tool is provided which includes a seal support ring, at least four seals and at least two recesses. The seal support ring has first, second, third and fourth spaced apart annular grooves formed on a surface thereof. First, second, third and fourth seals are bonded in respective ones of the first, second, third and fourth grooves, with the second and third seals being disposed between the first and fourth seals. A first annular recess is positioned between opposing side walls of the second groove, and a second recess is positioned between opposing side walls of the third groove.
[0014] These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIGS. 1A & B are quarter-sectional views of a prior art seal structure for a downhole tool;
[0016] [0016]FIG. 2 is an enlarged scale quarter-sectional view of a first seal structure embodying principles of the present invention;
[0017] [0017]FIG. 3 is an enlarged scale quarter-sectional view of a second seal structure embodying principles of the present invention;
[0018] [0018]FIG. 4 is an enlarged scale quarter-sectional view of a third seal structure embodying principles of the present invention; and
[0019] [0019]FIG. 5 is an enlarged scale quarter-sectional view of a fourth seal structure embodying principles of the present invention.
DETAILED DESCRIPTION
[0020] Representatively illustrated in FIG. 2 is a seal structure 30 which embodies principles of the present invention. In the following description of the seal structure 30 and other apparatus and methods described herein, directional terms, such as “above”, “below”, “upper”, “lower”, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
[0021] The seal structure 30 includes a seal support ring 32 and two seals 34 disposed in annular grooves 36 formed externally on the ring 32 . Of course, the seals 34 and grooves 36 could be internally formed on the ring 32 , if desired for a particular application, such as for sealing engagement with a cylindrical member within the ring. The seals 34 are bonded to the ring 32 in the grooves 36 .
[0022] Note that each of the seals 34 is positioned between opposing side walls 38 of the respective groove 36 . Specifically, the side walls 38 are on longitudinally opposite sides of the each of the seals 34 , relative to a longitudinal axis of the ring 32 . Thus, the seals 34 are retained between the side walls 38 of the grooves 36 .
[0023] A recess 40 is positioned between the side walls 38 of each of the grooves 36 . The depicted recesses 40 are generally rectangular in cross-section and are formed in the bodies of the seals 34 approximately midway between the side walls 38 of each of the grooves 36 . However, it is to be clearly understood that the recesses 40 may be otherwise shaped, may be otherwise positioned and may be formed in other components of the seal structure 30 , without departing from the principles of the present invention.
[0024] It may now be appreciated that the recesses 40 provide space for the seals 34 to displace inwardly toward the grooves 36 , without excessive compression of the seals. This reduced compression of the seals 34 reduces deterioration of the seals due to compressed abrasive material, and reduces the stabbing force needed for sealing engagement.
[0025] Referring additionally now to FIG. 3, another seal structure 50 embodying principles of the present invention is representatively illustrated. The seal structure 50 is similar in many respects to the seal structure 30 described above, and so elements of the seal structure 50 which are similar to those described above are indicated in FIG. 3 using the same reference numbers.
[0026] The seal structure 50 includes seals 52 disposed in the grooves 36 between respective ones of the side walls 38 . The seals 52 are bonded to the ring 32 in the grooves 36 . However, recesses 54 are formed in the seals 52 which differ substantially from the recesses 40 formed in the seals 34 .
[0027] The recesses 54 are generally semi-circular in cross-section. Thus, the recesses 54 each have a concave radiused internal surface. In addition, the recesses 54 are each adjacent one of the side walls 38 of its respective groove 36 , rather than being centrally positioned between the side walls.
[0028] Referring additionally now to FIG. 4, another seal structure 60 embodying principles of the present invention is representatively illustrated. The seal structure 60 is similar in many respects to the seal structure 50 described above, and so elements of the seal structure 6 o which are similar to those described above are indicated in FIG. 4 using the same reference numbers.
[0029] In the seal structure 60 , the radiused recesses 54 are positioned in the bodies of the seals 52 approximately midway between side walls 38 of the respective grooves 36 . Otherwise, the seal structure 60 is the same as the seal structure 50 . However, due to the different positioning of the recesses 54 , the seals 52 of the seal structure 6 o may react differently to a pressure differential applied thereacross.
[0030] Referring additionally now to FIG. 5, another seal structure 70 embodying principles of the present invention is representatively illustrated. The seal structure 70 includes a seal support ring 72 and four seals 74 , 76 , 78 , 80 disposed and bonded in four respective annular grooves 82 , 84 , 86 , 88 formed externally on the ring. Of course, the seals 74 , 76 , 78 , 80 and grooves 82 , 84 , 86 , 88 could be internally disposed on the ring 72 , in keeping with the principles of the present invention.
[0031] The outer seals 74 , 80 may be configured as “wiper” rings. That is, the seals 74 , 80 may be designed to wipe a seal surface free of abrasive material, debris, etc., before the inner seals 76 , 78 contact the seal surface. Alternatively, or in addition, the outer seals 74 , 80 may serve as initial seals for resisting a pressure differential, so that each of the inner seals 76 , 78 resists the pressure differential after the respective one of the outer seals 74 , 80 has failed.
[0032] Note that only the inner seals 76 , 78 are positioned between opposing side walls 90 , 92 of the respective inner grooves 84 , 86 . The outer grooves 82 , 88 do not have opposing side walls.
[0033] An annular recess 94 is formed in a body of the seal 76 , so that the recess 94 is positioned between the seal body and the upper side wall go of the groove 84 . The recess 94 is generally rectangular in cross-section.
[0034] A similar annular recess 96 is formed in a body of the seal 78 . However, the recess 96 is positioned between the seal 78 body and the lower side wall 92 of the groove 86 . The difference in positionings of the grooves 94 , 96 is due to the different directions in which a pressure differential will act on the seals 76 , 78 in a preferred use of the seal structure 70 . However, it is to be clearly understood that the recesses 94 , 96 may be positioned other than as depicted in FIG. 5, without departing from the principles of the present invention.
[0035] Note that, in the seal structures 30 , 50 , 60 , 70 described above, the seals 34 , 52 , 74 , 76 , 78 , 80 may be formed of materials which are able to withstand high temperatures and otherwise hostile environments. One such hostile environment is use with heavy metal completion fluids, such as zinc bromide, and temperatures above 275° F.
[0036] For example, the outer seals 74 , 80 of the seal structure 70 may be of a nitrile material and the inner seals 76 , 78 may be formed of a fluorocarbon material (such as Fluorel™, Viton™, etc.). The nitrile material provides strength, so that the outer seals 74 , 80 may act as wipers, as well as seals, and the fluorocarbon material provides enhanced chemical and temperature resistance.
[0037] The seal materials may be elastomers, they may be non-elastomeric, or a combination of these. Note that any seal material may be used, without departing from the principles of the present invention.
[0038] Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are contemplated by the principles of the present invention. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims. | A seal structure is provided for a downhole tool. In a described embodiment, a seal structure includes a seal support ring having at least one annular groove formed thereon and a longitudinal axis. At least one seal is included in the seal structure. The seal is disposed at least partially in the groove, and the seal is bonded to the ring. An annular recess is positioned longitudinally between opposing side walls of the groove. The recess may be formed in a body of the seal. | 4 |
PRIORITY CLAIM
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/045,204 filed Apr. 15, 2008, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Traditional caller name identification on mobile telephone networks is performed in a network architecture using a pair of service points known as a network control point (NCP) and a network termination point (NTP). Essentially the NTP manages signal traffic for terminating and connecting calls between carrier networks and to their subscribers. The NCP manages subscriber accounts and informatics for callers, including network-based caller information services. This architecture permits various carrier networks to interoperate and to evaluate and apply appropriate rules using the caller and receiver telephone numbers (such as billing and roaming rates, etc.). Caller identification services may be applied at this juncture, as well, provided that the caller identification information associated with the caller's telephone numbers can be obtained quickly so as not to delay the call flow (such as initiation, connection, and termination of the call) between the carrier networks and, ultimately, connection to the receiver's handset. One standard for such caller identification services is Caller Name (CNAM). An example of a CNAM service is offered by Verisign® (CITE VERISIGN DOCUMENTS). Other CNAM providers include products and services from Targus® and Syniverse®.
[0003] CNAM provides caller name and city/state locations by querying a high speed, high volume database (DB), referred to as a line information database (LIDB). CNAM services provide information about the calling party for a fee, typically billed to the subscriber's account. The fee varies by contract but is typically $0.01 per call. CNAM traffic on a telephone carrier network is also high volume. A hypothetical carrier with twenty million subscribers making seven calls on average per day results in 140 million possible CNAM transactions on a dedicated network. As there are many carriers in telephony, and many subscribers that maintain more than one phone line, the CNAM market has grown from servicing only land-line Public Switched Telephone Networks (PSTN) to include other communication networks, such as mobile and voice over Internet Protocol (VoIP) telephony. Thus, there is the potential for well over a billion CNAM transactions per day. In operation, a CNAM service takes an incoming call from the NTP, sends call information (including the caller's number and the dialed number) into the NCP, determines that the query can be billed to the subscriber, determines which carrier the inbound call is coming from, makes the query to a service which can query name and phone number databases (such as the Line Information Database (LIDB) of the caller's carrier), resolves a name or a city/state pair for a phone number transiting the network, and send that information along with the caller's Mobile Dialable Number (MDN) to the receiving handset for display when the call is received (typically during the incoming call ring).
[0004] Typically, a CNAM query is completed in less than 2 seconds. This permits the caller to experience normal “ring tones” during the call, with no perceived delay to the calling parties, and for the calling handset to have its call connected to the receiver in a reasonable amount of time. Once terminated on the receiving carrier's network termination point (NTP), the CNAM query result is sent as a text string along with the caller's CID to the receiver's phone and placed on the display of the receiving handset. While it is possible to make CNAM queries from the receiving handset, any significant delay placed upon the recipient of the incoming call by making a CNAM query from the mobile handset may create an unacceptable calling experience to one or both of the calling parties, such as a delay in the call termination for the calling party or a delay in the display of the caller information to the receiving party. In the case of a CNAM query from the receiving handset, the perceived delay occurs because the query is commenced after the network termination point (NTP) has connected the call to the receiving handset. With such a delay, the user may thus answer the call, or may choose to ignore the call, before the caller information is transmitted to the handset.
SUMMARY OF THE INVENTION
[0005] The present invention provides a phone network in a wireless environment that does not perform CNAM queries when a number is already stored in the receiving handsets' caller directory. CNAM query fees are charged only to obtain caller information on a new caller. The network does not make CNAM queries when the caller information is already available, whether in the contact information stored on the receiver's handset or through some other reliable source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings:
[0007] FIG. 1 is a schematic block diagram of an example system formed in accordance with an embodiment of the present invention;
[0008] FIG. 2 illustrates a flow diagram of an example method performed by the system shown in FIG. 1 ; and
[0009] FIG. 3 illustrates an example of the system in operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] The present invention adds some architectural (software and/or hardware) components to a carrier network in the form of a database and query logic to determine whether a CNAM query is needed in order to provide caller identification information.
[0011] As shown in FIG. 1 , an example wireless environment 20 includes a caller system 30 , a receiver system (network control point (NCP)) 32 , a data network 38 , a network server 36 , a database 40 , a Line Information Database (LIDB) 34 and a mobile handset (receiving device) 42 . The caller system 30 sends a call destined for the mobile handset 42 to the NCP 32 . The NCP 32 sends the caller number (CID) included in the call to the network server 36 over the data network 38 . The network server 36 queries the database 40 to determine if the database 40 indicates that a (CNAM) query is not needed because the mobile handset 42 already includes MDN information pertaining to the CID stored locally in the mobile handset 42 . If the MDN is not stored in the mobile handset 42 , then a traditional CNAM query is performed using the CID.
[0012] In one embodiment, the system above performs a traditional CNAM query based on an incoming number over a carrier network, which allows the carrier to supply the CID and the CNAM associated with the CID in a string for display on the mobile handset 42 when the call is received. This number and name can then be stored in the mobile handset caller directory for later reference. Alternatively, the owner of the receiving handset can enter or import contact information including names and telephone numbers into the handset.
[0013] When the network termination point NTP indicates that a call is in progress, dialing information is sent to the NCP 32 . The NCP 32 checks each incoming call CID against the database 40 associated with that NCP 32 or the network server 36 accessible with the NCP 32 . A table stored in the database 40 contains a copy of the receiving handset's caller directory (i.e., Mobile Directory Number (MDN)). At a minimum the table stores telephone numbers that were previously received by the mobile handset 42 . The caller directory list may be in a database table that is co-located with the NCP 32 , distributed on the carrier network, or on a network-addressable memory or storage device. The NCP 32 queries the caller directory table to determine whether the calling MDN is already stored in the caller directory (i.e., contact list) of the mobile handset 42 . Using the query result (Yes or No), the NCP 32 performs CNAM queries for numbers (incoming call, i.e. calling MDN) which are not already contained in the caller directory table, and does not perform a CNAM query when the calling MDN is associated with an MDN stored in the caller directory table.
[0014] In one embodiment, the mobile handset's caller directory table is updated via a network message (e.g. short message service (SMS) message or via the carrier's data network) sent from the mobile handset 42 each time an MDN is modified (added or subtracted) in the caller directory stored on the mobile handset 42 . A small client software component operating on the mobile handset 42 sends the phone numbers for those contacts which are stored in the mobile handset caller directory (also called the mobile user's ‘contacts’ or ‘address book’) to the network server 36 . The network server 36 stores the received information in the caller directory table in the database 40 when received. A CNAM query may be made and the result stored by the client software on the receiving handset 42 based on detected modifications to caller directory entries on the handset. Also, the information in the caller directory on the receiving handset 42 may also be refreshed periodically, by making CNAM queries either on a set period of time (e.g., every six months), or based on a certain count of incoming calls from that number (e.g., request a CNAM query to check the accuracy of the caller directory information (i.e., synchronizing the directory table with the caller directory on the mobile handset 42 ) every 15 th time the caller's MDN is detected on an incoming call). The above techniques maintain the accuracy of the caller information on the mobile handset 42 should names and/or phone numbers change, while avoiding CNAM queries for every call and intelligently using CNAM to maintain the accuracy of caller information in the caller directory.
[0015] In an alternate embodiment, privacy or network access restrictions may prevent copying the mobile handset caller directory to the caller directory table on the network server 36 . In this case, the table is updated with caller information only when an incoming call to the receiving handset 42 is made, the inbound number is recorded when the call is terminated. When a CNAM query is made, the resulting text string (containing the caller name and/or city/state information) is stored in the caller directory table. The first time a number is received (not in caller directory table), a CNAM query is made. Thereafter, no CNAM query need be made if the table contains those records. Caller identification information may be sent from the table directly to the receiving handset 42 or it may be assumed that the user previously stored the number and caller identification information that resulted from the initial call. In the latter case, the calling party is identified using the information stored locally on the mobile handset 42 .
[0016] The client software on the receiving handset 42 may also include a feature that encourages subscribers to move call list entries to the contact database (caller directory) on the handset 42 and provides an indication to the software to update the contact list in the database 40 .
[0017] The client software on the receiving handset 42 may also include a feature that automatically moves call list entries to the contact database on the handset 42 and provides an indication to the software to update the contact list in the database 40 with those entries.
[0018] The client software on the receiving handset 42 may also include a feature that automatically moves an inbound call's MDN directly into the contact database on the handset 42 and provides an indication to the client software to update the contact list in the database 40 with those entries.
[0019] On receiving the indication to update the contact list in the database 40 , the client software on the receiving handset 42 sends an indication that an MDN has been stored in the contact database on the handset 42 . This can take the form of sending any stored MDNs back to the network server 36 or sending a confirmation.
[0020] The contact list in the database 40 may also store all incoming MDNs and received caller identification information regardless of whether the receiving handset 42 stores the MDN in the local contact database. Thereafter, the client software on the receiving handset 42 may cooperate with the contact list in the database 40 by providing an indication for each MDN stored in the contact database on the receiving handset 42 rather than exchanging the caller information itself.
[0021] Similarly, the list of numbers associated with the subscriber in the contact list in the database 40 can be checked against the list stored in the directory on the handset 42 periodically and refreshed using CNAM services as described herein. The caller name information does not need to be requested by the carrier if it is available on the receiving handset. Only telephone numbers that are stored on the receiving handset need to be checked prior to determine if a CNAM query should be made.
[0022] The present invention is described for mobile networks but works for mobile, VoIP and traditional telephone networks provided there is a source for the network caller directory information (operating in the manner of the contact directory in a mobile handset described herein), an identifier or telephone number associated with the caller, and a communications carrier that provides network access to CNAM services.
[0023] FIG. 2 illustrates an example method 100 performed by the system shown in FIG. 1 . First at a block 104 a call is received at the NCP 32 of a mobile carrier. Next, at a decision block 108 , the NCP 32 or the network server 36 determines if the MDN of the received call is stored (associated with) contact information (table) stored in the database 40 . If it is determined that the MDN is stored in the database 40 , then CID information included in the database 40 is retrieved from the database 40 and sent to the recipient with the call. When the receiving handset 42 receives the call with the CID information, the CID information is displayed/outputted to the user. Where CID information is not stored in the database 40 , then an indicator is sent with the call to the recipient. When the receiving handset 42 receives the call with the indicator, the CID information is retrieved from the local caller directory (contact list) and displays/outputs it to the user.
[0024] If at the decision block 108 the NCP 32 or the network server 36 determines that the MDN of the received call is not stored (associated with) contact information (table) stored in the database 40 , then at a block 110 a CNAM query is executed using the LIDB 34 . At a block 114 , if the CNAM query finds an associated CID, then that CID is sent to the recipient with the call. At a block 116 , if the CNAM query does not find an associated CID, then the MDN of the sender is used to determine city/state information. The city/state information is then sent to the recipient with the call.
[0025] FIG. 3 illustrates examples of the how the wireless environment 20 of FIG. 1 operates. In a first example, callers from first and second MDNs (206.555.1212, 425.111.1234) are analyzed at the NCP 32 and the network server 36 . It is determined that corresponding records exist in the subscriber contacts database (the database 40 ). In this example, the mobile handset 42 displays the MDNs and associated names from the contact directory of the mobile handset 42 .
[0026] In another example, the first and second MDNs (206.555.1212, 425.111.1234) do not have corresponding records in the subscriber contacts database (the database 40 ). The NCP 32 looks in the LIDB 34 for CNAM information. In this example, if CNAM information exists in the LIDB 34 for the MDNs (206.555.1212, 425.111.1234), the NCP 32 sends the MDNs and CNAM query results to the mobile handset 42 for display. For the MDN 206.555.1212, if CNAM information does not exist in the LIDB 34 , the MDN is used to determine city and/or state information that is communicated along with the MDN to the mobile handset 42 for display/output. Note that the LIDB may be that of the subscriber's carrier (for in-network calls) or a third party carrier's LIDB (containing information on subscribers on other communication networks). CNAM services typically service caller information on one or more LIDBs to provide service to subscribers; this also permits them to aggregate access to the LIDBs to relieve the burden on the independent carriers and permit them to interoperate without having to maintain their own high speed database services for CNAM.
[0027] Although atypical of CNAM as traditionally offered, the present invention could also be practiced based on the caller's contact information being maintained in a contact list on database accessible by the NCP at the caller's carrier. A CNAM operation can be initiated on the caller's side, and the decision to query CNAM made using lists in caller directories associated and/or accessed over the network by the NCP of the caller's carrier. A CNAM query made in reference to the caller's contact list would then pass on the resulting caller name information without charge to the receiving party. This would be advantageous to the caller, such as a business enterprise, in that the call information and branding (e.g., corporate name) about their business can be maintained correctly by providing caller information to the caller's contacts. This would also permit private parties to share their contact information without the risk of spoofing or user error—since the information is provided in the first instance by CNAM, not the caller (assuming that the CNAM information is accurate, and properly stored in their caller directory on their handset). The present invention would permit this without undue expense to the calling party, since the caller information in the online directory would indicate that the receiving party already received the calling parties' information (since the receiving party is already stored in the caller's contact list). It is also noted that while calling on voice channels is the preferred embodiment, the present invention could be used to manage the CNAM queries and place sender identification information in incoming messages to devices on mobile networks, including SMS, email, data traffic, and so forth.
[0028] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. | A phone network in a wireless environment that does not perform CNAM queries when a number is already stored in the receiving handsets' caller directory. CNAM query fees are charged only to obtain caller information on a new caller. The network does not make CNAM queries when the caller information is already available, whether in the contact information stored on the receiver's handset or through some other reliable source. | 7 |
This application is a National Stage completion of PCT/EP2007/058609 filed Aug. 20, 2007, which claims priority from German patent application serial no. 10 2006 040 476.9 filed Aug. 29, 2006.
FIELD OF THE INVENTION
The invention concerns a hydraulic or pneumatic control device for an automated shift transmission, with at least two actuating devices each consisting of a double-action actuating cylinder having two pressure spaces separated by a piston, such that the pressure spaces of the actuating cylinder can each be connected selectively by a control valve to a pressure line or to an unpressurized line. The pressure line can be selectively connected to or cut off from a main pressure line by means of a main shut-off valve. The invention also concerns a method for controlling control elements of such a hydraulic or pneumatic control device.
BACKGROUND OF THE INVENTION
Control devices of the type indicated above, which work with a pressure medium such as hydraulic oil or compressed air, are known in various designs and are used with automated transmissions of motor vehicles to carry out gear changes. In passenger cars those control devices are usually hydraulic, whereas in contrast, in larger commercial vehicles such as trucks and buses, which have compressed air units, they mainly operate pneumatically.
Largely identical designs of such a control device are described for example in DE 199 31 973 A1 and in DE 101 31 853 A1. There, in each case a pump is provided by which a pressure medium can be drawn from a storage reservoir or oil sump and conveyed to a main pressure line. By means of a main shut-off valve, made as a 2/2-way magnetic switching valve, a pressure line can be selectively connected to, or disconnected from the main pressure line. To this pressure line are connected a plurality of control valves in the form of 3/2-way magnetic switching valves, which are associated in pairs with a respective actuating device. The actuating devices are each made as a double-action actuating cylinder with two pressure spaces separated by a piston, and the pressure spaces are in each case connected by a connection line to one of the associated control valves, by means of which they can be connected selectively to the pressure line or to an unpressurized line.
Depending on the structure of the transmission-internal shift actuating device, the actuating devices may have the function of a selector control element for selecting one among several shift gates, or of a gear control element for engaging and disengaging the gears of a shift gate concerned, or they may function exclusively as a gear control element. If the shift actuation is effected by an axially displaceable and rotatable shifting shaft, an actuating device that works as a selector control element is needed, by means of which, to select the shift gate, the shifting shaft can be manipulated into form-fitting engagement with the gearshift rod of the shift gate concerned, for example by means of a shift finger. Then, by virtue of another shift actuating device that acts as a shift control element, the associated gear is engaged and disengaged by the shifting shaft by axial displacement of the gearshift rod, which is engaged with an operating sleeve via a shifting fork.
It is also possible, however, for the gearshift rods or shift rockers to be actuated directly, in each case by an associated actuating device. In this case all the actuating devices act as gear control elements, and the shift gate is selected exclusively by actuating the gear control elements. In such a case the number of actuating devices needed corresponds to the number of shift gates, so in a simple automated shift transmission with six forward gears and one reverse gear at least four actuating devices are needed.
Starting from the last-mentioned example of a simple automated shift transmission with gearshift rods or shift rockers that can be actuated directly by the actuating devices, there are gearshifts which need a larger, and ones which need a smaller amount of pressure medium. In a gearshift between two gears associated with the same shift gate, i.e. which are engaged or disengaged by the same shifting rod or shift rocker, only one actuating device is used so the demand for pressure medium is only relatively small.
In contrast, if a shift takes place between two gears associated with different shift gates, i.e. which are engaged and disengaged by different shifting rods or shift rockers, then two actuating devices are used so the demand for pressure medium is greater. The pressure medium demand is even greater still in a so-termed multiple shift during which a plurality of successive gearshifts take place at short intervals.
The main shut-off valve is now required, during shift pauses, to cut off the pressure line with its connected control valves and the actuating devices from the main pressure line when in its closed condition. This then protects the control valves and actuating devices from the relatively high main pressure in the main pressure line, whereby otherwise possible leakage losses and perhaps also undesired movements of the actuating devices are avoided.
On the other hand, during shift phases the main shut-off valve is opened and the pressure line is therefore connected to the main pressure line in order to provide the control valves and the actuating devices to be operated by them with a sufficiently high pressure and a large enough volume flow. Consequently, the main shut-off valve is designed for a volume flow which, having regard to leaks that result from wear, corresponds to the maximum volume flow that can be required during a shift process. Thus, the main shut-off valve is usually of relatively large size and is consequently comparatively expensive and prone to malfunction; because of marked hysteresis its control properties are poor and when configured, as is usual, as a magnetic switching valve, it demands a relatively high control current. Furthermore, a malfunction of the main shut-off valve causes a failure of the entire control system and the associated shift transmission can no longer carry out gearshifts.
To avoid these disadvantages, at least in part, it is also known, instead of one large magnetic switching valve, to adopt a so-termed booster arrangement in which a correspondingly large, pressure-controlled main shut-off valve is positioned between the main pressure line and the pressure line, which can be acted upon with a control pressure via a smaller, interposed valve made as a magnetic switching valve and connected to the main pressure line. Owing to the rapid response behavior of and the low control current needed by this interposed valve, the controllability of this valve arrangement is at least partially improved. However, since two valves are needed this arrangement costs more and its operational reliability is to say the least not improved, since now only one defect in either one of the two valves, the pressure-controlled main shut-off valve or the electrically controlled interposed valve, can lead to failure of the control system.
SUMMARY OF THE INVENTION
Accordingly, the purpose of the invention is to propose a control device of the type described to begin with, by virtue of which a simple and inexpensive structure has better control properties and greater operational reliability. In addition, a method for actuating the control elements of such a control device is indicated.
These objectives are achieved by a hydraulic or pneumatic control device for an automated shift transmission, comprising actuating devices with actuating cylinders having pressure chambers, such that each pressure chamber of an actuating cylinder can be connected by a control valve to a pressure line and the pressure line can be selectively connected to or cut off from a main pressure line by means of a main shut-off valve. According to the invention, with this control device it is also provided that at least one further main shut-off valve is arranged in parallel with the first main shut-off valve between the main pressure line and the pressure line.
By virtue of this structure the at least two main shut-off valves can both be small, and because of the more rapid response behavior of these main shut-off valves the controllability of the control device is improved. Moreover the operational reliability of the control device is substantially increased, since if one of the main shut-off valves malfunctions the continuing functionality of the control device is ensured by the remaining, fault-free main shut-off valve, even though with somewhat restricted dynamics.
All the main shut-off valves are made as directly actuated 2/2-way magnetic switching valves, and can therefore be controlled directly, also being available inexpensively.
Likewise, it is expedient for all the main shut-off valves to be of identical structure, which makes for favorable purchase and logistics costs. Moreover, this simplifies the control of the main shut-off valves since they can all be controlled in accordance with the same characteristics.
It is also advantageous for the main shut-off valves to be controlled independently of one another by an associated control unit, since the main shut-off valves can then be controlled individually, for example as a function of the pressure medium demand at the time.
For this purpose it is also advantageous for the main shut-off valves to be of a size such that a maximum possible pressure medium demand can be covered by opening all and a smaller pressure medium demand can be covered by opening only one of the main shut-off valves.
To enable demand-related control of the main shut-off valves a pressure sensor connected to the pressure line can be used, by means of which the pressure p_dls and/or the pressure gradient (dp/dt)_dls in the pressure line can be determined.
The second objective is achieved by a method for actuating control elements of a hydraulic or a pneumatic control device of an automated shift transmission, which comprises actuating devices with actuating cylinders having pressure spaces, such that the pressure spaces of the actuating cylinders can each be connected via a control valve to a pressure line and the pressure line can be selectively connected to a main pressure line or cut off therefrom by means of a main shut-off valve. The method provides that if a plurality of main shut-off valves are arranged in parallel between the main pressure line and the pressure line, the pressure medium demand of the actuating devices and the associated control valves is determined and the main shut-off valves are controlled as a function of the pressure medium demand determined.
For this purpose it can be provided that before a shift operation the pressure medium demand is estimated and then, for the duration of the shift process, if the pressure medium demand is high a plurality of main shut-off valves are opened, whereas if the demand is low only one of the main shut-off valves, or only some of the main shut-off valves are opened.
In the case of shift operations requiring the opening of only one, or only some of the main shut-off valves, to avoid premature wear of one of the valves it is expedient, over several such shift operations, to use all the main shut-off valves in rotation in a predetermined sequence.
In this it should be borne in mind that premature wear of one of the main shut-off valves can take place both with above-average use due to frictional wear on seals and sealing surfaces, and with below-average use, i.e. long periods of inactivity, if seals stick to sealing surfaces and are torn apart when operation resumes. Both types of wear can be minimized by using all the main shut-off valves statistically with approximately the same frequency and in about the same distribution, and this also prolongs the life of the control device as a whole.
As an alternative to the above procedure it is also possible at first to open only one of the main shut-off valves at the beginning of a shift operation, determine the pressure p_dls and/or the pressure gradient (dp/dt)_dls in the pressure line during the shift operation by means of a pressure sensor connected to the pressure line, and if the pressure p_dls detected falls below a predetermined minimum value p_min and/or the pressure gradient (dp/dt)_dis detected falls below a predetermined minimum value (dp/dt)_min, to open further main shut-off valves one at a time in succession until the minimum pressure p_min and/or the minimum pressure gradient (dp/dt)_min in the pressure line has or have been reached or exceeded.
In shift operations with such sequential opening of the main shut-off valves as well, premature wear of one of the main shut-off valves can be avoided if, over a number of such shift operations, all the main shut-off valves are used in rotation in a predetermined sequence, i.e. in each case a different main shut-off valve is opened first.
Furthermore, it is advantageous for malfunctions of the main shut-off valves to be diagnosed, and if a fault is detected in one of them, then for only the fault-free main shut-off valves to be controlled and actuated. This can avoid malfunctions due to an undefined condition of the faulty main shut-off valve.
BRIEF DESCRIPTION OF THE DRAWINGS
To clarify the invention the description is attached of a drawing which shows:
FIG. 1 Schematic view of a control device according to the invention;
FIG. 2 : Schematic view of a first control device according to the prior art; and
FIG. 3 : Schematic view of a known, second control device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 , 2 and 3 show respective hydraulic or pneumatic control devices 1 , 1 ′, 1 ″ of an automated shift transmission of a motor vehicle, with the following features in common:
By means of a pump 3 driven by a motor 2 , a pressure medium such as hydraulic oil or compressed air can be delivered via a suction line 4 and a one-way valve 5 from a storage container 6 or oil sump 7 to a main pressure line 8 . To compensate for pressure fluctuations, a pressure reservoir 9 is connected to the main pressure line 8 .
The control devices 1 , 1 ′, 1 ″ comprise a plurality of actuating devices, of which in FIGS. 1 , 2 and 3 only two actuating devices 13 and 14 are shown. The actuating devices 13 and 14 which, depending on the type of structure of the transmission-internal shift actuation system, may be either a selector control element and a gearshift control element, or only gearshift control elements, are in each case made as a double-action actuating cylinder 15 , 16 each of which comprises two pressure spaces 19 a , 19 b and 20 a , 20 b respectively, separated by respective pistons 17 , 18 .
The pressure spaces 19 a , 19 b of the first actuating device 13 are each connected by a connection line 21 a , 21 b to the respective outlet of a control valve 22 a , 22 b made as a 3/2-way magnetic switching valve. By means of the associated first control valve 22 a the first pressure space 19 a of the first actuating device 13 can be connected selectively, via a return-flow line 23 a and a one-way valve 24 a, to the unpressurized line 12 or, via a flow inlet line 25 a , to a pressure line 26 . In a similar fashion the second pressure space 1 9 b of the first actuating device 13 can be connected selectively, via a return-flow line 23 b and a one-way valve 24 b , to the unpressurized line 12 or, via a flow inlet line 25 b , to the pressure line 26 .
In the same way the pressure spaces 20 a and 20 b of the second actuating device 14 are each connected by a connection line 31 a , 31 b to the outlet of a control device 32 a , 32 b made as a 3/2-way magnetic switching valve. By means of the associated first control valve 32 a the first pressure space 20 a of the second actuating device 14 can be connected selectively, via a return-flow line 33 a and a one-way valve 34 a , to the unpressurized line 12 or, via a flow inlet line 35 a , to the pressure line 26 . In a similar fashion the second pressure space 20 b of the second actuating device 14 can be connected selectively, via a return-flow line 33 b and a one-way valve 34 b , to the unpressurized line 12 or, via a flow inlet line 35 b , to the pressure line 26 .
To compensate for pressure fluctuations, a pressure reservoir 27 is connected to the pressure line 26 . In addition a pressure sensor 28 is connected to the pressure line 26 , which sensor, as also provided in DE 199 31 973 A1, can be used for the measurement, or as in DE 101 31 853 A1, for the computerized determination of the actuation pressures in the respective pressure spaces 19 a , 19 b and 20 a , 20 b of the actuating devices 13 and 14 .
Furthermore, a preferably electronically designed control unit 29 is provided, which is connected via electric control lines 30 a , 30 b , 40 a , 40 b to the control valves 21 a , 21 b , 31 a , 31 b of the actuating devices, via another electric control line 39 to the motor 2 , and via an electric sensor line 37 to the pressure sensor 28 .
In an embodiment of the control device 1 ′ according to FIG. 2 , known in principle from DE 199 31 973 A1 and DE 101 31 853 A1, a single main shut-off valve 38 is arranged between the main pressure line 8 and the pressure line 26 . The main shut-off valve 38 is made as a 2/2-way magnetic switching valve and is connected to the control unit 29 by an electric control line 39 .
The purpose of the main shut-off valve 38 , in order to avoid leakage loss, is to cut off the control valves 22 a , 22 b , 32 a , 32 b connected to the pressure line 26 from the main pressure line 8 when shift operations are not taking place, and to connect them to the main pressure line 8 during shift operations so that they are supplied with sufficient pressure and volume flow for the actuation of the actuating devices 13 and 14 . Since in this case there is only a single main shut-off valve 38 , this is designed for the maximum possible pressure medium demand of the actuating devices 13 , 14 and is therefore of relatively large size, which results in relatively poor control properties such as delayed response behavior and the need for a large control current, relatively high component costs, and in most shift operations unnecessarily high mechanical loading of the control valves 22 a , 22 b, 32 a , 32 b . In addition, a malfunction of the main shut-off valve 38 can cause the failure of the control system 1 ′ as a whole.
To limit the main pressure, the main pressure line 8 is connected, via a pressure-limiting valve 10 and a return-flow line 11 , to an unpressurized line 12 which leads to the storage container 6 or oil sump 7 .
In another known embodiment of the control device 1 ″ shown in FIG. 3 , again a single main shut-off valve 41 is arranged between the main pressure line 8 and the pressure line 26 , but in contrast to the design shown in FIG. 2 , this is now in the form of a pressure-controlled 2/2-way switching valve. To actuate the main shut-off valve 41 an interposed switching valve 42 is provided, which is made as a 2/2-way magnetic switching valve whose inlet is connected to the main pressure line 8 and whose outlet is connected via a pressure control line 43 to the control inlet of the main shut-off valve 41 , and which is connected by an electric control line 44 to the control unit 29 .
The magnetic switching valve acting as the interposed switching valve 42 is substantially smaller than the main shut-off valve 38 of the embodiment in FIG. 2 described earlier, so that the control properties and reliability of the magnetic switching valve 42 are better. On the other hand, no cost advantage and no improvement of operational reliability are achieved by the conjoint use of the two switching valves 41 and 42 .
In contrast to the known versions according to FIGS. 2 and 3 described above, in the control device 1 according to the invention shown in FIG. 1 a plurality of, for example two main shut-off valves 45 a , 45 b are connected in parallel between the main pressure line 8 and the pressure line 26 . The main shut-off valves 45 a and 45 b are in each case made as a 2/2-way magnetic switching valve and are each connected by respective electric control lines 46 a , 46 b to the control unit 29 , so that they can be actuated independently of one another.
Expediently, the main shut-off valves 45 a , 45 b are of relatively small size, which results in better response behavior. In addition the main shut-off valves 45 a, 45 b are preferably of identical structure and are designed such that a smaller pressure medium demand by the actuating devices 13 , 14 can be covered by opening only one of them ( 45 a or 45 b ) and a larger pressure medium demand by the actuating devices 13 , 14 can be covered by opening both main shut-off valves 45 a 45 b . This enables the main shut-off valves 45 a , 45 b to be controlled according to need, so that the mechanical loading of the control valves 22 a , 22 b , 32 a , 32 b and leakage losses during the shift process are substantially reduced.
For control according to need the pressure sensor 28 can also be used, so that during shift phases the main shut-off valves 45 a , 45 b can be opened in sequence as a function of the pressure p_dls and/or the pressure gradient (dp/dt)_dls in the pressure line 26 .
If one of the main shut-off valves 45 a or 45 b fails, then the functionality of the control device 1 is preserved by virtue of the fault-free main shut-off valve 45 b or 45 a , even though with reduced dynamics, i.e. longer shifting times in the shift transmission. Thus, compared with the known designs, the operational reliability of the control device 1 according to the invention is substantially improved by the parallel connection of a plurality of main shut-off valves 45 a , 45 b.
INDEXES
1 Control device
1 ′ Control device
1 ″ Control device
2 Motor
3 Pump
4 Suction line
5 One-way valve
6 Storage reservoir
7 Oil sump
8 Main pressure line
9 Pressure reservoir
10 Pressure-limiting valve
11 Return-flow line
12 Unpressurized line
13 Actuating device
14 Actuating device
15 Double-action actuating cylinder
16 Double-action actuating cylinder
17 Piston
18 Piston
19 a Pressure space
19 b Pressure space
20 a Pressure space
20 b Pressure space
21 a Connection line
21 b Connection line
22 a Control valve
22 b Control valve
23 a Return-flow line
23 b Return-flow line
24 a One-way valve
24 b One-way valve
25 a Inlet line
25 b Inlet line
26 Pressure line
27 Pressure reservoir
28 pressure sensor
29 Control unit
30 a Control line
30 b Control line
31 a Connection line
31 b Connection line
32 a Control valve
32 b Control valve
33 a Return-flow line
33 b Return-flow line
34 a One-way valve
34 b One-way valve
35 a Inlet line
35 b Inlet line
36 Control line
37 Sensor line
38 Main shut-off valve
39 Control line
40 a Control line
40 b Control line
41 Main shut-off valve
42 Interposed control line
43 Pressure control line
44 Control line
45 a Main shut-off valve
45 b Main shut-off valve
46 a Control line
46 b Control line | A hydraulic or pneumatic control device for an automated shift transmission including actuating devices with actuating cylinders ( 15, 16 ) having pressure spaces ( 19 a , 19 b ; 20 a , 20 b ). The pressure spaces ( 19 a , 19 b ; 20 a , 20 b ) of the actuating cylinders ( 15, 16 ) can be connected by a respective control valve ( 22 a , 22 b ; 32 a , 32 b ) to a pressure line ( 26 ), which can be selectively connected to or cut off from a main pressure line ( 8 ) by a main shut-off valve ( 45 a ). At least one additional main shut-off valve ( 45 b ) is arranged in parallel with the first main shut-off valve ( 45 a ) between the main pressure line ( 8 ) and the pressure line ( 26 ) to improve the control characteristics and increase the operational reliability. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 14/017,060, filed Sep. 3, 2013, which application claims the priority, under 35 U.S.C. §119, of U.S. Provisional Patent Application No. 61/696,239, filed Sep. 3, 2012, the prior applications are herewith incorporated by reference herein in their entireties.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
FIELD OF THE INVENTION
[0003] The present invention lies in the field of bird protection. The present disclosure relates to a protective shoe for birds.
BACKGROUND OF THE INVENTION
[0004] Poultry and other multi-toed birds are prone to foot injuries that lead to “bumblefoot,” an infection that is difficult to cure and often leads to infection of the foot bone and death. A device is desirable to establish a level of protection for the bird against bumblefoot and afford prompt healing to existing foot wounds while providing grip and a range of motion necessary for mobility, roosting, and perching. However, no device exists that is worn to protect a bird's foot and is adapted for protecting the feet of birds that perch, climb, or roost. Single shoe devices shaped and configured for affixture on the leg of a large bird such as an emu, as disclosed in U.S. Pat. No. 5,406,722 to Jones, are not intended to provide the protection and cushioning necessary for inhibiting and healing of bumblefoot, do not facilitate healing of wounds on toes or pads of feet, and lack the flexible configuration necessary to provide mobility to multi-toed birds who perch, climb or roost.
[0005] Thus, a need exists to overcome the problems with the prior art systems, designs, and processes as discussed above.
SUMMARY OF THE INVENTION
[0006] The invention provides a protective shoe for birds that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that prevents bumblefoot from forming, provides a barrier against dirt and moisture to enable healing of foot wounds, contains topical medication to facilitate wound care, and provides cushioning of wounded feet. The unique features that enhance durability and functionality of the shoe include a construction to protect the bird's foot while providing grip and the range of motion necessary for mobility, roosting, and perching. This shoe may be used on any multi-toed and/or webbed-toed birds such as poultry, fowl, psittacines, and raptors.
[0007] The protective shoe disclosed protects the feet of multi-toed birds. It can be used to prevent bumblefoot from forming, to enable the healing of existing foot or toe wounds, to facilitate wound care, and to provide cushioning of wounded feet. The shoe is durable and has the flexible configuration and grip necessary to enable birds to free-range, climb, perch, and roost while it is being worn.
[0008] With the foregoing and other objects in view, there is provided, in accordance with the invention, a bird shoe to accommodate at least one of toes and pads of a bird's foot, the shoe comprising a shoe body having an upper surface and a sole and defining bird toe covers corresponding in number to the number of front toes of the bird's foot; , an ankle cuff connected to the shoe body and having an ankle closure system formed to secure about an ankle of the bird's foot, and a closure tab connected to the shoe body and having a closure system formed to tighten the shoe body to the bird's foot.
[0009] In accordance with another feature of the invention, the bird toe covers include at least one of an open toe sleeve, open toe sleeves, a closed toe sleeve, closed toe sleeves, and a toe slit.
[0010] In accordance with a further feature of the invention, the bird toe covers include three toe slits or toe sleeves on a front of the shoe body and one toe slit or toe sleeve on a rear of the shoe body.
[0011] In accordance with an added feature of the invention, the bird toe covers include two toe slits or toe sleeves on a front of the shoe body and two toe slits or toe sleeves on a rear of the shoe body.
[0012] In accordance with an additional feature of the invention, the bird toe covers are open toe sleeves set to a length that allows nail tips of the bird to be exposed and, thereby, provide secure grip when climbing and perching.
[0013] In accordance with yet another feature of the invention, the bird toe covers include a linked set of toe coverings on a front of the shoe body and one toe slit or toe sleeve on a rear of the shoe body.
[0014] In accordance with yet a further feature of the invention, the ankle cuff has a first end attached to at least one of the upper surface and the sole or in between the upper surface and the sole and a second end left free.
[0015] In accordance with yet an added feature of the invention, the closure tab has a first end attached to at least one of the upper surface and the sole or in between the upper surface and the sole and a second end left free.
[0016] In accordance with yet an additional feature of the invention, the ankle cuff is attached to at least one of the top of the body and the sole of the body.
[0017] In accordance with again another feature of the invention, the shoe body is selected from at least one of the group consisting of neoprene, denim, canvas duck, leather, and nylon.
[0018] In accordance with again a further feature of the invention, the ankle cuff is selected from at least one of the group consisting of neoprene, denim, canvas duck, leather, and nylon.
[0019] In accordance with again an added feature of the invention, the ankle cuff is at least one of snaps, buttons, and hook-and-loop closures.
[0020] In accordance with again an additional feature of the invention, the closure tab is selected from at least one of the group consisting of neoprene, denim, canvas duck, leather, and nylon.
[0021] In accordance with still another feature of the invention, the closure tab is at least one of snaps, buttons, and hook-and-loop closures.
[0022] In accordance with still a further feature of the invention, the bird shoe is two shoes, a left shoe and a right shoe.
[0023] With the objects of the invention in view, there is also provided a method for protecting a foot of a bird with a shoe includes placing a shoe body onto a bird's foot by slipping at least one of the bird's front toes into at least one front toe cover, wrapping an ankle cuff around the bird's leg adjacent the bird's foot, feeding at least one back toe through at least one rear toe cover, and securing the ankle cuff at the bird's leg with an ankle closure system.
[0024] In accordance with another mode of the invention, the ankle closure system has opposite ends and is secured to the bird by marrying the opposite sides of the ankle closure system to each other.
[0025] In accordance with a further mode of the invention, a closure tab is tightened about the bird's foot to secure the shoe body to the bird's foot.
[0026] In accordance with an added mode of the invention, the closure tab is secured at one end to the shoe body and has an opposite end that is secured to the bird's foot by marrying one opposite end to the shoe body.
[0027] In accordance with an additional mode of the invention, the at least one front toe cover is a plurality of front toe covers corresponding in number to the number of front toes of the bird's foot and the shoe body is placed onto a bird's foot by slipping each of the bird's front toes into the at least one front toe cover.
[0028] In accordance with yet another mode of the invention, the at least one rear toe cover is a plurality of rear toe covers corresponding in number to the number of rear toes of the bird's foot and the shoe body is placed onto a bird's foot by slipping each of the bird's rear toes into the at least one rear toe cover.
[0029] In accordance with a concomitant mode of the invention, the placing, wrapping, feeding, and securing steps are carried out to place a shoe body on each of the bird's feet.
[0030] With the foregoing and other objects in view, there is provided, a a protective shoe to accommodate a foot of waterfowl having toes with nail tips includes a shoe body, an ankle cuff, and a closure tab. The shoe body is in approximately a shape of a waterfowl foot and has an upper surface and a sole connected together to define a left front opening, a center front opening, a right front opening, and a foot entrance opening into which the waterfowl foot is inserted. The front openings are sized to permit at least the nail tip of a respective toe to extend therethrough. The ankle cuff is connected to the shoe body and has an ankle closure system formed to secure about an ankle of the waterfowl's foot. The closure tab is connected to the shoe body and has a closure system formed to cover at least a portion of the foot entrance opening to secure the waterfowl's foot inside the shoe body.
[0031] In accordance with another feature, the upper surface and the sole are connected together at two connection areas to form the front openings.
[0032] In accordance with a further feature, the shoe body has a side and the foot entrance opening is a side opening at a side of the shoe body, the side opening defining an extent. In accordance with an added feature, the ankle cuff has a rear toe opening to permit at least a nail of a rear toe of the waterfowl foot to protrude therefrom.
[0033] In accordance with an additional feature, the shoe body has a rear toe opening to permit at least a nail of a rear toe of the waterfowl foot to protrude therefrom.
[0034] In accordance with yet another feature, the ankle cuff has a first end attached at least one of to the upper surface, to the sole, and in between the upper surface and the sole, and a second end left free.
[0035] In accordance with yet a further feature, the closure tab has a first end attached at least one of to the upper surface, to the sole, and in between the upper surface and the sole, and a second end left free.
[0036] In accordance with yet an added feature, the shoe body is selected from at least one of neoprene, denim, canvas duck, leather, and nylon.
[0037] In accordance with yet an additional feature, the ankle cuff is selected from at least one of neoprene, denim, canvas duck, leather, and nylon.
[0038] In accordance with again another feature, the ankle cuff is at least one of snaps, buttons, and hook-and-loop closures.
[0039] In accordance with again a further feature, the closure tab is selected from at least one of neoprene, denim, canvas duck, leather, and nylon.
[0040] In accordance with again an added feature, the closure tab is at least one of snaps, buttons, and hook-and-loop closures.
[0041] In accordance with again an additional feature, the bird shoe is two shoes, a left shoe and a right shoe.
[0042] With the objects in view, there is also provided a a method for protecting a foot of a waterfowl with a shoe includes the steps of providing a waterfowl shoe comprising a shoe body in approximately a shape of a waterfowl foot and having an upper surface and a sole connected together to define a left front opening, a center front opening, a right front opening, and a foot entrance opening into which the waterfowl foot is inserted, the front openings being sized to permit at least the nail tip of a respective toe to extend therethrough, an ankle cuff connected to the shoe body and having an ankle closure system formed to secure about an ankle of the waterfowl's foot, and a closure tab connected to the shoe body and having a closure system formed to cover at least a portion of the foot entrance opening to secure the waterfowl's foot inside the shoe body, placing the shoe body onto a waterfowl foot by slipping the foot into the foot entrance, wrapping the ankle cuff around the waterfowl's leg adjacent the waterfowl foot, and securing the ankle cuff at the waterfowl's leg with an ankle closure system.
[0043] In accordance with still another mode, the ankle cuff has a rear toe opening to permit at least a nail of a rear toe of the waterfowl foot to protrude therefrom and which further comprises feeding at least the nail of the rear toe through the rear toe opening.
[0044] In accordance with still a further mode, the ankle closure system has opposite ends and is secured to the waterfowl by marrying the opposite ends of the ankle closure system to each other.
[0045] In accordance with still an added mode, the closure tab is secured at one end to the shoe body and has an opposite end that secures the waterfowl foot therein by marrying the one end and the opposite end.
[0046] In accordance with a concomitant mode, the providing placing, wrapping, and securing steps are carried to place the shoe body on each of the waterfowl's feet.
[0047] Although the invention is illustrated and described herein as embodied in a protective shoe for birds, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.
[0048] Additional advantages and other features characteristic of the present invention will be set forth in the detailed description that follows and may be apparent from the detailed description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by any of the instrumentalities, methods, or combinations particularly pointed out in the claims.
[0049] Other features that are considered as characteristic for the invention are set forth in the appended claims. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention. While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, which are not true to scale, and which, together with the detailed description below, are incorporated in and form part of the specification, serve to illustrate further various embodiments and to explain various principles and advantages all in accordance with the present invention. Advantages of embodiments of the present invention will be apparent from the following detailed description of the exemplary embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which:
[0051] FIG. 1 is a top perspective view of an exemplary embodiment of a left bird shoe with three front-facing toe sleeves and one rear toe slit in a closed orientation;
[0052] FIG. 2 is a top perspective view of the left bird shoe of FIG. 1 in an open orientation
[0053] FIG. 3 is an exploded perspective view of a top side of the left bird shoe of FIG. 1 ;
[0054] FIG. 4 is a top perspective view of another exemplary embodiment of a bird shoe with three front-facing slits and one rear toe slit in a closed orientation;
[0055] FIG. 5 is a top perspective view of a further exemplary embodiment of a left bird shoe with two front-facing toe sleeves and two rear toe sleeves in a closed orientation;
[0056] FIG. 6 is a top perspective view of still another exemplary embodiment of a left bird shoe with two front-facing slits and two rear toe slits in a closed orientation;
[0057] FIG. 7 is a top perspective view of yet another exemplary embodiment of a left bird shoe with closed front-facing webbed toe sleeve and one rear toe slit in a closed orientation;
[0058] FIG. 8 is a top perspective view of a left bird shoe of an exemplary embodiment of FIG. 4 with three front-facing webbed slits and one rear toe slit in a closed orientation;
[0059] FIG. 9 is a bottom perspective view of a smaller version of a right bird shoe of an exemplary embodiment of FIG. 8 with three front-facing webbed slits and one rear toe slit in a closed orientation;
[0060] FIG. 10 is a bottom perspective view of a smaller version of a right bird shoe of an exemplary embodiment of FIG. 8 and larger than the shoe of FIG. 9 with three front-facing webbed slits and one rear toe slit in a closed orientation;
[0061] FIG. 11 is a top perspective view of an exemplary embodiment of the left bird shoe of FIG. 1 with three front-facing toe sleeves and one rear toe slit in an open orientation;
[0062] FIG. 12 is a top perspective view of the left bird shoe of FIG. 11 in a closed orientation;
[0063] FIG. 13 is a bottom perspective view of the left bird shoe of FIG. 11 in the closed orientation;
[0064] FIG. 14 is a bottom perspective view of the left bird shoe of FIG. 11 in the open orientation;
[0065] FIG. 15 is a fragmentary, perspective view of the left bird shoe of FIGS. 11 to 14 closed on a bird's foot; and
[0066] FIG. 16 is a fragmentary, perspective view of a right bird shoe of the exemplary embodiment of FIGS. 8 to 10 closed on a bird's webbed foot.
DETAILED DESCRIPTION OF THE INVENTION
[0067] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention. While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward.
[0068] Alternate embodiments may be devised without departing from the spirit or the scope of the invention. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.
[0069] Before the present invention is disclosed and described, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The terms “a” or “an”, as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0070] Relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0071] As used herein, the term “about” or “approximately” applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure.
[0072] Herein various embodiments of the present invention are described. In many of the different embodiments, features are similar. Therefore, to avoid redundancy, repetitive description of these similar features may not be made in some circumstances. It shall be understood, however, that description of a first-appearing feature applies to the later described similar feature and each respective description, therefore, is to be incorporated therein without such repetition.
[0073] A bird shoe described herein is made up of a body 1 and an ankle cuff 2 . FIGS. 1 through 7 show various exemplary embodiments of the bird shoe and its elements. With regard to FIGS. 1 to 3 , these elements are connected by attaching the ankle cuff 2 to the top and sole 4 of the body 1 (or by making the ankle cuff 2 integral with one or the other). A closure tab 3 also can be provided. The body 1 has a corresponding number of toe sleeves in the front or back to accommodate the particular bird's toes and the body 1 can be made with toe covers that include toe sleeves 5 and/or toe slits 6 (shown with dashed lines). The body 1 can be made with a top and sole 4 of one or more layers of various rip-, tear-, and/or puncture-resistant materials, such as, but not limited to, neoprene, denim, canvas duck, leather, nylon, but neoprene is a particularly good selection. The sole 4 or just the outer side of the sole 4 (see, e.g., FIG. 9, 13 , or 14 ) can be non-slip or textured neoprene, denim, canvas duck, leather, nylon, but neoprene is a particularly good selection. The ankle cuff 2 can be made of various materials, such as, but not limited to, neoprene, denim, canvas duck, leather, nylon, but neoprene is a particularly good selection. The ankle cuff 2 in an exemplary embodiment is sewn onto the body, but can be secured with various methods, such as, but not limited to, snaps, button, hook-and-loop closures, but sewing is a particularly good selection. The body 1 and ankle cuff 2 contain the corresponding number of toe sleeves 5 or slits 6 to accommodate the particular bird's back toes. The ankle cuff 2 contains an ankle closure system 7 such as, but not limited to, snaps, button, hook-and-loop closures, but hook-and-loop closures are a particularly good selection. The closure tab 3 can be made of various materials, such as, but not limited to, neoprene, denim, canvas duck, leather, nylon, but neoprene is a particularly good selection. The closure tab 3 contains one part of a closure system 8 and the top side of the body 3 contains the other part of the closure system 9 , such as, but not limited to, snaps, button, hook-and-loop closures, but hook-and-loop is a particularly good selection. The ankle closure system 7 and the closure tab 3 are sewn onto the body 1 but can be secured with various methods, such as, but not limited to, snaps, button, hook-and-loop closures, but sewing is a particularly good selection.
[0074] The location, shape, length and number of toe sleeves 5 or slits 6 on the shoe are dependent on the foot configuration of the particular bird. If the shoe is for a chicken, raptor, or other bird with three front-facing toes and one rear-facing toe, then the shoe is configured with three slits 6 or toe sleeves 5 on the front and one slit 6 or sleeve 5 on the back (see, e.g., FIGS. 1 to 4 ). If the shoe is for a psittacine, owl, or other bird with two front facing toes and two rear-facing toes, then the shoe is configured with two front sleeves 5 or toe slits 6 and two rear sleeves 5 or slits 6 (see, e.g., FIGS. 5 and 6 ). If the shoe is for a bird with webbed feet or a foot that needs protection from moisture, then the shoe is configured with an open or closed front toe sleeve 5 shaped to accommodate the webbed foot therein and a toe slit 6 or sleeve 5 in the back, as shown, for example, in FIGS. 7, 8, 9, 10, and 16 . The left foot of the shoes is depicted in FIG. 7 for brevity because the left and right shoes are mirror images of each other.
[0075] Described now are exemplary embodiments of the present invention. Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 , there is shown a first exemplary embodiment of a left bird shoe with three front-facing toe sleeves 5 and a slit 6 for a rear toe in a closed configuration. This style is used for birds having three front toes and one rear toe, such as chickens and raptors, who need coverage of both toes and the foot pad. The open sleeves 5 are lengthened appropriately so that the nail tips are exposed to enable the bird to scratch and to provide secure grip when jumping and roosting. As stated above, the right shoe is a mirror image and is, therefore, not depicted. The junction of the top and sole 4 portions of the body 1 within the closed closure tab 3 in FIG. 1 is not connected to form a pocket opening into which the bird's foot is guided to install the shoe. The direction that the bird's foot traverses when installing the shoe is indicated with the large arrow D in FIG. 1 .
[0076] FIG. 2 shows the left bird shoe of FIG. 1 with the three front-facing sleeves 5 and the one 6 rear toe slit in an open orientation. The shoe is placed onto the bird's foot by slipping the bird's foot in the direction D and inserting bird's front toes into the respective sleeves 5 . As the ankle cuff 2 is wrapped around the bird's leg, the back toe is fed through the rear toe slit 6 . The ankle closure system 7 on the ankle cuff 2 is used to secure the shoe to the bird by marrying the opposite sides of the ankle closure system 7 to each other. The shoe is tightened and closed upon the bird's foot by wrapping the closure tab 3 from the sole to the top side and marrying the two sides of the closure system 8 and 9 . As stated above, the right shoe is a mirror image and is, therefore, not depicted.
[0077] FIG. 3 is an exploded view of the left bird shoe of FIGS. 1 and 2 with the three front-facing toe sleeves 5 and the one rear toe slit 6 . As can be seen from FIG. 3 , the body 1 comprises the sole 4 attached to the top of the shoe. The ankle cuff 2 contains the rear toe slit 6 and the ankle closure system 7 . One end of the ankle cuff 2 (or a mid-portion) is attached to both the top side of the body and the sole 4 (or to one or the other or in between) and the other is left free. With regard to the closure system 3 , one side 9 is attached to the upper side of the top of the shoe, to the lower side of the sole 4 , or between the sole 4 and the top of the shoe and the other is left free to close the opening into which the bird's foot is inserted.
[0078] FIG. 4 shows another embodiment of a left bird shoe with three front-facing slits 6 and one rear toe slit 6 in a closed configuration. This style is used for birds with three front toes and one rear toe, such as chickens and raptors, who need only foot pad coverage. As stated above, the right shoe is a mirror image and is, therefore, not depicted. As above, the junction of the top and sole portions of the body 1 within the closed closure tab 3 in FIG. 4 is not connected to form a pocket opening into which the bird's foot is guided to install the shoe. The direction that the bird's foot traverses when installing the shoe is indicated with the large arrow D in FIG. 4 .
[0079] FIG. 5 shows an embodiment of a left bird shoe with two front-facing toe sleeves 5 and two rear toe sleeves 5 in a closed configuration. This style is used for bird with two front toes and two back toes, such as psitticines and owls, who need toes and foot pad covered. The open sleeves 5 are set to a respective length that allows the nail tips to be exposed and provide secure grip when climbing and perching. As stated above, the right shoe is a mirror image and is, therefore, not depicted. The junction of the top and sole portions of the body 1 within the closed closure tab 3 in FIG. 5 is not connected to form a pocket opening into which the bird's foot is guided to install the shoe. The direction that the bird's foot traverses when installing the shoe is indicated with the large arrow D in FIG. 5 .
[0080] FIG. 6 shows an embodiment of a bird shoe with two front-facing slits 6 and two rear toe slits 6 in a closed configuration similar to the embodiment of FIG. 6 . This style, however, is used for birds with two front toes and two rear toes, such as psittacines and owls, who only need foot pad coverage. As stated above, the right shoe is a mirror image and is, therefore, not depicted.
[0081] FIG. 7 shows an exemplary embodiment of a left shoe with joined toe sleeves 5 for water fowl, which have webbed feet, and chickens who have wounds that require protection from moisture, the shoe being in an entirely closed configuration. The toe slit 6 in the ankle cuff 2 accommodates the rear toe. As stated above, the right shoe is a mirror image and is, therefore, not depicted.
[0082] FIGS. 8, 9, and 10 show an exemplary embodiment of a left shoe with joined toe sleeves 5 for water fowl, which have webbed feet, this shoe being in an open configuration. In particular, two connection areas 10 securing the top and sole of the shoe form three toe openings 11 through which the bird's toes can protrude. These connection areas 10 together define a linked set of toe coverings that can be open as shown or entirely closed (not illustrated). Another connection area 12 can be provided at the foot entrance if desired to define the extent 13 of the opening of the foot entrance. The toe slit 6 in the ankle cuff 2 accommodates the rear toe. As stated above, the right shoe is a mirror image and is, therefore, not depicted. The difference between the configurations of FIGS. 8, 9, and 10 is the size of the foot to which the shoe corresponds. Each of the configuration is for a water fowl (i.e., duck-like avians). The smallest, shown in FIG. 9 , can be for a mallard, for example. The next larger size, shown in FIG. 10 , can be for a muscovy duck, for example. Finally, the largest size, shown in FIG. 8 , can be for, e.g., a goose. Each is shown as either the left or right foot but, if desired, each can comprise a left and right pair. The connection areas 10 are in an exemplary embodiment equal in size. However, if desired, as shown in FIG. 8 , the lengths of the connection areas 10 can be customized to fit the particular bird's foot.
[0083] FIGS. 11 to 14 show an exemplary embodiment of a left bird shoe similar to FIG. 1 with three front-facing toe sleeves 5 and a slit 6 for a rear toe. FIGS. 11 and 12 show the top of the shoe in the open and closed configurations, respectively, and FIGS. 13 and 14 , show the bottom of the shoe in the closed and open configurations, respectively. This style is used for birds having three front toes and one rear toe, such as chickens and raptors, who need coverage of both the toes and the foot pad. The open sleeves 5 are lengthened appropriately so that the nail tips are exposed to enable the bird to scratch and to provide secure grip when jumping and roosting. As stated above, the right shoe is a mirror image and is, therefore, not depicted. As above, the junction of the top and sole 4 portions of the body 1 within the closed closure tab 3 in FIGS. 12 and 13 is not connected to form a pocket opening into which the bird's foot is guided to install the shoe.
[0084] FIG. 15 illustrates an exemplary configuration of the shoe of FIGS. 11 to 14 installed on a foot of a chicken. FIG. 16 illustrates an exemplary configuration of the shoe of FIGS. 8 to 10 installed on a foot of a duck.
[0085] In any embodiment described herein, the seams on the inside of the opens toes can be sized to provide both adequate space for toes and structure to enable circulation of air. Such a configuration provides space sufficient for bandaging and padding of a wound, for example, with a cotton ball or two.
[0086] The bird shoes described herein provide an effective barrier and cushion between surfaces and the bird's foot. This flexible shoe can be worn by birds to prevent bumblefoot from forming, to provide a barrier against dirt and moisture to enable healing of foot wounds, to contain topical medication to facilitate wound care, and to provide cushioning of wounded feet. The unique features that enhance durability and functionality of the shoe include a construction that protects the bird's foot while providing grip and the range of motion necessary for mobility, roosting and perching. These shoes may be used on any multi-toed and/or webbed-toed birds such as poultry, fowl, psittacines and raptors.
[0087] It is noted that various individual features of the inventive processes and systems may be described only in one exemplary embodiment herein. The particular choice for description herein with regard to a single exemplary embodiment is not to be taken as a limitation that the particular feature is only applicable to the embodiment in which it is described. All features described herein are equally applicable to, additive, or interchangeable with any or all of the other exemplary embodiments described herein and in any combination or grouping or arrangement. In particular, use of a single reference numeral herein to illustrate, define, or describe a particular feature does not mean that the feature cannot be associated or equated to another feature in another drawing figure or description. Further, where two or more reference numerals are used in the figures or in the drawings, this should not be construed as being limited to only those embodiments or features, they are equally applicable to similar features or not a reference numeral is used or another reference numeral is omitted.
[0088] The foregoing description and accompanying drawings illustrate the principles, exemplary embodiments, and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art and the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims. | A protective shoe to accommodate a foot of waterfowl having toes with nail tips includes a shoe body, an ankle cuff, and a closure tab. The shoe body is in approximately a shape of a waterfowl foot and has an upper surface and a sole connected together to define left front, center front opening, and right front openings, and a foot entrance opening into which the waterfowl foot is inserted. The front openings are sized to permit at least the nail tip of a respective toe to extend therethrough. The ankle cuff is connected to the shoe body and has an ankle closure system formed to secure about an ankle of the waterfowl's foot. The closure tab is connected to the shoe body and has a closure system formed to cover at least a portion of the foot entrance opening to secure the waterfowl's foot inside the shoe body. | 0 |
This application is a 371 of PCT/EP95/01246 filed Apr. 5, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for the preparation of acetals of 2-amino-1,3-propanediol and, more particularly, it relates to a process for the preparation of 5-amino-1,3-dioxanes. The acetals of 2-amino-1,3-propanediol are advantageously used as synthetic intermediates in the preparation of the compound (S)-N,N'-bis-[2-hydroxy-1-(hydroxymethyl) ethyl]-5-[(2-hydroxy-1-oxopropyl)-amino]-2, 4,6-triiodo-1,3-benzenedicarboxamide, known with its International Nonproprietary Name Iopamidol (The Merck Index, XI Ed., page 799, No. 4943).
2. Discussion of the Background
Iopamidol was described for the first time by the Swiss Company Savac A. G. in the British patent No. 1,472,050 and is used in diagnostics as a non-ionic X-ray contrast medium.
The preparation of Iopamidol, described in said patent, comprises the condensation reaction of L-5-(2-acetoxy-propionylamino)-2, 4,6-triiodo-isophthalic acid dichloride with 2-amino-1,3-propanediol, better known as serinol, in dimethylacetamide and in the presence of a base.
Alternatively, in the same patent, a method comprising the condensation reaction of the above acid dichloride with an acetal of serinol is described; the subsequent acid hydrolysis of the resultant diacetal, carried out according to conventional techniques, allows then to obtain the desired product.
Among the possible acetals of serinol which can be used in said synthesis, for instance, 5-amino-1,3-dioxanes are cited.
Several processes for the preparation of 5-amino-1,3-dioxanes are reported in the literature.
The British patent application No. 2,081,256 (Rhone-Poulenc Industries) and the U.S. Pat. No. 3,812,186 (Eprova A. G.) describe the preparation of 5-amino-2,2-dialkyl-1,3-dioxanes by catalytic hydrogenation of the corresponding 5-nitro derivatives which, in turn, are prepared by direct cyclization of 2-nitro-1,3-propanediol with a suitable ketone, in the presence of boron trifluoride etherate.
In the U.S. Pat. No. 4,978,793 (W. R. Grace & Go.) it is described a preparation of 5-amino-2,2-dialkyl-1,3-dioxanes which comprises at first the synthesis of the corresponding 5-nitro derivatives, through a three step process starting from nitromethane and formaldehyde, and, subsequently, the reduction of the nitro group.
The processes for the preparation of 5-amino-1,3-dioxanes described in the literature evidence the remarkable drawback of using nitro derivatives, which are particularly unstable and explosive compounds, as intermediates.
Processes for the preparation of primary amines comprising the reduction of the corresponding oximes are also known in the literature.
Said reductions can be carried out by using conventional reducing agents or by means of catalytic hydrogenation [M. Hudlicky, Reduction in Organic Chemistry, Academic Press, (1984)].
Nevertheless, to the extent of our knowledge, the preparation of acetals of serinol through the reduction of the corresponding oximes has been never described in the literature.
SUMMARY OF THE INVENTION
Now we have found and it is the object of the present invention a process for the preparation of 5-amino-1,3-dioxanes of formula ##STR1## wherein
R and R 1 , the same or different, represent a hydrogen atom, a straight or branched C 1 -C 4 alkyl, an optionally substituted phenyl or, together with the carbon atom to which they are bonded, form a C 5 -C 6 cycloaliphatic ring, comprising the reduction of the oximes of formula ##STR2## wherein R and R 1 have the above reported meanings, by catalytic hydrogenation in a suitable solvent.
The compounds of formula I can be optionally hydrolyzed to serinol according to conventional techniques.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Either the serinol or the amino acetals of formula I are useful intermediates in the preparation of Iopamidol as described, for instance, in the aforementioned British patent No. 1,472,050. With the term acetal, we intend a compound obtained by reacting an alcohol, or even a diol, with either a ketone or an aldehyde (IUPAC Nomenclature of Organic Chemistry, 1979 Edition, Rule C-331, page 178).
With the term catalytic hydrogenation we intend a reduction reaction carried out in the presence of catalysts, wherein the reducing agent is hydrogen (J. March, Advanced Organic Chemistry, IV Ed., 1026). The process object of the present invention is of easy industrial application and the compounds of formula I and II, being stable, do not present the risk of explosions during the accomplishment of the process.
Specific examples of the compounds of formula I obtainable according to the process object of the present invention are:
5-amino-2,2-dimethyl-1,3-dioxane
5-amino-2,2-diethyl-1,3-dioxane
5-amino-2-ethyl-2-methyl-1,3-dioxane
5-amino-2-phenyl-1,3-dioxane
3-amino-1,5-dioxaspiro[5,5]undecane
3-amino-1,5-dioxaspiro[4,5]decane
The 1,3-dioxan-5-one oximes of formula II are new and they are a further object of the present invention.
Said compounds can be prepared by direct acetalization of 1,3-dihydroxyacetone oxime with a ketone or with an aldehyde in the presence of an acid.
It is clear to the man skilled in the art that the meanings of both R and R 1 substituents, for the compounds of formula I and II, will depend on the selected aldehyde or ketone.
In this connection, it is worth noting that, since the use to which the compounds of formula I are intended comprises their hydrolysis with loss of the R--CO--R 1 fragment, the nature of the groups R and R 1 is of little importance and their selection will be substantially guided by economic and availability criteria.
Specific examples of aldehydes or ketones which can be used in the above acetalization reaction are, for instance, formaldehyde, acetaldehyde, benzaldehyde, 4-methoxybenzaldehyde, 2-methylbenzaldehyde, acetone, butanone, 2-pentanone, 3-pentanone, cyclopentanone, cyclohexanone, acetophenone and benzophenone.
Alternatively, the preparation of 1,3-dioxan-5-one oximes of formula II can be carried out, in a preferred way, by reacting the corresponding 1,3-dioxan-5-ones with hydroxylamine hydrochloride, according to the methods usually adopted in the preparation of the oximes (J. March, Advanced Organic Chemistry, IV Ed., 906-907).
The above 1,3-dioxan-5-ones are known compounds and are prepared according to known methods [D. Hoppe et al., Tetrahedron, 45 (3), 687-694, (1989)].
The oximes of formula II according to the process object of the present invention are then catalytically hydrogenated to the compounds of formula I, in the presence of suitable reaction solvents.
Examples of employable catalysts are those commonly used in the reactions of catalytic hydrogenation.
Preferably, rhodium on alumina, Raney nickel and palladium on charcoal are used.
The catalyst is used in amounts preferably comprised between 0.001 and 0.01 moles per mole of substrate to be hydrogenated, i.e. the selected 1,3-dioxan-5-one oxime of formula II.
Larger amounts of catalyst, for instance up to 10-15% in moles with respect to the substrate, can also be used.
The hydrogenation reaction according to the process object of the present invention is carried out, as previously pointed out, in the presence of suitable inert solvents.
With the term inert solvents we intend the solvents which do not undergo chemical reactions with the reagents or with the reaction products.
Suitable solvents are those commonly used in the reactions of catalytic hydrogenation such as, for instance, lower C 1 -C 4 alcohols. Methanol and ethanol are preferably used.
Pressure and temperature do not represent critical parameters of the reaction.
Preferably, the hydrogenation is carried out at a pressure comprised between 1 and 10 bars (10 5 -10 6 Pa) and at a temperature comprised between 20° C. and 80° C.
More drastic conditions of pressure and temperature are equally effective but useless.
In a practical embodiment, the process object of the present invention is carried out according to the following operating conditions. A suitable amount of the compound of formula II in a suitable solvent (for instance methanol) is loaded into a reactor suitable to sustain internal pressures, and a suitable amount of catalyst is then added.
The resultant system is put under hydrogen atmosphere according to the commonly used techniques and kept under stirring for a few hours (5-24) at the preselected temperature and pressure [for instance 60° C. and 7 bars (7·10 5 Pa)].
Due to the following practical features such as, for instance, the easy industrial application, the accessibility of the starting material, the stability of the reagents and of the reaction products and the simple work-up of the reaction mixture, the present invention makes available a very advantageous process for the preparation of 5-amino-1,3-dioxanes.
With the aim to better illustrate the present invention, without however limiting it, the following examples are now given.
EXAMPLE 1
Preparation of 2,2-dimethyl-1,3-dioxan-5-one oxime
Hydroxylamine hydrochloride (5 g; 71.9 mmoles) was added, under stirring and in 30 minutes, to a solution of 2,2-dimethyl-1,3-dioxan-5-one (6.2 g; 47.7 mmoles) in pyridine (6.75 g; 85.4 moles), keeping the temperature at 15° C.
At the end, the reaction mixture was kept under stirring at 25° C. for 4 hours.
Methylene chloride (30 ml) and water (15 ml) were subsequently added, maintaining the stirring for further 5 minutes.
The phases were separated and the organic phase, washed with water (10 ml), was dried on anhydrous sodium sulphate and evaporated at reduced pressure.
2,2-Dimethyl-1,3-dioxan-5-one oxime (6.7 g) was thus obtained (97.5% 1 H-NMR titre, 95% yield).
1 H-NMR (300 MHz, DMSO-d 6 ): δ (ppm): 1.33 (s, 6H); 4.19 (s, 2H); 4.46 (s, 2H); 10.82 (s, 1H).
IR (NEAT): significative bands at 3360, 1440, 1380 cm -1
By working in a similar way but using 1,3-dioxan-5-one, 2,2-diethyl-1,3-dioxan-5-one and 1,5-dioxaspiro[5,5]undecan-3-one, in place of 2,2-dimethyl-1,3-dioxan-5-one, the following compounds were respectively obtained: 1,3-dioxan-5-one oxime, 2,2-diethyl-1,3-dioxan-5-one oxime and 1,5-dioxaspiro[5,5]undecan-3-one oxime.
EXAMPLE 2
Preparation of 5-amino-2,2-dimethyl-1,3-dioxane
2,2-Dimethyl-1,3-dioxan-5-one oxime (5 g; 34.4 mmoles), prepared as described in example 1, methanol (40 ml) and rhodium supported on alumina at 5% (0.35 g; 0.17 mmoles) were respectively loaded into a reactor provided with mechanical stirring.
After removing the surrounding air, hydrogen at a pressure of 7 bars (7·10 5 Pa) was added.
The resultant system was thus kept under stirring at 60° C. for 5 hours.
At the end of the reaction, after emptying the reactor, the catalyst was filtered off on a celite bed and the solvent was evaporated at reduced pressure.
A crude product (5 g) constituted by 5-amino-2,2-dimethyl-1,3-dioxane (65% G. C. titre, 72% yield), according to gas-chromatographic analysis, was thus obtained.
The desired product was then isolated by distillation of the reaction crude at 75° C. and 12 mm/Hg. | Described herein is a process for the preparation of 5-amino-1,3-dioxanes of formula (I), wherein R and R 1 have the meanings reported in the description, comprising the catalytic hydrogenation of the new oximes of formula (II). | 2 |
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2004-0093100, filed on Nov. 15, 2004, the content of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to an integrated circuit device, and more particularly, to a bias current generating circuit for an integrated circuit device.
BACKGROUND OF THE INVENTION
[0003] Bias current generating circuits are commonly employed in integrated circuit devices in order to generate a bias current from an external power supply voltage. An ideal bias current generating circuit generates a consistent bias current that is independent of variation in applied power, process parameters and temperature.
[0004] A conventional bias current generation circuit is disclosed in U.S. Pat. No. 6,201,436, the content of which is incorporated herein by reference. Such a circuit employs a first current generator in which a first generated current is proportional to absolute temperature (PTAT), or increases with increased temperature, and a second current generator in which a second generated current is inverse-proportional to absolute temperature (IPTAT), or decreases with increased temperature. The first and second generated currents are summed to generate a combined bias current with reduced susceptibility to variation in temperature and applied power.
[0005] In the conventional design, the PTAT and IPTAT current generators employ a resistor to generate the respective first and second currents. Since resistors are highly susceptible to process variation and operating temperature variation, the resulting bias current in the conventional approach is likewise susceptible to process and temperature variations.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a bias current generating circuit that generates a reliable and consistent bias current, irrespective of variation in applied power, process and temperature.
[0007] In particular, in one embodiment, the bias current generator of the present invention generates a bias current using a PTAT current generator and an IPTAT current generator comprising exclusively active circuit elements, for example transistors. No passive elements, such as resistors, are employed. The generated bias current is substantially a function of the respective aspect ratios of transistors of current paths of the device. In this manner, the resulting generated bias current has greatly reduced susceptibility to variation in applied power, process and temperature.
[0008] In one aspect, the present invention is directed to a bias current generator. The generator includes a proportional-to-absolute-temperature (PTAT) current generator comprising exclusively active circuit elements that generates a first current that is proportional to operating temperature. An inverse-proportional-to-absolute-temperature (IPTAT) current generator comprising exclusively active circuit elements generates a second current that is inversely proportional to the operating temperature. A summing circuit sums the first and second currents to generate a bias current.
[0009] In one embodiment, the bias current is generated substantially independent of the operating temperature.
[0010] In another embodiment, the PTAT current generator comprises: a PMOS cascode current mirror comprising: a first PMOS transistor and a second PMOS transistor connected in series between a first reference voltage and a first node, a gate of the first PMOS transistor being coupled to the first node and a gate of the second PMOS transistor being coupled to a first bias voltage; and a third PMOS transistor and a fourth PMOS transistor connected in series between the first reference voltage and a second node, a gate of the third PMOS transistor being coupled to the first node and a gate of the fourth PMOS transistor being coupled to the first bias voltage; an NMOS cascode current mirror comprising: a first NMOS transistor and a second NMOS transistor connected in series between the first node and a third node, a gate of the first NMOS transistor being coupled to a second bias voltage and a gate of the second NMOS transistor being coupled to the second node; and a third NMOS transistor and a fourth NMOS transistor connected in series between the second node and a fourth node, a gate of the third NMOS transistor being coupled to the second bias voltage and a gate of the fourth NMOS transistor being coupled to the second node; a first diode connected in series between the third node and a second reference voltage; and a second diode connected in series between the fourth node and the second reference voltage.
[0011] In another embodiment, the first reference voltage comprises a power supply voltage and the second reference voltage comprises a ground voltage.
[0012] In another embodiment, the first diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the third node and a base and collector of which are connected to the second reference voltage and wherein the second diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the fourth node and a base and collector of which are connected to the second reference voltage.
[0013] In another embodiment, the first bias voltage is at a voltage level that is sufficient to saturate the second and fourth PMOS transistors, and wherein the second bias voltage is at a voltage level that is sufficient to saturate the first and third NMOS transistors.
[0014] In another embodiment, the IPTAT current generator comprises: a fifth PMOS transistor and a sixth PMOS transistor connected in series between the first reference voltage and a fifth node, a gate of the fifth PMOS transistor being coupled to the first node and a gate of the sixth PMOS transistor being coupled to the first bias voltage; and a fifth NMOS transistor and a sixth NMOS transistor connected in series between the fifth node and the second reference voltage, the fifth and sixth NMOS transistors each being configured in a diode configuration; a seventh PMOS transistor connected between the first reference voltage and a sixth node, the gate of the seventh PMOS transistor being coupled to the sixth node; and a seventh NMOS transistor and an eighth NMOS transistor connected in series between the sixth node and the second reference voltage, a gate of the seventh NMOS transistor being coupled to the second node, and a gate of the eighth NMOS transistor being coupled to the fifth node.
[0015] In another embodiment, the summing circuit comprises: an eighth PMOS transistor and a ninth PMOS transistor connected in series between the first reference voltage and a seventh node, a gate of the eighth PMOS transistor being coupled to the first node and a gate of the ninth PMOS transistor being coupled to the first bias voltage; a tenth PMOS transistor connected between the first reference voltage and the seventh node, a gate of the tenth PMOS transistor being coupled to the sixth node; a ninth NMOS transistor connected between the seventh node and the second reference voltage, the gate of the ninth NMOS transistor being coupled to the seventh node; and a tenth NMOS transistor connected between a bias node at which the bias current is drawn and the second reference voltage, the gate of the tenth NMOS transistor being coupled to the seventh node.
[0016] In another embodiment, the bias current generator further comprises a bias voltage generator including a first bias voltage generator that generates the first bias voltage and a second bias voltage generator that generates the second bias voltage. The first bias voltage generator comprises: an eleventh PMOS transistor and an eleventh NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the eleventh PMOS transistor being coupled to the first node, the gate of the eleventh NMOS transistor being coupled to a junction between the eleventh PMOS transistor and the eleventh NMOS transistor; a twelfth PMOS transistor and a twelfth NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the twelfth PMOS transistor being coupled to a junction between the twelfth PMOS transistor and the twelfth NMOS transistor, the gate of the twelfth NMOS transistor being coupled to the gate of the eleventh NMOS transistor; and a thirteenth PMOS transistor, a fourteenth PMOS transistor and a thirteenth NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the thirteenth PMOS transistor being coupled to the gate of the twelfth PMOS transistor, the gate of the fourteenth PMOS transistor being coupled to a junction between the fourteenth PMOS transistor and the thirteenth NMOS transistor, the gate of the thirteenth NMOS transistor being coupled to the gate of the twelfth NMOS transistor, wherein the junction of the fourteenth PMOS transistor and the thirteenth NMOS transistor provides the first bias voltage. The second bias voltage generator comprises: a fifteenth PMOS transistor and a fifteenth NMOS transistor in series between the first reference voltage and an eighth node, the gate of the fifteenth PMOS transistor being coupled to the first node, the gate of the fifteenth NMOS transistor being coupled to a junction between the fifteenth PMOS transistor and the fifteenth NMOS transistor; a sixteenth PMOS transistor, a fourteenth NMOS transistor and a sixteenth NMOS transistor in series between the first reference voltage and the eighth node, the gate of the sixteenth PMOS transistor being coupled to the first node, the gate of the fourteenth NMOS transistor being coupled to a junction between the sixteenth PMOS transistor and the fourteenth NMOS transistor, the gate of the sixteenth NMOS transistor being coupled to the gate of the fifteenth NMOS transistor; and a third diode connected in series between the eighth node and the second reference voltage, wherein the junction of the sixteenth PMOS transistor and the fourteenth NMOS transistor provides the second bias voltage.
[0017] In another embodiment, the third diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the eighth node and a base and collector of which are connected to the second reference voltage.
[0018] In another embodiment, the bias current generator further comprises a start-up circuit that ensures that transistors in the PTAT current generator and the IPTAT current generator initialize beyond a degenerate bias.
[0019] In another embodiment, the start-up circuit comprises: a seventeenth PMOS transistor, an eighteenth PMOS transistor, a nineteenth NMOS transistor and a twentieth NMOS transistor connected in series between the first reference voltage and the second reference voltage, gates of the seventeenth and eighteenth PMOS transistors each being coupled to the second reference voltage, a gate of the nineteenth NMOS transistor being coupled to the second bias voltage and a gate of the twentieth NMOS transistor being coupled to the second node; a seventeenth NMOS transistor connected in series between the first node and the second reference voltage; and an eighteenth NMOS transistor connected in series between the first bias voltage and the second reference voltage.
[0020] In another embodiment, the summing circuit comprises: a first current mirror that generates a first mirrored current in response to the first current generated by the PTAT;. a second current mirror that generates a second mirrored current in response to the second current generated by the PTAT; and a third current mirror that generates the bias current based on the sum of the first mirrored current and the second mirrored current.
[0021] In another embodiment, the first current is generated further as a function of a first aspect ratio of at least one transistor along a first current path relative to a second aspect ratio of at least one transistor along a second current path, the second current path and first current path being in a current mirror configuration, the first and second aspect ratios for corresponding transistors in the first and second current paths being different.
[0022] In another embodiment, the second current is generated further as a function of a voltage generated in the PTAT current generator that is divided by an active circuit element in the IPTAT current generator to generate the second current.
[0023] In another embodiment, the PTAT current generator comprises: a first current path comprising a plurality of transistors; and a second current path comprising a plurality of transistors, at least one of the plurality of transistors of the second current path corresponding to one of the plurality of transistors of the first current path, at least one pair of the corresponding transistors of the first and second current paths having a different aspect ratio, wherein the first current is generated in response to the different aspect ratio of the corresponding transistors of the first and second current paths.
[0024] In another embodiment, the IPTAT current generator comprises: a third current path comprising a plurality of transistors, wherein the second current is generated as a function of a voltage generated in the PTAT current generator that is divided by a transistor in the third current path to generate the second current.
[0025] In another embodiment, the PTAT current generator comprises: a first diode connected in series between a first reference voltage and a third node; a second diode connected in series between the first reference voltage and a fourth node; a PMOS cascode current mirror comprising: a first PMOS transistor and a second PMOS transistor connected in series between the third node and a first node, and a third PMOS transistor and a fourth PMOS transistor connected in series between the fourth node and a second node, gates of the first and third PMOS transistors being coupled to the second node, and gates of the second and fourth PMOS transistors being coupled to a first bias voltage; and an NMOS cascode current mirror comprising: a first NMOS transistor and a second NMOS transistor connected in series between the first node and a second reference voltage, and a third NMOS transistor and a fourth NMOS transistor connected in series between the second node and the second reference voltage, gates of the first and third NMOS transistors being coupled to a second bias voltage, and gates of the second and fourth NMOS transistors being coupled to the first node.
[0026] In another embodiment, the first reference voltage comprises a power supply voltage and the second reference voltage comprises a ground voltage.
[0027] In another embodiment, the first diode comprises an NPN-type bipolar junction transistor, an emitter of which is connected to the third node and a base and collector of which are connected to the first reference voltage and wherein the second diode comprises an NPN-type bipolar junction transistor, an emitter of which is connected to the fourth node and a base and collector of which are connected to the first reference voltage.
[0028] In another embodiment, the first bias voltage is at a voltage level that is sufficient to saturate the second and fourth PMOS transistors, and wherein the second bias voltage is at a voltage level that is sufficient to saturate the first and third NMOS transistors.
[0029] In another embodiment, the IPTAT current generator comprises: a fifth PMOS transistor and a sixth PMOS transistor connected in series between the first reference voltage and a fifth node, the fifth and sixth PMOS transistors each being configured in a diode configuration; and a fifth NMOS transistor and a sixth NMOS transistor connected in series between the fifth node and the second reference voltage, a gate of the fifth NMOS transistor being coupled to the second bias voltage and a gate of the sixth NMOS transistor being coupled to the first node; a seventh PMOS transistor and an eighth PMOS transistor connected in series between the first reference voltage and a sixth node, a gate of the seventh PMOS transistor being coupled to the fifth node, and a gate of the eighth PMOS transistor being coupled to the second node; and a seventh NMOS transistor connected between the sixth node and the second reference voltage, the gate of the seventh NMOS transistor being coupled to the sixth node.
[0030] In another embodiment, the summing circuit comprises: an eighth NMOS transistor and a ninth NMOS transistor connected in series between a seventh node and the second reference voltage, a gate of the eighth NMOS transistor being coupled to the second bias voltage and a gate of the ninth NMOS transistor being coupled to the first node; a tenth NMOS transistor connected between the seventh node and the second reference voltage, a gate of the tenth NMOS transistor being coupled to the sixth node; and a ninth PMOS transistor connected between the first reference voltage and the seventh node, the gate of the ninth PMOS transistor being coupled to the seventh node; and a tenth PMOS transistor connected between the first reference voltage and a bias node at which the bias current is drawn, the gate of the tenth NMOS transistor being coupled to the seventh node.
[0031] In another aspect, the present invention is directed to a bias current generator. A proportional-to-absolute-temperature (PTAT) current generator generates a first current that is proportional to operating temperature. The PTAT current generator comprises a first current path comprising a plurality of transistors; and a second current path comprising a plurality of transistors, at least one of the plurality of transistors of the second current path corresponding to one of the plurality of transistors of the first current path, at least one pair of the corresponding transistors of the first and second current paths having a different aspect ratio, wherein the first current is generated in response to the different aspect ratio of the corresponding transistors of the first and second current paths. An inverse-proportional-to-absolute-temperature (IPTAT) current generator generates a second current that is inversely proportional to the operating temperature. The IPTAT current generator comprises a third current path comprising a plurality of transistors. The second current is generated as a function of a voltage generated in the PTAT current generator that is divided by a transistor in the third current path to generate the second current. A summing circuit sums the first and second currents to generate a bias current.
[0032] In one embodiment, the PTAT current generator comprises exclusively active circuit elements.
[0033] In another embodiment, the IPTAT current generator comprises exclusively active circuit elements.
[0034] In another embodiment, the bias current is generated substantially independent of the operating temperature.
[0035] In another embodiment, the PTAT current generator comprises: a PMOS cascode current mirror comprising: a first PMOS transistor and a second PMOS transistor connected in series between a first reference voltage and a first node, a gate of the first PMOS transistor being coupled to the first node and a gate of the second PMOS transistor being coupled to a first bias voltage; and a third PMOS transistor and a fourth PMOS transistor connected in series between the first reference voltage and a second node, a gate of the third PMOS transistor being coupled to the first node and a gate of the fourth PMOS transistor being coupled to the first bias voltage; an NMOS cascode current mirror comprising: a first NMOS transistor and a second NMOS transistor connected in series between the first node and a third node, a gate of the first NMOS transistor being coupled to a second bias voltage and a gate of the second NMOS transistor being coupled to the second node; and a third NMOS transistor and a fourth NMOS transistor connected in series between the second node and a fourth node, a gate of the third NMOS transistor being coupled to the second bias voltage and a gate of the fourth NMOS transistor being coupled to the second node; a first diode connected in series between the third node and a second reference voltage; and a second diode connected in series between the fourth node and the second reference voltage.
[0036] In another embodiment, the first reference voltage comprises a power supply voltage and the second reference voltage comprises a ground voltage.
[0037] In another embodiment, the first diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the third node and a base and collector of which are connected to the second reference voltage and wherein the second diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the fourth node and a base and collector of which are connected to the second reference voltage.
[0038] In another embodiment, the first bias voltage is at a voltage level that is sufficient to saturate the second and fourth PMOS transistors, and wherein the second bias voltage is at a voltage level that is sufficient to saturate the first and third NMOS transistors.
[0039] In another embodiment, the IPTAT current generator comprises: a fifth PMOS transistor and a sixth PMOS transistor connected in series between the first reference voltage and a fifth node, a gate of the fifth PMOS transistor being coupled to the first node and a gate of the sixth PMOS transistor being coupled to the first bias voltage; and a fifth NMOS transistor and a sixth NMOS transistor connected in series between the fifth node and the second reference voltage, the fifth and sixth NMOS transistors each being configured in a diode configuration; a seventh PMOS transistor connected between the first reference voltage and a sixth node, the gate of the seventh PMOS transistor being coupled to the sixth node; and a seventh NMOS transistor and an eighth NMOS transistor connected in series between the sixth node and the second reference voltage, a gate of the seventh NMOS transistor being coupled to the second node, and a gate of the eighth NMOS transistor being coupled to the fifth node.
[0040] In another embodiment, the summing circuit comprises: an eighth PMOS transistor and a ninth PMOS transistor connected in series between the first reference voltage and a seventh node, a gate of the eighth PMOS transistor being coupled to the first node and a gate of the ninth PMOS transistor being coupled to the first bias voltage; a tenth PMOS transistor connected between the first reference voltage and the seventh node, a gate of the tenth PMOS transistor being coupled to the sixth node; a ninth NMOS transistor connected between the seventh node and the second reference voltage, the gate of the ninth NMOS transistor being coupled to the seventh node; and a tenth NMOS transistor connected between a bias node at which the bias current is drawn and the second reference voltage, the gate of the tenth NMOS transistor being coupled to the seventh node.
[0041] In another embodiment, the bias current generator further comprises a bias voltage generator including a first bias voltage generator that generates the first bias voltage and a second bias voltage generator that generates the second bias voltage. The first bias voltage generator comprises: an eleventh PMOS transistor and an eleventh NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the eleventh PMOS transistor being coupled to the first node, the gate of the eleventh NMOS transistor being coupled to a junction between the eleventh PMOS transistor and the eleventh NMOS transistor; a twelfth PMOS transistor and a twelfth NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the twelfth PMOS transistor being coupled to a junction between the twelfth PMOS transistor and the twelfth NMOS transistor, the gate of the twelfth NMOS transistor being coupled to the gate of the eleventh NMOS transistor; and a thirteenth PMOS transistor, a fourteenth PMOS transistor and a thirteenth NMOS transistor in series between the first reference voltage and the second reference voltage, the gate of the thirteenth PMOS transistor being coupled to the gate of the twelfth PMOS transistor, the gate of the fourteenth PMOS transistor being coupled to a junction between the fourteenth PMOS transistor and the thirteenth NMOS transistor, the gate of the thirteenth NMOS transistor being coupled to the gate of the twelfth NMOS transistor, wherein the junction of the fourteenth PMOS transistor and the thirteenth NMOS transistor provides the first bias voltage. The second bias voltage generator comprises: a fifteenth PMOS transistor and a fifteenth NMOS transistor in series between the first reference voltage and an eighth node, the gate of the fifteenth PMOS transistor being coupled to the first node, the gate of the fifteenth NMOS transistor being coupled to a junction between the fifteenth PMOS transistor and the fifteenth NMOS transistor; a sixteenth PMOS transistor, a fourteenth NMOS transistor and a sixteenth NMOS transistor in series between the first reference voltage and the eighth node, the gate of the sixteenth PMOS transistor being coupled to the first node, the gate of the fourteenth NMOS transistor being coupled to a junction between the sixteenth PMOS transistor and the fourteenth NMOS transistor, the gate of the sixteenth NMOS transistor being coupled to the gate of the fifteenth NMOS transistor; and a third diode connected in series between the eighth node and the second reference voltage, wherein the junction of the sixteenth PMOS transistor and the fourteenth NMOS transistor provides the second bias voltage.
[0042] In another embodiment, the third diode comprises a PNP-type bipolar junction transistor, an emitter of which is connected to the eighth node and a base and collector of which are connected to the second reference voltage.
[0043] In another embodiment, the bias current generator further comprises a start-up circuit that ensures that transistors in the PTAT current generator and the IPTAT current generator initialize beyond a degenerate bias.
[0044] In another embodiment, the start-up circuit comprises: a seventeenth PMOS transistor, an eighteenth PMOS transistor, a nineteenth NMOS transistor and a twentieth NMOS transistor connected in series between the first reference voltage and the second reference voltage, gates of the seventeenth and eighteenth PMOS transistors each being coupled to the second reference voltage, a gate of the nineteenth NMOS transistor being coupled to the second bias voltage and a gate of the twentieth NMOS transistor being coupled to the second node; a seventeenth NMOS transistor connected in series between the first node and the second reference voltage; and an eighteenth NMOS transistor connected in series between the first bias voltage and the second reference voltage.
[0045] In another embodiment, the summing circuit comprises: a first current mirror that generates a first mirrored current in response to the first current generated by the PTAT; a second current mirror that generates a second mirrored current in response to the second current generated by the PTAT; and a third current mirror that generates the bias current based on the sum of the first mirrored current and the second mirrored current.
[0046] In another embodiment, the first current is generated further as a function of a first aspect ratio of at least one transistor along a first current path relative to a second aspect ratio of at least one transistor along a second current path, the second current path and first current path being in a current mirror configuration, the first and second aspect ratios for corresponding transistors in the first and second current paths being different.
[0047] In another embodiment, the second current is generated further as a function of a voltage generated in the PTAT current generator that is divided by an active circuit element in the IPTAT current generator to generate the second current.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0049] FIG. 1 is a circuit diagram of a first embodiment of a bias current generating circuit in accordance with the present invention.
[0050] FIG. 2 is a circuit diagram of a second embodiment of a bias current generating circuit in accordance with the present invention.
[0051] FIG. 3 is a circuit diagram of a third embodiment of a bias current generating circuit in accordance with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] FIG. 1 is a circuit diagram of a first embodiment of a bias current generating circuit in accordance with the present invention. With reference to FIG. 1 , the bias generating circuit includes a proportional-to-absolute-temperature (PTAT) current generator 200 , an inverse-proportional-to-absolute-temperature (IPTAT) current generator 400 , and a summing circuit 500 .
[0053] In one embodiment, the PTAT current generator 200 and the IPTAT current generator 400 employ exclusively active elements, such as NMOS and PMOS transistors and bipolar junction transistors, and therefore do not include passive elements, such as resistors. The PTAT current generator 200 generates a first sub-current I 1 that is proportional to temperature. The IPTAT current generator 400 generates a second sub-current I 2 that is inverse-proportional to temperature. The summing circuit 500 sums the first sub-current I 1 and the second sub-current I 2 to generate a sum current I 3 that is used to generate a bias current I bias . Since the PTAT current generator 200 and the IPTAT current generator 400 do not employ passive elements such as resistors, the bias current generating circuit of FIG. 1 has near insusceptibility to variation in process, applied voltage, and temperature.
[0054] In this embodiment, the PTAT current generator 200 includes a PMOS cascode current mirror 211 , an NMOS cascode current mirror 220 , and first and second PNP-type bipolar junction transistors 210 , 209 .
[0055] The PMOS cascode current mirror 211 includes a first PMOS transistor 208 and a second PMOS transistor 206 coupled in series between a first reference voltage VDD and a first node 240 . The PMOS cascode current mirror 211 further includes a third PMOS transistor 207 and a fourth PMOS transistor 205 coupled in series between the first reference voltage VDD and a second node 242 . Gates of the first PMOS transistor 208 and the third PMOS transistor 207 are coupled to the first node 240 . Gates of the second PMOS transistor 206 and the fourth PMOS transistor 205 are coupled to a first bias voltage Vcasp.
[0056] The NMOS cascode current mirror 220 includes a first NMOS transistor 204 and a second NMOS transistor 202 coupled in series between the first node 240 and a third node 244 . The NMOS cascode current mirror 220 further includes a third NMOS transistor 203 and a fourth NMOS transistor 201 coupled in series between the second node 242 and a fourth node 246 . Gates of the first NMOS transistor 204 and the third NMOS transistor 203 are coupled to a second bias voltage Vcasn. Gates of the second NMOS transistor 202 and the fourth NMOS transistor 201 are coupled to the second node 242 .
[0057] A first bipolar junction transistor 210 is coupled in a diode configuration between the third node 244 and a second reference voltage GND. The base of the first bipolar junction transistor 210 is coupled to the second reference voltage GND. A second bipolar junction transistor 209 is coupled in a diode configuration between the fourth node 246 and the second reference voltage GND. The base of the second bipolar junction transistor 209 is coupled to the second reference voltage GND.
[0058] By virtue of the operation of the current mirror configuration, the first sub-current I 1 , flowing through the first and second PMOS transistors 208 and 206 and the first and second NMOS transistors 204 and 202 is equal to the first mirror sub-current I 1 ′ flowing through the third and fourth PMOS transistors 207 and 205 and the third and fourth NMOS transistors 203 and 201 . According to the circuit configuration, the gate voltages of the third and fourth NMOS transistors 202 , 201 are the same, therefore:
V be1 +V gs201 =V be2 +V gs202 (1)
where the voltage at the fourth node, V be1 , is the base-emitter voltage of the second bipolar junction transistor 209 , V gs201 is the gate-source voltage of the fourth NMOS transistor 201 , the voltage at the third node, V be2 , is the base-emitter voltage of the first bipolar junction transistor 210 , and V gs202 is the gate-source voltage of the third NMOS transistor 202 .
[0059] Since the base-emitter voltage of a bipolar junction transistor can be represented as:
V be = V T · ln I C I S ( 2 )
where V T represents thermal voltage), I C is the collector current through the transistor and I S is the bipolar junction transistor saturation current,
and since the gate-source voltage of a MOS transistor can be represented as:
V gs = 2 I D μ n C ox ( W / L ) + V th ( 3 )
where I D is drain current), μ n is electron mobility, C ox is the gate unit capacitance, W/L is the aspect ratio of the transistor and V th is the transistor threshold voltage, then, ignoring the base current, equations (2) and (3) above can be substituted into equation (1) above to give:
V T · ln I 1 ′ I S209 + 2 I 1 ′ μ n C ox ( W / L ) 201 + V th201 = V T · ln I 1 I S210 + 2 I 1 μ n C ox ( W / L ) 202 + V th202 ( 4 )
If the transistor body effect is considered negligible, and the threshold voltage of the fourth NMOS transistor is assumed to be equal to the threshold voltage of the third NMOS transistor, V th201 =V th202 , and the first sub-current I 1 is considered equal to the first mirrored sub current I 1 ′, I 1 =I 1 ′, then equation (4) can be rewritten as:
V T · ln I S210 I S209 = 2 I 1 μ n C ox ( W / L ) 201 ( ( W / L ) 201 ( W / L ) 202 - 1 ) ( 5 )
With respect to current I 1 :
I 1 = μ n C ox ( W / L ) 201 ( kT q · ln m ) 2 2 ( n - 1 ) 2 ( 6 )
where k is the Boltzman constant, T is absolute temperature, m=I S210 /I S209 , q is the electron charge value and n=(W/L) 201 /(W/L) 202 . The parameter μ n C ox is proportional to T −1.5 , so the first sub-current I 1 is proportional to T 0.5 , I 1 ∝T 0.5 , and especially in the operational range of the bias circuit, namely in the industrial temperature range between −55 C and 125 C, the proportional rate is linear. In one embodiment, both m and n are chosen to be greater than 1 and, in one example, n=2 and m=7.
[0061] The gate voltage V gn of the fourth NMOS transistor 201 is used to generate the second sub-current I 2 at the IPTAT current generator 400 , and can be represented as the sum of the base-emitter voltage of the second bipolar junction transistor 209 , V be1 , and the gate-to-source voltage of the fourth NMOS transistor 201 , V gs201 . Substituting equation (3) above provides:
V gn = V be1 + V gs201 = V be1 + 2 I 1 μ n C ox ( W / L ) 201 + V th = V be1 + V th + kT q · ln m n - 1 ( 7 )
[0062] Returning to equation (2), and differentiating V be1 with respect to absolute temperature T provides:
∂ V be1 ∂ T = ∂ V T ∂ T ln I C209 + V T I C209 ∂ I C209 ∂ T - ∂ V T ∂ T ln I S209 - V T I S209 ∂ I S209 ∂ T ( 8 )
[0063] If the base current of the second bipolar junction transistor 209 is considered negligible, and ignored, then the current flowing through the second bipolar junction transistor I c209 is substantially the same as the first sub-current I 1 . Since the first sub-current I 1 is proportional to T 0.5 , then:
I C209 =c·T 0.5 (9)
where c represents a proportional constant, and T is absolute temperature.
[0064] The saturation current of the second bipolar junction transistor 209 , I S209 can be represented as:
I S209 =b·T 2.5 e −E g /kT (10)
where b represents a proportional constant and E g is the bandgap energy of silicon, or 1.12 eV.
[0065] From equations (9) and (10), it can be derived that:
∂ V T ∂ T ln I C209 = V T T ln I C209 ( 11 ) V T I C209 ∂ I C209 ∂ T = V T cT 0.5 · 1 2 cT - 0.5 = V T / 2 T ( 12 ) ∂ V T ∂ T ln I S209 = V T T ln I S209 ( 13 ) V T I S209 ∂ I S209 ∂ T = 5 2 V T T + E g kT 2 V T = 2.5 V T T + E g / q T ( 14 )
Substituting equations (11)-(14) into equation (8) provides for the temperature coefficient of the base-emitter voltage of the second bipolar junction transistor 209 , or the temperature coefficient of V be1 :
∂ V be1 ∂ T = V T T ln I C209 + V T / 2 T - V T T ln I S209 - 2.5 V T T - E g / q T = V be1 - 2 V T - E g / q T ( 15 )
In one example, the base-emitter voltage of the second bipolar junction transistor V be1 =0.8V, the thermal voltage V T =26 mV, the parameter Eg/q=1.12V, and the absolute operating temperature T=300K. In this case, the resulting temperature coefficient of the base-emitter voltage of the second bipolar junction transistor is equal to −1.2 mV/C.
[0066] Returning to equation (7), the temperature coefficient of the first term of the equation is −1.2 mV/C, the temperature coefficient of the second term of the equation is −2.5 mV/C, and the temperature coefficient of the third term of the equation is 0.4 mV/C. The stated coefficients are typical values, and can change from process to process.
[0067] In view of the above, it can be concluded that the gate voltage of the fourth NMOS transistor 201 , V gn201 , is inversely proportional to temperature, and especially in the industrial operating range of −55 C to 125 C, V gn is proportionally reduced, in other words, V gn decreases with increasing temperature.
[0068] Although the third term of equation (7) increases with temperature, for typical values of m and n (for example, m=7 and n=2), the slope of this term is 0.4 mV/C. Therefore, as temperature rises, the combined decrease of the first two terms dominates over the increase of the third term in equation (7). Thus, the net effect is that gate voltage of the fourth NMOS transistor V gn201 approximately decreases linearly with increasing temperature in the temperature range of interest. Therefore, the PTAT current generator circuit 200 generates both a first sub-current I 1 and a voltage V gn that decrease with temperature. This voltage V gn is used to generate the IPTAT current, as described below. Since no integrated resistors are used in the PTAT current generator 200 , the generated first sub-current I 1 is not sensitive to process variations.
[0069] The IPTAT current generator 400 includes a control voltage supply 410 and a second sub-current generator 412 .
[0070] The control voltage supply 410 includes a fifth PMOS transistor 401 and a sixth PMOS transistor 402 coupled in series between the first reference voltage VDD and a fifth node 414 . The gate of the fifth PMOS transistor is coupled to the first node 240 and the gate of the sixth PMOS transistor is coupled to the first bias voltage Vcasp. The control voltage supply 410 further includes a fifth NMOS transistor 403 and a sixth NMOS transistor 404 coupled in series between the fifth node 414 and the second reference voltage GND. The gates of the fifth NMOS transistor 403 and the sixth NMOS transistor 404 are coupled to their sources, so that the fifth and sixth NMOS transistors 403 , 404 are diode-connected and therefore operate as diodes.
[0071] The second sub-current generator 412 of the IPTAT current generator 400 includes a seventh PMOS transistor 407 coupled in series between the first reference voltage VDD and a sixth node 416 . The gate of the seventh PMOS transistor 407 is coupled to the sixth node 416 . The second sub-current generator 412 of the IPTAT current generator 400 further includes a seventh NMOS transistor 405 and an eighth NMOS transistor 406 coupled in series between the sixth node 416 and the second reference voltage GND. The gate of the seventh NMOS transistor 405 is coupled to the second node 242 at the gate of the fourth NMOS transistor V gn201 , and the gate of the eighth NMOS transistor 406 is coupled to the fifth node 414 .
[0072] The control voltage supplier 410 operates to ensure that the voltage supplied by the fifth node 414 to the gate of the eighth NMOS transistor 406 , V g406 , causes the eighth NMOS transistor to operate in the linear region. By ensuring operation of the eighth NMOS transistor 406 in the linear region, the eighth NMOS transistor operates in the same manner that a resistor operates.
[0073] As described above, the voltage at the gate of the fourth NMOS transistor V gn201 is inversely proportional to operating temperature. Since that voltage is applied to the gate of the seventh NMOS transistor 405 , the second sub-current I 2 is generated to be inversely proportional to the operating temperature.
[0074] The drain current I 2 of the eighth NMOS transistor 406 can be represented as:
I 2 = 1 1 / g m405 + r ds406 · V gn ≈ V gn r ds406 ( 16 )
where g m405 is the transconductance of the seventh NMOS transistor 405 , V gn is the gate voltage of the eighth NMOS transistor 406 , V g406 , and r ds406 is the drain-source resistance of the eighth NMOS transistor 406 . The approximation of equation (16) holds true if r ds406 >>1/g m405 , which can be achieved by providing the eighth NMOS transistor 406 with a relatively small aspect ratio (W/L ratio).
[0075] The resistance of the eighth NMOS transistor 406 , r ds406 , can be expressed as:
r ds 406 = 1 μ n C ox ( W / L ) 406 ( V g 406 - V th ) ( 17 )
[0076] The gate voltage of the NMOS transistor 406 , V g406 , can be represented as:
V g 406 = V gs 404 + V gs 403 = 2 I D 404 μ n C ox ( W / L ) 404 + V th + 2 I D 403 μ n C ox ( W / L ) 403 + V th = 2 I 1 ( W / L ) 401 / ( W / L ) 208 μ n C ox ( W / L ) 404 + 2 I 1 ( W / L ) 401 / ( W / L ) 208 μ n C ox ( W / L ) 403 + 2 V th = 2 ( W / L ) 401 ( W / L ) 208 μ n C ox ( W / L ) 404 μ n C ox ( W / L ) 201 ( kT g ln m ) 2 2 ( n - 1 ) 2 + 2 ( W / L ) 401 ( W / L ) 208 μ n C ox ( W / L ) 403 μ n C ox ( W / L ) 201 ( kT g ln m ) 2 2 ( n - 1 ) 2 + 2 V th = kT q · ln m n - 1 ( ( W / L ) 401 ( W / L ) 201 ( W / L ) 208 ( W / L ) 404 + ( W / L ) 401 ( W / L ) 201 ( W / L ) 208 ( W / L ) 403 + ) + 2 V th ( 18 )
where m=I S210 /I S209 and where n=(W/L) 201 /(W/L) 202 , from equation (6) above, and where the body effect of the fifth NMOS transistor is considered negligible.
[0077] Now, substituting equation (18) into equation (17), provides another expression for the resistance of the eighth NMOS transistor 406 , r ds406 :
r ds 406 = ( 1 ) μ n C ox ( W / L ) 406 [ kT q · ln m n - 1 ( ( W / L ) 401 ( W / L ) 201 ( W / L ) 208 ( W / L ) 404 + ( W / L ) 401 ( W / L ) 201 ( W / L ) 208 ( W / L ) 403 ) + V th ] ( 19 )
[0078] It can be seen in this representation that the first term of the bracket in the denominator is proportional to temperature and the second term of the bracket in the denominator, or V th , is inversely proportional to temperature, which is a known property of MOSFET devices. In this manner, the effective resistance of the eighth NMOS transistor 406 , r ds406 , is made to be independent of temperature, the resistance value r ds406 being exclusively controlled according to the aspect ratio (W/L), or the ratio of channel width W to channel length L, of the fifth PMOS transistor 401 , the fifth NMOS transistor 403 , the sixth NMOS transistor 404 and the eighth NMOS transistor 406 , the fourth NMOS transistor 201 , and the first PMOS transistor 208 . By controlling the aspect ratios in this manner, the eighth NMOS transistor can be made to operate as a resistor, while not being subject to temperature-dependence. Therefore, the IPTAT 400 including the eighth NMOS transistor 406 can be made to generate a second sub-current I 2 that is inversely proportional to temperature, since the gate voltage of the eighth NMOS transistor 406 , V g406 , is inversely proportional to temperature, while not being subject to temperature-dependent operation. This assumes that the effect of μ n in equation (19) is not considered. If this effect is considered, μ n αT 1.5 as mentioned previously, and r ds406 increases with temperature. Returning to equation (16), as temperature increases, the numerator (V gn ) decreases, while the denominator increases. Therefore, in this manner, the second sub-current I 2 decreases with temperature. Resistors are highly sensitive to process variation and are also temperature-dependent. Therefore, by eliminating resistors in the present configuration, sensitivity to process variation and temperature dependence in greatly reduced.
[0079] During operation, the first bias voltage V casp and the second bias voltage V casn ensure that the PMOS transistors 205 , 206 , and 402 and the NMOS transistors 203 , 204 respectively operate in the saturation region. In addition, in one embodiment, the respective aspect ratios of the first and third PMOS transistors 208 , 207 , the second and fourth NMOS transistors 206 , 205 , and the first and third PMOS transistors 204 , 203 are the same. This is because I 1 =I 1 ′ in the PTAT current generator circuit 200 .
[0080] The transistors having different aspect ratios are the fourth and second NMOS transistors 201 , 202 and the second and first bipolar junction transistors 209 , 210 . This ensures that m and n of equation (6) are not 1. If m and n are 1, equation (6) will no longer hold true.
[0081] The summing circuit 500 includes a first summing circuit current mirror 520 , a second summing circuit current mirror 530 , and a third summing circuit current mirror 540 .
[0082] The first summing circuit current mirror 520 includes an eighth PMOS transistor 508 and a ninth PMOS transistor 509 coupled in series between the first reference voltage VDD and a seventh node 514 . The gate of the eighth PMOS transistor 508 is coupled to the first node 240 and the gate of the ninth PMOS transistor 509 is coupled to the first bias voltage V casp . The first summing current mirror 520 provides a mirrored current of the first sub-current I 1 to the seventh node 514 .
[0083] The second summing circuit current mirror 510 comprises a tenth PMOS transistor 510 coupled between the first reference voltage VDD and the seventh node 514 . The gate of the tenth PMOS transistor 510 is coupled to the sixth node 416 . The second summing current mirror 530 provides a mirrored current of the second sub-current I 2 to the seventh node 514 .
[0084] At the seventh node, the mirrored currents of the first and second sub-currents I 1 , I 2 are combined, or summed, to provide a sum current I 3 . The sum current I 3 is applied to the third summing circuit current mirror 540 , which includes a ninth NMOS transistor 511 coupled between the seventh node 514 and the second reference voltage GND, and an tenth NMOS transistor 512 coupled between a bias node 516 and the second reference voltage GND. The gates of the ninth and tenth NMOS transistors 511 , 512 are coupled to each other and to the seventh node. The sum current I 3 flows through the ninth NMOS transistor 511 and is mirrored at the tenth NMOS transistor 512 , which draws the resulting bias current I bias from a circuit connected to the bias node 516 .
[0085] As mentioned above, the mirrored current of the first sub-current I 1 is proportional to temperature, while the mirrored current of the second sub-current I 2 is inversely proportional to temperature. Therefore, the summed bias current I bias , which is a mirrored current of the sum current I 3 , can be represented as:
I bias = [ ( W / L ) 508 ( W / L ) 208 I 1 + ( W / L ) 510 ( W / L ) 407 I 2 ] · ( W / L ) 512 ( W / L ) 511 ( 20 )
[0086] Therefore, by controlling the respective aspect ratios of the transistors 208 , 407 , 508 , 510 , 511 , and 512 , the bias current I bias can be maintained at a constant value that is entirely dependent on the aspect ratios of the transistors and is independent of temperature and process variation. The first sub-current I 1 and the second sub-current I 2 should be weighted ((W/L) 508 /(W/L) 208 and (W/L) 510 /(W/L) 407 ) before they are summed, so that the summation is constant with regard to temperature. Also, since different applications require a different bias current, this summation should be amplified or attenuated before it is applied, for example according to ((W/L) 512 I/(W/L) 511 ). Equation (20) ensures this.
[0087] FIG. 2 is a circuit diagram of a second embodiment of a bias current generating circuit in accordance with the present invention. With reference to FIG. 2 , the bias generating circuit includes a proportional-to-absolute-temperature (PTAT) current generator 200 , an inverse-proportional-to-absolute-temperature (IPTAT) current generator 400 , and a summing circuit 500 , as described above, and further includes a bias voltage generator 300 and a start-up circuit 100 .
[0088] The bias voltage generator 300 includes a first voltage generator 320 and a second voltage generator 330 . The first bias voltage generator 320 generates the first bias voltage V casp that is provided to the PMOS cascode current mirror 210 of the PTAT current generator 200 . The second bias voltage generator 330 generates the second bias voltage V casn that is provided to the NMOS cascode current mirror 220 of the PTAT current generator 200 .
[0089] The first bias voltage generator 320 includes an eleventh PMOS transistor 307 and an eleventh NMOS transistor 308 coupled in series between the first reference voltage VDD and the second reference voltage GND. In addition, a twelfth PMOS transistor 311 and a twelfth NMOS transistor 309 are coupled in series between the first reference voltage VDD and the second reference voltage GND. Also, thirteenth and fourteenth PMOS transistors 312 , 313 and a thirteenth NMOS transistor 310 are coupled in series between the first reference voltage VDD and the second reference voltage GND. The gate of the eleventh PMOS transistor 307 is coupled to the first node 240 . The gate of the eleventh NMOS transistor 308 is coupled to a junction between the eleventh PMOS transistor 307 and the eleventh NMOS transistor 308 , and is coupled to gates of the twelfth and thirteenth NMOS transistors 309 , 310 . The gate of the twelfth PMOS transistor 311 is coupled to a junction between the twelfth PMOS transistor 311 and the twelfth NMOS transistor 309 , and is coupled to the gate of the thirteenth PMOS transistor 312 . The gate of the fourteenth PMOS transistor 313 is coupled to a junction between the fourteenth PMOS transistor 313 and the thirteenth NMOS transistor 310 , and provides the first bias voltage V casp to the startup circuit 100 , the PTAT current generator 200 and the IPTAT current generator 400 .
[0090] The second bias voltage generator 330 includes a fifteenth PMOS transistor 301 and a fifteenth NMOS transistor 305 coupled in series between the first reference voltage VDD and an eighth node 518 . In addition, a sixteenth PMOS transistor 302 , a fourteenth NMOS transistor 303 and a sixteenth NMOS transistor 304 are coupled in series between the first reference voltage VDD and the eighth node 518 . A third PNP-type bipolar junction transistor 306 is coupled in a diode configuration between the eighth node and the second reference voltage GND. The gates of the fifteenth and sixteenth PMOS transistors 301 , 302 are coupled to the first node 240 . The gate of the fifteenth NMOS transistor 305 is coupled to a junction between the fifteenth PMOS transistor 301 and the fifteenth NMOS transistor 305 , and is coupled to a gate of the sixteenth NMOS transistor 304 . The gate of the fourteenth NMOS transistor 303 is coupled to a junction between the sixteenth PMOS transistor 302 and the fourteenth NMOS transistor 303 , and provides the second bias voltage V casn to the PTAT current generator 200 and the startup circuit 100 . The base of the third bipolar junction transistor 306 is coupled to the second reference voltage GND.
[0091] The second bias voltage V casn can be determined as follows:
V casn =V be3 +V ds304 +V gs303 (21)
where V be3 is the base-emitter voltage of the third bipolar junction transistor 306 , V ds304 is the drain-source voltage drop across the sixteenth NMOS transistor 304 , and V gs303 is the gate-source voltage at the fourteenth NMOS transistor 303 .
[0092] To generate a suitable voltage for V be3 , the combination of the currents flowing through the fifteenth and sixteenth PMOS transistors 301 and 302 should, in combination, be p times the current flowing through transistor 207 , where p represents the aspect ratio of third bipolar junction transistor 306 to that of the first bipolar junction transistor 209 . It is common for p to be chosen as 1, therefore,
( W L ) 301 + ( W L ) 302 = p ( W L ) 207 ( 22 )
[0093] In view of equation (22), to generate a suitable voltage for V ds304 , it should be maintained that:
( W L ) 304 + ( W L ) 305 = p ( W L ) 201 and ( 23 ) ( W / L ) 304 ( W / L ) 305 = ( W / L ) 302 ( W / L ) 301 ( 24 )
[0094] To generate a suitable voltage for V gs303 , it should be maintained that:
( W / L ) 303 ( W / L ) 203 = ( W / L ) 304 ( W / L ) 201 = ( W / L ) 302 ( W / L ) 207 ( 25 )
[0095] The first bias voltage V casp can be determined as follows:
V casp =VDD+V ds312 +V gs313 | (26)
where V ds312 is the drain-source voltage of the thirteenth PMOS transistor 312 and has a negative value, and V gs313 is the gate-source voltage of the fourteenth PMOS transistor 313 , and has a negative value.
[0096] To ensure a suitable value for V ds312 , and V gs313 , the sizes of the transistors should be selected such that:
( W / L ) 307 ( W / L ) 207 · ( W / L ) 309 ( W / L ) 308 · ( W / L ) 312 ( W / L ) 311 = ( W / L ) 313 ( W / L ) 205 and ( 27 ) ( W / L ) 310 ( W / L ) 309 = ( W / L ) 312 ( W / L ) 311 ( 28 )
in order to ensure that the second, fourth and sixth PMOS transistors 206 , 205 , 402 , operate in the saturation region.
[0097] The bias voltage generator 300 of FIG. 2 is an exemplary embodiment of a voltage generator for generating the first and second bias voltages. Other embodiments for generating the first and second bias voltages are equally applicable to the principles of the present invention.
[0098] The start-up circuit 100 of FIG. 2 ensures that the PTAT current generator can overcome degenerate bias upon system start-up. Degenerate bias refers to a state in which a transistor fails to conduct current, even though the transistor is in an on state.
[0099] The start-up circuit 100 includes seventeenth and a eighteenth PMOS transistors 101 , 102 and nineteenth and twentieth NMOS transistors 105 , 106 coupled in series between the first reference voltage VDD and the second reference voltage GND. An seventeenth NMOS transistor 103 is coupled between the first node 240 and the second reference voltage GND. An eighteenth NMOS transistor 104 is coupled between the first bias voltage V casp and the second reference voltage GND. Gates of the seventeenth and eighteenth PMOS transistors 101 , 102 are coupled to the second reference voltage GND. Gates of the seventeenth and eighteenth NMOS transistors 103 , 104 are coupled to a junction between the sixteenth PMOS transistor 102 and the nineteenth NMOS transistor 105 . A gate of the nineteenth NMOS transistor 105 is coupled to the second bias voltage V casn . A gate of the twentieth NMOS transistor 106 is coupled to the second node 242 .
[0100] When power is applied to the system, if transistors 204 and 202 carry no current, then transistors 105 and 106 likewise do not carry current. It follows that no current flows through transistors 101 and 102 . Therefore, the voltage at the drain node of transistor 105 , namely V st , must be high, which turns on 103 and 104 . In this case, in the start-up circuit, the voltages at the second node V gp and the second bias voltage V casn become low voltages. This, in turn, causes the activation of the first and second PMOS transistors 208 , 206 and current is injected into the first and second NMOS transistors 204 , 202 . This, in turn, raises the voltage levels of the second node V gp and the second bias voltage V casn . As a result, transistors 201 , 202 , 203 and 204 are turned on, and transistors 105 and 106 are likewise turned on. A relatively small aspect ratio (W/L) (1 μm/20 μm) ratio is selected for transistors 101 and 102 , such that when transistors 101 and 102 are turned on, the voltage V st is much less than the threshold voltage. Thereafter, when current flows through NMOS transistors 201 , 202 , 203 and 204 , NMOS transistors 103 and 104 are turned off, having no effect on the normal operation of the circuit. In this manner, the circuit is successfully started at power-up in a manner that overcomes degenerate bias.
[0101] FIG. 3 is a circuit diagram of a third embodiment of a bias current generating circuit in accordance with the present invention. Like the second embodiment described above, the bias current generating circuit of the third embodiment includes a start-up circuit 100 A, a PTAT current generator 200 A, a bias voltage generator 300 A, an IPTAT current generator 400 A and a summing circuit 500 A.
[0102] In the third embodiment, the purpose and operation of the start-up circuit 100 A, the PTAT current generator 200 A, the bias voltage generator 300 A, the IPTAT current generator 400 A and the summing circuit 500 A are essentially the same as those equivalent circuits of the first embodiment and second embodiment of FIGS. 1 and 2 . However, in the summing circuit 100 A, PMOS transistors 103 A, 104 A are used, instead of the seventeenth and eighteenth NMOS transistors 103 , 104 . In the PTAT current generator 200 A, NPN-type bipolar junction transistors 210 A, 209 A are positioned in series between the first reference voltage VDD and the PMOS cascode current mirror. In the second bias voltage generator 300 A, an NPN-type bipolar junction transistors 306 A, PMOS transistors 303 A, 304 A, 305 A and NMOS transistors 301 A, 302 A are employed. In the first bias voltage generator 320 A, PMOS transistors 309 A, 310 A and NMOS transistors 307 A, 308 A, 311 A, 312 a , and 313 A are used. In the IPTAT current generator 400 A, PMOS transistors 403 A, 404 A, 405 A, 406 A, and NMOS transistors 401 A, 402 A are employed. In the summing circuit 500 A, the first summing circuit current mirror 520 A comprises NMOS transistors 508 A, 509 A, the second summing circuit current mirror 530 A comprises NMOS transistor 510 A, and the third summing circuit current mirror 540 A comprises PMOS transistors 51 A, 512 A.
[0103] In this manner, the third embodiment of the present invention, like the first and second embodiments above, generates a bias current I bias that is a combination of a first sub-current I 1 that is proportional to increased temperature, and a second sub-current I 2 that is inversely proportional to increased temperature in a manner that mitigates or eliminates the effects of temperature and process variance.
[0104] While this invention has been particularly shown and described with references to preferred embodiments, thereof, it will be understood by those skilled in the art that various changes in form and details may be made herein without departing from the spirit and scope of the invention as defined by the appended claims. | A bias current generating circuit generates a reliable and consistent bias current, irrespective of variation in applied power, process and temperature. In one embodiment, the bias current generator generates a bias current using a PTAT current generator and an IPTAT current generator comprising exclusively active circuit elements, for example transistors. No passive elements, such as resistors, are employed. The generated bias current is substantially a function of the respective aspect ratios of transistors of current paths of the device. In this manner, the resulting generated bias current has greatly reduced susceptibility to variation in applied power, process and temperature. | 6 |
FIELD
The present disclosure relates to direct injection spark ignition engine with computer controlled intake valves.
BACKGROUND and SUMMARY
In direct spark ignition engines, fuel is injected directly into each combustion chamber. Accordingly, less fuel may be inducted past the intake valves than in port injected engines. Inducting fuel past the valves cleans carbon deposits which may deposit on the valves due to positive crankcase ventilation (PCV) and/or exhaust gas recirculation (EGR). Thus, reducing the amount of fuel inducted past the valves can result in increased deposits.
One approach to clean such deposits, using conventional cam timing and a throttle is described in U.S. Pat. No. 6,178,944. This approach injected fuel during a valve overlap period when the engine is throttled to draw fuel back into the intake port.
However, the inventors herein have recognized a disadvantage with such an approach. For example, this approach requires throttling which can increase pumping losses and increase fuel consumption. The additional fuel injected during vavle overlap also may increase fuel consumption since an additional injection of fuel is used. Further, in some engines, throttled conditions may be performed for an insufficient amount of the available operating range so that the opportunity to perform valve cleaning may be limited.
At least some of the above disadvantages may be overcome by a method for a vehicle traveling on the road having an engine with adjustable valve operation, the method comprising: performing a valve cleaning operation for reducing deposits on a valve of the engine; and at least during said operation, adjusting valve timing of at least a valve of the engine and a fuel injection amount to increase an amount of fuel pushed back from a cylinder past the valve with deposits and then re-inducted through the valve with deposits.
In this way, valve cleaning can be performed without requiring throttling conditions (although cleaning may be performed during throttled conditions, if desired).
An advantage of the above aspect is that fuel injected during the valve adjustments can be used to clean carbon deposits accumulated on and around an intake valve.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment in which the invention is used to advantage;
FIGS. 2A–C show various examples of variation in valve timing and injection timing; and
FIG. 3 shows a high level flow chart which depicts a portion of the operation of the embodiment shown in FIG. 1 .
DETAILED DESCRIPTION
Referring to FIG. 1 , direct injection internal combustion engine 10 , comprising a plurality of cylinders, one cylinder of which is shown, is controlled by electronic engine controller 12 . Engine 10 includes combustion chamber 30 and cylinder walls 32 with piston 36 positioned therein and connected to crankshaft 40 . Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via respective intake valve 52 an exhaust valve 54 . Each intake and exhaust valve is operated by an electromechanically controlled valve coil and armature assembly 53 . Armature temperature is determined by temperature sensor 51 . Valve position is determined by position sensor 50 . In an alternative example, each of valves actuators for valves 52 and 54 has a position sensor and a temperature sensor. While this example shows both electrically actuated intake and exhaust valves, various combinations of electrically actuated and cam actuated valves may be used. For example, electrically actuated intake valves and mechanically actuated exhaust valves may be used. Further, the exhaust valves may have variable cam timing, and/or may be hydraulically or otherwise deactivated.
Combustion chamber 30 is also shown having fuel injector 66 coupled therein for delivering liquid fuel in proportion to the pulse width of signal FPW from controller 12 . While FIG. 1 shows fuel injector 66 on the side of the combustion chamber, it may be positioned in various alternative locations. For example, fuel injector 66 may be positioned in the cylinder head similar to spark plug 92 .
Fuel may be delivered to fuel injector 66 by fuel system (not shown) including a fuel tank, fuel pump, and fuel rail (not shown). A high pressure fuel system may be used, including a high pressure and low pressure pump. In addition, intake manifold 44 is shown communicating with optional electronic throttle plate 125 controlled by an electronic throttle controller (not shown). The controller may include an electric motor, gears, position sensors, and various circuitries, which may communicate with controller 12 .
Distributorless ignition system 88 provides ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12 . Universal Exhaust Gas Oxygen (UEGO) sensor 76 is shown coupled to exhaust manifold 48 upstream of catalytic converter 70 . Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 76 . Two-state exhaust gas oxygen sensor 98 is shown coupled to exhaust manifold 48 downstream of catalytic converter 70 . Alternatively, sensor 98 can also be a UEGO sensor. Catalytic converter temperature is measured by temperature sensor 77 , and/or estimated based on operating conditions such as engine speed, load, air temperature, engine temperature, and/or airflow, or combinations thereof.
Converter 70 can include multiple catalyst bricks, in one example. In another example, multiple emission control devices, each with multiple bricks, can be used. Converter 70 can be a three-way type catalyst in one example.
Controller 12 is shown in FIG. 1 as a microcomputer including: microprocessor unit 102 , input/output ports 104 , and read-only memory 106 , random access memory 108 , 110 keep alive memory, and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10 , in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a position sensor 119 coupled to a accelerator pedal; a measurement of engine manifold pressure (MAP) from pressure sensor 122 coupled to intake manifold 44 ; a measurement (ACT) of engine air amount temperature or manifold temperature from temperature sensor 117 ; and a engine position sensor from a Hall effect sensor 118 sensing crankshaft 40 position. In a preferred aspect of the present description, engine position sensor 118 produces a predetermined number of equally spaced pulses every revolution of the crankshaft from which engine speed (RPM) can be determined.
As described in more detail below, with the ability to adjust valve timing, it may be possible to provide valve cleaning with less throttling. For example, if fuel is injected during an intake stroke, but the intake valve closing is delayed until some point in the compression stroke, some portion of the injected fuel and inducted air may be pushed back into the intake port where it can contact the back of the intake valve.
In other words, in one example embodiment, fuel is moved from inside the cylinder into the intake port where it can clean the back of an intake valve. This may be done by injecting fuel into the cylinder and then delaying the closing of the intake valve until after some of the fuel has been pushed back into the intake port. If fuel is injected during the intake stroke, and the intake valve closing is delayed, fuel (and air) may be pushed back into the intake port with or without the assistance of a lower manifold pressure caused by a throttle.
However, in this case, the amount of fuel injected may be adjusted to provide the appropriate amount of fuel for combustion. In one approach, for the first engine cycle, the fuel injected may be calculated as a function of the total mass of air inducted into the cylinder (including the air that is pushed back into the manifold). For subsequent engine cycles, the injected fuel may be adjusted to account for the fuel re-inducted from the intake manifold. Depending on the cylinder/injector/valve geometry, it may be desirable to inject the fuel late in the intake stroke, or even during the initial compression stroke (while the intake valve is still open) to maximize the quantity of fuel and the size of the fuel droplets pushed back into the intake port. Further, in one embodiment, injection pressure may be adjusted. In this way, injection pressure may be reduced, thereby resulting in less atomization of the fuel which can increase the amount of liquid fuel that is pushed back into the intake, to further improve cleaning.
Referring now to FIGS. 2A–C , various examples of valve timing adjustment and fuel timing adjustment are for a cylinder, with the x-axis representing crank angle degrees, where 0 represents bottom dead center (BDC) of an intake stroke. These figures describe example processes for removing valve deposits accumulated on and around intake valve 54 a and other intake valves not shown in FIG. 1 . Those skilled in the art will recognize that the processes described herein may be used to advantage with one-valve, two-valve, three-valve, four-valve, and any other number of intake valve combinations. Also, some examples provide the advantage of cleaning valve deposits on the intake port adjacent to the intake valve.
Returning now specifically to FIG. 2A , it shows an example where late intake valve closing timing is used in combination with adjusting the amount of injected fuel (as well as injection timing) to generate valve cleaning operation in response to a request for such operation. After two cycles of increase fuel injection and adjusted intake valve timing, further adjustments are performed to return to non-cleaning operation. FIG. 2B shows another embodiment where multiple fuel injections are used during valve cleaning operation to adjust the timing when fuel is injected relative to valve events and piston position. FIG. 2C shows still another embodiment where delaying injection timing is utilized.
While FIGS. 2A–C show various example, any combination of these features, or other adjustments, may be used, as described herein. Also, various adjustments may be made to valve timing, including adjusting intake valve opening timing early and/or later, adjusting intake valve closing timing early and/or later, adjusting exhaust valve opening timing early and/or later, adjusting exhaust valve closing timing early and/or later, and/or combinations thereof.
It should also be noted that while FIGS. 2A–C show operation of a single cylinder, the valve and fuel adjustments may be performed in each cylinder of the engine simultaneously during valve cleaning. Alternatively, a valve cleaning mode can be performed for some cylinders (or a single cylinder), while remaining cylinders carry out unmodified valve timing and fuel injection. Further, valve cleaning operation can be sequentially performed for each cylinder separately, if desired. In this way, any transients created by valve cleaning can be reduced.
Referring now to FIG. 3 , a high level flow chart is shown describing a method for cleaning carbon and/or other deposits accumulated on the intake valves and/or intake ports. During step 202 , an indication is provided that a valve cleaning cycle is requested. This indication may be provided by counting a predetermined number of elapsed engine cycles or by accumulating fuel delivered to the engine, and when such accumulation reaches a predetermined value, providing a valve cleaning indication. This routine then proceeds to step 304 to determine the operating mode. If the mode includes a mode in which cleaning is permitted (e.g., a homogeneous air/fuel combustion mode, or a homogenous compression ignition mode, etc.), then the routine proceeds to step 306 . Otherwise, the routine proceeds to the end.
Proceeding with the flow chart shown in FIG. 3 , in step 306 , additional fuel may be injected and valve timing and/or lift of the intake and/or exhaust valve may be adjusted to increase the pushback of air/fuel into the intake manifold intake valve 52 a . The additional fuel is thereby drawn from combustion chamber 30 , past intake valve 52 a , into intake manifold 58 . Subsequently, during later intake strokes, the additional fuel is drawn back from intake manifold 58 , past intake valve 52 a and the surrounding intake port to clean carbon deposits accumulated on and around intake valve 52 a.
As described above, initially additional fuel may be injected. However, during later cycles of the cleaning operation, injected fuel may be reduced in proportion to the additional fuel added previously to reduce an increase in torque or air/fuel excursion which might otherwise occur. The accumulated valve cleaning cycle time (VCC) is then incremented in step 308 . Then, in step 310 , if the count is above a threshold, a request to end valve cleaning operation is made in step 312 . The routine then ends.
Thus, in one example, the routine can vary the amount of injected fuel depending on whether the valve cleaning operation is commencing, in progress, or concluding.
As will be appreciated by one of ordinary skill in the art, the specific routine described below in the flowchart may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various steps or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages of the disclosure, but is provided for ease of illustration and description. Although not explicitly illustrated, one of ordinary skill in the art will recognize that one or more of the illustrated steps or functions may be repeatedly performed depending on the particular strategy being used. Further, the Figure graphically represents code to be programmed into a computer readable storage medium, such as in controller 12 .
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above approaches can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types.
The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure. | A method for a vehicle traveling on the road having an engine with adjustable valve operation is described. The method includes performing a valve cleaning operation for reducing deposits on a valve of the engine; and at least during said operation, adjusting valve timing of at least a valve of the engine and a fuel injection amount to increase an amount of fuel pushed back from a cylinder past the valve with deposits and then re-inducted through the valve with deposits. | 8 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for reducing nozzle failure in printheads that have been stored or otherwise unused for extended periods.
BACKGROUND OF THE INVENTION
[0002] Most inkjet printers dispense colorants or inks that are comprised of a dye and/or a pigment that is either dissolved or suspended in a volatile solvent. When the print head of the printer deposits the colorants on a recording media such as paper or film, the solvents in the colorants quickly evaporate, leaving the dyes and/or pigments behind on the recording media.
[0003] During the manufacturing process printheads for inkjet printers must be tested. Accordingly, it is customary to provide an inkjet printhead with a dye and/or pigment based colorant that will be dispensed from the printhead as a test to ensure that the printhead functions properly. It may also be necessary to include a colorant with a printhead so that a printer in which the printhead is installed may be tested.
[0004] However, where colorants are allowed to remain in a printhead for extended periods of time, it is often the case that the volatile solvents that make up the colorants will at least partially evaporate, leaving within the nozzles of the print head a residue of particles or a precipitate. FIGS. 1 a - 1 c illustrate how the evaporation of a volatile solvent from the colorant can result in the malfunction of the printhead.
[0005] FIG. 1 a is a schematic view of a typical nozzle 12 in an inkjet printhead 10 . As will be readily understood by those skilled in the art, a printhead 10 typically includes multiple nozzles 12 , each of which is connected to a reservoir (not shown) by a conduit 14 . Generally, a single conduit 14 will supply colorant 13 to multiple nozzles 12 . In a thermal inkjet printhead, a small resistor 16 will be provided adjacent to the opening of the nozzle 12 . The resistor 16 ejects colorant 13 from the nozzle 12 by rapidly raising the temperature of the colorant 13 so as to cause the solvent thereof to boil. The rapid expansion of the boiling solvent ejects a droplet (not shown) of colorant 13 from the opening of the nozzle 12 in a known manner. Other types of inkjet printheads may utilize a piezoelectric element in lieu of the resistor 16 .
[0006] The printhead 10 illustrated in FIG. 1 a represents a printhead that has been newly filled with the colorant 13 . FIG. 1 b, represents a printhead 10 that has been stored for a period of time. Over time the solvents present in the colorant 13 begin to evaporate as represented by arrows 18 . The evaporation of the solvents from the colorant 13 concentrates the pigments and/or dyes present in the colorant 13 . As more time passes, the pigments and/or dyes begin to form a solid accretion 2 . As can be seen in FIG. 1 c, the accretion 2 has grown to the point where it blocks the nozzle 12 , thereby preventing its proper functioning.
[0007] In order to retard the evaporation of the solvents from a colorant, it is common to either cover the nozzles of a printhead with tape or else to ensure that the printhead is otherwise covered with a cap. While such methods do slow the evaporation of solvents from the colorant, simply covering a nozzle is not sufficient to prevent the formation of accretions in a nozzle where the printhead is placed in storage for an extended period of time. Accordingly, there is a recognized need for a method and/or and apparatus that will prevent the formation of accretions in the nozzles of the printhead, particularly where the printhead must be stored for extended periods of time either before it is used or between uses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIGS. 1 a - 1 c are a schematic time-lapse depiction of a prior art printhead wherein solvents in a colorant evaporate to form an accretion in a nozzle;
[0009] FIG. 2 is a schematic representation of an exemplary printhead having a low concentration colorant inserted into a nozzle according to the present invention;
[0010] FIG. 3 is a schematic representation of an exemplary printhead and colorant supply system for operating a printhead such as that illustrated in FIG. 2 ; and,
[0011] FIG. 4 is a schematic representation of an exemplary printhead such as that illustrated in FIG. 2 and further including an exemplary nozzle priming system.
DETAILED DESCRIPTION
[0012] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, exemplary embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof.
[0013] FIG. 2 is a schematic representation of an exemplary printhead 20 having a single nozzle 22 formed therein. Note that in practice, inkjet printhead 20 would have multiple nozzles 22 . However, for the sake of clarity, this description will demonstrate a printhead having only a single nozzle.
[0014] Colorants are supplied to the nozzle 22 through a conduit 24 . The conduit 24 is fluidically connected to a reservoir (not shown) that provides a continuous supply of a colorant 26 . While the exemplary methods and apparatuses herein may apply to any printhead or printing mechanism that utilizes a colorant 26 that comprises a volatile solvent, this description focuses on an exemplary thermal inkjet printhead embodiment. A resistor 28 is electrically connected to a controller via conductor 30 . The controller (not shown) applies a current to the resistor 28 , which boils the solvent in the colorant 26 immediately adjacent to the resistor 28 . The boiling of the solvents creates a vapor bubble whose expansion ejects a droplet of the colorant 26 from the nozzle 22 so as to form an image on a recording media (not shown).
[0015] Because it may be necessary to test the printhead 20 after its manufacture, or test a printer (not shown) in which the printhead 20 has been installed, a first, dilute colorant 26 a is inserted into the printhead 20 so as to substantially fill the nozzle 22 . Note that the first colorant 26 a must fill that portion of the nozzle 22 immediately adjacent to its opening. The first colorant 26 a may also fill some portion of or the entire conduit 24 as well. Preferably, a second, more concentrated colorant 26 b is placed in a reservoir 32 (see FIG. 3 ) and reserved separately therein. However, in certain applications, the second colorant 26 b may be injected into the conduit 24 of the printhead 20 after the first colorant 26 a has been inserted therein.
[0016] It has been found that the number of malfunctioning nozzles 22 present in a printhead 20 is directly related to both the concentration of the colorant 26 and to the length of time that the printhead 20 is in storage. Accordingly, the insertion of a first, more dilute colorant 26 a directly into the nozzle 22 adjacent the opening thereof results in fewer malfunctioning nozzles 22 over a given period of time. Thus, as the solvents in the first colorant 26 a will likely continue to evaporate, the lower concentration of dyes and/or pigments in the first colorant 26 a results in the slower growth of accretions in the opening of the nozzle 22 .
[0017] In certain embodiments, the first colorant 26 a is simply a more dilute version of the more concentrated second colorant 26 b. Once the printhead 20 has been manufactured, the first colorant 26 a is inserted through the conduit 24 in into the nozzle 22 . The second colorant 26 b is then injected into the reservoir 32 . While the concentration of dyes and/or pigments in the first colorant 26 a is lower than that of the second colorant 26 b, the concentration is sufficient to allow the printhead 20 to be tested, as is commonly the practice, and yet yields fewer malfunctioning nozzles 22 after storage of the printhead 20 for a given period of time.
[0018] In certain other embodiments, the second colorant 26 b is inserted into the printhead 20 at least part way into the conduit 24 but possibly also partly into the nozzle 22 , keeping in mind that the first colorant 26 a is to occupy the majority of the nozzle 22 , and possibly all of the nozzle 22 . Note that the dimensions of the conduit 24 in the nozzle 22 are such that the colorants 26 a and 26 b will not be significantly mixed together. Accordingly, it is possible for colorants 26 a and 26 b, differing only in their concentration is of dyes and/or pigments, to coexist side-by-side for extended periods of time without any significant mixing.
[0019] In some instances it may be preferable to utilized dissimilar colorants 26 a and 26 b. As used herein, the term “dissimilar” should be taken to include colorants 26 comprising different combinations and concentrations of solvents, and coloring agents such as dyes and/or pigments. By way of example only, in some instances it may be desirable to utilize a colorant 26 a that has a different hue, or for that matter a completely different color, than the colorant 26 b. To further prevent mixing of the colorants 26 a, 26 b it may be desirable to select solvents for the respective colorants that are dissimilar or even immiscible with one another. Alternatively, it may be desirable to select a solvent or mixture of solvents for use in the colorant 26 a that have a relatively low volatility.
[0020] FIG. 3 illustrates an apparatus for implementing the present invention. In this embodiment, nozzles 22 are formed in a nozzle orifice plate 23 . Colorant is supplied to the nozzles 22 in the nozzle orifice plates 23 through a conduit 24 . As can be seen in FIG. 3 , the conduit 24 may be sized so as to include a modicum of storage place for colorants 26 . The conduit 24 is fluidically connected to a colorant delivery system 31 . The colorant delivery system 31 includes a colorant supply reservoir 32 that is connected to the conduit 24 by a line 33 that passes through a pump 34 and a valve 36 . Note that in some embodiments the colorant delivery system 31 may be located remotely from the printhead 20 . In other embodiments, the ink delivery system 31 may be formed as an integral part of the printhead 20 . It is to be understood therefore that line 33 is to be construed to include any coupling mechanism for connecting the reservoir 32 to the conduit 24 .
[0021] During normal operation, pump 34 is actuated to move colorant from the reservoir 32 through the line 33 into the conduit 24 . The valve 36 may be operated to selectively open and close the line 33 , thereby permitting or preventing, as the case may be, the flow of colorant from the reservoir 32 into the conduit 24 . The colorant 26 flows through the conduit 20 either due to the force of gravity or as the pump 34 has pressurized the colorant 26 in the conduit 24 .
[0022] As part of the manufacturing process, or as part of a “mothballing” procedure, the apparatus illustrated in FIG. 3 will have a predetermined quantity of the first colorant 26 a inserted into the conduit 24 as represented by fill line 27 . The amount of the first colorant 26 a inserted into the conduit 24 is sufficient to allow one or more required tests of the printhead 20 and to ensure that the nozzles 22 remain substantially filled with the first colorant 26 a. A port or other access point (not shown) may be provided in the printhead 20 so as to allow the injection of a quantity of the first colorant 26 a into the conduit 24 at the time of manufacture or later, after the printhead 20 has been installed in a printer. Such port or other access point may then be closed in some manner.
[0023] In certain exemplary embodiments, multiple reservoirs 32 may be used. In the illustrated embodiment, the printhead 20 is prepared for printing an image on recording media by actuating the colorant delivery system 31 to withdraw the first colorant 26 a from the printhead 20 and into a first reservoir 32 . Once the first colorant 26 a has been removed from the printhead 20 , the reservoir 32 containing the first colorant 26 a is uncoupled from the colorant delivery system 31 and a second reservoir 32 , this one having the second colorant 26 b contained therein, is coupled to the colorant delivery system 31 . The colorant delivery system 31 is then actuated to provide the second colorant 26 b to the printhead 20 for printing. The first colorant 26 a may be conserved in the first reservoir 32 or may be discarded. Where it is desirable to “mothball” the printhead 20 , the colorant delivery system 31 may be actuated to withdraw the second colorant 26 b from the printhead 20 back into its reservoir 32 for conservation. Thereafter, the first colorant 26 a may be reintroduced into the printhead 20 by coupling a reservoir 32 having the first colorant 26 a contained therein to the colorant delivery system 31 . The colorant delivery system 31 will then be actuated to reintroduce the first colorant 26 a into the printhead 20 .
[0024] The nozzles 22 of the printhead 20 may be closed as by capping or taping and as seems appropriate given the application to which the printhead 20 will be put. The printhead 20 may then be placed into storage or otherwise inactivated. Note that the printhead 20 may be detached from the line 33 and stored apart from the reservoir 32 , pump 34 and valve 36 , may be installed in a printer along with the reservoir 32 , pump 34 , and valve 36 for storage, or a combination of the reservoir 32 , pump 34 and valve 36 may be stored together with the printhead 20 in an integral package. For the purposes of the present application, the term “storage” should be taken to mean the reservation of the printhead 20 at a location remote from a printer or an extended period of inactivity where the printhead 20 is installed in a printer. The second colorant 26 b may be retained entirely within the reservoir 32 , leaving only the first colorant 26 a in the conduit 24 . Alternatively, the second colorant 26 b can be inserted into the conduit 24 behind and up to the first colorant 26 a up to line 27 as shown in FIG. 3 .
[0025] Where the printhead 20 is currently in use but is to undergo a period of prolonged in activity, a mothballing procedure may be performed upon the printhead 20 . During such a procedure, relatively concentrated colorant 26 b present in the conduit 24 and nozzles 22 is either ejected or is withdrawn into the reservoir 32 by means of the pumping action of the pump 34 through line 33 . Thereafter, dilute colorant 26 a may be inserted into the conduit 24 through the aforementioned port so as to substantially fill the nozzles 22 . In an alternate embodiment, and as it is likely that some quantity of concentrated colorants 26 b may be retained with in the conduit 24 and nozzles 22 , a compatible solvent not having a dye and/or pigments included therein may be inserted into the conduit 24 to be mixed with the second colorant 26 b remaining in the conduit 24 by means of pulsing the pump 34 as described hereinabove. Alternatively, the pure solvents added to the conduit 24 may be drawn through the conduit 24 and expelled from the nozzles 22 by the normal operation of the nozzles 22 , the nozzles 22 being operated so as to draw sufficient quantities of the pure solvents into the nozzles 22 to reduce the incidence of malfunction in the nozzles 22 when the printhead 20 is installed and/or reactivated.
[0026] Upon installation of the printhead 20 in a printer, or upon reactivation of the printhead 20 in a printer, printing of an image upon recording media may commence using the first colorant 26 a. The use of a dilute mixture of the second colorant 26 b as the first colorant 26 a may allow the printhead 20 to begin printing in such a way as to produce images of an acceptable quality where the color, hue, and/or intensity of the first colorant 26 a is near enough to satisfy the image quality requirements expected of images printed using the second colorant 26 b. Alternatively, one or more test images or patterns may be printed for the express purpose of exhausting the supply of the first colorant 26 a within the printhead 20 prior to the start of printing using the desired second colorant 26 b.
[0027] The apparatus illustrated in FIG. 3 may also be operated in such a way as to mix the first and second colorants 26 a, 26 b prior to the start of printing by the printhead 20 . In this embodiment, the first colorant 26 a is a dilute version of the second colorant 26 b. Upon installation of the printhead 20 in a printer, or upon reactivation of the printhead 20 after a period of inactivity, valve 36 is opened and pump 34 is operated so as to alternatively pump the second colorant 26 b from the reservoir 32 into the conduit 24 and to withdraw the first colorant 26 a from the conduit 24 into the reservoir 32 , thereby effectively mixing the first and second colorants 26 a and 26 b. In order to ensure that the colorant 26 used to print an image on a recording media retains a desired color intensity, the second colorant 26 b contained within the reservoir 32 may be highly concentrated or the reservoir 32 may be over-filled, the concentration and/or volume of the second colorant 26 b being such that the addition of a quantity of the dilute first colorant 26 a does not significantly affect desired colorant properties such as intensity, hue, or the like.
[0028] FIG. 4 illustrates another exemplary embodiment that includes a colorant delivery system 31 , a printhead 20 , and a nozzle priming system 40 . As described above, the ink delivery system 31 includes a reservoir 32 that is fluidically coupled to the conduit 24 of the printhead 20 by means of line 33 . While in the embodiment illustrated in FIG. 4 , no pump or valve has been included in line 33 , such may be added where warranted by the application under consideration. The nozzles 22 of the printhead 20 are included in the nozzle orifice plate 23 . See FIG. 3 . As illustrated, the printhead 20 is filled up to fill line 27 with a first colorant 26 a. While FIG. 4 does illustrate that the conduit 24 is at least partially filled with the first colorant 26 a, it must be kept in mind that all that is required is that the nozzles of the nozzle orifice plate 23 be partially or substantially filled with the dilute, first colorant 26 a. The more concentrated second colorant 26 b is contained within the reservoir 32 of the ink delivery system 31 and is supplied, upon demand, to the printhead 20 through line 33 . The nozzle priming system 40 comprises a priming cap 42 that is constructed and arranged to fit snugly over the nozzle orifice plate 23 , preferably forming a seal thereover. The priming cap 42 is connected through a pump 44 to a priming reservoir 46 by means of line 48 .
[0029] In operation, the printhead 20 is first installed in a printer or is reactivated after a period of inactivity; pump 44 is actuated to draw the first colorant 26 a from the nozzle orifice plate 23 and conduit 24 of the printhead 20 and into the priming cap 42 . The first colorant 26 a is then deposited into the priming reservoir 46 . In this embodiment, once the first colorant 26 a is removed from the printhead 20 in deposited in the priming reservoir 46 , it will not be reused. It is to be understood however that the first colorant 26 a may be reused where so desired.
[0030] As the first colorant 26 a is drawn from the printhead 20 , the action of the pump 44 will simultaneously draw the second colorant 26 b from the reservoir 32 into the condiut 24 and subsequently into the nozzles of the nozzle orifice plate 23 . At this point, the printhead 20 is ready to begin printing an image using the second colorant 26 b.
[0031] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the invention. It is manifestly intended that this invention be limited only by the following claims and equivalents thereof. | An inkjet printhead and a method for increasing the shelf life thereof are herein disclosed. The inkjet printhead has one or more nozzles for dispensing a colorant. These nozzles are fluidically connected to a reservoir. A first colorant substantially fills the nozzles while a second colorant is reserved in the reservoir. | 1 |
BENEFIT OF PRIOR APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/224,971, filed Jul. 13, 2009 whose disclosure is incorporated herein by reference.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The current invention relates to a controllable fin surface configuration for watercraft and specifically a fin surface configuration to enhance watercraft stability and movement. More specifically, embodiments of the present invention relate to a fin surface configuration and method to enhance stability and movement of a surf board and similar type watercraft.
[0003] In the specification and claims which follow, the term “watercraft” is meant to mean any boat or recreational craft meant to move above or partially submerged in the water. Salient examples of watercraft include but are not limited to: a surfboard; a wind surfboard; and a light boat propelled by oars and/or motors.
[0004] There are many kinds of watercraft utilizing unnecessary energy to overcome water resistance while moving through water. While many watercraft utilize a vertically configured stabilizer on the underside of the watercraft, one or more additional surfaces could have the potential to enhance watercraft stability and movement.
[0005] An example of prior art related to such vertically-configured stabilizer surfaces on the underside of the watercraft surfaces is US Patent Application Publication 2007/0093154 to Simpson, whose disclosure is incorporated herein by reference. Simpson describes a fin for use on a surfboard and other watercraft of a low-drag, high lift, and high aspect ratio, among other characteristics, to make the surfboard or watercraft more maneuverable and to stabilize the surfboard or watercraft.
[0006] Another example is U.S. Pat. No. 4,733,496 by Wallner et al., whose disclosure is incorporated herein by reference. Wallner likewise describes a fin for surfboards and watercraft, his fin including a pivoting rudder like section that swings out when a turn is commenced, enhancing the maneuverability of the surfboard. The fin described includes a stationary section with a pivoting blade section that can be mechanically adjusted.
[0007] A third example of a vertically configured stabilizer on the underside of the watercraft is that of Johnson, in U.S. Pat. No. 3,890,661, whose disclosure is incorporated herein by reference. In the referenced publication, a surfboard is steered by a fin that functions as a rudder in response to force due to gravity of the surfer's body. A vertical shaft connects the rudder-fin to the surfboard body. A lever arm adjustable in length is provided between the shaft and body of the surfboard to vary steerability characteristics.
[0008] The cited prior art hereinabove are representative of primarily single vertical fin configurations and they are directed at enhancing maneuverability of a surfboard or other craft. A fin configuration that has a horizontal component is described by Harper in U.S. Pat. No. 4,077,077, whose disclosure is incorporated herein by reference. Harper describes a stabilizer keel for water surface vehicles. The keel includes a pair of pivoted keel plates that are pivoted on a stationary base member by an integral hinge. The plates are urged apart from the axis of the hinge by a spring to normally form a V-configuration for the purpose of stabilizing the object to which the keel is mounted; for example a water ski. The hinge axis is inclined so the plates, when in the open V-configuration, will lift upwardly against the ski upon movement of the skin a forward direction. As forward velocity is increased, pressure against the plates also increases, causing them to swing inwardly against the resistance of the spring. At relatively high speeds, the pates come together to form a substantially standard shape keel.
[0009] Harper's stabilizer keel can be effective when used in a water ski and/or a watercraft which is powered by propeller or towed at higher speeds. However the “normally open” configuration of Harper's stabilizer keel ensures high resistance at relatively slow speeds, which could be disadvantageous, for example, with only human power especially when considering the case of a surfboard.
[0010] In surfing, a surfer wishing to leave the beach and go out to surf on a wave must first “power” his surfboard away from the beach to deeper water by paddling with his hands/arms. Paddling the surfboard against incoming waves involves strength, and the keel or other prior art surfaces described hereinabove offer little advantage or perhaps a serious disadvantage to the surfer. Likewise, when a surfer is preparing to catch a wave, he must quickly paddle towards the beach to increase his speed, with the prior art surfaces described above hardly serves any advantage, if at all.
[0011] In both cases of paddling out to sea or paddling to catch a wave, there is a need for a fin configuration that can be easily adapted to watercraft to stabilize the watercraft, and in the case of a surfer, to assist his efforts, especially at low speed.
SUMMARY OF THE INVENTION
[0012] According to the teachings of the present invention there is provided a controllable fin surface configuration positionable on the underwater surface of a craft having a bow and a stern, the craft having a direction of travel defined from the stern to the bow, the configuration comprising: at least one hinge adapted to mechanically support the fin surface configuration; and at least one fin surface mechanically attached to the hinge and having a range of motion definable from a closed state to an open state; wherein the closed state is defined by the fin surface configuration offering minimal resistance to relative water movement opposing the direction of travel and the open state is defined by the fin surface configuration offering maximum resistance to relative water movement in the direction of travel.
[0013] Preferably, the range of motion is from substantially 0 degrees in the closed state to as much as substantially 90 degrees in the open state. Most preferably, the hinge is configurable substantially perpendicular to the underwater surface and the configuration further comprises at least 2 fin surfaces. Typically, the fin surfaces are in the closed state when substantially parallel to each other. Most typically, the hinge is configurable substantially perpendicular to the direction of travel and substantially flush with the underwater surface. Preferably, the configuration further comprises a plurality of hinges, each of the plurality of hinges having at least one fin surface.
[0014] According to further teachings of the present invention there is provided a method for positioning a controllable fin surface configuration on the underwater surface of a craft having a bow and a stern, the craft having a direction of travel defined from the stern to the bow, the method comprising the steps of: locating a hinge to mechanically support the fin surface configuration; attaching at least one fin surface to the hinge, the at least one fin surface having a range of motion definable from a closed state to an open state; defining the closed state as the fin surface configuration offering minimal resistance to relative water movement opposing the direction of travel; and defining the open state as the fin surface configuration offering maximum resistance to relative water movement in the direction of travel. Preferably, the range of motion is from substantially 0 degrees in the closed state to as much as substantially 90 degrees in the open state. Most preferably, the hinge is configurable substantially perpendicular to the underwater surface and the configuration further comprises at least 2 fin surfaces. Typically, the fin surfaces are in the closed state when substantially parallel to each other.
[0015] Preferably, the hinge is configurable substantially perpendicular to the direction of travel and substantially flush with the underwater surface. Most preferably, the configuration further comprises a plurality of hinges, each of the plurality of hinges having at least one fin surface.
BRIEF DESCRIPTION OF THE DRAWINGS AND APPENDICES
[0016] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
[0017] FIG. 1 is a pictorial view of an under water surface of a craft showing a controllable fin surface configuration in an open state, in accordance with an embodiment of the current invention;
[0018] FIGS. 2 and 3 are pictorial representations of the craft as it begins to ride a wave and as the craft goes out against a wave, respectively, with the controllable fin surface configuration in an open state, in accordance with embodiments of the current invention;
[0019] FIG. 4 is a pictorial view of an under water surface of a craft showing a controllable fin configuration, in accordance with an embodiment of the current invention;
[0020] FIGS. 5A , B, C, and 5 D are detailed pictorial views of the controllable fin configuration of FIG. 4 , in various closed and open configurations, in accordance with an embodiment of the current invention;
[0021] FIG. 6 is a pictorial view of an under water surface of a craft showing an alternative of controllable fin configuration in an open state, in accordance with an embodiment of the current invention; and
[0022] FIG. 7 is a pictorial view of an under water surface of a craft showing an alternative of controllable fin configuration in an open state, in accordance with an embodiment of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The current invention relates to a controllable fin surface configuration for watercraft and specifically a fin surface to enhance watercraft stability and movement. More specifically, embodiments of the present invention relate to a fin surface configuration and method to enhance stability and movement of a surf board and similar type watercraft.
[0024] Reference is presently made to FIG. 1 , which a pictorial view of a watercraft (or “craft”) 6 having an underwater surface 8 and a controllable fin surface configuration 10 in an open state, in accordance with an embodiment of the current invention. Craft 6 typically has a bow 11 (ie a forward or leading end) and a stern 12 (ie a trailing end). A direction of travel of the craft is defined from the stern to the bow. The controllable fin surface configuration includes a controllable fin 13 attached to surface 8 near the stern, by a hinge 14 , where the hinge is oriented substantially perpendicularly to the direction of travel of craft 6 . Two vertically-oriented fins 18 , representing conventional stabilizing craft 6 —stabilizing fins, are optionally mounted on either side of controllable fin 13 . It should be noted that while the controllable fin surface is shown in FIG. 1 and in subsequent figures is shown near the stern, the controllable fin surface may be optionally or alternatively positioned near the bow or between the bow and stern to accomplish its functioning, as described hereinbelow.
[0025] The fin is hinged and free to move, so that when craft 6 moves forward in the water and/or when water moves in the direction from the bow to the stern more quickly than the forward movement of the craft, the relative water movement serves to create a force on controllable fin 13 to bias it to close against surface 8 (not shown in the figure)—yielding a “closed state”. However, when the watercraft advances more slowly than the surrounding water and/or when water moves from the stern to the bow more quickly than the forward movement of the craft, the relative water movement serves to create a force on controllable fin 13 to bias it to open away from surface 8 , yielding an “open state” of controllable fin configuration 10 , as shown in FIG. 1 . The range of movement of the controllable fin is substantially from 0 degrees (in line and parallel with surface 8 , ie. closed state) to as much as 90 degrees (perpendicular to surface 8 , ie. open state), although the open state may be represented by a value less than 90 degrees, dependent on specific design of the fin configuration.
[0026] A “braking effect” (braking backward movement of the craft) described hereinabove is further illustrated by referring to FIGS. 2 and 3 , which are pictorial representations of the craft as it moves away from the beach and against a wave 20 , and the craft as it is about to ride the wave, respectively, with controllable fin surface configuration 10 in an open state, in accordance with embodiments of the current invention. The dark arrow in both figures emphasizes the relative water direction as described hereinabove. The concept of relative water direction/movement is central in understanding embodiments of the current invention, as described hereinbelow.
[0027] Essentially, controllable fin surface 13 alternately assumes an open state (as shown in FIGS. 2 and 3 ) and a closed state, as described hereinabove. As such, the controllable fin surface, in its open state, acts to assist the surfer in the two situations shown in FIGS. 2 and 3 , namely to brake backward movement of the craft, such as when going against waves out to sea, and to aid in acceleration and “catching” a wave when surfing back towards the beach. The open state is characterized by an increase of surface area of controllable fin configuration 10 against the water, thereby yielding a resultant force on the craft, the force having a direction from the stern of the craft towards its bow.
[0028] Reference is now made to FIGS. 4 , 5 A, 5 B, 5 C, and 5 D which is a pictorial view of a craft 6 having an underwater surface 8 showing controllable fin configuration 110 and detailed pictorial views of controllable fin configuration 110 in various closed and open configurations, respectively, all in accordance with an embodiment of the current invention. Craft 6 is essentially similar to craft 6 of FIGS. 1-3 and in structure and function, apart from the differences noted hereinbelow. Craft 6 has an imaginary centerline (not indicated in the figures) running from the leading edge of the bow to stern 12 . Controllable fin configuration 110 includes two stationary supports 220 , mounted perpendicularly to surface 8 and located near the stern and symmetrically spaced about the imaginary centerline, each support having a hinge 222 which connects two controllable fins 224 and 226 to the respective support, allowing the controllable fins to move away from each other in an “open state” ( FIG. 5C ), a nearly open state ( FIGS. 4 and 5D ), and a “closed state” (FIGS. 5 A and 5 B)—all as shown. Controllable fins 224 and 226 each have a range of movement ranging from 0 degrees (in line with support 220 ) to substantially 90 degrees (perpendicular to support 220 ).
[0029] Each fin is hinged and free to move within the range of movement, so that when craft 6 moves forward in the water (and/or when water moves in the direction from the bow to the stern) the relative movement of the water relative to the craft serves to create a force on fins 224 and 226 to bias them to close against each other yielding the closed state. However, when the watercraft advances more slowly than the surrounding water (and/or when water moves from the stern to the bow) the relative movement of the water serves to create a force on fins 224 and 226 to bias the fins away from each other, yielding an open state of controllable fin configuration 10 . In this way, controllable fin configuration 110 serves to assist the surfer in much the same way as controllable fin configuration 10 does in the two situations shown in the FIGS. 2 and 3 , namely to brake backward movement of the craft, such as when going against waves out to sea, and to aid in acceleration and “catching” a wave when surfing back towards the beach.
[0030] Reference is now made to FIG. 6 , which is pictorial view of the under water surface of craft 6 showing an alternative controllable fin configuration 410 in an open state, in accordance with an embodiment of the current invention. Controllable fin configuration 410 is a combination of controllable fin configuration 10 of FIGS. 1 , 2 , and 3 and controllable fin configuration 310 of FIGS. 4-6B and the numerals used to express components of FIG. 7 are meant to be similar in structure and function as noted in the previous figures. In controllable fin configuration 410 , however, conventional fins 18 have been replaced with controllable fin configuration 310 . As noted hereinabove, while the controllable fin configurations shown in FIG. 6 and in previous figures have been located nearer to the stern of craft 6 , the controllable fin surface configuration may be optionally or alternatively positioned near the bow or between the bow and stern to accomplish its functioning, as described hereinabove. Furthermore, the controllable fin surface configuration may include not only 1, 2, or 4 fin surfaces as shown in previous figures and described hereinabove, but it may include a plurality of fin surfaces approaching/approximating a configuration associated with scales on a fish, as described hereinbelow.
[0031] Reference is presently made to FIG. 7 , which is a pictorial view of an under water surface of craft 6 showing a controllable fin configuration 510 in an open state, in accordance with an embodiment of the current invention. Controllable fin configuration 510 includes a plurality of individual fin configurations 511 similar in structure, but smaller in scale, and similar in function to fin configuration 10 of FIGS. 1 , 2 , 3 , and 6 , except as noted hereinbelow. Individual fin configurations 511 includes surface 513 connected to hinge 514 , similar in structure and function to surface 13 and hinge 14 of FIG. 1 , inter alia. As can be seen in FIG. 7 , individual fin configurations 511 are scaled smaller than fin configuration 10 . The individual fin configuration individually and collectively serve to brake and assist the craft in a manner similar to that described for configuration 10 .
[0032] It may be furthermore understood that scaled-down configurations of fin configuration 110 (as shown in FIG. 4 ) and/or scaled-down configurations of fin configuration 410 (as shown in FIG. 6 ) may be likewise distributed on the under water surface of craft 6 , similar to that described for configuration 510 hereinabove.
[0033] It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims. | A controllable fin surface configuration positionable on the underwater surface of a craft having a bow and a stern, the craft having a direction of travel defined from the stern to the bow, the configuration comprising: at least one hinge adapted to mechanically support the fin surface configuration; and at least one fin surface mechanically attached to the hinge and having a range of motion definable from a closed state to an open state; wherein the closed state is defined by the fin surface configuration offering minimal resistance to relative water movement opposing the direction of travel and the open state is defined by the fin surface configuration offering maximum resistance to relative water movement in the direction of travel. | 1 |
BACKGROUND OF THE INVENTION
It is well established that many β-adrenergic agents elicit more than a single biological effect following administration. Resolution of the optical isomers of these agents which contain asymmetric centers has, in many instances, demonstrated marked differences in potency between these isomers. In addition to increasing knowledge of receptor site topography, the pharmacologic profiles of the individual isomers may provide new and/or more desirable drug entities.
Previously, the optical isomers of β-adrenergic agents have most generally been obtained by one of three basic methods: (1) the fractional recrystallization of chiral acid salt derivatives; (2) synthesis of the single optical isomer using chiral epoxide intermediates; and, more recently, (3) column chromatography utilizing chiral stationary phases. The difficulties associated with application of these methods are well known to practitioners in the art, specifically, the tedious and time-consuming fractional recrystallizations and repeated chromatography; requisite chiral syntheses of epoxide intermediates with the attendant complications associated with stereospecific synthesis, and size limitation of quantities obtained via chromatography. Generally, preparation of a single enantiomer by these methods is quite expensive.
Another resolving method, derivatization with a chiral organic reagent, has been used for resolution of compounds which can form derivatives. β-Adrenergic agents in general have two functional moieties amenable to derivatization, i.e. secondary amino and alcohol functionalities. The resolution of amines and alcohols by derivatization with chiral acyl halides or isocyanates is well known in the chemical literature. The success of such a resolution strategy depends upon several factors, notably (1) formation of the diastereomeric derivatives in reasonably high yield, (2) facile separation of these diastereomers by chromatographic or crystallization techniques, and (3) the regeneration of the parent compound from the separated diastereomeric derivatives. To our knowledge, this technique has never been utilized for the resolution of β-adrenergic propanolamines.
The following references disclose β-adrenergic propanolamines having a urea moiety incorporated into their structure.
1. O'Donnell, et al, Clin. Exp. Pharmacol., 8/6, 614-615 (1981) disclose a β-adrenergic agent (ICI 89963) with a urea moiety in the terminal alkyl portion of the structure. ##STR1##
2. Eckardt, et al., Die Pharmazie, 30, 633-637 (1975) disclose β-blocking propanolamines with urea substituents on the aryl portion of the molecule: ##STR2## These urea compounds differ structurally from the urea intermediates of the instant process as the propanolamine nitrogen of the reference compounds is not a component of the urea grouping.
The next grouping of references relate to methods of resolution of optical isomers which are deemed most relevant to the instant process described herein.
3. J. Jacques, A. Collet, S. H. Wilen, in "Enantiomers, Racemates, and Resolutions", John Wiley & Sons, New York, N.Y. (1981), pp. 330-335. This reference describes, among other things, formation and separation of diastereomers comprising covalent derivatives of amines and alcohols. Specifically, amines may be resolved through conversion into diastereomeric ureas by reaction with optically active isocyanates; and, following separation of the diastereomeric ureas by crystallization or by chromatography, the resolved amine is recovered through pyrrolysis.
4. F. C. Whitmore in "Organic Chemistry", D. Van Nostrand Co., New York, N.Y. (1937), p. 551. This reference reports that dl-β-amino-lactic aldehyde dimethyl acetal, H 2 NCH 2 CHOHCH(OMe) 2 , gave diastereomeric ureas when treated with l-menthyl isocyanate, as part of a scheme to prepare optically active glyceraldehydes.
5. Kolomoietes, et al. Zh. Org. Khim., English Edition, 16/5, pp. 854-857 (1980). This reference describes kinetic resolution of secondary alcohols and amines using S-(-)-α-phenylethylisocyanate.
It is appreciated by the practitioner in the art, that derivatization of β-adrenergic aryloxypropanolamines might be expected to present difficulties by virtue of the molecule containing two reactive functionalities, e.g. both an amine and an alcohol moiety.
Reference 4., supra, is the only example of which we are aware that reports diastereomeric urea derivatization by isocyanate treatment of a molecule containing both amino and hydroxy moieties. The compound being derivatized in the work mentioned by Whitmore is not related to the β-adrenergic propanolamine structure. The terminal primary amino group as opposed to the secondary hydroxyl in H 2 NCH 2 CHOH(OMe) 2 would be expected to be more accessible sterically to electrophilic attack by an isocyanate. Any steric advantage of the amino group is negated in β-adrenergic structures in which the amino nitrogen is further substituted with an alkyl group, which is usually branched, thereby giving a more hindered secondary amine. It would reasonably be expected prior to the instant invention that reaction of an optically active isocyanate and a β-adrenergic aryloxypropanolamine would result in a complex product mixture containing both diastereomeric ureas and carbamates. In practice, it is discovered that the reaction takes place preferentially at the site of the amine moiety, even when sterically hindered, giving predominently as novel intermediates the diastereomeric urea derivatives. This reaction selectivity forms the basis for the first step of the instant process.
The other major complication accompanying derivative resolution is the regeneration of the parent compound from the separated diastereomeric derivative. It is appreciated that ureas as a class of compounds are inherently stable and generally require more stringent methods, e.g. pyrrolysis or strong hydrolyzing conditions, for their decomposition. Since many of the β-adrenergic aryloxypropanolamines, especially those with sensitive substituents, would be labile under these same conditions, the regeneration step of the instant process becomes quite important.
The following references relate to methods of cleaving ureas in order to produce a parent amine.
6. Woodward, Pure Appl. Chem., 17 (1968), pp. 524-525. Woodward discloses the resolution of a racemic amine mixture by forming diastereomeric ureas with optically active α-phenylethyl isocyanate. Following separation of the diastereomers, the optically active amine is generated by pyrrolysis of the urea.
7. (a) Manske, J. American Chemical Society, 51, (1929) p. 1202. (b) Houben-Weyl "Methoden der Organische Chemie". Vierte Auflage Stickstoff-Verbindungen II, 11/1 (1957), pp. 952-953. (c) P. A. S. Smith, "The Chemistry of Open-Chain Organic Nitrogen Compounds" Volume I, W. A. Benjamin, Inc., New York, N.Y. (1965), p 270. (d) D. Barton and W. D. Ollis, in "Comprehensive Organic Chemistry" Volume II, Nitrogen Compounds, Carboxylic Acids, Phosphorus Compounds, Pergamon Press, Ltd. (1979), p. 1095. These four references are representative of the chemical literature which teaches that hydrolysis of urea compounds is not easy and usually requires prolonged heating with strong mineral acid or alkali.
A convenient mild reaction for breakdown of the useful intermediate urea derivatives, thereby regenerating the desired amine in optically active form, has been developed as part of the instant process.
SUMMARY OF THE INVENTION
This invention describes an improved, convenient process for resolution of optical isomers of selected aryl- or hetaryloxypropanolamines of Formula I, a structural class of β-adrenergic agents. The process is amenable for large-scale manufacture. ##STR3## For compounds of Formula I: Z is substituted or unsubstituted aryl or hetaryl; Y is alkyl, aralkyl, or hetarylalkyl; and X is hydrogen or acyl.
This process comprises treatment of the racemic mixture of β-adrenergic propanolamines with a chiral isocyanate to give novel diastereomeric urea intermediates; separation of these into the individual diastereomers; and facile regeneration of each optical isomer of the starting amine by cleavage of the intermediate urea compound with hydrazine. Use of an α-keto carboxylic acid, such as pyruvic acid, in the regeneration reaction allows for improved isolation and purification of the optical isomers.
DETAILED DESCRIPTION OF THE INVENTION
β-Adrenergic aryl- or hetaryl-oxypropanol amines, resolved by the instant process, are characterized by structural formula I. ##STR4## Z in formula I represents a substituted or unsubstituted aryl group such as phenyl, tetralyl, indanyl, indenyl, and naphthyl; or a hetaryl group such as pyridine, benzopyridine, pyrrole, benzopyrrole, furan, benzofuran, thiophene, benzothiophene, pyrimidine, or thiadiazole.
These aryl or hetaryl systems can be substituted by one or more of the following groups comprising lower (C 1 -C 6 ) alkyl, lower alkoxy, lower alkenyl, lower alkenyloxy, lower alkynyl, lower alkynyloxy, lower alkoxy-lower alkyl, lower alkoxy-lower alkoxy, lower alkylthio, lower alkenylthio, lower alkylthio-lower alkyl, lower alkoxy-lower alkylthio, halogen, halogen-lower alkyl, hydroxyl, hydroxyl-lower alkyl, carboxyl, carbamoyl, N-lower alkyl carbamoyl, N,N-dilower alkyl carbamoyl, N-lower alkyl carbamoyl-lower alkyl, N,N-di-lower alkyl carbamoyl-lower alkyl, lower alkanoylamino-lower alkenyl, N-lower alkylamino, N,N-di-lower alkylamino, lower alkoxycarbonyl, lower alkoxy-carbonylamino, lower alkoxy-carbonylamino-lower alkyl, lower alkoxycarbonylamino-lower alkenyl, lower alkoxycarbonylamino-lower alkoxy, lower alkylcarbonylamino-lower alkyl, N'-lower alkyl-ureido, N,N'-di-lower alkyl-ureido, lower alkylsulfonylamino, cyano, nitro, lower alkanoyl, lower alkenoyl, lower cycloalkyl, lower cycloalkenyl, carbamoyl-lower alkyl, lower alkyl carbamoyl-lower alkoxy, lower alkyl-lower alkoxy, N-morpholino, hydroxy, and halogen. It is preferred that Z have ortho-substitution.
Y in Formula I is either C 1 to C 10 alkyl or AB wherein A is an alkyl chain from 1 to 10 carbons, branched and unbranched, and B is a substituted or unsubstituted aryl group, preferably phenyl, or hetaryl group such as pyridine, benzopyridine, pyrrole, benzopyrrole, furan, benzofuran, thiophene, benzothiophene, pyrrolidine, or piperidine. Substituent groups attached to A comprise lower alkyl, alkoxy, alkenyl, nitro, hydroxy, amino, cyano, or halogen.
X is hydrogen or ##STR5## wherein R is C 1 to C 10 alkyl, substituted or unsubstituted phenyl, or alkylphenyl.
The substituent groups of the radicals Z and Y, listed above, may be more specifically defined. The term lower alkyl as used hereinabove denotes cyclic, straight and branched chain alkyl groups of 1-6 carbon atoms inclusive, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert.-butyl, pentyl, or cyclohexyl radicals bonded in any desired position.
The term lower alkenyl denotes straight and branched chain alkenyl groups of 2-6 carbon atoms, especially allyl or methallyl radicals.
The term lower alkynyl includes the straight or branched chain alkynyl groups of 2-6 carbons, with the propargyl radical being especially suited.
The term lower alkyloxy or lower alkoxy denotes straight or branched chain alkoxy groups of 1-6 carbon atoms, for example, methoxy, ethoxy, propoxy, butoxy, and the like.
The term lower alkenyloxy denotes straight and branched chain lower alkenyloxy groups and the positional isomers thereof, having 2-6 carbons, for example, ethenoxy, propenoxy, butenoxy, and the like.
The term lower alkynyloxy embraces straight and branched chain alkynyloxy groups of 2-6 carbon atoms, such as ethynyloxy, 2-propynyloxy, 3-butynyloxy, and the like.
The term lower alkoxy-lower alkyl embraces methoxymethyl, ethoxymethyl, isopropoxyethyl, and the like. The term lower alkoxy-lower alkoxy embraces for example methoxymethoxy, methoxyethoxy, ethoxyethoxy, ethoxyisopropoxy, and the like. The term hydroxy-lower alkyl is, for example, hydroxymethyl, 1- or 2-hydroxyethyl and the like.
The term lower alkylthio is, for example, methylthio, ethylthio, isopropylthio, n-butylthio, and the like. The term lower alkenylthio is illustrated by 1-propenylthio, 1-butenylthio, 3-pentenylthio, and the like. Lower alkylthio-lower alkyl is illustrated by methylthiomethyl, methylthioethyl, 2-ethylthioethyl, and the like. Lower alkoxy-lower alkylthio is illustrated by methoxymethylthio, ethoxymethylthio, and the like.
The term halogen is depicted by fluorine, chlorine, bromine, and iodine, especially fluorine or chlorine. The term halogen-lower alkyl is exemplified by trifluoromethyl, trichloromethyl, and the like.
It should also be understood that certain substituents as the group set forth hereinabove may be attached to the Z ring at two sites, usually adjoining ring atoms, to give, for example: tetralins, tetralones, indanes, indanones, indenes, and the like.
Adrenergic propanolamines embraced by structure I for the purpose of this invention are exemplified by the following beneficial drugs which contain centers of asymmetry. Exemplary drugs are acebutolol or N-[3-acetyl-4-[2-hydroxy-3-[(1-methylethyl)amino]propoxy]phenyl]butanamide; alprenolol or 1-[(1-methylethyl)amino]-3-[2-(2-propenyl)-phenoxy]-2-propanol; atenolol or 1-p-carbamoylmethylphenoxy-3-isopropylamino-2-propanol; bevantolol or 1-[(3,4-dimethoxyphenethyl)amino]-3-(m-tolyloxy)-2-propanol; buprenolol or 1-(tert.-butylamino)-3-[(6-chloro-m-tolyl)oxy]-2-propanol; bunitrolol or 2-[3-[1,1-dimethylethyl)amino]-2-hydroxypropoxy]benzonitrile; bunolol or 5-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-3,4-dihydro-1(2H)-naphthalenone; exaprolol or 1-(o-cyclohexylphenoxy)-3-(isopropylamino)-2-propanol; indanolol or 1-[indan-4-yloxy]-3-[1-methylethylamino]-2-propanol; metoprolol or 1-(isopropylamino)-3-[p-(2-methoxyethyl)phenoxy]-2-propanol; moprolol or 1-(2-methoxyphenoxy)-3-[(1-methylethyl)amino]-2-propanol; oxprenolol or 1-(isopropylamino)-2-hydroxy-3-[o-(allyloxy)phenoxy]propane; pamatolol or methyl-[p-[2-hydroxy-3-(isopropylamino)propoxy]phenethyl]carbamate; penbutolol or 1-( 2-cyclopentylphenoxy)-3-[(1,1-dimethylethyl)amino]-2-propanol; pargolol or 1-(tert.-butylamino)-3-[o-(2-propynyloxy)phenoxy]-2-propanol; procinolol or 1-(o-cyclopropylphenoxy)-3-(isopropylamino)-2-propanol; practolol or 1-(4-acetamidophenoxy)-3-isopropylamino-2-propanol; tiprenolol or 1-[(1-methylethyl)amino]-3-[2-(methylthio)-phenoxy]-2-propanol; tolamolol or 4-[2-[[2-hydroxy-3-(2-methylphenoxy)propyl]amino]ethoxy]benzamide; toliprolol or 1-(isopropylamino)-3-(m-tolyloxy)-2-propanol; nadolol or 1-(tert.-butylamino)-3-[(5,6,7,8-tetrahydro-cis-6,7-dihydroxy-1-naphthyl)oxy]-2-propanol; pindolol or 1-(indol-4-yloxy)-3-(isopropylamino)-2-propanol; and timolol or 1-(tert.-butylamino)-3-[(4-morpholino-1,2,5-thiadiazol-3-yl)oxy]-2-propanol. These beta-adrenergic propanolamines are known to the art, appearing in the Merck Index, Unlisted Drugs, USAN and USP Dictionary of Drug Names, and Annual Reports in Medicinal Chemistry, Vol. 10, pages 51-60 (1975), and ibid., Vol. 14, pages 81-90 (1979).
Certain conventions are used by those skilled in the art to designate optical rotation and spatial configuration of optical isomers. Individual enantiomers are commonly designated according to the optical rotation they effect, by (+) and (-), (l) and (d), or combinations of these symbols. The symbols (L) and (D) and the symbols (S) and (R), which stand for sinister and rectus, respectively, designate an absolute spatial configuration of the enantiomer. A complete resolution utilizing the instant process is detailed in the following section entitled Description of Specific Embodiments. Assignment of absolute configuration to the enantiomers separated therein is tentative and is based on the usual assignment of S-configuration to the β-adrenergic aryloxypropanolamine enantiomer with negative rotation.
The following flow chart, Scheme 1, illustrates the resolution of a racemic mixture of β-adrenergic propanolamines utilizing the instant process. ##STR6##
In Scheme 1: X, Y, and Z are as defined above; Ar represents an aryl group such as phenyl, substituted phenyl or naphthyl, preferably 1-naphthyl; R 1 can be a C 1 -C 6 alkyl group, preferably methyl; and an asterisk denotes centers of asymmetry in the molecule. It is to be understood that other optically active isocyanates, e.g. menthyl isocyanate, may also be used in the instant process.
Step 1 of the Scheme outlined above involves the reaction of the adrenergic propanolamine with a chiral isocyanate of structure II to give a pair of novel diastereomeric ureas of Formula III. The reaction of step 1 is accomplished simply by stirring together equimolar quantities of the adrenergic amine, in its free base form, and the chiral isocyanate in an inert organic liquid medium for several hours at approximately 25° C. The temperature can range from ambient room temperature up to the reflux temperature of the particular organic liquid used as reaction medium. This reaction is usually complete within four to eight hours. Suitable reaction liquids include but are not limited to benzene, tetrahydrofuran, dibutylether, dimethoxyethane, etc. A preferred reaction liquid is benzene.
In many instances, choice of an appropriate reaction liquid affects separation of the diastereomeric ureas by virtue of one of the diastereomers being soluble in the liquid and the other being insoluble. In other instances, where separation is not so easily accomplished, the physical separation, designated in Scheme 1 as Step 2, is accomplished by fractional recrystallization or chromotography. Separation of diastereomeric pairs using standard methodology is familiar to those skilled in the art.
Following separation into individual diastereomeric ureas, the enantiomeric adrenergic amine is regenerated in step 3 by refluxing one equivalent of the urea compound (III) with excess 85-99% hydrazine hydrate in ethanol. The amount of excess hydrazine may range from 2 to 20 equivalents with 5 equivalents preferred. This reaction is usually complete in one hour or less. Isolation and purification of the amine enantiomer is greatly facilitated by use of a nucleophile-scavenger such as an α-keto carboxylic acid; preferably an α-keto alkanoic acid of 3 to 10 carbon atoms and most preferably pyruvic acid. Usually the α-keto carboxylic acid is employed in an excess amount equal to the equivalents of hydrazine used. Following binding of the excess hydrazine-type nucleophilic species with the α-keto acid, the resulting adduct is easily removed by treatment with base during aqueous washing of the reaction products dissolved in an organic phase.
The subject process, as mentioned, is particularly adaptable to large-scale resolution and in that respect is both economical and convenient. The entire process is carried out as a series of three steps going from the β-adrenergic amine in the form of a racemic mixture via diastereomeric ureas and regeneration into the optically pure isomers. The steps comprising the process are as follows:
(1) treating an appropriate β-adrenergic aryl- or hetaryl-oxypropanolamine, in the form of a racemic mixture, with a chiral isocyanate such as resolved 1-(1-naphthyl) ethyl isocyanate, by stirring for six to 12 hours in an inert organic liquid medium such as benzene at a temperature ranging from ambient room temperature up to the reflux temperature of the organic liquid, thereby giving a pair of diastereomeric ureas (III);
(2) separation of the diastereomeric pair into individual diastereomers using standard physical separation techniques well known to those skilled in the pertinent art; and
(3) reacting the respective diastereomer of the urea derivative at reflux for approximately one hour or less in alcohol, preferably ethanol, with excess 85-99% hydrazine hydrate following which, the ethanol solvent is removed and the residue is dissolved in acetonitrile and an excess of an α-keto carboxylic acid such as pyruvic acid is added and this mixture stirred at room temperature for eight to 12 hours.
Workup of the reaction mixture from step 3, including an acid-base extraction purification affords the respective amine enantiomer corresponding to the respective diastereomeric urea derivative employed.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The process of this invention is further illustrated by the following examples directed to one of the preferred embodiments but these examples should not be construed as limiting the scope of the present invention. Melting points were determined using a Thomas-Hoover capillary melting point apparatus and are uncorrected. All temperatures are expressed in degrees Celsius. Optical rotation measurements were obtained on a Bendix-NPL 1169 automatic polarimeter with digital readout. The (R)-(-)-(1-naphthyl) ethyl isocyanate can be prepared as reported in the literature (Pirkle, et al, J. Org. Chem., 39 (1974) pages 3904-3906) or is available commercially (Aldrich Chemical Company).
Scheme 2 illustrates a specific embodiment of this process as applied to bucindolol (IA) which is a novel antihypertensive agent currently under clinical investigation. ##STR7##
In examples which follow, the nuclear magnetic resonance (NMR) spectral characteristics refer to chemical shifts (δ) expressed as parts per million (ppm) versus tetramethylsilane (TMS) as reference standard. The relative area reported for the various shifts in the 2 H NMR spectral data corresponds to the number of hydrogen atoms of a particular functional type in the molecule. The nature of the shifts as to multiplicity is reported as broad singlet (bs), singlet (s), multiplet (m), or doublet (d). Abbreviations employed are DMSO-d 6 (deuterodimethylsulfoxide), CDCl 3 (deuterochloroform) and are otherwise conventional. The infrared (IR) spectral descriptions include only absorption wave numbers (cm -1 ) having functional group identification value. The IR determinations were employed using potassium bromide (KBr) as diluent. The elemental analyses are reported as percent by weight.
EXAMPLE 1
Diastereomeric Urea Derivatives of Bucindolol
A hot solution of bucindolol hydrochloride salt (100 g, 0.28 mole) and 2.5 L of H 2 O was made basic with a 10% solution of NaOH. Bucindolol is 2-[2-hydroxy-3-[[2-(1H-indol-3-yl)-1,1-dimethylethyl]amino]propoxy]benzonitrile; cf: Kreighbaum, et al, U.S. Pat. No. 4,234,595 patented Nov. 18, 1980, and Journal of Medicinal Chemistry, 23:3, 285-289 (1980). After being allowed to cool, the aqueous layer of the basic mixture was decanted and the residual gum rinsed with H 2 O and crystallized from isopropyl alcohol (500 mL) to provide 81 g of bucindolol free base, m.p. 126°-128° C. The aqueous layer was allowed to stand overnight at 15° C., and a precipitate was collected by filtration, washed with H 2 O, and dried in air overnight to give a further 3.5 g of bucindolol free base. This material, a mixture of (R,S)-bucindolol base, was then derivatized.
A mixture of (R,S)-bucindolol base (1.8 g, 0.005 mole), (R)-(-)-1-(1-naphthyl)-ethylisocyanate (1.0 g, 0.005 mole), and benzene (100 mL) was stirred at 25° for 6 hrs. A white solid was removed by filtration and dried in air to give 1.24 g of (S), (R)-N-[3-(2-cyanophenoxy)-2-hydroxypropyl]-N-[1,1-dimethyl-2-(1H-indol-3-yl)ethyl]-N'-[1-(1-naphthyl)ethyl]urea. This urea derivative melted at 167°-168° C. and gave a single spot on TLC (silica gel; CH 2 Cl 2 --EtOAc, 9:1) and rotation of [α] D 25 -14° (C 0.5%, CH 3 OH).
Anal. Calcd. for C 35 H 36 N 4 O 3 : C, 74.98; H, 6.48; N, 10.00. Found: C, 74.89; H, 6.46; N, 9.74.
NMR (DMSO-d 6 ): 1.38 (6,s); 1.52 (3,d [6.7 Hz]); 3.35 (4,m); 3.94 (3,m); 5.70 (1,m); 6.23 (1,bs); 7.01 (5,m); 7.59 (11,m); 8.27 (1,d [9.5 Hz]); 10.72 (1,bs).
IR (KBr): 745, 1110, 1260, 1490, 1530, 1600, 1630, 2230, 2930, 2970, 3050, 3350, and 3410 cm -1 .
The benzene filtrate from above was concentrated to dryness and the residual material chromatographed on silica gel eluting with CH 2 Cl 2 --EtOAc (9:1) to give 0.70 g of (R), (R)-N-[3-(2-cyanophenoxy)-2-hydroxypropyl]-N-[1,1-dimethyl-2-(1H-indol-3-yl)ethyl]-N'-[1-(1-naphthyl)ethyl]urea as a foam. This material which did not crystallize had a rotation of [α] D 25 -119° (C 0.5%, CH 3 OH).
Anal. Calcd. for C 35 H 36 N 4 O 3 .1/2EtOAc: C, 73.49; H, 6.67; N, 9.27. Found: C, 73.29; H, 6.60; N, 9.18.
NMR (DMSO-d 6 ): 1.36 (3,s); 1.52 (6,m); 3.36 (4,m); 3.92 (3,m); 5.76 (1,m); 6.30 (1,bs); 7.00 (5,m); 7.55 (11,m); 8.26 (1,d [9.0 Hz]); 10.78 (1,bs).
IR (KBr): 745, 1115, 1260, 1495, 1540, 1600, 1635, 2220, 2930, 2980, 3060, 3350, and 3420 cm -1 .
Treating racemic mixtures of other Formula I adrenergic amines with chiral isocyanates (II) using reaction procedures similar to those outlined above gives diastereomeric urea intermediates. Some additional examples of these are listed in Table 1.
TABLE 1__________________________________________________________________________Adrenergic Propanolamine Urea Derivatives ##STR8##I IIExampleX Y Z R Ar__________________________________________________________________________2 H ##STR9## 2-cyanopyridyl Me phenyl3 H i-Pr 2-(2-propenyl)phenyl Me 1-naphthyl4 H i-Pr 1-naphthyl Me 1-naphthyl5 H t-Bu ##STR10## Me phenyl6 H i-Pr 2-(2-propenyloxy)- Me phenyl phenyl7 H i-Pr 4-(1Hinodolyl) Et phenyl8 H i-Pr 4-acetanilide Me 1-naphthyl9 H i-Pr 2-(methylthio)phenyl Me 1-naphthyl10 H i-Pr 2-cyanopyridyl Et 1-naphthyl11 H t-Bu 2-cyanopyridyl Me 4-nitrophenyl12 acetyl 2-(benzothiophen- 2-cyanopyridyl Me 1-naphthyl 3-yl)-1,1-dimethyl ethyl13 H 2-(1Hindol-3-yl- 2-cyanopyridyl Me 1-naphthyl 1,1-dimethylethyl__________________________________________________________________________
EXAMPLE 14
(S)- And (R)-Bucindolol Enantiomers
A respective diastereomer of the urea derivative from Example 1 was heated at reflux for 0.5 hr in absolute ethanol with 5 equivalents of 99% hydrazine hydrate. After evaporation of the solvent at reduced pressure, the residue was dissolved in acetonitrile and 5 equivalents of pyruvic acid were added. The solution was stirred at 25° C. overnight and then concentrated at reduced pressure to give a residue that was dissolved in EtOAc. The EtOAc solution was washed with 3 portions each of 1N NaOH and H 2 O, dried (anhydrous MgSO 4 ), filtered, and concentrated. One equivalent of cyclohexanesulfamic acid was added to a solution of the weighed residue in absolute ethanol. After the mixture had cooled the precipitated salt was collected by filtration. Recrystallization from ethanol-isopropyl ether (Darco G-60) gave analytically pure samples of each isomer.
(S)-(-)-isomer, m.p. 180°-181° C., [α] D 25 -15.0° (C 1, CH 3 OH).
Anal. Calcd. for C 22 H 25 N 3 O 2 .C 6 H 13 NO 3 S: C, 61.98; H, 7.06; N, 10.33. Found: C, 62.12; H, 7.08; N, 10.31.
NMR (DMSO-d 6 ): 1.16 (4,m), 1.29 (6,s); 1.60 (4,m); 1.99 (2,m); 3.16 (5,m); 4.29 (3,m); 7.20 (6,m); 7.68 (3,m); 8.20 (4,bs); 11.12 (1,bs).
Ir (KBr): 745, 1040, 1210, 1250, 1450, 1495, 1600, 2230, 2860, 2930, 3050, 3300, and 3400 cm -1 .
(R)-(+)-isomer, m.p. 179°-180° C. [α] D 25 +15.5° (C 1, CH 3 OH).
Anal. Calcd. for C 22 H 25 N 3 O 2 .C 6 H 13 NO 3 S: C, 61.98; H, 7.06; N, 10.33. Found: C, 62.07; H, 7.14; H, 10.11.
NMR (DMSO-d 6 ): 1.14 (4,m); 1.28 (6,s); 1.60 (4,m); 1.94 (2,m); 3.70 (5,m); 4.25 (3,m); 7.20 (6,m); 7.68 (3,m); 8.00 (4,bs); 11.00 (1,bs).
IR (KBr): 745, 1035, 1215, 1245, 1450, 1495, 1600, 2220, 2860, 2940, 3050, 3210, and 3300 cm -1 .
Starting with appropriately derived urea diastereomers, other examples of Formula I adrenergic propanolamines may be resolved using substantially the same procedures as outlined hereinabove. Some additional Formula I propanolamines which may be resolved are shown in Table 2.
TABLE 2__________________________________________________________________________Adrenergic Propanolamines ##STR11##ExampleX Y Z__________________________________________________________________________15 H i-Pr 2-(2-propenyl)phenyl16 H i-Pr 1-naphthyl17 H t-Bu ##STR12##18 H i-Pr 2-(2-propenyloxy)phenyl19 H i-Pr (4-1Hindolyl)20 H i-Pr 4-acetanilide21 H i-Pr 2-methylthiopenyl22 H i-Pr 2-cyanopyridyl23 H t-Bu 2-cyanopyridyl24 acetyl 2-(benzothiophen-3-yl)- 2-cyanophenyl 1,1-dimethylethyl25 H 2-(indol-3-yl)-1,1- dimethylethyl26 H i-Pr ##STR13##27 H i-Pr ##STR14##28 H ##STR15## 3-methylphenyl29 H t-Bu ##STR16##30 H t-Bu 2-cyanophenyl31 H t-Bu 2-cyclohexylphenyl32 H i-Pr 4-indanyl33 H i-Pr 4- (or 7-) indenyl34 H i-Pr ##STR17##35 H i-Pr 2-methoxyphenyl36 H i-Pr ##STR18##37 H t-Bu 2-cyclopentylphenyl38 H t-Bu ##STR19##39 H i-Pr 2-cyclopropylphenyl40 H ##STR20## 2-methylphenyl41 H i-Pr 3-methylphenyl42 H t-Bu ##STR21##43 H t-Bu ##STR22##__________________________________________________________________________ | A process for resolving a racemic modification of β-adrenergic aryl- or hetaryl-oxypropanolamines such as (±)-2-[2-hydroxy-3-[[2-(1H-indol-3-yl)-1,1-dimethylethyl]amino]propoxy]benzonitrile into its individual enantiomers is described. The process comprises converting the racemic modification into a pair of diastereomeric urea derivatives by reaction with a chiral aralkylisocyanate; separation into the individual diastereomers; and facile regeneration of the starting amine by cleavage of the intermediate urea compound using hydrazine. This final step is improved by the addition of an α-keto carboxylic acid, such as pyruvic acid, which functions as a scavenger of nucleophilic by-products. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority of provisional application Ser. No. 60/605,029 filed Aug. 27, 2004.
FIELD OF THE INVENTION
The invention relates generally to the field of image sensors and, more particularly, to a flash flush structure for such image sensors.
BACKGROUND OF THE INVENTION
Most current-day, digital-still cameras (DSCs) usually employ a charge-coupled device (CCD) sensor for image capture. These image sensors include a two-dimensional array of photosites. The photosites, or pixels as they are commonly referred to in the art, collect incoming photons and convert them to electron-hole pairs (EHPs). The number of EHPs generated is a linear function of sensor-plane irradiance and a non-linear function of wavelength. Typically, the electrons from these EHPs are collected within the photosites, and subsequently transferred as charge packets within the CCD to an output structure wherein they are converted to a voltage. This voltage signal is detected by off-chip circuitry, which processes these signals and converts them into a digital image. In addition to the signal electrons contained within each charge packet, there is an unavoidable quantity of electrons that get collected as a result of dark-current generation. Since this additional dark-current charge did not result from the incoming image photons, it represents noise, and is hence, undesirable since it reduces the signal-to-noise ratio of the image. Therefore, it is desirable to suppress or eliminate as much of this dark-current charge as possible. There have been many manufacturing and device operational methods employed in the past to reduce the dark signal, as are well known in the art. For example, defect or impurity gettering methods can reduce the generation from depletion-region and/or bulk states, while accumulation-mode clocking is effective at suppressing the generation from surface-states. This is discussed in U.S. Pat. No. 5,115,458.
During normal, single-shot operation of a DSC, this dark current is collected prior to and during image integration, as well as the readout period. Reduction of the dark-current charge that accumulates in the period just prior to image capture, can be accomplished by quickly “flushing” the image area as described by Shepherd, et al. in U.S. Publication No. 2003/0133026. This method basically consists of quickly clocking out the CCD after the shutter button is depressed. The time between when the shutter button is depressed and the shutter actually opens is often referred to as the shutter latency or lag time. Although this prior-art flush method is highly effective, the more pixels the sensor contains, the longer it takes to accomplish. Therefore, as the trend in the industry for more and more pixels continues, the shutter lag starts to become noticeable and objectionable to the photographer. Also, high-speed clocking of the CCDs to flush out the residual dark current in accordance with U.S. Publication No. 2003/0133026 requires a significant amount of power. Therefore, there exists a need in the art to reduce the shutter latency and power consumption.
Consequently, the present invention describes a structure that allows quick and efficient removal of any dark current accumulated within the CCDs just prior to image capture for reduced shutter latency, while reducing power dissipation.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, the invention resides in an image sensor having a substrate; a plurality of pixels on the substrate, one or more of the pixels comprising: (i) first and second charge-storage regions having at least one photosensitive area; (ii) a lateral overflow drain; (iii) a first lateral overflow gate adjacent the first charge-storage regions that passes substantially all charges from the first charge-storage region to the lateral overflow drain; and (iv) a second lateral gate adjacent the second charge-storage region that passes excess photo-generated charge into the lateral overflow drain for blooming control.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
ADVANTAGEOUS EFFECT OF THE INVENTION
The present invention has the advantage of reducing shutter latency, dark current in the final image, and power consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the image sensor of the present invention;
FIG. 2 is a first side view of FIG. 1 ;
FIG. 3 is a second side view of FIG. 1 ;
FIG. 4 is a third side view of FIG. 1 ;
FIG. 5 is a timing diagram for the image sensor of FIG. 1 ; and
FIG. 6 is another timing diagram of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 , 2 , 3 and 4 , a top view and various cross-sectional views of the present invention embodied in a full-frame image sensor 10 with a lateral overflow drain (LOD) 20 for antiblooming protection is shown. Particular portions of the antiblooming structure have been described in U.S. Pat. No. 5,130,774 and U.S. Pat. No. 5,349,215. The present invention makes use of the drain region 20 of this prior-art LOD structure as a place to dump the dark current accumulated prior to integration. Hence, no extra pixel area is required by the present invention. To implement the flush feature within the structure, an additional gate electrode layer 30 is added to the process. This additional electrode 30 is placed underneath the electrode 40 for the V 2 phase as shown in cross section 2 - 2 . Although the preferred embodiment shows the V 2 electrode 40 to be formed out of indium-tin oxide (ITO), it is not a requirement of the present invention. Other materials such as polysilicon may be used, for example. The antiblooming channel region 50 is underneath the V 1 phase 60 , as usual, where it retains all of the same features and advantages as described in the prior art. It is noted that the fast-flush gate (FFG) electrode 30 runs on top of the polysilicon electrode 60 used to form phase 1 , as shown in cross section 3 - 3 . As a result, any gate voltage applied to the FFG 30 will have no effect on the channel potential within the B 3 region 50 , since it is screened from the B 3 region 50 by the V 1 electrode 60 . A cross section 4 - 4 through the two-phase CCD in the direction of charge transfer during image readout is shown in FIG. 4 .
Referring to FIGS. 5 and 6 , clocking diagrams along with the resulting channel-potential profiles within the silicon at various time intervals is shown. The time interval prior to when the shutter button is depressed is represented by t<t 1 . During this time, dark current accumulates within the CCD channel region under both phases V 1 and V 2 , (which are held in accumulation). The dark signal under V 1 is noted as 70 a and under V 2 as 70 b . At time t 1 , the shutter button is depressed and the V 2 clock voltage is pulsed high. This has the effect of collecting all of the dark signal 70 a and 70 b within the potential well under the V 2 electrode 40 . Then, at time t 2 , the FFG electrode 30 is pulsed high while the V 2 electrode goes low. This results in all of the dark signal (combination of 70 a and 70 b ) accumulated under V 2 40 in region 90 b to be transferred through the B 4 channel region 80 (see FIGS. 1 and 2 ) and dumped to the LOD 20 , where it is swept away by the large positive bias (Vlod) applied to it. It is important that the FFG electrode 30 is clocked high before the V 2 electrode 40 is turned off to insure that all the dark charge 70 a and 70 b dumps to the LOD 20 and none can possibly spill forward into the V 1 region 90 a (in the n-type region of the substrate). Note that since the fast-flush operation is accomplished by only single short pulses of V 2 40 and FFG 30 , the shutter latency and power dissipated are both extremely small. At time t 3 the FFG 30 is shut off (and remains off) by bringing it to a low voltage, the mechanical shutter is opened, and the integration period begins. It should be pointed out that the timing of the opening of the mechanical shutter with respect to the falling edge of the FFG voltage at t 3 is not too critical. It can be delayed some, without much consequence except to increase the shutter delay slightly. It could also overlap into the FFG pulse slightly, which would only result in the integration period not starting until the FFG pulse goes low at t 3 . It is noted that integration is performed with both V 1 60 and V 2 40 phases held in accumulation so as to reduce dark current as described in U.S. Pat. No. 5,115,458. The integration period ends at time t 4 where the mechanical shutter is closed and conventional, two-phase accumulation-mode readout of the image begins. Readout starts with the V 1 gate electrode 60 being pulsed high so as to “clip” or limit the integrated signal to the full-well capacity as defined by the B 3 channel potential. (Note that the B 3 region potential is made slightly deeper than that of the B 1 region. Since the B 3 and B 1 region potentials “track” one another, this optimizes charge capacity of the pixel while preventing a condition referred to as blooming on transfer.) Therefore, for high exposure levels, any excess above the capacity of the pixel will be dumped to the LOD so that none can potentially spill backwards during image readout. (This backwards spilling is what is known as blooming on transfer.) The V 1 pulse is followed by a V 2 pulse (high) at t 5 , as is the convention. Subsequent line transfers follow in the usual manner for this mode of clocking.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST
10 image sensor
20 lateral overflow drain
30 fast flush gate electrode
40 V 2 phase electrode
50 antiblooming channel region
60 V 1 phase electrode
70 a dark signal from V 1 phase
70 b dark signal from V 2 phase
80 fast flush channel region
90 a V 1 storage region
90 b V 2 storage region | An image sensor includes a substrate; a plurality of pixels on the substrate, one or more of the pixels comprises (i) first and second charge-storage regions having at least one photosensitive area; (ii) a lateral overflow drain; (iii) a first lateral overflow gate adjacent the first charge-storage regions that passes substantially all charges from the first charge-storage region to the lateral overflow drain; and (iv) a second lateral gate adjacent the second charge-storage region that passes excess photo-generated charge into the lateral overflow drain for blooming control. | 7 |
TECHNICAL FIELD
The present invention relates to pneumatic and hydraulic cylinders.
BACKGROUND OF THE INVENTION
Hydraulic and pneumatic cylinders suffer from the disadvantage that should there be any leakage, the cylinder will either extend or retract depending on its preloaded condition.
OBJECT OF THE INVENTION
It is the object of the present invention to overcome or substantially ameliorate the above disadvantage.
SUMMARY OF THE INVENTION
There is disclosed herein a hydraulic or pneumatic cylinder including:
a bore, the bore generally surrounding a chamber having opposite ends;
a piston in said bore and co-operating therewith to divide said chamber into a first and a second sub-chamber;
a piston rod fixed to and extending from said piston and extending beyond one of said ends;
means closing said opposite ends;
releasable locking means to retain said piston at a desired location within said bore, said locking means being released to permit movement of said piston upon delivery of a fluid under pressure to one of said chambers; and
duct means to provide for fluid flow from said second sub-chamber to said first sub-chamber when said locking means is engaged with said piston to retain said piston at said desired location.
Preferably, the locking means includes a pawl mounted in said body, and a recess in said piston, said recess being alignable with said pawl so as to be engaged therewith to retain the piston at said desired location, said pawl being movable between a first position at which it is engaged within said recess and a second position spaced from said recess to provide for movement of said piston.
Preferably, the cylinder includes a spring urging the pawl into engagement with said recess.
Preferably, the delivery of fluid under pressure to said first sub-chamber causes movement of said pawl from the first position to the second position thereof.
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 drawing which schematically depicts in section side elevation a pneumatic or hydraulic cylinder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the accompanying drawing there is schematically depicted a hydraulic or pneumatic cylinder 10 . The cylinder 10 has a body 11 providing a bore 12 generally surrounding a chamber 13 . The chamber 13 has opposite ends 14 and 15 which are closed by plug members 16 and 17 .
Mounted within the body 11 and slidably engaging the cylindrical surface of the bore 12 is a piston 18 . The piston 18 divides the chamber 13 into a first sub-chamber 19 and a second sub-chamber 20 . The piston 18 has a tapered leading surface 21 which is of frusto-conical configuration. The piston is further provided with an annular recess 22 as well as a wear ring 23 and seal 24 .
The body 11 includes a housing 25 providing a bore 39 which slidably receiving and guiding a pawl 26 . The pawl 26 has a leading projection 27 which is aligned with an aperture 28 in the body 11 . A spring 29 urges the pawl 26 to a position at which the projection 27 is located within the chamber 13 .
Located between the pawl 26 and an end cap 30 is a locking chamber 31 within which the spring 29 is located. Extending from the chamber 31 is a duct 32 extending to an aperture 33 . The aperture 33 communicates with the sub-chamber 20 when the piston 18 is located adjacent the end 15 .
The piston 18 is sized so that there is an annular space 34 permitting fluid to pass from the sub-chamber 19 to a position at which pressure can be applied to the pawl 26 .
Extending from the body 11 is a first fluid coupling 36 which provides for movement of fluid relative to the sub-chamber 19 while a second fluid coupling 35 provides for movement of fluid relative to the second sub-chamber 20 .
Attached to and extending from the piston 18 is a piston rod 37 which exits via the plug member 16 which sealingly engages the longitudinal peripheral surface of the piston rod 37 .
In operation of the above described hydraulic cylinder 10 , fluid under pressure is delivered to the sub-chamber 19 . Fluid passing the passage 34 and entering the chamber 40 causes retraction of the pawl 26 to a position at which the projection 27 is no longer engaged within the recess 22 . Pressure within the sub-chamber 19 causes movement of the piston 18 toward the end 14 . Fluid is allowed to leave the sub-chamber 20 via the fluid coupling 35 . When the pawl 26 moves to its retracted position, fluid within the chamber 31 is allowed to return to the chamber 13 via the duct 32 . When the piston 18 is spaced from the end 17 and fluid under pressure is delivered to the sub-chamber 20 , the piston 18 moves towards the end 15 and engages the projection 27 . The tapered surface 21 engages the projection 27 and causes the pawl 26 to move to a position at which the piston 18 can pass. Once the piston 18 is in the position depicted, the pawl 26 moves to a position at which the projection 27 is engaged within the recess 22 . Fluid from the sub-chamber 20 passes through the duct 32 to urge the pawl 26 to engage within the recess 22 . This movement is enhanced by means of the spring 29 .
The above mentioned duct 32 also enables the cylinder 10 to be used in a phasing circuit. In relation to the cylinder 10 being used in a phasing circuit, the pawl 26 is provided with a single acting seal 38 which permits the flow of fluid only from the chamber 31 past the pawl 26 to enter the sub-chamber 19 . When the cylinder 10 is used in a phasing circuit and the piston 18 located adjacent the end 15 , fluid can flow via the duct 32 past the seal 38 to exit via the coupling 36 from where it would pass to the next cylinder. Reverse flow is prevented by the seal 38 .
The above preferred embodiment ensures that the piston 18 is retained adjacent the end 15 until fluid under pressure is delivered to the sub-chamber 19 . | A pneumatic or hydraulic cylinder ( 10 ) having a bore ( 12 ) cooperating with a piston ( 18 ). Extending from the piston ( 18 ) is a piston rod ( 37 ). There is further provided a pawl ( 26 ) which is engageable with the piston ( 18 ) to retain the piston ( 18 ) at a desired location. The pawl ( 26 ) is moved from engagement with the piston ( 18 ) upon fluid under pressure being delivered to one end of the cylinder ( 10 ). | 5 |
TECHNICAL FIELD
[0001] The present invention relates generally to electronics packaging and more particularly to electronic packaging for micro-electrical mechanical system (MEMS) devices.
BACKGROUND OF THE INVENTION
[0002] Electro-Mechanical Systems (MEMS) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology. While the electronics are fabricated using integrated circuit (IC) process sequences (e.g., CMOS, Bipolar, or BICMOS processes), the micromechanical components are fabricated using compatible “micromachining” processes that selectively etch away parts of the silicon wafer or add new structural layers to form the mechanical and electro-mechanical devices. MEMS brings together silicon-based microelectronics with micromachining technology, making possible the realization of complete systems-on-a-chip devices. MEMS is an enabling technology allowing the development of smart products, augmenting the computational ability of microelectronics with the perception and control capabilities of microsensors and microactuators and expanding the space of possible designs and applications.
[0003] While microelectronic ICs work to control functional processing steps in the system, MEMS augments this decision-making capability to allow microsystems to sense and control the environment. Thus, the primary applications of MEMS technology include sensors that gather information from the environment through measuring such parameters as mechanical, thermal, bio-logical, chemical, optical, and magnetic phenomena. The MEMS electronics then process the information derived from the sensors and, through some decision-making capability, direct the actuators to respond by controlling the environment for some desired outcome or purpose. Because MEMS devices are manufactured using batch fabrication techniques similar to those used for integrated circuits, unprecedented levels of functionality, reliability, and sophistication can be achieved using small silicon MEMS chips at a relatively low cost.
[0004] In MEMS applications, such as automotive sensors, such as those having accelerometer or gyroscopic applications, it is often required for the sensor to be used in multiple applications with different axis of sensing. Normally, silicon-based sensors (MEMs) are designed to be sensitive in one axis with little or no sensitivity in other axis. In order for the sensor to be used in other axis, the surrounding MEMS device package must be designed to accommodate the specified orientation with variations in either an X, Y, or Z axis.
[0005] Prior art FIG. 1 illustrates a MEMS sensor package 100 oriented in a stand-up position where pins 101 are positioned to extend vertically from a body 103 where they are attached to a PC board. This type of MEMS package is generally required to withstand severe shock and vibration in safety applications such as vehicular frontal crash or roll over with an accordance of ±1 degree. In the past in order to meet these requirements, the sensor module was manufactured with “through hole” technology rather than surface mount technology (SMT). Similarly, FIG. 2 illustrates an example of a surface mounted MEMS sensor package 200 where the pins 201 extend from a flat package 203 whose body rests on the surface of a PC board. This type of MEMS device might be used depending on the required mounting axis. However, the utilization of separate packaging technologies tends to be costly both for the product manufacturing and its testing.
SUMMARY OF THE INVENTION
[0006] An embodiment of the present invention is directed to a surface mount multi-axis cavity package for micro-electrical mechanical systems (MEMS) devices that includes a substantially cubical housing having at least one internal cavity. A first group of solder pads are positioned on at least one side of the housing and a second group of solder pads are positioned on a bottom of the housing. A MEMS sensor is mounted within the internal cavity and a lead frame is positioned within a wall of the cubical housing for interconnecting the first group of solder pad connections and the second group of solder pad connections. The multi-axis package is very advantageous as it allows a MEMS device to be mounted within the package on its X or Y axis such that the package can then be connected on a printed circuit board for increasing the overall versatility of the MEMS device
[0007] These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specifications, claims, and appended drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is prior art diagram illustrating a stand-up MEMS sensor package;
[0010] FIG. 2 is prior art diagram illustrating a surface mounted MEMS sensor package;
[0011] FIG. 3 illustrates a surface mounted multi-axis cavity package for MEMS devices in accordance with an embodiment of the invention;
[0012] FIG. 4 a cross-sectional view of the surface mounted multi-axis cavity package through section lines IV-IV as shown in FIG. 3 ;
[0013] FIG. 5 is a cross-sectional view of the surface mounted multi-axis cavity package through section lines V-V as shown in FIG. 3 ;
[0014] FIG. 6 is a diagram illustrating use of a MEMS device on a printed circuit board with compliant pin outs;
[0015] FIG. 7 is a diagram illustrating use of a MEMS device on a print circuit board using a wire bond technique; and
[0016] FIG. 8 and FIG. 9 are cross-sectional diagrams illustrating use of the invention in a bottom and side mounting configuration.
[0017] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a surface mount multi-axis cavity package for with use with a microelectrical mechanical system (MEMS) device. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
[0019] In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0020] It will be appreciated that embodiments of the invention described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of microelectrical mechanical system (MEMS) packaging device described herein. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method to construct a microelectrical mechanical system (MEMS) packaging device. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
[0021] FIG. 3 illustrates a surface mounted multi-axis cavity package 300 for MEMS devices in accordance with an embodiment of the invention. The package 300 is a substantially cubic-like housing 302 having a lid or top 301 , bottom 303 , side 305 , side 307 , end 309 , and end 311 . The top 301 may be removable from the package 300 for access to an internal device (not shown) located within an internal cavity (not shown). The package 300 is constructed of a plastic, FR-4, or like material and is used to hold a MEMS package internally allowing a MEMS sensor device to be oriented and/or mounted to a PC board in any type of horizontal or vertical configuration. This is accomplished using a plurality of solder pads 313 , 315 , 317 , 319 that are positioned on the bottom 303 and side 305 of the package 300 . The solder pads 313 , 315 are positioned on the side 305 such that the cubic-like package can be positioned flat on top of a PC board where solder may be reflowed to the pads in a conventional style of solder oven manufacturing process. Similarly, solder pads 317 , 319 are positioned on the bottom 303 of the package 300 allowing it to positioned with the bottom side flat to the surface of a PC board. Whether the solder pads on either the bottom 303 or the side 305 of the package 300 will depend upon the orientation of the MEMS device oriented in an inside cavity as described herein.
[0022] FIG. 4 a cross-sectional view of the surface mounted multi-axis cavity package through section lines IV-IV as shown in FIG. 3 . The cross-sectional view of the package 400 includes one or more voids or cavities 401 for allowing a MEMS package 403 to be oriented inside the cavity in an X or Y direction depending on application. A MEMS sensor 405 is mounted within the MEMS package 403 onto a PC board 407 . The MEMS sensor 405 typically may be an accelerometer or gyroscopic device such that its orientation is critical to proper operation. The interior of the package 400 may include one or more mounting structures 409 , 411 for allowing the MEMS package 403 and PC board 407 to be mounted into a fixed position. As seen in FIG. 4 , a plurality of lead frames 409 are wires or substantially thin strips of metal that acts like a PC circuit board trace for electrically connecting the selective solder pads together. Each lead frame 409 is positioned within a wall 410 of the package 400 and allows each pad connected by the lead frame 409 to be interconnected no matter where it is located on the package 400 . This allows the MEMS sensor to have great versatility since package 400 can be connected to each respective lead frame 409 and thus mounted in any X-Y orientation since each interconnected pad on the side or bottom of the housing will have the same continuity.
[0023] FIG. 5 is a cross-sectional view of the surface mounted multi-axis cavity package through section lines V-V as shown in FIG. 3 . The package 500 shows the sensor package 405 mounted onto the PC board 407 . One or more wire bonds 501 are attached from the PC board 407 to the various solder pads 313 , 315 . Although shown in a vertical-like configuration in an “x” axis, those skilled in the art will recognize the invention has the versatility to orient the sensor package 405 substantially 90 degrees inside the cavity 401 such that solder pads along the bottom could be used. Alternatively, a smaller sensor package 405 could be used to orient the device in a “y” axis.
[0024] FIG. 6 is a diagram 600 illustrating use of the a MEMS device on a printed circuit board with compliant pin outs. A MEMS device 601 is mounted to a PC board 603 having a plurality of compliant pin outs 605 . These pin outs 605 are oriented in the multi-axis cavity package 607 such that one or more lead frames 609 can be connected to each corresponding pin out 605 . Similarly, FIG. 7 is a diagram illustrating use of the multi-axis package 700 having a MEMS device 701 mounted on a print circuit board 703 using a wire bond technique. In this embodiment, the PC board and its associated pin outs 703 can be wire bonded 705 to a particular lead frame each connecting to a solder pads on the multi-axis package 700 .
[0025] Finally, FIG. 8 and FIG. 9 are cross-sectional diagrams illustrating use of the invention in a bottom and side mounting configuration. FIG. 8 illustrates the use the multi-axis package 800 where an internally mounted MEMS device 801 is positioned in an upright manner allowing the multi-axis package 800 to be mounted such that the solder pads connected to lead frame 803 or solder pads connected to lead frame 805 can be used for connection. Similarly, FIG. 9 illustrates the multi-axis package 900 rotated 90 degrees such that the MBMS device 901 is now oriented on a side of the multi-axis package. Solder pads connected to lead frame 903 or solder pads connected to lead frame 905 can be used for connection. Both FIGS. 8 and 9 illustrate the versatility of the invention as it allows a MEMS device to be mounted in either its X or Y axis. This is very advantageous since it allows existing “off the shelf” MEMS packages to be used in various orientations without the high cost and expense associated with MEMS package tooling and redesign.
[0026] Thus, the present invention is directed to a surface mount multi-axis cavity package for MEMS sensor that can be mounted in multiple orientations. The multi-axis packages utilizes a leadfame that is insert molded in high temperature thermoplastic with exposed surfaces in a side and bottom of the package for solder mounting to a PC board. Inside the package cavity, a sensor and mating sensor are mounted to ceramic and/or organic circuit board via a flip chip technique or wirebonding. The PC board is connected to the package via wire bonding or other compliant pin outs. The multi-axis package can be used with a single integrated sensor, such as bare die or pre-packaged, as well as a two chip sensor, such as a sensor and application specific integrated circuit (ASIC) combination. After the sensor is packaged within the cube, it can be covered by a top or lid such that the multi-axis package can be mounted in any needed application.
[0027] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
[0028] It will be understood by those who practice the invention and those skilled in the art, that various modifications and improvements may be made to the invention without departing from the spirit of the disclosed concept. The scope of protection afforded is to be determined by the claims and by the breadth of interpretation allowed by law. | A surface mount multi-axis cavity package for micro-electrical mechanical systems (MEMS) devices includes a substantially cubical housing having a plurality of sides and at least one internal cavity. A first plurality of solder pads are positioned on at least one side of the housing and a second plurality of solder pads are positioned on a bottom of the housing. A MEMS sensor is then mounted within the at least one internal cavity in any axis for increasing the versatility of the MEMS device. | 1 |
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